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Biomedical subjects

C Ng

Publications and source records attributed to C Ng.

At least 19 recordsLinked to original sources
PubMed2006

Efficacy and safety of rifabutin-containing 'rescue therapy' for resistant Helicobacter pylori infection.

BACKGROUND: Current 'rescue' therapies provide inadequate Helicobacter pylori eradication rates because of antibiotic resistance. AIM: To test the efficacy of a modified triple regimen combining rifabutin, pantoprazole and amoxicillin as rescue therapy for patients in whom eradication of H. pylori had failed standard clarithromycin-based triple therapy. METHODS: One hundred and thirty patients (mean age 51.7 +/- 14.8 years) who had failed one or more eradication attempts with omeprazole, clarithromycin and amoxicillin were treated for 12 days with rifabutin 150 mg daily, amoxicillin 1 g or 1.5 g t.d.s, and pantoprazole 80 mg t.d.s. RESULTS: The intention-to-treat and per-protocol eradication rates were 90.8/90.8%. Metronidazole or/and clarithromycin resistance had no significant impact on H. pylori eradication rates. A higher overall eradication rate of 96.6% (95% CI: 92.1-101%) was obtained in patients treated with a regimen containing 1.5 g amoxicillin t.d.s compared with 90.7% (95% CI: 82-98.6%) using a regimen with 1 g amoxicillin t.d.s but the difference was not significant. Side-effects reported in 40% of patients were mild. CONCLUSION: A 12-day course of low dose of rifabutin with an increased dose of amoxicillin and pantoprazole is well-tolerated and highly effective against dual-resistant H. pylori infection after failure of triple therapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2006

Takayasu's arteritis: a cause of prolonged arterial stiffness.

OBJECTIVES: Cardiovascular disease is a major cause of mortality and morbidity in patients with Takayasu's arteritis (TA). Increased arterial stiffness is an independent risk factor and predictor of cardiovascular mortality in a variety of diseases. Pulse wave velocity (PWV) and the augmentation index (AI) are used as clinical measurements of arterial stiffness. METHODS: Data are presented from 10 patients with TA and 11 normal controls obtained between 2000 and 2004. Arterial compliance was assessed non-invasively by measurement of PWV, using the Complior system, and calculation of the aortic AI. RESULTS: TA patients (mean age 40.8+/-13.2 yr) were compared with a control group of healthy women from a parallel study (mean age 32.3+/-5.5 yr). The mean carotid-femoral PWV (PWV-CF) was higher in TA patients (P = 0.03). In addition, both aortic AI derived from the radial artery (P = 0.002) and carotid AI (P = 0.03) were higher in TA patients compared with controls. PWV-CF did not correlate with CRP (r = - 0.23, P = 0.23) or ESR (r = - 0.19, P = 0.27). Similar results were obtained for the correlation of carotid-radial PWV with CRP (r = 0.15, P = 0.32) and ESR (r = 0.33, P = 0.14). CONCLUSIONS: Our data show that TA is associated with elevated arterial stiffness in the central aorta, which may persist when the disease is quiescent. These data suggest that PWV represents a means by which cardiovascular risk can be detected and monitored in TA, and highlights the importance of effective management of cardiovascular risk factors in these patients.

Adult↗
PubMed2006

Distension technique influences the relationship between colonic and rectal hypersensitivity in irritable bowel syndrome.

