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Biomedical subjects

J Shi

Publications and source records attributed to J Shi.

At least 91 records · Page 5Linked to original sources

HOMSTRAD: adding sequence information to structure-based alignments of homologous protein families.

summary: We describe an extension to the Homologous Structure Alignment Database (HOMSTRAD; Mizuguchi et al., Protein Sci., 7, 2469-2471, 1998a) to include homologous sequences derived from the protein families database Pfam (Bateman et al., Nucleic Acids Res., 28, 263-266, 2000). HOMSTRAD is integrated with the server FUGUE (Shi et al., submitted, 2001) for recognition and alignment of homologues, benefitting from the combination of abundant sequence information and accurate structure-based alignments. AVAILABILITY The HOMSTRAD database is available at: http://www-cryst.bioc.cam.ac.uk/homstrad/. Query sequences can be submitted to the homology recognition/alignment server FUGUE at: http://www-cryst.bioc.cam.ac.uk/fugue/.

Computational Biology↗

Estrogens decrease reperfusion-associated cortical ischemic damage: an MRI analysis in a transient focal ischemia model.

BACKGROUND AND PURPOSE: Early identification of irreversible cerebral ischemia is critical in defining strategies that influence neuronal survival after stroke. We used MRI to investigate the effects of 17beta-estradiol (E2) on the temporal evolution of focal ischemia. METHODS: Female rats were ovariectomized and divided into 1 of 2 groups: ovariectomy alone (OVX; n=4) or ovariectomy with estrogen replacement (OVX+E2; n=3). Both groups were then subjected to 1-hour middle cerebral artery occlusion (MCAO), with the use of a standardized endovascular monofilament model, followed by reperfusion. Sequential diffusion-weighted (DWI) and T2-weighted (T2WI) MRI were obtained during and after the MCAO. In separate groups of animals (n=5 for OVX and OVX+E2), cerebral blood flow (CBF) was measured by laser-Doppler methods before, during, and after occlusion. RESULTS: DWI detected similar lesion characteristics during MCAO in both groups. In the OVX group, lesion size did not change during reperfusion, but the signal intensity ratio increased early and stabilized during the latter stages. In contrast, DWI lesion size decreased during reperfusion in OVX+E2 rats by 50% to 60% (P<0.05), a size reduction almost exclusively limited to cortical regions. During MCAO, the signal intensity ratio in OVX+E2 rats was reduced compared with OVX rats. Reperfusion further attenuated the signal intensity ratio in cortical but not subcortical regions (P<0.05 versus OVX). T2WI revealed no lesions in either group during MCAO, but it detected lesion sizes similar to that of DWI during reperfusion. Furthermore, similar patterns and magnitudes of estrogen treatment-related decrease in lesion size were noted after reperfusion. T2WI demonstrated less intense signal intensity ratio changes in both groups compared with DWI. There were no differences in CBF between groups either during occlusion, early reperfusion, or 1 day after reperfusion. CONCLUSIONS: This study strongly suggests that estrogens selectively protect cortical tissue from ischemic damage during MCAO and that this protection is exerted during both the occlusion and reperfusion phases of ischemia and does not involve an estrogen-related change in CBF.

Animals↗

Single-dose pharmacokinetics of sotalol in a pediatric population with supraventricular and/or ventricular tachyarrhythmia.

