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Biomedical subjects

P Becker

Publications and source records attributed to P Becker.

At least 145 records · Page 8Linked to original sources
PubMed1984

Tissue-specific DNaseI hypersensitive sites in the 5'-flanking sequences of the tryptophan oxygenase and the tyrosine aminotransferase genes.

The genes for tryptophan oxygenase (TO) and tyrosine aminotransferase (TAT) are expressed in a tissue- and development-specific manner and are regulated by glucocorticoids (TO and TAT) and glucagon or its intracellular mediator cAMP (TAT) in rat liver. We have analyzed the chromatin structure of these genes in the vicinity of the 5' ends with regard to DNaseI hypersensitivity and have found DNaseI hypersensitive sites upstream of each of the promoters. Mapping of this region reveals three closely spaced cleavage sites near the TO promoter and a doublet of sites near the TAT promoter. In both genes additional cleavage sites are found further upstream. All hypersensitive sites of both genes are absent in kidney nuclei and therefore appear to be specific for the tissue expressing the genes. A correlation of expression and modified chromatin structure was also observed in a hepatoma cell line expressing TAT but not TO: hypersensitive sites are present in TAT but not in TO chromatin. Upon glucocorticoid induction an additional hypersensitive site is detected approximately 2 kb upstream of the TAT promoter in liver and hepatoma cells.

Animals↗
PubMed1984

[Differences in IgM increase following operations in general anesthesia and paraspinal regional anesthesia].

The serum immunoglobin levels of 74 patients with a prosthetic hip operation were studied. 36 patients received general anaesthesia with thiopental sodium, succinylcholine, alcuronium and halothane, whereas 38 patients were given a catheter epidural anaesthesia (CEA) with bupivacaine. Both collectives were subdivided into four groups, in whom the loss of blood was substituted by either human albumin 5%, dextrane, gelatine, or hydroxyethyl starch. Patients with a general anaesthesia had a high increase in serum IgM on the 7th day after operation, whereas there was no increase in the patients who had received CEA. In all the other parameters there was no difference between the various anaesthetics; likewise, the individual volume substitution management procedures did not produce differences in these parameters. IgM elevation is interpreted as a reaction to an affection of the tracheo-bronchial system; this reaction did not occur with the CEA group. The cause of the reaction is the interaction of immunomodulating drugs, and changes in ventilation that lead to an activation of the immune system.

Anesthesia, Epidural↗
PubMed1983

[Time and incidence of peroperative cardiovascular complications in geriatric patients].

The incidence of intraoperative and postoperative complications was determined in a retrospective study via data evaluation by computer. Two groups of patients were examined, one group comprising patients below 60 years of age, whereas the other group consisted of persons above 60 years of age. The results show that complications of the cardiovascular system are three to four times more frequent in patients older than 60 years; severe hypotension or hypertensive reactions were seen in 2.9 and 9.3% of the patients, respectively, while arrhythmias occurred in 3.9%. No differences could be found in respect of the time at which these complications became manifest (intraoperatively or in the recovery room). Enumeration of the secondary diseases covered by this study, reveals significant differences; this can explain the limited range of compensation in persons of advanced age. Hence, an optimal preanaesthetic treatment and diagnosis, as well as monitoring are mandatory in geriatric patients to ensure safe anaesthesia.

Age Factors↗
PubMed1982

Rat cardiac muscle single cell automaticity responses to alpha- and beta-adrenergic agonists and antagonists.

Isolated cardiac muscle cells from neonatal rat ventricular myocardium have both alpha- and beta-adrenergic, positive chronotropic responses, with sensitivity to applied adrenergic agents more than 100 times greater than the intact neonatal heart. These highly sensitive isolated single cells and small groups of cells also reveal partial agonist activity of the alpha-adrenergic antagonist, phentolamine, and the beta-adrenergic antagonist, propranolol. The most likely explanation for the high sensitivity is the lack of a desensitization process that could involve both a desensitization substance and changes in receptors. These experiments suggest that all adrenergic antagonists could possibly show partial agonist activity.

Adrenergic alpha-Agonists↗
PubMed1981

State organization in neonates: developmental inconsistency indicates risk for developmental dysfunction.

Twenty-two healthy full-term infants were observed for 7 continuous hours in their homes weekly on weeks 2, 3, 4, and 5. Code recordings of their behavioral states and any mother-infant interactions were made every 10 seconds. An analysis was made of the distribution of the infant's state behaviors during the time it was left alone (mean = 279.6 minutes in 7 hours). The states were Waking Active, Quiet Alert, Fuss or Cry, Drowse or Transition, Active Sleep, and Quiet Sleep. Four state profiles were obtained for each infant, one for each week of observation; then a single quantitative measure of profile consistency over weeks was calculated. Infants with the four lowest profile consistency indices had major developmental problems between 3.5 and 30 months (p less than .001): one had aplastic anemia; a second had hypsarrhythmia, a third died of SIDS, and the fourth was hyperactive, both at home and in a testing situation. Other infants with low consistency scores showed minor developmental delays at 6 months and at 30 months. None of the infants at the upper end of the consistency continuum showed evidence of any developmental dysfunction by 30 months of age. The findings indicate that developmental inconsistency in state organization during the neonatal period is predictive of risk for later development.

Child Behavior↗
PubMed1980

[Different behaviour of street rabies and virus fixé strains in parabiotic rats (author's transl)].

To resolve the problem by which route rabies virus is migrating within the infected organism, coelioanastomosis was performed by operating two albino rats each so that a connection between blood vessels, however not between nerves was established. One of the partners was infected in each case. As soon as one of the parabionts exhibited specific disease, the animals were disconnected again. A comparison of street virus and strains of virus fixé that had been maintained by intracerebral, plantar, and intramuscular passage revealed basic differences. Street virus was found to be transmitted to the non-infected partner almost regularly while virus fixé maintained by intracerebral passage almost never was transmitted. After i.m. passages, plantar virus held an intermediate position.

Animals↗
PubMed1979

Time trends in the association of a rural or urban background with physician location.

The association of rural or urban background with choice of practice location was investigated in two time periods, 1950--1955 and 1963--1968, using the alumni of Marquette School of Medicine (now the Medical College of Wisconsin) in Milwaukee, Wisconsin. Background included size of communities of birth, high school, college, and internship. Small communities were screened to distinguish suburban from rural settings. It was found that in the 1950s the percentage of physicians from rural schools who chose to practice in rural areas was 2.2 times as great as this percentage for physicians from nonrural high schools (26 percent versus 12 percent). In the 1960s the ratio increased to 3.5, (35 percent versus 10 percent). This time trend was reversed for physicians more than 28 years old at the time of graduation from medical school. Place of birth and place of internship also were significantly associated with practice location; place of college showed a significant association with practice location only in the 1950s; and class rank was not associated with place of practice.

Age Factors↗