Displaying publications 1161 - 1180 of 1919 in total

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  1. Fulltext Mechanistic Studies of the Antiallergic Activity of Phyllanthus amarus Schum. & Thonn. and Its Compounds
    Abd Rani NZ, Lam KW, Jalil J, Mohamad HF, Mat Ali MS, Husain K
    Molecules, 2021 Jan 28;26(3).
    PMID: 33525733 DOI: 10.3390/molecules26030695
    Phyllanthus amarus Schum. & Thonn. (Phyllanthaceae) is a medicinal plant that is commonly used to treat diseases such as asthma, diabetes, and anemia. This study aimed to examine the antiallergic activity of P. amarus extract and its compounds. The antiallergic activity was determined by measuring the concentration of allergy markers release from rat basophilic leukemia (RBL-2H3) cells with ketotifen fumarate as the positive control. As a result, P. amarus did not stabilize mast cell degranulation but exhibited antihistamine activity. The antihistamine activity was evaluated by conducting a competition radioligand binding assay on the histamine 1 receptor (H1R). Four compounds were identified from the high performance liquid chromatography (HPLC) analysis which were phyllanthin (1), hypophyllanthin (2), niranthin (3), and corilagin (4). To gain insights into the binding interactions of the most active compound hypophyllanthin (2), molecular docking was conducted and found that hypophyllanthin (2) exhibited favorable binding in the H1R binding site. In conclusion, P. amarus and hypophyllanthin (2) could potentially exhibit antiallergic activity by preventing the activation of the H1 receptor.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  2. Fulltext Associations of gestational cardiovascular health with pregnancy outcomes: the Hyperglycemia and Adverse Pregnancy Outcome study
    Perak AM, Lancki N, Kuang A, Labarthe DR, Allen NB, Shah SH, et al.
    Am J Obstet Gynecol, 2021 02;224(2):210.e1-210.e17.
    PMID: 32768430 DOI: 10.1016/j.ajog.2020.07.053
    BACKGROUND: The American Heart Association's formal characterization of cardiovascular health combines several metrics in a health-oriented, rather than disease-oriented, framework. Although cardiovascular health assessment during pregnancy has been recommended, its significance for pregnancy outcomes is unknown.

    OBJECTIVE: The purpose of this study was to examine the association of gestational cardiovascular health-formally characterized by a combination of 5 metrics-with adverse maternal and newborn outcomes.

    STUDY DESIGN: We analyzed data from the Hyperglycemia and Adverse Pregnancy Outcome study, including 2304 mother-newborn dyads from 6 countries. Maternal cardiovascular health was defined by the combination of the following 5 metrics measured at a mean of 28 (24-32) weeks' gestation: body mass index, blood pressure, lipids, glucose, and smoking. Levels of each metric were categorized using pregnancy guidelines, and the total cardiovascular health was scored (0-10 points, where 10 was the most favorable). Cord blood was collected at delivery, newborn anthropometrics were measured within 72 hours, and medical records were abstracted for obstetrical outcomes. Modified Poisson and multinomial logistic regression were used to test the associations of gestational cardiovascular health with pregnancy outcomes, adjusted for center and maternal and newborn characteristics.

    RESULTS: The average age of women at study exam was 29.6 years old, and they delivered at a mean gestational age of 39.8 weeks. The mean total gestational cardiovascular health score was 8.6 (of 10); 36.3% had all ideal metrics and 7.5% had 2+ poor metrics. In fully adjusted models, each 1 point higher (more favorable) cardiovascular health score was associated with lower risks for preeclampsia (relative risk, 0.67 [95% confidence interval, 0.61-0.73]), unplanned primary cesarean delivery (0.88 [0.82-0.95]), newborn birthweight >90th percentile (0.81 [0.75-0.87]), sum of skinfolds >90th percentile (0.84 [0.77-0.92]), and insulin sensitivity <10th percentile (0.83 [0.77-0.90]). Cardiovascular health categories demonstrated graded associations with outcomes; for example, relative risks (95% confidence intervals) for preeclampsia were 3.13 (1.39-7.06), 5.34 (2.44-11.70), and 9.30 (3.95-21.86) for women with ≥1 intermediate, 1 poor, or ≥2 poor (vs all ideal) metrics, respectively.

    CONCLUSION: More favorable cardiovascular health at 24 to 32 weeks' gestation was associated with lower risks for several adverse pregnancy outcomes in a multinational cohort.

    Matched MeSH terms: Blood Pressure*
  3. Fulltext Isolation and partial characterization of Asian sea bass (Lates calcarifer) Vitellogenin
    Fazielawanie NM, Siraj SS, Harmin SA, Ina-Salwany MY
    Fish Physiol Biochem, 2013 Apr;39(2):191-200.
