Biomedical subjects

X Guo

Publications and source records attributed to X Guo.

At least 217 records · Page 12Linked to original sources

PubMed1999

Evidence of a major gene effect for angiotensinogen among Nigerians.

To dissect the genetic pathway of hypertension, we measured angiotensinogen in 685 members of 186 families recruited from a rural community in southwest Nigeria. Commingling and segregation analyses were carried out. A mixture of two and/or three distributions fits the data significantly better than a single distribution in commingling analysis, suggesting a major gene effect. Segregation analysis confirmed that a recessive major gene model for low values of angiotensinogen provides the best fit to the data and about 13% of the variance was due to the recessive gene segregation.

Adolescent↗

PubMed1999

Expression of membrane type 1-matrix metalloproteinase in laryngeal carcinoma.

Membrane type 1-matrix metalloproteinase (MT1-MMP) is a member of the recently identified unique membrane-type subgroup in the matrix metalloproteinase (MMP) family. MT1-MMP has proteolytic activity against components of the extracellular matrix and activates progelatinase A (MMP-2) at the cell surface. In this study, we analyzed the expression of MT1-MMP mRNA in 45 cases of laryngeal carcinoma by RT-PCR and investigated the relationship between MT1-MMP expression and survival in 18 cases. The result showed that the expression of MT1-MMP mRNA was higher in tumor tissue than in corresponding normal tissue. The tumoral expression in clinical stage III was higher than in stage II. The tumoral expression level of MT1-MMP mRNA in patients with lymph node metastasis was signigicantly higher than those with negative lymph nodes. The patients with high expression level showed significantly poorer 5 year survival than those with low expression level. Collectively, our findings suggest that the high level of MT1-MMP expression is closely related to the invasion and metastasis of laryngeal carcinoma, and indicates poorer prognosis.

Actins↗

PubMed1999

Signature sequences for the galectin-4 subfamily.

Galectins are a distinct family of animal lectins that have a cation-independent affinity for beta-galactoside sugars and share characteristic amino acid sequences. The cDNA encoding rabbit bladder galectin-4 has been cloned and sequenced (GenBank accession no. AF091738). The deduced 328 amino acid sequence predicts a multidomain structure consisting of an N-terminal peptide (19 residues) and two carbohydrate recognition domains (130 residues each) connected by a linker region (49 residues). Comparison of rabbit galectin-4 with related proteins reveals that two peptide motifs, M-A-F/Y-V-P-A-P-G-Y-Q-P-T-Y-N-P-T-L-P-Y in the N terminus and A-F-H-F-N-P-R-F-D-G-W-D-K-V-V-F in the first carbohydrate recognition domain are highly conserved in human, pig, rat, and mouse galectin-4 as well as in mouse galectin-6. The two peptide motifs are proposed here as the signature sequences to identify new members of the galectin-4 subfamily.

Amino Acid Sequence↗

PubMed1999

Food price policy can favorably alter macronutrient intake in China.

The rapid change in diets, physical activity and body composition in low income countries has led to the coexistence of large pockets of undernutrition and overnutrition. Public health strategies for addressing this situation may be necessary, and price policy options are examined for China. Longitudinal dietary data collected in China in 1989-1993 on a sample of 5625 adults aged 20-45 y were examined. Three-day averages of food group consumption and nutrient intake were used in longitudinal statistical models to examine separately the effects of food prices on the decision to consume each food group and then the amount consumed. The effects of changes in six food prices on the consumption of each of six food groups, not just the food group whose price had changed, and on three macronutrients were estimated. The effects show large and significant price effects. If the joint effects of the nutrition transition are to be considered, then there are clear tradeoffs among which foods to tax and which to subsidize. Most important is the effect of prices in reducing fat intake of the rich but not adversely affecting protein intake for the poor. Increases in the prices of pork, eggs and edible oils are predicted to lower fat intake. Only increases in pork prices led to reduced protein intakes. This raises questions about earlier policy changes being implemented in China and provides insight into an important and controversial area for public health policy.

