Biomechanical Effects of Angiotensin 1-7 in Diabetes Rats Femur / Efectos Biomecánicos de la Angiotensina 1-7 en el Fémur de Ratas Diabéticas

SUMMARY: It is known that diabetes mellitus has late complications, including microvascular and macrovascular diseases. Diabetes can affect bones through biochemical markers of bone structure, density, and turnover. This study aimed to biomechanically investigate the bone-protective effects of angiotensin 1-7 (Ang 1-7), one of the active peptides in the renin-angiotensin system, in rats with diabetes. Thirty male Wistar albino rats, three months old and weighing 250-300 g, were divided into four groups: diabetes, Ang 1- 7, diabetes plus Ang 1-7, and control. One month later, diabetes developed in rats; the rats were sacrificed, and their right femur was removed. Three-point bending biomechanical tests were performed on the femurs. The diabetic group had significantly higher bone fragility than the other groups (Pr >.05). Bone fragility was lower, and bone flexibility was higher in the Ang 1-7 groups (Pr>F value 0.05). As a result of our study, the effect of Ang 1-7 on the bones of rats with diabetes was investigated biomechanically. Ang 1-7 has a protective impact on the bones of rats with diabetes.

Se sabe que la diabetes mellitus tiene complicaciones tardías, incluyendo enfermedades microvasculares y macrovasculares. La diabetes puede afectar los huesos a través de los marcadores bioquímicos de la estructura, la densidad y el recambio óseo. Este estudio tuvo como objetivo investigar biomecánicamente los efectos protectores en los huesos de la angiotensina 1-7 (Ang 1-7), uno de los péptidos activos en el sistema renina-angiotensina, en ratas con diabetes. Treinta ratas albinas Wistar macho, de tres meses de edad y con un peso de 250-300 g, se dividieron en cuatro grupos: diabetes, Ang 1-7, diabetes más Ang 1-7 y control. Un mes después, se desarrolló diabetes en ratas; se sacrificaron los animales y se extrajo su fémur derecho. Se realizaron pruebas biomecánicas de flexión de tres puntos en los fémures. El grupo diabéticos tenía una fragilidad ósea significativamente mayor que los otros grupos (Pr > 0,05). La fragilidad ósea fue menor y la flexibilidad ósea fue mayor en los grupos Ang 1-7 (valor Pr>F 0,05). Como resultado de nuestro estudio, se determinó biomecánicamente el efecto de Ang 1-7 en los huesos de ratas con diabetes. Se concluye que Ang 1-7 tiene un impacto protector en los huesos de ratas diabéticas.

Evaluating the ototoxicity of an anti-MRSA peptide KR-12-a2 / Avaliando a ototoxicidade de um peptídeo anti-MRSA KR-12-a2

Abstract Introduction Methicillin-resistant staphylococcus aureus is an emerging problem for the treatment of chronic suppurative otitis media, and also for pediatric tympanostomy tube otorrhea. To date, there are no effective topical antibiotic drugs to treat methicillin-resistant staphylococcus aureus otorrhea. Objective In this study, we evaluated the ototoxicity of topical KR-12-a2 solution on the cochlea when it is applied topically in the middle ear of guinea pigs. Methods The antimicrobial activity of KR-12-a2 against methicillin-resistant staphylococcus aureus strains was examined by using the inhibition zone test. Topical application of KR-12-a2 solution, gentamicin and phosphate buffered saline were applied in the middle ear of the guinea pigs after inserting ventilation tubes. Ototoxicity was assessed by auditory brainstem evoked response and scanning electron microscope examination. Results KR-12-a2 produced an inhibition zone against methicillin-resistant staphylococcus aureus from 6.25 µg. Hearing threshold in the KR-12-a2 and PBS groups were similar to that before ventilation tube insertion. However, the gentamicin group showed elevation of the hearing threshold and there were statistically significant differences compared to the phosphate buffered saline or the KR-12-a2 group. In the scanning electron microscope findings, the KR-12-a2 group showed intact outer hair cells. However, the gentamicin group showed total loss of outer hair cells. In our experiment, topically applied KR-12-a2 solution did not cause hearing loss or cochlear damage in guinea pigs. Conclusion In our experiment, topically applied KR-12-a2 solution did not cause hearing loss or cochlear damage in guinea pigs. The KR-12-a2 solution can be used as ototopical drops for treating methicillin-resistant staphylococcus aureus otorrhea; however, further evaluations, such as the definition of optimal concentration and combination, are necessary.

