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Biomedical subjects

O H Iversen

Publications and source records attributed to O H Iversen.

At least 19 recordsLinked to original sources
PubMed1997

[Sedimentation rate and renal cancer].

This paper is based on two articles published in 1996 in Journal of Internal Medicine. One is an evaluation of the erythrocyte sedimentation rate (ESR) measured in 3910 subjectively healthy Norwegians of both sexes, with an age range of 20 to 90 years. The authors underline the difference between a population-based and a subject-based upper ESR reference level, and the benefit of knowing each single healthy person's subject-based ESR level. The other article shows that, in 70% of a sample of 236 randomly selected patients with renal cell carcinoma, a diagnosis could have been indicated several years before clinical symptoms or signs became apparent. Therefore, the ESR might be a predictive test for many such cancer cases. This type of cancer has a good prognosis when treated surgically at an early stage. In Norway, 432 new cases occurred in 1993, 264 in men and 168 in women. If our observations are generally applicable, and proper attention had been paid to a slowly increasing ESR value over time, about 300 of these cases could have been operated on much earlier. It is suggested that physicians and public might both benefit from this knowledge.

Adult↗
PubMed1996

[Martin Luther's somatic diseases. A short life-history 450 years after his death].

The article contains a short life-history of the religious reformer Martin Luther (1483-1546) with main emphasis on his many somatic diseases. The list comprises varicose ulcer, angina pectoris with anxiety, obesity, hypertension arterialis, Ménière's disease with vertigo, tinnitus and fainting fits, gastralgia, constipation with anal ulcers and haemorrhoids with bleeding, urolithiasis, arthritis urica, Roemheld's syndrome, and cataract in one eye. Mentally he had a manic-depressive cast of personality, and a tendency to emotional lability. In spite of this he had an enormous capacity for work.

Famous Persons↗
PubMed1996

Rising erythrocyte sedimentation rate during several years before diagnosis can be a predictive factor in 70% of renal cell carcinoma patients. The benefit of knowing subject-based reference values.

OBJECTIVES: A diagnosis of renal cell carcinoma (RCC) early enough for potentially curative surgery is difficult. We wanted to establish whether the erythrocyte sedimentation rate (ESR) in RCC patients had begun to rise before the appearance of any symptoms or signs and, if so, when. DESIGN: A retrospective study of the evolution of the ESR in 236 randomly selected RCC patients during several years before diagnosis, comparing the results with previously obtained population-based control values. RESULTS: It is generally held that RCC patients have a high ESR at diagnosis. In our material, however, 29.7% of the RCC cases had an ESR that at this time was at or below the population-based upper reference limit; it had not increased significantly, neither with time before diagnosis, nor with age. In 70.3% of RCC patients the ESR was increased and had been significantly rising for up to 6 years or more before diagnosis. This had not been adequately responded to, probably because the physicians lacked knowledge of the patients' baseline ESR, and because none of the prediagnostic readings had been above the population-based reference limit. CONCLUSIONS: Systematic ESR graphic recordings over time will enable a physician to determine each individual's baseline value, and hence note any continuously rising trend, which should lead to further investigations, e.g. an ultrasound kidney examination. This may provide an early clue to many otherwise non-symptomatic RCC cases. It is time for a reappraisal of the predictive value of the ESR to discover early RCC, and possibly other diseases as well.

Adult↗
PubMed1996

Population-based erythrocyte sedimentation rates in 3910 subjectively healthy Norwegian adults. A statistical study based on men and women from the Oslo area.

