Socio-epidemiological characterisation of blood donors with asymptomatic Leishmania infantum infection from three Brazilian endemic regions and analysis of the transfusional transmission risk of visceral leishmaniasis.

OBJECTIVES: This study assessed the prevalence of visceral leishmaniasis in blood donors from three endemic regions in Brazil and evaluated the risk of transmission by transfusion. BACKGROUND: Despite strong evidence of the transmission of visceral leishmaniasis through blood transfusion, the real risk, an essential condition for taking effective measures to control this serious disease, has not been determined. METHODS: A multicentre study was performed in highly endemic areas. Candidates eligible for their first blood donation underwent a socio-epidemiological interview, and blood samples were collected for enzyme-linked immunosorbent assay (ELISA) analysis, Western blot and polymerase chain reaction (PCR). Patients transfused with red blood cells or random platelet concentrates collected from these donors were also studied. The results were analysed using descriptive statistics and prevalence estimates, with significance defined as p-values <0·05. RESULTS: Of the 608 eligible donors, 37 (6·1%) were positive for visceral leishmaniasis as per ELISA. The socio-epidemiological analysis showed a significantly higher prevalence in non-Caucasians (p = 0·008). Among 296 patients who received blood components from these donors, the pre-transfusion seropositivity was 7·7%, and 13 patients received blood positive for Leishmania infantum. Six patients were followed up for 90 days, of which two (33·3%) had serological conversion at 60 days. CONCLUSIONS: The results confirm the high prevalence of L. infantum seropositivity among donors in the three regions; the seroconversion in a short period of time in two of six patients suggests the possibility of transmission of the infection by transfusion.

Physical and electrocardiographic evaluation of horses used for wagon traction / Avaliação física e eletrocardiográfica de cavalos utilizados para tração de carroças

The objective of this research was to evaluate the electrocardiogram (ECG) of horses used for wagon traction and to compare the results with the parameters obtained from inactive horses or horses submitted to a training routine. Fifty-six 3-15-year-old healthy horses (22 females and 34 males) were divided into three groups: control (without a work routine; N=21), wagon traction (N=25) and athlete (N=10) and submitted to physical examination and ECG (at rest). The rhythm, heart rate (HR), amplitude and duration of ECG waveforms and intervals were obtained from the frontal plane and base-apex leads. Heart score (HS) was calculated using the arithmetic mean of QRS duration in LI, LII and LIII. Measurements of ECG waves were smaller in control group, in comparison with wagon traction and athlete groups, suggesting that exercise can change ECG. Similar results were observed in the wagon traction and athlete groups, but the electrophysiological adjustments to exercise were not the same for these groups.(AU)

O objetivo deste trabalho foi avaliar o eletrocardiograma (ECG) de cavalos que tracionavam carroças (carroceiros; N=25), comparando os resultados com os parâmetros de cavalos que não realizavam essa atividade (controles; N=21), ou que apresentavam uma rotina de treinamento (atletas; N=10). O ECG foi precedido pelo exame físico do animal e, a partir das derivações no plano frontal e na base-ápice, determinou-se o ritmo, a frequência cardíaca, a amplitude e a duração das ondas e dos intervalos, em repouso. O escore cardíaco foi calculado pela média aritmética da duração do complexo QRS em DI, DII e DIII. O grupo controle apresentou menores valores de amplitude e duração das ondas do ECG, em comparação aos grupos carroceiro e atleta, sugerindo que o exercício pode alterar o ECG. Resultados semelhantes foram observados nos grupos carroceiro e atleta; contudo, os ajustes eletrofisiológicos ao exercício não foram os mesmos para esses dois grupos.(AU)

Aspects of the Macroscopic Testicular and Epididymal Morphology in the Greater Rhea, Rhea Americana (Linneaus - 1758) Birds.

The purpose of this research was to study the macroscopic testicular and epididymal morphology of the greater rhea. The testicles of 54 greater rhea bred in captivity were utilized. The samples were collected November 2005 (n = 14), December 2006 (n = 20) and May 2007 (n = 20). During commercial slaughter, the testicles and epididymides were collected and their following morphometric parameters were immediately measured: length, width, thickness, circumference, volume, weight of the parenchyma and the tunica albuginea, also aspects such as shape, cavity implantation, relationship with other organs and vascularization. The testicles presented cylindrical shape, with a thin, dense and transparent tunica albuginea, and the vascularization was accomplished by the testicular artery that ramifies from the cranial rectal artery. In the samples from December 2006 and May 2007, the media from the macroscopic measures of the right testicles were volume 58.7 and 14.7 ml, length 9.87 and 3.5 cm, width 2.4 and 0.6 cm, thickness 2.4 and 0.5 cm, circumference 8.0 and 2.3 cm, parenchyma weight 27.6 and 6.1 g and tunica albuginea weight 1.0 and 0.3 g, P < 0.05, respectively. The epididymides, the media from macroscopic measures December 2006 and May 2007 were volume 7.7 and 3.0 ml, length 5.8 and 1.3 cm, width 0.7 and 0.3 cm, thickness 0.6 and 0.3 cm, circumference 2.5 and 1.2 cm, tissue weight 6.4 and 2.8 g and capsule weight 0.4 and 0.1 g, P < 0.05, respectively. Some measures from the right testicle and epididymis were superior to measures taken from the left ones (P < 0.05), but these were not characterizing asymmetry. The morphometric parameters observed during November 2005 remained on an intermediate situation (P < 0.05); however, they were quantitatively closer to the means of December 2006, which may characterize it as a potential transition period between repose and sexual activity. Morphologically, the testicles and epididymides of greater rhea have common points with other researched birds; however, differences were observed. The testicles and epididymides of the Rhea americana are influenced by the environment, presenting reproductive activity season (November-December) during late spring, early summer and sexual repose season (May) during autumn-winter. The morphometric testicular and epididymal measurements were introduced. The morphometric parameters of testicles and epididymides exhibited differences between winter and spring-summer that could be established like sexual activity season.

