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Biomedical subjects

J Gross

Publications and source records attributed to J Gross.

At least 253 records · Page 14Linked to original sources
PubMed1986

Complement-dependent lysis of Erhlich ascites tumor cells by human serum (ascitolysin) is lowered in cancer patients and raised in pregnant women.

Normal human serum has been shown to contain IgM antibodies that are lytic to Ehrlich ascites tumor cells in the presence of complement. We call this activity ascitolysin (AL). Using a 51Cr release assay, the AL titers of 164 normal sera, 211 sera from patients with non-malignant disease, 62 sera from 25 pregnant women and 170 sera from cancer patients were estimated. The patient sera were taken preoperatively, and were assigned to the cancer or non-cancer group after histological diagnosis. In normals, higher titers were found in sera of A and O blood groups but not B and AB. The difference was due to a fraction absorbed by B red blood cells. Sera from untreated cancer patients showed significantly reduced titers when compared to normal, benign tumor, chronic and other non-malignant disease groups. In pregnancy, titers were positively correlated with duration and remained elevated for at least 6 weeks post partum. About 30% of AL activity was absorbed by the free galactose groups of agarose. This fraction was significantly lower in untreated cancer patients. Anti-T antigen antibodies do not contribute to AL levels. Galactophilic blocking factors were also found; eight times more frequently in cancer sera than in normals. The non-absorbed fraction was also lower in cancer sera. The data suggest that AL antibodies may be directed against human oncofetal antigens.

ABO Blood-Group System↗
PubMed1986

[Empirical studies of sexual behavior of psychotic patients--a review].

The review is based upon the observation that the topic of sexuality so far seems to be underrepresented in psychiatric research and practice. The present empirical studies concerning aspects of sexual behavior and experiences of patients with affective and schizophrenic psychoses are summarized in this paper. First, studies related on characteristics of the premorbid sexual behavior of the patient groups are considered. A summary of investigations concerning changes in the sexual life due to the psychiatric illness is divided into results on the changes in the frequency of sexual activities and changes in sexual appetence, results on sexual deviant acts, on sexual activities of psychiatric inpatients, and results on sexual orientation, especially for patients with paranoid symptoms. The review ends with a report of the most important results concerning characteristics of the sexuality specific for the disease and results on the frequency of sexual dysfunctions in different groups of patients. As the review shows, our knowledge about the sexual life of psychiatric patients so far seems very incomplete. More thoroughly performed empirical studies will help to counteract the distribution of stereotypic beliefs.

Drive↗
PubMed1986

Surgery in primary leiomyosarcoma of the heart.

Primary leiomyosarcoma of the heart is uncommon and we were able to find only 15 cases reported in the literature. Few of these cases were discovered during life and, as a result, even fewer have been treated surgically. We report a case of a right atrial leiomyosarcoma which was proven pathologically (histologically, immunohistochemically and ultrastructurally) after surgical resection. The clinical presentation, morphological, appearances and outcome are compared with those reported in the literature.

Adolescent↗
PubMed1986

Type VI collagen in extracellular, 100-nm periodic filaments and fibrils: identification by immunoelectron microscopy.

Filaments and fibrils that exhibit a 100-nm axial periodicity and occur in the medium and in the deposited extracellular matrix of chicken embryo and human fibroblast cultures have been tentatively identified with type VI collagen on the basis of their similar structural characteristics (Bruns, R. R., 1984, J. Ultrastruct. Res., 89:136-145). Using indirect immunoelectron microscopy and specific monoclonal and polyclonal antibodies, we now report their positive identification with collagen VI and their distribution in fibroblast cultures and in tendon. Primary human foreskin fibroblast cultures, labeled with anti-type VI antibody and studied by fluorescence microscopy, showed a progressive increase in labeling and changes in distribution with time up to 8 d in culture. With immunoelectron microscopy and monoclonal antibodies to human type VI collagen followed by goat anti-mouse IgG coupled to colloidal gold, they showed in thin sections specific 100-nm periodic labeling on extracellular filaments and fibrils: one monoclonal antibody (3C4) attached to the band region and another (4B10) to the interband region of the filaments and fibrils. Rabbit antiserum to type VI collagen also localized on the band region, but the staining was less well defined. Control experiments with antibodies to fibronectin and to procollagen types I and III labeled other filaments and fibrils, but not those with a 100-nm period. Heavy metal-stained fibrils with the same periodic and structural characteristics also have been found in both adult rat tail tendon and embryonic chicken tendon subjected to prolonged incubation in culture medium or treatment with adenosine 5'-triphosphate at pH 4.6. We conclude that the 100-nm periodic filaments and fibrils represent the native aggregate form of type VI collagen. It is likely that banded fibrils of the same periodicity and appearance, reported by many observers over the years in a wide range of normal and pathological tissues, are at least in part, type VI collagen.

