Expression dynamics of caveolin-1 in fibroblasts of newborn rats with chronic lung disease and its impact on lung fibroblast proliferation

Abstract Purpose: To evaluate the changes of caveolin-1 in lung fibroblasts in newborn Wistar rats when exposed to hyperoxic conditions, as well as lung fibroblasts cell cycle. Methods: One hundred newborn Wistar rats were randomly divided (50 rats/group) into experimental and control groups, exposed to hyperoxic conditions or normal air, respectively. The fraction of inspired oxygen (FiO2) in the experimental group was 90%, whereas this value was 21% in the control group. Lung fibroblasts were collected on days 3, 7, and 14 of the experiment. Caveolin-1 expression dynamics in lung fibroblasts was assayed in each group by immunofluorescence and Western blot analyses. Flow cytometry (FCM) was used to assess the proportions of lung fibroblasts at different stages of the cell cycle. Results: On day 3, no significant difference in caveolin-1 expression was observed between the hyperoxic and control groups; however, on days 7 and 14, caveolin-1 expression was significantly lower in the hyperoxic group than in the control (P<0.05). No apparent differences were observed in caveolin-1 expression in the control group at the different time points. Using FCM analysis, we showed that the proportion of lung fibroblasts in G0/G1 phase in the hyperoxic group decreased compared to that of the control group on day 7, while the proportion of S-phase cells increased (P<0.05). These differences were more significant when the groups were compared on day 14 (P<0.01). Conclusion: After seven days the exposure to hyperoxic conditions, lung fibroblasts proliferated and caveolin-1 expression decreased.

Pathology of dogs in Campo Grande, MS, Brazil naturally co-infected with Leishmania infantum and Ehrlichia canis / Patologia de cães naturalmente coinfectados por Leishmania infantum e Ehrlichia canis em Campo Grande, MS, Brasil

Different parasites that commonly occur concomitantly can influence one another, sometimes with unpredictable effects. We evaluated pathological aspects of dogs naturally co-infected with Leishmania infantum and Ehrlichia canis. The health status of the dogs was investigated based on histopathological, hematological and biochemical analyses of 21 animals infected solely with L. infantum and 22 dogs co- infected with L. infantum and E. canis. The skin of both groups showed chronic, predominantly lymphohistioplasmacytic inflammatory reaction. The plasmacytosis in the lymphoid tissues was likely related with the hypergammaglobulinemia detected in all the dogs. The disorganization of extracellular matrix found in the reticular dermis of the inguinal region and ear, characterized by the substitution of thick collagen fibers for thin fibers, was attributed to the degree of inflammatory reaction, irrespective of the presence of parasites. In addition, the histopathological analysis revealed that twice as many dogs in the co-infected group presented Leishmania amastigotes in the ear skin than those infected solely with Leishmania, increasing the possibility of becoming infected through sand fly vectors. Our findings highlight the fact that the health of dogs infected concomitantly with L. infantum and E. canis is severely compromised due to their high levels of total plasma protein, globulins, alkaline phosphatase and creatine kinase, and severe anemia.

A infecção simultânea por parasitas de diferentes espécies pode resultar em alterações imprevisíveis. O presente estudo avaliou a patologia de cães naturalmente coinfectados por Leishmania infantum e Ehrlichia canis. A saúde dos cães foi investigada pelas análises histopatológicas, hematológicas e bioquímicas de 21 cães infectados somente por L. infantum e 22 cães coinfectados por L. infantum e E. canis. Observou-se uma reação inflamatória crônica, predominantemente linfohistioplasmocítica, na pele dos dois grupos. A plasmocitose, encontrada nos tecidos linfóides, provavelmente estava relacionada com a hipergamaglobulinemia observada em todos os cães amostrados. A desorganização da matriz extracelular da derme da região inguinal e da orelha, demonstrada pela substituição das fibras de colágeno espessas por fibras finas, foi relacionada com o grau de reação inflamatória, independente da presença de parasitas. Ainda, observamos duas vezes mais animais do grupo coinfectado apresentando formas amastigotas na pele de orelha pela histopatologia comparado ao número de cães infectados apenas por Leishmania, tornando-os desta forma mais infectivos aos vetores. Nossos resultados ressaltam que a saúde de cães coinfectados estava severamente comprometida devido aos altos níveis de proteína plasmática total, globulinas, fosfatase alcalina, creatina quinase e anemia acentuada.

