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Hallstrand TS, Lai Y, Ni Z, Oslund RC, Henderson WR, Gelb MH, Wenzel SE. Relationship between levels of secreted phospholipase A₂ groups IIA and X in the airways and asthma severity. Clin Exp Allergy 2011; 41:801-10. [PMID: 21255140 PMCID: PMC3093436 DOI: 10.1111/j.1365-2222.2010.03676.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Background Secreted phospholipase A(2) (sPLA(2) ) may be important mediators of asthma, but the specific sPLA(2) s involved in asthma are not known. Objective To evaluate sPLA(2) group IIA, V, and X proteins (sPLA(2) -IIA, sPLA(2) -V, and sPLA(2) -X) in bronchoalveolar lavage (BAL) fluid, BAL cells, and airway epithelial cells of subjects with and without asthma, and examine the relationship between the levels of specific sPLA(2) enzymes and airway inflammation, asthma severity, and lung function. Methods The expression of sPLA(2) -IIA, sPLA(2) -V, and sPLA(2) -X in BAL cells and epithelial brushings was assessed by qPCR. The levels of these sPLA(2) proteins and sPLA(2) activity with and without group II and group X-specific inhibitors were measured in BAL fluid from 18 controls and 39 asthmatics. Results The airway epithelium expressed sPLA(2) -X at higher levels than either sPLA(2) -IIA or sPLA(2) -V, whereas BAL cells expressed sPLA(2) -IIA and sPLA(2) -X at similar levels. The majority of sPLA(2) activity in BAL fluid was attributed to either sPLA(2) -IIA or sPLA(2) -X. After 10-fold concentration of BAL fluid, the levels of sPLA(2) -X normalized to total protein were increased in asthma and were associated with lung function, the concentration of induced sputum neutrophils, and prostaglandin E(2) . The levels of sPLA(2) -IIA were elevated in asthma when normalized to total protein, but were not related to lung function, markers of airway inflammation or eicosanoid formation. Conclusions and Clinical Relevance These data indicate that sPLA(2) -IIA and sPLA(2) -X are the major sPLA(2) s in human airways, and suggest a link between the levels of sPLA(2) -X in the airways and several features of asthma.
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Zhu M, Li Y, Xia Q, Wang S, Qiu Y, Che M, Dai H, Qian J, Ni Z, Axelsson J, Yan Y. Strong impact of acute kidney injury on survival after liver transplantation. Transplant Proc 2011; 42:3634-8. [PMID: 21094830 DOI: 10.1016/j.transproceed.2010.08.059] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 06/03/2010] [Accepted: 08/26/2010] [Indexed: 01/17/2023]
Abstract
Acute kidney injury (AKI) is a major complication in orthotopic liver transplantation (OLT). In an evaluation of Acute Kidney Injury Network (AKIN) criteria in liver transplanted patients, we retrospectively analyzed the usefulness of these criteria to predict survival of 193 consecutive patients at a single center who underwent primary OLT for clinical parameters and peak AKI. Postoperative AKI according to AKIN occurred in 60.1% of the patients, namely, stages 1, 2, and 3 in 30%, 13% and 17.1% respectively. Using multivariate logistic regression, AKIN stage 1 and 2 AKI were independently associated with the pre-OLT Model for End-Stage Liver Disease (MELD) score and age, while stage 3 AKI was independently associated with MELD and Acute Physiology and Chronic Health Evaluation (APACHE) II scores. The 28-day and 1-year mortality post-OLT of AKI patients were 15.5% and 25.9% respectively compared with 0% and 3.9% among non-AKI patients (P < .05 for both). The survival rates of non-AKI and stages 1, 2, and 3 AKI subjects were 96%, 85.5%, 84%, and 45.3%, respectively. Cox regression analysis showed independent risk factors for mortality during the first year after transplantation to include post-OLT AKI (12.1; P < .05), post-OLT infection (HR 4.7; P < .01), pre-OLT hypertension (HR 4.4; P < .01) hazard ratio [HR] and post-OLT APACHE II ≥10 (HR 3.6; P < .05). We concluded that AKI as defined by the AKIN criteria is a major complication of OLT linked to a poor outcomes. It remains to be evaluated whether aggressive perioperative therapy to prevent AKI can improve survival among OLT patients.
