Biomedical subjects

Ping Hu

Publications and source records attributed to Ping Hu.

At least 55 records · Page 3Linked to original sources

PubMed2005

The "Kriging" model of spatial genetic structure in human population genetics.

This paper presents the application of Kriging technique in the field of human population genetics for quantifying the spatial genetic heterogeneity of HLA-A locus in the area of China,and for mapping its spatial genetic structure using the measurement of synthetic genetic structure (SPC) and the principal components (PC). Both principles of the method and the basic equations are given. The Kriging model has several advantages over other interpolation and smoothing methods. Firstly, it relies on the structure of the spatial genetic semivariogram model, which can be used to quantify the spatial genetic heterogeneity of the locus (loci) before mapping its spatial genetic structure. Secondly, it is virtually unbiased in the interpolation situation,where the location to be estimated is surrounded by data on all sides and is influenced within the range of these data. Thirdly, it allows of estimative error of interpolation, which can be used to appraise the predicting effect for the spatial estimation,and the error maps can be used to decide where to introduce new sampling population genetic data. However, the "Kriging" model also has some disadvantages. Firstly,when the theoretical spatial genetic semivariogram can not be fitted by any models, the "Kriging" model can not be set up. Secondly, if the Kriging model was built by a poor spatial genetic semivariogram,the Kriging estimation standard deviation is remarkably high in the whole area, hence the Kriging model can not be suitable to estimating the distribution of spatial genetic structure. In these situations,the interpolation algorithm, whose assumption is spatial random rather than spatial autocorrelation,such as the Cavalli-Sforza method in Genography, inverse distance-weighted methods, splines, should be used to estimate or map the distribution of spatial genetic structure.

Genetics, Population↗

PubMed2005

[The study of salivary-SIgA reaction to Streptococcus mutans in acid environment].

OBJECTIVE: To test the salivary immunoglobulin A antibody activity to Streptococcus mutans in normal with in acid environment. METHODS: Streptococcus mutans strains were isolated from 20 volunteers, serotyped by biochemical test and PCR, and genotyped by AP-PCR. Unstimulated secretions from submandibular glands and sublingual glands were collected from volunteers by modified collectors. Each identified Streptococcus mutans genotype was cultured in two groups: control group was cultured in BHI broth pH7.2 at 37 degrees C for 2 h; acid shock group were cultured in TYEG broth (pH5.5) at 37 degrees C for 2 h. Analysis of SIgA activity to Streptococcus mutans genotypes in different groups was detected by Western blot. RESULTS: (1) The SIgA of each individual could response to his own Streptococcus mutans strains and the reference strains; (2) The same individual had different SIgA activity to different genotype strains; (3) There were no significant difference between acid groups and control groups, in spite that some bands had strong or weak intensity. CONCLUSIONS: Although Streptococcus mutans could express acid shock proteins in stress, the present study suggests that these new proteins have no qualitative effect on the reaction of SIgA to Streptococcus mutans.

Adult↗

PubMed2005

[Studies on the optimized extraction technology of Paeonia suffruticosa].

OBJECTIVE: To obtain the optimized extraction technology of Paeonia suffruticosa by comparing several extraction method. METHOD: Extract P. suffruticosa by ethanol circumfluence, distillation-decoction, CO2-SFE and traditional decoction, and analyse the results according to the total extraction rate, extraction rate of paeono, extraction of other ingredients and production feasibility. RESULT: Total extraction rates of which are 12.66%, 13.51%, 7.28%, 7.56% respectively; extraction rates of paeonol are 2.45%, 2.26%, 0.31%, 1.15% in turn; Phenolic glycosides can be extracted by ethanol circumfluence, distillation-decoction, traditional decoction, but not by CO2-SFE. CONCLUSION: Distillation-decoction is the most proper extraction technology of P. suffuticosa at present.

Acetophenones↗

PubMed2005

[Dynamic changes in airway hyperresponsiveness as a result of allergen and therapeutic effects of budesonide in rats].

