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Biomedical subjects

H Qiu

Publications and source records attributed to H Qiu.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Low flow technique to perform static pressure-volume curve during mechanical ventilation].

OBJECTIVE: To describe a fast, simple method to acquire static pressure-volume (P-V) curve of the respiratory system and to compare it with airway occlusion technique. METHODS: ARDS sheep model was induced by intravenously infusing 3-6 micrograms/kg LPS, static P-V curves were determined by low flow technique and airway occlusion technique. Static compliance (Cst), lower inflection point (Pinfd and Pinfb) and airway pressure were compared between the two methods. RESULTS: Pinf were (8.91 +/- 0.82) cm H2O and (8.59 +/- 0.78) cm H2O determined by low flow technique and airway occlusion technique respectively, the correlation between which was good (r = 0.93, P < 0.05). Cst determined by low flow technique was similar to that determined by airway occlusion technique [(19 +/- 7) L/cm H2O vs (20 +/- 7) L/cm H2O, P > 0.05]. The time needed to acquire a static P-V curve by low flow technique was 3-4 minutes versus 30-35 minutes by airway occlusion technique. CONCLUSION: Accuracy and reliability of low flow technique are sufficient for clinical use, it is much less time consuming than the airway occlusion technique.

Animals↗
PubMed2001

[Application of posterior canal wall reconstruction and mastoid obliteration].

OBJECTIVE: To explore the obliteration of the old mastoid cavity and reconstruction of the posterior canal wall after radical mastoidectomy. METHOD: Posterior canal wall reconstruction and mastoid obliteration of 11 ears of 10 patients with old mastoid cavity for 1 to 6 years after radical mastoidectomy were done using the pedicle postauricular composite skin flap (PPCSF), and their tympanoplasty were performed at the same time. Follow-up was performed at 3 to 30 months. RESULT: All PPCSFs survived. The old mastoid cavity of 11 ears vanished and reconstructed posterior canal wall remained in normal position without retraction. The drying ear time took 2 to 3 weeks postoperatively, and the symptoms of the radical cavity disease after radical mastoidectomy were cleared up nearly, and the average hearing threshold decreased 13.6 dB HL. The otorrhea and perforation of tympanic membrane resulted from infection happened to 1 of 11 ears three month after the operation. CONCLUSION: The PPCSF is an effective method in the obliteration of old mastoid cavity and reconstruction of the posterior canal wall. It can reduce drying ear time postoperatively, treat the radical cavity disease after radical mastoidectomy and is beneficial to the tympanoplasty at the posterior external at the same time.

Adolescent↗
PubMed2001

[Sequencing of E2 gene and comparison analysis of four strains hog cholera virus (HCV)].

Four cDNA fragments of envelope glycoprotoin E2 gene of SM strain, HCLV strain, F03 strain and F07 strain were amplified respectively with RT-PCR method. The amplified E2 fragments of four HCV strains were all 1273 bp in length by agarose gel electrophoresis. Four E2 fragments were cloned respectively into pGEM-T easy vector. 1273 bp cDNA fragment of Four HCV E2 gene were sequenced and 381 residues amino acid sequence of E2 glycoprotein were deduced. The signal peptide sequence (WLLLVTGA) located in the N-terminal residues 683-690 and the transmenbrane region (TMR) sequence located in the C-terminal residues 1031-1063 of Four E2 gene were highly conserved and hydrophobic region. The conserved sequence among the E2 protein of pestiviruses, RYLASLH which located in the N-terminal residues 753-759 of domains B and C, was hydrophilic, and none of them were variable among the pestiviruses, and the greatest values of antigenic in all E2 antigenic domain. This suggest that the conserved sequence RYLASLH are involved in E2 epitopes. The number and locations of 15 cysteine residues in E2 are conserved among pestiviruses, suggesting that the structure of this glycoprotein is similar in pestiviruses and the first six cysteines are critical for the correct folding of E2 and essential for all identified epitopes. It is showed epitopes. between HCLV strains and field strains are not variable obviously by analysising the varintion of some main amino acid residuse substitutions of E2 major antigenic domains.

Amino Acid Sequence↗
PubMed2001

[Determination of lead and arsenic in copper aspirinate by graphite furnace atomic absorption spectrometry].

