CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 5-6 2006
Susumu Ogawa
SUMMARY 1Over the course of treatment with angiotensin-converting enzyme inhibitor (ACEI), plasma levels of aldosterone have been shown to increase and this increase would blunt the effectiveness of the ACEI (aldosterone escape phenomenon). 2In the present study, we assessed a potential renal benefit of additional aldosterone blockade with spironolactone in hypertensive diabetic patients treated with ACEI showing the phase of aldosterone escape. 3The present clinical study was a randomized prospective study to assess difference between the clinical effects of spironolactone and furosemide. Thirty hypertensive type II diabetics (DM2) with a urinary alubumin : creatinine ratio (ACR) above 30 mg/g creatinine (showing albuminuria) and plasma B-type natriuretic peptide (BNP) levels above 100 pg/mL (showing mild heart failure) were treated with an ACEI (imidapril 5 mg/day) for 1 year and then randomly divided into two groups, one group receiving additional spironolactone (25 mg/day) treatment and the other receiving furosemide (20 mg/day) treatment. Blood pressure, ACR and plasma BNP levels were monitored in both groups. 4Treatment with the ACEI reduced ACR initially but, in 1 year, ACR tended to increase. Additional spironolactone treatment progressively reduced ACR, whereas furosemide treatment did not show any effect. Plasma BNP levels were reduced by ACEI and were further reduced by additional spironolactone treatment, but not furosemide treatment. Blood pressure levels in both groups were comparable. 5In conclusion, additional therapy with spironolactone in ACEI treatment exerts a renoprotective, as well as cardioprotective, effect in hypertensive diabetes. [source]

EFFECT OF NAPROXEN, A NON-SELECTIVE CYCLO-OXYGENASE INHIBITOR, ON PENTYLENETETRAZOL-INDUCED KINDLING IN MICE

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 7 2005
Ashish Dhir
SUMMARY 1.,Epilepsy is one of the major neurological disorders of the brain, affecting approximately 0.5,1.0% of the population worldwide. Various neurotransmitter abnormalities, especially of GABA and glutamate, have been reported to play a key role in the pathophysiology of epilepsy. 2.,Cyclo-oxygenase (COX) is the rate-limiting enzyme in the production of prostaglandins and, as such, is a key target for many anti-inflammatory drugs. Cyclo-oxygenase has been reported to play a significant role in neurodegeneration. Recent studies have reported that COX plays a significant role in the pathophysiology of epilepsy. 3.,The aim of the present study was to explore the possible role of COX and the effect of COX inhibitors in epilepsy. 4.,Kindling is a chronic model of epilepsy. In the present study, kindling was induced in mice by chronic administration of a subconvulsive dose of pentylenetetrazole (PTZ; 40 mg/kg) on every other day for a period of 15 days. Naproxen was administered daily 45 min before PTZ or vehicle. The kindling score was recorded after PTZ administration. Seizure severity was measured according to a prevalidated scoring scale. Biochemical estimations were performed immediately after recording behavioural parameters on the 16th day of PTZ treatment. 5.,Chronic treatment with PTZ significantly induced kindling in mice. Pretreatment with the non-selective COX inhibitor naproxen (7 and 14 mg/kg, i.p.) showed significant protection against PTZ-induced kindling in mice. Biochemical analysis revealed that chronic treatment with PTZ significantly increased lipid peroxidation and nitrite levels (NO levels), but decreased reduced glutathione (GSH) levels in brain homogenates. 6.,In conclusion, the results of the present study strongly suggest that COX plays an important role in the pathophysiology of PTZ-induced kindling in mice and that COX inhibitors could be a useful neuroprotective strategy for the treatment of epilepsy. [source]

ADHERENCE TO CHOLINESTERASE INHIBITORS IN PATIENTS WITH ALZHEIMER'S DISEASE

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2009
Lucie Blais PhD
No abstract is available for this article. [source]

EFFECTS OF MUSCLE PROTEASES, ENDOGENOUS PROTEASE INHIBITORS AND MYOFIBRIL FRAGMENTATION ON POSTMORTEM AGING OF GOAT MEAT

JOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2006
N.S. NAGARAJ
ABSTRACT The present study was conducted to evaluate the extent of postmortem proteolysis in longissimus dorsi, biceps femoris, semimembranosus and semitendinosus goat muscles on postmortem aging at an ambient (27C) temperature. The activities of calpains and calpastatin were determined after separation on a (diethylamino)ethyl,Sephacel column (Sigma, St. Louis, MO) and cathepsin (B, B + L and H) by carboxymethyl,Sepharose column (Sigma). The results showed that the decrease in calpain I and calpastatin activities was significantly higher than that of calpain II. Cathepsin B, B + L, H and cystatin were found to fall by 30,80% after 12 h, whereas cathepsin D decreased significantly in all the muscles. The disappearance of titin 1 and nebulin, and the appearance of a 30-kDa component were confirmed by Western blot analysis. The appearance of the 30-kDa component reported here explains the time-induced structural changes of myofibrils. The Z-line degradation had occurred by 6 h postmortem. Cathepsins are not stable compared to calpains during postmortem aging, and both enzymes may play a significant role in the proteolysis of myofibrillar proteins at ambient temperature. [source]

