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Biomedical subjects

N Becker

Publications and source records attributed to N Becker.

At least 127 records · Page 7Linked to original sources
PubMed1984

Reactivation of the secretion from the prostatic gland in cases of reduced fertility. Biological study of seminal fluid modifications.

The efficiency of Pygenum africanum treatment was tested on a population where the acid phosphatase activity was shown to be reduced at two successive examinations. The treatment caused an increase in acid phosphatase activity and total protein secretion. However, the fact that the men who had IgA present in their ejaculate reacted more favorably to the treatment shows that Pygenum africanum is more efficient in cases where there is no prostate gland inflammation.

Acid Phosphatase↗
PubMed1984

Cancer risks associated with life events and conflict solution.

The anecdotally reported putative influence of psychosomatic factors on the clinical manifestation of cancer was examined in a prospective study on the relationship of typical attitudes and subsequent cancer incidence. The concept included an assessment of the typical reaction towards an important event and its duration rather than counting life events. The hypothesis - as derived from a preceding case-control study - was that adverse events causing a chronic conflict eventually leading to hopelessness and (masked) depression increase the susceptibility for malignant growths. In the cohort of 1,353 persons interviewed in 1966 (with a questionnaire containing 109 items), 204 cases of cancer were identified until 1976. Persons reporting hopelessness showed a steadily increasing risk ratio, depending on the intensity of this reaction. No risk elevation was found in those reporting anger and excitement after an important event. The duration had an influence in that already after 3 years of an uninterrupted hopelessness and depression the risk ratio was elevated and remained increased. Other diseases did not show the same consistent pattern. A gradual increase of cancer became evident more than 3 years after an event causing unresolved depression and hopelessness of more than 1 year's duration. These results have to be seen in the context of individual exposure to carcinogens as well as important host factors. They seem, however, to indicate that increased susceptibility to cancer and a timely relationship to its manifestation will have to be considered in a defined proportion of the population, determinable by psychosocial methods.

Adult↗
PubMed1983

Effects of saturated, monounsaturated, and omega-6 polyunsaturated fatty acids on plasma lipids, lipoproteins, and apoproteins in humans.

The effects of dietary fats on plasma cholesterol, serum lipoproteins, and apoproteins (Apo), A-1, B, and CIII were studied. Twelve men consumed three different cholesterol-free formula diets in which polyunsaturated and saturated fats were partially substituted (20% of calories) for monoenoic fats with a constant of 40% of calories from fat. Total cholesterol and low-density lipoprotein cholesterol dropped from base-line values of 166 and 103 to 133 and 81 mg/dl (sat), 127 and 71 mg/dl (mono), and 123 and 65 mg/dl (poly), respectively. High-density lipoprotein cholesterol changed very little from base-line values of 46 to 40 mg/dl (sat), 45 mg/dl (poly), and 43 mg/dl (mono). The plasma concentrations of ApoB declined from base-line values of 80.3 mg/dl to 54.6 mg (mono), 51.8 mg (poly), and 59.6 mg (sat) while Apo CIII and Apo AI did not show any changes. This study demonstrates that: 1) changes in dietary fat affect serum lipids, lipoproteins, and apoproteins even when consumed on a cholesterol-free diet, and 2) omega-6 polyunsaturated fat lowers low-density lipoprotein cholesterol, total cholesterol, and ApoB to a greater extent than monounsaturated or saturated fat, 3) consumption of a cholesterol-free formula diet results in significant decreases in the concentrations of total and low-density lipoprotein cholesterol in plasma when compared to values obtained on a mixed food home diet containing approximately 300 mg cholesterol/day.

Adult↗
PubMed1981

Usual interstitial pneumonia following Texas A2 influenza infection.

In two patients a documented Texas A2 influenza infection was associated with the development of interstitial pulmonary disease. One patient had an acute fulminating process resulting in respiratory failure and necessitating ventilatory assistance. Open lung biopsy revealed a histologic picture consistent with usual interstitial pneumonia (UIP). The other patient had a subacute course, and the pulmonary histology showed UIP with features of desquamative interstitial pneumonia. The influenza virus may have had an etiologic role in the development of the interstitial lung disease in our two patients.

Acute Disease↗
PubMed1980

An epidemic chain model.

An epidemic chain model is developed by assuming a beta distribution for the probability of being infected by contact with a given infective from the same household. This model includes, as a particular case, the epidemic chain model corresponding to the stochastic Kermack-McKendrick model and, as a limiting case, the Reed-Frost chain binomial model. The advantages of the more general model are illustrated with an application to household data for the common cold. Finally, it is shown how the coefficient of variation of the duration of the infectious period may be estimated without any direct observations on this duration.

Common Cold↗
PubMed1979

Protein-bound homocyst(e)ine in normal subjects and in patients with homocystinuria.

A method was developed to quantitate protein-bound homocyst(e)ine using 2-mercaptoethanol. Protein-bound homocyst(e)ine was discovered in the plasma from normal individuals, ranging from 0.5--2.2 nmole/ml. In two obligatory heterozygotes for classical homocystinuria, plasma protein-bound homocyt(e)ine was 3.5 and 4.8 nmole/ml, respectively. Untreated homozygotes showed approximately a 40-fold increase of plasma protein-bound homocyst(e)ine. Furthermore, using conventional methods, no free homocystine was detectable in the supernatant of plasma precipitate from two classical homocystinuric patients treated with pyridoxine, but plasma protein-bound homocyst(e)ine showed a 10-fold increase. Protein-bound homocyst(e)ine was also demonstrated in the liver, kidney, and brain tissues from a patient with methylenetetrahydrofolate reductase deficiency.

