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Biomedical subjects

M He

Publications and source records attributed to M He.

At least 109 records · Page 6Linked to original sources
PubMed1997

Motif III S5 of L-type calcium channels is involved in the dihydropyridine binding site. A combined radioligand binding and electrophysiological study.

The alpha1 subunit of L-type voltage-dependent Ca2+ channels (alpha1C) has been shown to harbor high affinity binding sites for the Ca2+ channel dihydropyridine (DHP) modulators. It has been suggested by a number of investigators that the binding site may be composed of III S6 and IV S6. Evidence with chimeric channels indicated the possible involvement of III S5 in DHP binding. Site-directed mutations were introduced in motif III S5 region of the alpha1C, changing the amino acids to their counterparts in the DHP-insensitive alpha1A channel. The mutant channels were expressed both in HEK 293 cells and in Xenopus oocytes. Equilibrium binding and electrophysiological studies showed that the Thr1006 to Tyr substitution produced a mutant channel with at least 1000-fold decreased affinity in [3H](+)isopropyl-4-(2,1, 3-benzoxadiazol-4-yl)-1,4-dihydro-(2, 6-dimethyl-5-methoxycarbonyl)pyridine-3-carboxylate (PN200-110, isradipine) binding and in sensitivity of R(-)-4(2,1, 3-benzoxadiazol-4-yl)-1,4-dihydro-2, 6-dimethyl-5-nitro-3-pyridincarboxylic acid isopropylester (R202-791) in terms of inhibition of current through the L-type voltage-dependent Ca2+ channels. Replacing Gln1010 with Met resulted in more than a 10-fold decrease in binding affinity for [3H](+)PN200-110 and in the potency of channel modulation by S202-791. Four additional mutations in this region also lead to a slight but statistically significant increase of KD values for [3H](+)PN200-110 binding. The binding and electrophysiological results show that certain residues of the transmembrane segment III S5 are important in contributing to the DHP binding "pocket" and are critical for DHP binding and for its calcium channel effect.

Amino Acid Sequence↗
PubMed1997

Study on the protective effects of compound blood-activating soup on bone marrow hematopoietic cells in acute radiation injured mice.

After irradiation with 8 Gy 60Co gamma-ray, mice were immediately given intraperitoneal injection of 200 mg 100% compound blood-activating soup twice a day. On the 3rd and 7th day, the P53 gene expression of bone marrow hematopoietic cells in Chinese drug group was found to be higher than that in normal group, and it was also significantly higher than that in control group. The expression level of GADD153 gene which was not expressed in normal group was much lower in Chinese drug group than that in control group. On the 7th day after irradiation, the P53 and GADD153 gene expression levels of splenic mononuclear cells were consistent with those of bone marrow hematopoietic cells both in Chinese drug group and control group. On the 3rd and 7th day, the bone marrow hematopoietic tissue volume in Chinese drug group was higher than that in control group, with no difference found between the two groups. While on the 14th day, the difference became significant (P < 0.01). The results showed that commonly used blood-activating and stasis-eliminating drugs may strengthen the viability of hematopoietic cells and promote the rehabilitation of hematopoiesis by inducing wt-P53 expression to block the bone marrow hematopoietic cells in G1 phase, during which DNA could be repaired.

Animals↗
PubMed1997

Study on oxygen supply and protection of bone marrow in acute radiation injured mice.

After irradiated by 8 Gy 60Co gamma-ray, mice were intraperitoneally injected immediately with 0.2 ml 100% compound blood-activating soup twice a day for 10 days. The in situ ulnar bone marrow partial pressure of oxygen (PbO2) was determined in vivo before, during and after irradiation respectively. The bone marrow sections in the same part were observed. Our results showed that the normal murine ulnar PbO2 was 12.72 +/- 1.05 kPa. During irradiation, the level of PbO2 decreased to 10.78 +/- 1.17 kPa (P < 0.001). And 3 days after irradiation, PbO2 decreased to 9.75 +/- 0.52 kPa, suggesting that the commonly used "blood-activating and stasis-eliminating" Chinese drugs could promote the rehabilitation and proliferation of bone marrow microvessels in the acute radiation injured mice, expand their areas, increase the oxygen supply of bone marrow microenvironment, thereby leading to PbO2 much higher increase than that of control group. It is also helpful in the proliferation and rehabilitation of hematopoietic cells.

Animals↗
PubMed1997

Sequence, specificity and crystallization of an oestrone-3-glucuronide antibody (3910).

