Nucleotide sequence of a novel HLA-DRB1 allele, DRB1*0810 [corrected].
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Alleles↗
Biomedical subjects
L P Zhang
Publications and source records attributed to L P Zhang.
Additive susceptibility to insulin-dependent diabetes conferred by HLA-DQB1 and insulin genes.
Several genomic polymorphisms at the insulin (INS) gene and its flanking regions were analyzed in 197 unrelated Caucasian patients affected by insulin-dependent diabetes (IDDM) and 159 ethnically matched, normal controls ascertained from the South-Eastern United States. We found that the frequency of homozygotes for the common variant at the insulin gene was significantly increased in the diabetic population (RR = 2.0, p < 0.005). However, the polymorphisms in the 5' and 3' regions flanking the INS were not significantly associated with IDDM. These results suggest that the IDDM susceptibility locus on chromosome 11p is located within the region extending from the 5' VNTR to the 3' end of the INS gene. We determined the HLA-DQB1 genotypes by denaturing gradient gel electrophoresis (DGGE) and/or sequence-specific primers (SSP) techniques to assess the possible interactions between INS and HLA. DQB1*0302 had the strongest predisposing effect on IDDM susceptibility (RR = 9.3) and DQB1*0602 the strongest protective effect (RR = 0.02). However, a significant predisposing effect of DQB1*0201 could be demonstrated only after removal of the effects of DQB1*0302 and DQB1*0602. Analyses of the genotypes revealed that all genotypes containing 0602 were protective and that the heterozygous genotype 0201/0302 and homozygous genotype 0302/0302 confer the highest risk (RR = 20.9 and 12.9 respectively). However, heterozygous genotypes 0302/X (X excludes 0201, 0302 and 0602) have a significantly lower predisposing risk. Similarly, there is heterogeneity in risk between predisposing 0201/0201 homozygous individuals and protective 0201/X individuals. When subjects were stratified by HLA genotypes, the relative risks conferred by INS did not vary, thus suggesting that the susceptibility effects conferred by HLA and INS are additive rather than interactive.
Base Sequence↗
[Inhibition of protein kinase C by stilbenoids].
The effect of 15 stilbenoids on protein kinase C (PKC) was studied in order to search for naturally occurring PKC inhibitors. All these compounds were isolated from Chinese medicines. Three oligomeric stilbenes from Caragana sinica, alpha-viniferin, kobophenol A and miyabenol C, were shown to intensely inhibit the activity of partially purified rat brain PKC with IC50 values of 62.5, 52.0, and 27.5 mumol.L-1, respectively. Kinetic analyses revealed that that inhibition was noncompetitive. The other compounds also showed the effect. Monomer stilbenes exhibited PKC inhibitory activity at higher mumol.L-1 concentrations than oligomeric stilbenes. Whenever they are methylated or acetylated perfectly, the inhibition weakens or disappears.
Animals↗
Parallel stranded DNA under the scanning tunnelling microscope.
Using scanning tunnelling microscopy, we have directly observed parallel stranded DNA helixes of 43 nucleotides in length. The double helix is right-handed and has an average spacing, 17.43 A (+/- 1 S.D.: 2.30 A), and an average apparent depth, 4.79 A (+/- 1 S.D.: 1.04 A) for each groove. The average pitch of the helical turn is 34 A (+/- 1 S.D.: 3.35 A) and consists of no more than ten base pairs. The diameter of the helix is approx. 17-20 A. Our results provide direct evidence for the existence of a parallel structure of DNA in vitro and some details of its fine structure.
Base Sequence↗
Synthesis, antiinflammatory and anticancer activity of cinnamic acids, their derivatives and analogues.
