Hemoglobin M equon beta 41 (C7) phenylalanine leads to tyrosine

A severe hemolytic crisis was observed in a 34-yr-old female of English- Irish extraction following a viral illness treated with acetaminophen. Heinz bodies and heat instability were present only during a transient hemolytic event. A challenge dose of acetaminophen caused no detectable hematologic abnormality. Structural studies of the hemoglobin during hemolysis and again after complete recovery localized the abnormality to tryptic peptide beta Tp-5, and automated sequencing of I 125-labeled beta chains indicated a replacement of phenylalanine (C7) beta 41 by tyrosine. Substitution of the next residue, phenylalanine (CD1) beta 42 by serine (Hb Hammersmith), has resulted in chronic severe Heinz body hemolytic anemia. The lack of chronic anemia in the present disorder may reflect the different relationships of beta41 and beta 42 and/or the similarities in volume and hydrophobicity of tyrosine and phenylalanine. It is suggested that substitution of tyrosine for phenylalanine in Hb Mequon may disturb the critical environment around the heme group and render it susceptible to oxidative denaturation in the presence of infections and/or drugs.     

Risk Factors for Acute Myocardial Infarction in Central India: A Case-Control Study

Background:

Atherosclerosis is a multi-factorial disease involving the interplay of genetic and environmental factors. Studies highlighting the public health importance of risk factors like chronic infections causing acute myocardial infarction (AMI) in the Indian context are scarce. This study was undertaken to study the association of socio-demographic and life-style factors with acute myocardial infarction in central India.

Materials and Methods:

The cases and controls were group-matched for age, gender, and socio-economic status. A blinded research associate administered the study questionnaire. We performed an unconditional multiple logistic regression analysis.

Results:

The case-control study included 265 cases of AMI and 265 controls. The results of final model of logistic regression analysis for risk factors of AMI included 11 risk factors at α = 0.05. They were waist hip ratio, body mass index, stress at home in last 1 year, hypertension, family history of CHD, past history of gingival sepsis, tobacco smoking, raised total serum cholesterol, Chlamydia pneumoniae, Helicobacter pylori and raised C-reactive protein.

Conclusion:

The findings confirm the role of conventional risk factors for cardiac disease and highlight need for research into the association between chronic infections with AMI.     

Extended pancreatic resections and lymphadenectomy: An appraisal of the current evidence

Surgery remains the mainstay of treatment for pancreatic ductal adenocarcinoma and complete removal of the cancer confers a definite survival advantage, especially in early disease. However, the majority of patients do not present with early disease, thus precluding the chance of a cure by standard pancreatoduodenectomy (PD), distal pancreatectomy or total pancreatectomy. For this reason, pancreatic surgeons have attempted to push the limits of resection over the last three decades. The aim of these resections has been to determine whether obtaining a complete resection by extending the limits of conventional resection in patients with advanced disease will yield the results seen with PD alone in early disease. This article revisits the data from such studies in an attempt to determine if the available literature supports the performance of extended resections for pancreatic cancer in terms of improvement of survival.     

Surgery for gallbladder cancer: The need to generate greater evidence

The outcomes for gallbladder cancer remain largely dismal to this day. Overall, the low incidence of gallbladder cancer around the world coupled with an even lower number of patients amenable to surgery at the time of presentation, has precluded the generation of evidence-based guidelines for the management of this cancer. However, while the incidence of the cancer may be decreasing in some parts of the world, in other countries such as India, Japan and Chile, gallbladder cancer continues to affect a sizeable population of patients. As such, there is a growing need to define what constitutes an adequate surgery for each stage of this cancer, based on sound evidence. This editorial provides a broad overview of the existing problems in the management of gallbladder cancer and appeals for multi-institutional studies aimed at answering some of the pertinent questions on the surgical management of gallbladder cancer.     

Pancreaticojejunostomy versus pancreaticogastrostomy: systematic review and meta-analysis

OBJECTIVE: Pancreaticojejunostomy (PJ) and pancreaticogastrostomy (PG) are the commonly preferred methods of anastomosis after pancreaticoduodenectomy (PD). The ideal choice of anastomosis remains a matter of debate. DATA SOURCES: Articles published until end of March 2006 comparing PJ and PG after PD were searched. STUDY SELECTION: Two reviewers independently assessed quality and eligibility of the studies and extracted data for further analysis. Meta-analysis was performed with a random-effects model by using weighted odds ratios. DATA EXTRACTION AND SYNTHESIS: Sixteen articles were included; meta-analysis of 3 randomized controlled trials (RCT) revealed no significant difference between PJ and PG regarding overall postoperative complications, pancreatic fistula, intra-abdominal fluid collection, or mortality. On the contrary, analysis of 13 nonrandomized observational clinical studies (OCSs) showed significant results in favor of PG for the outcome parameters with a reduction of pancreatic fistula and mortality in favor of PG. CONCLUSIONS: All OCSs reported superiority of PG over PJ, most likely influenced by publication bias. In contrast, all RCTs failed to show advantage of a particular technique, suggesting that both PJ and PG provide equally good results. This meta-analysis yet again highlights the singular importance of performing well-designed RCTs and the role of evidence-based medicine in guiding modern surgical practice.