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C Lau

Publications and source records attributed to C Lau.

At least 19 recordsLinked to original sources
PubMed2006

Prolonged function of macrophage, von Willebrand factor-deficient porcine pulmonary xenografts.

Porcine von Willebrand factor (vWF) activates human and primate platelets. Having determined the importance of pulmonary intravascular macrophages (PIMs) in pulmonary xenotransplantation, we evaluated whether, in the absence of PIMs, vWF might play a role in pulmonary xenograft dysfunction. Utilizing a left single-lung transplant model, baboons depleted of anti-alphaGal antibodies received lungs from either vWF-deficient (n = 2); MCP-expressing (n = 5); MCP PIM-depleted (n = 5); or vWF-deficient PIM-depleted swine (n = 3). Two out of three of the PIM-depleted, pvWF deficient grafts survived longer than any previously reported pulmonary xenografts, including PIM-depleted xenografts expressing human complement regulatory proteins. Depletion of PIM's from vWF-deficient lungs, like depletion of PIM's from hMCP lungs, resulted in abrogation of the coagulopathy associated with pulmonary xenotransplantation. Thus, in terms of pulmonary graft survival, control of adverse reactions involving pvWF appears to be equally or even more important than is complement regulation using hMCP expression. However, based on the rapid failure of PIM-sufficient, pvWF-deficient pulmonary xenografts, pVWF-deficient pulmonary xenografts appear to be particularly sensitive to macrophage-mediated damage. These data provide initial evidence that vWF plays a role in the 'delayed' (24 h) dysfunction observed in pulmonary xenotransplantation using PIM depleted hMCP organs.

Animals↗
PubMed2006

The Dietary Quality Score: validation and association with cardiovascular risk factors: the Inter99 study.

OBJECTIVE: To develop and assess the validity of the Dietary Quality Score (DQS) and investigate the association with cardiovascular risk factors. DESIGN: Cross-sectional population-based study. SETTING: Copenhagen County, Glostrup, Denmark. SUBJECTS: A random sample of 12,934 men and women aged 30-60 years were invited to a health examination. A total of 6542 participants were included in the statistical analysis. METHODS: The DQS was developed using eight questions from a 48-item food frequency questionnaire (FFQ) and validated using a 198-item FFQ. Associations between the DQS and fasting serum lipids, homocysteine, blood pressure and the absolute risk of ischaemic heart disease (IHD) were explored. RESULTS: A higher DQS was shown to be associated with higher dietary quality in general, including a low intake of fat, especially saturated fat; a high intake of fibre; various vitamins and minerals; and fruit, fish, vegetables and whole-grain products. A higher score according to the DQS was significantly negatively associated with total cholesterol (P=0.0031), triglyceride (P=0.0406), low-density lipoprotein-cholesterol (P=0.0071), homocysteine (P<0.0001) and the absolute risk of IHD (P<0.0001), adjusted for sex, age, smoking habits and physical activity level. CONCLUSIONS: The DQS is a simple, valid and quick tool to make a rough classification of individuals into groups with high, average and low dietary quality. The DQS is negatively associated with serum lipids, homocysteine and the absolute risk of IHD. SPONSORSHIP: The Inter99 study is supported economically by The Danish Medical Research Council, The Danish Centre for Evaluation and Health Technology Assessment, Novo Nordisk, Copenhagen County, The Danish Heart Foundation, The Danish Pharmaceutical Association, Augustinus Foundation, Ib Henriksen Foundation and Becket Foundation, Copenhagen County.

Adult↗
PubMed2006

Increased use of selective serotonin reuptake inhibitors in patients admitted with gastrointestinal haemorrhage: a multicentre retrospective analysis.

