Off-pump multivessel coronary artery surgery in high-risk patients

BACKGROUND: Coronary artery bypass surgery on cardiopulmonary bypass is associated with significant morbidity and mortality, which may be more marked in high-risk patients. We evaluated our results of off-pump coronary artery bypass (OPCAB) in high-risk patients with multivessel coronary artery disease and compared them with results in similar patients who underwent operation on cardiopulmonary bypass. METHODS: A total of 1,075 patients who underwent OPCAB between October 1996 and June 2001 and who had one or more of the following risk factors were included in the study: poor left ventricular function (EF < or = 30%), advanced age (> 70 years), left main stenosis, acute myocardial infarction, and redo coronary artery surgery. These patients were compared with 2,312 similar patients who underwent coronary artery bypass grafting on cardiopulmonary bypass during the same period. Preoperative risk factors, intraoperative variables, and postoperative results were analyzed and compared between two groups. RESULTS: The average number of grafts was 3.0 +/- 0.4 and 3.2 +/- 0.3 in the off-pump (OPCAB) and on-pump (CCAB) groups, respectively. Hospital mortality was 3.2% and 4.5% in OPCAB and CCAB groups respectively (p = 0.109). Perioperative myocardial infarction, requirement of inotropic agents, stroke, and renal dysfunction were comparable in two groups. Intubation time (19 +/- 5 vs 24 +/- 6 hours, p < 0.001), mean blood loss (362 +/- 53 vs 580 +/- 66 mL, p < 0.001), atrial fibrillation (14.3 vs 19.7%, p < 0.001), and prolonged ventilation (4.6 vs 7.6%, p = 0.002) were less in OPCAB group. Intensive care unit stay (20 +/- 8 hours) and hospital stay (6 +/- 3 days) were significantly less in the OPCAB group (p < 0.001). CONCLUSIONS: Off-pump coronary artery surgery can be safely performed in high-risk patients with multivessel coronary artery disease. Operative mortality is comparable to that associated with on-pump surgery, and avoidance of cardiopulmonary bypass is associated with reduced postoperative morbidity in these patients.     

Can computers improve patient care by primary health care workers in India?

OBJECTIVE: The objective was to test whether a decision support technology for non-physicians can increase health care utilization and quality. DESIGN: Before and after measurements were taken from a systematic random sample of patients and staff at randomly assigned intervention and control facilities. SETTING: The study took place at primary health facilities in rural Tamil Nadu, India. PARTICIPANTS: One thousand two hundred and eighty-six patients and 82 staff were interviewed. INTERVENTION: A computer-assisted decision support technology was introduced to assist with patient screening. MAIN OUTCOME MEASURES: Outcome measures included new patient visits per month, a Global Patient Assessment of Care Index, and health worker attitude variables. RESULTS: There was a difference of difference of 430 new patient visits per month at the intervention sites (P = 0.005), an increase from baseline of 18% at intervention sites compared with a decline of 5% at control sites. The intervention was associated with significant improvements in a Global Patient Assessment of Care Index (mean difference of difference 7.9, P < 0.001). The largest gains were made in patient communication, technical quality, and general satisfaction with care. The attitudes of public health workers toward the new technology and their jobs did not change. CONCLUSIONS: Decision support technologies have considerable potential to improve coverage and quality of health care for the poor and where there is no doctor, but the unreceptive attitude of public health workers would need to be overcome. Application of these technologies should take advantage of their popularity with patients and the opportunity to work through the private sector.     

