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Biomedical subjects

D H Liu

Publications and source records attributed to D H Liu.

At least 19 recordsLinked to original sources
PubMed2004

Supernumerary tricentric derivative chromosome 15 in two boys with intractable epilepsy: another mechanism for partial hexasomy.

Rearrangements of chromosome 15q, including isodicentric 15 chromosomes and interstitial duplications and triplications, have been previously reported in association with autism spectrum disorders. We have identified two boys with exceptionally large der(15) chromosomes that are tricentric and contain four copies of the proximal long arm, including the Prader Willi/Angelman critical region, and leading to hexasomy of the involved segment. Biallelic inheritance of maternal alleles and methylation analysis indicate that the markers are maternally derived. Clinical assessment of the boys indicated severe cognitive impairment associated with marked delays in gross and fine motor skills. Social and language deficits were present in both, although the severity of the mental retardation precluded diagnosis of autism (both were considered to have pervasive developmental disorder-not otherwise specified). Neurologic manifestations included infantile spasms evolving into intractable early-onset myoclonic seizures, psychomotor regression, and profound diffuse hypotonia. These patients represent the most severe end of the spectrum of phenotypes associated with segmental aneuploidy for chromosome 15q11-q13.

Abnormalities, Multiple↗
PubMed2004

Biphasic effect of daidzein on cell growth of human colon cancer cells.

Colorectal cancer is one of the most common cancers in the world, poorly responding to available chemotherapeutic agents. To investigate whether natural molecules can inhibit colon cancer progression, we investigated a principle phytoestrogen found in soybean known as daidzein, and determined its effects on the human colon cancer cell line LoVo. LoVo cells were treated with 0.1, 1, 5, 10, 50 and 100 microM daidzein for 2, 3, 4 or 5 d. The results indicated that daidzein stimulated the growth of LoVo cells at 0.1 and 1 microM whereas at higher concentrations (10, 50 and 100 microM) cell growth was inhibited in a dose-dependent manner. Treatment of daidzein at 10, 50 and 100 microM resulted in cell cycle arrest at G0/G1 phase, DNA fragmentation and increases in caspase-3 activity. There were no changes in alkaline phosphatase activity (ALP), an indicator of cell differentiation, upon treatment with daidzein when compared to controls. These results indicate that daidzein has a biphasic effect on LoVo cell growth and its tumor suppressive effect is by means of cell cycle arrest and apoptosis but not through cell differentiation.

Alkaline Phosphatase↗
PubMed2001

Expression of vascular endothelial growth factor and its role in oncogenesis of human gastric carcinoma.

AIM: To establish the role of vascular endothelial growth factor (VEGF) in the oncogenesis of human gastric carcinoma more directly. METHODS: The expression of VEGF and its receptor kinase-domain insert containing receptor (KDR) in human gastric cancer tissue were observed by immunohistochemical staining. VEGF levels were manipulated in human gastric cancer cell using eukaryotic expression constructs designed to express the complete VEGF(165) complimentary DNA in either the sense or antisense orientation. The biological changes of the cells were observed in which VEGF was up-regulated or down-regulated. RESULTS: VEGF-positive rate was 50%, and VEGF was mainly localized in the cytoplasm and membrane of the tumor cells, while KDR was mainly located in the membrane of vascular endothelial cells in gastric cancer tissues and peri-cancerous tissue. In 2 cases of 50 specimens, the gastric cancer cells expressed KDR, localized in both the cytoplasm and membrane. Introduction of VEGF(165) antisense into human gastric cancer cells (SGC-7901, immunofluorescence intensity, 31.6%)) resulted in a significant reduction in VEGF-specific messenger RNA and total and cell surface VEGF protein (immunofluorescence intensity, 8.9%) (P<0.05). Conversely, stable integration of VEGF(165) in the sense orientation resulted in an increase in cellular and cell surface VEGF (immunofluorescence intensity, 75.4%) (P<0.05). Lowered VEGF levels were associated with a marked decrease in the growth of nude mouse xenografted tumor (at 33 days postimplantation, tumor volume: 345.40 +/- 136.31 mm3)(P<0.05 vs control SGC-7901 group: 1534.40 +/- 362.88 mm3), whereas up-regulation of VEGF resulted in increased xenografted tumor size (at 33 days postimplantation, tumor volume: 2350.50 +/- 637.70 mm3) (P<0.05 vs control SGC-7901 group). CONCLUSION: This study provides direct evidence that VEGF plays an important role in the oncogenesis of human gastric cancer.