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) can adversely affect platelet function and impair haemostasis. Various bleeding complications have been reported in persons taking SSRIs including an increased risk of gastrointestinal haemorrhage (GIH). AIM: To evaluate SSRI use in patients hospitalized with GIH compared with controls. METHODS: A retrospective, multicentre case-control study determined use of SSRIs, non-steroidal anti-inflammatory drugs (NSAIDs), aspirin, clopidogrel, coumadin and enoxaparin in patients admitted with GIH and age- and sex-matched controls. Exclusion criteria included liver disease, portal hypertension or bleeding diathesis. RESULTS: A total of 579 cases were matched with 1000 controls. SSRI use was 19.2% in cases and 13.6% in controls [OR (95% CI) = 1.5 (1.2-2.0); P = 0.003]. NSAIDs were used by 7.3% of cases and 3.8% of controls [OR = 2.0 (1.3-3.1); P = 0.003]. SSRI use was more strongly associated with lower [1.8 (1.2-2.8)] rather than upper [1.3 (0.83-1.9)] GIH. Significant interactions existed for SSRI use with NSAIDs and aspirin. CONCLUSIONS: Patients admitted with GIH gastrointestinal bleeding were more likely to be taking SSRIs than controls. This association exists for lower as well as upper GIH. Physicians should be aware of this risk particularly in patients already using medications that increase GIH risk.

Black or African American↗
PubMed2005

Effect of an oral stimulation program on sucking skill maturation of preterm infants.

This study assessed the effect of an oral stimulation program on the maturation of sucking skills of preterm infants. Thirty-two preterm infants (13 males, 19 females), appropriate size for gestational age (gestational age at birth 28 wks, SD 1.2wks; birthweight 1002g, SD 251g), were randomly placed into experimental and control groups. The experimental group received a daily 15-minute oral stimulation program, consisting of stroking the peri- and intra-oral structures, for 10 days before the start of oral feedings. Sucking measures were monitored with a specially-designed nipple-bottle apparatus. Results indicate that the experimental group achieved full oral feedings 7 days sooner than the control group, and demonstrated greater overall intake (%), rate of milk transfer (mL/min), and amplitude of the expression component of sucking (mmHg). There was no difference in sucking stage maturation, sucking frequency, and amplitude of the suction component of sucking. Endurance, defined as ability to sustain the same sucking stage, sucking burst duration, and suction and expression amplitudes throughout a feeding session, was not significantly different between the two groups. The stimulation program enhanced the expression component of sucking, resulting in better oral feeding performance.

Bottle Feeding↗
PubMed2005

Effects of magnesium on atrial fibrillation after cardiac surgery: a meta-analysis.

OBJECTIVES: To assess the efficacy of the administration of magnesium as a method for the prevention of postoperative atrial fibrillation (AF) and to evaluate its influence on hospital length of stay (LOS) and mortality. METHODS: Literature search and meta-analysis of the randomised control studies published since 1966. RESULTS: 20 randomised trials were identified, enrolling a total of 2490 patients. Study sample size varied between 20 and 400 patients. Magnesium administration decreased the proportion of patients developing postoperative AF from 28% in the control group to 18% in the treatment group (odds ratio 0.54, 95% confidence interval (CI) 0.38 to 0.75). Data on LOS were available from seven trials (1227 patients). Magnesium did not significantly affect LOS (weighted mean difference -0.07 days of stay, 95% CI -0.66 to 0.53). The overall mortality was low (0.7%) and was not affected by magnesium administration (odds ratio 1.22, 95% CI 0.39 to 3.77). CONCLUSION: Magnesium administration is an effective prophylactic measure for the prevention of postoperative AF. It does not significantly alter LOS or in-hospital mortality.

Anti-Arrhythmia Agents↗
PubMed2004

Animal models for the study of the effect of prolonged stress on lactation in rats.

The suppressive effect of stress on lactation is well acknowledged. Animal models used to study this problem have used primarily acute stressors. As such, they are not adequate for the study of the effect of prolonged stress on lactation. This study aimed at developing a paradigm(s) in rats for the study of the effect on lactation of prolonged exposure to a stressful situation. Two models were examined. The first consisted of a separation paradigm whereby dams had 1, 2, 4, or 6 contacts per day with their pups, but only for a total of 4 h per day. The second model implicated the introduction of a male intruder into the home cage during the 12-h light period. Both protocols were implemented for four consecutive days beginning on Days 10/11 postpartum. Milk release was measured on Day 13/14 postpartum. For both models, milk release was significantly reduced following the preexposure period. During the assessment of milk release, maternal behavior of the experimental and control animals was similar at all times. It is advanced that these two rat models of stress are appropriate for the study of lactation following a prolonged exposure to stress.