    PMID: 22878544 DOI: 10.1007/s10695-012-9690-5
    A study was conducted to isolate, partial characterize Asian sea bass (Lates calcarifer) vitellogenin (vtg). Two-year-old juvenile L. calcarifer (n = 10) were given three intraperitoneal injections of 17-β estradiol (E2) at a dose of 2 mg/kg body weight to induce vitellogenesis. Blood was collected 3 days after the last injection, and plasma was purified through gel filtration chromatography. A broad single symmetrical peak consisting of vtg molecule was produced. Protein concentration was 0.059 mg/ml as determined by Bradfrod assay using bovine serum albumin as a standard. The protein appeared as one circulating form in Native PAGE considering the dimeric form of putative vtg with molecular weight of 545 kDa. In SDS-PAGE under reducing conditions, two major bands appeared at 232.86 and 118.80 kDa and minor bands at 100.60, 85.80 and 39.92 kDa, respectively. The purified vtg was used to generate a polyclonal antibody, and the specificity of antibody was assessed by Western blot analysis. Two major bands were immunoreacted, but no cross-reactivity was observed with plasma from non-induced males. The protein was characterized as phosphoglycolipoprotein as it positively stained for the presence of lipid, phosphorus and carbohydrate using Sudan Black B, methyl green and periodic acid/Schiff reagent solution, respectively. The amino acid composition was analyzed by high sensitivity amino acid analysis that showed high percentage of non-polar amino acids (~48 %). The results suggest the potential utilization of vtg as a basis tool to further study about reproductive physiology of this important economical species.
    Matched MeSH terms: Chromatography, High Pressure Liquid/veterinary
  4. The effects of heated vegetable oils on blood pressure in rats
    Jaarin K, Mustafa MR, Leong XF
    Clinics (Sao Paulo), 2011;66(12):2125-32.
    PMID: 22189740
    OBJECTIVES: The goal of this study was to determine the possible mechanism that is involved in the blood pressure-raising effect of heated vegetable oils.

    METHODS: Adult male Sprague-Dawley rats were divided into 11 groups; the control group was fed with rat chow, and the other groups were fed with chow that was mixed with 15% weight/weight palm or soy oils, which were either in a fresh form or heated once, twice, five, or ten times. Blood pressures were measured at the baseline and throughout the 24-week study. Plasma nitric oxide levels were assessed prior to treatment and at the end of the study. Following 24 weeks, the rats were sacrificed to investigate their vascular reactivity using the thoracic aorta.

    RESULTS: Palm and soy oils had no detrimental effects on blood pressure, and they significantly elevated the nitric oxide contents and reduced the contractile responses to phenylephrine. However, trials using palm and soy oils that were repeatedly heated showed an increase in blood pressure, enhanced phenylephrine-induced contractions, reduced acetylcholine- and sodium nitroprusside-induced relaxations relative to the control and rats that were fed fresh vegetable oils.

    CONCLUSIONS: The blood pressure-raising effect of the heated vegetable cooking oils is associated with increased vascular reactivity and a reduction in nitric oxide levels. The chronic consumption of heated vegetable oils leads to disturbances in endogenous vascular regulatory substances, such as nitric oxide. The thermal oxidation of the cooking oils promotes the generation of free radicals and may play an important contributory role in the pathogenesis of hypertension in rats.

    Matched MeSH terms: Blood Pressure/drug effects*
  5. The aporphine alkaloid boldine improves endothelial function in spontaneously hypertensive rats
    Lau YS, Machha A, Achike FI, Murugan D, Mustafa MR
    Exp Biol Med (Maywood), 2012 Jan;237(1):93-8.
    PMID: 22156043 DOI: 10.1258/ebm.2011.011145
    Boldine, a major aporphine alkaloid found in Chilean boldo tree, is a potent antioxidant. Oxidative stress plays a detrimental role in the pathogenesis of endothelial dysfunction in hypertension. In the present study, we investigated the effects of boldine on endothelial dysfunction in hypertension using spontaneously hypertensive rats (SHR), the most studied animal model of hypertension. SHR and their age-matched normotensive Wistar-Kyoto (WKY) rats were treated with boldine (20 mg/kg per day) or its vehicle, which served as control, for seven days. Control SHR displayed higher systolic blood pressure (SBP), reduced endothelium-dependent aortic relaxation to acetylcholine (ACh), marginally attenuated endothelium-independent aortic relaxation to sodium nitroprusside (SNP), increased aortic superoxide and peroxynitrite production, and enhanced p47(phox) protein expression as compared with control WKY rats. Boldine treatment significantly lowered SBP in SHR but not in WKY. Boldine treatment enhanced the maximal relaxation to ACh in SHR, but had no effect in WKY, whereas the sensitivity to ACh was increased in both SHR and WKY aortas. Boldine treatment enhanced sensitivity, but was without effect on maximal aortic relaxation responses, to SNP in both WKY and SHR aortas. In addition, boldine treatment lowered aortic superoxide and peroxynitrite production and downregulated p47(phox) protein expression in SHR aortas, but had no effect in the WKY control. These results show that boldine treatment exerts endothelial protective effects in hypertension, achieved, at least in part, through the inhibition of NADPH-mediated superoxide production.
