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Biomedical subjects

Y Xia

Publications and source records attributed to Y Xia.

At least 253 records · Page 14Linked to original sources
PubMed1996

[Clinical study on painless labor under drugs combined with acupuncture analgesia].

To study the analgesia efficacy of drugs combined with acupuncture analgesia for painless labor, 462 normal pregnancy women were observed. During the latent phase in labor, several analgesia methods: acupuncture analgesia, analgesics, magnetotherapy and auricular acupressure, TENS combined with dihydroetorphine were used respectively. While the intrauterine pressure and the peripheral content of beta-EP were measured during labor, the experiments of SEPS were also performed on healthy adults to demonstrate the analgesia efficacy of those analgesia methods. The combination of drugs with acupuncture is an excellent method for painless labor without any complications and all the mothers and babies are safety. The effectiveness is 97.5%. The results demonstrate that the mechanism of analgesia efficacy should be regulated the incoordinate uterine action and improve the hypertonic status of uterus, but also can decrease the pain threshold and elevate the tolerance of uterine contractions during labor.

Acupressure↗
PubMed1996

[Expression of p53 gene in oral squamous cell carcinoma and its relations with clinical and pathological parameters and prognosis of patients].

One hundred and eleven cases of oral squamous cell carcinoma (OSCC) were examined for overexpression of p53 protein by using immunohistochemical technique. Association of p53 protein overexpression with clinical and pathological parameters as well as prognosis of patients were also analyzed, p53 protein overexpression was commonly observed (69.4%) in the OSCC patients and might be used as a marker of carcinogenesis of OSCC. The level of p53 protein overexpression was correlated with the decreased three and/or five-year survival rate of OSCC. The presence of p53 was not correlated with patient's sex and age, site and size of tumor, degree of differentiation, node status or clinical stage of OSCC. Single factor COX proportional hazards regression model analysis indicated that there was no significant relationship between p53 overexpression and prognosis of OSCC. Multivariable COX model analysis failed to establish effective life function or risk rate function. This showed that all the parameters analyzed in this study as well as p53 overexpression were not significant or effective risk factors to predict prognosis of OSCC patients.

Adult↗
PubMed1996

[Influence of HPD on immunological functions in patients with nasopharyngeal carcinoma treated by radiotherapy].

Seventy-eight patients with nasopharyngeal carcinoma were equally divided into two groups: 39 patients were treated by HPD plus radiation and 39 patients by radiation alone. Immunological functions were evaluated in each patient before and after radiation. The results showed that (1) in patients treated by RPD and radiation, no statistical difference was observed on immunological functions before and after treatment; (2) in patients treatd by radiation alone, the immunological functions, including OKT3, OKT4, OKT4/OKT8 ratio and lymphocyte transformation, were significantly decreased after treatment. These findings indicate that the immunological functions in patients with nasopharyngeal carcinoma could be protected by HPD during radiotherapy.

Adolescent↗
PubMed1995

Expression of melanocortin 1 receptor in periaqueductal gray matter.

The localization of the melanocortin 1 (MC1) receptor in brain was investigated by in situ hybridization and immunohistochemistry. In rat periaqueductal gray matter (PAG), a small number of cells which displayed a punctate distribution showed a specific hybridization signal for MC1 receptor mRNA, whereas other regions studied were negative. In human PAG, the immunoreactivity for MC1 receptor was detected in scattered cells. These results indicate that a restricted distribution of MC1 receptor is present in the central nervous system.

Animals↗
PubMed1995

Self-diffusion monitors degraded cartilage.

This article demonstrates that both the bulk water self-diffusion coefficient (D) and the spatially resolved variation in D for lesion canine cartilage due to osteoarthritis is increased by about 25% over that of surrounding cartilage. This increase in D can be mimicked by enzymatic degradation of cartilage with trypsin, hyaluronidase, and collagenase, or by mechanical means. However, it is established here using excised disks of living cartilage whose proteoglycan and collagen contents were manipulated by biochemical intervention in tissue culture that the diffusion measurement is not sensitive to the proteoglycan content of cartilage. Instead, self-diffusion appears to monitor mesoscopic (nonspecific) tissue damage. These results show that D, measured in a spatially resolved manner by pulsed field gradient nuclear magnetic resonance imaging, can localize regions of cartilage degradation.

