RESUMEN

BACKGROUND: The optimal duration of zidovudine administration to prevent perinatal transmission of human immunodeficiency virus type 1 (HIV-1) should be determined to facilitate its use in areas where resources are limited. METHODS: We conducted a randomized, double-blind equivalence trial of zidovudine starting in the mother at 28 weeks' gestation, with 6 weeks of treatment in the infant (the long-long regimen), which is similar to protocol 076; zidovudine starting at 35 weeks' gestation, with 3 days of treatment in the infant (the short-short regimen); a long-short regimen; and a short-long regimen. The mothers received zidovudine orally during labor. The infants were fed formula and were tested for HIV DNA at 1, 45, 120, and 180 days. After the first interim analysis, the short-short regimen was stopped. RESULTS: A total of 1437 women were enrolled. At the first interim analysis, the rates of HIV transmission were 4.1 percent for the long-long regimen and 10.5 percent for the short-short regimen (P=0.004). For the entire study period, the transmission rates were 6.5 percent (95 percent confidence interval, 4.1 to 8.9 percent) for the long-long regimen, 4.7 percent (95 percent confidence interval, 2.4 to 7.0 percent) for the long-short regimen, and 8.6 percent (95 percent confidence interval, 5.6 to 11.6 percent) for the short-long regimen. The rate of in utero transmission was significantly higher with the two regimens with shorter maternal treatment (5.1 percent) than with the two with longer maternal treatment (1.6 percent). CONCLUSIONS: The short-short zidovudine regimen is inferior to the long-long regimen and leads to a higher rate of perinatal HIV transmission. The long-short, short-long, and long-long regimens had equivalent efficacy. However, the higher rate of in utero transmission with the short-long regimen suggests that longer treatment of the infant cannot substitute for longer treatment of the mother.

Asunto(s)

RESUMEN

A series of recombinant peptides of the human immunodeficiency virus type 1 (HIV-1) subtype E envelope were used to address the question of whether immunogenic epitopes similar to those described for the subtype B envelope are also present in structurally analogous regions of another HIV-1 subtype with divergent sequences. Five recombinant peptides, covering the V2 and V3 domains of gp120, the cysteine-loop region of gp41, a gp41 region involved in oligomerization, and the cytoplasmic tail of gp41, were found to react with >50% of the serum samples analyzed. All but the V2 region in the HIV-1 subtype B envelope have been reported to contain continuous epitopes that are highly immunogenic during natural infection. This finding suggests that, despite the sequence divergence between subtype E and B envelopes, most of the continuous epitopes that are highly immunogenic during natural infection are located at structurally analogous regions of the envelope.

Asunto(s)

Asunto(s)

RESUMEN

Penicillium marneffei produced and secreted a 38-kDa antigen that appeared to be specific for this dimorphic fungus. This component could not be detected in antigenic extracts of Histoplasma capsulatum, Cryptococcus neoformans, Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Candida albicans, and two other species of Penicillium by immunoblot analysis against the sera from patients with culture-confirmed penicilliosis marneffei. Antibody reactive with this antigen was found in a large proportion of human immunodeficiency virus (HIV)-positive patients, indicating a presumptive diagnosis of P. marneffei infection. A small number of asymptomatic HIV-seropositive patients and HIV-seropositive patients with other fungal infections were also found to be positive by this analysis, suggesting that subclinical or mixed fungal infections involving P. marneffei are not uncommon.

Asunto(s)

RESUMEN

Flow cytometer (FACScan) was used to determine the range of T lymphocyte subpopulations in normal Thai blood donors at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai. Reference population consisted of 150 healthy HIV seronegative blood donors. T lymphocyte subsets were analysed using two-color immunophenotyping of peripheral blood lymphocytes with a lysed whole blood technique and enumerated. The study showed that the normal values for CD3+ lymphocytes (percent), CD4+ lymphocytes (percent), CD8+ lymphocytes (percent), CD4/CD8 ratio, absolute CD3+ lymphocyte count, absolute CD4+ lymphocyte count and absolute CD8+ lymphocyte count were 64 +/- 8.8, 36.1 +/- 6.4, 25.7 +/- 7.3, 1.5 +/- 0.6, 1,630 +/- 600 cells/microl, 910 +/- 300 cells/microl and 670 +/- 350 cells/microl, respectively. We found that the values of CD3, CD4 and CD4/CD8 ratio were significantly lower than those in the Caucasians but those of CD8 was not significantly different. This observations have important clinical implication for the use of T lymphocyte subsets measurement, especially in the management of HIV infection in Thais. These normal ranges can be used as a reference for the decisions in clinical practice.

