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Biomedical subjects

G Weiss

Publications and source records attributed to G Weiss.

At least 289 records · Page 16Linked to original sources
PubMed1988

Isoelectric focusing in immobilized pH gradients with carrier ampholytes added for high-resolution phenotyping of bovine beta-lactoglobulins: characterization of a new genetic variant.

The genetic variants of bovine beta-lactoglobulin (beta-lg) from the "Murnau-Werdenfelser" breed were analyzed in three different isoelectric focusing (IEF) systems. While carrier ampholyte IEF with a pH gradient of 0.2 pH/cm did not resolve the new variant W from the B variant and IEF in immobobilized pH gradients (IPG) with 0.1 pH/cm only partially resolved it, adequate separation was achieved with IPG-IEF in a pH 5.25-pH 5.7 gradient, in presence of 0.8 % w/v carrier ampholytes, both over a 10 and 17 cm separation distance. Apparent isoelectric points (pI's) and genetic frequencies (f) were as follows: beta-lg A, pI = 5.370, f = 0.364; beta-lg B, pI = 5.485, f = 0.480; beta-lg W, pI = 5.492, f = 0.076; and beta-lg D, pI = 5.610, f = 0.080. The small difference of delta pI = 0.007 between beta-lg B and beta-lg W respectively, seems to originate from a "silent" substitution of neutral amino acid residues as compared to the larger delta pI's of the other genetic variants of beta-lg, which result from substitution of charged amino acids.

Animals↗
PubMed1988

Synergistic effect of relaxin and progesterone on cyclic adenosine 3',5'-monophosphate levels in the rat uterus.

Cyclic adenosine 3',5'-monophosphate is known to modulate smooth muscle contractility. Because both relaxin and progesterone have been demonstrated to affect myometrial cyclic adenosine monophosphate activity, we questioned whether the previously observed synergism of these two hormones in inhibiting uterine contractility is mediated via cyclic adenosine monophosphate. Immature rats were treated with estradiol benzoate (n = 7) or a combination of estradiol benzoate and progesterone (n = 7). Uterine horns were isolated, each horn was divided into two segments, and these horn segments were incubated in Ringer-Locke solution, either alone (control) or with 3-isobutyl-1-methylxanthine (MIX) 0.5 mM, MIX 0.5 mM + relaxin 10 ng/ml, or MIX 0.5 mM + relaxin 50 ng/ml. When compared with uterine segments incubated in MIX alone, treatment with MIX + relaxin 50 ng/ml significantly increased cyclic adenosine monophosphate levels in animals treated with estradiol benzoate alone or in combination with progesterone. Relaxin 10 ng/ml was sufficient to significantly elevate mean (+/- SEM) uterine cyclic adenosine monophosphate levels above that of control MIX-treated uteri in animals receiving both estradiol benzoate and progesterone (2.49 +/- 0.39 pm/micrograms deoxyribonucleic acid [DNA] versus 1.08 +/- 0.16 pm/microgram DNA, p less than 0.05) but not in animals receiving estradiol benzoate alone (2.08 +/- 0.32 pm/micrograms DNA versus 1.28 +/- 0.16 pm/micrograms DNA, NS). Compared with treatment with MIX only, MIX + relaxin 10 ng/ml and MIX + relaxin 50 ng/ml produced greater increases in uterine cyclic adenosine monophosphate in the steroid combination group than in the estradiol benzoate controls (144.8% and 233.7% versus 71.7% and 156.6%, respectively). These results suggest that the synergism of relaxin and progesterone in inhibiting uterine contractility may be mediated by intracellular cyclic adenosine monophosphate.

1-Methyl-3-isobutylxanthine↗
PubMed1988

The effect of thyrotropin-releasing hormone stimulation on serum levels of gonadotropins in women during the follicular and luteal phases of the menstrual cycle.

