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Biomedical subjects

G M Böhm

Publications and source records attributed to G M Böhm.

At least 19 recordsLinked to original sources
PubMed2005

Tongue disease in advanced AIDS.

OBJECTIVE: This study describes the involvement and the histological alterations found in the tongues of 92 autopsied patients who died with AIDS. MATERIALS AND METHODS: Sex, age, CD4 cell count and clinical history were obtained from the files of 92 patients who died with AIDS. All the tongues were examined for macroscopical alterations and stained using H&E, Gomori-Grocott, Ziehl-Neelsen, PAS, Brow-Hopps and Mucicarmine. Histological autopsy findings were grouped based on a protocol that was designed following the World Health Organization recommendations. RESULTS: The mean age of the patients who died of AIDS and CD4 cell count were 36 years and 82 cells microL(-1), respectively. Histological alterations of the tongues were found in 75% of the cadavers. The most common lesions were hairy leukoplakia (HL) (42 cases), candidosis (31 cases) and non-specific chronic glossitis (29 cases), followed by concomitant lesions (28 cases), non-specific chronic ulceration (17 cases), melanotic pigmentation (13 cases), herpes simplex (10 cases), lymphoepithelial cysts (two cases), cryptococcosis (two cases), mycobacteriosis (one case), histoplasmosis (one case), cytomegalovirus infection (one case) and non-Hodgkin Lymphoma (one case). HL with oral candidosis (n = 13) were the most common concomitant lesions. CONCLUSION: These findings indicate that the tongue is a favorite site to occurrence of reactive, infectious and concurrent lesions in the end-stage of AIDS patients.

AIDS-Related Opportunistic Infections↗
PubMed2003

Parotid gland involvement in advanced AIDS.

OBJECTIVE: This study describes the involvement and the histological alterations found in the parotid glands of 100 patients who died with AIDS. MATERIALS AND METHODS: Sex, age, CD4 cell count and clinical history were obtained from the files of 100 patients who died with AIDS. Histological analysis of the parotid glands was performed using H&E, Gomori-Grocott, Ziehl-Neelsen and Mucicarmine. Histological findings were grouped in reactive, infectious, cystic, neoplastic and concomitant lesions. RESULTS: None of the patients presented complaints or symptoms related to salivary gland alterations prior to death. The mean age of the patients and CD4 cell count were 36.4 years and 76.07 cells microliter-1, respectively. Histological alterations of the parotid glands were found in 51% of the patients. The most common alteration was non-specific chronic sialadenitis (29 cases), followed by infectious conditions (22 cases). Mycobacteriosis was the most common infectious disease (10 cases), followed by cytomegalovirus (nine cases), cryptococcosis (three cases) and histoplasmosis (two cases). Lymphoepithelial cysts occurred in six cases, Warthin's tumor and non-Hodgkin Lymphoma in one case each. CONCLUSIONS: These results indicate that infection and other lesions in the parotid glands are more frequent than hitherto described in the specialized literature in AIDS patients. Clinicians should consider parotid gland involvement, when evaluating disease extension in advanced AIDS patients.

AIDS-Related Opportunistic Infections↗
PubMed2003

Telemedicine model for training non-medical persons in the early recognition of melanoma.

A Web-based educational model, called JUTE, was developed for the early diagnosis of melanoma. It was compared with a control Website composed of information available on the Internet for teaching undergraduate medical students. The JUTE model was designed to allow the student linear navigation of the main topics that were assumed to be important in learning to make a diagnosis. The rate of success in correctly deciding to refer pigmented lesions to a dermatologist was compared among 34 new medical students who were randomly divided into two groups. There was no significant difference between the JUTE and control groups in the pre-test. When comparing the pre- and post-tests, the number of correct decisions increased significantly only in the JUTE group. In the JUTE group there was a slight but significant improvement when comparing decisions about thin melanoma before and after the training. The educational approach chosen for the JUTE Website appears to be useful for teaching the early recognition of melanoma and could be used for larger educational campaigns of skin cancer prevention.

Computer-Assisted Instruction↗
PubMed2003

Evaluation of an Internet-based teledermatology system.

We established a Website which allowed clinical dermatology cases to be submitted, with digital images, through a simple online form. The case could then be managed within the public health service. A database containing 6000 drug interactions was also available on the Website to help clinical management. The Website was tested by 10 junior doctors, who examined dermatology patients, filled in the electronic form with their clinical observations and descriptions, and forwarded digital images. Five dermatologists then evaluated the 71 cases stored on the Website. The agreement between the virtual evaluation and the definitive diagnosis (on face-to-face examination) was 95%. The Website could be used in national health strategies, as a tool for promoting voluntary medical attendance, and for multicentre epidemiological surveillance.

Databases as Topic↗
PubMed2000

Assessment of the effects of sugar cane plantation burning on daily counts of inhalation therapy.

