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At least 631 records · Page 35Linked to original sources
PubMed2004

Molecular modeling study of species-selective peroxisome proliferator-activated receptor (PPAR) alpha agonist; possible mechanism(s) of human PPARalpha selectivity of an alpha-substituted phenylpropanoic acid derivative (KCL).

In order to investigate the reason why phenylpropanoic acid derivative (KCL), a potent, human peroxisome proliferator-activated receptor (PPAR) alpha-selective agonist, shows this selectivity, we analyzed the binding modes of KCL and a related compound to the ligand-binding domain of human PPARalpha and rat PPARalpha by means of computer-aided molecular modeling. We concluded that the characteristic specificity of KCL is due to a specific hydrophobic contact between the hydrophobic tail part (the 4-trifluoromethyl group) and the key amino acid Ile272 located on the helix three region of the human PPARalpha ligand binding domain. We propose a possible binding mode of KCL with the ligand-binding domain of human PPARalpha. This binding model should offer important insights for further structural design of subtype-selective PPARalpha agonists for the treatment of altered metabolic homeostasis, such as dyslipidemia, obesity, and diabetes.

Animals↗
PubMed2001

[Cyclooxygenase (COX)-2 selective inhibitors: aspirin, a dual COX-1/COX-2 inhibitor, to COX-2 selective inhibitors].

Aspirin was developed as a non-steroidal anti-inflammatory drug (NSAID) in 1899. During the century after that, aspirin has been found to show its anti-inflammatory, analgesic and anti-pyretic activities by reducing prostaglandins biosynthesis through inhibition of cyclooxygenase (COX); and then COX was found to be constituted of two isoforms, constitutive COX-1 and inducible COX-2. Currently, novel NSAIDs, acting through selective inhibition of COX-2, that have efficacy as excellent as aspirin with significantly lower incidence of gastrointestinal adverse effects are available in America and some other countries, but not in Japan. Physiological and pathophysiological roles of COX-1 and COX-2 have been explained from studies in experimental animals, but there are many differences in species and diseases between animals and humans. Thus, physiological and pathophysiological roles of COX-2 were considered from the standpoint of clinical effects of the two latest COX-2 selective inhibitors, celecoxib and rofecoxib, on inflammation, pain, fever and colorectal cancer together with their adverse effects on gastrointestinal, renal and platelet functions; and the usefulness and limits of COX-2-selective inhibitors were discussed with the trends of new NSAIDs development.

Animals↗
PubMed1984

Two new opioid delta-receptor ligands: a highly selective agonist and a potent selective antagonist in in vitro isolated preparations.

N,N-Diallyl derivatives of enkephalin analogues were chemically synthesized, and their biological activities were estimated in vitro isolated preparations. N,N-Diallyl-[D-Ala2, D-Leu5]-enkephalin [test compound I] at doses up to 10 microM did not inhibit the electrically-evoked contractions of guinea-pig ileum, which had been suggested to contain opioid mu- and kappa-receptors, but it significantly depressed the contractions of mouse vas deferens, which had been indicated to contain mu-, kappa- and delta-receptors, suggesting that test compound I did not act on both mu- and kappa-receptors, but acted on delta-receptors. Additionally, the Ke (equilibrium dissociation constant) values against test compound I of naloxone were approximately 30 nM and similar to those of Mr 2266, also indicating that test compound I acted as a delta agonist. Moreover, the Ke values of ICI 154129 against compound I were approximately 340 nM, strongly suggesting that test compound I acted as a delta agonist. The Ke values of bis-[N,N-diallyl-[D-Ala2, Leu5]-enkephalyl]-cystine [test compound II] against [D-Ala2, D-Leu5]-enkephalin in mouse vas deferens and morphine or ethylketocyclazocine in guinea-pig ileum were 44.9 nM and 5.00 or 11.3 microM, respectively, showing that test compound II was a potent selective opioid delta antagonist. In conclusion, among compounds synthesized, two new opioid delta-receptor ligands, one being a highly selective agonist and the other being a potent selective antagonist in in vitro isolated preparations, were found in the present study.

Animals↗
PubMed1996

Selective blockade of endothelin receptor subtypes on systemic and renal vascular responses to endothelin-1 and IRL1620, a selective endothelin ETB-receptor agonist, in anesthetized rats.

