Ole Petter F. Clausen
Position: Professor emeritus
Phone: +47 23072741
Email:
 

Author network for Ole Petter F. Clausen by COREMINE medical


Publications 2016

Joshi S, Schjølberg AR, Ekstrøm PO, De Angelis PM, Zucknick M, Andersen SN, Clausen OP (2016)
Tp53/p53 status in keratoacanthomas
J Cutan Pathol, 43 (7), 571-8
PubMed 27020606

Publications 2015

Andersen IM, Fosby B, Boberg KM, Clausen OP, Jebsen P, Melum E, Line PD, Foss A, Schrumpf E, Karlsen TH (2015)
Indications and Outcomes in Liver Transplantation in Patients With Primary Sclerosing Cholangitis in Norway
Transplant Direct, 1 (9), e39
PubMed 27500239

Andresen K, Boberg KM, Vedeld HM, Honne H, Jebsen P, Hektoen M, Wadsworth CA, Clausen OP, Lundin KE, Paulsen V, Foss A, Mathisen Ø, Aabakken L, Schrumpf E, Lothe RA, Lind GE (2015)
Four DNA methylation biomarkers in biliary brush samples accurately identify the presence of cholangiocarcinoma
Hepatology, 61 (5), 1651-9
PubMed 25644509

Publications 2014

Friis-Ottessen M, Bendix L, Kølvraa S, Norheim-Andersen S, De Angelis PM, Clausen OP (2014)
Telomere shortening correlates to dysplasia but not to DNA aneuploidy in longstanding ulcerative colitis
BMC Gastroenterol, 14, 8
PubMed 24405569

Friis-Ottessen M, Burum-Auensen E, Schjølberg AR, Ekstrøm PO, Andersen SN, Clausen OP, De Angelis PM (2014)
TP53/p53 alterations and Aurora A expression in progressor and non-progressor colectomies from patients with longstanding ulcerative colitis
Int J Mol Med, 35 (1), 24-30
PubMed 25333414

Friis-Ottessen M, De Angelis PM, Schjølberg AR, Andersen SN, Clausen OP (2014)
Reduced hTERT protein levels are associated with DNA aneuploidy in the colonic mucosa of patients suffering from longstanding ulcerative colitis
Int J Mol Med, 33 (6), 1477-83
PubMed 24676865

Kriegbaum MC, Clausen OP, Lærum OD, Ploug M (2014)
Expression of the Ly6/uPAR-domain proteins C4.4A and Haldisin in non-invasive and invasive skin lesions
J Histochem Cytochem, 63 (2), 142-54
PubMed 25414274

Pomianowska E, Schjølberg AR, Clausen OP, Gladhaug IP (2014)
COX-2 overexpression in resected pancreatic head adenocarcinomas correlates with favourable prognosis
BMC Cancer, 14, 458
PubMed 24950702

Publications 2013

Mantaka P, Helsing P, Gjersvik P, Bassarova A, Clausen OP, Delabie J (2013)
Clinical and histopathological features of folliculotropic mycosis fungoides: a Norwegian patient series
Acta Derm Venereol, 93 (3), 325-9
PubMed 23053197

Publications 2012

Andresen K, Boberg KM, Vedeld HM, Honne H, Hektoen M, Wadsworth CA, Clausen OP, Karlsen TH, Foss A, Mathisen O, Schrumpf E, Lothe RA, Lind GE (2012)
Novel target genes and a valid biomarker panel identified for cholangiocarcinoma
Epigenetics, 7 (11), 1249-57
PubMed 22983262

Blonski KM, Blödorn-Schlicht N, Falk TM, Faye RS, Clausen OP (2012)
Increased detection of cutaneous leishmaniasis in Norway by use of polymerase chain reaction
APMIS, 120 (7), 591-6
PubMed 22716214

Bojesen KB, Clausen O, Rohde K, Christensen C, Zhang L, Li S, Køhler L, Nielbo S, Nielsen J, Gjørlund MD, Poulsen FM, Bock E, Berezin V (2012)
Nectin-1 binds and signals through the fibroblast growth factor receptor
J Biol Chem, 287 (44), 37420-33
PubMed 22955284

Folseraas T, Melum E, Rausch P, Juran BD, Ellinghaus E, Shiryaev A, Laerdahl JK, Ellinghaus D, Schramm C, Weismüller TJ, Gotthardt DN, Hov JR, Clausen OP, Weersma RK, Janse M, Boberg KM, Björnsson E, Marschall HU, Cleynen I, Rosenstiel P, Holm K, Teufel A, Rust C, Gieger C, Wichmann HE et al. (2012)
Extended analysis of a genome-wide association study in primary sclerosing cholangitis detects multiple novel risk loci
J Hepatol, 57 (2), 366-75
PubMed 22521342

Li J, Wang K, Gao F, Jensen TD, Li ST, DeAngelis PM, Kølvraa S, Proby C, Forslund O, Bolund L, Clausen OP (2012)
Array comparative genomic hybridization of keratoacanthomas and squamous cell carcinomas: different patterns of genetic aberrations suggest two distinct entities
J Invest Dermatol, 132 (8), 2060-6
PubMed 22534878

Pomianowska E, Grzyb K, Westgaard A, Clausen OP, Gladhaug IP (2012)
Reclassification of tumour origin in resected periampullary adenocarcinomas reveals underestimation of distal bile duct cancer
Eur J Surg Oncol, 38 (11), 1043-50
PubMed 22883964

Pomianowska E, Westgaard A, Mathisen Ø, Clausen OP, Gladhaug IP (2012)
Prognostic relevance of number and ratio of metastatic lymph nodes in resected pancreatic, ampullary, and distal bile duct carcinomas
Ann Surg Oncol, 20 (1), 233-41
PubMed 22893118

Westgaard A, Pomianowska E, Clausen OP, Gladhaug IP (2012)
Intestinal-type and pancreatobiliary-type adenocarcinomas: how does ampullary carcinoma differ from other periampullary malignancies?
Ann Surg Oncol, 20 (2), 430-9
PubMed 22956064

Publications 2011

Holm S, Ueland T, Dahl TB, Michelsen AE, Skjelland M, Russell D, Nymo SH, Krohg-Sørensen K, Clausen OP, Atar D, Januzzi JL, Aukrust P, Jensen JK, Halvorsen B (2011)
Fatty Acid binding protein 4 is associated with carotid atherosclerosis and outcome in patients with acute ischemic stroke
PLoS One, 6 (12), e28785
PubMed 22174896

Jørgensen KK, Grzyb K, Lundin KE, Clausen OP, Aamodt G, Schrumpf E, Vatn MH, Boberg KM (2011)
Inflammatory bowel disease in patients with primary sclerosing cholangitis: clinical characterization in liver transplanted and nontransplanted patients
Inflamm Bowel Dis, 18 (3), 536-45
PubMed 21456044

Westgaard A, Clausen OP, Gladhaug IP (2011)
Survival estimates after pancreatoduodenectomy skewed by non-standardized histopathology reports
APMIS, 119 (10), 689-700
PubMed 21917006

Publications 2010

Brackmann S, Aamodt G, Andersen SN, Roald B, Langmark F, Clausen OP, Aadland E, Fausa O, Rydning A, Vatn MH (2010)
Widespread but not localized neoplasia in inflammatory bowel disease worsens the prognosis of colorectal cancer
Inflamm Bowel Dis, 16 (3), 474-81
PubMed 19714748

Burum-Auensen E, Skotheim RI, Schjølberg AR, Røislien J, Lothe RA, Clausen OP (2010)
Spindle proteins are differentially expressed in the various histological subtypes of testicular germ cell tumors
J Carcinog, 9, 1
PubMed 20411023

Gladhaug IP, Westgaard A, Schjølberg AR, Burum-Auensen E, Pomianowska E, Clausen OP (2010)
Spindle proteins in resected pancreatic head adenocarcinomas: BubR1 is an independent prognostic factor in pancreatobiliary-type tumours
Histopathology, 56 (3), 345-55
PubMed 20459534

Hannisdal K, Burum-Auensen E, Schjølberg A, De Angelis PM, Clausen OP (2010)
Correlation between reduced expression of the spindle checkpoint protein BubR1 and bad prognosis in tonsillar carcinomas
Head Neck, 32 (10), 1354-62
PubMed 20146332

