Biomedical subjects

Hui Yu

Publications and source records attributed to Hui Yu.

At least 73 records · Page 4Linked to original sources

PubMed2003

Distinct roles of transcription factors EGL-46 and DAF-19 in specifying the functionality of a polycystin-expressing sensory neuron necessary for C. elegans male vulva location behavior.

Caenorhabditis elegans polycystins LOV-1 and PKD-2 are expressed in the male-specific HOB neuron, and are necessary for sensation of the hermaphrodite vulva during mating. We demonstrate that male vulva location behavior and expression of lov-1 and pkd-2 in the ciliated sensory neuron HOB require the activities of transcription factor EGL-46 and to some extent also EGL-44. This EGL-46- regulated program is specific to HOB and is distinct from a general ciliogenic pathway functioning in all ciliated neurons. The ciliogenic pathway regulator DAF-19 affects downstream components of the HOB-specific program indirectly and is independent of EGL-46 activity. The sensory function of HOB requires the combined action of these two distinct regulatory pathways.

Animals↗

PubMed2003

Hydrogen bond directed highly regioselective palladium-catalyzed allylic substitution.

The palladium-catalyzed allylic substitution of 5-vinyloxazolidinones and derivatives was investigated. Unusual and high regioselectivity for the branched product was observed. The regioselectivity was influenced by the type of substrate, the solvents, and the nucleophile. Imide-type nucleophiles were found to be directed to the internal carbon (branched:linear, 75:25 to >98:2), whereas sulfonamides, amines, and malonates added only to the terminal carbon of the allyl complex. Relatively nonpolar solvents such as toluene and THF favored the branched product (97:3 and 95:5, respectively). Acetonitrile and dichloromethane afforded lower regioselectivity (50:50 and 67:33, respectively), and the use of the protic solvent ethanol resulted in reversal of the regioselectivity (12:88). The directing group on the substrate was important. Amides afforded almost complete formation of the branched product, and carbamates gave a 50:50 mixture of regioisomers with phthalimide as the nucleophile. Evidence for direction of the nucleophile via hydrogen bonding was obtained by replacing the hydrogen of the amide with a methyl, resulting in the production of only the normal linear product.

Allyl Compounds↗

PubMed2003

Determination of the composition of Chinese ligustrum lucidum polysaccharide by capillary zone electrophoresis with amperometric detection.

In this paper, capillary zone electrophoresis with amperometric detection was firstly applied to indirectly determine the composition of Chinese ligustrum lucidum polysaccharide (LLPS) by analyzing its hydrolyzates: fucose, glucose, arabinose and rhamnose. Under the selected optimum conditions, the four monosaccharides could be perfectly separated within 30 min and showed significant current responses at the copper electrode. The linear ranges of fucose, glucose and arabinose were all from 5.0 x 10(-6) to 1.0 x 10(-4) mol l(-1) and that of rhamnose was from 1.0 x 10(-5) to 1.0 x 10(-4) mol l(-1), and their detection limits were lower or near 1.0 x 10(-6) mol l(-1) (S/N=3). Experiments showed that the mole ratio of fucose, glucose, arabinose and rhamnose in Chinese LLPS was 1.80:4.58:2.55:1.91, and the purity of this polysaccharide leached by the introduced leaching method was 93.3%. Analyzing polysaccharide by this method has some merits of quickness, low-volume sampling, simple instrument, high sensitivity and high reproducibility.

Copper↗

PubMed2003

Ketanserin stabilizes blood pressure in conscious spontaneously hypertensive rats.

