Biomedical subjects

M Yu

Publications and source records attributed to M Yu.

At least 127 records · Page 7Linked to original sources

PubMed2000

[Recognition of multiple information of human auricular points by linear model].

The three variables of the electric characteristic of human auricular points can be regarded as observed targets that reflect the physiologic or pathologic changes. Medical principle design follows the theory of the channels and collaterals and the viscera-state doctrine of traditional Chinese medicine and that of the pattern recognition. The linear integration model can be established by drawing the characteristic variables of the correlation groups of the auricular points and applying the multi-variable normalization. With this model, the recognition of the three variations of the auricular points can be of use for differential diagnosis. In this paper, the test to identify the cases of Upper-Digestive tract achieves good result. This research, based on the integration of modern science with traditional Chinese medicine, provides a method for building the specialist system of the auricular point diagnosis, and probably has some prospect in clinical application.

Acupuncture Points↗

PubMed2000

[Recombinant human IGF-1 prevents type 1 diabetes in female non-obese diabetic mice].

OBJECTIVES: To study whether recombinant human (rhIGF-1) can prevent the onset of type 1 diabetes in female non-obese diabetic (NOD) mice, and its influence on their immune system. METHODS: Ten mice were injected intraperitonally (i.p.) rhIGF-1 37.5 micrograms.kg-1.d-1 at 4 weeks old for 2 weeks at treated group; and the same volume of normal solution (NS) was used in 10 mice as control group. All mice were killed at 40 weeks old or 2 weeks after the diagnosis of diabetes. Blood glucose of tail vein blood was measured weekly using a glucometer. At the end of the experiment, serum C-peptide levels and antibodies to glutamic acid decarboxylase (GAD) were detected with RIA and ELISA methods, respectively. T cell subsets of spleen were undertaken two-color FACS analysis using Cy-chrome anti-CD4 and FITC-anti-CD8 monoclonal antibodies; pancreatic histopathology and immunohistochemistry of T cell were conducted. RESULTS: Treatment with rhIGF-1 at 4 weeks old reduced the total incidence of diabetes (40% vs 90%, P < 0.05) and delay its onset [(26.25 +/- 3.68) weeks vs (21.6 +/- 6.7) weeks] compared with control group (P < 0.05). RhIGF-1 showed the growth effect on NOD mice, because the wet weight of spleen and pancreas of groups treated with rhIGF-1 were higher than that of control mice (P < 0.01, respectively). Only 3.24 (0.92 islets/mouse) was observed in the control group at death, but they increased to 13.2 (3.14 islets/mouse) in the rhIGF-1 group. The insulitis score decreased from 0.738 +/- 0.194 to 0.098 +/- 0.035 in the later group. A marked reduction of insulitis severity of pancreatic glands was also observed. A strong proliferative response of CD8+ T subsets in splenocytes occurred in rhIGF-1 treated mice, and the imbalance of CD4+/CD8+ subgroup in control mice (2.03 +/- 0.72) was corrected in the later group (0.53 +/- 0.22, respectively, P < 0.01). The lymphocytes infiltrating islets in the rhIGF-1 group showed a reduction of CD4+ cells, and they existed only outside of islets. CONCLUSIONS: These data demonstrated the preventive effects of rhtIGF-1 on the onset of type 1 diabetes and the severity of insulitis in female NOD mice. The mechanisms of these effects may be related to the induction of a CD8+ Ts cell response that inhibits the spontaneous development of autoreactive CD4+ T subsets response, or inhibiting the homing of CD4+ T cells to islets.

Animals↗

PubMed2000

[Rapid detection of drug resistant HIV -1 to reverse transcriptase and protease inhibitors in HIV-infected patients receiving highly active antiretroviral therapies].