In irritable bowel syndrome (IBS), it remains unclear whether rectal hypersensitivity is a 'marker' of colonic hypersensitivity. Our aim was to examine the relation between colonic and rectal sensitivity in IBS patients, comprising phasic and ramp distension techniques. Twenty IBS patients and 12 healthy subjects (N) underwent stepwise ramp and random phasic barostat distensions in the colon and rectum in random order. The sensory threshold pressure (ramp distension) and the visual analogue scale score (VAS, phasic distension), for pain and non-pain, were recorded. Colonic thresholds were lower, and VAS scores were generally higher, for pain and non-pain sensitivities in IBS compared to N. Rectal thresholds were lower, and VAS scores were higher, for pain but not for non-pain, in IBS compared to N. In IBS, for phasic distension, there was good correlation between the colon and rectum for non-pain (e.g. at 16 mmHg, r=0.59, P=0.006) and pain (r=0.60, P=0.006) sensitivities. In contrast, there was no significant correlation between the colon and rectum for ramp distension. In conclusion, colonic and rectal sensitivity in IBS are correlated in response to phasic but not ramp barostat distensions. The rectum serves as a legitimate 'window' for evaluating colonic hypersensitivity in IBS, provided that phasic distensions are employed.

Adult↗
PubMed2004

Bioavailability of fluticasone propionate and mometasone furoate aqueous nasal sprays.

OBJECTIVES: To compare the systemic exposure for intranasal mometasone furoate (MF) and fluticasone propionate (FP) aqueous nasal sprays (ANS) in terms of serum and urinary cortisol parameters and plasma pharmacokinetics. METHODS: Twelve healthy subjects completed this three-way, cross-over study. They received FPANS (50 microg/spray), MFANS (50 microg/spray) or placebo ANS, eight sprays per nostril every 8 h for 4 days. Cortisol measurements were made at baseline and day 4. FP and MF plasma concentrations were also measured on day 4. RESULTS: MFANS produced similar mean plasma AUC (123 pmol/l h) to FPANS (112 pmol/l h). Despite the use of high doses, necessary to generate adequate pharmacokinetic data, only minor reductions in cortisol parameters were found, with no difference between FPANS and MFANS. CONCLUSIONS: FP and MF have similar and very low systemic bioavailability when administered intranasally using a high-dose regimen. It is therefore unlikely that therapeutic doses of intranasal FP or MF will produce dissimilar or significant degrees of systemic exposure or systemic effects.

Administration, Intranasal↗
PubMed2004

Which colorectal cancers are missed by double contrast barium enema?

BACKGROUND: The relative merits of either barium enema or colonoscopy for investigating lower gastrointestinal tract symptoms is still unclear. We studied the value of double contrast barium enema (DCBE) as the initial evaluation modality. We reviewed our 10-year experience of double contrast enemas as read by consultant radiologists. The study also aimed to identify which lesions are usually missed. PATIENTS AND METHODS: We reviewed clinical data for all patients who underwent DCBE within the 6 months prior to surgical resection of colorectal cancer between April 1989 and April 1999. Patient demographics and tumour characteristics were analysed for their effects on the likelihood of the lesions being missed at DCBE. RESULTS: There were 706 patients included in the study, 54.2% were male and the mean age was 63.7 years (SEM=0.5 years). The site along the colon and rectum of tumours missed by DCBE corresponded with the frequency of tumour occurrence at each site. The overall rate of missed lesions was 4.1% (29 of 706 patients); these patients were found on subsequent endoscopy to harbour cancer. Tumours less than 3 cm in length and with lesser extent of circumferential involvement were more likely missed at DCBE (p=0.05 and p=0.01, respectively). Age, sex, and tumour grade and stage were not significant predictors of the likelihood of missed lesions. Of the 29 patients with missed lesions, 77.2% had a serum concentration of carcinoembryonic antigen (CEA) above the normal range (3.5 microg/l). The mean follow-up was 65.3 months (SEM=1.8 months). The overall survival for this series was 60.1%. The inaccuracy of the initial DCBE was not found to cause statistically significant differences in the stage of the tumour at diagnosis nor the overall survival of the patients in our series. CONCLUSIONS: Smaller cancers without circumferential involvement may be missed when DCBE is performed to evaluate lower gastrointestinal symptoms. Further evaluation by colonoscopy must be recommended when symptoms persist, especially in the context of a raised CEA level.

Adult↗
PubMed2004

Comparison of the acute pharmacodynamic responses after single doses of ephedrine or sibutramine in healthy, overweight volunteers.

