Biomedical subjects

Q Cao

Publications and source records attributed to Q Cao.

At least 55 records · Page 3Linked to original sources

PubMed1999

Follow-up study on a susceptibility locus for schizophrenia on chromosome 6q.

Evidence for suggestive linkage to schizophrenia with chromosome 6q markers was previously reported from a two-stage approach. Using nonparametric affected sib pairs (ASP) methods, nominal p-values of 0.00018 and 0.00095 were obtained in the screening (81 ASPs; 63 independent) and the replication (109 ASPs; 87 independent) data sets, respectively. Here, we report a follow-up study of this 50cM 6q region using 12 microsatellite markers to test for linkage to schizophrenia. We increased the replication sample size by adding an independent sample of 43 multiplex pedigrees (66 ASPs; 54 independent). Pairwise and multipoint nonparametric linkage analyses conducted in this third data set showed evidence consistent with excess sharing in this 6q region, though the statistical level is weaker (p=0.013). When combining both replication data sets (total of 141 independent ASPs), an overall nominal p-value=0.000014 (LOD=3. 82) was obtained. The sibling recurrence risk (lambdas) attributed to this putative 6q susceptibility locus is estimated to be 1.92. The linkage region could not be narrowed down since LOD score values greater than three were observed within a 13cM region. The length of this region was only slightly reduced (12cM) when using the total sample of independent ASPs (204) obtained from all three data sets. This suggests that very large sample sizes may be needed to narrow down this region by ASP linkage methods. Study of the etiological candidate genes in this region is ongoing.

Chromosomes, Human, Pair 6↗

PubMed1999

Chromosomal aberrations during progression of chronic myeloid leukemia identified by cytogenetic and molecular cytogenetic tools: implication of 1q12-21.

To study the genomic abnormality underlying the acute transformation of chronic myeloid leukemia (CML), 15 CML patients in blast crisis (BC), 3 in accelerated phase (AP), and 20 in chronic phase (CP) were analyzed by conventional cytogenetics, comparative genomic hybridization (CGH), and dual-color chromosomal painting. Philadelphia (Ph) chromosome was identified in every case studied. Only 5 among 20 CP patients had additional abnormalities while 13 of 18 patients with disease progression (BC + AP) showed extra numerical and/or structural chromosomal aberrations. Cytogenetically, the most common chromosome gains during BC and AP were double or triple Ph chromosomes (5 of 14 cases) and trisomy 8 (5 of 14 cases). Trisomies 7 and 17 (1 of 14 cases each) were also observed. CGH analysis detected genetic imbalances in eight cases. Gains of chromosome 20 (3 cases) and 17q (2 cases) were observed, respectively. The recurrent chromosome loss was the deletion of the short arm of chromosome 17, seen in one case with i(17)(q10) and one case with an unbalanced translocation (1;17). In one case, a very complex chromosomal rearrangement, del(3),del(6),der(6)t(17;3;6),der(17)t(6;17), was seen. A novel finding of this work is the involvement of chromosome 1(q12-21qter) in CML disease progression. Overrepresentation of 1(q12-21qter) region was detected by CGH in one case which had a derivative chromosome 17. This abnormal chromosome was later confirmed by fluorescence in situ hybridization (FISH) painting to be a fusion between chromosome 1 and 17 to form the der(17)t(1;17) (q12-21;p11). Two other cases showed the same region being involved in translocations, t(1;10)(q12-21;q26) and t(1;11)(q12-21;p15). It is possible that one or more genes residing on chromosome 1q12-21 may be important in the acute transformation of CML. In conclusion, we find that the combined use of CGH, chromosome painting, and classic cytogenetic analysis allows a better evaluation of the genomic aberration involved in CML blastic transformation, and offers new directions for its further molecular investigations.

Adult↗

PubMed1999

Maskin is a CPEB-associated factor that transiently interacts with elF-4E.

In Xenopus, the CPE is a bifunctional 3' UTR sequence that maintains maternal mRNA in a dormant state in oocytes and activates polyadenylation-induced translation during oocyte maturation. Here, we report that CPEB, which binds the CPE and stimulates polyadenylation, interacts with a new factor we term maskin. Maskin contains a peptide sequence that is conserved among elF-4E-binding proteins. Affinity chromatography demonstrates that CPEB, maskin, and elF-4E reside in a complex in oocytes, and yeast two-hybrid analyses indicate that CPEB and maskin bind directly, as do maskin and elF-4E. While CPEB and maskin remain together during oocyte maturation, the maskin-elF-4E interaction is substantially reduced. The dissolution of this complex may result in the binding of elF-4E to elF-4G and the translational activation of CPE-containing mRNAs.