Identificación y expresión diferencial del factor de transcripción asociado a microftalmia en corazón y cardiomiocitos aislados de cobayo: su posible papel en la hipertrofia y la viabilidad / Identification and differential expression of the microphthalmia-associated transcription factor in heart and isolated cardiomyocytes from Guinea pigs: Possible role in hypertrophy and viability

Introducción. El factor de transcripción asociado a la microftalmia ( Microphtalmia-Associated Transcription Factor , MITF) regula la expresión de genes específicos, pero no se conoce su expresión y su función a nivel cardiaco. Objetivos. Identificar la expresión del MITF en corazón y en cardiomiocitos aislados de cobayo, describir los cambios morfológicos asociados con su disminución y evaluar los niveles relativos de su expresión en cardiomiocitos aislados en condiciones de preacondicionamiento isquémico. Materiales y métodos. El análisis de la expresión relativa de la isoforma específica de tejido cardiaco ( heart-type MITF, MITF-H), se determinó mediante reacción en cadena de la polimerasa (PCR) en tiempo real semicuantitativa, secuenciación y Western blot . La disminución del ARNm del MITF se indujo con un ARN pequeño de interferencia ( short hairpin RNA interference , shRNAi) específico. El tamaño, el diámetro y el número de fibras musculares se evaluaron por observación directa con microscopía de luz. Resultados. Se amplificó un fragmento de 281 pb de ADNc; el análisis de la secuencia confirmó la identidad del exón 1 y la isoforma H del MITF. La interferencia del ARNm del MITF se asoció con un mayor índice cardiaco (peso corazón/peso corporal: 5,46 x 10 -3 Vs. 4,6 x 10 -3 ) y un incremento del diámetro de las fibras cardiacas (50,2±16 µm Vs. 38,7±14,7 µm; p<0,05, n=150). En los cardiomiocitos aislados en condiciones de preacondicionamiento isquémico, se observó una expresión relativa del MITF-H mayor que en los miocitos en normoxia y expuestos a lesión por isquemia simulada (80 y 100 veces más, n=5, p<0,05, n=3). Conclusión. Los resultados sugieren que el MITF-H podría estar involucrado en la hipertrofia, la respuesta al estrés por isquemia y la supervivencia de cardiomiocitos de cobayo.

Introduction: The microphthalmia -associated transcription factor ( MITF ) regulates the expression of specific genes and its cardiac expression and function is not known. Objectives: To identify the expression of MITF in hearts and isolated cardiomyocytes from Guinea pigs, to describe morphological changes associated with mRNA interference of MITF and to evaluate their relative changes in expression in isolated cardiomyocytes under ischemic preconditioning. Materials and methods: The cardiac specific isoform, MITF-H, and relative expression level analysis, was determined by semi-quantitative real time PCR, sequencing and Western blotting. Reduction of mRNA-MITF-H was induced by transduction of specific-MITF-shRNAi interference. The cardiac morphological changes, diameter and number of cardiac fibers were evaluated by direct observation and light microscopy. Results: A cDNA fragment of 281 bp was amplified from heart and isolated ventricular cardiac myocytes. Sequence analysis confirmed the identity of the isoform MITF-H, exon 1. The MITF silencing was associated with an increase in cardiac index (heart weight/body weight vs . 5.46 x 10 -3 vs 4.6 x 10 -3 ) and higher diameter of cardiac fibers (50.2±16 µ m vs 38,7±14,7 µ m p<0.05, n=150). In isolated cardiac myocytes under ischemic preconditioning we observed a higher relative expression compared with that measured in myocytes exposed to normoxia and simulated ischemia (eighty and one hundred times, p <0.05, n = 5). Conclusion. The results suggest that MITF-H isoform may be involved in Guinea pig cardiac hypertrophy, response to stress by ischemia and cardiomyocytes survival.