The pharmacokinetics (PK) of the antiarrhythmic sotalol, which elicits Class III and beta-blocking activity, has not been adequately defined in a pediatric population with tachyarrhythmias. The goal of this single-dose study with administration of sotalol HCl at a dose level of 30 mg/m2 body surface area (BSA) was to define the PK of the drug in the following four age groups: neonates (0-30 days), infants (1 month to 2 years), younger children (> 2 to < 7 years), and older children (7-12 years) with tachyarrhythmias of either supraventricular or ventricular origin. The drug was administered in an extemporaneously compounded syrup formulation prepared from the tablets containing sotalol HCl. For safety, vital signs and adverse events were recorded and the QTc interval and heart rate telemetrically monitored. Scheduled blood samples were taken over a 36-hour time interval following dose administration. The drug concentrations in plasma were measured by a sensitive and specific LC/MS/MS assay. Standard compartment model-independent methods were applied to compute the salient PK parameters of sotalol. Twenty-four clinical sites enrolled 34 patients. Thirty-three had analyzable data. Sotalol was rapidly absorbed, with mean peak concentrations occurring 2 to 3 hours after administration. The elimination of sotalol was characterized by an average half-life of between 7.4 and 9.2 hours in the four age groups. There existed statistically significant linear relationships between apparent total clearance (CL/f) or apparent volume of distribution (V lambda z/f) after oral administration and the covariates BSA, creatinine clearance (CLcr), body weight (BW), or age. The best predictors for CL/f were CLcr and BSA, whereas BW best predicted the V lambda z/f. The total area under the drug concentration-time curve in the smallest children with a BSA < 0.33 m2 was significantly greater than that in the larger children. This finding indicated that the BSA-based dose adjustment used in this study led to a larger exposure in the smallest children, whereas the exposure to the drug was similar in the larger children. The dose of 30 mg/m2 was tolerated well. No serious drug-related adverse events were reported. It can be concluded that the PK of sotalol in the pediatric patients depended only on body size, except for the neonates and smallest infants in whom the disposition of sotalol was determined by both body size and maturation of eliminatory processes.

Adrenergic beta-Antagonists↗

Spontaneous platelet aggregation with congenital giant platelet containing large granules and thick membrane.

Inherited giant platelet disorders are a heterogeneous group of disorders. In the current study, a patient was reported with moderate bleeding tendency, giant platelets, and spontaneous platelet aggregation, which were not affected by the administration of aspirin or ticlopidine. The electron microscopy of platelets showed a black and thick plasma membrane with crystal-like fine hairs in the exterior coat and more large and variously shaped granules in the cytoplasm. The expression of glycoprotein (GP) Ib, GP IIb, and GP IIIa on platelet surface was normal, and no mutations in genes for GP Ib alpha, GP Ib beta, and GP IX were detected. These phenomena are so distinguishable from those of Mondreal platelet syndrome and other hereditary giant platelet disorders, that we propose that this patient probably has a novel platelet disorder, which has not yet been reported.

Blood Platelet Disorders↗

Function and regulation of cholecystokinin octapeptide, beta-endorphin and gastrin in anorexic infantile rats treated with ErBao Granules.

AIM: To study the role of cholecystokinin octapeptide (CCK-8),beta endorphin (beta EP), and gastrin in an anorexic infantile rat model and no subsequent regulation of nose peptides by the Yunpi complex prescription ErBao Granule. METHODS: We fed infantile rats with special prepared forage. A liquid extract of ErBao Granule was administered to the rats daily for 3 weeks, CCK-8, beta-EP, and gastrin concentrations in hypothalamus, gastric antrum, and plasma of the rats were measured by radioimmunoassay, and were compared with controls. RESULTS: Treatment of rats with ErBao Granule inhibited CCK-8 secretion and increased beta-EP and gastrin secretion. CCK-8 concentration in hypothalamus and plasma of model control group increased significantly and correlated negatively with food intake of models, respectively. beta-EP concentration in gastric antrum and plasma of model control group decreased significantly and showed a positive correlation with food intake of models, respectively. Hypothalamus concentration of beta-EP was similar in models and controls. Gastrin concentration in gastric antrum of models was lower than in the blank control group, and correlated positively to food intake of models. Finally, CCK-8 concentrations in plasma of rats showed a positive correlation with plasma beta-EP (r=-0.68, P<0.05). CONCLUSION: The increased plasma and hypothalamus concentration of CCK-8, decreased gastric antrum and plasma level of beta-EP, and decreased gastric antrum concentration of gastrin are associated significantly with the anorexia of infantile anorexic rat models produced by special for-age. ErBao Granule can reverse these changes, which may be the major mechanisms of ErBao Granule simulating feeding.

Animals↗

[The transference and distribution of tritium water in the soybean-soil system].

