The role of mucosal-associated invariant T cells in visceral leishmaniasis

Mucosal-associated invariant T (MAIT) cells are restricted by MR1 and are known to protect against bacterial and viral infections. Our understanding of the role of MAIT cells in parasitic infections, such as visceral leishmaniasis (VL) caused by protozoan parasites of Leishmania donovani, is limited. This study showed that in response to L. infantum, human peripheral blood MAIT cells from children with leishmaniasis produced TNF and IFN-γ in an MR1-dependent manner. The overall frequency of MAIT cells was inversely correlated with alanine aminotransferase levels, a specific marker of liver damage strongly associated with severe hepatic involvement in VL. In addition, there was a positive correlation between total protein levels and the frequency of IL-17A⁺ CD8⁺ MAIT cells, whereby reduced total protein levels are a marker of liver and kidney damage. Furthermore, the frequencies of IFN-γ⁺ and IL-10⁺ MAIT cells were inversely correlated with hemoglobin levels, a marker of severe anemia. In asymptomatic individuals and VL patients after treatment, MAIT cells also produced IL-17A, a cytokine signature associated with resistance to visceral leishmaniasis, suggesting that MAIT cells play important role in protecting against VL. In summary, these results broaden our understanding of MAIT-cell immunity to include protection against parasitic infections, with implications for MAIT-cell-based therapeutics and vaccines. At last, this study paves the way for the investigation of putative MAIT cell antigens that could exist in the context of Leishmania infection.

Incidence of congenital toxoplasmosis among infants born to HIV-coinfected mothers: case series and literature review

INTRODUCTION

There is a paucity of data on the occurrence of congenital toxoplasmosis in children born to mothers dually infected with HIV and Toxoplasma gondii.

OBJECTIVE

To evaluate aspects of the mother-infant pairs associated with vertical transmission of toxoplasmosis in women co-infected with HIV in a referral center for perinatally acquired infections in Belo Horizonte, Brazil.

METHODS

Descriptive study of HIV vertically exposed children, with congenital toxoplasmosis, followed at a referral center (cohort/Belo Horizonte). Prenatal and post-natal variables for the mother-infant pairs were evaluated. A literature review with no filtering for time and language was performed to identify reports of congenital toxoplasmosis in HIV vertically exposed children.

RESULTS

Among 2007 HIV vertically exposed children evaluated in the period from 1998 to 2011, 10 cases of congenital toxoplasmosis were identified (incidence: 0.5%, 95% confidence interval: 0.24-0.91). In searching the literature 22 additional cases in 17 reports were found. Combining the findings of our cohort with other reported cases, 50% (16/32) of congenital toxoplasmosis in HIV vertically exposed children were from Brazil. The cases of congenital toxoplasmosis in HIV vertically exposed children identified in Brazil occurred mainly in the post-Highly Active Antiretroviral Therapy era (p=0.002) and presented a lower death rate (p=0.003) than those from other countries. In the cohort/Belo Horizonte, HIV infection was identified mainly during gestation; T. gondii vertical transmission was observed in pregnant women with CD4(+)>500 cells/mm(3) and latent toxoplasmosis. High rates of ocular lesions (87.5%) and central nervous system involvement (70%) were detected.

CONCLUSIONS

The risk of vertical transmission of T. gondii in HIV-infected women is low and has been usually associated with maternal immunosuppression and elevated viral load. However, our findings of congenital toxoplasmosis in children born to HIV-infected mothers with latent toxoplasmosis and not immunosuppressed emphasize the need for careful follow-up in these cases.

[Notification of healthcare associated infections based on international criteria performed in a reference neonatal progressive care unity in Belo Horizonte, MG]

OBJECTIVE

To describe occurrence of Healthcare Related Infections in a neonatal unit of public reference service in Belo Horizonte-MG, based on international criteria.

METHODS

This is a descriptive study, performed by active searching, in the Progressive Care Unit Neonatal Hospital das Clinicas, Federal University of Minas Gerais (HC / UFMG), from 2008 to 2009. Notification of infections was based on National Healthcare Safety Network (NHSN) criteria. The database and analysis were performed in a internal program.

