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PubMed2006

The role of N-acetylcysteine in lower extremity ischemia/reperfusions.

AIM: To evaluate the efficacy of N-acetyl cysteine (NAC) in lower extremity ischemia/reperfusion. METHODS: A total of 23 patients who underwent surgical intervention due to acute femoral artery occlusion were assigned into 2 groups: control group (group 1, n=12); and NAC group (group 2, n=11). Patients in NAC group received NAC before reperfusion, and 8 and 16 h after reperfusion (3x300 mg), while patients in control group received only NaCl 0.9% (3x100 mL). Catalase, malondialdehyde (MDA) and thiol concentrations were determined in femoral vein samples collected at 6 different time points: before reperfusion (t1), and 30 min (t2), 2 h (t3), 6 h (t4), 12 h (t5) and 24 h (t6) after reperfusion. Alveolar-arterial oxygen gradient (A-aO2) was calculated in radial artery blood samples simultaneously collected at the same time points. RESULTS: No significant differences between the two groups with regard to age (control group 61+/-13 and NAC group 64+/-11 years), gender (control group M/F: 7/5, NAC 6/5) and the average time from onset of symptoms (control group 9.6+/-3.5 h, and NAC group 10.2+/-3.1 h) were present. Catalase enzyme activity increased with reperfusion in both groups and there were no differences between the two groups. MDA levels did not change significantly with reperfusion in NAC group, whereas they were significantly higher in control group at t2 and t3 compared to NAC group (P<0.05). Thiol concentrations decreased with reperfusion in control group, and in NAC group increases that started with reperfusion returned back to baseline levels after 24 hours. Although the A-aO2 gradient increased in both groups with the beginning of reperfusion, the most prominent increase occurred in control group (P<0.05). CONCLUSIONS: In control group, the significant increase in MDA levels and A-aO2 gradient in reperfusion phase were considered a sign of local and end organ injury. We did not observe these changes in NAC performed group thus showing the efficacy of NAC.

Acetylcysteine↗
PubMed1981

Evidence for existence of two acid groups controlling the conductance of sodium channel.

The inhibition of the sodium current in nodal membrane at low pH external solutions was studied under voltage clamp conditions. Analysis of the data for membrane potentials from +10 to +150 mV shows that the inhibition of the Na+ currents at high positive potentials cannot be described by a titration curve of a single acid group. The data can be explained on assumption that the conductance of each sodium channel is controlled by two acid groups: one is located within the pore, the other just near the outer mouth of the pore. The affinity of both groups for H+ is estimated.

Animals↗
PubMed2005

[Regulative effect of Opuntia powder on blood lipids in rats and its mechanism].

OBJECTIVE: To observe the regulative effect of opuntia powder on blood lipids in wistar rats and to explore its mechanism. METHOD: Forty normal rats were divided into four groups:control group (fed with basal feed), opuntia high, middle and low dosage groups (fed with basal feed and opuntia powder of high, middle and low dosage. The influence of opuntia powder on serum total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), arteriosclerosis index (AI), serum malondialdehyde (MDA), superoxide dismutase (SOD) were observed. (2) All of the hyperlipemia wistar rats for experiments were divided into four groups: model control group and other three groups (high, middle, low dosage groups respectively). Three weeks later, samples of blood were taken for survey of levels of TC, TG HDL-C, LDL-C, AI, MDA, SOD. RESULT: After opuntia powder treatment,the level of TC in nomal wistar rats was decreased. However, there was no significant difference comparing with control group (P > 0.05). The serum MAD level in the low, middle and high dosage groups were all obviously decreased, which were significantly lower than that in the control group. The SOD activities were all higher than that in the control group. The level of TC, LDL-C, AI (P < 0.01), TG (P < 0.05) were lower significantly in hyperlipemia wistar rats after treated by opuntia powder of high, middle and low dosage. The down-regulation of blood lipids was related with the dosage of opuntia powder. CONCLUSION: The opuntia powder may regulate the level of blood lipids in normal and hyperlipemia wistar rats. The effect is more obviously in hyperlipemia rats than that in normal rats.

