RESUMO
During ablation of tissue with laser pulses rapid sublimation of matter occurs and high pressures are exerted within the tissue, resulting in steam. smoke and particles being expelled. In this paper we report the speed of particles ejected from animal tissue exposed to CO2 laser pulses measured directly by laser Doppler velocimetry (LDV). Speeds recorded just above animal skin were in the range of 9 to 18 m s(-1) for laser pulses of 128 to 384 J cm(-2) respectively. Aerodynamic turbulence slowed the particles down to a critical speed Vc of 4 m s(-1) within a few millimetres above the laser ablation site. Once the particles reach this minimum speed, if no collisions occur, they will only decelerate by gravitational action and the residual kinetic energy will send the particles up to about 0.87 m from the skin surface. Since ejected particles may carry viable cells, acting as disease vectors during laser surgery, our results suggest that the LDV technique should be used to measure the speed of particles ejected from healthy or pathological human tissues, helping to establish safe conditions during laser surgery.
Assuntos
Dióxido de Carbono/metabolismo , Fluxometria por Laser-Doppler/métodos , Animais , Fenômenos Biofísicos , Biofísica , Feminino , Humanos , Cinética , Fluxometria por Laser-Doppler/instrumentação , Lasers , Masculino , Ratos , Ratos Wistar , Pele/patologia , Fatores de TempoRESUMO
The development of sporocysts of Schistosoma mansoni was monitored in pigmented and albino Biomphalaria glabrata from Puerto Rico and Brazil. The snails were exposed individually to 20 miracidia, and sporocysts were allowed to develop for 3 to 12 weeks. Most of the immature sporocysts were found in the seminal receptacle sac and vas deferens during development. In contrast, mature daughter sporocysts were detected everywhere except in the foot at 12 weeks after exposure to the miracidia. It was found that mature daughter sporocysts formed more rapidly in the pigmented than in the albino snails, but no difference was observed in the formative time between the same types of Puerto Rican and Brazilian snails. It seems likely that there is a correlation between the infection rate and the time required for formation of mature daughter sporocysts in B. glabrata.
Assuntos
Biomphalaria/parasitologia , Schistosoma mansoni/crescimento & desenvolvimento , Animais , Biomphalaria/anatomia & histologia , Brasil , Porto Rico , Fatores de TempoRESUMO
To establish the relationship between schistosome-associated morbidity and infection intensity in northeast Brazil, a parasitological and ultrasonographical study was carried out on 484 inhabitants of 4 villages (I, II, III and IV) in São Lourenço da Mata, Pernambuco, Brazil, where schistosomiasis is endemic. Quantitative stool examination using Knight's method demonstrated a high prevalence and moderate intensity of Schistosoma mansoni infection, and also that the subjects in village IV had a significantly lower prevalence and intensity of infection than those of the other villages. By ultrasonography, periportal fibrosis (PPF) and splenomegaly were found in 52% of the 299 infected subjects and 66% of the 146 infected subjects aged over 16 years old, respectively; 32% and 31% of the 299 infected subjects had abnormally high values of total bile acid (TBA) and alkaline phosphatase (ALP) activity, respectively. Liver and spleen size, PPF, and serum level of TBA and ALP were not correlated with infection intensity. There was no significant difference in the morbidity assessed by liver and spleen size, PPF, and serum analysis between the subjects in village IV and the other villages. These findings suggest the occurrence of a community with high morbidity associated with schistosomiasis regardless of low infection intensity.