1. It has been demonstrated that blood pressure variability (BPV) is increased in hypertension and related to organ damage. It will be important to lower BPV in the treatment of hypertension. The present study was designed to investigate the effect of ketanserin, a 5-HT2A receptor antagonist with a weak alpha1-adrenoceptor blocking effect, on BPV in conscious spontaneously hypertensive rats (SHR). 2. It was found that ketanserin decreased blood pressure (BP) and BPV in SHR when administered intravenously (3 mg/kg, i.v.). Ketanserin decreased BPV, but not the BP level, when administered intracerebroventricularly (50 microg/rat, i.c.v.). 3. Prazosin, an alpha1-adrenoceptor antagonist, lowered BP but did not affect BPV when given either i.v. (0.5 mg/kg) or i.c.v. (30 microg/rat). Ritanserin (0.625 mg/kg, i.v.; 40 microg/rat, i.c.v.), a 5-HT2A receptor antagonist, decreased BPV only when administered i.c.v. and did not modify the BP level. 4. Ketanserin enhanced arterial baroreflex function in SHR when given either i.v. or i.c.v. 5. The stabilizing effect of ketanserin on BP was persistent when administered intragastrically. This administration route is similar to oral administration clinically. 6. It is concluded that ketanserin is an antihypertensive agent with an effect of reducing BPV. This effect is mainly mediated by central 5-HT2A receptors and is probably attributable to the restoration of arterial baroreflex function.

Animals↗

PubMed2003

A step-wise application of methylprednisolone versus dexamethasone in the treatment of acute exacerbations of COPD.

OBJECTIVE: The aim of the study was to explore the clinical value of a step-wise application of methylprednisolone (MP) compared to dexamethasone (DXM) in acute exacerbations of COPD. METHODOLOGY: One hundred and forty-two patients with an acute exacerbation of COPD were divided randomly into two groups: 71 patients were treated with MP and the other 71 patients were treated with DXM. Otherwise each group was given the same basic treatments: antibiotics, bronchodilators, oxygen therapy as well as standard hospital care. The patients in the MP group were given a tapering dose of MP for 7-14 days, and the patients in the DXM group were given a corresponding tapering dose of DXM for 7-14 days. Then both groups were given a gradually reducing dose of oral prednisone for 2-3 weeks. Two weeks before the prednisone was tapered off, inhaled corticosteroid was introduced. The patients' symptom scores, physical signs, per cent predicted FEV1%, and arterial blood gases were monitored before treatment and after the seventh day of treatment. RESULTS: There was an obvious improvement in symptoms after 1-3 days in all 71 patients in the MP group, with their wheezing being distinctly reduced or disappearing entirely. The maximum benefit that occurred in the MP group (90.14%) was considerably higher than that of the DXM group (25.35%), P < 0.05. The predicted FEV1% in the MP group increased from 46.7 +/- 10.6 to 67.5 +/- 12.4, compared with an increase in the DXM group from 50.1 +/- 7.6 to 58.9 +/- 10.8. The difference between the two groups was significant (P < 0.05). CONCLUSIONS: An adequate and tapering dose of MP used in acute exacerbations of COPD can relieve the inflammatory reaction in airways and reduce airway spasm more promptly than DXM.

Acute Disease↗

PubMed2003

A retrospective study on clinical features of and treatment methods for 77 severe cases of SARS.

In this retrospective study, clinical data including clinical manifestations, routine blood tests, chest radiographic imaging from 77 severe cases of SARS treated with integrated Chinese and Western medicine were collected and statistically analyzed. Twenty-nine (37.6%) patients were admitted to the intensive care unit, non-invasive ventilation was used in 40 (51.9%) cases, and invasive ventilatory procedure was performed in eight (10.3%) cases. Seventy (90.9%) patients were clinically cured and seven (9.0%) died. The duration of defervescence was 8.3 +/- 5.0 days after admission. In the early stage, normal leucocyte count was seen in 46 (75.4%) of the 61 patients tested, decreased leucocyte count in 13 (21.3%) and elevated leucocyte count in only two (3.2%) cases. A decreased lymphocyte count was also seen in 23 (37.7%) cases of the 61 patients tested on admission, and by day 14, the number of patients with decreased lymphocyte count (1.11 +/- 0.66 x 10(9)) increased to 32 (47.7%) in 67 cases examined. Neutral granulocyte count was normal or decreased in 58 (95.0%) patients on admission, but elevated from the 7th day onward and peaked on day 21 in 32 (65.3%) of the 49 cases tested. All of the blood abnormalities returned to normal in the convalescent stage. Twenty-nine (37.6%) of the 77 severe cases of SARS patients demonstrated an extensive lung involvement. In comparison with the non-severe SARS cases, this group of patients showed significantly more pneumonic air-space opacities and ground glass-like changes on the chest radiographs (p < 0.05, chi2 test). The role Chinese medicine played in the treatment of SARS was discussed.

