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Biomedical subjects

Y He

Publications and source records attributed to Y He.

At least 307 records · Page 17Linked to original sources
PubMed1997

[Identification of G6PD gene mutations in several nationalities from Yunnan province].

OBJECTIVE: To analyze the G6PD gene mutations in several nationalities from Yunnan province. METHODS: G6PD gene mutation of 29 samples from G6PD deficient patients were analyzed by using common and mis-matched primering PCR followed by restriction enzyme digestion. The samples were collected from Yunnan province among several nationalities. RESULTS: In these 29 cases, 20 were of two known mutations, including 19 of 1388 (G-->A) and 1 of 1376 (G-->T) mutation. The 7 cases of national minorities, including 3 of Yi ([symbol: see text]), 2 of Bai ([symbol: see text]), 1 of Dai ([symbol: see text]), and 1 of Naxi ([symbol: see text]), were all 1388 mutations. No report of the G6PD gene 1388 mutation in these ethnic groups was published excepting for Dai. CONCLUSION: The mutation probably had been prevalent before the emergence of these national minorities. The approximate rate of G6PD gene mutations provided in Yunnan province may, in some respects, help to interpret the molecular evolution.

Asian People↗
PubMed1997

[A case of nt 1004C --> A G6PD gene mutation in Yunnan Han people].

OBJECTIVE: To search for novel G6PD gene mutation in Yunnan. METHODS: After excluding common mutations among Chinese, 2 approximately 12 exons of G6PD gene were screened by PCR-SSCP, and those with an abnormal electrophoretic pattern were further sequenced. RESULTS: During a survey of G6PD deficiency in a population of 823 individuals in Yunnan, 54 cases were found with the deficiency. The gene mutations were studied in 29 cases of them. Nineteen cases of nt 1388 G --> A, and 1 of nt 1381 G --> A mutations were identified. In the remaining 9 cases, an abnormal PCR-SSCP pattern was found in one case. A single base substitution of nt 1004 C --> A, which resulted in Ala339 --> Asp, was revealed by PCR-direct sequencing. CONCLUSION: This mutation is the second case in Chinese, and the first case in Yunnan province.

Adult↗
PubMed1997

[Studies on expansion ex vivo of murine bone marrow cells and its hematopoietic reconstitution capacity].

OBJECTIVE: To investigate the effects of stem cell factor (SCF) in combination with interleukin-1 (IL-1) or/and interleukin-3 (IL-3) on ex vivo expansion of 5FU treated bone marrow cells and hematopoietic recovery in lethally irradiated mice transplanted with the expanded cells. METHODS: 5FU treated bone marrow cells (d3-5FU-BMC) were cultured in a cytokines-containing medium, and the net increments of CFU-GM and high proliferative potential colony forming cell (HPP-CFC) were evaluated. RESULTS: CFU-GM increased by 33.7 +/- 18.1- or 18.1 +/- 6.3- fold, and HPP-CFC by 17.8 +/- 10.5- or 12.7 +/- 9.1- fold, respectively, in cultures containing SCF with IL- or IL-3, as compared with that in control; while SCF alone had little effect. Compared with fresh d3-5FU-BMC, transplantation of the expanded bone marrow cells accelerated the recovery of recipients' peripheral blood cell counts by 1 approximately 3 days and increased the survival rate of the transplanted animals (d3-5FU-BMC group 50% vs expansion group 8U approximately 100%). CONCLUSION: SCF in combination with IL-1 or IL-3 synergetically ex vivo expands hematopoietic cells. Transplantation of the expanded bone marrow cells accelerates the recipient's hematopoietic reconstitution.

Animals↗
PubMed1997

[Studies of magnetic circular dichroism and absorption spectra in alpha-NisO4 x 6H2O crystal].

Alpha-NiSO4 x 6H2O crystals were studied by magnetic circular dichroism (MCD) and absorption spectra measurements in the range lambda = 185-3300nm. The results show that there are three aborption bands, of which the peaks are related to the d-d transitions from the ground state to the excited states. The weak peaks of a progression of the three members were observed between the principal structures lambda = 654nm and lambda = 713nm due to spin-orbit coupling interacion. The weak peaks of a progression of four members were also observed around the new absorption peak at lambda = 585nm in MCD spectra.

English Abstract↗
PubMed1997

[The change of trace elements content in hair during the period of gestation].