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Nelson AJ, Hoque T, Gunraj C, Ni Z, Chen R. Impaired interhemispheric inhibition in writer's cramp. Neurology 2010; 75:441-7. [PMID: 20679637 DOI: 10.1212/wnl.0b013e3181ebdda0] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES Reduced cortical inhibition is a feature of focal hand dystonia and this likely contributes to excessive muscle contractions. Inhibition from the opposite hemisphere, known as interhemispheric inhibition (IHI), was studied bidirectionally in 7 right-handed patients with writer's cramp (WC) and age-matched healthy controls in a cross-sectional physiologic study. METHODS IHI was measured with paired transcranial magnetic stimulation with the conditioning stimulus applied to the motor cortex and the test stimulus applied to the contralateral motor cortex. Surface EMG was measured in right and left first dorsal interosseous muscles during rest, and while holding a pen between the thumb and index finger at 20% maximum voluntary contraction with the right dystonia-affected hand. The time course and magnitude of IHI was studied at interstimulus intervals of 6, 8, 10, 12, 30, 40, and 50 msec between the conditioning stimulus and test stimulus. RESULTS In WC at rest, IHI was significantly reduced in the dystonia-affected right hand (IHI from right to left motor cortex) at both short (SIHI, 10-12 msec) and long (LIHI, 30-40 msec) intervals compared to the unaffected hand. Compared to controls, SIHI and LIHI were reduced in the dystonia-affected hand only. There was no difference in IHI between controls and WC during the task of holding a pen. CONCLUSIONS In WC, both SIHI and LIHI are reduced in the dystonia-affected hand compared to the unaffected hand and to healthy controls. Impaired IHI may contribute to excessive muscle contraction in WC.
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Shao Y, Ni Z, Li Y. [Wnt signal transduction pathways and hair follicle stem cells]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2010; 27:945-948. [PMID: 20842878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Hair follicle stem cells (FSCs), which have characteristics of slow cycling and multipotential differentiations, play an important role in maintaining hair follicle cycling and repairing the epidermis during wound healing. The researches in this subject may be helpful to provide new ideals in treating the diseases of hair and skin. As we know, the Wnt signal transduction pathway has a significant meaning in controlling the proliferation and differentiation of FSCs, and different Wnt proteins have different functions in this process. In this paper, we review how the Wnt signal transduction pathway controls the FSCs and what the functions of different Wnt proteins are.
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Yun T, Ni Z, Liu G, Yu B, Chen L, Huang J, Zhang Y, Chen J. Generation of infectious and pathogenic duck hepatitis virus type 1 from cloned full-length cDNA. Virus Res 2010; 147:159-65. [DOI: 10.1016/j.virusres.2009.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 10/09/2009] [Accepted: 10/17/2009] [Indexed: 11/17/2022]
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Lin X, Lin A, Ni Z, Yao Q, Zhang W, Yan Y, Fang W, Gu A, Axelsson J, Qian J. Daily peritoneal ultrafiltration predicts patient and technique survival in anuric peritoneal dialysis patients. Nephrol Dial Transplant 2010; 25:2322-7. [DOI: 10.1093/ndt/gfq001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Kuriakose R, Saha U, Castillo G, Udupa K, Ni Z, Gunraj C, Mazzella F, Hamani C, Lang AE, Moro E, Lozano AM, Hodaie M, Chen R. The Nature and Time Course of Cortical Activation Following Subthalamic Stimulation in Parkinson's Disease. Cereb Cortex 2009; 20:1926-36. [DOI: 10.1093/cercor/bhp269] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Ni Z, Gunraj C, Nelson AJ, Yeh IJ, Castillo G, Hoque T, Chen R. Two Phases of Interhemispheric Inhibition between Motor Related Cortical Areas and the Primary Motor Cortex in Human. Cereb Cortex 2008; 19:1654-65. [DOI: 10.1093/cercor/bhn201] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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84