CT in the evaluation of complicated autosomal dominant polycystic kidney disease

Purpose: We retrospectively reviewed the CT findings in 24 cases of autosomal dominant polycystic kidney disease (ADPKD) to assess the role of CT in the diagnostic work-up of patients with complicated ADPKD.Material and Methods: Twenty-four patients with ADPKD underwent unenhanced and contrast-enhanced CT for flank pain, haematuria, or fever. The images were retrospectively reviewed for presence of complicated cysts, their morphological features and associated findings in the perinephric space/retroperitoneum.Results: Cyst haemorrhage was present in all patients, seen as high-density cysts, which were mostly bilateral. Most of these cysts had sharply outlined contours, sharp interfaces with adjacent renal parenchyma, imperceptible walls, and homogeneous density, and did not enhance following i.v. contrast administration. However, a few haemorrhagic cysts (9 cysts in 6 patients) showed inhomogeneous density (n=7), dependent layering of high-density blood leading to fluid-fluid level (n=2), and contour irregularity (n=3).CT revealed presence of cyst infection in 6 cases; the involved cysts were larger (average size 4.2 cm) than adjacent cysts, had only a mildly increased or near water density, and showed wall thickening and enhancement. Other findings included air within the infected cyst (n=1), thickening and enhancement of peri- and paranephric fasciae (n=5), and abscesses in the posterior paranephric space and adjoining psoas muscle (n=2). In 2 other patients, although CT suggested cyst infection because of presence of wall enhancement, diagnostic needle aspiration revealed only sterile haemorrhagic fluid. In 1 case, CT revealed a soft tissue density enhancing mass in one of the cysts; this proved to be a renal cell carcinoma by fine-needle biopsy. Calculi were observed in 7 patients, and cyst wall calcification in 11 cases.Conclusion: A combination of unenhanced and contrast-enhanced CT allows correct diagnosis and differentiation amongst the various complications affecting patients with ADPKD. However, in a small subgroup of patients, it may not be possible to differentiate between haemorrhage and infection; such cases require diagnostic needle aspiration for diagnosis.     

Magnesium levels in serum and in C.S.F. in febrile convulsions in infants and children

Summary Magnesium levels in the serum and in the C.S.F. in 100 children presenting with febrile convulsions were determined. This was repeated in 36 children after 2 weeks, of which 23 could be re-examined after a further period of 2 weeks. Nearly one-half of the cases on admission had magnesium levels in the serum lower than the average observed in normal children in this region and in over two-thirds of the cases the levels in the C.S.F. were lower than the average in the same region. The C.S.F. magnesium levels rose after 2–4 weeks. This was not found in the case of serum levels. These findings bear out the suggestion made in a pervious communication that there is some aetiological relationship between the magnesium levels in these two body fluids on the one hand and febrile convulsions on the other. From the Department of Pediatrics, M.G.M. Medical College and M.Y. Hospital, Indore. (M.P.)     

Cross-linked polymeric nanogel formulations of 5'-triphosphates of nucleoside analogues: role of the cellular membrane in drug release

Activation of cytotoxic nucleoside analogues in vivo depends primarily on their cell-specific phosphorylation. Anticancer chemotherapy using nucleoside analogues may be significantly enhanced by intracellular administration of active phosphorylated drugs. However, the cellular transport of anionic compounds is very ineffective and restricted by many drug efflux transporters. Recently developed cationic nanogel carriers can encapsulate large amounts of nucleoside 5'-triphosphates that form polyionic complexes with protonated amino groups on the polyethylenimine backbone of the nanogels. In this paper, the 5'-triphosphate of an antiviral nucleoside analogue, 3'-azido-2',3'-dideoxythymidine (AZT), was efficiently synthesized and its complexes with nanogels were obtained and evaluated as potential cytotoxic drug formulations for treatment of human breast carcinoma cells. A selective phosphorylating reagent, tris-imidazolylphosphate, was used to convert AZT into the nucleoside analogue 5'-triphosphate using a one-pot procedure. The corresponding 3'-azido-2',3'-dideoxythymidine 5'-triphosphate (AZTTP) was isolated with high yield (75%). Nanogels encapsulated up to 30% of AZTTP by weight by mixing solutions of the carrier and the drug. The AZTTP/nanogel formulation showed enhanced cytotoxicity in two breast cancer cell lines, MCF-7 and MDA-MB-231, demonstrating IC50 values 130-200 times lower than those values for AZT alone. The exact mechanism of drug release from nanogels remains unclear. One mechanism could involve interaction with negatively charged counterions. A high affinity of nanogels to isolated cellular membranes has been observed, especially for nanogels made of amphiphilic block copolymer, Pluronic P85. Cellular trafficking of nanogel particles, contrasted by polyethylenimine-coordinated copper(II) ions, was studied by transmission electron microscopy (TEM), which revealed membranotropic properties of nanogels. A substantial release of encapsulated drug was observed following interactions of drug-loaded nanogels with cellular membranes. A drug release mechanism triggered by interaction of the drug-loaded nanogels with phospholipid bilayer is proposed. The results illustrate therapeutic potential of the phosphorylated nucleoside analogues formulated in nanosized cross-linked polymeric carriers for cancer chemotherapy.