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Biomedical subjects

H Qiu

Publications and source records attributed to H Qiu.

At least 73 records · Page 4Linked to original sources
PubMed1998

A study on continuous low-flow perfusion with low-potassium dextran for donor isolated lung preservation.

OBJECTIVE: To test the validity of continuous low-flow perfusion with low-potassium dextran (LPD) to preserve rabbit lung. METHODS: Isolated rabbit lungs were preserved for eight hours either in Ringer's solution by simple storage (Group I) or in continuous low-flow perfusion with LPD (Group II). After preservation, lung functions were assessed to compare these two methods. RESULTS: The water gain in Group I was higher than that in Group II. During reperfusion, the functional test values for the immersed lungs were lower than those for the perfused lungs. The lipid peroxidation product (MDA) was significantly decreased in perfused lungs during reperfusion. CONCLUSIONS: Low-flow perfusion with LPD is better than immersion for the lung preservation.

Animals↗
PubMed1998

[A case-control study on the risk factors of accidental injury among 0-14 year-old children].

To investigate the risk factors resulting in accidental injury in children and to provide basis for the prevention and reduction of such incidence, 468 cases of children with accidental injuries were studied through a one to one matched case-control study. Data was analysed with conditional logistic analysis. Results from single-factor analysis showed that such cases were associated with following factors: a) multiple children in the family with parents illiterate or low income; b) pesticide or raticide was stored inside the rooms; c) negligence of the dangerous environment risk around their houses. Results from multiple-factors analysis showed that children with illiterate parents, house that had pesticide stored in, low family income and whose houses were under vulnerable condition of collapse were most likely to suffer accidental injuries. Author concluded that the accidental injuries to children were caused by multiple factors which are preventable.

Accidents↗
PubMed1998

[Cloning and expression of leptospiral protective antigen gene OmpL1 in BCG].

This study was intended to produce a new living vaccine against leptospirosis using BCG as vector. Leptospiral outer envelop antigen gene OmpL1 was amplified from the genome of pathogenic leptopira serova Lai 017 by PCR, and cloned in E. coli-BCG shuttle plasmid pY6002. Recombinant plasmids were isolated by dot blotting with Digoxigeninlabeled OmpL1 gene. After transforming the recombinant plasmids in BCG (Shanghai strain) by electroporation, the genomic DNA of all 21 transformants were prepared and hybridized with OmpL1. It showed that 6 of the 21 transformants were recombinants in which the OmpL1 gene had been integrated into the genome of BCG. By immunoblotting with OmpL1 infected rabbit antiserum, which was preabsorbed to remove antibody against E. coli and SPA-HRP, three recombinants, pLI1, pLI2 and pLI3, were detected to express OmpL1 protein. The ability of expression is in the order of pLI2 > pLI1 >> plI3. These studies provide the possibility of further research on the development of highly efficient recombinant vaccines against leptospirosis.

Cloning, Molecular↗
PubMed1998

[The relation between DNA replication error and clinicopathological features of colorectal carcinoma].

OBJECTIVE: To study the relationship between DNA replication error and development of colorectal carcinoma (CRC). METHODS: Silver staining PCR-SSCP and denatured polyacrylamide gel electrophoresis methods were used to detect microsatellites instability (MSI) at 4 loci on chromosome 2, 5, 17 in paraffin embedded specimens of 60 CRC and their paired normal tissue. If replication errors (RER) were found at 2 or more loci, then a diagnosis of RER+ was made. RESULTS: RER+ was observed in 19/60 CRC, among which 7 cases had CRC family history. According to Amsterdam criteria, 4 were diagnosed as HNPCC(hereditary nonpolyposis colorectal cancer), of which 3 cases were RER+. The ratio of RER+ in HNPCC (75%) was significantly higher than that among sporadic CRC (28.5%). Most RER+ CRC have features of poorly differentiated adenocarcinoma (P < 0.01), tendency for right side involvement of the colon (P < 0.05) and a higher proportion with family history (P < 0.05). Rate of Dukes A and B stage higher than C and D stage (P < 0.05). CONCLUSION: RER+ is a relatively common molecular event in CRC. RER+ CRC and RER- CRC have different clinicopathological features and behavior.