Animals↗
PubMed1995

NACP, the precursor protein of the non-amyloid beta/A4 protein (A beta) component of Alzheimer disease amyloid, binds A beta and stimulates A beta aggregation.

NACP, a 140-amino acid presynaptic protein, is the precursor of NAC [the non-amyloid beta/A4 protein (A beta) component of Alzheimer disease (AD) amyloid], a peptide isolated from and immunologically localized to brain amyloid of patients afflicted with AD. NACP produced in Escherichia coli bound to A beta peptides, the major component of AD amyloid. NACP bound to A beta 1-38 and A beta 25-35 immobilized on nitrocellulose but did not bind to A beta 1-28 on the filter under the same conditions. NACP binding to A beta 1-38 was abolished by addition of A beta 25-35 but not by A beta 1-28, suggesting that the hydrophobic region of the A beta peptide is critical to this binding. NACP-112, a shorter splice variant of NACP containing the NAC sequence, bound to A beta, but NACP delta, a deletion mutant of NACP lacking the NAC domain, did not bind A beta 1-38. Furthermore, binding between NACP-112 and A beta 1-38 was decreased by addition of peptide Y, a peptide that covers the last 15 residues of NAC. In an aqueous solution, A beta 1-38 aggregation was observed when NACP was also present in an incubation mixture at a ratio of 1:125 (NACP/A beta), whereas A beta 1-38 alone or NACP alone did not aggregate under the same conditions, suggesting that the formation of a complex between A beta and NACP may promote aggregation of A beta. Thus, NACP can bind A beta peptides through the specific sequence and can promote A beta aggregation, raising the possibility that NACP may play a role in the development of AD amyloid.

Alzheimer Disease↗
PubMed1995

Substrate control of free radical generation from xanthine oxidase in the postischemic heart.

While the free radical-generating enzyme xanthine oxidase is a central mechanism of injury in postischemic tissues, questions remain regarding how xanthine oxidase-mediated radical generation is triggered during ischemia and reperfusion. There is controversy regarding whether radical generation is caused by enzyme formation of that of its substrates xanthine and hypoxanthine. Therefore, studies were performed in isolated rat hearts correlating the magnitude and time course of radical generation with alteration in xanthine oxidase and its substrates. Radical generation was measured by electron paramagnetic resonance spectroscopy and correlated with spectrophotometric assays of tissue xanthine oxidase activity and chromatographic measurements of tissue and effluent concentrations of xanthine oxidase substrates and products. Xanthine oxidase was present in preischemic hearts and slightly increased during 30-min global ischemia. Hypoxanthine and xanthine were not present prior to ischemia but accumulated greatly during ischemia due to ATP degradation. These substrate concentrations rapidly declined over the first 5 min of reperfusion matching the observed time course of radical generation, whereas xanthine oxidase activity was largely unchanged. Both substrates were also observed in the coronary effluent during the first 5 min of reflow along with the product uric acid. Thus, the burst of xanthine oxidase-mediated free radical generation upon reperfusion is triggered and its time course controlled by a large increase in substrate formation that occurs secondary to the degradation of ATP during ischemia.

Adenosine Triphosphate↗
PubMed1995

Chronic hypoxia causes opposite effects on glucose transporter 1 mRNA in mature versus immature rat brain.

We have shown previously that chronic hypoxia can regulate the expression of membrane proteins. Since there are virtually no glucose stores in the brain and glucose transport can be rate-limiting during stress, the role of glucose transporters becomes crucial for cell survival under stress. In the present study, we asked whether mRNA levels for glucose transporter 1 (GT1), which is expressed in a variety of cells in the brain, especially in the microvessels for glucose transport from blood vessels to brain, change in response to chronic hypoxia. Because major developmental changes occur in the rat CNS in-utero and in the first few weeks postnatally, we studied brain GT1 mRNA using Northern blot analysis at different ages after exposure of fetuses (from embryonic day 10 to birth), developing rats (from birth to 30 day old) or adult rats (from 90 to 120 day old) to hypoxia (Fractional inspired O2 9%). Our data show that (i) GT1 mRNA level was much lower in the newborn than in the adult and increased with age; (ii) chronic hypoxia caused a decrease of approximately 65% in GT1 mRNA in adult brain but induced an increase in fetal (more than 50%) and developing (approximately 80%) rats and (iii) the response of housekeeping gene (glyceraldehyde 3-phosphate dehydrogenase) was not similar to that of GT1, suggesting that the changes of GT1 mRNA are specific to glucose transporter.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Polyclonal antibodies against human melanocortin MC1 receptor: preliminary immunohistochemical localisation of melanocortin MC1 receptor to malignant melanoma cells.

