Flexible communication and control protocol for injectable neuromuscular interfaces

BION2 is a system based on injectable neuromuscular implants whose main goal is to restore the functional movement of paralyzed limbs. To achieve this objective, the functional requirements of the implanted interfaces include not only stimulation but also integrated sensors in order to detect patient intention, to provide servocontrol of muscle activation and to sense posture to inform more global motor planning and coordination. The technical constraints for managing the system include the efficient use of forward and reverse telemetry channels with limited capacity, minimization of adverse consequences from errors in data transmission or intermittent loss of power to the implants, and ability to adjust stimulation rates and phases to achieve efficient fine control of muscle force while minimizing fatigue. This paper describes a communication and control architecture with several novel features that address these requirements.

Indirect evidence of submicroscopic pores in giant unilamellar [correction of unilamelar] vesicles

Formation of pore-like structures in cell membranes could participate in exchange of matter between cell compartments and modify the lipid distribution between the leaflets of a bilayer. We present experiments on two model systems in which major lipid redistribution is attributed to few submicroscopic transient pores. The first kind of experiments consists in destabilizing the membrane of a giant unilamellar vesicle by inserting conic-shaped fluorescent lipids from the outer medium. The inserted lipids (10% of the vesicle lipids) should lead to membrane rupture if segregated on the outer leaflet. We show that a 5-nm diameter pore is sufficient to ease the stress on the membrane by redistributing the lipids. The second kind of experiments consists in forcing giant vesicles containing functionalized lipids to adhere. This adhesion leads to hemifusion (merging of the outer leaflets). In certain cases, the formation of pores in one of the vesicles is attested by contrast loss on this vesicle and redistribution of fluorescent labels between the leaflets. The kinetics of these phenomena is compatible with transient submicroscopic pores and long-lived membrane defects.

Phylogenetic relationships between Puerto Rico and continental USA HIV-1 pol sequences: a shared HIV-1 infection

In order to investigate the existing notion that the human immunodeficiency virus type 1 (HIV-1) infection in Puerto Rico (PR) was imported from the continental United States of America (USA) we sequenced and analyzed 900 bases of the HIV-1 pol sequence from individuals in PR for comparison with pol sequences from the USA mainland. The sequences were derived by direct sequencing of reverse transcription-polymerase chain reaction products generated from plasma virus. The products were sequenced in both directions and the complementary strands were compared prior to analysis. These processed sequences and GenBank sequences from the continental USA were subjected to phylogenetic analyses. The PR and USA sequences did not form independent clusters, indicating a shared HIV-1 infection. This may be due to the continuous human traffic or, less likely, may indicate a similar evolution of a common source virus. Analysis of drug resistance mutations, fairly similar in frequency in the PR and USA sequences analyzed here, supports human traffic as a rationale for the common infection. This work indicates that an efficacious vaccine developed for use in the USA mainland will also be effective in prevention in PR and perhaps the other countries of the Caribbean region.

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."

Prevalence of erectile dysfunction in Colombia, Ecuador, and Venezuela: a population-based study (DENSA)

The purpose of this study was to estimate the prevalence of erectile dysfunction (ED) in Colombia, Ecuador, and Venezuela. A 49-item questionnaire was completed by 1946 men aged 40 years and older. The age-adjusted combined prevalence of minimal, moderate, and complete ED for all three countries was 53.4%, with 19.8% of all men reporting moderate to complete ED. Age was the variable most strongly linked to ED; the prevalence of complete ED increased markedly in men older than 79 y of age (31.9%) and 70-79 y (17.2%) compared with men aged 40-49 y (<3%). Several medical conditions, such as hypertension, benign prostatic hyperplasia, and diabetes, and the use of medications to treat these conditions were correlated with the prevalence of ED. This study corroborates earlier studies demonstrating that ED is very common, increases dramatically with age, and has multiple correlates, including some that are also risk factors for cardiovascular disease.

