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Biomedical subjects

J M Hutson

Publications and source records attributed to J M Hutson.

At least 109 records · Page 6Linked to original sources
PubMed1996

Retrograde balloon dilatation for primary pelvi-ureteric junction stenosis in children.

OBJECTIVE: To evaluate the efficacy of retrograde balloon dilatation for primary pelvi-ureteric junction (PUJ) stenosis (RBDP) in children. PATIENTS AND METHODS: Sixteen children (12 boys, four girls; mean age 29 months) with primary PUJ stenosis initially underwent RBDP. A double-pigtail catheter was left in the ureter for 6 weeks to provide drainage. The initial diagnosis of PUJ stenosis and the subsequent post-operative assessment were both made by diuretic renography in almost all patients. All children were followed up for between 9 and 38 months (mean 25) after the procedure. RESULTS: RBDP was unsuccessful in nine of 17 renal units. In three of these, failure was caused by inability to pass the catheter through the PUJ or vesico-ureteric junction (VUJ). In six cases, failure was caused by recurrent or persistent stenosis. In eight of 17 renal units, RBDP was successful in relieving the stenosis. The morbidity from the procedure was minimal. CONCLUSIONS: Long-term follow-up revealed a significant failure rate for RBDP, caused by the inability to pass the catheter through the VUJ or PUJ, or persistent and/or recurrent stenosis. Recurrent stenosis may result from excessive dilatation which traumatizes the PUJ and causes subsequent scarring. Failure to overcome the stenosis is thought to be caused by a large redundant renal pelvis, producing 'kinking' of the upper ureter. In these cases, only reduction pyeloplasty may be successful in relieving the obstruction.

Catheterization↗
PubMed1996

Scanning electron microscopy shows inhibited gubernacular development in relation to undescended testes in oestrogen-treated mice.

The morphological relationship between transabdominal testicular descent and the 'swelling reaction' of the gubernaculum was investigated in oestrogen-treated fetal mice by using scanning electron microscopy (scanning EM). In addition, flutamide was also administered to pregnant mice to determine whether androgens cause gubernacular growth and transabdominal testicular descent in offspring. In oestrogen-treated fetal mice, scanning EM showed that both the gubernacular 'swelling reaction' and transabdominal testicular descent were inhibited, in addition to inhibition of Müllerian duct regression. The gubernaculum showed a flat, thin bulb (widest diameter 0.25 +/- 0.04 mm) and an elongated cord (1.28 +/- 0.41 mm) after oestrogen treatment in utero, which was significantly different in appearance from that in normal control mice (width 0.44 mm +/- 0.06 mm, p < 0.001; length 0.27 +/- 0.19 mm, p < 0.0001). However, flutamide-treated mice showed much more normal gubernacular enlargement and transabdominal testicular descent. The width of the gubernacular bulb after flutamide exposure was 0.44 +/- 0.05 mm, which was comparable to that in control animals; the length of the intra-abdominal gubernaculum (0.44 +/- 0.15 mm) was slightly longer than in controls (p < 0.02). These results suggest that both the swelling reaction of the gubernaculum and transabdominal testicular migration are blocked by prenatal exposure to oestrogen. However, oestrogen exposure of the fetus does not block the swelling reaction of the gubernaculum by acting as an antiandrogen.

Androgen Antagonists↗
PubMed1996

Primary omental torsion in children.

OBJECTIVE: A retrospective review was conducted to establish the prevalence and clinical features of omental torsion or infarction as a cause of acute abdominal pain in childhood. METHODOLOGY: The case records were analysed for all patients admitted with primary omental pathology to the Department of General Surgery, Royal Children's Hospital, Melbourne, between January 1975 and July 1994. RESULTS: From 1975 to 1994 (20 years) 13 children were admitted to our General Surgical Department with primary omental disease. There were nine males and four females under 16 years of age. The presenting complaint was abdominal pain with vomiting or diarrhoea. Four children had major medical conditions. Pre-operative diagnosis in all cases was acute appendicitis. Appendicectomy and omentectomy were performed without complication in all cases. Histology of the omentum demonstrated torsion, infarction or haemorrhage. CONCLUSIONS: All children presented with features of acute appendicitis, a majority were male, and two out of the 13 patients were obese. The absence of any children under 4 years was consistent with the relative paucity of omental fat in younger children. We found no clear mechanism for primary omental torsion, although rotation around the right epiploic artery was observed.

