Biomedical subjects

R Chen

Publications and source records attributed to R Chen.

At least 145 records · Page 8Linked to original sources

PubMed2001

Copper transportion of WD protein in hepatocytes from Wilson disease patients in vitro.

AIM: To study the effect of copper transporting P-type ATPase in copper metabolism of hepatocyte and pathogenesis of Wilson disease (WD). METHODS: WD copper transporting properties in some organelles of the cultured hepatocytes were studied from WD patients and normal controls.These cultured hepatocytes were incubated in the media of copper 15 mg x L(-1) only, copper 15 mg x L(-1) with vincristine (agonist of P-type ATPase) 0.5mg x L(-1), or copper 15 mg x L(-1) with vanadate (antagonist of P-type ATPase) 18.39 mg x L(-1) separately. Microsome (endoplasmic reticulum and Golgi apparatus), lysosome, mitochondria, and cytosol were isolated by differential centrifugation. Copper contents in these organelles were measured with atomic absorption spectrophotometer, and the influence in copper transportion of these organelles by vanadate and vincristine were comparatively analyzed between WD patients and controls. WD copper transporting P-type ATPase was detected by SDS-PAGE in conjunction with Western blot in liver samples of WD patients and controls. RESULTS: The specific WD proteins (M(r)155,000 lanes) were expressed in human hepatocytes, including the control and WD patients. After incubation with medium containing copper for 2 h or 24 h, the microsome copper concentration in WD patients was obviously lower than that of controls, and the addition of vanadate or vincristine would change the copper transporting of microsomes obviously. When incubated with vincristine, levels of copper in microsome were significantly increased, while incubated with vanadate, the copper concentrations in microsome were obviously decreased. The results indicated that there were WD proteins, the copper transportion P-type ATPase in the microsome of hepatocytes. WD patients possessed abnormal copper transporting function of WD protein in the microsome, and the agonist might correct the defect of copper transportion by promoting the activity of copper transportion P-type ATPase. CONCLUSION: Copper transportion P-type ATPase plays an important role in hepatocytic copper metabolism. Dysfunction of hepatocytic WD protein copper transportion might be one of the most important factors for WD.

Adenosine Triphosphatases↗

PubMed2001

[Studies on neonatal screening, clinical and gene analysis for tetrahydrobiopterin deficiency in Southern Chinese].

OBJECTIVE: To find out the incidence of tetrahydrobiopterin deficiency(BH4D) among patients with hyperphenylalaninemia in Southern Chinese and evaluate the clinical outcome and gene mutations of tetrahydrobiopterin deficient patients. METHODS: Analyses of urinary neopterin(N) and biopterin(B) were done in 87 patients with hyperphenylalaninemia by high-performance liquid chromatography. The patients with BH4 deficiency and their parents were asked to undergo the gene mutation analysis and the patients were treated and followed up. RESULTS: Eleven cases of which the urinary N/B ratio was higher than 38 and B% lower than 5% were diagnosed as BH4 deficiency caused by 6-pyruvoyl-tetrahydropterin synthase(PTPS) deficiency. The incidence of BH4 deficiency among patients with hyperphenylalaninemia is 12% in Southern Chinese. PTPS gene mutations (P87S, N52S, D96N and G144R) were detected from 5 PTPS deficient families. The G144R mutation is a new mutation. The five PTPS-deficient patients were treated with synthetic BH4, neurotransmitter precursors L-dopa and 5-hydroxytryptophan. They had satisfactory physical and mental development after treatment, and 4 of them scored their IQ 70-80. CONCLUSION: The screening for BH4 deficiency should be carried out in all patients with hyperphenylalaninemia in order to minimize the misdiagnoses.

Biopterins↗

PubMed2001

[Isolation, purification and determination of polysaccharides X-C-3-III and X-C-3-IV from Angelica sinensis (Oliv) Diels].

