Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.109 (AST)
 6,066 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fumed oxides, such as silica, alumina, titania, and mixed X/silicas (X=Al(2)O(3) (AS), TiO(2) (TS), CVD-TiO(2), Al(2)O(3)/TiO(2) (AST)), pristine or covered by carbon deposits formed due to pyrolysis of cyclohexene, were studied using nitrogen adsorption-desorption, photon correlation spectroscopy particle sizing, and electrophoresis. A significant influence of the nature of surface-active sites and structural features of oxides (individual silica, mixed fumed, or prepared using chemical vapor deposition (CVD)) on the pyrolysis of cyclohexene is observed with respect to the pore size distributions due to differences between primary particles in aggregates and on their outer surfaces in the filling of channels by pyrocarbon, resulting also in a decrease in fractal dimension. Structural characteristics and dependences of the particle size distribution and electrokinetic potential of X/SiO(2) and C/X/SiO(2) on the pH of aqueous suspensions suggest that the carbon deposit covers mainly acidic sites at the X/SiO(2) interfaces and X phase patches possessing catalytic activity in pyrolysis, as the negative charge of particles is reduced by pyrocarbon grafting. Copyright 2000 Academic Press.
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PMID:Highly Dispersed X/SiO(2) and C/X/SiO(2) (X=Alumina, Titania, Alumina/Titania) in the Gas and Liquid Media. 1101 48

The iron chelating activity of deferoxamine (DFO) has been exploited to obtain protection against the peroxidative damage in rat heart which was induced by the administration of an acute dose of doxorubicin (DXR, 25 mg x kg(-1), i.v.). The peroxidative lesions were evaluated both biochemically and histopathologically, 48 h after DXR administration. Abnormal biochemical changes including a marked increase in the levels of serum creatine kinase isoenzyme (CK-MB), and lactate dehydrogenase (LDH), as well as elevated serum creatinine, blood urea nitrogen and transaminases (ALT and AST) levels were observed. Myocardial tissue from DXR treated rats showed a marked increase in malondialdehyde (MDA) production and depletion of reduced glutathione (GSH) contents. Similar results were also observed in both kidney and liver tissues. Pretreatment of rats with DFO, given i.p. 30 min prior to DXR injection, substantially reduced the peroxidative damage in the myocardium, hepatic and renal tissues and markedly lowered the serum CK-MB, LDH and the other biochemical variables. The protective effects obtained by DFO administration, however, were not complete and did not reach those of the control group. The significant protection against DXR-induced cardiomyopathy by DFO was evident from the histopathological findings observed by light microscopy. DFO at a dosing level equivalent to 10-fold of that of DXR was useful to obtain protective effects. Higher DFO dosing levels did not, however, show more improvement in the DXR-induced cardiotoxicity and at the same time exhibited hepatoxicity which was confirmed by microscopical examination. These results strongly suggest that DFO protects against acute DXR-induced cardiotoxicity in a dose-dependent manner with recognizing the presence of mild DFO-related biochemical and cytological hepatic toxicity.
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PMID:The preventive role of deferoxamine against acute doxorubicin-induced cardiac, renal and hepatic toxicity in rats. 1140 11

An effective health care program entails the prevention, diagnosis and treatment of medical problems. A knowledge of baseline values in clinically normal individuals is essential for determining the limits between good health and disease and for understanding the changes produced by pathogenic agents. However, very little information is currently available concerning the blood chemistry and haematological values of different species of monkeys, particularly new-world primates. The values of some haematological and chemical parameters in Cebus apella were determined. The aim of the present work was to verify the effect of age and sex on normal blood values. Blood samples were collected once a year for two successive years from 36 monkeys living in large captive social groups. Significant differences between males and females were found for AST, GGT, urea nitrogen and creatinine, erythrocytes, haemoglobin and haematocrit. Significant differences between juveniles and adults were found for calcium, AST, alkaline phosphatase, inorganic phosphorus, glucose, neutrophils, lymphocytes and serum protein parameters.
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PMID:Haematology and blood chemistry of Cebus apella in relation to sex and age. 1199 May 30

