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Biomedical subjects

C Qiu

Publications and source records attributed to C Qiu.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Extensive HLA class II studies in Chinese narcoleptic patients].

OBJECTIVE: Narcolepsy is a debilitating, lifelong sleep disorder. Its familial occurrence suggests that genetic factors may be of importance in the etiology. Narcolepsy is a very rare disease among Chinese, thus it was of interest to study the association of narcolepsy with the HLA system in Chinese narcoleptic patients. METHODS: To explore the role of HLA-DRB genes in the development of narcolepsy, we studied 10 narcoleptic patients and 50 race matched controls in whom HLA-DR typing was performed by the method of DNA amplification with sequence-specific primers (PCR-SSP). RESULTS: All narcoleptic patients were found to be of DRB1 * 1501 and DRB5 * 0101 genotype. CONCLUSION: These results indicate that HLA-DRB1 * 1501 is a better primary candidate susceptibility gene for narcolepsy in Chinese.

Adult↗
PubMed1999

[Association of HLA-DQA1 and DQB1 alleles with Vogt-Koyanagi-Harada syndrome in Han Chinese population].

OBJECTIVE: To access the association of HLA-DQA1 and -DQB1 alleles with Vogt-Koyanagi-Harada syndrome (VKH). METHODS: The alleles in DQA1 and DQB1 loci of patients with VKH matched with 50 healthy controls were subtyped by polymerase chain reaction-sequence specific primer (PCR-SSP) and PCR-restriction fragment length polymorphism (PCR-RFLP). RESULTS: DQA1 * 0301 and DQB1 * 0401 alleles were in close association with VKH syndrome, as compared to the controls (Pc < 10(-7)), with the relative risk (RR) 16.47 and 88.00, respectively. The frequency of DQA1 * 0301-DQB1 * 0401 haplotype in patients with VKH was also significantly higher than that in healthy controls (78.6%, 4.0%, Pc < 10(-7), RR = 88.00). Among the 15 patients who were negative for the haplotype of DQA1 * 0301-DQB1 * 0401, 7 of them were found to be positive for DRB1 * 15-DQA1 * 0102-DQB1 * 0602/3 haplotype, with the frequency significantly higher than that in the controls (46.7%, 12.5%, Pc = 0.01, RR = 6.13). However, DQA1 * 0103-DQB1 * 0601 was the only one of the DQA1-DQB1 haplotypes with a significantly lower frequency in patients with VKH in comparison with that in the controls (2.9%, 24%, Pc = 0.001, RR = 0.09). The susceptible haplotype was not related to the clinical features. CONCLUSIONS: The results suggest that DQA1 * 0301-DQB1 * 0401 and DRB1 * 15-DQA1 * 0102-DQB1 * 0602/3 be associated with the susceptibility in VKH. On the other hand, DQA1 * 0103-DQB1 * 0601 may play a role in resisting against VKH syndrome.

Adolescent↗
PubMed1999

[A study on relationship between hypertension and polymorphism of ACE gene in male Yi people in Liangshan Yi autonomous prefecture, Sichuan].

OBJECTIVE: To explore relationship between polymorphism of ACE gene and hypertension. METHODS: A cross-sectional study was conducted and PCR technique was used to analyze gene polymorphism. RESULTS: Genotypes DD, ID and II of ACE gene accounted for 13.0% and 9.7%, 50.9% and 48.4%, and 36.1% and 41.9%, respectively, in the normotensives and hypertensives. Frequencies of I and D alleles for ACE gene were 61.6% and 66.1%, and 38.4% and 33.9%, respectively, in the normotensives and hypertensives. There was no significant difference in distribution of II, ID and DD genotypes and I/D allele frequencies of ACE gene between the hypertensives and normotensives in male Yi people. CONCLUSION: Association between polymorphism of ACE gene and hypertension was uncertain.

Adult↗
PubMed1999

[Nucleotide sequence at position -155 to +25 of the 5' flanking region of the angiotensinogen gene of Han people].

OBJECTIVE: To study the polymorphism of 5'-flanking region of angiotensinogen gene and relations to essential hyperfension. METHODS: The nucleotide sequence at position -155 to +25 of the 5'-flanking region in angiotensinogen gene of Han people in Chinese population was identified by applying PCR-single stranded conformational polymorphism(SSCP) and PCR-directed sequencing. RESULTS: (1) The Han people carry an adenylate(A), instead of a cytidylate(C) at position -20 of the 5'-flanking region of AGT gene; (2) A new mutation T-->A at position -46 was detected and A-allele frequencies was similar in both hypertensives and normotensive controls. CONCLUSIONS: The variant T-->A at position -46 of AGT gene was not associated with hypertension, but an adenylate (A) at position -20 of the 5'-flanking region of AGT gene. might be an genetic marker for Hans people.