OBJECTIVE: To investigate the dynamic changes in airway hyperresponsiveness (AHR) in allergen-induced asthma in rats and the effects of budesonide. METHODS: Among 36 BALB/c female mice, 6 were randomized as negative control group (group C), the remaining mice were challenged with ovalbumin (OVA) to reproduce asthma. Kinetics of airway AHR of OVA-induced asthmatic mice was carried out as follows: on day 15, 18, 21 and 25 (A1, A2, A3, A4 groups), 6 mice were randomly chosen and sacrificed after measurement of airway AHR to investigate tidal volume (V(T)), airway resistance of expiring phase (R(A)), compliance of thorax and lung (C(T-L)) with different doses of methacholine chloride (MCH). In group B 6 mice were randomly chosen and treated with 1 mg budesonide aerosol once per day from day 15 to 17, then sacrificed on day 18. Their physiological and pathological changes were determined similarly to those of A2 group. RESULTS: (1) The increase of R(A) in group A1, A2 and A3 were significantly higher than that in group C when MCH reached the dose of 200 ng/g. (2) The decrease of C(T-L) in group A1 and A2 was significant with 100 ng/g and 200 ng/g MCH. (3) The value of V(T) markedly decreased in group A2 with 100 ng/g MCH and in all asthma model groups with 200 ng/g MCH than that in group C. (4) There was an eosinophil-dominant inflammatory infiltration in the asthma lungs, and the degree of infiltration peaked on day 15, and then alleviated afterwards. (5) With the dose of 200 ng/g MCH, the increase of R(A) in group B was significantly alleviated when compared with that in group A2, but there was no significant difference between group B and C. With the dose of 100 and 200 ng/g MCH, the decrease of C(T-L) in group B was significantly less marked compared with that in group A2 but there was no significant difference between group B and group C; the decrease of V(T) in group B was significantly lessened in degree when compared with that in group A2, while there was no statistical difference between group B and group C. The infiltration of inflammatory cells was obviously alleviated and the repair of airway epithelium was better in budesonide group. CONCLUSION: (1) Airway hyperresponsiveness increases greatly in mice challenged and sensitized with OVA, and it lasts for about 7 days and then declines afterwards. (2) Budesonide aerosol could effectively alleviate the eosinophil dominant inflammatory response and decrease AHR in the murine asthma model.

Allergens↗

PubMed2005

Spatial genetic structure of two HIV-I-resistant polymorphisms (CCR2-64 I and SDF1-3'A) alleles in population of Shandong Province, China.

OBJECTIVE: To explore the spatial genetic structure of two HIV-I-resistant polymorphisms (CCR2-64 I and SDF1-3'A) alleles in the population of Shandong Province, China. METHODS: Using the techniques of spatial stratified sampling and spatial statistics, the spatial genetic structure of the locus (CCR2-64 I and SDF1-3'A), which was shown to be important co-receptor for HIV infection, was quantified from the populations of 36 sampled counties of Shandong Province, and a total of 3147 and 3172 samples were taken for testing CCR2-64I and SDF1-3'A respectively from individuals without known history of HIV-I infection and AIDS symptoms. RESULTS: There were significantly spatial genetic structures of the two alleles at different spatial distance classes on the scale of populations, but on the scale of individuals, no spatial structure was found in either the whole area of Shandong Province or the area of each sampled county. Although the change of frequencies of the two alleles with geographic locations in Shandong Province both showed gradual increase trends, their changing directions were inverse. The frequency of CCR2-64I allele gradually increased from the southwest to the northeast, while the frequency of SDF1-3'A allele gradually increased from the northeast to the southwest. However the RH to AIDS of combined types of their different genotypes did not represent obvious geographic diversity on the whole area of the Province. CONCLUSION: The frequency of allele usually has some spatial genetic structures or spatial autocorrelation with different spatial distance classes, but the genotypes of individuals have random distribution in the same geographic area. Evaluating spatial distribution of the genetic susceptibility of HIV (AIDS) to CCR2-64I and SDF1-3'A alleles, should focus on the frequencies of combined genotypes of CCR2 and SDF1 based on the two-locus genotypes of each individual rather than the frequencies of CCR2-64I and SDF1-3'A alleles.

Acquired Immunodeficiency Syndrome↗

PubMed2005

[HPLC fingerprint for the Corydalis saxicola Bunting injection].

AIM: To establish the fingerprint of Corydalis saxicola Bunting injection. METHODS: It was performed by HPLC Kromasil column was used with acetonitrile and H2O as mobile phase. The flow rate was 0.5 mL x min(-1). The detection wavelength was 254 nm. The mass spectrometry detection was performed on a trap equipped with an ESI interface and operated in positive-ionization mode. RESULTS: Eleven components of Corydalis saxicola Bunting were identified by LC-MS and 7 of them were quantified. CONCLUSION: The fingerprint chromatogram could represent the characteristics of Corydalis saxicola Bunting injection. Evaluation of resemblances and results of precision were satisfactory. This method could be used as quality and quantity control.

