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Biomedical subjects

J Gross

Publications and source records attributed to J Gross.

At least 289 records · Page 16Linked to original sources
PubMed1984

Cartilage-degrading neutral proteinase secreted by Yoshida sarcoma cells. Purification and properties.

The Yoshida sarcoma, a malignant rat tumor, has been reported by Machinami ( Machinami , R. (1972) Acta Pathol. JPN 22, 19-39) to destroy cartilage matrix in vivo. We have characterized an enzyme secreted by Yoshida sarcoma cells in culture which degrades cartilage proteoglycan in solution and also in situ in organ culture ( Mikuni - Takagaki , Y., and Gross, J. (1981) in Proceedings of the 6th International Symposium on Glycoconjugates ( Yamakawa , T., Osawa , T., Handa , S., eds) pp. 491-492, Japan Scientific Societies Press, Tokyo) ( Mikuni - Takagaki , Y., and Gross, J. (1982) in The Extracellular Matrix ( Hawkes , S., and Wang, J.L., eds) pp. 379-385, Academic Press, New York). In this report we characterized the isolated enzyme with the help of a new assay system for measurement of proteoglycan core protein degradation, which utilizes aminopropyl glass beads derivatized with hyaluronic acid. This enzyme, with a neutral pH optimum and apparent molecular weight of about 30,000, is secreted into culture medium in an active form. It is resistant to cartilage-derived inhibitors and to alpha 2-macroglobulin as well as to synthetic and natural inhibitors of serine-, thiol- and carboxylproteinases . It is inhibited by a chelating agent, 1,10-phenanthroline and thiol compounds at relatively high concentrations, and therefore is probably a metalloproteinase. The enzyme degrades type V collagen, types I and II denatured collagen (gelatin), and casein in addition to cartilage proteoglycan, but not bovine serum albumin, myoglobin, fibrinogen, elastin or native collagen types I, II, III, and IV. These findings suggest that the Yoshida sarcoma may degrade cartilage matrix in vivo by means of a secreted, active, inhibitor-resistant enzyme.

Animals↗
PubMed1984

Monitoring of hospital emergency room visits as a method for detecting health effects of environmental exposures.

We excepted from the logs of the adult and children's emergency room at Soroka Hospital Medical Center the number and types of services requested by day for the year 1980. Both total visits and visits for respiratory conditions were examined in order to test whether rain, heat, or pollutants led to increased requests for emergency room care. The total visits for adults were 72,375, of which 1,727 (2.4%) were for selected respiratory conditions. The total visits for children were 19,232, and respiratory conditions were 3,980 (20.7%). There is marked seasonal excess for respiratory visits for children in winter, and a lesser excess for adult respiratory conditions. Non-respiratory conditions and overall visits are higher in summer months. Fewer visits occur on Saturday and on Friday, with the maximum on Sunday. Otitis and bronchitis among children show little day-of-week trends. "High event" days for admissions are determined by fitting a Poisson distribution to the numbers of admissions by day for various respiratory complaints, and we then examine the concordance between these high event days and days with rain, high pollution or temperature. Adult respiratory conditions were more likely to occur on days with high total particulates (TSP) and "respirable" particulates (RSP). When the mean values of RSP and TSP for high asthma and shortness of breath days were compared with a random day for the same month, significant differences were found for RSP for adults, but not for TSP. Natural dust is the more likely cause of this association. Emergency room monitoring should be useful in locations with high levels of man-made pollutants.

Adult↗
PubMed1984

Sex hormone binding globulin (SHBG) in breast cancer: a correlation with obesity but not with estrogen receptor status.

Plasma sex hormone binding globulin (SHBG) levels were determined in a group of 82 patients suffering from breast carcinoma with a known estrogen receptor status (ER). Overweight (greater than 20% of ideal weight) premenopausal patients had a significantly lower SHBG plasma level than their non-obese counterparts (43 pmol/ml vs 72.7 pmol/ml, P less than 0.001). No difference in plasma levels of SHBG was found between obese and non-obese postmenopausal patients. No correlation was found between SHBG levels and ER status either in non-obese premenopausal patients or in postmenopausal patients in general. Breast carcinoma patients had significantly higher SHBG plasma levels than a group of normal controls (57.9 pmol/ml vs 40.6 pmol/ml, P less than 0.01), but the stage of the disease did not influence the SHBG level within the breast carcinoma patients. Results of this study do not support a correlation between SHBG levels and ER status. SHBG plasma levels are significantly influenced by a patient's weight, particularly in those who are premenopausal.

Adult↗
PubMed1984

[Effect of psychopharmacologic therapy on sexual functioning].

