Anatomical landmarks for a proximal paravertebral thoracolumbar block in sheep: Cadaver and in-vivo study.

The objective of this study was to describe the anatomy of the spinal nerves, specifically the last thoracic nerve (T13) and the first to third lumbar nerves (L1 to L3), in order to safely carry out an accurate proximal paravertebral block (PPVB) in sheep. This study consisted of 2 phases. In Phase 1, 7 sheep cadavers were dissected to identify the path and relevant anatomical landmarks of spinal nerves T13 and L1 to L3. In Phase 2, 2 healthy sheep received bilateral injections of 0.35 mL/kg body weight (BW) for each hemithoracolumbar area (0.088 mL/kg BW per nerve) of a dye-lidocaine solution (50:50) using a PPVB approach and then assessed for 15 min for signs of systemic and local effects of lidocaine. After euthanasia, the infiltrated area was dissected to assess the spread of the dye. Successful nerve staining (> 2 cm in length), macroscopic evidence of intraneural/intravascular injection, and spread to the epidural space and the abdominal cavity were recorded. In Phase 1, each branch of all nerves was easily identified and located using the caudal aspect of the spinous apophysis and the lateral edge of the transverse process of the respective vertebrae. An overlap was observed between the costoabdominal (T13), the iliohypogastric (L1), and ilioinguinal (L2) nerves. In Phase 2, all nerves were stained at least 2 cm from the injection site. There was no diffusion of the dye into the epidural space or abdominal cavity. In conclusion, using the anatomical landmarks described specifically for sheep, the PPVB provided accurate perineural distribution of the injected dye-lidocaine solution, which could result in clinical analgesia of the flank.

L'objectif de cette étude était de décrire l'anatomie des nerfs rachidiens, en particulier le dernier nerf thoracique (T13) et les premier à troisième nerfs lombaires (L1 à L3), afin de réaliser en toute sécurité un bloc paravertébral proximal précis (PPVB) chez les moutons. Cette étude comportait deux phases. Dans la phase 1, sept cadavres de moutons ont été disséqués pour identifier le trajet et les repères anatomiques pertinents des nerfs rachidiens T13 et L1 à L3. Dans la phase 2, deux moutons en bonne santé ont reçu des injections bilatérales de 0,35 mL/kg de poids corporel (PC) pour chaque zone hémithoraco-lombaire (0,088 mL/kg de PC par nerf) d'une solution de colorant-lidocaïne (50:50) en utilisant une approche PPVB, puis évalué pendant 15 min pour des signes d'effets systémiques et locaux de la lidocaïne. Après l'euthanasie, la zone infiltrée a été disséquée pour évaluer la propagation du colorant. Une coloration nerveuse réussie (> 2 cm de longueur), une preuve macroscopique d'injection intraneurale/intravasculaire et une propagation à l'espace épidural et à la cavité abdominale ont été enregistrées. Dans la phase 1, chaque branche de tous les nerfs a été facilement identifiée et localisée en utilisant la face caudale de l'apophyse épineuse et le bord latéral de l'apophyse transverse des vertèbres respectives. Un chevauchement a été observé entre les nerfs costo-abdominal (T13), ilio-hypogastrique (L1) et ilio-inguinal (L2). Dans la phase 2, tous les nerfs ont été colorés à au moins 2 cm du site d'injection. Il n'y a pas eu de diffusion du colorant dans l'espace péridural ou la cavité abdominale. En conclusion, en utilisant les repères anatomiques décrits spécifiquement pour les moutons, le PPVB a fourni une distribution périneurale précise de la solution de colorant-lidocaïne injectée, ce qui pourrait entraîner une analgésie clinique du flanc.(Traduit par Docteur Serge Messier).

Immunosuppressive effects of protein derivatives from Mucuna pruriens on a streptozotocin-induced type 1 diabetes murine model.

