Infective endocarditis due to Streptococcus bovis: A report of 53 cases

Fifty patients (42 men; 11 women) with Streptococcus bovis infectiveendocarditis attended a tertiary cardiology hospital between1980 and 1991, and constituted 11% of the total number of infectiveendocarditis cases hospitalized there during that period Themean age was 59 ± 15 years; 15 had previously sufferedvalvular disease (12) or had a va/vu/ar prosthesis (3); onepatient had had a previous infective endocarditis. The infectiveepisode involved the aortic valve in 26 patients, both the aorticand mitral valves in 18 patients, the mitral valve only in sixand other valves in three. Echocardiographic examination showedone or more vegetations in 44 patients. Cardiac failure wasdiagnosed in 35 patients and embolic episodes in 22, of whom11 were cerebrovascu/ar accidents. The patients became afebrile19 ± 39 days after starting antibiotic treatment. Valvereplacement was performed in 37 patients during their initialhospitalization, and in four during follow-up. After a meanfollow-up of 4·6 ± 3·1 years with a 100%follow-up, 15 patients died: 1 pre-operatively, one in the first30 days after operation, 13 later (8/41 operated patients and5/12 non-operated patients). Actuarial survival was 73% at 5years. Gastrointestinal signs were present in 12 patients; 43patients (81%) had afull colonic examination which showed polypsin 20 patients and adenocarcinonws in seven. Of 11 late deathsfour were related to a malignant colonic tumour. This studyconfirms that Streptococcus bovis infective     

The cachexia associated with Trypanosoma cruzi acute infection in mice is attenuated by anti-TNF-a, but not by anti-IL-6 or anti-IFN-7 antibodies

BALB/c male mice acutely infected with Trypanosoma cruzi underwent a severe weight loss (around 20%, from day 18 to 31 post-infection), when compared to age-matched uninfected animals. Though mice regained weight later, when blood parasites were hardly detectable, wasting extended over the chronic phase of infection. The onset and the magnitude of weight loss were related to the mouse susceptibility to infection, since they were respectively earlier and higher in male mice which will die than in surviving ones, in males than in females, and in BALB/c than in B6D2 [(C57B1/6 × DBA/2)F1], a mouse strain more resistant to infection. Fat weight of infected mice (male BALB/c) was reduced by 60 to 80%, whereas lean mass was unaffected and water content rose by 6 to 10% in acute and chronic infection. Haematocrit was also decreased by 15–16% in acute infection. Animals failed to compensate their energetic loss since their food intake remained similar to that of uninfected animals. Injections of neutralizing anti-TNF-α monoclonal antibody into infected male mice, during the first two weeks but not later in infection, significantly attenuated the weight loss. Early administration of anti-IL-6 or anti-IFN-γ MoAbs did not improve the mouse wasting. Taken together, these data show that TNFis a key agent of cachexia occurring in the acute T. cruzi infection in mice.     

Pulmonary Effects to Repeated Exposures to Paraquat Aerosol in Guinea Pigs

Pulmonary Effects of Repeated Exposures to Paraquat Aerosolin Guinea Pigs. BURLEIGH-FLAYER, H. AND ALARIE, Y. (1988). Fundam.Appl. Toxicol 10, 717–729. Exposure to paraquat, a widelyused herbicide, has been shown to produce a concentration dependentrapid, shallow breathing pattern in guinea pigs 18 hr followingexposure (H. Burleigh-Flayer and Y. Alarie, 1987, Arch Toxicol.59(6), 391–396). To further explore the pulmonary effectsfollowing exposure to paraquat, two experiments were carriedout. The first experiment consisted of exposing a group of guineapigs for a period of 4 hr to 0.7 mg/m³ paraquat aerosol andmonitoring respiratory variables for 2 weeks following the exposure.In the second experiment, three groups of guinea pigs were repeatedlyexposed to three concentrations of paraquat aerosol (0.1,0.4,and 0.8 mg/m³) for 6 hr a day, 5 days a week for 3 weeks. Respiratoryvariables were measured each day of these 3-week experiments.The respiratory variables evaluated in both experiments weretidal volume (VT) and respiratory frequency (/). These variableswere monitored during air breathing and upon challenge with10% CO₂ in 20% O₂ and 70% N₂ in order to evaluate the pulmonaryeffects of exposure to paraquat. Following a single exposureto 0.7 mg/m³ paraquat aerosol, a decrease in VT and increasein f were seen during air and 10% CO₂ challenge which reacheda maximum several days following exposure. After reaching maximalchanges, the respiratory variables returned to control values.With repeated 6-hr exposures to paraquat aerosol, guinea pigsexposed to 0.4 and 0.8 mg/m³ also displayed a rapid, shallowbreathing pattern. Adaptation to the exposures for these twoconcentration groups was evidenced by a return of the respiratoryvariables toward control levels. This adaptation typically occurredduring the first 7 days of exposures. A cumulative effect wastherefore not detected with repeated exposures to paraquat aerosols.     

