Benzo(a)pyrene Exposure Causes Genotoxic and Biochemical Changes in the Midge Larvae of Chironomus sancticaroli Strixino & Strixino (Diptera: Chironomidae).

Benzo(a)pyrene (BaP) is a carcinogenic polycyclic aromatic hydrocarbon, also found in nature due to human activities. BaP adheres to sediments showing toxic effects on benthic organisms, including midge larvae of the family Chironomidae. We tested for toxic effects of benzo(a)pyrene on Chironomus sancticaroli Strixino & Strixino 1981 using biochemical and genotoxic biomarkers, to identify changes in metabolic and antioxidant pathways, besides neurotoxic and DNA damage. Enzyme activity was compared by exposing larvae to four nominal concentrations (0.47, 2.13, 3.41, and 4.73 µg l-1) and DNA damage to two concentrations (0.47 and 4.73 µg l-1), after exposure at 24, 48, 72, and 96 h. BaP caused neurotoxic effect, showing acetylcholinesterase alterations at different treatments. Changes in the biotransformation pathway were detected, with an increased activity of alpha and beta esterase in 48 h and reduction of glutathione-S-transferase activity in all periods at the highest concentrations. Damage to the antioxidant system was observed by the increase of the superoxide dismutase and reduction of the catalase, in 48 h. Genotoxicity was detected by an increased DNA damage at 48 and 72 h. The lowest concentration (0.47 µg l-1), even presenting low mortality, also altered the biochemical parameters of the larvae. Thus, these results indicate that BaP causes metabolic, neurotoxic, and genotoxic effects on C. sancticaroli, even at low concentrations and short-term exposure. BaP can cause damage of immature invertebrates, and the ecological dynamics can be affected, since these organisms have trophic importance in the aquatic environment.

House dust mites in the city of Lima, Peru.

Since mites are the most common house dust allergens, knowledge about the species most prevalent in a region is important for diagnostic and specific immunotherapy purposes. In order to establish the prevalence of house dust mites in different city districts, 100 house dust samples were collected from different parts of Lima. Lima is a city of tropical climate located along the coast of the Pacific Ocean. The relative air humidity is 80-90% and the various districts studied are located at altitudes ranging from 37-355 meters. The mite Blomia tropicalis was the organism most frequently detected, being present in 59% of the house dust samples. Dermatophagoides pteronyssinus occupied second place (15.9%), followed by Chortoglyphus arcuatus and Tyrophagus putrescentiae. These four mites, taken together, represented more than 90% of the mites detected. No specimen of the species Dermatophagoides farinae was detected. We conclude that B. tropicalis and D. pteronyssinus are the most common house dust mites in Lima. Considering the high prevalence of B. tropicalis in Lima and the fact that its cross-reactivity with antigens of the mites of the family Pyroglyphidae is minimal, we conclude that sensitization to this mite should be investigated separately in allergic patients living in Lima.

[Mite contamination in polished rice and beans sold at markets]. / Contaminacao por acaros em arroz polido e feijao comercializados a granel.

OBJECTIVE: To evaluate mite contamination rate in grains commercialized in nine municipal markets of the city of São Paulo, in the period from November 1989 to November 1990. METHODS: 23 samples of polished rice and 53 samples of beans were microscopically examined after sieving, once a week and during 42 days at air temperature. Other sample fractions were kept in an incubator at 25 degrees C and 75% Relative Humidity (RH) during 28 days. RESULTS: Samples were negative for mites in the first day of analysis and were detected after incubation. Samples incubated revealed a higher percentage of positive examinations for mites (incidence): 31.7% (and 1,845 mites); while samples kept at air temperature showed only 6.9% (and 45 mites). Samples of polished rice were more contaminated in comparison to the ones of beans. There was a larger amount of mites when the mean monthly temperature of the laboratory was between 21.5 degrees C to 22.5 degrees C (37. 8%) and humidity between 73.5% to 74.5% (31.1%). CONCLUSIONS: The predominant species was Tyrophagus putrescentiae and other identified species were Blomia tropicalis, Cheyletus spp., Blattisocius tarsalis, and others. Mite population had a higher proliferation rate during spring, summer and in the beginning of autumn, due to highest temperature and humidity. These results confirm the importance of improving grains storage, to avoid mites proliferation.

Oral anticoagulant therapy for heart disease: results in actual cardiology practice.

OBJECTIVE: To determine whether the success and complication rates of oral anticoagulation obtained in large, well controlled trials, upon which recommendations are based, are comparable with routine cardiology practice. DESIGN: An observational, prospective cohort study collected data on all patients followed at an anticoagulant clinic over one calendar year. PATIENTS: One thousand and seventy-eight patients anticoagulated for cardiovascular indications, mainly atrial fibrillation, prosthetic valves and ventricular dysfunction, were followed for 804 patient-years of treatment. No patient was lost to follow-up. INTERVENTIONS: Telephone conversations and regular verification of medical files were used to record and classify all bleeding and thromboembolic events according to severity. International normalized ratios (INR) were compared with target ranges. RESULTS: One hundred and twelve bleeding events, ie, 13.9/100 patient-years (% p-y), were recorded, of which 61 required medical attention. Major hemorrhages, defined as those requiring treatment or hospital observation for more than 24 h, occurred in 15 instances (1.9% p-y). Among these, 9 (1.1% p-y) were classified as life threatening, with four being fatal (0,5% p-y). Twenty-two thromboembolic events (2.7% p-y) occurred, of which 10 were major (1.2% p-y), leaving three patients (0.4% p-y) with long term sequelae and causing two deaths (0.25% p-y). INRs were within target range 62.3% of the time, with 2.2% of values recorded above 5 and 0.3% above 10. CONCLUSION: The low failure and complication rates obtained in large, controlled trials are similar to those observed in actual cardiology practice.