By using BQ-788 as a selective endothelin ETB-receptor antagonist and FR139317 as a selective endothelin ETA-receptor antagonist, we have characterized the receptor subtypes mediating the systemic and renal vascular effects of endothelin-1 and IRL1620, a selective endothelin ETB-receptor agonist (succinyl-[Glu9,Ala11,5]-endothelin-1(8-21)), in anesthetized rats. Bolus intravenous injection of endothelin-1 (0.5 nmol/kg) and IRL1620 (1.65 nmol/kg) produced a transient fall in systemic blood pressure followed by a sustained increase. The initial fall in blood pressure observed after endothelin-1 and IRL1620 administration was completely blocked by BQ-788 (0.5 mumol/kg, i.v.), whereas the pressor response was blocked by FR139317 (0.8 mumol/kg, i.v.). Renal blood flow was decreased and calculated renal vascular resistance was dramatically increased by endothelin-1 and IRL1620. The reduction of renal blood flow by endothelin-1 was significantly suppressed by FR139317 but potentiated by BQ-788. Both BQ-788 and FR139317 partially blocked the renal vasoconstriction by IRL1620. Pretreatment by BQ-788 itself decreased renal blood flow by 14.1%. These results indicate that the systemic depressor responses induced by endothelin-1 and IRL1620 are mediated through the endothelin ETB-receptor, and the pressor responses are mediated through the endothelin ETA-receptor. In the renal vasculature of anesthetized rats, it is suggested that vasoconstriction is mediated through both endothelin ETA- and ETB-receptors and that endothelin ETB-receptors may be also involved in vasodilating responses to endothelin peptides.

Anesthesia↗
PubMed2005

Gastrointestinal effects of selective and non-selective non-steroidal anti-inflammatory drugs.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly prescribed group of drugs. Patients receiving NSAIDs often experience abdominal discomfort, and some of them develop serious gastrointestinal complications, such as ulceration, bleeding, perforation, or obstruction. Gastrointestinal side effects of NSAIDs are mostly attributed to cyclooxygenase (COX) inhibition resulting in reduction of prostaglandin in gastric mucosa. Topical irritant effects are also contributed to their systemic effect of prostaglandin inhibition. Anti-inflammatory effects of NSAIDs are mediated by COX-2 inhibition, while COX-1 inhibition is responsible for gastric prostaglandin inhibition. Management of gastrointestinal complications of NSAIDs is costly. In order to prevent or treat the gastrointestinal complications of NSAIDs, anti-ulcer drugs can be used concomitantly. Other alternative is the application or substitution of COX-2 selective inhibitors, which spare gastric mucosal prostaglandin synthesis and do not damage the gastric mucosa. Application of COX-2 selective inhibitors as a first line treatment for arthritic disorders may not be cost-effective, if patients do not have any risk factors including advanced age, history of complicating peptic ulcer, concomitant anticoagulant and corticosteroid medication. Patients with risk factors or those developing gastrointestinal complications during the course of NSAID treatment can be treated with COX-2 selective inhibitors if necessary.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

Selection for immune response in goats: the antibody response to diphtheria toxoid after 12 years of selection.

A herd of Norwegian dairy goats was subject to selection for high and low antibody response to diphtheria toxoid for 12 yr, or approximately 5.5 generations because sires were used for one mating season, whereas dams were used several years. The herd comprised approximately 100 milking goats. Only sires were tested and selected, five to seven sires were used in each line each year, and the percentage of male kids used for breeding varied between 15 and 50%. The mean phenotypic values of the lines diverged until the 4th yr, but the lines did not diverge any further. The means of both lines decreased during the experimental period. The restricted maximum likelihood (REML) estimate of the heritability of the trait in the base population was .19, whereas the realized heritability approached zero in the last six cycles of selection. Using the REML-estimate of heritability in an individual animal model, the mean breeding values (BLUP) of the lines were significantly different. The difference in mean BLUP values between the lines increased throughout the study. Yet, this increase was only 40% from the 2nd to the 12th yr. No effect of a major gene was observed in a test based on individual BLUP.

Analysis of Variance↗
PubMed1991

The effects of selective and non-selective adrenoceptor blockade on the portal blood flow in patients with liver cirrhosis.