Undesirable effects of psychopharmacological treatment on sexual functioning in males and females are summarized in this paper. As the review suggests, all substances used in psychiatric pharmacotherapy might affect sexual functions to a marked extent, a fact which can be explained by different properties of the medication. Review of the literature reveals that the disturbances most frequently provoked by the different substances are diminished sexual interest and ejaculatory impairment. This conclusion can be drawn despite a lack of controlled studies giving indication as to the frequency and practical importance of the effects of psychopharmacological treatment on a patients sexuality. Contrary to expectations, sexual impairment in most of the reports is clearly attributable to a special substance and appears to be independent of the basic psychiatric disturbance. One of the most intriguing results of the review is that considerably fewer reports on the effects of the medication on female sexuality have been published than on male patients. Reports on female patients deal with impaired reproductive functioning, mainly menstrual cycle disturbances. The need for systematic investigation of the effects of psychopharmacological treatment on sexuality is discussed on the basis of the theoretical importance of these effects for the individual patient and in view of the fact that psychotropic medication is frequently prescribed to patients with sexual dysfunctions or deviations without knowledge of the actual effects of the substances on sexual behaviour.

Anti-Anxiety Agents↗
PubMed1984

Organization of collagen types I and V in the embryonic chicken cornea: monoclonal antibody studies.

To determine whether type V collagen is antigenically masked in situ by its fibrillar organization, two different methods were used to perturb selectively the structure of collagen fibrils in sections of embryonic chicken corneas. The experimentally modified tissues were probed by immunohistochemical procedures with monoclonal antibodies against types V and I. A lathyritic agent was used to block crosslinking of newly synthesized collagen. This results in reversible temperature-sensitive alterations in fibrillar packing, such that freshly formed collagen fibrils retain their aggregated state at 37 degrees C but become dissociated upon cooling. Type V-specific immunofluorescence remained masked at 37 degrees C but was revealed at 0 degree C. The effect of temperature was partially reversible, indicating that type V collagen is normally unavailable for antibody binding because of its fibrillar arrangement. In sections of normal corneas, treatment with corneal collagenase, which degrades type I collagen, but not type V, also unmasked the latter. This implicates type I collagen as the masking agent. We propose that collagen types I and V are incorporated together in heterotypic fibrils.

Animals↗
PubMed1984

Regulation of connective tissue collagenase production: stimulators from adult and fetal epidermal cells.

We have examined the ability of primary adult rabbit skin cells to regulate collagenase production in vitro. Dermal cells constitutively produce collagenase in culture, and enzyme production by these cells can be influenced by epithelial cells. Co-culture with skin epidermal cells resulted in more enzyme production by dermal cells, whereas co-culture with corneal epithelial cells yielded less enzyme activity. Connective tissue cells from a different source, cornea, also produced collagenase when co-cultured with skin epidermal cells, although the stromal cells alone made no enzyme. The drug cytochalasin B had very little influence on collagenase production by dermal cells, either alone or in co-culture with epidermal cells, but did significantly potentiate enzyme production by corneal stromal cells responding to epidermal effector molecules. Epidermal-cell-conditioned medium from both fetal and adult rabbit skin was a potent source of stimulators (apparent mol wt 20,500 and 55,000) of connective-tissue-cell collagenase production. Stimulator production by epidermal cultures was cell density dependent. Optimal production of stimulators occurred in adult cultures containing 10(6) epidermal cells/ml of medium, and in fetal cultures containing 10(5) cells/ml. Inhibitors of connective tissue cell enzyme production were not detected in conditioned medium from either adult or fetal epidermal cells.

Animals↗
PubMed1984

Thermal stability of the helical structure of type IV collagen within basement membranes in situ: determination with a conformation-dependent monoclonal antibody.

To examine the thermal stability of the helical structure of type IV collagen within basement membranes in situ, we have employed indirect immunofluorescence histochemistry performed at progressively higher temperatures using a conformation-dependent antibody, IV-IA8. We previously observed by competition enzyme-linked immunosorbent assay that, in neutral solution, the helical epitope to which this antibody binds undergoes thermal denaturation over the range of 37-40 degrees C. In the present study, we have reacted unfixed cryostat tissue sections with this antibody at successively higher temperatures. We have operationally defined denaturation as the point at which type IV-specific fluorescence is no longer detectable. Under these conditions, the in situ denaturation temperature of this epitope in most basement membranes is 50-55 degrees C. In capillaries and some other small blood vessels the fluorescent signal is still clearly detectable at 60 degrees C, the highest temperature at which we can confidently use this technique. We conclude that the stability of the helical structure of type IV collagen within a basement membrane is considerably greater than it is in solution, and that conformation-dependent monoclonal antibodies can be useful probes for investigations of molecular structure in situ.

Animals↗
PubMed1984

Evaluation of professional nursing practices in a community hospital cancer program: the methodology.

