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Biomedical subjects

A Sjoerdsma

Publications and source records attributed to A Sjoerdsma.

At least 91 records · Page 5Linked to original sources
PubMed1977

Reduced binding of added zinc in serum of patients with decompensated hepatic cirrhosis.

Binding of zinc to macromolecules when added to serum was measured by ultrafiltration. At a final ratio of 0.6 mol zinc per mol albumin, zinc dissociable by glycine was significantly greater in diluted serum from patients with decompensated alcoholic cirrhosis than in normal serum samples similarly prepared. Low serum zinc concentrations, often observed in patients with alcoholic cirrhosis, may be related in part to a reduced affinity of plasma albumin for exchangeable zinc.

Female↗
PubMed1977

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↗
PubMed1976

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↗
PubMed1975

Changes in plasma histaminase activity during normal early human pregnancy and pregnancy disorders.

A sensitive isotopic assay was employed to follow the changes in plasma histaminase activity during pregnancy in patients who become pregnant following spontaneous and induced ovulation. Values in nonpregnant women ranged from 0.2 to 2.7 pmoles of histamine deaminated per milliliter of plasma per hour. In pregnant women, plasma histaminase activity began to increase 9 to 28 days following the presumed day of ovulation and then rose exponentially with a doubling time of 4 to 5 days. Peak values, 1,500 pmoles per milliliter per hour, were reached during the third trimester of pregnancy. The data suggested that the increase in histaminase activity actually started at about the same time in all patients, although the early rise in enzyme activity was not apparent in women who had high histaminase activity before pregnancy. Plasma histaminase did not rise in patients with spontaneous abortion, blighted ovum with hydatidiform degeneration, or choriocarcinoma. The high levels of chorionic gonadotropin and low levels of histaminase activity seen in patients with trophoblastic neoplasia suggest that these tests may be of value in the diagnosis of trophoblastic neoplasia early in pregnancy.

Amine Oxidase (Copper-Containing)↗