Polysaccharides X-C-3-III and X-C-3-IV had been obtained from Angelica sinensis (Oliv) Diels. Their average MW were determined to be 85,000 and 65,765 by gel chromatography after the hydrolysates of X-C-3-III and X-C-3-IV, the compositions of them were identified by silanization method and capillary gas chromatography. X-C-3-III and X-C-3-IV are composed of galacose, arabinose, rhamnose, glucuronic acid and galacturonic acid. The molar ratio of those sugars were determined as 24.3:15.8:4.2:3.1:52.6 and 12.6:10.7:7.2:8.3:61.2, respectively.

Angelica sinensis↗

PubMed2001

[A study of gene products encoded by Wilson disease gene].

OBJECTIVE: To investigate the pathogenesis of Wilson disease (WD) by detecting its gene products encoded by WD gene (ATP7B). METHODS: Patients diagnosed as WD were analyzed by SDS-PAGE in conjunction with Western blot. Two antibodies were used, which are specially against the sixth copper binding domain (Anti-CuBD) and ATP binding domain (Anti-ABD) of WD protein. RESULTS: The WD proteins were not expressed in two patients when using anti-CuBD, and poorly expressed when using anti-ABD. CONCLUSIONS: WD is highly heterogeneous in clinical manifestations and inheritance pattern. Two WD patients might simultaneously have exon 5 mutations and exon 8 mutations. The study of WD gene products would probe into the pathogenesis of WD.

Adenosine Triphosphatases↗

PubMed2001

[A study of Wilson's disease gene encoded products and gene mutations].

OBJECTIVE: To investigate the pathogenesis of Wilson's disease(WD). METHODS: Hepatocytes were isolated from WD patients' bioptic hepatic samples and cultured in vitro; WD proteins, the gene putative encoded products, were detected by SDS-PAGE in conjunction with Western blotting in liver samples of three patients and two controls. Their genomic DNAs were analyzed by means of direct DNA sequencing of WD gene (ATP7B) on exon 8. RESULTS: The WD proteins lanes from two WD patients were found to be much weaker than that from the control, from which one WD patient was proven as heterozygote of 778 position CGG-->CTG(Arg778Leu) and 770 position CTC-->CTG change of ATP7B. CONCLUSION: WD is highly heterogeneous in clinical manifestations and inheritance pattern. Abnormally expressed putative WD proteins in WD patients might be the results of ATP7B mutations, and the study of ATP7B products would help to probe into the pathogenesis of WD.

Adenosine Triphosphatases↗

PubMed2001

[Manufacture and study of porous poly(l-lactic acid) (PLLA)/beta-tricalcium phosphate (beta-TCP) composite].

A promising alternative to supply bone substitutes is to develop living tissue substitutes based on biodegradable materials, which is called bone tissue engineering. One of the research high-lights of bone tissue engineering is to design and manufacture scaffolds for cell attaching, migrating, and proliferating. A process which consists of a solvent casting stage, a compression molding stage and a leaching stage has been used to fabricate macroporous composites of poly(l-lactic acid) (PLLA) and beta-tricalcium phosphate (beta-TCP). The effects of the weight fraction of porogen--NaCl, of the weight ratio of PLLA to beta-TCP and of the diameters of beta-TCP on the porosities, the average pore diameters and the compressive yield strength and compressive modulus have been studied. The results showed that the porosities and the average pore diameters increased and the compressive yield strength and modulus decreased when the weight fraction went from 50% to 90%. The compressive yield strength and compressive modulus could be improved by changing the weight ratio of PLLA to beta-TCP and the diameters of beta-TCP in low-porosity composites (lower than 70%). But high-porosity composites (90%) were not reinforced by changing the weight ratio.

Biocompatible Materials↗

PubMed2001

Body mass index profile in Hong Kong Chinese adults.

