Incidence of cryptorchidism and ascending testes in trisomy 21: a 10 year retrospective review

Children with Down syndrome have an increased risk of cryptorchidism, but the reported incidence is unclear. In a proportion of these children, the testes are within the scrotum at birth but later appear to have ascended to an ectopic position. Records of patients diagnosed with trisomy 21 who had surgery for undescended testes in two tertiary paediatric centres over a 10-year period were examined. Information on liveborn males with Down syndrome was obtained from the Victorian Genetic Registry, and then the incidence of congenital and acquired undescended testes was determined. The incidence of undescended testes in Down syndrome was found to be 6.52% (24/368), with 4.35% (16/368) being acquired undescended or ascending testes. In conclusion, there is an increased incidence of cryptorchidism in Down syndrome; in particular, there is a significant proportion of acquired undescended testes.

Female epispadias: are we missing the diagnosis?

OBJECTIVE

To describe three of four female patients with occult epispadias, as usually epispadias is reported to be a rare condition in females (1/480,000), and obvious and easy to diagnose, but less severe variants may still involve urethral sphincter incompetence in the absence of obvious clinical signs.

PATIENTS AND METHODS

The hospital records over a 10-year period (1 January 1991 to 31 December 2000) were reviewed to find all female patients diagnosed with epispadias. Data were collected from the Consultative Council on Obstetric and Paediatric Mortality and Morbidity for the number of live births per year for the decade studied, and the incidence of female epispadias determined.

RESULTS

Over the 10-year period there were 13 patients with a diagnosis of epispadias, from 636,698 total live births; four were female and nine male. Each of the female patients had varying degrees of epispadias; three had subtle signs with apparently normal external genitalia, and only one had a bifid clitoris. However, even the most minor variant case had a palpable notch in the symphysis pubis, and an 'oblong' external urethral meatus. Thus the incidence of female epispadias is at least 1/160,000.

CONCLUSION

Epispadias in females may be up to three times more common than previously expected, but even experienced clinicians can miss the diagnosis. The importance of a careful examination should be emphasized, especially in female patients with chronic wetting of unknown cause. A bifid clitoris is an important sign but not always present. Key diagnostic features include drug-resistant wetting, a very low leak pressure on cystometrography, a palpable gap in the pubic symphysis and an abnormal oval-shaped external urethral meatus.

Ranitidine-enhanced 99mtechnetium pertechnetate imaging in children improves the sensitivity of identifying heterotopic gastric mucosa in Meckel's diverticulum

Meckel's diverticulum is the most common congenital gastrointestinal anomaly. (99m )Technetium pertechnetate imaging (Meckel's scan) is the best noninvasive method used to diagnose this condition when heterotopic gastric mucosa (HGM) is present. Although cimetidine enhancement has been shown to improve sensitivity of the Meckel's scan, ranitidine enhancement has also been advocated; however, this recommendation is based on unpublished data. Thirty-seven children with confirmed Meckel's diverticulum were reviewed retrospectively. Of eight children with HGM in the Meckel's diverticulum who presented with profuse rectal bleeding and underwent the conventional Meckel's scan, three of them (37.5%) had a false negative study. Ranitidine, when administered either intravenously or orally for 24 h prior to the Meckel's scan, enhanced the sensitivity of this test to 87.5% in our patient cohort.

Renal Abnormalities in Rat Fetuses Exposed to Doxorubicin

PURPOSE

A rat model of the VATER (vertebral defects, anal atresia, tracheo-esophageal fistula with esophageal atresia, renal defects and radial limb dysplasia) association was created by exposing fetuses to doxorubicin early in gestation. Most fetuses had an absent bladder with ureters that were grossly dilated. We determined the effect of this absent bladder on kidneys development, particularly whether dysplasia was evident.

MATERIALS AND METHODS

Nine timed pregnant rats were injected intraperitoneally with doxorubicin at a dose of 2 mg/kg body weight on days 6 to 9 of gestation. The control group of 3 rats received saline. Fetuses were recovered on day 21 and examined macroscopically. Quantitative measurements were taken of renal wet and dry weights, renal length and ureteral diameter. Serial sections were then taken and stained alternately with hematoxylin and eosin or trichrome. The kidneys were compared under light microscopy. Comparisons between control and treated groups were made with the Student t test.

RESULTS

An absent bladder was confirmed in 50 of the 55 fetuses (91%). In most fetuses the kidneys were correctly located, although they were hydronephrotic and poorly developed. This finding was confirmed quantitatively with significant differences in treated and control fetuses in renal length (5.24 vs 4.13 mm, p <<0.01) and in the ratio of wet renal weight to body weight and dry weight (2.7 vs 3.4 mg, p <<0.01). Dilated, tortuous ureters were found bilaterally in most cases. Microscopically the kidneys had abnormal architecture and were less mature than in controls. Nephron induction was poor with abnormal configurations. Tubular differentiation was decreased and the medulla was thin and less cellular than in controls. Dilatation occurred mainly in the collecting system and ducts/tubules. There was no collagen deposition/fibrosis or aberrant tissue.