EFFECT OF FROZEN TEMPERATURE AND STORAGE TIME ON CALPAINS, CATHEPSINS (B, B + L, H AND D) AND THEIR ENDOGENOUS INHIBITORS IN GOAT MUSCLES

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2006
N.S. NAGARAJ
ABSTRACT The effects of frozen storage on the biochemical properties of myofibrils, muscle proteinases (cathepsins and calpains) and their endogenous inhibitors were investigated. Longissimus dorsi, biceps femoris, semimembranosus and semitendinosus muscles from goat were frozen (,15C) and studied up to 120 days. The results showed that the percentage change in sarcomere length was 8.4,13.1. The calpain activity was determined after separation on a diethylaminoethyl,Sephacel column (Sigma, St. Louis, MO). Significantly greater percentage of calpain II activity was recovered when compared to calpain I. There was a 15,25% loss in calpastatin inhibitory activity, and the cystatin level fell by 11,16% after 80 days. Cathepsin B, B + L, H and D were very stable when compared to calpains. The calcium concentration may also be the factor for calpain activation. The sodium dodecyl sulfate,polyacrylamide gel electrophoresis result showed the appearance of 55 kDa components. It was concluded that calpains, not cathepsins, play an important role in the proteolysis of myofibrillar proteins at the freezing temperature. [source]

PROPERTIES OF CYSTEINE PROTEINASE INHIBITORS FROM BLACK GRAM AND RICE BEAN

JOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2001
SOOTTAWAT BENJAKUL
ABSTRACT Cysteine proteinase inhibitors (CPI) were purified to 59 and 54 fold from black gram (Vignaraungo (L.) Hepper) and rice bean (Vignaumbellata Thunb.), respectively, by using heal treatment, followed by chromatography on a carboxymethyl (CM)-papain-Sepharose affinity column. The purified inhibitors were highly inhibitory to papain and Pacific whiting cathepsin L in a concentration dependent manner. They were detected as a dark band on tricine-SDS-PAGE gel stained for inhibitory activity. The apparent molecular weights of purified CPI from black gram and rice bean seeds were estimated to be 12, 000 daltons. The purified inhibitors were thermostable up to 90C and active in the neutral and alkaline pH ranges. [source]

INHIBITION OF GEL WEAKENING OF THREADFIN BREAM SURIMI USING THAI LEGUME SEED PROTEINASE INHIBITORS

JOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2000
SOOTTAWAT BENJAKUL
ABSTRACT Partially purified proteinase inhibitors from cowpea (Vigna unguiculata (L) Wasp), pigeon pea (Cajanus cajan (L.) Millsp.) and bdmbara groundnuts (Voandzeia subterranea (L.) Thou) effectively inhibited sarcoplasmic modori-inducing proteinase extracted from threadfin bream muscle in a concentration dependent manner. Incorporation of these proteinase inhibitors into threadfin bream surimi partially inhibited autolytic degradation and increased the gel force and deformation. Combination of setting and incorporating proteinase inhibitors from cowpea and bambara groundnut var. HY at the level of 30 Kcunits/g resulted in an increase in gel force and deformation by 60% and 26%, respectively. However, the lightness and whiteness of surimi gels decreased slightly when the proteinase inhibitor was added at a level of 30 kunits/g. [source]

ISOLATION AND CHARACTERIZATION OF TRYPSIN INHIBITORS FROM SOME THAI LEGUME SEEDS

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2000
SOOTTAWAT BENJAKUL
ABSTRACT Trypsin inhibitors from cultivars of cowpea (Vigna unguiculata (L.) Wasp.), pigeon pea (Cajanus cajan (L.) Millsp.) and bambara groundnuts (Voandzeia subterranea (L.) Thou) grown in Thailand were isolated and characterized. Extraction of seeds with NaCl rendered a higher recovery of trypsin inhibitor than other solvents tested (P<0.05). The extraction time affected the inhibitor recovery (P<0.05). The extraction time of 3 h was optimum for the recovery of trypsin inhibitor from pigeon and bambara groundnuts, whereas 1 h was optimum for cowpea. Based cn inhibitor activity of zones separated by electrophoresis, the molecular mass of the inhibitor from bambara groundnuts was 13 kDa. Two inhibitory bands were observed for cowpea (10 and 18 kDa) and pigeon pea (15 and 25 kDa). Partial purification of inhibitors was achieved by heat-treatment at 90C for 10 min, followed by ammonium sulfate precipitation with 30,65% saturation. The partially purified inhibitors from four seeds were heat stable up to 30 min at 90C at pH 7.0. The activities were also retained over a wide pH range at 25C but were lost when samples were treated with ,-mercaptoethanol prior to electrophoresis. [source]

THE EFFECT OF PRETREATMENT OF SHREDDED CELERIAC USING SOLUTIONS OF ENZYMATIC BROWNING INHIBITORS ON THE QUALITY OF MINIMALLY PROCESSED PRODUCT

