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Biomedical subjects

J B Weiss

Publications and source records attributed to J B Weiss.

At least 145 records · Page 8Linked to original sources
PubMed1979

Differential fixation of poly(L-arginine) and poly(L-lysine) by tannic acid and its application to the fixation of collagen in electron microscopy.

A differential fixation of poly(L-arginine) and poly(L-lysine) has been demonstrated by means of cellulose acetate electrophoresis and colorimetric titration. Electrophoresis showed that at pH 3.0 and concentrations between 0.025% and 2% the reagent interacts with poly(L-arginine) but not with poly(L-lysine). At pH 7.5, however, poly(L-lysine) also reacts, although at a higher concentration of tannic acid than was required to fix poly(L-arginine) at this pH. Colorimetric titration revealed that for poly(L-arginine) the reaction with tannic acid commences at pH 3.0 and is complete at pH 4.1 whereas for poly(L-lysine) the reaction commences at pH 3.5 and is complete at pH 4.9. It is suggested that the reaction is predominantly electrostatic. The results are discussed in relation to the use of tannic acid as a protein fixative in electron microscopy.

Animals↗
PubMed1979

Solid-phase radioimmunoassay for the detection of antibodies to collagen.

A solid-phase radioimmunoassay has been developed using polystyrene tubes for the detection of class-specific antibodies to collagen. The optimal conditions for the adsorption of collagen onto the tubes, followed by incubation with the antisera and finally the radiolabelled antibody to the class-specific antibody are described. Studies carried out on antisera raised in rats and rabbits using this assay confirm its sensitivity and applicability.

Animals↗
PubMed1979

Effects of maternal position on epidural anesthesia for cesarean section, acid-base status, and bupivacaine concentrations at delivery.

In 25 patients excellent clinical anesthesia for elective cesarean section was obtained with lumbar epidural block using an average dose of bupivacaine of 130 mg (18 ml of 0.75 per cent solution). Supplemental drugs were not needed. All infants had normal Apgar scores at delivery. Ten patients were kept in a 35--40 degree semi-sitting supine position during induction, while 15 patients were similarly semi-sitting but turned into the left lateral position. Maternal position did not affect the adequacy of the anesthesia or the clinical condition of the infants, but did alter acid-base state and bupivacaine concentrations in the infants. At delivery, the infants whose mothers had been supine had significantly lower pH values in umbilical cord blood than those whose mothers had been in the lateral position. Also, high concentrations of bupivacaine were found in the umbilical vein blood of infants whose mothers were supine.

Acid-Base Equilibrium↗
PubMed1979

[Is the term "blockage" just? (author's transl)].

The word "blockage" appeared the last ten years. It designs altogether a syndrom, a symptom and a pathogenic theory of squint. This term is analysed and discussed. The definitions, more or less precise, vary with the authors. The clinical signs attributed to the blockage are, in fact, due to the importance of the deviation. The electro-oculographic semeiology derives also partially of the magnitude of the angle of strabismus. The notion of a hypothetical nystagmus does not help for the understanding of the pathogenis of squint. The "faden operation", difficult and therefore dangerous in some hands, is perhaps an acquisition for the treatment of peculiar cases of nystagmus or paralysis. It would have been possible to expose the facts clearly by using only the terms of spasm and contracture. The confusion brought by the term of "blockage" is perhaps counterbalanced by the development of researches on the surgery of the arc of contact and on electro-oculography.

Adolescent↗
PubMed1978

Effect of sugar and monoglyceride on fatty acid esterification.

The effect of hexose and monoolein on fatty acid esterification was studied in everted rings of rat jejunum. By use of [3H]oleic acid and [U-14C]glucose, esterification via both phosphatidic acid and monoglyceride pathways was quantified. Our results showed that 1) metabolizable sugars stimulate fatty acids esterification regardless of their mode of transport; 2) in the presence of glucose alone, in vitro fatty acid esterification is mediated entirely by the phosphatidic acid pathway; 3) glucose stimulates both esterification pathways in the presence of monoolein; 4) monoolein stimulates only the monoglyceride pathway and has no effect on the phosphatidic acid pathway; and 5) the rate-limiting factor in the presence of monoolein alone is the formation of acyl-CoA, whereas in the presence of glucose alone, the rate-limiting factor is the formation of alpha-glycerophosphate.

Acyl Coenzyme A↗
PubMed1977

Successful extraction of intracardiac tumor thrombus of renal carcinoma.

Successful management of a patient with an intracardiac tumor thrombus of renal carcinoma is described. Important considerations in the management include precise localization of the upper limits of the tumor thrombus preoperatively, early ligation of the renal artery, control of the circulation through the inferior vena cava by temporary occlusion of the vena cava below the renal veins, the left renal vein and the hepatic circulation, and a team approach, using the expertise of the urologist and the cardiac surgeon, as well as cardiopulmonary bypass.

Cardiopulmonary Bypass↗