    Matched MeSH terms: Blood Pressure/drug effects
  6. Prevalence of hypertension, control of blood pressure and treatment in hypertensive with type 2 diabetes in Hospital University Sains Malaysia
    Abougalambou SS, Abougalambou AS, Sulaiman SA, Hassali MA
    Diabetes Metab Syndr, 2011 Jul-Sep;5(3):115-9.
    PMID: 22813562 DOI: 10.1016/j.dsx.2012.03.001
    AIMS: To determine the prevalence of hypertension, control of hypertension and patterns of antihypertensive medications in Malaysian type 2 diabetic patients who attended diabetes clinics in Hospital University Sains Malaysia (Tertiary Hospital).
    MATERIALS AND METHODS: The study design was observational prospective longitudinal follow-up study; the study was conducted with sample of 1077 type 2 diabetes mellitus outpatient recruited whom attended the diabetes clinics at Hospital Universiti Sains Malaysia (HUSM) in Kelantan. The study period was from January till December 2008. Blood pressure was defined as >130/80 or use of antihypertension medications. Demographic characteristics of patients, level of blood pressure control, use of antihypertensive medications and patterns of antihypertensive therapy.
    RESULTS: The prevalence of hypertension in Malaysian type 2 diabetic patients was 998 (92.7%),antihypertensive drugs were prescribed in 940 (94.2%) of hypertensive patients with type 2 diabetic mellitus. The achievement of blood pressure control (≤130/80 mmHg) was 471 (47.2%) %. The percentage of patients receiving one, two, three, and four drugs were 253 (25.3%), 311 (31.3%), 179 (17.9%), and 197 (19.7%) respectively. Calcium channel blockers were the most commonly prescribed antihypertensive agents 757 (75.7%) followed by Angiotensin-converting enzyme inhibitors 446 (44.6%), and Angiotensin receptor blockers 42.4 (42.4%).
    CONCLUSION: The prevalence of hypertension is high in Malaysian type 2 diabetic patients, hypertension was not controlled to the recommended levels of blood pressure in about one-half (52.8%) of diabetes patients. Calcium channel blockers were the most commonly prescribed antihypertensive agents. There is an urgent need to educate both patients and health care providers of importance of achieving target of treatment in order to reduce morbidity and mortality due to diabetes with hypertension.
    Matched MeSH terms: Blood Pressure/physiology*
  7. Guidelines adherence and hypertension control at a tertiary hospital in Malaysia
    Ahmad N, Hassan Y, Tangiisuran B, Meng OL, Abd Aziz N, Ahmad FU, et al.
    J Eval Clin Pract, 2013 Oct;19(5):798-804.
    PMID: 22583820 DOI: 10.1111/j.1365-2753.2012.01852.x
    RATIONALE, AIMS AND OBJECTIVES: Existing literature suggests that doctors' poor adherence with guidelines is one of the major contributing factors to suboptimal control of hypertension. This study aims to evaluate doctors' adherence with Malaysian clinical practice guideline (CPG 2008) in a tertiary care hospital, and factors associated with guideline adherence and hypertension control.
    METHODS: This was a cross-sectional study conducted at Hospital Pulau Pinang, Penang, Malaysia. Prescriptions written by 26 enrolled doctors to 650 established hypertensive outpatients (25 prescriptions per enrolled doctor) were noted on visit 1 along with patients' demographic and clinical data. The noted prescriptions were classified either as compliant or non-compliant to CPG (2008). Five hundred twenty (80%) of the enrolled patients (20 patients per enrolled doctor) were followed for one more visit. Blood pressure (BP) noted on visit 2 was related to the prescription written on visit 1. SPSS 16 (SPSS Inc., Chicago, IL, USA) was used for data analysis.