JOURNAL OF FOOD QUALITY, Issue 5 2007
BIETA, RADZIEJEWSKA-KUBZDELA EL
ABSTRACT The study investigated the effect of soaking celeriac flakes in solutions containing various concentrations of enzymatic browning inhibitors on the quality of stored minimally processed product. Ascorbic acid (0.2,0.5%), 4-hexylresorcinol (0.003,0.01%), sodium chloride (0.1,0.5%) and sodium lactate (2,3%) were used as browning inhibitors. On the basis of the conducted tests, it was found that among the applied browning inhibitors, only ascorbic acid had an advantageous effect on the quality of stored celeriac flakes. Along with an increase in its concentration in the solution (0.2,0.5%) used for the pretreatment of the flakes, the value of color parameter a* decreased, while the value of parameter b* increased. At the concentration of ascorbic acid in the solution exceeding 0.25%, flake color in the sensory examination was evaluated as desirable. An increase of ascorbic acid concentration in the solution in the range from 0.2 to 0.4% resulted in a decrease in the total mesophilic and psychrophilic bacteria counts, respectively, by 3 and 1 log cfu/g of the stored product. PRACTICAL APPLICATIONS Minimal processing of celeriac provides convenience for consumers and many economic benefits for producers. Minimal processing of celeriac can induce disadvantageous changes in tissue, which may lead to darkening of the flakes and deterioration of product sensory attributes. Moreover, shredded raw material constitutes an excellent medium for the development of microorganisms. This article contains information about the effectiveness of enzymatic browning inhibitors for extending the shelf life of celeriac flakes. We show a range of concentrations of inhibitors, which improve the preservation of color, intrinsic taste and microbial quality of minimally processed celeriac. [source]

EFFECT OF CARBONIC ANHYDRASE INHIBITORS ON THE INORGANIC CARBON UPTAKE BY PHYTOPLANKTON NATURAL ASSEMBLAGES,

JOURNAL OF PHYCOLOGY, Issue 1 2009
Jesús M. Mercado
The role of carbonic anhydrase (CA) in inorganic carbon acquisition (dissolved inorganic carbon, DIC) was examined in Alboran Sea phytoplankton assemblages. The study area was characterized by a relatively high variability in nutrient concentration and in abundance and taxonomic composition of phytoplankton. Therefore, the relationship between environmental variability and capacity for using HCO3, via external CA (eCA) was examined. Acetazolamide (AZ, an inhibitor of eCA) inhibited the primary productivity (PP) in 50% of the samples, with inhibition percentages ranging from 13% to 60%. The AZ effect was more prominent in the samples that exhibited PP >1 mg C · m,3 · h,1, indicating that the contribution of eCA to the DIC photosynthetic flux was irrelevant at low PP. The inhibition of primary productivity by AZ was significantly correlated to the abundance of diatoms. However, there was no a relationship between AZ effect and CO2 partial pressure (pCO2) or nutrient concentration, indicating that the variability in the PP percentage supported by eCA was mainly due to differences in taxonomic composition of the phytoplankton assemblages. Ethoxyzolamide (EZ, an inhibitor of both external and internal CA) affected 13 of 14 analyzed samples, with PP inhibition percentages varying from 50% to 95%. The effects of AZ and EZ were partially reversed by doubling DIC concentration. These results imply that CA activity (external and/or internal) was involved in inorganic carbon acquisition in most the samples. However, EZ effect was not correlated with pCO2 or taxonomic composition of the phytoplankton. [source]

ACUTE KIDNEY INJURY COMPLICATING MINIMAL CHANGE DISEASE: THE CASE FOR CAREFUL USE OF DIURETICS AND ANGIOTENSIN-CONVERTING ENZYME INHIBITORS

NEPHROLOGY, Issue 5 2007
RAJESH YALAVARTHY
[source]

Stratified analyses for selecting appropriate target patients with diabetic peripheral neuropathy for long-term treatment with an aldose reductase inhibitor, epalrestat

DIABETIC MEDICINE, Issue 7 2008
N Hotta
Abstract Aims The long-term efficacy of epalrestat, an aldose reductase inhibitor, in improving subjective symptoms and nerve function was comprehensively assessed to identify patients with diabetic peripheral neuropathy who responded to epalrestat treatment. Methods Stratified analyses were conducted on data from patients in the Aldose Reductase Inhibitor,Diabetes Complications Trial (ADCT). The ADCT included patients with diabetic peripheral neuropathy, median motor nerve conduction velocity , 40 m/s and with glycated haemoglobin (HbA1c) , 9.0%. Longitudinal data on HbA1c and subjective symptoms of the patients for 3 years were analysed (epalrestat n = 231, control subjects n = 273). Stratified analyses based on background variables (glycaemic control, grades of retinopathy or proteinuria) were performed to examine the relationship between subjective symptoms and nerve function. Multiple logistic regression analyses were conducted. Results Stratified subgroup analyses revealed significantly better efficacy of epalrestat in patients with good glycaemic control and less severe diabetic complications. In the control group, no improvement in nerve function was seen regardless of whether symptomatic benefit was obtained. In the epalrestat group, nerve function deteriorated less or improved in patients whose symptoms improved. The odds ratio of the efficacy of epalrestat vs. control subjects was approximately 2 : 1 (4 : 1 in patients with HbA1c , 7.0%). Conclusion Our results suggest that epalrestat, an aldose reductase inhibitor, will provide a clinically significant means of preventing and treating diabetic neuropathy if used in appropriate patients. [source]

