Perinatal lung development following maternal exposure to methylmercuric chloride

Mercury ingested from dietary sources has potent neurotoxic and teratogenic effects. Initial studies have shown that mercury may also affect fetal lung development. Since these pulmonary effects may play a role in subsequent neonatal morbidity and mortality due to compromising of the development of the lung, mercury effects in fetal and neonatal lung were investigated. Methylmercuric chloride (MMC), 1,000 ppm (15 mg/kg of body weight), was administered via an intragastric tube to timed-pregnant Swiss/Webster mice on day 9 of gestation. Lungs from fetuses on gestational day 18 and from neonates on days 1, 5, or 10 after birth were studied. Significant changes in MMC-exposed lungs compared to controls occurred at postnatal day 1. At this time, lung weight per gram body weight increased, phospholipid content per gram of lung or per microgram of DNA decreased, while DNA per gram of lung increased. Methylmercury appears to have delayed lung maturation. Cuboidal epithelial cells in alveolar tubules contained conspicuous glycogen deposits, and differentiation of alveolar type II cells was adversely affected. These results suggest that prenatal exposure to methylmercury may be detrimental to lung development, specifically to the initiation of surfactant synthesis, by delaying the normal pattern of maturation of the alveolar type II cells within the lungs. Pediatr Pulmonol. 1994; 17:11–21 . © 1994 Wiley-Liss. Inc.     

Congenital thrombophilia among patients with venous thromboembolism.

During a 3-year period we studied 393 adult patients (382 of whom were unrelated) with a history of acute venous thromboembolism. A congenital deficiency state known to predispose to thrombosis was found in 27.2%. Of these, most were due to deficiencies of protein C (9.2%), protein S (7.6%), antithrombin III (5%) or to increased plasma PAI-1 concentration (3.1%) which, in the absence of any known factor that predisposes towards thrombosis, results in a diminished fibrinolytic activity. There was a characteristic pattern between the age of onset (mean 34 years) of thrombosis and individual protein deficiency. Thrombosis appeared spontaneously in 73% of cases with recurrence in 80%. In contrast, in the remaining unrelated patients, 138 (35.1%) in whom venous thromboembolism was secondary and occurred at a mean age of 43 years, and in the other 140 (35.6%) who suffered thromboembolism spontaneously at a later age (mean age 55), there was no permanent protein deficiency state or alteration in fibrinolytic activity and thrombosis recurrence was lower (53.6% and 20.7% respectively). Of the 393 patients, deep vein thrombosis was the most common manifestation; however, in congenital thrombophilia, thrombosis of visceral vessels and Raynaud's syndrome (6%) were also detected.     

Pharmacokinetic evaluation of conventional and controlled release dosage form of propranolol

A comparative pharmacokinetic study of a new controlled release multiple unit propranolol formulation and a conventional propranolol tablet was carried out in twelve healthy human volunteers in a randomized balanced crossover design. Under a single dosage regimen, subjects were administered either a single capsule containing controlled release propranolol equivalent to 160 mg of the drug or 80 mg of conventional propranolol tablet, twelve hourly. Peak plasma propranolol concentrations were low which occurred later after controlled release administration than after the administration of the conventional tablet. Analysis of the area under the plasma concentration-time curve (AUC) for the two formulations indicate no significant difference of bioavailability despite a prolonged absorption time and maintenance of effective plasma concentration for the controlled release preparation.     

Reduction of glutathione is associated with growth restriction and enlargement of bovine pulmonary artery endothelial cells produced by transforming growth factor-beta 1.

In addition to inhibiting proliferation and causing enlargement of bovine pulmonary artery endothelial cells in culture, porcine platelet transforming growth factor-beta 1 (TGF-beta 1) (2 ng/ml) lowered glutathione (GSH) of these cells by 48% after 96 h in culture when GSH levels were normalized for cell counts. This lowering of cellular GSH was more marked when corrections were made for approximated cell volume. TGF-beta 1 produced only moderate inhibition of pulmonary artery smooth muscle cell proliferation and did not significantly reduce the GSH content of these cells, even at concentrations as high as 8 ng/ml. Elevation of GSH of endothelial cells above control levels by 0.05 mM diethylmaleate or 1 mM cystine prevented the inhibition of cellular proliferation produced by TGF-beta 1. Lowering cellular GSH levels by approximately 85% for 24 to 72 h with 0.01 mM buthionine sulfoximine (BSO) in the absence of TGF-beta 1 had no effect on proliferation or size of the endothelial cells. However, 0.01 mM BSO potentiated the inhibitory effect of TGF-beta 1 on endothelial cell proliferation and in combination with TGF-beta 1 caused cellular detachment at low endothelial cell densities. Thus, although TGF-beta 1 lowers the level of endothelial cellular GSH, this in itself does not appear to account for the inhibition of proliferation and enlargement of these cells produced by TGF-beta 1. Rather, the combination of another unidentified action of TGF-beta 1 in the presence of reduced cellular GSH likely accounts for these effects.     

Pancreatic pseudocysts: treated with dual drainage.

Four patients with retrogastric pancreatic pseudocysts were successfully treated by the combined placement of a transgastric external drain and a cystogastric stent. We describe the advantages of using external transgastric drainage along with the cystogastric stent.     

Peripheral analgesic activities of peptides related to alpha-melanocyte stimulating hormone and interleukin-1 beta 193-195.