Study on trace elements content change in hair during the period of gestation for 52 lying-in women was performed. The quantitative results for 7 elements have been obtained and the change tendencies for other 7 elements without standard value have been observed on the basis of a self comparison method for each individual.

Female↗
PubMed1997

Species differences in the distribution of the glutamate receptor subunit, GluR1, in the rat and monkey entorhinal cortex.

The distribution of the DL-alpha-amino-3-hydroxy-5-methylisoxazolepropionic acid (AMPA) receptor subunits GluR1 and GluR2/3 were studied by immunocytochemistry in the rat and monkey temporal neocortex and entorhinal cortex. The monkey neocortex was similar to the rat neo- and entorhinal cortex, in that non-pyramidal neurons were densely labelled for GluR1, while pyramidal neurons were lightly labelled. The monkey entorhinal cortex was very different, in that dense GluR1 labelling was present in the pyramidal neurons of layer V. Although many GluR2/3-positive pyramidal neurons were also present in layers II, III, V and VI of the monkey entorhinal cortex, the neuropilar staining in layer V was less intense for GluR2/3, than for GluR1. This suggests that there were fewer GluR2 or GluR3 subunits in that layer compared with GluR1, and it is possible that many of the GluR1 subunits exist as homomers. Since GluR1 homomeric channels are permeable to calcium ions and are inwardly rectifying, the high GluR1 content of the layer V pyramidal neurons could render these cells particularly susceptible to calcium influx, and consequently, calcium-mediated neuronal injury. This could therefore be one of the reasons why the entorhinal cortex shows some of the earliest and most severe pathological alterations in Alzheimer's disease.

Animals↗
PubMed1997

ABT-089 [2-methyl-3-(2-(S)-pyrrolidinylmethoxy)pyridine]: I. A potent and selective cholinergic channel modulator with neuroprotective properties.

Accumulating preclinical and clinical evidence data suggests that compounds that selectively activate neuronal nicotinic acetylcholine receptor (nAChR) subtypes may have therapeutic utility for the treatment of several neurological disorders. In the present study, the in vitro pharmacological properties of the novel cholinergic channel modulator ABT-089 [2-methyl-3-(2-(S)-pyrrolidinylmethoxy)pyridine], are described. In radioligand binding studies, ABT-089 was shown to display selectivity toward the high-affinity (-)-cytisine binding site present on the alpha4beta2 nAChR subtype (Ki = 16 nM) relative to the [125I]alpha-bungarotoxin binding site present on the alpha7 (Ki > or = 10,000 nM) and alpha1beta1deltagamma (Ki > 1000 nM) nAChR subtypes. In cation flux and channel current studies, ABT-089 displayed a more complex profile than (-)-nicotine having agonist, partial agonist and inhibitory activities depending on the nAChR subtype with which it interacts. ABT-089 differentially stimulated neurotransmitter release. The compound displayed a similar potency and efficacy to (-)-nicotine to facilitate ACh release (ABT-089, EC50 = 3 microM; (-)-nicotine, EC50 = 1 microM), but was markedly less potent and less efficacious than (-)-nicotine to stimulate dopamine release (ABT-089, EC50 = 1.1 microM; (-)-nicotine, EC50 = 0.04 microM). Additionally, ABT-089 was neuroprotective against the excitotoxic insults elicited by exposure to glutamate in both rat cortical cell cultures (EC50 = 10 +/- 3 microM) and differentiated human IMR32 cells (EC50 = 3 +/- 2 microM). The differential full agonist/partial agonist profile of ABT-089, as compared with (-)-nicotine and ABT-418, illustrates the complexity of nAChR activation and the potential to target responses at subclasses of the neuronal and peripheral receptors.

Acetylcholine↗
PubMed1997

Localisation of glutamate receptors in the substantia nigra pars compacta of the monkey.

The distribution of ionotropic glutamate receptor subunits GluR1, GluR2/3 and NMDAR1, and meta-botropic receptor mGluR1 alpha was studied in the monkey substantia nigra. High levels of immunoreactivity to GluR1, GluR2/3 and NMDAR1, and moderate levels of immunoreactivity to mGluR1 alpha were observed in the substantia nigra pars compacta. GluR1 and GluR2/3 were mostly in cell bodies and larger stem dendrites, whilst NMDAR1 and mGluR1 alpha were present on medium sized and small dendrites, respectively. The substantia nigra receives glutamatergic afferents from the subthalamic nucleus and the frontal cortex. Overactivity of the subthalamic nucleus, coupled with high levels of glutamate receptors on the neurons in the pars compacta, could predispose these neurons to excitotoxic injury, and could contribute to the development of Parkinson's disease.