Adolescent↗
PubMed1996

The genitofemoral nerve may link testicular inguinoscrotal descent with congenital inguinal hernia.

The genitofemoral nerve (GFN) hypothesis for inguinoscrotal testicular descent proposes that calcitonin gene-related peptide (CGRP), released from the genitofemoral nerve, controls the migration of the gubernaculum from the inguinal region to the scrotum between 26 and 40 weeks of gestation. The processus vaginalis provides a channel through which the testis descends from the abdomen to the scrotum. Following descent of the testis the processus vaginalis undergoes luminal obliteration and disappearance between the internal inguinal ring and the upper pole of the testis. The mechanism underlying closure of the processus is unknown and failure for it to occur normally results in congenital inguinal hernia, scrotal hydrocele and possibly even an 'ascending' testis. Recent work in our laboratory suggests that CGRP, released from the genitofemoral nerve, may cause fusion and disappearance of the processus vaginalis. We propose that abnormalities in the GFN link a spectrum of disorders encompassing congenital undescended testis, inguinal hernia, scrotal hydrocele and ascending testis.

Abdomen↗
PubMed1996

Primary peritonitis in children.

BACKGROUND: Primary peritonitis is a rare cause of the acute abdomen in children. It is often found at laparotomy for suspected appendicitis, or diagnosed by paracentesis in a child with an associated medical disorder. METHODS: Our experience over the past 5 ++years with this condition at the Royal Children's Hospital is reviewed and compared with a larger series previously published from the same institution 25 years ago. RESULTS: There were 26 cases from 1989 to 1994; 22 (85%) were female and 6 (23%) of the patients had a major underlying medical disorder. CONCLUSIONS: The incidence of primary peritonitis has remained unchanged at this institution since 1970 (4.7 cases per year), but neonatal primary peritonitis is no longer seen. Primary peritonitis is more common in females in whom there is no clear aetiology, but is presumed to be related to the retrograde passage of organisms through the genital tract. By contrast, in males primary peritonitis is rare but may be related to underlying medical conditions such as alpha-1-antitrypsin deficiency and renal disease.

Abdomen, Acute↗
PubMed1996

Does testosterone diffuse down the wolffian duct during sexual differentiation?

PURPOSE: Sexual differentiation in gonadal dysgenesis is commonly asymmetrical. In patients with true hermaphroditism there may be an ovary and müllerian duct on 1 side, and a testis and wolffian duct on the other side. Such asymmetry suggests that testicular hormones only act locally at this early stage of sexual differentiation. We tested the hypothesis that testosterone reaches the wolffian duct by transport down the duct rather than by simple diffusion. MATERIALS AND METHODS: Mouse 14-day urogenital ridges were placed in organ culture and microinjected with testosterone-albumin-fluorescein isothiocyanate. RESULTS: At 17 hours fluorescence was found throughout the wolffian duct and by 48 hours it was maximal in the dilated caudal end. CONCLUSIONS: Our results support the hypothesis that androgens may be transported along the wolffian duct. Secretion of testicular hormones into the wolffian duct may maintain hormone levels in the biologically active range.

Animals↗
PubMed1996

Factors affecting the development of the processus vaginalis in the rat.

