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Biomedical subjects

M Koch

Publications and source records attributed to M Koch.

At least 397 records · Page 22Linked to original sources
PubMed1987

Problems in establishing accurate family history in patients with ovarian cancer of epithelial origin.

A detailed family history was obtained from 90 ovarian cancer patients and 90 age-matched controls. Relatives who died in Alberta had their death year and cancer history verified. Year of death was accurate in 12/20 and negative history of cancer in 30/30. Cancer was reported in 229/2,544 relatives. Of these, 104 were or had been residents of Western Canada, but only 69 malignancies were confirmed through population-based cancer registries. This resulted in an error rate of 10/39 (26%) for parents, 7/31 (23%) for siblings, and 18/34 (53%) for uncles and aunts; error rate is similar for patients and controls. A "positive" history of cancer was reported by 53/90 (59%) of patients and 68/90 (76%) of the controls (chi 2 = 5.7); this difference disappears when the total number of relatives is considered: 92/1,179 (7.8%) in patients and 134/1,366 (9.8%) in controls (chi 2 = 3.3). The age of relatives should also be considered for age/sex-specific years at risk comparison. In summary, the validity of studies showing family history of cancer is questionable owing to the multiple sources of error and the lack of specificity of the methods of analysis.

Carcinoma↗
PubMed1986

Experimental chelation therapy in chromium, lead, and boron intoxication with N-acetylcysteine and other compounds.

The usefulness of N-acetylcysteine (NAC) as a chelating agent was studied for the toxin potassium dichromate, lead tetraacetate, and boric acid. Mature Sprague-Dawley rats were intoxicated with these substances and placed in metabolic cages. Urinary excretion rates of intoxicant and total urine volume were determined during treatment with N-acetylcysteine, calcium EDTA, and/or dimercaptosuccinic acid, N-acetylcysteine proved to be the most effective agent at increasing the excretion of chromium and boron and was also able to reverse the oliguria associated with these toxins. Dimercaptosuccinic acid was most effective at the chelation of lead. NAC did not increase the excretion of lead. We conclude that NAC may be useful in intoxications due to chromate and borate and is effective at reversing the oliguria associated with these intoxicants.

Acetylcysteine↗
PubMed1986

Fibrinogen--proteolysis in acute myelogenous leukemia (AML).

Fibrinopeptides were measured as direct indices of thrombin, plasmin and elastase in plasma samples obtained from patients with AML. Peptide patterns observed were consistent with spontaneous or drug induced plasmin-specific fibrinogenolysis (AML FAB M 1/3), elastase mediated proteolysis (AML FAB M 3/4) or DIC (AML FAB 4/5). DIC was also observed in septic, agranulocytotic patients.

Adult↗
PubMed1986

Semi-quantitative assessment of anti-insulin total IgG and IgG sub-classes in insulin-immunized patients using a highly sensitive immunochemical micromethod.

An immunochemical micromethod was designed to estimate total IgG and IgG sub-classes of anti-insulin antibodies in immunized diabetic patients. Insulin, immobilized on a solid phase, was allowed to react with serum samples containing anti-insulin antibodies. Bound anti-insulin IgG interacted with mouse monoclonal antibodies specific for total IgG or for each IgG isotype. The fixation of mouse monoclonal antibody was subsequently detected using a horseradish peroxidase-conjugated rabbit anti-mouse IgG in the presence of a chromogenic substrate. The test was standardized by an immunocapture assay utilizing coated rabbit anti-human IgG and known concentrations of purified human myelomatous proteins of each sub-class. Results of anti-insulin IgG and anti-insulin IgG sub-classes assay could therefore be expressed in ng equivalent myelomatous proteins per ml of serum. Analysis of serum samples from 24 insulin-immunized diabetic patients revealed a quasi absence of IgG2 anti-insulin antibodies and an increase of the relative abundance of the other three anti-insulin IgG isotypes. In our series, anti-insulin IgG1 was predominant, followed by IgG3 (in 17/24 patients) or IgG4 (in 7/24). Insulin immunization was deduced to be of polyclonal nature, the isotype pattern of which is not representative of the relative proportion of IgG sub-classes in whole normal serum.

Diabetes Mellitus, Type 1↗
PubMed1986

Informational needs of families of intensive care unit patients.

Although results of the study are specific to St Michael Hospital's ICU, the implications of those results are not limited to the study site. Families of patients admitted to any critical care unit may experience similar needs as those identified in this study. Intensive care unit nurses need to identify these needs as a first step in the process toward family-centered care. Critical care nurses can view families either as further stressors on their time or as integral components of their nursing plan and valuable resources in the well-being and recovery of their patients. Tailoring interventions to the main concerns of families can allow ICU nurses to maintain their high standards of professional care while helping families cope with critical illness. Using a unit-based quality assurance study, critical care nurses can implement research-based interventions to address the information and emotional needs of families.

Adult↗
PubMed1986

Interactions of pH and K+ conductance in cultured bovine retinal pigment epithelial cells.

Passive ion transport properties were studied in confluent monolayers of cultured bovine retinal pigment epithelial cells using intracellular microelectrode technique. The mean stable intracellular (designated by subscript i) potential was -59.1 +/- 0.8 (SE) mV. Extracellular (designated by subscript o) acidification induced a depolarization, whereas alkalinization induced a hyperpolarization. These effects were observed both in bicarbonate-free as well as in HCO3- Ringer (pHo changed by varying [HCO3-]o at constant pCO2). Acidification of pHi (changed by addition and removal of butyrate, CO2 or NH3) also caused a depolarization. Complete removal of HCO3-/CO2 at constant pHo caused a hyperpolarization. K+ transference, checked by applying high K+o, increased with K+o. It decreased with both extra and intracellular acidification and increased with alkalinization. In the presence of Ba2+, voltage reactions to changes in either pHo or pHi were greatly reduced. Depolarization by 40 mM K+ caused a similar reduction. It is suggested that K+ conductance of bovine retinal pigment epithelial cells is reduced by either intra- or extracellular acidification at normal [K+]o. Depolarization by high K+ induces an increase in K+ transference and reduces pH sensitivity.

