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.

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.

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.

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.

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.

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.

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.

Movement patterns of persons with HIV receiving treatment in public clinics in the Southern Health Region, Puerto Rico

Health planners suspect there is a pattern of movement, dubbed the "air bridge," between Puerto Rico and the continental United States by persons living with human immunodeficiency virus (HIV) who are seeking health services. The authors tested this hypothesis in publicly supported HlVclinics in the Puerto Rican Southern Health Region (SHR). A survey was conducted of 187 patients who were at least 18 years of age, confirmed HIV positive, and not incarcerated. Only 7% of the respondents had been outside the SHR for 2 weeks or more in the past year. Intravenous drug users and men who have sex with men were 7 to 8 times more likely to have traveled than were heterosexual respondents. Fifty-seven percent of all movement was within Puerto Rico, and no one had traveled to the United States primarily to receive medical services. Thus the results of this study do not support the concept of an "air bridge. "

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.

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)

Coexistence of two species of Leishmania in the digestive tract of the vector Lutzomyia ovallesi

Leishmania isolated from the digestive tract of a naturally infected Lutzomyia ovallesi sand fly were cultured in blood agar for rapid growth, cloning, and subsequent identification through schizodeme analysis, dot-blot hybridization, use of monoclonal antibodies with various specificities and absorbed polyclonal antibodies. Twenty-three clones isolated from the primary culture were identified. The results showed that parasites belonging to some clones corresponded to the L. mexicana complex, while others belonged to the L. braziliensis complex. These results clearly establish the coexistence of two Leishmania species in the digestive tract of a single Lu. ovallesi sand fly.

Vectors of cutaneous leishmaniasis in north-central Venezuela

An entomological survey was undertaken from January 1991 to February 1992 in El Ingenio, Miranda State, Venezuela, an endemic area of cutaneous leishmaniasis: prevalence of 10.7 cases per 100,000 inhabitants. A total of 4863 female sandflies (Phlebotominae) of fourteen species were collected in Shannon traps, then dissected and examined for leishmanial infections. Lutzomyia ovallesi (85.4%) and Lu. gomezi (11.2%) were the predominant anthropophilic species of sandfly. Fifty-one (1.19%) Lu.ovallesi and two (0.47%) Lu.gomezi had natural infection with Leishmania promastigotes. Identification of the parasites was done by using the polymerase chain reaction (PCR) and DNA hybridization. Two isolates from Lu.gomezi and forty-nine from Lu.ovallesi were typed as Leishmania braziliensis and three of the latter reacted with Le.mexicana also. This is the first report of Lu.gomezi with parasites typed as Le.braziliensis. We concluded that Lu.ovallesi is the primary vector of cutaneous leishmaniasis in the north-central area of Venezuela and Lu.gomezi should be regarded as an additional vector.

[Ultramicro ELISA to the detection of IgM antibodies in Mycobacterium leprae using dry blood samples]

In this work the adequate conditions for the detection of IgM antibodies to PGL-I in eluates from dried blood spots using the UMELISA HANSEN and the SUMA technology are established. A total of 300 blood donors and 58 leprosy patients samples were studied. For both populations, in the previously established conditions, we compared the results of the eluates from dried blood spots with the serum samples, and was obtained a correlation of 0.919 in blood donors, 0.969 in patients, and 0.954 for the total of both populations. It was also obtained a level of agreement of 98% in patients and 96% in blood donors. In the patients population was found a sensitivity of 93% and an specificity of 100% for the eluates of dried blood spots evaluated by the UMELISA HANSEN in the comparison with the serum samples analized by the same assay.

Cutaneous leishmaniasis in Tachira State, Venezuela

Cutaneous and mucocutaneous leishmaniases are widely spread in the mountainous Andean regions of South America. In Venezuela, these regions consist of the coffee-growing states of Trujillo, Merida and Tachira. Entomological and parasitological investigations in three geographically different climatic zones (Lomas Bajas, Delicias and La Grita) in Tachira state have shown a predominance of the sandfly species Lutzomyia spinicrassa (verrucarum group) and two Leishmania species, Leishmania mexicana and Leishmania braziliensis. Two transmission cycles appear to occur: a peridomestic cycle in Lomas Bajas and a sylvatic one in Delicias and La Grita.

Posttraumatic stress disorder in a clinical sample of adults sexually abused as children

Forty-seven help-seeking, adult survivors of childhood sexual abuse (CSA) were assessed to examine the relationship between the level of CSA exposure and the subsequent development of posttraumatic stress disorder. CSA exposure was operationalized to include the overall level of exposure, frequency and duration of the abuse, age of onset, use of force, perceived life threat, and the occurrence of penetration. Participants were administered standardized measures of PTSD, including the Structured Clinical Interview of DSM-III-R (SCID). On the SCID, 69% of the survivors met full DSM-III-R criteria for PTSD. Significant correlations were found between several overall exposure measures and PTSD diagnostic status and the intensity of PTSD symptomatology. Similar relationships were identified with the duration and frequency of the abuse, the age of onset, and the use of force. This study is important in that it utilized standardized measures of PTSD and found a significant incidence of PTSD among adult CSA survivors.

