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Biomedical subjects

X Wei

Publications and source records attributed to X Wei.

At least 73 records · Page 4Linked to original sources
PubMed2000

[Detection of minimal residual disease in childhood hematological malignancies and its clinical significance].

OBJECTIVE: Exploring the detection of minimal residual malignant cells in bone marrow from children with hematological malignancies to predict the prognosis. METHODS: Seventy-five patients with acute lymphoblastic leukemia (ALL), stage IV non-Hodgkin's lymphoma or stage IV neuroblastoma were studied. Complete remission was maintained for over 3 months before the detection. Minimal residual disease was detected by polymerase chain reaction (PCR) for IgH and TcRgamma rearrangements in lymphoid tumors by reverse transcriptase-polymerase chain reaction (RT-PCR) for neuroblastoma patients. RESULTS: Thirty five patients were positive for minimal residual disease, and 21 of them (60%) relapsed 3 - 40 months later, while only 7 (17%) negative patients relapsed (chi(2) = 12.59, P < 0.01). CONCLUSION: Minimal residual disease detection in bone marrow by PCR might predict prognosis in some childhood hematological malignancies.

Adolescent↗
PubMed2000

[Study of xixin, duzhong and mixture to the antioxidant system of D-galactose-induced senile mice].

D-galactose induced mice aging model were used in this experiment. This study investigated the effect of the herb on the activity of superoxide dismutase(SOD), glutahione peroxidase (GSH-Px) and NOS, in order to know the damages degree of body by free radical and determine the changes of above index after giving Duzhong, Xixin and their Mixture 15, 30 and 45 days, at the same time, the mechanism of their effect on antiaging was probed. The results were as follows: The activity of SOD, GSH-Px and NOS was increasing before middel age and decreasing after middelage(P < 0.01); Xixin and Duzhong could enhance the activity of SOD, GSH-Px and NOS; The time of effect for mixture and Duzhong to above index was short than Xixin's. The time of Mixture and Duzhong was 15 days, and Xixin was 30 days.

Aging↗
PubMed2000

[Histological study of the local-regional invasion of pyriform sinus carcinoma].

OBJECTIVE: In order to offer the basis for the operation of the pyriform sinus carcinoma, the local-regional invasion patterns of the pyriform sinus carcinoma were investigated. METHODS: Twenty-six surgical specimens obtained from patients who undergone laryngopharyngectomy were subjected to a whole organ section study. RESULTS: Tumors located in the lateral wall of the pyriform sinus spread mainly towards the lateral wall of the hypopharynx. Tumors located in the inner wall of the pyriform sinus spread mainly towards the larynx and opposite side pyriform sinus, the paraglottic space and thyroid cartilage were particularly frequent invaded. It was rare of the invading of the cricoid cartilage. The invasion of the epiglottis and preepiglottic space across the midline had not been found. There were two invading routines, the paraglottic space and preepiglottic space. The invasion of the paraglottic space was through the aryepiglottic fold and the inner surface of the thyroid cartilage. The invading of the preepiglottic space was through the aryepiglottic fold and the upper part of the inner surface of the thyroid cartilage. CONCLUSIONS: The invading of the preepiglottic space was not the contraindication of the partial laryngectomy. It is practicable to preserve the laryngeal function in most of the patients while tumors located on the lateral or inner wall of the pyriform sinus. There was a tendency to the invading to the contralateral side in the inner wall of the pyriform or postcricoidarytenoid region. Attention should be paid to the submucosal spreading in the postcricoidarytenoid region.

Adult↗
PubMed2000

Final report about Stage II Collaboration Project on Leprosy Rehabilitation.

OBJECTIVE: To undertake the pilot experiments of prevention of disability (POD) in 14 different geographical areas to serve as examples for future development of rehabilitation work in China and in Asia. METHODS: According to the principles and national criterion, 27 000 people affected by leprosy were selected and assessed using disability record forms at beginning and followed up regularly for observing changes of different indicators. RESULTS: A total of 197 neuritis cases were detected and treated with prednisolone out of 1 407 new or active cases. Self-care training of eyes, hands and feet were conducted for 10 500 disabled people affected by leprosy. Comprehensive therapy was given to 1 804 cases having complicated ulcers of which 1 055 cases have got their ulcers healed. Out of 706 prostheses, 613 were given to patients with satisfactory results. Surgical treatment was given to 269 cases and 251 have shown good progress. CONCLUSION: Most of patients have got benefit from the project in function or appearance which is very helpful for their going back to the society and agreed by foreign experts during the final evaluation. The experiences from the project can be implemented in the whole country.

China↗
PubMed2000

[Spectral study of the microenviroment change of aromatic amino-acid residues in BSA induced by pH].

