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Biomedical subjects

W Hanke

Publications and source records attributed to W Hanke.

At least 73 records · Page 4Linked to original sources
PubMed1996

Risk factors of intrauterine growth retardation: a study of an urban population in Poland.

The main objective of the study was to examine the role of selected socio-occupational factors on the development of intrauterine growth retardation (IUGR) in the urban population of Lódź, Poland. An epidemiological model of the case-control study was employed. Both the cases and controls were recruited from the female population covered by obstetric services in district hospitals during 1 January-30 June 1992. A group of cases included 92 females who delivered IUGR children, the control group-438 mothers of term born eutrophic babies. The presence of the relationship between IUGR manifestation and selected variables was initially assessed using the unadjusted odds ratio (OR). The variables described as significant were considered in the logistic regressions models, separately for all women and those with previous pregnancies. A comparison of the groups of cases and controls has revealed a significant excess of risk of delivering an IUGR child by mothers with the following characteristics: marital status-single, low educational level, low height (less than 1.60 m) low prepregnancy weight and low maternal weight gain. An elevated risk of delivering an IUGR child was found in the group of women who reported to have their first contact with the physician after 12 weeks of pregnancy. An adverse effect of prolonged vaginal bleeding was observed. Women who recently lost their job, compared to those employed continuously during pregnancy, were at an increased risk of IUGR. Cigarette smoking appeared to be the most important variable affecting the evaluated pregnancy outcome. For the women smoking 6-10 and more than 10 cigarettes a day, the risk of delivering an IUGR child was found to be almost 4 and 7 times, respectively, higher than for non-smokers. A logistic regression covering all the above mentioned maternal characteristics was employed. Only four of them proved to be significant: low maternal weight gain, prolonged vaginal bleeding, smoking and the marital status-single. The process of preventing IUGR and its consequences requires more effective activities aimed at increasing the level of health education and stimulating the development of appropriate, health-oriented behaviour.

Adult↗
PubMed1996

[The role of tobacco smoking as a risk factor for intrauterine growth retardation and preterm delivery].

The risk of intrauterine growth retardation (IUGR) and preterm delivery, in the group of 551 females from the area of Lódź, was related to the amount of cigarettes smoked per day. In subjects smoking 1-20 cigarettes a day, the risk of IUGR and preterm delivery was three times as high as in the nonsmoking females. The study has not provided any clear evidence for the prepregnancy smoking and the passive smoking as the risk factors for the pathologies under study.

Adolescent↗
PubMed1996

Properties of retinal glial cell potassium channels.

The patch-clamp technique was used to investigate the nature of potassium channels localised in the end-feet-membrane of Müller (glial) cells of the chicken retina. Two different preparations were used to examine ion channels in this membrane area. The ion channels were investigated either in eye-cup preparation, leaving the retina intact, or in isolated endfeet. In both preparations the ion channels showed identical characteristics. We found three K+ channels that could be distinguished by their electrical properties. In the inside-out configuration, in a standard bathing solution (6 mM potassium) with the pipette solution containing 100 mM potassium, these channels showed conductances of 15 pS, 29 pS and 68 pS. Whereas the 29 pS-channel was not voltage-dependent, the 15 pS- and 68 pS-channel showed significant voltage-dependence of the open-state probability. By membrane depolarisation the open-state probability of both channels types increased. The resting membrane potential of the glial cells was estimated to be about -80 mV, which is, as result of the high selectivity of the glial membranes for K+, more negative than that of retinal neurons.

Animals↗
PubMed1995

Effects of nitric oxide on the retinal spreading depression.

The retinal spreading depression has been used as a tool to investigate the action of nitric oxide (NO) as a diffusible neurotransmitter which in many cases acts by raising the cGMP level in target cells. The role of NO as a vasodilating agents has been well-established and it has been suggested that the vasodilatation concurrent with cortical SD may be mediated by NO. In this study, we present pure neuronal effects of NO on SD as the chicken retina is void of bloodvessels. We show that NO directly decreases the velocity of retinal SD waves in a concentration-and time-dependent manner. This effect can be partially mimicked by application of membrane-permeable cGMP derivatives. Furthermore, a NO-mediated speed up of the recovery of the intrinsic optical signal after the wave-front is shown.

Animals↗
PubMed1995

Hormonal response of primary hepatocytes of the clawed toad, Xenopus laevis.