Hannisdal K, Schjølberg A, De Angelis PM, Boysen M, Clausen OP (2010)
Human papillomavirus (HPV)-positive tonsillar carcinomas are frequent and have a favourable prognosis in males in Norway
Acta Otolaryngol, 130 (2), 293-9
PubMed 19680990

Kalgaard OM, Clausen OP, Mellbye OJ, Hovig T, Kvernebo K (2010)
Nonspecific capillary proliferation and vasculopathy indicate skin hypoxia in erythromelalgia
Arch Dermatol, 147 (3), 309-14
PubMed 21079053

Pankratova S, Kiryushko D, Sonn K, Soroka V, Køhler LB, Rathje M, Gu B, Gotfryd K, Clausen O, Zharkovsky A, Bock E, Berezin V (2010)
Neuroprotective properties of a novel, non-haematopoietic agonist of the erythropoietin receptor
Brain, 133 (Pt 8), 2281-94
PubMed 20435631

Publications 2009

Brackmann S, Andersen SN, Aamodt G, Langmark F, Clausen OP, Aadland E, Fausa O, Rydning A, Vatn MH (2009)
Relationship between clinical parameters and the colitis-colorectal cancer interval in a cohort of patients with colorectal cancer in inflammatory bowel disease
Scand J Gastroenterol, 44 (1), 46-55
PubMed 18609187

Brackmann S, Andersen SN, Aamodt G, Roald B, Langmark F, Clausen OP, Aadland E, Fausa O, Rydning A, Vatn MH (2009)
Two distinct groups of colorectal cancer in inflammatory bowel disease
Inflamm Bowel Dis, 15 (1), 9-16
PubMed 18618636

Lehne G, Grasmo-Wendler UH, Berner JM, Meza-Zepeda LA, Adamsen BL, Flack A, Reiner A, Clausen OP, Hovig E, Myklebost O (2009)
Upregulation of stem cell genes in multidrug resistant K562 leukemia cells
Leuk Res, 33 (10), 1379-85
PubMed 19394083

Schjølberg AR, Clausen OP, Burum-Auensen E, De Angelis PM (2009)
Aneuploidy is associated with TP53 expression but not with BRCA1 or TERT expression in sporadic colorectal cancer
Anticancer Res, 29 (11), 4381-7
PubMed 20032382

Westgaard A, Larønningen S, Mellem C, Eide TJ, Clausen OP, Møller B, Gladhaug IP (2009)
Are survival predictions reliable? Hospital volume versus standardisation of histopathologic reporting for accuracy of survival estimates after pancreatoduodenectomy for adenocarcinoma
Eur J Cancer, 45 (16), 2850-9
PubMed 19376696

Westgaard A, Schjølberg AR, Cvancarova M, Eide TJ, Clausen OP, Gladhaug IP (2009)
Differentiation markers in pancreatic head adenocarcinomas: MUC1 and MUC4 expression indicates poor prognosis in pancreatobiliary differentiated tumours
Histopathology, 54 (3), 337-47
PubMed 19236510

Publications 2008

Burum-Auensen E, DeAngelis PM, Schjølberg AR, Røislien J, Mjåland O, Clausen OP (2008)
Reduced level of the spindle checkpoint protein BUB1B is associated with aneuploidy in colorectal cancers
Cell Prolif, 41 (4), 645-59
PubMed 18699967

Søland TM, Husvik C, Koppang HS, Boysen M, Sandvik L, Clausen OP, Christoffersen T, Bryne M (2008)
A study of phosphorylated ERK1/2 and COX-2 in early stage (T1-T2) oral squamous cell carcinomas
J Oral Pathol Med, 37 (9), 535-42
PubMed 18284542

Westgaard A, Tafjord S, Farstad IN, Cvancarova M, Eide TJ, Mathisen O, Clausen OP, Gladhaug IP (2008)
Resectable adenocarcinomas in the pancreatic head: the retroperitoneal resection margin is an independent prognostic factor
BMC Cancer, 8, 5
PubMed 18194510

Westgaard A, Tafjord S, Farstad IN, Cvancarova M, Eide TJ, Mathisen O, Clausen OP, Gladhaug IP (2008)
Pancreatobiliary versus intestinal histologic type of differentiation is an independent prognostic factor in resected periampullary adenocarcinoma
BMC Cancer, 8, 170
PubMed 18547417

Publications 2007

Adamsen BL, Kravik KL, Clausen OP, De Angelis PM (2007)
Apoptosis, cell cycle progression and gene expression in TP53-depleted HCT116 colon cancer cells in response to short-term 5-fluorouracil treatment
Int J Oncol, 31 (6), 1491-500
PubMed 17982676

Burum-Auensen E, De Angelis PM, Schjølberg AR, Kravik KL, Aure M, Clausen OP (2007)
Subcellular localization of the spindle proteins Aurora A, Mad2, and BUBR1 assessed by immunohistochemistry
J Histochem Cytochem, 55 (5), 477-86
PubMed 17242465

Burum-Auensen E, Deangelis PM, Schjølberg AR, Røislien J, Andersen SN, Clausen OP (2007)
Spindle proteins Aurora A and BUB1B, but not Mad2, are aberrantly expressed in dysplastic mucosa of patients with longstanding ulcerative colitis
J Clin Pathol, 60 (12), 1403-8
PubMed 17322345

De Angelis PM, Stokke T, Beigi M, Flatberg G, Enger M, Haug K, Aass HC, Schjølberg A, Andresen PA, Ariansen S, Bø AS, Mjåland O, Clausen OP (2007)
Chromosomal 20q gain in the DNA diploid component of aneuploid colorectal carcinomas
Int J Cancer, 120 (12), 2734-8
PubMed 17354231

Løvig T, Andersen SN, Clausen OP, Rognum TO (2007)
Microsatellite instability in long-standing ulcerative colitis
Scand J Gastroenterol, 42 (5), 586-91
PubMed 17454879

Publications 2006

Boberg KM, Jebsen P, Clausen OP, Foss A, Aabakken L, Schrumpf E (2006)
Diagnostic benefit of biliary brush cytology in cholangiocarcinoma in primary sclerosing cholangitis
J Hepatol, 45 (4), 568-74
PubMed 16879890

Clausen OP, Aass HC, Beigi M, Purdie KJ, Proby CM, Brown VL, Mattingsdal M, Micci F, Kølvraa S, Bolund L, Deangelis PM (2006)
Are keratoacanthomas variants of squamous cell carcinomas? A comparison of chromosomal aberrations by comparative genomic hybridization
J Invest Dermatol, 126 (10), 2308-15
PubMed 16728973

Frich L, Bjørnland K, Pettersen S, Clausen OP, Gladhaug IP (2006)
Increased activity of matrix metalloproteinase 2 and 9 after hepatic radiofrequency ablation
J Surg Res, 135 (2), 297-304
PubMed 16934296

Frich L, Hol PK, Roy S, Mala T, Edwin B, Clausen OP, Gladhaug IP (2006)
Experimental hepatic radiofrequency ablation using wet electrodes: electrode-to-vessel distance is a significant predictor for delayed portal vein thrombosis
Eur Radiol, 16 (9), 1990-9
PubMed 16541225

Xie X, Clausen OP, Boysen M (2006)
Correlation of numerical aberrations of chromosomes X and 11 and poor prognosis in squamous cell carcinomas of the head and neck
Arch Otolaryngol Head Neck Surg, 132 (5), 511-5
PubMed 16702567

Publications 2005

Brandsaeter B, Schrumpf E, Bentdal O, Brabrand K, Smith HJ, Abildgaard A, Clausen OP, Bjoro K (2005)
Recurrent primary sclerosing cholangitis after liver transplantation: a magnetic resonance cholangiography study with analyses of predictive factors
Liver Transpl, 11 (11), 1361-9
PubMed 16184522

Publications 2004

Brandsaeter B, Schrumpf E, Clausen OP, Abildgaard A, Hafsahl G, Bjøro K (2004)
Recurrent sclerosing cholangitis or ischemic bile duct lesions--a diagnostic challenge?
Liver Transpl, 10 (8), 1073-4
PubMed 15390337

de Angelis PM, Fjell B, Kravik KL, Haug T, Tunheim SH, Reichelt W, Beigi M, Clausen OP, Galteland E, Stokke T (2004)
Molecular characterizations of derivatives of HCT116 colorectal cancer cells that are resistant to the chemotherapeutic agent 5-fluorouracil
Int J Oncol, 24 (5), 1279-88
PubMed 15067352