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Fang W, Qian J, Lin A, Rowaie F, Ni Z, Yao Q, Bargman JM, Oreopoulos DG. Comparison of peritoneal dialysis practice patterns and outcomes between a Canadian and a Chinese centre. Nephrol Dial Transplant 2008; 23:4021-8. [DOI: 10.1093/ndt/gfn372] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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85
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Ni Z, Gunraj C, Chen R. Two phases of interhemispheric inhibition between motor related cortical areas and the primary motor cortex in human. Brain Stimul 2008. [DOI: 10.1016/j.brs.2008.06.234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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86
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Ni Z, Anastakis D, Gunraj C, Chen R. Reversal of cortical plasticity in human primary motor cortex following thumb reconstruction. Brain Stimul 2008. [DOI: 10.1016/j.brs.2008.06.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Yeom J, Oh I, Field C, Radadia A, Ni Z, Bae B, Han J, Masel R, Shannon M. Enhanced toxic gas detection using a MEMS preconcentrator coated with the metal organic framework absorber. ACTA ACUST UNITED AC 2008. [DOI: 10.1109/memsys.2008.4443635] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Vaziri ND, Bai Y, Ni Z, Quiroz Y, Pandian R, Rodriguez-Iturbe B. Intra-renal angiotensin II/AT1 receptor, oxidative stress, inflammation, and progressive injury in renal mass reduction. J Pharmacol Exp Ther 2007; 323:85-93. [PMID: 17636006 DOI: 10.1124/jpet.107.123638] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Significant reduction of renal mass triggers a chain of events that result in glomerular hypertension/hyperfiltration, proteinuria, glomerulosclerosis, tubulointerstitial injury, and end-stage renal disease. These events are mediated by a constellation of hemodynamic, oxidative, and inflammatory reactions that are, in part, driven by local AT1 receptor (AT1r) activation by angiotensin II (Ang II). Here we explored the effects of 5/6 nephrectomy with and without AT1r blockade (losartan for 8 weeks) on AT1r and AT2r and Ang II-positive cell count, pathways involved in oxidative stress and inflammation [NAD(P)H oxidase, nuclear factor kappaB (NFkappaB), 12-lipooxygenase, cyclooxygenase (COX)-1, COX-2, monocyte chemoattractant protein (MCP)-1, plasminogen activator inhibitor (PAI)-1, renal T cell, and macrophage infiltration] as well as renal function and structure. The untreated group exhibited hypertension, deterioration of renal function and structure, reduced or unchanged plasma renin activity, aldosterone concentration, marked up-regulations of AT1r (250%), Ang II-expressing cell count (>20-fold), NAD(P)H oxidase subunits (gp91(phox,) p22(phox), and P47(phox); 20-40%), COX-2 (250%), 12-lipooxygenase (100%), MCP-1 (400%), and PAI-1 (>20-fold), activation of NFkappaB, and interstitial infiltrations of T cells and macrophages in the remnant kidneys. AT1r blockade attenuated the biochemical and histological abnormalities, prevented hypertension, and decelerated deterioration of renal function and structure. Thus, the study demonstrated a link between up-regulation of Ang II/AT1r system and oxidative stress, inflammation, hypertension, and progression of renal disease in rats with renal mass reduction.