Berberine↗

PubMed2005

[The "horse-shoe effect"of correspondence analysis for human population genetic structure and its population genetic explanation].

At present study, the reasons of "horse-shoe effect" in correspondence analysis for analyzing human population genetic structure was explained. Based on the structure of gene frequency matrix, we displaye the different patterns of Scallergram of correspondent analysis from different types of loci (HLA-A locus, and STR- CSF1PO locus in Chinese Han populations). The results indicate that different types of loci showed different patterns of Scallergram of correspondent analysis. When some alleles have very low frequency in the gene frequency matrix, there would be "horse-shoe effect" in the Scallergram of correspondent analysis. The reason is that the c2 distance measurement in correspondent analysis usually overrates the effect of the genes with low frequencies. To carry out the correspondent analysis of human population genetic structure, when the Scallergram presents "horse-shoe effect", one should examine the structure of gene frequency matrix, and confirm whether the "horse-shoe effect" shows the real pattern of population genetic structure. Only in this way, one can explain the "horse-shoe effect" correctly.

Alleles↗

PubMed2005

[Analysis and recognition of CD4 cell microscopic image].

This paper introduces the technology of recognizing CD4 cell by a computer, which successfully segments the objects from the background through image processing and analyses the four features including geometric features, optical density, color and texture features. The method based on Principal Component Analysis algorithm is used for feature extraction, and a Back Propagation neural network classifier is constructed, from which the CD4 cell can be well recognized. CD4 cell, image segmentation, feature analysis, Principal Component Analysis (PCA), Back Propagation (BP) neural network classifier is constructed, from which the CD4 cell can be well recognized.

Algorithms↗

PubMed2004

Roles of uroplakins in plaque formation, umbrella cell enlargement, and urinary tract diseases.

The apical surface of mouse urothelium is covered by two-dimensional crystals (plaques) of uroplakin (UP) particles. To study uroplakin function, we ablated the mouse UPII gene. A comparison of the phenotypes of UPII- and UPIII-deficient mice yielded new insights into the mechanism of plaque formation and some fundamental features of urothelial differentiation. Although UPIII knockout yielded small plaques, UPII knockout abolished plaque formation, indicating that both uroplakin heterodimers (UPIa/II and UPIb/III or IIIb) are required for plaque assembly. Both knockouts had elevated UPIb gene expression, suggesting that this is a general response to defective plaque assembly. Both knockouts also had small superficial cells, suggesting that continued fusion of uroplakin-delivering vesicles with the apical surface may contribute to umbrella cell enlargement. Both knockouts experienced vesicoureteral reflux, hydronephrosis, renal dysfunction, and, in the offspring of some breeding pairs, renal failure and neonatal death. These results highlight the functional importance of uroplakins and establish uroplakin defects as a possible cause of major urinary tract anomalies and death.

Animals↗

PubMed2004

A role for beta-actin in RNA polymerase III transcription.

When transcription from the human U6 snRNA gene is reconstituted with recombinant factors and purified RNA polymerase III (pol III), pol III must be treated with CK2 to be active. We show that highly purified pol III contains associated beta-actin, and beta-actin localizes to an active U6 promoter in vivo. Pol III immunoprecipitated from IMR90 cells treated with a genotoxic agent lacks associated beta-actin and is inactive in the reconstituted assay. Transcription is regained upon treatment of pol III with CK2 and addition of beta-actin. This suggests that beta-actin associated with pol III is essential for basal pol III transcription.

Actins↗

PubMed2004

CK2 phosphorylation of Bdp1 executes cell cycle-specific RNA polymerase III transcription repression.

RNA polymerase III (pol III) transcription from the human U6 snRNA promoter can be reconstituted with the recombinant factors SNAPc and Brf2-TFIIIB combined with purified pol III. In this system, CK2 treatment of the pol III complex is required for transcription, whereas treatment of Brf2-TFIIIB is inhibitory. Here we show that CK2 inhibits Brf2-TFIIIB by specifically phosphorylating its Bdp1 component. Bdp1 is phosphorylated by CK2 during mitosis, and this is accompanied by Bdp1 dissociation from the U6 promoter and from chromatin in general and by transcription repression. Remarkably, whereas inhibition of CK2 in mitotic extracts restores pol III transcription, inhibition of CK2 in active S phase extracts debilitates transcription. Thus, CK2 is directed to phosphorylate different targets within the basal pol III transcription machinery at different times during the cell cycle, with opposite transcriptional effects.

