Search PubMed⌕ Search

Biomedical subjects

A L Rothman

Publications and source records attributed to A L Rothman.

43 records · Page 3Linked to original sources

Dengue virus-specific murine T-lymphocyte proliferation: serotype specificity and response to recombinant viral proteins.

Definition of the T-lymphocyte responses to dengue viruses should aid in the development of safe and effective vaccines and help to explain the pathophysiology of dengue hemorrhagic fever and dengue shock syndrome. In this study, we demonstrated that dengue virus-specific T lymphocytes were detected in spleen cells from dengue virus-immune mice using an in vitro proliferation assay. Following immunization with a single dose of infectious dengue virus, murine lymphocytes showed increased proliferation when incubated in the presence of viral antigens of the same serotype but not in the presence of control antigens. Depletion experiments with antibody and complement showed that the population of responding cells expressed the Thy1+ L3T4+ Lyt2- phenotype. This indicates that the predominant proliferating cells are T lymphocytes of the helper-inducer phenotype. Dengue virus-specific memory lymphocyte responses were detectable for at least 22 weeks after immunization. The response to primary infection was primarily serotype specific, with some serotype cross-reactivity present at a low level. We demonstrated that lymphocytes from mice immunized with dengue 4 virus proliferate in response to a combination of dengue 4 virus C, pre-M, E, NS1, and NS2a proteins expressed in Sf9 cells with a recombinant baculovirus, and, to a lesser extent, to the dengue 4 virus E protein alone.

Animals↗

Carotid ultrasonography--the new "gold standard". Surgical and angiographic correlation.

Atherosclerotic plaques and high grade stenosis in the carotid circulation are responsible for symptoms of cerebral and retinal ischemia. Identification of these lesions by angiography has been the "gold standard" for which the decision of endarterectomy depended. The recent introduction of high resolution carotid ultrasonography has allowed us to compare thirty-seven surgical specimens with the results of preoperative screening with angiography. UCI had a 97% correlation whereas angiography was accurate only 70%. More importantly there were ten negative angiograms in patients with clinically active ulcerative plaque disease. If surgery were based solely on the angiographic appearance of ulcerative plaques or high grade stenosis, then less than half of the patients have received the correct treatment. UCI deserves to be considered the new reference standard.

Angiography↗

Focal vascular headaches with focal arterial disease. An ultrasonographic analysis.

The relationship between migraine and premature stroke and heart disease has been firmly established in the literature. The probable mechanism relates to release of vasoactive agents locally that produce intimal changes and if chronic may lead to permanent changes to the artery. We have attempted to identify individuals at risk for premature stroke utilizing the highly accurate B-mode real time carotid ultrasonogram. Sixteen patients demonstrated varying degrees of focal dilatation or plaque disease and 44% had abnormal Doppler flow studies. Since many of these patients were asymptomatic during the examination it is suggested that vascular changes may be more persistent than were previously suspected. These plaques, in the setting of increased platelet aggregability may be responsible for the augmented risk of stroke. Precise identification of these individuals can be easily accomplished with B-mode real time scanning (High resolution), and will allow for safe followup if specific dietary or drug interventions are contemplated.

Adolescent↗

T cell receptor Vbeta gene usage in Thai children with dengue virus infection.

T lymphocyte activation during dengue is thought to contribute to the pathogenesis of dengue hemorrhagic fever (DHF). We examined the T cell receptor Vbeta gene usage by a reverse transcriptase-polymerase chain reaction assay during infection and after recovery in 13 children with DHF and 13 children with dengue fever (DF). There was no deletion of specific Vbeta gene families. We detected significant expansions in usage of single Vbeta families in six subjects with DHF and three subjects with DF over the course of infection, but these did not show an association with clinical diagnosis, viral serotype, or HLA alleles. Differences in Vbeta gene usage between subjects with DHF and subjects with DF were of borderline significance. These data suggest that the differences in T cell activation in DHF and DF are quantitative rather than qualitative and that T cells are activated by conventional antigen(s) and not a viral superantigen.

Adolescent↗