3' Untranslated Regions↗

PubMed1999

Roles of glycoproteins and oligosaccharides found in human vaginal fluid in bacterial adherence.

Adherence of type 1-piliated Escherichia coli to carbohydrate structures of vaginal mucosa plays a major role in the pathogenesis of ascending urinary tract infections in women. Colonization of the vaginal introitus is influenced by interactions between pathogens, vaginal fluid, and vaginal epithelium. In this study, the type and amount of carbohydrates and glycoproteins present in vaginal fluid were determined. Free and protein-bound oligosaccharides in vaginal fluid specimens were analyzed by fluorophore-assisted carbohydrate electrophoresis (FACE) and high-pressure liquid chromatography (HPLC). Two-dimensional electrophoretic separations of vaginal fluid glycoproteins were performed together with bacterial overlay assays. The results of FACE showed that the majority of the oligosaccharides are in the free state and the bound oligosaccharides are undetectable. HPLC analysis of free sugars revealed glucose as the major sugar (3.3 +/- 0.3 mM), and the concentrations of mannose and glucosamine were 0.065 +/- 0.04 and 0.02 +/- 0.001 mM, respectively. Radiolabeled E. coli bound three vaginal fluid glycoproteins with the following molecular masses and pIs: 82 kDa and pI 5.5, 55 kDa and pI 4.5, and 55 kDa and pI 6.5. The binding was inhibited by mannose and by deglycosylation of the proteins prior to the overlay assay. One of these putative receptors was identified to be the heavy chain of secretory IgA (S-IgA). These data suggest that the free mannose in the fluid is less than that required to affect E. coli-epithelial cell binding interactions and that S-IgA may bind E. coli in the vaginal introitus.

Adult↗

PubMed1999

Alcoholic hepatitis as a T-cell mediated disorder: an hypothesis.

BACKGROUND: The mechanism by which alcohol induces alcoholic hepatitis, the precursor lesion for cirrhosis, has never been elucidated. In particular, direct toxicity has not been proven. This article reviews the hypothesis that a primary target of chronic alcohol ingestion is the T lymphocyte. The lesion in the T lymphocyte is characterized by reduced baseline secretion of cytokines, including tumor necrosis factor-alpha; although characterized by an exaggerated release of cytokines when stimulated by polyclonal activators such as endotoxin. High concentrations of cytokines, especially tumor necrosis factor-alpha, within the liver induce necrosis/apoptosis of hepatocytes. METHODS: Data supporting this hypothesis in rodent models are reviewed. CONCLUSION: A strategic approach for testing this concept in man is defined.

Animals↗

PubMed1999

Ethanol-altered liver-associated T cells mediate liver injury in rats administered Concanavalin A (Con A) or lipopolysaccharide (LPS).

BACKGROUND: Recent work from our laboratory implicates T cells in the pathogenesis of alcoholic liver disease. We have studied the role of liver-associated T cells in acute hepatitis produced in control rats administered Concanavalin A (Con A) after adoptive transfer of T cells from alcohol-consuming animals. METHODS: Liver-associated T cells from ethanol-consuming rats were transferred via tail vein to nonethanol-consuming rats. They then received Con A (20 mg/kg body weight) intravenously. This produced a severe hepatitis. Serum was collected for the assay of alanine aminotransferase (ALT) and cytokines. RESULTS: Hepatic necrosis was accompanied by an increase in plasma levels of ALT, interleukin-6, and tumor necrosis factor-alpha. These increases correlated with increased production of interleukin-6 and tumor necrosis factor-alpha in culture of liver-associated T cells stimulated or unstimulated with Con A. Immunohistology staining showed increased infiltration of inflammatory cells comprised of neutrophils and mononuclear cells, which included greater numbers of CD4+ T cells in the portal tract areas and around the central vein. Focal and lobular necrosis was seen with inflammatory cells in the necrotic area. Hepatocytes isolated from the liver showed increased apoptosis compared with rats that received liver-associated T cells from nonethanol-consuming rats. Injection of endotoxin LPS, in the same model, was associated with less hepatocyte injury indicating a distinct role for T cells as opposed to Kupffer cells in this model of liver disease. CONCLUSIONS: Chronic ethanol consumption induces a lesion in a pool of liver-associated T cells which can mediate liver injury after polyclonal mitogen activation.

Alanine Transaminase↗

PubMed1999

[Contraceptive efficacy of Sino-female condom: comparison with condom].