OBJECTIVE: With an increase in the incidence of obesity, tremendous effort has been devoted to the development of weight loss agents and the prospective surrogate markers of both a product's efficacy and safety. The objective of the present study was to compare the pharmacodynamic responses of ephedrine and sibutramine using surrogate markers of weight loss potential and potential adverse events. DESIGN AND SUBJECTS: The study was designed as a 5-way, randomized, double-blinded, placebo-controlled trial with 3 single doses of ephedrine sulfate (0.25, 0.5 and 1 mg x kg(-1)) followed by an open-labeled sibutramine (10 mg) treatment. Healthy, mildly overweight (BMI = 25) subjects were administered the respective treatment and pharmacokinetic and pharmacodynamic measurements (body surface temperature, resting metabolic rate, blood pressure, heart rate, glucose, glycerol, nonesterified fatty acids, triglycerides) were obtained for 8 hours post dose and for an additional 4 measurements during the sibutramine treatment period. RESULTS: Sibutramine treatment significantly increased resting metabolic rate compared to the placebo condition. Ephedrine significantly increased heart rate, systolic blood pressure and glucose but did not significantly affect other measurements. CONCLUSION: Both sibutramine and ephedrine have been shown to have weight loss potential, however, they elicit different metabolic and biochemical responses after a single dose. The nontherapeutic responses from these types of compounds may serve as a screening tool for the development of agents in the treatment of obesity.

Adult↗
PubMed2004

Laparoscopic ventral hernia repair: local experience.

INTRODUCTION: Laparoscopic ventral hernia repair (LVHR) is a recent development that has been shown to be an effective way of treating ventral hernias. We present the first local series of LVHR with a review of the literature on laparoscopic ventral herniorrhaphy. METHODS: We retrospectively reviewed all our patients who underwent laparoscopic surgery for ventral hernias from December 1998 to May 2002. Results of LVHR such as operative time, length of hospital stay, complications and recurrence rates were evaluated. RESULTS: Twenty patients underwent LVHR. There were 16 female and four male patients. The average age was 54 years. The mean fascial defect was 46 square cm. An ePTFE Mesh was used in all the patients except for one patient who had a prolene mesh. The mean operative time was 117 minutes and the hospital stay was two days. There were two minor complications and no major complications. With a mean follow-up period of 14.9 months, the recurrence rate was 5.0 percent with a single recurrence at four months. CONCLUSION: Our initial experience with this modality shows that LVHR a feasible option with great potential in both treatment success and reduction of surgical morbidity.

Adult↗
PubMed2004

Inflammatory fibroid polyp of the caecum in a patient with neurofibromatosis.

INTRODUCTION: Inflammatory fibroid polyp of the large intestine is uncommon. To our knowledge, this condition has not been reported in a patient with neurofibromatosis. CLINICAL PICTURE: In this report, a 66-year-old woman with neurofibromatosis was found to have a large polyp in the caecum. TREATMENT: Right hemicolectomy was performed because of the size of the polyp. OUTCOME: Pathological examination showed that the polyp was an inflammatory fibroid polyp. CONCLUSION: Clinicians should be aware that inflammatory fibroid polyps could be one of the many manifestations of neurofibromatosis in the gastrointestinal tract.

Aged↗
PubMed2002

Further evidence for the decay K+ -->pi+nu(nu).

Additional evidence for the rare kaon decay K+-->pi+nu(nu) has been found in a new data set with comparable sensitivity to the previously reported result. One new event was observed in the pion momentum region examined, 211 pi+nu(nu)) = 1.57(+1.75)(-0.82)x10(-10).

Journal Article↗
PubMed2001

Comparison of [(18)F]altanserin and [(18)F]deuteroaltanserin for PET imaging of serotonin(2A) receptors in baboon brain: pharmacological studies.