    RESULTS: Three hundred forty-nine (67.1%) patients received guidelines compliant pharmacotherapy. In multivariate analysis, hypertension clinic had significant negative association with guidelines adherence. Two hundred sixty-five patients (51%) were at goal BP on visit 2. In multivariate analysis, angiotensin-converting enzyme inhibitors and guidelines adherence had significant positive, while renal disease, diabetes mellitus and diabetic clinic had significant negative association with hypertension control.
    CONCLUSIONS: An overall fair level of adherence with guidelines and better control of hypertension was observed. Guidelines compliant practices resulted in better control of hypertension. The gaps between what guidelines recommend and clinical practice were especially seen in the pharmacotherapy of uncomplicated hypertension and hypertension with diabetes mellitus and renal disease.
    KEYWORDS: Malaysia; adherence; guidelines; hypertension
    Study site: Cardiology, nephrology, diabetic and hypertension clinics, Hospital Pulau Pinang, Malaysia
    Matched MeSH terms: Blood Pressure Monitoring, Ambulatory/statistics & numerical data
  8. Fulltext Engineering the production of major catechins by Escherichia coli carrying metabolite genes of Camellia sinensis
    Umar KM, Abdulkarim SM, Radu S, Abdul Hamid A, Saari N
    ScientificWorldJournal, 2012;2012:529031.
    PMID: 22645428 DOI: 10.1100/2012/529031
    A mimicked biosynthetic pathway of catechin metabolite genes from C. sinensis, consisting of flavanone 3 hydroxylase (F3H), dihydroflavonol reductase (DFR), and leucoanthocyanidin reductase (LCR), was designed and arranged in two sets of constructs: (a) single promoter in front of F3H and ribosome-binding sequences both in front of DFR and LCR; (b) three different promoters with each in the front of the three genes and ribosome-binding sequences at appropriate positions. Recombinant E. coli BL (DE3) harbouring the constructs were cultivated for 65 h at 26 °C in M9 medium consisting of 40 g/L glucose, 1 mM IPTG, and 3 mM eriodictyol. Compounds produced were extracted in ethyl acetate in alkaline conditions after 1 h at room temperature and identified by HPLC. Two of the four major catechins, namely, (-)-epicatechin (0.01) and (-)-epicatechin gallate (0.36 mg/L), and two other types ((+)-catechin hydrate (0.13 mg/L) and (-)-catechin gallate (0.04 mg/L)) were successfully produced.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  9. Serum C-reactive protein level and prehypertension in two Asian populations
    Sabanayagam C, Shankar A, Lee J, Wong TY, Tai ES
    J Hum Hypertens, 2013 Apr;27(4):231-6.
    PMID: 22418747 DOI: 10.1038/jhh.2011.117
    Few previous studies in Western populations have reported an association between C-reactive protein (CRP) and prehypertension. However, no previous study has examined this association in Asians. We examined individuals who were free of hypertension from two independent population-based studies in Singapore: the Singapore Prospective Study Programme (SP2, n=2843 Chinese, Malay and Indians aged 24 years) and the Singapore Malay Eye Study (SiMES, n=957 Malays, aged 40-80 years). Prehypertension was defined as systolic blood pressure (BP) 120-139 mm Hg or diastolic BP 80-89 mm Hg. CRP was analyzed as categories (<1, 1-3, >3 mg l(-1)). The prevalence of prehypertension increased with increasing categories of CRP in both cohorts (P for trend <0.05 in both cohorts). After adjusting for potential confounders including body mass index (BMI), smoking and diabetes, persons with higher levels of CRP were more likely to have prehypertension in both SP2 (compared with CRP <1 mg l(-1), odds ratio (OR) 1.23, 95% confidence interval (CI) 1.03-1.48 for CRP 1-3 and OR 1.67, 95% CI 1.32-2.10 for >3 mg l(-1)) and SiMES (OR 1.45, 95% CI 1.04-2.01 and OR 1.56, 95% CI 1.07-2.27) respectively. In conclusion, data from two population-based Asian cohorts suggest that elevated serum CRP levels are associated with prehypertension.
    Matched MeSH terms: Blood Pressure*
  10. Method development and validation for the simultaneous determination of imatinib mesylate and N-desmethyl imatinib using rapid resolution high performance liquid chromatography coupled with UV-detection
    Tan KL, Ankathil R, Gan SH
    J Chromatogr B Analyt Technol Biomed Life Sci, 2011 Nov 15;879(30):3583-91.