The effects of different types of adrenoceptor blocking agents on portal venous blood flow were studied in 10 patients with liver cirrhosis by using a duplex Doppler system. Oral atenolol (selective beta 1 blocker), propranolol (non-selective beta blocker), and labetalol (non-selective adrenoceptor blocker) were compared. The drugs were administered at random at an interval of 3 days or more. Hemodynamic measurements were done before and after 1 h, 2 h, and 3 h of therapy. Atenolol and propranolol produced significant decrease in the portal vein cross-sectional area, portal blood velocity, and estimated volume of the portal blood flow. The portal blood velocity decreased by 13.1 +/- 7.2% 3 h after atenolol and by 16.2 +/- 6.5% 3 h after propranolol administration (p less than 0.05). Labetalol had no significant influence on portal venous hemodynamics. These results support the hypothesis that a decrease in portal venous flow induced by beta blockers is at least partly mediated with alpha-adrenergic receptors.

Adult↗
PubMed1986

Selective properties of trains of real and complex RF micropulses in slice-selective spin-echo MRI.

The spin nutation properties of frequency selective (space selective in combination with a magnetic field gradient) trains of radiofrequency micropulses were studied in a numeric model. Two cases were considered, one simulating the 90 degrees excitation pulse in spin-echo MRI, the other the 180 degrees spin inversion pulse. Image reconstruction according to the 2-D Fourier transform technique requests that the effect of the 180 degree pulse is independent of the initial phase of the spin vector relative to the radiofrequency field. It was found that with a train of phase-stable radiofrequency micropulses with an envelope of the traditional 'sinc' type the result of the spin inversion pulse was depending on the initial phase whereas this was not the case for a train of phase-shifted (complex) micropulses. The complex train of radiofrequency micropulses also had better selective properties both for excitation and spin inversion than the real one.

Electron Spin Resonance Spectroscopy↗
PubMed1984

Responses to dietary self selection and calories in liquid form by weight selected lines of chickens.

Feed intake of adult White Plymouth Rock male chickens from lines selected for high (HW) and low (LW) juvenile body weight was examined as a function of dietary self selection, glucose solutions in lieu of water, and environmental temperature. More energy was consumed by LW males allowed to select between high protein and high energy diets and when glucose solutions were provided in lieu of water, than on complete diets. In contrast, these regimens had relatively little influence on caloric intake in the HW line. On split diets, protein consumption was reduced in both the HW and LW lines, indicating that both populations overconsumed protein when fed complete diets.

Animals↗
PubMed1991

Divergent selection for growth in Japanese quail under split and complete nutritional environments. 5. Feed intake and efficiency patterns following nineteen generations of selection.

High (H) and low (L) quail lines divergently selected for 4-wk BW under complete-diet (CD) and split-diet (SD) environments were evaluated to examine changes in feed intake and feed efficiency before and after the age at selection. Progeny from the four quail lines (H-SD, L-SD, H-CD, L-CD) were fed the CD in Generation 17 and the SD in Generation 19. The BW of H-line quail were highest under their respective selection environments, and the BW of quail in the L lines were highest under reciprocal environments. However, the BW of the two H lines were similar as were those of the two L lines. Relative growth rates of H-line quail were superior to those of L-line quail for the first 2 wk posthatch but L-line rates were superior after Week 4. However, the BW of H-line birds were always higher than for the L-line birds. Adjusted feed intake (grams of feed per 100 g of BW) values for the H lines were similar but lower than values for the L lines. Differences in adjusted feed intake between the H and L lines from 1 to 10 wk remained constant, although adjusted feed intake declined with age in all lines. Feed efficiencies (grams of gain divided by grams of feed) were superior in the H lines for Weeks 1 through 3 and superior in the L lines for Weeks 5 through 9. The same relative shifts between lines were observed in relative growth rates. Therefore, feed efficiency, in addition to feed intake, appears to play an important role in the divergence of BW in the H- and L-quail lines.

Abdomen↗
PubMed2000

Selective intraoperative cholangiography during laparoscopic cholecystectomy: how selective?