Animals↗
PubMed2005

[Effects of anti-platelet drugs on myocardial no-reflow after acute myocardial infarction and reperfusion: experiment with mini-swine model].

OBJECTIVE: To evaluate the effects of anti-platelet drugs on myocardial no-reflow after acute myocardial infarction (AMI) and reperfusion. METHODS: Thirty-two mini-swine were randomized into 4 equal groups: Control Group, without any intervention; Group A approximately C, pretreated with aspirin-clopidogrel (A-C) combination (300 mg loading dose followed by 75 mg per day of clopidogrel and 10 mg x kg(-1) x d(-1) of aspirin for 3 days), Group Tirofiban, given an intravenous infusion of tirofiban (15 microg/kg in intravenous bolus followed by 0.5 microg x kg(-1) x min(-1) in continuous intravenous infusion from 30 min before occlusion to the end of protocol; and Sham Operation Group, undergoing sham operation. The former 3 groups underwent three-hour occlusion of the left anterior descending (LAD) coronary artery followed by one-hour reperfusion Before the adminisfration of drngs and hefore lipation of LAD flood sanpks were collocfed to detoif the platelet aggregation rate (PAR). Hemodynamic examination and myocardial contrast echocardiography (MCE) were performed before AMI, 3 h after AMI, and 1 h after reperfusion. The coronary ligation area (LA) and area of no-reflow (ANR) were determined with both MCE in vivo and pathological examination after the swine were killed. RESULTS: The platelet aggregation rates (MAR) after AMI were 46.8% and 45.7% respectively in tirofiban group and A-C Combination group, and significantly decreased to 12.9% and 14.3% respectively after the administration of drugs (both P < 0.01) with equivalent potency (P > 0.05). The left ventricular function was significantly improved in tirofiban group in comparison with control group (P < 0.05 - 0.01), the coronary blood flow volume (CBV) 1 h after reperfusion was 73.2% in tirofiban group, significantly higher than that of control group (45.8%, P < 0.01), and the ANR of tirofiban group was 22.8% and 23.2% judged by MCE and pathological examination respectively, both significantly smaller than those of control group (78.5% and 82.3%, both P < 0.01), and the NA of tirofiban group was 89.2%, significantly smaller than that of Control Group (98.5%, P < 0.05). However, there were not significant differences in left ventricular function, central blood volume, ANR and NA between A-C combination group and control group (all P > 0.05). CONCLUSION: Tirofiban is markedly effective in attenuating myocardial no-reflow after reperfusion; in contrast, A-C combination is totally ineffective.

Animals↗
PubMed2002

Effects of amnio-allantoic fluid exchange on bowel contractility in chick embryos with gastroschisis.

BACKGROUND/PURPOSE: Intestinal damage in patients with gastroschisis is characterized by bowel wall thickening, intestinal dilatation, mesenteric shortening, and a fibrous peel. The prevention of intestinal damage in gastroschisis by amnio-allantoic fluid (AAF) exchange has been reported using histologic and macroscopic evaluation of intestines, but the effects of this treatment on bowel contractility have not been investigated. The current study was performed to determine the effect of AAF exchange on the intestinal contractility in chick embryos with gastroschisis. METHODS: Thirteen-day-old fertilized chick eggs were used. Gastroschisis was created through amnio-allantoic cavity. There were 3 study groups: control group, gastroschisis-only group, and gastroschisis-plus-exchange group. The bowels were evaluated by an in vitro muscle strip technique, and the response was expressed as a percentage of the maximum acetylcholine evoked contraction (E(max)) in each tissue obtained. Additionally, parasympathetic ganglion cells per 10 plexus at the intestinal wall were counted. Differences between groups were analyzed by analysis of variance (ANOVA) followed by Tukey-Kramer. Probabilities of less than 5% were considered significant. RESULTS: The intestines were thickened and covered by fibrous peel in the gastroschisis-only group when compared with the control group and the gastroschisis exchange group morphologically. There was a statistically significant decrease in contractility in the gastroschisis-only group compared with the control group (P <.05). It exerted 42.03 +/- 46.73% contraction of control group's E(max). This decrease in contractility was significantly reversed in the exchange group (P <.05; E(max) value of gastroschisis plus exchange group was 71.45 +/- 23.54% of control group's E(max)). Although the number of ganglia per 10 plexus was 76.7 +/- 4.3 in the control group, it was measured 28% less in the gastroschisis-only group (P <.05). There was no significant difference between the ganglion numbers of control and exchange groups. CONCLUSIONS: Prenatal AAF exchange treatment prevents decreased bowel contractility in gastroschisis. Gastroschisis does not affect intestinal ganglia morphology, but the number of ganglion cells decreases. AAF exchange prevents these functional and morphologic adverse effects of disease. By these findings the expectancy of a better clinical result in gastroschisis with intrauterine pretreatment by amniotic fluid exchange increases.

