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Biomedical subjects

J Gross

Publications and source records attributed to J Gross.

At least 361 records · Page 20Linked to original sources
PubMed1978

[Disorders of phagocytic and fungicide function of granulocytes in chronic muco-cutaneous candidiasis].

The granulocytes which are distributed by blood circulation close to the extern and intern body surfaces as well as in all organs protect the organism from microbial perils by phagocytosis and intracellular killing of bacteria and fungi so constituting a very important component of the granulocytic functions seriously impairs the host resistance and may entail a state of persisting infectious disease. As chronic mucocutaneous candidosis (CMCC) represents such a persistent generalized infection, we studied in vitro several functional activities of the granulocytes of 5 patients suffering from CMCC. 2 of them presented a non-familiar type of CMCC, the remaining 3 patients (father and 2 daughters) were subject to the hereditary type of CMCC. For comparison, by the same way we investigated the granulocytic functions of 51 clinically and immunologically healthy adult persons. Each of our 5 patients exhibited a reduced ability of the granulocytes to phagocytize and kill Candida albicans. In the CMCC family, the father had a marked deficiency of the oxidase activity of the granulocytes whereas in his daughters, the oxidase deficiency proved to be of a minor grade. In the sera of both daughters a phagocytosis inhibiting factor could be assumed to exist in addition to the granulocytic abnormalities. When heat-inactivated Candida albicans cells, however, were used for experiments, the granulocytes of each patient were able to phagocytize the germs at the same rate as did the granulocytes taken from the controls. With regard to alterations of the T cell function previously reported in CMCC, in all patients we also could demonstrate various symptoms of a T cell-dependent immunodeficiency. The results of the present in vitro-experiments furnish good evidence of a state of fundamental deficiency of the microphages in patients with CMCC, which may be the dominating cellular factor in the aetiopathogenesis of CMCC.

Adult↗
PubMed1978

ATP-dependent Ca uptake into plant membrane vesicles.

Membrane vesicles were extracted from etiolated and light-grown plants, a plant cell suspension culture, and an alga. Upon addition of ATP and Mg(2+), active Ca(2+) uptake into the vesicles against a concentration gradient was shown. The dependence of this uptake on ATP and Mg(2+) concentrations, pH, and temperature is described. In the absence of oxalate, equilibrium between Ca(2+) uptake and efflux was reached after about 30 min. In the presence of oxalate, Ca(2+) accumulation continued for at least 120 min. Ca(2+) efflux from preloaded vesicles did not depend on ATP. Addition of the ionophores A23187 and Ro 20-0006/006 caused an immediate release of accumulated free Ca(2+). ATP-dependent Ca(2+) uptake was not inhibited by 10 muM oligomycin.

Journal Article↗
PubMed1978

Regulation of corneal collagenase production: epithelial-stromal cell interactions.

Mixtures of epithelial and stromal cells isolated from normal adult rabbit cornea, when cocultured in the presence of cytochalasin B, produced latent collagenase, whereas neither cell type alone, nor the mixture in the absence of this agent, did so. The enzyme, a characteristic animal collagenase, required proteolytic activation. The relative concentrations of epithelial and stromal cells had a profound effect on on collagenase production, the enzyme activity bieng directly proportional to the number of stromal cells but inversely proportional to the number of epithelial cells. The amount of enzyme released into the medium was also directly proportional to cytochalasin B concentration. Media conditioned by cytochalasin B-treated epithelial or stromal cells did not stimulate collagenase secretion by the other cell type. The data suggest direct cell contact or close proximity as the mode of productive interaction and tentatively identify the stromal cell as the source of enzyme and the epithelial cell as a stimulator.

Animals↗
PubMed1978

[Bilirubin UDP-glucuronyltransferase activity in human fetal liver homogenates].

The bilirubin UDP GT-activity of the liver was studied from week 15 of pregnancy in 23 human fetuses and mature and immature dead newborns, respectively. No measurable bilirubin UDP GT-activity was found up to week 26 of pregnancy. The development of enzymatic activity presumably starts only postnatally, irrespective of gestational age of birth weight. Up to the fifth day the bilirubin UDP GT-activity is less than 0.2 mg of conjugated bilirubin/g liver/h, reaching in the second week values that correspond to approximately 20--30% of adult values. This activity is sufficient to prevent a clinically important hyperbilirubinemia because the concentration of unconjugated serum bilirubin was in all children below 12mg/100 ml.

Bilirubin↗
PubMed1978

[Separation of bone marrow cells of normal and anemic rabbits using isopycnic dextran density gradient].

Bone-marrow cells of normal and anemic (phenylhydrazine) rabbits were separated in the isopyknotic continuous 50-ml dextran density gradient. The separated cells were divided into 3 groups according the benzidine-peroxide-Giemsa staining after Brosook: nucleated, nonerythroid (A), nucleated, erythroid (B), and nonnucleated, erythroid (C). The highest proportion of erythroid, nucleated cells was found in fractions of medium density: in normal animals 20%, in anemic ones 45%. The group B/A ratio in the unseparated suspension is 0.7 in normal animals and 1.7 in anemic ones; and in the most favourable density fraction 0.3 and 1.9 respectively. Thus an unimportant accumulation of erythroid bone-marrow cells of rabbit is observed. In constrast, an accumulation of nucleated leukocytes of 80--90% can be reached in the low-density fractions.

Anemia↗
PubMed1978

[Change in inorganic pyrophosphatase during maturation and aging of red blood cells from newborns].

