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Biomedical subjects

J Gross

Publications and source records attributed to J Gross.

At least 217 records · Page 12Linked to original sources
PubMed1988

The intracellular distribution of influenza virus matrix protein and nucleoprotein in infected cells and their relationship to haemagglutinin in the plasma membrane.

Pre- and post-embedding immune electron microscopy techniques employing ferritin and large and small gold markers to detect cell surface and intracellular antigens respectively, have been combined in a study of influenza virus-infected cells. This has permitted, for the first time, the simultaneous detection of intracellular virus matrix protein (M), nucleoprotein (NP) and membrane haemagglutinin (HA). The technique facilitated an investigation of the possible physical interrelationship between these three proteins both in the infected cell, and on the infected cell membrane. Electron-dense bodies uniformly labelled by antibody to M protein were observed in the nucleus and cytoplasm. Similarly, NP was detected in both the nucleus and cytoplasm. Approximately 50% of the nuclear NP was located in close proximity to the M protein-containing dense bodies but mainly on the perimeter of the structures. A similar relationship of NP to the M-containing dense bodies was observed in the cytoplasm. M protein and NP were readily detected in sections of budding virions. Labelling of these proteins was also observed on the cytoplasmic face of the plasma membrane but the density of labelling only occasionally approached that of newly formed virions. These findings suggest that budding occurs very quickly after the internal proteins arrive at the plasma membrane. Double labelling experiments on the cell surface indicate that NP and HA behave as independent molecules and do not form tight complexes with each other.

Animals↗
PubMed1988

Concentration of hypoxanthine in both cerebrospinal fluid and brain tissue increases under intensive hypoxia only.

The relationships between the concentrations of glycogen, glucose, lactate, adenosine triphosphate (ATP) and hypoxanthine in the brain tissue, and the hypoxanthine and lactate concentration in cerebrospinal fluid and blood were examined after exposure of rats to hypoxia. The animals (1 and 10 days old) were exposed to hypobaric hypoxia for 1-12 h, pO2 11.3 kPa (mild), pO2 8.6 kPa (moderate), pO2 6.4 (strong) and pO2 4.7 kPa (severe) in inspired air. The concentration of hypoxanthine in both cerebrospinal fluid and brain tissue increases in severe hypoxia. This severe hypoxia was related to a decrease of ATP level in brain tissue. This study showed that the level of hypoxanthine in blood did not closely correlate to the level of hypoxanthine in brain tissue and cerebrospinal fluid. Extremely high hypoxanthine values in the blood might indicate a decrease in ATP content in brain tissue.

Adenosine Triphosphate↗
PubMed1988

Striated muscle fibers differentiate in primary cultures of adult anterior pituitary cells.

Anterior pituitary cells from adult male rats were cultured on a natural extracellular matrix (ECM). From the 5th day, spindle-shaped cells, fusing to form elongated fibers, were observed among the epithelial cells. These fibers later increased in size and number and were identified as striated muscle fibers, based on their multi-nucleation, cross-striation and rhythmic contraction. Striated muscle development was further validated by the appearance of cholinergic-nicotinic receptors, as demonstrated by the binding of 125I-alpha bungarotoxin (a-Btx). The effect of various supplements added to the cultures on a-Btx binding was used as a measure of muscle cell differentiation. ECM and serum were essential for myotube formation. Insulin (or IGF-I) and cortisol synergistically caused a 20-fold increase in myogenesis. FGF and EGF were effective only in the presence of insulin and cortisol. The data suggest that: (a) cells, derived from adult pituitary, differentiate, in primary culture, into striated muscle fibers; (b) the induction of this differentiation is multi-factorial; ECM, serum, insulin and glucocorticoids facilitate this myogenesis.

Animals↗
PubMed1988

The relationship of hypoxia to hypoxanthine concentration during pregnancy and delivery.

