In vitro and in vivo assessment of nanotoxicity of CdS quantum dot/aminopolysaccharide bionanoconjugates.

The nanotoxicity of Cd-containing quantum dots (QDs) for biomedical applications is very controversial and not completely understood. In this study, we evaluated the cytotoxicity of surface-biofunctionalized CdS QDs with chitosan directly synthesized via aqueous route at room temperature. These core-shell CdS-chitosan nanoconjugates showed different degrees of cytotoxic responses using MTT cell proliferation assay toward three human cell cultures, human osteosarcoma cell line (SAOS), non-Hodgkin's B cell lymphoma (Toledo), and human embryonic kidney cell line (HEK293T), under three exposure times (1, 3, and 5days) and three colloidal concentrations (10nM, 50nM, and 100nM). The results clearly demonstrated that the CdS QDs, regardless to the fact that they were coated with a biocompatible aminopolysaccharide shell, induced a severe dose- and time-dependent inhibition of cell viability. In addition, the HEK293T and SAOS cell lines showed much more sensitive response compared to Toledo, which indicated that the cytotoxicity was also cell-type dependent. The exceptional resistance of Toledo cells to toxic effects of CdS nanoconjugates even at severe test conditions was assigned to specific role of B-lineage cells of the immune defense system. Remarkably, no conclusive evidence of toxicity of CdS nanoconjugates was observed in vivo using intravenous injections of CdS nanoconjugates in BALB/c mouse animal models for 30days, but localized fluorescence was detected in ex-vivo liver tissue samples. Therefore, these results prove that there is no guarantee of "risk-free" use of CdS nanoconjugates for in vivo applications, even when functionalized with biopolymer ligands, as they can pose an excessive threat due to unpredicted and uncorrelated responses under in vitro and in vivo biological assays with highly toxic cadmium ions.

Risk factors for human immunodeficiency virus infection among Brazilian blood donors: a multicentre case-control study using audio computer-assisted structured interviews.

BACKGROUND: Although risk factors for HIV infection are known, it is important for blood centres to understand local epidemiology and disease transmission patterns. Current risk factors for HIV infection in blood donors in Brazil were assessed. METHODS: A case-control study was conducted at large public blood centres located in four major cities between April 2009 and March 2011. Cases were persons whose donations were confirmed positive by enzyme immunoassays followed by Western blot confirmation. Audio computer-assisted structured interviews (ACASI) were completed by all cases and controls. Multivariable logistic regression was used to estimate adjusted odds ratios (AORs) and associated 95% confidence intervals (CIs). RESULTS: There were 341 cases, including 47 with recently acquired infection, and 791 controls. Disclosed risk factors for both females and males were sex with an HIV-positive person AOR 11.3, 95% CI (4.1, 31.7) and being an IVDU or sexual partner of an IVDU [AOR 4.65 (1.8, 11.7)]. For female blood donors, additional risk factors were having male sex partners who also are MSM [AOR 13.5 (3.1, 59.8)] and having unprotected sex with multiple sexual partners [AOR 5.19 (2.1, 12.9)]. The primary risk factor for male blood donors was MSM activity [AOR 21.6 (8.8, 52.9)]. Behaviours associated with recently acquired HIV were being a MSM or sex partner of MSM [13.82, (4.7, 40.3)] and IVDU [11.47, (3.0, 43.2)]. CONCLUSION: Risk factors in blood donors parallel those in the general population in Brazil. Identified risk factors suggest that donor compliance with selection procedures at the participating blood centres is inadequate.

Transmission potential, skin inflammatory response, and parasitism of symptomatic and asymptomatic dogs with visceral leishmaniasis.