Effects of erythromycin on γ-glutamyl cysteine synthetase and interleukin-1β in hyperoxia-exposed lung tissue of premature newborn rats / Efeitos da eritromicina sobre a γ-glutamil-cisteína-sintetase e a interleucina-1β no tecido pulmonar exposto à hiperóxia de ratos recém-nascidos prematuros

Objective: To explore the effect of erythromycin on hyperoxia-induced lung injury. Methods: One-day-old preterm offspring Sprague-Dawley (SD) rats were randomly divided into four groups: group 1, air + sodium chloride; group 2, air + erythromycin;group 3, hyperoxia + sodium chloride; and group 4, hyperoxia + erythromycin. At one, seven, and 14 days of exposure, glutathione (GSH) and interleukin-1 beta (IL-1 beta) were detected by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA), and bicinchoninic acid (BCA) was used to detect GSH protein. γ-glutamine-cysteine synthetase (γ-GCS) mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). Results: Compared with group 1, expressions of GSH and γ-GCS mRNA in group 3 were significantly increased at one and seven days of exposure (p < 0.05), but expression of γ-GCS mRNA was significantly reduced at 14 days; expression of IL-1 beta in group 3 was significantly increased at seven days of exposure (p < 0.05), and was significantly reduced at 14 days. Compared with group 3, expressions of GSH and γ-GCS mRNA in group 4 were significantly increased at one, seven, and 14 days of exposure (p < 0.05), but expressions of GSH showed a downward trend at 14 days; expression of IL-1 beta in group 4 was significantly reduced at one and seven days of exposure (p < 0.05). Conclusions: Changes in oxidant-mediated IL-1 beta and GSH are involved in the development of hyperoxia-induced lung injury. Erythromycin may up-regulate the activity of γ-GCS, increasing the expression of GSH, inhibiting the levels of oxidant-mediated IL-1 beta and alleviating hyperoxia-induced lung injury via an antioxidant effect. .

Objetivo: Explorar o efeito da eritromicina sobre lesões pulmonares induzidas por hiperóxia. Métodos: Uma prole de ratos Sprague-Dawley (SD) prematuros com um dia de vida foi dividida aleatoriamente em quatro grupos: grupo 1 ar + cloreto de sódio, grupo 2 ar + eritromicina, grupo 3 hiperóxia + cloreto de sódio e grupo 4 hiperóxia + eritromicina. Com um, sete e 14 dias de exposição, foram detectadas Glutationa (GSH) e Interleucina-1 beta (IL-1 beta) pelo ensaio imunossorvente ligado à enzima (ELISA), e o ácido bicinconinico (BCA) foi utilizado para detectar a proteína GSH. O mRNA da γ-glutamil-cisteina-sintetase (γ-GCS) foi detectado por reação em cadeia da polimerase via transcriptase reversa (RT-PCR). Resultados: Comparadas ao grupo 1, as expressões do mRNA da GSH e da γ-GCS no grupo 3 aumentaram significativamente com um e sete dias de exposição (p < 0,05), porém a expressão de mRNA da γ-GCS diminuiu significativamente aos 14 dias; a expressão de IL-1 beta no grupo 3 aumentou significativamente aos 7 dias de exposição (p < 0,05) e diminuiu significativamente aos 14 dias. Comparadas ao grupo 3, as expressões do mRNA da GSH e da γ-GCS no grupo 4 aumentaram significativamente com um, sete e 14 dias de exposição (p < 0,05), porém as expressões de GSH mostraram uma tendência de queda aos 14 dias; a expressão de IL-1 beta no grupo 4 foi reduzida significativamente com um e sete dias de exposição (p < 0,05). Conclusões: As variações de IL-1 beta e GSH mediadas por oxidantes estão envolvidas no desenvolvimento de lesão pulmonar induzida por hiperóxia. A eritromicina poderá regular positivamente a atividade da γ-GCS, aumentando a expressão de GSH, inibindo os níveis de interleucina-1beta mediada por ...