    PMID: 22000961 DOI: 10.1016/j.jchromb.2011.09.048
    We developed a simple and sensitive method for the simultaneous detection of imatinib mesylate (IM) and its active metabolite, N-desmethyl imatinib (M1), in human serum samples. Separation was successfully achieved using an Agilent(®) ZORBAX Eclipse plus C(18) reversed phase column (50 mm × 2.1 mm, i.d.; 1.8 μm) under isocratic mobile phase conditions consisting of acetonitrile: 0.02 M potassium dihydrogen phosphate with 0.2% triethylamine at pH 3 (25:75, v/v) and ultra-violet detection was achieved at 235 nm. Extraction of the target compounds was completed using 100% cold acetonitrile. Good linearities (r(2)>0.99) for both IM and M1 were achieved for the concentration ranges of 50-1800 ng/mL and 50-360 ng/mL, respectively. The detection limits were 20 ng/mL and 10 ng/mL for M1 and IM, respectively. The intra- and inter-day precisions were less than 1% with percent recoveries of more than 90%. The method was successfully applied to calculate the pharmacokinetic parameters of chronic myeloid leukemia patients receiving imatinib. The method is suitable to be routinely applied for determination of IM and M1 in serum.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  11. Fulltext Antimycobacterial, antimicrobial, and biocompatibility properties of para-aminosalicylic acid with zinc layered hydroxide and Zn/Al layered double hydroxide nanocomposites
    Saifullah B, El Zowalaty ME, Arulselvan P, Fakurazi S, Webster TJ, Geilich BM, et al.
    Drug Des Devel Ther, 2014;8:1029-36.
    PMID: 25114509 DOI: 10.2147/DDDT.S63753
    The treatment of tuberculosis by chemotherapy is complicated due to multiple drug prescriptions, long treatment duration, and adverse side effects. We report here for the first time an in vitro therapeutic effect of nanocomposites based on para-aminosalicylic acid with zinc layered hydroxide (PAS-ZLH) and zinc-aluminum layered double hydroxides (PAS-Zn/Al LDH), against mycobacteria, Gram-positive bacteria, and Gram-negative bacteria. The nanocomposites demonstrated good antimycobacterial activity and were found to be effective in killing Gram-positive and Gram-negative bacteria. A biocompatibility study revealed good biocompatibility of the PAS-ZLH nanocomposites against normal human MRC-5 lung cells. The para-aminosalicylic acid loading was quantified with high-performance liquid chromatography analysis. In summary, the present preliminary in vitro studies are highly encouraging for further in vivo studies of PAS-ZLH and PAS-Zn/Al LDH nanocomposites to treat tuberculosis.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  12. Role of adenosine receptors in resveratrol-induced intraocular pressure lowering in rats with steroid-induced ocular hypertension
    Razali N, Agarwal R, Agarwal P, Kumar S, Tripathy M, Vasudevan S, et al.
    Clin Exp Ophthalmol, 2015 Jan-Feb;43(1):54-66.
    PMID: 24995479 DOI: 10.1111/ceo.12375
    BACKGROUND: Steroid-induced ocular hypertension is currently treated in the same way as primary open-angle glaucoma. However, the treatment is often suboptimal and is associated with adverse effects. We evaluated the oculohypotensive effects of topical trans-resveratrol in rats with steroid-induced ocular hypertension and involvement of adenosine receptors (AR) in intraocular pressure (IOP) lowering effect of trans-resveratrol.
    METHODS: The oculohypotensive effect of unilateral single-drop application of various concentrations of trans-resveratrol was first studied in oculonormotensive rats. Concentration with maximum effect was similarly studied in rats with steroid-induced ocular hypertension. Involvement of AR was studied by observing the alterations of IOP in response to trans-resveratrol after pretreating animals with AR subtype-specific antagonists. Additionally, we used computational methods, including 3D modelling, 3D structure generation and protein-ligand interaction, to determine the AR-trans-resveratrol interaction.
    RESULTS: All concentrations of trans-resveratrol produced significant IOP reduction in normotensive rat eyes. Maximum mean IOP reduction of 15.1% was achieved with trans-resveratrol 0.2%. In oculohypertensive rats, trans-resveratrol 0.2% produced peak IOP reduction of 25.2%. Pretreatment with A₁ antagonist abolished the oculohypotensive effect of trans-resveratrol. Pretreatment with A₃ and A₂A AR antagonists produced significant IOP reduction in both treated and control eyes, which was further augmented by trans-resveratrol application in treated eyes. Computational studies showed that trans-resveratrol has highest affinity for A₂B and A₁, followed by A2A and A₃ AR.
    CONCLUSION: Topically applied trans-resveratrol reduces IOP in rats with steroid-induced ocular hypertension. Trans-resveratrol-induced oculohypotension involves its agonistic activity at the A₁ AR.