Adult↗

PubMed1999

Arginine carboxypeptidase (CPR) in human plasma determined with sandwich ELISA.

There are two types of carboxypeptidases present in human blood, carboxypeptidase N (CPN) and arginine carboxypeptidase (CPR). CPR is generated during coagulation from a precursor (proCPR) which can be converted to the active form by trypsin in vitro. Since it is difficult to distinguish the two types of carboxypeptidases in human blood by the measurement of enzyme activity, we established a quantitative sandwich ELISA by which CPR can be quantitated. The amount of CPR in plasma, fresh serum and heated serum were essentially the same. Therefore the ELISA assay does not distinguish proCPR, activated CPR and inactivated CPR. With the ELISA method, CPR was quantitated in plasma from fifty patients with rheumatoid arthritis and eleven patients with severe hepatitis as well as healthy individuals. The amount of CPR in plasma obtained from patients with rheumatoid arthritis was not found to be lower than that of normal subjects. Furthermore, the patients who suffered severe hepatitis and had very low levels of CPR-total were fatal. This suggests that a decrease of CPR level might be a good indication of a patient's prognosis to death by hepatitis.

Antibodies, Monoclonal↗

PubMed1999

Construction and preliminary characterization of a library of "lethal" preterminal protein mutant adenoviruses.

Adenoviruses containing lethal in-frame insertion mutant alleles of the preterminal protein (pTP) gene were constructed with cell lines that express pTP. Thirty in-frame insertion mutant alleles, including 26 alleles previously characterized as lethal and 4 newly constructed mutant alleles, were introduced into the viral chromosome in place of the wild-type pTP gene. The viruses were tested for ability to form plaques at 37 degrees C in HeLa-pTP cells and at 32 degrees C and 39.5 degrees C in HeLa cells. Two of the newly constructed viruses exhibited temperature sensitivity for plaque formation, one virus did not form plaques in the absence of complementation, seven additional mutants exhibited a greater than 10-fold reduction in plaque formation in the absence of complementation, and another eight mutants exhibited stronger phenotypes than did previously characterized in-frame insertion mutants in the plaque assay. These mutant viruses offer promise for analysis of pTP functions.

Adenoviruses, Human↗

PubMed1999

Linkage information content of polymorphic genetic markers.

The Polymorphism Information Content (PIC) value is often used to measure the informativeness of a genetic marker for linkage studies. The PIC value was first derived for the case of a rare dominant disease, when one of the parents is affected, and is a function of the particular mode of disease inheritance. We first generalize the definition of the PIC value in such a way that it does not depend on the mode of inheritance of the trait being studied, and then develop a Linkage Information Content (LIC) value to measure the informativeness of a marker about the identity-by-descent sharing status of particular types of pairs of relatives. Knowing the LIC value, it is possible to determine the effective number of fully informative pairs in a study when we have incomplete marker information.

Gene Frequency↗

PubMed1999

In vitro biotransformation of a novel antimalarial cysteine protease inhibitor in human liver microsomes.

4-Dimethylamino-4'-(imidazol-1-yl)chalcone (RL3142) is a newly developed antimalarial cysteine protease inhibitor. Four metabolites (M1-M4) were found in human liver microsomes and their structures were identified by LC/MS/MS. Two primary metabolites, M2 (minor) and M4 (major), were determined to be the N-demethylated product (M2) and the product (M4) resulting from 1,2-hydrogenation of the alpha, beta-unsaturated ketone moiety of the parent compound. A combined approach utilizing selective P450 inhibitors, immunoinhibition with CYP3A and NADPH P450 reductase antibodies, and cDNA expressed human CYP3A4 and NADPH P450 reductase, was used for identification of enzymes responsible for the biotransformation. For formation of M2, both a rabbit CYP3A polyclonal antibody (110 microliter/mg microsomal protein) and ketoconazole (2 micromol/l), a CYP3A inhibitor, showed about 50% inhibitory effects; other specific inhibitors of CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6 and CYP2E1 showed no significant effects. For formation of M4, neither CYP3A antibody nor the above mentioned CYP inhibitors exhibited inhibitory effects. Anti-rat NADPH P450 reductase serum (50 microliter/100 microgram microsomal protein) exhibited 70 and 58% inhibitory effects on M2 and M4 formation, respectively. Incubation of RL3142 with cDNA expressed human NADPH P450 reductase yielded formation of M4, but not M2. Carbon monoxide inhibited formation of M2 and M1 (the reduced product of M2), but had no effect on M4 and M3 (the reduced product of M4) formation. Collectively, NADPH P450 reductase solely catalyzed reduction of RL3142 to M4, whereas CYP3A contributed in part to formation of M2.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1999