Thyrotropin-releasing hormone (TRH) can stimulate the secretion of adenohypophyseal thyroid-stimulating hormone and prolactin (PRL). The effect of TRH on gonadotropin secretion has not been well defined. This study investigated the effect of TRH administration on the peripheral levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) during the early follicular and midluteal phases of the menstrual cycle in five ovulatory, euthyroid, and normoprolactinemic women. Two hundred micrograms of TRH were administered intravenously on days 3 to 5 and on days 21 to 23 of the same cycle. LH and FSH were measured prior to and every 30 minutes for 2 hours following TRH injection. Ovulation was confirmed in all cycles by midluteal progesterone. All women had normal thyroid-stimulating hormone (TSH) and PRL responses to TRH stimulation in both cycle phases. Baseline and stimulated gonadotropin levels were analyzed by analysis of variance. Thirty minutes following TRH infusion, follicular and luteal levels of LH (mIU/ml, mean +/- standard error of the mean) significantly increased from 6.0 +/- 0.8 to 8.0 +/- 1.1 (P less than 0.005), and from 4.8 +/- 0.6 to 7.6 +/- 0.7 (P less than 0.005), respectively. Levels of FSH increased during both phases of the cycle, but the elevation was not statistically significant. These results suggest that TRH can stimulate gonadotrope secretion of LH, but not of FSH, in both the follicular and luteal phases of the cycle.

Adult↗
PubMed1988

Varicella pneumonia during pregnancy. Treatment of two cases with acyclovir.

Pneumonia is a rare but serious complication of varicella during pregnancy. Maternal mortality has been reported to be 41% with fetal and neonatal mortality at 65%. Treatment has included respiratory support and prophylactic antibiotics. Acyclovir has been prescribed with the intent to decrease the impact of the infection. It was added to the treatment protocol of two cases of varicella pneumonia in pregnancy. Despite the high maternal and perinatal mortality both pairs of patients and infants survived. Acyclovir did not appear to adversely influence the fetus, and may have contributed to the survival of mother and child.

Acyclovir↗
PubMed1988

Two subgroups of hyperactives as adults: correlations of outcome.

This prospective study explored the association of continuing symptoms of the hyperactive syndrome with adult outcome. A fifteen year follow-up compared 61 hyperactive subjects and 41 matched controls. Outcome measures examined included continuing symptoms of the hyperactive syndrome, antisocial behaviour, substance use, and emotional difficulties. Two subgroups of the hyperactive population were identified. Those hyperactive subjects with moderate or severe continuing symptoms were characterized by significant emotional difficulties, alcohol use, and antisocial behaviour. By contrast, hyperactive subjects with none or only mild continuing symptoms at follow-up did not have other difficulties in psychosocial functioning, and were, in addition, similar to the control group in many respects. The importance of continuing symptoms in determining the adult outcome of children with a diagnosis of ADDH is discussed. Accordingly, the need for comprehensive early, and ongoing interventions is emphasized.

Adult↗
PubMed1988

[Measurement of the fibrous dusts in West Germany. Fiber concentration in the vicinity of objects and buildings with asbestos-containing building materials].

Ambient air concentrations of fibrous dusts were measured in the vicinity of buildings with weathered and corroded asbestos-cement (AC)-products during 1983-1985. The concentrations of the total dust (TSP) were higher (mean value of 150 micrograms/m3) than the background concentrations. The mean value of ambient air asbestos concentrations lay at 750 fibers/3 for long asbestos fibers (longer than 5 microns). The maximum values were in the range of 10(3) fibers/m3. About 37% of the measured asbestos fiber concentrations (long fibers) were in the range above 500 fibers/m3; 12% of all long asbestos fiber concentrations were higher than 1000 fibers/m3. In the case of a proposed preventive concentration limit of 400 long asbestos fibers/m3, the asbestos fibers released from the corroded surfaces of AC-products on buildings, mean additional health risk not only for the house residents but in some cases also for the general population.

Air Pollution↗
PubMed1988

Peripheral relaxin levels during pregnancy in a woman with homozygous familial hypobetalipoproteinemia.

A case of a normal pregnancy conceived spontaneously in a 22-year-old woman with hypobetalipoproteinemia evidenced peripheral levels of relaxin in the range of uncomplicated singleton pregnancies in conjunction with low peripheral levels of progesterone. The establishment and maintenance of uterine quiescence in this hypoprogestational pregnancy may be attributable to these "normal" relaxin concentrations or to local uterine factors, including decidual relaxin production, which would not be reflected in circulating relaxin levels.

Adult↗
PubMed1987

Nail-bed melanoma.