Development of thrombocytosis in HIV+ drug users: impact of antiretroviral therapy

With the exception of hemolytic anemia, the potential hematological toxicity of antiretrovirals (ARV) and combination treatments in HIV treated individuals has not been well established. We report, for the first time, hematological toxicity defined as thrombocytosis in 9% of the HIV+ patients receiving highly active antiretroviral treatment (HAART) being followed in a nutritional clinical trial. Participants were evaluated every 6 months during a 2-year period (1998-2000) and blood drawn for biochemical, hematological and immunological parameters. NK cells were negatively correlated with platelet counts in the total cohort (P = 0.018) and persistently elevated with ARVT. Chronic thrombocytosis was associated with significantly lower NK percentages (P = 0.005). Twenty-five percent of the patients with thrombocytosis developed a cardiovascular disease. Together, these results support the proposal that HAART may increase the risk of hematological dysfunction and impact the risk of cardiovascular disease.

Involvement of gntS in the control of GntI, the main system for gluconate metabolism in Escherichia coli

The initial steps of gluconate metabolism in E. coli, transport and phosphorylation, occur through duplicate activities. These activities have been included in two systems designated as GntI (main) and GntII (subsidiary), encoded by differently regulated operons located at the 76.4-77 and 95.3-96.9 regions on the map respectively. Despite recent molecular advances related to genetics and physiology of these systems, there is no information about the coordination of their expression when E. coli grows on gluconate. Under these conditions, the subsidiary gluconokinase (gntV gene, min 96.8) as well as the GntI activities are expressed in inducible form. Therefore it was of interest to find out if GntS, the positive regulator of gntV has a similar effect on GntI activities expression. Our results agree with this hypothesis. GntS, in addition to its regulatory action on the gntV gene, seems to assist, direct or indirectly, the expression of the GntI activities. A gntS E. coli mutant does not grow on gluconate but spontaneously pseudoreverts to a gluconate growing phenotype at high rate per cell generation when cultivated in rich media with or without gluconate or mineral medium containing any other suitable carbon source. In the pseudorevertants, the thermosensitive gluconokinase remains repressed while the GntI activities are inducibly expressed. At present, the location and nature of the gntS suppressor mutation are not known. Phage P1Kc mediated transductions have ruled out that it alters the gntT gene. This is the first report on GntI activities alteration due to a lesion located out of the bioH-asd region.

Effect of sequence length, sequence frequency, and data acquisition rate on the performance of a Hadamard transform time-of-flight mass spectrometer

Various factors influencing the performance of a Hadamard transform time-of-flight mass spectrometer (HT-TOFMS) have been investigated. Using a nitrogen corona discharge to produce an ion stream of N2+, N3+, and N4+, it is found for spectra containing only N4+ that the signal-to-noise ratio (SNR) closely approaches the value calculated from the ion background by assuming that the ion background follows a Poisson distribution. In contrast, for a more intense beam containing N2+, N3+, and N4+, the SNR is less than its theoretical value because of the appearance of discrete spikes in the mass spectrum caused by deviations in the actual modulation sequence from the ideal one. These spikes can be reduced, however, by decreasing the modulation voltage. Under these optimized conditions, the pseudo-random sequence length is varied to understand how it alters SNR, mass resolution, and scan speed. When the length of the pseudo-random sequence is doubled, the SNR increases by the square root of 2 while the time necessary to record a mass spectrum also doubles. Mass resolution can be varied between 500 and 1200 at m/z = 609 as the sequence length, modulation speed (10 MHz, 25 MHz), and acquisition rate (up to 50 MHz) are changed. Scan speeds of 6000 passes per s can be obtained using a sequence containing 4095 elements modulated at 25 MHz. The capability to tailor the HT-TOFMS to increase the scan speed and resolution with a constant 50% duty cycle makes the technique extremely appealing as a mass analyzer for measuring rapid changes in the composition of an ion stream.

High-risk behaviours in men from Bogotá, Colombia and the spread of HIV

Our objective was to identify sexual behaviours related to risk of HIV infection. A cluster survey of sexually experienced men from diverse sociodemographic settings in Bogotá, Colombia was carried out using a standardized self-administered questionnaire. A high response rate (96%) resulted in the enrollment of 553 men. Most participants 129/442 reported having intercourse with women and 51/111 reported having sex with other men. Most respondents (90%) engaged in high-risk sexual practices; only 2% knew their HIV-1 serostatus. Consistent condom use was reported by 20% of those who practised anal sex, and was even lower (5%) among men who had sex with women during menses. Heterosexuals exhibited a higher degree of risky sexual patterns than homosexual/bisexuals (P=0.01). In conclusion, high-risk sexual practices are prevalent among men in Bogotá, particularly heterosexuals, attesting to the urgent need for effective and specific interventions to prevent HIV transmission.

