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Biomedical subjects

J Gross

Publications and source records attributed to J Gross.

At least 235 records · Page 13Linked to original sources
PubMed1987

Morphometric and ultrastructural analyses of melanocytes, nevus cells, and melanoma cells.

Cytological atypia, revealed in the course of routine light microscopy, is considered a valuable indicator of malignancy in melanocytic lesions. A clear definition of the term cytological atypia, however, is lacking. Therefore, by morphometric analysis of ultrathin sections of 11 malignant melanomas (7 invasive, 3 in situ, and 1 lentigo maligna melanoma) and 10 compound nevi, we evaluated the discriminating power of the various facets of cytological atypia, i.e., nuclear area, area of the nucleolus, area of the total cell, and nuclear irregularity. In each case, at least 50 intraepidermal melanocytic cells were examined. The two-sided U-test showed significant differences between intraepidermal nevus and melanoma cells, with regard to the mean values (mean) and standard deviations (s) of the nuclear area (mean and s, p = 0.00011), area of the nucleolus (mean, p = 0.00043; s, p = 0.00011), and area of the total cell (mean, p = 0.00011; s, p = 0.00093). However, only the mean values and standard deviations of the nuclear area allowed a clear distinction in each individual case. The area of the nucleus can be estimated in the course of routine histology. We therefore think that the size and variation of the nuclear area should be considered in the histological differential diagnosis between malignant melanomas and benign nevi.

Cell Nucleolus↗
PubMed1987

Prevalence of weight reducing and weight gaining in adolescent girls and boys.

This is a survey of the prevalence of weight reducing and weight gaining in high school children. Our sample of 1,373 high school girls and boys was geographically, racially, and economically diverse. On the day of the survey, 63% of the girls and 16.2% of the boys reported being on weight reducing regimens; 9.1% of the girls and 28.4% of the boys were trying to gain weight. Most female reducers and male gainers were already normal weight. Compared to other racial groups, whites and Hispanics were more likely to be reducing, whereas blacks were more likely to be gaining. Exercise and moderate caloric reduction were most popular for weight reducing, and a small but significant number were regularly using fasting, vomiting, laxatives, and appetite suppressants. The direction of weight modification for girls and boys conformed to stereotyped physical ideals. The rate of weight reducing in female high school adolescents has increased significantly since similar surveys of American youths 20 years ago.

Adolescent↗
PubMed1987

Attitudes of physicians and nurses towards the role of social workers in primary health care: what promotes collaboration?

Many writers have indicated that the future of social work in primary health care is dependent on the attitudes of physicians and nurses. This article reviews the literature in the field and describes the results of a study of 95 physicians and 78 nurses in Israel which found that physicians have a more positive attitude towards social work intervention than nurses and explores the differences in these attitudes in relation to particular personal characteristics. Physicians who were young, had recently received their MD degree and had been educated in Israel had by far the most positive attitudes towards social workers. Those aged over 60 years old, who had received their MD degree in Western countries more than 25 years ago were more positively inclined towards social work in the clinics than middle-aged physicians educated in Eastern European countries. The personal characteristics of the nurses made little difference to their generally poor attitude towards social work in the clinics. Those who received their nursing education more recently were more positive than other nurses.

Adult↗
PubMed1987

The effect of the duration of the second stage of labour on the acid-base state of the fetus.

A prospective study was made in 153 patients with a second stage of labour lasting 1 to 120 min. Maternal venous, umbilical artery and vein blood were analysed for acid-base variables and lactate levels. Blood was obtained immediately at delivery. Fetal heart rate monitoring data and blood test results were related to the duration of the second stage of labour and clinical outcome. In primiparae and multiparae there was a steady rise in umbilical artery lactate levels, with duration of second stage of labour, P less than 0.025 and P = 0.023, respectively. The median umbilical artery pH decreased significantly from 7.31 in patients with a second stage of labour that lasted less than or equal to 15 min to a pH of 7.25 in patients with a second stage of labour that lasted more than 30 min. Changes in PO2 and PCO2 were not statistically significant.

Acid-Base Equilibrium↗
PubMed1987

Synaptosomal uptake and release of dopamine in rat striatum after hypoxia.