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Li J, Tian H, Li Q, Wang N, Wu T, Liu Y, Ni Z, Yu H, Liang J, Luo R, Li Y, Huang L. Improvement of insulin sensitivity and beta-cell function by nateglinide and repaglinide in type 2 diabetic patients - a randomized controlled double-blind and double-dummy multicentre clinical trial. Diabetes Obes Metab 2007; 9:558-65. [PMID: 17587398 DOI: 10.1111/j.1463-1326.2006.00638.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To evaluate the efficacy of nateglinide vs. repaglinide in blood glucose (BG) control and the effect on insulin resistance and beta-Cell function in patients with type 2 diabetes. METHODS A randomized controlled double-blind and double-dummy multicentre clinical trial was conducted. A total of 230 Chinese patients with type 2 diabetes were enrolled in five clinical centres. The patients were divided randomly into group A [repaglinide 1.0 mg three times daily (t.i.d.), n = 115] or group B (nateglinide 90 mg t.i.d., n = 115). At baseline and end of the 12-week clinical trial, standard mixed meal tolerance tests were performed. RESULTS A total of 223 patients (96.9%) completed the trial. There was no significant difference between repaglinide and nateglinide groups in the effects of reducing fasting blood glucose (FBG), 30-, 60- and 120-min BG during 12 weeks (p > 0.05). At week 12, no significant difference was shown between the two groups in BG or haemoglobin A(1c) (HbA(1c)) (p > 0.05). However, the effect on HbA(1c) in repaglinide group was stronger than that in nateglinide group (p < 0.05). After 12-week treatment, area under the curve (AUC) of BG decreased (p < 0.05), and AUC of insulin and C-peptide (CP) increased in both groups (p < 0.05). The effects of nateglinide on AUC of BG, insulin and CP were similar to that of repaglinide (p > 0.05). There was no significant difference between the two groups in AUC of BG, insulin or CP in week 12 (p > 0.05). Furthermore, homeostasis model assessment of insulin resistance (HOMA-IR) and beta-cell function indexes measured by HOMA-beta, DeltaI(30)/DeltaG(30) and (DeltaI(30)/DeltaG(30))/HOMA-IR were improved significantly in both groups during 12 weeks (p < 0.05). The effects of improving HOMA-IR and beta-cell function indexes in nateglinide group were comparable with that of repaglinide group (p > 0.05). CONCLUSIONS The efficacy of repaglinide and nateglinide in FBG, postprandial glucose excursion and early-phase insulin secretion is similar. But the effect of repaglinide 1.0 mg t.i.d. on HbA(1c) is stronger than that of nateglinide 90 mg t.i.d.. This trial had shown that nateglinide and repaglinide could comparably improve insulin sensitivity and beta-cell function.
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Li Z, Rodríguez-Iturbe B, Ni Z, Shahkarami A, Sepassi L, Vaziri ND. Effect of hereditary obesity on renal expressions of NO synthase, caveolin-1, AKt, guanylate cyclase, and calmodulin. Kidney Int 2006; 68:2766-72. [PMID: 16316351 DOI: 10.1111/j.1523-1755.2005.00747.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Obesity has emerged as a major cause of diabetes, cardiovascular disease, and renal insufficiency worldwide. Obese Zucker rats exhibit hyperphagia, obesity, insulin resistance, hyperlipidemia, and glomerulosclerosis and are frequently used as a model to study hereditary form of metabolic syndrome. Nitric oxide plays a major role in preservation of renal function and structure. The present study was designed to test the hypothesis that renal disease in this model may be associated with down-regulation of endothelial (eNOS) and neuromal NO synthases (nNOS) in the kidney. The study further sought to explore expressions of caveolin-1, phospho AKt, and calmodulin, which regulate activities of constituitive NOS isoforms, as well as soluble guanylate cyclase (sGC), which is involved in NO signaling. METHODS Twenty-two-week-old male obese and lean Zucker rats were studied. Body weight, serum lipids, urine albumin excretion, and renal tissue abundance of the above proteins were determined. RESULTS Serum glucose and arterial pressure were unchanged, whereas urinary NO metabolite (NO(chi)) excretion and renal tissue nitrotyrosine abundance were markedly reduced (denoting depressed NO production) in the obese versus lean Zucker rats. This was accompanied by significant glomerulosclerosis, tubulointerstitial damage, renal immune cell infiltration, marked down-regulations of renal tissue eNOS and nNOS, mild reduction of caveolin-1, and unchanged calmodulin, phospho-AKt, and sGC. CONCLUSION Hereditary obesity can result in down-regulations of kidney eNOS and nNOS, marked reduction of NO production, and glomerulosclerosis prior to the onset of frank diabetes and hypertension.