Halvorsen B, Waehre T, Scholz H, Clausen OP, von der Thüsen JH, Müller F, Heimli H, Tonstad S, Hall C, Frøland SS, Biessen EA, Damås JK, Aukrust P (2004)
Interleukin-10 enhances the oxidized LDL-induced foam cell formation of macrophages by antiapoptotic mechanisms
J Lipid Res, 46 (2), 211-9
PubMed 15547296

Xie X, Clausen OP, Boysen M (2004)
Bag-1 expression as a prognostic factor in tongue squamous cell carcinomas
Laryngoscope, 114 (10), 1785-90
PubMed 15454773

Publications 2003

Boberg KM, Jebsen P, Clausen OP, Aabakken L, Brekke I, Schrumpf E (2003)
Cholangiocarcinoma in situ in primary sclerosing cholangitis: diagnosis by brush cytology and treatment by liver transplantation
J Hepatol, 39 (3), 453
PubMed 12927935

Forslund O, DeAngelis PM, Beigi M, Schjølberg AR, Clausen OP (2003)
Identification of human papillomavirus in keratoacanthomas
J Cutan Pathol, 30 (7), 423-9
PubMed 12859739

Løvig T, Thorstensen L, Hofstad B, Andersen SN, Clausen OP, Vatn M, Lothe RA, Rognum TO (2003)
Genetic and protein markers related to in situ growth and multiplicity in small sporadic colorectal adenomas
Scand J Gastroenterol, 38 (3), 298-306
PubMed 12737446

Mala T, Frich L, Aurdal L, Clausen OP, Edwin B, Soreide O, Gladhaug I (2003)
Intraoperative contrast-enhanced MR-imaging as predictor of tissue damage during cryoablation of porcine liver
Magn Reson Imaging, 21 (7), 733-40
PubMed 14559337

Mala T, Frich L, Aurdal L, Clausen OP, Edwin B, Søreide O, Gladhaug IP (2003)
Hepatic vascular inflow occlusion enhances tissue destruction during cryoablation of porcine liver
J Surg Res, 115 (2), 265-71
PubMed 14697293

Xie X, Clausen OP, Boysen M (2003)
Prognostic value of Bak expression in oral tongue squamous cell carcinomas
Oncol Rep, 10 (2), 369-74
PubMed 12579274

Publications 2002

Björnsson E, Boberg KM, Cullen S, Fleming K, Clausen OP, Fausa O, Schrumpf E, Chapman RW (2002)
Patients with small duct primary sclerosing cholangitis have a favourable long term prognosis
Gut, 51 (5), 731-5
PubMed 12377815

Clausen OP, Beigi M, Bolund L, Kølvraa S, Gjersvik PJ, Mørk G, de Angelis PM (2002)
Keratoacanthomas frequently show chromosomal aberrations as assessed by comparative genomic hybridization
J Invest Dermatol, 119 (6), 1367-72
PubMed 12485441

Lehne G, Sørensen DR, Tjønnfjord GE, Beiske C, Hagve TA, Rugstad HE, Clausen OP (2002)
The cyclosporin PSC 833 increases survival and delays engraftment of human multidrug-resistant leukemia cells in xenotransplanted NOD-SCID mice
Leukemia, 16 (12), 2388-94
PubMed 12454743

Oie E, Clausen OP, Yndestad A, Grøgaard HK, Attramadal H (2002)
Endothelin receptor antagonism attenuates cardiomyocyte apoptosis after induction of ischemia in rats
Scand Cardiovasc J, 36 (2), 108-16
PubMed 12028875

Xie X, Clausen OP, Boysen M (2002)
Prognostic significance of p21WAF1/CIP1 expression in tongue squamous cell carcinomas
Arch Otolaryngol Head Neck Surg, 128 (8), 897-902
PubMed 12162767

Publications 2001

Andreyev HJ, Norman AR, Cunningham D, Oates J, Dix BR, Iacopetta BJ, Young J, Walsh T, Ward R, Hawkins N, Beranek M, Jandik P, Benamouzig R, Jullian E, Laurent-Puig P, Olschwang S, Muller O, Hoffmann I, Rabes HM, Zietz C, Troungos C, Valavanis C, Yuen ST, Ho JW, Croke CT et al. (2001)
Kirsten ras mutations in patients with colorectal cancer: the 'RASCAL II' study
Br J Cancer, 85 (5), 692-6
PubMed 11531254

Clausen OP, Andersen SN, Strøomkjaer H, Nielsen V, Rognum TO, Bolund L, Køolvraa S (2001)
A strategy combining flow sorting and comparative genomic hybridization for studying genetic aberrations at different stages of colorectal tumorigenesis in ulcerative colitis
Cytometry, 43 (1), 46-54
PubMed 11122484

De Angelis PM, Stokke T, Beigi M, Mjåland O, Clausen OP (2001)
Prognostic significance of recurrent chromosomal aberrations detected by comparative genomic hybridization in sporadic colorectal cancer
Int J Colorectal Dis, 16 (1), 38-45
PubMed 11317696

Fleming KA, Boberg KM, Glaumann H, Bergquist A, Smith D, Clausen OP (2001)
Biliary dysplasia as a marker of cholangiocarcinoma in primary sclerosing cholangitis
J Hepatol, 34 (3), 360-5
PubMed 11322195

Oldereid NB, Angelis PD, Wiger R, Clausen OP (2001)
Expression of Bcl-2 family proteins and spontaneous apoptosis in normal human testis
Mol Hum Reprod, 7 (5), 403-8
PubMed 11331661

Publications 2000

Bergan A, Gladhaug IP, Schjolberg A, Bergan AB, Clausen OP (2000)
p53 accumulation confers prognostic information in resectable adenocarcinomas with ductal but not with intestinal differentiation in the pancreatic head
Int J Oncol, 17 (5), 921-6
PubMed 11029493

Boberg KM, Schrumpf E, Bergquist A, Broomé U, Pares A, Remotti H, Schjölberg A, Spurkland A, Clausen OP (2000)
Cholangiocarcinoma in primary sclerosing cholangitis: K-ras mutations and Tp53 dysfunction are implicated in the neoplastic development
J Hepatol, 32 (3), 374-80
PubMed 10735605

Clausen OP, Olsen G, Tjønnfjord GE (2000)
[Flow cytometry--use in cell biology and benefits in clinical medicine]
Tidsskr Nor Laegeforen, 120 (4), 489-95
PubMed 10833942

Gjersvik P, Egass E, Clausen OP (2000)
Grzybowski's generalized eruptive keratocanthomas: a case report
Eur J Dermatol, 10 (2), 135-8
PubMed 10694314

Oie E, Bjørnerheim R, Clausen OP, Attramadal H (2000)
Cyclosporin A inhibits cardiac hypertrophy and enhances cardiac dysfunction during postinfarction failure in rats
Am J Physiol Heart Circ Physiol, 278 (6), H2115-23
PubMed 10843911

Publications 1999

Andersen SN, Lovig T, Clausen OP, Bakka A, Fausa O, Rognum TO (1999)
Villous, hypermucinous mucosa in long standing ulcerative colitis shows high frequency of K-ras mutations
Gut, 45 (5), 686-92
PubMed 10517904

De Angelis PM, Clausen OP, Schjølberg A, Stokke T (1999)
Chromosomal gains and losses in primary colorectal carcinomas detected by CGH and their associations with tumour DNA ploidy, genotypes and phenotypes
Br J Cancer, 80 (3-4), 526-35
PubMed 10408863

Jensen P, Clausen OP, Bryne M (1999)
Differences in sialyl-Tn antigen expression between keratoacanthomas and cutaneous squamous cell carcinomas
J Cutan Pathol, 26 (4), 183-9
PubMed 10335895

Xie X, Boysen M, Clausen OP, Bryne MA (1999)
Prognostic value of Le(y) and H antigens in oral tongue carcinomas
Laryngoscope, 109 (9), 1474-80
PubMed 10499058