Adenosine Triphosphate↗
PubMed1986

A departmental policy addressing chemical substance abuse.

Substance abuse is a major socioeconomic problem. However, the ready availability of potent narcotic and sedative drugs probably constitutes a unique risk for anesthesiologists. Until recently, few anesthesia departments were prepared to recognize or safely manage afflicted colleagues. Because we felt it important to educate our staff and residents and to have a response mechanism established prior to the advent of a substance abuse problem, a departmental committee was formed to develop a Substance Abuse Policy. The policy has served to increase our general awareness and to direct our actions effectively when dealing with physician impairment. It is presented here in the belief that other departments might find it useful in tailoring their approach to this problem.

Anesthesiology↗
PubMed1986

Effects of hypoxia and anoxia on the ex vivo release of prostaglandins from mouse cortical slices.

Arachidonic acid is transiently accumulated in the brain as a result of a variety of pathological conditions. The synthesis and release of some of its metabolites, namely, prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) from cortical slices of mice were studied following exposure to 6 min of hypoxia (7% O2), 45 s of anoxia, and 5 min-4 h of reoxygenation following anoxia. Hypoxia induced a slight increase in the rate of TXB2 release and a slight decrease in the rate of PGE2 release, whereas 6-keto-PGF1 alpha was unaffected. Anoxia (45 s) followed by reoxygenation induced a transient increase in the release of PGE2 and of 6-keto-PGF1 alpha with a return to the normal rate at 30 min and 2 h of recovery, respectively. However, the rate of TXB2 synthesis and release reached its peak (twofold increase) after 1 h and remained significantly higher than the control rate even after 4 h of normal air breathing. Our results demonstrate that hypoxia and anoxia, even of short duration, selectively trigger the activity of thromboxane synthetase and that this elevated rate of synthesis and release persists long after normal oxygen supply is restored. We suggest that enhanced thromboxane synthesis, with normal prostacyclin levels, might have a role in the pathophysiology of ischemic cell damage.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

The stimulation of sugar transport in heart cells grown in a serum-free medium by picomolar concentrations of thyroid hormones: the effects of insulin and hydrocortisone.

Chick embryo heart cells were propagated in a defined serum-free medium. They formed a confluent, synchronously contracting monolayer that is not different from myocytes grown in serum containing media. The uptake of 2-deoxy-D-[1-3H]glucose in these cells was stimulated by exposure to physiological concentrations of T3 (1 pM) and T4 (10 pM). Actinomycin-D and puromycin did not block the stimulation of 2-deoxy-D-[1-3H]glucose uptake when given with T3 throughout a 6-h incubation period. Cells grown in the absence of both insulin and hydrocortisone were unresponsive to T3. Insulin at 200 nM restored the sensitivity of the cells to 0.1 pM T3. Addition of 10 nM hydrocortisone to the growth medium enhanced the effects of T3 synergistically. The T3-stimulated sugar uptake was completely blocked by 5 X 10(-6) M cytochalasin B, suggesting that T3 acts, like insulin, by the translocation of glucose transporters to the plasma membrane.

Animals↗
PubMed1986

Behaviour of cell physiological and biochemical indicators of maturation and aging of red blood cells in density fractionated red blood cells during a bleeding anaemia of the rabbit.

