Effects of pneumonectomy on nitric oxide synthase expression and perivascular edema in the remaining lung of rats

Pneumonectomy is associated with high mortality and high rates of complications. Postpneumonectomy pulmonary edema is one of the leading causes of mortality. Little is known about its etiologic factors and its association with the inflammatory process. The purpose of the present study was to evaluate the role of pneumonectomy as a cause of pulmonary edema and its association with gas exchange, inflammation, nitric oxide synthase (NOS) expression and vasoconstriction. Forty-two non-specific pathogen-free Wistar rats were included in the study. Eleven animals died during or after the procedure, 21 were submitted to left pneumonectomy and 10 to sham operation. These animals were sacrificed after 48 or 72 h. Perivascular pulmonary edema was more intense in pneumonectomized rats at 72 h (P = 0.0131). Neutrophil density was lower after pneumonectomy in both groups (P = 0.0168). There was higher immunohistochemical expression of eNOS in the pneumonectomy group (P = 0.0208), but no statistically significant difference in the expression of iNOS. The lumen-wall ratio and pO2/FiO2 ratio did not differ between the operated and sham groups after pneumonectomy. Left pneumonectomy caused perivascular pulmonary edema with no elevation of immunohistochemical expression of iNOS or neutrophil density, suggesting the absence of correlation with the inflammatory process or oxidative stress. The increased expression of eNOS may suggest an intrinsic production of NO without signs of vascular reactivity.

Consequences of cerebroventricular insulin injection on renal sodium handling in rats: effect of inhibition of central nitric oxide synthase

In the present study, we investigated the effects of acute intracerebroventricular (icv) insulin administration on central mechanisms regulating urinary sodium excretion in simultaneously centrally NG-nitro-L-arginine methylester (L-NAME)-injected unanesthetized rats. Male Wistar-Hannover rats were randomly assigned to one of five groups: a) icv 0.15 M NaCl-injected rats (control, N = 10), b) icv dose-response (1.26, 12.6 and 126 ng/3 µL) insulin-injected rats (N = 10), c) rats icv injected with 60 µg L-NAME in combination with NaCl (N = 10) or d) with insulin (N = 10), and e) subcutaneously insulin-injected rats (N = 5). Centrally administered insulin produced an increase in urinary output of sodium (NaCl: 855.6 ± 85.1 Δ%/min; 126 ng insulin: 2055 ± 310.6 Δ%/min; P = 0.005) and potassium (NaCl: 460.4 ± 100 Δ%/min; 126 ng insulin: 669.2 ± 60.8 Δ%/min; P = 0.025). The urinary sodium excretion response to icv 126 ng insulin microinjection was significantly attenuated by combined administration of L-NAME (126 ng insulin: 1935 ± 258.3 Δ%/min; L-NAME + 126 ng insulin: 582.3 ± 69.6 Δ%/min; P = 0.01). Insulin-induced natriuresis occurred by increasing post-proximal sodium excretion, despite an unchanged glomerular filtration rate. Although the rationale for decreased urinary sodium excretion induced by combined icv L-NAME and insulin administration is unknown, it is tempting to suggest that perhaps one of the efferent signals triggered by insulin in the CNS may be nitrergic in nature.

Participation of neuronal nitric oxide synthase in experimental neuropathic pain induced by sciatic nerve transection