INTRODUCTION: Obesity has now become an epidemic with increasing prevalence in most parts of the world. However, information on the problem of obesity in Asians is limited. SUBJECTS AND METHODS: From April 1996 to August 1997, 17,121 Chinese adult subjects from the community of Hong Kong presented themselves voluntarily at the United Christian Nethersole Community Health Service Centers for primary health care check-up. Demographic data including height and weight were documented. Their body mass indexes (BMI) were measured. The prevalence rates of overweight and obese subjects were calculated according to the 1995 World Health Organization criteria. RESULTS: There were 4781 (27.9%) men and 12,340 (72.1%) women. The mean age (+/- SD) was 51.3 +/- 16.0 years (range 20 to 96 years, median 49.8 years). Of the 17,121 subjects, 4939 (28.85%) were overweight and 656 (3.83%) were obese. Based on the 1997 Hong Kong Census statistics of the overall Hong Kong population data, the age-standardised prevalence rates of overweight and obese subjects were 30.52% and 3.19% in men and 22.14% and 3.35% in women, respectively. Of the 10,937 subjects of working age (20 to 65 years), the prevalence rates of overweight and obese subjects were 28.98% and 3.55%, respectively. Of the 6648 subjects aged > or = 60 years, the prevalence rates of overweight and obese subjects were 36.31% and 4.81%, respectively. CONCLUSIONS: In Hong Kong, the age-standardised prevalence rate of overweight and obese subjects were 30.5% and 3.2% in men and 22.1% and 3.4% in women, respectively. This information provides some useful estimations of the extent of an important public health problem, obesity, in Hong Kong.

Adult↗

PubMed2001

Human umbilical cord blood cells ameliorate Huntington's disease in transgenic mice.

Human umbilical cord blood mononuclear cells given in megadose quantity (71-74 x 10(6) and 100-105 x 10(6)) were able to increase the life span of B6CBA-TgN(Hdexon1)62Gpb mice (Huntington disease) from an average of 88 days to 97.8 and 103.4 days respectively. The rate of weight loss, which begins in these mice before the onset of symptoms of chorea, was far less in the animals receiving human cord blood mononuclear cells (p<0.01) than the weight loss in untreated control mice. With the full understanding that additional histological and behavioral studies are indicated, but because of the potential clinical significance, a brief report is being submitted.

Animals↗

PubMed2001

Human umbilical cord blood cells ameliorate Alzheimer's disease in transgenic mice.

Having had success in extending the life of mice with a transgene for amyotropic lateral sclerosis (SOD1) mice and Huntington's disease (Hdexon1), we administered megadoses of human umbilical cord blood mononuclear cells to mice with Alzheimer's disease. These mice have an over-expression of human Alzheimer amyloid precursor protein (APP), die early and develop a CNS disorder that includes neophobia. When given 110 x 10(6) human umbilical cord blood mononuclear cells, these mice (HuAPP 695.SWE) had considerable extension of life with a p value of 0.001 when compared to control animals.

Alzheimer Disease↗

PubMed2001

[The role of beta3-adrenergic receptor Trp/Arg mutation in childhood obesity].

OBJECTIVE: To understand with greater clearness the role of beta3- adrenergic receptor Trp/Arg mutation in childhood obesity. METHODS: One hundred and seventy-seven children, aged 6-12 years, were selected. The genotype was detected by restricted fragment length polymorphism, the children's dietaries were surveyed by a 3-day recalling and recording method. Their height, weight were measured, and the data on their living habits were collected from their parents. RESULTS: The intake of total amount of food and energy of obese children were higher in children with Trp/Trp genotype, but there was no difference between the obese and non-obese children with Trp/Arg genotype. Among children with the Trp/Arg genotype, obese children were less active and did less exercise, they slept more, but there was no difference among children with Trp/Trp genotype. CONCLUSION: The children with beta3-AR Trp/Arg mutation may become obese because of the low energy metabolism; less active and exercise may increase the risk of obesity.

Child↗

PubMed2001

OPC-28326, a selective femoral vasodilator, is an alpha2C-adrenoceptor-selective antagonist.