Casein Kinase II↗

PubMed2004

Penetrating cardiac wounds: principles for surgical management.

Stab wounds are the main type of penetrating cardiac injury in China and they have a fairly good prognosis when the patient receives expeditious and appropriate management. The objective of this study is to present the experience of managing the patients with penetrating cardiac injuries. A retrospective study involving 82 cases with penetrating wounds of the heart in the past 16 years was carried out. Stab wounds accounted for 86.58% of this series (71 of 82 patients). All 82 cases were treated operatively. The amount of preoperative infusion as fluid resuscitation for shock was less than 1,000 ml in 65.85% of the present study. Only in three patients was preoperative pericardiocentesis performed, yielding a false-negative result in one. Six patients sustaining cardiac arrest soon after arrival were subjected to emergency room thoracotomy (ERT), and five of them survived. The overall survival rate was 96.34%. One patient died of exsanguination due to injury of multiple chambers; of the remaining 2 deaths after operation 1 was associated with abdominal injuries and the other with failure of cerebral resuscitation. From the experience reported in this study, early establishment of diagnosis and prompt thoracotomy against time are the fundamental factors affecting the outcome of penetrating cardiac injuries. Preoperative massive transfusion and pericardiocentesis are not advocated.

Adolescent↗

PubMed2004

Critical role of endogenous Akt/IAPs and MEK1/ERK pathways in counteracting endoplasmic reticulum stress-induced cell death.

Endoplasmic reticulum (ER) stress has been implicated in the pathogenesis of many diseases and in cancer therapy. Although the unfolded protein response is known to alleviate ER stress by reducing the accumulation of misfolded proteins, the exact survival elements and their downstream signaling pathways that directly counteract ER stress-stimulated apoptotic signaling remain elusive. Here, we have shown that endogenous Akt and ERK are rapidly activated and act as downstream effectors of phosphatidylinositol 3-kinase in thapsigargin- or tunicamycin-induced ER stress. Introduction of either dominant-negative Akt or MEK1 or the inhibitors LY294002 and U0126 sensitized cells to ER stress-induced cell death in different cell types. Reverse transcription-PCR analysis of gene expression during ER stress revealed that cIAP-2 and XIAP, members of the IAP family of potent caspase suppressors, were strongly induced. Transcription of cIAP-2 and XIAP was up-regulated by the phosphatidylinositol 3-kinase/Akt pathway as shown by its reversal by dominant-negative Akt or LY294002. Ablation of these IAPs by RNA interference sensitized cells to ER stress-induced death, which was reversed by the caspase inhibitor benzyloxycarbonyl-VAD-fluoromethyl ketone. The protective role of IAPs in ER stress coincided with Smac release from mitochondria to the cytosol. Furthermore, it was shown that mTOR was not required for Akt-mediated survival. These results represent the first demonstration that activation of endogenous Akt/IAPs and MEK/ERK plays a critical role in controlling cell survival by resisting ER stress-induced cell death signaling.

Amino Acid Chloromethyl Ketones↗

PubMed2004

Inflammation in sympathetic ganglia proximal to sciatic nerve transection in rats.

Comparison was made between recruitment of T-lymphocytes and macrophages into lumbar sympathetic ganglia (SGs) and dorsal root ganglia (DRGs) following sciatic nerve transection in rats. In both control and lesioned SGs, resident (ED2+) macrophages expressed less major histocompatibility complex class II (MHC II), but MHC II+ macrophage density was higher, than in equivalent DRGs. The influx of T-cells was larger and the influx and activation of macrophages were more sustained in SGs than in DRGs. Only two of the five subtypes of macrophage that invade lesioned DRGs were recruited to SGs. While some MHC II+ cells phagocytosed dead sympathetic neurones, most phagocytes in SGs lacked a macrophage marker. The different patterns of response between ganglia may provide clues about macrophage involvement in neuronal death and hyperexcitability after peripheral nerve lesions.