Animals↗
PubMed2004

Prognostic significance of serum vascular endothelial growth factor and endostatin in patients with hepatocellular carcinoma.

BACKGROUND: Vascular endothelial growth factor (VEGF) and endostatin stimulate and inhibit tumour angiogenesis respectively. Recent studies have demonstrated the prognostic value of serum levels of both VEGF and endostatin in patients with various types of cancer. Their significance in patients with hepatocellular carcinoma (HCC) remains unclear. METHODS: Serum VEGF and endostatin levels were measured by enzyme immunoassay in 108 patients with HCC before surgical resection and in 20 healthy controls. Preoperative serum VEGF and endostatin levels were correlated with clinicopathological features and long-term survival. RESULTS: Serum VEGF levels in patients with HCC were significantly higher than those in controls, but serum levels of endostatin were similar in the two groups. High serum levels of VEGF, but not endostatin, were significantly associated with venous invasion and advanced tumour stage. Patients with a serum VEGF level higher than median (over 245.0 pg/ml) had significantly worse overall and disease-free survival than those with a lower level (P = 0.012 and P = 0.022 respectively). On multivariate analysis, serum VEGF level was an independent prognostic factor (hazard ratio 1.86 (95 per cent confidence interval 1.10 to 3.92); P = 0.032). Serum endostatin levels did not have significant prognostic influence on overall or disease-free survival. CONCLUSION: A high serum level of VEGF is a predictor of poor outcome after resection of HCC. Serum VEGF, but not endostatin, may be a useful prognostic marker in patients with HCC.

Adolescent↗
PubMed2004

A survey of attitudes to Traditional Chinese Medicine in Hong Kong pharmacy students.

OBJECTIVES: To study the attitudes and personal experiences with Traditional Chinese Medicine (TCM) use in pharmacy students. DESIGN: Prospective cross-sectional study. SETTING: University School of Pharmacy. METHODS: Pharmacy students were asked 17 questions according to an anonymous survey questionnaire. RESULTS: All 91 students (46% males) participated in the survey. The attitude toward TCM use was positive in 40%, neutral in 59% and negative in only 1%. On scales from 0 to 10, the mean (SD) scores for the adequacy of the current curriculum in TCM training and state of TCM knowledge were 3.2 (2.0) and 3.6 (1.6), respectively. Of the 35 participants who had used TCM in the past year, nearly half did so without any TCM practitioner consultation. Seventy-four percent reported that they had not been told of any side effects of TCM. When comparing the third year with first or second year students, there was no significant difference between any of these findings. CONCLUSION: The training in TCM within this 3-year pharmacy curriculum appears inadequate. Most students are not aware of any possible side effects in TCM. The attitude and practice do not appear to vary significantly between successive year of pharmacy students.

Age Factors↗
PubMed2003

Coordination of suck-swallow and swallow respiration in preterm infants.

UNLABELLED: Safe oral feeding of infants necessitates the coordination of suck-swallow-breathe. Healthy full-term infants demonstrate such skills at birth. But, preterm infants are known to have difficulty in the transition from tube to oral feeding. AIM: To examine the relationship between suck and swallow and between swallow and breathe. It is hypothesized that greater milk transfer results from an increase in bolus size and/or swallowing frequency, and an improved swallow-breathe interaction. METHODS: Twelve healthy preterm (<30 wk of gestation) and 8 full-term infants were recruited. Sucking (suction and expression), swallowing, and respiration were recorded simultaneously when the preterm infants began oral feeding (i.e. taking 1-2 oral feedings/d) and at 6-8 oral feedings/d. The full-term infants were similarly monitored during their first and 2nd to 4th weeks. Rate of milk transfer (ml/min) was used as an index of oral feeding performance. Sucking and swallowing frequencies (#/min), average bolus size (ml), and suction amplitude (mmHg) were measured. RESULTS: The rate of milk transfer in the preterm infants increased over time and was correlated with average bolus size and swallowing frequency. Average bolus size was not correlated with swallowing frequency. Bolus size was correlated with suction amplitude, whereas the frequency of swallowing was correlated with sucking frequency. Preterm infants swallowed preferentially at different phases of respiration than those of their full-term counterparts. CONCLUSION: As feeding performance improved, sucking and swallowing frequency, bolus size, and suction amplitude increased. It is speculated that feeding difficulties in preterm infants are more likely to result from inappropriate swallow-respiration interfacing than suck-swallow interaction.