1. The hyperalgesic effects of interleukin-1 beta (IL-1 beta) and prostaglandin E2 (PGE2) were measured in rats. 2. Hyperalgesic responses to IL-1 beta were inhibited in a dose-dependent manner by alpha-melanocyte stimulating hormone (alpha-MSH)-related peptides with the following order of potency: [N1(4),D-Phe7]alpha-MSH greater than alpha-MSH greater than Lys-D-Pro-Val greater than Lys-Pro-Val greater than Lys-D-Pro-Thr greater than D-Lys-Pro-Thr. 3. Hyperalgesic responses to PGE2 were not inhibited by Lys-D-Pro-Thr and D-Lys-Pro-Thr but were inhibited in a dose-dependent manner by the other peptides with the same order of potency as against IL-1 beta. 4. The potencies of [N1(4), D-Phe7]alpha-MSH and alpha-MSH were greatly diminished by deletion of their C-terminal tripeptide, Lys11-Pro-Val13. 5. Nor-binaltorphimine (Nor-BNI) largely reversed the analgesic effects of alpha-MSH, [N1(4), D-Phe7]alpha-MSH, Lys-Pro-Val and Lys-D-Pro-Val indicating that kappa-opioid receptors mediated the analgesic activity of these peptides. 6. Nor-BNI did not antagonize the inhibition by Lys-D-Pro-Thr and D-Lys-Pro-Thr of IL-1 beta evoked hyperalgesia indicating that these peptides were not acting via kappa-opioid receptors.     

Benzazepinone calcium channel blockers. 2. Structure-activity and drug metabolism studies leading to potent antihypertensive agents. Comparison with benzothiazepinones.

As part of a program to discover potent antihypertensive analogues of diltiazem (3a), we prepared 1-benzazepin-2-ones (4). Benzazepinones competitively displace radiolabeled diltiazem, and show the same absolute stereochemical preferences at the calcium channel receptor protein. Derivatives of 4 containing a trifluoromethyl substituent in the fused aromatic ring show potent and long-acting antihypertensive activity. Studies of the metabolism of 4 lead to the metabolically stable antihypertensive calcium channel blockers 5a and 5c. Benzazepinone 5a is a longer acting and more potent antihypertensive agent than the second generation diltiazem analogue TA-3090 (3e).     

Community survey of primary dystonia in the city of Kolkata, India.

An epidemiological study on dystonia has not been reported from India. As part of a major study to find out the prevalence of major neurological disorders in the large urban city of Kolkata, Eastern India, we planned to determine the prevalence of primary dystonia. The study design was a cross-sectional study of a sample population obtained through stratified random selection and conducted in a two-stage procedure of screening by a nonprofessional team followed by confirmation of screened positive cases by the study neurologist. A total population of 52,377 was screened, and 29 subjects with dystonia were diagnosed. Out of them 23 subjects had primary dystonias [crude prevalence rate (CPR), 43.91/100,000; 95% confidence interval (CI), 28.41-64.81; age-standardized rates to world standard population, 49.06 (95% CI,31.74-72.41)] and all cases were focal type and predominantly of limb dystonia variety. Mean onset of dystonias were earlier in women (43.5 years) as compared to men (46.6 years). Thus our study on primary dystonia shows higher prevalence when compared with that of many studies globally, predominantly of focal type, earlier onset among women, and more cases of limb dystonias when compared with more prominent blepharospasm and cervical dystonias in western reports.     

Endocardial catheter ablation of ventricular tachycardia in patients with ventricular assist devices

BACKGROUND: The outcomes of patients with ventricular assist devices (VADs) who undergo catheter ablation for ventricular tachycardia (VT) have not been reported. OBJECTIVE: The purpose of this study was to assess the feasibility, safety, and efficacy of endocardial VT ablation in patients with VADs. METHODS: We retrospectively reviewed three cases at our institution where endocardial catheter ablation was performed in patients with VADs and incessant VT. RESULTS: Three patients with underlying cardiomyopathies and VADs underwent VT ablation for incessant VT refractory to multiple antiarrhythmic medications. In each case, VT was either eliminated or significantly ameliorated by catheter ablation. No procedure-related complications occurred. The hemodynamic stability afforded by the VAD played an important role in facilitating ablation in two of the cases. CONCLUSION: Catheter ablation for VT in VAD patients appears to be feasible, safe, and effective based on our initial experience. Several technical issues, such as decreases in ventricular volumes that can limit maneuverability of the ablation catheter and potential entrapment of the mapping catheter in the inflow cannula, need to be considered at the time of ablation.     

Bancroftian filariasis in Pondicherry, south India--epidemiological impact of recovery of the vector population.

An Integrated Vector Management (IVM) strategy was implemented from 1981 to 1985 in one part of Pondicherry, South India, for the control of the bancroftian filariasis vector Culex quinquefasciatus (the IVM area). The rest of the town (the comparison area) received the conventional larvicidal input. After 1985 both the areas were managed conventionally. The switch to conventional strategy resulted in an increase of vector density in both areas. The microfilaraemia prevalence in humans showed a general decline (P less than 0.05) from 1986 to 1989 only in the IVM area whereas its intensity did not change significantly in either area. While the age-specific rate of gain of infection was generally unchanged in the IVM area, an increase in all age classes was observed after 1985 in the comparison area, where the Annual Transmission Index was high during the previous years. In both areas the rate of loss of infection increased during 1986-9 compared to 1981-6. The results suggest that 3 years is too short a period to relate the changes in entomological parameters to those in the microfilaraemia status of the population.