Cyclododecatriene (CDDT, CAS No. 4904-61-4) was administered daily by oral gavage to groups of Crl:CD (SD)IGS BR rats at dose levels of 0 (control), 30, 100, or 300 mg/kg/day. Female rats were dosed for four weeks premating, through mating, gestation, and lactation (a total of 55 to 63 days of treatment). Male rats were treated for 55 days (four weeks premating and through mating). Premating, body weights, food consumption, and clinical signs were recorded. Hematology, clinical chemistry, and urine analyses were conducted at the end of the premating period. A neurobehavioral test battery was conducted prior to and after four weeks of treatment. After the premating period, females were paired with males from the same groups for 1-2 weeks. Litters were delivered, pups were evaluated for structural integrity, and pup body weights were recorded on days 0 and 4 postpartum. Lactating females and their offspring were sacrificed on postpartum day 4. Selected organs were weighed and the tissues were examined microscopically from the lactating females. Offspring were examined for clinical abnormalities. A test substance-related reduction in body weight gain occurred in male rats administered 300 mg/kg/day. Decreased body weight gain in the 300 mg/kg/day males was accompanied by increased food consumption and decreased food efficiency. Females administered 100 or 300 mg/kg/day had test substance-related, significantly decreased body weight and body weight gain during gestation, that was accompanied by a significant increase in food consumption (300 mg/kg/day group only), and significantly decreased food efficiency. There were no test-substance related effects on clinical observations in males or females during the premating phase, or in females during gestation or lactation. Neurobehavioral parameters and motor activity were unaffected by CDDT-treatment. During this study, statistically significant treatment-related changes were observed in several clinical pathology parameters. The decreases in red cell mass (RBC, HGB, HCT) were minimal and, due to the magnitude, were not expected to result in biological effects. Similarly, minimally increased potassium and mildly decreased triglycerides were not of a magnitude to be biologically significant. Finally, changes in serum enzymes (AST, ALT, ALP), urea nitrogen, and serum protein occurred in directions that are not associated with toxicity. The changes in urine volume, urine concentration, and urea nitrogen may be the result of elevated glomerular filtration rate and altered tubular fluid flow, in the absence of any histopathological change. No effects on reproduction in parental males or females were produced by CDDT. Body weights of pups in the 300 mg/kg group were significantly decreased on postpartum days 0 and 4. There were no test-substance related effects on clinical observations, number of pups born, and the number of pups born alive, or the number of pups surviving through lactation day 4. The no-observed-adverse-effect level (NOAEL) for CDDT was 30 mg/kg/day based on decreased body weight and body weight gain, increased food consumption, and decreased food efficiency in females administered 100 or 300 mg/kg/day. The NOEL in pups was 100 mg/kg/day, based on decreased body weights of pups in the 300 mg/kg/day group during lactation.
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PMID:Reproductive and repeated dose toxicity of cyclododecatriene (CDDT) in rats following oral (gavage) treatment. 1202

The aim of the present study was to determine if treatment with an oral adsorbent (AST-120, Kremezin) might decrease the urinary albumin excretion and serum indoxyl sulfate (s-IS), and prevent glomerular sclerosis in early-stage renal failure, i.e. 0.9-1.2 mg/dl of serum creatinine (s-Cr) and 60-95 mg/dl of blood urea nitrogen (BUN), in subtotal (3/4) nephrectomized rats. Levels of s-Cr and s-IS in the AST-120-treated rats were significantly lower than those in the untreated control rats. The AST-120-treated rats showed an increase of creatinine clearance. Urinary protein and indoxyl sulfate excretion in the AST-120-treated rats were also significantly lower than those in the untreated control rats. The ratio of glomerular tuft area to the area of Bowman's capsules (GT/BC) in the AST-120-treated rats was significantly lower than that in the untreated control rats. The degree of glomerular sclerosis and tubulointerstitial fibrosis in the AST-120-treated rats was significantly lower than that in the untreated control rats. Furthermore, there was a significant relationship among the degree of GT/BC, glomerular sclerosis, tubulointerstitial fibrosis and the levels of urinary protein excretion. It appears that AST-120 might decrease the accumulation of s-Cr and s-IS, and prevent glomerular sclerosis in early stage renal failure in the subtotal nephrectomized rats.
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PMID:Effects of oral adsorbent AST-120 (Kremezin) on renal function and glomerular injury in early-stage renal failure of subtotal nephrectomized rats. 1211 81

A 66-year-old man with erysipelas was admitted with complaints of oliguria and massive proteinuria/hematuria. He was diagnosed as having acute poststreptococcal glomerulonephritis(APSGN) due to erysipelas infected by group A streptococcus pyogenes. On admission, his white cell count increased to 31,000, and CRP was 27.3 mg/dl. Serum urea nitrogen and creatinine were increased to 90.1 mg/dl and 4.5 mg/dl, respectively. He had diabetes mellitus(HbA1c 7.9%) and liver dysfunction(total bilirubin 3.5 mg/dl, AST 76 IU, ALT 41 IU) caused by alcoholic liver cirrhosis. Hypocomplementemia was found in addition to ASO 216 U/ml and ASK 10,240 x. After antibiotics treatment was initiated, inflammation of the erysipelas began to improve. Disseminated intravascular coagulation syndrome, probably due to sepsis, occurred on the 5th hospital day. He died of gastrointestinal bleeding on the 18th hospital day. Renal autopsy revealed 37% formation of fibrocellular crescents, and marked mesangiolysis was noted by light microscopy. Granular deposition of C3 and IgG was seen along the capillary walls on immunofluorescence study. Intramembranous deposits were scattered on electron microscopy. This case illustrates a fulminant type of APSGN, which was in part attributed to the presence of diabetes and alcoholic liver cirrhosis. Histological findings of crescent formation and marked mesangiolysis may account for the fulminant clinical course.
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PMID:[A case of fulminant acute poststreptococcal glomerulonephritis showing mesangiolysis and crescent formation preceded by erysipelas]. 1247 94

