RESUMEN
PURPOSE: The rapid spread of the SARS-CoV-2 pandemic around the world caused most healthcare services to turn substantial attention to treatment of these patients and also to alter the structure of healthcare systems to address an infectious disease. As a result, many cancer patients had their treatment deferred during the pandemic, increasing the time-to-treatment initiation, the number of untreated patients (which will alter the dynamics of healthcare delivery in the post-pandemic era) and increasing their risk of death. Hence, we analyzed the impact on global cancer mortality considering the decline in oncology care during the COVID-19 outbreak using head and neck cancer, a known time-dependent disease, as a model. METHODS: An online practical tool capable of predicting the risk of cancer patients dying due to the COVID-19 outbreak and also useful for mitigation strategies after the peak of the pandemic has been developed, based on a mathematical model. The scenarios were estimated by information of 15 oncological services worldwide, given a perspective from the five continents and also some simulations were conducted at world demographic data. RESULTS: The model demonstrates that the more that cancer care was maintained during the outbreak and also the more it is increased during the mitigation period, the shorter will be the recovery, lessening the additional risk of dying due to time-to-treatment initiation. CONCLUSIONS: This impact of COVID-19 pandemic on cancer patients is inevitable, but it is possible to minimize it with an effort measured by the proposed model.
Asunto(s)
COVID-19 , Carcinoma de Células Escamosas/epidemiología , Atención a la Salud , Neoplasias de Cabeza y Cuello/epidemiología , SARS-CoV-2 , Tiempo de Tratamiento , Carcinoma de Células Escamosas/etiología , Carcinoma de Células Escamosas/mortalidad , Salud Global , Neoplasias de Cabeza y Cuello/etiología , Neoplasias de Cabeza y Cuello/mortalidad , Humanos , Modelos Teóricos , Factores de RiesgoRESUMEN
Superabsorbent hydrogels (SAHs) are three dimensional networks formed by polymers that can absorb aqueous solution of over 100% of their initial weight. This work aimed to develop and characterize SAHs of Chitosan/Xanthan gum (CG), Chitosan/Alginate (CA) and controlled Chitosan (C), Xanthan gum (G), and Alginate (A) produced using "onion-like" methodology. The swelling performance, the morphological structure, the crystallinity, and the Fourier transformed infrared spectroscopy characteristics of SAH were used for the characterization of polyelectrolytes complex. Swelling analysis showed that chitosan has a strong influence on the maintenance of hydrogels structure after swelling, mainly in the acid environment (pH = 2). The chitosan hydrogel presented around 3000% of acidic fluid absorption after 24 h. The chitosan:xanthan gum (1:1 and 2:1 named as C1G1 and C2G1, respectively) hydrogels were the best combination regarding swelling performance in an acid environment, reaching 1665% and 2024%, respectively, as well at pH 7.0, presenting 1005% (C1G1) and 667% (C2G1). Scanning electron microscopy analysis showed samples with pores, and with different shapes. The X-ray diffraction showed the presence of a characteristic peak at 2θ = 20° in all developed composition because of the crystalline nature of chitosan. This work shows the possibility of developing eco-friendly biopolymer-based SAHs at a low cost with a good swelling capacity and stability.
RESUMEN
Tissue engineering is a multidisciplinary science that combines a structural scaffold and cells to form a construct able to promote regeneration of injured tissue. Bioactive glass foam produced by sol-gel is an osteoinductive material with a network of interconnected macropores necessary for cell colonization. The use of human adipose-derived stem cell (hASC) presents advantages as the potential for a large number of cells, rapid expansion in vitro and the capability of differentiating into osteoblasts. The use of a bioreactor in three-dimensional cell culture enables greater efficiency for cell nutrition and application of mechanical forces, important modulators of bone physiology. The hASC seeded in a bioactive glass scaffold and cultured in osteogenic Leibovitz L-15 medium in a bioreactor with a flow rate of 0.1 mL min(-1) demonstrated a significant increase in cell proliferation and viability and alkaline phosphatase (ALP) activity peak after 14 days. The immunofluorescence assay revealed an expression of osteopontin, osteocalcin and type I collagen from 7 to 21 days after culture. The cells changed from a spindle shape to a cuboidal morphology characteristic of osteoblasts. The polymerase chain reaction assay confirmed that osteopontin, osteocalcin, and ALP genes were expressed. These results indicate that hASCs differentiated into an osteogenic phenotype when cultured in bioactive glass scaffold, osteogenic Leibovitz L-15 medium and a perfusion bioreactor. Therefore, these results highlight the synergism between a bioactive glass scaffold and the effect of perfusion on cells and indicate the differentiation into an osteogenic phenotype.