A graphite furnace atomic absorption spectrometric method has been established to determine trace lead and arsenic in copper aspirinate, a new anti-inflammatory and anti-thrombotic agent. The sample is pretreated by ashing at 530 degrees C in the presence of Ni (NO3)2, followed by dissolution with HNO3. The method is simple and has a low detection limit. The relative standard deviation is 11%-15%, the recovery is 92%-112% for lead and 86%-119% for arsenic.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Lack of correlation between expression of retinoic acid receptor-beta and loss of heterozygosity on chromosome band 3p24 in esophageal cancer.

Loss of heterozygosity (LOH) on chromosome arm 3p occurs frequently in human cancers, including esophageal cancer, suggesting that tumor suppressor genes may be located on this chromosome arm. The retinoic acid receptor-beta (RARB) gene is localized on chromosome band 3p24, and its expression is progressively lost during esophageal carcinogenesis. Furthermore, growth inhibition of esophageal cancer cell lines by all-trans retinoic acid has been associated with the constitutive and induced expression of RARB. We therefore assessed LOH on chromosome arm 3p and RARB expression in esophageal cancer to investigate the mechanism of altered RARB expression during carcinogenesis. We first analyzed LOH in 65 paired surgical specimens of normal mucosa and esophageal cancer by using 10 microsatellite markers, which resulted in 44 informative cases for subsequent study. LOH on chromosome band 3p24 was found to occur at an overall rate of 36.4% (16/44) by three markers (D3S1293, THRB, and D3S1283). LOH for these three individual markers was 14.0%, 47.4%, and 20.9%, respectively. Meanwhile, RARB expression was lost in 43.2% (19/44) of these 44 samples. The loss of RARB expression was not correlated with LOH on chromosome band 3p24 (gamma = -0.22, -0.069, and -0.02, P = 0.15, 0.78, and 0.9 for D3S1293, THRB, and D3S1283, respectively), although both altered RARB expression and LOH in esophageal cancer were statistically significant (P = 0.001 and 0.0001, respectively), indicating that the loss of RARB expression cannot be explained by LOH on 3p24.

Chromosome Banding↗
PubMed2000

Molecular prognostic factors in rectal cancer treated by radiation and surgery.

PURPOSE: The aim of this study was to determine the biologic significance of tumor response and the prognostic value of molecular markers in a group of patients with rectal cancer treated with preoperative radiation therapy and radical surgery. METHODS: Microsatellite instability, microvessel count, and immunohistochemistry for proliferating cell nuclear antigen, p53, p21, bcl-2, and vascular endothelial growth factor were performed in the preradiation biopsy specimen of 72 patients with rectal cancer treated by preoperative radiation therapy and radical curative surgery. Preoperative tumor stage by endorectal ultrasound was compared with pathology stage of the resected specimen. Mean follow-up was 50 months. RESULTS: Twenty-eight patients (39 percent) responded to radiation therapy. The response was complete in 8 (12 percent) and partial in 20 patients (27 percent). Tumors with positive nodes in the surgical specimen were less likely to have responded to preoperative radiation (P = 0.03). Only p21 expression was individually associated with response to radiation (56 vs. 30 percent; P = 0.03). Tumors that were p53-negative/p21-positive or p21-positive/bcl-2-positive were also more likely to respond to radiation (83 vs. 35 percent; P = 0.03 and 71 vs. 31 percent; P = 0.01, respectively). The tumor relapsed in 21 patients (29 percent): locally in 7 (10 percent) and distally in 14 (19 percent). Recurrence was associated with lack of response to radiation, female gender, distal tumor location, high proliferating cell nuclear antigen labeling index, and low microvessel count. Probability of survival was greater for patients with well or moderately differentiated tumors and tumors that responded completely to radiation. CONCLUSIONS: Tumor response to radiation is associated with improved tumor control and overall survival rate, and p21 expression is a marker of tumor radiosensitivity in patients with rectal cancer. Furthermore, a high proliferating cell nuclear antigen labeling index and a low microvessel count in the preradiation biopsy specimen may be prognostic indicators for tumor recurrence.

Adult↗
PubMed2000

Study on the expression of Fas ligand on the surfaces of human cytotrophoblasts in normal pregnancy.