Nerve injury leads to a neuropathic pain state that results from central sensitization. This phenomenom is mediated by NMDA receptors and may involve the production of nitric oxide (NO). In this study, we investigated the expression of the neuronal isoform of NO synthase (nNOS) in the spinal cord of 3-month-old male, Wistar rats after sciatic nerve transection (SNT). Our attention was focused on the dorsal part of L3-L5 segments receiving sensory inputs from the sciatic nerve. SNT resulted in the development of neuropathic pain symptoms confirmed by evaluating mechanical hyperalgesia (Randall and Selitto test) and allodynia (von Frey hair test). Control animals did not present any alteration (sham-animals). The selective inhibitor of nNOS, 7-nitroindazole (0.2 and 2 µg in 50 µL), blocked hyperalgesia and allodynia induced by SNT. Immunohistochemical analysis showed that nNOS was increased (48% by day 30) in the lumbar spinal cord after SNT. This increase was observed near the central canal (Rexed’s lamina X) and also in lamina I-IV of the dorsal horn. Real-time PCR results indicated an increase of nNOS mRNA detected from 1 to 30 days after SNT, with the highest increase observed 1 day after injury (1469%). Immunoblotting confirmed the increase of nNOS in the spinal cord between 1 and 15 days post-lesion (20%), reaching the greatest increase (60%) 30 days after surgery. The present findings demonstrate an increase of nNOS after peripheral nerve injury that may contribute to the increase of NO production observed after peripheral neuropathy.

Lack of tolerance for the anti-dyskinetic effects of 7-nitroindazole, a neuronal nitric oxide synthase inhibitor, in rats

7-Nitroindazole (7-NI) inhibits neuronal nitric oxide synthase in vivo and reduces l-DOPA-induced dyskinesias in a rat model of parkinsonism. The aim of the present study was to determine if the anti-dyskinetic effect of 7-NI was subject to tolerance after repeated treatment and if this drug could interfere with the priming effect of l-DOPA. Adult male Wistar rats (200-250 g) with unilateral depletion of dopamine in the substantia nigra compacta were treated with l-DOPA (30 mg/kg) for 34 days. On the 1st day, 6 rats received ip saline and 6 received ip 7-NI (30 mg/kg) before l-DOPA. From the 2nd to the 26th day, all rats received l-DOPA daily and, from the 27th to the 34th day, they also received 7-NI before l-DOPA. Animals were evaluated before the drug and 1 h after l-DOPA using an abnormal involuntary movement scale and a stepping test. All rats had a similar initial motor deficit. 7-NI decreased abnormal involuntary movement induced by l-DOPA and the effect was maintained during the experiment before 7-NI, median (interquartile interval), day 26: 16.75 (15.88-17.00); day 28: 0.00 (0.00-9.63); day 29: 13.75 (2.25-15.50); day 30: 0.5 (0.00-6.25); day 31: 4.00 (0.00-7.13), and day 34: 0.5 (0.00-14.63), Friedman followed by Wilcoxon test,vs day 26, P < 0.05;. The response to l-DOPA alone was not modified by the use of 7-NI before the first administration of the drug (l-DOPA vs time interaction, F1,10 = 1.5, NS). The data suggest that tolerance to the anti-dyskinetic effects of a neuronal nitric oxide synthase inhibitor does not develop over a short-term period of repeated administration. These observations open a possible new therapeutic approach to motor complications of chronic l-DOPA therapy in patients with Parkinson’s disease.

Morphometric evaluation of nitric oxide synthase isoforms and their cytokine regulators predict pulmonary dysfunction and survival in systemic sclerosis

Because histopathological changes in the lungs of patients with systemic sclerosis (SSc) are consistent with alveolar and vessel cell damage, we presume that this interaction can be characterized by analyzing the expression of proteins regulating nitric oxide (NO) and plasminogen activator inhibitor-1 (PAI-1) synthesis. To validate the importance of alveolar-vascular interactions and to explore the quantitative relationship between these factors and other clinical data, we studied these markers in 23 cases of SSc nonspecific interstitial pneumonia (SSc-NSIP). We used immunohistochemistry and morphometry to evaluate the amount of cells in alveolar septa and vessels staining for NO synthase (NOS) and PAI-1, and the outcomes of our study were cellular and fibrotic NSIP, pulmonary function tests, and survival time until death. General linear model analysis demonstrated that staining for septal inducible NOS (iNOS) related significantly to staining of septal cells for interleukin (IL)-4 and to septal IL-13. In univariate analysis, higher levels of septal and vascular cells staining for iNOS were associated with a smaller percentage of septal and vascular cells expressing fibroblast growth factor and myofibroblast proliferation, respectively. Multivariate Cox model analysis demonstrated that, after controlling for SSc-NSIP histological patterns, just three variables were significantly associated with survival time: septal iNOS (P=0.04), septal IL-13 (P=0.03), and septal basic fibroblast growth factor (bFGF; P=0.02). Augmented NOS, IL-13, and bFGF in SSc-NSIP histological patterns suggest a possible functional role for iNOS in SSc. In addition, the extent of iNOS, PAI-1, and IL-4 staining in alveolar septa and vessels provides a possible independent diagnostic measure for the degree of pulmonary dysfunction and fibrosis with an impact on the survival of patients with SSc.