Adult↗
PubMed2001

[The metabolism of trehalose and intracellular glycerol in Candida krusei responding to high osmosis].

The trehalose and intracellular glycerol contents of osmotolerant yeast Candida krusei cells rapidly increased in response to the medium containing NaCl. Addition of NaCl at early exponential phase or steady phase increased trehalose content only, but the content of extracellular glycerol increased gradually. Development of resistance was accompanied by accumulation of trehalose and was apparently unrelated to intracellular glycerol content which was always low under these conditions. There seems to be an overlap function between trehalose and glycerol in Candida krusei cells in response to the osmotic conditions.

Candida↗
PubMed2001

Uptake and accumulation of copper by roots and shoots of maize (Zea mays L.).

The effects of different concentrations of copper sulfate on root and shoot growth of maize(Zea mays L.) and the uptake and accumulation of Cu2+ by its roots and shoots were investigated in the present study. The concentrations of copper sulfate (CuSO4 x 5H2O) used were in the range of 10(-5)-10(-3) mol/L. Root growth decreased progressively with increasing concentration of Cu2+ in solution. The seedlings exposed to 10(-3) mol/L Cu2+ exhibited substantial growth reduction, yielding only 68% of the root length of the control. The shoot growth of the seedlings grown at 10(-5)-10(-4) mol/L Cu2+ were more or less the same as the control seedlings. The leaves treated with 10(-3) mol/L Cu2+ were obviously inhibited in shoot growth. The fresh and dry weights both in roots and shots decreased progressively with increasing Cu2+ concentration. This fits well with the above mentioned effects of copper sulfate on root growth. Zea mays has considerable ability to remove Cu from solutions and accumulate it. The Cu content in roots of Z. mays increased with increasing solution concentration of Cu2+. The amount of Cu in roots of plants treated with 10(-3), 10(-4) and 10(-5) mol/L Cu2+ were 10, 8 and 1.5 fold, respectively, greater than that of roots of control plant. However, the plants transported and concentrated only a small amount of Cu in their shoots.

Copper↗
PubMed2001

[Changes in aldosterone binding activity of kidney cytosol after stress in rats and the regulation].

To observe the changes in aldosterone binding activity of kidney cytosols after pathological stress in rats and the regulation, binding capacity (Rt) and apparent dissociation constant (Kd) of aldosterone binding activity of kidney cytosols in normal, low-degree or heavy-degree scalded rats were measured by radioligand binding assay using [3H]aldosterone as the ligand. Changes in Rt and Kd of aldosterone binding activity were observed after injection of anti-rat TNF alpha and IL-1 beta antibodies, alpha-melanocyte-stimulating hormone (alpha-MSH) and KPV peptide (Ac-D-Lys-L-Pro-D-Val). The results indicated that there were two types of aldosterone binding activities in kidney cytosol with different Rt and Kd, and the Rt of heavy-degree scalded rats (Rt1: 22.4 +/- 5.4 fmol/mg pro, Rt2: 196.3 +/- 32.5 fmol/mg pro) was lower than that of the control group (Rt1: 41.6 +/- 7.2 fmol/mg pro, Rt2: 317.6 +/- 70.0 fmol/mg pro) (P < 0.01; P < 0.01); while the Rt of low-degree scalded rats (Rt1: 41.4 +/- 5.0 fmol/mg pro, Rt2: 314.8 +/- 45.7 fmol/mg pro) was not significantly different from that of the control group (P > 0.05; P > 0.05). Injection of anti-rat TNF alpha and IL-1 beta antibodies, alpha-MSH and KPV prevented Rt of aldosterone binding activity from decrease in kidney cytosol of rats with heavy-degree scald. These findings suggest that aldosterone binding activity may be down-regulated in heavy-degree scalded rats, but it may be reversed by injection of anti-rat TNF alpha and IL-1 beta antibodies, alpha-MSH and KPV.

Aldosterone↗
PubMed2000

[Enhancement of fermentative glycerol yield with heat shock treatment].

A heat shock treatment was studied in glycerol fermentation of osmotolerant yeast Candida krusei. The experiment results showed that the optimal temperature and duration time for heat shock is 45 degrees C and 30 min respectively, and the optimal start time of the treatment is at the mid term in exponential growth stage. With such treatment, glycerol yield was enhanced greatly, while no significant effects on both cell growth and glucose consumption were observed.

Candida↗
PubMed1996

Purification and characterization of endogenous digoxin-like immunoreactive factors in chicken blood.