Brain↗
PubMed1979

The uses of epidemic models.

This paper is concerned with models formulated to describe the spread of infectious diseases through a community. Some standard epidemic models are introduced and an overview of their uses is provided. The paper includes a discussion of the advantages of simple models over complex ones and the advantages of stochastic models over deterministic ones. The role that epidemic models can play in helping us to understand the spread of diseases and to plan control policies for diseases is explained. The paper also contains a review of some major insights gained from a study of epidemic models and from statistical analyses of disease data using epidemic models. Some explicit suggestions for future research projects are made.

Disease Outbreaks↗
PubMed1977

Estimation for discrete time branching processes with application to epidemics.

Certain estimators for the mean of the offspring distribution of a Galton-Watson process are considered. The asymptotic behaviour of each of these estimators is studied when the true underlying model is in fact a multitype branching process or a branching process with a random environment. It is revealed which of the estimators remain consistent indicators of whether or not the process is subcritical, under these alternative underlying models. It is then indicated how this "robustness" result might influence the choice of an estimator by considering the problem of estimating the level of immunity required in a community in order to prevent major epidemics. The application is illustrated with references to smallpox using data from an outbreak in São Paulo, Brazil.

Disease Outbreaks↗
PubMed1976

Estimation for an epidemic model.

In many epidemic models the initial infection rate, suitably defined, plays a fundamental role in determining the probability of a major epidemic. An estimate for this rate is suggested on the basis of least squares and maximum likelihood methods. The model used to arrive at the estimate is a Galton-Watson process modified by letting the offspring distribution change from generation to generation in a way as to approximate to an epidemic process. The estimates of the parameter and its associated variance are easily computed and compare well with other computationally tedious methods in an application to smallpox data.

Disease Outbreaks↗
PubMed1976

Effects of manganese on carcinogenicity and metabolism of nickel subsulfide.

Nickel subsulfide, Ni3S2, alone or combined with manganese or chromium dusts, was administered i.m. to Fischer rats to study the effects of the metals upon Ni3S2 induction of sarcomas at the injection site. The incidence of sarcomas within 2 years after injection of Ni3S2 (1.2 mg) plus manganese (1.0 mg) was 7%, versus 77% in rats that received only Ni3S2 (1.2 mg), and 80% in rats that received Ni3S2 (1.2 mg) plus chromium (1.0 mg) (p less than 0.005). No local sarcomas occurred in rats that received the injection vehicle, or in rats that received manganese or chromium without Ni3S2. Admixture of manganese diminished the solubility of 63Ni3S2 in rat serum, serum ultrafiltrate, or water, in vitro. Admixture of manganese with 63Ni3S2 did not affect the mobilization or excretion of 63Ni in vivo, nor did it alter the acute pathological reactions to Ni3S2. 63Ni concentrations in ultrafiltrates of supernatant fractions of homogenates of injection sites averaged 2.8 (S. D. +/- 0.7) ng/ml at 5 to 6 months after injection of 63Ni3S2 (1.2 mg) plus manganese (1.0 mg), versus 5.4 +/- 2.0 ng/ml after injection of only 63Ni3S2 (1.2 mg) (p less than 0.02). This study demonstrates that admixture of manganese dust and Ni3S2 inhibits Ni3S2 tumorigenesis in rats, and reveals that manganese dust affects the subcellular distribution of 63Ni derived from 63Ni3S2, without influencing 63Ni kinetics as estimated by compartmental analysis.

Animals↗
PubMed1975

Total pancreatectomy with primary mesenteric vascular reconstruction.

Total pancreaticoduodenectomy with resection of the superior mesenteric artery and vein was performed in a sixty-two year old man with islet cell carcinoma of the pancreas. Arterial reconstruction was accomplished with an aortomesenteric interposition Dacron graft. The venous system was reanastomosed primarily, the infrapancreatic superior mesenteric vein to the portal vein in the hepatic hilum. This procedure, although it did not result in long-term survival, demonstrates the technical feasibility of wide regional resection for tumors of the pancreas impinging upon the mesenteric vasculature in the region of the neck and uncinate process.

Adenoma, Islet Cell↗
PubMed1975

Altered hypothalamic-pituitary-adrenal responsiveness to dexamethasone-insulin tolerance test in active acromegaly.

Eight acromegalic patients showed a plasma cortisol (11-OHCS) rise after insulin hypoglycemia which was similar to that seen in control patients, with mean peak values (+/-SEM) of 23.2 +/- 3.5 mug/100 ml and 27.2 +/- 3.3 mug/100 ml, respectively. One mg of dexamethasone was given the evening prior to repeat insulin hypoglycemia (DEX-ITT). After dexamethasone, the control subjects showed a mean post hypoglycemic plasma 11-OHCS rise to 18.3 +/- 2.3 mug/100 ml. In contrast, acromegalic patients had a negligible rise is plasma 11-OHCS, despite a comparable degree of hypoglycemia. These data indicate that, in active acromegaly, abnormal hypothalamic-pituitary-adrenal suppressibility can be induced to insulin hypoglycemia after dexamethasone.

11-Hydroxycorticosteroids↗