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Biomedical subjects

F Friedrich

Publications and source records attributed to F Friedrich.

At least 55 records · Page 3Linked to original sources
PubMed1987

Effects of bradykinin on electrical properties of Madin-Darby canine kidney epithelioid cells.

In the present study we have investigated the influence of bradykinin on the potential difference across the cell membrane (PD) of Madin Darby Canine Kidney (MDCK)-cells. In the absence of bradykinin PD averages -52.6 +/- 0.9 mV (n = 52). Increasing extracellular potassium concentration from 5.4 to 10 and 20 mmol/l depolarizes the cell membrane by +5.2 +/- 0.3 mV (n = 8) and +14.9 +/- 1.0 mV (n = 9), respectively. The application of 0.1 mumol/l bradykinin leads to a transient hyperpolarization of the cell membrane to -70.3 +/- 0.6 mV (n = 30). During this transient hyperpolarization increasing extracellular potassium concentration from 5.4 to 10 and 20 mmol/l depolarizes the cell membrane by +10.4 +/- 0.7 mV (n = 10) and +29.2 +/- 0.8 mV (n = 8) respectively. Application of fragments of bradykinin (0.1 mumol/l) are without significant effect on the potential difference across the cell membrane. 1 mmol/l barium depolarizes the cell membrane by +15.8 +/- 1.2 mV (n = 9) and abolishes the effect of step increase of extracellular potassium concentration from 5.4 to 10 mmol/l. In the presence of barium, bradykinin leads to a transient hyperpolarization by -24.7 +/- 1.3 mV (n = 7). During this transient hyperpolarization, the cell membrane is sensitive to extracellular potassium concentration despite the continued presence of barium. In the nominal absence of extracellular calcium, bradykinin leads to a transient hyperpolarization, which can be elicited only once. The transient hyperpolarization is not affected by the presence of verapamil or indomethacin. In conclusion, bradykinin hyperpolarizes MDCK-cells by increasing the apparent potassium conductance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Electrical properties of Madin-Darby-canine-kidney cells. Effects of extracellular sodium and calcium.

In incompletely confluent Madin Darby canine kidney cells continuous measurements of the potential difference across the cell membrane (PD) were made with conventional microelectrodes during rapid changes of extracellular sodium and/or calcium concentration. During control conditions PD averages -50.6 +/- 0.7 mV. Reduction of extracellular sodium concentration from 131.8 to 17.8 mmol/l leads to a reversible hyperpolarization of the cell membrane to -65.3 +/- 1.1 mV. This hyperpolarization is not significantly reduced by omission of glucose or presence of amiloride (1 mmol/l) in the perfusates. Instead, 1 mmol/l amiloride depolarizes the cell membrane by +5.2 +/- 0.4 mV. 1 mmol/l barium depolarizes the cell membrane to -31.3 +/- 1.1 mV. Step increases of extracellular potassium concentration from 5.4 to 10 and 20 mmol/l depolarize the cell membrane by +5.5 +/- 0.5 mV and +16.5 +/- 1.8 mV respectively. In the presence of barium, the depolarizing effect of increasing extracellular potassium concentration and of amiloride is almost abolished. Reduction of extracellular sodium concentration in the presence of barium, however, leads to a transient hyperpolarization of the cell membrane. During this transient hyperpolarization, increasing extracellular potassium concentration depolarizes the cell membrane despite the continued presence of barium. Omission of extracellular calcium (EDTA) depolarizes the cell membrane by +36.7 +/- 3.2 mV. In the absence of extracellular calcium, the hyperpolarizing effect of reduced extracellular sodium concentration is markedly reduced (-4.5 +/- 1.2 mV). 2 mumol/l A23187 in the presence of extracellular calcium hyperpolarizes the cell membrane to -72.5 +/- 0.6 mV.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

[Determination of progesterone in serum. Clinical significance in early pregnancy].

The aim of the study was to define the limits of normal and subnormal function of the corpus luteum of pregnancy. Between the 5th and 10th week of gestation blood samples were taken from 149 women and progesterone was measured by RIA. 50 women with normal pregnancies had progesterone values ranged from 10-48 ng/ml (M: 21,9 ng/ml +/- 8,5 sd). 26 women with bleedings in early pregnancy (threatened abortion) had significantly lower progesterone values (M: 17,0 ng/ml +/- 8,3 sd, range: 5-38 ng/ml serum). All 26 pregnancies ended with a living child. The 74 women with complicated early pregnancy showed a wider range: 2-120 ng/ml serum (M: 20,7 ng/ml +/- 15,2 sd). All 74 women delivered a living child. Progesterone serum values below 10 ng/ml prior to 10 weeks of gestation indicate subnormal corpus luteum function. We therefore perform hormone treatment in patients with bleedings in early pregnancy only if subnormal progesterone values are found.

Abortion, Spontaneous↗
PubMed1983

[The betamethasone test in the diagnosis of placental insufficiency].