OBJECTIVE: To develop and validate a rapid and sensitive method that can be used to detect emergence of HIV-1 drug resistant viruses in HIV-infected patients receiving highly active antiretroviral therapies (HAART). METHODS: HIV-1 viral RNA was extracted from plasma and amplified by nested RT-PCR. Nucleotide sequences of the reverse transcriptase (RT) and protease (PR) genes were determined by automated DNA sequencing. RESULTS: RT and PR sequences can be reliably determined with a minimum 2,000 copies/ml of viral RNA in plasma. Emergence of drug resistant viruses can he detected as soon as it reached to > 25% of the total viral populations. By using this method, drug-resistant viral populations were found to correlate with rebound of viral RNA level after prolonged antiretroviral therapies in HIV-infected children. CONCLUSIONS: This rapid and sensitive HIV-1 genotyping method can be used to predict and confirm emergence of HIV-1 drug resistance in HIV-infected patients receiving HAART.

Drug Resistance, Viral↗

PubMed2000

[Clinical study on super-selective camptothecin microsphere's embolization of internal iliac artery for bladder carcinoma].

OBJECTIVE: To evaluate the efficacy of camptothecin microsphere's embolization of the internal iliac artery for bladder carcinoma. METHODS: Eighteen patients with inoperable and advanced bladder carcinoma were treated with camptothecin microsphere's super-selective embolization of the internal iliac artery. RESULTS: Tumor size was reduced significantly, and tumor cells were damaged to various degrees in 17 patients. Adverse effects were not found. CONCLUSION: Camptothecin microsphere's embolization of the internal iliac artery is a safe and effective therapy for inoperable and advanced bladder carcinoma.

Adult↗

PubMed2000

[Dynamic changes in dermal cell cycles, contents of hydroproline and ratios of collagen type I/III in the burned wound].

OBJECTIVE: To study the dynamic changes in the dermal cell cycles contents of hydroproline and ratios of collagen type I/III in the burned wound. METHODS: The dermal cell cycles, contents of hydroproline, ratios of collagen type I/III and pathologic changes were dynamically observed in 48 deep partial burn rats (TBSA 10%), attempting to investigate the process of deep partial burn wound healing. RESULTS: The percentage of S-phase reached the highest point on PBD 10. On PBD21, it was still significantly higher than that of normal group. OHP increased gradually after burn, and peaked on PBD14. On PBD21, the level of OHP was still significantly higher than that of normal group. The ratios of collagen type I/III decreased gradually and significantly lower than those of the normal group after burn. The strips of WBC infiltrating into wound were observed on PBD3, 7 and 10. On PBD 14, a large number of regenerative epidermal cells crept over wound surface. CONCLUSIONS: The inflammation is obvious from PBD3 to PBD10. The proliferation of dermal cell and the synthesis, deposition of new collagen are predominant from PBD10 to PBD14, and the repair of dermis is not complete on PBD21. The proliferation and migration of epidermal cells are major activities from PBD14 to PBD21.

Animals↗

PubMed2000

[Studies on three types of natural foci of tsutsugamushi disease in eastern part of China].

OBJECTIVE: In order to identify the types of natural foci of tsutsugamushi disease to provide basis for prevention, a series of studies were carried out in Fujian, Zhejiang and Jiangsu Provinces. METHODS: (1) Representative points for investigation in three Provinces were selected. (2) Data on geographical landscape and epidemiology were collected. (3) Field survey and experimental studies on rats and chigger mites in relation to the disease. RESULTS: Three representative types of natural foci of tsutsugamushi disease were demonstrated. They were (1) Coastal island type, mainly in Fujian with major reservoir host as Rattus losea and major vector mite as L. deliense; prevalent season: summer; type of Rt: Gilliam: (2) Inland mountain - forest type in Zhejiang with major reservoir host as R. confucianus and major vector miteas L. gaohuense; prevalent season: summer; type of Rt: Gilliam. (3) Inland plain - hills type in Jiangsu with major reservoir hosts: Apodemus agrarius, R. confucianus, R. norvegicus and Crocidura lasiura; major vector mite: L. scutellare; prevalent seasons: autumn and winter; type of Rt: Kawasaki. CONCLUSION: The types of Rt, reservoir hosts, vector chigger mites and epidemiological features of tsutsugamushi disease in Fujian, Zhejiang and Jiangsu Province were found different. Thus, the preventive measures should also be distinct from one another.