Storage mite allergy in perennial rhinitis patients not sensitized to house dust mites.

Antigens from house dust mites are the most important indoor allergen involved in the immunopathogenesis of perennial allergic rhinitis and asthma. Storage mites have been identified in the dust of homes in many tropical and temperate climates. The role of these mites in allergic respiratory conditions needs to be clarified. We studied sensitivity to the storage mites Biomia tropicalis and Tyrophagus putrescentiae in patients previously considered non-allergic, based on negative reactions to skin tests with common inhalant allergens in our region. It was possible to verify that some of these patients were in fact sensitized exclusively to the storage mite allergens.

IgG and IgE antibody responses to dust mite allergens among children with asthma in Brazil.

We compared exposure and levels of IgE and IgG antibodies to inhalant allergens in 20 children with asthma and positive skin tests to Dermatophagoides pteronyssinus, living in São Paulo, to 20 control children without history of asthma or allergy and negative skin tests to D. pteronyssinus, D. farinae, and Blomia tropicalis. In 16/20 and 17/20 houses of asthmatic and control children, respectively, at least one sample was obtained which contained > 10 micrograms Der p I/g of dust. Serum IgE antibodies to D. pteronyssinus and Blomia tropicalis were > 200 RAST U/mL in 19/20 and in 16/20 asthmatic children, respectively. In the control group, IgE antibodies to either mite species were < 40 RAST U/mL in most cases. IgG anti-Der p I and anti-Der f I antibodies were detected in 17/20 asthmatics, as opposed to 3/20 controls. Neither cat nor cockroach allergens caused significant sensitization among asthmatic or control children. Although exposure to high levels of mite allergens was common in São Paulo, significant IgE and IgG antibody responses were detected only in children with asthma.

[Lyme disease. Report of a case observed in Brazil]. / Doença de Lyme. Relato de um caso observado no Brasil.

Lyme disease is an infectious disease caused by spirochete Borrelia burgdorferi transmitted by Ixodid tick bite. The geographic distribution of the disease is universal, but the disease has not been identified definitely in South America yet. We report a probable case of Lyme disease in a woman, living in Jaguaré slum (São Paulo), who showed characteristics skin lesions of erythema chronicum migrans, with fever, weakness, headache, muscular pain, cough, arthralgia and sensitive radicular neuropathy in the left arm. The sequential serology made by ELISA method, using Borrelia burgdorferi whole sonicated antigen from Dr. Allen C. Steere laboratory, showed high titers of IgM antibody (1:1600). Because of the persistence of high IgM response for two months, we decided to treat the patient with tetracycline 2g/day during 10 days and the sorology became negative two months. The western blotting confirmed ELISA results showing presence of five bands (IgM). This report fulfills CDC criteria for Lyme disease diagnosis.

[Epidemiological study of Lyme disease in Brazil]. / Estudo epidemiológico da doença de Lyme no Brasil.

Lyme disease is a tick-born infection first reported in United States of America in 1977 by Allen C. Steere. It occurred in the state of Connecticut; other cases have been discovered in others states of USA and also in other countries (Canada, Soviet Union, Japan, China, Australia). This disease has not been reported in South America yet. In order to investigate this disease in Brasil, a multi-disciplinary group including microbiologists, entomologists and clinicians was created at the University of São Paulo. The aim of this report is to describe the elaboration of this research in our center and also to present the preliminary results.

Exposure and sensitization to dust mite allergens among asthmatic children in São Paulo, Brazil.

A group of 20 mite allergic asthmatic children aged 6-12 years old, living in São Paulo, Brazil, was studied regarding their degree of sensitization to house dust mites and exposure to mite allergens in their homes. In 18 out of 20 houses at least one dust sample was obtained which contained greater than 10 micrograms Der p I/g of dust. The highest levels of Dermatophagoides pteronyssinus allergens, Der p I and Group II, were measured in bedding samples (geometric mean 38.4 and 36.6 micrograms/g, respectively), followed by bedroom floor, TV room and kitchen. Mite allergen levels in Brazilian houses were as high as those reported to be associated with sensitization and acute attacks of asthma in other parts of the world. In keeping with previous reports that D. farinae is rarely found in Brazil, Der f I was undetectable or found in very low levels (less than 0.5 micrograms/g). Levels of cat allergen Fel d I of greater than 8 micrograms/g of dust were obtained only in 2 houses only. Cockroach allergen Bla g I was detected in five out of 20 houses. Levels of IgE antibodies to D. pteronyssinus were greater than 200 RAST U/ml in 19 out of 20 children (geometric mean 1588 RAST U/ml). IgE antibodies to cat, cockroach, A. fumigatus, ragweed and rye grass pollens were undetectable or less than 80 RAST U/ml. IgE antibodies to the mite Blomia tropicalis were also measured, and levels greater than 200 RAST U/ml were observed in 13 out of 20 sera.(ABSTRACT TRUNCATED AT 250 WORDS)

[Occurence of Ornithoros talaje Guérin et Méneville, in the township of Santo Inácio, Bahia (author's transl)]. / Ocorrência de Ornithodoros talaje Guérin et Méneville, 1849, (ixodides: Argasidae), na localidade de Santo Inácio, Bahia, Brasil.

It is reported in the paper, the ocurrence of Ornithodoros talaje in the township of Santo Inácio, near Xique-Xique, situated in a special region called "Caatinga Nordestina", in the State of Bahia, Brazil. Some informations about the geological composition of the region and of the tick's ecologycal behaviour, are also presented.