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Biomedical subjects

L A Ribeiro

Publications and source records attributed to L A Ribeiro.

At least 19 recordsLinked to original sources

Failure of chloramphenicol prophylaxis to reduce the frequency of abscess formation as a complication of envenoming by Bothrops snakes in Brazil: a double-blind randomized controlled trial.

Bites by many species of venomous snake may result in local necrosis at, or extending from, the site of the bite. The use of prophylactic antibiotics to prevent infection as a complication of local necrotic envenoming is controversial. A double-blind randomized controlled trial was carried out to assess whether antibiotic therapy is effective in this situation. Two hundred and fifty-one patients, with proven envenoming by snakes of the genus Bothrops, admitted to two hospitals in Brazil, between 1990 and 1996, were randomized to receive either oral chloramphenicol (500 mg every six hours for five days) or placebo. One hundred and twenty-two of these patients received chloramphenicol (group 1) and 129 were given placebo (group 2). There were no significant differences between the groups at the time of admission. Necrosis developed in seven (5.7%) patients in group 1 and in five (3.9%) patients in group 2 (P>0.05) while abscesses occurred in six patients (4.9%) in group 1 and in six (4.7%) patients in group 2 (P>0.05). In conclusion, the use of orally-administered chloramphenicol for victims of Bothrops snake bite with signs of local envenoming on admission, is not effective for the prevention of local infections.

Abscess↗

[Epidemiologic aspects of snakebites in Vale do Ribeira, São Paulo, 1985-1989].

This study reports on the incidence of snakebites from January 1985 to December 1989 in Vale do Ribeira, S o Paulo, Brazil. Overall incidence ranged from 68.7 to 84.2/100,000. There were 840 snakebites during this period, with higher frequency from October to May. The highest incidence rates were observed in the districts of Jugui and Eldorado (159.4 and 131.4/100,000, respectively). Most of the patients were male. Agricultural workers were the most heavily affected. Most of the patients received treatment within 2 hours after the bite. Morbidity was not severe and lethality was 0.2%.

English Abstract↗

Epidemiology of snakebite in a central region of Brazil.

The aim of this article is to acquire knowledge about the aspects of snakebite epidemiology in a central region of Brazil. From 1993 to 1995, 90 cases of Crotalinae (Bothrops and Crotalus genera) and two cases of Micrurus snakebite were attended to in a general hospital. Epidemiological information about 73 out of the 90 Crotalinae victims was prospectively collected from interviews with the patients and/or their companions. Data from medical records were obtained for the 17 remaining cases. The snakes of Bothrops, Crotalus, and Micrurus genera were responsible for 74, 24 and 2% of the accidents, respectively. Most of the Crotalinae accidents occurred from October to March (68%) and from 06:00 to 12:00 a.m. (93%). Males (89%) and patients between 20 and 30 years-old (27%) were the most common victims. The main bite sites were: foot (24%), leg (23%), hand (22%) and ankle (21%). Among the 73 interviewed Crotalinae victims, farm workers were bitten more frequently (53%). The accidents often occurred during work (59%), and 90% of the patients wore footwear, but 30% were wearing only sandals. Tourniquet, squeezing, suction of the bite site and magic blessing were attempted in 47, 38, 8 and 10% of cases, respectively.

Adolescent↗

Identification and characterization of novel mutations of the aspartoacylase gene in non-Jewish patients with Canavan disease.

Canavan disease, an inherited leukodystrophy, is caused by mutations in the aspartoacylase (ASPA) gene. It is most common among children of Ashkenazi Jewish descent but has been diagnosed in many diverse ethnic groups. Two mutations comprise the majority of mutant alleles in Jewish patients, while mutations in the ASPA gene among non-Jewish patients are different and more diverse. In the present study, the ASPA gene was analysed in 22 unrelated non-Jewish patients with Canavan disease, and 24 different mutations were found. Of these, 14 are novel, including five missense mutations (E24G, D68A, D249V, C152W, H244R), two nonsense mutations (Q184X, E214X), three deletions (923delT, 33del13, 244delA), one insertion mutation (698insC), two sequence variations in one allele ([10T>G; 11insG]), an elimination of the stop codon (941A>G, TAG-->TGG, X314W), and one splice acceptor site mutation (IVS1 - 2A>T). The E24G mutation resulted in substitution of an invariable amino acid residue (Glu) in the first esterase catalytic domain consensus sequence. The IVS1 - 2A>T mutation caused the retention of 40 nucleotides of intron 1 upstream of exon 2. The results of transient expression of the mutant ASPA cDNA containing these mutations in COS-7 cells and assays for ASPA activity of patient fibroblasts indicated that these mutations were responsible for the enzyme deficiency. In addition, patients with the novel D249V mutation manifested clinically at birth and died early. Also, patients with certain other novel mutations, including C152W, E214X, X314W, and frame shift mutations in both alleles, developed clinical manifestations at an earlier age than in classical Canavan disease.