The microenvironment change of aromatic amino-acid residues in BSA at various pH were studied by fluorescence spectra and ultraviolet absorption spectra. It suggested that the change of protein surface and surface hydrophobicity from result. Compared to neutral pH, the Trp microenvironment seemed to be more hydrophobic at lower pH indicating less local surface hydrophobicity of BSA. At higher pH, the protein undergo conformational changes and unhold, the more buried Phe exposed to solvents consistent with stronger surface hydrophobicity of BSA.

Amino Acids, Aromatic↗
PubMed2000

[Kinetic fluorimetric determination of trace oxalate].

A new kinetic fluorimetric method for the determination of trace oxalate is described. The method is based on the enhancing effect of oxalate on the oxidation of butyl rhodamine B by potassium dichromate in the solution of hydrochloric acid. The linear range of the determination is 1.20-10.0 micrograms.mL-1. This method has been used to determine trace oxalate in spinach with satisfactory results.

Fluorometry↗
PubMed2000

[Study on the determination of free iron oxide in soil extract by FIA-ICP-AES].

Free iron oxide in soil extract is determined by flow injection analysis-inductively coupled plasma-atomic emission spectrometry. The effects of the volume of the loading sample and the concentration of the extractants(NH2OH.HCl,H2C2O4) were investigated. When 50 microL sampling ring is selected and the concentration of two extractants is controlled under 10 mg.mL-1, sprayer nozzle is not blocked and feeding is smooth, the background interference is checked effectively as well. The recoveries of standard addition are 97.6%-100% with precision 2.3%-3.5% RSD(n = 5).

Ferric Compounds↗
PubMed1999

Differential display and cloning of the hippocampal gene mRNas in senescence accelerated mouse.

Identification of genes that are specifically expressed in the hippocampus of senescence accelerated mouse (SAM) is important for understanding the molecular basis of the pathological changes in the brain and of the deterioration of learning and memory in SAM-prone/8 (SAMP8), a substrain of SAM. The differential display technique was applied to compare mRNAs expression between SAMP8 and SAM-resistance 1 (SAMR1), another substrain of SAM. Complementary DNA fragments corresponding to several apparently differentially expressed mRNAs were recovered and sequenced. Six differentially expressed cDNA bands were identified. Sequence analyses demonstrated that W4 and W5 cDNA fragments corresponded to unknown genes. W1 and W6 showed 66.1 and 62.3% homology to rat GTP-exchange protein (eIF-2B) and rat phospholipase D, respectively, while W2 and W3 showed 89.2 and 90.8% homology to human bullous pemphigoid antigen and human glucogen debranching enzyme isoform 1/2/3/4/6, respectively. The results suggested that these genes are closely related to the malfunction of the brain in SAM.

Aging↗
PubMed1999

Maturation-dependent durability of spontaneous cartilage repair in rabbit knee joint.

The spontaneous healing of osteochondral defects in the knee joints of immature rabbits within the first 12 weeks after surgery showed a faster filling and earlier tissue specialization than in adult animals. The purpose of the present study was to investigate whether the better short-term quality of spontaneous repairs in immature animals lasted over a period of 48 weeks. A full-thickness osteochondral defect was created on the medial femoral condyle in both knees of 10 young, 10 adolescent, and 10 adult rabbits. Equal numbers of animals were evaluated after 24 and 48 weeks. At both time intervals, bonding to adjacent cartilage and proteoglycan content of the matrix were better in the repairs of young than in adult animals. Repairs in the former had cellularity similar to the adjacent cartilage and were composed of 90% hyaline-like cartilage, which did not decrease with time. In contrast, repairs in older animals formed less hyaline-like cartilage and had a lower cellularity than the adjacent cartilage. However, the surface of the repaired tissue was similarly disrupted in all age groups, and the mechanical properties remained inferior to adjacent or normal cartilage. Repairs in older animals showed signs of degeneration with time. The initial better repair quality in a young, growing animal remained up to 48 weeks when the animal had already reached maturity, indicating that successful initial promotion of cartilage repair may even lead to better results in the long term. However, it has to be pointed out that the morphologically good repairs with hyaline-like cartilage appearance, normal cellularity, and durability of up to 48 weeks were unable to reestablish and maintain a cartilage-like mechanical function.

Age Factors↗
PubMed1999

Increased protein phosphorylation of cytoplasmic dynein results in impaired motor function.

Inhibition of serine/threonine protein phosphatases in rat hepatocytes by okadaic acid and microcystin increased the phosphorylation of several components of the cytoplasmic dynein complex. UV light/vanadate cleavage and Western blot analysis revealed that two of these components with molecular masses of approx. 400 kDa and 74 kDa were dynein heavy- and intermediate-chains respectively. This increased phosphorylation resulted in inhibition of dynein ATPase activity, and reduced motor-dependent avidity of endosomal/lysosomal membranes for microtubules.

