Decreased expression of surfactant Protein-C and CD74 in alveolar epithelial cells during influenza virus A(H1N1)pdm09 and H3N2 infection.

The primary replication site of Influenza A virus (IAV) is type II alveolar epithelial cells (AECII), which are central to normal lung function and present important immune functions. Surfactant components are synthesized primarily by AECII, which play a crucial role in host defense against infection. The aim of this study was to analyze if the impact of influenza infection is differential between A(H1N1)pdm09 and A/Victoria/3/75 (H3N2) on costimulatory molecules and ProSP-C expression in AECII from BALB/c mice infected and A549 cell line infected with both strains. Pandemic A(H1N1)pdm09 and A/Victoria/3/75 (H3N2) were used to infect BALB/c mice and the A549 cell line. We evaluated the surface expression of co-stimulatory molecules (CD45/CD31/CD74/ProSP-C) in AECII and A549 cell lines. Our results showed a significant decrease in ProSP-C+ CD31- CD45- and CD74+ CD31- CD45- expression in AECII and A549 cell line with the virus strain A(H1N1)pdm09 versus A/Victoria/3/75 (H3N2) and controls (non-infection conditions). Our findings indicate that changes in the expression of ProSP-C in AECII and A549 cell lines in infection conditions could result in dysfunction leading to decreased lung compliance, increased work of breathing and increased susceptibility to injury.

Hepatitis C virus among non-injecting cocaine users (NICUs) in South America: can injectors be a bridge?

AIM: To investigate the factors associated with hepatitis C virus (HCV) infection among non-injecting cocaine users (NICUs) and to compare practices associated with HCV and HIV infection. DESIGN: An intercountry cross-sectional study. Setting Buenos Aires and Montevideo metropolitan areas. PARTICIPANTS: A total of 871 NICUs. MEASUREMENTS: NICUs were interviewed and their blood was drawn and used for HCV, HIV, HBV surface antigen (HbsAg), HB-anticore and Venereal Disease Research Laboratory (VRDL) antibody assays. Bivariate and multivariate logistic regression analyses included comparisons of HCV and HIV mono-infected participants with HCV-HIV seronegatives. FINDINGS: Prevalence rates were 8.8 [95% confidence interval (CI): 6.9-10.8) for HCV and 7.9 (95% CI: 6.1-9.7) for HIV. HCV-infected NICUs were twice as likely as HCV-HIV seronegatives to have shared straws for cocaine snorting or sniffing, even when adjusted for other variables. HCV prevalence rates ranged from 3.6% among NICUs who denied sharing straws and having had an injection drug user (IDU) or an HIV-positive sexual partner to 12.6% among participants who reported ever having shared straws or having had either an IDU- or HIV-positive sexual partner (χ(2) (trend) = 6.56, P = 0.01). CONCLUSIONS: Non-injecting cocaine users from South America are vulnerable to multiple infections and HCV infection appears to occur through the sharing of straws. HCV infection is associated with intimate relationships with IDUs or HIV-seropositive partners, supporting the hypothesis that HCV risk may be due primarily to risk-taking behaviour associated with drugs in this population.

[Prevalence of human immunodeficiency virus (HIV)-Trypanosoma cruzi co-infection and injectable-drugs abuse in a Buenos Aires health center]. / Prevalencia de la coinfección virus de la inmunodeficiencia humana (VIH)-Trypanosoma cruzi e impacto del abuso de drogas inyectables en un centro de salud de la ciudad de buenos aires.

The aim of this study was to evaluate the prevalence of human immunodeficiency virus (HIV)-Trypanosoma cruzi co-infection in a Buenos Aires health center. A retrospective analysis of the clinical charts of 602 HIV-infected patients was performed. Only 51.3% of the patients were evaluated against T. cruzi. The global co-infection prevalence was 4.2%, being more frequent among injectable drug users (IDU) (8.9% vs. 2.6%, < 0.05). The indication of T. cruzi testing should be stressed for HIV-infected patients, especially in those centers where IDU are assisted.