Oral adsorbent, AST-120 removes uremic toxins (such as indoxyl sulfate) and retards the progression of chronic renal failure (CRF). However, its mechanism of action has not been precisely clarified. Since indoxyl sulfate elicits renal tubular nuclear factor-kappaB (NF-kappaB) activation in vitro, the present experiments were conducted to elucidate the involvement of NF-kappaB in the beneficial effects of AST-120 using rats with 3/4 nephrectomy, a model of early-stage CRF. Daily administration of AST-120 was started at 6 weeks after 3/4 nephrectomy and continued for 18 weeks. Sham-operated rats, untreated CRF rats and AST-120-treated CRF rats were compared for NF-kappaB DNA-binding activity, gene expression and renal histology. Systolic blood pressure was increased in CRF rats, and this increase was not affected by AST-120. Blood urea nitrogen, serum creatinine and urinary protein were increased in CRF rats. Although AST-120 attenuated these increases, it did not do so to a statistically significant extent. Indoxyl sulfate, which was accumulated in serum of CRF rats, was significantly eliminated by AST-120. Renal cortical NF-kappaB DNA-binding activity was increased in CRF rats. AST-120 significantly inhibited this increase. Monocyte/macrophage infiltration and increased monocyte chemoattractant protein-1 (MCP-1) mRNA observed in CRF rats were attenuated by AST-120. Furthermore, AST-120 significantly blocked renal fibrosis with concomitant inhibition of transforming growth factor beta1 (TGF-beta1) gene expression. It appeared that AST-120 reduced NF-kappaB activation and possibly the activity of NF-kappaB-dependent pathways of interstitial inflammation including MCP-1 expression and macrophage infiltration. The anti-inflammatory effect of AST-120 mediated via inhibition of NF-kappaB is a possible mechanism by which AST-120 retards the progression of renal fibrosis in CRF.
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PMID:Possible involvement of nuclear factor-kappaB inhibition in the renal protective effect of oral adsorbent AST-120 in a rat model of chronic renal failure. 1465 84

The variation in inhibitor specificity for five different amine inhibitors bound to CST, BT, and the cold-adapted AST has been studied by use of association constant measurements, structural analysis of high-resolution crystal structures, and the LIE method. Experimental data show that AST binds the 1BZA and 2BEA inhibitors 0.8 and 0.5 kcal/mole more strongly than BT. However, structural interactions and orientations of the inhibitors within the S1 site have been found to be virtually identical in the three enzymes studied. For example, the four water molecules in the inhibitor-free structures of AST and BT are channeled into similar positions in the S1 site, and the nitrogen atom(s) of the inhibitors are found in two cationic binding sites denoted Position1 and Position2. The hydrophobic binding contributions for all five inhibitors, estimated by the LIE calculations, are also in the same order (-2.1 +/- 0.2 kcal/mole) for all three enzymes. Our hypothesis is therefore that the observed variation in inhibitor binding arises from different electrostatic interactions originating from residues outside the S1 site. This is well illustrated by AST, in which Asp 150 and Glu 221B, despite some distance from the S1 binding site, lower the electrostatic potential of the S1 site and thus enhance substrate binding. Because the trends in the experimentally determined binding energies were reproduced by the LIE calculations after adding the contribution from long-range interactions, we find this method very suitable for rational studies of protein-substrate interactions.
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PMID:Trypsin specificity as elucidated by LIE calculations, X-ray structures, and association constant measurements. 1504 35

