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Biomedical subjects

B Herzog

Publications and source records attributed to B Herzog.

At least 19 recordsLinked to original sources
PubMed1992

Is a testis located at the superficial inguinal pouch (Denis Browne pouch) comparable to a true cryptorchid testis?

In a clinical study 96 prepubertal boys with 100 testes located in the superficial inguinal pouch underwent routine orchiopexy. Of 65 patients 45 (69%) who had received hormonal treatment before the surgical procedure had a closed processus vaginalis compared with only 11 of 35 (31%) who had not (p less than 0.0002). A normal epididymis was also present significantly more often in those patients receiving hormonal treatment than in those who did not (p less than 0.039). While those testes located in the superficial inguinal pouch had significantly better histology and a greater number of germ cells than those located in a high inguinal or abdominal position (p less than 0.01), the number of germ cells per tubule was nonetheless lower than that seen in the normal controls (p less than 0.01). In conclusion, a testis located at the superficial inguinal pouch behaves as a true cryptorchid testis. Furthermore, hormonal treatment before surgery has a significant effect on epididymal development and closure of the processus vaginalis.

Adolescent↗
PubMed1992

Subureteral collagen injection for the endoscopic treatment of vesicoureteral reflux in children. Followup study of 97 treated ureters and histological analysis of collagen implants.

Endoscopic subureteral injection has become an established alternative means for treating vesicoureteral reflux in select children. However, which injection material to use remains a controversy. Polytetrafluoroethylene (Teflon) has been injected in more than a thousand patients with few complications, although experimental and clinical studies have demonstrated migration of the injected particles into distant organs, such as the lungs and the brain, as well as local and metastatic granuloma formation. Therefore, we introduced, following experimental studies in the mini-pig model, glutaraldehyde cross-linked, highly purified bovine collagen for injection. Between June 1988 and October 1991, 97 refluxing ureters in 66 children were treated by endoscopic subureteral collagen injection. In 58.8% of the ureters reflux was cured after 1 and in 77.3% after 2 injections. Considering improvement to grades I and II reflux without further treatment as success, the success rate increased to 68.0% after 1 and to 89.7% after 2 injections. Mean followup was 18.5 months (range 3 to 39 months). After 2 failed injections the patients either returned to antibiotic long-term prophylaxis or the reflux was operatively corrected. The operative procedure was never compromised by the preceding injection. A direct correlation between deficient length of the submucosal tunnel of the intravesical ureter and the iatrogenic malposition of the collagen deposits, and the failures could be demonstrated. Granuloma formation at the site of injection was not found. The results of the histological investigation of the collagen deposits removed at open ureteral reimplantation for failures are reported. It could be demonstrated that endogenous fibroblasts invade the bovine collagen implant and that these cells show active production of new human collagen, types I and III, replacing the implant.

Adolescent↗
PubMed1991

The morphometric histopathology of undescended testes and testes associated with incarcerated inguinal hernia: a comparative study.

The underlying injury to undescended testes may be hormonal, a transient perinatal form fruste of hypogonadotropic hypogonadism characterized by blunting of the surge in gonadotropins normally seen at age 60 to 90 days. Ischemia is the underlying injury to testes associated with incarcerated inguinal hernias. To determine if the histopathology of these 2 injuries is different histomorphometric analyses were performed on semithin microscopic sections of biopsies of 21 control testes, 17 undescended testes and 13 intrascrotal testes associated with incarcerated inguinal hernias. The infants in all groups were 30 to 120 days old. The results showed that, as in previous studies, undescended testes at this age are characterized by hypoplasia of Leydig cells, normal germ cell counts and defective maturation of gonocytes into adult dark spermatogonia. In contrast, testes associated with incarcerated inguinal hernias were characterized by hyperplasia of Leydig cells, reduced germ cell counts and normal maturation of gonocytes into adult dark spermatogonia. One might conclude that the underlying injury of undescended testes, presumably the blunted surge of gonadotropins, causes a primary hypoplasia and hypofunction of Leydig cells, which in turn causes a secondary defect in transformation of gonocytes into spermatogonia. In contrast, ischemia may primarily cause a tubular epithelial lesion leaving the hypothalamic-pituitary-gonadal axis intact and allowing normal transformation of gonocytes into spermatogonia. Reduced gonadotropins and ischemia appear to produce distinctly different primary and secondary pathophysiological effects on the testes.

Biopsy↗
PubMed1991

Kinetically controlled synthesis of dipeptides using ficin as biocatalyst.