This study was designed to evaluate the association between sugar cane plantation burning and hospital visits in Araraquara in the state of São Paulo, Brazil. From June 1 to August 31, 1995, the daily number of visits of patients who needed inhalation therapy in one of the main hospitals of the city was recorded and used as health impairment estimation. Sedimentation of particle mass (the amount of particles deposited on four containers filled with water) was measured daily. The association between the weight of the sediment and the number of visits was evaluated by means of Poisson regression models controlled for seasonality, temperature, day of the week, and rain. We found a significant and dose-dependent relationship between the number of visits and the amount of sediment. The relative risk of visit associated with an increase of 10 mg in the sediment weight was 1.09 (1-1.19), and the relative risk of an inhalation therapy was 1.20 (1.03-1.39) on the most polluted days (fourth quartile of sediment mass). These results indicate that sugar cane burning may cause deleterious health effects in the exposed population.

Agriculture↗
PubMed1999

Air pollution and respiratory illness of children in São Paulo, Brazil.

This investigation reports the association between air pollution and paediatric respiratory emergency visits in São Paulo, Brazil, the largest city in South America. Daily records of emergency visits were obtained from the Children's Institute of the University of São Paulo for the period from May 1991 to April 1993. Visits were classified as respiratory and non-respiratory causes. Respiratory visits were further divided into three categories: upper respiratory illness, lower respiratory illness and wheezing. Daily records of SO2, CO, particulate matter (PM10), O3 and NO2 concentrations were obtained from the State Air Pollution Controlling Agency of São Paulo. Associations between respiratory emergency visits and air pollution were assessed by simple comparative statistics, simple correlation analysis and by estimating a variety of regression models. Significant associations between the increase of respiratory emergency visits and air pollution were observed. The most robust associations were observed with PM10, and to a lesser extent with O3. These associations were stable across different model specifications and several controlling variables. A significant increase in the counts of respiratory emergency visits--more than 20%--was observed on the most polluted days, indicating that air pollution is a substantial paediatric health concern in São Paulo.

Adolescent↗
PubMed1998

Association between air pollution and intrauterine mortality in São Paulo, Brazil.

The associations among daily counts of intrauterine mortality and pollutant concentrations (NO2, SO2, CO, O3, and particulate matter (3/4)10 microm) were investigated for the period ranging from January 1991 to December 1992 in the city of São Paulo, Brazil. We used Poisson regression techniques, adjusted for season and weather. The association between intrauterine mortality and air pollution was strong for NO2 (coefficient = 0.0013/ microg/m3; p<0.01) but lesser for SO2 (coefficient = 0.0005/ microg/m3; p<0.10) and CO (coefficient = 0.0223/ppm; p<0.10). A significant association was observed when an index that combined these three pollutants was considered in the models instead of considering each pollutant individually (p<0.01). These associations exhibited a short time lag, not over 5 days. In addition, some evidence of fetal exposure to air pollution was obtained by disclosing a significant association between the levels of carboxyhemoglobin of blood sampled from the umbilical cord and ambient CO levels in children delivered by nonsmoking pregnant women in the period from May to July 1995. Our results suggest that air pollution in São Paulo may promote adverse health effects on fetuses.

Adult↗
PubMed1997

Urban air pollution enhances the formation of urethane-induced lung tumors in mice.

This paper investigates the association between air pollution and lung neoplasia in an animal model. The experimental exposures were done in two locations with different air pollution profiles: a polluted area (downtown São Paulo) and a "clean" environment (Atibaia). Swiss mice were employed and urethane (3 g/kg) was used as carcinogenic substance. Two experiments were performed: Experiment I was designed to verify whether air pollution acts as initiator and/or promoter of lung cancer, using 300 mice; Experiment II employed 250 animals and aimed to verify if the effects of air pollution on the development of lung tumors was dose dependent. A significant effect of air pollution in augmenting lung carcinogenecity induced by urethane was observed. This effect was shown to be dose-dependent and reproducible on two different occasions. In addition, morphometric studies revealed that pollution may influence tumor phenotype. These results support the hypothesis that air pollution plays a significant role in the development of lung tumors.

Air Pollutants↗
PubMed1995

Rheological determinants of mucociliary transport in the nose of the rat.

The present work was designed to investigate whether the rheological determinants for nasal mucociliary transport are the same in the intact preparation (in situ), as they are when the mucus is added exogenously to the isolated, mucus-depleted frog palate (in vitro). We evaluated the association between estimators of mucociliary transport in both conditions and rheological parameters using multiple regression techniques. Two kinds of rats were used: (a) specific pathogen free (SPF) rats, representing the normal condition of respiratory epithelium; (b) non-SPF rats (NSPF), which have a chronic inflammatory process in the airways. In situ mucociliary clearance (MCC) was determined by measuring the displacement of charcoal particles placed in the nasal septum. In vitro mucociliary transport (MCT) of rat nasal mucus was measured using the isolated frog palate preparation. Mucus rheologic properties were determined by magnetic microrheometry, in oscillatory deformations performed at 1, 10 and 100 radians/sec. No differences were detected between SPF and NSPF rats in terms of rheological parameters. A decreased MCC was found in NSPF in comparison with the SPF group, but no differences were observed between groups in terms of MCT, as could be predicted by rheological data. When all animals were pooled, in situ transport was significantly associated with the viscosity/elasticity ratio, whereas in vitro transport was dependent on the total mechanical impedance of the mucus sample. In conclusion, in situ mucus transport is influenced by other rheological parameters than those associated with in vitro transportability.