Animals↗

PubMed2000

[Toxic effects of aluminum on human embryonic cerebral neurocytes in vitro studies].

OBJECTIVE: To study the toxic effect of aluminum on human embryonic cerebral neurocytes in vitro studies. METHODS: Human embryonic cerebral neurocytes were divided into three groups (control, low Al and high Al groups). The growth, development and morphology of neurocytes were observed by light and electron microscopy. The protein, DNA, lipid peroxide (LPO) contents and the activity of neuron-specific enolase (NSE) and cholinesterase (CHE) of neurocytes were detected. RESULTS: The number of viable cells in high Al group was significantly lower than that in the control group (P < 0.05). The number of swelling, degenerated and necrotic cells was significantly increased in high Al group. The DNA content and the activity of NSE and CHE of neurocytes were significantly decreased with the increase of Al concentrations (P < 0.05). The LPO content of neurocytes in the high Al group was significantly higher than that in the control group (P < 0.05). There was a positive correlation between the Al dose and LPO content of neurocytes (P < 0.05). The electron microscopy study showed that the membrane structure of cell was damaged in the high Al group and the arrangement of microtubules in the processes was disordered. CONCLUSIONS: The growth, development and function of human embryonic cerebral neurocytes was inhibited in the high Al group. The neurotoxicity of Al may be caused by lipid peroxidation and the damage of cell membrane.

Aluminum↗

PubMed2000

[Selection of population-based controls in pair-matched case-control study analyzing risk factors for lung cancer].

OBJECTIVE: To explore the methods to select population-based controls in a pair-matched case-control study of risk factors for lung cancer and to lay foundation for development of their monitoring in urban areas. METHODS: Data of cases of lung cancer and their three different groups of pair-matched control based on population from the "Study on surveillance for incidence and mortality of common malignant tumor and their risk factors" in Beijing, Tianjin, Shanghai and Chongqing were personally-interviewed and analyzed with conditional multivariate logistic regression using STATA software involving 1 312 pairs aged 35 - 74. RESULTS: Odds ratios for main risk factors were consistent with the three groups of controls, and there was certain difference in ORs for dietary factor, etc. between the studies with three difference control groups. There was little differences in frequencies of exposure to risk factors between studies with neighbor-controls and normal-controls. Cigarette smoking, lower body mass index, long-time depressed mood, lower capability of emotion regulation, previous respiratory diseases, family history of cancer in the first-degree relatives significantly increased the risk for lung cancer after adjusted for age, education level, family average income and other risk factors. CONCLUSION: It was feasible to use population-based controls instead of neighbor controls in surveillance for risk factors of lung cancer.

Adult↗

PubMed2000

[A case-control study of the risk factors of lung cancer in Beijing, Tianjin, Shanghai, Chongqing metropolitan areas].

OBJECTIVE: To analysis the risk factors of lung cancer and determine the surveillance index in urban areas in four metropolises in China. METHODS: The paper used the data from the in-person interviews of National Research on Malignant Tumor Morbidity, Mortality and Surveillance Methods in 1996. We carried out a 1:1 matched case-control study based on population involving 1 312 cases and 1 312 neighborhood controls aged 35 - 74 from Beijing, Tianjin, Shanghai, Chongqing urban areas. The relationships between risk factors and lung cancer were analyzed by conditional univariant and multivariate logistic regression on the computer package, STATA. RESULTS: Cigarette smoking, lower body mass index, longtime depressed mood, lower capability of emotion regulation, previous respiratory diseases, family history of cancer in first-degree relatives significantly increased the risk of lung cancer after adjusted by age, education, family average income and other risk factors. The odds ratios of these risk factors were 3.46 (95% CI 2.70 - 4.45), 1.18 (95% CI 1.22 - 1.40), 2.64 (95% CI 1.95 - 3.57), 2.71 (95% CI 2.02 - 3.65), 2.28 (95% CI 1.81 - 2.88), 1.79 (95% CI 1.38 - 2.32), respectively. The odds ratio associated with the highest quartile of fresh vegetables consumption compared with the lowest was 0.75 (95% CI 0.65 - 0.87), showed an inverse relationship. Exercising more often had a significant inverse association between cases and controls, and its odds ratio was 0.81 (95% CI 0.74 - 0.89). CONCLUSION: Cigarette smoking, psychological factor, previous respiratory diseases and family history of cancer were the main risk factors of lung cancer in four cities. They were the important surveillance index of lung cancer. The relation between lung cancer and environmental tobacco smoke, dietary factors and the factors related with female etc. should conduct further studies or special studies which defined the exposures carefully and exactly.