Synthesis of Novel Macrolactam and Macroketone Analogues of Migrastatin from D -Glucal and Comparison with Macrolactone and Acyclic Analogues: A Dorrigocin A Congener Is a Potent Inhibitor of Gastric Cancer Cell Migration

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 11 2008
Guillaume Anquetin
Abstract Novel macrolactam and macroketone analogues of the migrastatin macrolide core have been synthesised from tri- O -acetyl- D -glucal in order to facilitate structure-activity studies. The Horner olefination, followed by ring-closing metathesis were key steps in the synthesis of the macroketone. The ability of the macroketone and macrolactam derivatives to inhibit the migration of gastric tumour cells as determined using a transwell migration assay were compared with macrolactone analogues and dorrigocin A analogues. One dorrigocin A congener was the most potent inhibitor of gastric cancer cell migration.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

First Total Synthesis of (+)-Adenophorine, a Naturally Occurring Inhibitor of Glycosidases,

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 29 2007
Morwenna S. M. Pearson
Abstract The first total synthesis of a naturally occurring iminosugar, (+)-adenophorine, in 14 steps from the (+)-enantiomer ofGarner's aldehyde, is reported. The strategy is based onthe preparation and functionalization of enantiomericallypure trans -6-ethyl-2-hydroxymethyl-1,2,5,6-tetrahydropyridine. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

Archazolid-7- O -,- D -glucopyranoside , Isolation, Structural Elucidation and Solution Conformation of a Novel V-ATPase Inhibitor from the Myxobacterium Cystobacter violaceus

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2007
Dirk Menche
Abstract The novel polyketide macrolide archazolid-7- O -,- D -glucopyranoside (3) has been isolated from the myxobacterium Cystobacter violaceus and the structure of this first archazolid-glycoside has been determined by spectroscopic and degradative methods. A synthesis of simplified 7- O analogues, based on regioselective derivatisation of archazolid A, was elaborated. These structurally novel archazolids of natural and synthetic origin were evaluated in detail for V-ATPase inhibition and their biological activities are discussed in terms of their solution conformations, as determined by high-field NMR studies, including J -based conformation analysis and constrained molecular dynamics simulations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

First Synthesis of Argadin: A Nanomolar Inhibitor of Family-18 Chitinases

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 24 2006
Mark J. Dixon
No abstract is available for this article. [source]

On the Way to Glycoprocessing Inhibitors , Synthesis of an Imidazolo-Nectrisine-Phosphono Acid Derivative: A Potential Glycosyltranferase Inhibitor

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 15 2003
Théophile Tschamber
Abstract Assuming the transition state of glycosyltransferase inhibitors to be similar to those encountered with potent glycosidase inhibitors , i.e. a flattened conformation with a positively charged anomeric centre , we worked out a synthesis of the D - arabino -configured phosphonic acid target molecule 2 derived from an imidazolo-sugar. The key synthetic intermediate is the linear imidazolo L - xylo compound 10 which could be obtained, either from L - threo precursor 6 by a coupling reaction with imidazole derivative 5, or from L -sorbose. A multi-step and site specific iodination of 10 gave the mono-iodo- L - xylo derivative 14 which was cyclised to the D - arabino -configured bicyclic azasugar 15. Phosphorylation of the Grignard derivative of the latter, followed by mono-esterification with citronellol along with some protection-deprotection steps led to target molecule 2. The potential inhibitor 2 is supposed to be protonated at its most basic N atom by a carboxylic acid residue in the arabinosyl-transferase active site. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

Bumetanide, the Specific Inhibitor of Na+ -K+ -2Cl, Cotransport, Inhibits 1,,25-Dihydroxyvitamin D3 -Induced Osteoclastogenesis in a Mouse co-culture System