OPC-28326 has been reported to selectively increase femoral blood flow in open-chest dogs and autoperfused canine femoral artery preparations. Preliminary data indicated that OPC-28326 has a high affinity at the alpha2-adrenoceptor. In the present study, we tested OPC-28326 in isoflurane anesthetized rats at a dose of 3 mg/kg of body weight, given intraduodenally. OPC-28326 significantly increased femoral blood flow, by 44.7 +/- 13.8%, 45 min after drug administration, whereas carotid blood flow increased by only 3.6 +/- 5.5% (n = 6). Chinese hamster ovary cell lines overexpressing rat alpha2D-, alpha2B-, or alpha2C-adrenoceptor were established. These cells also coexpress luciferase, driven by cAMP elevation. In radioligand binding assays using cell membrane preparations, OPC-28326 dose dependently competed with [3H]RX821002 binding, with calculated K(i) values of 3840 +/- 887, 633 +/- 46, and 13.7 +/- 1.9 nM on alpha2D-, alpha2B-, and alpha2C-adrenoceptor, respectively. A similar affinity and rank order of potency were also found for OPC-28326 on the alpha2-subtypes using epinephrine as agonist in luciferase assays. No agonistic effect of OPC-28326 was detected on any of the alpha2-adrenoceptors. Finally, in situ hybridization performed on skeletal muscle tissue sections collected from rat hind limb (musculus gastrocnemius) demonstrated a high level expression of alpha2C in the vascular tissues. Thus, the abundance of alpha2C in the skeletal muscle may account for the selective effect of OPC-28326 in increasing femoral blood flow.

Adrenergic alpha-2 Receptor Antagonists↗

PubMed2001

Complications of laparoscopic procedures after concentrated training in urological laparoscopy.

PURPOSE: To increase the safety and efficiency of laparoscopic surgery clinical training programs have been developed to increase the skill and efficiency of urological trainees. We evaluated the impact of dedicated laparoscopy training on the rate and type of complications after trainees entered clinical practice. MATERIALS AND METHODS: Data were obtained from 13 centers where laparoscopy was performed by a single surgeon with at least 12 months of training in urological laparoscopy before clinical practice. Data included training experience, laparoscopic procedures performed after commencing clinical practice and associated complications. Procedures were classified as easy, moderate and difficult. RESULTS: During training each surgeon participated in a mean of 71 cases. In clinical practice a total of 738 laparoscopic cases were performed with the group reporting an overall complication rate of 11.9%. The rate was unchanged when the initial 20, 30 and 40 cases per surgeon were compared with all subsequent cases (12%, 11.9% and 12% versus 11.8 to 12%, respectively). The re-intervention rate was 1.1%. The complication rate increased with case difficulty. Overall and early complication rates attributable to laparoscopic technique in the initial 20, 30 and 40 cases were identical. The most common complications were neuropathy in 13 patients, urine leakage/urinoma in 9, transfusion in 7 and ileus in 5. CONCLUSIONS: The complication rate of surgeons who completed at least 12 months of laparoscopy training did not differ according to initial versus subsequent surgical experience. Intensive training seems to decrease the impact of the learning curve for laparoscopy.

Humans↗

PubMed2001

[Effect of EGTA and La2+ on induction of sesquiterpene cyclase gene expression in leaves of Capsicum annuum by several abiotic elicitors].

To destroy Ca2+ signal system, the detached leaves of Capsicum annuum were pretreated with EGTA, a commonly used Ca2+ chelator, or La3+, an ion which competitively inhibits Ca2+ movement through plasma membrane channels. The induction of sesquiterpene cyclase gene expression in the pretreated pepper leaves under the treatments of CuCl2, HgCl2 and UV was conducted in this paper. The result showed that no hindrance of sesquiterpene cyclase enzyme activity was detected in the EGTA or LaCl3 pretreated leaves, compared to the controls treated with CuCl2, HgCl2, and UV without the pretreatment, while the pretreatment with EGTA enhanced the inductivity of the above exogenous abiotic elicitors on the enzyme activity. The sesquiterpene cyclase activity was also detected in leaves treated with EGTA only, and the result of Northern Blot analysis indicated that the enhancement of EGTA on the enzyme activity was due to the induction of EGTA on the gene transcription. It is suggested that there might exist other signal pipelines, in addition to the Ca2+ signal system in sesquiterpene cyclase gene expression in pepper leaves, and the mechanism of induction of abiotic elicitors on sesquiterpene cyclase in C. annuum differed from that of biotic elicitors.

Calcium Signaling↗

PubMed2001

[The role of exogenous hRAR beta gene on the growth inhibition and differentiation induction of HL-60R Cells].

