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Biomedical subjects

C O Povlsen

Publications and source records attributed to C O Povlsen.

At least 19 recordsLinked to original sources
PubMed1988

Campylobacter pylori detected by indirect immunohistochemical technique.

An immunohistochemical assay for staining C. pylori is described. The method is compared with cultivation of C. pylori and observation of campylobacter-like organisms (CLOs) in hematoxyline-eosine (HE) stained sections. Eighteen biopsies from which C. pylori was cultivated but not seen in HE stained sections and three culture negative biopsies with CLOs seen in HE stained sections were selected from 331 biopsies including 113 culture positive biopsies. There were agreements between cultivation of C. pylori and CLOs seen in HE stained sections in the remaining 310 biopsies. Fourteen of the 18 and one of the three biopsies were found positive by the immunohistochemical assay. In addition 21 culture-positive control biopsies and one of 18 culture-negative control biopsies were also found positive. When the immunohistochemical assay was compared with cultivation the predictive value of positive result is 93% and of negative result 89%. By this method we were able to detect single organisms and no cross-reactions to other curved bacteria on the gastric epithelium were observed.

Bacteriological Techniques↗
PubMed1987

Campylobacter pyloridis in peptic ulcer disease. I. Gastric and duodenal infection caused by C. pyloridis: histopathologic and microbiologic findings.

In this study 153 patients with dyspepsia were biopsied in the gastric antrum and duodenum. All specimens were investigated histopathologically and microbiologically for the presence of Campylobacter pyloridis, and the type of inflammation was recorded in accordance with Morson's criteria. C. pyloridis was found beneath the mucus close to the epithelial cells and mostly in connection with granulocytic infiltration (active gastritis). C. pyloridis was cultured from all of 10 patients with histologically active gastritis and active duodenitis, in 86% of 64 patients with active gastritis and morphologically normal duodenum, and in only 5% of 79 patients without morphologic gastric and duodenal changes. The close relation between active gastritis and C. pyloridis shows that C. pyloridis plays an important role in gastric inflammation, as it fulfils the criterion for a localized bacterial infection.

Adolescent↗
PubMed1985

Parietal cell density in gastric biopsies from patients with and without duodenal ulcer disease.

During gastroscopy biopsy specimens were taken from 4 different areas of gastric corpus mucosa in 51 patients with duodenal ulcer disease (DU) and 26 patients without ulcer disease and the patients underwent an acid stimulation test by injection of 6 micrograms 5-gastrin/kg bodyweight. A parietal cell density study was carried out, using a direct counting of cell nuclei in a standardized lattice. The method was found fully acceptable when compared with stereological analysis of parietal cell density per unit volume (Nv) and was found having a low variation in and between observers. There was no significant variation of parietal cell density locally or regionally in the oxyntic mucosa. No correlation was found in DU group between Basic Acid Output (BAO), Peak Acid Output (PAO) and the parietal cell density, but in the non-DU group a rather poor, but significantly positive correlation was demonstrated. We conclude that the parietal cell mass is not exactly correlated to acid production and that the term "Parietal cell mass" have to include acidogenic area and the secretory ability of the parietal cells.

Biopsy↗
PubMed1984

Acute effects of ultraviolet light B on morphology and epidermal cell kinetics in human skin transplanted to nude mice.

Grafts of human skin on nude mice were irradiated with varying doses of ultraviolet light B and at various intervals were subjected to histological examination and determination of the epidermal 3H-thymidine labelling index. The studies showed that the human skin in the foreign milieu of the nude mouse retained its ability to respond to phototoxic damage. The findings suggest that the nude mouse/human skin model could be a valuable tool in human photodermatological research.

Aged↗
PubMed1984

Antigen-free diet in adult patients with atopic dermatitis. A double-blind controlled study.

The efficacy of an antigen-free diet on the activity of atopic dermatitis was examined in a double-blind study, comprising 33 adults with severe atopic dermatitis. The antigen-free diet (Vivasorb) was compared to a placebo diet during three weeks of hospitalization. Twenty-five patients were evaluable, two of whom had their diet stopped after a few days due to exacerbation. Nine patients improved, while 16 patients were unchanged. Among those who improved five patients had Vivasorb and four placebo diet. In the remaining group 11 patients had Vivasorb and five had placebo. Four patients reported of less pruritus, sleeplessness and antihistamine consumption (three Vivasorb, one placebo) while 21 did not (13 Vivasorb, eight placebo). Thus, there were no significant differences between the groups. Paraclinical studies of circulating eosinophilocytes, serum IgE, orosomucoid, HLA-antigens, and immunofluorescence of skin biopsies showed no differences between the Vivasorb and the placebo groups. The results from the examination of this relatively small number of patients suggest that elementary intolerance plays little role in the etiology of atopic dermatitis in adults.

Adolescent↗
PubMed1984

[Necrobiosis lipoidica in a patient with bronze diabetes].