The regional distribution in brain, distribution volumes, and pharmacological specificity of the PET 5-HT(2A) receptor radiotracer [(18)F]deuteroaltanserin were evaluated and compared to those of its non-deuterated derivative [(18)F]altanserin. Both radiotracers were administered to baboons by bolus plus constant infusion and PET images were acquired up to 8 h. The time-activity curves for both tracers stabilized between 4 and 6 h. The ratio of total and free parent to metabolites was not significantly different between radiotracers; nevertheless, total cortical R(T) (equilibrium ratio of specific to nondisplaceable brain uptake) was significantly higher (34-78%) for [(18)F]deuteroaltanserin than for [(18)F]altanserin. In contrast, the binding potential (Bmax/K(D)) was similar between radiotracers. [(18)F]Deuteroaltanserin cortical activity was displaced by the 5-HT(2A) receptor antagonist SR 46349B but was not altered by changes in endogenous 5-HT induced by fenfluramine. These findings suggest that [(18)F]deuteroaltanserin is essentially equivalent to [(18)F]altanserin for 5-HT(2A) receptor imaging in the baboon.

Analysis of Variance↗
PubMed2001

Cardiac metastasis from a myxoid liposarcoma.

Intracardiac metastases due to solid tumours are rare. We describe a patient with a myxoid liposarcoma of the thigh and a secondary lesion in the interventricular septum, which was treated with radiotherapy.

Antineoplastic Agents↗
PubMed2001

Human paraoxonase-3 is an HDL-associated enzyme with biological activity similar to paraoxonase-1 protein but is not regulated by oxidized lipids.

Paraoxonase-1 (PON1) is a secreted protein associated primarily with high density lipoprotein (HDL) and participates in the prevention of low density lipoprotein (LDL) oxidation. Two other paraoxonase (PON) family members, namely, PON2 and PON3, have been identified. In this study, we report the cloning and characterization of the human PON3 gene from HepG2 cells. Tissue Northern analysis identifies an approximately 1.3-kb transcript for PON3 primarily in the liver. PON3-specific peptide antibodies detect an approximately 40-kDa protein associated with HDL and absent from LDL. Pretreatment of cultured human aortic endothelial cells with supernatants from HeLa Tet On cell lines overexpressing PON3 prevents the formation of mildly oxidized LDL and inactivates preformed mildly oxidized LDL. In contrast to PON1, PON3 is not active against the synthetic substrates paraoxon and phenylacetate. Furthermore, PON3 expression is not regulated in HepG2 cells by oxidized phospholipids and is not regulated in the livers of mice fed a high-fat atherogenic diet.

Animals↗
PubMed2001

Regulation of Golgi structure and function by ARF-like protein 1 (Arl1).

Arl1 is a member of the ARF-like protein (Arl) subfamily of small GTPases. Nothing is known about the function of Arl1 except for the fact that it is essential for normal development in Drosophila and that it is associated with the Golgi apparatus. In this study, we first demonstrate that Arl1 is enriched at the trans side of the Golgi, marked by AP-1. Association of Arl1 with the Golgi is saturable in intact cells and depends on N-terminal myristoylation. Over-expression of Arl1(T31N), which is expected to be restricted to the GDP-bound form and thus function as a dominant-negative mutant, causes the disappearance of the Golgi apparatus (marked by Golgi SNARE GS28), suggesting that Arl1 is necessary for maintaining normal Golgi structure. Overexpression of Arl1(Q71L), a mutant restricted primarily to the activated GTP-bound form, causes an expansion of the Golgi apparatus with massive and stable Golgi association of COPI and AP-1 coats. Interestingly, Golgi ARFs also become stably associated with the expanded Golgi. Transport of the envelope protein of vesicular stomatitis virus (VSV-G) along the secretory pathway is arrested at the expanded Golgi upon expression of Arl1(Q71L). The structure of stacked cisternae of the Golgi is disrupted in cells expressing Arl1(Q71L), resulting in the transformation of the Golgi into an extensive vesicule-tubule network. In addition, the GTP form of Arl1 interacts with arfaptin-2/POR1 but not GGA1, both of which interact with GTP-restricted ARF1, suggesting that Arl1 and ARF1 share some common effectors in regulating cellular events. On the basis of these observations, we propose that one of the mechanisms for the cell to regulate the structure and function of the Golgi apparatus is through the action of Arl1.