OBJECTIVE: To investigate the role of hRAR beta gene in HL-60R cells and in their response to retinoids. METHODS: By electroporation, the recombinant pcDNA3-hRAR beta plasmid was transfected into the hRNA beta gene not expressed human myleocytic leukemic cell line HL-60R. In the presence of RAR-selected agonist Ch55, the effect of RAR beta gene on HL-60R was studied by the efficiency of colony formation in soft agar, cell morphology NBT reduction assay and flow cytometry. RESULTS: The HL60R-hRAR beta cells with stable hRAR beta gene expression were obtained. The growth and colony formation in soft agar of HL60R-hRAR beta cells were remarkably reduced as compared with that of their parent cells, and the cells were induced into granulocytic differentiation by Ch55 treatment at 10(-7). CONCLUSION: The expression of exogenous hRAR beta gene in HL-60R cells could resume their sensitivity to retionoids in inhibiting cell proliferation and inducing granulocytic differentiation.

Cell Differentiation↗

PubMed2001

[An epidemiological and clinical study of primary gout].

OBJECTIVE: To evaluate the prevalence of primary gout in Shantou and Beijing area, and understand it's clinical features. METHODS: Three epidemiological studies in Chenghai downtown, and the one of study in Beijing were studied. Clinical, laboratory and radiology data were collected and analyzed. RESULT: The prevalence of primary gout in Chenghai surveys was 0.17%, 0.15% and 0.26% respectively; no case of primary gout was found in Beijing survey. Among the patients, male to female ratio was 21:1; average onset age of females was significantly higher than that of males. The numbers of patient in the recent 10 years was increasing. At the first attack, the first metatarsophalangeal joint was involved among 79.7% of all cases; no fourth metatarsophalangeal joint involvement had been found. Hyperlipemia was the most common accompanying abnormal laboratory test (57.1%). Radiographic bone erosion was found in 49.4% patients, most of them, the duration of disease was over 5 years. CONCLUSION: The prevalence of primary gout was higher in Shantou area than that in Beijing, and it was increasing in the recent 10 years in Shantou area. The difference of geography, climate, food and lifestyle could be responsible for the different prevalence in different area.

Adult↗

PubMed2001

[Study of telomerase activity and its related genes expression in leukemia cells].

OBJECTIVE: To investigate the changes of telomerase activity and its related genes expression in leukemia cells and their roles in leukemogenesis. METHODS: The telomerase activity in bone marrow cells of 47 leukemia patients were detected by a semi-quantitative telomeric repeat amplification protocol (TRAP)-silver staining, and the expression of telomerase related genes hEST2, TP1 and hTR by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: The telomerase activity and expression of telomerase related genes were significantly higher in 42 leukemia patients in progress stage than that in complete remission/chronic stage and in normal/anemia cases (P < 0.01). The telomerase activity and expression of TP1, hTR gene in 14 cases of acute leukemia complete remission (AL-CR)/chronic myelogenous (CML)-chronic stage were higher than that in normal/anemia cases (P < 0.05). Low levels of telomerase activity and telomerase related genes expression could be detected in part of normal bone marrow cells. The levels of telomerase activity and telomerase related genes expression in 3 cases of anemia increased after short-term culture. CONCLUSIONS: High level of telomerase activity and its related genes expression were specific markers of malignant hematopoietic cells and their changes might be useful for observation of treatment effectiveness in leukemia. Low level of telomerase activity was associated with hematopoietic stem cells with the ability of proliferation. hEST2 gene might be a up-regulation gene of telomerase; hTR might be related to feedback regulation of telomerase.

Adolescent↗

PubMed2001

[Effects of selective RAR or/and RXR retinoids on the proliferation and differentiation of NB4 cells and their mechanisms].