5' Flanking Region↗
PubMed1998

Cationic liposomes enhance adenovirus entry via a pathway independent of the fiber receptor and alpha(v)-integrins.

The ability of adenoviral vectors to mediate efficient gene delivery both in vitro and in vivo is limited by the availability of specific cell surface receptors and alpha(v)-containing integrins. We tested whether this limitation could be overcome by enhancing viral entry with cationic liposomes. In cultured vascular smooth muscle cells, delivery of adenoviral vectors in the presence of cationic liposomes increased vector-encoded transgene expression up to 20-fold. The increase in transgene expression was associated with the formation of adenovirus-lipid aggregates and an increase in the amount of vector DNA in the cells, suggesting that enhanced viral entry was responsible for the increase in gene expression. Treatment of the cells with an RGD-containing peptide or adenovirus type 5 fiber protein did not diminish liposome enhancement of transgene expression, indicating that liposomes increase viral entry via a pathway independent of the fiber receptor and of alpha(v) integrin-assisted endocytosis. Liposomes also significantly enhanced transgene expression from adenoviral vectors delivered to cells deficient in alpha(v)-containing integrins. The magnitude of liposome enhancement of transgene expression in cultured smooth muscle cells was greatest during brief periods of virus-cell contact and at low concentrations of virus. Despite these promising in vitro results, addition of liposomes did not improve in vivo adenoviral gene delivery into injured rat carotid arteries. Liposomes can improve adenoviral gene delivery in vitro; however, application of this observation to accomplish improved in vivo gene delivery remains a challenge.

Adenoviridae↗
PubMed1998

Evolution of chronic nitric oxide inhibition hypertension: relationship to renal function.

We conducted longitudinal measurements of blood pressure and renal function in the conscious, chronically catheterized rat before and during acute nitric oxide synthase inhibition (N-nitro-L-arginine methylester [L-NAME], 37 micromol/kg IV) and then chronic administration of oral L-NAME (approximately 37 micromol/kg per 24 hours). These studies specifically investigate the impact on plasma and renal renin as well as volume status during the evolution of this hypertension in rats not subjected to acute experimental stress. Blood pressure progressively increased with chronic administration of L-NAME and reached values greatly above those seen with acute administration of L-NAME. There were parallel increases in renal vascular resistance and development of proteinuria, and glomerular filtration rate began to decline at day 21, coincident with the appearance of renal damage. Twenty-four-hour urinary nitrite and nitrate excretion remained depressed, reflecting reduced nitric oxide synthesis. The plasma renin activity was variable and only increased transiently at 21 days, thus the angiotensin II dependence of this hypertension is not caused by stimulated plasma renin activity. Despite severe hypertension, sodium intake and excretion were unchanged over the 21 days of L-NAME administration. Plasma volume was significantly reduced at days 2 and 12 of L-NAME administration; thus the prolonged plasma volume contraction must result from the acute natriuretic response to the initial acute L-NAME administration.

Animals↗
PubMed1998

HLA-DRB1 genes in 5 rheumatic disease multi-case families.

OBJECTIVE: To detect HLA-DRB1 (DR1-10) alleles in 5 families with multi-case rheumatic diseases, and to study the possible influence of DRB1 genes in the pathogenesis of rheumatic diseases. METHODS: Sequence-Specific Primer PCR (PCR-SSP) method was used to examine HLA-DRB1 alleles. Totally 36 members of 5 families and 166 healthy people were involved in this study. The results were assessed by Chi-square test. RESULTS: The HLA-DRB1 allele frequency in the patients and their relatives was similar. No significant difference was found. But DR4 allele frequency in the patients (90.9%) and their relatives (68%) was much higher than that in normal controls (16.8%) and the difference was statistically significant (P < 0.0001). In family 4, two RA patients have different DRB1 alleles, while in family 5, two patients have the same DRB1 alleles, one developed SLE and the other developed RA. CONCLUSIONS: DR4 is closely related to rheumatoid arthritis. The nelatives of RA patients may be at greater risk to develop RA than individuals without family history. Some patients had the same DRB1 allele but developed different rheumatic diseases. This suggested that there might be some common pathways in genetic predisposing of rheumatic diseases. On the other hand, only a few patients with the same DRB1 allele developed rheumatic diseases during their life, so other factors besides DRB1 gene might also be involved in the pathogenesis of rheumatic diseases.