Resumo Introdução O staphylococcus aureus resistente à meticilina é um problema emergente não só para a otite média supurativa crônica, mas também para casos de otorreia crônica em crianças com tubo de ventilação. Até o momento, não há antibióticos tópicos efetivos para a otorreia causada por staphylococcus aureus resistente à meticilina. Objetivo Nesse estudo, avaliamos a ototoxicidade da solução tópica de KR-12-a2 na cóclea quando aplicada topicamente na orelha média de cobaias. Método A atividade antimicrobiana de KR-12-a2 contra cepas de staphylococcus aureus resistente à meticilina foi avaliada utilizando-se o teste de zona de inibição de crescimento. Foram aplicados na orelhas médias de 3 grupos de cobaias, ou solução tópica de KR-12-a2, ou gentamicina ou solução salina tamponada com fosfato após timpanostomia. A ototoxicidade foi avaliada através do exame auditivo de potencial evocado auditivo de tronco encefálico e por microscopia eletrônica de varredura. Resultados O KR-12-a2 produziu uma zona de inibição contra o staphylococcus aureus resistente à meticilina a partir de 6,25 µg. Alterações do limiar de audição no grupo KR-12-a2 e no grupo com solução salina foram semelhantes aos observados antes da inserção do tubo de ventilação. No entanto, o grupo gentamicina apresentou um limiar auditivo mais elevado, estatisticamente significativo em comparação ao grupo solução salina ou ao grupo KR-12-a2. Nos achados da microscopia eletrônica, o grupo KR-12-a2 apresentou células ciliadas externas intactas. No entanto, o grupo gentamicina apresentou perda total das células ciliadas externas. Em nosso experimento, a solução de KR-12-a2 aplicada topicamente não causou perda auditiva ou dano coclear em cobaias. Conclusão Em nosso experimento, a solução de KR-12-a2 aplicada topicamente não causou perda auditiva ou dano coclear em cobaias. A solução de KR-12-a2 pode ser utilizada como gotas otológicas para o tratamento da otorreia causada por staphylococcus aureus resistente à meticilina; no entanto, são necessárias outras avaliações, para a definição da concentração e das associações ideais.

Factibilidad del uso de bivalirudina como anticoagulante en soporte vital extracorpóreo / Experience with anticoagulation with bivalirudin during extracorporeal membrane oxygenation

Background: Extracorporeal membrane oxygenation (ECMO) is used with increasing frequency in patients with respiratory and cardiac failure. The achievement of an adequate anticoagulation is critical to avoid patient and circuit complications. Aim: To assess the feasibility and safety of anticoagulation with bivalirudin, as an alternative to unfractionated heparin (UFH), in patient with ECMO. Material and Methods: Observational study, which included all patients receiving anticoagulation with bivalirudin during ECMO, according to a standardized protocol, between august 2015 to May 2016. Results: Bivalirudin was used in 13 out 70 patients connected to ECMO. Ten procedures were for cardiac support and three for respiratory support. Mortality was 43%. ECMO lasted 31 ± 31 days. The time of UFH use before changing to bivalirudin was 7 ± 7 days. The reasons to change to bivalirudin were inadequate levels of partial thromboplastin time (PTT) in nine patients, and heparin induced thrombocytopenia (HIT) in four patients. The time of bivalirudin use was 24 ± 33 days. Per patient, a mean of 2.7 ± 4 oxygenators were changed. These had a useful life of 11.4 and 19.1 days during UFH and bivalirudin use, respectively. The mean bivalirudin dose was 0.08 ± 0.04 mg/kg/h. There was no significant bleeding, thrombosis or circuit obstruction during its use. PTT levels (p < 0.01) and platelet count (p < 0.01) increased significantly after the start of bivalirudin use in patients with UHF resistance and HIT, respectively. Conclusions: Bivalirudin was a safe and efficient drug for anticoagulation during ECMO. It is important to have an alternative drug for anticoagulation in ECMO patients.