EXPERIMENTAL PHYSIOLOGY, Issue 5 2003
Hyun-A Lee
The Na+ -K+ -2Cl, cotransporter (NKCC1) is responsible for ion transport across the secretory and absorptive epithelia, the regulation of cell volume, and possibly the modulation of cell growth and development. It has been reported that a variety of cells, including osteoblasts, contain this cotransporter. In this study, the physiological role of NKCC1 in osteoclastogenesis was exploited in a co-culture system. Bumetanide, a specific inhibitor of NKCC1, reduced the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells. In order to investigate the mechanism by which bumetanide inhibits osteoclastogenesis, the mRNA expressions of the receptor activator of nuclear factor (NF)-,B ligand (RANKL) and osteoprotegerin (OPG) were analysed by RT-PCR. Exposure of osteoblastic cells to a medium containing 1 µM bumetanide reduced RANKL mRNA expression induced by 10 nM 1,,25-dihydroxyvitamin D3 (1,,25(OH)2D3, in a dose-dependent manner. In addition, RANKL expression was also analysed with enzyme-linked immunosorbant assay (ELISA) using anti-RANKL antibody. The expression of RANKL was decreased with the increase of bumetanide concentration. In contrast, the expression of OPG mRNA, a novel tumour necrosis factor (TNF) receptor family member was increased in the presence of bumetanide. These results imply that bumetanide inhibits osteoclast differentiation by reducing the RANKL/OPG ratio in osteoblastic cells. However, no significant difference in M-CSF mRNA expression was observed when bumetanide was added. Also, we found that the phosphorylation of c-Jun NH2 -terminal kinase (JNK), which regulates the activity of various transcriptional factors, was reduced by bumetanide treatment. Conclusively, these findings suggest that NKCC1 in osteoblasts has a pivotal role in 1,,25(OH)2D3 -induced osteoclastogenesis partly via the phosphorylation of JNK. [source]

Recent Use of Proton Pump Inhibitor-Based Triple Therapies for the Eradication of H. pylori: A Broad Data Review

HELICOBACTER, Issue 2 2003
Hans-Joachim Ulmer
abstract Introduction. For the eradication of Helicobacter pylori a 1-week triple therapy combining proton pump inhibitors with two antibiotics has been recommended as a gold standard therapy. However, a recent broad data review on the efficacy of the different regimens is missing. Therefore, the aim of this study was to systematically review the recent literature. Methods. We undertook a broad data review of the efficacy of nine different 7-day triple therapies consisting of a proton pump inhibitor (lansoprazole, pantoprazole, omeprazole) in its standard dosage and two antibiotics. Relevant original papers on H. pylori eradication in adults, published in English or German between 1995 and 2000, were identified from MEDLINE searches. Studies were reviewed and selected according to predefined criteria. Results. Our predefined criteria were fulfilled by 79 full paper articles including 112 study arms with 8383 patients on intention-to-treat, or 6787 patients on per-protocol basis, respectively. The mean eradication rates unweighted or weighted by the number of patients in the study arm vary from 71.9% to 83.8% for intention-to-treat analysis and from 78.5% to 91.2% for per-protocol analysis. Conclusions. All nine PPI based triple therapy regimens are very effective in H. pylori eradication. The current literature review underlines that the use of either lansoprazole, omeprazole, or pantoprazole combined with two antibiotics yield similar high eradication rates. [source]

, -Cyclodextrin as Inhibitor of the Precipitation Reaction between Berberine and Glycyrrhizin in Decoctions of Natural Medicines: Interaction Studies of Cyclodextrins with Glycyrrhizin and Glycyrrhetic Acid by 1H-NMR Spectroscopy and Molecular-Dynamics Calculation

HELVETICA CHIMICA ACTA, Issue 9 2008
Miyoko Kamigauchi
Abstract To prevent the precipitation reaction between glycyrrhizin (1) and berberine (3) in the decoctions of Glycyrrhiza/Coptis rhizome or Glycyrrhiza/Phellodendron bark, the presence of cyclodextrin (CD) in the mixture was proven to be effective. The preventing effect decreased in the order , -CD>, -CD, and no effect was observed for , -CD. On the other hand, the extraction degree of 1 from the natural medicine Glycyrrhia was considerably increased in the presence of , -CD, , -CD being much more effective than , - or , -CD. Thus, the blocking effect of CD on the precipitate formation between 1 and 3 is suggested to be primarily dependent on the stability of the inclusion complex of the CD with 1. To establish the structure of such a preferred inclusion complex, the interactions of 1 with , - and , -CDs were investigated by 1H-NMR spectroscopy and molecular-dynamics (MD) calculations. The 1H-NMR measurements showed that the increase in solubility of 1 in H2O is dependent on the degree of its inclusion into the CD, which depends on the molecular size of the CD. The MD calculations suggested that the H-bond interactions are sufficiently strong to form a stable [1/, -CD] complex, in which the lipophilic rings C, D, and E of 1 are fully inserted into the molecular cavity of , -CD, thus forming a kind of structure covered by a hydrophilic molecular capsule, while such an interaction mode is impossible for , - or , -CD. [source]

Human inhibitor of growth 1 inhibits hepatoma cell growth and influences p53 stability in a variant-dependent manner,