Bilirubin Activates Transcription of HIF-1alpha in Human Proximal Tubular Cells Cultured in the Physiologic Oxygen Content

The expression of hypoxia-inducible factor (HIF) is influenced by reactive oxygen species (ROS). Effect of bilirubin on HIF-1 expression in proximal tubular cells was investigated under physiological oxygen concentration, which is relative hypoxic condition mimicking oxygen content in the medulla of renal tissue. The human kidney (HK2) cells were cultured in 5% oxygen with or without bilirubin. HIF-1alpha protein expression was increased by bilirubin treatment at 0.01-0.2 mg/dL concentration. The messenger RNA expression of HIF-1alpha was increased by 1.69+/-0.05 folds in the cells cultured with 0.1 mg/dL bilirubin, compared to the control cells. The inhibitors of PI3K/mTOR, PI3K/AKT, and ERK 1/2 pathways did not attenuate increased HIF-1alpha expression by bilirubin. HIF-1alpha expression decreased by 10 microM exogenous hydrogen peroxide (H2O2); scavenger of ROS with or without bilirubin in the HK2 cells increased HIF-1alpha concentration more than that in the cells without bilirubin. Exogenous H2O2 decreased the phosphorylation of P70S6 kinase, which was completely reversed by bilirubin treatment. Knockdown of NOX4 gene by small interfering RNA (siRNA) increased HIF-1alpha mRNA expression. In coonclusion, bilirubin enhances HIF-1alpha transcription as well as the up-regulation of HIF-1alpha protein translation through the attenuation of ROS and subunits of NADPH oxidase.

The effect of hypoxia and reoxygenation in the response of mesangial cells to angiotensin II in vitro / Efeito da hipóxia e reoxigenação na resposta à angiotensina II em células mesangiais in vitro

INTRODUCTION: Mesangial cells (MC) may be involved in the glomerular alterations induced by ischemia/reperfusion injury. OBJECTIVE: To evaluate the response of immortalized MC (IMC) to 30 minutes of hypoxia followed by reoxygenation periods of 30 minutes (H/R30) or 24 hours (H/R24). METHODS: The intracellular calcium concentration ([Ca+2]i) was measured before (baseline) and after adding angiotensin II (AII, 10-5 M) in the presence and absence of glybenclamide (K ATP channel blocker). We estimated the level of intracellular ATP, nitric oxide (NO) and PGE2. RESULTS: ATP concentration decreased after hypoxia and increased after reoxygenation. Hypoxia and H/R induced increases in basal [Ca+2]i. AII induced increases in [Ca+2]i in normoxia (97 ± 9%), hypoxia (72 ± 10%) or HR30 (85 ± 17%) groups, but there was a decrease in the response to AII in group H/R24 since the elevation in [Ca+2]i was significantly lower than in control (61 ± 10%, p < 0.05). Glybenclamide did not modify this response. It was observed a significant increase in NO generation after 24 hours of reoxygenation, but no difference in PGE2 production was observed. Data suggest that H/R injury is characterized by increased basal [Ca+2]i and by an impairment in the response of cells to AII. Results suggest that the relative insensibility to AII may be at least in part mediated by NO but not by prostaglandins or vasodilator K ATP channels. CONCLUSION: H/R caused dysfunction in IMC characterized by increases in basal [Ca+2]i during hypoxia and reduction in the functional response to AII during reoxygenation.