District health systems: users' preferences for services in Benin

The function of district health systems in Benin Republic wascritically assessed, and special consideration was given tothe acceptability of available health services from the users'point of view. Using a representative household survey, servicerecords, a survey amongst service users, participant observationand qualitative interviews, we obtained data on the use of differentservices offered by the modern public health system, as wellas on reasons for non-use and preference for treatment by traditionalpractitioners or within the family. Although in the last 15 years accessibility to health serviceshas improved remarkably, services are not fully accepted. Under-utilizationof services seems to be due to their low quality, and users'reluctance to consult them. Users are faced with prohibitivecosts, and staff attitudes have further decreased confidence.A major reason for this seems to be staff incompetence in counsellingpatients and clients. Health systems research studies focusing on the clients' viewsmay provoke a critical reflection of everyday practices, providea review of the objectives of district health systems, and leadto discussions on how to improve the performance and qualityof district health teams. This paper gives an account of thepositive experience with participatory workshops at differentlevels of the health system, which constitute a way of ensuringthat study results will be discussed and used at district andnational level.     

The Feasibility of Systematic Use of a Combined Diagnostic and Interventional 6 Fr Guide Catheter in Patients with Suspected Coronary Restenosis

This prospective study assessed the feasibility of re-percutaneous transluminal coronary angioplasty for coronary restenosis using routinely the new 6 Fr diagnostic/interventional Diaventional catheter with a large internal lumen (0.057) in 80 consecutive patients. Two patients had restenosis on two vessels. The restenosed coronary artery more frequently was the left anterior descending coronary artery (52%). In the first six patients, the over-the-wire technique was used; in the other patients, we used a balloon-on-a-wire device or a rapid-exchange balloon catheter. With these latter techniques, angiographic visualization was satisfactory, even when the balloon was placed through the stenosis. The balloon size varied from 2.0-3.5 mm (mean 2.9 ± 0.4 mm). In two patients, an immediate recoil needed reintervention with the same equipment and yielded a satisfactory final result. All but one procedure (81/82) were successful (in one patient, a total chronic occlusion could only transiently be reopened). However, in four patients, a complementary 6 Fr or 8 Fr technique, using standard guiding catheters, had to be used for a large dissection (two patients) and for failure to cross a tight stenosis (two patients). The overall success rate was 94% (77/82), with a 9.2% reduction of the total cost of the invasive procedure. In coronary restenosis, the use of the new 6 Fr diagnostic/interventional Diaventional catheter is possible with an excellent overall success rate and a reduction of the total cost of the invasive procedure.     

Unipolar Electrogram Models for Prediction of Outcome in Radiofrequency Ablation of Accessory Pathways

Meticulous catheter positioning dose to the accessory pathway is essential for successful radiofrequency ablation. The aim of this study was to identify local unipolar electrogram characteristics predictive of radiofrequency ablation outcome, enabling more accurate accessory pathway localization and catheter positioning. So far mainly bipolar electrogram parameters have been evaluated, stressing the importance of the presence of an accessory pathway potential. However, especially in the absence of this parameter, the unipolar recording mode can be expected to hold severol advantages. Nine local unipolar electrogram characteristics were analyzed in preexcited sinus rhythm directly preceding radiofrequency pulses in 35 consecutive patients with a manifest occessory atrioventricular pathway. A total of 1,230 unipolar electrogram complexes were analyzed and recorded at 138 ablation sites. Ablation was successful in 30/35 patients (86%). Multivariate analysis provided two unipolar models for prediction of ablation outcome: in Model I, sites with a suspected accessory pathway potential, local AV interval ≤ 30 msec and catheter stability had 76% probability of success, but no more than 1% in their absence. In contrast, using the bipolar recording mode, presence of a suspected accessory pathway potential was the only one of these parameters shown to differentiate between successful and unsuccessful sites, with a predicted chance of success of 48%. Model II, not requiring assessment of possible accessory pathway potentials, showed a 63% probability of success for the combination of initial positivity of the local ventricular signal ≤ 0.1 mV, AV interval ≤ 30 msec, and catheter stability, but no more than 7% in their absence. Moreover, gradual decrease of initial ventricular positivity and AV interval while approaching a subsequently successful site allows the use of these parameters as dynamic mapping tools. Local unipolar electrogram parameters may thus facilitate precise accessory pathway localization and catheter positioning while offering important information supplementary to the bipolar mode, and enable accurate prediction of ablation outcome at a given site also in the absence of accessory pathway potential recording.     

Trypanosoma cruzi infection in mice enhances the membrane expression of low-affinity Fc receptors for IgG and the release of their soluble forms

The membrane expression of low-affinity Fc receptors for IgG (FcγRII/III) on cells and the number of FcγRII/III(+) cells were studied by flow cytometry, using the 2-4G2 MoAb, in mice infected by Trypanosoma cruzi. Cells from spleen, mesenteric lymph nodes and peritoneum were collected on days 10, 20, 30 and 40 post infection (p.i.). The in vivo serum level of soluble FcγRII/III, as well as its in vitro release by cells from infected mice were studied. Parasitaemia and IgG1, IgG2a and IgG2b T. cruzi-specific antibody titres were also recorded. Both the expression of FcγR on cell membrane and the absolute number of FcγR(+) cells increased in spleen and in mesenteric lymph nodes, but not in peritoneum. The modifications in spleen occurred in the early and late parasitaemic phase of infection, i.e., before and after detection of T. cruzi-specific antibodies (from day 10 to 40 p.i.). In mesenteric lymph nodes, the variations were observed only in the early acute infection, when antibodies were not yet detectable at significant levels (on days 10 and 20 p.i.). Higher levels of soluble FcγR were detected in sera and in culture supernatants of spleen and lymph node cells from day 20 to 40 p.i. These results show that T. cruzi infection in mice upregulates the expression and the release of FcγRII/III, in the acute phase of infection, before as well as after the rise of antibody response.