Asunto(s)
Tejido Adiposo/citología , Materiales Biocompatibles/química , Reactores Biológicos , Vidrio/química , Osteogénesis , Células Madre/citología , Ingeniería de Tejidos/instrumentación , Diferenciación Celular , Proliferación Celular , Supervivencia Celular , Células Cultivadas , Femenino , Humanos , Osteoblastos/citologíaRESUMEN
PURPOSE: Evaluate corneal endothelium by means of specular microscopy exam in patients with Keratoconus, before and after Cornealring® corneal intrastromal ring surgery. METHODS: One hundred and two eyes of 67 patients, aged between 12 and 45, with the average age of 27.31 ± 8.15 years, 30 females and 37 males, were selected to be submitted to the implant of Cornealring® corneal ring segments in pre- and post-surgery (six months after the procedure) in the External Diseases and Cornea Ward of the Instituto Panamericano da Visão. RESULTS: Of the 102 eyes treated, only those that received two rings of equal thickness up to 250 µ showed statistical significance between the initial and final mean number of endothelial cells (P = 0.008), a decrease of 10.1% in the mean coefficient of variation (P = 0.003), and a 9.75% decrease in initial and final hexagonal cell counts. The other eyes receiving rings of other thicknesses showed no statistically significant differences between the mean initial and final SM examinations. CONCLUSION: A longer segment is necessary for the confirmation or not of the alterations found in this study, particularly regarding the thickness of the ring used, because with the new technologies and the improvement in the result of deep lamellar transplantation, the decrease in the cell count might represent a problem in the indication of this procedure following thick corneal ring implants.
Asunto(s)
Sustancia Propia/cirugía , Endotelio Corneal/citología , Queratocono/cirugía , Polimetil Metacrilato , Prótesis e Implantes , Adolescente , Adulto , Niño , Femenino , Humanos , Queratocono/patología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto JovenRESUMEN
Hunter syndrome, or Mucopolysaccharidosis type II (MPS II), is a rare X-linked recessive disorder caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). The phenotypic spectrum varies from severe to attenuated clinical forms. We report a large Brazilian family with 16 affected individuals exhibiting a very attenuated form of MPS II. Fourteen female carriers were also identified. Twelve affected male patients, whose ages ranged from 1 to 35 years, were examined. Molecular analysis showed a novel missense mutation (p.A77D) in the IDS gene, confirming the diagnosis. Nine of the family members presented some degree of heart damage, though only the proband became symptomatic and required heart transplantation. One 19-year-old adult and 1-year-old twin boys each had a normal echocardiogram. Short stature was found in two adults while macrocephaly was found in one; the remaining adults had anthropometric measures within normal range. All affected adults had normal cognitive development and were able to perform normal daily activities, except one who had mild learning disability. Two patients died due to natural causes beyond 70 years of age. The female carriers did not present any signs of disease. In this large family with a mild form of MPS II and variable degree of clinical manifestations, it is noteworthy that several affected individuals have remained asymptomatic even at advanced age and even without enzyme replacement therapy.