Xie X, Clausen OP, De Angelis P, Boysen M (1999)
The prognostic value of spontaneous apoptosis, Bax, Bcl-2, and p53 in oral squamous cell carcinoma of the tongue
Cancer, 86 (6), 913-20
PubMed 10491515

Xie X, De Angelis P, Clausen OP, Boysen M (1999)
Prognostic significance of proliferative and apoptotic markers in oral tongue squamous cell carcinomas
Oral Oncol, 35 (5), 502-9
PubMed 10694951

Publications 1998

Andersen SN, Rognum TO, Bakka A, Clausen OP (1998)
Ki-67: a useful marker for the evaluation of dysplasia in ulcerative colitis
Mol Pathol, 51 (6), 327-32
PubMed 10193513

Clausen OP, Lothe RA, Børresen-Dale AL, De Angelis P, Chen Y, Rognum TO, Meling GI (1998)
Association of p53 accumulation with TP53 mutations, loss of heterozygosity at 17p13, and DNA ploidy status in 273 colorectal carcinomas
Diagn Mol Pathol, 7 (4), 215-23
PubMed 9917132

De Angelis PM, Stokke T, Thorstensen L, Lothe RA, Clausen OP (1998)
Apoptosis and expression of Bax, Bcl-x, and Bcl-2 apoptotic regulatory proteins in colorectal carcinomas, and association with p53 genotype/phenotype
Mol Pathol, 51 (5), 254-61
PubMed 10193519

Jensen P, Huang YQ, Li JJ, Clausen OP, Friedman-Kien AE (1998)
Herpes virus-like DNA (HHV-8) in immunosuppressive therapy-related, HIV-related and classical Kaposi's sarcoma in Norwegian patients
Acta Derm Venereol, 78 (3), 205-6
PubMed 9602228

Lehne G, De Angelis P, Clausen OP, Rugstad HE (1998)
Differential resistance to anthracyclines in P-glycoprotein-expressing human hepatoma cells
Int J Clin Pharmacol Ther, 36 (2), 89-92
PubMed 9520154

Trondsen E, Rosseland AR, Bakka A, Ruud TE, Martinsen T, Clausen OP, Bergan A, Aasen AO (1998)
An experimental study on effects of monopolar diathermy on the bile ducts
Eur J Surg, 164 (4), 297-303
PubMed 9641372

Xie X, Clausen OP, De Angelis P, Boysen M (1998)
Bax expression has prognostic significance that is enhanced when combined with AgNOR counts in glottic carcinomas
Br J Cancer, 78 (1), 100-5
PubMed 9662258

Publications 1997

De Angelis PM, Stokke T, Clausen OP (1997)
NO38 expression and nucleolar counts are correlated with cellular DNA content but not with proliferation parameters in colorectal carcinomas
Mol Pathol, 50 (4), 201-8
PubMed 9350304

Fjeld JG, Erichsen K, Pfeffer PF, Clausen OP, Rootwelt K (1997)
Technetium-99m-tetrofosmin for parathyroid scintigraphy: a comparison with sestamibi
J Nucl Med, 38 (6), 831-4
PubMed 9189124

Fosså SD, De Angelis P, Kraggerud SM, Evenson D, Theodorsen L, Clausen OP (1997)
Prediction of posttreatment spermatogenesis in patients with testicular cancer by flow cytometric sperm chromatin structure assay
Cytometry, 30 (4), 192-6
PubMed 9298838

Jørgensen N, Müller J, Jaubert F, Clausen OP, Skakkebaek NE (1997)
Heterogeneity of gonadoblastoma germ cells: similarities with immature germ cells, spermatogonia and testicular carcinoma in situ cells
Histopathology, 30 (2), 177-86
PubMed 9190360

Lange D, Heyden A, Lie E, Brandtzaeg P, Boysen M, Clausen O (1997)
Lack of prognostic significance for p53-overexpression and Ki-67-immunoreactivity in oral T1-2 squamous cell carcinomas
Oncol Rep, 4 (4), 737-42
PubMed 21590131

Oyen O, Clausen OP, Brekke IB, Bakka A, Pope FM (1997)
Spontaneous rupture of the renal artery in a patient with Ehlers-Danlos syndrome type IV
Eur J Vasc Endovasc Surg, 13 (5), 509-12
PubMed 9166275

Trondsen E, Rosseland AR, Clausen OP, Bakka A, Engh E, Rødland EA, Aasen AO (1997)
An experimental study on effects of occlusion of the cystic duct in mice with or without emptying of the gallbladder
Eur Surg Res, 29 (2), 150-8
PubMed 9058083

Xie X, Clausen OP, Sudbö J, Boysen M (1997)
Diagnostic and prognostic value of nucleolar organizer regions in normal epithelium, dysplasia, and squamous cell carcinoma of the oral cavity
Cancer, 79 (11), 2200-8
PubMed 9179068

Xie X, Stenersen TC, Clausen OP, Boysen M (1997)
Nucleolar organizer regions and prognosis in glottic squamous cell carcinoma
Head Neck, 19 (1), 20-6
PubMed 9030940

Publications 1996

Lehne G, De Angelis P, Clausen OP, Rugstad HE (1996)
Human hepatoma cells rich in P-glycoprotein are sensitive to aclarubicin and resistant to three other anthracyclines
Br J Cancer, 74 (11), 1719-29
PubMed 8956784

Lützow-Holm C, De Angelis P, Clausen OP (1996)
Calcitriol and its analog KH 1060 induce similar changes in keratinocyte cell cycle progression after topical application to mouse skin. A bromodeoxyuridine pulse-chase flow cytometric study
J Investig Dermatol Symp Proc, 1 (1), 54-9
PubMed 9627693

Norheim Andersen S, Breivik J, Løvig T, Meling GI, Gaudernack G, Clausen OP, Schjölberg A, Fausa O, Langmark F, Lund E, Rognum TO (1996)
K-ras mutations and HLA-DR expression in large bowel adenomas
Br J Cancer, 74 (1), 99-108
PubMed 8679466

Publications 1995

De Angelis P, Stokke T, Smedshammer L, Lothe RA, Lehne G, Chen Y, Clausen OP (1995)
P-glycoprotein is not expressed in a majority of colorectal carcinomas and is not regulated by mutant p53 in vivo
Br J Cancer, 72 (2), 307-11
PubMed 7640210

Evenson D, Jost L, Gandour D, Rhodes L, Stanton B, Clausen OP, De Angelis P, Coico R, Daley A, Becker K (1995)
Comparative sperm chromatin structure assay measurements on epiillumination and orthogonal axes flow cytometers
Cytometry, 19 (4), 295-303
PubMed 7796694

Franzén G, Nordgård S, Boysen M, Larsen PL, Halvorsen TB, Clausen OP (1995)
DNA content in adenoid cystic carcinomas
Head Neck, 17 (1), 49-55
PubMed 7883549

Hauer-Jensen M, Skjonsberg G, Moen E, Clausen OP (1995)
Intestinal morphology and cytokinetics in pancreatic insufficiency. An experimental study in the rat
Dig Dis Sci, 40 (10), 2170-6
PubMed 7587784

Heyden A, Lützow-Holm C, Clausen OP, Brandtzaeg P, Huitfeldt HS (1995)
Topical application of 12-O-tetradecanoylphorbol-13-acetate induces dyssynchronous expression of keratins K1 and K10 in mouse epidermis
Cytometry, 19 (4), 313-9
PubMed 7540972

Jensen P, Clausen OP, Geiran O, Simonsen S, Relbo A, Hansen S, Langeland T (1995)
Cutaneous complications in heart transplant recipients in Norway 1983-1993
Acta Derm Venereol, 75 (5), 400-3
PubMed 8615064

Jørgensen PF, Brekke IB, Bakka A, Clausen OP (1995)
[Severe mucormycosis after organ transplantation. Report of a case]
Tidsskr Nor Laegeforen, 115 (19), 2392-4
PubMed 7667856

Lehne G, De Angelis P, Clausen OP, Egeland T, Tsuruo T, Rugstad HE (1995)
Binding diversity of antibodies against external and internal epitopes of the multidrug resistance gene product P-glycoprotein
Cytometry, 20 (3), 228-37
PubMed 7587708