Bottle Feeding↗
PubMed2002

Selective plasma filtration for treatment of fulminant hepatic failure induced by D-galactosamine in a pig model.

BACKGROUND: Plasma exchange may be useful for treating patients with fulminant hepatic failure but during the procedure growth factors that are important for hepatic regeneration are discarded. Addition of a selective plasma filter to the plasmapheresis circuit could eliminate protein bound toxic substances and retain growth factors for hepatic regeneration. This process is called selective plasma filtration. AIMS: To determine if selective plasma filtration could be a useful treatment modality for fulminant hepatic failure. METHODS: The system was tested in five groups of pigs with fulminant hepatic failure induced by galactosamine: group I, diseased control group (n=5); group II, sham control, (n=6); group III, plasma exchange (n=6); group IV, treatment with AC-1770 selective plasma filter (n=7); and group V, treatment with AC-1730 selective plasma filter which had a smaller pore size than AC-1770 (n=7). Fresh pig plasma was given to replace filtered plasma in pigs of groups III, IV, and V. Treatment was initiated 48 hours after administration of 0.75 g/kg galactosamine. The efficacy of selective plasma filtration was assessed by survival rate and improvement in haematological, biochemical, and immunohistological parameters. RESULTS: Pigs treated with AC-1770 or AC-1730 selective plasma filters survived longer than the other groups (group I: 55 (10) hours; group II: 68 (7) hours; group III: 91 (10) hours; group IV: 269 (156) hours; group V: 950 (555) hours). One pig in group IV survived for 50 days; one pig in group V survived for 77 days and another pig in group V is still alive (>150 days). After treatment, plasma levels of aspartate aminotransferase, bilirubin, bile acid, ammonia, lactate dehydrogenase, and alpha-glutathione-S-transferase decreased. Substantial amounts of tumour necrosis factor alpha (TNF-alpha) and endotoxin were found in the filtrate. The selective plasma filtration groups retained significantly higher amounts of hepatocyte growth factor than plasma exchange alone. Similar TNF-alpha clearance was observed in the selective plasma filtration groups and the plasma exchange group. On day 4, significant improvement in liver function, as measured by the indocyanine green clearance test, was observed in groups IV and V but not in the other groups. A higher regeneration index of hepatocytes was also observed in the groups treated with AC-1770 and AC-1730 selective plasma filters. CONCLUSION: Selective plasma filtration improved survival time and expedited liver regeneration in pigs with fulminant hepatic failure.

Animals↗
PubMed2001

A chemiluminescence reaction between hydrogen peroxide and acetonitrile and its applications.

Here we report a new chemiluminescence reaction between basic aqueous H2O2 and acetonitrile. Its ultraweak chemiluminescence could be greatly enhanced by luminol, isoluminol-labeled streptavidin, and an Edman-type fluorescent reagent. Light emission was intense and long-lived, and this facilitated the initiation of the reaction and the measurement of the light emission. The present results permit us to propose a series of convenient, highly sensitive, and enzyme-free techniques for the detection and quantification of luminol, related conjugates, acetonitrile, and amino acids. Overall, this new chemiluminescence reaction will be quite promising for numerous applications in immunoassay, DNA hybridization, environmental monitoring. and postcolumn chromatographic detection.