A case of necrobiosis lipoidica in a patient with idiopathic hemochromatosis and diabetes mellitus is presented. Histologic examination revealed excessive amounts of iron pigment in macrophages in the corium of the necrobiotic skin. There were no iron deposits in the normal skin.

Diabetes Mellitus, Type 1↗
PubMed1983

Comparative studies of normal, 'spontaneously' transformed and malignant human urothelium cells in vitro.

In numerous in vitro studies of cell-mediated cytotoxicity directed against transitional cell carcinomas (TCC) urothelial cells of normal origin have served as control material. In the present work, which includes 13 human bladder cell lines of non-malignant or malignant origin, a comparison was made of morphology, chromosomal mode, growth fraction and tumorigenicity in nude mice. Signs of apparently spontaneous transformation were seen in two cell lines of non-malignant origin. The possibilities for cross-contamination as an explanation of these signs of 'spontaneous' transformation are discussed. During these studies radiation-dependent cytotoxicity of disposable microtissue culture plates was revealed as another important source of error.

Aged↗
PubMed1983

Immunological reconstitution of nude mice transplanted with human malignant tumours.

The effects of neonatal murine thymus grafts implanted in nude mice previously transplanted with three different human malignant tumours were studied. Reconstitution resulted in tumour rejection, which started 2-3 weeks after thymus implantation and was complete after 3-6 weeks. The rejection process showed a characteristic histologic picture with 3 phases, an early, an intermediate, and a late phase, which were similar in the 3 tumour types examined. Histological examination of lymphoid tissues of successfully thymus grafted mice showed reconstitution of varying degrees. Numbers of plaque forming cells (PFC) of the spleen of tumour transplanted, thymus grafted mice were equal to or higher than the numbers of PFC in normal BALB/c controls. Mice, thymus grafted only always showed intermediate PFC-values. Responses to the T-cell mitogen, phytohaemagglutinin-P (PHA) were only partially reconstituted, whether the nude mice were tumour transplanted or not. In addition tumour rejection in tumour-bearing nude mice treated with T-cells only, was studied. The rejection process was similar to that observed when a whole thymus gland was implanted. Finally, implantation of embryonic bovine thymus grafts was performed in tumour transplanted nude mice. When these grafts were accepted, tumours were also rejected. Possible mechanisms of reconstitution and the reasons for the varying results are discussed.

Adenocarcinoma↗
PubMed1982

Clonal evolution demonstrated by flow cytometric DNA analysis of a human colonic carcinoma grown in nude mice.

A spontaneous change in DNA content of a human colonic carcinoma grown in nude mice was observed fortuitously. The tumor initially had a G1 cell DNA content of 1.3 times that of normal cells. Flow cytometric DNA analysis showed in transplant generation 56 the appearance of a new subpopulation which in three passages completely overgrew the original population. The DNA content of the new subpopulation was twice that of the original population. The observation supports the hypothesis of clonal evolution of tumor cell populations. The growth rates of the tumor before and after the change showed no significant difference (p greater than 0.05). Cell kinetic factors, therefore, offer no obvious explanation of how the overgrowth took place. It is not known whether the original population disappeared completely or survived as a small population below the detection limit. The heterogeneity created by clonal evolution of a tumor would be less pronounced if old subpopulations often become extinct as new ones emerge. Heterogeneity of human tumors is of clinical importance because the individual subpopulations may have different sensitivity patterns to antineoplastic drugs.

Animals↗
PubMed1981

Immunological reconstitution of tumour-transplanted and thymus-grafted nude mice.

Two different malignant tumours were transplanted prior to or after thymus grafts in nude mice, and the degree of immunological reconstitution was studied. All mice which rejected either of the tumour types had reconstitution as expressed by an excess of splenic plaque-forming cells. The level of response was dependent upon the age of the thymus graft and whether a tumour was transplanted or not. In contrast, the result of the phytohaemagglutinin stimulation assays of spleen cells were always subnormal in thymus-grafted as well as in thymus- plus tumour-transplanted mice.

Animals↗
PubMed1981

Mucosal changes of the Billroth II resected stomach. A follow-up study of patients resected for duodenal ulcer,with special reference to gastritis, atypia and cancer.

In a follow-up study of a consecutive series of 1000 patients, who underwent Billroth II resection for duodenal ulcer 22-30 years earlier, the mucosal changes of the gastric stump could be studied by endoscopy and biopsy in 196 cases. At the histological examination only 7.1% of the patients had a normal gastric mucosa: the remaining 92.9% had chronic atrophic gastritis., which was diffuse and most marked at the gastro-jejunostomy. In 7.1% of the cases the inflammation was accompanied by focal accumulation of lipophages. 12.2% had non-neoplastic polyp formation caused either by cystic glandular dilatation of the mucosa at the gastro-jejunostomy, eosinophilic granulomatous polyps or protrusion of the mucosa at the lesser curvature caused by invagination at the resection. 14.8% of the patients had epithelial atypia close to the anastomosis, but no cancers were found, and it is concluded that the presented results do not indicate a cancer prophylactic endoscopic screening of patients treated with Billroth II resection for duodenal ulcer.