PURPOSE: We examined the factors that influence development of the processus vaginalis in the rat. MATERIALS AND METHODS: Neonatal Sprague-Dawley rats 0 to 3 days old underwent distal or proximal gubernaculotomy, unilateral orchiectomy or proximal genitofemoral nerve transection. At ages 28 to 60 days the rats were sacrificed, position of the testis was noted and length of the processus vaginalis was measured. RESULTS: There was no development of the processus vaginalis after distal gubernaculotomy. Proximal gubernaculotomy enabled the processus vaginalis to achieve a mean length similar to that of controls (p = 0.06) when the testis descended into the scrotum. Mean length of the processus after proximal gubernaculotomy with an abdominal testis, surgical orchiectomy and torsion of the testis after proximal gubernaculotomy was similar (p = 0.9) but less than that of controls (p < 0.05). Proximal division of the genitofemoral nerve produced variable results depending on how and when the surgical procedure was performed, and whether the psoas muscle was divided. CONCLUSIONS: Distal attachment of the gubernaculum is essential for normal development of the processus vaginalis. Distal gubernaculotomy prevents development of the processus vaginalis because of mechanical disruption of the gubernaculum. Proximal attachment is not essential for normal development of the processus vaginalis but it serves to anchor the testis to the region of the internal inguinal ring, allowing intra-abdominal pressure to facilitate descent of the testis. In the presence of an innervated gubernaculum the processus vaginalis achieves greater length when the testis descends into the scrotum, suggesting that its complete development demands the presence of a testis in the sac. The timing of genitofemoral nerve division may be crucial in determining the subsequent effect on the development of the processus vaginalis and testicular descent, since programming of the gubernaculum by calcitonin gene-related peptide released from the genitofemoral nerve appears to occur just before birth in the rat.

Animals↗
PubMed1996

Prune-belly syndrome: ongoing controversies regarding pathogenesis and management.

Classical prune-belly syndrome (also known as Triad syndrome, Eagle-Barrett syndrome, abdominal muscular deficiency syndrome) consists of a triad of anomalies: deficient abdominal wall musculature, urinary tract dilatation, and cryptorchidism. Although most investigators consider prune-belly syndrome a distinct entity, there is no consensus as to its pathogenesis despite extensive study of clinical cases and pathological material. Prognosis may vary from death in utero to a near-normal life expectancy. The lack of understanding of pathogenesis and wide range of severity result in dilemmas in treatment planning, and surgeons vary widely in their approach. This article discusses prune-belly syndrome, presents the currently favored hypotheses regarding its pathogenesis, and gives an overview of accepted management strategies.

Abdominal Muscles↗
PubMed1995

Physiological effects in vitro of calcitonin gene-related peptide on gubernacular contractility with or without denervation.

The gubernaculum in neonatal rats has been shown previously by direct observation to contract rhythmically in response to exogenous calcitonin gene-related peptide (CGRP), but the physiological properties of these contractions were unknown. In the first study the authors investigated gubernacular contractility in vitro using a strain gauge to see if there were characteristics of skeletal or smooth muscle. Both the frequency and the amplitude of contractions were significantly enhanced by CGRP, and isotonic tension of the gubernaculum and the duration of contractions were also increased after CGRP. The effect of CGRP on gubernacular contractions appeared several minutes after adding CGRP, and it was independent of the acetylcholine action, which induced only a single twitch response of the gubernaculum. In the second study the authors investigated the effect on gubernacular contractility of prior transection of the genitofemoral nerve (GFN), which contains CGRP. Vigorous contractions occurred in 85% of denervated gubernacular compared with 46% of controls (P < .01). These data provide the first quantitative evidence of rhythmic gubernacular contractions, and suggest that CGRP enhances gubernacular contractility by a direct effect independent of acetylcholine. Further, the contractile properties resemble those of differentiated cardiac muscle or primitive embryonic skeletal muscle. GFN transection enhances the gubernacular contractile response to exogenous CGRP, which is consistent with the GFN being the normal source of CGRP for the gubernaculum in vivo.

Animals↗
PubMed1995

Characterization of the gubernacular contractile response to calcitonin gene-related peptide in the mouse.