Asunto(s)

RESUMEN

We investigated whether V3-binding assays might be useful to analyze human immunodeficiency virus type 1 (HIV-1) variants in different geographic regions. We showed that strong cross-reactivity between subtype-specific V3 peptides is almost inevitable in standard indirect enzyme-linked immunosorbent assays (EIA), impairing precise serological subtyping. We therefore developed a subtype-specific EIA (HIV-1 SSEIA) that uses the principle of blocking by an excess of peptide in the liquid phase. Using 231 serum samples collected from HIV-1-infected individuals in 10 different geographical areas from 4 continents, we showed that this approach detected the dominant subtype reactivity in more than 97% of the cases. Internal controls (0 and 100% blocking) were used for every sample such that comparative analysis was possible, independent of both the individual humoral response and the time of collection during the course of infection. This was validated by the excellent concordance of the serological profiles of couples and the temporal stability of the serological profile in individuals. The geographical distribution of the various subtypes in the SSEIA was in agreement with the present knowledge of the distribution of the various genotypes. Although the goal of this study was not an extensive seroepidemiological survey, our results showed that the various profiles in most of the regions were relatively homogeneous, but in central Africa there was a large diversity of serological profiles. Cluster analysis identified a limited number of V3 serogroups of serotypes within the HIV-1 group M. Five serogroups, some of them divided into subgroups, were identified and characterized by a mean serological profile. Our data confirmed that subtypes A and C, although being dissimilar genetic subtypes, present conserved antigenic properties in the V3 region, and that the D subtype is probably the most divergent within the group M (B Korber et al., J Virol 1994;68:6730). Cluster analysis showed a clear correlation between position within the dendrogram and geographical origin of the samples. This is further support for the reliability and thereof the usefulness of the SSEIA. This simple methodology may help facilitate the analysis of the distribution of various HIV-1 subtypes circulating in different populations and regions.

Asunto(s)

RESUMEN

Heterosexual transmission by vaginal intercourse accounts for most transmission of human immunodeficiency virus-type 1 (HIV-1) in Africa and Asia but is less important in the HIV-1 epidemics of the United States and Western Europe. Epithelial Langerhans' cells (LCs) represent a possible source of initial cell contact for vaginal infection. Fifteen primary isolates of HIV-1 from U.S. homosexuals and 18 HIV-1 isolates from Thailand heterosexuals were evaluated for growth in LCs of U.S. origin. All the viruses from the Thai heterosexuals, which were subtype E, grew more efficiently in the LCs than any of the viruses from the U.S. homosexuals, which are subtype B. These results suggest that LC tropism is associated with the efficiency of heterosexual transmission of HIV.

Asunto(s)

Asunto(s)

RESUMEN

PIP: The human immunodeficiency virus (HIV) has, since it was first reported in 1981, become a worldwide epidemic. The immunosuppressive nature of HIV results in opportunistic infections, neoplasms, and other pathological conditions. Clinical manifestations of these conditions are often the first indication that an individual is infected with HIV. This article reports and describes the clinical findings for 174 HIV-positive patients and is intended to educate Thai physicians concerning the rising HIV infection rate in Thailand. The opportunistic infectious agents included fungal, parasitic, viral, and bacterial organisms. Cryptococcosis, penicillosis, candidiasis, and histoplasmosis are fungal diseases which are discussed. Protozoal organisms and diseases covered are Pneumocystis carinii, toxoplasmosis, cryptosporidiosis, isosporiosis, and Demodex folliculorum. Bacterial infections addressed are tuberculosis, syphilis, and salmonellosis. The parasite causing nocardiosis is also discussed. Viral infections addressed are cytomegalovirus infection, herpes simplex, and hairy leukoplakia. Neoplasms or tumors discussed are Kaposi's sarcoma and non-Hodgkins lymphoma. Other pathological conditions described are brain atrophy, HIV retinopathy, and HIV wasting syndrome. In most cases, a suggested therapy regime is given for the condition discussed.^ieng

Asunto(s)

Asunto(s)