To further study the mechanism of maternal-fetal immune tolerance, the expression of Fas ligand (FasL) on the surfaces of human cytotrophoblasts in normal pregnancy was detected by using immunohistochemical method. High precise color-image measure system for immuno-histochemistry was used to quantitatively analyze the expression of FasL. The results showed that FasL were expressed on the surfaces of placental cytotrophoblasts throughout normal pregnancy. The variance among the first, second and term pregnant stages was also detected. It was suggested that the expression of FasL on the surfaces of placental cytotrophoblasts might play an important role both in the maintenance of pregnancy and in the normal development of fetus. The maternal specific T cell apoptosis induced by Fas/FasL is one of the significant mechanisms of maternal-fetal immune tolerance.

Adult↗
PubMed2000

The phase diagram of the monoolein/water system: metastability and equilibrium aspects.

Interest in the liquid crystal structure, transport and membrane protein crystallizing properties of the monoolein/water system has grown in the recent past. Monoolein is also an important homolog in a series of monoacylglycerols used to decipher how lipid molecular structure relates to liquid crystal phase behavior--information needed for rational design applications and for understanding the origin of membrane lipid diversity. To make intelligent use of the monoolein/water system, a reliable and detailed temperature-composition phase diagram is needed. The phase diagram of Briggs et al. (J Phys II France 1996;6:723-51) was constructed for this purpose. However, we have established that the liquid crystal phases in the latter below ca. 20 degrees C are metastable. By implementing a sub-zero degree (degrees C) sample incubation prior to data collection in the heating direction, we can reset the system into the lamellar crystal phase which we assume represents equilibrium behavior. We have re-examined the low-temperature part of the phase diagram and characterized structurally the new 'equilibrium' phases by static and time-resolved low- and wide-angle X-ray diffraction and by differential scanning calorimetry. A more complete phase diagram that incorporates the new equilibrium behavior at low temperatures is reported.

Calorimetry, Differential Scanning↗
PubMed2000

Uncharged tRNA activates GCN2 by displacing the protein kinase moiety from a bipartite tRNA-binding domain.

Protein kinase GCN2 regulates translation in amino acid-starved cells by phosphorylating elF2. GCN2 contains a regulatory domain related to histidyl-tRNA synthetase (HisRS) postulated to bind multiple deacylated tRNAs as a general sensor of starvation. In accordance with this model, GCN2 bound several deacylated tRNAs with similar affinities, and aminoacylation of tRNAphe weakened its interaction with GCN2. Unexpectedly, the C-terminal ribosome binding segment of GCN2 (C-term) was required in addition to the HisRS domain for strong tRNA binding. A combined HisRS+ C-term segment bound to the isolated protein kinase (PK) domain in vitro, and tRNA impeded this interaction. An activating mutation (GCN2c-E803V) that weakens PK-C-term association greatly enhanced tRNA binding by GCN2. These results provide strong evidence that tRNA stimulates the GCN2 kinase moiety by preventing an inhibitory interaction with the bipartite tRNA binding domain.

Binding Sites↗
PubMed2000

Defects in tRNA processing and nuclear export induce GCN4 translation independently of phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2.

Induction of GCN4 translation in amino acid-starved cells involves the inhibition of initiator tRNA(Met) binding to eukaryotic translation initiation factor 2 (eIF2) in response to eIF2 phosphorylation by protein kinase GCN2. It was shown previously that GCN4 translation could be induced independently of GCN2 by overexpressing a mutant tRNA(AAC)(Val) (tRNA(Val*)) or the RNA component of RNase MRP encoded by NME1. Here we show that overexpression of the tRNA pseudouridine 55 synthase encoded by PUS4 also leads to translational derepression of GCN4 (Gcd(-) phenotype) independently of eIF2 phosphorylation. Surprisingly, the Gcd(-) phenotype of high-copy-number PUS4 (hcPUS4) did not require PUS4 enzymatic activity, and several lines of evidence indicate that PUS4 overexpression did not diminish functional initiator tRNA(Met) levels. The presence of hcPUS4 or hcNME1 led to the accumulation of certain tRNA precursors, and their Gcd(-) phenotypes were reversed by overexpressing the RNA component of RNase P (RPR1), responsible for 5'-end processing of all tRNAs. Consistently, overexpression of a mutant pre-tRNA(Tyr) that cannot be processed by RNase P had a Gcd(-) phenotype. Interestingly, the Gcd(-) phenotype of hcPUS4 also was reversed by overexpressing LOS1, required for efficient nuclear export of tRNA, and los1Delta cells have a Gcd(-) phenotype. Overproduced PUS4 appears to impede 5'-end processing or export of certain tRNAs in the nucleus in a manner remedied by increased expression of RNase P or LOS1, respectively. The mutant tRNA(Val*) showed nuclear accumulation in otherwise wild-type cells, suggesting a defect in export to the cytoplasm. We propose that yeast contains a nuclear surveillance system that perceives defects in processing or export of tRNA and evokes a reduction in translation initiation at the step of initiator tRNA(Met) binding to the ribosome.