HEPATOLOGY, Issue 2 2009
Zhi Zhu
Inhibitor of growth 1 (ING1) is a type II tumor suppressor that affects cell function by altering chromatin structure and regulating transcription. Recently, three ING1 splice variants have been cloned, but their roles in apoptosis and p53 regulation in human hepatocellular carcinoma (HCC) have not been fully elucidated. The present study found that ING1, in a variant-dependent manner, inhibited hepatoma cell proliferation and colony formation, induced apoptosis and cell cycle arrest at G0/G1 phase, and postponed tumor formation in nude mice. Expression of p33ING1b and p24ING1c variants, but not p47ING1a, was markedly reduced in HCC samples. Reverse transcription polymerase chain reaction and western blotting analysis revealed that ectopic overexpression of p33ING1b or p24ING1c variant increased the expression of p53 downstream genes such as p21waf1 and bax, and repressed bcl-2 expression (P < 0.01), whereas p47ING1a inactivated p21waf1 promoter (P < 0.01). Furthermore, we found that p33ING1b and p24ING1c repressed Mdm2 expression (P < 0.01) and competed with Mdm2 for binding to p53. Interestingly, p33ING1band p24ING1c did not directly bind to Mdm2 protein but strongly increased p14arf expression (P < 0.01) and interacted with p14arf protein to stimulate p53. Moreover, we found that ectopic overexpression of p33ING1b or p24ING1c significantly induced p53 protein acetylation at Lys-373/Lys-382 residue, but did not alter the phosphorylation status of p53. Conclusion: ING1 variants p33ING1b and p24ING1c may modulate p53 activity and subsequently inhibit hepatoma cell growth by at least two possible mechanisms: interacting with Mdm2 and p14arf to stabilize and activate p53, or increasing p53 acetylation. (HEPATOLOGY 2009.) [source]

Cutting through the statistical fog: understanding and evaluating non-inferiority trials

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 10 2010
W. S. Weintraub
Summary Every year, results from many important randomised, controlled trials are published. Knowing the elements of trial design and having the skills to critically read and incorporate results are important to medical practitioners. The goal of this article is to help physicians determine the validity of trial conclusions to improve patient care through more informed medical decision making. This article includes a review of 162 randomised, controlled non-inferiority (n = 116) and equivalence (n = 46) hypothesis studies as well as the larger Stroke Prevention using Oral Thrombin Inhibitor in atrial Fibrillation V study and the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial. Evaluation of data from small and large trials uncovers significant flaws in design and models employed and uncertainty about calculations of statistical measures. As one example of questionable study design, discussion includes a large (n = 3922), double-blind, randomised, multicentre trial comparing the efficacy of ximelagatran with warfarin for prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation and additional stroke risk factors. Investigators concluded that ximelagatran was effective compared with well-controlled warfarin for prevention of thromboembolism. However, deficiencies in design, as well as concerns about liver toxicity, resulted in the rejection of the drug by the US Food and Drug Administration. Many trials fail to follow good design principles, resulting in conclusions of questionable validity. Well-designed non-inferiority trials can provide valuable data and demonstrate efficacy for beneficial new therapies. Objectives and primary end-points must be clearly stated and rigorous standards met for sample size, establishing the margin, patient characteristics and adherence to protocol. [source]

In Vivo Function of a Differentiation Inhibitor, Id2

IUBMB LIFE, Issue 4 2001
Yoshifumi Yokota
Abstract Cell differentiation is an essential process for the development of various cell types that constitute multicellular organisms. During development, the large family of factors bearing a helix-loop-helix (HLH) motif participates profoundly in this process and these factors serve as good experimental tools for investigating mechanisms underlying tissue-specific differentiation. The HLH family includes both positive and negative regulators of cell differentiation: basic HLH (bHLH)-type transcription factors and Id proteins, respectively. Following an exciting decade focusing on bHLH factors, advances achieved in studies of the inhibitory factors in the last couple of years have placed them in the front line of the research on differentiation and proliferation control. Here, we present and discuss recent results obtained using Id2 -deficient mice, which manifest intriguing phenotypes in various systems. [source]

Effect of Statin (HMG-Co-A-Reductase Inhibitor) Use on 1-Year Mortality and Hospitalization Rates in Older Patients with Cardiovascular Disease Living in Nursing Homes

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2002
Charles B. Eaton MD
OBJECTIVES: To quantify the effect of statins on 1-year mortality, hospitalizations, and decline in physical function among patients with cardiovascular disease (CVD) aged 65 and older living in nursing homes. DESIGN: Retrospective cohort study. SETTING: All Medicare/Medicaid certified nursing homes (N = 1,492) in Maine, New York, Mississippi, and South Dakota. PARTICIPANTS: We identified 51,559 older patients with CVD from a population database that merged sociodemographic data and functional, clinical, and drug treatments from more than 300,000 newly admitted nursing home residents from 1992 to 1997. Statin users (n = 1,313) were matched with nonusers (n = 1,313) in the same facilities. MEASUREMENTS: All-cause mortality, hospitalization, combined endpoint of mortality or hospitalization, and decline in physical function were determined at 1 year, and survival analysis was performed. RESULTS: Prevalence of statin use in this frail older cohort with CVD was 2.6%. Statin use varied by age, gender, comorbid condition, medication use, and cognitive and physical function. One-year mortality was 229/1,000 person-years in the statin group and 404/1,000 person-years in the nonusers, with an adjusted hazard rate ratio (HRR) of 0.69, 95% confidence interval (CI) = 0.58,0.81. The estimated number needed to treat was seven (95% CI = 5,13). This association with improved all-cause mortality was evident for women and men and for age groups 75 to 84, and 85 and older. CONCLUSION: Statin therapy is associated with improved clinical outcomes, including reduction in 1-year all-cause mortality, and the combined endpoint of death or hospitalization in a frail older population with CVD. Some caution should be taken in interpreting these results because potential bias from residual confounding could affect these results. [source]