Angiotensin-(1-7) relieved renal injury induced by chronic intermittent hypoxia in rats by reducing inflammation, oxidative stress and fibrosis

We aimed to study the renal injury and hypertension induced by chronic intermittent hypoxia (CIH) and the protective effects mediated by angiotensin 1-7 [Ang(1-7)]. We randomly assigned 32 male Sprague-Dawley rats (body weight 180-200 g) to normoxia control, CIH, Ang(1-7)-treated normoxia, and Ang(1-7)-treated CIH groups. Systolic blood pressure (SBP) was monitored at the start and end of each week. Renal sympathetic nerve activity (RSNA) was recorded. CTGF and TGF-β were detected by immunohistochemistry and western blotting. Tissue parameters of oxidative stress were also determined. In addition, renal levels of interleukin-6, tumor necrosis factor-α, nitrotyrosine, and hypoxia-inducible factor-1α were determined by immunohistochemistry, immunoblotting, and ELISA. TUNEL assay results and cleaved caspase 3 and 12 were also determined. Ang(1-7) induced a reduction in SBP together with a restoration of RSNA in the rat model of CIH. Ang(1-7) treatment also suppressed the production of reactive oxygen species, reduced renal tissue inflammation, ameliorated mesangial expansion, and decreased renal fibrosis. Thus, Ang(1-7) treatment exerted renoprotective effects on CIH-induced renal injury and was associated with a reduction of oxidative stress, inflammation and fibrosis. Ang(1-7) might therefore represent a promising therapy for obstructive sleep apnea-related hypertension and renal injury.

Hyperbaric Oxygen Pretreatment Improves Cognition and Reduces Hippocampal Damage Via p38 Mitogen-Activated Protein Kinase in a Rat Model

PURPOSE: To investigate the effects of hyperbaric oxygen (HBO) pretreatment on cognitive decline and neuronal damage in an Alzheimer’s disease (AD) rat model. MATERIALS AND METHODS: Rats were divided into three groups: normal saline (NS), AD, and HBO+AD. In the AD group, amyloid β peptide (Aβ)₁₋₄₀ was injected into the hippocampal CA1 region of the brain. NS rats received NS injection. In the HBO+AD group, rats received 5 days of daily HBO therapy following Aβ₁₋₄₀ injection. Learning and memory capabilities were examined using the Morris water maze task. Neuronal damage and astrocyte activation were evaluated by hematoxylin-eosin staining and immunohistochemistry, respectively. Dendritic spine density was determined by Golgi-Cox staining. Tumor necrosis factor-α, interleukin-1β, and interleukin-10 production was assessed by enzyme-linked immunosorbent assay. Neuron apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling. Protein expression was examined by western blotting. RESULTS: Learning and memory dysfunction was ameliorated in the HBO+AD group, as shown by significantly lower swimming distances and escape latency, compared to the AD group. Lower rates of neuronal damage, astrocyte activation, dendritic spine loss, and hippocampal neuron apoptosis were seen in the HBO+AD than in the AD group. A lower rate of hippocampal p38 mitogen-activated protein kinase (MAPK) phosphorylation was observed in the HBO+AD than in the AD group. CONCLUSION: HBO pretreatment improves cognition and reduces hippocampal damage via p38 MAPK in AD rats.

