Homograft valve bank: our experience in valve banking.

BACKGROUND: A cardiac homograft valve bank with cryopreservation facility was established at the Institute of Cardiovascular Diseases, Madras Medical Mission, Chennai in July 1995. METHODS AND RESULTS: During the last 7 1/2 years of its existence, from July 1995 to March 2003, 588 hearts were processed. The valves harvested were 390 aortic, 400 pulmonary and 39 others including mitral valve, aortic conduits, pericardium etc.; 176 (29.9%) hearts were discarded for various reasons which included failure to sterilize, HBV, HIV, HCV, treponema pallidum hemagglutination test positivity, atheromatous/fatty streaks, incompetent valves, and dissection mistakes. The valves were sterilized using an antibiotic cocktail of vancomycin, amikacin, streptomycin, cefotaxime and amphotericin B in Hank's balanced salt solution. Of the 585 valves issued for clinical use, 247 were aortic, 323 pulmonary and 15 others (mitral valve, pericardium, conduits). Gram negative bacilli were the predominant contaminants from the hearts during the first half (July 1995 to February 1999) and gram positive organisms were the predominant contaminants during the later half (March 1999 to March 2003) of the study period. A variety of fungal contaminants like candida, aspergillus, penicillium and other fungi were also isolated from the homograft hearts at procurement. The valves were used most commonly for Rastelli procedure/right ventricular-pulmonary artery conduit (48.71%) followed by Ross procedure (23.41%). The other procedures were aortic valve replacement (6.15%), truncus repair (5.81%), unifocalization with conduit repair (6.49%), aortoplasty (0.512%), left ventricular-pulmonary artery conduit (0.512%), pulmonary valve replacement (0.512%), aneurysm repair (0.34%), Norwood repair (0.34%), mitral valve replacement (0.17%) and other procedures (7%). CONCLUSIONS: We have established a viable and functioning cardiac homograft valve bank to suit Indian conditions and till date, have issued 585 homograft valves for clinical use.

Nocardia asteroides mediastinitis complicating coronary artery bypass surgery.

A 63 years diabetic male was admitted with mediatinitis and sternal dehiscence. Nocardia asteroides sensu stricto Type VI was isolated from the mediastinal tissue and fluid during debridement. Prompt surgical intervention and treatment with ofloxacin both intravenously and later orally led to the cure.

A comparative study of the intestinal parasites prevalent among children living in rural and urban settings in and around Chennai.

A comparative analysis of the various intestinal parasites detected among children attending schools was carried out in a rural and urban location in and around Chennai. A total of 324 stool samples were examined by routine microscopy using normal saline and Lugol's iodine preparation as well as by saturated sodium chloride flotation technique. All suspicious samples were subjected to zinc sulphate concentration technique as well as modified Ziehl Neelson stain and Trichrome stains to identify the other uncommon intestinal parasites. Out of 125 specimens tested from the rural location, the overall prevalence of intestinal parasites was 91%. Ascaris lumbricoides was the most common helminthic parasite detected (52.8%) followed by Trichuris trichura (45.6%), Ancylostoma duodenale (37.6%), Strongyloides stercoralis (3.2%) and Hymenolepis nana (1.6%). Giardia lamblia was the most common protozoan parasite detected (16%), followed by Entamoeba histolytica (4%). In contrast under urban settings, out of the 199 stool specimens tested the positivity rate was 33%. Giardia was the most common parasite detected (22.6%) followed by Entamoeba histolytica (10.6%). All other intestinal parasites such as T. trichura (2.01%), H. nana (1.01%) and A. lumbricoides (0.50%) were found to have much lower prevalence in comparison to the rural area tested. Enterobius vermicularis (0.50%) was also detected. Ancylostoma duodenale and Strongyloides stercoralis were not encountered at all in the urban setting studied.

Prevalence, species distribution and antifungal sensitivity of vaginal yeasts in infertile women.

A total of 326 high vaginal swabs from infertile women attending the Institute of Reproductive Medicine were cultured from June 1999 to May 2000. Candida species was isolated from 42(12.88%) patients. Candida albicans (40.47%) followed by Candida glabrata (38.09%) were the most common isolates. Other species included Candida tropicalis (14.28%) and Candida krusei (7.14%). All isolates were tested for sensitivity by disc diffusion method on Yeast Nitrogen Agar base towards four antifungals. Seven (16.7%) candida strains showed resistance to Fluconazole and 19(45.23%) of the strains showed resistance to Itraconazole, and 4(9.5%) strains showed resistance to Nystatin. There was no resistance to Amphotericin B. Of the 7 strains resistant to Fluconazole, 3 were Candida krusei, 3 were Candida glabrata and 1 was Candida tropicalis.

Vaginal carriage of group B Streptococcus in infertile women.

From May, 1999 to April, 2000, 256 high vaginal swabs were culture from asymptomatic infertile women attending the out-patient department of the Institute of Reproductive Medicine. 41 strains of Streptococcus agalactiae were isolated from 33 patients (12.89%). Five patients had repeated isolations even after adequate therapy.