    KEYWORDS: adenosine receptors; docking simulation; intraocular pressure; resveratrol; topical
    Matched MeSH terms: Intraocular Pressure/drug effects*
  13. Fulltext Prevalence of metabolic syndrome among staff in a Malaysian public university based on Harmonised, International Diabetes Federation and National Cholesterol Education Program Definitions
    Heng KS, Hejar AR, Rushdan AZ, Loh SP
    Malays J Nutr, 2013 Apr;19(1):77-86.
    PMID: 24800386 MyJurnal
    Metabolic syndrome (MetSyn) as defined by the latest Harmonised definition and the agreement between the Harmonised definition and other definitions is poorly studied among Malaysians. This study was conducted to determine and compare the prevalence of MetSyn according to the Harmonised, International Diabetes Federation (IDF) and National Cholesterol Education Program (NCEP ATPIII) definitions among Malay staff of Universiti Putra Malaysia (UPM).
    Matched MeSH terms: Blood Pressure/physiology
  14. Fulltext Transcription factor CREB3L1 regulates vasopressin gene expression in the rat hypothalamus
    Greenwood M, Bordieri L, Greenwood MP, Rosso Melo M, Colombari DS, Colombari E, et al.
    J Neurosci, 2014 Mar 12;34(11):3810-20.
    PMID: 24623760 DOI: 10.1523/JNEUROSCI.4343-13.2014
    Arginine vasopressin (AVP) is a neurohypophysial hormone regulating hydromineral homeostasis. Here we show that the mRNA encoding cAMP responsive element-binding protein-3 like-1 (CREB3L1), a transcription factor of the CREB/activating transcription factor (ATF) family, increases in expression in parallel with AVP expression in supraoptic nuclei (SONs) and paraventicular nuclei (PVNs) of dehydrated (DH) and salt-loaded (SL) rats, compared with euhydrated (EH) controls. In EH animals, CREB3L1 protein is expressed in glial cells, but only at a low level in SON and PVN neurons, whereas robust upregulation in AVP neurons accompanied DH and SL rats. Concomitantly, CREB3L1 is activated by cleavage, with the N-terminal domain translocating from the Golgi, via the cytosol, to the nucleus. We also show that CREB3L1 mRNA levels correlate with AVP transcription level in SONs and PVNs following sodium depletion, and as a consequence of diurnal rhythm in the suprachiasmatic nucleus. We tested the hypothesis that CREB3L1 activates AVP gene transcription. Both full-length and constitutively active forms of CREB3L1 (CREB3L1CA) induce the expression of rat AVP promoter-luciferase reporter constructs, whereas a dominant-negative mutant reduces expression. Rat AVP promoter deletion constructs revealed that CRE-like and G-box sequences in the region between -170 and -120 bp are important for CREB3L1 actions. Direct binding of CREB3L1 to the AVP promoter was shown by chromatin immunoprecipitation both in vitro and in the SON itself. Injection of a lentiviral vector expressing CREB3L1CA into rat SONs and PVNs resulted in increased AVP biosynthesis. We thus identify CREB3L1 as a regulator of AVP transcription in the rat hypothalamus.
    Matched MeSH terms: Osmotic Pressure/physiology
  15. Combination of saponification and dispersive liquid-liquid microextraction for the determination of tocopherols and tocotrienols in cereals by reversed-phase high-performance liquid chromatography
    Shammugasamy B, Ramakrishnan Y, Ghazali HM, Muhammad K
    J Chromatogr A, 2013 Jul 26;1300:31-7.
    PMID: 23587317 DOI: 10.1016/j.chroma.2013.03.036
    A simple sample preparation technique coupled with reversed-phase high-performance liquid chromatography was developed for the determination of tocopherols and tocotrienols in cereals. The sample preparation procedure involved a small-scale hydrolysis of 0.5g cereal sample by saponification, followed by the extraction and concentration of tocopherols and tocotrienols from saponified extract using dispersive liquid-liquid microextraction (DLLME). Parameters affecting the DLLME performance were optimized to achieve the highest extraction efficiency and the performance of the developed DLLME method was evaluated. Good linearity was observed over the range assayed (0.031-4.0μg/mL) with regression coefficients greater than 0.9989 for all tocopherols and tocotrienols. Limits of detection and enrichment factors ranged from 0.01 to 0.11μg/mL and 50 to 73, respectively. Intra- and inter-day precision were lower than 8.9% and the recoveries were around 85.5-116.6% for all tocopherols and tocotrienols. The developed DLLME method was successfully applied to cereals: rice, barley, oat, wheat, corn and millet. This new sample preparation approach represents an inexpensive, rapid, simple and precise sample cleanup and concentration method for the determination of tocopherols and tocotrienols in cereals.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  16. Blunted endogenous GABA-mediated inhibition in the hypothalamic paraventricular nucleus of rats with streptozotocin-induced diabetes
    Hassan Z, Sattar MZ, Suhaimi FW, Yusoff NH, Abdulla MH, Yusof AP, et al.
