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Biomedical subjects

P J Schechter

Publications and source records attributed to P J Schechter.

At least 91 records · Page 5Linked to original sources

Antiseizure activity of gamma-acetylenic gamma-aminobutyric acid: a catalytic irreversible inhibitor of gamma-aminobutyric acid transaminase.

gamma-Acetylenic gamma-aminobutyric acid (gamma-acetylenic GABA) produces several-fold sustained elevations of brain GABA concentrations when administered intraperitoneally to mice. It protects mice against seizures induced by audiogenic stimuli, electroshock, thiosemicarbazide, isoniazid and strychnine. The duration and degree of audiogenic seizure protection appears to correlate with elevations in whole brain GABA levels. gamma-Acetylenic GABA does not protect against seizures induced by pentylenetetrazol or picrotoxin even at doses that increase brain GABA concentrations approximately 6-fold. This differential antiseizure activity suggests that the GABA system may play a role in some, but not all experimentally produced seizures.

4-Aminobutyrate Transaminase↗

Distribution of serum zinc between albumin and alpha2-macroglobulin in patients with decompensated hepatic cirrhosis.

Lower concentrations of total serum zinc (540 +/- 111 mug/1, mean +/- SEM), and of albumin-bound serum zinc (295 +/- 113 mug/1) and a higher concentration of alpha2-macroglobulin-bound zinc (245 +/- 69 mug/1) were found in 25 patients with decompensated hepatic cirrhosis, compared to 28 healthy subjects (835 +/- 91; 679 +/- 83; 156 +/- 27 mug/1 respectively). Levels of total and albumin-bound zinc were significantly and positively correlated with serum albumin levels. Higher levels of alpha2-macroglobulin-bound zinc were associated with higher levels of alpha2-macroglobulin in these patients (2.8 +/- 0.8 g/1) compared to normals (2.3 +/- 0.6). Hence, not only do decompensated cirrhotics exhibit a lower serum zinc level but a greater proportion of this zinc is associated with the tightly bound, and presumably metabolically more inert, serum fraction. This situation exaggerates the zinc deficiency state of the severe cirrhotic.

Humans↗

A study of zinc distribution in human serum.

The partition of zinc in human serum between two major zinc-binding proteins, albumin and alpha2-macroglobulin, was studied in 28 control subjects and in 156 hospitalized patients. Albumin-bound zinc was both the major and the more dynamic of the serum zinc components. Over a wide range of values the concentrations of albumin-bound zinc and total serum zinc were highly correlated (r=0.91) with each other, as were concentrations of albumin and albumin-bound zinc (r=0.69). alpha2-Macroglobulin-bound zinc was not strongly correlated either with total serum zinc or with the serum concentration of alpha2-macroglobulin. Twenty-four hour urinary excretion of zinc was not correlated with any of the serum zinc parameters. To a large extent it appears that total serum zinc concentration reflects serum albumin concentration.

Binding Sites↗

Diminished albumin binding of zinc in serum of pregnant women.

1. Distribution of zinc between the metalloprotein alpha 2-macroglobulin and albumin was determined in samples of serum obtained from twenty-three women in their third trimester of pregnancy and eighteen women who were not pregnant. 2. The decrease observed in total serum zinc in the group of pregnant women could be accounted for in large part by a decreased concentration of albumin-bound zinc. 3. The concentration of serum albumin was lower in the pregnant women, thus hypoalbuminaemia, which is often invoked to explain hypozincaemia in pathological situations, may in part account for hypozincaemia in pregnancy. 4. The affinity of albumin for zinc added to serum from pregnant women was less than that of albumin from non-pregnant women. This was determined by competition experiments between albumin and glycine for zinc. Decreased affinity of serum albumin for zinc may also contribute to the hypozincaemia associated with pregnancy.

Adolescent↗

Abnormalities of taste and smell after head trauma.

Abnormalities of taste and smell were studied in 29 patients after head trauma. These abnormalities included decreased taste acuity (hypogeusia), a distortion of taste acuity (dysgeusia), decreased smell acuity (hyposmia), and a distortion of smell acuity (dysosmia). This syndrome can occur even after minimal head trauma and can begin months after the moment of injury. The patients exhibited a significant decrease in total serum zinc concentration (patients, 77 ± 3 μg/100 ml, mean ± 1 SEM, vs controls, 99 ± 2 μg/100 ml, P>0·001) and a significant increase in total serum copper concentrations (113 ± 4 μg/100 ml vs 100 ± 2 μg/100 ml, P<0·001) compared with control subjects. Symptoms of hypogeusia, dysgeusia, and dysosmia are frequent sequelae of head injury and are important to the patients and to their care after trauma.

Adult↗

Direct pathway to the brain.

Whole-body autoradiographic stuidies demonstrated that, when isotopically labeled glucose is placed in the ligated oropharynx, there is a rapid movement of the isotope directly to the intracranial cavity. This passage involves nonspecific diflision, bypassing all recognized rouctes to the brain.

Animals↗