Acetylcholine↗
PubMed2006

Febrile seizure, but not hyperthermia alone, induces the expression of heme oxygenase-1 in rat cortex.

BACKGROUND: Febrile seizure (FS) is the most common seizure disorders. Approximately one third of children with a febrile seizure have recurrent events. The mechanism of FS remains unclear. Heme oxygenase-1 (HO-1) is a member of the heat shock proteins family and can be induced in the brain by various stresses, including hyperthemia and seizure. This study aimed at investigating the changes of HO-1 in the cortex of rats after recurrent FS. METHODS: FS in rats was induced ten times, once every 2 days. In a bath of warm water, developing rats were randomly divided into two groups: control group (n = 16) and warm water-treated group (n = 50). The latter group was subdivided into hyperthermia group (n = 19) and FS group (n = 23). The expression and content of HO-1 mRNA in cortex were observed using in situ hybridization and quantitative reverse transcription-polymerase chain reaction (RT-PCR). The content of HO-1 protein in cortex was measured using Western blotting. RESULTS: HO-1 mRNA expression of cortex neurons in FS group was markedly increased in comparison with those in hyperthermia and control groups (P = 0.00), however, there was no statistic difference between hyperthermia group and control group (P = 0.16). The relative amount of HO-1 mRNA in cortex in FS group was increased by 53.13% and 96% in comparison with those in hyperthermia group and control group respectively (P = 0.00), but there was no obvious difference between the later two groups (P = 0.051). Western blotting analysis showed that the HO-1 protein content in cortex in FS group was increased by 198% and 246% in comparison with those in hyperthermia group and control group respectively (P = 0.00). There was no obvious difference in HO-1 protein content between the later two groups (P = 0.09). CONCLUSIONS: Recurrent FS in rats can cause the increase of HO-1 mRNA and protein in cortex which may be involved in the mechanism of FS. The short-time recurrent hyperthermia can not induce the increase of HO-1 mRNA and protein.

Animals↗
PubMed1989

Foam at inner eye canthus in office workers, compared with an average Danish population as control group.

Foam formation in the eye canthus is well-known. The presence of foam was observed in 169 office workers in 4 town halls in Copenhagen County compared with 112 control persons from the general population in the same area. The presence of foam depends on age and gender. A significant increase with age was observed in the control population (P = 0.0078). In both groups, females had a significantly lower occurrence of foam than males (P = 0.0043, P = 0.010). This difference was mainly caused by the use of eye make-up. After correction for age, gender and use of eye make-up, the prevalence of foam was significantly lower in the office population than in the control population (P less than 0.0001). Furthermore, low foam formation was significantly correlated to reported subjective eye irritation in the office population (P = 0.0074), but not in the control population (P = 0.40). Also, significant positive correlation between absence of foam and different degrees of dry eyes (expressed as a combination of premature break-up of the precorneal tearfilm and lissamine green stained epithelial damage of the bulbar conjunctiva) was found both in the office population and in the control population (P = 0.0090, P = 0.0034). However, after correction for the more frequent appearance of dry eyes in the office population, foam was still observed significantly less frequently in the office population than in the control population (P = 0.0001). It is concluded that the decreased foam formation in the office worker constitutes a key symptom in the development of 'office eye syndrome'. In what way the office environment influences the foam formation is unknown. Possible mechanisms are discussed.