Peptides of 11 and 15 residue lengths were synthesised according to the sequence of the N-terminal region of the human MC1 melanocyte stimulating hormone receptor. The peptides were conjugated to thyroglobulin and used for preparation of antisera in the rabbit. Each of the conjugates raised antisera which showed high titre and specificity for its respective peptide antigen when evaluated in an ELISA test. Both types of antisera immunostained MC1 receptor expressing COS-7 cells. By contrast, the sera did not stain control COS-7 cells not expressing the MC1 receptor. Moreover, preimmune sera or antiserum preadsorbed with its respective peptide did not stain the MC1 receptor expressing cells. The antisera were used to immunostain sections of normal human skin, as well as samples of cutaneous malignant melanoma tumours obtained from a patient. The cells of the melanoma tumours were very strongly immunostained with the MC1 receptor antisera. By contrast, melanocytes which were present in the normal skin could not be visualised with our antisera.

Amino Acid Sequence↗
PubMed1995

The CYP2D6B mutant allele is overrepresented in the Lewy body variant of Alzheimer's disease.

Approximately one-fourth of neuropathologically confirmed cases of Alzheimer's disease (AD) also have brainstem and neocortical Lewy bodies, constituting a Lewy body variant of AD. Because Lewy bodies are a pathologic hallmark of Parkinson's disease (PD), this subpopulation of AD subjects may have the same risk factors as PD subjects. Analyses of the cytochrome P450 CYP2D6-debrisoquine 4-hydroxylase mutant B allele, a susceptibility gene for PD, revealed a higher representation of this allele in the Lewy body variant of AD than in pure AD or non-AD without Lewy bodies.

Alleles↗
PubMed1995

The CYP2D6B allele is associated with a milder synaptic pathology in Alzheimer's disease.

Both genetic and environmental factors affect the progression of Alzheimer's disease (AD). The presence of cortical Lewy bodies in AD patients is associated with an altered presentation of AD pathology suggestive of an interaction between the pathogenesis of Lewy bodies and AD lesions. Since the CYP2D6B mutant allele is often present in patients with Lewy body diseases (Parkinson's disease and Lewy body variant of AD), we extended these prior observations by studying the neuropathology associated with the presence of the CYP2D6B mutant allele in a pure AD population without Lewy bodies. AD patients who possessed the CYP2D6B mutant allele, in comparison with those without the CYP2D6B allele, were found to have a smaller decline in two synaptic markers, choline acetyltransferase and synaptophysin, in the frontal cortex relative to normal control values. On the other hand, senile plaques and neurofibrillary tangles were not significantly affected by the presence of the CYP2D6B mutant allele in the frontal cortex of AD patients. Association of the CYP2D6B mutant allele with Lewy body formation in both Parkinson's disease and the Lewy body variant of AD and with the milder synaptic pathology in pure AD without Lewy bodies suggest that depending on the contribution of other genetic and environmental factors, this mutant allele may be involved with different aspects of neurodegeneration.

Aged↗
PubMed1995

Perceptions of fear in other children and adolescents: the role of gender and friendship status.

Gender differences in fear were examined in 693 Chinese children and adolescents. Subjects were asked to rate their own fears, the fears of their best friends, and the fears of "other" classmates using the Fear Survey Schedule for Children--Revised (Ollendick, 1983). Consistent with previous investigations in Western and Eastern countries, girls rated themselves as more fearful than boys. In addition, both girls and boys rated their best friends as similar in number, content, and intensity of fears. However, girls rated their classmates as less fearful than themselves or their best friends, while boys rated their classmates as more fearful then themselves or their best friends. Findings are discussed in terms of gender role expectations and similarity-attraction hypotheses.

Adolescent↗
PubMed1995

Developmental expression of N-methyl-D-aspartate (NMDA)-induced neurotoxicity, NMDA receptor function, and the NMDAR1 and glutamate-binding protein subunits in cerebellar granule cells in primary cultures.

