Biomedical subjects
Publications and source records attributed to D D Ho.
Clinical manifestations of acute viral encephalitis are described, differential diagnoses are outlined, and a diagnostic approach is recommended. Encephalitic syndromes caused by arboviruses, herpesviruses, enteroviruses, and parainfectious processes are discussed.
Primary infection with the human T-lymphotropic virus type III (HTLV-III) was documented in three patients by virus isolation during acute illness and concurrent or subsequent HTLV-III seroconversion. All patients had fevers, rigors, arthralgias, and myalgias. Additional symptoms included truncal maculopapular rash, urticaria, abdominal cramps, and diarrhea. Lymphocytic meningitis accompanied the febrile illness in two patients. The estimated incubation period was 4 to 6 weeks, and the symptoms lasted 2 to 3 weeks. Seroconversion occurred 8 to 12 weeks after presumed exposure and was manifested by a characteristic antibody response pattern. Physicians should consider the possibility of primary HTLV-III infection when evaluating patients who belong to one of the risk groups for the acquired immunodeficiency syndrome and who have prolonged febrile illnesses.
Human T-lymphotropic virus type III (HTLV-III) is the probable etiologic agent for the acquired immune deficiency syndrome (AIDS). HTLV-III was isolated from semen and blood of a healthy homosexual man whose serum contains antibodies to HTLV-III. The finding of virus in semen supports epidemiologic data that suggest that AIDS can be transmitted sexually. In addition, the demonstration of HTLV-III in the blood and semen of a healthy individual establishes an asymptomatic, virus-positive carrier state which may be important in the dissemination of HTLV-III and, consequently, AIDS.
Lymphadenopathy is an important clinical problem in homosexual men. Over a period of 10 months, three homosexual patients were treated for chronic lymphadenopathy and spontaneous lymphadenitis of the inguinal lymph nodes. All patients presented with fever, chills, and rapidly enlarging inguinal masses. In each case, cultures showed group A beta-hemolytic streptococci. None of the patients had an obvious portal of entry for infection, and all had responses to penicillin and surgical drainage. Streptococcal lymphadenitis should be considered in any homosexual man with chronic lymphadenopathy in whom rapidly enlarging inguinal nodes develop.
We studied the effects of human T-lymphotropic virus type I (HTLV-I) on human endothelial cells in vitro. During cocultivation with an HTLV-I producer cell line (C91/PL), endothelial cells formed characteristic multinucleated syncytial giant cells. Inoculation with concentrated cell-free supernatant fluid from C91/PL cultures produced similar cytopathic effects, which were neutralized by pretreatment with HTLV-I specific human serum. HTLV-I antigens were detected in the cytoplasm of the multinucleated cells by indirect immunofluorescence. When endothelial cells showed maximal cytopathic changes, reverse transcriptase activity was demonstrated in the supernatant fluid and HTLV-I was isolated by cocultivation with peripheral blood mononuclear cells. This study demonstrates that HTLV-I tropism is not limited to lymphoid cells but extends to human endothelial cells as well.
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Campylobacter jejuni has become one of the most important causes of infectious diarrhea in the United States. We examined the utility of Gram's stain of stool for the rapid presumptive diagnosis of Campylobacter enteritis in a large, urban hospital and found that this test has a sensitivity of 43.5% and a specificity of 99.4%. We believe that Gram's stain of stool could be used to direct the early management of up to one half of patients infected with this pathogen.
The purpose of this study was to propose a standard protocol for administering the Moberg pickup test. One hundred subjects (53 male and 47 female subjects, aged 11 to 77 years) volunteered. A wide variety of occupations were represented. No subjects had a history of upper extremity dysfunction. The materials and the testing procedures were clearly described to the subjects. Both hand dominance and gender difference were found to have significant effects on test performance. Norms were established for dominant/nondominant hands and for male/female subjects. Standard scores were calculated and used for comparison. The inter-rater reliability of the test was also determined. Administered with a standard protocol, the Moberg pickup test is a valuable test of functional sensibility. It is simple and quick to administer, easy to replicate, and inexpensive to acquire.
Seropositivity to human T-cell lymphotrophic virus-III (HTLV-III) can have profound implications for the individual in whom it is detected. Simple and reliable tests are needed to confirm positivity by screening assays. In this study, detection of human antibodies by indirect immunofluorescence (IFA) on acetone-fixed HTLV-III infected H9 cells was evaluated in blood donors, patients with infectious or auto-immune diseases, and men with or at high risk for developing acquired immune deficiency syndrome (AIDS). Specific and nonspecific patterns of immunofluorescent reactivity were distinguished easily. None of 98 serums from blood donors was positive, while two of 33 serums from patients attending an infectious disease clinic, both homosexual men, were positive. Ninety-six percent of 24 serums from men with AIDS, 87 percent of 70 serums from men with lymphadenopathy, and 50 percent of 135 serums from healthy gay men were positive. These results paralleled those obtained by Western blotting and membrane immunofluorescence. In contrast, 11 and 4 percent, respectively, of these serums were judged as borderline or not interpretable by an enzyme-linked immunosorbent assay (ELISA). Of these serums, those that were positive by IFA were positive by Western blots, and 16 of the 17 IFA-negative serums were negative by Western blots. These studies indicate that IFA is a sensitive and specific assay for HTLV-III antibodies in human serums.
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Viral interactions may occur whenever a host is infected simultaneously with two viruses. Persons at high risk for acquired immunodeficiency syndrome (AIDS) may provide a substrate for such interactions. These could include complementary immunosuppression, potentiation of infection by altered receptors or genetic complementation, phenotypic mixing, or genetic recombination. The possibility of such interactions should be considered in the pathogenesis of AIDS.
In just six years after the initial description of the acquired immunodeficiency syndrome, much has been learned about the etiologic agent, the human immunodeficiency virus. The pathogenic mechanisms utilized by this virus to infect selectively and persistently T4+ lymphocytes and monocyte/macrophages, leading to immunodeficiency and neurologic dysfunction, are slowly becoming clear. Better understanding of the pathogenesis of human immunodeficiency virus infection is essential for the rational design of therapeutic and preventive strategies to combat this deadly virus.
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