PubMed Health⌕ Search

Biomedical subjects

B Schenck

Publications and source records attributed to B Schenck.

At least 19 recordsLinked to original sources
PubMed1999

[Extra-intestinal manifestations and complications in chronic active ulcerative colitis in childhood and adolescence].

HISTORY AND CLINICAL FINDINGS: A 18-year-old girl suffered from chronic active ulcerative colitis for ten years with growth retardation, primary amenorrhoea and osteopenia, so that total colectomy had been discussed as a possible treatment option. However, clinical remission was reached using a medication with budesonide (9 mg), mesalazine (3 g) and azathioprine (100 mg) when a painful ulcer occurred at the right lower leg. INVESTIGATIONS: The clinical examination revealed an ulcer of 7 cm diameter with a red-bluish margin at the right lower leg. The typical clinical features led to the diagnosis of pyoderma gangrenosum. TREATMENT AND COURSE: High doses of orally administered prednisolone induced the healing of the pyoderma gangrenosum within 2 months. After another 2 months systemic steroids were discontinued. Further laboratory tests confirmed secondary adrenal and ovarian failure (negative CRH-GnRH-test). Change of drug therapy to hydrocortisone (25 mg) in combination with mesalazine (3 g) and azathioprine (100 mg) improved the clinical course. Hydrocortisone was gradually reduced until CRH-GnRH-response returned to normal. CONCLUSION: Drug therapy with azathioprine can be regarded as a treatment option in pediatric patients with chronic active inflammatory bowel disease. It can be concluded from this case report that faced with controversial therapeutic options in adolescent patients the decision mainly depends on the clinical experience of the physician than on the results of controlled clinical trials.

Adolescent↗
PubMed1980

Fine structure of the Sertoli cells of the rat testis in experimental unilateral cryptorchidism.

Mature rats were made unilaterally cryptorchid for 28 days. ABP concentrations of the abdominal epididymis were significantly reduced, indicating impaired secretory activity of the Sertoli cells. The FSH serum level was increased and testosterone levels both of the serum and of homogenates of the cryptorchid testis were slightly reduced. Sertoli cells of the cryptorchid testis showed signs of regression. Although Sertoli cell junctions were still impermeable to lanthanum, a reduction of membrane particles forming the Sertoli cell junctions was observed in freeze-fracture replicas. In thin sections it was seen that the plasma membrane-apposed cisternae of endoplasmic reticulum or the adjaacent microfilaments were partially lacking. No such changes were observed in the scrotal testis.

Animals↗
PubMed1980

Effects of cyproterone acetate on experimentally induced canine prostatic hyperplasia. A morphological and histochemical study.

The effect of 3 alpha-androstanediol (3 alpha-diol), 17 beta-estradiol (E2) and cyproterone acetate (CA) on prostates in castrated beagle dogs were investigated by histological and histochemical examinations. A significant increase of prostatic weight occurred after 6 months' treatment with 3 alpha-diol alone and in combination with E2. Histologically and histochemically, two different types of prostatic enlargement were observed: first, administration of 3 alpha-diol resulted in diffuse glandular hyperplasia with replacement of functional activity monitored by strongly positive reactions for acid phosphatase, aminopeptidase and zinc. Second, 3 alpha-diol plus E2 produced stratified squamous metaplasia with cystic lumina and loss of the typical morphological structure. These glands showed negative reactions for acid phosphatase, aminopeptidase and zinc. In both types of prostatic hyperplasia CA abolished epithelial or metaplastic proliferation and induced atrophy of glandular epithelium. In estrogenized dogs activation of the fibromuscular stroma was obvious. CA prevented prostatic hyperplasia by atrophying epithelial effects.

Acid Phosphatase↗
PubMed1979

Biochemical and histological studies on prostates in castrated dogs after treatment with androstanediol, oestradiol and cyproterone acetate.