The isotope trace techniques of simulation contamination were applied to explore the rule of transference and distribution of tritium water in a simulated soybeam-soil ecosystem. The activity ratio of two forms of tritium in plant and soil sample were measured by 50 days simulation experiment. The results showed that when tritium water was entered the soil, it not only was transferred to other compartments in the system, but also vaporized into atmosphere rapidly. Both free water tritium and bound tritium were found in the soybean and the soil. The activity ratio of free water tritium reduced after reaching the maximum (19.4 Bq.g-1 in root, 12.3 Bq.q-1 in stem and leaf) at 6th hour in the soybean. The bound tritium increased slowly. The activity ratio of total tritium in soybean root was upper than those in stem and leaf in the earlier stage, they reach equipoise each other in the later stage. The activity ratio of two tritium in the surface soil reduced continuously. The compartment model of tracer kinetic was applied to imitate the experimental data. The activity ratio of soil Cs = 88.37e-11.847t + 7.38e-0.030t and the activity ratio of soybean Cb = 10.30(e-0.030t - e-11.847t) were gained.

Soil↗

[Comparison of denaturing high performance liquid chromatography with direct sequencing in the detection of single nucleotide polymorphism].

OBJECTIVE: Investigate the sensitivity and accuracy of the denaturing high performance liquid chromatography(DHPLC) technique for the detection of single nucleotide polymorphism(SNP). METHODS: Forty-one samples were detected by both DHPLC and direct sequencing. RESULTS: The comparison demonstrated that DHPLC detected all heterozygous sequences found by direct sequencing. No false-positive signals were seen in the cases of homozygous sequences. Furthermore, no false-negative results were ever obtained with heterozygous mutations or polymorphisms, or both. CONCLUSION: DHPLC is a potent method for SNP identification especially SNP typing in large scale screening.

Chromatography, High Pressure Liquid↗

[No evidence for association between the alpha 2-macroglobulin polymorphism and Alzheimer's disease in the Han Chinese].

OBJECTIVE: To determine the effect of the pentanucleotide deletion polymorphism adjacent to a consensus splice site in intron 17 of alpha 2-macroglobulin(A2M) gene on the development of late-onset Alzheimer's disease (LOAD) in the Han Chinese in Guangzhou area. METHODS: A2M and apolipoprotein E genotypes were examined by polymerase chain reaction(PCR) and restriction fragment length polymorphism (RFLP) techniques in the patients(32 men and 65 women) with LOAD and age-matched healthy elderly Chinese subjects (57 men and 54 women). RESULTS: The A2M gene deletion allele frequency was 2.6% in the cases with LOAD and 2.7% in the controls. In the LOAD cases, the frequency of apoE-epsilon4 increased significantly (Z=3.32, P<0.01). ApoE-epsilon4 was associated with LOAD (RR=2.67, chi(2)=10.71, P<0.01) while the A2M deletion polymorphism was not associated with LOAD even the samples were stratified according to the presence of the apoE-epsilon4 allele. CONCLUSION: The above data demonstrate that there is no evidence for the association of A2M polymorphism with the development of LOAD in the Han Chinese population in Gaungzhou.

Alzheimer Disease↗

[A simple and rapid new method for SNP typing by single-tube bi-directional allele specific amplification].

OBJECTIVE: To establish a new method for single nucleotide polymorphism(SNP) typing based on allele specific PCR: single-tube bi-directional amplification (SB-ASA), and study the influence on specific extension by introducing a mismatch at the third 3'terminal base of allele specific primers. METHODS: Two allele specific primers, with a mismatch introduced at the third 3'terminal base, were both included in PCR system; they extended in opposite directions and amplified two allele specific fragments different in size. The genotype was determined by observing the length of amplified fragments after agarose electrophoresis. The proper ranges of annealing temperature (Ta) under which primers can specifically extend were achieved by observing the amplification status at different temperatures. RESULTS: SB-ASA was successfully used to type 36 samples for four different kinds of SNPs. Typing results were completely consistent with those by directional sequencing. Proper Ta ranges of two primers were expanded respectively from 64-69 degrees centigrade to 46-66 degrees centigrade and from 60-62 degrees centigrade to 56-61 degrees centigrade by introducing a mismatch at the third 3'terminal base. CONCLUSION: SB-ASA is a simple, rapid and efficient new method for SNP typing. During allele specific PCR reaction, specific primers with a mismatch at the third 3'terminal base have more power to identify two alleles.

Alleles↗

[Mutations of mitochondrial 12S rRNA gene in type 2 diabetes].