Adenocarcinoma↗
PubMed1998

[Clinical study of physiologic work of breathing as a weaning parameter in mechanically ventilated patients].

OBJECTIVE: To evaluate the physiologic work of breathing (WOBphy) as a predicting Parameter of weaning and extubation. METHODS: WOBphy was obtained by the patient's work of breathing (WOBt), minuting the imposed work of breathing (WOBimp). In weaning trial, if the patients could not meet predefined extubation criteria, but WOBphy < 0.70 J/L, the patients were also extubated immediately. RESULTS: In a group of 28 patients who met the predefined criteria (group 1), 27 patients were successfully extubated. In another group of 13 patients who could not meet the criteria, but WOBphy < 0.70 J/L (group 2), extubation was successful in 12 patients. WOBt and WOBimp were significantly higher in group 2 (1.37 +/- 0.50 and 0.82 +/- 0.37 J/L) than group 1 (0.96 +/- 0.38 and 0.55 +/- 0.27 J/L, P < 0.05), while WOBphy was higher in group 2, but did not reach statistical significance. CONCLUSIONS: WOBphy < 0.70 J/L may be safe as the weaning and extubation criterion and enables earlier extubation.

Adult↗
PubMed1998

[Clinical study on chanlibao in accelerating second stage of labor].

OBJECTIVE: To find out a new way to strengthen the uterine contraction and shorten the second stage of labor, for improving the prognosis of mother and newborn. METHODS: Primiparae observed were divided into three groups randomly and Chanlibao (CLB, a preparation of Chinese herbal medicine) or oxytocin (OTC) was given to the CLB group (80 cases) and the OTC group (52 cases) respectively, to the third group, as a control group (29 cases) of natural labor, without any drug was given. Time of second stage of labor (TSL) and prognosis of mother and newborn of different groups were observed and compared. And intrauterine pressure (IP) and fetal heart rate were monitored by means of electronic-monitor. RESULTS: TSL and postpartum hemorrhage in the CLB group were less than those in the control group. The average IP in former was higher than that in latter, but with no difference as compared with the OTC group. No side effect of CLB was found. CONCLUSION: CLB could obviously strengthen uterine contraction and shorten the TSL, it is cheap, convenient and with no side-effect, so it is a new safe, effective method for improving prognosis of primiparae and newborn, especially for those nonindicated in using oxytocine or infusion of fluid profusely.

Adult↗
PubMed1998

[A study on the induction of mutation of paddy rice under space conditions].

Rice seeds were carried into space by the recoverable satellite. After recovery the seeds were sowed on the earth so as to observe the character performance and genetic variation of their later generations. The preliminary results showed that the main characters of the SP1 generation didn't show significant difference from the control. Among the individual plants of the SP2 generation strong broad-spectrum segregation appeared in the 9 main agronomic characters. Mutation frequency is 4.66%. The individual plants of the SP3 generation were obviously correlated with the SP4 generation in the average character values of the 5 main characters. Stable plant strains were obtained in the SP4 generation. The SP5 and SP6 generations were put into control and polt tests. As a conclusion, it may be considered that certain variations of rice seeds induced by the space conditions are heritable to the offsprings, therefore, it can be used as a new method for mutagenic seed breeding.

Genes, Plant↗
PubMed1998

[A new saikosaponin from Bupleurum Chinese DC].

Bupleurum chinese DC. is a well-known and very important traditional Chinese drug. It is often used to treat common cold with fever, alternating chill and fever, the feeling of fullness and oppression in the chest. A new saikosaponin was isolated from Bupleurum chinese DC. and its structure was identified as 3 beta, 16 beta, 28-trihydroxy-11-alpha-methoxy-olean-12-ene-3-O-beta-D-glucosyl-(1-->3)-beta D-fucoside on the basis of chemical and spectral evidence. In addition, six known saikosaponins were isolated and characterized as saikosaponin a, saikosaponin d, saikosaponin c, saikosaponin f, saikosaponin b3 and saikosaponin b2. All these compounds were isolated from Bupleurum chinese DC. for the first time.

