MRI biomarker of muscle composition is associated with severity of pelvic organ prolapse.

BACKGROUND: The pathophysiology of pelvic organ prolapse is largely unknown. We hypothesized that reduced muscle mass on magnetic resonance defecography (MRD) is associated with increased pelvic floor laxity. The aim of this study was to compare the psoas and puborectalis muscle mass composition and cross-sectional area among patients with or without pelvic laxity. METHODS: An observational retrospective study was conducted on women > age 18 years old who had undergone MRD for pelvic floor complaints from January 2020 to December 2020 at Stanford Pelvic Health Center. Pelvic floor laxity, pelvic organ descent, and rectal prolapse were characterized by standard measurements on MRD and compared to the psoas (L4 level) and puborectalis muscle index (cross-sectional area adjusted by height) and relative fat fraction, quantified by utilizing a 2-point Dixon technique. Regression analysis was used to quantify the association between muscle characteristics and pelvic organ measurements. RESULTS: The psoas fat fraction was significantly elevated in patients with abnormally increased resting and strain H and M lines (p < 0.05) and increased with rising grades of Oxford rectal prolapse (p = 0.0001), uterovaginal descent (p = 0.001) and bladder descent (p = 0.0005). In multivariate regression analysis, adjusted for age and body mass index, the psoas fat fraction (not muscle index) was an independent risk factor for abnormal strain H and M line; odds ratio (95% confidence interval) of 17.8 (2-155.4) and 18.5 (1.3-258.3) respectively, and rising Oxford grade of rectal prolapse 153.9 (4.4-5383) and bladder descent 12.4 (1.5-106). Puborectalis fat fraction was increased by rising grades of Oxford rectal prolapse (p = 0.0002). CONCLUSIONS: Severity of pelvic organ prolapse appears to be associated with increasing psoas muscle fat fraction, a biomarker for reduced skeletal muscle mass. Future prospective research is needed to determine if sarcopenia may predict postsurgical outcomes after pelvic organ prolapse repair.

Laparoscopy versus ultrasonography for the evaluation of Mullerian structures in children with complex disorders of sex development.

PURPOSE: The diagnosis of children with disorders of sex development (DSD) requires a karyotype, different biochemical and radiological investigations in the context of a multidisciplinary team. The aim of this study was to compare the diagnostic accuracy of laparoscopy (L) versus ultrasonography (US) in the assessment of children with complex DSD. METHODS: We retrospectively examined the theatre database searching for children with DSD who underwent laparoscopic surgery from 1999 to 2011. The medical and radiological records were reviewed. RESULTS: Eighteen patients were identified. Age at diagnosis ranged from birth to 14 years (mean 2.5 years). There were seven patients with 46XY dysgenetic testicular DSD (4 mosaic Turner, 3 mixed gonadal dysgenesis), seven patients with 46XY non-dysgenetic testicular DSD (4 persistent Mullerian duct syndrome, 2 complete androgen insensitivity syndrome, one unknown), two patients with ovotesticular DSD, one patient with 46XX DSD (congenital adrenal hyperplasia) and one patient with 46XY DSD complete sex reversal. Fifteen underwent ultrasonography prior to laparoscopy. Both modalities identified Mullerian structures in seven (47 %) patients, in one (7 %) patient US and L confirmed the absence of Mullerian structures, while in six (40 %) patients there was discordance, with US failing to visualize pelvic Mullerian structures. In the last patient with 46XY non-dysgenetic testicular DSD, the rectum was thought to be a dilated uterus on ultrasonography. CONCLUSIONS: Pelvic ultrasonography failed to identify Mullerian structures in 40 % of patients with complex DSD. On the contrary, laparoscopy allowed excellent visualization of pelvic structures and gonads in children with complex DSD.

Inhibition of recombinant human mitochondrial aldehyde dehydrogenase by two intermediate metabolites of disulfiram.

