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Biomedical subjects

Michael C Carr

Publications and source records attributed to Michael C Carr.

25 records · Page 2Linked to original sources
PubMed2004

The physical characteristics of young males with varicocele.

OBJECTIVE: To determine if there is an association with habitus in young males with varicocele, as adolescent boys with varicoceles appear to be mostly taller and leaner than age-matched controls. PATIENTS AND METHODS: Retrospectively reviewing our records we obtained the height and weight of 43 consecutive males (mean age 14.3 years, range 11-19) under long-term follow-up for varicocele. The body mass index (BMI), heights and weights were compared with values from the respective growth charts for boys aged 2-20 years (Center for Disease Control and Prevention), and the statistical significance of differences determined using the chi-square test. RESULTS: The height and weight distributions of patients with varicocele indicated a significant deviation from normal in the 25-95th percentiles for stature and in the 25-75th for weight (P < 0.05). Deviations in BMI were insignificantly different from normal at each percentile. CONCLUSION: These results indicate that patients with varicocele are significantly taller and heavier than age-matched controls. Future studies to address the key areas identified in this study will help to further assess the distribution of the incidence of varicocele in closely defined subsets of adolescent growth and development, which may provide some insight into the cause of varicoceles.

Adolescent↗
PubMed2003

Molecular epidemiology of hypospadias: review of genetic and environmental risk factors.

Hypospadias is one of the most common congenital anomalies in the United States, occurring in approximately 1 in 125 live male births. It is characterized by altered development of the urethra, foreskin, and ventral surface of the penis. In this review, the embryology, epidemiology, risk factors, genetic predisposition, and likely candidate genes for hypospadias are described. Recent reports have identified increases in the birth prevalence of mild and severe forms of hypospadias in the United States from the 1960s to the present. Studies in consanguineous families and small case series have identified allelic variants in genes controlling androgen action and metabolism that cause hypospadias, but the relevance of these findings to the general population is unknown. Concern has also focused on whether exposure to endocrine disrupting chemicals (EDC) with antiandrogenic activity is the cause of this increase. Hypospadias is believed to have a multifactorial etiology in which allelic variants in genes controlling androgen action and metabolism predispose individuals to develop this condition. When genetic susceptibility is combined with exposure to antiandrogenic agents, a threshold is surpassed, resulting in the manifestation of this birth defect. A clear role for exposure to antiandrogenic environmental chemicals has yet to be established in the etiology of hypospadias, although results from laboratory animal models indicate that a number of environmental chemicals could be implicated. Molecular epidemiology studies that simultaneously examine the roles of allelic variants in genes controlling androgen action and metabolism, and environmental exposures are needed to elucidate the risk factors for these anomalies and the causes of the increased rate of hypospadias.

Genetic Predisposition to Disease↗
PubMed2003

Ureteral stenting in the management of urinoma after severe blunt renal trauma in children.

Posttraumatic urinomas are well-described complications associated with the nonoperative management of major blunt renal injuries. Urinoma drainage using a percutaneously placed catheter has been the traditional method used to alleviate symptoms and promote resolution without the need for open intervention. The authors describe 2 pediatric cases in which urinomas associated with grade IV renal lacerations were treated successfully utilizing internal ureteral stents.

Adolescent↗
PubMed2003

Testis histopathology in boys with cryptorchidism correlates with future fertility potential.

PURPOSE: We studied the ability of testis biopsy to predict eventual fertility potential. MATERIALS AND METHODS: A total of 25 patients with unilateral undescended testis and 11 with bilateral undescended testes who previously underwent orchiopexy at a median age of 9 years were followed until after age 18 years. Semen analysis, testicular volume, follicle-stimulating hormone, luteinizing hormone, testosterone and inhibin B were compared to previously obtained biopsies of each testis. Biopsies were graded as mild, moderate or severe histology based on published data for normal and undescended testis histology. RESULTS: Patients with unilateral undescended testis and moderate histology were more likely to have a sperm density of greater than 20 million per cc than those with severe histology (p = 0.006), although no difference in hormonal parameters was noted. Patients with bilateral undescended testes and moderate histology were more likely to have normal follicle-stimulating hormone and inhibin B than those with severe histology (p = 0.05 and 0.002, respectively), although no difference in semen analysis was observed. Overall 7 of the 9 patients with bilateral undescended testes had less than 20 million sperm per cc. CONCLUSIONS: Testis biopsy provides useful prognostic information about semen analysis in patients with unilateral undescended testis. In the 9 patients with bilateral undescended testes testis biopsy divided them into normal and abnormal groups in terms of hormonal parameters. Testis biopsy was not able to provide additional prognostic information on semen analysis in patients with bilateral undescended testes since they were uniformly poor.

Adolescent↗
PubMed2002

The ascending testis and the testis undescended since birth share the same histopathology.

PURPOSE: The etiology of the ascending testis is controversial. We propose that ascending testis, defined as a testis previously thought to be descended and later noted to be out of the scrotum, is due to mild hypogonadotropic hypogonadism affecting both testes. The diagnosis of these low types of true undescended testes is difficult to make clinically in children since they are frequently confused with retractile testes. In this study we compared testicular biopsies in a group of boys with ascending testes with those in boys who had an undescended testis since birth (primary undescended testis). MATERIALS AND METHODS: Between 1985 and 1995, 91 patients with ascending testes underwent orchiopexy and bilateral testis biopsy. The total germ cell count, processus vaginalis status, age at surgery and whether followup was done by a pediatrician or pediatric urologist were compared in patients with ascending and unilateral primary undescended testes. RESULTS: The total germ cell count was similar in the undescended and the contralateral descended testis in patients with ascending and primary undescended testes. The processus vaginalis was more likely to be closed in ascending testes (57% versus 36%, p = 0.0001). Age at surgery and the total germ cell count were similar in patients followed by pediatricians and pediatric urologists. CONCLUSIONS: The ascending testis has the same germ cell count as the primary undescended testis. Yearly followup by the primary care physician is recommended for patients with retractile testes.

Biopsy↗
PubMed2002

Magnetic resonance imaging of fetal urinoma.

Extrarenal collections of urine have long been associated with obstructive uropathy and may preserve renal function by acting as a "popoff" valve. Although urinary extravasation manifested as urinary ascites carries a favorable prognosis, perinephric urinomas occurring prenatally are associated with poor renal function in most cases. We report the case of a baby girl with a urinoma diagnosed by fetal magnetic resonance imaging and discuss the significance of this radiologic finding.

Abnormalities, Multiple↗