RESUMEN
This work evaluated the effect of freezing on chondrocytes maintained in culture, aiming the establishment of a cell bank for future application as heterologous implant. Chondrocytes extracted from joint cartilage of nine healthy New Zealand White rabbits were cultivated and frozen with the cryoprotector 5 percent dimethylsulfoxide for six months. Phenotypic and scanning electron microscopy analyses were carried out to identify morphological and functional differences between fresh and thawed cells. After enzymatic digestion, a total of 4.8x10(5)cells per rabbit were obtained. Fresh chondrocytes showed a high mitotic rate and abundant matrix was present up to 60 days of culture. Loss of phenotypic stability was notable in the thawed chondrocytes, with a low labeling of proteoglycans and weak immunostaining of type II collagen. The present study showed important loss of chondrocyte viability under the freezing conditions. For future in vivo studies of heterologous implant, these results suggests that a high number of cells should be implanted in the host site in order to achieve an adequate number of viable cells. Furthermore, the chondrocytes should be implanted after two weeks of culture, when the highest viability rate is found.
Avaliaram-se os efeitos do congelamento sobre condrócitos mantidos em cultura, com o objetivo de se estabelecer um banco celular para futura aplicação como implante heterólogo. Condrócitos extraídos da cartilagem articular de nove coelhos saudáveis, da raça Nova Zelândia Branca, foram cultivados e submetidos ao congelamento, com o citoprotetor sulfóxido de dimetila a 5 por cento, por um período de seis meses. Análises fenotípicas e de microscopia eletrônica de varredura foram realizadas com o objetivo de identificar diferenças morfológicas e funcionais entre as células frescas e as descongeladas. Após a digestão enzimática, foram obtidas 4,8x10(5) células por coelho. Os condrócitos frescos apresentaram elevada taxa mitótica e abundante presença de matriz até os 60 dias de cultura. Nas culturas dos condrócitos descongelados, a perda de estabilidade fenotípica foi marcante, o que foi demonstrado pela baixa intensidade da coloração dos proteoglicanos e pela fraca imunomarcação do colágeno tipo II. Sob as condições de congelamento utilizadas, houve importante perda de viabilidade condrocítica. Para futuros estudos in vivo de implante heterólogo, estes resultados sugerem que o elevado número de células deve ser implantado no sítio hospedeiro, com o objetivo de se obter maior quantidade de células viáveis, e que os condrócitos deverão ser implantados com duas semanas de cultivo, período em que apresentam melhor taxa de viabilidade.
Asunto(s)
Animales , Conejos , Condrocitos/citología , Congelación , Microscopía Electrónica de Rastreo , Tratamiento Basado en Trasplante de Células y TejidosRESUMEN
This work evaluated the effect of freezing on chondrocytes maintained in culture, aiming the establishment of a cell bank for future application as heterologous implant. Chondrocytes extracted from joint cartilage of nine healthy New Zealand White rabbits were cultivated and frozen with the cryoprotector 5 percent dimethylsulfoxide for six months. Phenotypic and scanning electron microscopy analyses were carried out to identify morphological and functional differences between fresh and thawed cells. After enzymatic digestion, a total of 4.8x10(5)cells per rabbit were obtained. Fresh chondrocytes showed a high mitotic rate and abundant matrix was present up to 60 days of culture. Loss of phenotypic stability was notable in the thawed chondrocytes, with a low labeling of proteoglycans and weak immunostaining of type II collagen. The present study showed important loss of chondrocyte viability under the freezing conditions. For future in vivo studies of heterologous implant, these results suggests that a high number of cells should be implanted in the host site in order to achieve an adequate number of viable cells. Furthermore, the chondrocytes should be implanted after two weeks of culture, when the highest viability rate is found.(AU)