Prevalencia de la coinfección virus de la inmunodeficiencia humana (VIH)- Trypanosoma cruzi e impacto del abuso de drogas inyectables en un centro de salud de la ciudad de Buenos Aires / Prevalence of human immunodeficiency virus (HIV)- Trypanosoma cruzi co-infection and injectable-drugs abuse in a Buenos Aires health center

Se evaluó la prevalencia de coinfección virus de la inmunodeficiencia humana (VIH)- Trypanosoma cruzi ( T. cruzi) en pacientes atendidos en un centro asistencial de Buenos Aires, Argentina. Se realizó un análisis retrospectivo de las historias clínicas de 602 individuos VIH positivos. Sólo en el 51,3% de estos pacientes se había investigado la presencia de T. cruzi. La prevalencia global de coinfección fue del 4,2%, siendo más elevada en usuarios de drogas inyectables (UDI) (8,9% vs. 2,6%, p<0,05). Sobre la base de estos resultados, concluimos que debería enfatizarse el cumplimiento de la indicación de diagnóstico para la enfermedad de Chagas en pacientes VIH positivos, especialmente en UDI.

The aim of this study was to evaluate the prevalence of human immunodeficiency virus (HIV)- Trypanosoma cruzi co-infection in a Buenos Aires health center. A retrospective analysis of the clinical charts of 602 HIV-infected patients was performed. Only 51.3% of the patients were evaluated against T. cruzi. The global co-infection prevalence was 4.2%, being more frequent among injectable drug users (IDU) (8.9% vs. 2.6%, p<0.05). The indication of T. cruzi testing should be stressed for HIV-infected patients, especially in those centers where IDU are assisted.

Two immunomodulators, curcumin and sulfasalazine, enhance IDV antiretroviral activity in HIV-1 persistently infected cells.

Since the appearance of resistance to antiretroviral treatment is unavoidable, the host cell's transcription factor NF-kappaB is a novel HIV target. The goal of this study was to characterize the effect of two immunomodulators, curcumin (Cur) and sulfasalazine (Sul), with a protease inhibitor, indinavir (IDV), on HIV-1 persistently infected CD4+ T-cells. Viral p24 antigen production, viral infectivity (tested on MAGI cells) and viral relative infectivity (viral infectivity/p24) were analysed. When used alone, both immunomodulators were able to reduce viral infectivity. When in combination, both 10 microM IDV plus 10 microM Cur and 10 microM IDV plus 250 microM Sul showed a significant reduction in viral infectivity and viral relative infectivity when compared to the reduction produced by IDV alone. Thus, the use of immunomodulators with IDV could help to reduce HIV-1 production in persistently infected cells.

High prevalence of syphilis-HIV co-infection at four hospitals of the city of Buenos Aires, Argentina.

A cross-sectional anonymous study of 261 STD (sexually transmitted diseases) outpatients and 288 outpatients from other hospital departments was conducted at four major city hospitals in Buenos Aires. High prevalence of human immunodeficiency virus (HIV) (14.5%) and syphilis (30.2%) was noted. Fifty-two persons were diagnosed with both HIV and syphilis. Of the 87 HIV cases observed, 52 (59.7%) were co-infected with syphilis. Stratified analysis by gender showed that the prevalence of HIV, syphilis and HIV/syphilis co-infection was significantly (p < 0.001) higher in men than women (HIV: 20.1% vs. 4.6%; syphilis: 39.3% vs. 17.4%; co-infection: 13.6% vs. 1.7%). Integrated HIV/STD intervention programs and more effective surveillance are required in Argentina.

Insulin-like growth factor I improves intestinal barrier function in cirrhotic rats.

BACKGROUND AND AIMS: In liver cirrhosis, disruption of the intestinal barrier facilitates bacterial translocation and spontaneous bacterial peritonitis. Insulin-like growth factor I (IGF-I) is an anabolic hormone synthesised by hepatocytes that displays hepatoprotective activities and trophic effects on the intestine. The aim of this study was to investigate the effect of IGF-I on intestinal barrier function in cirrhotic rats. METHODS: In rats with carbon tetrachloride induced cirrhosis, we investigated the effect of IGF-I therapy on: (a) portal pressure; (b) intestinal histology and permeability to endotoxin and bacteria; (c) intestinal expression of cyclooxygenase 2 (COX-2) and tumour necrosis factor alpha (TNF-alpha), two factors that influence in a positive and negative manner, respectively, the integrity of the intestinal barrier; (d) intestinal permeability to 3H-mannitol in rats with bile duct ligation (BDL); and (e) transepithelial electrical resistance (TER) of polarised monolayers of rat small intestine epithelial cells. RESULTS: IGF-I therapy reduced liver collagen expression and portal pressure in cirrhotic rats, induced improvement in intestinal histology, and caused a reduction in bacterial translocation and endotoxaemia. These changes were associated with diminished TNF-alpha expression and elevated COX-2 levels in the intestine. IGF-I reduced intestinal permeability in BDL rats and enhanced barrier function of the monolayers of epithelial intestinal cells where lipopolysaccharide (LPS) caused a decrease in TER that was reversed by IGF-I. This effect of IGF-I was associated with upregulation of COX-2 in LPS treated enterocytes. CONCLUSIONS: IGF-I enhances intestinal barrier function and reduces endotoxaemia and bacterial translocation in cirrhotic rats. IGF-I therapy might be useful in the prevention of spontaneous bacterial peritonitis in liver cirrhosis.