OBJECTIVE: To investigate mutations at points 1310, 1438 and 1442 of mitochondrial 12S rRNA gene in Chinese type 2 diabetes and screen for new mutations associated with type 2 diabetes in this area. METHODS: The mitochondrial DNAs (mtDNAs) of 86 patients with type 2 diabetes and those of 70 normal controls were analyzed using PCR-SSCP and PCR product direct sequencing technique. RESULTS: One patient was found with the mitochondrial DNA G --> A mutation at point 1438, and one with the G two head right arrow A mutation at point 1442, whereas none of the normal controls was found to have mutation at these two points. No C --> T mutation at nucleotide pair 1310 of the mitochondrial 12S rRNA gene was identified. CONCLUSION: The G --> A mutation at points 1438 and 1442 is likely to be associated with the development of type 2 diabetes; the occurrence of the C -->T mutation at point 1310 is probably rare in the blood cells, and the development of type 2 diabetes may be related to heterogeneity in mitochondrial genetic changes.

Adult↗

[A novel point mutation in the transmembrane domain of platelet glycoprotein IX gene identified in a Bernard-Soulier syndrome patient].

OBJECTIVE: To diagnose a patient with Bernard-Soulier syndrome (BSS) and investigate her gene abnormality. METHODS: Platelet size and structure were studied under light and electron microscopies. Platelet membrane glycoproteins (GP) were measured by flow cytometry. PCR and DNA sequencing were used to identify gene abnormality. RESULTS: The patient had thrombocytopenia with giant platelets. Ristocetin-induced platelet agglutination was absent. GP I b/IX complex in the platelet membrane was significantly decreased, which was resulted from an Ala139 Thr substitution in the transmembrane domain of GPIX. CONCLUSION: Ala139 Thr mutation of the GPIX gene in this patient is a novel missense mutation, which has not been reported in BSS.

Adult↗

Point mutations of muscle mitochondrial DNA from patients with mitochondrial encephalomyopathies.

OBJECTIVE: To study the relation between point mutations at nt3243 and nt8344 of muscle mitochondrial DNA from patients with mitochondrial encephalomyopathies and phenotypes. METHODS: DNA was extracted from muscle specimens from 5 patients with mitochondrial encephalomyopathies and and amplified by PCR method, using corresponding oligonucleotide primers. DNA fragments were digested with restriction enzymes Bgl I and Apa I, then the digested DNA fragments were analyzed with an electrophoresis method. RESULTS: The point mutation at nt3243 of mtDNA was found in 2 patients, one with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) and another with myoclonic epilepsy with ragged red fibers (MERRF). The point mutation at nt8344 was found in 2 patients with MERRF, including the one with point mutation at nt3243. CONCLUSION: The point mutation of DNA at nt3243 correlated with MELAS and nt8344 correlated with MERRF. In addition, the detection of point mutations at both nt3243 and nt8344 in a patient with MERRF shows the association of mutation with diversity in clinical manifestations of mitochondrial encephalomyopathies.

Adolescent↗

[Neo-adjuvant chemotherapy for breast cancer].

OBJECTIVE: To study the value and indications of a neo-adjuvant chemotherapy for breast cancers. METHODS: Forty-three breast cancer patients were given the NF neo-adjuvant chemotherapy (Navelbine 25 mg/m2 and 5-Fu 500 mg/m2) for 3 cycles before the operation. Epirubicin (EPI 40 mg/m2) was added in patients with locally advanced lesions. G-CSF 75 micrograms subcutaneous injection was used to increase the white count as needed. RESULTS: The overall response rate was 95.0%. Pre-operative neo-adjuvant chemotherapy showed CR in 3 patients (7.5%) and PR in 35 patients (87.5%) even though 2 patients (5.0%) were refractory. The follow-up ranged from 4 to 37 months (median 20 months). All patients are alive though 4 have developed recurrence or metastasis. CONCLUSION: The pre-operative neo-adjuvant chemotherapy may preferably be given in 3 cycles from which those who benefit most are the breast cancer patients with inoperable lesions and who are planned to undergo breast-preserving surgery.

Adult↗

[Effect of calcium hydroxide on human pulp cell intracellular calcium ion in vitro].