Avaliaram-se os efeitos do congelamento sobre condrócitos mantidos em cultura, com o objetivo de se estabelecer um banco celular para futura aplicação como implante heterólogo. Condrócitos extraídos da cartilagem articular de nove coelhos saudáveis, da raça Nova Zelândia Branca, foram cultivados e submetidos ao congelamento, com o citoprotetor sulfóxido de dimetila a 5 por cento, por um período de seis meses. Análises fenotípicas e de microscopia eletrônica de varredura foram realizadas com o objetivo de identificar diferenças morfológicas e funcionais entre as células frescas e as descongeladas. Após a digestão enzimática, foram obtidas 4,8x10(5) células por coelho. Os condrócitos frescos apresentaram elevada taxa mitótica e abundante presença de matriz até os 60 dias de cultura. Nas culturas dos condrócitos descongelados, a perda de estabilidade fenotípica foi marcante, o que foi demonstrado pela baixa intensidade da coloração dos proteoglicanos e pela fraca imunomarcação do colágeno tipo II. Sob as condições de congelamento utilizadas, houve importante perda de viabilidade condrocítica. Para futuros estudos in vivo de implante heterólogo, estes resultados sugerem que o elevado número de células deve ser implantado no sítio hospedeiro, com o objetivo de se obter maior quantidade de células viáveis, e que os condrócitos deverão ser implantados com duas semanas de cultivo, período em que apresentam melhor taxa de viabilidade.(AU)
Asunto(s)
Animales , Congelación , Condrocitos/citología , Conejos/clasificación , Tratamiento Basado en Trasplante de Células y TejidosRESUMEN
The aim of the study was to characterize clinically and biochemically mucopolysaccharidosis type II (MPS II) heterozygotes. Fifty-two women at risk to be a carrier, with a mean age of 34.1 years (range 16-57 years), were evaluated through pedigree analysis, medical history, physical examination, measurement of iduronate sulfatase (IDS) activities in plasma and in leukocytes, quantification of glycosaminoglycans (GAGs) in urine, and analysis of the IDS gene. Eligibility criteria for the study also included being 16 years of age or older and being enrolled in a genetic counselling programme. The pedigree and DNA analyses allowed the identification of 40/52 carriers and 12/52 non-carriers. All women evaluated were clinically healthy, and their levels of urinary GAGs were within normal limits. Median plasma and leukocyte IDS activities found among carriers were significantly lower than the values found for non-carriers; there was, however, an overlap between carriers' and non-carriers' values. Our data suggests that MPS II carriers show lower plasma and leukocyte IDS activities but that this reduction is generally associated neither with changes in levels of urinary GAGs nor with the occurrence of clinical manifestations.
Asunto(s)
Heterocigoto , Mucopolisacaridosis II/genética , Adolescente , Adulto , Biomarcadores/análisis , Biomarcadores/orina , Estudios de Casos y Controles , Análisis Mutacional de ADN , Familia , Salud de la Familia , Femenino , Glicoproteínas/análisis , Glicoproteínas/genética , Glicosaminoglicanos/análisis , Glicosaminoglicanos/orina , Humanos , Persona de Mediana Edad , Mucopolisacaridosis II/diagnóstico , Mucopolisacaridosis II/orina , Linaje , Examen Físico , Adulto JovenRESUMEN
Intestinal failure is the patient's inability to maintain hydroelectric and nutritional support by the digestive route, arising from massive enterectomy or diseases in which the bowel is incapable of adequately absorbing fluids and nutrients. Patients with intestinal failure associated with short bowel syndrome (SBS) and with other functional diseases with malabsorption or with total parenteral nutrition-related complications (recurrent sepsis and thrombosis of one or more deep venous accesses) are candidates for small bowel transplantation (SBT), which can be an isolated small bowel, a combined liver and small bowel, or a multivisceral graft. At our institution, three isolated SBTs were performed as our initial experience with this transplant.