Amidohydrolases↗

A biolistic process for in vitro gene transfer into chicken embryos.

Chicken embryos kept in culture medium were bombarded using a high helium gas pressure biolistic device. To optimize the factors that affect transformation efficiency, the lacZ gene under control of the human cytomegalovirus immediate early enhancer/promoter was used as a reporter gene. There was an inverse relationship between survival rate and transformation efficiency. The best conditions obtained for high embryo survival and high transformation efficiency were achieved with 800 psi helium gas pressure, 500 mmHg vacuum, gold particles, an 8 cm DNA-coated microparticle flying distance to the embryo and embryo placement 0.5 cm from the center of the particle dispersion cone. Under these conditions, transformation efficiency was 100%, survival rate 25% and the number of expression units in the embryo body cells ranged from 100 to 1,000. Expression of green fluorescent protein was also detected in embryos bombarded under optimal conditions. Based on the results obtained, the biolistic process can be considered an efficient method for the transformation of chicken embryos and therefore can be used as a model system to study transient gene expression and tissue-specific promoters.

Animals↗

Envenoming by the South American pit viper Bothrops neuwiedi Wagler.

Between 1975 and 1992, 18 cases of envenoming by Bothrops neuwiedi presented at the Hospital Vital Brazil, in São Paulo. Most of these cases were male (67%) and most had been bitten during the day (83%), between November and May (83%), either on the foot/ankle (50%) or hand (39%). Most (72%) of the cases arrived at the hospital 1-6 h after the bite. All presented with pain and most (83%) had oedema, but fewer had ecchymosis (50%), necrosis (17%), abscess (5%) and/or systemic blood-coagulation disorders (12%). Polyspecific Bothrops antivenom was administered to 16 (89%) of the patients. The results of B. neuwiedi bites therefore appear very similar to those of the much better known B. jararaca, even in terms of the gravity of the envenoming. Impairment in blood coagulation, however, seems less frequent among those bitten by B. neuwiedi than in those bitten by B. jararaca.

Adolescent↗

Bites by the colubrid snake Philodryas olfersii: a clinical and epidemiological study of 43 cases.

Less than 10 cases of bites by Philodryas olfersii (Colubridae) have been reported in the literature. In this study, 43 patients admitted to the Instituto Butantan, São Paulo, Brazil, with the diagnosis of P. olfersii bite from 1982 to 1990 were reviewed. The 32 male (74.4%) and 11 female (25.6%) patients presented mainly from November to February (65%). The most common clinical features were local pain (37.2%), swelling (34.9%), erythema (18.6%) and ecchymosis (9.3%). The 20 minute whole blood clotting test was performed in 11 patients and in all of them the blood was coagulable. Most of the accidents occurred during the hottest months and during daylight hours. The most common bite site was the hands. Severe envenoming is not frequent in these accidents.

Adolescent↗

Prognostic factors for amputation in the case of envenoming by snakes of the Bothrops genus (Viperidae).

The prognostic factors for amputation following envenoming by snakes of the Bothrops genus were identified from the medical records of 3139 patients. Each of these patients had been bitten by Bothrops sp. and treated in the Hospital Vital Brazil, in São Paulo, Brazil, between 1981 and 1990. The 21 (0.67%) of the patients who had undergone amputation were compared with the 3118 who had not, with respect to the characteristics of the accident, the snake, the victim, the local and systemic manifestations of the envenoming and the treatment. There was an association between amputation and the month of the accident, the time of day when the accident happened, the length of the attacking snake, the anatomical region bitten, systemic bleeding and renal failure. Patients bitten in the fingers, during the cooler months, between 00.00 and 12.00 hours and/or by snakes > 60 cm in length, who developed blisters and abscesses at the site of the bite, systemic bleeding and/or renal failure underwent amputation more frequently than the others (P < 0.05 for each).

