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Biomedical subjects

D Zhu

Publications and source records attributed to D Zhu.

At least 289 records · Page 16Linked to original sources
PubMed1992

Blocking of lung endothelial cell adhesion molecule-1 (Lu-ECAM-1) inhibits murine melanoma lung metastasis.

The 90-kD lung endothelial cell adhesion molecule-1 (Lu-ECAM-1) selectively promotes Ca(2+)-dependent adhesion of lung-metastatic B16 melanoma cells. Corresponding with their metastatic performance, high lung-metastatic B16-F10 melanoma cells bind in significantly higher numbers to Lu-ECAM-1 than their intermediate and low lung-metastatic counterparts B16-L8-F10 and B16-F0, respectively. Maximum attachment is observed at a density of approximately 2.4 x 10(2) Lu-ECAM-1 sites/microns2 of plastic surface. B16 melanoma cell binding to Lu-ECAM-1 is blocked by mAb 6D3 and is competitively inhibited by soluble Lu-ECAM-1. C57B1/6 mice passively immunized with anti-Lu-ECAM-1 mAb 6D3 or actively immunized with purified Lu-ECAM-1 exhibit an anti-Lu-ECAM-1 antibody titer-dependent reduction in the number of B16 experimental metastases. Lu-ECAM-1 promotes neither binding nor metastasis of other lung-metastatic tumor cells (e.g., KLN205). Our data indicate that an "antiadhesion" therapy directed at interfering with the adherence of blood-borne tumor cells to organ-specific vascular endothelium is efficient in the control of metastasis formation in selective organ sites.

Animals↗
PubMed1992

Disease expression and molecular genotype in congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

Genotyping for 10 mutations in the CYP21 gene was performed in 88 families with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Southern blot analysis was used to detect CYP21 deletions or large gene conversions, and allele-specific hybridizations were performed with DNA amplified by the polymerase chain reaction to detect smaller mutations. Mutations were detected on 95% of chromosomes examined. The most common mutations were an A----G change in the second intron affecting pre-mRNA splicing (26%), large deletions (21%), Ile-172----Asn (16%), and Val-281----Leu (11%). Patients were classified into three mutation groups based on degree of predicted enzymatic compromise. Mutation groups were correlated with clinical diagnosis and specific measures of in vivo 21-hydroxylase activity, such as 17-hydroxyprogesterone, aldosterone, and sodium balance. Mutation group A (no enzymatic activity) consisted principally of salt-wasting (severely affected) patients, group B (2% activity) of simple virilizing patients, and group C (10-20% activity) of nonclassic (mildly affected) patients, but each group contained patients with phenotypes either more or less severe than predicted. These data suggest that most but not all of the phenotypic variability in 21-hydroxylase deficiency results from allelic variation in CYP21. Accurate prenatal diagnosis should be possible in most cases using the described strategy.

Adrenal Hyperplasia, Congenital↗
PubMed1992

Detection of IgE antibodies specific for 1-phenyl-2,3-dimethyl-3-pyrazoline-5-one by RAST: a serological diagnostic method for sensitivity to pyrazoline drugs.

Certain adverse reactions to pyrazoline drugs resemble IgE-mediated hypersensitivity. However, convincing evidence of antigen-antibody interactions is not fully demonstrated. In this study, IgE antibodies specific for 1-phenyl-2,3-dimethyl-3-pyrazoline-5-one have been found in 17 out of 19 serum samples from individuals sensitive to pyrazoline drugs with 4-aminoantipyrine discs by Radio Allergo Sorbent Test (RAST). In contrast, we have not found any positive results from 10 normal donors without sensitivity to pyrazoline drugs after ingestion of metamizol 500 mg/day for 14 days. Therefore, our results provide further evidence in favor of an IgE-dependent mechanism in patients suffering from sensitivity to pyrazoline drugs. The determination of specific IgE antibodies could be used as a serodiagnostics method.

Adult↗
PubMed1992

The presence of specific IgE to salicyloyl and O-methylsalicyloyl in aspirin-sensitive patients.

Certain adverse reactions to aspirin (ASA), nonsteroidal anti-inflammatory drugs (NSAIDs) and pyrazoline derivatives resemble IgE-mediated hypersensitivity. However, convincing evidence of antigen-antibody interactions or of the inhibition of the cyclooxygenase pathway of arachidonic acid metabolism leading to an increase in the generation of leukotrienes (LTs) and a decrease in the generation of prostaglandins (PGs) was not fully demonstrated. In this study, two types of specific IgE antibodies have been found in 27 serum samples from 28 ASA-sensitive patients with salicyloyl-discs and O-methylsalicyloyl-discs by Radio Allergo Sorbent Tests (RAST). The positive rates were 96.4% and 71.4%, respectively. In contrast, no positive results could be found in 10 normal donors without ASA sensitivity after ingestion of ASA 500 mg/day for 14 days. Further investigation of the chemical structure of epitopes was done by cross inhibition studies. Our results are an increasing evidence in favour of an IgE-dependent mechanism in patients suffering from ASA sensitivity. Hopefully, the determination of specific IgE antibodies will be a safe diagnostic method of ASA sensitivity in vitro.