Viral reactivation and pseudotype production in an in vitro superinfection system with two different strains of HIV-1.

Viral production and variability of HIV-1 is normally high in vivo causing the necessary conditions for cellular superinfection. In order to evaluate the superinfection dynamics in vitro, H9HTLVIIIB cell line was superinfected with HIVMN. Superinfected cells showed nearly 50% cell mortality at day 1 post-superinfection (ps), which increased significantly up to day 4 ps. Superinfecting genome was detectable until day 10 ps. The superinfecting strain was found in the supernatant only on day 1 ps, but was recovered up to day 4 ps by coculture with non-infected cells. The existing strain (HIVHXB2) was recovered throughout the studied period. Pseudotype formation by the HIVHXB2 genome and envelope proteins of the superinfecting strain (HIVMN) was observed from day 1 to 6 ps. Viral production was increased by 1.7 LOG in superinfected cells from day 1 ps. Both viral production increase and pseudotype formation could be relevant for HIV pathogenesis in vivo.

Oxytocin and prostaglandins F2alpha and E2 do not enhance HIV antigen production in vitro.

Oxytocin and prostaglandins (PGs) are hormones involved in labor and are used clinically for its induction. In this study the effect of oxytocin, PGF(2alpha), and PGE(2) on Humour immunodeficiency virus-1 production in acutely and persistently infected cells was measured. No significant effect on p24 antigen production was found with oxytocin or PGs, except for a transient decrease in persistently infected cells treated with 1 micro M PGF(2alpha). These results showed that oxytocin and PGs could be used clinically for labor induction without any direct enhancement in viral production. Besides, the results with PGF(2alpha) at the highest concentration studied may indicate a pharmacological effect.

[HIV-1 virus transmission through maternal milk]. / Transmisión del HIV-1 a través de la leche materna.

Human immunodeficiency virus type 1 (HIV-1) may be vertically transmitted during the pre, peri or postpartum period. Postnatal transmission as well as an increased risk of vertical transmission with breastfeeding has been shown for HIV-1 in several reports. Breastfeeding was here analyzed as a risk of HIV-1 transmission in a group of infants born to HIV-1 infected mothers. Among the 215 children studied in our population a significant difference was detected between those who were breastfed vs those who were bottle fed and finally became infected (p < 0.000000, R.R. = 4.29). We also report the case of a postnatal infection in a baby born to an HIV-1 seropositive father and a seronegative mother. Due to the risk of infection of the mother she had been thoroughly controlled when pregnant and after delivery. Mother and child were negative when retested at delivery, and at 10 months post-partum. At the age of 32 months the child attended the outpatient clinic with generalized lymphadenopathy and right parotitis. HIV-1 infection was then confirmed in both mother and child. At that time it was discovered that the baby had been breastfed up to the age of 24 months. This is the first reported child in Argentina whose infection may undoubtedly be attributed to breastfeeding.

Human immunodeficiency virus bDNA assay for pediatric cases.

Techniques to quantify plasma HIV-1 RNA viral load (VL) are commercially available, and they are adequate for monitoring adults infected by HIV and treated with antiretroviral drugs. Little experience on HIV VL has been reported in pediatric cases. In Argentina, the evaluation of several assays for VL in pediatrics are now being considered. To evaluate the pediatric protocol for bDNA assay in HIV-infected children, 25 samples from HIV-infected children (according to CDC criteria for pediatric AIDS) were analyzed by using Quantiplex HIV RNA 2.0 Assay (Chiron Corporation) following the manufacturer's recommendations in a protocol that uses 50 microliters of patient's plasma (sensitivity: 10,000 copies/ml). When HIV-RNA was not detected, samples were run with the 1 ml standard bDNA protocol (sensitivity: 500 HIV-RNA c/ml). Nine samples belonged to infants under 12 months of age (group A) and 16 were over 12 months (group B). All infants under one year of age had high HIV-RNA copies in plasma. VL ranged from 30,800 to 2,560,000 RNA copies/ml (median = 362,000 c/ml) for group A and < 10,000 to 554,600 c/ml (median = < 10,000) for group B. Only 25% of children in group B had detectable HIV-RNA. By using the standard test of quantification, none of the patients had non detectable HIV-RNA, ranging between 950 and 226,200 c/ml for group B (median = 23,300 RNA c/ml). The suggested pediatric protocol could be useful in children under 12 months of age, but 1 ml standard protocol must be used for older children. Samples with undetectable results from children under one year of age should be repeated using the standard protocol.