Lützow-Holm C, De Angelis P, Clausen OP (1995)
Topical application of retinoic acid induces murine epidermal proliferation without reducing the cell cycle time. A bivariate BrdUrd/DNA flow cytometric study
Epithelial Cell Biol, 4 (1), 2-7
PubMed 8563792

Lützow-Holm C, Heyden A, Huitfeldt HS, Brandtzaeg P, Clausen OP (1995)
Topical application of calcitriol alters expression of filaggrin but not keratin K1 in mouse epidermis
Arch Dermatol Res, 287 (5), 480-7
PubMed 7542861

Xie X, Stenersen T, Clausen O, Boysen M (1995)
Stereologic estimation of nuclear volume in glottic squamous-cell carcinoma
Oncol Rep, 2 (6), 1049-54
PubMed 21597851

Zeller B, Westvik J, Clausen OP, Selberg T (1995)
[Fibrodysplasia (myositis) ossificans progressiva]
Tidsskr Nor Laegeforen, 115 (28), 3496-8
PubMed 7491602

Publications 1994

Bang G, Donath K, Thoresen S, Clausen OP (1994)
DNA flow cytometry of reclassified subtypes of malignant salivary gland tumors
J Oral Pathol Med, 23 (7), 291-7
PubMed 7965883

Giwercman A, Clausen OP, Bruun E, Frimodt-Moller C, Skakkebaek NE (1994)
The value of quantitative DNA flow cytometry of testicular fine-needle aspirates in assessment of spermatogenesis: a study of 137 previously maldescended human testes
Int J Androl, 17 (1), 35-42
PubMed 7911790

Heyden A, Lützow-Holm C, Clausen OP, Brandtzaeg P, Huitfeldt HS (1994)
Expression of keratins K6 and K16 in regenerating mouse epidermis is less restricted by cell replication than the expression of K1 and K10
Epithelial Cell Biol, 3 (3), 96-101
PubMed 7534576

Heyden A, Lützow-Holm C, Clausen OP, Thrane EV, Brandtzaeg P, Roop DR, Yuspa SH, Huitfeldt HS (1994)
Application of cantharidin or 12-O-tetradecanoylphorbol-13-acetate on mouse epidermis induces a cell population shift that causes altered keratin distribution
Differentiation, 57 (3), 187-93
PubMed 7527355

Lehne G, Deangelis P, Clausen O, Hall K, Huitfeldt H, Rugstad H (1994)
Pharmacokinetics and cytotoxicity of epirubicin (epi) in drug-resistant human hepatoma-cells (hb8065)
Int J Oncol, 4 (6), 1229-35
PubMed 21567042

Lie ES, Engh V, Boysen M, Clausen OP, Kvernvold H, Stenersen TC, Winther FO (1994)
Squamous cell carcinoma of the respiratory tract following laryngeal papillomatosis
Acta Otolaryngol, 114 (2), 209-12
PubMed 7515551

Lützow-Holm C, Heyden A, Huitfeldt HS, Brandtzaeg P, Clausen OP (1994)
Differential effects of topical retinoic acid application on keratin K1 and filaggrin expression in mouse epidermis
Differentiation, 57 (3), 179-85
PubMed 7527354

Xie X, Stenersen T, Larsen P, Clausen O, Boysen M (1994)
Prognostic value of nuclear volume in adenoid cystic carcinoma of the head and neck
Oncol Rep, 1 (2), 427-32
PubMed 21607379

Publications 1993

Deangelis P, Stokke T, Smedshammer L, Lothe R, Meling G, Rofstad M, Chen Y, Clausen O (1993)
P53 expression is associated with a high-degree of tumor DNA aneuploidy and incidence of p53 gene mutation, and is localized to the aneuploid component in colorectal carcinomas
Int J Oncol, 3 (2), 305-12
PubMed 21573365

Engh E, Clausen OP, Purvis K, Stien R (1993)
Sperm quality assessed by flow cytometry and accessory sex gland function in spinal cord injured men after repeated vibration-induced ejaculation
Paraplegia, 31 (1), 3-12
PubMed 7680446

Engh E, Schølberg A, Clausen OP, Purvis K (1993)
DNA flow cytometry of sperm from normozoospermic men in barren couples and men of proven fertility
Int J Fertil Menopausal Stud, 38 (5), 305-10
PubMed 8298671

Lützow-Holm C, De Angelis P, Grøsvik H, Clausen OP (1993)
1,25-Dihydroxyvitamin D3 and the vitamin D analogue KH1060 induce hyperproliferation in normal mouse epidermis. A BrdUrd/DNA flow cytometric study
Exp Dermatol, 2 (3), 113-20
PubMed 8162327

Meling GI, Lothe RA, Børresen AL, Graue C, Hauge S, Clausen OP, Rognum TO (1993)
The TP53 tumour suppressor gene in colorectal carcinomas. I. Genetic alterations on chromosome 17
Br J Cancer, 67 (1), 88-92
PubMed 8094008

Meling GI, Lothe RA, Børresen AL, Graue C, Hauge S, Clausen OP, Rognum TO (1993)
The TP53 tumour suppressor gene in colorectal carcinomas. II. Relation to DNA ploidy pattern and clinicopathological variables
Br J Cancer, 67 (1), 93-8
PubMed 8427784

Sandsmark M, Eskeland G, Ogaard AR, Abyholm F, Clausen OP (1993)
Treatment of large congenital naevi. A review and report of six cases
Scand J Plast Reconstr Surg Hand Surg, 27 (3), 223-32
PubMed 8272774

Schlichting E, Clausen OP, Hanssen AS, Buanes TA (1993)
Ploidy and survival in resectable pancreatic cancers. A retrospective study over 9 years
Eur J Surg, 159 (4), 229-33
PubMed 8102544

Aarnaes E, Clausen OP, Kirkhus B, De Angelis P (1993)
Heterogeneity in the mouse epidermal cell cycle analysed by computer simulations
Cell Prolif, 26 (3), 205-19
PubMed 8324071

Publications 1992

Clausen OP, Berg KA, Kirkhus B, De Angelis P, Huitfeldt H (1992)
BrdUrd incorporation studies for evaluation of spermatogenesis in the blue fox
Cytometry, 13 (4), 374-80
PubMed 1526196

Engh E, Clausen OP, Scholberg A, Tollefsrud A, Purvis K (1992)
Relationship between sperm quality and chromatin condensation measured by sperm DNA fluorescence using flow cytometry
Int J Androl, 15 (5), 407-15
PubMed 1428199

Kirkhus B, Clausen OP (1992)
Circadian variations in cell cycle phase progression of mouse epidermal cells measured directly by bivariate BrdUrd/DNA flow cytometry
Epithelial Cell Biol, 1 (1), 32-8
PubMed 1307935

Kirkhus B, Glasø M, Clausen OP (1992)
Multivariate flow cytometry of epidermal regeneration provoked by a skin irritant and a tumor promoter
Cytometry, 13 (3), 267-74
PubMed 1576892

Lützow-Holm C, De Angelis P, Clausen OP (1992)
Retinoic acid provokes a regeneration-like proliferative response in murine epidermis. A bivariate DNA/bromodeoxyuridine flow cytometric study
Arch Dermatol Res, 284 (7), 418-23
PubMed 1288424

Meling GI, Rognum TO, Clausen OP, Børmer O, Lunde OC, Schlichting E, Grüner OP, Hognestad J, Trondsen E, Havig O (1992)
Serum carcinoembryonic antigen in relation to survival, DNA ploidy pattern, and recurrent disease in 406 colorectal carcinoma patients
Scand J Gastroenterol, 27 (12), 1061-8
PubMed 1475624

Publications 1991

Clausen OP (1991)
[Should DNA separation analyses be a routine in all pathological laboratories?]
Tidsskr Nor Laegeforen, 111 (13), 1609-10
PubMed 2063353

Clausen OP, Giwercman A, Jørgensen N, Bruun E, Frimodt-Møller C, Skakkebaek NE (1991)
DNA distributions in maldescended testes: hyperdiploid aneuploidy without evidence of germ cell neoplasia
Cytometry, 12 (1), 77-81
PubMed 1671832