Examining the side effects of sucrose for pain relief in preterm infants: a case-control study

Sucrose solution is recommended as relevant pain relief management in neonates during acute painful procedures; however, only a few studies have analyzed the potentially adverse effects of sucrose administration to preterm neonates. The goal of this study was to examine the potential side effects of sucrose for pain relief in preterm infants, assessing feeding and weight gain during hospitalization and their feeding patterns postdischarge. The study sample consisted of 43 preterm neonates divided into two groups: a sucrose group (SG, n=18) and a control group (CG, n=25) in which no sucrose was administered. The SG received 0.5 mL/kg 25% oral sucrose for 2 min prior to all acute painful procedures during three consecutive days. A prospective review of medical charts was performed for all samples. The study was done prior to implementation of the institutional sucrose guidelines as a routine service, and followed all ethical requirements. There were no statistically significant differences between groups in terms of weight gain, length of stay with orogastric tubes, and parenteral feeding. Postdischarge, infant nutritional intake included feeding human milk to 67% of the SG and 74% of the CG. There were no statistically significant differences between groups regarding human milk feeding patterns postdischarge. Neonate feeding patterns and weight gain were unaffected following the short-term use of sucrose for pain relief.

Changes in cardiac aldosterone and its synthase in rats with chronic heart failure: an intervention study of long-term treatment with recombinant human brain natriuretic peptide

The physiological mechanisms involved in isoproterenol (ISO)-induced chronic heart failure (CHF) are not fully understood. In this study, we investigated local changes in cardiac aldosterone and its synthase in rats with ISO-induced CHF, and evaluated the effects of treatment with recombinant human brain natriuretic peptide (rhBNP). Sprague-Dawley rats were divided into 4 different groups. Fifty rats received subcutaneous ISO injections to induce CHF and the control group (n=10) received equal volumes of saline. After establishing the rat model, 9 CHF rats received no further treatment, rats in the low-dose group (n=8) received 22.5 μg/kg rhBNP and those in the high-dose group (n=8) received 45 μg/kg rhBNP daily for 1 month. Cardiac function was assessed by echocardiographic and hemodynamic analysis. Collagen volume fraction (CVF) was determined. Plasma and myocardial aldosterone concentrations were determined using radioimmunoassay. Myocardial aldosterone synthase (CYP11B2) was detected by quantitative real-time PCR. Cardiac function was significantly lower in the CHF group than in the control group (P<0.01), whereas CVF, plasma and myocardial aldosterone, and CYP11B2 transcription were significantly higher than in the control group (P<0.05). Low and high doses of rhBNP significantly improved hemodynamics (P<0.01) and cardiac function (P<0.05) and reduced CVF, plasma and myocardial aldosterone, and CYP11B2 transcription (P<0.05). There were no significant differences between the rhBNP dose groups (P>0.05). Elevated cardiac aldosterone and upregulation of aldosterone synthase expression were detected in rats with ISO-induced CHF. Administration of rhBNP improved hemodynamics and ventricular remodeling and reduced myocardial fibrosis, possibly by downregulating CYP11B2 transcription and reducing myocardial aldosterone synthesis.