The effect of cyproterone acetate (CA) on experimentally induced benign prostatic hyperplasia (BPH) in the castrated dog was investigated. BPH was induced by 6 months' treatment with 3 alpha-androstanediol (3 alpha-diol) alone and in combination with 17 beta-oestradiol (Oe2). RNA, DNA and zinc content of the glands were determined in addition to histological examination and measurement of the prostates. Two different types of prostatic enlargement were observed. First, 3 alpha-diol induced typical diffuse canine hyperplasia with replacement of functional activity. DNA, RNA and the zinc content of total glands were increased compared with intact controls. Second, 3 alpha-diol plus Oe2 produced on the one hand a more striking increase of prostatic weights, but on the other a loss of typical morphological structure and function. Histologically, transformation of simple glandular epithelium into stratified squamous metaplasia occurred in addition to stimulation of fibromuscular tissue. Biochemically, a relative decrease of DNA per mg tissue was measured with a fall in the RNA to DNA ratio and zinc to the values of castrates. Administration of CA resulted in an abolition of the 3 alpha-diol effect. Biochemical determinations and histological examinations revealed an effect similar to castration after treatment with 3 alpha-diol plus CA. After treatment with 3 alpha-diol plus Oe2 plus CA fibromuscular stimulation as an oestrogen effect predominated in addition to glandular atrophy and metaplastic changes, especially in prostatic ducts. Epithelial hyperplasia is an effect of 3 alpha-diol, whereas metaplastic proliferation only occurs in oestrogenized and androgenized dogs. In both types of prostatic enlargement CA prevents development of hyperplastic prostate.

Androstane-3,17-diol↗
PubMed1978

A study of the capacity for regeneration of rat and human Leydig cells.

The capacity of Leydig cells for regeneration was investigated in 12 patients with prostatic carcinoma, who underwent subcapsular orchidectomy, and in rats after testicular necrosis produced by cadmium chloride. In rats, reappearance of Leydig cells originating from the tunica albuginea could be demonstrated by histology. Testosterone concentrations increased parallel to regeneration of Leydig cells, while LH concentrations declined. In contrast to these findings, no rise of testosterone concentrations could be observed in patients up to 8 months after subcapsular orchidectomy. Human Leydig cells seem to have no capacity for regeneration, or endocrine function, despite the fact that some of these cells, which are present morphologically in the tunica albuginea or spermatic cord, remained.

Animals↗
PubMed1978

[Testosterone serum concentrations after subcapsular orchiectomy (author's transl)].

Twelve patients with prostatic carcinoma in stage C or D underwent subcapsular orchiectomy. Testosterone serum concentrations were measured by radioimmunoassay before and up to eight months following orchiectomy. After an initial decrease, testosterone concentrations remained between 0.42 ng and 0.67 ng/ml serum throughout the observation period. Stimulation with 5000 IU hCG/day for three days did not cause an increase in testosterone concentrations.

Aged↗
PubMed1977

Comparison of the biological effectiveness of injected testosterone propionate and testosterone released from silastic capsules.

The in vitro release and biological effectiveness of silicone rubber implants containing testosterone in orchidectomized male rats was investigated over a period of 20 weeks. A marked reduction in release in 0.9% saline solution could be observed in vitro relative to the incubation time in the medium. The reduction in release was greatest during the first few weeks of the experiment. Rat seminal vesicles and prostates, which were greatly stimulated at the start of the experiment, lost weight corresponding to the release rate in vitro. The implants containing testosterone used here were 4 to 26 times more effective than testosterone propionate injected s.c.

Animals↗
PubMed1976

The influence of pharmaceutical compounds on male fertility.