Bilateral central retinal vein occlusion in Eisenmenger syndrome

PURPOSE

To report a case of bilateral central retinal vein occlusion in a patient with Eisenmenger syndrome.

METHODS

Case report. A 60-year-old woman with Eisenmenger syndrome secondary to a congenital ventricular septal defect presented with a 2-week history of decreased vision in both eyes.

RESULTS

Ophthalmic examination revealed bilateral central retinal vein occlusion. Laboratory findings included hematocrit of 50.3% and pO(2) of 52 mm Hg while on O(2) 5 L/min per nasal cannula, despite having undergone phlebotomy 2 weeks earlier.

CONCLUSION

Chronic hypoxia caused by Eisenmenger syndrome may result in polycythemia with resultant hyperviscosity and bilateral central retinal vein occlusion.

Gas chromatography/mass spectrometry method to quantify blood hydroxycitrate concentration

Hydroxycitrate (HCA), a popular dietary supplement for weight loss, is a competitive inhibitor of ATP-citrate lyase, an extramitochondrial enzyme involved in the initial steps of de novo lipogenesis (DNL). Although animal studies have shown that HCA effectively inhibits DNL and induces weight loss, these findings have not been consistent in humans. This raises the possibility that the bioavailability of HCA may differ among species. We developed a new GC/MS method to measure HCA levels in blood, using [U-(13)C]citrate (CA*) as internal standard to account for losses associated with the isolation, derivatization, and measurement of HCA. HCA and CA* were derivatized with BSTFA + 10% TMCS and analyzed using PCI/GC/MS (CA*, m/z 471; and HCA, m/z 553). The plasma HCA concentration was measured over a 3.5-h period in four subjects having ingested 2 g of HCA. Their plasma HCA concentration ranged from 0.8 to 8.4 microg/ml 30 min and 2 h after ingestion, respectively. These results demonstrate that when taken acutely, HCA is absorbed, yet present in small quantities in human plasma. This simple method requiring minimal sample preparation is able to measure trace amounts of HCA with accuracy and precision.

[Leaf anatomy study in Solanaceae of Venezuela. V. leaf anatomy of eleven species of Cestrum L]

Leaf anatomy of the following eleven species: C. buxifolium Kunth, C. humboldtii Francey, C. lindenii Dunal, C. mariquitense Kunth, C. megalophyllum Dunal, C. olivaceum Francey, C. pariense Steyerm., C petiolare Kunth, C. scandans Vahl, C. strigilatum Ruiz et Pavón and C. tomentosum L.f. is described. Transverse sectioning, bruise and clearing according to the classical methods for optical microscopy were made. The species studied show dissimilitude in relation to a) fohar blade: thickness and sinuosity of epidermal cell walls; type, density and presence of trichornes, leaf type according the position of the stomata, thickness of both palisade and spongy parenchy-ma, number of spongy parenchyma layers, occurrence or not of paranchymatous sheath and sclerifled cells in mesophyll, tmbeculae or projection walls b) Midvein: degree of development and arrangement of the parenchyma and collenchyma, c) Petiole: size and form in transverse section, presence of ornamented cuticle, peridermis and degree of development of the sclerenctiyma next to vascular bundles.