Late onset angiotensin-converting enzyme induced angioedema: case report and review of the literature.

Angiotensin-converting enzyme inhibitors (ACEI) such as enalapril, captopril, and lisinopril are well established as effective treatments of arterial hypertension and congestive heart failure. They are widely used and generally well tolerated. Angioedema is a rare but serious adverse effect of ACEI therapy. Most frequently, edema involves the face, oral cavity, and the glossopharyngeal or glottic area. Visceral edema induced by ACEI has also occurred. Life threatening and even fatal cases associated with ACEI have been reported. Although angioedema typically occurs within the first weeks of ACEI therapy, some cases with latencies of several months to years have been reported. This paper reports a case of late onset and recurrent angioedema in a patient treated with lisinopril for hypertension. A discussion of ACEI angioedema follows.

Angioedema↗

PubMed1999

[Loss of heterozygosity and microsatellite instability in laryngeal carcinoma near p16 gene].

OBJECTIVE: To search for the minimal overlap region of tumor suppressor gene in laryngeal carcinoma and discuss the correlation of p16 gene with laryngeal carcinogenesis. METHODS: Five microsatellite polymorphism markers near p16 gene were selected to detect loss of heterozygosity (LOH) and microsatellite instability (MI) in 60 cases of laryngeal squamous cell carcinoma. RESULTS: The frequencies of LOH in 5 markers were less than 23.1%, while the frequencies of MI in 2 markers were higher, with the highest frequency (46.1%) in D9S1752. CONCLUSION: The results suggest that the deletion of p16 gene does not play an important role in the laryngeal carcinogenesis and there may exist a gene around D9S1752 participating in the development of laryngeal carcinoma, which correlates with the mutation of repair gene.

Gene Deletion↗

PubMed1999

High glucose enhances mitogenic response to endothelin-1 in rabbit vascular smooth muscle cells.

AIM: To examine the effects of high glucose on the mitogenic response of rabbit aortic vascular smooth muscle cells (VSMC) to endothelin-1 (ET-1). METHODS: VSMC were cultured in normal glucose (5.5 mmol.L-1), high glucose (25 mmol.L-1) or high osmolality (glucose 5.5 mmol.L-1, plus mannitol 19.5 mmol.L-1). DNA synthesis was measured by [3H]thymidine incorporation. The expression of phospho-p44/42 MAPK was determined by Western blot. RESULTS: At a concentration range from 10(-12) to 10(-8) mol.L-1, ET-1 stimulated [3H]thymidine incorporation and phospho-p44/42 MAPK expression in VSMC in a concentration-dependent manner. From 10(-11) to 10(-8) mol.L-1, the mitogenic effect of ET-1 was higher in VSMC cultured in high glucose at equivalent concentration than cells cultured in normal glucose or high osmolality (P < 0.05 or P < 0.01), but no marked difference was observed in the growth response between cells cultured under the latter two conditions. Similarly, ET-1 increased expression of phospho-p44/42 MAPK by 60%-65% in VSMC cultured in high glucose, compared with cells in normal glucose or high osmolality. CONCLUSION: VSMC cultured in high glucose exhibited increased mitogenic response to ET-1, which seemed to be related to the enhanced expression of phospho-p44/42 MAPK.

Animals↗

PubMed1999

Inhibition of platelet aggregation by bovine endocardial apyrase.

