Antibiotic prophylaxis for pit viper envenomation: prospective, controlled trial.

The efficacy of prophylactic antibiotics for preventing infectious complications at the site of pit viper envenomation has not been well studied. We undertook a prospective, controlled trial of antibiotic treatment versus no antibiotic treatment among 114 victims of crotalid envenomation in Ecuador's Amazon rain forest. A group of 59 patients received intravenous gentamicin and chloramphenicol, and 55 patients did not. All other aspects of care were identical. There were no statistically significant differences between antibiotic-treated and untreated patients with regard to demographics, delay in treatment, clinical and laboratory evidence of severity of envenomation, or use of antivenin. Nine abscesses occurred, six in the antibiotic-treated group and three in the untreated group. The results of this study did not show any statistically significant differences in outcome in terms of the number of abscesses that occurred between antibiotic-treated and untreated patients. Based on this lack of differences, routine use of prophylactic antibiotics for prevention of infectious complications of crotalid envenomation cannot be recommended.

Prevalence of modalities of headaches and bruxism among patients with craniomandibular disorder.

This study compared the presence of headache and bruxing behavior among 133 craniomandibular disorder patients (CMD) referred to the The Center For the Study Of Craniomandibular Disorders and to the presence of headache and bruxing behavior occurring in 133 controls seeking routine dental care. Both patients and controls were consecutive referrals to the clinic occurring over a three year period. The mean age of the CMD group was 38 years (range 28-42), and the mean age of the controls was 37 years (range 25-44). The information gathered included questionnaire and clinical examination. Different types of headaches, signs and symptoms of CMD, and bruxing behavior were assessed both in the CMD group and in the corresponding control group. Results of this study showed that bruxing behavior and headache pain were significantly more prevalent in the CMD group (57%, 76%) than in the corresponding control group (37%, 49%). Of the three types of headache observed, tension and combination headaches were more prevalent in the CMD group (n = 48 = 36% and n = 37 = 28%). Migraine headache was more prevalent in the CMD group (n = 16 = 12%) than in the control group (n = 3 = 2%). It was concluded that headache and bruxing behavior predominated in CMD patients. This data reinforces the need to assess headache pain and signs and symptoms of bruxing behavior in CMD patients, particularly in those suffering chronic facial pain and headache.

Treatment of snake bites by Bothrops species and Lachesis muta in Ecuador: laboratory screening of candidate antivenoms.

Bothrops xanthogrammus/asper, B. atrox and Lachesis muta are probably responsible for most cases of severe envenoming in Ecuador. In recent years, the most widely used antivenom ('Myn' Ronti, imported from Mexico) has proved clinically ineffective. There is an urgent need to identify an effective alternative for clinical testing. Five antivenoms with activity against Bothrops venoms were compared using standard World Health Organization rodent and in vitro assays: (i) 'Myn', Ronti Mexico SA ('B. atrox', 'Crotalus terrificus'), (ii) Instituto Butantan (Bothrops polyvalent, Brazil), (iii) Instituto Nacional de Hygiene y Medicina Tropical (Bothrops polyvalent, Ecuador), (iv) Instituto Nacional de Salud (B. asper, C. durissus and Lachesis muta, Colombia), and (v) Laboratorios Probiol (Bothrops, Lachesis and Crotalus, Colombia). The venoms against which these antivenoms were tested were Ecuadorian B. atrox, B. asper and B. xanthogrammus. Brazilian antivenom proved to be the most effective, followed by the Ecudorian and Colombian antivenoms. Mexican antivenom was completely ineffective in neutralizing the lethal effects of Ecuadorian Bothrops venoms. Monospecific Brazilian L. muta antivenom (Instituto Butantan) proved effective against Ecuadorian L. muta venom, but the Colombian polyspecific antivenoms did not. Clinical trials of Brazilian and Ecuadorian antivenoms are planned in the Amazon region of Ecuador in the near future.

Tropical pyomyositis in eastern Ecuador.

In the ten year period 1980-1989, 97 patients were treated for tropical pyomyositis at Hospital Vozandes Oriente in eastern Ecuador, accounting for 2.2% of surgical admissions. Operation records from an affiliated hospital in Quito showed that, high on the Andean plateau, pyomyositis accounted for only 0.1% of surgical admissions. Among the patient population of Ecuador's eastern tropical rain forest, persons who were members of an indigenous ethnic group were affected with pyomyositis twice as often as would be expected from their representation in the general population.

Chemical shift imaging of human brain: axial, sagittal, and coronal P-31 metabolite images.

Multivoxel magnetic resonance (MR) spectroscopy and novel data analysis techniques were developed to obtain high-quality phosphorus-31 metabolite images from the human brain and to overlay each metabolite distribution directly onto corresponding hydrogen-1 MR images. The P-31 MR spectroscopic data were acquired by means of three-dimensional chemical shift imaging (phase encoding in three spatial dimensions) on a 1.5-T clinical instrument equipped with a specially designed quadrature P-31 birdcage coil constructed in the authors' laboratory. Axial, sagittal, and coronal metabolite images based on the area for any one of five peak regions (phosphodiester; phosphocreatine; gamma, alpha, and beta adenosine triphosphate) were generated from 8 X 8 X 8 or 12 X 12 X 8 CSI arrays with voxel sizes of 27 cm3 and 12 cm3, respectively. The positions of these images were aligned with anatomic features by means of the voxel-shifting capability of the Fourier transform. Direct overlays of these metabolite images on corresponding proton images demonstrated excellent correlation with anatomy, factors indicating the utility of this technique for viewing P-31 metabolite levels in all areas of the brain simultaneously.