Enhanced interferon-gamma by CD8+ CD28- lymphocytes from HIV+ patients

Flow cytometric analysis of T cells from HIV+ and normal individuals activated for 15 hr showed that the percentage of cells producing interferon-gamma (INFgamma) was enhanced approximately threefold (39 compared to 14%) in the HIV+ CD8+ population. Activation modes, other than anti-CD3 with PMA, were ineffective, and in no case did the percentage of HIV+ CD4+ T cells show increased INFgamma production over controls. Enhanced INFgamma production was not induced by either anti-CD3 or PMA alone, or anti-CD3 or ConA with anti-CD28, or enhanced by N-acetylcysteine. In contrast to INFgamma production, the percentage of CD4+ T cells producing interleukin-2 (Il-2) greatly exceeded that of the CD8+ T cells. The results from flow cytometry analyses of HIV+ CD8+ T cells was supported by quantitative analysis of INFgamma mRNA (by PCR) and INFgamma secretion by ELISA. These methods showed a sixfold and three- to fivefold increase, respectively, on a per cell basis. As HIV infection progresses, as shown by loss of CD4+ T cells, the proportion of CD8+ CD28- T cells increases, and it is this T cell subset that is responsible for 80% or more of the enhanced INFgamma production. The enhanced INFgamma in HIV+ patients derives from two factors: the increase in CD8+ CD28- cells to 70% and the percentage producing INFgamma (60%, compared to 21% for CD8+ CD28+ cells). Our findings of a substantial increase in INFgamma production in HIV infection arising from the increased number of CD8+ CD28- T cells are compatible with clinical studies which show elevated INFgamma in HIV+ serum and INFgamma producing CD8+ T cells dominating HIV+ lymph nodes. We also found a significantly decreased proliferative response of the HIV+-derived CD8+ T cell fraction with coactivator anti-CD-28, in contrast to PMA (with anti-CD3), which is probably a reflection of the diminished population of CD8+ CD28+ T cells in HIV+ donors compared to normal donors (30.7 compared to 67.9%).

Nanoengineered structures for holding and manipulating liposomes and cells

We describe the fabrication of nanoengineered holding pipets with concave seating surfaces and fine pressure control. These pipets were shown to exhibit exceptional stability in capturing, transporting, and releasing single cells and liposomes 1-12 microm in diameter, which opens previously inaccessible avenues of research. Three specific examples demonstrated the utility and versatility of this manipulation system. In the first, carboxyrhodamine was selectively incorporated into individual cells by electroporation, after which nearly all the medium (hundreds of microliters) surrounding the docked and tagged cells was rapidly exchanged (in seconds) and the cells were subsequently probed by laser-induced fluorescence (LIF). In the second study, a single liposome containing carboxyrhodamine was transported to a dye-free solution using a transfer pipet, docked to a holding pipet, and held firmly during physical agitation and interrogation by LIF. In the third study, pairs of liposomes were positioned between two microelectrodes, held in contact, and selectively electrofused and the resulting liposomes undocked intact.

Respiratory syncytial virus infection of gene gun vaccinated mice induces Th2-driven pulmonary eosinophilia even in the absence of sensitisation to the fusion (F) or attachment (G) protein

Complete protection against respiratory syncytial virus (RSV) infection was induced in mice vaccinated on two occasions with 2.5 microg of DNA, encoding the fusion (F) protein of RSV, precipitated onto gold microbeads. In contrast, immunisation with DNA encoding the attachment (G) protein of RSV resulted in a significant reduction in viral load following infection, but did not afford complete protection. Gene gun delivery of DNA-F elicited a T helper-2 (Th2) biased immune response that could not be modulated by the co-delivery of plasmids encoding IL-2, IL-12 or IFNgamma. Similarly gene gun delivery of DNA-G primed a Th2 response. Thus, all gene gun vaccinated mice produced a predominant Th2 biased pulmonary immune response characterised by the production of IL-4 and IL-5 with little IFNgamma following RSV challenge. Analysis of bronchoalveolar lavage (BAL) cells, 5 days post challenge, indicated that there was only a two-fold increase in the number of inflammatory cells in vaccinated compared with control animals. Despite the strong Th2 cytokine bias of lung lymphocytes and the predominant recruitment of CD4(+) T cells, following challenge, there was not a marked pulmonary eosinophilic response (range from 2 to 7% of BAL). In contrast, the BAL from mice vaccinated with control plasmid contained significantly more eosinophils than any other group.