RESULTS

A total of 325 episodes of infection in newborns were notified and overall incidence density of infections was 22.8/1,000 patient-days, with a rate of 36.7% of newborns. Sepsis was the main infection (62.5%) reported. The incidence density of infections was higher in neonates weighing lower than 750g (42.4/1,000 patient-days). There were 18.15 episodes of central venous catheter related sepsis/1,000 central venous catheter-day and 19.29 umbilical catheter related sepsis /1,000 umbilical catheter-days. Microorganisms were isolated in 122 (37.5%) cases of reported infections, mainly defined as Staphylococcus coagulase negative and Staphylococcus aureus (51 cases). Mortality and lethality rates were 4.3% and 17,12%, respectively.

CONCLUSION

The use of standardized criteria for reporting infections is necessary for the construction of indicators in neonatology, which are scarce in the country and highlight the need for evaluation of national criteria proposed by National Agency of Sanitary Surveillance (ANVISA).

Infecções relacionadas à assistência a saúde baseada em critérios internacionais, realizada em unidade neonatal de cuidados progressivos de referência de Belo Horizonte, MG

OBJETIVO: Descrever a ocorrência de infecções relacionadas à assistência à saúde em uma unidade neonatal de serviço público de referência em Belo Horizonte, MG, baseando-se em critérios internacionais. MÉTODOS: Trata-se de estudo descritivo, realizado por busca ativa, na Unidade Neonatal de Cuidados Progressivos do Hospital das Clínicas da Universidade Federal de Minas Gerais (HC/UFMG), de 2008 a 2009. A notificação de infecções baseou-se nos critérios do National Healthcare Safety Network (NHSN). O banco de dados e análise foi realizado em programa interno do serviço. RESULTADOS: Foram notificados 325 episódios de infecção nos recém-nascidos, com densidade de incidência de 22,8/1.000 pacientes-dia e incidência proporcional geral de infecção de 36,7%. A sepse foi a principal infecção (62,5%) notificada. A densidade de incidência de infecções foi maior em neonatos com peso menor que 750g (42,4/1.000 pacientes-dia). Observou-se 18,15 episódios de Sepse Relacionada a Cateter/1.000 Cateter Venoso Central-dia e 19,29/1.000 episódios de Sepse Relacionada a Cateter Umbilical/1.000 Cateter umbilical-dia. Em 122 (37,5%) casos de infecção notificada houve isolamento de microorganismos, predominando Staphylococcus coagulase negativo e Staphylococcus aureus (51 casos). A mortalidade e letalidade foram 4,3% e 17,12%, respectivamente. CONCLUSÃO: A utilização de critérios padronizados para notificação de infecções é necessária para a construção de indicadores em neonatologia, que são escassos no país e ressaltam a necessidade de avaliação dos critérios nacionais propostos pela Agencia Nacional de Vigilância Sanitária (ANVISA).

Characterization of a methionine-rich protein from the seeds of Cereus jamacaru mill. (Cactaceae)

We describe here the isolation and characterization of a major albumin from the seeds of Cereus jamacaru (Cactaceae), to which we gave the trivial name of cactin. This protein has a molecular mass of 11.3 kDa and is formed by a light chain (3.67 kDa) and a heavy chain (7.63 kDa). This protein was isolated using a combination of gel filtration chromatography and reverse-phase HPLC. The amino acid composition of cactin was determined and found to resemble that of the 2S seed reserve protein from the Brazil nut, a protein remarkable for its high methionine content. The usefulness of cactin as a molecular marker in the taxonomy of the Cactaceae is discussed.