Adrenal Cortex Hormones↗

PubMed2003

Clinical and laboratory studies of expression of cyclin A in leukemia cells.

Uncontrolled cell proliferation is the basic feature of cancer. Some of the prime cell cycle regulators are involved directly in tumorigenesis. Cyclin A, one of the G(1)/S cyclin, can cause transformation. The purpose of this research was to investigate whether cyclin A overexpression was involved in leukemogenesis and proliferation of leukemia cells. The expression of cyclin A at S-phase in leukemia cell line HL-60, blast cells of acute leukemia patients, bone marrow cells of outpatients without malignant hematological disease and peripheral blood cells of healthy donors was investigated by simultaneous indirect immunofluorescence staining of intracellular antigen and DNA. To further investigate whether cyclin A played as a key molecular in cell proliferation, HL-60 cells were exposed to different concentrations of hexamethylene bisacetamide (HMBA). MTT dye absorbance of living cells and cell cycle analysis were adopted to evaluate growth arrest. Differentiation was evaluated by detection of the change of expression of CD11b and CD33 on cell surface. The results showed that overexpression of cyclin A was only found among specimens from acute leukemia and leukemia cell line. There was no elevated cyclin A detection for cyclin A among specimens from outpatients and healthy donors. In HMBA interference experiment, HMBA was able to induce growth arrest and monocytic macrophage differentiation of HL-60 cells in a dose-dependent manner, and all these changes were associated with a marked down-regulation of cyclin A expression. In conclusion, aberrant overexpression of cyclin A at S-phase was only found in leukemia cell lines and blast cells from acute leukemia. The dose-dependent effect of HMBA on cell growth and differentiation of HL-60 cell line which was consistent with the decrease of cyclin A expression in these cells suggested that the molecular mechanisms of HMBA inducement involved downregulation of cyclin A expression.

Acetamides↗

PubMed2003

A randomized control trial on interruption of HBV transmission in uterus.

OBJECTIVE: To study the interruptive effect of hepatitis B virus (HBV) specific immunolobulin (HBIG) before delivery in attempt to prevent intrauterine transmission of HBV. METHODS: Nine hundred and eighty HBsAg carrier pregnant women were randomly divided into HBIG group and control group. Each subject in the HBIG group received 200 IU or 400 IU of HBIG intramuscularly at 3, 2 and 1 month before delivery. The subjects in the control group did not receive any specific treatment. All newborn infants received 100 IU of HBIG intramascularly after venous blood samples were taken at birth and 2 weeks after birth, followed by 30 micro g plasma-derived HB vaccine or 5 micro g recombinant yeast-derived hepatitis B vaccine at 1, 2 and 7 months of age. Blood tests were performed for all the lying-in women and their neonates. Blood specimens were tested for HBsAg and HBeAg by enzyme immunoassay. All infants were followed up for 1 year. RESULTS: In the HBIG group, 491 neonates were born to 487 HBV carrier mothers; and in the control group, 496 neonates were born to 493 HBV carrier mothers. The rates of intrauterine transmission in the two groups were 14.3% and 5.7% respectively (chi(2) = 20.280, P < 0.001), and the rates of chronic hepatitis B in the two groups were 2.2% and 7.3% respectively (chi(2) = 13.696, P < 0.001). The high risk factors of intrauterine HBV infection included HBsAg HBeAg double positive and HBV DNA positive in the peripheral blood of pregnant women. CONCLUSION: HBV infection in the uterus may be interrupted by injecting multiple intramuscular HBIG injections before delivery without causing any side-effects.

Adult↗

PubMed2002

On the 6-exo atom transfer radical cyclization reactions of 3-butenyl 2-iodoalkanoates.

