Seroprevalence of human T lymphotropic virus type I in Puerto Rico.

Serum specimens from Puerto Rican residents were tested for antibodies to human T lymphotropic virus type I (HTLV-I) using an enzyme immunoassay, Western immunoblot, and radioimmunoprecipitation assays. Of 1,279 specimens obtained during a dengue virus surveillance program in 1986 and 1987, 3 (0.2%) tested positive; an additional 11 were indeterminate. Of 602 specimens obtained from blood donors in Ponce in 1987, 1 (0.2%) was positive; an additional specimen was indeterminate. Of 21 persons hospitalized for problems related to intravenous drug use in 1986 and 1987, 1 (5%) tested positive for HTLV-I antibodies.

[Interferon and its potential use in the treatment of infectious diseases]. / Interferón y su uso potencial en el tratamiento de enfermedades infecciosas.

Modern recombinant biotechnology has made possible the production of large amount of interferons and their use as immunotherapeutic agents. Most of the biological, physical and chemical characteristics of interferons has been established, including their classification, genetic structure, chemical composition and possible mechanisms of action. Interferons have been utilized in clinical studies with human and experimental animals against bacterial, mycotic, parasitic and viral infections. Success has been reported mainly when administered prophylactically against acute infections. Favorable results have been obtained, both prophylactic and therapeutically, in some chronic diseases and in those in which the microorganism has an intracellular phase during its life cycle. Moreover, a promising future has been suggested for the combined use of interferon with other antimicrobial drugs.

Abnormal immunological response to Mycobacterium tuberculosis antigens in a patient with chronic myelocytic leukemia and active tuberculosis.

The pathogenic mechanisms of immunosuppression leading to susceptibility of Mycobacterium tuberculosis (MT) infection in chronic myelocytic leukemia (CML) are not clear. To address this issue, we measured the proliferative response, variation of T cell subpopulations (CD4+, CD8+, TCR-V delta 2 and TCR-V beta 8 T cells) and the cytokine profile (IL-1 beta, IL-2, IL-4, IL-6, IL-10, TNF-alpha, IFN-gamma) after MT stimulation of peripheral blood mononuclear cells (PBMC) in a patient with concomitant CML and active pulmonary tuberculosis. The results were compared to four patients with active pulmonary tuberculosis and no other coexistent diseases. The immunologic response to phytohemagglutinin (PHA) was also evaluated. In contrast to controls, the CML PBMC failed to proliferate in response to MT antigens. Mycobacterium-reactive CD4+, V delta 2 and V beta 8 T cells did not expand after MT stimulation of the CML PBMC. In MT antigens-stimulated cultures from the CML patient, IL-2 was not produced and mild reduction of IL-1 beta and INF-gamma were observed. In contrast, IL-10 was markedly elevated in these cultures. Similarly, PHA-stimulated PBMC from the CML patient showed no expansion of CD4+ and CD8+. T cells. In these cell cultures, INF-gamma concentration in supernatants was decreased and IL-10 was significantly elevated. This study suggests that patients with CML may present a profound immunosuppression of essential cellular and molecular immune effectors, a scenario which might contribute to the development of active tuberculosis. These findings further support the need of establishing immunotherapeutic modalities with potential value for myeloproliferative disorders.

Plants from Puerto Rico with anti-Mycobacterium tuberculosis properties.

OBJECTIVE: This study assesses the antitubercular potential of natural products obtained from plants reputed to have medicinal properties and collected from the tropical flora of Puerto Rico. BACKGROUND: The increase in persons infected with Mycobacterium tuberculosis (MTB) the world over and the development of resistance to antibiotics by this microbe and other infectious bacteria has created the need for new drugs to replace those which have lost effectiveness. METHOD: In Phase I of this study, ethanolic leaf extracts of fifty local plants were submitted to preliminary screening to assess their in vitro Mycobacterium smegmatis inhibitory activity using the Bauer-Kirby disk diffusion method. In Phase II, the definitive screening of the six most promising extracts which inhibited M. smegmatis were assayed for their MTB inhibitory activity using the BACTEC 460 susceptibility test method. The brine shrimp bioassay was used as a toxicity bioassay and the mice inoculation test was used to determine mice tolerance to the effect of the daily intraperitoneal inoculations of the plant extracts. RESULTS: MTB showed varying degrees of susceptibility to each plant extract. This effect was dependent upon the plant species, dose and time of exposure. Evidence is provided suggesting that: (1) Six crude plant extracts (12%) tested possessed inhibitory capacity at the amount of 500 micrograms per disc; (2) Mammea americana extract yielded the strongest inhibitory effect at 50 micrograms per disc, followed by Marchantia polymorpha, Mangifera indica, Callistemon citrinus, Syzygium jambos and Momordica charantia; (3) the bactericidal inhibitory pattern of MTB growth, exposed to Mammea americana extract, was comparable to streptomycin; and (4) the transitory reduction pattern of MTB growth, produced by Callistemon citrinus, Marchantia polymorpha extracts at 100 micrograms and 250 micrograms, was similar to that of bacteriostatic agents. CONCLUSION: Of 50 plants screened six extracts tested for their anti-MTB activity yielded positive results with varying degrees of inhibition. Mammea americana showed the greatest inhibitory activity suggesting that certain plant species yield valuable anti-Mycobacterium tuberculosis substances. The procedures employed in this study, including the BACTEC 460 modified method, are useful for in vitro screening of plant extracts with potential antitubercular activity.