Adolescent↗

Aeromonas hydrophila soft-tissue infection as a complication of snake bite: report of three cases.

Aeromonas hydrophila soft-tissue infection has been associated with fish and reptile bites. There have bee three recent cases from Brazil of abscesses complicating snake bites in which A. hydrophila was isolated from the purulent exudates. One of the snakes responsible for the bites was a specimen of Bothrops moojeni, and the others were most probably also lance-headed vipers. These snakes have a local necrotizing, myotoxic, oedema-inducing venom that must have favoured the multiplication in the injured tissue of A. hydrophila strains, which were probably present in the mouth, fangs or venom of the snakes. The use of a tourniquet by two of the patients probably worsened the local envenoming, and contributed to the occurrence of soft-tissue infection. The patients had a good outcome after the abscesses were incised and drained, and after being treated with chloramphenicol. Chloramphenicol appears to be a good alternative for the empirical treatment of soft-tissue infection complicating snake bite in Brazil, because: it is active against the majority of the anaerobic and aerobic bacteria found in these abscesses, including A. hydrophila; it can be administered by the oral route; and its is inexpensive. Suitable alternatives are cotrimoxazole or fluoroquinolones, to which aeromonads are usually susceptible in vitro, associated with antibiotics, such as clindamycin and metronidazole, with an anti-anaerobic spectrum.

Adolescent↗

Snakebite by the bushmaster (Lachesis muta) in Brazil: case report and review of the literature.

The bushmaster (Lachesis muta) of Central and South America, the world's longest pit viper, is capable of injecting a large dose of potent venom when it bites. A 28-year-old man, bitten by a 1.82 m long L. m. muta in Brazil, developed pain and oedema at the bite site, nausea, vomiting, diarrhoea and sweating. There was peripheral neutrophil leucocytosis and evidence of fibrinogen consumption with secondary activation of the fibrinolytic system. Two hours after the bite, eight ampoules of Instituto Butantan Lachesis antivenom was administered, and haemostasis was normal 24 hr later. A review of reports of 20 cases of bites in humans reliably attributed to this snake in Costa Rica, French Guiana, Brazil, Colombia and Venezuela confirms a syndrome of nausea, vomiting, abdominal colic, diarrhoea, sweating, hypotension, bradycardia and shock, possibly autopharmacological or autonomic in origin, not seen in victims of other American crotaline snakes. These, and other symptoms of bushmaster envenoming, are explained by haemorrhagic, coagulant and neurotoxic venom activities. The therapeutic efficacy of non-specific Bothrops/Crotalus polyvalent antivenoms in these cases has been unimpressive. For the treatment of bites by a snake which potentially injects a large dose (> 300 mg dry weight) of venom with a range of life-threatening activities, there is an urgent need to develop more potent specific antivenoms and to treat the dramatic and life-threatening cardiovascular symptoms.

Accidents, Occupational↗

Snake bites by the jararacuçu (Bothrops jararacussu): clinicopathological studies of 29 proven cases in São Paulo State, Brazil.

The jararacuçu, one of the most dreaded snakes of Brazil, southern Bolivia, Paraguay and northeastern Argentina, is a heavily-built pit viper which may grow to a length of 2.2 m. Up to 1000 mg (dry weight) of highly-lethal venom may be milked from its venom glands on a single occasion. It has accounted for 0.8% to 10% of series of snake bites in São Paulo State, Brazil. We examined 29 cases of proven jararacuçu bites recruited over a 20-year period in two São Paulo hospitals. Severe signs of local and systemic envenoming, (local necrosis, shock, spontaneous systemic bleeding, renal failure) were seen only in patients bitten by snakes longer than 50 cm; bites by shorter specimens were more likely to cause incoagulable blood. Fourteen patients developed coagulopathy, six local necrosis (requiring amputation in one) and five local abscesses. Two became shocked and four developed renal failure. Three patients, aged 3, 11 and 65 years, died 18.75, 27.75 and 83 h after being bitten, with respiratory and circulatory failure despite large doses of specific antivenom and intensive-care-unit management. In two patients, autopsies revealed acute renal tubular necrosis, cerebral oedema, haemorrhagic rhabdomyolysis at the site of the bite and disseminated intravascular coagulation. In one survivor with chronic renal failure, renal biopsy showed bilateral cortical necrosis; the patient remains dependent on haemodialysis. Effects of polyspecific Bothrops antivenom were not impressive, and it has been suggested that anti-Bothrops and anti-Crotalus antivenoms should be given in combination.