Isolation and characterization of a reserve protein from the seeds of Opuntia ficus-indica (Cactaceae)

We describe here the isolation and characterization of a major albumin from the seeds of Opuntia ficus-indica (Cactaceae). This protein has a molecular mass of 6.5 kDa and was isolated by a combination of gel filtration chromatography and reverse-phase HPLC. The amino acid composition of this protein was determined and it was shown to have similarities with the amino acid composition of several proteins from the 2S albumin storage protein family. The N-terminal amino acid sequence of this protein is Asp-Pro-Tyr-Trp-Glu-Gln-Arg.

Serum vitamin A distribution curve for children aged 2-6 y known to have adequate vitamin A status: a reference population

Serum vitamin A was determined before and 30-45 d after the administration of 60.6 mg (212 mumol) vitamin A to 544 Brazilian children residing in slum areas of Recife. The frequency-distribution curves were compared in a subgroup of children whose vitamin A status was assessed initially by the relative-dose-response (RDR) test. The curves of children with negative (adequate status) and positive (inadequate status) RDR tests were different. The difference disappeared after supplementation. The shape of the distribution curve after supplementation was close to normal with a mean, median, and 95% confidence interval of 1.78 +/- 0.49, 1.68, and 1.02-2.90 mumol/L, respectively. The postsupplementation curve derived from this underprivileged child population may serve as a reference for diagnostic, surveillance, and program-evaluation purposes.

A re-examination of the stability of retinol in blood and serum, and effects of a standardized meal

We examined the stability of retinol in blood and serum samples, kept in the dark, under different handling procedures. Samples not protected from contact with air oxygen were highly unstable, even when kept at ice temperature. Samples collected under anaerobic conditions, with Vacutainer Tubes, or treated with nitrogen after collection to displace the air from the tubes were stable during the usual interval between collection and freezing or analysis in biochemical surveys. Ingestion of a moderate amount of vitamin. A significantly increased serum retinol concentrations in normal volunteers, showing the importance that survey samples be preprandial.

A re-examination of the stability of retinol in blood and serum, and effects of a standardized meal

We examined the stability of retinol in blood and serum samples, kept in the dark, under different handling procedures. Samples not protected from contact with air oxygen were highly unstable, even when kept at ice temperature. Samples collected under anaerobic conditions, with Vacutainer Tubes, or treated with nitrogen after collection to displace the air from the tubes were stable during the usual interval between collection and freezing or analysis in biochemical surveys. Ingestion of a moderate amount of vitamin. A significantly increased serum retinol concentrations in normal volunteers, showing the importance that survey samples be preprandial.

Effect of an infection on vitamin A status of children as measured by the relative dose response (RDR)

The effect of an infective episode of chickenpox on the vitamin A status of preschool-aged children was evaluated by use of the relative dose response (RDR) test. Status was determined before and 30, 120, and 180 d after administration of a single oral high-dosage (200,000 IU) supplement of vitamin A. No differences in mean blood levels of retinol or percentage of children showing a positive RDR were apparent until after the infective episode that occurred approximately 90 d after dosing. At 180 d postsupplementation, 74% of children who had been infected tested positive by the RDR, indicative of an inadequate liver reserve of vitamin A, in contrast to only 10% who had not been infected. Paired RDR observations at 0 and 180 d postsupplementation confirmed that the infective episode caused an accelerated depletion of liver reserves of vitamin A.

The use of anhydrotrypsin-Sepharose for isolation of trypsin inhibitors from Vigna unguiculata seeds

The preparation of anhydrotrypsin-Sepharose 4B for the isolation of trypsin inhibitors by affinity chromatography was described. Soybean trypsin inhibitor and an acetic acid extract of Vigna unguiculata seed meal were used to evaluate the binding of trypsin inhibitors. Both soybean trypsin inhibitor and Vigna trypsin inhibitors were retained at pH 7.6 and desorbed at pH 2.0. The Vigna trypsin inhibitors isolated by the Sepharose-4B anhydrotrypsin did not differ by SDS-polyacrylamide gel electrophoresis and isoelectric focusing from native inhibitors, indicating that partial proteolysis obtained with trypsin affinity columns can be avoided by using anhydrotrypsin, the enzymatically inactive form of the enzyme which retains the capacity to bind inhibitors.