Type 1 diabetes is an autoimmune disease induced by abnormal insulin secretions from ß-cells in pancreas. The present study aimed to investigate the immunosuppressive effects from protein derivatives of Mucuna pruriens on a murine model of Type 1 diabetes. Hydrolyzate and five peptide fractions with different molecular weight were administered orally by 14 days, followed T1D murine model was built by intraperitoneal injection of streptozotocin over 5 days. The mice weight, blood glucose levels, anti-insulin, and anti-pancreatic islet ß-cells antibodies, pro-inflammatory cytokines as tumor necrosis factor alpha and interleukin-6 were determined in four times (0, 15, 30, and 45 day). Mice were sacrificed and pancreatic tissues samples were obtained and staining with hematoxylin and eosin to determine the degree of damage. The study demonstrated immunosuppressive activity in four of the six treatment groups: (a) T1D PPH, (b) T1D F 5-10 kDa, (c) T1D F 3-5 kDa, and (d) T1D F 1-3 kDa. PRACTICAL APPLICATIONS: Due to the high content of native protein in seeds of Mucuna pruriens, studies have reported potential in the elaboration of hydrolysates and peptides with biological activity. These protein derivatives could help in the treatment of immunological disorders that are observed in several chronic non-communicable disease and inflammatory diseases, such as T1D. Activated macrophages and lymphoplasmacytic infiltrate plays a crucial role in the initiation and maintenance of T1D; therefore, several studies has focused to reduce the effector functions of this cells for diminishing the clinical manifestations in inmmunocompromised patients. Thus, this study indicates the potential application of hydrolyzate and peptide fractions of M. pruriens in functional foods and dietary supplements could be developed for the treatment of inflammatory and chronic non-communicable diseases.

Quantitative and histological assessment of maternal-fetal transmission of Trypanosoma cruzi in guinea pigs: An experimental model of congenital Chagas disease.

OBJECTIVE: We evaluated the effect of Trypanosoma cruzi infection on fertility, gestation outcome, and maternal-fetal transmission in guinea pigs (Cavia porcellus). METHODS: Animals were infected with T. cruzi H4 strain (TcI lineage) before gestation (IBG) or during gestation (IDG). Tissue and sera samples of dams and fetuses were obtained near parturition. RESULTS: All IBG and IDG dams were seropositive by two tests, and exhibited blood parasite load of 1.62±2.2 and 50.1±62 parasites/µl, respectively, by quantitative PCR. Histological evaluation showed muscle fiber degeneration and cellular necrosis in all infected dams. Parasite nests were not detected in infected dams by histology. However, qPCR analysis detected parasites-eq/g heart tissue of 153±104.7 and 169.3±129.4 in IBG and IDG dams, respectively. All fetuses of infected dams were positive for anti-parasite IgG antibodies and tissue parasites by qPCR, but presented a low level of tissue inflammatory infiltrate. Fetuses of IDG (vs. IBG) dams exhibited higher degree of muscle fiber degeneration and cellular necrosis in the heart and skeletal tissues. The placental tissue exhibited no inflammatory lesions and amastigote nests, yet parasites-eq/g of 381.2±34.3 and 79.2±84.9 were detected in IDG and IBG placentas, respectively. Fetal development was compromised, and evidenced by a decline in weight, crow-rump length, and abdominal width in both groups. CONCLUSIONS: T. cruzi TcI has a high capacity of congenital transmission even when it was inoculated at a very low dose before or during gestation. Tissue lesions, parasite load, and fetal under development provide evidence for high virulence of the parasite during pregnancy. Despite finding of high parasite burden by qPCR, placentas were protected from cellular damage. Our studies offer an experimental model to study the efficacy of vaccines and drugs against congenital transmission of T. cruzi. These results also call for T. cruzi screening in pregnant women and adequate follow up of the newborns in endemic areas.

A canine model of experimental infection with Leishmania (L.) mexicana.

BACKGROUND: Cutaneous leishmaniasis is a tropical disease affecting over one million patients annually and Leishmania (L.) mexicana is one of the major etiological agents in the Americas. Here we established the first experimental infection of L. (L.) mexicana in canids. METHODS: Beagle dogs were infected intradermally with culture-derived L. (L.) mexicana. We followed skin ulcer development, histopathological signs, parasite burden and the immune status of the infected dogs. RESULTS: All infected dogs developed uniform oval-craterform ulcers similar to those observed in humans, associated with mixed T helper 1/T helper 2 immune responses. Parasites were detected in the healed lesions 15 weeks post-infection. Higher anti-Leishmania IgG levels correlated with larger lesions and high IgG1/IgG2 ratio was associated with some level of splenomegaly. CONCLUSIONS: The canine model described in this work will be of use for further understanding of L. (L.) mexicana immunopathogenensis, and for drug and vaccine development.