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Biomedical subjects

J Born

Publications and source records attributed to J Born.

At least 235 records · Page 13Linked to original sources
PubMed1980

Invading meningiomas of the sphenoid ridge.

The authors report a series of 34 meningiomas of the sphenoid ridge. Eight tumors were totally removed uneventfully: two from the middle sphenoid ridge and six from the pterion or Sylvian point. Five tumors were not operated on because of their extensions or the patient's age. Twenty-one tumors raised serious surgical problems, resulting in a classification into three groups: deep or clinoidal, invading beyond the sphenoid wings, and a combination of both. Histological study of the hyperostotic bone showed meningiomatous cells in the bone in 12 of 13 cases so examined. Surgical limitations included invasion of the cavernous sinus (15 cases), of the dura mater of the sella turcica (seven cases), of the lateral part of the sphenoid body at the insertion point of the ala magna (seven cases), and of the common tendinous annulus of Zinn in the orbit (five cases), and basilar extracranial extension, particularly in the pterygomaxillary fossa (three cases). Following extensive removal, there were no early recurrences and three late recurrences (9 years and more). In 13 cases with a follow-up period of 1 to 8 years, there were no clinical recurrences. In only two cases was the meningioma totally removed. There were three postoperative deaths, two cases of hemiparesis with aphasia and epilepsy, one case with a frontal lobe syndrome, and nine with slight oculomotor, visual, or esthetic sequelae.

Adult↗
PubMed1979

Chicken ribosomal DNA: gene frequency and purification by R-loop hybridization.

The genes for ribosomal RNA of chicken are present in about 200--240 copies per haploid genome. The ribosomal genes were separated from the bulk of DNA by different methods. In CsCl-actinomycin D gradients the GC-rich ribosomal DNA is shifted to the lower density side of the bulk of DNA. After hybridization with iodinated ribosomal RNA under conditions where R-loops are formed ribosomal DNA has an increased density. The R-loops can be separated from the bulk of DNA in Cs2-SO4 gradients.

Animals↗
PubMed1978

A proteoglycan with affinity for the vegetalizing factor: characterization by density gradient centrifugation.

A crude proteoglycan fraction isolated from chicken embryos has an affinity for the vegetalizing factor, which induces mesodermal and endodermal tissues in gastrula ectoderm of Triturus alpestris. Binding of the factor to the crude proteoglycan results in inactivation of the vegetalizing factor. The crude proteoglycan was centrifuged in CsCl and CsCl-urea density gradients. Most of the inactivating material was recovered from the gradients in the high density proteoglycan fraction. Part of the inactivating material was found in glycoproteins of lower density. It is concluded that not all of the polysaccharide moiety of the proteoglycan is involved in binding of the vegetalizing factor. The proteoglycan is inactivated by incubation with hyaluronidase.

Animals↗
PubMed1977

Template active chromatin structures: degradation by deoxyribonuclease I.

Chicken embryos were pulse-labelled in vivo with [3H]uridine (10 min), the chromatin isolated and treated with DNAse I. The residual chromatin was separated from the degradation products by centrifugation. The nascent pulse-labelled RNA is completely recovered in the residual chromatin even after prolonged incubation with DNAase I, whereas the DNA is completely degraded to 80 base polynucleotide fragments and smaller fragments.

Animals↗
PubMedDate not supplied

Smoking behavior and attitude toward smoking regulations and passive smoking in the workplace. A study among 974 employees in the German metal industry.

BACKGROUND: Smoking regulations at the workplace have been found to be acceptable and effective in many studies conducted in the United States. There is limited knowledge, however, on acceptance and effects of smoking regulations in European countries, particularly among blue collar employees. METHODS: We conducted a survey on smoking behaviour and attitude toward smoking regulations and passive smoking in a South German metal company. A self-administered questionnaire was mailed to 1,500 predominantly blue collar employees of whom 974 participated in the study (response rate 64.9%). RESULTS: About 30% of the employees were not allowed to smoke at their immediate work area. Among them, about 95% of both smokers and nonsmokers agreed with this smoking policy. More than 60% of nonsmoking blue collar workers were bothered by passive smoking at work whether or not smoking was allowed at their immediate work area. In contrast, the proportion of nonsmoking white collar employees who were bothered by passive smoking varied from 52% if smoking was allowed at their immediate work area to 18% if smoking was not allowed. Prevalence of active smoking and average amount of smoking among active smokers were considerably lower among employees who were not allowed to smoke at work than among other employees. These differences were partly due to confounding by occupation, however, which was strongly related to both smoking habits and smoking policy. CONCLUSIONS: Our results, which confirm and extend previous findings, give further support to the acceptability and potential effectiveness of smoking regulations at the workplace. Particular efforts should be devoted to limit both active and passive smoking among blue collar employees.

Adult↗
PubMedDate not supplied

Glucocorticoid influences on the auditory brain-stem responses in man.

The present study was designed to test whether human auditory brain-stem responses (ABRs) are sensitive to peripheral endocrine signals as reflected by changes in the plasma glucocorticoid concentration. ABRs were recorded following treatment with 50 mg hydrocortisone or placebo in 13 healthy male adults. Experiments were double-blind and designed according to a latin-square within-subject comparison. Treatment was applied 1 h prior to testing as an i.v. infusion over a period of 20 min. Subjects were tested in each session under 3 X 3 conditions, i.e., ABRs were obtained to series of clicks presented at 3 different intensities (80, 60, 40 dB HL) and with 3 different stimulus rates (39, 10, 5 clicks/sec). Additionally, oral temperature was monitored. Hydrocortisone significantly reduced latencies of waves III, V, and VI (and subsequent negative troughs) when low stimulus intensities were used. Furthermore, the glucocorticoid reduced latencies of waves Vn, VI and VIn when the clicks were presented at a slow stimulus rate. Further studies have to specify the underlying mechanisms of these changes.

Adult↗
PubMedDate not supplied

Elevated plasma cortisol levels during interferon-gamma treatment.

We investigated plasma levels of cortisol and ACTH in 9 patients with advanced metastatic tumors before and during treatment with interferon-gamma (IFN-gamma), 2-4 h after administration of IFN-gamma there was a sharp rise in plasma cortisol levels. The rise coincided with the onset of fever. Highest cortisol levels were reached 4-6 h after IFN-gamma injections, whereas IFN-gamma serum levels peaked 6-10 h after the IFN-gamma injections. Elevated cortisol levels during IFN-gamma treatment may be part of a homeostatic response of the neuroendocrine system to the immunological stimulus induced by IFN-gamma. On the other hand, the increased plasma levels of cortisol in response to pharmacological doses of IFN-gamma may dampen the in vivo effectiveness of IFN-gamma.

Adrenocorticotropic Hormone↗