The application of the sulfhydryl protease ficin as biocatalyst is proposed as a novel method for enzyme-catalyzed synthesis of dipeptides. The negligible peptidase but considerable esterase activity at alkaline pH facilitated the kinetically controlled formation of peptide bonds by coupling the ester substrates Z-Ala-OMe and Z-Gly-OMe with L-alanine, D-alanine, L-glutamine, D-glutamine and L-Cys(acetamidomethyl) respectively. The reaction is accomplished without the occurrence of secondary peptide hydrolysis. Under optimum reaction conditions (pH 9.2, high ratio nucleophile/carboxyl component, 4.8% ethanol, 40 degrees C), the peptide yields ranged from 5 to 91%, depending on the structure of the amino and/or carboxyl component. No racemization was observed in the enzymatic reaction. Application of short-chain peptides has been advocated recently in clinical nutrition. Ficin-catalyzed peptide synthesis might be an attractive biotechnological approach for the synthesis of suitable dipeptides in this respect.

Amino Acids↗
PubMed1990

Does hydrocele affect later fertility?

The purpose of this study was to investigate the prognosis for fertility in children with hydrocele. Our results show that hydrocele seems to be more of a symptom than an actual pathological entity. It occurs both with an open and a closed processus vaginalis. Bilateral hydrocele seems to be a rare occurrence, mostly affecting infants or children under 1 year of age. Hydrocele on its own seems to have no direct effect on later fertility. In the presence of certain associated pathological findings, however, the testes are significantly altered. Children with hydrocele and pathological findings are significantly older than hydrocele patients with no associated pathology. As a practical recommendation, hydrocele does not require immediate surgery. In the presence of hydrocele and certain associated pathology, however, surgery makes good sense.

Cryptorchidism↗
PubMed1990

Testicular tumours in infancy and childhood--a review of 10 germ cell tumours and 10 non germ cell tumours.

Between 1961 and 1989 twenty testicular tumours were treated at the Basel University Children's Hospital. Ten were non germ cell tumours (50%) and a further 10 (50%) were germ cell tumours. Of the germ cell tumours six were benign teratomas, two yolk sac tumours and a further two were teratocarcinomas. In the non germ cell group eight tumours originated from paratesticular structures, one of which was a malignant rhabdomyosarcoma. The remaining two neoplasms originated from the supporting testicular tissues. The clinical presentation, the protocol of treatment and the long-term outcome are discussed. We advocate local tumour excision in benign cases (proven by instant frozen section) if normal testicular tissue can be preserved. In malignant germ cell tumours primary orchiectomy and high spermatic cord ligation is the treatment of choice. Secondary chemotherapy and/or retroperitoneal lymph node dissection is only added if the tumour markers alpha-fetoprotein and beta-human chorionic gonadotropin remain present in high serum levels postoperatively. Rhabdomyosarcomas are treated by surgical excision, primary chemotherapy and radiotherapy. All of the five patients (25%) suffering from malignant testicular tumours survived. A long-term follow-up (mean 12 years) did not show any evidence of recurrent local or metastatic disease.

Adolescent↗
PubMed1989

Critical spacing between two essential cysteine residues in the interdomain linker of the Bradyrhizobium japonicum NifA protein.

A special sequence motif in the Bradyrhizobium japonicum NifA protein, consisting of two functionally essential cysteines separated by four other amino acids (Cys-aa4-Cys), has been proposed to be part of a potential metal-binding site [(1988) Nucleic Acids Res. 16, 2207-2224]. Using the techniques of oligonucleotide-directed mutagenesis, we report here that several of the four intervening amino acids can be replaced by others without loss of NifA function. The deletion of one amino acid to give a Cys-aa3-Cys motif renders the protein inactive whereas the creation of a Cys-aa5-Cys motif (one amino acid inserted) still leads to a partially active NifA protein.

Amino Acid Sequence↗
PubMed1989

Testicular and vascular changes in children and adults with varicocele.

We analyzed bilateral testicular biopsies of 188 infertile patients with idiopathic left varicocele. The left side had significant pathological tubular testicular changes compared to the right side, whereas in only 7 per cent of the patients tubular damage was more pronounced on the right side. The Leydig cell pathological score was identical in both testes in 95 per cent of the patients. However, the lower the Leydig cell pathological score the better the testicular histology, suggesting an association between Leydig cell score and testicular function. Of the 188 patients 11 boys and 8 adults were randomly selected, and they displayed clear endothelial proliferative lesions of the capillaries at the ultrastructural level. Proliferative endothelial lesions in the patients with varicocele preceded the testicular changes. This, together with the prevalence of tubular damage at the site of the varicocele and the reversibility of these changes postoperatively, emphasizes the deleterious effects of varicocele as a cause of infertility in these patients. Early surgery for boys in whom the first signs of testicular atrophy occur is highly recommended.

Adolescent↗
PubMed1989

[Y-ureterocutaneostomy in congenital hydroureter--causal therapy?].

