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Biomedical subjects

M D Altschule

Publications and source records attributed to M D Altschule.

At least 55 records · Page 3Linked to original sources
PubMed1982

Soluble lipofuscin in commercially-available human serum albumin solutions.

Two studied commercial human serum albumin solutions had developed yellow colors during storage. These yellow materials were isolated and shown to be soluble lipofuscin. Aqueous solutions of this lipofuscin exhibited fluorescence spectra with 355 nm excitation and 432 nm emission maxima. After acid hydrolysis of this lipofuscin a nonhydrolysable lipid-melanin fraction was obtained. Ethanol-ether extraction yielded a lipid-containing solution. When evaporated and mixed with water, a solution-suspension was obtained that produced very similar fluorescence spectra to those described above, with 368 nm excitation and 432 nm emission maxima. The separated melanin component was not fluorescent. The isolated lipofuscin exhibited a weak electron paramagnetic resonance spectrum and its g-value has been found to be 2.0069 and its line width 9.8 G. The albumin solution contained approximately 0.23 g of melanin precipitate per 9.31 g of soluble lipofuscin isolated from 25 g of albumin. The deleterious cardiac, pulmonary, renal and clotting changes associated with the use of albumin solution might be due to this lipofuscin.

Color↗
PubMed1981

Isolation of melanin from human plasma lipofuscin.

Human plasma lipofuscin and its melanin component were isolated and quantified. Electron paramagnetic resonance, infrared, ultraviolet and visible spectra of this melanin exhibited absorption characteristics very similar to those of known melanins. The human plasma lipofuscin contained approximately 85% protein, 3% melanin, 0.4% lipid and 0.25% mucoprotein constituents and emitted yellow-green fluorescence in 366-nm light. The ethanol-ether lipid extract obtained after acid hydrolysis from the lipid-melanin fraction of this lipofuscin was also found to fluoresce in yellow-green color in 366-nm light and produced similar fluorescence excitation and emission spectra as those of the human plasma lipofuscin in water solution. The isolated melanin component was not fluorescent.

Electron Spin Resonance Spectroscopy↗
PubMed1981

Quantification of hyperbaric oxygen-induced toxicity utilizing a malarial system.

This study was undertaken in recognition of the need to develop quantitative systems to evaluate the toxicity associated with hyperbaric oxygen (HBO) exposure. Malaria-infected (P. berghei berghei) mice were briefly exposed to 100% oxygen at 3 ATA on day 10 of infection. At 25, 48, and 72 h thereafter, the levels of circulating erythrcytes and percent parasitized RBC were monitored and compared to those of infected non-exposed controls. The total erythrocyte counts of the infected HBO-exposed and non-exposed mice did not differ significantly. In contrast, percent parasitized cells in the oxygen-exposed mice were lowered to 55-60% control values at 24, 48, and 72 h. The mechanism of this difference needs further study, but we believe that P. berghei-infected erythrocytes are preferentially hemolyzed as a consequence of HBO exposure. this mode system is useful in the study of HBO-induced toxicity because of its high degree of selectivity and sensitivity and its amenability to strict quantification over a period of at least several days.

Animals↗
PubMed1980

Studies on rheomelanins. VI. The apparent lipofuscin characteristics of rheomelanins.

The positive histochemical tests obtained on rheomelanins indicate a relationship with tissue lipofuscins, which are also melanins in part. In addition chemical analysis indicates that the rheomelanins contain protein and lipid just as lipofuscins do. Fluorescence exhibited by the rheomelanins also seems to ally them to the lipofuscins.

Coloring Agents↗
PubMed1979

"The colouring substance of blood.".

Over a century ago, Stokes wrote on the oxidation and reduction of "the colouring substance of the blood." The mechanisms that govern the binding of oxygen to hemoglobin have been defined in even greater detail and higher orders of accuracy, even to the ends of the oxyhemoglobin dissociation curve. The Bohr effect has ceased to be a reduction in the affinity of hemoglobin for oxygen due to an increasing hydrogen ion concentration and according to a mere logarithmic equilibration constant. The constant has become a variable, subject to the interactions of temperature, carbon dioxide, organic phosphate, and ionic concentrations. This interdependence of so many variables has rendered the once inaccurate, but precise prediction of the effect of tht, well beyond the means of the average physician managing the treatment of a sick patient.

Biological Transport↗
PubMed1978

Studies on rheomelanins. V. Hemolysis associated with the transformation of catechol into rheomelanin in human blood.

Incubation of 2 mg amounts of catechol in 5 ml samples of heparinated blood plasma from four subjects at 38 degrees C for 24 h produced plasma-soluble rheomelanins. These solutions had the brown color and the yellow-green fluorescence in ultraviolet light of 366 nm of other rheomelanins. Their differential ultraviolet and visible spectra showed a rheomelanin absorption maximum at 344 nm. Paper chromatograms of the rheomelanin-plasma solutions in 5% methanol-95% water showed elongated spots of rheomelanins with RF values of 0.82, on Whatman No. 1 paper. Using heparinated distilled water adjusted to pH 7.4 with sodium bicarbonate instead of human blood plasma gave markedly different findings from those obtained with the plasma rheomelanin solutions. Incubation of 4 mg amounts of catechol in 10 ml samples of heparinated whole blood from four subjects for 24, 32 and 48 at 38 degrees C produced rheomelanins as found in the plasma separated from the blood after incubation. The differential ultraviolet and visible spectra of these solutions revealed hemolysis caused by the catechol rheomelanins; this was more marked with longer incubations. The hemolysis was manifested by two absorption peaks at about 270 and 400 nm. Paper chromatography revealed the brown elongated spots of catechol rheomelanins with an RF value of 0.82. Other spots owing to the products of hemolysis were also present.

Catechols↗
PubMed1977

Bad law, bad medicine.

In this Comment, Dr. Altschule contends that in a variety of ways the American legal system currently is endangering the existence of positive physician-patient relationships, which are essential to the effective practice of medicine. First, he contends, physicians are exposed to an excessively high risk of liability for malpractice, and as a result must substitute the use of "defensive," often unnecessary laboratory tests for reliance on their own sound medical judgment. Second, the confidentiality of communications between physicians and patients is receiving inadequate legal protection; therefore, patients often are hesitant to reveal aspects of their medical history that may be critical to their case. Third, the federal government, by its medically inappropriate attempts to ban drugs that do not meet certain federal "safe and effective" standards, and to ban food additives that fail to pass certain federally controlled tests aimed at determining whether the additive causes cancer, is making it increasingly difficult for physicians to prescribe substances that may be of great value to their patients. The author warns that our society's failure to substantially alleviate such problems is likely to lead to an inferior brand of medical practice.

Animals↗