Hepatic inducible nitric oxide synthase expression increases upon exposure to hypergravity

Stimulation by a number of conditions, including infection, cytokines, mechanical injury, and hypoxia, can upregulate inducible nitric oxide synthase (iNOS) in hepatocytes. We observed that exposure to hypergravity significantly upregulated the transcription of the hepatic iNOS gene. The aim of this study was to confirm our preliminary data, and to further investigate the distribution of the iNOS protein in the livers of mice exposed to hypergravity. ICR mice were exposed to +3 Gz for 1 h. We investigated the time course of change in the iNOS expression. Hepatic iNOS mRNA expression progressively increased in centrifuged mice from 0 to 12 h, and then decreased rapidly by 18 h. iNOS mRNA levels in the livers of centrifuged mice was significantly higher at 3, 6, and 12 h than in uncentrifuged control mice. The pattern of iNOS protein expression paralleled that of the mRNA expression. At 0 and 1 h, weak cytoplasmic iNOS immunoreactivity was found in some hepatocytes surrounding terminal hepatic venules. It was noted that at 6 h there was an increase in the number of perivenular hepatocytes with moderate to strong cytoplasmic immunoreactivity. The number of iNOS-positive hepatocytes was maximally increased at 12 h. The majority of positively stained cells showed a strong intensity of iNOS expression. The expression levels of iNOS mRNA and protein were significantly increased in the livers of mice exposed to hypergravity. These results suggest that exposure to hypergravity significantly upregulates iNOS at both transcriptional and translational levels.

Homocysteine induces glyceraldehyde-3-phosphate dehydrogenase acetylation and apoptosis in the neuroblastoma cell line Neuro2a

High plasma levels of homocysteine (Hcy) promote the progression of neurodegenerative diseases. However, the mechanism by which Hcy mediates neurotoxicity has not been elucidated. We observed that upon incubation with Hcy, the viability of a neuroblastoma cell line Neuro2a declined in a dose-dependent manner, and apoptosis was induced within 48 h. The median effective concentration (EC50) of Hcy was approximately 5 mM. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) nuclear translocation and acylation has been implicated in the regulation of apoptosis. We found that nuclear translocation and acetylation of GAPDH increased in the presence of 5 mM Hcy and that higher levels of acetyltransferase p300/CBP were detected in Neuro2a cells. These findings implicate the involvement of GAPDH in the mechanism whereby Hcy induces apoptosis in neurons. This study highlights a potentially important pathway in neurodegenerative disorders, and a novel target pathway for neuroprotective therapy.

The effects of water and sucrose contents on the physicochemical properties of non-directly expanded rice flour extrudates

Rice flour was processed by extrusion cooking in the presence of variable contents of water and sucrose. The process was carried out in a twin-screw extruder under the conditions given by a centre rotational experimental design of second order. The effects of the independent variables, water content (27.9 to 42.1%), and sucrose content (0.1 to 19.9%) on the physicochemical properties of the extrudates were investigated. The water absorption index (WAI), water solubility index (WSI), volumetric expansion index (VEI), and bulk density (BD) were determined as dependent variables. BD was determined for samples before and after frying. An increase in water contents resulted in higher WAI and VEI, and lower WSI and BD for extrudates before and after frying. Higher sucrose levels led to increased values of WAI and VEI and to reduced values of WSI and BD. Both independent variables had significant influence on the physicochemical properties of rice flour extrudates. However, the sucrose content was the most significant. The interaction between these two independent variables and their quadratic effect were also important for the responses studied.

Elongated cells of Listeria monocytogenes in biofilms in the presence of sucrose and bacteriocin-producing Leuconostoc mesenteroides A11

Listeria monocytogenes is a foodborne pathogen which may survive in biofilms and persist in food processing plants. In this study, the ability of Leuconostoc mesenteroides (bac+ and bac-) to inhibit biofilm formation by L. monocytogenes ATCC 19115 was studied with stainless steel coupons immersed in BHI broth and BHI broth plus sucrose in combination with the Lactic Acid Bacteria (LAB). Adhered cells were collected with swabs and enumerated on selective agars (Oxford for listeria and MRS for leuconostoc). Leuconostoc mesenteroides bac+ in co-culture with L. monocytogenes was effective to inhibit biofilm formation by listeria for up to 3 hours of incubation, but at 24 hours, biofilm was present in all conditions tested, as confirmed by observations of stainless steel coupons under Scanning Electron Microscopy (SEM). It was also observed that in the presence of L. mesenteroides bac+ in BHI plus sucrose, a high number of elongated cells of L. monocytogenes was present, which may indicate an adaptation response of the pathogen to stress conditions with important implications for food safety.