INTRODUÇÃO: Células mesangiais (CM) podem estar envolvidas na lesão glomerular induzida por hipoxia/reperfusão (H/R). OBJETIVO: Avaliar a resposta de CM imortalizadas (CMI) à hipoxia por 30 minutos seguida de reoxigenação por 30 minutos (H/R30) ou 24 horas (H/R24). MÉTODOS: Concentração de cálcio intracelular ([Ca+2]i) foi avaliada antes (basal) e após a adição de angiotensina II (AII, 10-5 M), na presença e na ausência de glibenclamida (bloqueador de canais K ATP). Foram estimados o nível de ATP intracelular, de óxido nítrico (NO) e de PGE2. RESULTADOS: Nível de ATP diminuiu após hipóxia e aumentou após a reoxigenação. H/R induziu aumento na [Ca+2]i basal. A AII elevou a [Ca+2]i nas condições de normoxia (97 ± 9%), hipoxia (72 ± 10%) ou HR30 (85 ± 17%), porém no grupo H/R24, houve diminuição significativa na resposta à AII, uma vez que a elevação da [Ca+2]i foi mais baixa do que no controle (61 ± 10%, p < 0,05). Glibenclamida não alterou esta resposta. Houve um aumento significativo na geração de NO após 24 horas de reoxigenação, mas não foi observada nenhuma diferença na produção de PGE2. Os dados indicam que a injuria celular causada pela hipoxia/reoxigenação é caracterizada pelo aumento na [Ca+2]i basal e por uma diminuição na reatividade celular à AII. Resultados sugerem que a insensibilidade ao agonista constritor pode ser pelo menos em parte, mediada pelo NO, mas não pelas prostaglandinas ou por canais K ATP. CONCLUSÃO: H/R resultou em disfunção das CMI, caracterizada pelo aumento na [Ca+2]i basal durante a hipóxia e redução da resposta funcional a AII durante a reoxigenação.

Survival of hypoxic human mesenchymal stem cells is enhanced by a positive feedback loop involving miR-210 and hypoxia-inducible factor 1

The use of mesenchymal stem cells (MSCs) has emerged as a potential new treatment for myocardial infarction. However, the poor viability of MSCs after transplantation critically limits the efficacy of this new strategy. The expression of microRNA-210 (miR-210) is induced by hypoxia and is important for cell survival under hypoxic conditions. Hypoxia increases the levels of hypoxia inducible factor-1 (HIF-1) protein and miR-210 in human MSCs (hMSCs). miR-210 positively regulates HIF-1alpha activity. Furthermore, miR-210 expression is also induced by hypoxia through the regulation of HIF-1alpha. To investigate the effect of miR-210 on hMSC survival under hypoxic conditions, survival rates along with signaling related to cell survival were evaluated in hMSCs over-expressing miR-210 or ones that lacked HIF-1alpha expression. Elevated miR-210 expression increased survival rates along with Akt and ERK activity in hMSCs with hypoxia. These data demonstrated that a positive feedback loop involving miR-210 and HIF-1alpha was important for MSC survival under hypoxic conditions.

Superoxide dismutase functional regulation in neonatal hypoxia: Effect of glucose, oxygen and epinephrine.

Hypoxia is one of the major causes of damage to the fetal and neonatal brain and cardiac functions. In earlier studies, we have reported the brain damage caused by hypoxia and resuscitation with oxygen and epinephrine and have found that glucose treatment to hypoxic rats and hypoxic rats treated with oxygen shows a reversal of brain damage. The neonatal rats are shown to be deficient in free radical scavenging system, which offers a high risk of oxidative stress. In the present study, we induced hypoxia in neonatal Wistar rats and resuscitated with glucose, oxygen and epinephrine. Heart tissue and cerebral cortex were used to study the kinetics of superoxide dismutase activity in experimental groups of rats to assess the free radical status. Results showed that glucose supplementation in hypoxia (Hx + G) and hypoxic + oxygen (Hx + O) had an efficient free radical scavenging capability, compared to all other experimental groups. The observation was ascertained by studying the activity of catalase, another antioxidant enzyme in the body. Our results suggested that in neonatal rats during hypoxic condition, damage to heart and brain was more prominent in all groups, except when supplemented with glucose. These findings may have clinical significance in the proper management of heart and brain function.