Acetonitriles↗
PubMed2001

Perinatal exposure to polychlorinated biphenyls Aroclor 1016 or 1254 did not alter brain catecholamines nor delayed alternation performance in Long-Evans rats.

Several reports have indicated that polychlorinated biphenyls (PCB) altered development of biogenic amine systems in the brain, impaired behavioral performances, and disrupted maturation of the thyroid axis. The current study examines whether these developmental effects of PCB are correlated. Timed-pregnant Long-Evans rats were gavaged with the PCB mixture Aroclor 1016 (A-1016, 10 mg/kg) from gestation day (GD) 6 to parturition. Some pups continued to receive daily oral administration of PCB (10 mg/kg) until weaning at postnatal day (PD) 21. Another group of pregnant rats was given Aroclor 1254 (A-1254, 8 mg/kg) daily from GD 6 to weaning. At various age intervals, rats were sacrificed and six brain regions (prefrontal cortex, striatum, hippocampus, diencephalon, cerebellum, midbrain + brain stem) were removed and analyzed for dopamine (DA) and norepinephrine (NE) levels by high-performance liquid chromatography. In addition, transmitter turnover rates were determined after an acute treatment of alpha-methyl-p-tyrosine. Serum samples were collected and analyzed for triiodothyronine (T(3)) and thyroxine (T(4)) by radioimmunoassay. Behaviorally, rats were evaluated for spatial learning and memory by means of T-maze delayed alternation and Morris maze tasks on PD 23 and PD 70, respectively. A-1016 treatment produced only small and transient reductions in body weight gain, and generally did not alter the thyroid status of the developing rats. It did not cause any significant changes in DA or NE level, or turnover rate in any of the brain regions examined, nor did it affect behavioral measures of cognitive development. In contrast, perinatal exposure to A-1254 led to marked deficits of growth, and sharply reduced serum T(4), although T(3) remained largely unaffected. Accompanying this hormonal imbalance, brain NE contents in the A-1254-exposed pups were reduced, although brain DA was not significantly affected; no demonstrable neurobehavioral deficits were seen in the T-maze or Morris maze tests. These results indicated that development of central noradrenergic neurons was compromised by perinatal exposure to A-1254 but not A-1016, and both PCB mixtures failed to alter behavioral performances.

Animals↗
PubMed2001

p15(PAF), a novel PCNA associated factor with increased expression in tumor tissues.

Proliferating cell nuclear antigen (PCNA) is an essential protein in both DNA replication and DNA damage repair. A novel 15 kD protein, p15(PAF), was identified as a PCNA-associated factor in a yeast two-hybrid screen using PCNA as the bait. p15(PAF) is localized primarily in the nucleus. p15(PAF) shares the conserved PCNA binding motif with several other PCNA binding proteins including CDK inhibitor p21. Overexpression of p15(PAF) competes with p21-PCNA binding. Mutation of this motif in p15(PAF) abolished its PCNA-binding activity. Notably, p15(PAF) expression in several types of tumor tissues was significantly increased, especially in esophageal tumors. Like PCNA, p15(PAF) may possess prognostic significance in a broad array of human cancers.

Amino Acid Sequence↗
PubMed2001

Exposure-disease continuum for 2-chloro-2'-deoxyadenosine, a prototype ocular teratogen. 1. Dose-response analysis.