Assuntos
Esquistossomose mansoni/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Anticorpos Anti-Helmínticos/sangue , Brasil/epidemiologia , Criança , Pré-Escolar , Fezes/parasitologia , Feminino , Fibrose/diagnóstico por imagem , Humanos , Lactente , Fígado/diagnóstico por imagem , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Morbidade , Contagem de Ovos de Parasitas , Veia Porta/diagnóstico por imagem , Veia Porta/patologia , Prevalência , Saúde da População Rural , Esquistossomose mansoni/diagnóstico por imagem , Esquistossomose mansoni/imunologia , Esplenomegalia/diagnóstico por imagem , UltrassonografiaRESUMO
A questionnaire survey of blood donors at Santa Cruz General Hospital, Bolivia, showed that while there were no seropositive cases of syphilis, HBsAg, and HIV, the prevalence of Chagas' disease was very high (23%) among the 225 blood donors who responded to this questionnaire. Actual cases of Chagasic seropositive blood being used for blood transfusion were seen, including the urgent need for a program for Chagas' disease in Bolivia. From the results of this study, it is recommended that for blood donors from South American countries, the presence/absence of Chagas' disease should be confirmed.
Assuntos
Doadores de Sangue , Doença de Chagas/epidemiologia , Adolescente , Adulto , Animais , Anticorpos Antiprotozoários/análise , Bolívia/epidemiologia , Feminino , Testes de Hemaglutinação , Humanos , Masculino , Pessoa de Meia-Idade , Trypanosoma cruzi/imunologiaRESUMO
Parasitological examinations were carried out during July to December, 1989, on 485 inhabitants of four villages in São Lourenço da Mata, 25 km northwest of Recife, Pernambuco, Brazil. Approximately 99.6% of the inhabitants were infected with at least one species of intestinal parasites. A high prevalence of Schistosoma mansoni (82.1%), hookworm (80.2%) Trichuris trichiura (69.9%), Ascaris lumbricoides (61.9%) and Entamoeba coli (36.7%) infections were demonstrated. Test tube cultivation revealed that the most common species of hookworm in this region was Necator americanus (88.4%), and also that the prevalence of Strongyloides stercoralis was 5.8%. Three hundred and thirty-four sera were serologically examined for amoebiasis by the gel diffusion precipitation test (GDP) and enzyme-linked immunosorbent assay (ELISA). No positive reaction was observed in all sera as examined by GDP, while 24 sera were positive by ELISA.
Assuntos
Disenteria Amebiana/epidemiologia , Enteropatias Parasitárias/epidemiologia , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , Disenteria Amebiana/diagnóstico , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Feminino , Humanos , Imunodifusão , Lactente , Enteropatias Parasitárias/diagnóstico , Masculino , Pessoa de Meia-Idade , Prevalência , Saúde da População RuralRESUMO
Soros de pacientes com esquistosomiase mansonica do Hospital das Clinicas da Universidade Federal de Pernambuco (N = 10), de residentes da cidade do Cabo (PE) - 51 casos ovo-positivo e 452 casos ovo-negativo -, de pacientes do Hospital Instituto Materno Infantil de Pernambuco (IMIP) (N = 37), de imigrantes japoneses residentes na cidade de Petrolina (PE) (N = 127), assim como de japoneses supostamente saudaveis (N = 30) foram examinados sorologicamente atraves de testes como ELISA; os antigenos utilizados foram preparados a partir de ovos (ELISA-ovo) e de vermes adultos de Schistosoma mansoni (ELISA-adulto). Em 100 por cento dos soros de individuos nao infectados residentes em areas nao endemicas, tanto na ELISA-ovo como na ELISA-adulto os resultados foram negativos. No tocante a reacoes cruzadas, em 78 soros provenientes de individuos portadores de diferentes parasitas intestinais, apenas um apresentou reatividade frente aos antigenos de vermes adultos e ovos. O ELISA-ovo realizado com o soro de 51 individuos portadores de ovos de S. mansoni revelou uma alta sensibilidade (98 por cento de casos ovo-positivos); contudo grande numero de resultados falso-negativos foi observado em reacoes como ELISA-adulto, Ouchterlony usando antigeno de verme adulto, reacao periovular e intradermo-reacao. Em casos de jovens portadores
Assuntos