    Acta Neurol Belg, 2013 Sep;113(3):319-25.
    PMID: 23242937 DOI: 10.1007/s13760-012-0165-3
    The hypothalamic paraventricular nucleus (PVN) is involved in the regulation of sympathetic outflow and particularly affects the heart. This study sets out to determine the role of GABA of the paraventricular nucleus (PVN) in cardiovascular regulation in streptozotocin-induced diabetic rats. Pharmacological stimulation of glutamatergic receptors with DL-Homocysteic acid (200 mM in 100 nL) in the PVN region showed a significant depression in both mean arterial pressure (MAP) and heart rate (HR) of diabetic rats (Diabetic vs. non-diabetic: MAP 15.0 ± 1.5 vs. 35.8 ± 2.8 mmHg; HR 3.0 ± 2.0 vs. 30.0 ± 6.0 bpm, P < 0.05). Microinjection of bicuculline methiodide (1 mM in 100 nL), a GABAA receptor antagonist, produced an increase in baseline MAP and HR in both non-diabetic and diabetic rats. In the diabetic rats, bicuculline injection into the PVN reduced the pressor and HR responses (Diabetic vs. non-diabetic: MAP 6.2 ± 0.8 vs. 25.1 ± 2.2 mmHg; HR 1.8 ± 1.1 vs. 25.4 ± 6.2 bpm, P < 0.05). A microinjection of muscimol (2 mM in 100 nL), which is a GABAA receptor agonist, in the PVN elicited decreases in MAP and HR in both groups. The diabetic group showed a significantly blunted reduction in HR, but not MAP (Diabetic vs. non-diabetic: MAP -15.7 ± 4.0 vs. -25.0 ± 3.8 mmHg; HR -5.2 ± 2.1 vs. -39.1 ± 7.9 bpm). The blunted vasopressor and tachycardic responses to bicuculline microinjection in the diabetic rats are likely to result from decreased GABAergic inputs, attenuated release of endogenous GABA or alterations in GABAA receptors within the PVN.
    Matched MeSH terms: Blood Pressure/drug effects
  17. Heterologous expression of human cytochrome P450 (CYP) 2C19 in Escherichia coli and establishment of RP-HPLC method to serve as activity marker
    Pan Y, Mak JW, Ong CE
    Biomed Chromatogr, 2013 Jul;27(7):859-65.
    PMID: 23386533 DOI: 10.1002/bmc.2872
    In this study, a simple and reliable reverse-phase high-performance liquid chromatography (RP-HPLC) method was established and validated to analyze S-mephenytoin 4-hydroxylase activity of a recombinant CYP2C19 system. This system was obtained by co-expressing CYP2C19 and NADPH-CYP oxidoreductase (OxR) proteins in Escherichia coli (E. coli) cells. In addition to RP-HPLC, the expressed proteins were evaluated by immunoblotting and reduced CO difference spectral scanning. The RP-HPLC assay showed good linearity (r(2) = 1.00) with 4-hydroxymephenytoin concentration from 0.100 to 50.0 μm and the limit of detection was 5.00 × 10(-2) μm. Intraday and interday precisions determined were from 1.90 to 8.19% and from 2.20 to 14.9%, respectively. Recovery and accuracy of the assay were from 83.5 to 85.8% and from 95.0 to 105%. Enzyme kinetic parameters (Km , Vmax and Ki ) were comparable to reported values. The presence of CYP2C19 in bacterial membranes was confirmed by immunoblotting and the characteristic absorbance peak at 450 nm was determined in the reduced CO difference spectral assay. Moreover, the activity level of co-expressed OxR was found to be comparable to that of the literature. As a conclusion, the procedures described here have generated catalytically active CYP2C19 and the RP-HPLC assay developed is able to serve as CYP2C19 activity marker for pharmacokinetic drug interaction study in vitro.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  18. Upregulation of catalase and downregulation of glutathione peroxidase activity in the kidney precede the development of hypertension in pre-hypertensive SHR
    Sundaram A, Siew Keah L, Sirajudeen KN, Singh HJ
    Hypertens Res, 2013 Mar;36(3):213-8.