Action Potentials↗
PubMed1986

Factors affecting recurrence rates in superficial bladder cancer.

A prospective study of all patients with superficial bladder cancer diagnosed in Northern Alberta (population 1.2 million) from 1977 to 1983 was performed to establish patterns of recurrence. Of the 761 patients with all stages of bladder cancer at diagnosis, 642 were deemed to be free of disease after primary treatment consisting of transurethral resection, fulguration, or laser surgery. Follow-up of these patients showed that approximately two-thirds of first recurrences occur within 18 months of diagnosis and that more of these patients have died of unrelated causes (n = 73) than of bladder cancer (n = 34). Censored disease-free interval comparisons showed that initial recurrences occurred sooner in patients with multifocal rather than unifocal disease and also sooner in females than in males. Known risk factors (occupational exposure to chemicals and cigarette smoking) and suspected risk factors (coffee consumption and artificial sweetener use) had no effect on disease-free interval and are not related to tumor multiplicity.

Adolescent↗
PubMed1985

Sibs of probands with neural tube defects--a study in the Federal Republic of Germany.

Data for the risk of neural tube defects in sibs of affected children are needed for genetic counselling, for decision on prenatal studies, and for planning of preventive measures. Data have been reported from various populations but were lacking for Germany. This study presents data on the siblings of 240 index patients in the Western part of the Federal Republic of Germany. The prevalence among sibs of affected individuals was found to be 2.6%. This figure agrees well with reports from other countries in Continental Europe and the United States, and fits the expectation of lower recurrence risks in low incidence populations.

Abortion, Spontaneous↗
PubMed1985

Analysis of "time to second primary" in patients with gynecological cancers.

Lifetable survival curves have been adapted to measure "time to second primary" and used to compare incidence of second primary in all patients in the Alberta Cancer Registry with a primary malignancy in cervix, endometrium and ovary. Comparisons were also obtained within each diagnostic category between patients treated or not treated with radiation. Results show that there are no statistically significant differences in the 25 years following diagnosis of the first primary in "time to second primaries" in patients with cancer of the cervix, endometrium or ovary. Similarly, within each diagnostic category, there are no differences between radiation treated patients and those not treated by radiation, when adjustments for age differences are made and when patients are selected by length of survival.

Adolescent↗
PubMed1985

Effects of antifertility estrogens and progestins on the endometrial surface of early pregnant rats. A scanning electron microscopic study.

Two estrogens, mestranol and 3-methoxy-14 beta, 15 beta-methyleneestra-1,3,5(10)triene-17 beta-ol (STS 593), and two progestins, levonorgestrel and 17 alpha-cyanomethyl-17 beta-hydroxyestra-4,9(10)-diene-3-one (STS 557), all having antifertility properties in rodents, were examined for their effects on the uterine luminal surface of early pregnant rats. Scanning electron microscopic studies showed that there are clear qualitative differences between the effects of estrogens and progestins on both morphology and microvillous pattern of the endometrial surface while STS 557 showed intermediate effects. The results are discussed with respect to the anti-implantation activity of steroids.

Animals↗
PubMed1985

Further report on the endocrinological profile of two synthetic estrogens with antifertility properties, STS 456 and STS 593.

Two synthetic estrogens, STS 456 and STS 593, with noteworthy post-coital antifertility properties in the rat were studied for their estrogenic, antiestrogenic, progestagenic, antiprogestagenic, antigonadotrophic, androgenic and antiandrogenic effects in laboratory animals. Beside their weak estrogenic activity which corresponds to their slight affinity to the uterine estrogen receptor in the rat, both steroids show remarkable antiestrogenic effects. No progestagenic, androgenic and antiandrogenic effects were found but STS 593 showed some antiprogestagenic activity. The antigonadotrophic efficacy of STS 456 was relatively high while STS 593 was scarcely active. The results are discussed with respect to possible application of these drugs for interceptive purposes.

Anabolic Agents↗
PubMed1985

[Tetrasomy 9p].

A newborn male with multiple malformations and an extrachromosome is presented. The cytogenetic study of peripheral blood lymphocytes revealed tetrasomy 9p: 47,XY, + t(9;9)(pter----q13::p11----pter). The C-banding pattern provided evidence for maternal origin of the extrachromosome. Tetrasomy for the short arm of chromosome 9 is a very rare condition; reports about only ten further patients have been found in the literature. The phenotypic expression resembles trisomy 9p, but tetrasomy 9p has more severe additional malformations.

Abnormalities, Multiple↗
PubMed1985

Relationship between patient variables and lithium dosage requirements.

The relationships between several patient variables and lithium dosage requirements were determined in 71 inpatients receiving a slow-release lithium product. Age, weight, ideal body weight, sex, body surface area, creatinine clearance, presence of depression, concurrent use of tricyclic antidepressants, and acuteness of symptoms were significantly related to dosage requirements. The contribution of each factor to dosage requirements was further defined using multiple regression analysis and used to assess a published patient variable-based lithium dosing technique. Addition to that model of information concerning presence of depression, acuteness of symptoms, and creatinine clearance minimally improved predictability. The published model is recommended as an alternative to empiric methods.

Adult↗