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Biomedical subjects

A David

Publications and source records attributed to A David.

At least 307 records · Page 17Linked to original sources
PubMed1977

Experimental evidence for a kinetic and electrochemical memory in enzyme membranes.

The existence of hysteresis phenomena in artificial enzyme membranes due to the coupling of simple kinetic enzyme properties with diffusion transport processes is reported. The intramembrane pH of a urease coating on the surface of a glass pH electrode exhibits a hysteresis loop when the pH of the bulk solution varies cyclically. The steady-state potential of a urease membrane, as a function of the substrate concentration in the bulk solution, also exhibits a memory effect. The influence of the membrane's history on its overall behavior is visualized by electron microscopy. We interpret the results in terms of a coupling between the enzyme reactions and diffusion processes, without taking into account molecular effects.

Diffusion↗
PubMed1977

Stilbestrol administration in the puerperium and its effect on the prolactin excretion of non-lactacting patients.

The relationship between stilbestrol treatment and placebo treatment was studied in 2 groups of non-nursing patients. Plasma prolactin levels were evaluated in these 2 groups on day 1, 3 and 7 of the treatment, by a radioimmunoassay technique with the double antibody method using Serono hPRL kit. Our results show that prolactin values increased significantly in the stilbestrol-group and decreased in the placebo group. It seems that the main reason for "the drying up of milk" is the lack of stimulation of the nipples, which after a releatively constant time of 5--10 days will lead to decreased prolactin levels. Stilbestrol treatment is not effective in "drying up" the milk more rapidly in patients who do not want to nurse. When patients have symptoms a combination of analgesia and breast support usually brings relief within 24 to 48 hours.

Clinical Trials as Topic↗
PubMed1977

[Comparative study of nitrogen sparing during parenteral feeding as a function of carbohydrate intake].

The nitrogen balance of two groups of patients, A and B, was studied during the first four post-operative days. Groups A (31) received a daily intake of one liter of Totamine concentrée glucidique with glucose 10 p. 100 1,5 liter. Groups B received Totamine concentrée glucidique with glucose 30 p. 100 1,5 liter. There was no statistically significant difference in nitrogen balance between both groups. On the other hand, the cumulative nitrogen balance was positive for both groups for the first four post-operative days.

Adult↗
PubMed1976

Artificial insemination donor: clinical and psychologic aspects.

Forty-four sterile sterile couples in whom the main cause of infertility was the male factor were investigated. Artificial insemination donor (AID) was performed, timed according to the basal body temperature chart. It was found that it is important to match not only the physical appearance of the couple to that of the donor but also the blood group of at least one of the future parents. Patients were interviewed by a psychologist in order to define their marital relationship, their attitude toward the infertility, their feelings about AID in comparison to adoption, their attitude toward the donor and pregnancy, and their attitude toward their physician. The role of the psycholgist in AID treatment was found to be important for careful selection of cases. He can also guide and prepare these couples to face family life in the future.

Adult↗
PubMed1976

Separation of beta-galactosidases and beta-glucosidases from human liver.

Various fractions obtained from normal human liver homogenates by gel chromatography and selective adsorption and elution from insolubilized concanavalin A were compared as to their beta-galactosidase and beta-glucosidase activities. The high-molecular-weight acidic beta-galactosidase form was converted into the smaller major form by sodium dodecyl sulfate treatment. Electrophoresis and electrofocusing on acrylamide slabs revealed, in addition to the two major isoenzyme forms (acid and neutral), another five minor bands with enzymatic activity.

Galactosidases↗
PubMed1976

Tubal plastic surgery at the Tel Hashomer Hospital: a critical study.

The study presents 93 patients in whom tubal surgery was carried out for primary or secondary mechanical infertility. A classification of these patients into five groups is suggested. Twenty-four uterine pregnancies were recorded, eighteen of which reached term. A plea for enlarging the scope and number of interventions in more patients of the older group and of the more complex pathologic group is presented and discussed. This approach may lower the the over-all success rate but may benefit some of this group of patients. Last but not least, the follow-up of these patients, who constantly move from one physician to another, seeking more treatment, is difficult. Liaison with referring gynecologists and standardization of methods would be of great help in the follow-up.

Abortion, Incomplete↗
PubMed1975

Congenital absence of the vagina. Clinical and psychologic aspects.

Seventeen patients with congenital absence of the the vagina are presented. The clinical results of conservative and surgical treatment are briefly described. Psychologic problems produced in the patients by knowledge of the anomaly and following the operative procedure were studied by a retrospective interview technique and are discussed. It is concluded that the gynecologist and psychologist must together undertake psychologic preparation of the patient for the operation--and its mental aftermath--as early as possible if the best clinical and psychologic results are to be obtained.

Adolescent↗