ADP-Ribosylation Factors↗
PubMed2001

Biliary tract disease and acute non-A-E hepatitis in Hong Kong: prospective study.

OBJECTIVE: To investigate the role of biliary tract disease in patients with acute non-A-E hepatitis. DESIGN: Prospective study. SETTING: Infectious diseases unit, government hospital, Hong Kong. PATIENTS: Sixty-one consecutive patients, admitted with the diagnosis of acute hepatitis and negative hepatitis serology for hepatitis A, B, C, D, and E virus. MAIN OUTCOME MEASURES: Abdominal ultrasound and endoscopic retrograde cholangiopancreatography findings; clinical outcome. RESULTS: Ultrasonographic abnormalities indicating biliary tract disease were found in 30% (18/61) of patients. Endoscopic retrograde cholangiopancreatography performed in 78% (14/18) of patients with abnormal ultrasound finding(s) confirmed the presence of biliary tract disease. Age, sex, serum alanine aminotransferase level, and serum albumin level were independent predictors of biliary tract disease in the patients studied. CONCLUSION: Biliary tract diseases were found in 20% of patients with acute non-A-E hepatitis. Serum amylase and abdominal ultrasonography should be performed for all patients presenting with acute non-A-E hepatitis. Endoscopic retrograde cholangiopancreatography is indicated for those with apparent gallstones or abnormal biliary tract findings.

Acute Disease↗
PubMed2001

Assessment and intervention knowledge of nurses in managing catheter patency in continuous bladder irrigation following TURP.

Continuous bladder irrigation (CBI) is an established procedure designed to prevent the formation and retention of blood clots following transurethral prostatectomy (TURP). The purpose of this study was to evaluate a tool designed to determine what steps the nurse should follow to assess whether a catheter is blocked and the actions to be taken to restore catheter patency for CBI.

Analysis of Variance↗
PubMed2000

Further search for the decay K+-->pi(+)nunu;

A search for additional evidence for the rare kaon decay K+-->pi(+)nunu; has been made with a new data set comparable in sensitivity to the previous exposure that produced a single event. No new events were found in the pion momentum region examined, 211 pi(+)nunu;) = 1.5(+3.4)(-1.2)x10(-10).

Journal Article↗
PubMed2000

Efficacy and cognitive effects of right unilateral electroconvulsive therapy.

The efficacy, memory, and cognitive effects of right unilateral (RUL) electroconvulsive therapy (ECT) at 2.5 times threshold in 32 inpatients with moderate to severe major depressive disorder were evaluated at baseline, during the course of treatment, and 1 month after treatment. Neuropsychological assessment included the Randt Memory Test, Personal Memory Test, short-version Wechsler Adult Intelligence Scale-Revised, and Self-Rating Scale of Memory Functions. At the treatment end point, although the Hamilton Depression Rating Scale mean score was decreased by 54.2%. the response rate of 2.5 times threshold RUL ECT using stringent criteria was only 31.2%. Treatment was associated with significant anterograde memory impairment in the short term. Mean total scores of the Randt Memory Test and Personal Memory Test were decreased from baseline by 14.8% and 32.5%, respectively, after six sessions of ECT. These memory deficits were significantly improved by the 1 month follow-up examination. Subjective memory scores increased consistently during treatment, correlating with improvements in mood. No adverse effects on nonmemory cognition were found. Although RUL ECT at 2.5 times threshold is not associated with marked or persistent cognitive disturbances, its efficacy may be insufficient in clinical practice.

Adult↗