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N Rodriguez

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Adaptation, Psychological↗

The re-emergence of American visceral leishmaniasis in an old focus in Venezuela. II. Vectors and parasites.

As part of an epidemiological study in an old focus of American Visceral Leishmaniasis (AVL) in Venezuela (Guayabita, Aragua State), a longitudinal entomological survey (January 1993-June 1994) was carried out. A total of 3,239 males and 6,043 females belonging to 11 phlebotomine sandfly species were collected. The two recognised vectors of AVL in the New World, Lutzomyia evansi and Lu. longipalpis were found to be sympatric. Lutzomyia evansi was the dominant species (86.4%), almost ten fold times more abundant than Lu. longipalpis (10.6%). The two species alternated seasonally: Lu evansi peaked at the end of the rainy season while Lu. longipalpis, almost virtually absent during such period, increased in the dry season. This species seems more greatly influenced by the temperature. Seven of 4,559 Lutzomyia evansi (0.15%) and one of 353 Lu. longipalpis (0.28%) were found positive for suprapyloric promastigotes. Using the polymerase chain reaction (PCR) with universal primers, all isolates were identified as Leishmania spp. Two cultures from Lu. evansi, IEVA/VE/93/UCNA-2 and IEVA/VE/93/UCNA-3, were established. k-DNA restriction analysis showed high homologies between these isolates and Leishmania chagasi. High hybridization signal with L. chagasi specific kDNA confirmed these results. These findings suggest that Lu. evansi may play a role as vector of visceral leishmaniasis in this area. The identity of the parasite carried by Lu. longipalpis needs to be confirmed.

Animals↗

Infusion phlebitis in post-operative patients: when and why.

BACKGROUND: The most common complication of intravenous therapy is infusion phlebitis. This study was done to prospectively assess its frequency in a series of consecutive patients who will undergo surgery, and to identify which variables may predict an increased risk for phlebitis. PATIENTS AND METHODS: 400 consecutive patients who will undergo surgery in a general surgery department were included. Only the first catheter, inserted the day before surgery, was taken into account. Eighteen variables (from the infusion, the catheter and from the patient) were prospectively evaluated for their contribution to the occurrence of phlebitis. RESULTS: 60/400 patients (15%) developed phlebitis, and most of them needed insertion of a further catheter. The univariate analysis showed that patients who developed phlebitis were older, and their pre-operative levels of both blood haemoglobin and neutrophil cound were significantly higher than those in patients who did not develop phlebitis. However, the multivariate analysis only confirmed the association with blood haemoglobin levels: the risk of phlebitis sharply increased in the patients with the highest haemoglobin levels. As to the influence of time on phlebitis development, there was a significant decrease in the day-specific risk, from the 5th day on. COMMENTS: In our series, blood haemoglobin levels were found to be the only variable associated to a higher risk of phlebitis. Besides, in contrast with the recommendations by the Centers for Disease Control, no significant increase in the day-specific risk of phlebitis was found. Thus, a guideline to select the type of catheter to be inserted in an individual patient is suggested.

Adolescent↗

Epidemiologic aspects of American visceral leishmaniasis in an endemic focus in Eastern Venezuela.

An endemic focus of American visceral leishmaniasis (AVL) in eastern Venezuela has been evaluated in terms of patients (n = 48), immunologic reactivity to Leishmania in household contacts (n = 187) and neighborhood controls (n = 170), detection of Leishmania (L. donovani complex) in dogs and wild animals by the polymerase chain reaction (PCR) and characteristics of the sandfly population. The male:female ratio of patients was 1.18:1; 89.6% were < or =12 years old. Serologic reactivity was significantly higher in household contacts than in controls (P = 0.0008), as was the size of leishmanin reactions in contacts < or =10 years of age (P = 0.0141). Leishmania donovani complex-specific PCRs were positive in dogs, an opossum (Didelphis marsupialis), and a black rat (Rattus rattus). Lutzomyia longipalpis and Lu. evansi, both implicated in the transmission of AVL, were identified among the 386 sand flies examined. These observations provide the bases for an active control program as well as further studies of reservoirs and vector-host relationships in this area.

