Actinobacillus actinomycetemcomitans prosthetic valve endocarditis

Actinobacillus actinomycetemcomitans, a fastidious gram-negative bacillus, has been reported as the cause of prosthetic valve endocarditis in 11 patients. Two additional patients are reported and the literature is reviewed. All cases occurred greater than 1 year after implantation of the prosthesis. Six of the 13 patients had had recent dental work or had poor dentition. Three patients had received endocarditis prophylaxis. Ten of 13 were cured with antibiotics alone. Only one patient suffered from congestive heart failure, and only one had documented evidence of major systemic emboli during antimicrobial therapy. Valve replacement was necessary in only two during antimicrobial therapy. A actinomycetemcomitans should be considered as a possible etiologic agent in late prosthetic valve endocarditis, particularly when blood cultures are initially negative. A regimen of a beta-lactam antibiotic in combination with an aminoglycoside is recommended for 4-6 weeks. The excellent in vitro activity of the third-generation cephalosporins and rifampin promise new therapeutic options.     

Regular ingestion of tea does not inhibit in vivo lipid peroxidation in humans.

Prospective studies suggest that tea may protect against cardiovascular disease. A potential mechanism for such an effect involves inhibition of lipid peroxidation by polyphenolic antioxidants derived from tea. Our objective was to determine whether regular ingestion of tea could inhibit in vivo lipid peroxidation. Two controlled intervention studies assessed the effects of regular ingestion of tea on lipid peroxidation determined by measurement of urinary F(2)-isoprostane excretion. Study 1: The effects of 1000 mL/d of green tea and black tea were compared with hot water containing caffeine in 13 subjects with elevated blood pressure using a randomized 3-period (7 d each) crossover design. Study 2: The effects of 1250 mL/d of black tea were compared with hot water in 22 subjects with mildly raised serum total cholesterol concentrations using a randomized 2-period (4 wk each) crossover design. F(2)-isoprostane excretion was not altered after regular ingestion of green tea (273 +/- 48 pmol/mmol creatinine) or black tea (274 +/- 39 pmol/mmol creatinine) in comparison with hot water (263 +/- 47 pmol/mmol creatinine; Study 1), or by regular ingestion of black tea (334 +/- 71 pmol/mmol creatinine) in comparison with hot water (355 +/- 75 pmol/mmol creatinine; Study 2). These results do not support the suggestion that polyphenolic antioxidants derived from tea inhibit in vivo lipid peroxidation.     

Patellar instability after total knee arthroplasty

Twenty-five knees with symptomatic lateral patellar instability after total knee arthroplasty (TKA) were treated by operative realignment. Causes of instability include errors in surgical technique, quadriceps imbalance, and trauma. Fourteen knees had proximal realignment, nine had combined proximal and distal realignment, and two had component revision. At an average follow-up period of 50 months, 20 knees had normal patellar tracking and five had recurrent instability. Two patellar tendon ruptures occurred after combined realignment. Proximal realignment alone, in the absence of component malposition, is recommended for the management of patellar instability. Component malposition should be corrected by component revision. Combined proximal and distal realignment procedures are recommended only with great caution because of the predisposition to serious complications such as patellar tendon rupture.     

Specialist training

Specialist training must be reshaped to meet the challenges of new systems for the delivery of health care and rapid expansion in biomedical knowledge. An adequate and affordable supply of trained specialists and generalists able to deal with the health problems of populations served, is the responsibility of governments and policymakers that fund and those who deliver graduate education. Clearly defined objectives for specialist training are needed, linked to planning for the medical workforce size. A balance between numbers of specialists and generalists is essential, although flexibility in programmes should allow individuals to change. Curricula for all specialties should be published. Strategies and methods for delivery of graduate education and training must be coherent with those of medical schools. Training should be planned and sequenced to meet the identified needs of individuals. Those who teach should themselves learn how to train and assess trainees. The location for training should reflect present and future clinical practice if disfunction between medical education and the health of populations served and their need is to be avoided. Specialist training should form the basis for continuing education by encouraging lifelong, evidence-based learning. Any reshaping of specialist training must be consistent with the continuum of medical education. Instruments for assessment of specialists in training have to be refined, based on action research. Ensuring mastery in the competencies of each component of the curriculum is essential. Those competencies will change in consequence of altered societal needs plus advances in technology and biomedical knowledge.     

Pathways of lymph flow through intestinal lymph nodes in the horse

In the horse, several thousand lymph nodes receive lymph from the intestine, part of which is very large and contains microorganisms that enable the animal to utilize refractory dietary constituents such as cellulose. The aim of this study was to describe the pathways by which lymph is delivered into, traverses, and is drained from these lymph nodes. These pathways were studied with either Microfil or methacrylate casting materials and with light and electron microscopy. The afferent lymphatic vessel delivering lymph into one of the nodes divides over the capsular surface and within trabeculae into terminal branches, and these are continuous with the subcapsular and trabecular sinuses through rounded holes up to 30 μm across. Lymph is conveyed from the subcapsular and trabecular sinuses through the cortex by four types of sinuses: trabecular sinuses, cortical tubular sinuses, tubulelike sinuses with a network of stellate cell processes, and sinuses between cortical cords. It is conveyed through the medulla by sinuses both within and between medullary cords. Lymph is drained from these sinuses by initial efferent lymphatics of three types: those between medullary cords, those within the subcapsular sinus overlying medullary or cortical cords, and those within trabeculae. All three types are continuous with surrounding sinuses through holes 5–30 μm across. These three alternative routes for lymph drainage may ensure adequate lymph flow during different intranodal conditions that may exist when the node is responding to microcrganisms or other foreign materials.     

Quality development.

The problem with improving quality in dental practice is not so much a difficulty with understanding exactly what quality means, but more a lack of clear guidance as to how to take the simple, practical steps to achieving that improvement in the daily pressures of practice life. This article describes Quality Development, a simple and practical method that can be used in general practice to help the dental team achieve the objectives in quality care that are appropriate to them.     

Nimodipine treatment in poor-grade aneurysm patients. Results of a multicenter double-blind placebo-controlled trial

A multicenter, randomized placebo-controlled double-blind trial of nimodipine in poor-grade aneurysm patients was carried out in 17 Canadian hospitals. Of 188 patients enrolled in the trial, 32 were excluded for protocol violations and two were excluded due to statistical considerations, leaving 154 patients for valid outcome analysis. Nimodipine treatment was associated with a significantly better outcome (p less than 0.001): 21 (29.2%) of 72 nimodipine-treated patients had a good outcome at 3 months after subarachnoid hemorrhage (SAH) compared to eight (9.8%) of 82 placebo-treated patients. Delayed ischemic deficits from vasospasm alone were significantly less frequent in the nimodipine group (p less than 0.05) with permanent deficits occurring in five nimodipine-treated patients (6.9%) and in 22 placebo-treated patients (26.8%). Improvement in the good outcome rate and reduction in delayed ischemic deficits from vasospasm alone occurred in both Grade 3 and 4 patients, with no difference between nimodipine- and placebo-treated patients being found in Grade 5 patients. Repeat angiography after Day 4 was carried out in 124 patients. There was no significant difference in the incidence of moderate or severe diffuse spasm, which was seen in 64.3% of nimodipine-treated patients and 66.2% of placebo-treated patients. The authors conclude that nimodipine treatment in poor-grade patients with SAH results in an increase in the number of good outcomes and a reduction in the incidence of delayed neurological deterioration due to vasospasm. This effect occurs by a mechanism other than prevention of large-vessel spasm as visualized on angiography.