OBJECTIVE: To investigate the effects of RARbeta selective agonist and RARalpha antagonist (RARbeta +/RARalpha -) BMS453 in combination with RXR selective agonist (RXR+) BMS649 on the proliferation and differentiation of NB4 cells, and illustrate the mechanism. METHODS: The proliferation and differentiation of NB4 cells were detected by cell count, morphological observation, NBT reduction assay, immunofluorescence analysis, flow cytometry and RT-PCR. RESULTS: BMS453 in combination with BMS649 could significantly inhibited the growth of NB4 cell in the manner of dose and time dependence. NB4 cells treated with BMS453 and BMS649 were irreversibly committed to morphologically and functionally more differentiated granulocytic cells. When NB4 cells were treated with BMS453 and BMS649 for 0, 1, 3, 12, 24 and 48 h, RARalpha, RARbeta and RXRalpha expressions were up regulated at 1 h and 3h, respectively. As compared to ATRA, the situations had no significant difference. In contrast, BMS453 or BMS649 alone was ineffective on NB4 cells. CONCLUSION: BMS453 (RARbeta+/RARalpha-) in combination with BMS649 (RXR+) significantly and synergistically inhibit proliferation of NB4 cells and induce them into granulocytic differentiation, the mechanism of which may be mediated by the AF-2 activity of RXR.

Cell Differentiation↗

PubMed2001

[Systemic side effects of long-term treatment with low dose inhaled corticosteroids in children with asthma].

OBJECTIVE: To observe the systemic side effects of low dose inhaled Beclomethasone dipropionate (BDP) in children with mild asthma. METHODS: 30 children with mild asthma were randomly divided into 3 groups to receive treatment with inhaled placebo (group A), BDP 200 micrograms/d (group B) and BDP 400 micrograms/d (group C) respectively. Bronchial hyperresponsiveness (BHR), height growth, bone mineral density (BMD), calcium and phosphate metabolism and hypothalamic-pituitary-adrenal axis (HPAA) function were measured. RESULTS: Inhaled BDP of 200 micrograms/d and 400 micrograms/d reduced BHR in mild asthmatic children and there was no significant difference between two groups [log(PD20-FEV1)]:(2.04 +/- 0.47) micrograms to (2.70 +/- 0.13) micrograms in group A and (1.94 +/- 0.46) micrograms to (3.15 +/- 0.18) micrograms in group B (P < 0.01). Serum osteocalcin, calcium, phosphate, alkaline phosphatase, basic cortisol and BMD didn't change significantly after BDP treatment in three groups (all P > 0.05) [In group A, B and C, concentrations serum osteocalcin were (29 +/- 12) micrograms/L, (22 +/- 6) micrograms/L, (31 +/- 11) micrograms/L, serum calcium: (2.49 +/- 0.11) mmol/L, (2.39 +/- 0.28) mmol/L, (2.20 +/- 0.35) mmol/L, serum phosphate: (1.8 +/- 0.6) mmol/L, (1.7 +/- 0.7) mmol/L, (1.5 +/- 0.4) mmol/L, radius BMD: (0.44 +/- 0.02) g/cm2, (0.42 +/- 0.05) g/cm2, (0.40 +/- 0.10) g/cm2, ulna BMD:(0.35 +/- 0.04) g/cm2, (0.36 +/- 0.08) g/cm2, (0.32 +/- 0.07) g/cm2, serum alkaline phosphatase: (410 +/- 113) U/L, (337 +/- 99) U/L, (351 +/- 122) U/L, serum basic cortisol: (350 +/- 86) nmol/L, (407 +/- 199) nmol/L, (365 +/- 71) nmol/L, lumbar spine (L4-5) BMD: (0.64 +/- 0.06) g/cm2, (0.59 +/- 0.08) g/cm2, (0.62 +/- 0.09) g/cm2 respectively]. Height growth had a trend of reducing after BDP treatment though not reaching statistical difference. Height standard deviation score (SDS): 1.1 +/- 0.7 to 1.2 +/- 0.9 in group A, 1.3 +/- 0.7 to 1.3 +/- 0.9 in group B and 1.1 +/- 0.7 to 1.0 +/- 0.7 in group C. Serum cortisol after ACTH stimulation reduced significantly in group C [(621 +/- 199) nmol/L to (482 +/- 97) nmol/L, P < 0.01]. CONCLUSION: The results of this study suggest that 200 micrograms/d BDP can reduce BHR significantly and has no detected systemic side effects in mild asthmatic children, and 400 micrograms/d BDP can reduce serum cortisol after ACTH stimulation. The long-term dose of BDP should be controlled to be less than 400 micrograms/d in children with mild asthma.

Administration, Inhalation↗