OBJECTIVE: To compare the contraceptive efficacy of Sino-female condom with condom. METHODS: 603 volunteer couples were randomly divided into two groups: 304 couples using female condom for contraception, and 299 using condom. Using lifetable method and log rank test, we compared the pregnancy rates and other discontinuation rates after follow-up for 6 months in two groups. RESULTS: No abnormal findings of cervical and vaginal smears were detected before and after this clinical trial in all 603 women. The follow-up rates at 6 months were 99.01% and 99.67% in the female condom group and condom group, respectively. The 6-month gross cumulative pregnancy rates were 1.06 and 1.69 per 100 women and the discontinuation rates due to allergy were 1.39 and 0.34, respectively. No difference was statistically significant (P > 0.05). However, the discontinuation rate for other causes in the female condom group was significantly higher than that in the condom group (P < 0.01). The main cause was that more than half of subjects were used to applying condom before this study. CONCLUSION: The contraceptive efficacy of Sino-female condom is as same as that of condom, and its clinical use is quite safe.

Adult↗

PubMed1999

[Evidence for involvement of NO/NOS-cGMP signal system in morphine dependence].

The present study was undertaken to observe changes in cGMP contents, calcium-dependent and non-calcium-dependent NOS activities in brain regions isolated from morphine-dependent mice as well as the effect of NOS inhibitor (L-NMMA) on the development of this dependence. It was found that (1) cGMP contents in cerebellum, striatum, hippocampus and cerebral cortex were significantly decreased. (2) Calcium-dependent NOS activity was noticeably increased in striatum and cerebral cortex, which was inhibited by PKA inhibitor. No similar changes were found in cerebellum and hippocampus. Changes of non-calcium-dependent NOS activity did not occur in morphine-dependent mice brain. (3) In the striatum and cerebral cortex of morphine-dependent mice, the level of 150 kD protein phosphorylation in vitro was noticeably decreased, which was inhibited by IP20 (PKA inhibitor). (4) NOS inhibitor injected (icv) 15 min prior to daily morphine injection could prevent the development of morphine dependence. (5) All the changes above were not observed in mice treated with naloxone 30 min prior to daily morphine injection. Our data suggest that the reduction of cGMP contents and the increase of calcium-dependent NOS activity in striatum and cerebral cortex isolated from morphine-dependent mice may be mediated by opioid receptors and involved in the development of morphine-dependence. Why the increase of NOS activity was in association with the reduction of cGMP contents remains to be answered and it implies that the effect of NO/NOS involved in morphine-dependence may be produced through other mechanisms other than those producing cGMP signal. NOS phosphorylation in some other brain regions, which may be regulated by PKA, probably contributes to the increase of NOS activity in morphine-dependent mice.

Animals↗

PubMed1999

[Chromosomal abnormalities in 38 CML cases of various phases].

OBJECTIVE: To study the genomic abnormality underlying the blast crisis of chronic myeloid leukemia(CML). METHODS: 15 CML patients in blast crisis (BC), 3 in accelerated phase (AP) and 20 in chronic phase (CP) were analyzed by conventional cytogentics, comparative genomic hybridization (CGH) and dual color chromosomal painting. RESULTS: Philadelphia (Ph) chromosome was identified in every case studied. Only 5 among 20 CP patients had additional abnormalities while 12 out of 14 patients with disease progression (BC + AP) showed extra numerical and/or structural chromosmal aberrations. Cytogenetically, the most common chromosome gains during BC and AP were double or triple Ph chromosome(5/14), trisomy 8(5/14), trisomy 7(1/14) and 17 (1/14). Three cases showed the same region being involved in translocations t(1;17)(q12-21;q10), t(1;10) (q12-21;q26) and t(1;11)(q12-21;p15). CGH analysis detected genetic imbalances in 8 cases. In one case, a very complex chromosmal translocation del(3), del(6)(q13-21), der(6)t(17;3;6), der(17)t(6;17) was characterized by chromosomal painting. CONCLUSION: We find that the combined use of CGH, chromosomal painting, and classic cytogenetic analysis allows a better evaluation of the genomic aberration involved in CML blastic transformation, and offers new directions for its further molecular investigation.

Adult↗

PubMed1999

[Dynamic monitoring of serum soluble HLA class I antigens in renal transplant recipients].

OBJECTIVE: To investigate the relations between serum soluble HLA class I antigens (sHLA-I) and the period of acute rejection and infection in renal transplant recipients. METHODS: We measured the serum levels of sHLA-I in 36 renal transplant recipients with ELISA dynamically. RESULTS: The serum sHAL-I levels were higher in uremia patients than in normal controls [(2.94 +/- 0.34) microg/L vs. (0.76 +/- 0.33) microg/L, P < 0.05]. After renal transplantation, the serum sHLA-I levels decreased significantly in stable patients [(0.63 +/- 0.33) microg/L], but increased significantly 3 days before acute rejection and 5 or 7 days after infection. CONCLUSIONS: The serum sHLA-I levels can be used as a parameter for monitoring acute rejection and infection in renal transplantation.

