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Biomedical subjects

W Rohde

Publications and source records attributed to W Rohde.

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

[Correlation between the morphological and functional parameters in hypophyseal adenomas of acromegalic patients].

A series of 50 human pituitary adenomas with acromegaly has been investigated morphologically and densitometrically by use of a system for automated microscope picture analysis (AMBA). Twenty nuclear and tissue features have been measured. The tumors were divided into eosinophilic, eosinophilic/chromophobe and chromophobe adenomas. We found no correlation between the analysed karyometric features and the blood hormone levels. But considering the results of the hematoxylin-eosin-staining, significant differences exist between the three histological subtypes. Eosinophilic adenomas show higher blood hormone levels than mixed and chromophobe tumors. Significant differences between the subtypes in some nuclear and tissue features allow a classification. Eosinophilic adenomas have bigger nuclei with higher extinction (that means higher DNA-content). The parameter EXTK (expected extinction at the borderline of the nuclei) was of great importance for the separation of mixed and chromophobe adenomas. The size of the adenomas had no influence on the blood hormone levels. Further studies are necessary to answer the question whether these results are a true expression of a different functional state.

Acromegaly↗
PubMed1983

The influence of adrenaline on plasma testosterone in adult and newborn male rats.

In adult male intact and adrenalectomized rats a significant decrease of plasma testosterone was found following five days of subcutaneous treatment with adrenaline. LH was significantly decreased in adrenalectomized, adrenaline treated males. Plasma testosterone was also found to be diminished in the male offspring of females treated with adrenaline during pregnancy. In view of these findings catecholamines may also play a role in the stress-induced drop of plasma testosterone in adult animals as well as in the production of androgen deficiency in male fetuses and newborns of stress-exposed pregnant females.

Adrenalectomy↗
PubMed1983

Effects of tamoxifen on the levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL), 17 beta-oestradiol (E2), total and free testosterone (T) and total and free dihydrotestosterone (DHT) in blood of patients with benign prostatic hyperplasia.

Treatment of 9 patients with benign prostatic hyperplasia with 20 mg tamoxifen daily for 6 weeks resulted in a significant increase of LH (211%), FSH (215%), E2 (231%), total T (157%), free T (148%) and total DHT (148%) levels in blood. The increase of plasma free DHT (152%) levels was not significant and PRL concentrations in serum were unchanged during treatment. Comparison of the increases between total T and free T, total T and total DHT as well as free T and free DHT failed to reveal any significant differences. These results imply (1) a marked anti-oestrogenic effect of tamoxifen at the level of hypothalamo-hypophysial axis (2) no effect at the hepatic oestrogen receptor sites indicated by unchanged SHBG-bound T and DHT in plasma and (3) no significant inhibitory effect of tamoxifen on 5 alpha-reductase activity concluded from the T/DHT ratio in peripheral circulation. In view of these findings tamoxifen appears to be unsuitable for therapy of benign prostatic hyperplasia.

Dihydrotestosterone↗
PubMed1983

Long-term effects of early postnatal nutrition on subsequently body weight gain, emotionally and learning behaviour in male rats.

Male rats have been reared as litters of 2 pups (group A) or 12 pups (group B) during the first 3 weeks of life. Males of group A exhibited higher body weights from day 10 to day 430, reached puberty at earlier age and showed lower emotionality as well as diminished learning capability and decreased memory capacity in adulthood as compared to males of group B. Furthermore, adult males of group A developed an increased ratio of insulin to glucose serum concentration at 90 minutes after glucose administration.

Animals↗
PubMed1983

On the LH response to oestrogen and LH-RH in transsexual men.