Experimental study on the cryopreservation of LLC-PK1 epithelial cells with hypoxic UW solution / 华中科技大学学报（医学）（英德文版）

The effects of oxygen partial pressure on cryopreservation of the cells with organ preservation solution were explored. Hypoxic UW solution was made by purging the UW solution with argon. The pig proximal tubule epithelial cells (LLC-PK1 cells) were cryopreserved in hypoxic UW solution (Ar-UW group) or standard UW solution (UW group) at 4 degrees C for 48 h. Trypan blue staining and LDH detection were performed to evaluate the injury of the cells. The results showed that the oxygen partial pressure in Ar-UW group was significantly declined from 242+/-6 mmHg to 83+/-10 mmHg. After cryopreservation at 4 degrees C for 48 h, LDH leakage rate and Trypan blue-stained rate in Ar-UW group were (11.3+/-3.4)% and (10.5+/-4.7)%, respectively, which were significantly lower than in UW group [(49.5+/-6.9)% and (47.6+/-9.3)% respectively, both P<0.01]. It was concluded that lower oxygen partial pressure of UW solution was more beneficial to the cryopreservation of LLC.

A nicotina atua como fator deletério na reparação da parede abdominal / Nicotine has a deleterious effect on the healing of abdominal wall

Objetivo: Avaliar o efeito da nicotina na cicatrização da camada musculoaponeurótica da parede abdominal. Métodos: Estudo experimetnal em que foram usados 16 ratos da raça Wistar pesando em média 210+/-8g, separados aleatoriamente em 2 grupos de 8. Nos animais do grupo A foi implantado disco de nicotina (Nicotinel Ó) na dose de 5mg/kg de peso/dia no subcutâneo da região dorsal, trocando a cada dois dias, a partir do 5§ dia antes da operação em que foi feita laparotomia mediana de 5 cm, até o 10§ dia de observação. No grupo B (controle) foram usados discos de celulose com o mesmo diâmetro. Tubo de silicone multiperfurado foi implantado no subcutâneo a 1cm da lesão da parede abdominal. A camada musculoaponeurótica e a pele foram suturadas com fio de nylon 5-0. No 10§ dia pós-operatório foi colhido 1ml de líquido seroso do tubo de silicone por punção percutânea para dosagem de pO2 e os animais receberam dose letal de anestésico. Foi ressecado um segmento da camada musculoaponeurótica com 2cm de largura para tensiometria, em seguida processado e corado em HE e tricrômico de Masson para análise quantitativa dos dados histopatológicos em sistema digitalizado. A análise estatística foi feita pelo ANOVA e teste Newman-Keus, com significância 0,05. Resultados: No grupo A a p)2 do líquido tecidual atingiu o valor 17,75+/-3,4 mmHg e no grupo B (controle) a pO2 +40,75+/-6,4 mmHg(p<0,01). A resistência à tensão apresentou o valor de 728, 5+/-161,75gf no grupo A e 1241,6+/-232gf no grupo de controle (p<0,01), coincidindo com os achados da pO2. A densidade média dos elementos histopatológicos estudados foi de 105+/-17,1 nos animais do grupo A e 146,2+/-8,8 no grupo B (p<0,01). Conclusão: Após avaliação da pO2 tecidual, tensiometria e histopatologia, conclui-se que a nicotina por via subcutânea exerce efeito deletério sobre a cicatrização de lesões da parede abdominal de ratos.

A novel strategy of oxygen restriction by some diazotrophic enteric bacteria.

Protection of nitrogenase against oxygen inactivation in diazotrophs involves numerous strategies. Glutathione is known to play an important role in scavenging oxyradicals in many living systems. The involvement of glutathione (reduced) (GSH), glutathione peroxidase (GPX) and glutathione reductase (GR) in the protection of nitrogenase in free living diazotrophs is reported here for the first time. Reduced glutathione content and the activity of glutathione peroxidase and glutathione reductase increased with increase in oxygen concentration under nitrogen fixing conditions but decreased under anaerobic and nitrogenase repressed conditions. This correlation is used to postulate a protecting role for GSH-GPX-GR system against oxygen inactivation of nitrogenase.