Changes of the density, MCV, MCHC, RNA-concentration and the activities of the enzyme G6PD and ASAT due to maturation and aging of rbc were investigated by repeated density gradient separation of these cells during a bleeding anaemia of the rabbit. The mean density of reticulocytes and erythrocytes decreases during the course of the anaemia by 14 and 10 g/l respectively. The difference between the density of both cell types increases from 3 to 6 to 12 g/l during the anaemia. Maturation and aging of rbc are characterized by an increase of the MCHC from 200 to 350 g/l cells and the decrease of MCV by 10-25%. The RNA concentration and the ASAT activity show an almost parallel behaviour in cells of different densities during the anaemia. Remarkable differences are observed between the ASAT activity and the G6PD activity: The G6PD activity decreases mainly during the aging process and almost not during the maturation, while the ASAT activity falls constantly during maturation and aging. As observed in former studies we could distinguish and isolate 4 characteristic populations of reticulocytes in certain density fractions during the anaemia: Normal young reticulocytes, line 2 reticulocytes, megaloreticulocytes and reticulocytes of high density.

Anemia↗
PubMed1986

Pilot study of the efficacy of spent grain dietary fiber in the treatment of constipation.

Spent grain is the crude fiber obtained by decanting the fermented distillate of barley. The spent grain was processed to yield dietary fiber composed of: cellulose and hemicellulose 65.6% (by weight), lignin 5.2%, pectin 2.2%, protein 10.9% and lipid 8.0%. Biscuits and scones were prepared by 25% substitution of wheat flour by fiber, yielding 7 to 8 g fiber per biscuit/scone. Nineteen ambulatory patients with chronic, laxative-dependent constipation were treated in a pilot study for 4 weeks with 20 to 25 g fiber daily. Fifteen patients (79%) showed improvement in some or all of five factors, while four patients were largely unresponsive to fiber. Specific symptoms improved as follows: bowel movement frequency in 15 patients (79%), flatulence in 12 (63%), abdominal pain in 10 (53%), stool consistency in 8 (42%) and laxative dependence in 14 (74%). A 4-week post-treatment follow-up showed a return to prefiber status in 11 of 13 improved subjects. This preliminary study suggests a role for spent grain fiber in the treatment of constipated patients, and a comparative study with placebo and wheat fiber is now warranted.

Adult↗
PubMed1986

Influence of postnatal hypoxia on 32P-labeling of polyphosphoinositides and phosphatidic acid in striatum synaptosomes from rat brain.

Striatum synaptosomes prepared from adult rats which had been exposed to postnatal hypoxia incorporate 32P-phosphate into phosphatidylinositol-4,5-trisphosphate (PI-4,5-P2) with decreased rate. 32P-incorporation amounted to 57% of the control for PI-4,5-P2 labeling and was slightly diminished for phosphatidic acid and PI-4-P. Exposure to hypoxia of adult rats did not affect inositol phospholipid labeling. The inhibitory effect of dopamine on 32P-phosphate incorporation was reduced only after postnatal hypoxia. 32P-incorporation rates and the dopamine inhibitory effect were not influenced by external calcium. A working hypothesis is suggested for the dopamine action on specific receptors which may be linked to the polyphosphoinositide metabolism and membrane calcium release. The long lasting effects of an early postnatal hypoxia on 32P-incorporation rates into polyphosphoinositides and phosphatidic acid could reflect the role of the proposed dopamine receptor interaction.

Animals↗
PubMed1986

Influence of a perinatal hypoxia on the carbonic anhydrase activity in different brain regions of the rat.

Homogenates of striatum, hippocampus and cerebral cortex of the rat brain were investigated for carbonic anhydrase activities. During ontogeny the enzyme activities increase with proceeding gliogenesis. At the 5th postnatal day (PD) prenatal hypoxia (17th day of gestation (GD)--birth) is followed by a 4-fold increase of carbonic anhydrase (CA) activity in the hippocampus. After postnatal hypoxia (2nd-10th day of life) CA activity in all investigated brain regions rise. At the 11th PD the values were 190 (cerebral cortex), 242 (striatum) and 176 (hippocampus) per cent of control. Noradrenaline (10(-6)M) enhanced CA activity in cerebral cortex and hippocampus about 2-fold. Dopamine (10(-6)M) caused an increase in the striatum up to 210% of control. The increased CA activity after hypoxia is assumed to be a functional response to activation of the glia by catecholamines.

