Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 6--Breeding in empty conditions of rice fields in south-eastern Brazil.

Studies on culicid breeding in empty rice fields were carried out during the cultivation cycle from May to November 1993. This period corresponded to stages 1 and 2, when empty conditions prevailed. Breeding occurred in stage 1 and the first part of stage 2, corresponding respectively to fallow uncultivated and ploughing situations.

[Neuropsychological tests of simple application for diagnosing dementia].

Thirty patients with dementia defined by DSM-III-R criteria (Alzheimer's disease (22), vascular dementia (3), Parkinson's disease, frontal lobe dementia, possible diffuse Lewy body dementia, normal pressure hydrocephalus and uncertain diagnosis), with scores below 24 points in the Mini-Mental Status Examination and more than 4 years of education were submitted to a neuropsychological evaluation. The scores in the neuropsychological tests were compared to those obtained by thirty normal volunteers paired for age, sex and education. Sensitivity, specificity and accuracy of the tests in the distinction of demented and normal volunteers were determined.

The basic reproduction ratio of HIV among intravenous drug users.

A new approach for the estimation of the Basic Reproduction Ratio R0 for HIV among intravenous drug users (IVDU) is proposed. This approach is based in an adaptation of the models proposed by Ross and Macdonald for vector-borne infections. A straightforward adaptation of Macdonald's model is presented first: biological vectors are replaced by needles and syringes and we consider a homogeneous population of IVDUs; next we present a modified model where several heterogeneities are considered.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 5--breeding of Anopheles albitarsis in flooded rice fields in south-eastern Brazil.

Studies on breeding Anopheles albitarsis and association with rice growth in irrigated paddy fields were carried out during the rice cultivation cycle from December 1993 to March 1994. This period corresponded to the length of time of permanent paddy flooding. Breeding occurred in the early stage up until five weeks after transplantation when rice plant height was small.

Rubella seroepidemiology in a non-immunized population of São Paulo State, Brazil.

A rubella serological survey of 476 individuals selected by cluster sampling technique from Caieiras, a small town located in the outskirts of São Paulo city, southeastern Brazil, was carried out over the period November 1990-January 1991. The aim of the study was to characterize rubella epidemiology in a representative non-immunized community in south east Brazil. The survey comprised a seroprevalence study, stratified by age (0-40 years) and a seroconversion study of rubella vaccine in non-infected children below 2 years of age.

A model-based design of a vaccination strategy against rubella in a non-immunized community of São Paulo State, Brazil.

A mixed vaccination strategy against rubella is proposed. We describe how the vaccination strategy was designed with the help of mathematical techniques. The strategy was designed for application in a non-immunized community of the State of São Paulo, Brazil, and was implemented by local health authorities in 1992.

Association between air pollution and mortality due to respiratory diseases in children in São Paulo, Brazil: a preliminary report.

This work presents the results of a time series study relating air pollution and respiratory mortality in children under 5 years of age in the metropolitan area of São Paulo, Brazil. Daily records of mortality (excluding neonatal mortality) for the period May 1990 to April 1991 were collected along with daily records of relative humidity, temperature, SO2, CO, particulates (PM10), O3, and NOx concentrations. Using multiple regression methods we demonstrated a significant association between mortality due to respiratory diseases and the NOx levels.

Malaria vaccines: lessons from field trials.

Malaria vaccine candidates have already been tested and new trials are being carried out. We present a brief description of specific issues of validity that are relevant when assessing vaccine efficacy in the field and illustrate how the application of these principles might improve our interpretation of the data being gathered in actual malaria vaccine field trials. Our discussion assumes that vaccine evaluation shares the same general principles of validity with epidemiologic causal inference, i.

Malaria prevalence amongst Brazilian Indians assessed by a new mathematical model.

An alternative way to estimate the endemic level of malaria amongst Brazilian indians is proposed. This is achieved by estimating the age-related 'force of infection' of malaria (the effective inoculation rate), applying a mathematical model, described elsewhere, to serological data. In addition we present a way to estimate the Basic Reproductive Rate of malaria in the same area.

Malaria transmission rates estimated from serological data.

A mathematical model was used to estimate malaria transmission rates based on serological data. The model is minimally stochastic and assumes an age-dependent force of infection for malaria. The transmission rates estimated were applied to a simple compartmental model in order to mimic the malaria transmission.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 4--Survey of resting adults and synanthropic behaviour in south-eastern, Brazil.