Assessment of fructooligosaccharides production from sucrose in aqueous and aqueous-organic systems using immobilized inulinase from Kluyveromyces marxianus NRRL Y-7571

This work investigated the fructooligosaccharides (FOS) synthesis by immobilized inulinase obtained from Kluyveromyces marxianus NRRL Y-7571 in aqueous and aqueous-organic systems using sucrose as substrate. The sequential strategy of experimental design was used to optimize the FOS conversion in both systems. For the aqueous-organic system, a 2(6-2) fractional design was carried out to evaluate the effects of temperature, sucrose concentration, pH, aqueous/organic ratio, enzyme activity, and polyethylene glycol concentration. For the aqueous system, a central composite design for the enzyme activity and the sucrose concentration was carried out. The highest fructooligosaccharides yield (Y FOS) for the aqueous-organic system was 18.2 ± S0.9 wt%, at 40 ºC, pH 5.0, sucrose concentration of 60% (w/w), enzyme activity of 4 U.mL-1, and aqueous/organic ratio of 25/75 wt%. The highest Y FOS for the aqueous system was 14.6 ± 0.9 wt% at 40 ºC, pH 5.0, sucrose concentration of 60 wt%, and enzyme activity of 4.0 U.mL-1.

Sensory and physicochemical evaluation of acerola nectar sweetened with sucrose and different sweeteners

This paper aims to evaluate the physicochemical characteristics, sensory acceptance, and purchase intent of acerola nectar sweetened with sucrose and other sweeteners (neotame, sucralose and stevia extracts with 40%, 60%, 80%, and 95% rebaudioside A). The analyses were carried out for pH, soluble solids, total titratable acidity, ascorbic acid, and colorimetry (L*a*b). The acceptance test was performed by 120 consumers who evaluated the appearance, aroma, flavor, texture, and overall impression of the samples using a 9-cm unstructured hedonic scale. Furthermore, the consumers were asked to rate overall purchase intent along the scale anchored with (1) "would definitely not purchase" to (5) "would definitely purchase." The results were evaluated using analysis of variance/Tukey test and the internal preference mapping technique. The acerola nectar samples did not differ significantly (p>0.05) between themselves in terms of vitamin C content and total titratable acidity. As for appearance and aroma, there was no significant difference (p>0.05) between the samples, and as for flavor and overall impression, the most accepted samples were those with sucrose and sucralose. The internal preference mapping indicated that the most accepted samples were those with sucrose, sucralose, and neotame were. The highest frequency of positive purchase intent scores was observed for sucrose and sucralose.

Effect of preparation practices and the cowpea cultivar Vigna unguiculata L.Walp on the quality and content of myo-inositol phosphate in akara (fried bean paste)

Akara is one of Brazil's national treasures prepared from cowpea (Vigna unguiculata L.Walp), grated onions and salt and deep-fried in crude palm oil. The results of this study on akara preparation methods showed that, in general, cowpeas were soaked for up 3 hours at room temperature, and the seed coats were then removed. The akara makers preferred the olho de pombo cultivar, because of its cream hue, or the macassar cultivar because it produces a crispier paste. The seeds purchased from street markets had lower ranges of InsP6, InsP5, and InsP4 (1.03-7.62 ∝mol.g- 1; 0.14-1.31 ∝mol.g- 1; and 0.0-0.10 ∝mol.g- 1, respectively) than both the paste and akara (6.72-19.24 ∝mol.g- 1; 1.29-4.57 ∝mol.g- 1; 0.0-0.76 ∝mol.g- 1; 3.31-13.71 ∝mol.g- 1; 0.0-4.48 ∝mol.g- 1; and 0.0-1.32 ∝mol.g- 1). These results suggest that other beans or cowpea varieties have been used in the preparation of akara and that the phytate levels do not affect its nutritional quality.