Bupleurum↗
PubMed1998

Pharmacokinetics, formulation, and safety of insect repellent N,N-diethyl-3-methylbenzamide (deet): a review.

This review is intended to provide the reader with an overview of the all-purpose topical insect repellent N,N-diethyl-3-methylbenzamide (deet), with emphasis on its pharmacokinetics, formulation, and safety aspects. N,N-diethyl-3-methylbenzamide is effective against a variety of mosquitoes, flies, fleas, and ticks, and its protection efficacy depends on factors such as type of formulation, application pattern, physical activity of the user, environment, and species and feeding behavior of the insects. It offers an inexpensive and practical means of preventing the attack of biting insects and, more importantly, the transmission of vector-borne diseases. In both humans and animals, deet skin penetration and biodistribution are rapid and extensive, and metabolism and elimination appear to be complete. As evidenced by over 4 decades of human experience and rigorous animal testing, deet is generally safe for topical use if applied as recommended, although it has occasionally been related to side effects such as toxic encephalopathy, seizure, acute manic psychosis, cardiovascular toxicity, and dermatitis, along with a few cases of death due to extensive skin absorption. N,N-diethyl-3-methylbenzamide may compete in metabolism with and alter the biodistribution properties of other compounds to which a subject is simultaneously exposed, resulting in an added risk of side effects. The appropriate use of formulation techniques and new formulation excipients not only offers a way to extend the duration of protection, but also reduces deet skin penetration. In addition to extended repellency, minimal skin penetration of deet should be an important consideration in the evaluation of a deet formulation during new product development.

Animals↗
PubMed1997

1,25-Dihydroxyvitamin D3 and its analogues inhibit acute myelogenous leukemia progenitor proliferation by suppressing interleukin-1beta production.

We hypothesized that 1,25-dihydroxyvitamin D3 (1,25D3) and its analogues may inhibit acute myelogenous leukemia (AML) proliferation by interrupting IL-1beta-mediated growth-stimulatory signals. The incubation of the IL-1beta- responsive AML cell line OCIM2 with 10 nM 1,25D3 reduced growth 80% in liquid culture, and a 100-1000-fold lower concentration of 20-epi analogues (MC1288 and MC1301) was sufficient to achieve similar growth inhibition. The growth inhibition was associated with a rapid but transient downregulation of IL-1beta and IL-1beta-converting enzyme (ICE) mRNAs in 1,25D3- and 20-epi analogue- treated cells, and the 20-epi analogue was more effective than 1,25D3 in repressing ICE expression. An examination of long-term changes in the levels of mature IL-1beta and its precursor revealed that 24-h incubation of OCIM2 with either 1,25D3 or its 20-epi analogues abolished the production of mature IL-1beta. The effect of 1,25D3 and its analogues on growth of fresh bone marrow cells from seven AML patients was tested by a clonogenic assay. Growth inhibition of 60% was reached in only one of seven 1,25D3-treated samples, but all seven samples were inhibited 60-90% by the 20-epi analogue MC1301. Growth inhibition by 1,25D3 and the analogue was reversible by addition of IL-1beta. These results suggest that 1,25D3 and its 20-epi analogues interrupt IL-1beta autocrine growth regulation by inhibiting IL-1beta production and processing but not the response to IL-1beta.

Antineoplastic Agents↗
PubMed1997

A DNA decamer with a sticky end: the crystal structure of d-CGACGATCGT.

