Potentiation of cholinergic activity with pyridino[1,2-a]imidazo[5,4-b]indole: in vitro studies

1. Effects of a novel imidazoindole derivative on cholinergic function were studied in isolated tissue preparations. 2. The compound demonstrated a dose-dependent (10(-11)-10(-9) potentiation (20-60%) of acetylcholine induced tension in guinea pig ileal tissue. 3. Increases in the size of end-plate potentials and nerve evoked muscle twitches were observed in frog nerve-skeletal muscle preparations. 4. Cholinesterase activity was not inhibited. 5. The results suggest that the compound has actions at the post-synaptic muscarinic receptor complex in smooth muscle and causes pre-synaptic increases in ACh release at the neuromuscular junction.     

Alteration of pregnancy related hormones and fetal survival in F-344 rats exposed by inhalation to benzo(a)pyrene

The objective of this study was to evaluate the effect of subacute exposure to inhaled benzo(a)pyrene (BaP) on fetal survival and luteal maintenance using timed-pregnant Fisher 344 rats. Prior to assignment of pregnant rats to treatment and control groups, numbers of implantation sites were determined on gestation day (GD) 8 via midventral laparotomy. Subsequently, animals were assigned randomly to three treatment groups and two control groups. Treatment consisted of subacute exposure of rats via inhalation to BaP 25, 75, and 100 μg/m³, 4 h daily for 10 days (GD-11–20). Control animals were either sham exposed to carbon black (CB) to control for inert BaP carrier or remained unexposed (UNC). Blood samples were collected on days 15 and 17 of gestation via sinus orbital veini-puncture for plasma. Number of pups per litter was determined postpartum and fetal survival rate was expressed as a percentage of the corresponding implantation sites. Radioimmunoassays were used to determine plasma progesterone, estrogen, and prolactin (indirect measurement of decidual luteotropin) concentrations. Fetal survival among BaP-treated rats declined in a dose-dependent manner (25 μg/m³, 78.3% per litter; 75 μg/m³, 38.0% per litter; 100 μg/m³, 33.8% per litter; P<0.05) compared with CB (96.7% per litter) and UNC (98.9% per litter). Plasma progesterone, estrogen, and prolactin concentrations also declined as a result of subacute exposure of rats to BaP compared to controls. These data suggest that inhaled BaP compromised fetal survival and consequently luteotropic activity in the exposed animals.     

Partial small bowel resection with sleeve gastrectomy increases adiponectin levels and improves glucose homeostasis in obese rodents with type 2 diabetes

Background  

The aim of this study was to examine the effect of small bowel resection with and without sleeve gastrectomy on glucose homeostasis in an obese rodent model of type 2 diabetes.     

Hydroxyurea-induced denaturation of normal and sickle cell hemoglobins in vitro

Use of hydroxyurea (HU) to treat sickle cell disease is usually associated with increments in fetal hemoglobin (Hb F) production; however, in vitro studies show that HU may also induce hemoglobin denaturation. Whole blood samples from Hb AA, Hb AS, and Hb SS patients were treated in vitro with 100, 150, 200, 250, and 300 μg/mL HU, incubated at 30°C for up to 12 days, and analyzed by high-performance liquid chromatography (HPLC). Hb AA levels show decrements of 91 to 14% with 100 μg/mL and 89 to 4% with 150 μg/mL after 12 days; 86 to 2% with 200 μg/mL after 10 days; 86 to 8% with 250 and 300 μg/mL after 8 days. Similar treatment and incubation times for Hb AS whole blood demonstrate that HU equally degrades the A and S components of Hb AS. A comparable approach for Hb SS whole blood samples, using a 300 μg/mL HU treatment, showed a hemoglobin denaturing pattern that went from 93% to 1% after 12 days. Globin chain analysis of these samples by reverse-phase HPLC showed that the denaturing effects occur mostly on the β-globin chain. J. Clin. Lab. Anal. 11:208–213, 1997. © 1997 Wiley-Liss, Inc.     

Paternal origin of trisomy 21 following intracytoplasmic sperm injection (ICSI)

One important aspect in the debate on the genetic risks associated with intracytoplasmic sperm injection (ICSI) is the possible increased rate of chromosomal abnormalities in resulting pregnancies. ICSI was performed in a 27 year old man with asthenoteratozoospermia and his 25 year old wife. There was a spontaneous miscarriage at 9 weeks of gestation. Cytogenetic investigation revealed trisomy 21. Analysis of two polymorphic microsatellite markers showed that the additional chromosome was paternal. This is in contrast to the fact that the vast majority of trisomic concepti are maternal in origin. Identifying the parent of origin in trisomic conceptions achieved by ICSI may reveal whether ICSI is associated with an increased risk of paternally derived aneuploidy.