Studies have been performed to determine whether an endogenous material capable of binding to digoxin antibodies is present in the chicken plasma. In the blood of 12 chickens without feed control, endogenous digoxin-like immunoreactive factors (DLIF) binding of digoxin antibodies in enzyme immunoassays amounted to 866 / 302 pg digoxin equivalents/mL of plasma (mean +/- SEM). Immunoreactivity of DLIF increased to 1848***331 pg/mL with a double value of control after boiling and acid pretreating the plasma. The major purification steps employed in this report were gel filtration column chromatography, high performance liquid chromatography (HPLC) and isoelectric focusing (IEF). Using HPLC for the separation, at least 10 chicken DLIFs with different molecular weight (MW) have been found. The MW of the smallest is 300 daltons (Da) while the largest is 100 kDa. The value of the isoelectric point of the most abundant type of DLIF from untreated chicken plasma is 6.3 as determined by IEF. The partially purified DLIF inhibits Na+, K(+)-ATPase from a porcine cerebral cortex as well as three human red blood cell membrane preparations in a dose-response fashion.

Animals↗
PubMed1995

Computed tomography of pulmonary metastases from oral and maxillofacial tumors.

Computed tomographic scans were done on 14 oral and maxillofacial malignant tumors in which pulmonary metastases occurred but were poorly delineated by conventional chest radiography and tomography. Computed tomography promotes the accurate diagnosis of small and occult pulmonary metastases. Optimal nonlinear computed tomographic windows are recommended for the diagnosis of pulmonary metastases.

Adult↗
PubMed1994

[Effects of high-level-manganese sewage irrigation on children's neurobehavior].

The neurobehavioral status was tested for 92 matched-pair pupils aged 11-13 in an area with high-level-manganese sewage irrigation and a control area. Results showed there was significant difference in manganese contents of drinking water between the area with sewage irrigation and the control area during 1990-1992, ranged 0.241-0.346 mg/L and 0.030-0.040 mg/L, respectively, with P < 0.01. Hair manganese content of children in the area with sewage irrigation (1.252 micrograms/g) was significantly higher than that in the control area (0.961 micrograms/g) with P < 0.01. Scores in digit span, Santa Ana manual dexterity, digit symbol, Benton visual retention test and pursuit aiming test for children in the area with sewage irrigation were significantly lower than those in the control area (P < 0.01). Hair manganese contents of the children in the area with sewage irrigation correlated negatively with most of those scores. It suggested high level of manganese in drinking water of the area with sewage irrigation might be an important factor affecting children's neurobehavioral changes.

Adolescent↗
PubMed1994

Patellar thickness in total knee replacement.

The question of patellar thickness after total knee replacement (TKR) is an important issue. From November 1989 to June 1993, a total of 294 TKR were performed on 219 patients (34 males, 185 females) with an average age of 67 years. Tricon-M prostheses were used in TKRs performed before October 1992, and PCA prostheses were used after that date. In each TKR, all polyethylene patellar components used on patellar resurfacing were cemented in place. The average preoperative patellar thickness was 21.2 +/- 1.8 mm. The thickness was preserved in 106 knees, while for 53 knees, a slight increase in thickness (mean, 1.5 +/- 0.9 mm) was recorded, and for 120 knees, a slight decrease in thickness (mean, 1.5 +/- 0.8 mm) was recorded. Lateral retinacular release was performed in 96 knees (40%) of the 238 TKR with a Tricon-M prosthesis, but in only seven knees (17%) among the 41 TKR using the PCA prosthesis. Patellar subluxation and dislocation after TKR occurred in 13 knees of 11 patients (10 females, one male, mean body weight 63.5 kg) with the Tricon-M prosthesis. The mean time from arthroplasty to occurrence of patellar instability was eight months. Six knees were treated by proximal realignment procedure while seven knees were given conservative treatment, with good results and no recurrence reported. The use of a patellar cutting jig allows better control of patellar thickness when performing patellar resurfacing for small patella. No complications such as patellar fracture, infection or patellar component-loosening were encountered in the 294 TKRs performed.

Aged↗
PubMed1993

[Initial investigation of the value of CT in pulmonary metastases originating from head and neck malignant tumors]

CT image and its diagnostic value were analyzed and compared with plain chest film on 12 cases of pulmonary metastases originating from malignant tumors of head and neck,all cases were pathologically verified.CT scan performed on each cases who had definite or suspicious lesion on plain chest film.The result presents that CT can:(1)confirm the suspiciousness of metastatic lesion.(2)confirm the number of metastatic lesion.(3)early detection on pulmonary metastasis. 4.identification on occult pulmonary metastasis. 5.Find out costal bone and pleural metastasing accuracy of pulmonary metastasis,but also provide information for clinical selecting treatment.