Adult↗
PubMed1992

Canine bone shape analysis by use of a radiographic image-classification system.

A radiographic image-classification system was developed to analyze and compare the shape of the humerus of neonatal Labrador Retriever and Labrador Retriever x Beagle pups that were either phenotypically normal or affected with an ocular-skeletal dysplasia syndrome. The system consistently defined the shape of the humerus within the groups of pups studied and indicated a difference in the shape of the humerus between normal and affected pups. Results indicated that the radiographic image-classification system may be able to identify Labrador Retriever pups affected by the ocular-skeletal dysplasia syndrome at or shortly after birth.

Animals↗
PubMed1992

[A study of genetic polymorphism of isozymes in natural populations of Drosophila virilis in east China].

A study of genetic variation at Est-alpha, Est-beta, A my, Acph and alpha-Gpdh loci in local samples of Hefei, Wuhu, Jiujiang, Nanchang, Changzhou, Fuzhou and Quanzhou Drosophila virilis population is presented. The employment of standard techniques of polyacrylamide electrophoresis and agarose electrophoresis reveals that the former three loci are highly polymorphic in all these populations. According to the allelic frequency of the 5 loci, a genetic distance between the above-mentioned populations was calculated. Along with the results obtained by Mr He Chaozheng from Hongze, Nanjing, Hangzhou and Ningbo populations, a dendrogram was made. It was found that Quanzhou and Fuzhou populations differed from the others in allelic frequencies and genetic distances which suggests that this difference is related to the extent of geographic isolation among them.

Animals↗
PubMed1991

Transfection of C6 glioma cells with connexin 43 cDNA: analysis of expression, intercellular coupling, and cell proliferation.

C6 glioma cells express low levels of the gap junction protein connexin 43 and its mRNA and display very weak dye coupling. When implanted into the rat cerebrum, these cells quickly give rise to a large glioma. To investigate the role of gap junctions in the tumor characteristics of these cells, we have used Lipofectin-mediated transfection to introduce a full-length cDNA encoding connexin 43. Several transfected clones were obtained that exhibited various amounts of connexin 43 mRNA transcribed from the inserted cDNA. Immunocytochemical analysis revealed an increase in the amount of connexin 43 immunoreactivity in the transfected cells, being localized at areas of intercellular contact as well as in the cytoplasm. The level of dye coupling was also assessed and found to correlate with the amount of connexin 43 mRNA. When cell proliferation was followed over several days, cells expressing the transfected cDNA grew more slowly than non-transfected cells. These transfected cells will be useful in examining the role of gap junctions in tumorigenesis.

Animals↗
PubMed1991

Comparative significance in systolic ventricular interaction.

STUDY OBJECTIVE: The aim was to measure the systolic coupling between the ventricles and to determine the relative importance of ventricular interaction in the pressure development of each ventricle. DESIGN: Acute studies were done in dogs to measure the changes in right and left ventricular pressures (dPr, dPl) caused by sudden changes in left ventricular pressure (dPl') with release of an aortic constriction, and sudden changes in right ventricular pressure (dPr') with release of a pulmonary artery constriction, respectively. The instantaneous cross talk gain [dPr/dPl' (Klr) or dPl/dPr' (Krl)] was calculated during the ejection phase. The potential systolic pressure generated by the contralateral ventricle was evaluated as the cross talk gain multiplied by the contralateral systolic developed pressure. EXPERIMENTAL MATERIAL: Studies were done in eight random source dogs (12-18 kg), anaesthetised with sodium pentobarbitone. MEASUREMENTS AND MAIN RESULTS: The maximal Klr was lower than the maximal Krl, at 0.09 (SD 0.05) v 0.25 (0.06), and the mean Klr also was lower than the mean Krl, at 0.04 (0.02) v 0.10 (0.03), p less than 0.05. The potential right ventricular pressures developed by the left ventricle [maximum 10.3(5.6), mean 4.8(2.7) mm Hg] were not significantly different from the potential left ventricular pressures developed by the right ventricle [maximum 8.8(2.7), mean 3.4(0.7) mm Hg]. However, the ratio between the potential transmitted pressure and the measured developed pressure was greater in the right ventricle [maximum 39.0(21.1), mean 17.8(8.9)%] than in the left ventricle [maximum 11.1(7.1)%, p less than 0.05; mean 3.9(1.5)%, p less than 0.01]. This suggests that about 20-40% of the right ventricular systolic pressure may result from the left ventricle and about 4-10% of the left ventricular systolic pressure may result from right ventricle. CONCLUSIONS: Although the pressure coupling was greater in right to left ventricular interaction, right ventricular pressure generation may be more dependent on the left ventricle. Systolic ventricular interaction may be more important for right ventricular systolic function. Further, the parameters of right ventricular systolic function currently used may be considerably affected by the left ventricle.