The necessity for intraoperative cholangiography during laparoscopic cholecystectomy has been debated for some time. Numerous retrospective studies favor selective intraoperative cholangiography. Surgeons in favor of the selective policy differ in their personal selective criteria. The aim of this prospective study was to evaluate whether intraoperative cholangiography can be safely omitted during laparoscopic cholecystectomy on all patients who fit a standard set of criteria: normal liver function tests, common bile duct diameter less than 10 mm, and no history of gallstone pancreatitis or jaundice. We undertook a prospective study on 155 consecutive patients treated in a county teaching hospital with symptomatic gallbladder disease who met the above standard set of criteria. One hundred and fifty-five patients meeting these criteria underwent laparoscopic cholecystectomy during a 2-year period from February 1996 through February 1998. Data analyzed included patient history, laboratory and ultrasound findings, operative results, postoperative stay, and intraoperative and postoperative complications. The patients were followed by periodic interviews, physical examination, liver function tests, and/or biliary ultrasound for up to 3 1/2 years with a mean follow-up of 26 months for retained common bile duct stones. Intraoperative cholangiography was performed in only one of the 155 patients studied to confirm common bile duct injury. There were four postoperative complications (2.6%) and one common bile injury (0.6%). Postoperative stay averaged one day. No patients, by history, biliary ultrasound, liver function tests or endoscopy, were found to have retained common bile duct stones during the follow-up period. Our study shows that intraoperative cholangiography is not necessary for patients undergoing laparoscopic cholecystectomy who have normal liver functions tests, common bile duct diameter less than 10 mm, and no history of gallstone pancreatitis or jaundice.

Adolescent↗
PubMed2001

A selective review of selective attention research from the past century.

Research on attention is concerned with selective processing of incoming sensory information. To some extent, our awareness of the world depends on what we choose to attend, not merely on the stimulation entering our senses. British psychologists have made substantial contributions to this topic in the past century. Celebrated examples include Donald Broadbent's filter theory of attention, which set the agenda for most subsequent work; and Anne Treisman's revisions of this account, and her later feature-integration theory. More recent contributions include Alan Allport's prescient emphasis on the relevance of neuroscience data, and John Duncan's integration of such data with psychological theory. An idiosyncratic but roughly chronological review of developments is presented, some practical and clinical implications are briefly sketched, and future directions suggested. One of the biggest changes in the field has been the increasing interplay between psychology and neuroscience, which promises much for the future. A related change has been the realization that selection attention is best thought of as a broad topic, encompassing a range of selective issues, rather than as a single explanatory process.

Attention↗
PubMed2001

A selective review of selective attention research from the past century.

Research on attention is concerned with selective processing of incoming sensory information. To some extent, our awareness of the world depends on what we choose to attend, not merely on the stimulation entering our senses. British psychologists have made substantial contributions to this topic in the past century. Celebrated examples include Donald Broadbent's filter theory of attention, which set the agenda for most subsequent work; and Anne Treisman's revisions of this account, and her later feature-integration theory. More recent contributions include Alan Allport's prescient emphasis on the relevance of neuroscience data, and John Duncan's integration of such data with psychological theory. An idiosyncratic but roughly chronological review of developments is presented, some practical and clinical implications are briefly sketched, and future directions suggested. One of the biggest changes in the field has been the increasing interplay between psychology and neuroscience, which promises much for the future. A related change has been the realization that selection attention is best thought of as a broad topic, encompassing a range of selective issues, rather than as a single explanatory process.

Journal Article↗
PubMedDate not supplied

Selective and non-selective apoptosis induction in transformed and non-transformed fibroblasts by exogenous reactive oxygen and nitrogen species.

This paper defines selective and nonselective apoptosis induction in transformed and nontransformed fibroblasts by extracellular reactive oxygen and nitrogen species (ROS and RNS). Superoxide anions do not exhibit direct apoptosis inducing potential, whereas their dismutation product hydrogen peroxide induces apoptosis nonselectively in transformed and nontransformed fibroblasts. Myeloperoxidase converts hydrogen peroxide into the selective apoptosis mediator HOCl, which interacts with transformed target cell-derived superoxide anions and generates apoptosis-inducing hydroxyl radicals. Nitric oxide does not induce apoptosis directly in fibroblasts. However, interaction of nitric oxide with transformed cell-derived superoxide anions leads to the generation of the ultimate apoptosis inducer, peroxynitrite. Peroxynitrite by itself does not discriminate between transformed and nontransformed cells. The direction of generation of apoptosis inducing ROS and RNS to the site of superoxide anion production has relevance for the selectivity of ROS and RNS-based natural antitumor systems, as extracellular superoxide anion generation represents a hallmark of the transformed state.