In summary, this evaluation plan is designed to assess current oncology nursing practices in a community setting. The focus of the plan is on patient problems identified in the CHCP Cancer Nursing Guidelines and the Hospice Nursing Guidelines. Critical decisions regarding which patient problems to focus on and the implementation of the evaluation plan remain with the CHCP committees. Technical assistance is provided by a CHCP Evaluation Specialist. Finally, summary reports will be generated at regular intervals so as to maximize the impact on current program development. There are several implications for this nursing evaluation plan, both immediate and long range. In the immediate, we hope that the results will help CHCP committees and individual hospitals make informed decisions about future program development. More importantly perhaps, we are for the first time in our local community identifying services central to nursing and developing base line data on the frequency of the delivery of these services. Looking into the future, we see additional implications for these studies. Currently, our evaluation system is a paper system, and paper systems are by their very nature time consuming and somewhat awkward. It is our hope that in the future information about nursing services will be registered on a computerized information system. Then, reports about the types of nursing services and amount of time spend with cancer patients could be automatically generated on a weekly basis, if so desired. However, if we are to attain this goal, we need to systematically identify common patient problems central to oncology nursing care that can be documented and studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Hospitals, Community↗
PubMed1984

Effects of piracetam on brain development in newborn rats exposed to hypoxia.

Perinatal hypoxia is one of the main causes of disturbances of the function of the CNS during childhood. In this study the protective effect of the nootropic drug piracetam (oxo-2-pyrrolidinyl-1)-2-acetamide was tested. One-day-old Wistar rats were exposed together with their mothers to hypoxia up to the 10th day of life (11 h daily, pO2 = 9.86 kPa). On the 11th day a 48% decrease of body weight and a 30% decrease of brain weight was found in the hypoxic animals. The protein/DNA ratio and the AChE activity in the brain cortex were decreased indicating retarded brain development. Piracetam (daily 100 mg/kg, s. c., before hypoxic exposure) did not affect the mortality rate, the somatic development of the animals, or the estimated basic neurochemical markers in the cortex of the brain. At the age of 3 months the fractional efflux rate (FER) of dopamine (DA) evoked chemically or electrically as a characteristic functional feature of chemical synaptic transmission, was examined. It was found that postnatal hypoxia induces a long lasting increase of FER of DA of striatum slices. Animals exposed postnatally to hypoxia and treated with piracetam showed an increased FER of DA (potassium as stimulus) by comparison with those animals also exposed postnatally to hypoxia but left untreated with piracetam.

Animals↗
PubMed1984

[Psychotropic drug-induced changes in sexuality--frequency and relevance in psychiatric practice].

As a review of the literature concerning sexual side effects of psychotropic drugs in psychiatric patients reveals, sexual disturbances (such as erectile or orgasmic dysfunctions) seem to be a common consequence of psychopharmacological treatment. The frequency and relevance of these effects in psychiatric practice were estimated in a questionnaire study with 68 psychiatrists, working either in a practice or a clinic. According to the physicians answers, few patients report sexual side effects of drugs spontaneously, through these are supposed to be more common. Different kinds of sexual impairment are reported as specific effects of the drugs. As the physicians assume these effects generally provide a problem, both for the patients self-esteem as well as for treatment and compliance. Based on the psychiatrists experience patients are in a surprisingly good position to differentiate between the influences of their basic illness and a specific medication as far as sexual changes are concerned. One part of the questionnaire asked for the observed effects of specific psychotropic substances on sexual behaviour. The results support the evidence reported in the literature that neuroleptics and antidepressants are most likely to provoke sexual impairment. The results of the study are discussed in relation to the theoretical relevance of sexual side effects for the patient and the treatment and to the possibilities of a psychiatrist to prepare and inform his patient.

Adult↗
PubMed1983

Severe head trauma and the changes of concentration of neuron-specific enolase in plasma and in cerebrospinal fluid.

In nine patients with severe head trauma, the concentration of neuron-specific enolase in cerebrospinal fluid and in plasma was determined and compared with the activity of creatine kinase and alpha-hydroxybutyrate dehydrogenase, and with the concentration of lactate. In patients who died of the head trauma, a concentration of neuron-specific enolase of 6.8-64 micrograms/l in the plasma (reference range: 3.0-6.0 micrograms/l) and of 2.2-9.0 micrograms/l in the cerebrospinal fluid (reference range: 0.5-2.0 micrograms/l) was detected. Investigations of three patients showed that the changes of the concentration of neuron-specific enolase in plasma and in cerebrospinal fluid were independent of each other. Furthermore, the initial concentration of neuron-specific enolase in the plasma after the accident and the dynamics of its changes during the disease show a close relationship to the outcome.

Adult↗
PubMed1983

The Abraham lens with the neodymium-YAG laser.