Asunto(s)
Intestino Delgado/trasplante , Adulto , Anciano , Brasil , Resultado Fatal , Femenino , Hospitales de Enseñanza/estadística & datos numéricos , Humanos , Enfermedades Intestinales/cirugía , Masculino , Síndrome del Intestino Corto/cirugía , Resultado del TratamientoRESUMEN
It has been shown previously that malnourished rats are resistant to acute gastric lesions but not to subchronic gastric ulceration. It also has been demonstrated that the essential oil obtained from the bark of Croton cajucara (Sacaca) has antiulcer properties. In the present study, the ability of this essential oil to prevent the formation of gastric ulcers in rats fed a diet with 17% protein (normoproteic rats) or 6% protein (malnourished rats) was investigated. At a dose of 100 mg/kg body weight, orally, the essential oil significantly reduced the gastric injury caused by indomethacin (25% after 2 h and 70% after 4 h) only in normoproteic rats. In the pylorus ligature model, the essential oil increased the pH and gastric volume, but decreased the total acid concentration in both groups when compared to the respective control group. The essential oil significantly increased prostaglandin E2 production in glandular cells by 50% compared to the controls in both groups of rats. In addition, the amount of gastric mucus was two-fold higher in malnourished rats than in normoproteic rats. The present results show that the enhanced protective effect of essential oil in malnourished rats involved an increase in prostaglandin E2 production and mucus secretion, which are both factors that protect the gastric mucosa against damage. In agreement with this, malnourished rats always had a lower number of acute gastric ulcers.
Asunto(s)
Croton , Aceites Volátiles/uso terapéutico , Fitoterapia/métodos , Desnutrición Proteico-Calórica/complicaciones , Úlcera Gástrica/prevención & control , Animales , Antiulcerosos/uso terapéutico , Dinoprostona/biosíntesis , Femenino , Jugo Gástrico/metabolismo , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patología , Concentración de Iones de Hidrógeno/efectos de los fármacos , Extractos Vegetales/uso terapéutico , Desnutrición Proteico-Calórica/metabolismo , Desnutrición Proteico-Calórica/patología , Ratas , Ratas Wistar , Úlcera Gástrica/complicaciones , Úlcera Gástrica/metabolismo , Úlcera Gástrica/patologíaRESUMEN
The aim of the study was to evaluate the effect of GH on body weight, body composition and cardiovascular risk factors in android obese men. Forty non-diabetic subjects aged 20 to 50 years-old with android obesity (WHR > 1) were divided in two groups, on a prospective randomized double-blind basis to receive treatment with GH (0.050 U/kg/day) or placebo for three months. Bioimpedance analysis, DEXA, indirect calorimetry and cardiovascular risk factors were done at the beginning and at the end of the study. Anthropometric measurements were evaluated monthly. Body weight was reduced (3.5 +/- 2.9 kg), as well as BMI (1.2 +/- 1.0 kg/m2), WHR (0.04 +/- 0.01) and fat mass (2.4 +/- 1.0 kg), total cholesterol (4.0 +/- 3.3 mg/dL) and LDL-cholesterol (5.7 +/- 2.7 mg/dL) in GH-treated patients. Percentual changes were statistically different from placebo. Benefits and risks of long-term GH use in obese patients are still largely unknown.
Asunto(s)
Hormona de Crecimiento Humana/uso terapéutico , Grasa Intraabdominal/efectos de los fármacos , Obesidad/tratamiento farmacológico , Absorciometría de Fotón , Adulto , Composición Corporal/efectos de los fármacos , Calorimetría Indirecta , Método Doble Ciego , Impedancia Eléctrica , Humanos , Masculino , Persona de Mediana Edad , Obesidad/sangre , Estudios Prospectivos , Proteínas Recombinantes/uso terapéutico , Factores de RiesgoRESUMEN
O objetivo do estudo foi avaliar os efeitos do GH sobre peso, composição corporal, metabolismo de repouso e fatores de risco cardiovascular na obesidade visceral. O estudo foi prospectivo randomizado duplo-cego em 40 homens não diabéticos de 20 a 50 anos com RAQ (relação abdômen-quadril) > 1 tratados com GH (0,050 U/kg/dia) ou placebo por três meses. Foram avaliados peso, composição corporal por bioimpedância e DEXA, metabolismo de repouso através da calorimetria indireta e exames de fatores de risco cardiovasculares no início e fim do tratamento. O grupo de obesos tratados com GH teve reduções de peso (3,5 ± 2,9 kg), IMC (1,2 ± 1,0 kg/m²), RAQ (0,04 ± 0,01) e massa adiposa (2,4 ± 1,0 kg). As reduções porcentuais foram significantemente diferentes das observadas no grupo placebo. Também houve diminuição nos níveis de colesterol total (4,0 ± 3,3 mg/dL) e LDL-colesterol (5,7 ± 2,7 mg/dL) no grupo GH, em relação ao grupo placebo. Os outros fatores de risco não se alteraram significantemente. Concluímos que obesos tratados com GH por três meses apresentaram uma redução significante de peso corporal, gordura visceral e massa adiposa, e melhora do perfil lipídico. O benefício/risco do GH a longo prazo em obesos é desconhecido.
