Improving liveweight gain of lambs infected by multidrug-resistant nematodes using a FECRT-based schedule of treatments.

The aim of this study was to compare the liveweight gain of lambs, infected by multidrug-resistant nematodes, treated by conventional schemes of helminth control or using a schedule based on fecal egg count reduction test (FECRT). The flock was selected after a FECRT (experiment 1) which revealed a parasite population resistant to benzimidazoles, imidazothiazoles, macrocyclic lactones (ivermectin), salicylanilides, nitrophenols, and organophosphates. Despite the parasite resistance to ivermectin (an avermectin), the moxidectin (a milbemycin) was effective against the gastrointestinal nematodes (PR > 90%). In experiment 2, 48 suckling lambs were distributed in four randomized blocks (G1, G2, G3, and G4) by previous body weighings. G1 was kept as untreated control; G2 was treated following a FECRT-based schedule with drugs chosen based on fecal analysis (first drench with moxidectin, second drench with a combination of moxidectin and levamisole, and third drench with praziquantel, an anti-cestode drug); G3 and G4 received three drenches with ivermectin or disophenol, respectively. Body weighings and fecal analysis of these lambs were performed every 2 weeks over a 98-day period. An effective control of gastrointestinal nematodes was obtained with two nematicidal drenches following the FECRT-based schedule of treatments. On the other hand, eggs per gram of feces (EPG) counts were no different among untreated control, G3, and G4. Lambs treated using the FECRT-based schedule had the greatest liveweight gain among the groups tested. Additionally, liveweight gain was no different among the groups G3, G4, and G1. The FECRT-based schedule of anthelmintic treatments was beneficial regarding productivity and sustainability of helminth control in lambs infected by multidrug-resistant nematodes.

Nested-PCR multiplex test with increased sensitivity for detection of allogeneic cells transplanted from male to female mice / Nested-PCR multiplex com aumento da sensibilidade de detecção de células alogênicas transplantadas de camundongos machos para fêmeas

Cell therapy has shown encouraging perspectives for human and veterinary medicine. Experimentally, genetic manipulation allows to mark and locate allogeneic cells. However, this makes their genotype/phenotype different from non-marked cells used clinically. Alternatively, the presence of the Y-chromosome enables male donor cells detection in female organisms. However, the concentration of engrafted cells may be minimal in tissues, due to systemic distribution. In this study, a nested-PCR multiplex test was developed, aiming to increase the sensitivity of the presence/absence diagnosis of male mice adipose-derived (ADSC-Y) and bone marrow mononuclear (BMNC-Y) cells in samples of blood and lungs from females, after endovenous transplantation. Four females received placebos; four females received ADSC-Y from two males; and four females received BMNC-Y from two males. The PCR first-step included two primer sets (multiplex): one for amplification of a Y-chromosome fragment (SRYout; 300bp); the other for amplification of an X-chromosome (DXNds3 gene) fragment. In the PCR second-step, one primer set (SRYinn) was used for amplification of a 110bp fragment, restrained in the SRYout amplification product. The PCR internal control (DXNds3 gene) was detected in all DNA samples, whereas the SRY gene external fragment (300bp) was detected exclusively in ADSC-Y and BMNC-Y pure DNA samples. The SRY gene internal fragment (110bp) was detected in 100% of the blood and lung samples from the ADSC-Y and BMNC-Y female recipients. The nested-PCR technique increased sensitivity and reliability for molecular diagnostic of presence or absence of male mice cells in body fluids and tissues of female recipients after endovenous transplantation.

A terapia celular traz perspectivas encorajadoras à medicina humana e veterinária. Experimentalmente, a manipulação genética permite a marcação e a localização de células alogênicas. Porém, isso torna seu genótipo/fenótipo diferente daquelas usadas clinicamente, sem marcação. Alternativamente, a presença do cromossomo Y possibilita detectar células de doadores machos no organismo de fêmeas. Todavia, a concentração de células transplantadas pode ser mínima em certos tecidos, pela distribuição sistêmica. Neste estudo, foi desenvolvida uma nested-PCR multiplex, visando a aumentar a sensibilidade do diagnóstico de presença/ausência de células derivadas do tecido adiposo (CDTA-Y) e derivadas da fração mononuclear da medula óssea (CFMO-Y) de camundongos machos, em amostras de sangue e de pulmões de camundongos fêmeas, após transplante endovenoso. Quatro fêmeas receberam placebo; quatro fêmeas receberam CDTA-Y de dois machos; e quatro fêmeas receberam CFMO-Y de dois machos. A primeira fase da PCR teve dois pares de primers (multiplex): um para amplificação de fragmento do cromossomo Y (SRYout; 300pb); outro para amplificação de fragmento do cromossomo X (gene DXNds3). Na segunda fase da PCR, foi usado um par de primers para amplificação de fragmento de 110pb (SRYinn) interno ao produto amplificado pelo SRYout. O controle interno da reação (gene DXNds3) foi detectado em todas as amostras de DNA testadas, enquanto que o fragmento externo do gene SRY (300pb) foi detectado apenas nas amostras puras de DNA de CDTA-Y e CFMO-Y. O fragmento interno do gene SRY (110pb) foi detectado no sangue e nos pulmões de 100% das receptoras de CDTA-Y e CFMO-Y. A técnica de nested-PCR aumentou a sensibilidade e a segurança do diagnóstico molecular de presença ou ausência de células de camundongos machos em fluidos e tecidos de receptoras fêmeas após transplante endovenoso.