Between 1975 and 1987 30 patients with congenital hydronephrosis and megaureter were treated by Y-cutaneostomy according to Sober. 28 are still under our control. 5 of them showed normalisation of urine drainage. No further operation except the closure of the stoma was necessary.

Female↗
PubMed1988

[The Lich-Grégoir extravesical antireflux-plasty].

Between 1974 and 1986 96 children underwent the Lich-Grégoir antireflux procedure, in 63 patients on both sides in one session. 17 patients had double ureter. In totally 153 controlled operations we found 4 persistent reflux (2.6%) and 1 stenosis (0.7%). The success ratio is, therefore, 96.7%.

Child↗
PubMed1988

[Cervical thymic cyst in childhood].

In three children (2, 4 and 10 years of age) a cervical thymic cyst was removed. We found multilocular cysts with xanthochromic luminal fluid covered with a fibrous capsule. Histological features are lymphatic follicles, partly atrophic, as well as regular thymic tissue with cortex, marrow and Hassall's corpuscles.

Child↗
PubMed1987

Development of cryptorchid testes.

Development of normal germ cells during childhood is a continuous process which ends at puberty. Cryptorchid gonads have severe impairment of their germ cell development which is more pronounced the higher the gonads are situated. However, all newborns with intra-abdominal testes had a normal number of germ cells. This strongly supports the theory that cryptorchidism is a disease and not a malformation. As a consequence, adequate and early treatment of cryptorchid boys should be undertaken in order to preserve good chances of fertility.

Biopsy↗
PubMed1987

Primary and secondary testicular atrophy.

1. (a) Primary and secondary testicular atrophy is caused by ischaemia, most frequently after intrauterine and prepuberal testicular torsion. (b) After standard orchiopexy, and especially after orchiopexy in high undescended testis, secondary testicular atrophy is frequent. (c) The histological condition of a cryptorchid testis does not predict atrophy. Immediate detorsion and/or prophylactic fixation as well as subtle technique in orchiopexy are essential. 2. Sympathetic orchiopathy of a unilateral atrophic testis was not proven in cryptorchidism and testicular torsion. There is considerable evidence of primary bilateral disease. 3. Testicular atrophy as an aetiological factor in the development of testicular tumor remains open to debate.

Atrophy↗
PubMed1987

Treatment of cryptorchidism with low doses of buserelin over a 6-months period.

In a collaborative study, 48 prepubertal boys with undescended testes ranging in age from 15 months to 11 years were treated with low-dose intranasal buserelin following an every-other-day programme for a period of 6 months. Urinary LH, FSH, and testosterone were not altered during the treatment period. Boys over 7 years of age experienced a slight but significant rise in testosterone at the end of treatment. Testicular descent was achieved in only 17% of boys. In the remainder, bilateral testicular biopsies were obtained during orchiopexy. Grouped analysis showed a significant increase in the number of germ cells per tubule in both unilateral and bilateral cryptorchid boys, suggesting that buserelin treatment of the testis in a cryptorchid position is capable of improving fertility potential. If time-matched controls are compared to treated boys of the same age, again a significant difference is observed indicating that buserelin treatment does increase the germ cell count.

Administration, Intranasal↗
PubMed1987

Screening for cryptorchid boys risking sterility and results of long-term buserelin treatment after successful orchiopexy.

This long-term prospective follow-up study showed that in cryptorchid patients a significant correlation exists between the number of germ cells at the time of orchiopexy (prepuberty) and the spermiogram, and thus a biopsy has a prognostic value. Fifty percent of our patients had a germ cell count of less than 0.1 per tubule and belong to the risk group for sterility. Successful surgery could not induce a significant increase of germ cells in the risk group, although it does prevent secondary testicular damage. Patients with cryptorchidism developed after birth have significantly better chances of fertility than those with primary cryptorchidism. The priming effect of testosterone in the first months of life is important for male fertility. In patients belonging to the risk group treated with buserelin, a significant age-dependent increase in germ cell count occurred.

Adult↗
PubMed1987

Long-term effect of luteinizing hormone-releasing hormone analogue (buserelin) on cryptorchid testes.

We studied 48 prepubertal boys with cryptorchidism between 1 year 3 months and 11 years old who were treated with buserelin every other day for 6 months. Urinary luteinizing and follicle-stimulating hormones, and testosterone remained unchanged during the entire treatment period. In boys older than 7 years a slight but significant increase in testosterone was noted in the first morning voided urine at the end of treatment. Testicular biopsies were obtained at orchiopexy in all patients in whom testicular descent was not complete (83 per cent). A significant increase in the number of germ cells was observed in patients with unilateral and those with bilateral cryptorchidism, indicating that 6 months of buserelin therapy improved the fertility status even when testes were in an undescended position during treatment.

Administration, Intranasal↗