Adult↗
PubMed1999

Mechanical effects and volatile sulfur compound-reducing effects of chewing gums: comparison between test and base gums and a control group.

OBJECTIVE: Chewing gum may act as a masking or a therapeutic agent against the different chemical compounds that are responsible for oral malodor. An open-label exploratory study investigated the effect of mastication and aromatic components of chewing gum on reducing oral volatile sulfur compounds. METHOD AND MATERIALS: Twelve dental students (5 males and 7 females) acted as their own controls. Toothbrushing stopped 12 hours before observations. Measurements included organoleptic and volatile sulfur compound scores and the pH of the anterior and posterior zones of the dorsal tongue. Measurements were made at 9 AM and 12 PM on 1 day for 3 successive weeks; week 1, no gum (control); week 2, test gum; week 3, unsweetened gum base. This open-label study was then completed by an observer-blind study, according to the same schedule; the recorded measurement was the plaque index. RESULTS: The pH, volatile sulfur compounds, and organoleptic scores were similar for all groups. The pH was more basic in the posterior part than in the anterior zone of the dorsal tongue, irrespective of time and presence or absence of chewing gum. In addition, the volatile sulfur compound score rose transiently immediately after the test gum, and the organoleptic score fell in the first hour only after the test gum. The two chewing gum groups seemed to have a greater reduction in plaque index than did the control (no gum) group. CONCLUSION: Chewing gum may have a valuable mechanical role in cleaning dental surfaces, and the test gum may temporarily control bad breath. After 3 hours, similar volatile sulfur compound scores were observed for subjects who chewed either test or unsweetened gum base and control subjects.

Analysis of Variance↗
PubMed1992

Relative importance of informational units and their role in long-term recall by closed-head-injured patients and control groups.

The purpose of this study was to apply qualitative analysis to the information recalled by control Ss and closed-head-injured (CHI) patients. The Logical Memory subtest of the Wechsler Memory Scale (Wechsler, 1945) was administered to 40 CHI and 40 control Ss. Recall was tested immediately after administration, 40 min later, and 24 hr later. The analysis took into account the importance of recalled information as determined by a prior rating according to 3 levels of importance. Results suggest that CHI patients have difficulty selectively retrieving the most important information after a long delay.

Adolescent↗
PubMed1975

Antibody to herpes simplex virus type 2-induced nonstructural proteins in women with cervical cancer and in control groups.

Sera obtained from 15 patients with cervical cancer, 10 patients with breast cancer, and 15 control women, individually matched with the cervical cancer patients, were examined for antibodies to early proteins synthesized in herpes simplex virus type 2 (HSV-2)-infected cells. The method used was an indirect radioimmune precipitation test followed by polyacrylamide gel electrophoretic analysis of immune precipitates. The relative reactivity to a major early nonstructural protein (VP134) was used to compare these selected sera. The results obtained suggest that cervical cancer patients possess sera with a higher reactivity to VP134 than breast cancer patients or matched healthy women,and that serum reactivity is independent of the level of neutralizing antibodies to HSV-2.

Antibodies, Viral↗
PubMed2000

PTS performance by flight- and control-group macaques.

A total of 25 young monkeys (Macaca mulatta) were trained with the Psychomotor Test System, a package of software tasks and computer hardware developed for spaceflight research with nonhuman primates. Two flight monkeys and two control monkeys were selected from this pool and performed a psychomotor task before and after the Bion 11 flight or a ground-control period. Monkeys from both groups showed significant disruption in performance after the 14-day flight or simulation (plus one anesthetized day of biopsies and other tests), and this disruption appeared to be magnified for the flight animal.

Adaptation, Psychological↗
PubMed1993

Chronic exposure to a beta 2-adrenoceptor agonist increases the airway response to methacholine.