Animals↗

PubMed2004

An improved method for acute isolation of neurons from the hippocampus of adult rats suitable for patch-clamping study.

An improved method is described for fast and reliable isolation of neurons from hippocampus of adult rats by a combination of mechanical and enzymatic means. The procedure allows the isolation of neurons from 500-600-d-old rats (over 300 g), preserving the proximal dendritic structure without impairing the electrical characteristics of the cells. Morphologically distinct neurons can be recognized. Using cell-attached, inside-out and whole-cell configurations of patch clamp technique, it was shown that the enzymatically isolated neurons in hippocampus from rats weighing more than 300 g exhibited voltage-gated calcium, sodium and potassium currents, outwardly rectifying chloride channel and large conductance Ca(2+)-activated potassium channel currents. Approximately, 95% of healthy cells allowed the formation of giga-ohm seals.

Animals↗

PubMed2004

Deletion mapping suggests that the 1p22 melanoma susceptibility gene is a tumor suppressor localized to a 9-Mb interval.

Loss of the short arm of chromosome 1 is frequently observed in many tumor types, including melanoma. We recently localized a third melanoma susceptibility locus to chromosome band 1p22. Critical recombinants in linked families localized the gene to a 15-Mb region between D1S430 and D1S2664. To map the locus more finely we have performed studies to assess allelic loss across the region in a panel of melanomas from 1p22-linked families, sporadic melanomas, and melanoma cell lines. Eighty percent of familial melanomas exhibited loss of heterozygosity (LOH) within the region, with a smallest region of overlapping deletions (SRO) of 9 Mb between D1S207 and D1S435. This high frequency of LOH makes it very likely that the susceptibility locus is a tumor suppressor. In sporadic tumors, four SROs were defined. SRO1 and SRO2 map within the critical recombinant and familial tumor region, indicating that one or the other is likely to harbor the susceptibility gene. However, SRO3 may also be significant because it overlaps with the markers with the highest 2-point LOD score (D1S2776), part of the linkage recombinant region, and the critical region defined in mesothelioma. The candidate genes PRKCL2 and GTF2B, within SRO2, and TGFBR3, CDC7, and EVI5, in a broad region encompassing SRO3, were screened in 1p22-linked melanoma kindreds, but no coding mutations were detected. Allelic loss in melanoma cell lines was significantly less frequent than in fresh tumors, indicating that this gene may not be involved late in progression, such as in overriding cellular senescence, necessary for the propagation of melanoma cells in culture.

Base Sequence↗

PubMed2004

Category norms as a function of culture and age: comparisons of item responses to 105 categories by american and chinese adults.

Understanding how aging influences cognition across different cultures has been hindered by a lack of standardized, cross-referenced verbal stimuli. This study introduces a database of such item-level stimuli for both younger and older adults, in China and the United States, and makes 3 distinct contributions. First, the authors specify which item categories generalize across age and/or cultural groups, rigorously quantifying differences among them. Second, they introduce novel, powerful methods to measure between-group differences in freely generated ranked data, the rank-ordered logit model and Hellinger Affinity. Finally, a broad archive of tested, cross-linguistic stimuli is now freely available to researchers: data, similarity measures, and all stimulus materials for 105 categories and 4 culture-by-age groups, comprising over 10,000 fully translated unique item responses.

Adolescent↗

PubMed2004

Planning of randomized early detection trials.

Consider a randomized clinical trial to evaluate the benefit of screening an asymptomatic population. Suppose that the subjects are randomized into a usual care and a study group. The study group receives one or more periodic early detection examinations aimed at diagnosing disease early, when there are no signs or symptoms. Early detection clinical trials differ from therapeutic trials in that power is affected by: i) the number of exams, ii) the time between exams and iii) the ages at which exams will be given. These design options do not exist in therapeutic trials. Furthermore; long-term follow-up may result in a reduction of power. In general, power increases with number of examinations, and the optimal follow-up time is dependent on the spacing between examinations. Clinical trials in which the usual care group receives benefit are also discussed. Two designs are discussed, for example the 'up-front design' in which all subjects receive an initial exam and then are randomized to the usual care and study groups and the 'close-out design' in which the usual care group receives an exam which is timed to be given at the same time as the last exam in the study group. Both families of designs significantly reduce the power. Power calculations are made for two clinical trials, which actually used these two designs.

Adult↗