OBJECTIVES: To establish age- and sex-specific reference limits for the erythrocyte sedimentation rate (ESR) in asymptomatic Norwegian adults. DESIGN: Single ESR recordings were obtained by the classical or a modified Westergren method from 2145 men and 1765 women (93% being blood donors) with age range 20-90 years, and analysed statistically. RESULTS: There was a significant positive association between ESR level and age, consistent with a parabolic pattern in men but a linear one in women. The mean values for men were about 3 mm h-1 at 20 years, 6 mm h-1 at 55 years, and 10 mm h-1 at 90 years, and 6, 9, and 11 mm h-1 respectively for women. These averages (predicted by regression lines) were significantly higher in women up to the age of 75 years, after which the estimated sex-specific 95% confidence limits for mean values were found to overlap. CONCLUSIONS: The upper reference levels expected to be exceeded only by chance in 5% of single individual recordings at the ages of 20, 55 or 90 years, respectively, were estimated to be 12, 14 and 19 mm h-1 for men, and 18, 21 and 23 mm h-1 for women. Higher values should be controlled and, if confirmed, lead to a clinical check-up. However, about 76% of our overall material had ESR values lower than 9 mm h-1. Knowledge of each person's baseline ESR value might increase the disease-predictive ability of the test. If several measurements over years reveal a steeper rise with age than depicted in our population-based curves, it should be taken seriously, even when each reading is below the population-based reference limits.

Adult↗
PubMed1995

Of mice and men: a critical reappraisal of the two-stage theory of carcinogenesis.

The two-stage theory of carcinogenesis attempts to reduce a very complex set of data to simple terms: it defines a carcinogen as "an agent that causes a neoplasm by a two-step process involving initiation and promotion". The theory has achieved the status of a paradigm, and all new experiments carried out by two-stage supporters are designed according to its premises and therefore will eo ipso tend to confirm it. Popper's dictum that any scientific hypothesis should be put to the strongest test, namely, by trying to refute it, has rarely (or never) been observed. The two-stage theory was originally based on standard mouse skin-painting experiments. All the original work is grounded on classic skin carcinogenesis, and only later was it extended to also comprise carcinogenesis in other organs, thereby becoming a general theory. On the basis of the same standard skin painting experiments and in accordance with Popper's dictum, the present review shows how the following generally accepted corollaries of the two-stage theory have been refuted: initiation must come first in time; in previously initiated mouse skin promotion always leads to a synergistic increase in tumor crop, whereas complete carcinogens at subthreshold does (regarded as merely initiating) have only an additive effect; the reverse experiment is innocuous; there is a qualitative difference between the effect of initiators and that of promoters; initiators only initiate at low dose levels, but abruptly become rather complete carcinogens at higher doses, promotion must take place over a long period, and repeated exposure without prolonged intervals is essential; pure initiators exist, for example, urethane for the epidermis; pure promoters exist, e.g., TPA; skin inflammation and persistent hyperplasia are essential parts of promotion; increased levels of the enzyme ODC followed by increasing levels of polyamines are casually involved in promotion; the appearance of many dark epidermal cells is a sign of promotion and the dark cells are stem cells from which tumors arise. Carcinogenesis is a very complicated process characterized not only by disturbances in cell cycle control, cell differentiation and/or maturation, but also by changes in the normal ability of cells to respect organ and tissue boundaries. Infiltrative growth and metastases are the most dangerous properties of cancer, and the two-stage theory does not provide an explanation for these two most serious aspects of the disease.

Animals↗
PubMed1994

A course of very small doses of DMBA, each of them allegedly with no promoting potency, acts with clear synergistic effect as a strong promoter of DMBA-initiated mouse skin carcinogenesis. A comparison of the tumorigenic and carcinogenic effects of DMBA (7,12-dimethylbenz-alpha-anthracene) and TPA (12-O-tetradecanoyl-phorbol-13-acetate) used as initiators and promoters in classical two-stage experimental protocols.