Disulfiram is used in aversion therapy for alcoholism. S-Methyl-N,N-diethylthiocarbamate (MeDTC) sulfoxide, a potent inhibitor of the target enzyme mitochondrial aldehyde dehydrogenase (ALDH2), is thought to be the principal active metabolite of disulfiram in vivo. We examined the effects on recombinant human ALDH2 of two intermediate metabolites of disulfiram, S-methyl-N,N-diethyldithiocarbamate (MeDDC) sulfoxide and MeDDC sulfine. MeDDC sulfoxide was a potent inhibitor of ALDH2 with an IC50 of 2.2 +/- 0.5 microM (mean +/- SD, N = 4) after preincubation with enzyme for 30 min. MeDDC sulfine was a relatively weak inhibitor of ALDH2 under the same conditions with an IC50 value of 62 +/- 14 microM. The inhibition of ALDH2 by both compounds was irreversible and did not require the cofactor NAD. The latter finding demonstrates that inactivation of ALDH2 is independent of the dehydrogenase activity of the enzyme. GSH blocked almost completely the inhibition by 20 microM of MeDDC sulfoxide and greatly diminished the inhibition by 200 microM of MeDDC sulfine. Inactivation by MeDDC sulfoxide was time dependent. MeDTC sulfoxide was a more potent inhibitor of recombinant human ALDH2 (IC50 = 1.4 +/- 0.3 microM after preincubation for 15 min) than either of the intermediate metabolites, and its inhibition was unaffected by GSH. Our results suggest that these newer intermediate metabolites of disulfiram, especially the more potent MeDTC sulfoxide, have the potential to inhibit the target enzyme ALDH2 in patients receiving disulfiram. However, until the significance of the interactions of the inhibitors with GSH is more fully understood, the contribution of MeDDC sulfine and MeDDC sulfoxide to the pharmacological effects of disulfiram in vivo is uncertain.

Inhibition of recombinant human mitochondrial and cytosolic aldehyde dehydrogenases by two candidates for the active metabolites of disulfiram.

We expressed recombinant human cytosolic (ALDH1, high Km) and mitochondrial aldehyde dehydrogenase (ALDH2, low Km) in Escherichia coli and purified the enzymes to homogeneity to examine the nature of inhibition of human ALDH by disulfiram, its confirmed metabolite S-methyl N,N-diethylthiocarbamate (MeDTC) sulfoxide, and its proposed metabolite MeDTC sulfone. Disulfiram, MeDTC sulfoxide, and MeDTC sulfone, respectively, were potent inhibitors with IC50 values of 0.15 +/- 0.02 microM, 0.27 +/- 0.04 microM, and 0.12 +/- 0.02 microM for ALDH1, and 1.45 +/- 0.40 microM, 1.16 +/- 0.56, and 0.40 +/- 0.10 microM for ALDH2. Extensive dialysis did not restore the activity of the inactivated enzyme, indicating irreversible inhibition. Both the esterase and dehydrogenase activities of ALDH2 were inhibited to the same extent by MeDTC sulfone and sulfoxide, suggesting that both catalytic sites are closely linked. The time course of inhibition of ALDH appeared to be first-order for both MeDTC sulfone and MeDTC sulfoxide. Kitz and Wilson plots of the half-life of inactivation versus 1/[inhibitor] indicated that the reactions between ALDH and inhibitors were bimolecular. The pseudobimolecular rate constants (k3/KI) for the ALDH-inhibitor reactions were 1 x 10(5), 1 x 10(4), 3 x 10(3), and 1 x 10(3) s-1 M-1 ALDH1-sulfone, ALDH1-sulfoxide, ALDH2-sulfone, and ALDH2-sulfoxide, respectively. ALDH2 was not significantly protected from inactivation from either MeDTC sulfoxide or MeDTC sulfone by NAD alone, but high concentrations of NAD and acetaldehyde completely prevented inhibition. Since disulfiram is rapidly metabolized in vivo, it is believed that disulfiram is too short-lived to inhibit ALDH directly. The results of our study indicate that MeDTC sulfoxide and sulfone are potent inhibitors of human ALDH and are reasonable candidates for the proximal inhibitors of ALDH following disulfiram administration.

Infrequent vertical transmission of hepatitis C virus.

The rate of vertical transmission of hepatitis C virus (HCV) was determined by a combination of assays for anti-HCV antibody and the polymerase chain reaction (PCR) in 66 children born to infected mothers. Only 4 children showed evidence of infection with HCV, being positive for anti-HCV in all samples collected from 6 months to 5 years of age. All samples from the remaining 62 children were repeatedly anti-HCV-negative on screening by two second-generation antibody assays. Furthermore, samples collected at age 12 months from 30 antibody-negative children born of HCV-infected mothers were uniformly PCR-negative, showing that "seronegative" infection with HCV was rare or absent in this study group. Serologic reactivity to HCV-encoded antigens in samples from infected children was largely confined to the HCV core protein. Infection with human immunodeficiency virus in the mother was not a significant cofactor for mother-to-child transmission of HCV.