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Pham A, Ni Z, Sepassi L, Vaziri N. Effect of Renal Mass Reduction on Adenosine Triphosphate Binding Cassette A-1 and Scavenger Receptors Sr-A1 and Sr-B1 in the Kidney. J Investig Med 2006. [DOI: 10.1177/108155890605401s230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Pham AH, Ni Z, Sepassi L, Vaziri ND. 347 EFFECT OF RENAL MASS REDUCTION ON ADENOSINE TRIPHOSPHATE BINDING CASSETTE A-1 AND SCAVENGER RECEPTORS SR-A1 AND SR-B1 IN THE KIDNEY. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0004.346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Vaziri ND, Ni Z. Expression of NOX-I, gp91phox, p47phox and P67phox in the aorta segments above and below coarctation. Biochim Biophys Acta Gen Subj 2005; 1723:321-7. [PMID: 15814300 DOI: 10.1016/j.bbagen.2005.03.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Revised: 02/28/2005] [Accepted: 03/03/2005] [Indexed: 10/25/2022]
Abstract
Aorta coarctation results in hypertension (HTN) in the arterial tree proximal to stenosis and, as such, provides an ideal model to discern the effects of different levels of blood pressure on the vascular tissue in the same animal. Compelling evidence has emerged supporting the role of oxidative stress as a cause of HTN. However, whether or not HTN (independent of the circulating humoral factors) can cause oxidative stress is less certain. NAD(P)H oxidase isoforms are the main source of reactive oxygen species (ROS) in the vascular tissues. We therefore compared the expressions of NOX-I, gp91phox and the regulatory subunits of the enzyme in the aorta segments residing above and below coarctation in rats with abdominal aorta banding. Rats were studied 4 weeks after aorta banding above the renal arteries or sham operation. Subunits of NAD(P)H oxidase and its NOX-I isoform as well as endothelial NO synthase (eNOS) and nitrotyrosine (footprint of NO oxidation by superoxide) were measured in the aorta segments above and below coarctation. The gp91phox, p47phox, and p67phox subunits of NAD(P)H oxidase, NOX-I isoform, eNOS and nitrotyrosine were markedly increased in the aorta segment above coarctation (hypertensive zone), but were virtually unchanged in the segment below coarctation. Since, excepting blood pressure, all other conditions were constant, the upregulation of NAD(P)H oxidase isoforms and the increased NO oxidation in the aorta segment above, but not below, coarctation prove that HTN, per se, independent of circulating mediators can cause oxidative/nitrosative stress in the arterial wall. These observations suggest that HTN control may represent a specific form of antioxidant therapy for hypertensive disorders.