    PMID: 23096233 DOI: 10.1038/hr.2012.163
    Although oxidative stress has been implicated in the pathogenesis of hypertension in spontaneously hypertensive rats (SHRs), there is little information on the levels of primary antioxidant enzymes status (AOEs) in pre-hypertensive SHR. This study therefore determined the activities of primary AOEs and their mRNA levels, levels of hydrogen peroxide (H2O2), malondialdehyde (MDA) and total antioxidant status (TAS) in whole kidneys of SHR and age-matched Wistar-Kyoto (WKY) rats aged between 2 and 16 weeks. Compared with age-matched WKY rats, catalase (CAT) activity was significantly higher from the age of 2 weeks (P<0.001) and glutathione peroxide (GPx) activity was lower from the age of 3 weeks (P<0.001) in SHR. CAT mRNA levels were significantly higher in SHR aged 2, 4, 6 and 12 weeks. GPx mRNA levels were significantly lower in SHR at 8 and 12 weeks. Superoxide dismutase activity or its mRNA levels were not different between the two strains. H2O2 levels were significantly lower in SHR from the age of 8 weeks (P<0.01). TAS was significantly higher in SHR from the age of 3 weeks (P<0.05). MDA levels were only significantly higher at 16 weeks of age in the SHR (P<0.05). The data suggest that altered renal CAT and GPx mRNA expression and activity precede the development of hypertension in SHR. The raised CAT activity perhaps contributes to the higher TAS and lower H2O2 levels in SHR. In view of these findings, the precise role of oxidative stress in the pathogenesis of hypertension in SHR needs to be investigated further.
    Matched MeSH terms: Blood Pressure/physiology
  19. Time to achieve first blood pressure control after diagnosis among hypertensive patients at primary health care clinics: a preliminary study
    Cheong AT, Mohd Said S, Muksan N
    Asia Pac J Public Health, 2015 Mar;27(2):NP485-94.
    PMID: 23343640 DOI: 10.1177/1010539512472361
    This study aimed to examine the duration to achieve first blood pressure (BP) control after the diagnosis of hypertension. This was a retrospective cohort study on 195 hypertensive patients' (age ≥18 years) records from a primary health care clinic. The median time to achieve first BP control was 7.2 months (95% confidence interval [CI] = 4.99-9.35). Cox proportional hazards regression results showed female patients were 1.5 times more likely to achieve BP control when compared with male patients (hazard ratio [HR] = 1.50, 95% CI 1.09-2.09, P = .013). Those with monotherapy were 2 times more likely (HR = 2.09, 95% CI = 1.39-3.13, P < 0.001) and those on 2 drugs were 3.5 times more likely (HR = 3.49, 95% CI = 1.65-7.40, P = .001) to achieve BP control than those with nonpharmacological treatment. The median time to achieve BP control was longer than the recommended time. Doctors may need to consider starting the pharmacological treatment early and be more aggressive in hypertensive management for male patients.
    Matched MeSH terms: Blood Pressure; Blood Pressure Determination
  20. Clonidine and a novel clonidine analog AL-12 cause sympathoinhibition in spontaneously hypertensive and diabetic spontaneously hypertensive rats
    Lazahari MI, Sattar MA, Abdullah NA, Khan MA, Johns EJ
    Methods Find Exp Clin Pharmacol, 2008 Apr;30(3):193-9.
    PMID: 18597003 DOI: 10.1358/mf.2008.30.3.1166221
    This study examined the sympathoinhibitory effects of clonidine and a novel clonidine analog, AL-12, in rat models of genetic hypertension and a combined state of genetic hypertension and diabetes. Rats in the treatment groups were given either clonidine or AL-12 while the respective control groups received either saline or Tween 80 for 6 days. Physiological data were collected during this period, which was followed by acute studies on day 7 when bolus administrations (i.v.) of graded doses of noradrenaline, phenylephrine and methoxamine were carried out. It was observed that in AL-12-treated nondiabetic spontaneously hypertensive rats (SHR), the pressure responses to all adrenergic agonists were greater (p < 0.05) in the treated group, while in the diabetic SHR rats a larger pressure response was observed only to noradrenaline (p < 0.05). In nondiabetic SHR rats treated with clonidine, a greater (p < 0.05) pressure response was observed only in the case of phenylephrine. In the diabetic SHR rats treated with clonidine, the pressure responses to the adrenergic agonists were similar (p > 0.05) in the treated and its control animals except that methoxamine caused a greater (p < 0.05) pressure response in the control group. The data obtained suggest that clonidine and AL-12 act possibly via vascular alpha1 and alpha2 adrenoceptors present at both pre- and postsynaptic locations.
    Matched MeSH terms: Blood Pressure/drug effects*
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