RESUMEN

Although the Widal test is simple, inexpensive and the most widely used for serodiagnosis of typhoid fever, the sensitivity and specificity of the test is sometimes doubtful. In this study, an enzyme-linked immunosorbent assay (ELISA) was developed for the detection of serum IgG and IgM antibodies to protein and lipopolysaccharide (LPS) antigens of Salmonella typhi which was compared with the Widal test in various groups of subjects. In typhoid patients with hemocultures positive for S. typhi (TP group), ELISA positivity was found on 100% for IgG antiprotein, 94.44% for IgG anti-LPS and 88.89% for IgM to both the protein and LPS antigens. In contrast, the Widal test was positive in only 61.11% for anti-O and 83.33% for anti-H antibodies. In healthy control subjects (HC group), only 5% of serum samples were positive for IgG anti-protein and none was positive for IgG anti-LPS or IgM to either the protein or LPS. In contrast, the Widal test was positive in 7.5% of HC group for anti-O and 17.5% for anti-H antibodies. In blood bank donors (BB group), both ELISA and Widal tests were positive in 23-40% of sera. Since the hospital records of BB group were incomplete. It might be possible that some of these subjects had recently been infected with S. typhi. Our data indicate that the standard Widal test was associated with false negative reactions in 16-39% of blood culture positive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Asunto(s)

RESUMEN

Immunoregulation in various types of leprosy patients was evaluated in vitro using peripheral blood mononuclear leukocytes (PBML) stimulated with phytohemagglutinin-P (PHA-P) or concanavalin A (ConA) for a cell-mediated immune (CMI) assay or pokeweed mitogen (PWM) for a humoral-mediated immune (HMI) assay. The immune responses were evaluated by a lymphocyte transformation test (LTT) and lymphocyte-mediated cytotoxicity (LMC) for the immunoregulation of CMI, and a reverse hemolytic plaque assay for measuring the plaque-forming cells (PFC) and a sandwich ELISA for measuring IgG concentrations for the immunoregulation of HMI. In LTT with PHA-P or ConA, the mean of the normal controls was not significantly different from the means of the untreated LL, BL, BB, BT, and TT leprosy patients. However, a wide variation of LTT results from BT to LL patients was noted: the LTT results of TT patients and normal controls were less variable. A similar pattern of immune responses was noted when studied by LMC in untreated LL, BL, BB, BT, and TT leprosy patients and normal controls. When the untreated patients and normal controls were studied for PFC, using PBML stimulated with PWM, a very similar pattern of PFC was obtained with the different types of leprosy patients. The immunoregulatory role of lymphocytes in leprosy patients was further evaluated by cell mixing cultures. ConA-stimulated PBML from lepromatous leprosy patients were mixed with normal PBML and then stimulated with PHA-P.(ABSTRACT TRUNCATED AT 250 WORDS)

Asunto(s)

RESUMEN

The capabilities of monocytes and lymphocytes in peripheral blood mononuclear leukocytes (PBML) to produce interleukin-1 (IL-1), IL-2, and interferon (IFN), respectively, were evaluated in various types and treatments of leprosy patients. IL-1 production in response to lipopolysaccharide was significantly lower in LL, BL, BB, and BT patients than in normal controls. However, there were no differences in IL-1 levels between TT patients and normal controls. The percentages of nonspecific-esterase-positive cells adhering to the plastic surfaces were not different in LL, BB and TT patients when compared to normal controls. However, they were significantly higher in BT and BL patients than in normal controls. When PBML from leprosy patients were stimulated with concanavalin-A (ConA) for IL-2 production, there were no differences in the IL-2 levels in treated BL/LL, untreated BL/LL, treated BT/TT, and untreated BT/TT patients compared to normal controls. Similar results were obtained when PBML were stimulated with phytohemagglutinin-P (PHA-P). However, when purified protein derivative (PPD) was used as the stimulating agent, there were significantly lower IL-2 levels in treated BL/LL, untreated BL/LL, treated BT/TT, and untreated BT/TT patients when compared to normal controls. There were also lower IL-2 levels in untreated BL/LL and BT/TT patients compared to treated BL/LL and BT/TT patients, respectively. PBML were stimulated with PHA-P or ConA for IFN production.(ABSTRACT TRUNCATED AT 250 WORDS)

Asunto(s)

RESUMEN

A 43-year-old monk had generalized purpura, arthritis of both shoulders, erythrocyanosis of lip and oral mucous membrane, Raynaud's phenomenon and uveitis. Platelets were normal. Cryoglobulin and cryofibrinogen were positive. Biopsy revealed vasculitis. No underlying infection, collagen vascular disease, lymphoproliferative, myeloproliferative and malignancy were found. He was diagnosed as having essential cryoglobulinemia and cryofibrinogenemia.

Asunto(s)

RESUMEN

A 22-year-old, female patient came to see the allergists because of a 10-year history of chronic urticaria. Widespread pruritic, urticarial papules developed at times of stress and exercise, each papule being surrounded by a striking blanched vasoconstricted halo. The halo hives could be replicated with an intradermal injection of adrenaline. This is the first report of adrenergic urticaria from Thailand.