Animals↗
PubMed1997

Distribution of amyloid beta-protein immunoreactivity in the hippocampus of rats injected with kainate.

The distribution of amyloid beta-protein immunoreactivity was investigated in the hippocampus of rats injected intravenously with kainate. Very light labelling was observed in cell bodies and dendrites of pyramidal neurons and dentate granule cells in the normal hippocampus. At 6,7,9,10,12 and 20 days postinjection, moderately densely labelled astrocytes were present in the stratum oriens and lacunosum moleculare, extending thick processes towards the stratum radiatum which was degenerating. Immunoreactivity was present as floccules in the mitochondria-rich but glial-filament-poor portions of reactive astrocytes, and in fibrillar form in the neuropil. This suggests that amyloid beta-protein might be present in fibrillar (presumably polymerised) form in degenerating profiles and the neuropil, but in floccular (presumably non-polymerised) form in reactive astrocytes.

Amyloid beta-Peptides↗
PubMed1997

[The effect of climatic factors on the onset of acute myocardial infarction].

The results of the single-relative analysis on the three climatic factors of air temperature, pressure and relative humidity to the attack of acute myocardial infarction in Shenyang city located in the cold Northeastern China area, showed that the attack was more frequent in summer time with high temperature, humidity and low air pressure. The attack was positively related to temperature (r = 0.7463 P < 0.01) and humidity (r = 0.6466 P < 0.01) while is negatively related to air pressure (r = -0.7300 P < 0.05). And specifically, in Shenyang area the incidence was obviously increased with average temperature > 20 degrees C, air pressure < 1010, and relative humidity > 70%. Patients should reduce the activities in high or low temperature environment. Proper precautions should be taken well in advance to avoid the attack on the patients in a particular season. And different nursing measures should be taken in different seasons to comply with changes of climate, for averting the attacks caused by the climate.

Aged↗
PubMed1997

Dihydropyrimidine dehydrogenase activity in hepatocellular carcinoma: implication in 5-fluorouracil-based chemotherapy.

Dihydropyrimidine dehydrogenase (DPD) is the initial, rate-limiting enzyme in the catabolism of 5-fluorouracil, one of the most widely used cancer chemotherapeutic agents. Previous studies have demonstrated the clinical importance of determination of DPD in cancer patients, suggesting that the efficacy and toxicity of 5-fluorouracil may directly relate to the DPD activity in both tumor and host tissues. In the present study, DPD activity was determined in 50 pairs of tumor and uninvolved liver specimens in Chinese cancer patients with hepatocellular carcinoma. Mean enzyme activity in uninvolved liver tissues (0.45 +/- 0.02 nmol/min/mg protein) was significantly higher than that in tumor specimens (0.34 +/- 0.03 nmol/min/mg protein). Statistical analysis revealed no significant differences in DPD activity of tumor and uninvolved liver specimens among different age and gender groups. Compared to previously reported tumor studies, hepatomas were found to have relatively high DPD activity. Since high levels of DPD would be expected to metabolize 5-fluorouracil, these findings may provide an explanation for the relative 5-fluorouracil resistance of hepatoma and may have implications for designing a new therapeutic strategy such as modulation of 5-fluorouracil chemotherapy by DPD inhibitors.

Adult↗
PubMed1996

The number of stenotic coronary arteries and passive smoking exposure from husband in lifelong non-smoking women in Xi'an, China.

The relationship between the number of stenotic coronary arteries and passive smoking exposure from the husband was examined in a retrospective study of 78 cases with stenotic coronary arteries and 83 controls with normal coronary arteries. All the 161 subjects were examined by coronary arteriography and were Chinese women who had never smoked cigarettes (i.e. lifelong non-smokers). The Pearson's and Spearman's correlation coefficients between the number of stenotic coronary arteries and passive smoking exposure indices were 0.27-0.29 and 0.25-0.28 (all with P < 0.01), respectively. The linear prediction equations from multiple regression analysis showed that passive smoking exposure, after adjustment for other major risk factors, was a significant predictive variable for the number of stenotic coronary arteries. The multiple response logistic regression model was used to estimate the odds ratio of stenotic coronary arteries for passive smoking exposure categories. The crude and adjusted odds ratios showed that the number of stenotic arteries increased with the amount of exposure to passive smoking from the husband. These results provide new evidence to support that passive smoking is causally associated with coronary heart disease.

