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Biomedical subjects

R Winter

Publications and source records attributed to R Winter.

At least 289 records · Page 16Linked to original sources
PubMed1985

[Endothelium protective effect of hyaluronic acid].

In an experimental study the endothelia of porcine corneas were exposed to mechanical trauma under controlled conditions. Endothelial damage was caused by a polymethylmethacrylate (PMMA) plastic sphere shaped like the optical part of an intraocular implant. Two power settings were investigated. At the high power setting an average damage of 4.63 mm2 (+/- 1.33) was observed under saline, whereas application of hyaluronic acid 1% reduced the endothelial cell loss to 3.006 mm2 (+/- 0.87). At a low power setting the endothelial cell loss under saline was 2.18 mm2 (+/- 0.65); the average damage under hyaluronic acid was 0.55 mm3 (+/- 0.29). The results were statistically significant. The cell protective effect of a viscous substance against a mechanically shearing force was thus demonstrated in a biomechanical model.

Animals↗
PubMed1985

Technical aspects in ultra-large corneal grafts.

The larger the corneal graft, the more difficult is the excision of the button and especially suturing of the graft. The instruments and microsurgical unit are adapted to size and dimensions of animal surgery. The mathematical correlation between the diameter of the graft, the thickness of the cornea, and the length of the wound edges and suturing material can be calculated.

Animals↗
PubMed1985

Amniotic fluid glucose values in normal and abnormal pregnancies.

Glucose values were determined in 102 urine samples of newborn infants and in 2295 amniotic fluid (AF) samples of women between the 14th and 42nd week of pregnancy. One thousand, six hundred fifty-five of the AF samples derived from normal pregnancies, 50 from pregnancies with fetal malformations, 115 from cases of hydramnios, 246 from pregnant women with an abnormal oral glucose tolerance test, and 230 from insulin-dependent diabetics. Mean AF glucose concentration rises slightly between the 14th and 17th week of pregnancy, decreasing from 46 to about 16 mg% at the end of pregnancy. In cases of fetal malformations, 68% of the glucose levels was below the tenth percentile of normal values. Hydramnios showed no deviation from normal values. In patients with abnormal glucose tolerance, AF glucose increased by a total of 42% and by 67% in fetal hyperinsulinism. Insulin-dependent diabetics had glucose values elevated by a total of 77% and by 106% in fetal hyperinsulinism. The AF glucose profile reflects the level of maternal blood glucose that is transported to the fetus and excreted in the fetal urine as a major source of glucose in AF.

Amniotic Fluid↗
PubMed1984

[Prepartal diagnosis of fetal abnormalities from the viewpoint of the obstetrician].

Over a period of 51/2 years 685 amniocenteses were carried out for genetic and obstetric indications at the University Department of Obstetrics and Gynecology Graz. In 39 cases (5,7%) the procedure had to be repeated. Chromosome diagnosis was achieved in altogether 99% of cases. Chromosome aberrations or malformations were found in 25 patients (3,6%). 18 pregnancies (2,6%) ended with a miscarriage or missed abortion up to the 28th week of gestation following amniocentesis. Leakage of amniotic fluid following amniocentesis was recorded in eight women. Seven of these gave birth at term, while one woman had an abortion. No case of maternal injury, bleeding or infection was recorded. In conclusion, when the risk of giving birth to a malformed child is compared with possible complications following amniocentesis there can be no doubt that this procedure is definitely indicated.

Amniocentesis↗
PubMed1984

[Doppler sonogram in basilar artery thromboses].

We have investigated 6,380 patients with directional c-w Doppler sonography within the last 3 1/2 years, and have suspected obstruction of the basilar artery or of both distal vertebral arteries in 7 cases. Either bilateral sonographic silence or an absent diastolic flow component of the vertebral arteries were employed as criteria in the sonographic evaluation. Angiography of the vertebro-basilar system, performed in 6 cases, confirmed the diagnoses: basilar artery occlusion was found in 4 patients, 1 patient revealed tight stenosis of the basilar artery in its entire length, and 1 patient exhibited occlusion of both distal vertebral arteries. Three further basilar artery occlusions were detected by means of angiography despite initially negative Doppler sonography within the same period of time; 1 of those patients, however, met the above criteria for basilar artery occlusion upon sonographic reevaluation on the following day. Thus, we believe that directional c-w Doppler sonography is very useful in the diagnosis of basilar artery obstruction.

Adult↗
PubMed1984

[Possibilities and biological properties of variously applied methods of corneal preservation].

As the demand for donor corneas increases, not only fresh donor material but also increasing numbers of preserved corneas are being transplanted. The simple eye-banking procedures such as the moist chamber and the McCarey-Kaufman medium provide sufficient endothelial cell viability for short periods. The methods of organ culture of corneoscleral disks extend storage periods to up to four weeks. Cryopreservation as a method of long-term storage has not come to be widely used owing to the complicated procedure involved and the considerable damage thus caused to endothelial cells. Thus, the organ culture method may represent a compromise between extended storage periods and good endothelial cell viability.

Cornea↗
PubMed1984

Insulin levels in amniotic fluid of normal and abnormal pregnancies.