In male rats, androgen deficiency during a critical period of sexual brain differentiation was shown to give rise to a predominantly female-differentiated brain. Such animals displayed "homosexual behaviour", i.e., they were sexually attracted preferentially to partners of the same sex. In addition, they exhibited a sex-specific evocability of a positive oestrogen feedback effect. A positive oestrogen feedback effect on LH secretion was also induced in homosexual transsexual men, in contrast to hetero- or bisexual transsexual men. Thus in homosexual transsexual men, an intravenous injection of 20 mg Presomen (Premarin) produced a significant decrease of serum LH levels followed by a significant increase above the initial LH values. In hetero- or bisexual transsexual men, by contrast, intravenous oestrogen administration, while producing a significant decrease of serum LH levels, was not followed by an increase above the initial LH values. A positive oestrogen feedback effect on LH secretion was also found in homosexual non-transsexual men, in contrast to heterosexual men. These findings suggest that transsexual as well as non-transsexual homosexual men possess a predominantly female-differentiated brain which may be based, at least in part, on androgen deficiency during sexual differentiation of the central nervous system. Homosexual transsexual men also showed an increased LH and FSH response to LH-RH as compared to hetero- or bisexual transsexual men.

Adult↗
PubMed1983

Acute effects of maternal stress on fetal blood catecholamines and hypothalamic LH-RH content.

The acute effects of maternal stress (restraint for 20 to 140 min) on the plasma levels of epinephrine, norepinephrine and dopamine in pregnant rats and their fetuses as well as on the catecholamine content of fetal adrenals and the LH-RH content of fetal hypothalami, were investigated at day 22 of gestation. Despite of a relatively moderate increase of maternal plasma catecholamines a significant increase of norepinephrine (p less than 0.05) and dopamine (p less than 0.05) levels in plasma of the fetuses 30 min after starting maternal stress was observed. The fetal blood concentrations of catecholamines before and during maternal stress were significantly higher than those of the mothers (p less than 0.05 to p less than 0.001). A gradual decrease of the fetal adrenal content of epinephrine and norepinephrine was found, whereas an unchanged content of dopamine of fetal adrenals was registered during maternal restraining. The LH-RH content of fetal hypothalami rose significantly (p less than 0.005) 60 min after starting maternal stress and returned to initial values 140 min after starting restraining.

Adrenal Glands↗
PubMed1983

Increase of FSH secretion in immature female rats following lesioning of the medial amygdaloid nucleus.

Immature female rats were bilaterally lesioned or sham-lesioned in the anterior part of the medial amygdaloid nucleus (AMN) at 21 days of age, and the serum FSH and LH concentrations were estimated in groups of rats autopsied at daily intervals from day 21 through day 28. Whereas the LH concentration did not differ between lesioned females and the controls, a highly significant elevation of the circulating FSH level was recorded in the lesioned rats from day 22 till day 24. A further experiment demonstrated that similar lesions did not change the FSH and LH-inhibiting effect of estrogen in rats that were ovariectomized on day 22, daily injected with 0.05 microgram estradiol benzoate per 100 g b.w. on days 22 and 23, and sacrificed 24 hr after the last injection. The results suggest that the AMN exerts a restraining influence on the hypophyseal FSH secretion around 21 days of age, and that this inhibitory activity does not depend upon sensitization to the negative feed-back of estrogen.

Amygdala↗
PubMed1983

Influence of neonatally administered dehydroepiandrosterone on reproduction of rats.

Male and female rats were injected with dehydroepiandrosterone (DHEA) from day 2 after birth to day 12 on alternate days. The inhibition of the growth of testes, seminal vesicles, adrenal glands and pituitary was found immediately after cessation of treatment. When adult, the neonatally DHEA treated males showed diminished copulatory activity. In contrast, no impairment of sexual behaviour could be found in females. However, neonatal DHEA treatment resulted in a dose dependent impairment of cyclicity in the females, accompanied by sub- or infertility. These findings suggest that DHEA shows some dissociation between its organizing influence on gonadotropin secretion and sexual behaviour.

Animals↗
PubMed1983

[Automated morphometric and densitometric studies of pituitary adenomas].

A set of 131 pituitary adenomas has been investigated morphometrically and densitometrically by use of a system for automatical microscope picture analysis (AMPA). About 500 nuclei per adenoma have been scanned for estimating 20 nuclear and tissue parameters (5 and 10 min per adenoma). Endocrine inactive adenomas differ significantly by some parameters from active adenomas. The cell nuclei of inactive tumors are smaller, of more spherical and have higher extinction values on an average. The nuclei of adenomas from patients with Cushing's syndrome differ from the nuclei of prolactinomas and acromegalics because of their lower similarity to spheres. We found no correlation between the nuclear and tissue parameters analyzed in this study and the blood hormone levels.