Adolescent↗

PubMed1999

[Effects of long-term morphine exposure on the cAMP system and c-Fos phosphorylation in differentiated SH-SY5Y cells].

OBJECTIVE: To further understand the effects of long-term morphine exposure on the cAMP system and c-Fos phosphorylation in differentiated SH-SY5Y human neuroblastoma cells. METHODS: Cellular changes of cAMP, PKA and c-Fos were detected by protein competitive conjunction, enzyme activity and isotope incorporation methods respectively. RESULTS: (1) Long-term exposure (2 min-36 h) to morphine (100 mumol/L) could induce the biphasic changes in cAMP contents. Treament for 2 min to 1 h, morphine caused rapid and siginificant decrease of the cAMP level and then gradully recovered and apparently increased at 36 h. At that time, naloxone added to the incubation media caused an overshoot of cellular cAMP; (2) Long-term exposure to morphine could also induce the biphasic changes in cytosolic PKA activity. This is consistent with the changes of cAMP during the chronic treatment of cells with morphine. But no changes were observed in membrane PKA activity; (3) In morphine dependent-like cells decreased c-Fos phosphorylation level was observed. PKA inhibitor could significantly inhibit this change; (4) Concomitant administration of naloxone could block the changes in PKA activity and c-Fos phosphorylation described above. CONCLUSIONS: The up-regulation of cAMP system in differentiated SH-SY5Y cells may be involved in the development of morphine dependent and in morphine dependent-like SH-SY5Y cells and PKA was suggested to regulate c-Fos dephosphorylation through activating phosphatase and then activate some genes transcription, which might be one of the important mechanism regardingas cellular adaptive responses underlying dependence to opioid drugs.

Cyclic AMP↗

PubMed1998

Effects on rapid cooling of small samples in quenching.

Rapid cooling of small samples is necessary both to cryofixation for electron microscopy and to vitrification for cryopreservation. Several effects on the cooling rates of small samples quenched into liquid nitrogen were studied, including the diameter of samples, the subcooling of liquid nitrogen, the quenching speed, and the quenching distance. The heat flux is 1.4 x 10(6) W/m2; the cooling rate is also up to 8200 K/s at the CHF point of boiling curves for sphere of diameter 0.287 mm quenching into subcooled liquid nitrogen. It is also found that if the time of sample moving inside the liquid nitrogen is not longer than the time required for forming stable vapor in the liquid, the quenching boiling heat transfer is not influenced by the quenching speed. Several equation for calculating heat flux of samples are also presented.

Cryopreservation↗

PubMed1998

Detection of chromosome over- and underrepresentations in hyperdiploid acute lymphoblastic leukemia by comparative genomic hybridization.

Chromosomal analysis of acute lymphoblastic leukemia (ALL) is often difficult because of the suboptimal in vitro growth of the immature lymphoid cell and the poor morphology obtained. In this study, we describe the application of comparative genomic hybridization (CGH) to investigate the genomic abnormalities in 14 patients with ALL, all of whom had cytogenetically identified numerical aberrations or gross chromosomal structural alteration. With the use of CGH, regional or whole chromosome overrepresentation or both were found to be more frequent than underrepresentation (52 gains vs. 6 losses), the most common gains being chromosomes 21 and X. The results of the comparison between CGH and conventional R-banding analysis could be classified into three categories: (1) in three cases, including two with trisomy, CGH and banding analysis gave identical results; (2) in six cases with hyperdiploidy and two cases presenting chromosome structural abnormalities, the results were consistent but with minor discrepancies; (3) in three cases, including two with triploidy and tetraploidy and one with chimeric karyotype together with +22, the data from CGH and cytogenetical analysis were discrepant. CGH could not find the triploidy and tetraploidy. Our results suggest that CGH has certain value in the detection of gains or losses of chromosome materials in hyperdiploid ALL. Nevertheless, the combination of CGH and conventional karyotyping provides more precise information on the genomic imbalance in ALL.

Adolescent↗

PubMed1998

The sensitivity of denaturing gradient gel electrophoresis: a blinded analysis.