Elgjo K, Reichelt KL, Clausen OP, de Angelis P (1991)
Inhibitory epidermal pentapeptide modulates proliferation and differentiation of transformed mouse epidermal cells in vitro
Virchows Arch B Cell Pathol Incl Mol Pathol, 60 (3), 161-4
PubMed 1679266

Engh E, Clausen OP, Purvis K (1991)
Acrosomal integrity assessed by flow cytometry in men with variable sperm quality
Hum Reprod, 6 (8), 1129-34
PubMed 1806574

Hall KS, Lien B, Mørkrid L, Clausen OP, Bergan A, Rugstad HE (1991)
Long-term toxicity of preoperative 4'-epidoxorubicin (Epi-adriamycin) in partially hepatectomized rats
Eur Surg Res, 23 (2), 114-22
PubMed 1936080

Huitfeldt HS, Heyden A, Clausen OP, Thrane EV, Roop D, Yuspa SH (1991)
Altered regulation of growth and expression of differentiation-associated keratins in benign mouse skin tumors
Carcinogenesis, 12 (11), 2063-7
PubMed 1718620

Kirkhus B, Olsen WM, Clausen OP (1991)
A comparison between the epidermal regenerative responses provoked by a skin irritant and a tumor promoter using anti-BrdUrd/DNA flow cytometry
Carcinogenesis, 12 (5), 833-7
PubMed 2029747

Meling GI, Clausen OP, Bergan A, Schjølberg A, Rognum TO (1991)
Flow cytometric DNA ploidy pattern in dysplastic mucosa, and in primary and metastatic carcinomas in patients with longstanding ulcerative colitis
Br J Cancer, 64 (2), 339-44
PubMed 1892760

Meling GI, Lothe RA, Børresen AL, Hauge S, Graue C, Clausen OP, Rognum TO (1991)
Genetic alterations within the retinoblastoma locus in colorectal carcinomas. Relation to DNA ploidy pattern studied by flow cytometric analysis
Br J Cancer, 64 (3), 475-80
PubMed 1911187

Meling GI, Rognum TO, Clausen OP, Chen Y, Lunde OC, Schlichting E, Wiig JN, Hognestad J, Bakka A, Havig O (1991)
Association between DNA ploidy pattern and cellular atypia in colorectal carcinomas. A new clinical application of DNA flow cytometric study?
Cancer, 67 (6), 1642-9
PubMed 2001553

Vatn MH, Hoff G, Clausen OP (1991)
Epidemiology and histopathogenesis of colorectal cancer
Eur J Cancer Prev, 1 Suppl 2, 5-12
PubMed 1842733

Publications 1990

Andersen Berg K, Clausen OP, Huitfeldt HS (1990)
The spermatogenic cycle in the blue fox (Alopex lagopus): relative frequency and absolute duration of the different stages
Int J Androl, 13 (4), 315-26
PubMed 2387650

Clausen OP, Potten CS (1990)
Heterogeneity of keratinocytes in the epidermal basal cell layer
J Cutan Pathol, 17 (3), 129-43
PubMed 2197302

Kirkhus B, Clausen OP (1990)
Cell kinetics in mouse epidermis studied by bivariate DNA/bromodeoxyuridine and DNA/keratin flow cytometry
Cytometry, 11 (2), 253-60
PubMed 1690627

Purvis K, Rui H, Schølberg A, Hesla S, Clausen OP (1990)
Application of flow cytometry to studies on the human acrosome
J Androl, 11 (4), 361-6
PubMed 2211342

Spydevold O, Sørensen H, Clausen OP, Gautvik KM (1990)
Dexamethasone inhibition of rat hepatoma cell growth and cell cycle traverse is reversed by insulin
Biochim Biophys Acta, 1052 (1), 221-8
PubMed 2182131

Aarnaes E, Kirkhus B, Clausen OP (1990)
Mathematical model analysis of mouse epidermal cell kinetics measured by bivariate DNA/anti-bromodeoxyuridine flow cytometry and continuous [3H]-thymidine labelling
Cell Tissue Kinet, 23 (5), 409-24
PubMed 2245440

Publications 1989

Hall KS, Lien B, Paulsen JE, Clausen OP, Bergan A, Rugstad HE (1989)
Effect of preoperative 4'-epidoxorubicin (epi-adriamycin) treatment on the regeneration and function of the liver in partially hepatectomized rats
Eur Surg Res, 21 (3-4), 196-204
PubMed 2806348

Johansen TE, Clausen OP, Nesland JM (1989)
The effect of non-union of testis and epididymis and of cryptorchidism on the development of epididymis and ductus deferens in the rat
Andrologia, 21 (5), 441-8
PubMed 2573293

Johnansen TE, Haug E, Clausen OP (1989)
Endocrine effects of early non-union of testis and epididymis and of cryptorchidism in the rat
Andrologia, 21 (3), 256-64
PubMed 2570538

Oldereid NB, Rui H, Clausen OP, Purvis K (1989)
Cigarette smoking and human sperm quality assessed by laser-Doppler spectroscopy and DNA flow cytometry
J Reprod Fertil, 86 (2), 731-6
PubMed 2760898

Vatn MH, Hoff G, Clausen OP, Foerster A (1989)
Enzyme patterns and flow cytometric DNA measurements in colorectal hyperplastic polyps and tubular adenomas less than five millimeters
Scand J Gastroenterol, 24 (9), 1031-8
PubMed 2595264

Publications 1988

Clausen OP, Bolstad KG, Mjelva E (1988)
In vivo growth kinetics of P388 and L1210 leukemias
Virchows Arch B Cell Pathol Incl Mol Pathol, 54 (5), 278-83
PubMed 2895540

Clausen OP, Kirkhus B, Elgjo KM, Yuspa SH, Kilkenny AE, Hennings H (1988)
Selective detachment of a tetraploid subline of primary keratinocytes after treatment with the tumor promoter 12-0-tetradecanoylphorbol-13-acetate
APMIS Suppl, 2, 100-10
PubMed 2460111

Clausen OP, Schjølberg AR (1988)
Turnover and maturation kinetics in regenerating mouse epidermis
APMIS Suppl, 2, 111-9
PubMed 3179031

Erichsen A, Clausen OP, Torjesen P, Dahl E, Wetteland P, Hansson V (1988)
A transplantable rat Leydig cell tumour. 6. Effect of castration and hypophysectomy on tumour growth, morphology and plasma levels of pituitary hormones and testosterone
Acta Endocrinol (Copenh), 119 (2), 291-300
PubMed 3140553

Giwercman A, Clausen OP, Skakkebaek NE (1988)
Carcinoma in situ of the testis: aneuploid cells in semen
Br Med J (Clin Res Ed), 296 (6639), 1762-4
PubMed 3136829

Johansen TE, Clausen OP, Nesland JM (1988)
A comparative study of the effects of non-union of testis and epididymis and cryptorchidism on testicular development and spermatogenesis in the rat
Andrologia, 20 (3), 189-201
PubMed 2902815

Kirkhus B, Clausen OP, Fjordvang H, Helander K, Iversen OH, Reitan JB, Vaage S (1988)
Characterization of bladder tumours by multiparameter flow cytometry with special reference to grade II tumours
APMIS, 96 (9), 783-92
PubMed 3166807

Thorud E, Clausen OP, Aarnaes E (1988)
Turnover and maturation kinetics in the hairless mouse epidermis. Continuous [3H]TdR labelling and mathematical model analyses
Cell Tissue Kinet, 21 (4), 301-14
PubMed 3233646

Publications 1987

Clausen OP (1987)
DNA synthesis rate and unlabeled cells with S-phase DNA content in P388 leukemic cells in vivo studied by flow cytometry and cell sorting
Cytometry, 8 (6), 612-7
PubMed 3428043

Kirkhus B, Clausen OP (1987)
Persisting long-term effects of a single carcinogenic dose of methylnitrosourea on epidermal growth in mice
Carcinogenesis, 8 (2), 271-4
PubMed 3802411

Smith AJ, Mondain-Monval M, Andersen Berg K, Gordeladze JO, Clausen OP, Simon P, Scholler R (1987)
Sexual development in the immature male blue fox (Alopex lagopus), investigated by testicular histology, DNA flow cytometry and measurement of plasma FSH, LH, testosterone and soluble testicular Mn2+-dependent adenylate cyclase activity
J Reprod Fertil, 81 (2), 505-15
PubMed 3123658