In our series of 348 patients treated over a 10-year period, six (1.7%) had their primary lesions in the nail bed. Five of the subungual melanomas occurred in the toes and one in the thumb. Four of the lesions were of the acral lentiginous type. The delay in diagnosis was 7 months to 6 years. Four of the patients presented with advanced, neglected tumors. One had distant metastases at diagnosis. The treatment was mainly surgical. Digital amputation was carried out for local control. Five patients underwent lymph node dissection and in three of them regional metastases were found. Of the four patients with regional and distant metastases at the time of diagnosis, three died within 6 to 60 months and the fourth is alive with metastatic spread. Of the two patients with melanoma confined to the nail bed, one is free of disease 50 months following diagnosis and the other suffered from a local recurrence and has been free of disease for 30 months following wide excision and limb perfusion.

Aged↗
PubMed1987

Antibodies not directed against the acetylcholine receptor in myasthenia gravis. An immunoblot study.

Sera of 45 patients with myasthenia gravis (MG) and of 30 healthy controls were screened for antibodies against muscle antigens in an immunoblotting solid-phase assay using a preparation of human amputated muscle as the substrate. In each group, the sera showed several bands on the blots. The findings are thought to indicate that antibodies against muscle components are normally present in human sera. Sera from patients or controls could be distinguished by differences in the band staining patterns. It is suggested that antibodies which are not directed against the acetylcholine receptor may nonetheless play an important role in the pathogenesis and clinical course of myasthenia gravis.

Adult↗
PubMed1987

Free alpha-subunit response to gonadotropin-releasing hormone in women with polycystic ovaries.

The response of glycoprotein hormone free alpha-subunit to gonadotropin-releasing hormone (GnRH) was evaluated in 12 women with polycystic ovaries (PCOs). Six of these women were premedicated for 3 days with micronized 17 beta-estradiol before receiving a 100-micrograms bolus of GnRH. In nonmedicated PCO patients, GnRH did not significantly alter basal free alpha-subunit levels. In four of the six PCO patients receiving estrogen premedication, a significant increase in free alpha-subunit was observed; these four patients had low progesterone levels at the time of the GnRH test. Among the six premedicated patients, two had elevated (greater than 4 ng/ml) progesterone levels, and the GnRH tests showed no significant effect on the levels of free alpha-subunit. The study revealed a dissociation between the free alpha-subunit responses to GnRH and the responses of luteinizing hormone; a closer relationship was observed between free alpha-subunit and follicle-stimulating hormone responses. It was concluded that the lack of a free alpha-subunit response to GnRH in PCO patients is not due to a primary inability of the pituitary gonadotroph to produce free alpha-subunit but is a consequence of an altered estrogenic milieu, and a free alpha-subunit response to GnRH may reflect the replenishment of both follicle-stimulating hormone and luteinizing hormone in the gonadotrope.

Adult↗
PubMed1987

Human semen relaxin and its correlation with the parameters of semen analysis.

The relaxin content of 92 normal semen samples and 85 semen samples selected at random was correlated to the parameters measured on routine semen analysis in those samples. The concentration of immunoactive relaxin in a sample of semen plasma did not correlate with any of the parameters commonly used for semen analysis: count, percent motility, grade of forward progression, volume, and morphology.

Humans↗
PubMed1986

Progesterone and relaxin secretion in relation to the ultrastructure of human luteal cells in culture: effects of human chorionic gonadotropin.

This report describes the first study to correlate the ultrastructure of long-term monolayer cultures of human luteal cells with their secretion of relaxin and progesterone under basal and human chorionic gonadotropin-stimulated conditions. In culture from 14 to 28 days, cells from both corpora lutea of the menstrual cycle and corpora lutea of pregnancy took on characteristics of granulosa luteal cells, particularly after exposure to human chorionic gonadotropin. Relaxin was detectable in the luteal cell cultures only at early time points. The effect of human chorionic gonadotropin on media relaxin levels differed in cells of the cycle and cells of pregnancy. In the cells of the cycle, relaxin was detectable only on day 2 and was decreased by human chorionic gonadotropin (p less than 0.01). In cells of pregnancy, relaxin was detectable for the first 4 days of culture and was not affected by human chorionic gonadotropin. Progesterone was detectable in all the luteal cell cultures and was enhanced by human chorionic gonadotropin (10 and 50 IU/ml) after 24 days of exposure. At earlier time points in both the luteal cells of the cycle and the luteal cells of pregnancy, the human chorionic gonadotropin-induced increases in progesterone levels were not as consistent. However, in all cases of progesterone enhancement, smooth-surfaced endoplasmic reticulum was increased in the human chorionic gonadotropin-treated cells compared with corresponding controls, consistent with more active steroid production. In addition, gap junctions, considered to be responsive to trophic hormones, were increased in the treated cells. In conclusion, this long-term monolayer culture of human luteal cells, as monitored by ultrastructural and hormonal changes, retained the differentiated function of progesterone secretion and exhibited responsiveness to human chorionic gonadotropin. Therefore, morphologic and functional aspects of progesterone secretion may be investigated more closely with use of this long-term luteal cell culture system.