Effect of oxygen derived free radicals and glycine on sodium-potassium adenosine triphosphatase in the basolateral membrane of the kidney in ischemia-reperfusion

The aim of the present study was to examine the effect of exposing rats to ischemia-reperfusion while breathing 100% oxygen or room air, to find the effect of glycine on renal sodium-potassium adenosine triphosphatase [Na +/- K+ATPase] and endogenous antioxidant enzymes, superoxide dismutase and catalase, also to ascertain the effect of ischemia-reperfusion on renal nitric oxide and lipid peroxides. This study was carried out at King Saud University, Riyadh, Kingdom of Saudi Arabia, over a period of 11 months, February to December 2001. All previous measurements were carried out on the renal homogenate after 60 minutes ischemia, then after reperfusion while animals breathed room air or 100% oxygen and also after glycine treatment. The activity of Na +/- K+ATPase, catalase and superoxide dismutase concentration was decreased significantly in the ischemic rats compared to the control, a further decrease was found after 20 minutes of reflow while breathing room air. Breathing 100% oxygen resulted in a significant decrease in catalase and Na +/- K+ATPase activity and concentration of superoxide dismutase, glycine caused insignificant change of these enzymes after ischemia-index of lipid peroxidation and nitric oxide they were significantly elevated following reperfusion while rats breathed room air and further elevation was noticed after breathing 100% oxygen. However, potassium and creatinine did not change in all study groups, showed significant decrease after ischemia and ischemia-reperfusion may be due to marked Na+ loss in urine and lack of Na+ reabsorption. The inhibition of superoxide dismutase and catalase can be explained by increased reactive oxygen species during reperfusion and hyperoxia, also due to nitric oxide production and lipid peroxidation as shown by high malondialdehyde. Lack of Na+K+ATPase can be contributed to loss of antioxidant enzymes, nitric oxide production, and high reactive oxygen species. Hyperoxia in ischemia-reperfusion induces severe damage to cellular defence mechanisms and enhances reactive oxygen species injury. Glycine, as antioxidant, is involved in kidney protection from massive injury induced by ischemia-reperfusion, protects renal antioxidant enzymes and Na +/- K+ATPase, normalizes malondialdehyde, and nitric oxide levels. This data further supports the possible role of glycine therapy as an adjunct in the treatment of renal failure

Inhaled nitric oxide and high concentrations of oxygen in pediatrics patients with congenital cardiopathy and pulmonary hypertension: report of five cases

Five patients with ages ranging from 6 months to 3 years were analyzed. All received inhaled nitric oxide (NO - 20 parts per million (ppm)) and oxygen (O2 - at a concentration of 90-95 percent) by means of an oxygen hood. Mean Pulmonary Artery Pressure (MPAP), Mean Aortic Pressure (MAoP), Pulmonary Vascular Resitance (PVR) and Systemic Vascular Resistance (SVR) were measured and the calculation of their relationship to pulmonary/systemic flow (Qp/Qs) was performed by the catheterization of the femoral artery vein. Three patients presented reduction in PVR and increase in Qp/Qs. There were no systemic alterations or any side effect from using NO.

Avaliaçäo do uso do sevofluorano como agente de manutençäo anestésica em cäes, em diferentes concentraçöes de oxigênio e óxido nitroso / Sevoflurane as an anesthetical maintenance agent in dogs in differents oxygen and nitrous oxide concentration