The investigation of emerging and re-emerging viral diseases: a paradign.

Emerging virus infections are defined as previously nonthreatening viruses that can decimate new populations by finding fresh hosts and vectors--often with the help of humans who introduce new species into virgen environment, Several etiologic agents of these diseases, some of the interacting factors that contribute to their development and the role of molecular medicine in their understanding is discussed.

Characterization of the antitumor activity of a polyantigenic immunomodulator (PAI): I--Utilization of cimetidine and cyclosporine A.

Cimetidine (CMT), cyclosporine A (CsA), interleukin 2 (IL 2), were used to characterize the anticancerous effect of a polyantigenic immunodulator (PAI). PAI consists of a mixture of inactivated bacteria and influenza virus in a peanut oil-arlacel A-aluminum monoesterate emulsion. Antitumoral activity was tested on Ehrlich's ascites tumor (EAT) implanted into Swiss-Webster (allogeneic) or C57BL/6J (syngeneic) mice. PAI antitumor activity was enhanced by CMT acting synergistically by reducing substantially the tumor growth and increasing the percentage of surviving mice, while CsA suppressed this activity. PAI or its individual components were able to induce significant lymphocyte blastogenesis in mouse (C57BL/6J)-spleen lymphocytes and IL-2 enhanced considerably this lymphoproliferative response. The results suggest that PAI acts at the level of cellular immunity.

Characterization of the antitumor activity of a polyantigenic immunomodulator (PAI): II--Involvement of NK cells and adoptive immunotherapy.

Natural killer (NK) cell activity and adoptive immunotherapy were used to characterize the anticancerous effect of a polyantigenic immunomodulator (PAI). PAI consists of a mixture of inactivated bacteria and influenza virus in a peanut oil-arlacel A-aluminum monoesterate emulsion, shown previously to have antitumoral activity in mice implanted with Ehrlich's ascites tumor. The administration of PAI, its bacterial or viral component strongly increased the in vitro activity of NK cells of splenocyte populations obtained from Swiss-Webster (allogeneic) and C57BL/6J (syngeneic) mice, specially during the early post-induction period. On the other hand, PAI-sensitized, allogeneic or syngeneic lymphocytes were transferred successfully to tumor-bearing mice implanted with Ehrlich's ascites tumor, reducing tumor growth and increasing survival. The results confirm our previous suggestions that PAI acts probably at the level of cellular immunity. Therefore complex polyantigenic substances such as PAI could be used directly alone, in combination with other immunoadjuvants or to sensitize in a global manner immunocompetent cells to be employed in adoptive immunotherapy.

HCV genotype analysis in HCV-HIV-co-infected Puerto Ricans who are injecting drug users: undetermined and mixed infections.

Direct percutaneous exposure is the main route of HCV transmission. In Puerto Rico half of people infected with HIV use illicit drugs. The effects of HCV in the course of HIV infection and vice versa have been extensively studied, but remain highly controversial. This may be due to HCV genetic heterogeneity. Therefore, a complex classification into genotypes has emerged that prompted us to determined how this impacts a population of intravenous drug users (IDUs) co-infected with HIV-1. Using Inno-LiPa II technique, we analyzed samples from 171 HCV-HIV-1-co-infected IDUs and 375 from a general HCV population of unknown HIV or source of infection status. Similar HCV genotype distribution was detected in these populations. HCV genotype 1a was the most frequently in IDUs-co-infected with HIV-1, followed by 1b and 3a. Twenty mixed infections and 5 undetermined genotypes were reported. A reduced HCV viral load was observed in HIV-1 positives with wasting syndrome. Individuals with a high HIV-1 viral load presented a low HCV viral load. There were no correlation between HCV genotypes and AIDS-related event. Patients with genotype 1b showed a higher HCV viral load. Males presented higher HCV viral load than females. Females were predominantly affected by genotype 1a, and men by 1a and 1b. Neither the HCV viral load nor the frequency of genotypes were influenced by the antiretroviral modality. The importance of continuous genotype monitoring is stressed.

Correlation of the suppressive activity of a biological response modifier on the proliferation of peripheral blood mononuclear cells and the reduction of HIV titer.