Mixed inflammatory/regulatory cytokine profile marked by simultaneous raise of interferon-gamma and interleukin-10 and low frequency of tumour necrosis factor-alpha(+) monocytes are hallmarks of active human visceral Leishmaniasis due to Leishmania chagasi infection.

Considering the complexity of the immunological events triggered during active visceral Leishmaniasis (VL), the relevance of the segregation of the immune response during human VL into type 1 and type 2 still remains unclear. For this purpose, in individuals living in risk areas for VL, we have evaluated especially asymptomatic individuals and patients with active VL, the plasmatic levels of cytokines and reactive nitrogen species under ex vivo conditions. In addition, we have also performed an analysis of intracellular cytokine patterns of circulating leucocytes after short-term culture, particularly in the absence of antigenic-specific stimulation, in order to reflect dynamic events of immune response in vivo during Leishmania chagasi infection. Although asymptomatic individuals and non-infected subjects presented a similar immunological profile, an outstanding inflammatory/regulatory profile, based on higher plasmatic levels of cytokines such as interleukin (IL)-8, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, IL-6 and IL-10, was associated with clinical status observed in active VL. In this context, we hypothesize that IL-10, through its ability to inhibit anti-leishmanial macrophage activation, associated with the lower frequency of TNF-alpha(+) monocytes and ordinary levels of nitrite and nitrate are the major mechanisms associated with disease onset.

Immune response in human visceral leishmaniasis: analysis of the correlation between innate immunity cytokine profile and disease outcome.

We investigated the cytokine profile of cells of the innate immune response and its association with active (ACT), asymptomatic (AS) and cured (CUR) human visceral leishmaniasis (VL), as well as noninfected (NI) subjects. The frequency of cytokine-producing cells was determined after short-term in vitro incubation of whole peripheral blood samples with soluble Leishmania antigen (SLA). Our data demonstrated a predominant type 2 cytokine profile in NI and ACT. In NI, we observed an increase of IL-4+ neutrophils, IL-10+ eosinophils besides a decrease of tumour necrosis factor (TNF)-alpha+ eosinophils/monocytes. Yet in ACT, we observed an increase of IL-4+ neutrophils and natural killer (NK) cells and IL-10+ monocytes, a reduced frequency of IL-12+ and IFN-gamma+ eosinophils and lower levels of TNF-alpha+ and IL-12+ monocytes. AS presented a mixed profile, characterized by an increase of IFN-gamma+ neutrophils/eosinophils and NK cells, of IL-12+ eosinophils/monocytes, as well as increase of IL-4+ neutrophils and NK cells and IL-10+ eosinophils/monocytes. In contrast, CUR was characterized by a type 1 response with an increase of IFN-gamma+ neutrophils/eosinophils and NK cells, associated with an increase in IL-12+ monocytes. In conclusion, we show a correlation between innate immune cytokine patterns and clinical status of VL, suggesting that these cells, in addition to other factors, may contribute to the cytokine microenvironment in which Leishmania-specific T cells are primed and to disease outcome.

Congelamento de sêmen e inseminação artificial em cães, revisão / Semen freezing and artificial insemination in dogs, review

Foram utilizados para esta revisão trabalhos que estudassem o congelamento do sêmen canino. Os resultados na maioria das pesquisas constataram que o sêmen canino é de baixa qualidade. Publicações relatam obtenção de melhores resultados utilizando o tris-frutose-ácido cítrico como diluidor, glicerol como crioprotetor, método de congelamento lento e descongelamento em água a 37º C.

Phase 2 trial of WR6026, an orally administered 8-aminoquinoline, in the treatment of visceral leishmaniasis caused by Leishmania chagasi.

There are no recognized orally administered treatments for any of the leishmaniases. The 8-aminoquinoline WR6026 is an orally administered analog of primaquine that cured 50% of patients with kala-azar in Kenya at a dose of 1 mg/kg/day for 28 days. A further phase 2, open-label, dose-escalating safety and efficacy study was performed for kala-azar in Brazil. Cure rates for Brazilian patients treated for 28 days were as follows: 1 mg/kg/day: 0 of 4 (0%); 1.5 mg/kg/day: 1 of 6 (17%); 2.0 mg/kg/day: 4 of 6 (67%); 2.5 mg/kg/day: 1 of 5 (20%); and 3.25 mg/kg/day: 0 of 1 (0%). Nephrotoxicity that was not anticipated from preclinical animal studies or from phase 1 studies was seen at 2.5 mg/kg/day in 2 patients and in the single patient administered 3.25 mg/kg/day. WR6026 demonstrated the unusual clinical features of lack of increased efficacy against Brazilian kala-azar with increased dosing above 2 mg/kg/day and toxicity that was not present in previous investigations.