Animals↗
PubMedDate not supplied

Evaluation of VIDAs Immuno-concentration Salmonella assay Plus selective plate method (Hektoen enteric, bismuth sulfite, Salmonella identification) for detection of Salmonella in selected foods: collaborative study.

The VIDAS Immuno-concentration Salmonella (ICS) plus selective plate method (Hektoen enteric, bismuth sulfite, Salmonella identification) method for the detection of Salmonella was compared to the Bacteriological Analytical Manual (BAM)/AOAC culture method in a collaborative study. Thirty-two laboratories participated in the evaluation. Each laboratory tested one or more of the 6 test products: milk chocolate, nonfat dry milk, dried whole egg, soy flour, ground black pepper, and ground raw turkey. The 2 methods were in agreement for 1,283 of the 1,440 test samples. Of the 157 test samples not in agreement, 82 were VIDAS ICS plus selective plate-positive and BAM/AOAC-negative, and 75 were VIDAS ICS plus selective plate-negative and BAM/AOAC-positive.

Animals↗
PubMedDate not supplied

Salmonella in selected foods by VIDAS immuno-concentration Salmonella plus selective plate method (Hektoen enteric, xylose lysine desoxycholate, bismuth sulfite): collaborative study.

The VIDAS Immuno-concentration Salmonella (ICS) plus selective plate method (Hektoen enteric, xylose lysine desoxycholate, bismuth sulfite) method for the detection of Salmonella was compared to the Bacteriological Analytical Manual (BAM)/AOAC culture method in a collaborative study. Thirty-two laboratories participated in the evaluation. Each laboratory tested one or more of the 6 test products: milk chocolate, nonfat dry milk, dried whole egg, soy flour, ground black pepper, and ground raw turkey. The 2 methods were in agreement for 1,297 of the 1,455 samples. Of the 158 samples not in agreement, 82 were VIDAS ICS plus selective plate-positive and BAM/AOAC-negative, and 76 were VIDAS ICS plus selective plate-negative and BAM/AOAC-positive.

Animals↗
PubMed2001

Selective thyromimetics: tissue-selective thyroid hormone analogs.

Thyroid hormone coordinates a diverse array of physiological events in development and homeostasis. Many of the actions of thyroid hormone are tissue-specific and are primarily mediated by a panel of thyroid hormone receptor isoforms that are expressed in different ratios in different tissues. Because these tissue-specific hormone signaling pathways are linked to a number of metabolic diseases, the development of synthetic thyroid hormone analogs that have tissue-selective hormone actions (i.e., selective thyromimetics) is highly desirable. There is a powerful collection of tools available today for this pursuit including efficient receptor binding and activation assays, receptor structures and a variety of thyroid hormone receptor knockout mice. The medicinal chemistry efforts in this area demonstrate that selective thyromimetics can be produced from a variety of approaches. These compounds are proving useful as probes to better define thyroid hormone actions and may one day find use in the clinic for the treatment of metabolic disorders.

Animals↗
PubMed1992

[Usefulness of selective endoscopic retrograde pancreatography (selective ERP) and endoscopic pancreatic biopsy (EPB) in the diagnosis of mucin-producing tumor of the pancreas].

Selective ERP and EPB were employed in the diagnosis of mucin-producing tumor (MPT) of the pancreas and their usefulness was evaluated. Thirty five cases of MPTs were subdivided into three subtypes, i.e., 1) main duct type, 2) branch duct type and 3) peripheral type (mucinous cystadenoma/cystadenocarcinoma). Selective ERP was proved to be useful in demonstrating precise and whole pancreatograms, especially in revealing multiple lesions, when compared with standard ERP. Selective ERP could demonstrate communication between cystic tumors of the peripheral type and the pancreatic duct in seven (88%) of eight cases of the peripheral type, which suggests high frequency of the communication in the peripheral type. For preoperative tissue diagnosis, EPB was shown to be a useful method to yield sufficient tissue materials for histopathological evaluation and may be used as an adjunction method to diagnose the intraductal extent of the tumorous lesion.

Adenocarcinoma, Mucinous↗