CONCLUSIONS

In this rat model the kidneys are exposed to obstruction early in development since the bladder does not form. The resulting kidneys are hydronephrotic with decreased parenchyma and poor differentiation. However, there is no fibrosis or aberrant tissue.

Twenty-one cases of small bowel intussusception: the pathophysiology of idiopathic intussusception and the concept of benign small bowel intussusception

Ultrasonography (US) was used to study intussusceptions prospectively at Kiyama Hospital in 1999 and 2000 under the classification of small bowel intussusception (SBI) and large bowel or ileo-ileo-colic intussusception (LBI). The clinical features, management, outcome and etiology were analyzed. All LBIs and SBIs with ischemic symptoms and SBIs complicated by LBI were treated by enema reduction, whereas SBIs considered to be nonischemic were observed. SBI was seen in 21 patients with a mean age of 62.6+/-31.2 months. Four cases (19.0%) were diagnosed during the course of LBI. US showed mesenteric lymphoid hyperplasia in 15 (71.4%). Hydrostatic enema reduction was successful in 9/9, and SBI reduced naturally in the other 12 (benign SBI). LBI occurred in 38 patients with a mean age of 27.8+/-21.2 months. Mesenteric lymphoid hyperplasia was observed in 29 (76.3%). Hydrostatic enema reduction was successful in 37/38. SBI occurs more frequently and in a wider age group than previously considered. Many SBIs reduced naturally, suggesting that they were only transient invagination phenomena and should be called benign SBI. The frequent association of SBI with LBI and also the frequent association of mesenteric lymphoid hyperplasia with both SBI and LBI seem the key to the pathophysiology of intussusception.

The broad ligament: A review of its anatomy and development in different species and hormonal environments

The broad ligament is a double fold of peritoneum forming a mesentery for the human female genital tract. We investigated the anatomy of the broad ligament in different species and its hormonal regulation to determine if it had a role in gonadal positioning. The medical and veterinary literature was reviewed for descriptions of broad ligament anatomy and development. In addition, four adult female rats were dissected to compare the macroscopic anatomy of the broad ligament with any homologous structures in the male (n = 2). Detailed review was made of human males with persistent Müllerian duct syndrome (PMDS) and of bovine freemartin calves to determine the effect of abnormal hormonal environments on broad ligament development. Human and veterinary texts show variable broad ligament development between species, most being consistent with the size and shape of the uterus and uterine tubes. The broad ligament in adult female rats is a simple peritoneal fold and is homologous with the mesentery of the testis and vas deferens in males. Patients with PMDS and bovine freemartins have a broad ligament with intermediate anatomy. In PMDS the broad ligament is elongated and narrow, and not attached to the pelvic wall. The broad ligament is the mesentery of the genital ducts, and its anatomy varies with the degree of Müllerian duct fusion. The absence of a human male homologue is unusual, as the genital mesentery persists in male rodents. Apparent lack of a male homologue in the human may relate to obliteration of the processus vaginalis. The variable development of the broad ligament in pathological conditions is consistent with a role for steroid hormones in its development.

The gubernaculum in testicular descent and cryptorchidism

The gubernaculum plays an essential role in the complex mechanism of testicular descent and inguinal hernia closure. Understanding this complex developmental process is gradually allowing us insight into how to regulate normal descent and also treat maldescended testes.

Cholinergic transmission to colonic circular muscle of children with slow-transit constipation is unimpaired, but transmission via NK2 receptors is lacking

Tachykinins (TKs) colocalize with acetylcholine in excitatory motor neurones supplying human colonic circular muscle (CCM). Some children with slow-transit constipation (STC) have reduced TK-immunoreactivity in nerve terminals in CCM suggesting a deficit in neuromuscular transmission. This study aimed to test this possibility. Seromuscular biopsies of transverse colon were obtained laparoscopically from STC children (37, 17 with low density of TK-immunoreactivity). Specimens of transverse (17) and sigmoid colon (20) were obtained from adults undergoing colonic resection for cancer. CCM contractions were measured isotonically and responses to carbachol, neurokinin A (NKA) and electrical field stimulation (EFS) recorded. Carbachol and NKA-evoked contractions in adult and STC colon. Hyoscine (2 micromol L-1) significantly depressed responses to EFS in all preparations. Blockade of NK2 receptors (SR 48968, 2 micromol L-1) significantly depressed EFS-evoked contractions of adult transverse CCM, but had no effect on STC preparations. Thus, neuromuscular transmission in both adults and STC children is predominantly cholinergic and this component is unimpaired in the latter, indicating that reduced TK-immunoreactivity is not a marker for depressed cholinergic responses. Although pharmacologically responsive TK receptors are present in STC colon, we did not detect neuromuscular transmission mediated by release of TKs in these preparations.