Animals↗
PubMed1991

Fluid resuscitation with deferoxamine prevents systemic burn-induced oxidant injury.

We studied the effect of deferoxamine (DFO) infused after burns on hemodynamic stability as well as local and systemic inflammation and oxidant-induced lipid peroxidation. Eighteen anesthetized sheep were given a 40% of total body surface burn and fluid resuscitated to restore oxygen delivery (DO2) and filling pressures to baseline values. Animals were resuscitated with lactated Ringer's (LR) alone or LR plus 1,500 ml of a 5% hetastarch complexed with DFO (8 mg/ml). Animals were killed 6 hours postburn. The sheep resuscitated with LR and LR plus hetastarch demonstrated significant lung inflammation and significant increases in lung and liver malondialdehyde (MDA) from controls of 47 +/- 6 and 110 +/- 7 nMol/gm to 63 +/- 13 and 202 +/- 59 for LR and 67 +/- 4 and 211 +/- 9 for LR + hetastarch, respectively. The group resuscitated with hetastarch alone required 15% less fluid. VO2 returned to baseline values in both groups by 2 hours. Resuscitation with the 5% hetastarch-DFO decreased total fluids by 30% over LR and prevented the increase in lung and liver MDA. In addition, postburn VO2 increased by 25% above baseline values. Burn tissue edema, measured as protein-rich lymph flow, was significantly increased with the administration of DFO compared with the other groups. We conclude that DFO used for burn resuscitation prevents systemic lipid peroxidation and decreases the vascular leak in nonburn tissues while also increasing O2 utilization. Resuscitation with hetastarch-DFO may accentuate burn tissue edema, possibly by increased perfusion of burn tissue.

Animals↗
PubMed1991

[Studies on assessment of intensity of infection of Schistosoma japonicum in cattle].

In order to carry out quantitative epidemiological survey of animal schistosomiasis, a sensitive egg-counting method was studied both in the laboratory and in the field. Fecal material was filtered by a copper gauze (60 meshes/inch) into a nylon-tissue bag with 2 layers, 150 and 260 meshes/inch respectively. Thin smears were made from the residue in the bag. The mean recovery rate of mature schistosome eggs by previously adding 100 eggs to 5g of feces from noninfected cattle was 67.5%, ranging from 53 to 81%. To compare the egg-concentration thin smear method mentioned above, with egg-concentration thick smear method after hyalinization, various numbers of eggs, namely, 25, 50 and 100, were added to 5g of feces. The mean recovery rates of fecal eggs were 57.6%, 57.6% and 69.1% respectively, for the thin smear method and 3.2%, 13.8% and 19.5% for the thick smear method. The coefficients of variability in the former were from 12.9% to 17.4% and in the latter, from 30.7% to 98.8%. The total number of schistosome eggs per 5g of feces found in 34 egg-positive cattle in the field were 434 and 178 by the thin smear method and the thick smear method, respectively. A correlation analysis performed on the numbers of detected eggs in a total volume of fecal sediment and from half a volume of fecal sediment multiplied by two, showed a correlation coefficient of 0.98 (P less than 0.01), indicating that half a volume of fecal sediment may be used instead of a whole volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Effects of liuwei dihuang decoction and its compositions on blood sugar and glycogen in mice].

We have studied the effects of liuwei dihuang decoction (LDD) and its compositions on blood sugar and glycogen in mice, and found that sanbu, shanzhuyu-danpi and shanyao-fuling matched pairs can reduce the level of blood sugar, while LDD, sanbu, shudi-zexie and shanzhuyu-danpi matched pairs can increase the content of glycogen in liver. The present study is only a preliminary research on the effects of LDD and its compositions on the metabolism of sugar in the body.

Animals↗
PubMed1990

Assignment of the Nance-Horan syndrome to the distal short arm of the X chromosome.