Aged↗

PubMed2000

[Study on the clinical characteristics of biphenotypic acute leukemia].

OBJECTIVE: To analyze the biological characteristics and the treatment outcome of adult biphenotypic acute leukemia. METHODS: Immunophenotypes were examined using indirect immunofluorescence method. Biphenotypic acute leukemia (BAL) was diagnosed according to EGIL scoring system. RESULTS: (1) The incidence of BAL in acute leukemia was 3.4%. Percentage for coexpression of B lymphoid and myeloid antigens was 68.4%, for T lymphoid and myeloid antigens 21.1%, for B, T lymphoid and myeloid antigens 10.5%. (2) CD(34) was expressed in 43.75% of the BAL cases. (3) Cytogenetic analysis revealed normal and abnormal karyotypes in 41.7% and 58.3% of the BAL cases, respectively. (4) Six of 19 patients achieved completed remission (CR), but the disease free survivals were all less than 6 months. Treatment outcomes were negatively related to the expression of CD(34) antigen and cytogenetic findings. The BAL patients were poorly responded to therapeutic regimens directed to AML. CONCLUSION: Coexpression of B/M antigens is the commonest subtype in BAL. BAL had a poor prognosis, especially treated with induction regimen directed to AML.

Acute Disease↗

PubMed2000

[Comparison of total saponin content in three wild species of Gynostemma on Mount Emei].

Analysed by TLC and spectrometry, the content of the total saponin in three wild species of Gynostemma on Mount Emei is found to be the highest in July and to be the lowest in the seedling stage. Among the three, the content of the total saponin in Gynostemma pentaphyllum is the highest, that in Gynostemma pubescens lower and that in Gynostemma longipes the lowest.

Altitude↗

PubMed2000

[Effect of Tripterygium Wilfordii Hook T4 monomer on proliferation and interleukin-6 production of synovial fibroblasts of patients with rheumatoid arthritis].

OBJECTIVE: Tripterygium Wilfordii Hook multi-glycosides T2 has been wildly used in China in treatment of RA. T4 was abstracted from T2 and was reported much more efficient in anti-inflammatory and immune suppression than T2. This study was to investigate the effect Tripterygium Wilfordii Hook T4 monomer on proliferation and interleukin-6 production of synovial fibroblasts of patients with rheumatoid arthritis. METHODS: Synovium was obtained from patients with rheumatoid arthritis undergoing synovectomies or joint replacement. Cultures of synovial fibroblasts were established. After 3 generations, cultured synovial fibroblasts were stimulated with IL-1. Then 1.5 ng/ml, 5 ng/ml and 15 ng/ml T4 were added, and synovial fibroblasts were cultured in the presence of T4 for 48 hours. Cell proliferation was assayed using MTT method. IL-6 level of supernatant was measured by ELISA. RESULTS: Proliferation of synovial fibroblasts was inhibited by T4. The proliferation inhibition effect of T4 was dose dependent and inhibition rate was 5.18%, 10.95% and 21.37%, respectively. And T4 had no effect on IL-6 production by IL-1 stimulated synovial fibroblasts. CONCLUSIONS: T4 might control the disease activity of RA by inhibiting the proliferation of synoviocyte. And T4 might not influence the concentration of IL-6 in synovial fluid, as a central effect, since IL-6 has protective effect on articular cartilage.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1999

Myocardial expression of rat bradykinin receptors and two tissue kallikrein genes in experimental diabetes.

