Comparison of granulation tissue formed beneath epithelial transplants with high and low bone-inducing potential.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to T Ksiazek.
Explore the source record for details and available documents.
Multiplication of chondrocytes during growth of rabbit auricular cartilage was estimated on the basis of total DNA determination and compared with the population doubling level reached by these chondrocytes in vitro. The results indicate that the in situ aging of auricular chondrocytes is caused by factors other than the intrinsic depletion of their growth potential.
Explore the source record for details and available documents.
A prospective study of diarrhea was conducted among 98 U.S. Army soldiers during their first six weeks in South Korea. Diarrhea developed in 54 (55%) of 98 soldiers and had a mean duration of five days. Infections with Salmonella, Shigella, Vibrio, enterotoxigenic Escherichia coli, enteroviruses, and intestinal parasites were uncommon. Four (8%) of 50 soldiers with documented diarrhea, two (6%) or 32 with a history of diarrhea, and one (3%) of 29 who denied gastrointestinal symptoms had serologic evidence of a recent rotavirus infection. The etiology of diarrhea among U.S. soldiers who had recently arrived in South Korea differed from the etiology among travelers in warmer climates, where enterotoxigenic strains of E. coli were responsible for the majority of cases. Further efforts are needed to define other enteric pathogens in the etiology of diarrhea among new arrivals in different parts of the world.
Explore the source record for details and available documents.
A serosurvey was conducted during October and November 1989 to estimate the prevalence of selected arboviral, rickettsial, and Hantaan viral antibody among a sample of schoolchildren from 4 villages in the Bilbeis area of the Nile river delta, Egypt. Blood specimens were obtained from subjects aged 8 to 14 years. Enzyme immunoassay testing of the sera indicated that the prevalence of antibody was 9% (21/223) for Sicilian sandfly fever, 4% (8/223) for Rift Valley fever, 3% (15/437) for West Nile virus and 9% (28/315) for Hantaan (HTN) virus. Antibody was demonstrated among 22% (93/418) of the same study subjects against Coxiella burnetti, 53% (199/373) against Rickettsia typhi, and 37% (137/371) against R. conorii.
Human sera collected during the 1987 Rift Valley fever (RVF) epidemic in the Senegal River basin were analysed using three enzyme immunoassays to establish the best method for rapid diagnosis of RVF. A biotin-avidin-enhanced antigen detection method utilizing monoclonal antibodies proved most sensitive. Eighty-two viremic human sera were tested, and this assay detected antigen in 29.3% of the samples.
In order to collect epidemiological data about the Rift Valley fever epidemic in Mauritania, we decided to use the filter paper method. The mean recovery level of specific antibodies from filter paper, tested using an immunoenzymatic method, is around one fourth. Taking the mean haematocrit into account, we estimated the extract square with a 1/300 dilution. This method was very useful for epidemiological studies, we observed few patient refusals, but it is necessary to know the exact specificity of the antibodies.
Three epidemiological investigations were carried out during and after the 1987 Rift Valley fever (RVF) epidemic in South Mauritania: a case control study, a cross-sectional study in the town of Rosso and a cross-sectional study of villages and encampments around Rosso. The case control study showed an association between epizootic and epidemic outbreaks. The study in Rosso town showed housing and district effects. Also, a medical survey of hospital staff showed the absence of interhuman contamination. The cross-sectional study of villages and encampments around Rosso showed heterogeneity corresponding to a village and ethnic effect. The human epidemic was linked to epizootic disease, but the "vectors" of the disease are not as yet known.
Nipah virus, family Paramyxoviridae, caused disease in pigs and humans in peninsular Malaysia in 1998-99. Because Nipah virus appears closely related to Hendra virus, wildlife surveillance focused primarily on pteropid bats (suborder Megachiroptera), a natural host of Hendra virus in Australia. We collected 324 bats from 14 species on peninsular Malaysia. Neutralizing antibodies to Nipah virus were demonstrated in five species, suggesting widespread infection in bat populations in peninsular Malaysia.
Calcified cartilage transplants induce bone formation. This process may be inhibited if the recipient is immunized by the transplant. To study the relation between the degree of antigen incompatibility between the donor and recipient and bone formation in more detail, chondrocytes isolated from cartilaginous epiphyses of five-day-old mice were transplanted within a fully compatible syngeneic system and across weak (H-Y, non-H-2) and strong (H-2) histocompatibility barriers. Reconstruction of cartilage occurred in all cases. In these transplants, which did not evoke immunologic reaction (fully compatible system, transplants across H-Y barrier in nonrejector strain), reconstructed cartilage hypertrophied, calcified, yielded to resorption by mesenchyme, and finally, was replaced by bone. When (independently of the degree of antigenic difference) cartilage was surrounded by mononuclear infiltration, bone formation did not occur or was delayed. The presence of infiltrations around transplants led to the degeneration of chondrocytes as well as of matrix in peripheral regions of cartilage. Immunologic infiltration may prevent endochondral osteogenesis by inhibiting cartilage invasion by vascularized mesenchyme, and/or interfering with matrix mineralization. The function of the chondrocyte is not yet defined, but in endochondral ossification, it plays more than a passive role.
Explore the source record for details and available documents.