1. Steroid hormones can affect spermatogenesis and thereby fertility directly and/or indirectly. All antigonadotropically active steroids inhibit spermatogenesis via inhibition of gonadotropin secretion, mainly that of H. Androgens and steroids occurring in the biosynthetic chain of testosterone synthesis have a direct promoting effect on spermatogenesis if applied in high doses. It has not been possible as yet to make clinical use of this positive effect since it is obviously not possible to achieve the necessary intratesticular androgen concentrations. 2. As concerns the different androgens and the steroids in the androgen biosynthetic chain, and also all synthetic anabolics, there is no parallelism between the direct spermatogenic activity, the androgenic activity and the antigonadotropic activity. 3. Estrogens and synthetic gestagens do not inhibit spermatogenesis directly at the testicular level. All effects of estrogens can be abolished experimentally by adequate substitution with gonadotropins or androgens, or a combination of androgens and gonadotropins. 4. Only those antiandrogens inhibit spermatogenesis with additional antigonadotropic properties (e.g. cyproterone acetate). Pure antiandrogens, like flutamide or cyproterone, have a slight and transient influence on spermatogenesis at the most. If at all, they merely cause transient subfertility. 5. Beside steroids and several centrally active pharmaceutics (e.g. psychotropic drugs and several antihypertensive compounds), only siloxanes and methallibur seem to affect spermatogenesis via inhibition of gonadotropin secretion. Other antispermatogenic agents act by inhibition of mitosis (Colchicine, alkylating agents) or presumably via damage of the Sertoli cells. 6. Based on present knowledge, contraception in men could be principally managed by administration of a) androgens alone, b) gestagen/androgen combinations, c) estrogen/androgen combinations, d) certain antiandrogens. 7. The difficulties of contraception in men by steroid hormones or steroid hormone combinations have been pointed out. As regards the usefulness of antiandrogens for contraception, no definite conclusions can be drawn at the moment. All non-steroidal inhibitors of spermatogenesis which have been found up to the present are not suitable because of toxic effects.

Androgen Antagonists↗
PubMedDate not supplied

Some interrelationships between plasma levels of LH, FSH, oestradiol 17beta, androgens and semen analysis data in male infertility patients.

Serum LH, FSH and immunoreactive testosterone-like substances (TLS) have been measured by radioimmunoassay in 130 male infertility patients and oestradiol 17beta in 26 cases. A weak but significant negative correlation was found between FSH and sperm count (rs = -0.19, p less than 0.05) but not LH and sperm count. However, LH and FSH were strongly correlated in the azoospermic (rs = 0.71, p less than 0.01) and oligozoospermic (rs = 0.53, p less than 0.01) groups and levels of both gonadotrophins were significantly elevated in the azoospermic and oligozoospermic as compared to the normozoospermic group. The elevated LH levels in the oligozoo- and azoospermic groups could not be explained by reduced negative feedback of testosterone or oestradiol 17beta since firstly, TLS and oestradiol 17beta levels were similar in all three groups and, secondly, within-group correlations between LH and TLS were either non-significant or positive (azoospermic group r = 0.37, p = 0.06). It is suggested that spermatogenesis-related feedback factor(s) may inhibit LH as well as FSH secretion. No role for oestradiol 17beta as a selective inhibitor of FSH secretion seemed likely as oestradiol 17beta levels were similar in the three groups and were correlated (r = 0.51, p less than 0.01) to TLS levels i.e. to leydig cell rather than spermatogenic function. Seminal fructose was negatively correlated (r = -0.26, p less than 0.01) with sperm count but not significantly with plasma TLS. It would thus seem unlikely that the tendency for seminal fructose levels to increase as sperm count decreases is due to increased androgen production or that seminal fructose can be used as an index of a patient's androgenic status. Patients with varicoceles had hormone levels similar to other patients of similar sperm count. Both sperm morphology and motility were strongly correlated to log sperm count (r = 0.84 and 0.55 respectively) and semen volume was significantly greater in oligozoospermic than normozoospermic patients (p less than 0.01).

Androgens↗
PubMedDate not supplied

Formal genesis of giant cells in the germinal epithelium in the rat thioglucose model.

The formal genesis of polymorphnucleated giant cells in the testis has been studied in the rat thioglucose model. The giant cells derive mainly from clumped spermatids (greater than 90%) which have lost their contact to Sertoli cells. The process of spermatogenesis and spermiogenesis as well as the synchronisation of germ cell maturation apparently depend on intercellular bridges of the germ cell populations. Lightmicroscopic findings have shown that with the formation of polymorphnucleated giant cells these links are lost.

Animals↗