Rupture and migration of the venous segment of LeVeen shunt: an unreported complication

The LeVeen peritoneovenous shunt has been used for nearly 20 yr in the treatment of refractory ascites due to liver cirrhosis. However, the technique encompasses a high incidence of serious complications. We report the case of a 59-yr-old man presenting with right pulmonary artery embolization caused by ruptured venous segment of a LeVeen shunt. After localizing it arteriographically, we were able to satisfactorily remove the segment by tying it up with a catheter introduced through the femoral vein.

Molecular approaches applied to the epidemiology of leishmaniasis in Venezuela

Leishmaniasis is on the increase in Venezuela (ca 30,000 new cases per year) due to deterioration in health management, increased risk groups among inmunosuppressed individuals and increased human penetration into the ecological habitats of sandfly vectors. An STD2-funded project (1989-1992) focused on the Andean state of Táchira, which showed the highest annual index of new cases (ca 200-250). The project aimed at contributing to vector/parasite identification through a combination of molecular and well established field techniques: Newly developed molecular methods distinguished among Lu. spinicrassa, Lu. youngi and Lu. townsendi. These three species of the Verrucarum group are sympatric in the Northeast of the state and could be successfully identified by CHA, DNA probes and RAPD. A Le. braziliensis specific KDNA probe used with squash blots indicated that Lu. spinicrassa is the main vector and that Le. braziliensis is the main parasite species in Táchira state, Venezuela. PCR and the Le. brasiliensis specific DNA probe, schizodemes, isoenzymes and polyclonal antibodies agreed as taxonomic criteria for classification of Leishmania isolated from parasitologically confirmed cases in Tachira. Considerable degree of antigen heterogeneity in Venezuelan Le. braziliensis complex and Le. mexicana complex isolates from Tachira suggests multiple candidate antigens for improving the specificity of immunological diagnosis. The methods developed and tested in Táchira state should be valuable in order to help solving other outstanding epidemiological problems such as following of the epidemiological impact of intervention and vector control measures in highly endemic areas. Future work (STD3 funded, 1993-1996) aims to apply these molecular techniques to a vector control pilot study in Lara state, an area showing the highest incidence of new cases in the country.

Use of an ATP-supplemented medium for the conservation of human semen and the effect of caffeine on the motility of preserved sperm. Results in artificial insemination

Human semen can be preserved at 4 degrees C in an artificial medium containing 15% ATP-MgCl2 for up to 5 d. This method has been applied to samples from subjects with either normal or abnormal semen. After the conservation period the recovery of sperm motility observed was good when low doses of caffeine (3.5 or 7.0 mM) were added.

Nonoperative management of splenic injuries

The traditional management of splenic trauma has undergone major revision in recent years. Given the physiological importance of the spleen, certain controversy has arisen regarding the most appropriate method of managing this type of trauma. Nonoperative therapy in children has proven to be successful not only in the case of kidney lesions but also for splenic lesions. Nonoperative management carried out in the authors' hospital on a group of 56 patients (49 adults and seven children over the age of 7 years) has proved successful in 37 cases. The success of this technique requires a well-formulated protocol, diagnostic methods (ultrasound and computed tomography), rigorous patient control in the emergency room during the initial phase (first 48 hours), the availability of a medical team if surgical intervention becomes necessary (persistent or recurrent hemorrhage), and complementary measures which facilitate the cicatrization of the splenic injury (bed rest, antibiotic therapy).

Effect of the ingestion of an extract from Bauhinia monandra seeds on rats

Bauhinia monandra is a leguminous plant that would be used in human nutrition, however it shows a high hemagglutinating activity against trypsin-treated erythrocytes of rabbit, 2 ml of a NaCl-solution extract of the seeds was given to a group of rats for 10 days. Intestinal disaccharidase activity was determined. Histopathological and histochemical examinations were also performed. Lectins from Bauhinia monandra seeds did not cause any visible intestinal damage even when they seem to be able to bind to the enterocyte brush border. The low disaccharidase activity in the membrane and enterocyte fractions, which represent the enzyme synthesis level, indicates that lectins could reduce the synthesis of these enzymes rather than inhibit the active sites of the enzymes. This effect could be in turn related with the binding action of lectins, because no effect of the autoclaved extract on the disaccharidase activity was observed.

Contribution of insulin resistance to catabolic effect of prednisone on leucine metabolism in humans

To determine the role insulin resistance may play in the catabolic effect of high-dose prednisone therapy, healthy volunteers were studied on four occasions with the hormone-clamp technique at two insulin infusion rates. Subjects were studied after 5 days of prednisone (60 mg/day) or no steroid treatment and were infused with somatostatin, glucagon, growth hormone, [3H]glucose, [14C]leucine, and insulin (0.1 or 0.2 mU.kg-1.min-1). At each rate of insulin infusion, the rate of leucine oxidation was increased (P less than .001) after steroid treatment. Leucine flux, an indicator of whole-body proteolysis, was similar in the presence or absence of steroid treatment (2.26 +/- 0.08 vs. 2.13 +/- 0.04 mumol.kg-1.min-1, respectively) at the lower rate of insulin infusion but was higher during steroid treatment (2.18 +/- 0.06 vs. 1.84 +/- 0.13 mumol.kg-1.min-1) at the 0.2-mU.kg-1.min-1 insulin infusion. Steroid pretreatment had no significant effect on the nonoxidative rates of leucine disappearance. These data provide strong evidence that the protein wasting associated with glucocorticosteroid therapy is in part the result of steroid-induced resistance to the antiproteolytic effect of insulin and an increase in the oxidation (and thus wasting) of one essential amino acid, leucine.