Mutations in herpes simplex virus glycoprotein D distinguish entry of free virus from cell-cell spread

Herpes simplex virus type 1 (HSV-1) glycoprotein D (gD) is an essential component of the entry apparatus that is responsible for viral penetration and subsequent cell-cell spread. To test the hypothesis that gD may serve distinguishable functions in entry of free virus and cell-cell spread, mutants were selected for growth on U(S)11cl19.3 cells, which are resistant to both processes due to the lack of a functional gD receptor, and then tested for their ability to enter as free virus and to spread from cell to cell. Unlike their wild-type parent, HSV-1(F), the variants that emerged from this selection, which were named SP mutants, are all capable of forming macroscopic plaques on the resistant cells. This ability is caused by a marked increase in cell-cell spread without a concomitant increase in efficiency of entry of free virus. gD substitutions that arose within these mutants are sufficient to mediate cell-cell spread in U(S)11cl19.3 cells but are insufficient to overcome the restriction to entry of free virions. These results suggest that mutations in gD (i) are sufficient but not necessary to overcome the block to cell-cell spread exhibited by U(S)11cl19.3 cells and (ii) are insufficient to mediate entry of free virus in the same cells.

The epidemiology and control of leishmaniasis in Andean countries

This paper reviews the current knowledge of leishmaniasis epidemiology in Venezuela, Colombia, Ecuador, Peru, and Bolivia. In all 5 countries leishmaniasis is endemic in both the Andean highlands and the Amazon basin. The sandfly vectors belong to subgenera Helcocyrtomyia, Nyssomiya, Lutzomyia, and Psychodopygus, and the Verrucarum group. Most human infections are caused by Leishmania in the Viannia subgenus. Human Leishmania infections cause cutaneous lesions, with a minority of L. (Viannia) infections leading to mucocutaneous leishmaniasis. Visceral leishmaniasis and diffuse cutaneous leishmaniasis are both rare. In each country a significant proportion of Leishmania transmission is in or around houses, often close to coffee or cacao plantations. Reservoir hosts for domestic transmission cycles are uncertain. The paper first addresses the burden of disease caused by leishmaniasis, focusing on both incidence rates and on the variability in symptoms. Such information should provide a rational basis for prioritizing control resources, and for selecting therapy regimes. Secondly, we describe the variation in transmission ecology, outlining those variables which might affect the prevention strategies. Finally, we look at the current control strategies and review the recent studies on control.

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.

Biobehavioral factors are associated with obesity in Puerto Rican children

The purpose of this case-control study was to identify predictors of obesity among Puerto Rican children from Hartford, CT. The study included 53 prepubertal children, 31 girls and 22 boys, between 7 and 10 y of age. Children were classified as obese [n = 29, body mass index (BMI) >/= 85th percentile] or controls (n = 24, BMI < 85th percentile). Multivariate logistic regression analyses indicated that frequency of fruit juice consumption [odds ratio (OR), 95% confidence interval (CI); 4.02, 1.48-10.95], hours of daily TV viewing (1.86, 1.02-3.42), maternal BMI (1.39, 1.10-1.77) and lower dairy product intake (0.41, 0.19-0.93) were associated with obesity. Television viewing was correlated (P < 0.05) with lower physical activity in girls, and with higher snacking frequency and sweets consumption in boys. Obese children were more likely than controls to have higher systolic and diastolic blood pressures and to have experienced more ear infections and diarrhea during the previous year. Results provide evidence of the multifactorial nature of childhood obesity in this community.

Leishmania (Viannia) guyanensis: a new minicircle class exclusive to this specie isolated from a DNA cosmid library useful for taxonomic purposes

A new minicircle class exclusive to this specie isolated from a DNA cosmid library useful for taxonomic purposes. Experimental Parasitology 94, 143-149. In this paper we describe a new minicircle class exclusive to Leishmania (Viannia) guyanensis. The minicircle class was obtained with the aid of a total DNA cosmid library. The library was screened with an EcoRI fragment isolated from L. (V.) guyanensis (M4147). After screening seven clones were selected which showed strong hybridisation. Clones were digested and hybridised with the same probe. After hybridisation only one clone containing the desired fragment was positive. The fragment sized around 1000 bp was subcloned into pBluescript for sequencing. Sequence analysis using the GCG programme showed no substantial homology with any sequences previously reported, apart from the expected homology with the conserved region of Leishmania kDNA sequences. The probe hybridised strongly only to L. (V.) guyanensis kDNA after medium stringency washing.

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.

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.

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).