Asunto(s)
Humanos , Masculino , Adulto , Persona de Mediana Edad , Hormona de Crecimiento Humana/uso terapéutico , Grasa Intraabdominal/efectos de los fármacos , Obesidad/tratamiento farmacológico , Proteínas Recombinantes/uso terapéutico , Absorciometría de Fotón , Composición Corporal/efectos de los fármacos , Calorimetría Indirecta , Enfermedades Cardiovasculares , Método Doble Ciego , Impedancia Eléctrica , Obesidad/sangre , Estudios Prospectivos , Factores de RiesgoRESUMEN
Beta-glucans are soluble fibers with physiological functions, such as interference with absorption of sugars and reduction of serum lipid levels. The objective of the present study was to analyze the distribution of beta-glucans in different tissues of the African grass species Rhynchelytrum repens and also to evaluate their hypoglycemic activity. Leaf blades, sheaths, stems, and young leaves of R. repens were submitted to extraction with 4 M KOH. Analysis of the fractions revealed the presence of arabinose, glucose, xylose, and traces of rhamnose and galactose. The presence of beta-glucan in these fractions was confirmed by hydrolyzing the polymers with endo-beta-glucanase from Bacillus subtilis, followed by HPLC analysis of the characteristic oligosaccharides produced. The 4 M KOH fractions from different tissues were subjected to gel permeation chromatography on Sepharose 4B, with separation of polysaccharides with different degrees of polymerization, the highest molecular mass (above 2000 kDa) being found in young leaves. The molecular mass of the leaf blade polymers was similar (250 kDa) to that of maize coleoptile beta-glucan used for comparison. The 4 M KOH fraction injected into rats with streptozotocin-induced diabetes showed hypoglycemic activity, reducing blood sugar to normal levels for approximately 24 h. This performance was better than that obtained with pure beta-glucan from barley, which decreased blood sugar levels for about 4 h. These results suggest that the activity of beta-glucans from R. repens is responsible for the use of this plant extract as a hypoglycemic drug in folk medicine.
Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Hipoglucemiantes/farmacología , Poaceae/química , Polisacáridos/farmacología , beta-Glucanos/farmacología , Animales , Cromatografía Líquida de Alta Presión , Hipoglucemiantes/aislamiento & purificación , Masculino , Extractos Vegetales/farmacología , Polisacáridos/aislamiento & purificación , Ratas , Ratas Wistar , beta-Glucanos/aislamiento & purificaciónRESUMEN
ß-Glucans are soluble fibers with physiological functions, such as interference with absorption of sugars and reduction of serum lipid levels. The objective of the present study was to analyze the distribution of ß-glucans in different tissues of the African grass species Rhynchelytrum repens and also to evaluate their hypoglycemic activity. Leaf blades, sheaths, stems, and young leaves of R. repens were submitted to extraction with 4 M KOH. Analysis of the fractions revealed the presence of arabinose, glucose, xylose, and traces of rhamnose and galactose. The presence of ß-glucan in these fractions was confirmed by hydrolyzing the polymers with endo-ß-glucanase from Bacillus subtilis, followed by HPLC analysis of the characteristic oligosaccharides produced. The 4 M KOH fractions from different tissues were subjected to gel permeation chromatography on Sepharose 4B, with separation of polysaccharides with different degrees of polymerization, the highest molecular mass (above 2000 kDa) being found in young leaves. The molecular mass of the leaf blade polymers was similar (250 kDa) to that of maize coleoptile ß-glucan used for comparison. The 4 M KOH fraction injected into rats with streptozotocin-induced diabetes showed hypoglycemic activity, reducing blood sugar to normal levels for approximately 24 h. This performance was better than that obtained with pure ß-glucan from barley, which decreased blood sugar levels for about 4 h. These results suggest that the activity of ß-glucans from R. repens is responsible for the use of this plant extract as a hypoglycemic drug in folk medicine.