Scheduled chronic administration of beta 2-adrenoceptor agonist bronchodilators in patients with asthma recently has been reported to be associated with a worsening of symptoms and an increase in bronchial responsiveness. We wanted to determine whether a 28-day in vivo exposure to albuterol (beta 2-adrenoceptor agonist) altered the response of rabbit airways to the cholinergic agonist methacholine. We found, using in vitro tissue bath techniques, that in mainstem bronchi from rabbits given a 28-day exposure to albuterol, maximum contraction to methacholine was increased in the albuterol-treated group (control group = 1.10 +/- 0.11 g vs. treated group = 1.50 +/- 0.13 g, P < 0.05). The potency (EC75) was also increased in the albuterol-treated group. The potency for the control group was 5.6 microM (95% confidence limit: 2.3-13 microM) and was 1.7 microM (95% confidence limit: 1.1-2.8 microM, P < 0.05) for the albuterol-treated group. In a subgroup of animals, maximum contraction to KCl, a receptor-independent contractile stimulus, was not significantly different between the groups (control group = 0.79 +/- 0.23 g vs. treated group = 0.82 +/- 0.20 g). The potency (EC50) for KCl-induced contractions was also not significantly different between the groups: control = 12 mM (95% confidence limit: 3.3-44 mM) vs. treated 19 mM (95% confidence limit: 18-20 mM). These data demonstrate that chronic in vivo exposure to a beta 2-adrenoceptor agonist can alter the in vitro tissue bath response of airway smooth muscle to methacholine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1999

Two groups control light-induced Schiff base deprotonation and the proton affinity of Asp85 in the Arg82 his mutant of bacteriorhodopsin.

Arg(82) is one of the four buried charged residues in the retinal binding pocket of bacteriorhodopsin (bR). Previous studies show that Arg(82) controls the pK(a)s of Asp(85) and the proton release group and is essential for fast light-induced proton release. To further investigate the role of Arg(82) in light-induced proton pumping, we replaced Arg(82) with histidine and studied the resulting pigment and its photochemical properties. The main pK(a) of the purple-to-blue transition (pK(a) of Asp(85)) is unusually low in R82H: 1.0 versus 2.6 in wild type (WT). At pH 3, the pigment is purple and shows light and dark adaptation, but almost no light-induced Schiff base deprotonation (formation of the M intermediate) is observed. As the pH is increased from 3 to 7 the M yield increases with pK(a) 4.5 to a value approximately 40% of that in the WT. A transition with a similar pK(a) is observed in the pH dependence of the rate constant of dark adaptation, k(da). These data can be explained, assuming that some group deprotonates with pK(a) 4.5, causing an increase in the pK(a) of Asp(85) and thus affecting k(da) and the yield of M. As the pH is increased from 7 to 10.5 there is a further 2.5-fold increase in the yield of M and a decrease in its rise time from 200 micros to 75 micros with pK(a) 9. 4. The chromophore absorption band undergoes a 4-nm red shift with a similar pK(a). We assume that at high pH, the proton release group deprotonates in the unphotolyzed pigment, causing a transformation of the pigment into a red-shifted "alkaline" form which has a faster rate of light-induced Schiff base deprotonation. The pH dependence of proton release shows that coupling between Asp(85) and the proton release group is weakened in R82H. The pK(a) of the proton release group in M is 7.2 (versus 5.8 in the WT). At pH < 7, most of the proton release occurs during O --> bR transition with tau approximately 45 ms. This transition is slowed in R82H, indicating that Arg(82) is important for the proton transfer from Asp(85) to the proton release group. A model describing the interaction of Asp(85) with two ionizable residues is proposed to describe the pH dependence of light-induced Schiff base deprotonation and proton release.

Absorption↗
PubMed1999

[Glutamine dipeptide enriched enteral nutrition improving gut permeability in sever burns].

