PubMed Health⌕ Search

Biomedical subjects

J S Meyers

Publications and source records attributed to J S Meyers.

6 recordsLinked to original sources
PubMed2001

Treatment of anal fissures with topical nitroglycerin.

Anal fissure is a painful condition that is caused by anodermal tearing after the passage of hard stool. Severe cases result in involuntary internal anal sphincter spasm and have traditionally been treated surgically with a lateral sphincterotomy. Investigators have demonstrated that nitric oxide causes relaxation of the smooth muscle of the anal canal, so topical nitroglycerin ointment preparations have recently been studied as an efficacious alternative to surgery. Despite the fact that there are a number of trials examining topical nitroglycerin for the treatment of anal fissures, there remains no consensus about concentrations, compositions and applications necessary to obtain good results. This review summarises current literature regarding topical nitroglycerin pharmacotherapy for anal fissure.

Administration, Topical↗
PubMed1990

Maternal modulation of growth hormone secretion in the neonatal rat: involvement of mother-offspring interactions.

Serum GH levels increased in 2- or 8-day-old rat pups when sucking mammary glands whose main milk ducts were ligated. Although intragastric administration of rat milk has been shown to increase serum GH levels in neonatal rats, ingestion of milk during suckling did not increase serum GH values further. In another experiment, 2-day-old pups obtained no milk when they were suckled by anaesthetized mothers, and in this instance the serum GH concentration of the pups decreased. This decrease was prevented if the mothers were injected with oxytocin to counteract the depressant effect of the anaesthesia on milk ejection; nevertheless, GH levels in neonatal animals failed to increase following suckling. Thus some aspect of maternal activity appears to be involved in the suckling-induced increase of serum GH in rat pups. To elucidate which components of maternal activity might be involved, the effects of manipulations of ambient temperature as well as stimulation of the oral or anogenital regions were examined. Exposing rat pups to 37 degrees C (nest temperature) during the 6-h separation period before suckling prevented the separation-induced decrease in serum GH levels of 2-day-old pups. Moreover, exposure to 37 degrees C for 30 min following a 6-h separation at room temperature (22 degrees C) mimicked the effect of suckling in increasing serum GH levels in the pups. Suckling following separation at 37 degrees C was unable to increase serum GH values further.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Maternal modulation of growth hormone secretion in the neonatal rat. I. Involvement of milk factors.

The present experiments investigated the time course of maternal modulation of GH secretion and examined the possible role of milk in the regulation of GH secretion in neonatal rats. Serum GH concentrations in neonatal rats were high at birth and declined over time postpartum. Separation of rat pups from their mothers decreased, while a subsequent period of suckling increased, serum GH levels in rat pups on postpartum days 1-14, but not on day 20. The water-soluble fraction (infranatant) of rat milk contained immunoreactive (ir) rat GH-releasing hormone (rGHRH)-like material (725.06 +/- 81.29 pg/ml), ir-somatostatin-like activity (1.64 +/- 0.2 ng/ml), and irGH (4.79 +/- 0.73 ng/ml). The concentrations of these hormones tended to decrease with time postpartum and were positively correlated with each other (r = 0.70; P less than or equal to 0.0001). IrPRL was also present in the infranatant (148.44 +/- 14.55 ng/ml), but levels were not correlated with the other hormones detected. Milk infranatant stimulated GH secretion from perifused neonatal rat pituitary glands in vitro. Milk infranatant also stimulated GH secretion in vivo when administered sc or intragastrically to 2- or 8-day-old rat pups. The GH-releasing effect was not due to gastric distension or nonspecific nutritive components, as neither 0.9% saline nor nutrients (5% glucose and 10% BSA) increased serum GH levels. The presence of high concentrations of irGHRH in rat milk infranatant and the strong correlation between the irGHRH concentrations of milk samples and the in vitro GH response (r = 0.71; P less than or equal to 0.005) suggested that this peptide is a major candidate for producing the in vitro and in vivo GH-stimulating activity in rat milk. However, the minimally effective concentration of synthetic rGHRH required to stimulate GH release in the superfusion system was between 1-10 nM, which exceeds milk irGHRH levels by 100- to 1000-fold. Moreover, in vivo administration of synthetic rGHRH (sc or intragastrically) was unable to increase serum GH concentrations in 2-day-old pups, although a large dose (100 ng/g) of human GHRH sc was effective. These findings indicate that rat milk may be an important maternal factor that modulates GH secretion and, consequently, growth during the neonatal period. Rat milk has GH-releasing activity both in vivo and in vitro in neonatal rats, but the GH-releasing activities of milk are probably only minimally due to its rGHRH content.

Aging↗