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Biomedical subjects

A Zucker

Publications and source records attributed to A Zucker.

At least 19 recordsLinked to original sources
PubMed1998

Death and language: some comments on Haussamen.

Brock Haussamen argues inventively that there are features of language that are the source of our belief in an afterlife, that something deep about language prevents us from talking about the dead as if they are really dead. He speaks of "language as forcing." In this response to Haussamen's article, the author attempts to show that Haussamen's arguments and examples are not strong enough to make his point. The major suggestion is that there is more to the "deep structure" of language than Haussamen has assumed. Once this is realized, it is easier to see that it is we who choose to speak of the dead as we do. It is we who choose to believe in an afterlife. Language does no forcing.

Attitude to Death↗
PubMed1996

Hyperbaric oxygenation upregulates rat lung Na,K-ATPase.

Exposure of rats to hyperoxia is associated with increased active Na+ transport in rat lungs and increased Na,K-adenosine triphosphate (ATPase) expression in alveolar epithelial cells. Hyperbaric oxygenation (HBO) has been reported to act as an accelerated model of hyperoxic cell damage. Sublethal and intermittent exposure to HBO, however, has been suggested to upregulate endogenous protective mechanisms. In the present study, we tested whether short-term HBO, prior to inducing lung injury, would upregulate lung Na,K-ATPase. The results show that HBO, either intermittent or single 2.5 h exposure, increased lung Na,K-ATPase alpha-1 and beta-1 messenger ribonucleic acid (mRNA) transcript levels up to fourfold. Na,K-ATPase activity in lungs of rats exposed to HBO increased twofold during the first 2 h following removal from the hyperbaric chamber, and remained elevated for up to 6 h following HBO. Conceivably, the increase in Na,K-ATPase activity following HBO is due to an increase in activity from a basal to a higher rate, or possibly due to recruitment/translocation of Na,K-ATPases from inner membranes to the plasma membrane.

Analysis of Variance↗
PubMed1993

Chapman's reflexes: medicine or metaphysics?

Clinical medicine is a pragmatic discipline. Because of its aim to alleviate pain and suffering as well as to foster well-being, its practitioners can be lulled into thinking that there are times when basic science is irrelevant to the practice of medicine. This attitude is evaluated by comparing a 19th century medical curiosity, the nasogenital reflex, to a set of reflexes, the little used and little known Chapman's reflexes. We must always attempt to substantiate the principles of clinical medicine.

Female↗
PubMed1992

Baby marrow: ethicists and privacy.

A family had a child in large part to use its marrow in the hopes of saving the life of an older child afflicted with leukaemia. Public response from medical ethicists was negative. This paper argues that what the family did was not clearly wrong and that the ethicists should not have made public pronouncements calling the morals of the family into question.

Adolescent↗
PubMed1990

Zona pellucida-binding of boar sperm acrosin is associated with the N-terminal peptide of the acrosin B-chain (heavy chain).

Recently, it has been shown that boar acrosin exhibits a carbohydrate-binding activity with a specificity to fucose, by which it can bind to the oocyte zona pellucida. By limited autoproteolysis of a high-molecular mass acrosin (55/53 kDa), designated as alpha-acrosin, a 15 kDa fragment was generated which interacts strongly with the porcine zona pellucida. Zona-binding was demonstrated on protein blots and by the solid-phase zona-binding assay utilizing biotinylated zona proteins. The zona-binding peptide was isolated by reversed-phase HPLC and analyzed for amino acid sequence. Its single N-terminal sequence corresponded to that of the acrosin B-chain (heavy chain). These data indicate that the zona-binding properties of acrosin are associated with the N-terminal peptide of the acrosin heavy chain.

Acrosin↗
PubMed1990

Cell biology of acrosomal proteins.

Acrosin is a multifunctional enzyme combining several functional properties within a single molecule: the catalytic triad of the proteinase, hydrophobic domains responsible for the special membrane-associating character of the enzyme and the carbohydrate binding sites by which the molecule can bind to the zona pellucida. Acrosin occurs in the sperm acrosome as an inactive precursor, proacrosin, with a molecular mass of 53-55 kDa. Proacrosin is activated by a single proteolytic clip between Arg23 and Val24 generating the high molecular mass acrosin. The activation of proacrosin to the biologically active enzyme which occurs concomitantly with the acrosome reaction appears to be regulated on and by the zona pellucida. It is hypothesized that alternating cycles of binding to the zona, digestion of the zona and release from the zona together with the forward motility of the spermatozoon would be required to achieve penetration.

Acrosin↗
PubMed1990

Is sperminogen a modified proacrosin? Isolation, purification, and partial characterization of low-molecular-mass boar proacrosin.

Low-molecular-mass zymogen was extracted from boar spermatozoa together with proacrosin using 10% acetic acid supplemented with 10% glycerol, and was purified by the sequential use of gel filtration on Sephadex G-75 and (FPLC) reversed-phase chromatography. LMM zymogen represented approximately 5% of the latent trypsin-like activity present in the sperm extract. SDS-PAGE indicated a molecular mass of 33 kDa. The zymogen reacted with both mouse monoclonal and rabbit polyclonal antibodies to boar acrosin. Determination of the N-terminal sequence of 34 amino-acid residues revealed its identity with the known N-terminal sequence of boar proacrosin.