Bis(tributyltin)-initiated atom transfer cyclization reactions of 3-butenyl iodoalkanoates in the presence of BF3.OEt2 as the catalyst afforded the 6-exo cyclization products as a mixture of 3,4-cis- and trans-substituted tetrahydro-2H-pyran-2-ones in 53-71% yield with the major isomers being the cis ones. Ab initio calculations at the B3LYP/6-31G level on the transition states of the radical cyclization and on the cyclized products revealed that the reactions are kinetically controlled and the transition states for the 6-exo radical cyclization are in boat conformations. Moreover, the cis-oriented transition states are of lower energy than the corresponding trans-oriented ones, which are in excellent agreement with experimental results.

Journal Article↗

PubMed2002

Converting radical oligomers to a single product.

Atom-transfer radical oligomerizations of omega-alkenyl iodoacetates followed by rearrangemental deoligomerization via treatment with concentrated H2SO4 or heating led to the formations of gamma-lactones in high yield, demonstrating the important value of radical oligomers in organic synthesis.

Journal Article↗

PubMed2002

Determination of codeine and its metabolite in human urine by CE with amperometric detection.

The amperometric detection of codeine and its metabolite, morphine following capillary zone electrophoretic separation is described. A carbon-disk electrode used as working electrode for two analytes exhibited a good response at 0.90 V (vs. Ag/AgCl). The optimal conditions of separation and detection were pH 8.4 phosphate buffer solution (0.06 mol x l(-1)), 12 kV for the separation voltage, sample injection at 12 kV for 10 s. The linear ranges were from 3.1 x 10(-7) to 2.5 x 10(-5) mol x l(-1) for codeine and 1.9 x 10(-7) to 1.5 x 10(-5) x mol l(-1) for morphine with a correlation coefficient of 0.9996 and 0.9999, respectively. The detection limits for codeine and morphine were 1.6 x 10(-7) and 6.8 x 10(-8) x mol l(-1). The method developed was successfully applied to the determination of codeine and its metabolite, morphine in the human urine without any other sample pretreatment except filtration, and the results were satisfactory.

Analgesics, Opioid↗

PubMed2002

A novel gene IC53 stimulates ECV304 cell proliferation and is upregulated in failing heart.

C53, cloned from rat brain cDNA library, can bind to p35, the precursor of activator of Cdk5. A novel gene with 84% homolog to C53, named IC53, was cloned from our 5300 EST database of human aorta cDNA library (GenBank Accession No. AF110322). Computational analysis showed that IC53 cDNA is 2538 bp long, encoding 419 amino acids, mapped to chromosome 17q21.31 with 12 exons, ubiquitously expressed in 12 tested normal tissues and 8 tumor cell lines from MTN membranes and vascular endothelial cells by Northern blot and in situ hybridization, and upregulated in the rat models of subacute heart failure and chronic ischemic heart failure by left coronary ligation. Stable transfection of IC53 stimulates ECV304 cell proliferation by 2.1-fold compared to cells with empty vector (P<0.05). The results support that IC53 is a novel gene, mainly expressed in vascular endothelial cells and mediates cell proliferation.

Amino Acid Sequence↗

PubMed2002

CARP is a novel caspase recruitment domain containing pro-apoptotic protein.

Many CARD-containing caspase mediators interact with CARD-containing caspases and participate in activation or suppression of caspases. We cloned a novel CARD-containing protein from our EST database, named CARP. Computational characterization revealed that CARP encoded 445 amino acids with predicted MW 49.7 kDa, localized at chromosome 10p13 with 15 exons, and four putative function domains, one CARD domain (aa 160-243), one nuclear receptor-binding motif, two EF-hand motifs, and 42% alpha-helix content. Stable transfection of CARP into lung carcinoma A549 and HEK293S cells leads to 23% of the cells undergoing apoptosis, but only 3% in the cells transfected with empty control vector. The cell proliferation was significantly inhibited by 1.2-5 folds (P<0.02) in seven CARP-transfected tumor cell lines-lung carcinoma A549 and PG, melanoma WM451, prostate cancer PC-3 and PC-3M, liver cancer H7402, and bladder cancer BIU87. Our results suggest that CARP is a novel CARD-containing pro-apoptotic protein.