OBJECTIVE: To investigate the influence of calcium hydroxide to intracellular calcium ion of human pulp cells in vitro. METHODS: The sixth generation of human pulp cells were maintained in RPMI 1640 medium supplemented with Fluo-3 probe and Ca (OH)2 for restimulation. The intracellular calcium ion concentration was detected by laser confocal microscope. RESULTS: The intracellular calcium ion level in Ca (OH)2 pretreatment group increased after Ca (OH)2 stimulation, while it didn't response to Ca (OH)2 stimulus in group without Ca (OH)2, CaCl2 or NaHCO4 pretreatment. CONCLUSION: It is important to pretreat the pulp cells with Ca(OH)2 in order to increase the intracellular calcium.

Calcium↗

Dynamic changes of interleukin-1, interleukin-6 and tumor necrosis factor in intermingled skin graft in burned rats.

OBJECTIVE: To compare the dynamic changes of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in intermingled skin graft with those in other types of skin grafts in rats. METHODS: A 10%-15% third-degree burn was created in 180 Sprague-Dawley (SD) rats. After removing the scar, skin grafts were performed on the open wounds immediately with autoskin (aus, n=54), alloskin (als, n=54) and intermingled skin (n=36). That is to say, in the intermingled skin graft, a big piece of alloskin (mals) was grafted first, and 3 days later, small pieces of autoskin (maus) wer e embedded in the alloskin. The rest 36 rats were taken as the controls. And the biological activities of IL-1, IL-6 and TNF in graft sheets in each group were detected after skin graft. RESULTS: The levels of IL-1, IL-6 and TNF in the aus group decreased steadily after their initial elevations, whereas in the als group they increased significantly and kept on the peak level in the later phases. In the in termingled group, there appeared a lowest IL-1 level in the mals and a highest one in the maus simultaneously at 7 (4) days (The number out of parenthesis is t he days after transplanting with alloskin sheets, and the number in parenthesis is the days after embedding autoskin sheets in the intermingled skin graft. Similarly hereinafter.) after skin graft (P<0.01), and the high level in the maus abruptly decreased at 14 (11) days after skin graft. At exactly the same phase on day 7 (4), a prominent peaked IL-6 in the mals occurred. In the later phases, the levels of TNF remained relatively low both in the m als and in the maus. From day 7 (4) on, each cytokine fluctuation in the mals synchronized with that in the maus. The longer the post transplantation period lasted, the more the positive cytokine correlated between the mals and the maus. CONCLUSIONS: The low levels of IL-1 and TNF may be important f actors to lighten the intensity of local rejection in the intermingled skin graft. The temporarily peaked IL-6 is both an inducer which induces the production of local IL-1 receptor antagonists and soluble TNF receptors and a signal which indicates a local enhancement of Th(2) cells. The mild rejection process and th e synchronized cytokine level during the later phases suggest a possible chimerism between the mals and the maus.

Animals↗

[Leaching and vertical transport of Zirconium-95 in soils].

The leaching and vertical transport of Zirconium-95 in three representational soils (paddy soil, red-yellow earth and sea mud) in Zhejiang province and the influence of salinity on the activities of Zirconium-95 in sea mud were studied with soil-pole installation. The results show that: 1. The content of Zirconium-95 in collected leachate was low after passing through soil column with 250 ml, 500 ml, 750 ml leaching amount. The amount of Zirconium-95 in collected leachate of paddy soil, sea mud and red-yellow earth was about 5.33%-7.68%, 0.77%-1.32% and almost 0 of labelled amount respectively. And with increasing the total amount of leaching water, the content of Zirconium-95 in collected leachate varied indistinctively, which indicated that once Zirconium-95 was absorbed by soils, it was very difficult to desorb. 2. In paddy soil, red-yellow earth and sea mud, 45.99%-50.02%, 96.02%-97.16% and 95.94%-98.01% radioactivity of Zirconium-95 was concentrated in the 0.4 cm upper layer soils respectively, which illustrated that most of Zirconium-95 remained in the surface soils. 3. With the increase of salinity in leaching water, the amount of Zirconium-95 in surface soils (0-0.2 cm) presented obviously increased, which demonstrated that increasing salinity could raise the adsorption rate of Zirconium-95 in soils.