Asunto(s)
Animales , Masculino , Ratas , Diabetes Mellitus Experimental/tratamiento farmacológico , Hipoglucemiantes/farmacología , Poaceae/química , Polisacáridos/farmacología , beta-Glucanos/farmacología , Cromatografía Líquida de Alta Presión , Hipoglucemiantes/aislamiento & purificación , Extractos Vegetales/farmacología , Polisacáridos/aislamiento & purificación , Ratas Wistar , beta-Glucanos/aislamiento & purificaciónRESUMEN
Protein malnutrition can adversely affect all tissues. The aim of the present study was to test the hypothesis that protein deprivation influences gastric ulcer formation, as well as metabolism and organ growth, in rats. In the present study, there was a significant reduction in the body and organ weight of rats fed a low-protein diet (P<0.001). Malnourished rats were less susceptible to ulceration of the gastric mucosa in ethanol and indomethacin models of acute gastric ulcers when compared with rats fed a normoproteic diet (17 % protein). Mucus production and prostaglandin E2 formation increased in malnourished rats, possibly explaining the lower number of acute ulcers in these animals. Pylorus ligature altered gastric juice composition (increased pH and gastric volume, and decreased total acid concentration) in the animal group fed a low-protein diet compared with the group fed a diet containing 17 % protein (P<0.05). The gastric mucosa was more damaged in malnourished rats than in normal rats evaluated for 14 d after acetic acid injection (P<0.001). Malnourished rats exhibited resistance to acute gastric lesions, owing to an increase in prostaglandin GE2 release and mucus secretion, which protected their gastric mucosa. This phenomenon was not seen in subchronic gastric ulceration.
Asunto(s)
Deficiencia de Proteína/complicaciones , Úlcera Gástrica/complicaciones , Ácido Acético , Animales , Peso Corporal , Corticosterona/sangre , Citoprotección , Dinoprostona/biosíntesis , Etanol , Femenino , Mucosa Gástrica/metabolismo , Indometacina , Moco/metabolismo , Tamaño de los Órganos , Polisorbatos , Deficiencia de Proteína/patología , Ratas , Ratas Wistar , Somatostatina/sangre , Úlcera Gástrica/inducido químicamente , Úlcera Gástrica/patologíaRESUMEN
Irradiance is a crucial factor in plant development. Different radiant energy levels cause different responses related to plant growth and the production and distribution of dry matter. Considering the relationship between light availability and metabolism of carbohydrates and derived compounds, the aim of this work was to assess the effects of irradiance on non-structural carbohydrate contents and composition, as well as on the hypoglycemiant activity of Rhynchelytrum repens, a pantropical grass species popularly used for diabetes treatment. Plants of R. repens growing under natural irradiance (NI) showed increased content of total soluble carbohydrate (TSC), higher fluctuations in starch content (SC) and higher number of tillers. The flowering process of these plants was preceded by an increase in sucrose. However, their water content was low when compared to that of plants cultivated under low irradiance (LI). The ratio root/aerial organs and SC showed no significant differences in plants grown under LI, although TSC increased and a lower number of tillers were observed during the experimental period. In both conditions, sucrose was the ubiquitous sugar and seemed to be involved in the flowering process. A reduction in the blood sugar level was observed through the intra-peritoneal (IP) administration of the precipitate of aqueous extracts obtained from plants growing in both conditions of light; the supernatant fraction showed no hypoglycemic effect.