Amino Acid Motifs↗

PubMed2002

[Effect of hexamethylene bisacetamine on proliferation and apoptosis of human leukemia cells in vitro and relevant mechanisms].

OBJECTIVES: To investigate the in vitro effect of hexamethylene bisacetamine (HMBA) on the proliferation, cell cycle regulation, and apoptosis of human leukemia cells and to study the relevant mechanisms. METHODS: K562 and U937 human leukemia cells were cultured and then suspensions thereof without HMBA or with HMBA of different concentrations (1, 2, and 4 mmol/L) were made. The optical absorbance value at 595 nm of these suspensions were tested every 24 hours. The suspensions were mixed with 4% trypan blue dye solution. Live and dead cells were observed with microscope and the live cell rate was calculated. Double staining of cellular cyclin A protein/DNA was used to detect the expression levels of cyclin A protein in cytoplasm. Fluorescein isothiocyanate (FITC)-labeled annexin V/Propidiumiodide) was used to detect the apototic cells fluorescence-activated cell sorter. Gel electrophoresis was conducted to detect DNA contents. RESULT: After exposure to HMBA for 6 days, the optical absorbance values at 595nm of K562 leukemia cells of the control group and groups with 1, 2, and 4mmol/L HMBA were 1.03, 0.81, 0.58, and 0.36 respectively. After treatment of HMBA, the percentages of cyclin A positive K562 leukemia cells in control group and groups with 1, 2, and 4 mmol/L HMBA were 34.4% +/- 5.2%, 16.1% +/- 2.5%, 9.9% +/- 1.7%, and 7.6% +/- 2.0% respectively (P < 0.01). No drug-related apoptosis was found in both cell lines. CONCLUSION: HMBA inhibits cell proliferation and reduces S-phase-fraction in both cell lines dose-dependently through down-regulating the expression of cyclin A. Apoptosis is not a consequence of the proceeding mitosis arrest and is induced p53-dependently by HMBA. In both leukemia cell lines (U937 and K562) lacking wt-p53, a nonapoptotic death pathway may exist during HMBA induction.

Acetamides↗

PubMed2002

Transforming growth factor-beta1 inhibits steroidogenesis in human trophoblast cells.

Transforming growth factor-beta (TGF-beta) is an important regulator of placental development and function. In this study, we have investigated the effect of TGF-beta1 on steroidogenesis, as well as its sites of action in the steroidogenic pathway by using a choriocarcinoma cell line, JEG-3, and a normal trophoblast cell line (NPC). The effect of TGF-beta1 on progesterone and estradiol production was evaluated in the absence or presence of a membrane-permeable analogue of cholesterol and some intermediate substrates of steroidogenic enzymes. The effect of TGF-beta1 on P450 aromatase (P450arom) mRNA levels was determined by Northern blot analysis. TGF-beta1 significantly decreased progesterone production in both NPC and JEG-3 cells. The inhibitory effect of TGF-beta1 on progesterone production was reversed by addition of 22R-hydroxycholesterol, a membrane-permeable analogue of cholesterol, or pregnenolone. In JEG-3 cells, TGF-beta1 also inhibited estradiol production when androstenedione, but not estrone, was added to the culture. Estradiol production was too low to be detected in NPC cells. Treatment with TGF-beta1 also suppressed aromatase mRNA levels. This study has demonstrated that TGF-beta1 inhibits progesterone and estradiol production by trophoblast cells, and that the sites of TGF-beta1 action on progesterone and estradiol production are likely to be cholesterol transport and P450arom respectively.

Activins↗

PubMed2002

[Clinical analysis of seven patients with occult breast cancer and literature reviews].