There are three types of X-linked cataracts recorded in Mendelian Inheritance in Man (McKusick 1988): congenital total, with posterior sutural opacities in heterozygotes; congenital, with microcornea or slight microphthalmia; and the cataract-dental syndrome or Nance-Horan (NH) syndrome. To identify a DNA marker close to the gene responsible for the NH syndrome, linkage analysis on 36 members in a three-generation pedigree including seven affected males and nine carrier females was performed using 31 DNA markers. A LOD score of 1.662 at theta = 0.16 was obtained with probe 782 from locus DXS85 on Xp22.2-p22.3. Negative LOD scores were found at six loci on the short arm, one distal to DXS85, five proximal, and six probes spanning the long arm were highly negative. These results make the assignment of the locus for NH to the distal end of the short arm of the X chromosome likely.

Abnormalities, Multiple↗
PubMed1990

Effect of endotoxin and a burn injury on lung and liver lipid peroxidation and catalase activity.

Both endotoxin and a burn alone produce oxidant-induced tissue lipid peroxidation. The endotoxin response is due in large part to hydrogen peroxide. The combination of endotoxin after a burn results in an increased liver, but not lung, oxidant injury. Our purpose was to determine whether the burn oxidant injury inactivated endogenous liver tissue catalase, thereby amplifying a subsequent H2O2 insult. Twenty-six adult sheep were studied. Twelve sheep had a 15% TBS burn. Tissue catalase activity, measured in lung and liver 3 days postburn, was significantly decreased from a control of 3.58 +/- 1.8 and 193 +/- 63, respectively, to 1.72 +/- 0.63 and 148 +/- 33 k(sec-1)/0.5 gram tissue. The addition of endotoxin 3 days postburn resulted in an increase in liver malondialdehyde, MDA, a measure of lipid peroxidation, from a control of 110 +/- 80 to 450 +/- 54 nmol/gram tissue. This value was significantly greater than the 210 +/- 80 nmol/gram tissue seen after endotoxin alone. Lung tissue MDA with burn and endotoxin was 65 +/- 8 compared to 42 +/- 7 for control and 80 +/- 6 nmol/gram for endotoxin alone. We conclude that a decrease in liver catalase activity occurs after a burn. The decrease corresponds to an accentuated oxidant-induced lipid peroxidation after an added endotoxin insult where H2O2 is known to be an etiologic agent. The catalase activity also decreases in postburn lung, but accentuated lung damage was not seen, indicating a variable tissue response from the burn-induced decrease in antioxidant activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Induction of tumor necrosis factor by macrophage colony-stimulating factor in vivo.

The effect of human urinary colony-stimulating factor (CSF-1) on the production of tumor necrosis factor (TNF) in vivo was assessed. Purified CSF-1 was administered i.v. to rabbits 4 days prior to injection with lipopolysaccharide (LPS). TNF in the serum prepared from rabbits bled 90 min after LPS injection was measured using cytotoxicity assays employing mouse L929 cells and antirabbit TNF monoclonal antibody. The results indicated that CSF-1 was able to induce the production of TNF in vivo and had a synergistic effect with Propionibacterium acnes.

Animals↗
PubMed1990

Changes in catalase activity in lung and liver after endotoxemia in sheep.

Endotoxemia in the sheep produces oxidant-induced cardiopulmonary dysfunction and lung and liver lipid peroxidation, which can be prevented with exogenous catalase, indicating a role for hydrogen peroxide. We determined whether endotoxin-induced oxidant release altered endogenous catalase activity to help explain the lipid peroxidation. Unanesthetized sheep were given 2 micrograms/kg Escherichia coli endotoxin and killed at 5 hr or 24 hr. Lung and liver lipid peroxidation, measured as malondialdehyde, and catalase activity were determined after endotoxin and compared with controls. Lung tissue MDA increased by 100% at 5 hr and was still elevated by 50% at 24 hr, while catalase activity decreased by 50% at 5 hr and remained decreased, suggesting irreversible inactivation. Liver MDA was also doubled at both 5 and 24 hr, but catalase activity remained unchanged. We conclude that endotoxemia results in a significant inactivation of endogenous catalase activity in lung, but not in liver. The lung may be more prone to a subsequent H2O2 injury before restoration of catalase activity.

Animals↗
PubMed1990

[Studies on molluscicidal effect of bromoacetamide against Ganesella virgo].

Molluscicidal effect of bromoacetamide against the snails in laboratory and field trials were observed. Grassland of Guiliu River in Keerqinyouyiquanqi District, Neimengol Autonomous Region was selected for field trials. The results showed that bromoacetamide was fairly effective against Ganesella virgo, the intermediate host of Dicrocoelium chinensis and Eurytrema pancreaticum. In field trials, 7 days after spraying at a dosage of 0.5g/m2, 74.7-84.7% of snails were killed. When a dosage of 1g/m2 was used, the mortality of snails reached 84.8-95.7%.

Acetamides↗