Cerebellar granule cells maintained in vitro as primary cultures are a relatively homogeneous neuronal population that can be used to evaluate the developmental expression of neurotransmitter receptors and to assess their role in cell survival and degeneration. The toxicity induced by N-methyl-D-aspartate (NMDA) in granule cells maintained under partially depolarizing conditions and in the presence of physiologic extracellular concentrations of Mg2+ was greatest for the neurons maintained for 14 days in vitro (DIV). However, following NMDA receptor activation neurons as young as 5 DIV exhibited increases in the concentration of intracellular free Ca2+ which were as large as those achieved with cells at 8-9 or 13-14 DIV. The less mature neurons exhibited a "down-regulation" of responses to increasing concentrations of NMDA and the more mature cells maintained elevated intracellular Ca2+ levels during the inter-stimulus periods. Immunochemical analyses of the expression of the NMDA receptor-associated proteins NMDAR1 and glutamate-binding protein (GBP) in granule cells indicated a developmental increase in both proteins, albeit the pattern of expression of NMDAR1 was the more complex. No definite correlation has yet been established between toxicity induced by NMDA and the expression of these two proteins. Finally, although the developmental expression of nitric oxide synthase, an enzyme that catalyzes the formation of the potentially neurotoxic radicals nitric oxide and superoxide anion, increased progressively with the maturation of neurons in culture, an inhibitor of this enzyme did not protect neurons from NMDA-induced toxicity. Therefore, the developmental changes in granule cells that lead to increased vulnerability following excessive activation of NMDA receptors are not yet completely defined.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed1995

Off-resonance effects on 2D NMR nutation spectra of I = 3/2 quadrupolar nuclei in static samples.

The off-resonance effects on 2D NMR nutation of I = 3/2 quadrupolar nuclei are demonstrated with perturbation theory and numerical calculation in static samples. The off-resonant (delta omega) rf field (omega 1) enlarges a nutation frequency and consequently increases the measurement range of nuclear quadrupolar interaction parameters. When omega e > omega Qmax, and arctg(omega 1/delta omega) = +/- 54.7 degrees (magic angle), the satellite lines (produced by coherence transfers) in a nutation spectrum are superimposed with the line of central transition, and hence the nutation spectrum is simplified and its sensitivity is enhanced. The nuclear quadrupolar interaction parameters of 23Na nuclei in Na omega molecular sieve are obtained using 2D NMR nutation.

Magnetic Resonance Spectroscopy↗
PubMed1995

Oxidative stress-inducible protein tyrosine phosphatase in glomerulonephritis.

Previously we found that rat mesangial cells express 3CH134/CL100 protein-tyrosine phosphatase (PTPase) in response to reactive oxygen intermediates (ROIs), and we now extend these studies to glomerulonephritis (GN), where ROI have been demonstrated to play a role. The rat homologue of 3CH134/CL100 was cloned from a rat macrophage cDNA library. The rat 3CH134/CL100 mRNA was strongly induced in the lung, liver, and heart the first day after birth, suggesting that hyperoxic adaption might be involved in the induction of the PTPase mRNA. In anti-glomerular basement membrane (GBM) antibody (Ab) GN in rats, the 3CH134/CL100 PTPase mRNA was expressed in glomeruli as early as 30 minutes after anti-GBM Ab injection. The 3CH134/CL100 mRNA expression was modulated by the ROI scavenger dimethylthiourea (DMTU), indicating that its induction was ROI related. In contrast to the glomerular lesion, PTPase mRNA expression was not induced in experimental tubulointerstitial nephritis. In situ hybridization suggested that mesangial and some infiltrating cells were the major glomerular cell sources of the PTPase mRNA. These results indicate that rat CCH134/CL100 PTPase is actively induced in glomeruli as part of an acute immune injury at least in part related to oxidative stress. PTPase induction in GN and potentially other forms of inflammation may play an important regulatory role in protein kinase signaling pathways.

Animals↗
PubMed1995

The stability and prediction of fears in Chinese children and adolescents: a one-year follow-up.

The stability in number, level, content, and pattern of fears over a one-year period was examined in Chinese children and adolescents aged 7-17. In addition, perceptions of fear in friends and parents as well as perceptions of the controllability and modifiability of fears were explored as predictors of subsequent fear level. Evidence for moderate stability of fears was obtained. However, stability was qualified by age and sex interaction effects. A developmental-cultural hypothesis was put forth to account for those findings. Hierarchical regression analyses revealed that perceptions of fears in friends and parents, along with perceptions of the controllability and modifiability of fears, were predictive of fear level at follow-up. Limitations of the study are noted.

Adolescent↗