Animals↗
PubMed1994

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. After controlling for weather and season effects, the odds of dying due to respiratory diseases, considering the mean levels of NOx in São Paulo, was estimated at 1.3 (+/- 0.13). This result is in accord with previous animal studies conducted by our group and indicates that air pollution in São Paulo has reached levels high enough to have adverse health effects on the exposed population.

Air Pollution↗
PubMed1994

Quantitative pathology of nasal passages in rats exposed to urban levels of air pollution.

In order to assess the adverse effects of urban levels of air pollution, rats were used as biological indicators in a chronic exposure experiment. Animals were housed for 6 months in the center of São Paulo (the largest South American town) and compared to controls kept for the same period in a clean area. Pollution levels were obtained from a state air pollution monitoring station, 200 m distant from exposure location, which provided the levels of CO, SO2, particulates, and ozone. The nasal septum was submitted to quantitative analysis of morphological and histochemical parameters, comprising the measurement of volume of epithelium and lamina propria per unity of surface of basal lamina, the amount of mucus stored in the surface epithelium, the volume densities of neutral and acidic mucus in the lamina propria glands, and the densities of secretory and ciliated cells in the epithelium. The results obtained in the present investigation suggest that chronic exposure to urban levels of air pollution induces secretory hypertrophy, combined with a shift toward acidic mucus secretion and ciliary damage. The results are consistent with the idea that prolonged exposure to low levels of air pollution deteriorates respiratory defenses against infectious agents and may cause an increase in respiratory morbidity and perhaps mortality.

Air Pollutants↗
PubMed1991

A comparison between the isovolume and the end-inflation occlusion methods for measurement of lung mechanics in rats.

The isovolume method is one of the most used techniques to assess the mechanical properties of the lungs in ordinary challenge tests and in toxicological studies. It has been considered that isovolume lung resistance (RL) could assess central airway calibre in such tests, whereas dynamic elastance (EL,dyn) would reflect the elastic properties of lung parenchyma. However, peripheral phenomena, such as Pendelluft and stress relaxation, can interfere with RL measurements, especially in disease. In order to investigate the contribution of such phenomena to isovolume RL and EL,dyn, we compared the results provided by isovolume technique with those given by the end-inflation occlusion method (EIOM) in 12 normal Wistar rats. We found similar values for total lung resistance (RL,max) and isovolume RL. Homogeneous resistance (RL,mm), which describes airway calibre, comprised about 30% of RL in the tidal volume range. Values of EL,dyn calculated by the EIOM were approximately 20% greater than the corresponding value measured during spontaneous breathing. Our data indicate that isovolume RL is significantly affected by tissue forces and cannot be interpreted as a pure index of airway size.

Airway Resistance↗
PubMed1990

Assessment of the mutagenic potential of ethanol auto engine exhaust gases by the Salmonella typhimurium microsomal mutagenesis assay, using a direct exposure method.

The mutagenic activity of the new Brazilian fuel, ethanol, was determined by employing the Salmonella typhimurium microsomal mutagenesis assay (TA97, TA98, TA100, TA102, and TA104) and a direct exposure method. This methodology was first used to determine the mutagenic activity of gasoline, revealing mutagenic activity of base-pair substitution without any need for metabolic activation, indicating the presence of direct-action mutagens. Experiments with ethanol suggest an indirect mutagenic activity of the oxidant type. The exposure system was considered suitable for future studies of gaseous mixtures.

Animals↗
PubMed1989

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. The results showed lesions of the distal and upper airways in rats exposed in Cubatão, whereas the animals from São Paulo showed only alterations of the upper airways but of greater intensity than those observed in the Cubatão group. There are both qualitative and quantitative differences in the pollutants of these places: in São Paulo automobile exhaust gases dominate and in Cubatão the pollution is due mainly to particulates of industrial sources. The correlation of the pathological findings with the pollutants is discussed and it is concluded that biological indicators are useful to monitor air pollutions which reached dangerous levels in São Paulo and Cubatão.

Air Pollutants↗
PubMed1986

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. Several biological parameters were assessed after the exposure including pulmonary function, mutagenicity, and hematological, biochemical, and morphological examinations. The results demonstrated that the chronic toxicity of the gasoline-fueled engine is significantly higher than that of the ethanol engine.

Animals↗