Smith AJ, Mondain-Monval M, Andersen Berg K, Simon P, Forsberg M, Clausen OP, Hansen T, Møller OM, Scholler R (1987)
Effects of melatonin implantation on spermatogenesis, the moulting cycle and plasma concentrations of melatonin, LH, prolactin and testosterone in the male blue fox (Alopex lagopus)
J Reprod Fertil, 79 (2), 379-90
PubMed 3572874

Smith AJ, Mondain-Monval M, Simon P, Andersen Berg K, Clausen OP, Hofmo PO, Scholler R (1987)
Preliminary studies of the effects of bromocriptine on testicular regression and the spring moult in a seasonal breeder, the male blue fox (Alopex lagopus)
J Reprod Fertil, 81 (2), 517-24
PubMed 3430468

Publications 1986

Buchmann MS, Clausen OP (1986)
Effects of cholestanol feeding and cholestyramine treatment on the tissue sterols in the rabbit
Lipids, 21 (12), 738-43
PubMed 3821387

Clausen OP, Kirkhus B, Schjølberg AR (1986)
Cell cycle progression kinetics of regenerating mouse epidermal cells: an in vivo study combining DNA flow cytometry, cell sorting, and [3H]dThd autoradiography
J Invest Dermatol, 86 (4), 402-5
PubMed 3745959

Clausen OP, Kirkhus B, Thorud E, Schjølberg A, Moen E, Cromarty A (1986)
Evidence of mouse epidermal subpopulations with different cell cycle times
J Invest Dermatol, 86 (3), 266-70
PubMed 3745951

Elgjo K, Hennings H, Clausen OP (1986)
Altered growth kinetics precede calcium-induced differentiation in mouse epidermal cells
In Vitro Cell Dev Biol, 22 (6), 332-6
PubMed 3759789

Magnus O, Purvis K, Rui H, Clausen OP, Abyholm T, Gordeladze JO (1986)
Biochemical correlates of asthenozoospermia: a lesion at the level of the sperm adenylyl cyclase
Arch Androl, 17 (3), 165-72
PubMed 3606270

Publications 1985

Clausen OP, Kirkhus B (1985)
Effects of pulse labelling with tritiated thymidine on the circadian rhythmicity in epidermal cell-cycle distribution in mice
Cell Tissue Kinet, 18 (1), 83-9
PubMed 3971418

Clausen OP, Kirkhus B, Elgjo K, Pedersen S, Bolund L (1985)
DNA synthesis rate changes during the S phase in mouse epidermis
Cell Tissue Kinet, 18 (4), 445-55
PubMed 4005938

Hoff G, Clausen OP, Fjordvang H, Norheim A, Foerster A, Vatn MH (1985)
Epidemiology of polyps in the rectum and sigmoid colon. Size, enzyme levels, DNA distributions, and nuclear diameter in polyps of the large intestine
Scand J Gastroenterol, 20 (8), 983-9
PubMed 4081637

Johansen PW, Clausen OP, Haug E, Fossum S, Gautvik KM (1985)
Effects of bromocriptine on cell cycle distribution and cell morphology in cultured rat pituitary adenoma cells
Acta Endocrinol (Copenh), 110 (3), 319-28
PubMed 4072574

Thorud E, Aarnaes E, Clausen OP, Bjerknes R, Anker P (1985)
Estimation of circadian variations in cell cycle phase durations in murine epidermal basal cells
Cell Tissue Kinet, 18 (3), 279-95
PubMed 3986872

Publications 1984

Clausen OP, Iversen OH, Thorud E (1984)
Circadian variation in the susceptibility of mouse epidermis to tumour induction by methylnitrosourea
Virchows Arch B Cell Pathol Incl Mol Pathol, 45 (3), 325-9
PubMed 6146223

Clausen OP, Aarnaes E, Kirkhus B, Pedersen S, Thorud E, Bolund L (1984)
Subpopulations of slowly cycling cells in S and G2 phase in mouse epidermis
Cell Tissue Kinet, 17 (4), 351-65
PubMed 6733749

Korsgaard R, Clausen OP, Thorud E (1984)
Establishment of a human meningeal cell line in culture
Anticancer Res, 4 (1-2), 83-9
PubMed 6712180

Smith AJ, Clausen OP, Kirkhus B, Jahnsen T, Møller OM, Hansson V (1984)
Seasonal changes in spermatogenesis in the blue fox (Alopex lagopus), quantified by DNA flow cytometry and measurement of soluble Mn2+ -dependent adenylate cyclase activity
J Reprod Fertil, 72 (2), 453-61
PubMed 6512769

Thorud E, Clausen OP, Kauffman SL (1984)
Different epidermal cell kinetic effects of hydroxyurea when injected at two different times of the day
Cell Tissue Kinet, 17 (6), 549-56
PubMed 6488273

Publications 1983

Clausen OP (1983)
Flow cytometry of keratinocytes
J Cutan Pathol, 10 (1), 33-51
PubMed 6188766

Clausen OP, Elgjo K, Kirkhus B, Pedersen S, Bolund L (1983)
DNA synthesis in mouse epidermis: S phase cells that remain unlabeled after pulse labeling with DNA precursors progress slowly through S
J Invest Dermatol, 81 (6), 545-9
PubMed 6644097

Elgjo K, Clausen OP (1983)
Mouse epidermal cell proliferation after a single application of dimethyl sulphoxide (DMSO)
Cell Tissue Kinet, 16 (4), 343-9
PubMed 6861193

Elgjo K, Clausen OP (1983)
Proliferation-dependent effect of skin extracts (chalone) on mouse epidermal cell flux at the G1-S, S-G2 and G2-M transitions
Virchows Arch B Cell Pathol Incl Mol Pathol, 42 (2), 143-51
PubMed 6133388

Publications 1982

Clausen OP, Parvinen M, Kirkhus B (1982)
Stage-related variations in DNA fluorescence distribution during rat spermatogenic cycle measured by flow cytometry
Cytometry, 2 (6), 421-5
PubMed 7075402

Clausen OP, Thorud E, Elgjo K (1982)
Epidermal proliferation characteristics are similar in the pilary canal of mouse hair follicles and in interfollicular epidermis
Virchows Arch B Cell Pathol Incl Mol Pathol, 39 (3), 259-66
PubMed 6126031

Clausen OP, Thorud E, Iversen OH (1982)
Adrenalin has differential effects on epidermal cell cycle progression in mice
J Invest Dermatol, 78 (6), 472-6
PubMed 7086167

Clausen OP, Thorud E, Kauffman SL (1982)
Circadian rhythms in mouse epidermis: variation in the numbers of basal and differentiating cells, cell density, and cell loss
Int J Chronobiol, 8 (2), 83-93
PubMed 7141750

Gordeladze JO, Abyholm T, Cusan L, Clausen OP, Hansson V (1982)
Cellular localization of the Mn2+-dependent adenylyl cyclase in the human testis
Arch Androl, 8 (3), 199-204
PubMed 6808940

Gordeladze JO, Parvinen M, Clausen OP, Hansson V (1982)
Stage dependent variation in Mn2+-sensitive adenylyl cyclase (AC) activity in spermatids and FSH-sensitive AC in sertoli cells
Arch Androl, 8 (1), 43-51
PubMed 6802089

Jutte NH, Jansen R, Grootegoed JA, Rommerts FF, Clausen OP, van der Molen HJ (1982)
Regulation of survival of rat pachytene spermatocytes by lactate supply from Sertoli cells
J Reprod Fertil, 65 (2), 431-8
PubMed 6808129

Publications 1981

Abyholm T, Clausen OP (1981)
Clinical evaluation of DNA flow cytometry of fine needle aspirates from testes of infertile men
Int J Androl, 4 (5), 505-14
PubMed 6797952

Clausen OP, Purvis K, Hansson V (1981)
Age-related changes in [125I]hLH specific binding to rat interstitial cells
Acta Endocrinol (Copenh), 96 (4), 569-76
PubMed 6259866

Clausen OP, Thorud E, Aarnaes E (1981)
Evidence of rapid and slow progression of cells through G2 phase in mouse epidermis: a comparison between phase durations measured by different methods
Cell Tissue Kinet, 14 (3), 227-40
PubMed 7237512