Alcohol Oxidoreductases↗
PubMed2000

[Studies on vitrectomy cases associated with complicated branch retinal vein occlusion].

PURPOSE: To examine the factors affecting visual outcome in vitrectomized cases associated with complicated branch retinal vein occlusion (BRVO). MATERIALS AND METHODS: Of 114 eyes of 113 patients with BRVO, ages, general complications, distribution of occluding vessels, location of retinal breaks, classification of vitreoretinal pathology and number of cases, period from onset of BRVO to vitreous hemorrhage and from vitreous hemorrhage to vitrectomy, number of operations, relationship between posterior vitreous detachment (PVD) and number of operations, post and preoperative pholocoagulation status, pre and postoperative visual acuity, and cases with poor visual outcome were analyzed. RESULTS: The visual prognosis was much better in the cases with vitreous hemorrhages only than those with proliferative membrane and retinal detachment (p = 0.0029). Repeated operations were needed in the cases of incomplete PVD (p = 0.0023). CONCLUSIONS: Early vitrectomy, especially in the cases of incomplete PVD, seems to be essential for management and treatment for better visual acuity.

Adult↗
PubMed2000

[Amplification and sequence of human CD14 gene from human mononuclear cell in peripheral blood].

OBJECTIVE: To introduce a new method for getting human CD14 gene. METHODS: Based on the character of CD14 gene, the authors amplified the CD14 gene directly from genome DNA of human mononuclear cell in peripheral blood by PCR for the first time. RESULTS: A human CD14 gene about 1.1 kb was successfully amplified from genome DNA of human mononuclear cell in peripheral blood, and the sequence analysis has indicated that the CD14 gene cloned in this way is the same as the sequence reported by other authors. CONCLUSION: It is a simple and effective method to obtain human CD14 gene from genome DNA of human mononuclear cell in peripheral blood.

Base Sequence↗
PubMed2000

Fluidity and fatty acid components of erythrocyte membranes in diabetic retinopathy.

BACKGROUND: Recently, numerous anomalies of erythrocyte rheology and function have been reported in diabetic patients. These changes are thought to be related to the alteration of erythrocyte membrane fluidity and may play an important role in diabetic retinopathy (DR). Nonetheless, the principal factors contributing to fluidity change remain undetermined. The influence of erythrocyte membrane fatty acid components on membrane fluidity and retinopathy was evaluated in patients with type 2 diabetes. METHODS: The fatty acid components and fluidity of erythrocyte membranes in 63 patients with type 2 diabetes with and without retinopathy were examined using high-performance liquid chromatography and fluorescence polarization. RESULTS: The content and composition of erythrocyte membrane arachidonate (C20:4n-6) was significantly lower in diabetics than in controls, and diabetics had significantly increased erythrocyte membrane microviscosity compared with controls. Furthermore, membrane microviscosity was higher in diabetics with DR than those without DR. In the diabetic patients, arachidonic acid contents of erythrocyte membranes were significantly, inversely correlated with erythrocyte membrane microviscosity, fasting blood glucose, glycosylated hemoglobin, triglycerides and cholesterol, and positively correlated with the insulin sensitivity index. CONCLUSIONS: The results suggest that erythrocyte membrane fatty acid components may contribute to alterations in membrane fluidity in patients with type 2 diabetes. Alterations in membrane fluidity may play an important role in the development of diabetic microangiopathy.

Aged↗
PubMed2000

[Effects of permissive hypercapnia on pulmonary mechanics and hemodynamics in sheep with acute lung injury].

