Genes for skeletal muscle myosin heavy chains are clustered and are not located on the same mouse chromosome as a cardiac myosin heavy chain gene.

Myosin heavy chain (MHC) genes are expressed as several distinct isoforms in a tissue- and stage-specific manner; three skeletal muscle MHC isoforms appear sequentially during development. We have isolated cDNA clones, identified by RNA blot hybridization and by nucleotide sequence determination as coding for portions of the embryonic (pMHC2.2), perinatal (pMHC16.2A), and alpha(V1) cardiac (pMHC141 and pMHC101) MHC isoforms. These four probes and the adult skeletal MHC probe (pMHC32) have been used on Southern blots of genomic DNA to detect restriction fragment length polymorphisms defining the alleles for these genes in mouse species Mus musculus and Mus spretus. In this way, we followed the segregation of skeletal and cardiac MHC genes in 42 offspring resulting from an interspecies backcross. We found that the embryonic, perinatal, and adult skeletal MHC genes are clustered on chromosome 11 near the locus nude, the skeletal and cardiac MHC genes do not cosegregate, and the alpha(V1) cardiac MHC gene is located on chromosome 14 close to Np-1. This result is in contrast to that for other contractile protein genes such as the alkali myosin light chain and the actin multigene families, which are dispersed in the genome.     

Does an intraabdominally placed LNG-IUS have an adverse effect on fertility? a case report

This case of secondary infertility with an associated intraabdominal levonorgestrel intrauterine system (LNG-IUS) demonstrates the importance of adequate imaging in women with a missing intrauterine contraceptive device and the possible fertility implications of an extrauterine LNG-IUS.     

Endoscopic Removal of a Cervical Esophageal Duplication Cyst

A 6-month-old female presented for 2 months of noisy breathing. Flexible laryngoscopy showed limited bilateral vocal fold abduction. Computed tomography revealed a non-enhancing 3.6 × 2.3 × 3.5 cystic prevertebral mass spanning C2-T. Using an endoscopic approach, the overlying mucosa was incised, and the cyst was freed and fully excised from the surrounding mucosa with blunt microlaryngeal instruments without complication. Three months postoperatively she had no respiratory issues and was eating well. Flexible laryngoscopy revealed bilateral vocal fold mobility. We propose that endoscopic removal of a cervical esophageal duplication cyst in selected cases is an alternative to open excision. Laryngoscope, 130:2053–2055, 2020     

Protective effect of a PAF-acether antagonist, BN 52021, in trichothecene toxicosis

Trichothecenes are mycotoxins which produce lethal toxicosis in humans and animals, yet no adequate therapeutic regimen has been developed. This study provides evidence that the selective platelet activating factor (PAF) antagonist, BN 52021 (5-15 mg/kg i.v.) can prolong the survival of conscious rats exposed to a highly lethal T-2 toxicosis. These data also suggest that PAF is an important mediator of this unique toxicosis.     

Levels of cholesterol and phospholipids in freshly ejaculated sperm and Percoll-gradient-pelletted sperm from fertile and unexplained infertile men

Cholesterol and phospholipid levels were determined in individual sperm samples obtained from 20 fertile and 20 unexplained infertile men. The determination was performed on both washed freshly ejaculated sperm and Percoll-gradient-pelletted sperm. Although sperm cholesterol levels in unexplained infertile patients were significantly lower, i.e., 10.6 +/- 1.3 (mean +/- SD) nmol/10(7) freshly ejaculated sperm and 5.4 +/- 0.7 nmol/10(7) Percoll-gradient-pelletted sperm as compared with 19.9 +/- 1.9 nmol/10(7) and 12.6 +/- 1.5 nmol/10(7) for corresponding sperm populations in fertile donors. Motility parameters measured in 10 sperm samples of the two groups of fertile and unexplained infertile men revealed increases in the amplitude of lateral head displacement and decreases in percent of straightness in sperm tracks from unexplained infertile men.     

Effect of hypoxia and catecholamines on the habituation rates of chronically catheterized ovine fetuses

Integrated electromyographic, electrocortical (ECoG) and electro-ocular activity were recorded in 13 chronically prepared fetal sheep (130-145 days). Fetal movements and the rate of habituation to repeated suffusions of cold saline against the fetal skin were recorded. Experiments were repeated during an intravenous infusion of noradrenaline to the fetus (0.4 microgram/kg estimated fetal weight/min) and during hypoxia induced by altering the oxygen content of the inspired air to the ewe to 9%. Repeated stimulation with cold saline resulted in an increase in fetal movements (p = 0.009). The number of stimuli for habituation was similar in high-voltage and in low-voltage ECoG activity. The rate of fetal habituation was significantly faster during the infusion of noradrenaline compared with control measurements (p = 0.009). During hypoxia, the number of spontaneous fetal movements prior to stimulation decreased (p = 0.002). Habituation rates were also faster during hypoxemia compared with control measurements (p = 0.003). These findings may help to explain the rapid habituation rates seen in some human fetuses in at 'at risk' pregnancies.     

A comparison of Dextran 70 with carbon dioxide as the distention medium for hysteroscopy in patients with infertility or requesting reversal of a prior tubal sterilization

Our previous publications have demonstrated a high prevalence of hysteroscopic findings, particularly adhesions and polyps. It was the purpose of this study to compare the findings in 992 women in whom hysteroscopy was successfully performed by Dextran 70 with a similar group of 335 women in whom hysteroscopy was performed by CO2 as the distention medium. The incidence of uterine abnormalities in women with primary infertility, secondary infertility, and requesting reversal of sterilization when Dextran was used as the distention medium was 29%, 41%, and 33%, respectively, but only 7.2%, 11%, and 6%, respectively, when CO2 was used. It was concluded from these data that many of the findings of our preliminary studies were probably artifactual and a function of the technique of hysteroscopy and that our early reports must be read with caution.