Calcitonin gene-related peptide (CGRP) has no effect on quiescent skeletal muscle, but cultured neonatal mice gubernacula show rhythmic contractions in response to CGRP. This study investigated whether these contractions (1) require calcium ions, (2) are activated via acetylcholine receptors, or (3) require dihydropyridine receptors. Gubernacula (n = 20 for each experiment) from male mice aged 7 days old were preincubated for 30 minutes in aerated culture medium (Krebs-Henseleit solution) with (1) up to 1.8 mmol/L of calcium with or without CGRP (714 nmol/L), (2) up to 5.0 mumol/L of curare with CGRP and calcium (1.8 mmol/L), or (3) up to 1 mumol/L of nifedipine with CGRP and calcium. Then they were placed on agar-coated grids over the same compound solutions, and observed for 2 days by video camera to see contractions. Of gubernacula cultured with calcium (1.8 mmol/L) and CGRP, 90% showed contractions, which decreased to 20% without CGRP (P < .001) and 15% without calcium (P < .001). Only 5% of gubernacula cultured without both CGRP and calcium showed contractions. Also these contractions in response to CGRP depended on calcium concentrations in a dose-dependent manner. Curare did not suppress contractions. With increasing dose of nifedipine, the percentage of gubernacula contracting decreased from 95% to 0%. These results suggest that developing mouse gubernacular contractions in response to CGRP require influx of calcium ions to the sarcoplasm via dihydropyridine receptors in a similar manner to contractions of immature cardiac or smooth muscles, and these contractions are not activated via acetylcholine receptors.

Animals↗
PubMed1995

Fecal incontinence after the surgical treatment of Hirschsprung disease.

We examined 60 children 8.9 years (+/- 2.6 years) after surgical treatment of Hirschsprung disease to determine the extent of fecal incontinence. Thirty-two children (53%) had significant fecal soiling and 16 (27%) less severe soiling. The prevalence of incontinence did not diminish with increasing age.

Anal Canal↗
PubMed1995

Pyloromyotomy: comparison between laparoscopic and open surgical techniques.

Several reports have appeared in the literature recently describing various techniques of performing pyloromyotomy laparoscopically. Although there is no doubt that this is now technically feasible, there are unanswered questions with regard to its safety, efficacy, and potential benefits or otherwise to the patient. In an attempt to resolve some of these issues, we compared the results in 37 infants who underwent open pyloromyotomy with 26 who underwent laparoscopic pyloromyotomy. The two groups were similar in terms of sex, age, weight, and presenting pH, although they could not be randomized. The time from feeding to discharge was less for the laparoscopic group (1.4 days) compared with the open group (1.8 days) (p = 0.04). Postoperative vomiting was not significantly different between the two groups. The operating time was identical for groups, 29 min vs 27 min. There were 3 complications in the open surgical group and 1 in the laparoscopic group. On the criteria measured, our results suggests that laparoscopic pyloromyotomy is at least as good as conventional surgery, and offers the potential benefits of shortened hospital stay and minimal cosmetic deformity.

Female↗
PubMed1995

Human chorionic gonadotropin (hCG) fails to stimulate gonocyte differentiation in newborn mouse testes in organ culture.

The primitive germ cells within the postnatal testis differentiate through several steps to form primary spermatocytes, which are required for postpubertal spermatogenesis. It is postulated that this germ cell development is controlled by the hypothalamic-pituitary-gonadal axis. To study the effect of human chorionic gonadotropin (hCG) on postnatal testicular germ cell differentiation, especially on gonocytes, newborn mouse testes (n = 75) were cultured for 7 days in vitro. The synthetic serum-free medium contained either hCG or exogenous human recombinant müllerian inhibiting substance (MIS) plus transferrin, insulin and retinoic acid (TIRA). Fetal calf serum 10% (FCS) was used for control medium. Thirty-eight newborn mouse testes were cultured with hCG (0.1 to 2.0 IU/ml). The percentages of differentiated type-A spermatogonia were not significantly increased compared with synthetic medium alone (NS, p > 0.05), but were only 5 to 7% (p < 0.001) of that of serum-containing medium. By contrast, normal transformation from gonocytes to type-A spermatogonia occurred in newborn mouse testes (n = 10) cultured with serum-free medium containing exogenous MIS. The percentage of differentiated type-A spermatogonia was approximately 77% (NS, p > 0.05) of those seen in serum-containing medium. These findings demonstrate that the transformation of gonocytes to type-A spermatogonia is regulated by MIS, rather than hCG. As early germ cell transformation is deficient in boys with cryptorchidism, the role of hCG in the treatment of infertility associated with undescended testes should be reevaluated.