Cinnamic acids were selected as lead compounds of antiinflammatory and anticancer agents through the investigation of their biological properties. Their esters and related styryl ketones were also studied. A total of nineteen compounds, fifteen of them not reported previously, were synthesized and found to be of considerable pharmacological interest. In preliminary biological tests, compounds IA, IB, IC, II2C and II5C showed significant inhibiting effect on croton oil induced mouse ear edema, IB, II5A, II5C and IIID exhibited good activity on HL-60 human cancer cells in vitro. It is well worth noticing that compounds IB and II5C exhibited excellent antiinflammatory action as well as anticancer activity.
Anti-Inflammatory Agents, Non-Steroidal↗
Frontal bone advancement and compensatory craniofacial growth changes in rabbits with experimental coronal suture immobilization.
Recent clinical advances in the surgical correction of coronal suture synostosis involve the overcorrection of a frontal bone segment to allow for unrestricted expansion of the developing neurocapsular matrix. However, the effects of such large-scale calvarial repositioning on subsequent brain mass growth trajectories and compensatory cranio-facial growth changes is unclear. This study was designed to investigate this relationship in an experimental rabbit model of bilateral coronal suture synostosis. Amalgam markers were placed across the frontonasal, coronal, and anterior lambdoid sutures in thirty-one 1.5-week-old rabbits. Twenty-one animals underwent bilateral coronal suture immobilization using methyl-methacrylate. Ten animals were left untreated and served as sham controls. At 6 weeks of age, the coronal suture was released by frontal bone craniotomy or frontal bone craniotomy with a 6-mm frontal bone advancement. Lateral head radiographs were taken at 1.5, 6, 7, 9, 12, and 18 weeks of age. Results revealed that by 6 weeks of age, animals with coronal suture immobilization exhibited growth disturbances across the various sutures resulting in altered craniofacial and cranial vault shape compared to control animals. Following coronal suture release, animals that underwent craniotomy showed rapid restenosis, which resulted in significantly altered cranial vault shape and cranial orthocephalization by 18 weeks of age. Animals that underwent frontal bone advancement exhibited normal overall craniofacial growth by 18 weeks of age compared with control animals but did exhibit regional compensatory growth disturbances at the frontonasal and anterior lambdoid sutures, possibly related to neural tissue distension.(ABSTRACT TRUNCATED AT 250 WORDS)
Analysis of Variance↗
Galactose-1-phosphatase in rat brain.
A prominent galactose-1-phosphatase was isolated from rat brain and partially purified by chromatography on diethylaminoethyl-Sephacel, hydroxylapatite, and Sephacryl S-300 columns. The galactose-1-phosphatase was separated from alkaline phosphatase, and from two forms of glucose-1-phosphatase. The three columns gave a 10-fold increase in specific activity to 290 mol/min/mg of protein, with a yield of 15%. Of the eight sugar phosphates tested, galactose-1-phosphate was the best substrate for the purified enzyme, followed by glucose-1-phosphate, which was hydrolyzed 40% as rapidly as galactose-1-phosphate. Galactose-1-phosphatase had an optimum pH of 8.5 and a Km value of 2.5 mM for galactose-1-phosphate hydrolysis. Mg2+ was required for activity, and supported half-maximal activity at a concentration of 1.25 mM. Phosphate was the only potent inhibitor found ATP, arsenate, and vanadate caused moderate inhibition of 10 mM levels, whereas AMP, L-homoarginine, and L-phenylalanine stimulated enzyme activity. Galactose-1-phosphatase was determined to have a Stokes radius of 30 A and a sedimentation coefficient of 4.1S. These values were used to calculate a molecular weight of 50,200 and a frictional ratio showing the enzyme to be a globular protein. It is hypothesized that a similar phosphatase may play a role in reducing brain galactose-1-phosphate concentrations in patients with galactosemia.
Animals↗
Immunological properties of antibodies against Mg(2+)-ATPase from Acholeplasma laidlawii membranes.