Adolescent↗
PubMed1998

[HLA-DRB alleles polymorphism in susceptibility to asthma in Beijing Chinese].

OBJECTIVES: To investigate whether susceptibility or resistance to asthma associated with HLA-DRB alleles and analyze the relationship between HLA-DRB genes and clinical phenotype of asthma (TIgE, sIgE, BHR). METHODS: Using PCR-SSP(sequence-specific primer polymerase chain reaction), we tested the frequency distribution of HLA-DRB alleles in 50 asthmatic patients and 80 healthy volunteers from Beijing China. All patients had their serum TIgE, IgE antibody specific to house dust mite measured by RAST, bronchial responsiveness assessed by methacholine bronch-provocation (if FEV1% > or = 70%), and broncho-dilation measurement by inhaling salbutamol. RESULTS: There was significantly increased gene frequency of alleles DR6(13), DR52 in asthmatics compared with normal controls (17% vs 4.3%, P < 0.01; 50% vs 17.5%, P < 0.01), and RR was 7.55 and 4.7 respectively. The frequency of DR2(15), DR51 was lower in asthmatics than in controls (7% vs 18% P < 0.01; 2% vs 33.8% P < 0.01). The percentage of HLA haplotype DR6(13)-DR52 was higher in asthmatics than in healthy volunteers (20% vs 4%, P < 0.01, RR 6.4). 70% of individuals sharing DR6(13) gene and 56% of subjects carrying DR52 gene had elevated serum d1 sIgE antibody (> or = +4). There was no relationship between HLA-DRB alleles and total IgE, BHR. CONCLUSIONS: Alleles DR6(13), DR52 are significantly implicated in their susceptibility to asthma, at least they may be closely associated with this disorder. Conversely DR2(15), DR51 alleles might confer protection against asthma. Positive associations between DR6(13), DR52 and IgE response to d1 allergen are noted. HLA-DRB genes are particularly involved in regulating human atopic immune response.

Adult↗
PubMed1998

[Angiotension I converting enzyme gene polymorphism in Chinese patients with obstructive sleep apnea syndrome].

OBJECTIVE: To investigate the relationship of an insertion/deletion (I/D) polymorphism of the angiotension-converting enzyme (ACE) gene to obstructive sleep apnea syndrome (OSAS). METHOD: Genomic DNA was extracted from blood samples and amplified by polymerase chain reaction (PCR). PCR primers were flanking the polymorphic region in intron 16 of the ACE gene. RESULT: The distribution of the DD, ID, and II ACE genotypes was 16%, 52%, and 32% in the control subjects and 0%, 56%, and 44% in OSAS patients, respectively. The estimated frequencies of the insertion allele and the deletion allele were 58%, 42% in the control subjects and 72%, 28% in OSAS patients, respectively. The differences were statistically significant(P < 0.05). The OSAS patients with I/I genotype had significantly longer apnea time (P < 0.05), lower minimum SaO2(P < 0.05) and more severe AHI (P < 0.05) than did the OSAS patients with I/D genotype. CONCLUSION: These results indicate that the II genotype and I allele might be a risk factor for OSAS in Chinese.

Alleles↗
PubMed1998

[Deletion polymorphism in the angiotensin converting enzyme gene associated with essential hypertension in Hans Chinese population].

OBJECTIVE: To investigate whether the polymorphism of the angiotensin-converting enzyme(ACE) gene is associated with essential hypertension in Chinese. METHODS: A case-control study was carried out using 134 hypertensive (HT) and 165 normotensive (NT) subjects. The insertion/deletion (I/D) polymorphism of ACE gene was detected by polymerase chain reaction (PCR). RESULTS: The difference of genotype and derived allele frequencies for deletion of ACE gene between hypertensive and normotensive subjects were statistically significant(i.e. 51.9% vs 15.7 and 0.69 vs 0.31 for hypertensive and normotensive respectively, P < 0.05). CONCLUSIONS: The possession of D/D homozygote genotype of the ACE gene might be a marker for genetic susceptibility to Hans hypertension in Chinese.