Animals↗
PubMed1995

The role of the genitofemoral nerve and calcitonin gene-related peptide in congenitally cryptorchid mutant TS rats.

We investigated whether previous gubernacular denervation in TS rats changes the gubernacular contractile response to or binding capacity of calcitonin gene-related peptide receptors. In TS rats there is excessive calcitonin gene-related peptide in the genitofemoral nerve and 85% of the male rats have cryptorchidism. TS rats and controls underwent genitofemoral nerve transection or sham operation at day 0. On day 3 gubernacula were cultured with or without calcitonin gene-related peptide to observe contractions. Gubernacular frozen sections were incubated with 125iodine calcitonin gene-related peptide with or without unlabeled calcitonin gene-related peptide. Exposed x-ray films were quantified by computerized densitometry. In the sham operated controls contractility increased from 15 to 55% by adding calcitonin gene-related peptide compared with 5% and 10%, respectively, in the TS rats. After genitofemoral nerve denervation exogenous calcitonin gene-related peptide increased contractility to 90% in controls and 75% in TS rats. Previous genitofemoral nerve transection increased specific 125iodine calcitonin gene-related peptide binding 21% in controls and about 100% in TS rats. Genitofemoral nerve transection in TS rats restored gubernacular contractile response to calcitonin gene-related peptide in vitro and doubled the binding capacity of calcitonin gene-related peptide receptors.

Animals↗
PubMed1995

Voiding cystourethrography in boys: does the presence of the catheter obscure the diagnosis of posterior urethral valves?

OBJECTIVE: In voiding cystourethrography, the urethral catheter may or may not be left in place during voiding. The main argument for removing the catheter is that the diagnosis of posterior urethral valves may be missed because the catheter can hold open the valve, efface it, and render it invisible. However, if the catheter does not prevent the diagnosis of urethral disease, it is preferable to leave it in place. The catheter makes it possible to repeat the procedure easily if necessary, and using it to drain the bladder provides information about ureteric obstruction in the presence of vesicoureteric reflux. Accordingly, the purpose of this study was to determine whether leaving the urethral catheter in place throughout voiding cystourethrography affects the efficacy of the procedure for the diagnosis of posterior urethral valves. MATERIALS AND METHODS: Three radiologists reviewed the preoperative voiding cystourethrograms obtained in 48 boys who ranged in age from 1 day to 10 years old (mean, 1.5 years). All patients had a diagnosis of posterior urethral valves made at cystoscopy, which was used as the gold standard. The voiding cystourethrogram was obtained with a catheter in place during voiding in 28 (58%) of the 48 boys, without a catheter in 17 (35%), and with and then without a urethral catheter during the voiding phase of the study in three (6%). RESULTS: Posterior urethral valves were detected on 25 (89%) of the 28 voiding cystourethrograms obtained with a urethral catheter in place and in 15 (88%) of the 17 voiding cystourethrograms done without a urethral catheter. The five children in whom posterior urethral valves had been diagnosed by cystoscopy but were not detected on voiding cystourethrography had no dilatation of the posterior urethra nor any other evidence of obstruction; these were possibly false-positive cystoscopic diagnoses. CONCLUSION: Our results show that a urethral catheter does not obscure posterior urethral valves in boys and need not be removed routinely during the voiding phase of voiding cystourethrography.

Child↗