To characterize the role of the kallikrein-kinin system in diabetic cardiopathy, we studied the effect of streptozotocin (STZ) on the regulation of the myocardial bradykinin (BK) receptors, the B1 and B2 type, and two tissue kallikrein genes, rat kallikrein 1 (rKLK1) and rKLK7, in severely hyperglycemic rats. Experiments were performed in STZ-induced diabetic male Wistar rats (n = 7) and compared to controls (n = 7). After extraction of myocardial total RNA, specific oligonucleotides were used to generate reverse transcription PCR (RT-PCR) products from myocardial rKLK1 and rKLK7 mRNA. Southern blot analyses of these RT-PCR products were hybridized with appropriate gene-specific oligonucleotide probes. Myocardial B1 and B2 receptor expression were analyzed by RNase protection assays using specific probes from the coding region of the receptor genes. Twelve weeks after diabetes induction, the rats were normotensive and hyperglycemic and polyuric. We observed an impairment of the main myocardial kinin-forming enzymes, indicated by a reduction of the expression of both, rKLK1 and rKLK7. At this time the myocardial expression of the B1 receptor was not detectable in either group. Thus, the B1 receptor does not play a regulatory role in either the healthy or in STZ-diabetic heart. In contrast, the B2-receptor expression was detectable but did not differ significantly in either group. The reduced synthesis of myocardial tissue KLK implies a reduced capacity to generate BK in diabetic rats. This reduction is not compensated by elevated BK receptor levels. We suggest that alterations of the KKS may contribute to myocardial dysfunction in diabetes mellitus.

Animals↗

PubMed1999

Characterization of the human Forssman synthetase gene. An evolving association between glycolipid synthesis and host-microbial interactions.

Differences in glycolipid expression between species contribute to the tropism of many infectious pathogens for their hosts. For example, we demonstrate that cultured human and monkey urinary epithelial cells fail to bind a canine Escherichia coli uropathogenic isolate; however, transfection of these cells with the canine Forssman synthetase (FS) cDNA enables abundant adherence by the same pathogen, indicating that addition of a single sugar residue to a glycolipid receptor has marked effects on microbial attachment. Given the contribution of glycolipids to host-microbial interactions, we sought to determine why human tissues do not express Forssman glycolipid. Query of the GenBank(TM) data base yielded a human sequence with high identity to the canine FS cDNA. Reverse transcription polymerase chain reaction and Northern blotting demonstrated the presence of FS mRNA in all tissues examined. A human FS cDNA was characterized, revealing identities with the canine FS gene of 86 and 83% at the nucleotide and predicted amino acid sequences, respectively. In contrast to the canine FS cDNA, transfection of COS-1 cells with the human FS cDNA resulted in no detectable FS enzyme activity. These results suggest that variability in glycolipid synthesis between species is an important determinant of microbial tropism. Evolutionary pressure from pathogenic organisms may have contributed to diversity in glycolipid expression among species.

Amino Acid Sequence↗

PubMed1999

Genomic sequence, structural organization, molecular evolution, and aberrant rearrangement of promyelocytic leukemia zinc finger gene.

The promyelocytic leukemia zinc finger gene (PLZF) is involved in chromosomal translocation t(11;17) associated with acute promyelocytic leukemia. In this work, a 201-kilobase genomic DNA region containing the entire PLZF gene was sequenced. Repeated elements account for 19.83%, and no obvious coding information other than PLZF is present over this region. PLZF contains six exons and five introns, and the exon organization corresponds well with protein domains. There are at least four alternative splicings (AS-I, -II, -III, and -IV) within exon 1. AS-I could be detected in most tissues tested whereas AS-II, -III, and -IV were present in the stomach, testis, and heart, respectively. Although splicing donor and acceptor signals at exon-intron boundaries for AS-I and exons 1-6 were classical (gt-ag), AS-II, -III, and -IV had atypical splicing sites. These alternative splicings, nevertheless, maintained the ORF and may encode isoforms with absence of important functional domains. In mRNA species without AS-I, there is a relatively long 5' UTR of 6.0 kilobases. A TATA box and several transcription factor binding sites were found in the putative promoter region upstream of the transcription start site. PLZF is a well conserved gene from Caenorhabditis elegans to human. PLZF paralogous sequences are found in human genome. The presence of two MLL/PLZF-like alignments on human chromosome 11q23 and 19 suggests a syntenic replication during evolution. The chromosomal breakpoints and joining sites in the index acute promyelocytic leukemia case with t(11;17) also were characterized, which suggests the involvement of DNA damage-repair mechanism.