Cells, Cultured↗
PubMed1986

Partial purification of relaxin from human seminal plasma.

Human seminal plasma contains approximately 50 ng/ml of relaxin (specific activity = 1.3 ng/mg protein). During preliminary purification, semen plasma was delipidated, rehydrated, and loaded onto small octadecyl silica columns that were eluted with a TEAF/acetonitrile gradient system. Results were monitored by radioimmunoassay. The resultant partially purified human relaxin demonstrated biologic activity in the rat uterine segment bioassay. Nine liters of semen plasma was delipidated, rehydrated in TEAF, and subjected to high-performance liquid chromatography by a step gradient followed by a linear gradient. The active eluate was further purified by ion exchange chromatography. Pooled recovery fractions provided a total of 45.8 micrograms of relaxin. An aliquot flash evaporated and desalted by gel filtration chromatography provided 1.85 micrograms of relaxin in 25.2 mg protein, specific activity 73.4. This material is being used as immunogen in the production of antihuman relaxin antibodies by monoclonal technique. Our procedure represents the first and only successful partial purification of human relaxin to yield sufficient quantity and purity for antibody production.

Animals↗
PubMed1986

Controlled prospective fifteen year follow-up of hyperactives as adults: non-medical drug and alcohol use and anti-social behaviour.

This is a fifteen year prospective controlled study of the non-medical drug and alcohol use and antisocial behaviour of 61 hyperactives, and 41 matched control subjects, (mean age 25 years). The data was collected from detailed interviews with the subjects as well as computerized court records to verify subjects reports. Generally hyperactives did not differ significantly from controls on current drug and alcohol use and antisocial behaviour. However one sees trends of greater drug alcohol and antisocial involvement in the hyperactive group. All the subjects who have antisocial behaviour at 15 year follow-up (mean age 25) had early and persistent histories of antisocial behaviour beginning at initial assessment (mean age 8) or at 5 year follow-up (mean age 13). However many hyperactives do not continue their antisocial behaviour into adulthood (mean age 25). There thus appears to be a small subgroup of hyperactive subjects who have more negative outcomes with significantly greater social, emotional and psychological difficulties. It is this subgroup which we need to identify early and treat vigorously.

Adolescent↗
PubMed1986

The effect of relaxin and prostaglandin E2 on the motility of human spermatozoa.

Relaxin and prostaglandin E2 (PGE2) are present in human semen and have been shown to affect sperm motility. The authors further examined the effects of porcine relaxin and PGE2 on the motility of human spermatozoa. A dose-response study revealed that PGE2 at a concentration of 25 micrograms/ml is most effective in improving the motility of washed human sperm. Relaxin (100 ng/ml), PGE2 (25 micrograms/ml), or the two combined have no effect on the motility of spermatozoa in fresh, normal semen, suggesting that the constituents of fresh semen are optimal for motility. Relaxin and PGE2 individually improve the motility of washed spermatozoa. However, relaxin, but not PGE2, improves the motility of sperm in semen incubated at 37 degrees C for 5 hours (aged). In contrast to the individual substances, a combination of relaxin + PGE2 has no effect on the motility of washed spermatozoa or aged spermatozoa, suggesting that these two substances antagonize each other's actions on sperm motility. The presence of both relaxin and PGE2 in seminal plasma with normal motility spermatozoa suggests that other factors in seminal plasma regulate the effects of these substances on sperm motility.

Animals↗