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Vaziri ND, Ding Y, Ni Z, Barton CH. Bradykinin Down-Regulates, Whereas Arginine Analogs Up-Regulates, Endothelial Nitric-Oxide Synthase Expression in Coronary Endothelial Cells. J Pharmacol Exp Ther 2005; 313:121-6. [PMID: 15640399 DOI: 10.1124/jpet.104.076497] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bradykinin (BK) is an endogenous vasoactive peptide that promotes vasodilation by stimulating the release of nitric oxide (NO) from endothelial cells via activation of endothelial NO synthase (eNOS). Although the role of BK in modulation of eNOS activity is well understood, its possible effect on eNOS expression remains uncertain. Several studies have demonstrated negative feedback regulation of eNOS by NO. Therefore, we hypothesized that sustained stimulation with BK may down-regulate eNOS expression in endothelial cells. Human coronary endothelial cells were incubated for 24 h with either BK alone or BK plus BK receptor type 1 or type 2 blockers. NO production and eNOS abundance (Western analysis) were determined. In separate experiments, cells were incubated with either an NOS inhibitor alone or in combination with BK. Incubation with BK caused a concentration-dependent rise in NO production and a dose-dependent decline in eNOS protein expression. These effects were abrogated by BK-2 blockade but unaffected by BK-1 blockade. In contrast, NOS inhibitors lowered NO production and raised eNOS abundance in a dose-dependent fashion. The effects of BK on NO production and eNOS expression were abrogated by the NOS inhibitor. Thus, sustained activation of eNOS by BK results in a compensatory down-regulation of eNOS, whereas its sustained inhibition leads to a compensatory up-regulation of eNOS. The observed modulations of eNOS expression are mediated by NO and represent an adaptive physiologic response.
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Abstract
Melasma (or chloasma) is a common disorder of cutaneous hyperpigmentation predominantly affecting sun-exposed areas in women. The pathogenesis of melasma is not fully understood and treatments are frequently disappointing and often associated with side effects. Pycnogenol is a standardized extract of the bark of the French maritime pine (Pinus pinaster), a well-known, potent antioxidant. Studies in vitro show that Pycnogenol is several times more powerful than vitamin E and vitamin C. In addition, it recycles vitamin C, regenerates vitamin E and increases the endogenous antioxidant enzyme system. Pycnogenol protects against ultraviolet (UV) radiation. Therefore its efficacy in the treatment of melasma was investigated. Thirty women with melasma completed a 30-day clinical trial in which they took one 25 mg tablet of Pycnogenol with meals three times daily, i.e. 75 mg Pycnogenol per day. These patients were evaluated clinically by parameters such as the melasma area index, pigmentary intensity index and by routine blood and urine tests. After a 30-day treatment, the average melasma area of the patients decreased by 25.86 +/- 20.39 mm(2) (p < 0.001) and the average pigmentary intensity decreased by 0.47 +/- 0.51 unit (p < 0.001). The general effective rate was 80%. No side effect was observed. The results of the blood and urine test parameters at baseline and at day 30 were within the normal range. Moreover, several other associated symptoms such as fatigue, constipation, pains in the body and anxiety were also improved. To conclude, Pycnogenol was shown to be therapeutically effective and safe in patients suffering from melasma.
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Tian D, Ma H, Feng Z, Xia Y, Le XC, Ni Z, Allen J, Collins B, Schreinemachers D, Mumford JL. Analyses of micronuclei in exfoliated epithelial cells from individuals chronically exposed to arsenic via drinking water in inner Mongolia, China. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2001; 64:473-484. [PMID: 11732698 DOI: 10.1080/152873901753215939] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The groundwater in Bayingnormen (Ba Men), located in Central West Inner Mongolia, China, is naturally contaminated with arsenic at concentrations ranging from 50 microg/L to 1.8 mg/L. Various adverse health effects in this region, including cancer, have been linked to arsenic exposure via drinking water. A pilot study was undertaken to evaluate frequencies of micronuclei (MN), as measures of chromosomal alterations, in multiple exfoliated epithelial cell types from residents of Ba Men chronically exposed to arsenic via drinking water. Buccal mucosal cells, airway epithelial cells in sputum, and bladder urothelial cells were collected from 19 residents exposed to high levels of arsenic in drinking water (527.5 +/- 24 microg/l), and from 13 control residents exposed to relatively low levels of arsenic in drinking water (4.4 +/- microg/L). Analytical results from these individuals revealed that MN frequencies in the high-exposure group were significantly elevated to 3.4-fold over control levels for buccal and sputum cells, and to 2.7-fold over control for bladder cells (increases in MN frequency significant at p < .001 for buccal cells; p < .01 for sputum cells; p < .05 for bladder cells). When smokers were excluded from high-exposure and control groups the effects of arsenic were observed to be greater, although only in buccal and sputum cells; approximately 6-fold increases in MN frequency occurred in these tissues. The results indicate that residents of Ba Men chronically exposed to high levels of arsenic in drinking water reveal evidence of genotoxicity in multiple epithelial cell types; higher levels of induced MN were observed in buccal and sputum cells than in bladder cells.
