RESUMO
The purpose of this work was to investigate the influence of acid treatment on the surface properties and in vivo performance of titanium grade 5 (Ti6Al4V) alloy. Mini-implants with surface treatment were inserted into New Zealand rabbit tibia for 1, 4 and 8 weeks. SEM analysis showed intercommunicated micropores in acid treated samples. AFM showed micron and sub-micron roughness. The thickness of the titanium oxide layer increased with surface treatment, with a significant reduction of Al and V concentration. Acid treated implant removal torque was larger than without treatment. The implants/bone interface of acid treated implants showed dense adhered Ca/P particles with spreading osteoblasts after 4 weeks and newly formed bone trabeculae after 8 weeks. Analysis of rabbit blood that received treated implant showed lower Al and V contents at all times. Acid treatment improved surface morphology and mechanical stability, which allowed initial events of osseointegration, while Al-V ion release was reduced. GRAPHICAL ABTSRACT.
Assuntos
Materiais Biomédicos e Odontológicos , Materiais Revestidos Biocompatíveis/química , Ácido Clorídrico/farmacologia , Implantes Experimentais , Titânio/química , Ligas , Animais , Materiais Biomédicos e Odontológicos/síntese química , Materiais Biomédicos e Odontológicos/química , Parafusos Ósseos , Interface Osso-Implante , Materiais Revestidos Biocompatíveis/síntese química , Implantação Dentária Endóssea/instrumentação , Implantes Dentários , Feminino , Osseointegração , Porosidade/efeitos dos fármacos , Coelhos , Propriedades de Superfície/efeitos dos fármacosRESUMO
PURPOSE: To evaluate glomerular injury in the rat model during renal warm ischemia (WI), comparing artery and vein (AV) clamping with artery only (AO) clamping. MATERIALS AND METHODS: Twenty-four adult male rats underwent 60 minutes of renal WI in the left kidney. The animals were divided into three groups: AV clamping, AO clamping, and Sham surgery. After 30 days, the animals were euthanized, and both kidneys were processed for paraffin embedding and stained with hematoxylin and eosin. Glomerular volume density (Vv[glom]), mean glomerular volume (MGV), and number of glomeruli per mm(3) (Nv[glom]) were evaluated in the renal cortex. RESULTS: The Vv[glom] was reduced in the left kidney (ischemic) when compared with the right kidney in both AV and AO groups by 11.1% and 35.4%, respectively; however, the difference was significant only in the AV group. The Nv[glom] was reduced in the left kidney when compared with the right kidney in both AV and AO groups by 11.6% and 31.4%, respectively; nevertheless, the difference was significant only in the AV group. The MGV of left and right kidneys was the same in both Sham and AO groups and was diminished by 6.7% in the AV group-not significant. CONCLUSION: AV clamping causes a significant decrease in the number of glomeruli in the rat model, while AO clamping reduces the glomerular number, but not significantly. To minimize renal injury, AO clamping may be preferred over AV clamping when WI is necessary in patients with previously compromised renal function.
Assuntos
Isquemia/prevenção & controle , Glomérulos Renais/irrigação sanguínea , Artéria Renal/cirurgia , Veias Renais/cirurgia , Isquemia Quente/métodos , Animais , Constrição , Modelos Animais de Doenças , Taxa de Filtração Glomerular , Isquemia/etiologia , Isquemia/fisiopatologia , Rim/irrigação sanguínea , Rim/fisiopatologia , Rim/cirurgia , Nefropatias/fisiopatologia , Testes de Função Renal , Glomérulos Renais/fisiopatologia , Masculino , Ratos , Ratos WistarRESUMO
PURPOSE: Radiotherapy is widely used for cancer treatment but has harmful effects. This study aimed to assess the effects of L-arginine and glycine supplementation on the colon wall of rats submitted to abdominal irradiation. METHODS: Forty male Wistar rats were randomly divided into four groups: I-healthy, II-irradiated with no amino acid supplementation, III-irradiated and supplemented with L-arginine, and IV-irradiated and supplemented with glycine. The animals received supplementation for 14 days, with irradiation being applied on the eighth day of the experiment. All animals underwent laparotomy on the 15th day for resection of a colonic segment for stereologic analysis. Parametric and nonparametric tests were used for statistical analysis, with the level of significance set at p ≤0.05. RESULTS: Stereologic analysis showed that irradiation induced a reduction of the total volume of the colon wall of group II and III animals compared to healthy controls, but not of group IV animals supplemented with glycine. The mucosal layer of the irradiated animals of all groups was reduced compared to healthy group I animals, but supplementation with L-arginine and glycine was effective in maintaining the epithelial surface of the mucosal layer. CONCLUSION: The present results suggest that glycine supplementation had a superior effect on the irradiated colon wall compared to L-arginine supplementation since it was able to maintain the thickness of the wall and the epithelial surface of the mucosa, whereas L-arginine maintained the partial volume of the epithelium and the epithelial surface, but not the total volume of the intestinal wall.