Denaturing gradient gel electrophoresis (DGGE) is considered one of the most sensitive and specific of the mutational scanning techniques, yet blinded analyses have not been reported. We report the results of a blinded study of the efficiency of DGGE to detect mutations in the Human Coagulation Factor IX. Two overlapping genomic DNA sequences from exon 8 of Factor IX (290 bp and 539 bp length) with an unknown number of mutations were amplified with a 40 bp GC-clamp and tested blindly by DGGE. DGGE detected all mutations in the 290 bp genomic DNA segment. DGGE detected all but one mutation in the 539 bp genomic segment after experimental conditions were fully optimized but missed multiple mutations in an initial blinded experiment. These results demonstrate the utility of blinded analyses and confirm the exquisite power of DGGE for detecting mutations.

DNA↗

PubMed1998

IL-6, IFN-gamma and TNF-alpha production by liver-associated T cells and acute liver injury in rats administered concanavalin A.

The relationship between the development of acute hepatitis and the production of TNF-alpha IFN-gamma and IL-6 by liver-associated T lymphocytes following intravenous injection of concanavalin A (Con A) was studied in rats. Following a single injection of Con A, there was a dose and time-dependent correlation in the serum levels of serum alanine aminotransferase (ALT), IL-6, IFN-gamma and TNF-alpha. These increases correlated with an increase in the numbers of CD4+, CD8+ and CD25+ T cells in blood and CD4+ and CD25+ T cells in the liver perfusate, but not with CD8+ T cells in liver perfusate. Increased levels of IL-6, IFN-gamma and TNF-alpha were constitutively produced by liver-associated CD4+ T cells when cultured. In Con A-stimulated cultures, liver-associated CD4+ T cells secreted increasing levels of TNF-alpha in a time-dependent manner following Con A injection, but TNF-alpha production by peripheral blood lymphocytes was transient with peak levels detected at 1 h which then declined over 24 h. Histological examination of the liver revealed fatty change, hepatocyte degeneration and necrosis, with an associated cell infiltrate of neutrophils and CD4+ T cells both in the portal areas and around the central veins. These results support the hypothesis that Con A-induced liver damage is mediated by CD4+ T cells acting within the liver, at least in part through the secretion of TNF-alpha, IFN-gamma and IL-6.

Alanine Transaminase↗

PubMed1998

Disseminated intravascular coagulation and status epilepticus.

Status epilepticus has been associated with disseminated intravascular coagulation (DIC), but little is known regarding the pathogenesis of this uncommon association. We describe a 41-year-old woman with status epilepticus resulting in death in whom laboratory data demonstrated profound activation of the coagulation and fibrinolytic systems; autopsy findings were consistent with DIC. The occurrence of DIC in status epilepticus may be related to widespread endothelial damage secondary to seizure-induced hyperpyrexia. Body temperature should be closely monitored in patients with prolonged seizures.

Adult↗

PubMed1998

Effects of electroacupuncture at neiguan on myocardial microcirculation in rabbits with acute myocardial ischemia.

This paper reports the effects of electroacupuncture (EA) at Neiguan (P 6) on myocardial microcirculation and electrical activity observed in rabbits with acute myocardial ischemia (AMI) by employing the vascular casting method and taking monophasic action potential (MAP) as an index. It was found that in the ischemic border zone of the heart, the electrical excitability was strengthened, the shortening of the phase repolarization inhibited, and the number of the micrangia increased in some degree following EA. This suggests that EA can relieve arteriolospasm, inhibit extreme dilatation of blood capillaries, modulate imbalance of micro-vasomotion of the coronary artery, improve myocardial blood-supply, and promote normalization of electrical activities of the ischemia myocardium. This fact not only elucidates the recovery mechanism of the ischemic myocardium promoted by EA at Neiguan (P 6), but also provides morphological basis for the theory of relationship between Neiguan of the Pericardium Meridian and the heart.

Action Potentials↗

PubMed1998

[Detection of CBF beta-MYH11 fusion transcript and inv(16)(p13;q22) in acute myelomonocytic leukemia(M4) by RT-PCR and FISH].

OBJECTIVE: To study the clinical significance of inv(16) and CBF beta-MYH11 fusion gene in the diagnosis and prognosis for M4Eo. METHODS: CBF beta-MYH11 fusion transcripts and inv (16) were analyzed by reverse-transcriptase polymerase chain reaction(RT-PCR) and fluorescence in situ hybridization(FISH), respectively, in acute myelomonocytic leukemia(M4) with or without eosinophilia. RESULTS: In fifteen cases tested, one case of M4Eo and one of 9 M4 without eosinophilia were found to have CBF beta-MYH11 fusion transcript. Follow-up of the M4Eo patient showed residual PCR positivity 2 months after complete remission. CONCLUSION: The data suggest that screening by both RT-PCR and FISH should be performed in all AML-M4 regardless of morphologic features to allow accurate diagnosis and prognosis of M4 patients.

Adolescent↗