The crystal structure of d-CGACGATCGT has been determined to a resolution of 2.6 A. The molecule was synthesized by standard phosphoramidite procedures, and purified by anion-exchange HPLC. Crystals are monolclinic, space group P2(1), with unit cell dimensions, a = 26.45 A, b = 34.66 A, c = 32.17 A, beta = 113.45 degrees and Z = 4, containing a B-DNA double helix in each crystallographic asymmetric unit. The structure was solved using molecular replacement, aided by an isomorphous derivative, in which a bromine atom was attached to the 5 position of cytosine 8. Problems of fit between the search model and the structure ultimately obtained necessitated the use of Patterson correlation procedures between the determination of the orientation and the translation of the molecule. In all, 69 solvent molecules have been identified, and the structure has been refined to an R-factor of 0.214, using the 1421 reflections with F > 2sigma(F), collected at -120 degrees C. The sequence produces a molecule containing eight Watson-Crick base-pairs and a two-nucleotide 5'-sticky end at each end of the duplex. The sticky ends cohere with one another, so the molecules form continuous 10-fold double helices throughout the crystal, with each strand being interrupted by inherent staggered nicks. The relative angular relationships between helices in the structure differ from each other; most of the arrangements differ from Holliday junctions, whose rotational orientations are phased by a crossover and which are modeled to contain double helices that are exactly parallel or antiparallel. However, one helical juxtaposition in this crystal is similar to the alignment of double helices in parallel Holliday junctions. A survey of DNA decamers that also form infinite helices in crystals reveals relationships that approximate both parallel and antiparallel Holliday junction alignments.

Crystallography, X-Ray↗
PubMed1997

Angiotensinogen gene variation in a population case-control study of preeclampsia/eclampsia in Australians and Chinese.

Preeclampsia/eclampsia (PE/E) is a common disease of human pregnancy with a strong genetic component. The etiology of PE/E is unknown. Two recent reports indicated that the angiotensinogen gene (AGT) could be involved in susceptibility to PE/E. We performed a population-based case-control study in Australian and Chinese populations to investigate whether AGT is a good candidate gene for PE/E. A microsatellite polymorphism within AGT was typed as well as a molecular variant T235 (Met-->Thr) of AGT using allele-specific PCR and allele-induced restriction site PCR. The allele distributions of the microsatellite and the variant T235 of AGT were significantly different between the two ethnic groups. However, no significant allele associations were found with disease when comparing PE/E patients and controls in Australian or Chinese populations, which is in contrast to the two earlier reports. The results suggest that the contribution of AGT to the occurrence of PE/E is small, if anything, and is not constant across populations.

Alleles↗
PubMed1997

CTL induction using synthetic peptides delivered in emulsions--critical role of the formulation procedure.

Emulsions have been used with variable degrees of success to deliver antigen to stimulate immune responses. We have investigated three different ways of incorporating peptide antigen into soybean emulsions to induce CTL responses in mice. Two of these emulsions (oil-in-water, o/w, and water-in-oil-in-water, w/o/w) had peptide incorporated at the formulation stage, while the third had peptide added to a pre-formed o/w emulsion. High levels of CTL activity were induced when peptide was dispersed into the o/w or w/o/w emulsions, in contrast to addition of peptide to the pre-formed o/w emulsion, which did not stimulate a CTL response. Induction of CTL activity was independent of emulsion globule size but was correlated with a negative zeta potential and dispersion of peptide in the oil phase. The ability of peptide in soybean oil emulsion to induce CTL is critically dependent on dispersion of peptide at the time of emulsion formation.

Adjuvants, Immunologic↗
PubMed1997

Pharmacokinetics of insect repellent N,N-diethyl-m-toluamide in beagle dogs following intravenous and topical routes of administration.

The common topical insect repellent N,N-diethyl-m-toluamide (DEET) has caused serious adverse effects in the users of DEET products due to its high skin permeability. This study investigated the pharmacokinetics of DEET following i.v. and dermal routes of administration in beagle dogs. The pharmacokinetics of DEET was linear over the dose range of 2.5-6.0 mg/kg. Following the i.v. dosing, plasma DEET concentrations declined biexponentially with an elimination half-life of 2.56 h. Volume of distribution at steady-state, systematic clearance, and mean residence time were estimated as 6.21 L/kg, 2.66 L/h/kg, and 2.34 h, respectively, indicating that DEET underwent extensive extravascular distribution and rapid elimination. After the dermal application of a commercial lotion and a new DEET lotion at 15 mg of DEET/kg, plasma DEET concentrations peaked at 1-2 h postdose. The DEET transdermal bioavailability and mean absorption time were 18.3% and 2.05 h, respectively, for the commercial lotion and 14.0% and 2.66 h, respectively, for the new lotion. The difference in DEET transdermal absorption between the two lotions suggested that commercial DEET products could be optimized for reduced DEET absorption for safer use.

Administration, Cutaneous↗