Assuntos
Arginina/farmacologia , Suplementos Nutricionais , Glicina/farmacologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Radiação , Cicatrização/efeitos dos fármacos , Animais , Arginina/administração & dosagem , Peso Corporal/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Glicina/administração & dosagem , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
BACKGROUND AND AIMS: Radiotherapy is frequently used for cancer treatment, but it may be associated with several complications. Thus, this study aimed to evaluate the role of L-glutamine and/or glycine supplementation on the colonic wall in rats submitted to abdominal radiation. MATERIALS AND METHODS: Sixty adult Wistar rats were randomly divided into six groups: I-healthy, II (control)-irradiated rats without amino acid supplementation, III-irradiated rats with glycine supplementation, IV-irradiated rats with L-glutamine supplementation, V-irradiated rats with glycine supplementation 7 days before irradiation and with L-glutamine supplementation 7 days after irradiation, and VI-irradiated rats with L-glutamine supplementation 7 days before irradiation and with glycine supplementation 7 days after irradiation. Abdominal irradiation was employed with a dose of 1,000 cGy on the eighth day of the experiment. All animals underwent laparotomy on the 15th day for resection of a colonic segment for stereologic analysis. Parametric and nonparametric tests were used for statistical analysis, with the level of significance set at pAssuntos
Colo/efeitos dos fármacos
, Glutamina/farmacologia
, Glicina/farmacologia
, Lesões Experimentais por Radiação/prevenção & controle
, Protetores contra Radiação/farmacologia
, Animais
, Colo/patologia
, Colo/efeitos da radiação
, Glutamina/uso terapêutico
, Glicina/uso terapêutico
, Mucosa Intestinal/efeitos dos fármacos
, Mucosa Intestinal/patologia
, Mucosa Intestinal/efeitos da radiação
, Masculino
, Lesões Experimentais por Radiação/etiologia
, Lesões Experimentais por Radiação/patologia
, Protetores contra Radiação/uso terapêutico
, Radioterapia/efeitos adversos
, Ratos
, Ratos Wistar
, Fatores de Tempo
RESUMO
OBJECTIVES: During the past decade, numerous studies in both humans and animals have demonstrated that C-peptide, although not influencing blood sugar control, might play a role in preventing and potentially reversing some of the chronic complications of type 1 diabetes. The aim of this paper is to present an up-to-date review of C-peptide, focusing on its role in insulin biosynthesis and in the classification of diabetes mellitus, as well as its potential clinical applications. METHODS AND RESULTS: The relevant literature cited in the MEDLINE database shows that the measurement of C-peptide production combined with screening for the presence of islet-cell and other autoantibodies seems to exert an important role in the accurate differentiation between patients with type 1 and type 2 diabetes. Also, both experimental and clinical data provide evidence suggesting that combined replacement of insulin and C-peptide has potential therapeutic value in patients with type 1 diabetes. CONCLUSIONS: Further study in this area is warranted, but the findings that pancreas transplants promote the reversal of diabetic neuropathy and stabilization of diabetic retinopathy and that both pancreas and islet transplants lead to the reversal of diabetic nephropathy lend credence to the concept that combined replacement of insulin and C-peptide may more effectively mitigate the inexorable progression of diabetes-related complications.