O sevofluorano, um anestésico halogenado introduzido na prática clínica há pouco tempo, vem sendo utilizado em animais e em homens, tendo como principal característica o baixo coeficiente de solubilidade, possibilitando induçäo e recuperaçäo anestésica rápidas. Trinta cäes S.R.D. adultos, clinicamente sadios, de ambos os sexos, foram pré-tratados com levomepromazina (0,5 mg/kg, i.v.) e tiopental (12,5 mg/kg, i.v.) e divididos aleatoriamente para a manutençäo anestésica em três grupos como se segue: G1=Sevofluorano + 100 por cento de 0²; G2=Sevofluorano +50 por cento de 0² e 50 por cento de N²0 e G3=Sevofluorano +37 por cento 0² e 63 por cento de N²O. A concentraçäo de sevofluorano utilizada em cada grupo foi ajustada de acordo com a obtençäo de nenhuma resposta a estímulo interdigital. A temperatura retal, as pressöes arteriais média e sistólica diminuíram significativamente e a diastólica diminuiu somente nos grupos 1 e 3. A freqüência cardíaca aumentou significativamente após a induçäo mantendo-se em valores maiores que os basais em todos os grupos. A freqüência respiratória e o volume corrente variaram de maneira a diminuir o volume minuto, elevando os níveis de ETCO² e PaCO² com consequente diminuiçäo do pH, o que demonstra depressäo respiratória. Os valores de PaO² e de saturaçäo de O² na hemoglobina mantiveram-se inalterados. A concentraçäo de sevofluorano necessária para manter o plano anestésico nos animais do grupo 1 foi de 2,4 por cento (1 CAM), 2,2 por cento no grupo 2 (0,9 CAM) e de 1,4 por cento no grupo 3 (6 CAM). Esta reduçäo foi estatisticamente significativa somente no grupo 3. Concluiu-se que o sevofluorano é um agente adequado para a manutençäo anestésica em cäes produzindo efeitos cardiorrespiratórios aceitáveis e, com a associaçäo de 63 por cento de óxido nitroso, a necessidade anestésica reduz-se significativamente.

Effect of dissolved oxygen levels on biosynthesis of aureofungin by Streptoverticillium cinnamoneum var. terricola.

Biosynthesis of aureofungin by Streptoverticillium cinnamoneum var, terricola was found to be an oxygen dependent reaction. An accelerated rate of aureofungin production, along with a better yield coefficient were obtained under conditions of enhanced aeration during fermentation. A higher oxygen transfer rate was found to stimulate aureofungin A, and suppresses aureofungin B formation.

Non-linear pattern of radiation induced lipid peroxidation is not affected by vitamin E, Fe2+ ions and molecular oxygen.

Results of the present study on liposomes have clearly shown that non-linear pattern of radiation-induced lipid peroxidation was not changed even in the presence of vitamin E, Fe2+ ions or molecular oxygen. These results are important from biological point of view as lipid peroxidation is used as a measure of membrane damage.

Chemical radiosensitization by misonidazole: production and repair of DNA single-strand breaks in Yoshida ascites tumor cells.

Formation of strand-breaks in DNA and its repair in Yoshida ascites tumor cells exposed to gamma radiation (100-400 Gy) in presence and absence of misonidazole (10 mM) were studied. The methodology involved pre-labelling of cellular DNA by 3H-thymidine during cell proliferation in rats, irradiation of cells in vitro and analysing sedimentation profile of DNA by ultracentrifugation in alkaline sucrose density gradients. Irradiation under euoxic conditions resulted in formation of about 1.5 times greater number of strand breaks as compared to those formed during irradiation under hypoxic conditions. Misonidazole (10 mM) by its presence along with the cells during irradiation under hypoxic conditions caused a 3-fold increase in the number of single strand breaks, but under euoxic conditions of irradiation the presence of misonidazole did not enhance the strand break formation. Incubation of cells irradiated in absence of misonidazole for 1 hr in tissue culture medium at 37 degrees C resulted in repair of substantial fraction of the strand breaks while there was no repair of the DNA strand breaks in cells irradiated in the presence of the chemical.

Spectroscopic evidence for structural oscillations in DNA caused by oxygen.

It has been shown that interaction of dissolved oxygen with DNA in an aqueous solution causes oscillations in the DNA structure and leads to the formation of a loose DNA-oxygen complex. These results have been compared with those obtained with solution of DNA in high salt concentration.