AIM: To study the anti-aggregatory effect of bovine endocardial endothelial cell (EEC)-associated apyrase. METHODS: Cultured bovine EEC was used. Adenosine diphosphate (ADP) was analyzed by reversed phase HPLC, and rabbit platelet aggregation was measured turbimetrically. RESULTS: Incubation of EEC with ADP 500 mumol.L-1 resulted in a progressive decrease in ADP concentration, which was paralleled by the decrease in platelet aggregating potential of the unmetabolized ADP. In the presence of aspirin (Asp 1 mmol.L-1)-treated EEC 1 x 10(9) cells.L-1, the aggregation of Asp (1 mmol.L-1) and methylene blue (10 mumol.L-1)-treated platelets in response to thrombin 500 U.L-1 and platelet activating factor (PAF 1 nmol.L-1) was markedly inhibited and was reversible, which was very similar to that in apyrase-treated platelets. The supernatants of EEC had no effect on platelet aggregation. EEC inhibited ADP (5 mumol.L-1)-induced platelet aggregation, but failed to inhibit adenosine 5'-O-(2-thiodiphosphate) (ADP-beta-S, an unmetabolizable structural analog of ADP, 15 mumol.L-1)-induced platelet aggregation. CONCLUSION: ADP hydrolysis by EEC-associated apyrase is a major anti-thrombotic mechanism of bovine EEC.

Adenosine Diphosphate↗

PubMed1999

[The use of reverse fasciocutaneous pedicle flap in repairing electrical burn wound on extremity].

OBJECTIVE: This is to introduce a method for reconstruction of extremities with electrical injury. METHODS: Thirty-six reverse fasciocutaneous pedicle flaps were designed to be used for the reconstruction of extremities with electrical injury in 20 patients. The size of the flaps ranged from 5 cm x 3 cm to 18 cm x 8 cm. The length and width of the pedicle ranged 3-6 cm and 1.5-4 cm. The ratio of the length to width of the flap ranged from 1.6:1 to 4.5:1. All flaps had been successfully transplanted with 180 degrees rotation. RESULTS: All flaps survived, except individual flaps showing mild swelling and disperse blisters. CONCLUSION: Satisfactory results both in functional and cosmetic aspects had been achieved with this kind of flap after followed-up for over one year.

Adolescent↗

PubMed1999

[WT1 gene expression in leukemia patients and its correlation with prognosis and multidrug resistance].

OBJECTIVE: To evaluate the value of expression of WT1 gene in predicting the prognosis of leukemia patients, and explore the relationship between WT1 gene expression and multidrug resistance and cell apoptosis. METHODS: Expressions of WT1, MRP and mdr1 were measured in 68 leukemia patients by RT-PCR method. Expression of bcl-2 was measured in 32 AML patients by immunofluorescence flow cytometry. RESULTS: Expression of WT1 was revealed in 36 of 68 leukemia patients and none of 23 normal controls. Complete remission rate (59.46%) was lower in WT1 positive patients than that (87.10%, P = 0.011) in WT1 negative patients. The rate of MRP expression was also higher in patients with WT1 expression (58.33%), than in those without WT1 expression (32.26%, P = 0.033). Thirty-two AML patients were divided into high-, intermediate-, and low-risk groups according to the expression of WT1 and bcl-2. CR rates were significantly different among these 3 groups (33.33% for high-, 47.37% for intermediate-, and 100% for low-risk group, P < 0.05). CONCLUSION: The expression of WT1 can predict the treatment outcome and the prognosis for leukemia patients. Expression of WT1 is the most important risk factor, and the coexpression of WT1 and bcl-2 predicts poor prognosis of AML patients.

Adult↗

PubMed1999

Indepth exploration on history of Qing doctors traveling to Japan.