OBJECTIVE: To study the effects of permissive hypercapnia (PHC) on pulmonary mechanics and hemodynamics in sheep with acute lung injury (ALI). METHODS: In 18 sheep with LPS induced ALI, gas exchange, pulmonary mechanics and hemodynamics were observed at different tidal volumes (VT). RESULTS: When VT was decreased from 16 ml/kg to 4-7 ml/kg, PHC was induced. Arterial pressure of carbon dioxide increased markedly, arterial oxygen pressure, oxygen saturation and mixed venous oxygen saturation decreased (P < 0.05). Airway pressure decreased significantly (P < 0.05), but the airway resistance increased. Systemic and pulmonary vascular resistance index, right and left ventricular stroke work index increased in PHC, but heart rate decreased (P < 0.05). Compared with VT 16 ml/kg, cardiac index decreased markedly in PHC. In static pressure-volume curve, the pressure of upper inflection point was (21.8 +/- 3.2) cm H2O, volume was (10.7 +/- 1.3) ml/kg. CONCLUSIONS: Alveolar overdistention may be prevented only when airway plateau pressure is less than 20-25 cm H2O, but cardiac index is decreased.

Animals↗
PubMed2000

Oral mucosal conditions and some related factors in 140 Uygur centenarians.

OBJECTIVE: To investigate the condition of the oral mucosae in Xinjiang Uygur centenarians and explore some related factors. METHODS: The oral mucosae and mucosal exfoliative cells of 140 Xinjiang Uygur centenarians were examined. Saliva and blood were collected from some centenarians. Salivary immunoglobulins (IgA, IgM, IgG), complements (C3 and C4), nitrous oxide (NO), 10 trace elements, serum sex hormones, thyroid hormones and osteocalcin (OST) were analysed using immunoglobulin, complement and NO kits, an ionochromatophotometer, and the kits for sex hormones and thyroid hormones, and fluorescence enzyme-linked immunosorbent assay, respectively. RESULTS: Most centenarians (64.29%) had normal labial, buccal, palatal and gingival mucosae. The abnormal changes in mucosae were mainly vascular nevus patches and senile plaques. Their mucosal exfoliative cells showed similar characteristics to those in elderly Han. The centenarians who had normal mucosae had higher level of the trace element molybdenum (Mo) in their saliva than who had abnormal mucosae (P < 0.01). CONCLUSION: The oral mucosal condition of Uygur centenarians was generally good. The abnormal changes in oral mucosae of the centenarians were lesions not harmful to health and may be related to the lower level of Mo in their saliva.

Aged↗
PubMed2000

Advanced glycosylation end products, protein kinase C and renal alterations in diabetic rats.

OBJECTIVE: To study the relationship between advanced glycosylation end products (AGE) and protein kinase C (PKC), and their effects on renal alteration in diabetic rats. METHODS: Insulin or aminoguanidine was administered to diabetic rats. Blood glucose, hemoglobin A1c (HbA1c), glomerular tissue extracts AGE (GTE-AGE), PKC, glomerular basement membrane thickness (GBMT) and urine protein/creatinine (Pr/Cr) ratio in diabetic rats were measured and analysed. RESULTS: Levels of blood glucose, HbA1c and AGE, PKC activity, the Pr/Cr ratio and GBMT were all significantly increased (P values all less than 0.01) in diabetic rats. Insulin could decrease the formation of HbA1c and AGE, and improve PKC activity. Aminoguanidine had no influence on PKC activity (P > 0.05) although it decreased the formation of AGE. Both drugs could delay the increase of urine Pr/Cr ratio and GBMT (P < 0.05 or P < 0.01). CONCLUSIONS: Chronic hyperglycemia may lead to an increase of PKC activity. HbA1c and AGE may not directly contribute to alterations of PKC activity, but the increase of PKC activity could promote the action of AGE on GBM thickening. It is important to inhibit the formation of AGE and reduce the PKC activity so as to prevent or delay the development of diabetic nephropathy.

Animals↗
PubMed2000

[An epidemiology study on limb injuries in infants aged 0 - 14 years old in Tengzhou area during 1994 - 1998].

OBJECTIVE: To find out epidemiological features on limb injuries in infants. METHODS: Stratified random sampling was carried out to investigate limb injuries in children aged 0 - 14 years old in four villages and townships, Tengzhou city Shandong province from 1994 to 1998. RESULTS: Results showed that the total rate of limb injuried was 2.96% with a ratio of male/female 3.20:1. The injury on arms was higher than on legs. The first three leading rates of injuries were falling, hurt by sharp stuff and traffic accidents. The highest rate of injury took place from May to October during the year. The rate of limb injuried seemed to be increasing with a disabled rate of 115.97/100,000. CONCLUSION: Measures should be taken to reduce the rate of injuries, according to the epidemiological findings.

Accident Prevention↗