Adult↗
PubMed1997

Sensitivity of the segmental renal arterioles to angiotensin II in the aging rat.

With advancing age the old rat kidney becomes tonically vasoconstricted by endogenous angiotensin II (ANGII) (C. Baylis. Am. J. Kid. Dis., (1993) 842). The present study was designed to investigate the sensitivity of the cortical glomerular microvasculature of the old rat kidney (19-22 months of age) to exogenous ANGII, using the in vivo micropuncture technique. In the baseline state, glomerular blood pressure (P(GC)) in old male rate was higher compared to young rats (4-5 months of age). During exogenous ANGII infusion (40 ng/kg/min), a significant rise in arterial blood pressure and renal vasoconstriction occurred in both young and old rats. In young rats, the ANGII induced fall in renal plasma flow (RPF) and glomerular plasma flow (QA) was accompanied by a rise in PGC and thus the glomerular hydrostatic pressure gradient, with little change in Kf. Therefore, the glomerular filtration rate (GFR) and single nephron GFR (SNGFR) were unchanged by ANGII infusion in young rate. In old rats, RPF and QA fell, a rise occurred in PGC and also a fall was seen in the glomerular capillary ultrafiltration coefficient (Kf), thus GFR and SNGFR fell significantly. The magnitude of the pressor and renal vasoconstriction response to ANGII were not affected by age; of interest, ANGII increased preglomerular and efferent arteriolar resistance (RA, RE) and PGC by similar accounts in young and old rats. SNGFR was reduced in old rats, due to the marked ANGII-induced decline in Kf. Neither absolute nor fractional proximal reabsorbtion were affected by ANGII infusion in either young or old rats. by 19-22 months of age, old rats had much more injured glomeruli than young rats. These data demonstrate that the afferent and efferent arterioles had similar sensitivity to exogenous pressor dose of ANGII in both young and old rats, but Kf was more sensitive to ANGII in old rats leading to a significant fall in SNGFR.

Aging↗
PubMed1997

Gestational diabetes: should it be added to the syndrome of insulin resistance?

OBJECTIVE: The significance of gestational diabetes mellitus (GDM) results from its short-term detrimental effects on the fetus and its long-term prediction of NIDDM in the mother. We compared several variables associated with insulin resistance between GDM and non-GDM pregnant women to show the similarities between GDM and NIDDM (and thus insulin resistance). RESEARCH DESIGN AND METHODS: On the basis of a 3-h oral glucose tolerance test (OGTT), 52 GDM patients and 127 non-GDM patients were recruited from pregnant, non-diabetic women who had a nonfasting 1-h-50-g glucose screening test > or = 7.2 mmol/l (130 mg/dl) performed between 16 and 33 weeks of gestation (a total of 518 of 3,041 women drawn from six community health care prenatal clinics were screened positive). During the OGTT, several potential markers of insulin resistance were measured at fasting and 2-h time points, in addition to the standard glucose measurements. The relationship of these variables with the diagnosis of GDM was studied. RESULTS: GDM patients, compared with non-GDM patients, had 1) higher prepregnancy weight (P = 0.011), prepregnancy BMI (P = 0.006), C-peptide at fasting (P = 0.002) and at 2 h (P < 0.001), insulin at fasting (P = 0.001) and at 2 h (P < 0.001), triglycerides at fasting (P = 0.005) and at 2 h (P = 0.003), free fatty acids at fasting (P = 0.017), beta-hydroxybutyrate at fasting (P = 0.007); and 2) lower HDL cholesterol at fasting (P = 0.029). These variables were all predictive of GDM (P < 0.036) individually. Using stepwise logistic regression with all of these variables available, fasting (P = 0.019) and 2-h (P < 0.001) insulin levels, fasting free fatty acids (P = 0.031), and fasting beta-hydroxybutyrate (P = 0.036) were statistically significant as jointly predictive of GDM. Comparisons between GDM patients and non-GDM patients matched by BMI confirmed that the metabolic abnormalities persisted when difference in BMI was taken into account. Concomitant blood pressure measurements in women with GDM did not differ significantly from those without GDM. CONCLUSIONS: Our results show that many of the known metabolic components of the syndrome of insulin resistance (syndrome X) are predictive of GDM. These results are in keeping with the argument that GDM is one phase of the syndrome of insulin resistance. We suggest that GDM be looked upon as a component of the syndrome of insulin resistance that provides an excellent model for the study and prevention of NIDDM in a relatively young age-group.