Acromegaly↗
PubMed1982

Viroid RNA is accepted as a template for in vitro transcription by DNA-dependent DNA polymerase I and RNA polymerase from Escherichia coli.

The RNA genome of potato spindle tuber viroid (PSTV) is transcribed in vitro into complementary DNA and RNA by DNA-dependent DNA polymerase I and RNA polymerase, respectively, from Escherichia coli. In vitro synthesis of complementary RNA produces distinct transcripts larger than unit length thus reflecting the in vivo mechanism of viroid replication. The influence of varying experimental conditions on the transcription process is studied; actinomycin D is found to drastically reduce complementary RNA synthesis from the PSTV RNA template by RNA polymerase.

DNA Polymerase I↗
PubMed1982

In vitro transcription of viroid RNA into full-length copies by RNA-dependent RNA polymerase from healthy tomato leaf tissue.

RNA-dependent RNA polymerase from healthy tomato plant tissue accepts potato spindle tuber viroid (PSTV) RNA as a template for the in vitro synthesis of full-length RNA copies of the PSTV genome. Viroid transcription requires the presence of Mn2+ and /or Mg2+ ions and is not inhibited by concentrations of 10(-5) M alpha-amanitin. This is the first report of a well-defined product synthesized in vitro by an RNA-dependent RNA polymerase from healthy plants.

Amanitins↗
PubMed1982

Affinity chromatography of viroid RNAs.

The application of a structure- and GC-specific affinity adsorbent for the purification of viroid RNAs is described. Cross-linked bisacrylamide gels to which the intercalating dye phenyl neutral red is covalently attached [2] constitute a powerful tool for the rapid, quantitative, and selective isolation of viroid as well as viroid complementary RNAs from crude, plant polysaccharides containing nucleic acid fractions.

Aminoacridines↗
PubMed1982

Enzyme immunoassay of 17-hydroxyprogesterone in plasma, microfilter paper blood and saliva of newborns, children and patients with congenital adrenal hyperplasia.

An enzyme immunoassay for the measurement of 17-hydroxyprogesterone (OHP) is described. The antigens, OHP-3-CMO-BSA and 11-deoxycortisol-21-hemisuccinate-BSA have been used to produce antisera in rabbits. The enzyme marker was horseradish peroxidase. Bound/free separation was achieved by the double antibody/polyethylene glycol method. The method was used for plasma samples, capillary blood dried on paper disc and for saliva. The normal values for OHP in newborns and children were determined. This method makes possible a selected screening program for congenital adrenal hyperplasia in the newborns.

17-alpha-Hydroxyprogesterone↗
PubMed1982

Perisuprachiasmatic lesions enhance the increase of gonadotropin secretion in acutely ovariectomized rats.

Diestrous female rats were bilaterally lesioned in the perisuprachiasmatic region (peri-SCN region) or in the medial preoptic area (MPOA) and ovariectomized immediately after lesioning. Blood was collected at one hour before and at 4.24 and 48 h after surgery. Radioimmunological determination of the serum gonadotropin concentrations revealed that lesioning of the peri-SCN region enhanced significantly the castration-induced increase of FSH and LH secretion at 4 and 24 h, whereas MPOA lesions did not influence the serum hormone levels as compared to the sham-lesioned controls. The findings suggest that the peri-SCN region, but not the MPOA may be involved in the control of the increase of gonadotropin secretion following ovariectomy in rats.

Animals↗
PubMed1981

DNA-dependent RNA polymerase II of plant origin transcribes viroid RNA into full-length copies.

DNA-dependent RNA polymerase II purified from healthy plant tissue is capable of synthesizing linear (-)-viroid RNA copies of full length from (+)-viroid RNA templates in vitro. Together with the specific alpha-amanitin sensitivity of viroid replication observed in vivo, these findings suggest that viroids replicate by an entirely novel mechanism in which infecting viroid RNA molecules are copied by the host enzyme which is normally responsible for the synthesis of nuclear precursors to messenger RNA.

Amanitins↗