Enteric campylobacter: purging its secrets?

Campylobacterial infections are the most common cause of bacterial enterocolitis in humans. Among children, especially in developing countries, Campylobacter infections can cause severe life-threatening diarrheal disease. Although usually associated with a benign outcome in the developed world, the burden of illness posed by Campylobacter infections is enormous, and serious neurologic sequelae also can occur. For a variety of reasons our understanding of the molecular and cellular pathogenesis of Campylobacter infection has lagged far behind that of other enteric pathogens. However, recent completion of the genome sequence of Campylobacter jejuni promises to open up the Campylobacter research field with the prospect of developing novel therapeutic and preventive strategies.     

Off-pump myocardial revascularization is associated with less incidence of stroke in elderly patients

Several recent studies have highlighted the potential benefits of using off-pump coronary artery bypass (OPCAB) surgery, particularly in high-risk patients. The aim of this meta-analysis is to assess the effect of OPCAB on the incidence of stroke compared with coronary artery bypass grafting using cardiopulmonary bypass (CPB) in elderly patients. We performed a meta-analysis of all observational studies, published in MEDLINE between 1999 and 2002 and a comparison between the OPCAB and CPB techniques in elderly patients was performed with the outcome of interest being the incidence of stroke. Elderly patients were defined as those aged 70 years or older. Nine studies are included in the meta-analysis. The total number of subjects included was 4,475 patients, of which, 1,253 underwent OPCAB (28%) and 3,222 (72%) underwent CPB. The meta-analysis showed that the OPCAB technique was associated with significantly lower incidence of stroke in elderly patients compared with the CPB technique (1% vs 3%), with an odds ratio of 0.38% to 95% (CI, 0.22 to 0.65). We did not identify any significant heterogeneity and funnel plot asymmetry between the studies included in the meta-analysis. Meta-regression analysis including variables predicting stroke, mortality, and study characteristics did not show any associations affecting the calculated odds ratio of stroke. Despite the fact that this is a meta-analysis of observational studies and adjustment for differences in baseline risk factors between OPCAB and CPB patients was not possible, we believe that this study suggests that the OPCAB technique might be associated with reduced incidence of stroke in the elderly patients undergoing coronary artery bypass grafting.     

Dual-energy X-ray absorptiometry applied to the assessment of tibial subchondral bone mineral density in osteoarthritis of the knee

Objective Plain X-ray is an imprecise tool for monitoring the subchondral bony changes associated with the development of knee osteoarthritis (OA). Our objective was to develop and validate a technique for assessing tibial subchondral bone density (BMD) in knee OA using dual energy X-ray absorptiometry (DXA).Design Patients with OA of at least one knee underwent DXA scanning of both knees. Regions of interest (ROI) were placed in the lateral and medial compartments of tibial subchondral bone. Weight-bearing plain X-rays and Te ^99m scintiscans of both knees were obtained and scored.Results One hundred and twelve patients (223 knees) underwent DXA and radiography. Intra-observer CV% was 2.4% and 1.0% for the medial and lateral ROI respectively. Definite OA (Kellgren and Lawrence Grade 2, 3 or 4) was correlated with age-related preservation of subchondral BMD compared to radiographically normal knees. Raised BMD was also associated with subchondral sclerosis, and positive scintigraphy.Conclusion DXA may provide a safe, rapid and reliable means of assessing knee OA. Cross-sectional age-related subchondral tibial BMD loss is attenuated by knee OA.Work completed at Bristol Royal Infirmary, Bristol, BS2 8HW, UK     

The clinical outcome and quality of life following minimally invasive direct coronary artery bypass surgery

BACKGROUND: Minimally invasive direct coronary artery bypass (MIDCAB) through a limited anterior small thoracotomy has been shown to be a promising technique of surgical treatment for single or double vessel disease. Little is known about the Health-Related Quality Of Life (HRQOL) in this group of patients. METHODS: The records of 75 consecutive patients who underwent MIDCAB procedure at Harefield Hospital between April 2000 and January 2002 were reviewed retrospectively. HRQOL assessment was planned in a cross-sectional design. Patients were contacted by telephone to conduct a semi-structured interview and were sent two questionnaires: the Short Form health survey (SF-36) and the Hospital Anxiety and Depression Scale (HADS). RESULTS: There was no in-hospital death. Patients stayed in the Intensive Therapy Unit (ITU) for 11.56 +/- 4.55 hours and stayed in hospital for 3 +/- 2.34 days. None of the study patients had perioperative myocardial infarction (MI) or neurological complications including permanent and transient strokes. We were able to contact all the 75 patients by telephone and they also completed the SF-36 and HADS. The SF-36 scores were compared to an age-matched group of normal British people. The MIDCAB group had an excellent general health perception compared to the normal group (p < 0.001), but similar scores otherwise. The HADS scores showed that only 1 patient (1.3%) had mild depression, 5 patients (6.7%) had mild anxiety, and 2 patients (2.6%) had moderate anxiety. CONCLUSION: MIDCAB is a safe surgical treatment and provides excellent clinical and HRQOL outcomes.     