In the present study, antibodies were raised against the Mg(2+)-ATPase and the immunological relationships between the enzyme and other ATPase from a variety of biological membranes were determined. The anti Mg(2+)-ATPase antiserum inhibited 85% of the enzyme activity from A. laidlawii membranes. We demonstrate a specific selectivity of Mg(2+)-ATPase antiserum for antigenic determinants of the A. laidlawii membranes. Immunoblot studies of A. laidlawii membrane peptides indicated labeling of five bands, 66KD, 49KD, 34KD, 26KD and 13KD, corresponding to five subunits of the ATPase in A. laidlawii membranes.
Acholeplasma laidlawii↗
Frontal bone advancement stability with or without microplate fixation: an experimental study in rabbits.
Recent advancements in surgical correction of coronal suture craniosynostosis involve the overcorrection of a frontal bone segment to allow unrestricted growth of the developing brain. However, problems with segment stability and collapse have been reported. Such problems may be alleviated with microplate fixation of the segments. The present experimental study tests this hypothesis in a growing rabbit frontal bone advancement model. Sixteen 6-week-old rabbits were divided into three groups, consisting of animals with short bone segments advanced with two bone struts and fixed with Vicryl, long bone segments advanced with one bone strut and fixed with Vicryl, or long bone segments advanced with one bone strut and fixed with microplates. Frontal bone advancement collapse was assessed from lateral x-rays through 12 weeks postoperatively. Animals with microplate fixation exhibited significantly (p less than 0.01) less collapse (about 1% height reduction) compared to animals with short segments (about 30%) and long segments (about 45%). These results support, with experimental evidence, the utility of rigid three-dimensional fixation afforded by the microplate system in overcoming the effects of cranial growth and scalp and epicranial musculature closing tensions.
Analysis of Variance↗
Phospholipid hydroperoxide glutathione peroxidase: specific activity in tissues of rats of different age and comparison with other glutathione peroxidases.
The tissue distribution of phospholipid hydroperoxide glutathione peroxidase (PHGPX) was studied in rats of different ages. In the same samples the activities of Se-dependent glutathione peroxidase (GPX), and non-Se-dependent glutathione peroxidase (non Se-GPX) were also determined using specific substrates for each enzyme. Enzymatically generated phospholipid hydroperoxides were used as substrate for PHGPX, hydrogen peroxide for GPX, and cumene hydroperoxide for non-Se-GPX (after correction for the activity of GPX on this substrate). PHGPX specific activity in different organs is as follows: liver = kidney greater than heart = lung = brain greater than muscle. Furthermore, this activity is reasonably constant in different age groups, with a lower specific activity observed only in kidney and liver of young animals. GPX activity is expressed as follows: liver greater than kidney greater than heart greater than lung greater than brain = muscle, and substantial age-dependent differences have been observed (adult greater than old greater than young). Non-Se-GPX activity was present in significant amount only in liver greater than lung greater than heart and only in adult animals. These results suggest a tissue- and age-specific expression of different peroxidases.
Aging↗
Lunar phases, myocardial infarction and hemorrheological character. A Western medical study combined with appraisal of the related traditional Chinese medical theory.
Lunar phases and their connections with acute myocardial infarction (AMI) and hemorrheological character (HCh) are studied with the lunar calendar (LC) instead of the solar calendar. AMI onset is maximal on the 1st day of the LC month, decreasing with an obvious trough around the 15th day. After the 15th day, occurrence increases gradually. The end and beginning of the lunar months show sharp peaks of AMI incidence. This study shows also that HCh variations have similar LC monthly rhythms. Our investigation demonstrates the correctness of traditional Chinese medical theory. This monthly rhythm forecasts the onset of AMI peaks and contributes to the secondary prevention of coronary heart disease (CHD).
Adult↗
[Studies on attenuation of cardiovascular responses during endotracheal intubation following rapid-sequence induction of anesthesia].
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Adolescent↗
[The ratio of a formalin and potassium permanganate preparation in a sealed container and its bacteriocidal effect].
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Bacillus subtilis↗