Bite force measurements with hard and soft bite surfaces.

Bite force has been measured by different methods and over a wide variety of designs. In several instruments, the fact that bite surface has been manufactured with stiff materials might interfere in obtaining reliable data, by a more prompt activation of inhibitory reflex mechanisms. The purpose of this study was to compare the maximum voluntary bite force measured by a digital occlusal force gauge (GM10 Nagano Keiki, Japan) between different opponent teeth, employing semi-hard or soft bite surfaces. A sample of 34 young adults with complete natural dentition was studied. The original semi-hard bite surface was exchanged by a soft one, made of leather and rubber. Maximum voluntary bite force recordings were made for each tooth group and for both bite surfaces. Statistical analyses (Student's t-test) revealed significant differences, with higher scores while using the soft surface across sexes and tooth groups (P < 0·05). Differential activation of periodontal mechanoreceptors of a specific tooth group is mainly conditioned by the hardness of the bite surface; a soft surface induces greater activation of elevator musculature, while a hard one induces inhibition more promptly. Thus, soft bite surfaces are recommended for higher reliability in maximum voluntary bite force recordings.

[Serological and epidemiological features of canine American tegumentary Leishmaniasis from Maricá, Rio de Janeiro, Brazil]. / Aspectos sorológicos e epidemiológicos da leishmaniose tegumentar americana canina em Maricá, Rio de Janeiro, Brasil.

A sample of 261 dogs from 134 households located in a periurban area of Maricá, Rio de Janeiro, Brazil, was studied to evaluate serologic reactions and active infection of american tegumentary leishmaniasis (ATL). Eight dogs presented lesions suggestive of ATL, but this was isolated in only three. Using ELISA, 24.5% (64/261) of the dogs studied were positive (sensitivity = 66% and specificity = 76%), associated with isolation in 2 animals and 0.4% (1/261) by indirect immunofluorescence assay (IIF) with no association with isolation. In order to reduce the unspecific reactions to ELISA, a second criterion was used to obtain the cutoff (sensitivity = 33% and specificity = 93%), resulting in a reactivity of 6.9 % (18/261) associated to isolation in a single animal. As observed in this study, serologic results by IIF were not associated with active infection and ELISA showed high unspecific reactions, indicating that the serologic reactions alone are not recommended for ATL diagnosis. ATL scars were been observed in 7 persons in the region and active lesion, under treatment, was observed in one patient. The finding of active lesions, either in dogs or humans, confirmed the existence of active tegumentary leishmaniasis in Maricá, indicating the need for further studies to evaluate the importance of this infection in the municipality.

[The enteroparasitic contamination of commercial vegetables in the cities of Niterói and Rio de Janeiro, Brazil]. / Contaminação por enteroparasitas em hortaliças comercializadas nas cidades de Niterói e Rio de Janeiro, Brasil.

The aim of this study was to evaluate the parasitological contamination of vegetables to be consumed raw and commercialized in Niterói and Rio de Janeiro cities. We studied 128 samples of vegetables--lettuce (Lactuca sativa) and watercress (Nasturtium officinale)--from supermarkets, greengrocer shops and self-service restaurants. Only 6.2% of the samples were positive for parasitic structures with morphological aspects similar to those of animal parasites. We detected acarids, acarid eggs, insects, nematode larvae and ciliated protozoa in most of the samples (96.1%), including those from restaurants. This high percentage suggests a risk of human infection since parasite structures capable of infecting man may exist in association with these agents.

Coronary venous retroperfusion support during high risk angioplasty in patients with unstable angina: preliminary experience.

Synchronized coronary venous retroperfusion was used during coronary balloon angioplasty to support the ischemic myocardium of 20 patients with unstable angina and anatomy at high risk of a coronary event. Hemodynamics and left ventricular function were the major end points of the study. Coronary venous catheterization and retroperfusion were successfully performed in 15 patients. The target vessel was an unprotected left main artery in 2, left anterior descending artery in 10, left circumflex coronary artery in 1 and right coronary artery in 2 patients. A nonsupported balloon inflation (mean 44 +/- 13 s) was compared with a later retroperfusion-supported inflation (mean 145 +/- 21 s). Right anterior oblique left ventriculograms, aortic blood pressure, pulmonary artery pressure and thermodilution cardiac output were obtained before and during peak untreated and treated balloon inflations and on completion of angioplasty. All patients had either a baseline left ventricular ejection fraction less than 0.40 or greater than 40% of contracting myocardium estimated to be at risk for severe ischemia during angioplasty. The cardiac (liters/min per m2) and stroke work (g.m/m2) indexes decreased from mean baseline values of 2.5 +/- 0.52 and 52 +/- 15 to 1.7 +/- 0.47 and 27 +/- 12 (mean +/- SD), respectively, during nonsupported balloon inflations but decreased only to 2.1 +/- 0.52 (p less than 0.01 vs. nonsupported) and to 36 +/- 14 (p = 0.01 vs. nonsupported), respectively, during retroperfusion-supported inflations. Ejection fraction (n = 8) decreased from a baseline value of 55 +/- 13% to 27 +/- 7.3% during nonsupported inflations but only to 39 +/- 10% during retroperfusion-supported inflations (p = 0.01 vs. nonsupported). Regional wall motion (area change) in the ischemic (target) region was reduced from a baseline value of 49 +/- 17% to 11 +/- 16% during nonsupported inflations but only to 27 +/- 15% during retroperfusion-supported inflations (p less than 0.01 vs. nonsupported). All but two patients had a favorable hemodynamic response to retroperfusion. There were no serious adverse effects related to the procedures and no hospital deaths. It is concluded from this preliminary study that coronary venous retroperfusion appears to be safe, to provide hemodynamic support and to improve left ventricular function during angioplasty in patients with unstable angina and anatomy at high risk of a coronary event.