Initial experience with ocriplasmin in the treatment of vitreomacular traction / Experiência inicial com ocriplasmina no tratamento da tração vitreorretiniana

ABSTRACT This study aimed to report the clinical and structural outcomes of intravitreal ocriplasmin in the treatment of vitreomacular interface disorders in two tertiary centers in Brazil. A retrospective study was performed by reviewing medical records and spectral domain optical coherence tomography (SD-OCT) findings of seven patients who were treated with a single ocriplasmin injection. A total of 57.14% of patients achieved resolution of vitreomacular traction as evidenced by SD-OCT. Regarding our functional results, 87.71% maintained or improved visual acuity after follow-up. To the best of our knowledge, this is the first study reporting initial results of ocriplasmin therapy in Brazil.

RESUMO O objetivo desse estudo é relatar os resultados iniciais, tanto do ponto de vista funcional quanto anatômico, no tratamento das doenças da interface vítreo-macular com a ocriplasmina em 2 serviços terciários no Brasil. Um estudo retrospectivo foi realizado através de revisão de prontuários, além de análise de achados em tomografia de coerência óptica de domínio espectral (SD-OCT) em 7 pacientes tratados com uma única injeção intravítrea de ocriplasmina. Em nosso estudo 57,14% dos pacientes apresentaram resolução da tração vítreo-macular no SD-OCT. Em relação aos resultados funcionais, 87,71% dos pacientes mantiveram, ou melhoraram sua acuidade visual durante o acompanhamento. Para nosso conhecimento, trata-se do primeiro estudo em nosso país, mostrando resultados iniciais com ocriplasmina em pacientes tratados no Brasil.

Angiotensina-(1-9) disminuye el daño renal en la hipertensión arterial renina independiente / Angiotensin (1-9) decreases renal damage in hypertension with low renin

Antecedentes: Angiotensina [Ang-(1-9)] disminuye la presión arterial (PA) y el remodel amiento cardíaco en la hipertensión arterial experimental independiente de renina. No hay antecedentes sobre el efecto de Ang-(1-9) en la progresión de daño renal de ratas hipertensas por expansión de volumen (con renina baja). Objetivo: Determinar la participación de Ang-(1-9) en la progresión del daño renal en ratas hipertensas (DOCA-sal). Métodos: Se utilizaron ratas Sprague Dawley macho de 150 +/- 10 g uninefrectomizadas tratadas con DOCA (60mg/Kg/2 veces sem, im) por 4 semanas. Como controles (Sham) se usaron ratas uninefrectomizadas. Desde la 2a semana las ratas DOCA, con presión arterial sistólica (PAS) > 140 mmHg, recibieron vehículo o Ang-(1-9) [602 ng/Kg min] por 2 semanas (minibomba Alzet). Se evaluó la respuesta inflamatoria y el daño renal profibrótico por la presencia de macrófagos infiltrativos y de mio-fibroblastos intersticiales. Se determinó, además, la presión arterial sistólica (PAS), masa corporal (MC), masa del riñón derecho (MR) y masa renal relativa (MRR). Resultados: Se observó una disminución del daño renal en las ratas DOCA-sal, cuando recibieron Ang-(1-9), respecto a aquellas que no la recibieron, evidenciado por una significativa disminución de macrófagos infiltrativos y miofibroblastos en el intersticio renal. El bloqueo de los receptores Mas y AT2, no tuvieron efectos adicionales. Conclusion: En este modelo experimental, Ang-(1-9) disminuyó la hipertensión y redujo significativamente la infiltración de macrófagos y la aparición de miofibroblastos en el intersticio renal. Estos resultados son la primera evidencia de que Ang-(1-9) reduce la fibrosis túbulo-intersticial renal y el daño renal hipertensivo.