Adult↗

Cytogenetic evaluation of 20 primary breast carcinomas.

Chromosome analysis was performed on samples from 20 Brazilian patients with breast cancer. All the samples were from untreated patients who presented the clinical symptoms for months or years before surgical intervention. Six cases showed axillary lymph node metastases. Clonal chromosome abnormalities were detected in all cases. The numerical alterations most frequently observed involved the loss of chromosomes X, 19, 20, and 22 followed by gain of chromosomes 9 and 8. Among the structural anomalies observed, there was preferential involvement of chromosomes 11, 6, 1, 7, 3, and 12, supporting previous reports that these chromosomes may harbour genes of importance in the development of breast tumors. Two cases with a family history of breast cancer had in common total or partial trisomy 1.

Adult↗

[Epidemiology of accidents due to bites of poisonous snakes: a study of cases attended in 1988].

The attendance given to patients by ta specialized Hospital, in S. Paulo, Brazil, during 1988 is studied. The study is based on the medical records of 322 patients and on questionnaires filled out by author during interviews with 209 patients or their companions. The 322 snake-bites occurred mainly between October and April, in the diurnal period, mainly in the afternoon. Most of patients were adult males, mainly between 10 and 20 years of age. The parts of the body most frequently affected were the feet, hands and legs. The snakes of the genera Bothrops, Crotalus and Micrurus were responsible, respectively, for 306 (95.0%) 14 (4.4%) and 2 (0.6%) of the accidents under study. Among the 160 snakes that were classified at the Herpetological Section of the IB, 152 were Bothrops; 142 B. Jararaca, mostly young reptiles, and 8 were of the genus Crotalus. Of the patients, 90.4% recovered completely, 2.2% presented sequelae, 7.5% were transferred and thus it was impossible to follow them up. Of the 209 persons interviewed, the occupational group most prone to snake bites was agricultural workers, followed by studentes; nearly 60% of the accidents ocurred during work; most of the patients had their inferior extremities unprotected at the moment of the bite. On hundred and sixty patients (76.6%) submitted to some from of treatment before coming to the HVB-IB, the more common being the use of a tourniquet (50.2%), local squeezing in an attempt to remove part of the venom (33.5), application of substances on the site of the snake bite (36.8%) and the ingestion of others (12.9%). Slightly over a quarter of the patients underwent some kind of medical treatment before coming to the HVB-IB, the most common being antissepsis (8.2%), administration of antivenom (6.2%), antihistamines (5.7%) and analgesics (5.3%). The snake was seen before it struch by 187 (89.5%) of the 209 persons interviewed and in most cases it adopted the strike posture just before the first bite.

Adolescent↗

Microbiological studies of abscesses complicating Bothrops snakebite in humans: a prospective study.

Forty patients with abscesses at the site of Bothrops bite were evaluated. Ten brought the snake responsible for the bite, Bothrops jararaca in all cases. On admission a sample was collected from each case for aerobic and anaerobic culture, and no abscesses drained spontaneously. None of the patients had received antibacterial therapy at this time. The bacteria most frequently isolated were Morganella morganii (23 patients), Providencia rettgeri (7) Enterobacter sp. (4), Escherichia coli (3), group D streptococcus (11) and Bacteroides sp. (6). All enterobacteria tested were sensitive to chloramphenicol, aminoglycosides and cefotaxime. Group D streptococci were sensitive to chloramphenicol, ampicillin and penicillin G, whereas anaerobic bacteria were sensitive to chloramphenicol and tetracycline. These results suggest that in cases of abscess formation secondary to Bothrops bite, chloramphenicol alone is a good choice, being both safe and cheap.

Abscess↗

Wolf spider bites in São Paulo, Brazil: a clinical and epidemiological study of 515 cases.

Data obtained from 515 victims of bites of wolf spiders (family Lycosidae) who were attended in Vital Brazil Hospital, São Paulo City, Brazil, in a 5-year period (1979-1983) were analysed. Bites were more frequent in males (56%). All age groups were involved. Foot and hand were the preferential sites of bite (79%), and pain, generally mild, was the predominant symptom (83%). No local necrosis, a severe complication described in the previous literature, was detected, suggesting that those old cases were due to misdiagnosed Loxosceles spider bites. Specific antivenom was employed in only three cases which is evidence that physicians do not consider wolf spider bites to be severe.

Adolescent↗