Transabdominal testicular descent is disrupted in mice with deletion of insulinlike factor 3 receptor

BACKGROUND

Several factors are implicated in transabdominal testicular descent, including insulinlike factor 3 (INSL3) hormone and Müllerian-inhibiting substance (MIS). A transgene insertional mutation found on chromosome 5 in the mouse, known as crsp, causes deletion of a transmembrane G protein-coupled receptor gene, Great, which is highly expressed in the gubernaculum. The authors describe here a detailed analysis of the testicular descent and gubernacular development in crsp mice to determine the role of the Great gene in this process.

METHODS

Homozygous (crsp/crsp) mutant and wild-type heterozygous (crsp/+) mice were examined at birth (D 0) and at days 10 (D 10) and 30 (D 30) postnatally. Serial sagittal or coronal sections were analyzed for position of the gonads and cremaster sac development.

RESULTS

Transabdominal testicular descent was absent at D 0 in crsp/crsp homozygous mice with no swelling reaction in the gubernacula. By D 10 the cremaster sac was significantly thinner (P <.05) and contained less collagen in the mutants than in the wild-type controls. On D 30 the cremaster sacs of mutant males were similar in thickness to those in females.

CONCLUSIONS

Disruption of the Great gene causes failure of the transabdominal phase of descent, identical to that seen in the Insl3-deficient mutants, consistent with the recent data suggesting that Great gene encodes the Insl3 transmembrane receptor. No differences between D 30 mutant males and females were found in the gubernacula, suggesting that Insl3/Great signaling regulates gubernacular development.

The absence of lateral fusion in cloacal partition

BACKGROUND/PURPOSE

The mechanism by which the cloaca becomes partitioned into a dorsal rectal part and a ventral genitourinary sinus has been the subject of speculation for more than a century. Despite repeated suggestions that partitioning of the cloaca by fusion of lateral folds does not occur, the concept continues to hold sway in many student and surgical texts. The authors reviewed the histologic and 3-dimensional appearance of the urorectal septum in human and rat embryos to see if there was any evidence of lateral fusion in its formation.

METHODS

Sprague-Dawley rat embryos (n = 143) were examined between 11 and 21 days' gestation and compared with human embryo sections (57 embryos) held in historical collections in Europe. Rat embryos were examined by microscopy, dissection, and serial histologic section. In addition, some specimens were sectioned in wax until the lumen of the cloaca was reached, after which they were dewaxed and the internal cavities imaged with scanning electronmicroscopy (n = 18 of 143).

RESULTS

Cloacal "partitioning" resulted from a combination of growth of the mesenchyme of the hindgut and genitourinary sinus, an alteration in the position of the cloaca in relation to surrounding structures secondary to growth in the ventral, infraumbilical abdominal wall and changes in the curvature of the developing spine, and apoptosis in the dorsal wall of the cloaca with shortening of the dorsal cloacal wall. There was no septum, as it is usually defined, between the developing bladder and hindgut. There was no evidence on either histologic section or scanning electronmicroscopy of any process of fusion occurring between the 2 lateral folds within the lumen of the cloaca.

CONCLUSIONS

Lateral fusion of the side walls of the cloaca does not play a role in cloacal "partition." Development of the bladder and hindgut occurs by a process that involves growth, differentiation, and remodeling.

Rules for clinical diagnosis in babies with ambiguous genitalia

Intersex disorders are rare and complex; yet, in each case of genital ambiguity, accurate and expeditious management is required of the clinician. This article reviews the embryology of sexual differentiation, from which some 'rules' of diagnosis are derived. A simplified approach to the interpretation of clinical signs in ambiguous genitalia is presented and discussed.

A surviving infant with sirenomelia (Mermaid syndrome) associated with absent bladder

The authors report a case of a surviving infant with sirenomelia (Mermaid syndrome). The child is now 4 years of age. The authors believe that this is only the fourth reported case of an infant with sirenomelia surviving beyond the neonatal period and the first associated with absent bladder. The abnormal distal aorta shown in this case supports the theory that sirenomelia is an extreme form of caudal dysgenesis rather than occurring secondary to vascular steal.

Signs and symptoms of slow-transit constipation versus functional retention

BACKGROUND/PURPOSE

Slow-transit constipation (STC) has been described recently in children. This retrospective study correlated symptoms, signs, transit times, and immunohistochemistry to determine the diagnostic differences between STC and functional fecal retention (FFR).