Angiotensin [Ang] - (1-9) decreases blood pressure (BP) and cardiac remodeling in renin independent hypertension. There are not studies about the effect of Ang- (1-9) in the progression of hypertensive renal damage by volume overload (low-renin). The aim of this study was to determine the effect of Ang- (1-9) on renal damage in volume overload hypertensive rats by (DOCA-salt rats). Methods: Male Sprague Dawley rats, 150 +/- 10 g, were uni-nephrectomized and treated with DOCA (60mg/Kg) 2 times per week, for 4 weeks. Uninephrec-tomized rats were used as controls (Sham). From the 2nd week on DOCA rats with systolic blood pressure (SBP)> 140 mmHg received vehicle or Ang- (1-9) [602 ng / kg min] for 2 weeks (Alzet minipump). Inflammatory and profibrotic renal damage was evaluated by the presence of infiltrating macrophages and interstitial myofibroblasts. Results: Compared to rats receiving vehicle renal damage in DOCA-salt rats decreased when they received Ang- (1-9), as evidenced by a significant decrease in infiltrating macrophages and myofibroblasts in the renal interstitium. Mas and AT2 receptor blockade had no additional effect. The SBP, body mass (BM), mass of the right kidney (MR) and relative renal mass (MRR) were also determined. Conclusion: in this experimental model, Ang-(1-9) decreased hypertension and significantly reduced macrophage infiltration and the appearance of myofibroblasts in the renal interstitium. These results are the first evidence that Ang-(1-9) reduces renal tubulointerstitial fibrosis and hypertensive renal damage.

Polymeric nanoparticle formulation of Octapeptide (NP-OP): In vitro release and in vivo effect in common marmosets, Callithrix jacchus Linn.

yielded an average particle size of 120 nm with 70% encapsulation-efficiency. In vitro release profile of NP-OP showed sustained release of OP for 21 days. In vivo anti-fertility studies were conducted in marmosets. Results indicated that control animals conceived in the same cycle while two of three treated animals failed to conceive in treatment cycle. The in vivo studies thus corroborate with in vitro release of OP, demonstrating its anti-fertility activity in 66% of animals.

The pressor effect of angiotensin-(1-7) in the rat rostral ventrolateral medulla involves multiple peripheral mechanisms

OBJECTIVE: In the present study, the peripheral mechanism that mediates the pressor effect of angiotensin-(1-7) in the rostral ventrolateral medulla was investigated. METHOD: Angiotensin-(1-7) (25 pmol) was bilaterally microinjected in the rostral ventrolateral medulla near the ventral surface in urethane-anesthetized male Wistar rats that were untreated or treated (intravenously) with effective doses of selective autonomic receptor antagonists (atenolol, prazosin, methyl-atropine, and hexamethonium) or a vasopressin V1 receptor antagonist [d(CH2)5 -Tyr(Me)-AVP] given alone or in combination. RESULTS: Unexpectedly, the pressor response produced by angiotensin-(1-7) (16 ± 2 mmHg, n = 12), which was not associated with significant changes in heart rate, was not significantly altered by peripheral treatment with prazosin, the vasopressin V1 receptor antagonist, hexamethonium or methyl-atropine. Similar results were obtained in experiments that tested the association of prazosin and atenolol; methyl-atropine and the vasopressin V1 antagonist or methyl-atropine and prazosin. Peripheral treatment with the combination of prazosin, atenolol and the vasopressin V1 antagonist abolished the pressor effect of glutamate; however, this treatment produced only a small decrease in the pressor effect of angiotensin-(1-7) at the rostral ventrolateral medulla. The combination of hexamethonium with the vasopressin V1 receptor antagonist or the combination of prazosin, atenolol, the vasopressin V1 receptor antagonist and methyl-atropine was effective in blocking the effect of angiotensin-(1-7) at the rostral ventrolateral medulla. CONCLUSION: These results indicate that angiotensin-(1-7) triggers a complex pressor response at the rostral ventrolateral medulla that involves an increase in sympathetic tonus, release of vasopressin and possibly the inhibition of a vasodilatory mechanism.