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Abstract
BACKGROUND Abdominal aortic coarctation above the renal arteries leads to severe hypertension (HTN) above the stenotic site. We have recently shown marked up-regulations of endothelial nitric oxide synthase (eNOS) in heart and thoracic aorta and of neuronal NOS (nNOS) in the brain of rats with severe aortic coarctation above the renal arteries. We hypothesize that the presence of severe regional HTN in the face of marked up-regulation of NO system may be partly due to enhanced NO inactivation by reactive oxygen species (ROS) leading to functional NO deficiency. METHODS Tissue nitrotyrosine (which is the footprint of NO interaction with ROS) was determined by Western blot in sham-operated control and aortic-banded (above renal arteries) rats three weeks postoperatively. Intra-arterial pressure and tissue nitrotyrosine (Western blot) were measured. RESULTS The banded group showed a marked rise in arterial pressure measured directly through a carotid cannula (203 +/- 9 vs. 131 +/- 2 mm Hg, P < 0.01). Compared with the sham-operated controls, the banded animals exhibited significant increases in nitrotyrosine abundance in the heart, brain, and the aorta segment above the stricture. In contrast, nitrotyrosine abundance was unchanged in the abdominal aorta segment below the stricture wherein blood pressure was not elevated. CONCLUSION Coarctation-induced HTN is associated with increased nitrotyrosine abundance in all tissues exposed to high arterial pressure, denoting enhanced ROS-mediated inactivation and sequestration of NO in these sites. This can, in part, account for severe regional HTN in this model. The normality of nitrotyrosine abundance in the abdominal aorta wherein blood pressure is not elevated points to the role of baromechanical factors as opposed to circulating humoral factors that were necessarily similar in both segments.
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Vaziri ND, Ding Y, Ni Z. Compensatory up-regulation of nitric-oxide synthase isoforms in lead-induced hypertension; reversal by a superoxide dismutase-mimetic drug. J Pharmacol Exp Ther 2001; 298:679-85. [PMID: 11454931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
Chronic exposure to low levels of lead causes hypertension (HTN) that is, in part, due to increased inactivation of nitric oxide (NO) by reactive oxygen species (ROS). The latter results in functional NO deficiency and compensatory up-regulation of NO synthase (NOS). We have previously shown evidence for increased hydroxyl radical (*OH) activity in rats with lead-induced HTN. Since in the biological systems *OH is primarily derived from superoxide (O2*) we hypothesize that lead-induced oxidative stress and HTN must be due to increased O2* production and as such could be ameliorated by administration of a cell-permeable O2* scavenger. We, therefore, studied the effects of the superoxide dismutase (SOD)-mimetic drug tempol (15 mmol/kg/day i.p. x 2 weeks) and placebo in lead-exposed (given lead acetate, 100 ppm in the drinking water for 12 weeks) and normal control rats. Lead exposure resulted in a marked elevation of blood pressure, a significant reduction in urinary NO metabolites (NO(chi)) excretion, and up-regulations of endothelial and inducible NOS abundance in the kidney, aorta, and heart and of neuronal NOS in the cerebral cortex and brain stem. Administration of tempol ameliorated HTN, increased urinary NO(chi) excretion, and reversed the compensatory up-regulation of NOS isoforms in rats with lead-induced HTN. These abnormalities recurred within 2 wk after discontinuation of tempol. In contrast to the lead-exposed rats, the normal control rats showed no change in either blood pressure, urinary NO(chi) excretion, or tissue NOS expression in response to either administration or discontinuation of tempol. Thus, the study supports the presence of increased O2* activity and its role in the pathogenesis of HTN and altered NO metabolism in lead-exposed animals.