The activity of inorganic pyrophosphatase (PPase) of red blood cells (rbc) from newborns is about 40% higher than that of adults. To answer the question whether the higher activity was due to the enhanced reticulocyte count of the newborn's cell population, the rbc of both newborns and adults were separated into different density subpopulations by means of isopycnic density gradient centrifugation in dextran. To judge the quality of separation in the individual age populations of rbc, the activity of glucose-6-phosphate dehydrogenase (G-6-PD) and the reticulocyte count were determined. The activity fall of PPase during maturation and aging of rbc is stronger than that of G-6-PD. The density subpopulations of rbc from newborns and adults with equal reticulocyte counts show the same PPase activities yet different G-6-PD activities. Obviously, the higher PPase activity of a cell population of newborns is due to the higher proportion of reticulocytes. The inorganic PPase is well suited as a guiding criterion to judge the maturity and age of rbc of newborns.

Adult↗
PubMed1978

[Influence of hypoxia and hyperoxia on the 2,3-diphosphoglycerate concentration in rat red blood cells].

The influence of hypoxia (pO2 = 85 mmHg) lasting 5 h, a strong single bleeding of the animals, and the effect of hyperoxia (pO2 = 745 and 1520 mmHg) lasting 24 and 5 h, respectively, on the 2.3-DPG concentration of red cells from rat has been studied. A distinct increase in 2.3-DPG concentration at hypoxia and bleedig, but no reliable alteration in hyperoxia were found. When bled and anemic animals are exposed to hyperoxia (24 h, pO2 = 745 mmHg, normal air pressure) there is also observed a rise of 2.3-DPG concentration, which is much less than in normoxia. A non-linear relationship was established between the change of 2.3-DPG concentration and the percentage of deoxyhemoglobin in the centralvenous blood.

Anemia↗
PubMed1977

Relationship between steroid excretion patterns and breast cancer incidence in Israeli women of various origins.

A nationwide study of the steroid excretion patterns in postmenopausal Israeli migrant women demonstrated differences between high- and low-risk groups for breast cancer in the following variables: age at first parturition, number of pregnancies, number of live births, height, and weight. The direction of the differnces was in line with those observed for breast cancer patients. The groups also differed in the exretion of estriol, 17-ketosteroids, and allotetrahydrocortisol. Multiple regression analysis revealed that the exretion of estriol was significantly lower in population groups in whom breast cancer incidence was high. Possibly this trend--which has also been observed in adolescent and premenopausal women--reflected environmental influences on peripheral estrogen metabolism.

17-Ketosteroids↗
PubMed1977

Separation and characterization of red blood cells from newborns and infants during the first trimenon of life by means of a dextran density gradient. Density distribution curves of erythrocytes and reticulocytes.

Longitudinal studies on the density of erythrocytes and reticulocytes were performed by means of the isopyknic density gradient centrifugation in dextran on three mature newborns and six premature infants during the first 3 months of life. Striking changes of the density distribution curves of red blood cells took place during the first trimenon. Median density (D50) reached its maximum between the 7th and 28th day of life. D50 of reticulocytes was lower than that of the total red blood cell population and shows similar changes to the whole cell population during the first trimenon after birth. Based on the close relationship between D50 and the percentage of lightest cells, the evaluation of the percentage of the lightest cells was recommended as a simple test to study the changes in median density.

Blood Cell Count↗
PubMed1977

The mechanism of damping of the serum thyroxine and triidothyronine levels caused by increasing thyrotropin dosage in mice.

The time course of the effect of bovine TSH (bTSH) on serum concentrations of thyroxine (T4) and triiodothyronine (T3) was measured in the normal mouse. The basal, unstimulated levels were 3.2+/-1.1 mug/100 ml T4 and 104+/-25 ng/100 ml T3 (mean+/-SD). With doses of bTSH from 0.5 to 100 mU the peak levels of the thyroid hormones were only 2.6 and 1.8 times the basal level for T4 and T3, respectively. With increasing doses of bTSH there was a proportional prolongation of the increased serum levels of thyroid hormones, i.e., about 2 h for 0.5mU to 12 h for 100 mU TSH. The integrated response with time was linearly related to the log dose. This would suggest a control mechanism which prevents excessive concentration of thyroid hormones in the serum. This pattern of response to TSH differs somewhat from that obtained by following radioiodine release in the McKenzie type bio-assay. To avoid the problems of changing blood concentrations of thyroid hormones and TSH, the release of T4 and T3 from the mouse thyroid was measured in vitro. The secretion increased with bTSH concentrations in the range of 0.02-0.8 mU/ml for T4 and 0.02-0.4 mU/ml for T3. The maximal response was 8.8+/-0.5 ng T4/3h/thyroid and 3.6+/-0.3 ng T3/3h/thyroid as against the basal secretion of 2.4+/-0.2ng T4 and 0.8+/-0.1 ng T3 (mean+/-SEM). Further in crease in bTSH concentration was associated with a decreased rate of thyroid hormone release. Thyroidal cAMP accumulation was enhanced with increasing bTSH concentration, even when there was a decrease in secretion. The dichotomy in the dose-response pattern between the two parameters indicated that the effect of high TSH concentrations on the release was induced at a step beyond cAMP accumulation. This was corroborated by the similar pattern of release induced by increasing concentration of DBcAMP. These findings indicate the existence of an intrathyroidal autoregulatory mechanism which prevents excess increase of thyroid hormone levels in the blood.

Animals↗