Humanos , Enteropatias Parasitárias/diagnóstico , Esquistossomose mansoni/diagnóstico , Brasil , Ensaio de Imunoadsorção Enzimática , Japão/etnologia , Esquistossomose mansoni/etnologia , Sensibilidade e EspecificidadeRESUMO
Sera from the patients (N = 10) with schistosomiasis mansoni of the hospital of Federal University of Pernambuco, the Schistosoma mansoni egg-positive (N = 51) and -negative (N = 452) inhabitants in Cabo City area, out-patients (N = 37) of the IMIP hospital and Japanese immigrants (N = 127) in Petrolina City area of northeast Brazil as well as Japanese healthy subjects (N = 30) were examined by serological tests including an enzyme-linked immunosorbent assay with antigens prepared from eggs (ELISA-egg) and adult worms (ELISA-adult). The ELISA with egg or adult antigen correctly identified 100% of the uninfected individuals lived in non-endemic area of schistosomiasis. Moreover, when examined cross-reactivity of our ELISA with sera isolated from 78 subjects infected with various intestinal parasitic infections, only one of these sera reacted with the egg and adult antigens. On the examination of 51 sera from the egg-positive subjects, the ELISA-egg revealed the highest sensitivity (98.0%), whereas a large number of false negative reactions of ELISA-adult, Ouchterlony method using adult antigen, circumoval precipitation and immediate intradermal skin test were observed. A low sensitivity of these serologic tests except for ELISA-egg appears to be primarily due to their inability to detect antibody in the sera from egg-positive infantiles. There was no positive correlation between the absorbance values of these two types of ELISA among the sera isolated from ELISA-positive subjects. Rather, by the reactivity of these sera to egg or adult antigen, they could be divided into two subgroups; one reacted more positively with egg antigen and the other with adult antigen. Moreover, it was confirmed that the sera from young subjects (under 20 years old) appear to be highly reactive to the egg antigen than did aged ones. These data suggest that the ELISA with egg antigen, but not with the adult antigen, appears to be useful for the serological survey of schistosomiasis mansoni in the endemic area of northeast Brazil.
Assuntos
Enteropatias Parasitárias/diagnóstico , Esquistossomose mansoni/diagnóstico , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Humanos , Lactente , Recém-Nascido , Enteropatias Parasitárias/epidemiologia , Japão/etnologia , Pessoa de Meia-Idade , Esquistossomose mansoni/epidemiologia , Sensibilidade e EspecificidadeRESUMO
Serum levels of several markers for liver fibrosis were measured utilizing three groups of human subjects related with schistosomiasis mansoni in northeast Brazil; (1) 20 Schistosoma mansoni egg-positives, who have never been administered with anti-schistosomal drugs, (2) 29 egg-negative inhabitants in the endemic area of schistosomiasis, and (3) 23 egg-negative Japanese immigrants in the non-endemic area. None of these sera were positive for antibody to the surface antigen of human hepatitis B (HBs) and circulating HBs antigen. There was no significant difference in the serum levels of N-terminal peptide of procollagen type-III between the egg-positive subjects and either of the egg-negative Brazilian or Japanese immigrants, whereas the mean value of serum laminin significantly increased in the egg-positive subjects. A significantly higher concentration of serum immunoreactive beta-subunit of prolyl 4-hydroxylase (IR beta PH) was also observed in the egg-positive subjects only in comparison with that of the egg-negative Brazilian. Serum laminin and IR beta PH concentrations of the egg-positive subjects did not correlate with the absorbance of enzyme-linked immunosorbent assay (ELISA) which utilized crude antigens isolated from schistosome adults or eggs. No significant difference in these two parameters was observed between two subgroups of the egg-negative Brazilian or Japanese immigrants divided according to the serological data by ELISA. These findings suggest that serum laminin and IR beta PH levels are worth further evaluation for their usefulness as the marker for liver fibrosis in schistosomiasis.