Inhibiting the Inhibitor: A New Route to Bone Anabolism,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2009
Robert L Jilka
No abstract is available for this article. [source]

A Vacuolar ATPase Inhibitor, FR167356, Prevents Bone Resorption in Ovariectomized Rats With High Potency and Specificity: Potential for Clinical Application,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 9 2005
Kazuaki Niikura MS
Abstract FR167356, a novel inhibitor of vacuolar ATPase, has high potency against osteoclast V-ATPase and low potency against lysosomal V-ATPase. FR167356 is the first compound of this nature to be tested. It has the potential to be useful for clinical application. Introduction: It has been suggested that the key issue regarding the therapeutic usefulness of V-ATPase inhibitors is their selectivity. Materials and Methods: In in vitro and in vivo studies, we compared FR167356 with other vacuolar ATPase (V-ATPase) inhibitors, bafilomycin A1 and SB242784. H+ transport by various membrane vesicles was assayed by measuring uptake of acridine orange. Inhibitory activity against in vitro bone resorption was examined by measuring the Ca2+ release from cultured calvariae. In vivo, hypercalcemia was induced by retinoic acid in thyroparathyroidectomized-ovariectomized rats, and the effect on serum Ca2+ level was assessed. Ovariectomized rats were treated with FR167356 or SB242784. One week after surgery, free deoxypyridinoline levels in 24-h urine samples, which were collected from 6 h after administration of FR167356, were measured by ELISA. After 4 weeks of treatment, plasma biochemical parameters were analyzed. BMD of the distal femur metaphysis was measured with pQCT. Histomorphometric analysis of the proximal tibias was performed. Blood gases of rats treated with FR167356 were measured with a blood gas analyzer for estimating the effect of FR167356 on in vivo function of renal V-ATPase. Results: FR167356, which is distinctly different from other V-ATPase inhibitors, has a high potency against osteoclast V-ATPase and low potency against lysosomal V-ATPase. Similarly, FR167356 inhibited bone resorption in vitro when stimulated by PTH, IL-1, and IL-6. FR167356 reduced retinoic acid-induced hypercalcemia in thyroparathyroidectomized-ovariectomized rats in a dose-dependent manner. Moreover, FR167356 was shown to restore BMD of ovariectomized rats caused by the inhibition of bone resorption. Ovariectomized rats treated with FR167356 did not show adverse symptoms, whereas SB242784 caused a decrease in body weight gain and significant changes in two plasma biochemical parameters. Interestingly, FR167356 treatment did not affect blood acid-base balance; however, FR167356 inhibited renal V-ATPase with a similar potency as for osteoclast V-ATPase inhibition. Conclusion: Comparison of FR167356 with SB242784 implies that the characteristics of FR167356 may be more appropriate for clinical application as a V-ATPase inhibitor. [source]

Prostaglandin E2 -Mediated Anabolic Effect of a Novel Inhibitor of Phosphodiesterase 4, XT-611, in the In Vitro Bone Marrow Culture,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2003
Ken-Ichi Miyamoto
Abstract The mechanism of osteoblast formation by a novel PDE4 inhibitor, XT-611, was studied in the in vitro bone marrow culture system. The compound potentiated the osteoblast differentiation through accumulation of cyclic AMP after autocrine stimulation of EP4 receptor by PGE2 in pro-osteoblastic cells. Introduction: We previously reported that inhibitors of phosphodiesterase (PDE)4 isoenzyme increase osteoblast formation in an in vitro bone marrow culture system and inhibit bone loss in animal osteoporosis models. Here we investigated the mechanism of the effect of a novel PDE4 inhibitor, 3,4-dipropyl-4,5,7,8-tetrahydro-3H -imidazo[1,2- i]-purin-5-one (XT-611), on osteoblast formation in the in vitro bone marrow culture system. Materials and Methods: Rodent bone marrow cells were cultured in the presence of 0.2 mM ascorbic acid phosphate ester, 1 mM ,-glycerophosphate, and 10 nM dexamethasone for 10 days. Drug treatments were done for 24 h on day 3 of culture. Results: PDE4 inhibitors, including XT-611, but not PDE3 and PDE5 inhibitors, increased mineralized nodule formation in rat and mouse bone marrow cell cultures. During culture of the bone marrow cells, prostaglandin E2 (PGE2) production increased with a peak on day 4, but the increase was completely inhibited by indomethacin, an unselective cyclo-oxygenase (COX) inhibitor. Spontaneous and XT-611-induced mineralized-nodule formation was also inhibited by indomethacin and COX-2 inhibitors, in a similar potential. Alkaline phosphatase-positive nodule formation in the absence or presence of XT-611 was inhibited by an antagonist of EP4 receptor, AH23848B, and synergistically potentiated by 11-deoxy-PGE1, but it was not influenced by other EP antagonists and agonists examined. The expression of PDE4 and EP4 mRNAs was observed in bone marrow cells. The effect of XT-611 was also confirmed to involve an increase of cyclic AMP and the cyclic AMP-dependent protein kinase pathway. Conclusion: These results suggest that PGE2 stimulates differentiation of osteoblast progenitor cells through the EP4 receptor in an autocrine manner, and the PDE4 inhibitor potentiates the differentiation by inhibiting hydrolysis of cyclic AMP in the cells. [source]