During the one hundred years and more from the beginning of the 18th century to the beginning of the 19th century, about 16 Chinese doctors, at the invitation of Japanese, went to Japan successively by trade ships to practice medicine and teach Chinese medicine. They also conducted academic exchanges with Japanese doctors. Because both the Japanese authorities of that time and the emperor of Qing dynasty implemented the policy of closing the country, they could only do things in certain areas within limited time. By consulting a vast amount of data and following the footprints of some of the Chinese doctors in Japan, the author has got things into shape about the comings and goings of the doctors who went to Japan during the century and their activities, with the stressed point laid on the achievements of such influential doctors as Zhu Laizhang, Zhu Zizhang, Zhou Qilai, Zhao Songyang, Li Renshan, Hu Zhaoxin and so on.

China↗

PubMed1999

[Studies of microsatellite instability and loss of heterozygosity at chromosome 17 in non-small cell lung carcinoma].

OBJECTIVE: To identify the presence of microsatellite instability (MI) and loss of heterozygosity (LOH) in non-small cell lung carcinoma (NSCLC). METHODS: Four microsatellite markers TP53(17p13.1), THRA1 (17q11.2-12), D17S579(17q12-21) and D17S855(17q21) were used to examine 35 cases of NSCLC tumor-normal paired tissues for MI and LOH at chromosome 17 using PCR based analysis. RESULTS: 22 of 35 tumors(63%) displayed MI or LOH. 14 tumors(40%) exhibited MI, 11 tumors(31%) exhibited LOH, while 3 tumors (9%) exhibited MI and LOH concurrently. The frequency of MI or LOH was obviously higher in the early-stage(stages I and II, 79%) than in the advanced-stage (stage III, 44%), P < 0.05. However, the frequency of MI or LOH had no significant difference between high-grade differentiated NSCLC tumors and low-grade ones, P > 0.05. No relationship was observed between the presence of MI or LOH and the histologic subtype of NSCLC, P > 0.05. CONCLUSIONS: The results suggest that MI and LOH at chromosome 17 may play a significant role in the development of NSCLC. The high frequency of MI or LOH in the early-stage tumors indicates that these genetic alterations could occur early during NSCLC development.

Carcinoma, Non-Small-Cell Lung↗

PubMed1999

[Investigation of the diplopia after intraocular lens implantation].

OBJECTIVE: To investigate the pathogenesis, mechanism and prognosis of diplopia after cataract extraction with intraocular lens implantation (IOL). METHODS: Besides routine ocular examinations, refraction, ocular position, ocular movement, fusional function and image of diplopia were examined on all the patients. Forced duction was examined on partial patients. RESULTS: Among 24 cases with diplopia after IOL implantation, there were 19 cases of binocular diplopia and 5 cases of monocular diplopia. Of the binocular diplopia, there were 17 cases of strabismic diplopia and 2 cases of diplopia due to central fusional impairment. Of the cases with monocular diplopia, there were 4 cases resulted from operative complication and one case with congenital iridocoloboma. CONCLUSIONS: The pathogenesis of strabismic diplopia resulted from dysfunction of ocular movement is unknown. Most of the patients can obtain binocular vision by early active treatment. Monocular diplopia is partly resulted from operative complication.

Adult↗

PubMed1999

Increased phosphorylation of DARPP-32 by D1 agonistic action of l-stepholidine in the 6-OHDA-lesioned rat striatum.

In order to explore the characteristics of l-stepholidine (SPD) activating the postsynaptic D(1) receptors, the effects of SPD on DARPP-32 phosphorylation in vivo with back-phosphorylation assay and on the postsynaptic D(1) receptor densities with radioligand assay were observed in the striatum of 6-OHDA-lesioned rat. The results showed that following subcutaneously administration of 20 or 40 mg/kg SPD for 21 d, (32)P phosphate incorporation into the DARPP-32 protein in the denervated striatum showed a 50% reduction (P<0.01) vs the intact striatum, indicating an increase of DARPP-32 phosphorylation in vivo in the denervated striatum. However,the D(1) receptor B(max) was decreased from 385.0+/-26.1 to 319.7+/-20.1 fmol/mg protein. It is suggested that D(1) agonist action of SPD decreases the D(1) receptor density but increases the phosphorylation of DARPP-32 in the striatum of 6-OHDA-lesioned rat, which may be responsible for the regulation of D(1) receptor signal transduction in brain neurons.

Animals↗