OBJECTIVE: To determine the effect of glutamine dipeptide on gut permeability in severe burns. METHODS: Twenty-four severe burn patients were randomly divided into two groups: control group and GLN group. All patients received enteral nutrition for 12 days after burn. Both groups were isocaloric and isonitrogen. GLN group patients were given nutrition solution enriched with glutamine dipeptide at a dosage at 0.5 g.kg-1.day-1 (equivalent to L-glutamine 0.3 mg.kg-1.day-1). On the day 1 and 12 after burn, the plasma amino acid was measured by a standard amino acid analyzer. On the day 1, 3, 6 and 12, the gut permeability was detected with Lactulose and Manitol assay by HPLC-PED, and then wound healing rate of burn area was determined on the day 30 and hospital stay was recorded. ANOVA was done for data analysis. RESULTS: The plasma GLN concentrations decreased in both groups on day 1, (control group: 361.3 +/- 70.8 microns/L, GLN group: 348.6 +/- 52.5 microns/L, P = 0.624, normal value: 659.5 +/- 35.0 microns/L), and the GLN group showed high plasma GLN concentration on day 12 (566.4 +/- 128.3 microns/L), with significant difference between control group (417.6 +/- 74.8 microns/L, P = 0.002). On day 1, L/M ratio value was the highest in both groups. On day 3, L/M ratio in the GLN group became lower than that of control group, and returned to normal on day 6 and maintained to day 12. There were significant differences of wound healing rate between the two groups and the length of hospital stay on day 30 (CONTROL GROUP: (81 +/- 7)%, GLN group: (89 +/- 7)%, 0.018) (CONTROL GROUP: 68 +/- 27 days, GLN group: 49 +/- 13 days, P = 0.049). CONCLUSION: The glutamine-dipeptide enriched enteral nutrition can improve the plasma GLN level after severe burn, decrease the gut permeability from early stage, ameliorate wound healing rate on day 30, and reduce hospital stay.

Adolescent↗
PubMed2003

Influence of acute hyperglycemia in human sepsis on inflammatory cytokine and counterregulatory hormone concentrations.

AIM: In human sepsis, a prominent component of the hypermetabolite is impaired glucose tolerance (IGT) and hyperglycemia. Elevations in plasma glucose concentration impair immune function by altering cytokine production from macrophages. We assessed the role of glucose in the regulation of circulating levels of insulin, glucagon, cortisol, IL-6 and TNF-alpha in human sepsis with normal or impaired glucose tolerance. METHODS: According to the results of intravenous glucose tolerance test, forty patients were classified into two groups: control group (n=20) and IGT group (n=20). Plasma glucose levels were acutely raised in two groups and maintained at 15 mmol/L for 3 hours. Plasma insulin, glucagon and cortisol levels were measured by radioimmunoassay, the levels of TNF-alpha and IL-6 were detected by ELISA. RESULTS: In IGT group, the fasting concentrations of plasma glucose, insulin, glucagon, cortisol, IL-6 and TNF-alpha levels were significantly higher than those in control group (P<0.05). During clamp, the control group had a higher average amount of dextrose infusion than the IGT group (P<0.01). In control group, plasma insulin levels rose from a basal value to a peak at an hour (P<0.05) and maintained at high levels. Plasma glucagon levels descended from a basal value to the lowest level within an hour (P<0.01) and low levels were maintained throughout the clamp. In IGT group, plasma insulin was more significantly elevated (P<0.01), and plasma glucagon levels were not significantly declined. Plasma cortisol levels were not significantly changed in two groups. In control group, plasma IL-6 and TNF-alpha levels rose (P<0.01) within 2 hours of the clamp and returned to basal values at 3 hours. In IGT group, increased levels of plasma cytokine lasted longer than in control group (3 hours vs 2 hours, P<0.05), and the cytokine peaks of IGT group were higher (P<0.05) than those of control group. CONCLUSION: Acute hyperglycemia pricks up hyperinsulinemia and increases circulating cytokine concentrations and these effects are more pronounced in sepsis with IGT. This suggests a potential modulation of immunoinflammatory responses in human sepsis by hyperglycemia.

Acute Disease↗