Animals↗
PubMed1999

Three-dimensional visualization of transcription sites and their association with splicing factor-rich nuclear speckles.

Transcription sites are detected by labeling nascent transcripts with BrUTP in permeabilized 3T3 mouse fibroblasts followed by laser scanning confocal microscopy. Inhibition and enzyme digestion studies confirm that the labeled sites are from RNA transcripts and that RNA polymerase I (RP I) and II (RP II) are responsible for nucleolar and extranucleolar transcription, respectively. An average of 2,000 sites are detected per nucleus with over 90% in the extranucleolar compartment where they are arranged in clusters and three-dimensional networklike arrays. The number of transcription sites, their three-dimensional organization and arrangement into functional zones (Wei et al. 1998) is strikingly maintained after extraction for nuclear matrix. Significant levels of total RP II mediated transcription sites (45%) were associated with splicing factor-rich nuclear speckles even though the speckles occupied <10% of the total extranucleolar space. Moreover, the vast majority of nuclear speckles (>90%) had moderate to high levels of associated transcription activity. Transcription sites were found along the periphery as well as inside the speckles themselves. These spatial relations were confirmed in optical sections through individual speckles and after in vivo labeling of nascent transcripts. Our results demonstrate that nuclear speckles and their surrounding regions are major sites of RP II-mediated transcription in the cell nucleus, and support the view that both speckle- and nonspeckle-associated regions of the nucleus contain sites for the coordination of transcription and splicing processes.

3T3 Cells↗
PubMed1999

Assessment of effectiveness of Vaxigrip.

In order to assess the effectiveness of Vaxigrip in 1996-1997, we chose 1356 people in the Chinese Army, who had not recently had influenza and who were divided into an injection group and a control group. The injection group consisted of 80 children aged 3-6 years, 363 adults aged 18-59 years and 235 people over 60 years of age. The control group consisted of 88 children aged 3-6, 372 adults aged 18-59 and 218 people over 60. They were observed from the 21st day to the 6th month after Vaxigrip administration. Each person was requested to report having a body temperature over 38.5 degrees C, headache, myalgia or arthalgia, cough, pharyngodynia or nasal obstruction. Fever due to other causes was not included in the influenza symptoms. We counted the symptoms of influenza and common cold only once during the observation period. Our final finding was that the incidence rates of the influenza and common cold symptoms were reduced by 84.8% in children, 74.0% in adults and 68.6% in elderly people. In comparison with the control group, the incidence rate of influenza-like symptoms was reduced by 71.1% in the injection group, and the incidence rate of common cold symptoms in the injection group was lower than that in the control group. There was no large difference by age. The incidence rate of symptoms of upper respiratory tract infection in the injection group was 47.5% lower than that in the control group. Our findings are basically the same as those in other countries.

Adolescent↗
PubMed1999

Mapping the sensitivity of T cells with an optical trap: polarity and minimal number of receptors for Ca(2+) signaling.

Contact with antigen-presenting cells (APCs) initiates an activation cascade within T lymphocytes, including a rise in cytosolic calcium, lymphokine production, and cell division. Although T cell-APC physical contact is required for an immune response, little is known about the patterns of cellular interactions and their relation to activation. Calcium imaging combined with an optical trap enabled the T cell contact requirements and polarity to be investigated at the single-cell level. APCs or anti-CD3 mAb-coated beads were trapped with a laser and placed at different locations along the T cell, which has a polarized appearance defined by the shape and direction of crawling. T cells were 3-fold more sensitive to APC contact made at the leading edge of the T cell than with contact made at the tail. Anti-CD3 mAb-coated 6-micrometer beads induced calcium signaling with approximately 10-fold higher frequency and approximately 4-fold shorter latency on contact with the leading edge of the T cell than on contact with the trailing edge. Alterations in antibody density (2 to 500 per micrometer(2)) and bead size (1 to 6 micrometer in diameter) were used to determine the spatial requirements and the minimal number of receptors which must be engaged to transmit a positive signal. T cell response percentage, latency, and calcium-signaling pattern (transient vs. sustained or oscillatory) depended on antibody density on the bead. The presence of approximately 170 anti-CD3 mAb within the contact area elicited a detectable T cell calcium response. We propose here that engagement of no more than 340 T cell receptors (approximately 1% of the total on the cell) is sufficient to initiate Ca(2+) signaling. The minimal contact area was approximately 3 micrometer(2).

Animals↗
PubMed1999

Alzheimer's disease-related gene expression in the brain of senescence accelerated mouse.