Journal Article↗
PubMed1991

Nuclear location of the 16K non-structural protein of tobacco rattle virus.

An antiserum, elicited by a synthetic peptide coupled to bovine serum albumin, reacted specifically with the non-structural 16K protein of tobacco rattle virus. The protein was detected in extracts of systemically infected Nicotiana clevelandii leaves, but only in those made with the aid of SDS, urea and 2-mercaptoethanol. Immunogold labelling of ultrathin sections showed that the protein was mainly associated with nuclei, but was also present in the cytoplasm. These observations suggest that the 16K protein binds to macromolecular components of infected cells, especially in nuclei, but do not clarify its function.

Amino Acid Sequence↗
PubMed1991

[Studies on the determination of the circulating antigen in experimental toxoplasmosis].

This paper reports on the regular pattern of growth and decline of the circulating antigen (CA) determined by I-ELISA in experimentally infected rabbits. Toxoplasma antigen was demonstratable in the circulation in 64.7% rabbits 1 day after tachyzoite inoculation and the level of the CA in sera from infected rabbits showed an increase on d4 and reached its peak level on d10-13 after inoculation but declined soon thereafter. CA was not detectable on days 60 to 90 after inoculation. The results suggest that determining CA is a useful means for diagnosing active toxoplasmosis and that I-ELISA might be a promising approach to detect CA in toxoplasmosis.

Animals↗
PubMed1991

[A study of the relationship of total urinary hydroxyproline: creatinine ratio to body height].

The body heights of 226 pupils (8-12 year old) in primary schools were measured and it was found that, the height increase was greater in spring and summer than in autumn and winter. But there was no such difference among girls of 11 & 12 yrs old. Urines were collected from them in Oct. Nov. Dec. 1983 and Mar. Apr. May. 1984 and her urinary total hydroxyproline (THP) : Creatinine (Cr) Ratios (THP/Cr) were determined and found that the Mar-May ratio was higher than the Oct-Dec ratio, which was consistent with that of height of the coefficients of correlation between THP/Cr and increase of height 2/3 from boys of 10-12 years old, and 1/2 of the coefficients of correlation from a group of 8-9 years old girls were significant. 32 correlations from girls of 10-12 yrs of age were significant or highly significant (P less than 0.01 or less than 0.05) of 12 months or 20 months with the THP/Cr. THP/Cr is therefore a sensitive index of recent height growth (1-2 yrs) during the adolescent period.

Body Height↗
PubMed1990

[Biliary fistula and bleeding after cholecystectomy].

The authors analysed 303 cases of cholecystectomy performed in their hospital and found that there were 22 cases of biliary fistula (7.2%), subhepatic infection ensued in 3 (0.9%), and massive postoperative bleeding in 5 (1.7%) with two deaths. The histology of the gallbladder bed was studied under microscope in 60 bodies. It was found that the intact gallbladder bed, rich in collagenous, elastic, and reticular fibers was a strong fibromembranous lining adhering to the liver surface, with numerous small blood vessels, bile ductuli, and lymphangiomas going through it. Leaving the lining intact and through and through sutures of any bleeding spots during the process of cholecystectomy and routine drainage of the subhepatic space were suggested by the authors in order to prevent postoperative bile leakage and bleeding.

Adult↗
PubMed1990

[Reconstructive method of the alimentary tract after total gastrectomy].

In this report, four different procedures were adopted to reconstruct the alimentary tract after total gastrectomy performed for gastric carcinoma in 92 cases. They were end to side (or end to end) esophagojejunostomy (48 cases), rho-shaped esophagojejunostomy (28 cases), and end to end esophagoduodenostomy (16 cases). The incidence of anastomotic leakage was 4.3%, the operative mortality 2.2%. No anastomotic leakage occurred in the rho-shaped esophagojejunostomy group which is considered to be safe and effective. Though end to end esophagoduodenostomy has the advantage of being simple and time sparing, it can not be applied to all patients for the tension at the site of anastomosis. It might be indicated when the tumor is located in the greater or lesser curvature with the cardiac or pyloric end not involved, or when the distance between the lower end of the esophagus and the upper border of duodenum cone is not larger than the width of 1.5 vertebral body.

Adult↗