Activation of CD4+ cells is a prerequisite for infection by the human immunodeficiency virus (HIV). Thus, any agent capable of suppressing CD4+ cell proliferation could create a refractory stage that would impede viral infection. We have reported, in a previous publication, that a biological response modifier (BRM), polyantigenic immunomodulator (PAI) substantially reduces HIV-1 titer (from 20 to 100%) in peripheral mononuclear cells (PBMC) cultures with high viral titer (p24 = 10(2)-10(5) pg/ml). We are presenting data suggesting that the reported reduction in virus titer seems to be associated with a suppressive activity of PAI on the proliferation of PBMC from intravenous drug users (IVDU) infected and non-infected with HIV-1. PAI, a well characterized BRM, is a mixture of inactivated bacterial and influenza virus vaccines. PBMC from healthy donors and IVDU individuals were exposed to PAI, phytohemagglutinin (PHA), interleukin-2 (IL-2) and to combinations of PAI with either PHA or IL-2. Appropriate controls were included. 3H-thymidine pulsing was used as indicator of cell proliferation. The stimulation index and the difference between mean cpm of test sample and control were used to measure proliferative activity. There was a low proliferative response in the PBMC cultures from IVDU and HIV-1 positive patients, but it was substantially lower in the later group. When PBMC cultures from the same group of individuals were exposed to PAI, PHA and IL-2, and to the combination of either PAI plus PHA or IL-2, the response observed in the PAI treated group was uniformly lower than in the other treated cultures. Moreover, when PAI was combined with PHA, it exerted a significant reduction in the measured parameters. The effect of PAI on IL-2 activity was negligible. A suppressive effect of a PAI has been detected on the proliferation of PBMC from IVDA and HIV-1 positive individuals. This activity may be associated with the capacity of PAI to reduce HIV titers in infected PBMC cultures.

A multicenter hospital surveillance of invasive Streptococcus pneumoniae, Puerto Rico, 2001

Although antimicrobial resistance to Streptococcus pneumoniae has been increased dramatically worldwide, there is limited information of pattern of susceptibility for this pathogen in Puerto Rico. Hospital-based surveillance for invasive pneumococcal infections was begun among 38 hospitals island-wide in Puerto Rico from January to December, 2001. One hundred ninety-two cases of invasive pneumococcal disease were identified. Of the 177 isolates available for susceptibility testing, 50.3were susceptible to penicillin and 49.7were nonsusceptible (intermediate (I) and resistance (R)) (19.2I, 30.5R). Resistance was documented for expanded spectrum cephalosporins and macrolides. All isolates were susceptible to vancomycin. Diabetes, cardiovascular disease, smoking and bronchial asthma were the most common risk factors associated with invasive pneumococcal disease of the adult population. Bronchial asthma was the most common disease in the pediatric population with a fatality rate of 21. There was no increased mortality detected among patients infected with penicillin resistant strains. Most of the isolates serotypes are represented in the 23-valent polysaccharide vaccine (78) and 7-valent conjugate vaccine (62). Penicillin-resistant isolates (47) were 14, 19F, 6B, 6A, 9V, 23F, 19A and 35B serotype. Our data indicated a high prevalence for drug-resistant strains of S. pneumoniae in Puerto Rico. Continue surveillance for this common but serious pathogen is needed. Asthma is an important risk factor for pneumococcal disease. The pneumococcal vaccine should be recommended for all age groups with this risk factor.

The investigation of emerging and re-emerging viral diseases: a paradign

Emerging virus infections are defined as previously nonthreatening viruses that can decimate new populations by finding fresh hosts and vectors--often with the help of humans who introduce new species into virgen environment, Several etiologic agents of these diseases, some of the interacting factors that contribute to their development and the role of molecular medicine in their understanding is discussed

Prevalence of primary and secondary resistant mutations to antiretroviral drug in a population of Puerto Rican infected with HIV

INTRODUCTION: Several studies have reported increasing number of therapeutic failures with HAART in HIV-infected individuals. In order to assess the impact HIV antiretroviral resistance could have on treatment, we decided to determine the prevalence of primary and secondary antiretroviral resistant genotypes in a population of HIV-infected Puerto Ricans and compare the mutational distribution pattern with that reported in Europe and US. METHOD: In a total of 80 plasma samples from patients with detectable viral load of over 1,000 RNA copies/ml, the Trugene Visible Genetics HIV sequencing method was used to detect antiretroviral resistance mutations. RESULTS: We found 55 subjects (69 per cent) with high level of resistance to ZDV in the reverse transcriptase gene and 46 subjects (58 per cent) with high level of resistance to NFV in the protease gene. Mutation frequencies to the NRTI ranged in appearance from as high as 54 per cent (i.e., M184V) in the studied subjects to a low of less than 5 per cent (i.e., M184I and V75T). For the NNRTI the most common mutation was K103N in 40 per cent of the subjects and found to confer cross resistance to NVP, DLV and EFV. Another concerning finding is the increasing trend of the frequency of primary and secondary resistant mutations from year 2000 to 20001. Nine (23 per cent) of the total detected primary mutations, to either RTI or PI, showed an increase of at least 5 per cent from one year to the other. Similarly, there were 6 (11 per cent) secondary resistant mutations showing an increase of at least 5 per cent during the two years studied. CONCLUSIONS: In two year period we detected a tendency to increase in primary and secondary HIV-resistant mutation in a population of HIV-infected Puerto Ricans.