Hypoxia induces alterations of central monoaminergic transmission and of behavior. We studied the effect of hypoxia on adult and newborn rats to obtain more information about long-lasting changes of dopamine (DA) transmission caused by neonatal hypoxia. One single exposure of adult rats to hypoxia leads to short-term alterations of DA uptake: decreased affinity of the uptake carrier to DA (Km, 269.5% versus control) and a sharp increase of Vmax up to 301.4% resulting in an increase of total uptake of DA into the striatum synaptosomes. The K+-evoked DA release decreased to 69.5%. After 1 week of recovery all parameters are normalized. Chronic postnatal hypoxia (postnatal day 2-11) caused long-lasting changes of DA release and uptake opposite to those observed in adult rats. Three months after hypoxia, the K+-stimulated DA release was enhanced (132% of control), and the uptake was reduced due to decreased affinity of the uptake carrier system for the substrate (Km, 187% of control value). In conclusion, the alterations observed after chronic postnatal hypoxia reflect special adaptive processes that are related to the high plasticity of the immature neonatal brain and contribute to an increased DA function in the nigrostriatal system.

Animals↗
PubMed1987

Neuron specific enolase in amniotic fluid--a possible indicator for fetal distress and brain implication.

It can be suggested that a NSE concentration in body fluids above the normal range may indicate brain damage, because NSE is found in neurons and neuroendocrine cells only. In this paper the concentration of the neuron specific enolase (NSE) in the amniotic fluid of normal and high risk pregnancies was investigated. Sixty-three samples of amniotic fluid were collected from 55 pregnant women and women in labor between the 19th and the 42nd gestational week. In 24 normal pregnancies 1.02 +/- 0.31 microgram NSE/L (mean +/- SD) were found. A relationship of NSE concentration was not found for gestational age, uterine contractions, age and parity of the mother, infant's birth weight or 1 min Apgar score. Maternal diseases such as diabetes mellitus, hypertension and others do not result in any increase of NSE concentration in the amniotic fluid (N = 20; 1.06 +/- 0.24 microgram NSE/L). Fetal and birth related high risk factors such as meconium stained amniotic fluid, cord around the neck, severe decelerations of the fetal heart rate or combinations of these factors caused the NSE concentration to exceed significantly normal values (N = 17; 2.22 +/- 0.87 microgram NSE/L). Due to its high organ and cell specificity, NSE may be a possible parameter for brain damage due to hypoxia in the fetus and newborn; however, only subsequent neurological and psychological examinations of these children can indicate the prognostic value of an elevation of NSE concentration in amniotic fluid.

Amniotic Fluid↗
PubMed1987

T3 stimulation of 2-deoxy-D-glucose uptake in cultured chick embryo carcass derived cells, requires neosynthesis of proteins.

T3 stimulated, in a dose dependent manner, the uptake of 2-deoxy-D-glucose (2-DOG) into cultured chick embryo carcass derived cells. A significant increase in sugar uptake was seen already at a T3 concentration of 1 pmol/l. The stimulation of 2-DOG uptake increased with time during the 6 h of exposure to T3. The hormone also stimulated, within 45 min, the incorporation of [3H]leucine and [3H]uridine into the trichloroacetic acid precipitable material of these cells. Actinomycin-D (100 micrograms/l) and cycloheximide (1 mg/l) each were capable of blocking the stimulatory effect of 10(-8) mol/l T3 on sugar uptake and on uridine and leucine incorporation. Thus, T3 in these cultured chick embryo cells stimulated sugar transport through processes dependent on neosynthesis of proteins. In this respect the effect of T3 is different from that seen in cultured chick embryo cardiomyocytes.

Animals↗
PubMed1987

TSH binding proteins in rat and human serum.

When serum of hypothyroid rats was fractionated on a Sephadex G-100 column, most of the immunoreactive TSH was found as a front running peak, together with the high molecular weight serum proteins. Similarly, a rTSH preparation (10 mU), chromatographed in the presence of 1 ml of normal rat serum also migrated at the front, however, when a high load of TSH (4.4 U) was added to 1 ml of serum, two immunoreactive peaks were found, suggesting the saturation of the front running fraction. Immunoelectrophoresis and autoradiography of rat or human sera containing the respective 125I-labelled TSHs showed binding of the labelled TSH to IgG, alpha-2-macroglobulin, and to a third unidentified protein, migrating near the albumin line. In order to determine if the bound TSH is biologically active, the high molecular weight protein fraction was separated from hypothyroid rat serum by 45% ammonium sulphate precipitation. Immunoreactivity was determined by RIA and the biological activity was determined, in vitro, by the stimulation of 99Tc uptake by FRTL-5 cells. The 45% ammonium sulphate precipitate contained almost all of the immunoreactivity and the bioactivity of the TSH of whole serum. These results indicate that: a) The endogenous circulating TSH in the hypothyroid rat exists mainly in a protein-bound form and this protein-bound TSH contains most of the hormonal bioactivity of the serum. b) Exogenous TSH binds to serum proteins in euthyroid and hypothyroid rats and in humans. There are three protein fractions in these sera that bind TSH, one of which is an immunoglobulin. The occurrence of TSH binding immunoglobulins may involve autoimmune mechanisms.