Acrosin↗
PubMed1989

Bioethics laws.

Explore the source record for details and available documents.

Bioethics↗
PubMed1988

Freud, Fliess, and the nasogenital reflex: did a look into the nose let us see the mind?

Wilhelm Fliess, a Berlin nose and throat surgeon, and Sigmund Freud, the father of psychoanalysis, collaborated to treat one of Freud's earliest patients, Emma Eckstein. The basis for the treatment was their belief in the "Nasogenital Reflex," a widely accepted theory that has disappeared from the literature of otolaryngology. The outcome of Emma's treatment may have profoundly altered the history of psychiatry, by suggesting the role of the unconscious and the existence of the Oedipus complex.

Austria↗
PubMed1984

Blind use of the double-lumen plugged catheter for diagnosis of respiratory tract infections in critically ill children.

Transtracheal aspiration, percutaneous lung biopsy, and tracheal aspiration can be dangerous and/or unreliable methods for obtaining specimens of pulmonary secretions for culture. Using a blind technique, we evaluated the efficacy of a double-lumen catheter (DLC) with a polyethylene glycol plug in obtaining specimens of respiratory tract secretions for culture, and compared these results with simultaneously obtained cultures of tracheal aspirates. Twenty-seven intubated children already receiving antibiotic therapy were studied. Sixteen (59%) DLC specimens were sterile, as opposed to only 6 (22%) tracheal aspirates. Only 2 (8%) of the DLC specimens were contaminated. Two DLC specimens yielded significant bacterial growth (at least 10(5) colony-forming units/ml). Using DLC culture data, there was an 81% success rate in making decisions concerning antibiotic selection. We conclude that blind use of the DLC is a safe and reliable method of obtaining pulmonary secretion specimens for culture.

Adolescent↗
PubMed1984

Hypomagnesemia is a common complication of aminoglycoside therapy.

Normal therapeutic dosages of aminoglycosides can cause hypomagnesemia in more than one-third of patients. Hypomagnesemia occurs early in therapy, results in renal Mg++ wasting and may produce hypocalcemia and hypokalemia. Patients who are NPO, eating poorly or not receiving supplemental Mg++ are at high risk for hypomagnesemia. Hypomagnesemia, hypocalcemia and hypokalemia respond to Mg++ replacement therapy. We recommend serial monitoring of serum Mg++ levels in patients receiving aminoglycoside therapy.

Aminoglycosides↗
PubMed1983

Effect of water deprivation on urinary excretion of PGE2 in the dog.

We examined the influence of the state of hydration on the urinary excretion of prostaglandin E2 (PGE2) and kallikrein in the dog. Immunoreactive PGE2 and kallikrein were measured in the urine of conscious dogs during periods of water deprivation and periods of free access to drinking water and in the urine of time-control dogs that had free access to water throughout the study. During water deprivation the excretion of kallikrein did not change significantly, but PGE2 excretion increased by 50 and 75% (P less than 0.05) after 2 and 4 days, respectively, associated with reductions of body weight and urine flow and with elevation of plasma renin activity, plasma sodium, and both plasma and urine osmolality. Dehydrated dogs drank copiously when allowed free access to water, and over the following 4 days both PGE2 excretion and plasma renin activity fell significantly, associated with elevation of body weight and urine volume and with lowering of plasma sodium and plasma and urine osmolality. In contrast, if after 4 days of water deprivation the dogs were kept at a constant level of dehydration by restricting their water allotment on subsequent days to 300 ml/day, PGE2 excretion and most other variables remained at the dehydration level. In conclusion, these results suggest that renal PGE2 production is dependent on the state of hydration in the dog.

Animals↗
PubMed1982

Dietary sodium intake: a determinant of postprandial plasma sodium concentration in the dog.

1. The effect of dietary sodium intake on pre- and post-prandial plasma sodium concentrations and on the pattern of sodium and potassium excretion was determined in conscious female dogs, who were allowed free access to water and were fed on commercial low sodium diets supplemented with 0, 50, 100 or 250 mmol of sodium chloride/day for 6 days. 2. The preprandial plasma sodium concentration was not altered by the dietary sodium intake. However, the 4 h postprandial plasma sodium concentration was linearly related to the magnitude of dietary sodium intake, whereas the 8 h postprandial plasma sodium concentration was elevated only in dogs receiving 250 mmol of sodium/day. 3. The (0-8 h/0-24 h) ratio for urinary sodium excretion was significantly correlated with both the dietary sodium intake and the postprandial increase in plasma sodium concentration. 4. The 24 h excretion of potassium was not markedly affected by the dietary sodium intake; however, the (0-8 h/0-24 h) ratio for potassium excretion was significantly correlated with both the dietary sodium intake and the (0-8/0-24 h) ratio for sodium excretion. 5. These data indicate that: (a) postprandial increases in plasma sodium concentration need to be considered when evaluating the mechanisms involved in the daily regulation of sodium balance; (b) the daily pattern of potassium excretion is closely linked to the dietary sodium intake.

Animals↗