Differences between NMRI and DBA/2J mice in the development of somites and susceptibility to methylnitrosourea-induced skeleton anomalies

ABSTRACT The development of DBA/2J mouse strain embryos is nearly 12 h - or 6 somite pairs - delayed as compared to the outbred NMRI mouse embryos of the same age on gestation days (GD) 8-12. To evaluate inter-strain differences in susceptibility to teratogens, dams were treated with methylnitrosourea (MNU, 5 mg/kg body weight i.p.) on defined gestation days (NMRI: GD 9, 91/2 or 10; DBA/2J: GD 10 or 101/2). Skeletal anomalies produced by MNU on both mouse strains varied with the GD of treatment. The pattern of anomalies produced by MNU on a given GD markedly differed between the two mouse strains, yet they were similar -with a few exceptions- when exposures at equivalent embryonic stages are compared. Findings from this study indicated that strain-dependent differences in the developmental stage of mouse embryos of the same gestational age occur, a possibility that has been often neglected when inter-strain differences in susceptibility to developmental toxicants are interpreted.

Magnetic Resonance Evaluation of Mullerian Remnants in Mayer-Rokitansky-Kuster-Hauser Syndrome

OBJECTIVE: To analyze magnetic resonance imaging (MRI) findings of Mullerian remnants in young females clinically suspected of Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome in a primary amenorrhea workup. MATERIALS AND METHODS: Fifteen young females underwent multiplanar T2- and transverse T1-weighted MRI at either a 1.5T or 3.0T MR imager. Two gynecologic radiologists reached consensus decisions for the evaluation of Mullerian remnants, vagina, ovaries, and associated findings. RESULTS: All cases had bilateral uterine buds in the pelvic cavity, with unilateral cavitation in two cases. The buds had an average long-axis diameter of 2.64 +/- 0.65 cm. In all cases, bilateral buds were connected with fibrous band-like structures. In 13 cases, the band-like structures converged at the midline or a paramedian triangular soft tissue lying above the bladder dome. The lower one-third of the vagina was identified in 14 cases. Fourteen cases showed bilateral normal ovaries near the uterine buds. One unilateral pelvic kidney, one unilateral renal agenesis, one mild scoliosis, and three lumbar sacralization cases were found as associated findings. CONCLUSION: Typical Mullerian remnants in MRKH syndrome consist of bilateral uterine buds connected by the fibrous band-like structures, which converge at the midline triangular soft tissue lying above the bladder dome.

MURCS association: a case report

MURCS association is a rare developmental disorder that affects females. The acronym MURCS stands for Mullerian, Renal, Cervicothoracic Somite abnormalities. It appears to occur randomly [sporadic] with a frequency of 1 in 50.000 females. In this paper, we present a two-year-old girl with typical features of this syndrome in association with right deviation of anorectal canal, subglottic stenosis and unilateral oblique inguinal hernia