Animals↗
PubMed1987

The effect of storage media on the proliferation of periodontal ligament fibroblasts.

The effect of storage media, which are routinely used in replantation, upon the proliferative capacity of periodontal ligament fibroblasts, was compared with the effect of a tissue culture medium. The periodontal tissue was obtained from mandibular central incisors of White New Zealand rabbits. The experiments were performed in fibroblasts derived during second subculture. The storage media were physiologic salt solution, Ringer's solution and Rivanol; the tissue culture medium was alpha-minimum essential medium without nucleosides. The incubation period was 1 hour. [3H]-thymidine incorporation and cell counts were taken to indicate changes in the proliferative capacity of the fibroblasts. The tissue culture experiments showed that the proliferative ability of the periodontal ligament fibroblasts was dependent upon the composition of the storage medium. Physiologic salt solution, Ringer's solution and Rivanol were unable to maintain the metabolism of the fibroblasts. alpha-MEM medium, however, was capable of stimulating proliferation of the periodontal ligament fibroblasts.

Animals↗
PubMed1987

Creatine and density of red blood cells in perinatal hypoxia.

Signs of stimulated erythropoiesis, such as increased creatine and decreased density of red cells are good indicators of hypoxemia in adults and older children. The sensitivity of both tests in perinatal hypoxia was found to be reduced. The causes for this reduction were investigated.

Animals↗
PubMed1987

A large-scale, orthogonal network of microfibril bundles in the corneal stroma.

Orthogonal and parallel arrays of microfibril bundles are described in the corneal stroma of embryonic and adult chickens. The arrays lie parallel to the corneal surface and are distributed in the extracellular matrix between Bowman's layer and Descemet's membrane. The individual microfibril bundles measure 0.1-0.25 micron in diameter and consist of 20-30 "tubular" rods, of approximately 15 nm diameter, and an apparently structureless matrix. The arrays have a spacing of approximately 3 microns. We speculate that the microfibril bundles serve as a scaffolding for the corneal stroma or as a light-diffracting element. With some variations in distribution and organization, the arrays of microfibril bundles also occur in calf, rabbit, rat, newborn mice, toad, and goldfish, but not in adult human corneas.

Aged↗
PubMed1987

Limited joint mobility and other rheumatological manifestations in diabetic patients.

Limited joint mobility was diagnosed in 42.9% of Type I and 37.3% of Type II diabetic patients. Abnormally thick skin was detected in 31.4% of Type I and 33.7% of Type II diabetic patients. Skin abnormalities were observed mainly in patients with L.J.M. There was a high prevalence of hand flexor tendon abnormalities (18.6%). Decreased range of shoulders and hips and flexor tendon abnormalities were significantly more common in patients with LJM. No significant association was found between LJM and grip strength, joint complaints, family history of rheumatic diseases, hypoglycemic attacks, cardiovascular diseases and autonomic neuropathy.

Adolescent↗
PubMed1986

Regenerate epithelium and skin glands of the adult newt react to the same monoclonal antibody.

A search for specific proteins involved in newt limb regeneration, using monoclonal antibodies against forelimb blastemas, led to the detection of an antigen in the regenerate epithelium. Fluorescent-antibody-labeled cells first appeared just prior to blastema outgrowth. From bud through early digit stages this antibody reacted with nearly all of the regenerate epithelial cells. Other tissues also reacted, including nerve, blood vessels, and gastrointestinal tract. The behavior of the reactive cells in the regenerate epithelium, and their close association with immediately adjacent skin glands, raises several new possibilities for the origin of the regenerate epithelium.

Animals↗
PubMed1986

A comparison of saccade evoked potentials recorded during reading and tracking tasks.

The influence of visual processing demands on saccade-triggered evoked potentials was investigated at P3, P4 and Oz recording sites during reading and tracking tasks. To maximize the physical similarities between tasks, subjects tracked a series of lights that flashed in a stereotypic reading pattern behind a page of text; eye movements recorded during reading initiated the light sequence. In the first experiment, a significant decrease observed in the latency of the major positive peak recorded from Oz during tracking was attributed to the smaller amplitude of tracking, relative to reading, saccades. To confirm this interpretation, the experiment was repeated with modification to the light display. As anticipated, equating saccade amplitudes across tasks eliminated waveform differences in the second experiment. Although peak latencies and amplitudes were not influenced reliably by visual processing demands, tracking potentials exhibited a negative DC shift relative to reading waveforms that was significant at 174 msec at the Oz site. These data suggest that the saccade-triggered evoked potential components generally are insensitive to task differences within the visual modality when visual configuration and eye movement parameters are controlled.

Adult↗