Fatal and life threatening rupture of splenic artery aneurysms in children with portal hypertension

Aneurysms of the splenic artery (SAAs) are a rare complication of portal hypertension in adults. Although the risk of rupture is small, associated mortality is high. Furthermore, circulatory changes that occur following liver transplantation (OLT) may increase the risk of SAA rupture. The incidence in children with portal hypertension is unknown and thus we present our experience with two children who had ruptured SAA, one of whom died. Although there are no accepted methods for routine screening, hepatic angiography should be considered in children with long-standing portal hypertension (more than 10 yr), in order to detect and consider resection of the aneurysms, either before or at the time of liver transplantation.     

Postweaning exposure to aflatoxin results in impaired child growth: a longitudinal study in Benin, West Africa

Aflatoxins are dietary contaminants that are hepatocarcinogenic and immunotoxic and cause growth retardation in animals, but there is little evidence concerning the latter two parameters in exposed human populations. Aflatoxin exposure of West African children is known to be high, so we conducted a longitudinal study over an 8-month period in Benin to assess the effects of exposure on growth. Two hundred children 16-37 months of age were recruited from four villages, two with high and two with low aflatoxin exposure (50 children per village). Serum aflatoxin-albumin (AF-alb) adducts, anthropometric parameters, information on food consumption, and various demographic data were measured at recruitment (February) and at two subsequent time points (June and October). Plasma levels of vitamin A and zinc were also measured. AF-alb adducts increased markedly between February and October in three of the four villages, with the largest increases in the villages with higher exposures. Children who were fully weaned at recruitment had higher AF-alb than did those still partially breast-fed (p < 0.0001); the major weaning food was a maize-based porridge. There was no association between AF-alb and micronutrient levels, suggesting that aflatoxin exposure was not accompanied by a general nutritional deficiency. There was, however, a strong negative correlation (p < 0.0001) between AF-alb and height increase over the 8-month follow-up after adjustment for age, sex, height at recruitment, socioeconomic status, village, and weaning status; the highest quartile of AF-alb was associated with a mean 1.7 cm reduction in growth over 8 months compared with the lowest quartile. This study emphasizes the association between aflatoxin and stunting, although the underlying mechanisms remain unclear. Aflatoxin exposure during the weaning period may be critical in terms of adverse health effects in West African children, and intervention measures to reduce exposure merit investigation.     

Chemical constituents from the Colombian medicinal plant Maytenus laevis

The methanol extract of the bark of the Colombian medicinal plant Maytenus laevis gave six new compounds and 28 known compounds. The structures of the new and known compounds were elucidated on the basis of spectroscopic evidence. Several of these compounds were screened for cytokine-inducing activity on human PBMCs to investigate antitumor effects, and canophyllol (12) demonstrated the most effective induction of the cytokines.     

Analysis of the immuno-activation mechanism of OK-432--phagocytosis, release of active components and TLR4 signaling

Although we have reported that Toll-like receptor (TLR) 4 is involved in OK-432-induced anti-cancer immunity, its detailed mechanism remained uncertain. We hypothesized that OK-432 may first be captured, dissolved by phagocytes, and then active components released from the cells may stimulate TLR4. This hypothesis was examined by the current in vitro experiments. We used TS-2 MoAb which recognizes OK-PSA, an active component of OK-432. First, we observed that OK-432-induced cytokine production by dendritic cells (DCs) and macrophages was significantly inhibited by cytochalasin B, a phagocytosis inhibitor. Immunofluorescence staining by using TS-2 clearly demonstrated that OK-432 was captured and dissolved by these cells. OK-PSA was detected in the supernatants derived from OK-432-treated DC culture by ELISA with TS-2. The supernatants from OK-432-treated DC culture, but not from untreated DC culture, increased NF-kappaB activity in TLR4-expressing cells. The increased NF-kappaB activity was inhibited by TS-2. These findings elucidated the mechanism mediated by phagocytosis and TLR4 signaling in the OK-432 action.