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Biomedical subjects

E Weber

Publications and source records attributed to E Weber.

At least 577 records · Page 32Linked to original sources
PubMedDate not supplied

Immunological investigations in a group of workers exposed to various levels of polycyclic aromatic hydrocarbons.

To evaluate a possible immunotoxic effect of chronic exposure to polycyclic aromatic hydrocarbons (PAHs), several immune parameters were investigated in two groups of coke-oven workers. Exposure levels were different for both groups, one group being employed in a new coking facility of sophisticated technical standard, and the other in a facility with rather high emission of PAH-containing dust, built during the late 1960s. Immunomodulating effects of exposure were found on three levels of immunity: a reduced mitogenic response of T cells to phytohaemagglutinin observed by a reduced rate of DNA synthesis and a retardation in the expression of interleukin 2 receptor; an impairment of B cell activity, observed by a reduced proliferation of B cells and a low synthesis of immunoglobulin M after Staphylococcus aureus stimulation; a reduced oxidative burst in monocytes after challenge with E. coli. The differences in numbers of lymphocytic subpopulations in peripheral blood and in immunoglobulin levels of serum were statistically insignificant. The data of the present investigations point to significant, albeit slight, changes in immune function by PAH exposure. But these changes could not yet be related to health impacts of the exposure.

Adult↗
PubMedDate not supplied

Investigations on immune parameters in welders.

The aim of the present investigation was to study the effects of welding fumes on the human immune system. Thirty male subjects who had regularly welded and 16 control persons without occupational exposure were examined. Cellular immunity was evaluated by phenotyping of peripheral leucocytes, measurement of mitogenic T cell response and T cell stimulation in a heterologous mixed lymphocyte reaction. Non-specific immune reactions were quantified by oxidative burst of granulocytes and monocytes and the cytotoxicity of lymphokine-activated killer (LAK) cells. Serum immunoglobulin levels and immunoglobulin production by stimulated B cells served to demonstrate humoral immune reactions. Welding fumes retarded the kinetics of DNA synthesis after phytohaemagglutinin stimulation of T cells and reduced the cytotoxic activity of LAK cells. No effects on lymphocytic subpopulations, mixed lymphocyte reaction, the phagocytosis of leucocytes or the production of immunoglobulins were observed. Several welders reported on recurrent respiratory infections or bronchitis, a few on allergic skin reactions and one worker was affected by asthmatic symptoms. With the exception of a reduced activity of LAK cells, these effects could not be related to any impairment of immune reactions as they were measured by the immunotoxicity tests applied.

Adolescent↗
PubMedDate not supplied

Changing metastatic patterns of a transplantable rat osteosarcoma.

Metastatic behavior patterns in 303 untreated Sprague-Dawley rats bearing a transplantable cerium-144-induced osteosarcoma is described. The influence of survival time, sex, age of donor and recipient animals at time of transplantation, on the development of metastasis in lungs, kidneys, lymph nodes and liver was investigated. Nearly all (98.7 per cent) rats bearing osteosarcomas in the knee region developed primary hematogeneous lung metastases and 10.6 per cent of these developed secondary metastasis in the kidneys. A further primary, lymphogenous metastatic spread occurred in 15.5 per cent of the animals. Ninety-two per cent of the rats died because of lung metastases, but animals with long survival times developed significantly more extrapulmonary metastases than animals with a shorter survival time. This is an agreement with the observed change in metastatic patterns in osteosarcoma patients with prolonged survival after adjuvant chemotherapy. Moreover, the age of the donor-tumors and the recipient animals influenced survival time and consequently metastatic patterns. It was therefore possible to keep available several groups of osteosarcoma-bearing animals with different expectations of survival time. The results of transplantation of the same tumor by the intraperitoneal and the intravenous route are also presented.

Age Factors↗
PubMedDate not supplied

Immunohistochemical localization of dynorphin (1-8) in hypothalamic magnocellular neurons: evidence for absence of proenkephalin.

Dynorphin(1-8) immunoreactivity was visualized by immunohistofluorescence in hypothalamic magnocellular neurons of the rat. No immunoreactive met-enkephalin-Arg6-Gly7-Leu8, a fragment of the adrenal medulla pro-enkephalin molecule, was detected in magnocellular neurons. However, a strong met-enkephalin-Arg6-Gly7-Leu8-like immunostaining was seen in other regions of the brain. These results suggest that in magnocellular neurons dynorphin(1-8) exists independently from pro-enkephalin and therefore the magnocellular neurons represent a third opioid peptide neuronal system in brain. These observations, however, do not rule out a coexistence of proenkephalin and dynorphin-related peptides in other regions of the brain.

Animals↗
PubMedDate not supplied

Hypothalamo-posterior pituitary system in Brattleboro rats: immunoreactive levels of leucine-enkephalin, dynorphin (1-17), dynorphin (1-8) and alpha-neo-endorphin.

The levels of immunoreactive leucine-enkephalin, alpha-neo-endorphin, dynorphin (1-17) and dynorphin (1-8) have been determined in the hypothalamus and posterior pituitary from male and female Brattleboro rats homozygous (unable to produce vasopressin) and heterozygous (producing vasopressin) for diabetes insipidus, and from male and female Long Evans rats. In the hypothalamus we found no significant differences in the levels of these peptides while there were great differences in extracts from the posterior pituitary: female homozygous animals have greatly reduced levels in all four peptides compared to the heterozygous controls. In male homozygous animals the differences in the dynorphin (1-17) and leucine-enkephalin levels were small whereas the concentrations of alpha-neo-endorphin and dynorphin (1-8) showed a significant decrease compared to the male heterozygous controls. The results indicate a reduction in opioid peptides linked to the vasopressin deficiency in a partially sex dependent manner.

Animals↗
PubMedDate not supplied

Nursing home resuscitation policies and practices for residents without DNR orders.

The purpose of this study was to explore the policies and practices of nursing homes with respect to the resuscitation of residents who do not have a do-not-resuscitate (DNR) order. Responses from a survey of 36 facilities revealed that most residents had DNR orders and most facilities were capable of providing basic cardiopulmonary resuscitation (CPR). Less than 30% had performed CPR in the past 6 months, and 22.8% had no written CPR policies. More facilities required CPR in witnessed arrests of non-DNR residents (79.3%) than in unwitnessed arrests (24%). Methods for identifying CPR status need improvement to enable accurate identification and prompt resuscitation of residents who want CPR.

Advance Directives↗