Kinetics↗

[Immunogenicity and safety of recombinant yeast-derived hepatitis B vaccine (YDV) on adults].

OBJECTIVE: To study the immunogenicity and safety of recombinant yeast-derived hepatitis B vaccine (YDV) on adults. METHODS: One hundred twenty-four healthy teachers of 22 - 58 years old, were randomly selected in Beipiao city, Liaoning province. Their HBsAg, anti-HBs and anti-HBc were all negative and temperature was normal. They were vaccinated with 5 microgram/0.5 ml of YDV, which was made in Beijing Institute of Biologic Products, at 0, 1, 6 months. RESULTS: The positive rates of anti-HBs were 35.0%, 83.3%, 67.2% (P < 0.01) with the mean geometric titre (GMT) of anti-HBs 12.63 mIU/ml, 402.04 mIU/ml and 70.28 mIU/ml (P < 0.01) at 3th, 7th, 12th months respectively. The positive rates of anti-HBs and GMT of anti-HBs became the highest at 7th month, then began to decrease sharply. At 3th, 7th, 12th months the positive rates of anti-HBs and GMT of anti-HBs were higher on female compared to male, but only GMT of anti-HBs was significantly different at 3th month; the positive rates of anti-HBs in below 35 years old group was higher than 35 and over years old group, but it was significantly different only at 12th month. GMT of anti-HBs between the two groups was no obvious difference. Local or systematic addictive reactions were not found in all the subjects in 3 days after injection. CONCLUSION: YDV is effective and safety to adults. The duration of anti-HBs should be further observed.

Adult↗

[A clinical observation of preserved donor tarsal plate transplantation for repair of tarsus defect].

OBJECTIVE: To investigate the effect of preserved donor tarsal plate transplantation on the repair of the tarsus defect at the time of eye lid tumor removal. METHODS: Donor tarsal plates preserved in pure glycerin were used for the repair of tarsus defects of 58 cases after the complete removal of the eye lid tumors. The grafts were covered with rotated or slid myocutaneous and conjunctival flaps. The associations of the effect with the blood supply, with the size and the preserved time of the donor tarsal plates, as well as with the follow-up time were analyzed by chi(2) test. RESULTS: Of the 43 cases whose plates were fully covered with conjunctival flaps, new blood vessels began growing into the donor tarsal plates one week after the operation. The grafts were vascularized one month later. The donor tarsal plates of 15 cases were only partly covered with conjunctival flaps. As a result, the grafts were vascularized in 2 -- 3 months, and there was dissolution to varying degrees at the surface of the exposed parts of the plates. The effects of the 43 cases with good blood supply were significantly better than the effects of 15 cases with poor blood supply (chi(2) = 5.81, P < 0.05). The sizes of the donor tarsal plates ranged from 5 x 10 mm(2) to 8 x 29 mm(2). Eleven cases were equal or shorter than half of the original sizes of donor tarsal plates, 34 cases were subtotal and 13 cases were total plates. The differences of the sizes led to different results (chi(2) = 6.28, P < 0.05). The preserved times of donor tarsal plates were from 1 week to 2.5 years. However, the results were similar in all cases (chi(2) = 0.99, P > 0.05). All the patients were followed up for 6 months to 10 and half years (mean, 1.8 years). The effects had no statistical significance (chi(2) = 0.85, P > 0.05). The cilia of the donor tarsal plates were preserved in 3 cases, but all of them were totally lost during post-operative one month. After operation slight entropion occurred in 8 cases, slight ectropion in 3 cases, lagophthalmos for 2 -- 3 mm in 7 cases, notch of the palpebral margin in 5 cases and thinness of the donor tarsal plates in 4 cases, but the functional and aesthetic results were normal. Thirty-one cases were cured, 11 cases acquired tangible results and 12 cases were improved. The total effective rate was 93.1%. CONCLUSIONS: The more blood supplies of the donor tarsal plates, the better the effects. So we must make all our efforts to improve the blood supplies of the donor tarsal plates. The effects were associated with the sizes of the plates, but not associated with the preserved times of the grafts and the follow-up times. Preserved donor tarsal plate transplantation for the repair of tarsus defect is a relatively simple operation, the rejection is slight and the result satisfactory, thus it is an ideal plastic material.

Adult↗