BACKGROUND: Treatment of pregnant mice with 2-chloro-2'-deoxyadenosine (2CdA) on day 8 of gestation induces microphthalmia through a mechanism coupled to the p53 tumor suppressor gene. The present study defines 2CdA dosimetry with respect to exposure (pharmacokinetics), p53 protein induction, and disease (microphthalmia). METHODS: Pregnant CD-1 mice dosed with 0.5-10.0 mg/kg 2CdA on day 8 provided fetuses for teratological evaluation; 2CdA was measured by HPLC in the antimesometrium through 180 min postexposure, and p53 was assessed with immunostaining of the embryo through 270 min. 5'-/3'-RACE was used to sequence the candidate gene for 2CdA bioactivation from target cells. RESULTS: Microphthalmia appeared first in the dose-response curve. The highest 2CdA dose having no observable adverse effect (NOAEL) was 1.5 mg/kg; the benchmark dose that produced an extra 5% risk of microphthalmia (BMD(5)) was 2.5 mg/kg, and the lower confidence limit (BMDL) was 2.0 mg/kg. Pharmacokinetic parameters for doses encompassing the threshold (1.5-2.5 mg/kg) were modeled at 1.0-1.8 microM (C(max)) and 30-80 microM-min (AUC). The p53 response was not detected below the BMDL; however, a low-grade response appeared 4.5 hr after a teratogenic dose (5.0 mg/kg), and high-grade induction followed an embryolethal dose (10.0 mg/kg). RACE identified a novel splice variant of mitochondrial deoxyguanosine kinase, dGK-3, as the likely candidate for 2CdA bioactivation in the embryo. CONCLUSIONS: Microphthalmia represented the critical effect malformation of 2CdA. The findings suggest a mitochondrial mechanism for 2CdA bioactivation, leading to an embryonic p53 response only after 2CdA elimination and implying pharmacodynamic coupling to the exposure-disease continuum. Published 2001 Wiley-Liss, Inc.

Amino Acid Sequence↗
PubMed2001

Quantitative evaluation of infant's nonnutritive and nutritive sucking.

Two important aspects of the clinical feeding evaluation of infants are the assessment of their nonnutritive and nutritive sucking skills. Nonnutritive sucking is monitored routinely by using a gloved finger and nutritive sucking by observing infants' sucking while bottle feeding. This approach, however. provides only a subjective and descriptive evaluation. In this study, we developed a finger pressure device that allows for quantification of specific measures of nonnutritive sucking. We are proposing that its use, in combination with the nipple/bottle system developed for the monitoring of nutritive sucking. will allow therapists to conduct objective and quantitative evaluations of infants' nonnutritive and nutritive sucking. The suction and expression components of sucking are monitored via two catheters placed at the tip of the index finger of a disposable glove and at the tip of a bottle nipple. The observations made from the standard clinical feeding evaluation and from these two instruments were compared. In addition to providing quantitative measures of sucking, the latter techniques allowed the review/reassessment of data, the monitoring of the maturation of oral motor skills over time, and the comparison of these measures between infants. It is proposed that the concurrent use of these devices will allow therapists to conduct more objective and detailed evaluations of infants' feeding skills than can be obtained at present.

Bottle Feeding↗
PubMed2001

Correlation of serum basic fibroblast growth factor levels with clinicopathologic features and postoperative recurrence in hepatocellular carcinoma.

BACKGROUND: Basic fibroblast growth factor (bFGF) is an important positive regulator of tumor angiogenesis. This study evaluated the role of serum bFGF as a biological marker of tumor invasiveness and postresection recurrence in hepatocellular carcinoma (HCC). METHODS: Concentrations of bFGF in preoperative serum samples in 88 patients undergoing resection of HCC were measured by a quantitative enzyme-linked immunosorbent assay. A single pathologist performed histopathologic examination of all tumor specimens. All patients were prospectively monitored for tumor recurrence. RESULTS: The preoperative serum bFGF levels ranged from <0.22 to 71.2 pg/mL (median 10.8 pg/mL). There was significant correlation between high serum bFGF levels and large tumor >5 cm, presence of venous invasion or advanced pTNM stage. Patients with a serum bFGF level >10.8 pg/mL had worse disease-free survival than those with a level <10.8 pg/mL (median disease-free survival 11.2 versus 20 months, P = 0.044). Serum bFGF level >10.8 pg/mL (P = 0.035) and tumor size >5 cm (P = 0.004) were independent preoperative factors that predicted early recurrence after resection of HCC. CONCLUSIONS: This study supports a role of bFGF in tumor growth and invasion in HCC. A high preoperative serum bFGF level appears to be predictive of invasive tumor and early postoperative recurrence. The clinical implications of serum bFGF level in HCC warrant further investigation.

Biomarkers, Tumor↗