Prevalence of cardiovascular risk factors in Indian patients undergoing coronary artery bypass surgery.

BACKGROUND: Conventional cardiovascular risk factors (CVRFs) are known to influence short-term and long-term outcome following coronary artery bypass graft surgery (CABG). There has been recent increase in prevalence of CVRFs in general population in India. However no information is available regarding the prevalence of same in patients undergoing CABG. METHODS AND RESULTS: In this cross-sectional study, one thousand consecutive patients undergoing elective CABG were included and data on major CVRFs was obtained in them. Mean age of the patients was 59.73 +/- 9.5 years and 884/1000 (88.4%) patients were males. 505/994 (50.8%) patients had BMI > or = 25.0 kg/m2 and 747/994 (75.2%) had BMI > or = 23.0 kg/m2. Diabetes mellitus was present in 475/1000 (47.5%) patients (46.5% men and 55.2% women), hypertension in 709/1000 (70.9% overall; 70.8% men and 71.6% women) and dyslipidemia in 781/913 patients (85.6% overall; 84.5% men and 93.9% women). 213/913 (23.3%) patients had LDL > or = 100mg/dl, 662/913 (72.5%) patients had low HDL and 338/913 (37.0%) patients had elevated triglycerides. 199/1000 (19.9%) patients (18.7% men and 29.3% women) had family history of premature CAD and 545/1000 (54.5%) patients (53.4% men and 62.9% women) had at least one family member having CAD (irrespective of the age of onset). 94/1000 (9.4%) patients (10.4% men and 1.7% women) were current smokers and another 302/1000 (30.2% overall; 33.7% men and 3.4% women) had history of smoking in the preceding one year. 876/913 (95.9%) of all the patients had at least one of the five major CVRFs and only 37/ 913 (4.1%) patients (4.1% men and 4.3% women) were free of all these risk factors. Sixty-one of the 1000 patients (6.1%) were younger than 45.0 years of age. As compared to older patients, dyslipidemia, family history of premature CAD and smoking were commoner in patients less than 45 years of age. In contrast, diabetes and hypertension were more prevalent in the older individuals. CONCLUSIONS: The present study showed high prevalence of most of the conventional CVRFs, esp. diabetes, hypertension and dyslipidemia in Indian population undergoing CABG.

Adsorption of esters of p-hydroxybenzoic acid by filter membranes: mechanism and effect of formulation and processing parameters.

The adsorption of esters of p-hydroxybenzoic acid (parabens) by filter membranes was studied by a flow-through technique. The hydrophobic effect was the major mechanism of adsorption. Propylparaben was more extensively adsorbed by all the membranes than was methylparaben. Hydrophobic membranes exhibited the greatest degree of adsorption, whereas adsorption was minimal for hydrophilic membranes. The charge of the filter membrane did not affect paraben adsorption. Formulation factors studied included the concentration of paraben, the presence of a tonicity-modifying agent (sodium chloride, mannitol, glycerin), and the presence of a chelating agent (edetate sodium). Paraben adsorption was directly related to paraben concentration. The presence of a tonicity modifier or chelating agent did not alter paraben adsorption to membrane filters. Processing parameters studied included flow rate, temperature, autoclaving, flow interruption, and filter membrane presaturation. Presaturation of the filter membranes for up to 1 hr reduced but did not eliminate paraben adsorption during simulated use. Interrupting the flow of the paraben solution through the filter membrane allowed for additional paraben adsorption and caused the concentration of paraben in the restarted filtrate to be less than 100% of theory.

Adsorption of benzalkonium chloride by filter membranes: mechanisms and effect of formulation and processing parameters.

The purpose of this study was to elucidate the mechanism(s) of adsorption of benzalkonium chloride (BAK) by filter membranes and to determine the effect of formulation and processing parameters on the adsorption of BAK. Six different sterilizing grade filter membranes were used in this study. Adsorption was monitored by passing an aqueous solution of BAK at pH 6 through a 47-mm (14.2 cm2 effective filter area) disk filter membrane and measuring the UV absorption of the filtrate with a UV micro flow cell. Hydrophobic and/or electrostatic forces were chiefly responsible for adsorption. The adsorption properties of each filter membrane could be related to its composition. Membranes that were hydrophilic and nonionic or hydrophilic and cationic adsorbed little BAK. However, membranes that were hydrophobic or anionic exhibited significant BAK adsorption. Adsorption followed the Langmuir equation and adsorptive capacities ranged from 116 to 429 micrograms/47 mm membrane (8.17-30.23 micrograms/cm2). Formulation factors studied included the concentration of BAK, the presence of a tonicity-modifying agent (sodium chloride, mannitol, glycerin), and the presence of a chelating agent (edetate disodium). The greatest increase in adsorption of BAK occurred when sodium chloride or edetate disodium was used with membranes that contained cationic sites. The effects of flow rate, temperature, autoclaving, interrupting the flow, and presaturating the filter membrane were the processing parameters studied. The rate of adsorption was inversely related to flow rate and the extent of adsorption was inversely related to temperature. Presaturation of the filter membrane with BAK was an effective method to reduce the adsorption of BAK during filtration.