BACKGROUND: Visceral leishmaniasis in Brazil is caused by the protozoan Leishmania (Leishmania) chagasi and it is transmitted by sandfly of the genus Lutzomyia. Dogs are an important domestic reservoir, and control of the transmission of visceral leishmaniasis (VL) to humans includes the elimination of infected dogs. However, though dogs are considered to be an important element in the transmission cycle of Leishmania, the identification of infected dogs representing an immediate risk for transmission has not been properly evaluated. Since it is not possible to treat infected dogs, they are sacrificed when a diagnosis of VL is established, a measure that is difficult to accomplish in highly endemic areas. In such areas, parameters that allow for easy identification of reservoirs that represents an immediate risk for transmission is of great importance for the control of VL transmission. In this study we aimed to identify clinical parameters, reinforced by pathological parameters that characterize dogs with potential to transmit the parasite to the vector. RESULTS: The major clinical manifestations of visceral leishmaniasis in dogs from an endemic area were onicogriphosis, skin lesions, conjunctivitis, lymphadenopathy, and weight loss. The transmission potential of these dogs was assessed by xenodiagnosis using Lutzomyia longipalpis. Six of nine symptomatic dogs were infective to Lutzomyia longipalpis while none of the five asymptomatic dogs were infective to the sandfly. Leishmania amastigotes were present in the skin of all clinically symptomatic dogs, but absent in asymptomatic dogs. Higher parasite loads were observed in the ear and ungueal region, and lower in abdomen. The inflammatory infiltrate was more intense in the ears and ungueal regions of both symptomatic and asymptomatic dogs. In clinically affected dogs in which few or none Leishmania amastigotes were observed, the inflammatory infiltrate was constituted mainly of lymphocytes and macrophages. When many parasites were present, the infiltrate was also comprised of lymphocytes and macrophages, as well as a larger quantity of polymorphonuclear neutrophils (PMNs). CONCLUSION: Dogs that represent an immediate risk for transmission of Leishmania in endemic areas present clinical manifestations that include onicogriphosis, skin lesions, conjunctivitis, lymphadenopathy, and weight loss. Lymphadenopathy in particular was a positive clinical hallmark since it was closely related to the positive xenodiagnosis.

Geographic diversity of adult t-cell leukemia/lymphoma in Brazil. The Brazilian ATLL Study Group.

We describe 195 cases of adult T-cell leukemia/lymphoma (ATLL) reported to the national registry of T-cell malignancies in Brazil between 1994 and 1998. We compared the effect of demographic differences and clinical features of 150 consecutive ATLL cases in different regions of this diverse country. At diagnosis, the predominant clinical sub-type was the acute type (60%), followed by lymphoma (22%), chronic (10%) and smoldering (8%) types. Although we expected that different sub-types would be present in different regions, on the basis of immunogenetic factors determined by ethnicity, we did not demonstrate these differences. There were no significant differences among ATLL subtypes by age or gender. No ethnic group predominated in the total population of patients, but significant differences were noted when examining ethnic distribution by region. Reflecting the general population distribution, white patients were seen more often in São Paulo and black patients in Bahia, than in other regions. In most regions, cases were equally distributed between blacks and mulattos, except in Pernambuco, where blacks were less frequent. The main clinical features were lymphadenopathy, skin lesions, hypercalcemia and hepatomegaly. Fourteen patients (9%) suffered from HTLV-I-associated myelopathy (HAM/TSP), either at diagnosis or during follow-up of ATLL. All cases but one had antibodies to HTLV-I, with concordant results with ELISA, WB and PCR analyses. For the antibody-negative case, pol and tax gene sequences were present in tumor cells when subjected to PCR analyses. The prognosis was generally poor, suggesting that the disease in Brazil behaves in similar fashion regardless of ethnic or geographical differences.

HTLV-I and HTLV-II infections in hematologic disorder patients, cancer patients, and healthy individuals from Rio de Janeiro, Brazil.

To clarify the seroprevalence of human T-cell lymphotropic virus type I (HTLV-I) among hematologic and cancer patients in the State of Rio de Janeiro, Brazil, we investigated sera from 2430 individuals from the following groups: 152 patients with T-cell diseases, 250 with B-cell disorders, 67 with myeloid leukemia, 41 with Hodgkin's disease, 351 with a history of multiple blood transfusions, 235 patients with solid tumors of different types, and 109 family members of HTLV-I-infected patients. Antibodies to HTLV-I were screened by enzyme-linked immunosorbent assay or particle agglutination assays (or both). Repeatedly reactive samples were tested by Western blot and polymerase chain reaction assay to differentiate HTLV-I from HTLV-II. We found an increased seroprevalence rate of HTLV-I among those with lymphoid malignancies, mainly in T-cell diseases (28.9%), and these results were important in characterizing 44 cases of adult T-cell leukemia/lymphoma. We confirmed the presence of HTLV-I and HTLV-II infections in blood donors (0.4% and 0.1%, respectively), in patients exposed to multiple blood transfusions (10.2% and 0.8%, respectively), and in 30 (27.5%) of 109 family members of HTLV-I- or HTLV-II-infected patients. We also confirmed the high rate occurrence of adult T-cell leukemia/lymphoma among lymphoproliferative disorders in Rio de Janeiro, Brazil.