The normal level of insulin in amniotic fluid between the 13th and 42nd weeks of pregnancy was determined by means of 988 single analyses in individual healthy women. Insulin passes into the amniotic fluid via the fetal urine, and its level does not depend on fetal gender. Between the 13th and 25th weeks of gestation, the insulin level increases by an average of 1.3 to 5.1 microU/ml. From the 27th to the 42nd weeks, an increase of 6 to 9.1 microU/ml is observed. In the same period, the 97th percentile rises from 11.2 to 18 microU/ml. In 543 patients with pregnancy disorders, lower levels of insulin in amniotic fluid were observed in intrauterine fetal death, placental insufficiency, fetal growth retardation, and malformations. Elevated levels of insulin were observed in rhesus disease. In the treatment of pregnant women with betamimetics and glucocorticoids, the mean amniotic fluid insulin level rose to more than double the normal values.

Adrenergic beta-Agonists↗
PubMed1984

Gestational diabetes and screening during pregnancy.

The oral glucose tolerance test is an unreliable test in screening for diabetogenic fetal disease. In diabetogenic fetopathy due to gestational diabetes (White class A diabetes), the insulin content in the umbilical cord blood as well as in the fetal urine is considerably raised. As increased amounts of insulin pass into the amniotic fluid via the fetal urine, the fetal disease can be diagnosed from the amniotic fluid insulin content. In 75 pregnant women with potential diabetes, the blood sugar value was below 160 mg/dL at maximum under glucose loading in 28 patients; it was over 200 mg/dL in 25 patients. However, diabetogenic fetopathy was present in only 14 patients. The endangered and the healthy fetus could be distinguished in each case by amniotic fluid insulin content. The mean amniotic fluid insulin values in diabetogenic fetopathy were about seven times the normal.

Amniotic Fluid↗
PubMed1984

Fetal insulin balance: gestational diabetes and postpartal screening.

It must be determined whether high neonatal birth weight (greater than or equal to 4000 g) is due to genetic factors or to a disorder of maternal carbohydrate metabolism. Oral glucose tolerance tests are known to be unreliable during the puerperium. If the mother's carbohydrate metabolism was disturbed during pregnancy, neonatal overweight may result from fetal hyperinsulinism. This can be diagnosed by determining the insulin in the umbilical cord blood. Mature neonates of metabolically healthy women show an insulin level of 9.2 +/- 4.4 microU/ml (N = 180) in the umbilical cord blood. The third, tenth, 50th, 90th, and 97th percentiles were calculated as 1.4, 4.3, 8.8, 15.4, and 17.7 microU/ml, respectively. With insulin values over 20 microU/ml in the umbilical cord blood, a disturbance of maternal carbohydrate metabolism during pregnancy is likely. Among 4560 births in one year, 335 neonates weighed 4000 g and more, corresponding to a proportion of 7.35%. In one quarter of the infants over 4000 g, high birth weight was associated with fetal hyperinsulinism. This corresponds to a frequency of 1.8% of all births.

Birth Weight↗
PubMed1984

[Effect of low doses of lead and cadmium on glyoxalase I and glyoxalase II activities of the liver and brain of rats].

The effects of low doses of lead and cadmium on the activities of glyoxalase I and glyoxalase II in liver and brain of male Wistar rats were examined. Generations P, F1 and F2 received lead acetate and cadmium acetate in drinking water. The doses were as follows: group I-Pb 5 ppm, group II-Pb 50 ppm, group III-Cd 0,1 ppm, group IV-Cd 5 ppm. group V-Pb 5 ppm + Cd 0,1 ppm, group VI-Pb 50 ppm--Cd 5 ppm. The control group received sodium acetate with water. P population received Pb and Cd for 40 days before fertilization, and then the pregnant females were given the same doses until the end of pregnancy. Animals of F1 and F2 generation were killed after 30, 60 or 90 days. In liver and brain homogenates the activities of glyoxalase enzyme system were determined by the spectrophotometric method at 240 nm. A little inhibition of glyoxalase I was observed in rats that were given lead for 30 days, while in rats treated for 60 and 90 days the activities of glyoxalase I increased. Glyoxalase II was activated both by lead and cadmium in all groups. In vitro examinations demonstrated that lead and cadmium inhibited the activity of glyoxalase I and activated glyoxalase II.

Animals↗
PubMed1983

[Prenatal diagnosis of fetal malformations from the obstetrician's viewpoint].

Over a period of 5 1/2 years 685 amniocenteses were carried out for genetic and obstetric indications at the University Department of Obstetrics and Gynaecology Graz. In 39 cases (5.7%) the procedure had to be repeated because of amniocentesis failures, cell culture problems or borderline values for alphafetoprotein (AFP). Chromosome diagnosis was achieved in altogether 99% of cases. There were 14 twin pregnancies. Chromosome aberrations or malformations were found in 25 patients (3.6%). Therapeutic abortion was induced in 21 of these women and in each case the diagnosis was confirmed after termination. One woman had a spontaneous abortion before pathological findings were received and three women decided against therapeutic abortion. Balanced translocation was detected prenatally in 7 cases. 18 pregnancies (2.6%) ended with a miscarriage or missed abortion up to the 28th week of gestation following amniocentesis. This figure must be compared with 56 cases (7.5% of 741 women originally referred for amniocentesis) of miscarriage or missed abortion before amniocentesis could be carried out. Leakage of amniotic fluid following amniocentesis was recorded in 8 women; 7 of these gave birth at term, while one woman had an abortion. No case of maternal injury, bleeding or infection was recorded following amniocentesis. In conclusion, when the risk of giving birth to a malformed child is compared with possible complications following amniocentesis there can be no doubt that this procedure is definitely indicated.

Abnormalities, Multiple↗