The levels of Alzheimer's disease (AD)-related genes, including beta-amyloid precursor protein(APP), presenilin-1 (PS-1), PS-2, apoE, tau, c-fos, neural cell adhesion molecular 180 (NCAM-180), TGF-beta 1, IL-1 alpha/beta, IL-6, TNF-alpha/beta, alpha-2-Macroglobulin (alpha 2M), class II major histocompatibility antigen la (MHCII la), bcl-2 alpha, glucocorticoid receptor-alpha (GR alpha) and mineralocorticoid receptor (MR) mRNAs were determined by reverse transcription polymerase chain reaction (RT-PCR) in the hippocampus and cerebral cortex of senescence accelerated mouse (SAM). The levels of TGF-beta 1, IL-1 alpha, TNF-beta, c-fos, NCAM-180, PS-1 and APP mRNAs were normally expressed in SAMP8 compared with age-matched other subline that is resistant (SAMR1). The levels of apoE, GR alpha and MR mRNAs in the hippocampus of SAMP8, especially GR alpha, were evidently lower than those in the hippocampus of SAMR1. While bcl-2 alpha, PS-2 and tau mRNA levels of SAMP8 were significantly higher than those of SAMR1. Inflammatory cytokines (IL-1 beta, IL-6, TNF-alpha), alpha 2M and MHCII la antigen mRNAs were not detected in the brain of SAM. The differences of gene expression in the cerebral cortex were less evident than in the hippocampus. The results indicated that some genes abnormally expressed in the AD brain were also found in the brain of SAMP8, which may contribute to its age-related deterioration of learning and memory. Our results also suggested that functional and pathological changes which occurred in the brain of SAMP8 possessed some different aspects in comparison with the AD in consideration of the differences in gene expression.

Aging↗
PubMed1999

13-cis-Retinoic acid alters neural crest cells expressing Krox-20 and Pax-2 in macaque embryos.

This study investigates hindbrain and associated neural crest (NCC), otocyst, and pharyngeal arch development in monkey embryos following teratogenic exposure to 13-cis-retinoic acid (cRA). cRA was orally administered (5 mg/kg) to pregnant long-tailed macaques (Macaca fascicularis) between gestational days (GD) 12 and 27. Embryos were surgically collected at desired stages during treatment, analyzed for external morphological changes, and processed for immunohistochemistry. Two transiently expressed nuclear proteins, Krox-20 and Pax-2, were used as markers for the target cellular and anatomical structures. Rhombomere (r) expression patterns of Pax-2 (r4/r6) and Krox-20 (r3/r5) were maintained after cRA treatment, but r4 and r5 were substantially reduced in size. In untreated embryos, Krox-20 immunoreactive NCC derived from r5 migrated caudally around the developing otocyst to contribute to the third pharyngeal arch mesenchyme. In cRA-treated embryos, a subpopulation of NCC rostral to the otocyst also showed Krox-20 immunoreactivity, but there was a substantial reduction in Krox-20 post-otic NCC. Pax-2 immunoreactive NCC migrating from r4 to the second pharyngeal arch were substantially reduced in numbers in treated embryos. Alteration in the otic anlage included delayed invagination, abnormal relationship with the adjacent hindbrain epithelium, and altered expression boundaries for Pax-2. cRA-associated changes in the pharyngeal arch region due to cRA included truncation of the distal portion of the first arch and reduction in the size of the second arch. These alterations in hindbrain, neural crest, otic anlage, and pharyngeal arch morphogenesis could contribute to some of the craniofacial malformations in the macaque fetus associated with exposure to cRA.

Animals↗
PubMed1999

High-efficiency transfer of cystic fibrosis transmembrane conductance regulator cDNA into cystic fibrosis airway cells in culture using lactosylated polylysine as a vector.

To find more efficient vectors for the transfer of CFTR cDNA, lactosylated polylysine was explored for transfer into airway epithelial cells in primary culture. The efficacy and high efficiency of transfection were shown by several criteria: expression of both mRNA and protein for CFTR and the functional correction of the Cl- channel activity. Using specific combinations of agents to enhance the transfection, an efficiency of 90% was obtained as detected by in situ hybridization with digoxigenin-labeled probes generated against exon 14 of CFTR. The highest efficiency was observed by adding E5CA peptide (10 microg) and 5% glycerol to the transfection mixture. The degree of transfection could be controlled by the enhancing agents, thus modulating the efficiency of transfection. The highest level of transfection efficiency is equivalent to that reported for viral vectors. None of the agents or their combinations in the concentrations used were cytotoxic to the primary cells. Antibody pAb3145 was used to detect the expression of the CFTR protein in the cells. When an N-terminal GFP-CFTR fusion gene was used to transfect the CF cells a functional correction of the CFTR Cl- channel was detected by patch-clamp electrophysiology. The high efficiency of CFTR gene transfer with lactosylated polylysine leads to the conclusion that lactosylated polylysine is a promising vector to transfer the CFTR gene into human airway cells in culture.

Base Sequence↗