Large-scale clinical trials have shown that the oral adsorbent AST-120 improves renal function and delays the initiation of dialysis in chronic renal failure (CRF) secondary to chronic glomerulonephritis. If renal failure progresses via common mechanisms, then the same effects can be expected in diabetic nephropathy. However, no study on diabetic nephropathy has been reported. Thus, we enrolled patients with statistically significant progression of CRF secondary to diabetic nephropathy, and analyzed the changes in renal function after AST-120 therapy, and the clinical factors associated with response to therapy. We enrolled 276 patients with diabetic nephropathy, whose serum creatinine (Scr) had increased from 3.4 to 4.5 mg/dL during the 4.5 +/- 3.7 months prior to the study. These patients took AST-120 at a dose of 5.0 +/- 1.4 g/day for 6 months. The clinical data were analyzed by dividing the patients into three groups based on the changes in Scr after AST-120 therapy, with responders showing a decrease (N = 82), partial responders showing <1.5-fold increase (N = 144), and non-responders showing >/=1.5-fold increase (N = 50). AST-120 significantly lowered the slope of 1/Scr-time line, suggesting that AST-120 suppressed the progression of renal impairment. No responders required dialysis, whereas 24.3% of the partial responders and 36.0% of the non-responders started dialysis therapy. In responders, the 1/Scr-time slope showed a negative-to-positive shift and serum urea nitrogen decreased significantly, whereas the improvement was moderate in partial responders and minimal in non-responders. Among responders, AST-120 therapy significantly improved renal function despite the presence of hypoproteinemia, hyperlipidemia, anemia or hypertension in many patients. The beneficial effect of AST-120 was significantly more marked in patients with blood pressure controlled within the normal ranges and hematocrit maintained at 30% or above. AST-120 reversed renal dysfunction or delayed the initiation of dialysis therapy in patients with progressive aggravation of CRF secondary to diabetic nephropathy, independent of hypoproteinemia, hyperlipidemia, anemia and hypertension. Active use of AST-120 may be recommended in patients with good control of blood pressure and hematocrit above 30%.
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PMID:Protective effect of an oral adsorbent on renal function in chronic renal failure: determinants of its efficacy in diabetic nephropathy. 1515 77

The effect of heat stress on changes in milk production, rectal temperature, respiratory rate and blood chemistry was evaluated in three groups of six mature Holstein, Jersey and Australian Milking Zebu (AMZ) dairy cows. These animals were subjected to a cool environment when the mean temperature-humidity index (THI) was 72+/-1.4 (dry bulb temperature of 22.2-24.4 degrees C and relative humidity of 100-60%) during the month of December. This experiment was repeated during the hotter month of July of the following year, when the mean THI was 93+/-3.1 (dry bulb temperature of 35.6-43.9 degrees C and relative humidity 95-35%). Holstein cows produced more (p <0.01) milk than AMZ and Jersey cows during the cooler months of the year and all the cows were dry during the hotter months from June until September. Heat stress increased (p<0.01) rectal temperature and respiratory rate in all three breeds. Heat stress had no effect on blood pH in Holstein and AMZ cows but lowered (p <0.01) blood pH from 7.42 to 7.34 in Jersey cows. In addition, heat stress lowered (p <0.01) blood pCO2 (kPa), bicarbonate (HCO3, mmol/L), base excess (BE, mmol/L) and plasma chloride (Cl-, mmol/L) in all three breeds. The total haemoglobin (THb, g/dl) was elevated (p <0.01) in all three breeds when they were subjected to heat stress. Heat stress increased (p<0.01) oxygen saturation (O2SAT, %) in Jersey and AMZ cows but lowered it (p <0.01) in Holstein cows. On the other hand, heat stress increased (p <0.01)pO2 (kPa) in Holstein and Jersey cows but lowered it (p <0.01) in AMZ cows. Heat stress increased (p <0.01) plasma potassium (K, mmol/L) and calcium (Ca, mmol/L) only in Holstein and Jersey cows but lowered them (p<0.01) in AMZ cows. The plasma glucose (GLU, mmol/L) increased (p<0.01) with heat stress in Holstein and AMZ cows but decreased (p <0.01) in Jersey cows. Heat stress increased (p<0.01) plasma creatinine (CR, (mol/L) but lowered (p<0.01) plasma creatinine phosphokinase (CPK, IU/L), aspartate aminotransferase (AST, IU/L) and blood urea nitrogen (BUN, mmol/L) in all three breeds. These results indicate that heat-stressed Holstein and AMZ cows were able to maintain their acid-base balance with a marginal change in their pH of 0.02 when their rectal temperatures increased by 0.47 and 0.38 degrees C, respectively. When heat stress increased the rectal temperature in Jersey cows by 0.70 degrees C, the pH decreased (p<0.01) from 7.42 to 7.34. However, even with this decrease 0.08 the pH is still within the lower physiological limit of 7.31.
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PMID:Effect of heat stress on milk production, rectal temperature, respiratory rate and blood chemistry in Holstein, Jersey and Australian Milking Zebu cows. 1556 29


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