Mice Lacking the Plasminogen Activator Inhibitor 1 Are Protected from Trabecular Bone Loss Induced by Estrogen Deficiency

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2000
E. Daci
Abstract Bone turnover requires the interaction of several proteases during the resorption phase. Indirect evidence suggests that the plasminogen activator/plasmin pathway is involved in bone resorption and turnover, and recently we have shown that this cascade plays a role in the degradation of nonmineralized bone matrix in vitro. To elucidate the role of the plasminogen activator inhibitor 1 (PAI-1) in bone turnover in vivo, bone metabolism was analyzed in mice deficient in the expression of PAI-1 gene (PAI-1,/,) at baseline (8-week-old mice) and 4 weeks after ovariectomy (OVX) or sham operation (Sham) and compared with wild-type (WT) mice. PAI-1 inactivation was without any effect on bone metabolism at baseline or in Sham mice. However, significant differences were observed in the response of WT and PAI-1,/, mice to ovariectomy. The OVX WT mice showed, as expected, decreased trabecular bone volume (BV/TV) and increased osteoid surface (OS/BS) and bone formation rate (BFR), as assessed by histomorphometric analysis of the proximal tibial metaphysis. In contrast, no significant change in any of the histomorphometric variables studied was detected in PAI-1,/, mice after ovariectomy. As a result, the OVX PAI-1,/, had a significantly higher BV/TV, lower OS/BS, lower mineral apposition rate (MAR) and BFR when compared with the OVX WT mice. However, a comparable decrease in the cortical thickness was observed in OVX PAI-1,/, and WT mice. In addition, the cortical mineral content and density assessed in the distal femoral metaphysis by peripheral quantitative computed tomography (pQCT), decreased significantly after ovariectomy, without difference between PAI-1,/, mice and WT mice. In conclusion, basal bone turnover and bone mass are only minimally affected by PAI-1 inactivation. In conditions of estrogen deficiency, PAI-1 inactivation protects against trabecular bone loss but does not affect cortical bone loss, suggesting a site-specific role for PAI-1 in bone turnover. [source]

Prevention of Ventricular Fibrillation by Cilostazol, an Oral Phosphodiesterase Inhibitor, in a Patient with Brugada Syndrome

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2002
TAKESHI TSUCHIYA M.D.
Cilostazol and Brugada Syndrome. We report the case of 67-year-old man with Brugada syndrome, in whom daily episodes of ventricular fibrillation (VF) occurred every early morning for 4 days. The episodes of VF were completely prevented by an oral administration of cilostazol, a phosphodiesterase inhibitor. This effect was confirmed by the on-and-off challenge test, in which discontinuation of the drug resulted in recurrence of VF and resumption of the drug again prevented VF. This effect may be related to the suppression of Ito secondary to the increase in heart rate and/or to an increase in Ca2+ current (ICa) due to an elevation of intracellular cyclic AMP concentration via inhibition of phosphodiesterase activity. This drug might have an anti-VF potential in patients with Brugada syndrome. [source]

Induction of Id2 expression by cardiac transcription factors GATA4 and Nkx2.5

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2008
Joong-Yeon Lim
Abstract Inhibitor of differentiation/DNA binding (Id) proteins function as a regulator of helix-loop-helix proteins participating in cell lineage commitment and differentiation. Here, we observed a marked induction of Id2 during cardiomyocyte differentiation from P19CL6 murine embryonic teratocarcinoma stem cells, prompting us to investigate the upstream regulatory mechanism of Id2 induction. Computer analysis of Id2 promoter and subsequent electrophoretic mobility shift assay revealed several binding sites for GATA4 and Nkx2.5 within the Id2 promoter. By further deletion and mutation analysis of the respective binding site, we identified that two motifs located at ,497/,502 and ,264/,270 were functionally important for Id2 promoter activation by GATA4 and Nkx2.5, respectively. Overexpression of GATA4 and/or Nkx2.5 induced not only Id2 promoter activity but also Id2 protein expression. Additionally, Id proteins significantly inhibit the GATA4 and Nkx2.5-dependent transcription, suggesting Id proteins may play a regulatory role in cardiogenesis. Collectively, our results demonstrate that GATA4 and Nkx2.5 could be one of the upstream regulators of Id2. J. Cell. Biochem. 103: 182,194, 2008. © 2007 Wiley-Liss, Inc. [source]