Troublesome diagnosis in two children born to HIV-1 infected mothers.

In order to assess early HIV infection vertically transmitted in children it is necessary to use techniques that directly detect HIV. Positive results were found in some rare cases who later seemed to have cleared the infection. We communicate two cases of children with troublesome diagnosis. Two girls born to HIV-1 infected mothers were followed-up since birth up to 40 months old, with viral culture, polymerase chain reaction (PCR), p24 antigen detection and serologic techniques. PCRs were positive in three opportunities at 2, 8 and 30 months of age in the first child and confirmatory tests for specific antibodies remained indeterminate up to the age of 34 months. Positive viral DNAs were detected in two opportunities in the second child at 2 and 4 months of age. Western Blots were negative since 25 months. No virus was recovered nor was p24 antigen detected during the whole period of study in either child. Sequestration of the virus in lymphatic tissue, low replicative ability of the virus and/or immunological tolerance can be postulated in the first case. In patient 2, it could be hypothesized that infection, if any, had cleared up.

[Evaluation of indirect immunofluorescence as a supplementary test for the diagnosis of HIV-1 infection]. / Evaluación de la inmunofluorescencia indirecta como prueba suplementaria para el diagnóstico de la infección por HIV-1.

In order to be used as an alternative or complementary test to confirm HIV-1 infection, the efficiency of indirect immunofluorescence assay (IFA) was compared with Western blot (WB) in 362 samples from persons with high and low risk behaviour. A panel of sera with 220 WB positive, 122 WB negative and 20 WB indeterminate sera were tested by an "in house" IFA. The sensitivity of IFA was found to be 98.63% and the specificity 98.36%. Therefore, IFA appeared to be an efficient alternative method to WB, since the cost of testing by IFA is less than 10% of WB testing. We observed a direct relationship between WB protein reactivity and IFA results. In 15 samples with coincident indeterminate results for WB and IFA, antibody reactivity to p24 and gp160 presented the highest frequency. On the other hand, antibodies to viral glycoproteins were always present in IFA weak positive samples, showing their high predictive value.

Troublesome diagnosis in two children born to HIV-1 infected mothers

Para determinar la infección vertical por HIV-1 en niños en forma temprana es necesario el uso de técnicas de diagnóstico virológico directo tales como la detección del ADN proviral por la reacción en cadena de la polimerasa (PCR), el aislamiento viral por cocultivo y la detección de antígeno p24 en plasma. Con el uso de estos métodos se describieron casos con resultados positivos en niños que finalmente resultaron no estar infectados. En este trabajo se describen dos casos de niñas hijas de madres HIV-1 positivas que presentaron dificultad para su diagnóstico. Se realizó el seguimiento clínico y de laboratorio de las dos pacientes hasta los 40 meses de edad. Las dos pacientes presentaron un desarrollo pondoestatural y madurativo normal, sin síntomas de enfermedad relacionados con el HIV. En ambas pacientes se encontró, como único hallazgo, la detección del genoma proviral por PCR en más de una muestra. Sin embargo la pérdida de anticuerpos específicos en pacientes con función inmune normal, clínicamente sanas, descartaría la infección por HIV-1. Cabría plantearse la infección con una variante defectuosa, una infección silente o la expresión de tolerancia inmunológica. Además podría plantearse como hipótesis el clearence viral

Evaluación de la inmunofluorescencia indirecta como prueba suplementaria para el diagnóstico de la infección por HIV-1 / Evaluation of indirect inmunofluorescence as a confirmatory test for the diagnosis of HIV-1 infection