Cervical spine involvement in rheumatoid arthritis: prevalence and relationship with overall disease severity.

Rheumatoid arthritis (RA) affects the cervical spine in 20-90% of patients in Western countries. We report the prevalence of cervical spine involvement in RA and its relationship with duration of disease, seropositivity, hand joint erosions and symptoms and signs suggestive of cervical spine involvement. 100 patients with RA criteria were included. Apart from clinical history and examination, study included X-rays of the cervical spine in AP, open mouth and lateral views and posteroanterior view of hands and rheumatoid factor estimation. All X-rays were read by a radiologist who was unaware of the clinical details. Cervical spine involvement was seen in 65% of patients. The commonest abnormality was erosions of the odontoid process (47%), followed by atlanto-axial dislocation and apophyseal joint involvement (24%). Only 5% of patients had abnormalities of spinous processes or vertebral bodies. Patients with abnormal cervical spine radiographs had higher prevalence of rheumatoid factor and erosions on hand radiographs. Severity of cervical spine changes was related to duration of disease (> 5 years). No correlation was seen between symptoms and radiological abnormalities except when neurological deficit was present. Patients with seropositivity, erosive disease and disease duration greater than five years should be screened for cervical spine disease.

Geographic variations in structure and composition of gallstones and their correlation with brittleness.

Cholesterol gallstones obtained from different geographic regions have been reported to show significant differences in their minor chemical constituents. We undertook the present study with two objectives: (i) to investigate the possible physiochemical and radiological differences between cholesterol gallstones obtained from Indian and German patients; and (ii) to compare the brittleness of the two stone groups. Forty Indian and 36 German gallstones (matched in size and shape) were subjected to assessment of physical characteristics, in vitro computed tomography (CT) and chemical analysis. German stones more often had a stone density distribution index of > or = 50 Hounsfield units (HU) (26 vs 14; P < 0.01), peripheral calcification (18 vs 9; P < 0.02), maximum CT density > or = 90 HU (17 vs 9; P < 0.05) and significant calcium carbonate (9 vs 5; P < 0.05), compared to Indian stones. The in vitro lithotripsy performed with the Siemens Lithostar Plus machine at a constant energy level showed the German stones to be more brittle (easy to fragment), more often requiring < 1000 shocks for fragmentation (25/36; 69%) compared to Indian stones (18/40; 45%, P < 0.05). Gallstones from different geographic regions may show significant variations in their physicochemical characteristics that may explain the differences in their brittleness to lithotripsy.

Brittleness of gallstones to lithotripsy: effect of physicochemical and ultrastructural characteristics.

Why some gallstones do not fragment easily to lithotripsy is unclear. The aim of the present study was to determine gallstone factors associated with resistance to fragmentation. Seventy-six cholesterol rich gallstones were subjected to physical evaluation, in vitro computed tomography, chemical analysis by infra red spectroscopy, and ultrastructural studies (of 26 matched stones) by scanning electron microscopy and energy dispersive X-ray microanalysis. In vitro lithotripsy was performed with the Siemens Lithostar Plus machine at a constant energy level. Of 76 stones, 33 required > 1000 shocks for effective fragmentation (largest diameter < or = 5 mm); they had significantly higher maximum diameter (P < 0.001), volume (P < 0.001), weight (P < 0.001) and lower stone density distribution (SDD) index (P < 0.05) and lower calcium bilirubinate content (P < 0.001) than those requiring < or = 1000 shocks. Large (> 15 mm; P < 0.05), round stones (P < 0.02) and gallstones with SDD index of < 50 HU (P < 0.02) and gallstones with SDD index of < 50 HU (P < 0.05) were more difficult to fragment. Clinical application of these parameters may help in better selection of patients for this non-surgical mode of therapy for gallstones.

Cholecystectomy and drainage: ultrasonographic and radioisotopic evaluation.

Eighty patients undergoing cholecystectomy were either assigned deliberately (n = 30) or randomized (n = 50) to drainage (n = 38) or nondrainage (n = 42). Subhepatic collections were seen on ultrasonography (US) after 48 to 72 hours in 12 of 35 patients with drainage and 24 of 42 patients without drainage (p < 0.05). Only two patients with subhepatic collections were symptomatic, and none required treatment. Postoperative infective complications were seen in 13 of 38 patients with drainage and with a collection, and none of the 18 patients without drainage and without a collection had postoperative infective complications (p < 0.05). Cholecystectomy was then performed in 100 patients without using a drain. BULIDA radioisotope scans revealed a bile leak in only 4 of 34 patients studied. Subhepatic collections were seen on US after 48 to 72 hours in 42 patients. The collection resolved in 22 patients and was smaller in 6 on repeat US. None of the patients with collection was symptomatic, and none required treatment. Postoperative infective complications were seen in 7 of 42 patients with a collection and 5 of 58 patients without a collection (not significant). We conclude that (1) cholecystectomy with drainage is associated with more infective complications than when a drain is not used; (2) cholecystectomy without drainage is safe; and (3) asymptomatic nonbilious subhepatic collections are common after cholecystectomy without drainage but do not require treatment, resolving spontaneously.