BACKGROUND AND OBJECTIVE: Occult breast cancer is a kind of specific seldom clinically seen breast cancer. This study was designed to investigate the diagnosis and treatment of the patients with breast cancer. METHODS: Retrospective study was conducted in 7 cases of occult breast cancer from May 1990 to May 2001. RESULTS: All cases were female and account for 0.59% of the total breast cancer treated in the same period. Axillary node enlargement was presented as first sign and no breast mass was palpable in physical examination. Fine needle aspiration or excisional biopsy revealed metastatic adenocarcinoma before surgery. All cases were taken mammography and 1 case was suspicious of malignancy. 3 cases were taken ultrasonography and 1 case was suspicious of malignancy. 5 cases underwent radical mastectomy and 2 cases underwent modified radical mastectomy. Pathological examination of the removed specimen found the primary breast cancer leison in 4 case and showed infiltrative carcinoma in 3 cases and intraductal carcinoma in 1 case. After surgery, 2 cases received radiotherapy plus chemotherapy, 5 case received chemotherapy and 4 case received tamoxifen therapy. All case were still alive and 3 cases survived over 54 months and 1 case survived for 7 years. CONCLUSION: Occult breast cancer should be considered when axillary lymph node is enlarged in female. Fine needle aspiration and excisional biopsy are helpful in pathologic diagnosis preoperatively. Mammography and ultrasonography have low sensitivity in identifying primary tumor. Radical or modified radical mastectomy with adjuvant radiotherapy and chemotherapy is a suitable choice for the patients with occult breast cancer and the prognosis is superior or similar to those patients who with palpable mass both in breast and axillary.

Adult↗

PubMed2002

[Prevalence survey on Cyclospora cayetanensis and Cryptosporidium ssp. in diarrhea cases in Yunnan Province].

OBJECTIVE: To investigate the prevalence and distribution characteristics of Cyclospora cayetanensis and Cryptosporidium ssp. infection in diarrhea cases of Yunnan Province. METHODS: To collect fresh faeces from diarrhea cases in 7 counties/cities, examine the specimens by direct smear with iodine staining and modified acid-fast staining. RESULTS: The infection rate of C. cayetanensis and Cryptosporidium ssp. was 3.97% and 5.29%, respectively. The infection rate of the two pathogenic coccidians was as high as 10.64% and 8.51% in preschool children. C. cayetanensis was found in 3 counties and Cryptosporidium in 6 counties. CONCLUSION: Both C. cayetanensis and Cryptosporidium ssp. are prevalent in Yunnan Province with the latter distributed more widely, and the two pathogens are more prevalent in preschool children.

Adolescent↗

PubMed2002

A pilot study on the combined therapy of granulocyte-macrophage colony-stimulating factor and hepatitis B vaccine on chronic hepatitis B virus carrier children.

OBJECTIVE: To observe the efficacy of treating intrauterine infected chronic hepatitis B virus (HBV) carrier children with a combination of granulocyte-macrophage colony-stimulating factor (GM-CSF) or hepatitis B immunoglobulin (HBIG) plus recombinant hepatitis B vaccine (rHBvac). METHODS: A total of 27 chronic HBV infected children, who were born to HBV carrier mothers and received hepatitis B immunoprophylaxis at birth, were randomized into 2 groups: one receiving a combined therapy of 50 micro g of GM-CSF plus 10 micro g of rHBvac injected intramuscularly at the same location (GM-CSF group, 14 children) or 200 IU HBIG and 10 micro g rHBvac in different muscles (HBIG group, 13 children) on a monthly four-dose schedule. HBV-DNA quantification and other HBV serological markers were tested before and after the four-dose therapy. RESULTS: Twelve children in each group completed the study. Of them, 3 children in the GM-CSF group and 4 in the HBIG group had elevated serum alanine transaminase (ALT) before the trial, and then 2 in each group became ALT normal after the treatment. Before the therapy, hepatitis B e antigen (HBeAg) positivity was found in nine children in the GM-CSF group and 10 in the HBIG group. One from each group had an HBeAg/anti-HBe seroconversion after the treatment. The quantity of HBV-DNA was significantly lower after the treatment (P = 0.023) in GM-CSF group, but was not significantly reduced in HBIG group. No subjects were found to be negative for hepatitis B surface antigen (HBsAg) after the treatment, and no serious adverse events occurred in either group. CONCLUSION: Combined GM-CSF and rHBvac therapy inhibit HBV replication in carrier children who were not protected after treatment with immunoprophylaxis.

Carrier State↗