Adolescent↗

Death at the border.

"Debates about United States border control policies have generally ignored the human costs of undocumented migration. We focus attention on these costs by estimating the number, causes and location of migrant deaths at the southwest border of the United States between 1993 and 1997.... Deaths from hyperthermia, hypothermia and dehydration increased sharply from 1993 to 1997 as intensified border enforcement redirected undocumented migration flows from urban crossing points to more remote crossing areas where the migrants are exposed to a greater risk of death."

Americas↗

Suppression of intracellular hydrogen peroxide generation and catalase levels in CD8+ T-lymphocytes from HIV+ individuals.

CD8+ T-lymphocytes from HIV+ individuals contain short telomeres, a sign of cell senescence. To test our hypothesis that the cell type is functionally defective in the biochemical indices related to cell proliferation, we investigated the profiles of intracellularly generated H2O2 levels with or without PMA as well as immunoreactive catalase levels using flow cytometric method. We observed that, in HIV+ but not in HIV- individuals, the constitutively generated H2O2 level was significantly lower in CD8+ T-cells compared with CD4+ T-cells. Importantly, activated effector CD8+CD28- cells showed remarkably low H2O2 levels compared with CD8+CD28+ cells, and the latter in HIV+ individuals also showed low levels. A similar defect of CD8+ cells of HIV+ individuals was also seen with H2O2 levels stimulated with PMA in the presence of a catalase inhibitor. Furthermore, the immunoreactive catalase content was lower in CD8+ cells compared with CD4+ cells only in HIV+ individuals. These results suggest that CD8+ T-lymphocytes are functionally defective with the constitutively generated and PMA-elicited levels of H2O2 and the corresponding scavenger. Diminished immunocompetence of HIV+ individuals may be caused, in part, by the functional defect of CD8+ T-cells.

Adult↗

Genomic DNA repeat from Leishmania (Viannia) braziliensis (Venezuelan strain) containing simple repeats and microsatellites.

In this paper the Leishmania (Viannia) braziliensis complex is defined as containing all species of the actual subgenus Viannia. Organisms of the L. (V) braziliensis complex are the causative agents of localized human cutaneous and mucocutaneous leishmaniasis in South America, much of Central America and some ares of North America. In our search for better species and subspecies diagnostic probes we focused our research on repetitive DNA, since it provides a greater number of target sites for hybridization. In this work we report the isolation and sequencing of a 1.8 kb DNA region, LbJ38, which is probably tandemly repeated or dispersed at least 4 times along one chromosome and is naturally present in L. (V) braziliensis genomic DNA. This region contains microsatellites and simple repeat DNA sequences and was isolated by screening a genomic DNA cosmid library with complex- and species-specific probes. No homology was found with other Leishmania microsatellite or repetitive DNA. The utility of this repetitive sequence and primers derived from it in the identification of L. (V) braziliensis is demonstrated. As far as we are aware, this is the first report of sequence characterized repetitive microsatellite and GC rich simple repeat DNA from the nuclear genome of New World Leishmania.

Animals↗

Posttraumatic stress disorder in adult female survivors of childhood sexual abuse: a comparison study.

This study compared symptoms of posttraumatic stress disorder (PTSD) in a group of 45 adult women in outpatient treatment for childhood sexual abuse (CSA) and a group of 31 women who reported no CSA. The comparison group consisted of women in outpatient treatment for problems in their committed relationships with male living partners. This research also investigated the traumatic impact of dual abuse (both childhood sexual and physical abuse). Standardized assessment instruments were used to measure PTSD, CSA, and childhood physical abuse (CPA). Results indicated that 86.7% of the CSA group met criteria for current PTSD in accordance with the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised; American Psychiatric Association, 1987), compared with 19.4% of the relationship distress group, providing support for CSA as an etiological agent for PTSD. In addition, 89% of the CSA survivors reported CPA. Multivariate analysis revealed that both CSA and CPA exposure variables accounted for a significant portion of the variance in PTSD symptoms in the CSA group.

Adult↗

Mechanisms associated with defective TH1 cytokine production in HIV infection.