Recombinant in vitro assembled hepatitis C virus core particles induce strong specific immunity enhanced by formulation with an oil-based adjuvant

In the present work, immunogenicity of recombinant in vitro assembled hepatitis C virus core particles, HCcAg.120-VLPs, either alone or in combination with different adjuvants was evaluated in BALB/c mice. HCcAg.120-VLPs induced high titers of anti-HCcAg.120 antibodies and virus-specific cellular immune responses. Particularly, HCcAg.120-VLPs induced specific delayed type hypersensitivity, and generated a predominant T helper 1 cytokine pro file in immunized mice. In addition, HCcAg.120-VLPs prime splenocytes proliferate in vitro against different HCcAg.120-specific peptides, depending on either the immunization route or the adjuvant used. Remarkably, immunization with HCcAg.120-VLPs/Montanide ISA888 formulation resulted in a significant control of vaccinia virus titer in mice after challenge with a recombinant vaccinia virus expressing HCV core protein, vvCore. Animals immunized with this formulation had a marked increase in the number of IFN-γ producing spleen cells, after stimulation with P815 cells infected with vvCore. These results suggest the use of recombinant HCV core particles as components of therapeutic or preventive vaccine candidates against HCV.

Enfuvirtide: el primer paso de una nueva estrategia de tratamiento antirretroviral / Enfuvirtide: the first step for a new strategy of antiretroviral therapy

Enfuvirtide (antes T-20) es el primer inhibidor de la entrada a la célula del HIV-1 en ser aprobado. Es un péptido análogo de la porción HR2 de la glucoproteína de superficie viral gp41. Su mecanismo de acción consiste en la unión competitiva a la porción HR1 de la gp41 para impedir los cambios conformacionales del complejo gp41-gp120 tras la unión del HIV-1 a los receptores celulares, impidiendo así el acercamiento y posterior fusión entre el virus y la célula. Se aplica por vía subcutánea. Los resultados de los principales estudios clínicos (TORO 1 y 2) llevados a cabo en pacientes con fallo virológico, tratamientos previos con antirretrovirales y portadores de cepas virales altamente resistentes, mostraron que quienes recibieron enfuvirtide + HAART optimizado, elegido mediante un test de resistencia, presentaron mayores beneficios que quienes sólo recibieron HAART optimizado, en términos de mejor recuperación inmune y mayor descenso de la carga viral de HIV. Los mejores resultados se observaron en el subgrupo de pacientes con más drogas útiles en el HAART según el test de resistencia, una menor carga viral de HIV y un mayor recuento de linfocitos CD4 basales. El principal efecto adverso es el desarrollo de lesiones por hipersensibilidad en los sitios de aplicación. El alto costo de enfuvirtide se vio compensado por una reducción en los costos de internación.

Enfuvirtide (T-20) is the first approved HIV-1 entry into cells' inhibitor. It is a peptide with an amino acid sequence analogue to HR2 region of the viral surface glycoprotein gp41. Its mechanism of action is the competitive binding to HR1 region of the gp41, preventing the interaction between HR1 and HR2 and impeding the conformational changes in gp41 necessary for fusion of the virus with the cell. Its application is by subcutaneous injection. The main clinical trials of enfuvirtide (TORO 1 and 2) were performed in HIV-infected patients with virological failure, high antiretroviral experience and highly resistant viral isolates. Those trials showed that the addition of enfuvirtide to an optimized HAART (chosen with a resistance test) provided better results than HAART alone, measured by drop in viral load and immunologic benefit. The best results were observed in the subgroup of patients with more useful drugs in HAART (according to the information of the resistance test), a lower viral load, and a higher CD4 cell count at baseline. The most important adverse event is the production of injection drug hypersensitivity reaction in 98% of patients. The high cost is compensated by a reduction in costs derived from admissions.