METHODS

One hundred eighty children with intractable constipation underwent clinical assessment, nuclear transit study (NTS), with or without laparoscopic colonic muscle biopsy. Patients were divided by NTS into those with STC and those with FFR. Parents completed questionnaires on presenting symptoms.

RESULTS

In 161 patients with STC and 19 with FFR, there were no differences in gender, gestation, or timing of symptom onset. Over 20% had the first meconium delayed more than 24 hours after birth even in FFR (4 of 19). Bloating and soiling were more common in STC. There were no differences between patients with STC but different histology on biopsy. More STC patients had soft stools (39%) than FFR (16%), and a lower stool frequency of less than once a week (STC 26% compared with 11% FFR). FFR was managed more often with medication or diet alone (53%) compared with STC (29%), where enemas, lavage, or surgery were more common.

CONCLUSIONS

Children with STC showed similar symptoms and signs to those with FFR, but more had bloating and soiling, softer stools, and longer intervals between bowel actions. Delayed meconium stool beyond 24 hours after birth was common in both groups. Diagnosis of STC or FFR required NTS and was not possible on symptoms alone.

Effect of an anti-androgen on testicular descent and inguinal closure in a marsupial, the tammar wallaby (Macropus eugenii)

Androgens are essential for testicular descent in eutherian mammals, but little is known about its hormonal control in marsupials. This study reports the effects of daily treatment with the anti-androgen flutamide (10 mg kg(-1)) from day 9 to day 75 after birth on the descent of the testis and inguinal closure in tammar wallabies. By day 75 after birth, the testes of control males had descended and the prostate gland was well developed. The testes of all flutamide-treated males had passed through the inguinal canal and were situated in the base of the scrotum. Three of the nine flutamide-treated males had unilateral inguinal hernias. The size of the inguinal canal, regardless of whether a hernia was present, was significantly wider than that of control males. Development of the prostate gland was significantly inhibited. By day 75 after birth, the phallus was significantly longer in control males than in females, whereas the phallus of flutamide-treated males was similar to that of control females. In flutamide-treated males, the lumbar 1 dorsal root ganglia was feminized and significantly fewer cell bodies expressed calcitonin gene- related peptide. As the anti-androgen treatment resulted in a reduction in the number of calcitonin gene-related peptide-positive cell bodies in the dorsal root ganglion supplying the genitofemoral nerve, the process of inguinal closure in tammar wallabies may be mediated by calcitonin gene-related peptide via the genitofemoral nerve, as indicated in humans. Flutamide treatment inhibited development of the prostate gland and phallus, which are both androgen-dependent structures, but it did not affect the normal descent of the testis, indicating that testicular descent can proceed when the action of androgens is blocked.

Laparoscopic placement of the Chait cecostomy device via appendicostomy

The authors describe their experience with a series of 11 patients in whom they have carried out Chait cecostomy catheter insertion into a laparoscopically formed appendicostomy. This technique has several advantages compared with percutaneous insertion and we now insert the device at the primary procedure. The authors have had one minor complication in their 11 patients, with mean follow-up of 8 months. This technique is recommended for the management of refractory constipation, for etiologies including spina bifida, anorectal malformation, distal intestinal obstruction syndrome, and slow-colonic transit.

Human chorionic gonadotrophin (hCG) stimulates spermatogenesis in immature mice in vivo

BACKGROUND/PURPOSE

Spermatogenesis in postnatal testes is controlled by the hypothalamic-pituitary-gonadal axis. To determine if pituitary hormones can induce precocious spermatogenesis once primary spermatocytes (PS) have formed, prepubertal mice were treated with human chorionic gonadotrophin (hCG).

METHODS

Day 12 immature mice (n = 10) were injected every third day with hCG (3 or 6 IU) dissolved in 100 microL phosphate-buffered saline (PBS). Control mice (n = 10) were either uninjected or injected with 100 microL PBS alone. On day 20 to 22 the excised testes were examined histologically with tubule counts.

RESULTS

HCG-treated mice had fewer tubules at stage I (P <.001) and more at stage III than the PBS-treated group (P <.001). Mean thickness of the round spermatid layer per tubular cross section in the hCG-treated group was significantly increased compared with the PBS-treated group (P <.01). Similarly, the percentage of the tubules at stage III (containing round spermatids) in the hCG-treated group was significantly increased, from 25% to 71%, compared with the PBS-treated group (P <.01). With increasing doses of hCG the testosterone levels were significantly higher than in controls (P <.01), but hCG did not alter testis weight or position.

CONCLUSIONS

These results show that hCG stimulates the transformation of PS to round spermatids even in immature mouse testes. These findings suggest that hCG treatment of prepubertal cryptorchid boys may initiate premature spermatogenesis.