A carcinogen has recently been defined as an agent that causes a neoplasm by a two-step process involving initiation and promotion. The difference between the two steps is said to be qualitative rather than quantitative. According to this theory, the hydrocarbon carcinogen, 7,12-dimethylbenz-alpha-anthracene (DMBA) has both initiating and promoting properties, and it has been claimed that when the dose level is lowered, the promoting activity is first reduced while its initiating activity is retained, until at a small dose even the promoting property has completely disappeared, and only the initiating property remains. The theory also says, however, that for carcinogens individual doses are additive, and for pure initiators individual doses are additive even at subthreshold doses. Promoters are said to act in a synergistic way on initiated skin, and a threshold exists below which there is no effect. Experiments were carried out to test the validity of these claims. DMBA was applied twice a week in very small (10 or 4 nmol) doses to the skin of hairless mice, with or without previous initiation. When, after DMBA initiation, DMBA or 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were applied twice a week at small equimolar doses, a real synergistic effect, said to characterize promotion, was obtained with DMBA also, and with an even higher tumor crop and many more carcinomas than those elicited by TPA. Promotion with repeated doses of 10 nmol DMBA resulted in very significantly more carcinomas than with 4 nmol DMBA, which again gave more carcinomas than promotion with 10 nmol TPA. Repeated doses of TPA alone gave a 9% tumor rate, and TPA is thus a complete carcinogen. Reverse experiments were not innocuous. These results contradict the hypothesis that very small doses of DMBA have only initiating properties with only additive and not synergistic effects, and that TPA is only a promoter. It is most probable that the difference between the tumorigenic and carcinogenic effects of DMBA and TPA is not qualitative, but quantitative. TPA is highly toxic; it induces cell death followed by pronounced regeneration, and even DNA alterations. It is a complete, but weak carcinogen. DMBA is a strong complete carcinogen, binding covalently to DNA and altering it in various ways, but in equimolar doses it is less acutely toxic than TPA.(ABSTRACT TRUNCATED AT 400 WORDS)

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1993

Moderate enhancement of the promotion phase of skin tumorigenesis in hairless mice by topical pretreatment with a mitosis-inhibiting epidermal pentapeptide.

The effect of the physiological epidermal proliferation inhibitory substance (EPP) pGlu-Glu-Asp-Ser-GlyOH on the promotion phase in two-stage carcinogenesis was investigated. EPP could be the active component in what has been called epidermal chalone. Hairless mice were given an initial application of 100 nmol 7,12-dimethylbenz[a]anthracene in 200 microliters acetone. One week later promotion was started with topical applications of 17 nmol 12-O-tetradecanoylphorbol-13-acetate (TPA) twice a week. Ninety minutes before each TPA application the control group received a topical application of 200 microliters reagent grade acetone and the two experimental groups were given either 0.005% or 0.01% EPP in 200 microliters acetone. The mice were observed for time of occurrence and time of regression of papillomas. The number of tumors produced by the group given the inhibitory substances before TPA increased, and so did the percentage of tumor-bearing animals. There was also a tendency towards a higher degree of papilloma regression in the animals treated with EPP before TPA. We have previously shown that EPP enhances methylnitrosourea (MNU) carcinogenesis. Since we regard TPA as a skin-irritating promoter with weak carcinogenic potency, very different from MNU, the fact that EPP has the same enhancing effect on promotion as it has on complete MNU carcinogenesis raises some very interesting questions, and may indicate a similarity between the mechanisms in promotion and complete carcinogenesis. Some possible explanations of the results are discussed, e.g. whether the transit zone late G1/S of the cell cycle is the most sensitive one for carcinogenic or tumorigenic effects.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1993

Blue rubber bleb nevus syndrome with manifestations in the vulva.

The blue rubber bleb nevus syndrome (BRBNS) is a rare vascular disorder, manifesting with hemangiomas which are usually located in the gastrointestinal tract and/or in the skin. These lesions can cause local, sometimes severe bleedings or cosmetic problems. This report describes a young woman with BRBNS manifestations on the buttocks and in the vulva, the latter giving rise to symptoms specific to this location. The blood-filled blebs were successfully treated by argon laser. As far as we know, manifestations of this disease in the female genital tract have not previously been described.

Adult↗