Asunto(s)

RESUMEN

A method for the enumeration of IL2-producing cells from rat spleen has been developed. Rat spleen cells were stimulated with concanavalin A (Con A), washed, then mixed with IL2-dependent cells (3 day Con A blasts) and plated in soft agar. Clusters of IL2-dependent cells formed around IL2-producing cells, giving colonies which were easy to count under a dissecting microscope. All experimental factors influencing development of colonies of IL2-producing cells surrounded by IL2-dependent cells were evaluated and set up. Optimum number of effector cells was 2.5 x 10(5) cells/culture, while optimum number of IL2-dependent cells was 6 x 10(6) cells/culture. Optimum concentration of Con A for IL2 stimulation was 40 micrograms/ml with an optimal stimulation time of 10 hours. Optimum incubation time for development of IL2-producing cell colonies was 5 days. The number of IL2-producing cells by this technique had a good correlation with the level of IL2 in the cell culture fluid (r = 0.885). When colonies were aspirated from agar and stained by Wright stain, a big purple stained cell at the center was surrounded by small cells in almost all colonies examined. All cells from colonies were fluoresed with anti-mouse Thy 1.2-fluorescein conjugate. However, they were negative with anti-mouse Ig-fluorescein conjugate. The number of IL2-producing cells was 816-2080 cells/10(6) of rat spleen cells with mean +/- S.E.M. = 1404 +/- 154/10(6) cells.

Asunto(s)

RESUMEN

Soluble interleukin 2 receptors (IL-2R) in sera of leprosy patients from Chiang Mai, Thailand, were quantified with a solid phase enzyme immunoassay using two monoclonal antibodies to the IL-2R. The IL-2R levels of untreated lepromatous, borderline lepromatous or midborderline patients and treated lepromatous and borderline lepromatous or treated borderline tuberculoid and tuberculoid patients were comparable to those of the Thai household or nonhousehold contacts; and they were significantly higher than the levels of USA control subjects. In contrast, IL-2R of untreated tuberculoid or borderline tuberculoid patients were significantly reduced. Patients with ongoing reversal reaction had very high circulating IL-2R, the levels of which correlated with fever and extent of skin lesions. Although erythema nodosum leprosum patients also had elevated IL-2R levels, they were significantly below those of patients with reversal reaction. When treated with corticosteroid, precipitous reduction of IL-2R was noted in all patients with reversal reaction but not in patients with erythema nodosum leprosum.

Asunto(s)

RESUMEN

This study was carried out on the effect of histamine hydrochloride and its antagonists on the production of interleukin-1 (IL-1) by lipopolysaccharide (LPS)-stimulated adherent human monocytes (AHM) from normal healthy blood donors. IL-1 activity was evaluated by incorporation of [3H]-thymidine in mouse thymocytes in samples of 1:3 dilution. The result indicated that histamine hydrochloride significantly suppressed IL-1 production by AHM at 10(-3) M and 10(-10) M in 14 donors with maximal suppression observed at 10(-3) M. A 1-hr incubation with histamine hydrochloride (10(-3) M) before addition of LPS was found to be appropriate. Cimetidine, an H2-antagonist at 10(-3) M, 10(-5) M, and 10(-7) M significantly inhibited the effect of histamine hydrochloride (10(-3) M) and gave maximum inhibition at 10(-5) M, whereas chlorpheniramine maleate, and H1-antagonist had no significant inhibitory effect at the concentrations studied (10(-4) M, 10(-5) M, and 10(-7) M). Histamine hydrochloride (10(-3) M) added alone had no significant suppressive effect, while cimetidine (10(-5) M) alone had a significant stimulatory effect on IL-1 production by AHM.

Asunto(s)

Asunto(s)

RESUMEN

In vitro studies were carried out on the nature of immunoglobulin synthesis and secretion by peripheral blood mononuclear leukocytes (PBMLs) and on the function of T and B cells from malaria patients. The mean values of secreted IgG and IgM concentrations of 22 malaria patient PMBLs were significantly higher than those of 20 normal PBMLs. When the suppressor T cell activity and the function of B cells in response to suppressor T cells were assayed by the cell co-culture technique, it was found that there was a decrease in suppressor T cell activity and the B cell function in response to normal suppressor T cells in malaria patients. The defects of these T and B cell functions may play some role in the immunological abnormalities seen in some malaria patients.

Asunto(s)