Asunto(s)
Metabolismo de los Hidratos de Carbono , Diabetes Mellitus Experimental/terapia , Hipoglucemiantes/farmacología , Luz , Poaceae/efectos de la radiación , Animales , Hipoglucemiantes/aislamiento & purificación , Hipoglucemiantes/uso terapéutico , Extractos Vegetales/farmacología , Poaceae/química , Poaceae/crecimiento & desarrollo , Ratas , Factores de TiempoRESUMEN
A irradiância é um fator crucial em reações vitais para o crescimento e desenvolvimento das plantas. A utilização da energia radiante pelos vegetais afeta diferentes respostas em relação ao padrão de desenvolvimento e à produção de matéria seca e sua conseqüente distribuição. Tendo em vista a intrínseca relação entre disponibilidade de luz, acúmulo de biomassa e metabolismo de carboidratos e compostos relacionados, os objetivos deste trabalho foram avaliar o efeito da irradiância sobre o conteúdo e a composição dos carboidratos não-estruturais, sobre o desenvolvimento e sobre a atividade hipoglicemiante de Rhynchelytrum repens, uma gramínea pantropical de origem africana utilizada popularmente no tratamento de diabetes. O cultivo a pleno sol (PS) estimulou aumento no conteúdo de carboidratos solúveis totais (CST), no perfilhamento das plantas e nas flutuações do conteúdo de amido (CA). O florescimento dessas plantas foi precedido por um aumento de CST, especialmente de sacarose. Foi observado também menor conteúdo de água nas plantas sob PS quando comparado com as plantas cultivadas sob irradiância reduzida (IR). Nesta última condição, o CA e a razão raiz/parte aérea não sofreram alterações significativas, porém houve aumento no conteúdo de CST ao longo do período experimental, menor grau de perfilhamento e formação de raízes adventícias aéreas. Em ambas as condições de luminosidade, a sacarose foi o açúcar mais abundante e com maiores variações. Esse açúcar parece estar envolvido nos processos de florescimento da espécie. Uma redução no nível de glicose plasmática foi observada a partir da administração do precipitado do extrato aquoso de R. repens obtido de plantas cultivadas em PS e IR, não havendo diferença significativa entre os tratamentos. A fração sobrenadante não apresentou efeito hipoglicemiante.
Asunto(s)
Animales , Ratas , Carbohidratos , Diabetes Mellitus Experimental , Hipoglucemiantes , Luz , Poaceae , Extractos Vegetales , Factores de TiempoRESUMEN
Ipomoea imperati (Convolvulaceae) lives on the sandy shores of the Brazilian coast and in other areas of the world. The anti-inflammatory activity of a methanol-water extract of the leaves of I. imperati was investigated in experimental models of acute and subchronic inflammation. Topical application of the extract (10 mg/ear) inhibited mouse ear edema induced by croton oil (89.0 +/- 1.3% by the lipid fraction with an IC50 of 3.97 mg/ear and 57.0 +/- 1.3% by the aqueous fraction with an IC50 of 3.5 mg/ear) and arachidonic acid (42.0 +/- 2.0% with an IC50 of 4.98 mg/ear and 31.0 +/- 2.0% with an IC50 of 4.72 mg/ear). Phospholipase A2, purified from Apis mellifera bee venom, was also inhibited by the extract (5.0 mg/ml lipid and aqueous fraction) in vitro in a dose-dependent manner (85% by the lipid fraction with an IC50 of 3.22 mg/ml and 25% by the aqueous fraction with an IC50 of 3.43 mg/ml). The methanol-water extract of I. imperati (1000 mg/kg) administered by the oral route also inhibited the formation of cotton pellet-induced granulomas (73.2 +/- 1.2% by the lipid fraction and 56.14 +/- 2.7% by the aqueous fraction) and did not cause gastric mucosal lesions. I. imperati extracts (10 mg/ml) also inhibited in a dose-dependent manner the muscle contractions of guinea pig ileum induced by acetylcholine and histamine (IC50 of 1.60 mg/ml for the lipid fraction and 4.12 mg/ml for the aqueous fraction). These results suggest the use of I. imperati as an anti-inflammatory and antispasmodic agent in traditional medicine.