The concentration of hypoxanthine in plasma was suggested as an indicator of hypoxic conditions in newborns. We examined the concentration of hypoxanthine in maternal venous as well as in umbilical cord blood during pregnancy and during and after labor. The concentration of hypoxanthine in the cubital venous blood of nonpregnant healthy women and in healthy pregnant women and in women with complicated pregnancies was the similar. During birth there is an increase of the hypoxanthine concentration in maternal blood. This could be caused by the muscular work involved in giving birth (contraction, pushing, breathing). The values increased from 2.0-4.1 mumol/l in normal and abnormal pregnancy up to values of 9.4-11.8 mumol/l immediately after delivery. At the end of delivery the level of hypoxanthine is higher in the venous blood of the mother than in the umbilical blood. The concentration of hypoxanthine in umbilical venous blood and umbilical arterial blood did not show any significant differences. When clinical symptoms of hypoxia (depressed state of the neonate, high Thiringer asphyxia score, low Apgar score) were observed in the neonate, the hypoxanthine concentration in the umbilical vessels was increased (normal 4.7 mumol(l; slightly depressed 7.6 mumol/l, severely depressed 10 mumol/l).

Cardiotocography↗
PubMed1988

[The status of sexuality in routine psychiatric practice--results of a personal survey].

Based upon the observation that aspects of sexuality are rarely considered in psychiatric practice, a questionnaire study was performed to differentially assess the attitudes and experiences of psychiatric staff with this topic. 145 members of different professional groups and several psychiatric in-patient institutions answered the questions. The results of the study indicate for example that sexuality generally is more important in psychiatric institutions than one could have expected according to the psychiatric literature. Stereotypical attitudes concerning the sexual life of psychiatric patients were rare and more frequently found to be unspecific for psychiatry, for example those related to differential meanings of female and male sexuality. A further result of the study showed that sexual knowledge and confidence in handling conversations about sexuality seemed to be less important for the reduction of problems in the staff's reactions to sexually active patients than the possibility to discuss the own uncertainties and their recognition. Generally, the results could serve as a basis for psychiatric staff to facilitate the consideration of sexual matters within their institutions.

Adult↗
PubMed1988

[Effect of human uremic serum on the survival of fetal rat hepatocytes].

Children suffering from chronic renal insufficiency frequently show a liver cell damage. It is not clarified, whether this damage is caused immediately by chronic renal insufficiency. In the model of fetal rat hepatocytes, which were isolated by trypsin digestion, we have investigated the influence of normal and uremic serum on the lactate dehydrogenase release and the staining with trypan blue, respectively. Fetal rat hepatocytes under incubation conditions seems to be a useful model in the investigation of the influence of uremic metabolism on the liver cell. In our liver cell model the uremic serum did not influence the membrane permeability of hepatocytes for macromolecules. However, the viability of hepatocytes was impaired by 23% compared with normal serum. The vitality-reducing factor of the uremic serum is not dialysable.

Adolescent↗
PubMed1988

Early vs. late refeeding in acute infantile diarrhea.

A randomized ambulatory trial was performed to compare early (6-h) vs. late (24-h) refeeding in acute infantile diarrhea. Ninety infants with mild dehydration were enrolled in the study. Following an initial oral rehydration period (WHO formula), refeeding was introduced using a diet based on either breast milk or cow's milk. Early (n = 53) and late (n = 37) refeeding groups were similar in ethnic background, socioeconomic level, relevant past history, nutritional and clinical state, and stool pathogens. Infants were assessed upon their initial visit, at 24 and 48 h, and at 7 and 14 days thereafter for evaluation of weight, hydration state, stool frequency and need of hospitalization. No significant differences in the above parameters were observed between the two groups. Different patterns of refeeding (breast milk vs. cow's milk) in both early and late refeeding groups showed no significant differences in the features studied. Since the short-term clinical outcome following early refeeding in acute infantile diarrhea is not different from late refeeding, we suggest that early refeeding should be preferred, particularly in developing populations, in order to minimize the adverse nutritional effects of prolonged fasting during recurrent bouts of gastroenteritis.