Freshly isolated hepatocytes of the clawed toad, Xenopus laevis, were cultured for at least 3 days. The viability of the cells was characterized using staining and biochemical methods. In particular, the glucose and glycogen balance was tested. After culture for 16-20 hrs, the cells were subjected to hormonal treatment. Both adrenaline and arginine vasotocin stimulated the release of glucose in a dose dependent manner. 10(-6) M concentrations were strongly effective. The determination of the glycogen balance made it clear that the glucose release is mainly due to glycogenolysis. Using receptor antagonists and agonists, it has been shown that the effect of adrenaline is clearly mediated by beta-type receptors. Arginine vasotocin stimulated glycogenolysis via a type of receptor which is similar to the V2-receptor of mammals. This means that cAMP is involved in the response to both types of hormones which is in contrast to that which is known about the effect of nonapeptides on the liver of mammals.

Animals↗
PubMed1995

[Social-occupational risk factors for fetal growth retardation and preterm birth. I. Role of occupational and non-occupational work].

Clinical and control examinations were performed in order to assess the effect of certain demographic, social and occupational factors on a relative risk for fetus hypotrophia and preterm birth. Two groups of cases were distinguished: mothers of hypotrophic children (72 women) and mothers of eutrophic premature babies (41 women). The control group was composed of women who had given birth to eutrophic babies (438 persons). An analysis of individual variables indicated the following risk factors for preterm birth: mother's age over 35 years, unmarried status of mothers, a low level of education; while unmarried status increased the risk for fetus hypotrophia. Only a half of women under study worked when pregnant, and no relationship between working during pregnancy and increased risk for the pathologies discussed, were found. An aggravated risk for preterm birth in women overloaded with housekeeping duties was noted. This observation applied, in particular, to women who had not been working occupationally during pregnancy. Bearing in mind a multifactorial etiology of fetus hypotrophia and preterm birth, in the authors' opinion it would be useful to analyse an unrelated effect of individual risk factors with concomitant control of confounding factors.

Confounding Factors, Epidemiologic↗
PubMed1995

[Social-occupational risk factors for fetal growth retardation and preterm birth. II. An analysis of the independent effect of variables under study].

In the study covering 551 female inhabitants of Lodz, a model for clinical and control examinations was used in order to identify risk factors (estimated by means of odds ratio) for fetus hypotrophia and preterm birth. Logistic regression was employed to determine independent variables and those contributing directly to the occurrence of both pathologies. The following risk factors for preterm birth and fetus hypotrophia were identified: smoking during pregnancy, bleeding in more than one trimester of pregnancy and low weight gain by mothers during pregnancy. Late reporting to a doctor, uterus cervical insufficiency, recent loss of the job, excessive responsibility for the management of household affairs and premature baby or a baby with low birth weight as an outcome of the previous pregnancy were proved to be specific risk factors responsible for preterm birth, while marital status, namely single young mothers, and short stature of mothers were responsible for fetus hypotrophia. The results obtained did not provide the basis for drawing a conclusion that work during pregnancy exerted an adverse effects and contributed to the magnitude of the analysed obstetric pathologies. Nevertheless, risk factors identified should be taken into account in the planning of mother and child care. The authors stress the need for taking further steps to eliminate, wherever possible, the aforesaid risk factors.

Adolescent↗
PubMed1994

Pharmacology and biophysical properties of alpha 7 and alpha 7-alpha 8 alpha-bungarotoxin receptor subtypes immunopurified from the chick optic lobe.

Two chick optic lobe alpha-bungarotoxin receptor subtypes (alpha 7 and alpha 7-alpha 8) were immunopurified using polyclonal antibodies raised against synthetic peptides of chick alpha 7 and alpha 8 alpha-bungarotoxin receptor subunits. The alpha 7 subtype contained the M(r) 57,000 alpha 7 subunit, and represented 60-70% of the alpha-bungarotoxin receptors; the alpha 7-alpha 8 subtype contained the M(r) 57,000 alpha 7 and alpha 8 subunits, and represented only 20-25% of the receptors. Both subtypes also had an additional M(r) 52,000 subunit. The affinity of these subtypes for alpha-bungarotoxin as well as antagonists was similar. However, the alpha 7-alpha 8 subtype displayed consistently higher affinities for agonists. When reconstituted in planar lipid bilayers, the alpha 7-alpha 8 subtype displayed several conductance states of 10-50 pS; the alpha 7 subtype had only one conductance state of 45 pS. The alpha 7-alpha 8 subtype was activated by lower agonist concentrations than the alpha 7 subtype. When expressed in Xenopus oocytes, the alpha 8 subunit formed functional homomeric receptors that desensitized rapidly. These channels were blocked by alpha-bungarotoxin and displayed a higher affinity for agonists than the alpha 7 homomeric receptor. Taken together, these data indicate that at least two alpha-bungarotoxin subtypes are present in the chick optic lobe. They operate as ligand-gated channels and display different agonist sensitivities and kinetics/conductance properties.

Animals↗