A trial to evaluate a functional test of the fetoplacental unit by measuring the extent of suppression of maternal estriol serum levels by glucocorticoids is described. 21 women between the 30th and 40th week of gestation received 4 mg betamethason intravenous injection at 8.30 a.m. Blood samples were collected immediately before betamethason application and at 1.00 p.m., 4.00 p.m., 8 p.m. o'clock and at 8.30 a.m. on the next day. Estriol (E3), cortisol, dehydroepiandrosterone sulfate (DHEA-S) and human placental lactogen (HPL) were determined from serum samples by radioimmunologic methods. Patients were divided into 3 groups: severe placental insufficiency (group I, n = 6) described by growth retardation of the fetus of more than 2 weeks, normal gestations (group II, n = 8) and slight growth retardation (group III, n = 7). After temporary suppression in groups II and III, E3, DHEA-S and cortisol levels showed a significant increase the day after betamethason. In group I an increase of these parameters was observed 2 to 5 days after betamethason. These results show that a low intravenous dosage of betamethason and collection of blood samples for E3 assays in intervals of 12 hours can be used as a functional test of the fetoplacental unit.

Betamethasone↗
PubMed1982

[Treatment of amenorrhea with a LH-RH-analogue as nasal spray].

29 amenorrhoic women were treated with the Buserelin nasal spray (HOE 766) developed by Hoechst A. G. in a dosis of 50 microgram daily during 2 weeks. 22 of the patients desired restoration of menstrual cycle, 7 women were wanting a child. As result of the treatment 16 women menstruated, 6 ovulated, 2 became pregnant. With Buserelin nasal spray menstruation was induced in 12 out of 16 women with amenorrhea WHO group II.

Adolescent↗
PubMed1982

[Estriol serum levels following betamethasone treatment for induction of fetal lung maturity (author's transl)].

23 pregnant women with 28 to 37 weeks of gestation, threatened by premature labor, received Betamethasone 8 mg at admission and 4 mg 24 hours later to prevent newborn-RDS. Four women experienced this treatment twice. Blood was sampled for determination of estriol before each administration of Bethametasone and 24 hours after. Group I, patients with no signs of placental insufficiency, showed a drop in estriol levels at the second sample, but these recovered at the third one. There was no recovery seen at the third sample with group III, representing patients with proven placental insufficiency. Patients demonstrating pathologic CTG or delivering babies with low Apgar scores (Group II) showed no consistent course with their estriol levels. The course of estriol after administration of Betamethasone may be used as a test to determine the quality of the feto placental unit.

Betamethasone↗
PubMed1981

[Functional and hormonal differences between group I and group II amenorrhoea (WHO classification) (author's transl)].

77 amenorrhoeic women were classified as responding positively or negatively to clomiphene. The results of iterative LRH tests and studying feed-back reactions to steroid administration showed that the two collectives strictly correspond to groups I and II of the WHO classification of amenorrhoea. The LH response to the LRH test was significantly higher in group II than in group I, while there was no difference between the two groups in the FSH response. Oestradiol 17 beta was significantly higher in group II than in group I, but both groups showed a significant increase in E2 three hours after the LRH test. The possible mechanisms of LH production and pool formation, as well as FSH regulatory factors are discussed. This paper demonstrates that clomiphene appears to be ideally suited as a test substance for the classification of amenorrhoea according to its degree of severity.

Adult↗
PubMed1980

[Urinary catecholamine excretion in women with a normal menstrual cycle (author's transl)].

The daily excretion of epinephrine and norepinephrine was analysed throughout one menstrual cycle in 8 normal women under every day circumstances. Blood levels of LH, FSH, prolactin, oestradiol, progesterone, testosterone and cortisol were determined by RIA every other day, or daily around the time of ovulation. No characteristic cyclic variations were found in epinephrine except for a peak in the premenstrual period, whilst norepinephrine was increased during menstruation and at about the time of ovulation in all women. The cortisol patterns showed no characteristic cyclic changes. Possible correlations are discussed between cyclic catecholamine changes and the well known psychological and emotional changes corresponding with the phases of the menstrual cycle.

Catecholamines↗
PubMed1980

[Visual field changes in normal pregnancy].

The hormonal regulation of normal pregnancy by the pituitary gland is summarized: during pregnancy the pituitary temporarily becomes enlarged and usually exerts pressure on the anterior angle of the chiasm from behind and below. The report then compares the results of quantitative kinetic perimetry obtained by one investigator using the same Goldmann perimeter with findings obtained at the same time at the 2nd Clinic for Obstetrics and Gynecology of Vienna University.

Adult↗
PubMed1980

[Process for producing fluorescein for injection purposes (author's transl)].

The authors report of a process for producing high-purity fluorescein for injection purposes which is characterized by the fact that synthesis-induced by-products are separated from the raw fluorescein, obtained by any process, by means of a clean-up chain consisting in step-by-step monoacetylation in an aqueous-alkaline solution, subsequent diacetylation in pyridine or a pyridine-glacial acetic acid mixture, saponification of the diacetyl product by sodium methoxide in methanol, and precipitation of the fluorescein with anhydrous formic acid.

Drug Contamination↗
PubMed1979

Partial long arm deletion of one X chromosome in a patient with secondary amenorrhea.

A partial long arm deletion of one X chromosome was observed in a patient with secondary amenorrhea and with no features of Turner's syndrome. It was shown that the deleted X chromosome was the inactivated one in all metaphases of the lymphocyte culture and of the tissue culture from gonadal biopsy. The patient was detected during a cytogenetic study of secondary amenorrhea of ovarian origin.

Adult↗