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Ni Z, Gao D, Bouali-Benazzouz R, Benabid AL, Benazzouz A. Effect of microiontophoretic application of dopamine on subthalamic nucleus neuronal activity in normal rats and in rats with unilateral lesion of the nigrostriatal pathway. Eur J Neurosci 2001; 14:373-81. [PMID: 11553287 DOI: 10.1046/j.0953-816x.2001.01644.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The subthalamic nucleus (STN) receives dopamine inputs from the substantia nigra but their implication in the pathophysiology of parkinsonism is still debated. Extracellular microrecordings were used to study the effect of microiontophoretic injection of dopamine and the D1 receptor agonist SKF 38393 on the activity of STN neurons in normal and 6-hydroxydopamine-lesioned rats under urethane anaesthesia. Dopamine and SKF induced an increase in the firing rate of the majority of STN neurons in both normal and 6-OHDA rats. In rats with 6-OHDA lesions, the percentage of firing rate increase did not differ from that of controls. When GABA, glutamate and dopamine were all applied to the same individual STN neurons, GABA induced an inhibitory effect and glutamate and dopamine caused an excitatory effect in both groups. This excitatory response was suppressed by the application of GABA. Systemic administration of apomorphine provoked a decrease in the firing rate of STN neurons in rats with 6-OHDA lesions. These results show that dopamine exerts an excitatory influence on STN neurons, suggesting that the inhibitory effect induced by the systemic injection of apomorphine is due to the GABAergic inputs from the globus pallidus as predicted by the current model of basal ganglia organization. In addition, we show that dopamine, GABA and glutamate can act on the same STN neuron and that GABA can reverse the excitatory effect of dopamine and glutamate, suggesting the predominant influence of GABAergic inputs to the subthalamic nucleus.
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Ni Z, Bouali-Benazzouz R, Gao D, Benabid AL, Benazzouz A. Intrasubthalamic injection of 6-hydroxydopamine induces changes in the firing rate and pattern of subthalamic nucleus neurons in the rat. Synapse 2001; 40:145-53. [PMID: 11252026 DOI: 10.1002/syn.1036] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The subthalamic nucleus (STN) receives dopaminergic projections from the substantia nigra pars compacta (SNc). To investigate the role of direct and indirect dopaminergic influences on STN neurons, the spontaneous activity was studied in four groups of animals: normal rats, rats with intrasubthalamic or intranigral injection of 6-hydroxydopamine (6-OHDA), and sham STN injection rats by using extracellular recordings 4 weeks postsurgery. After intrasubthalamic injection of 6-OHDA, the mean firing rate significantly decreased (7.29 +/- 0.39 spikes/sec, P < 0.01 vs. 11.13 +/- 0.59 spikes/sec in normal or 11.26 +/- 0.57 spikes/sec in sham group), and the percentage of STN neurons discharging regularly decreased significantly (81%, P < 0.05 vs. 90% in normal group or P < 0.01 vs. 92% in sham group) and that of bursty cells increased (19%, P < 0.05 vs. 10%; in normal group or P < 0.01 vs. 8% in sham group). In the group of rats with SNc lesion, the firing rate of subthalamic neurons did not show a significant difference (11.61 +/- 0.81 spikes/sec) compared with normal group. However, the firing pattern was dramatically changed: 74% of cells exhibited bursty pattern and only 26% of cells discharged regularly or slightly irregularly. Immunohistochemical results showed that intrasubthalamic injection of 6-OHDA induced a marked degeneration of dopaminergic cells in the lateral part of the ipsilateral SNc, whereas 6-OHDA injection into the SNc induced a total in situ lesion of dopamine cells. These results suggest that the SNc exerts an excitatory influence on STN neurons and that the loss of this dopaminergic projection could, at least partially, account for the changes in the firing pattern of STN neurons in the 6-OHDA rat model of parkinsonism.
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