Acute Disease↗
PubMed1987

Relation of serum total cholesterol and high-density lipoprotein cholesterol percentage to the incidence of definite coronary events: twenty-year follow-up of the Donolo-Tel Aviv Prospective Coronary Artery Disease Study.

This 20-year follow-up report presents the incidence of definite coronary events and its relation to serum total cholesterol (TC) and alpha-lipoprotein cholesterol percentage (percentage of serum TC bound with alpha-lipoprotein), now usually called high-density lipoprotein cholesterol percentage (HDL-C%). The cohort consists of 1,454 men and 1,481 women, presumably healthy, aged 35 to 64 years at the time of entrance examination in 1964. During the follow-up period 123 men and 44 women died from coronary disease. Ninety-six men and 42 women had nonfatal myocardial infarctions. The incidence of definite coronary events increased from 6% in men with TC levels of less than 200 mg/dl to 25% in men with levels of more than 264 mg/dl. The corresponding figures in women were 3% and 10%. The incidence of definite coronary events was inversely correlated to HDL-C%. The incidence of definite coronary events in 225 men with HDL-C% of less than 14% was 28%, and in 669 men with HDL-C% of 21% or more, 7%. The corresponding figures in 234 women with HDL-C% of less than 17% was 14%, and in 853 women with HDL-C% of 23% or more, 2%. Two HDL-C% subsets were assessed: "low" and "high" subsets refer to HDL-C% of less than 21% and 21% or more, respectively, in men and less than 23% and 23% or more in women.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Identification of a novel T cell surface disulfide-bonded dimer distinct from the alpha/beta antigen receptor.

Hybridomas were prepared from the spleen of a BALB/c mouse immunized with EL-4 T lymphoma cells. One, designated A1, was found to secrete a monoclonal antibody that reacted with two T lymphoma cells of C57BL origin, EL-4 and C6VLB, but not with normal C57BL/6 splenocytes or thymocytes, C57BL/6 T cell clones, or other T or B lymphomas by complement-mediated cytotoxicity or indirect immunofluorescent staining. Monoclonal antibody (MAb) A1 precipitated a protein that migrated at 85 kD under nonreducing and 43 kD under reducing conditions. The fact that the antigen defined by MAb A1 was a disulfide-linked dimer, together with the essentially clone-specific distribution of the reactive epitope, raised the possibility that the antibody defined an epitope of the antigen receptor. However, several additional observations revealed that the antibody defined a distinct and novel T cell surface structure. MAb 124-40, previously shown to react with the antigen receptor of C6VLB cells, reacted with variants of C6VLB that failed to express the A1 epitope. Sequential immunoprecipitation indicated that MAb A1 and MAb 124-40 reacted with distinct molecular species on C6VLB cells. Endoglycosidase digestion showed that the structure reactive with MAb A1 was not derived from that reactive with MAb 124-40 by addition of N-linked oligosaccharide residues. Two-dimensional gel electrophoretic analysis of precipitates obtained from radioiodinated C6VLB cells with MAb 124-40 resolved the alpha and beta subunits of the antigen receptor. Similar analysis of precipitates obtained with MAb A1 revealed only a single basic chain under reducing conditions, although anomalous mobility suggestive of a second, more acidic chain was observed under nonreducing conditions. Two-dimensional maps of tyrosine-containing chymotryptic peptides of the proteins isolated with MAb A1 and MAb 124-40 were completely different, suggesting that the molecules shared no peptides and were distinct in primary structure. Finally, cross-linking studies performed with a cleavable reagent indicated that the A1 molecule, unlike the antigen receptor defined with MAb 124-40, was not associated with additional, T3-like structures on the surface of C6VLB cells. Although the MAb A1 was unreactive with normal cells in cytotoxicity or staining assays, a molecule of the appropriate size was immunoprecipitated in small amounts from lysates of radioiodinated normal spleen and thymus cells. These data indicate that MAb A1 defines a novel disulfide-linked T cell surface molecule distinct from the antigen receptor.

Animals↗