Alternative Splicing↗

PubMed1999

Adaptive numerical morphological filter for identifying chromatographic signals.

A morphological algorithm has been proposed to filter away impulsive noises confounded in the chromatographic signal. Compared with the conventional median filtering method, the results showed that the proposed method has the advantages of a better filtering effect and less distortion. In particular, the morphological filter with adaptive scale gives very good results.

Algorithms↗

PubMed1999

Cloning and characterization of a human genotoxic and endoplasmic reticulum stress-inducible cDNA that encodes translation initiation factor 1(eIF1(A121/SUI1)).

We report the cloning and characterization of a DNA damage-inducible (DDI) transcript DDI A121. The full-length human DDI A121 cDNA contains an open reading frame of 113 amino acids, corresponding to a protein of 12.7 kDa. The deduced amino acid sequence of A121 shows high homology to the yeast translation initiation factor (eIF) sui1 and also exhibits perfect identity to the partial sequence of recently purified human eIF1. Expression of human A121 corrected the mutant sui1 phenotype in yeast, demonstrating that human A121 encodes a bona fide translation initiation factor that is equivalent to yeast sui1p. The mammalian A121/SUI1 gene exhibits two transcripts (1.35 kilobases and 0.65 kilobases) containing a common coding region but differing in their 3'-untranslated region. The long and short A121/SUI1 mRNAs are differentially regulated by genotoxic and endoplasmic reticulum stress. The genotoxic stress induction of A121/SUI1 mRNA is conserved in both humans and rodents and occurs in a p53-independent manner. Our identification of a stress-inducible cDNA that encodes eIF1 suggests that modulation of translation initiation appears to occur during cellular stress and may represent an important adaptive response to genotoxic as well as endoplasmic reticulum stress.

Amino Acid Sequence↗

PubMed1999

Spontaneous regression of primary autoreactivity during chronic progression of experimental autoimmune encephalomyelitis and multiple sclerosis.

Experimental autoimmune encephalomyelitis (EAE) is a widely used animal model for multiple sclerosis (MS). EAE is typically initiated by CD4(+) T helper cell type 1 (Th1) autoreactivity directed against a single priming immunodominant myelin peptide determinant. Recent studies have shown that clinical progression of EAE involves the accumulation of neo-autoreactivity, commonly referred to as epitope spreading, directed against peptide determinants not involved in the priming process. This study directly addresses the relative roles of primary autoreactivity and secondary epitope spreading in the progression of both EAE and MS. To this end we serially evaluated the development of several epitope-spreading cascades in SWXJ mice primed with distinctly different encephalitogenic determinants of myelin proteolipid protein. In a series of analogous experiments, we examined the development of epitope spreading in patients with isolated monosymptomatic demyelinating syndrome as their disease progressed to clinically definite MS. Our results indicate that in both EAE and MS, primary proliferative autoreactivity associated with onset of clinical disease invariably regresses with time and is often undetectable during periods of disease progression. In contrast, the emergence of sustained secondary autoreactivity to spreading determinants is consistently associated with disease progression in both EAE and MS. Our results indicate that chronic progression of EAE and MS involves a shifting of autoreactivity from primary initiating self-determinants to defined cascades of secondary determinants that sustain the self-recognition process during disease progression.

Acute Disease↗