Qualitative and quantitative changes in immune functions of different T-cell subsets associated with infection by human immunodeficiency virus type 1 (HIV-1) were analyzed by flow cytometric assessment of intracytoplasmic cytokines. The T(H)1 cytokines, interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), were produced by both CD4 and CD8 T-cell subsets. When normal peripheral blood mononuclear cells (PBMC) were activated in culture, both cytokines were produced predominantly by CD4 (CD4) cell and only a minor fraction of normal CD8 cells produced these cytokines. In the cultures of PBMC from HIV-1-infected individuals (HIV+PBMC), more HIV+CD8 cells produced IL-2 and IFN-gamma. Production of IFN-gamma by HIV+CD4 cells was markedly reduced, while IL-2nd tumor necrosis factor-alpha (TNF-alpha) production by HIV+CD4 remained relatively intact until the disease progressed further. Normal CD4 cells which were isolated by using a cell sorter, FACSCalibur was still able to produce IL-2 and TNF-alpha. But for full production of IFN-gamma, normal CD4 required some accessory cells, the identity of which could not yet be established.

CD4-Positive T-Lymphocytes↗

The proliferative response of HIV+ T-cells (CD4+ and CD8+) are severely suppressed via CD28 coactivation.

Several studies have suggested that regulation of expression of the costimulatory molecule CD28 on the T-cell surface may play an important role in AIDS pathogenesis. In a study of T-cells from HIV+ donors, we find that activation with anti-CD3 plus anti-CD28 results in a mitogenic response which was approximately 86% suppressed for both CD4+ and CD8+ T-cells when compared to normal control cells. With PMA costimulation (instead of anti-CD28), the anti-CD3 response was suppressed much less, by 64 and 61%, respectively. With Con A as opposed to CD3 stimulation, the degree of suppression was less with either coactivator but still more severe with CD28 than with PMA coactivation. It has been reported that the CD28 subset of CD8+ T-cells is diminished in HIV+ individuals and could account for these results. It is possible as well that the CD28 costimulatory pathway in the CD4+ T-cells particularly is altered due to intervention by the HIV. While our data do not differentiate between these two possibilities, it show that the immune status is compromised in the HIV+ individual not only in terms of number of CD4+ T-cells, but in their activation response as well.

Adult↗

Posttraumatic stress disorder in a clinical sample of adult survivors of childhood sexual abuse.

One hundred seventeen help-seeking adult survivors of childhood sexual abuse (CSA) were assessed to investigate the relationship between the level of self-reported CSA and posttraumatic stress disorder (PTSD). CSA was measured utilizing the Sexual Abuse Exposure Questionnaire, a new research instrument. Further preliminary psychometric properties of the instrument were reported. CSA was operationalized to include severity, duration, age of onset, number of perpetrators, and use of force. PTSD diagnostic status was assessed utilizing a standardized instrument, the Structured Clinical Interview for DSM-II-R. Eighty-six percent of survivors met full DSM-III-R criteria for a PTSD diagnosis at some point during their lives. Multivariate analysis indicated that CSA severity and duration accounted for significant portions of the variance in PTSD symptoms, providing support for their role as traumagenic variables.

Adult↗

Treatment of patients with cirrhosis and refractory ascites using LeVeen shunt with titanium tip: comparison with therapeutic paracentesis.

It has recently been suggested that insertion of a titanium tip at the venous end of the LeVeen shunt drastically reduces the rate of shunt obstruction. To assess whether the LeVeen shunt with titanium tip improves the results obtained with therapeutic paracentesis, 81 patients with cirrhosis and refractory ascites were randomly assigned to therapy with paracentesis plus intravenous albumin (42 patients) or LeVeen shunt with titanium tip (39 patients). If patients were readmitted for ascites during follow-up, those in the first group were treated with paracentesis, and those in the LeVeen shunt group by the insertion of a new valve or a new shunt if obstruction was demonstrated. During first hospitalization, both treatments were equally effective in removing ascites. Complications were similar in both groups except for a higher rate of severe bacterial infection in the LeVeen shunt group. The mean duration of hospitalization was shorter in the paracentesis group than in the shunt group. During follow-up, the total number of readmissions and the number of readmissions for ascites were higher in the paracentesis group than in the shunt group (252 vs. 99, P < .001; and 193 vs. 43, P < .001, respectively). The total time in hospital, however, was similar (38 +/- 38 vs. 39 +/- 43 days, P = NS). Three patients had obstruction of the shunt during first hospitalization and 14 patients had a total of 22 obstructions during follow-up. Long-term survival was similar in both groups. The insertion of a titanium tip at the venous end of the LeVeen shunt does not prevent obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

A new flow cytometric method for quantitative assessment of lymphocyte mitogenic potentials.