Adolescent↗
PubMed1997

Same eyes, different doctors: differences in primary care physician referrals for diabetic retinopathy screening.

OBJECTIVE: To analyze eye care specialist referral patterns for the diabetic patients of primary care physicians. RESEARCH DESIGN AND METHODS: In 1993, we conducted a census of primary care physicians to evaluate practice patterns relating to diabetes care in the state of Indiana. Using a logistic regression model and data from this census, we compared 1) physicians' odds of referring type II diabetic patients to an optometrist, as opposed to an ophthalmologist, with those of type I diabetic patients and 2) the referral odds ratios of type II to type I diabetic patients between metropolitan and nonmetropolitan counties. RESULTS: Overall, 10% of the physicians in our study most often refer some patients to an optometrist. Physicians are more likely to refer their type II diabetic patients to an optometrist, as opposed to an ophthalmologist, than they are to refer type I diabetic patients, both before and after adjustment for covariates. Physicians who practice in metropolitan counties are 1.55 times more likely to refer their type II diabetic patients than their type I diabetic patients to an optometrist. In nonmetropolitan counties, physicians are 2.5 times more likely to refer their type II diabetic patients to an optometrist. The difference between metropolitan and nonmetropolitan physicians is significant (P = 0.027). CONCLUSIONS: Some physicians mostly refer their diabetic patients to optometrists, instead of ophthalmologists, for eye examinations intended to discover early signs of diabetic eye disease. Type II diabetic patients are more likely to be referred to an optometrist, instead of an ophthalmologist, than are type I diabetic patients. In nonmetropolitan areas, the difference in referral patterns becomes even more marked.

Censuses↗
PubMed1997

[Study on the relationship between primary Sjögren syndrome and HLA-DRbeta gene].

The pathogenesis of primary Sjögren syndrome (PSS) is unclear yet. In order to investigate the role of genetic factor playing in the mechanism of this disorder, we studied the HLA-DR beta gene distributed in 70 patients with PSS and 136 normal subjects by using PCR-SSP technique. The results showed that the gene frequences of HLA-DR3, DR52 and DR2 in patients with PSS were significantly higher than that in normal controls. However, the gene frequencies of HLA-DR5 and DR9 in PSS patients were lower than that in the control group. There were the same genetic phenomena in the siblings of two PSS patients' families. We also found the relationship between HLA-DR52 and the anti-antibodies of SSA or SSB. Our results concluded that the genetic factor is involved in the pathogenesis of primary Sjögren syndrome.

Adult↗
PubMed1997

[Sequence of HLA-DQA1 promoter region in the Han people].

Polymorphism of HLA-DQA1 promoter region (QAP) in the Han people has been identified. The results revealed a number of differences, some of which are in the critical class II boxes, and generally conserved in HLA-DQA1 promoter region. The major differences occurred in the X box, Y box and S box. Within the X box, the Hans carry a A at position -111, instead of a G, and a G or a A can be present at position -98. Within the S box, the Hans carry a G at position -131. Within the Y box, position -71 is a A rather than a G. Some single base substitutions have been detected from IDDM patients at the 5'-flanking region of the S box and between X box and Y box. Particularly, the insertion of CCA bases has been identified at the position between -157 and -158 in a IDDM patient. These data suggest that the polymorphism of HLA-DQA1 promoter region may play a role in susceptibility to IDDM.

Adult↗
PubMed1997

[Study on the association of HLA-DR4 with IDDM susceptibility in a Chinese population].

HLA-DR4 and its subtypes were studied by PCP/SSP, PCR/SSOP, and PCR/RFLP methods in 81 patients with IDDM and 106 normal controls in the Han's nationality Chinese population. The results showed no difference in frequencies of DR4 between the IDDM group and the controls (21.0% vs 17.9%), but DRB1*0405, as a subtype Dw15, was significantly associated with IDDM susceptibility (58.8% vs 21.1%, RR = 2.67, P < 0.05). In a family with 2 IDDM patients, it has been found the haplotype DRB1*0405-DQB1*0302 was to be cosegregated with IDDM. It was suggested that DW15 subtype might be associated with IDDM in Chinese because of linkage disequilibrium with DQw8 (DQB1*0302). As an additional evidence, the findings above mentioned may account for the different association of different DR4 subtypes with IDDM in various ethnic groups.

Adolescent↗