Resting adults Culicidae were collected from January 1992 through January 1993 in several habitats of the Ribeira Valley region. The diversity of species found among them suggested that the vegetation remaining within human settlements favored the survival and the population increase of some mosquitoes. Among there are: Ae.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 3--Survey of adult stages at the rice irrigation system and the emergence of Anopheles albitarsis in south-eastern, Brazil.

A study of adult Culicidae ecology was carried out from January 1992 through January 1993 at the rice irrigation system of the Ribeira Valley Experimental Station. The adaptation of Anopheles albitarsis to the anthropic environment became evident through the adult collections made at its various habitats represented by the irrigation system and the edge of the residual pond, as well as at those made within the local patchy residual woods. Other potential disease vectors were prevalent in the irrigated system too.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 2. Immature stages research at a rice irrigation system location in south-eastern Brazil.

A relation between a rice irrigation system and mosquito breeding was established in a study undertaken at the Ribeira Valley Experimental Station, from January through December 1992. Flooding favoured Anopheles (Nyssorhynchus) and Culex (Melanoconion) species, while empty paddies condition were propitious to Aedes scapularis and Culex (Culex) species. Compared with a more primitive area of the same region, several species showed high a degree of adaptation to the anthropic environment.

Modeling and simulating the evolution of resistance against antibiotics.

An epidemiological model is proposed for the spread of resistance against antibiotics in populations of bacterial pathogens. The host population, which is assumed to be constant, is divided into three compartments, viz. susceptible, hosts infected by an antibiotic-sensitive strain and hosts infected by a resistant strain.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 1--Parity of blood seeking Anopheles (Kerteszia) in south-eastern Brazil.

Populations of Anopheles (Kerteszia) were sampled fortnightly over a one-year period (August 1991 to July 1992) at Ribeira Valley, S. Paulo State, Brazil. Indoor and outdoor collections were made on human bait at evening crepuscular period.

Effects of vaccination programmes on transmission rates of infections and related threshold conditions for control.

This study addresses the problem of the existence of conditions for persistence or eradication of age-dependent directly transmitted infections. The usual system of differential equations describing the dynamics of the disease is transformed into integral equations. The authors show how to solve these equations and, by applying the contraction mapping theorem, give conditions for the persistence or eradication of the infection.

[An experimental study of the tissue reactions in rats induced by different concentrations of benzathine penicillin G].

The search of scientific answers to problems due to procedures involving professional actions is a permanent challenge to the nurses committed with the improving of nursing care. In face of the intensive muscle soreness provoked by penicillin G benzatin shots, an experimental evaluation of this procedure was carried out in order to observe the influences of concentration and volumes used. This evaluation could give some insights to improve the nursing care, particularly those linked to the manipulation of the penicillin injection.

Biological effects of air pollution in São Paulo and Cubatão.

Rats were used as biological indicators of air quality in two heavily polluted Brazilian towns: São Paulo and Cubatão. They were exposed for 6 months to ambient air in areas where the pollution was known to be severe. The following parameters were studied and compared to those of control animals: respiratory mechanics, mucociliary transport, morphometry of respiratory epithelium and distal air spaces, and general morphological alterations.

A mathematical model for spirometry.

A model originally designed to fit population growth data was investigated to determine whether it could fit spirometric traces as a function of time in normal and ill humans and in normal rats, obtained, respectively, by spirometer and whole-body plethysmography. The model showed great accuracy when applied to a simple spirometer coupled with an analog-to-digital converter interfaced with a personal computer. It also proved to be a good alternative for the more expensive and less accurate electronic devices, as derivative systems, and may be an attractive method for research and/or diagnostic centers.

Stability of 1% rifampin suspensions prepared in five syrups.

The stability and microbiological activity (potency) of rifampin in 1% w/v suspensions prepared extemporaneously using five syrups was studied. The contents of four 300-mg rifampin capsules (Rifadin, Merrell Dow Pharmaceuticals Inc.) were crushed and placed in amber glass bottles.

Toxicity of prolonged exposure to ethanol and gasoline autoengine exhaust gases.

A comparative chronic inhalation exposure study was performed to investigate the potential health effects of gasoline and ethanol engine exhaust fumes. Test atmospheres of gasoline and ethanol exhaust were given to Wistar rats and Balb C mice housed in inhalation chambers for a period of 5 weeks. Gas concentration and physical parameters were continually monitored during the exposure period.