A new flow cytometric method was developed to quantitatively assess lymphocyte proliferation simultaneously for different subsets. The cells were stained with a fluorescent dye, PKH-26 and were stimulated with mitogens. The fluorescence intensities (FL2) of proliferating cells were measured by flow cytometry; and each subset was identified by the use of a monoclonal antibody (Mab)-fluorescein-isothiocyanate (FITC) (FL1). FL2 histograms were then analyzed by the cell proliferation model based on the ModFit software (Verity). This new method revealed information which could not be obtained by conventional mitogen assays. For example, the CD4+ and the CD4- T-subsets responded to phytohemagglutinin (PHA) quite differently from each other and it was indicated that activation of one population could significantly alter the response of the other. In addition, even within a subset, all activated cells did not proliferate uniformly. Some cells divided only once while others underwent further cellular division during the same time period. The method is, therefore, invaluable for studying the nature and the extent of interactions between different cellular subsets within a culture.

Antibodies, Monoclonal↗

Anti-CD4 cytotoxic T lymphocyte (CTL) activity in HIV+ patients: flow cytometric analysis.

A new cell proliferation analysis by flow cytometry was applied to the mitogen induced cultures of peripheral blood mononuclear cells (PBMC) from either normal, healthy donors or those individuals who are infected by human immunodeficiency virus, type 1 (HIV-1). While phytohemagglutinin (PHA) stimulation of normal PBMC (nPBMC) yielded propagation of both CD4 (nCD4) and CD8 (nCD8) T cell subsets, similar activation of PBMC from certain HIV-1-infected individuals (HIV-PBMC) produced active proliferation of CD8 (HIV-CD8) cells but varying degrees of CD4 (HIV-CD4) cell destruction. However, no measurable viral p24 antigen was produced extracellularly. On the other hand, when the purified HIV-CD4 cells were similarly activated, no such cell death was noted and high titer p24 was detected in the culture supernatants. Addition of exogenous IL-2 to either HIV-PBMC or HIV-CD4 cultures, did not alter either CD4 cell death or HIV-1 p24 production. Isolated HIV-CD8 killed not only HIV-CD4 but also nCD4, when co-cultured and less proliferative fractions of CD4 cell population was the more preferred targets of the HIV-CD8 CTL activity. The presence of anti-CD4 CTL activity was closely associated with high CD8, but not with CD4 counts, of the HIV+ patients.

CD4 Lymphocyte Count↗

Current prevalence of Paget's disease of bone in a region of France (Anjou).

To study the prevalence of Paget's disease in a region of France (Anjou) we conducted a two-part study. 1) One hundred randomly selected medical records of Paget's disease patients managed in a rheumatology department were studied to determine the rates of occurrence of pagetic lesions at each skeletal site. Availability of a radionuclide bone scan done before treatment initiation and of radiographs of hyperactive areas was required for inclusion into the study. In 91% of patients, pagetic lesions were visible on the lumbar spine-pelvis-femoral head film. 2) We looked for pagetic lesions on intravenous urograms done in 600 urology department patients (to minimize recruitment bias). The 307 males and 293 females had a mean age of 65.4 +/- 8.7 years (range 50-91). Films classified by the evaluator as showing definite or doubtful pagetic lesions were read by five other evaluators in a blind manner. Among the 11 patients (seven males and four females) found to have Paget's disease, only one was younger than 65 years. Prevalence was higher in males (2.50 +/- 0.79% than in females (1.50 +/- 0.5%). These prevalences are lower than those reported in the United Kingdom.

Aged↗