Aging↗
PubMed1986

Postnatal administration of L-dopa normalizes hypoxia-induced long-term changes in dopamine release from striatum slices and in avoidance learning.

Newborn rats exposed to a mild chronic postnatal hypoxia always displayed at the age of 2-3 months an increased fractional efflux rate of dopamine (DA) from striatum slices combined with a decreased capacity for learning and retention. The protective effect of the administration of L-DOPA on these long-term changes was tested by the injection of L-DOPA 5-30 min prior to the beginning of daily exposure to hypoxia. L-DOPA administration during postnatal hypoxia prevents in a dose dependent manner the long-term effects of postnatal hypoxia as described. This finding supports the hypothesis that long-term changes in DA release and in behaviour due to early postnatal hypoxia may be brought about by changes in the DA-metabolism during a critical period of development.

Animals↗
PubMed1986

The vulnerable period of perinatal hypoxia with regard to dopamine release and behaviour in adult rats.

The relations between a perinatal exposure schedule and the outcome of dopamine (DA) release from striatum slices on the one hand and behaviour on the other, were studied in order to identify the vulnerable period. A mild chronic postnatal hypoxia (2nd-10th day of life) induces long-term effects on the DA release rate (FER) from striatum slices. A 10 h daily exposure to hypoxia for 5 days (2nd-6th day of life) induces the same long-term effects. Adult rats exposed to hypoxia (pO2 8.6 kPa) for 16 h respond with a drastic decrease of FER of DA. Exposure to early postnatal hypoxia prevented this drastic decrease of FER of DA when adult rats were again exposed to hypoxia. 3 ten h periods of hypoxia within the first 10 days of life were enough to the long lasting effects. Prenatal hypoxia as well as hypoxia during the adolescent period did not show any long-term effects on the dopaminergic system. Alterations in behaviour (decreased learning capacity as well as decreased reaction to stimuli after prolonged stress in adulthood) were found after 3-9 days of hypoxia between the 2nd and 10th day of life.

Aging↗
PubMed1986

Effect of early and late postnatal hypoxia on subcellular synaptosomal fractions from cerebral cortex of rats. I. An electron-microscopical and biochemical study.

Synaptosomal fractions of brain cortex of rats exposed to moderate intermittent hypobaric hypoxic conditions during the first or second decade of the postnatal life were investigated electron microscopically one day or up to one week after the hypoxia experiment. Mitochondria and synaptosomes with impaired morphology were observed to occur more frequently in fractions obtained from hypoxic animals. Synaptosomes showed lesions of the outer membrane and loss of the synaptoplasmatic content, or condensation of the synaptosomal content with increasing electron density, deformation of the synaptosomes in size and shape, disappearance of structural details, degeneration of intrasynaptosomal mitochondria in form of strong condensation and, finally, formation of intrasynaptosomal vacuoles with dense core inclusions. The mitochondrial reaction was characterized by two antagonistic configurations: condensation of the matrix with secondary enlargement of the intracistal spaces and of the outer compartment and, finally, the decay of the matrix condensate in several crumbs. On the other hand, swelling of the matrix with strong enlargement of the whole mitochondrium, later defects in the outer membrane and the degeneration into empty mitochondrial ghosts, appearing in the upper fractions. Some characteristic marker enzymes were tested in the fractions. The results hint at an elevated vulnerability of synaptosomes obtained from animals exposed to postnatal hypoxia, as indicated by the lowered quotient of LDH activities after and before addition of Triton X-100. Furthermore, there are clues to a decrease in the number of synaptic connections within the cortex of hypoxia exposed animals, as is concluded from the diminished AChE activity in the subcellular fractions of these animals. However, no different effect of early or late postnatal hypoxia exposition was evident in the biochemical parameters.

Acetylcholinesterase↗