Se comparó la eficiencia diagnóstica de la inmunofluorescencia indirecta (IFI) como método confirmatorio de la infección por HIV-1 en muestras de suero de 362 personas con conductas de alto y bajo riesgo. El panel compuesto por 220 positivos, 122 negativos y 20 indeterminados por Western blot (WB) fue ensayado por una técnica de IFI desarrollada en nuestro laboratorio. La sensibilidad calculada fue 98,63 por ciento y la espicificidad 98,36 por ciento, indicando que la IFI es un método alternativo para la confirmación de la presencia de anticuerpos contra el HIV-1. Dado que su costo es menor que el 10 por ciento comparado con el del WB, se justifica su introducción en el algoritmo de diagnóstico serológico de HIV-1. Se observó también una relación directa entre la reactividad de las proteínas del WB y los resultados de IFI. En 15 muestras con resultado indeterminado por WB e inespecífico por IFI, las bandas más observadas fueron la p24 seguida de la gp160; por otro lado los anticuerpos contra las glicoproteínas virales son los que presentan mayor frecuencia en las muestras positivas débiles, demostrando su alto valor predictivo

Different integrated and unintegrated HIV-1 DNA after superinfection and cell to cell transmission.

Efficient superinfection of H9HTLVIIIB cell line (persistently infected with HIVHXB2 strain) with HIVMN strain is reported. The superinfecting viral DNA was found in the chromosomic and extrachromosomic fractions at early stages, but at 48 hours post superinfection, it remained mainly unintegrated. Interestingly, superinfected cells only produced HIVHXB2 in the supernatant and no increase of viral yield of this persistent virus was observed. Remarkably, virions of both strains. HIVHXB2 and HIVMN, were recovered after cocultivating superinfected cells with MT2 cell line. In the extrachromosomic fractions of seven different superinfected subclons of H9HTLVIIIB, viral DNA of the superinfecting HIVMN strain predominated while in the chromosomic fraction, the proportion of superinfecting viral DNA differed. The study of the presence of different integrated and unintegrated genomes in a single cell could be crucial in the understanding of HIV biology.

Different integrated and unintegrated HIV-1 DNA after superinfection and cell to cell transmission

Efficient superinfection of H9HTLVIIIB cell line (persistently infected with HIVHXB2 strain) with HIVMN strain is reported. The superinfecting viral DNA was found in the chromosomic and extrachromosomic fractions at early stages, but at 48 hours post superinfection, it remained mainly unintegrated. Interestingly, superinfected cells only produced HIVHXB2 in the supernatant and no increase of viral yield of this persistent virus was observed. Remarkably, virions of both strains, HIVHXB2 and HIVMN, were recovered after cocultivating superinfected cells with MT2 cell line. In the extrachromosomic fractions of seven different superinfected subclons of H9HTLVIIIB, viral DNA of the superinfecting HIVMN strain predominated while in the chromosomic fraction, the proportion of superinfecting viral DNA differed. The study of the presence of different integrated and unintegrated genomes in a single cell could be crucial in the understanding of HIV biology.

Diagnosis of perinatally acquired HIV-1 infection using an IgA ELISA test.

The clinical utility of the detection of anti-HIV-1 IgA antibodies using a modified commercial ELISA (EIA) test for the early diagnosis of perinatally acquired HIV-1 infection was evaluated. One hundred and seventeen sera were obtained from 86 infants born to HIV-1-infected mothers and tested for HIV IgA antibodies by an ELISA test (third generation) after removal of IgG with recombinant protein G. Infants were classified according to the Center for Disease Control and Prevention's (CDC) classification system after 15 months of age; 46 were classified as HIV-infected children and 40 as uninfected. HIV-IgA antibodies were detected in 53 of 64 serum samples from all infected children. No significant differences were observed in IgA detection among symptomatic or asymptomatic infected children. However, when analyzed by age a significant difference was observed in IgA detection when children who were over 6 months of age were compared with the younger group (Fisher exact test, p = 0.0000053). All 53 samples from 40 noninfected children were IgA-negative. Statistical analysis was assessed comparing IgA results with HIV infection status as the gold standard. Sensitivity (95%) and specificity (100%), positive predictive value (100%), and negative predictive value (94%) of IgA antibody determination were analyzed taking into account only one sample per child and only children older than 6 months. Positive likelihood ratio was 95.9% and negative likelihood ratio was 94%. Test efficiency was 97%. The detection of IgA HIV antibodies using EIA is an effective method for early diagnosis of HIV-infected infants in comparison with conventional IgG HIV antibody tests. It is a simple and inexpensive method that could be used in both developed and developing countries.