Adult↗
PubMed1996

Increased iron in the substantia nigra of 6-OHDA induced parkinsonian rats: a nuclear microscopy study.

The trace elemental concentrations, including iron, in the substantia nigra (SN) of a 6-OHDA induced rat model of Parkinson's disease were measured using nuclear microscopy. Only rats that exhibited amphetamine induced rotation of more than 7 turns/min were used. The results showed that the iron levels were significantly increased in the 6-OHDA lesioned SN, compared with the intact contralateral SN, and the SN of normal control rats injected with ascorbic acid, which showed no significant difference in iron levels between injected and non-injected sides. In both 6-OHDA lesioned and ascorbic acid injected SN, there were no alterations in the levels of calcium, magnesium, copper and zinc. In the 6-OHDA lesioned SN there was an almost complete loss of tyrosine hydroxylase positive cells in the SN. These results suggested that the 6-OHDA induced dopaminergic cell death may be related to the increased iron.

Animals↗
PubMed1996

Transcriptional repression by the proto-oncogene BCL-6.

In up to 45% of reported cases of the non-Hodgkin's lymphoma, diffuse large cell lymphoma, there are translocations of the BCL-6 gene, which are presumed to deregulate its expression. The BCL-6 protein, which is unmutated in these lymphomas, contains six Krüppel-like zinc fingers at its carboxy terminus and a 121 amino acid domain at its amino terminus, termed the POZ domain, which bears homology with amino terminal domains in a subset zinc finger transcription factors. In this study, we tested whether BCL-6 regulates transcription and if the POZ domain has a role in this function. The BCL-6 POZ domain, when fused to the GAL4 DNA binding domain, strongly repressed transcriptional activation initiated from several different promoters including the SV40 enhancer/promoter. Repression was also observed when the fusion protein was bound at a distance of 200 bp 5' of the promoter. When the GAL4/BCL6 POZ domain fusion protein was expressed in yeast, it was able to homodimerize in the nucleus. Nevertheless, in contrast with mammalian cells, the fusion protein did not repress transcription. To test the ability of the full length BC1-6 protein to repress transcription when bound to DNA through its zinc finger DNA binding domain, high affinity BCL-6 binding sites were selected from a pool of random oligonucleotides. Full length BCL-6 was able to strongly repress transcription when bound to its cognate site cloned upstream of the thymidine kinase promoter. This repression was mediated, in large measure, by the POZ domain, although a variant of BCL-6 lacking the POZ domain was able to repress transcription modestly. The ability of BCL-6 to function as a transcriptional repressor may contribute to its ability to transform B lymphocytes in diffuse large cell lymphoma.

Base Sequence↗
PubMed1996

Novel HPV types present in oral papillomatous lesions from patients with HIV infection.

Patients infected with the human immunodeficiency virus (HIV) often develop multiple papillomatous lesions of the oral cavity. In the present study, a total of 67 biopsies from benign oral lesions were analyzed for the presence of human papillomavirus (HPV) DNA using Southern-blot hybridization in combination with a polymerase chain reaction designed to detect all known HPV types, as well as unidentified types. These samples, collected at random from a high-risk population, were subsequently divided into 57 biopsies originating from patients with confirmed HIV infection and 10 biopsies from patients with unknown HIV status. Each sample was amplified with 7 different combinations of degenerate primers. All amplified products were sequenced. HPV DNA sequences were detected in 67% (45/67) of the samples. HPV 7 (19%) and HPV 32 (28%) were the predominant HPV types. HPV 32 was present in 2/4 fibromas tested. Two new HPV types, HPV 72 and HPV 73, were identified in oral warts with atypia. The complete genomes of these viruses were cloned and sequenced. Other HPV types detected were HPV 2a, HPV 6b, HPV 13, HPV 16, HPV 18, HPV 55, HPV 59 and HPV 69.

Base Sequence↗