Cusan L, Gordeladze JO, Parvinen M, Clausen OP, Hansson V (1981)
Protein carboxylmethylase and germ cell adenylyl cyclase at specific stages of the spermatogenic cycle of the rat
Biol Reprod, 25 (5), 915-9
PubMed 7326306

Elgjo K, Clausen OP, Thorud E (1981)
Epidermis extracts (chalone) inhibit cell flux at the the G1-S, S-G2 and G2-M transitions in mouse epidermis
Cell Tissue Kinet, 14 (1), 21-9
PubMed 6451294

Gordeladze JO, Purvis K, Clausen OP, Rommerts FF, Hansson V (1981)
Cellular localization of the Mn2+-dependent adenylyl cyclase (AC) in rat testis
Int J Androl, 4 (2), 172-82
PubMed 7251202

Aarnaes E, Thorud E, Clausen OP (1981)
Model analysis of circadian rhythms in mouse epidermal basal cell proliferation
J Theor Biol, 88 (2), 355-70
PubMed 7266008

Publications 1980

Clausen OP, Abyholm T (1980)
Deoxyribonucleic acid flow cytometry of germ cells in the investigatin of male infertility
Fertil Steril, 34 (4), 369-74
PubMed 7418890

Clausen OP, Thorud E (1980)
Perturbation of cell cycle progression in mouse epidermis prior to the regenerative response
J Invest Dermatol, 74 (6), 433-6
PubMed 7381234

Clausen OP, Thorud E (1980)
Perturbation of cell cycle progression in mouse epidermis prior to the regenerative response
J Invest Dermatol, 75 (2), 129-32
PubMed 7410881

Clausen OP, Thorud E, Bolund L (1980)
DNA synthesis in mouse epidermis. Labelled and unlabelled basal cells in S phase after administration of tritiated thymidine
Virchows Arch B Cell Pathol Incl Mol Pathol, 34 (1), 1-11
PubMed 6108002

Purvis K, Clausen OP, Hansson V (1980)
Effects of age and hypophysectomy on responsiveness of rat Leydig cells to hCG
J Reprod Fertil, 60 (1), 77-86
PubMed 7431331

Thorud E, Clausen OP (1980)
Epidermal cell kinetics in hairless mice after bleomycin. II. Perturbations after multiple doses
Cancer Treat Rep, 64 (10-11), 1039-45
PubMed 6161698

Thorud E, Clausen OP, Bjerknes R, Aarnaes E (1980)
The stathmokinetic method in vivo. Time-response with special reference to circadian variations in epidermal cell proliferation in the hairless mouse
Cell Tissue Kinet, 13 (6), 625-34
PubMed 7417979

Publications 1979

Clausen OP (1979)
Regenerative proliferation of mouse epidermal cells following application of a skin irritant (cantharidin). Flow microfluorometric DNA measurements and [3H]TdR incorporation studies of isolated basal cells
Cell Tissue Kinet, 12 (2), 135-44
PubMed 427873

Clausen OP, Purvis K, Hansson V (1979)
Endocrine correlates of meiosis in the male rat
Arch Androl, 2 (1), 59-66
PubMed 443922

Clausen OP, Thorud E, Bjerknes R, Elgjo K (1979)
Circadian rhythms in mouse epidermal basal cell proliferation. Variations in compartment size, flux and phase duration
Cell Tissue Kinet, 12 (3), 319-37
PubMed 476779

Purvis K, Clausen OP, Hansson V (1979)
Androgen effects on rat Leydig cells
Biol Reprod, 20 (2), 304-9
PubMed 222365

Purvis K, Clausen OP, Hansson V (1979)
LH contamination may explain FSH effects on rat Leydig cells
J Reprod Fertil, 56 (2), 657-65
PubMed 573330

Purvis K, Clausen OP, Olsen A, Haug E, Hansson V (1979)
Prolactin and Leydig cell responsiveness to LH/hCG in the rat
Arch Androl, 3 (3), 219-30
PubMed 229781

Publications 1978

Clausen OP (1978)
Regenerative proliferation of mouse epidermal cells following application of a carcinogenic skin irritant (MCA). Micro-flow fluorometric DNA measurements and 3H-TdR incorporation studies of isolated basal cells
Virchows Arch B Cell Pathol, 27 (3), 205-15
PubMed 96581

Clausen OP, Gautvik KM, Haug E (1978)
Effects of cortisol, 17beta-estradiol and thyroliberin on prolactin and growth hormone production, cell growth and cell cycle distribution in cultured rat pituitary tumour cells
J Cell Physiol, 94 (2), 205-14
PubMed 413837

Clausen OP, Purvis K, Hansson V (1978)
Assessment by microflow fluorometry of the purity of interstitial cell suspensions from the rat testis
J Reprod Fertil, 52 (2), 387-90
PubMed 633223

Purvis K, Clausen OP, Brandtzaeg P, Hansson V (1978)
LH receptors and Leydig cell responsiveness to hCG in vitro
Arch Androl, 1 (4), 299-310
PubMed 216326

Purvis K, Clausen OP, Hansson V (1978)
Age-related changes in responsiveness of rat Leydig cells to hCG
J Reprod Fertil, 52 (2), 379-86
PubMed 633222

Purvis K, Clausen OP, Hansson V (1978)
Decreased Leydig cell responsiveness in the testicular feminized male rat
Endocrinology, 102 (4), 1053-60
PubMed 217612

Thorud E, Clausen OP (1978)
Epidermla cell kinetics in hairless mice after bleomycin. I. Perturbations after different single doses
Cancer Treat Rep, 62 (3), 351-61
PubMed 77187

Publications 1977

Clausen OP, Gautvik KM, Lindmo T (1977)
Cell cycle distributions, growth characteristics, and variation in prolactin and growth hormone production in cultured rat pituitary cells
Virchows Arch B Cell Pathol, 23 (3), 195-207
PubMed 403669

Clausen OP, Purvis K, Hansson V (1977)
Application of micro-flow fluorometry to studies of meiosis in the male rat
Biol Reprod, 17 (4), 555-60
PubMed 922090

Iversen OH, Clausen OP, Elgjo K, Iversen UM, Rohrbach R (1977)
Effects of bleomycin on the epidermal content of growth-regulatory substances (chalones)
Cell Tissue Kinet, 10 (1), 71-9
PubMed 66992

Purvis K, Haug E, Clausen OP, Naess O, Hansson V (1977)
Endocrine status of the testicular feminized male (TFM) rat
Mol Cell Endocrinol, 8 (4), 317-34
PubMed 924015

Publications 1976

Clausen OP, Lindmo T (1976)
Regenerative proliferation of mouse epidermal cells following adhesive tape stripping. Micro-flow fluorometry of isolated epidermal basal cells combined with 3H-TdR incorporation and a stathmokinetic method (colcemid)
Cell Tissue Kinet, 9 (6), 573-87
PubMed 1000570

Clausen OP, Lindmo T, Sandnes K, Thorud E (1976)
Separation of mouse epidermal basal and differentiating cells for microflow fluorometric measurements: a methodologic study
Virchows Arch B Cell Pathol, 20 (4), 261-75
PubMed 820057

Iversen OH, Clausen OP, Elgjo K, Iversen UM, Rohrbach R (1976)
Growth parameters of the hairless mouse epidermis after bleomycin treatment: possible interaction with epidermal chalones
Prog Biochem Pharmacol, 11, 110-8
PubMed 63957

Iversen PH, Clausen OP, Iversen UM, Rohrbach R (1976)
Some effects of bleomycin on the proliferation, maturation time and protein synthesis of hairless mouse epidermis
Cell Tissue Kinet, 9 (1), 77-97
PubMed 57003

Publications 1975

Clausen OP (1975)
The effect of bleomycin on rapidly proliferating epidermis. A comparative investigation using micro-flow fluorometry, H3Tdr incorporation and a stathmokinetic method (colcemid)
Virchows Arch B Cell Pathol, 19 (4), 337-48
PubMed 54977

Iversen OH, Clausen OP, Iversen UM, Rohrbach R (1975)
[Effect of bleomycin on the proliferation and maturity of epidermal cells in nude mice]
Verh Dtsch Ges Pathol, 59, 562
PubMed 56102