Adult↗
PubMed1980

Heterotransplants of human tumors in nude mice.

A short review of 10 years experience with the use of thymus-aplastic nude mice in onocology is given. All major human tumor types, e.g. lung, breast, gastrointestinal, genitourinary, malignant melanomas are now established and serially grown in nude mice. Rare human tumors with endocrine activity have also been transplanted successfully to nude mice. Transplanted tumors grow locally at the site of inoculation and metastatic spread to lymph nodes and organs is a rare event. The growth rate of the individual tumors remain constant even after several years of serial transfer. Light and electron microscopy show a close similarity of mouse grown tumors to the human donor material. As judged from isozyme studies, chromosome analyses and immunological investigations human characteristics are preserved in nude mouse grown tumors. Chemotherapy of different types of transplanted human tumors has shown that responses obtained with different tumor/drug combinations in nude mice are comparable with the results obtained by the same tumor/drug combinations in clinical practice. This model is now being employed as a secondary screening method for evaluation selected anticancer agents that are to be used in clinical trials.

Animals↗
PubMed1979

Effects of thymus grafts in nude mice transplated with human malignant tumors.

The effect of neonatal thymus grafts implanted in nude mice previously transplanted with three different human malignant tumors - an adenocarcinoma of the colon, a malignant melanoma and a Burkitt's lymphoma - were studied. In all immunologically reconstituted animals tumord were rejected. Tumor rejection stated 2-3 weeks after thymus implantation, and was completed after 30-6 weeks. Histological examination of lymphoid tissues showed a correlation between immunological reconstitution and tumor rejection. The rejection process showed a characteristic histologic picture with 3 phases - an early, an intermediate and a late phase - these were similar in the three tumor types examined. The possible mechanisms of reconstitution and tumor rejection are discussed.

Adenocarcinoma↗
PubMed1976

Heterotransplantation of human malignant melanomas to the mouse mutant nude.

In 32 experiments involving transplantation of human malignant melanomas to the mouse mutant nude, tumourtake was observed in 14 instances. The tumour tissue which took and grew after inoculation was derived from malignant melanoma metastases of the skin (10 takes from 13 transplantations), and from primary malignant melanomas of the eye (4 takes from 6 transplantations). Not one of 13 attempts to transplant primary tumours of the skin was successful. In 7 instances serial transfers of transplanted tumour were successful, the degree of success ranging from 3 to 41 passages. Some passages were wilfully interrupted but two are continuing. The transplanted tumours grow locally. Neither lymph node metastases nor organ metastases have been observed. Histological appearances of the transplanted tumours, also after serial passages, were identical with those of the original human donor material. The human tumour/nude mouse system is contrasted and compared with other heterotransplantation models.

Adult↗
PubMed1975

Growth patterns and chromosome constitutions of human malignant tumours after long-term serial transplantation in nude mice.

Five human malignant tumours, heterotransplanted to athymic nude mice, have been re-investigated after long-term serial transplantation, and their growth patterns and chromosomal constitutions compared with their early appearance. After 27-56 passages over 3 1/2--5 1/2 years, all of the tumours--two adenocarcinomas of the colon, two malignant melanomas, and one Burkitt's lymphoma--retained the cytological and histological appearance of the inoculated human material. All the mitoses observed in the chromosome studies were of human karyotype. The fact that no total chromosomal species shift, no interspecies hybridization, and no changes in biological properties appeared--as observed in some other heterotransplantation systems--would indicate that human tumours grafted to nude mice are more suitable models in, e.g., studies concerning cancer chemotherapeutics.

Adenocarcinoma↗
PubMed1975

Chemotherapy of a human malignant melanoma transplanted in the nude mouse.

The effects of single agent therapy with 1-(-chloroethyl)-3-cyclohexyl-1-nitrosourea, 5-fluorouracil, and 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide on a human malignant melanoma transplanted and passed serially in thymusless nude mouse were studied. Tumor response varied. A single dose of 1-(-chloroethyl)-3-cyclohexyl-1-nitrosourea induced initial tumor regression, but thereafter growth resumed at a rate similar to that in the untreated control animals. Wehn 1-(-chloroethyl)-3-cyclohexyl-1-nitrosourea was given in divided dosage at an interval of 8 days, marked and persistent tumor regression was observed. 5-Fluorouracil had no effect. Treatment with 5-(3,3 dimethyl-1-triazeno)-imidazole-4-carboxamide was always reflected by almost total regression of tumors, an effect that was independent of dose within the range tested in this study. The results resemble those reported from clinical practice in patients with disseminated malignant melanomas treated with the same agents. This suggests that the pattern of drug susceptibility is preserved after transplantation of tumors in the nude mouse. The human tumor-nude mouse system is advocated as a new in vivo model for determination of individual tumor response to chemotherapeutic agents, and its potential as a model for the proving of new chemotherapeutic agents is suggested.

Animals↗