We have used the neodymium-yttrium-aluminum-garnet (YAG) laser effectively to cut posterior capsules and pupillary membranes, but the procedure was difficult. Using the Abraham contact lens facilitated the procedure, but may be related to the development of retinal damage.

Aged↗
PubMed1983

On the state of aggregation of newly secreted procollagen.

Procollagen and partially processed procollagen from cultures of primary chicken embryo tendon cells appeared as segment-long-spacing (SLS)-like aggregates when drops of medium were negatively stained and examined by electron microscopy. Similar aggregates were obtained after negative staining of medium partially purified by gel filtration and also after staining thin sections of fixed, dehydrated, and embedded pellets formed by prolonged ultracentrifugation of whole culture medium. In contrast to results from electron microscopy, analysis by velocity density gradient sedimentation or sedimentation equilibrium indicated the exclusive presence of procollagen or partially processed procollagen monomers in solution. These contradictory data can be reconciled if procollagen exists in monomeric form when greatly diluted (as in culture medium), and in specific aggregated form (SLS) at high concentration. We believe that cells in vivo secrete procollagen in high, local concentration packaged in the SLS form. We propose that such zero-D arrayed packages are the precursors of native collagen fibrils.

Animals↗
PubMed1983

Defining the role of the social worker in primary health care.

However difficult and controversial, the task of defining the role of social workers is often a practical necessity, especially in contexts involving professional collaboration. The approach reported here used a list of psychosocial problems and accompanying protocols to define the role of social workers in primary care clinics.

Adolescent↗
PubMed1983

Stimulation of sugar transport in cultured heart cells by triiodothyronine (T3) covalently bound to red blood cells and by T3 in the presence of serum.

T3, covalently bound to red blood cells (RBCs), stimulated the uptake rate of 2-deoxy-D-glucose (2-DOG) in cultured chick embryo heart cells. The response, measured 6 h after exposure, was at least the same than that to free T3. An inhibitor of rhodamine-T3 internalization, bacitracin, did not affect the stimulation of sugar uptake by T3 regardless of whether T3 was covalently bound or free. Pretreatment of RBC-T3 with anti-T3 immunoglobulin G completely blocked the effect of T3, whereas normal rabbit immunoglobulin G failed to do so. Addition of 5% chick serum to the medium stimulated 2-DOG uptake to 144% of the control at 6 h. Adding T3 (10 nM) to the serum-containing medium increased 2-DOG uptake to 171% of the control. The effect of T3 alone or in the presence of serum was not inhibited by cycloheximide, puromycin, or actinomycin D. A T3 dose response curve, in medium containing 10% dehormonized serum, showed enhancement of the T3 effect when compared with the curve obtained in the serum-free medium. The minimal effective concentration of T3 was 10 pM in the presence of serum and 100 pM in its absence. The slope of the linear portion of the dose response curve was greatly increased and the maximal response markedly enhanced by serum. The ED50 was 0.33 nM vs. 0.43 nM in terms of total T3 concentration and 0.16 nM vs. 0.43 nM in terms of free T3 in the presence or absence of serum, respectively. These data suggest that T3, in physiological concentrations, activates sugar transport through an external contact with the cell surface.

Animals↗
PubMed1983

Thyrotrophin and growth hormone secretion and cell morphology in hypothyroid pituitary cells cultured on a natural extracellular matrix.

Hypothyroid rat pituitary cells were cultured on an extracellular matrix (ECM) produced by corneal endothelial cells. ECM markedly affected the following parameters. 1) Cell attachment, spreading and proliferation were improved, resulting in a more rapid formation of confluent cell monolayers. 2) In the presence of ECM the production of both thyrotrophin (TSH) and growth hormone (GH) was larger than in its absence. Immunofluorescence studies revealed that 20% of the cells in these monolayers were thyrotrophs; consequently, TSH content was higher while GH level was lower than in control cultures of euthyroid pituitaries. These data suggest that the in vivo physiological differences are maintained by the conditions of the culture. 3) ECM enabled the response of both the somatotrophs and the thyrotrophs to thyrotrophin releasing hormone (TRH) and the cells remained responsive for at least 10 days. Maximal stimulation (1.3- to 6-fold) was obtained with 14 nM of TRH. In the absence of ECM the cells failed to respond to TRH. 4) Cell morphology was examined by scanning electron microscopy (SEM). Cells grown on ECM were characteristically epithelial, whereas those cultured on plastic plates had a fibroblast-like appearance. Four types of cells were identified in the epithelial cell monolayers by the appearance of their surface. TRH induced a 2-fold increase in the number of cells covered with microvilli and a corresponding decrease in the number of smooth surfaced cells. This suggests that hormone secretion is associated with the formation of microvilli.

Animals↗