We describe the specificity profile and V region sequences of a high-affinity monoclonal antibody (mAb), 3910, directed against oestrone-3-glucuronide (E3G). Inhibition studies show that the D-ring is critical for steroid specificity, while the glucuronic acid attached to the A ring is required for high binding affinity, suggesting that both 'ends' of the E3G ligand are recognized. The VH domain is encoded by a gene from the VH7183 family, while VL appears to be encoded by the Vk5.1 gene (kappa II subgroup) with a deletion of six residues from complementarity-determining region-1 (CDR1). The VH CDR3 is 10 amino acid residues in length, of which D/N contributes five residues. Comparison of VH CDR of 3910 with those of mAb against progesterone (DB3) and digoxin (26-10, 40-50), for which crystal structures have been determined, suggests that aromatic side chains are important for E3G binding and that tyrosine residues H50, H97 and H100 may interact with the ligand. The Fab fragment of 3910 has been crystallized in its native and steroid (E3G and oestriol-3-glucuronide) complexed forms. An X-ray diffraction data set to 3 A resolution has been collected for the native Fab.

Amino Acid Sequence↗
PubMed1997

[Relationship between enteroviral infection and dilated cardiomyopathy].

To investigate the role of enteroviral infection in the patho genesis of dilated cardiomyopathy (DCM), we used the nested reverse transcription polymerase chain reaction to detect enteroviral RNA in 21 myocardial specimens and 17 peripheral blood samples from patients with DCM and 21 patients (controls) with cerebral trauma. Enteroviral RNA was detected in 9 of 21 myocardial tissues and 6 of 17 blood samples, whereas all controls myocardial samples were negative. In addition, antibodies of coxsackievirus group B were detected in 4 of the 17 patients with DCM by neutralization test. The present study suggested that DCM might be associated with persistent enteroviral infection.

Adolescent↗
PubMed1997

[Analysis and prevention of road traffic fatalities in Sichuan Province].

This is an epidemiological survey of the fatalities from road traffic accidents in Sichuan. All fatal accidents that occurred in Sichuan from January 1994 to December 1994 were analysed. The mortalities per million kilometers of vehicle travel, per 100,000 registered motor vehicles and per 100,000 resident population were 4.35, 42.41 and 3.92 respectively. These figures were compared with international death rates and those reported by other countries. The results showed that Sichuan had higher mortalities per million kilometers of vehicle travel and per 100,000 registered vehicles but lower mortality per 100,000 resident population, compared with some industrialized and rich develeping countries. The majority of the victims were males aged 21 to 40. Road traffic fatalities constituted the leading cause of all accident deaths. The cost of road accidents in Sichuan was estimated to be sixty million Yuan. Further strategies and methods to minimize the rate of such accidents have been suggested.

Accidents, Traffic↗
PubMed1997

[Extraction and sequencing of trace DNA from cornu Cervi pantotrichum].

The trace DNA extraction method was used to extract DNA from the blood, hair, Cornu cervi pantotrichum, hairy antler of the sika deer, Cervus nippon, and penis of Bulbalus bublis and Asinus vulgaris. A 307 bp fragment of mitochondrial DNA cytochrome b gene was amplified with primers L14841 and H15149 for these extractions. The purified PCR products were sequenced by the dideoxy method. DNA sequence obtained from the Cornu cervi pantotrichum is the same as that obtained from the fresh blood and hair of the sika deer, but the sequence of the so-called hairy antler is quite different, implying that it is not from the sika deer. In addition, the phylogenetic relationships among different species are congruent with the traditional known phylogeny.

Animals↗
PubMed1997

[Pediatric ocular trauma: a retrospective survey].

PURPOSE: To determine the risk factors for pediatric ocular injuries, especially those resulting in severe visual impairment, and to identify the trends and preventable causes. METHODS: A retrospective survey was conducted for all pediatric trauma cases at Zhongshan Ophthalmic Center from January 1989 through December 1992. Four hundred eighty-seven cases of 15 years old or younger were recruited in this study. Stepwise regression analysis was used to identify the relations between the visual prognosis and the potential risk factors (age, gender, time after injury, type of injury, and cause of injury) RESULTS: The male to female ratio was approximately 3:1, and most were 4 to 8 years old. Non--perforating trauma in the anterior segment was the most common type of injury. The final recorded best corrected visual acuity was 0.3 or better in 65% of the patients, while 19% were found to be 0.05 or worse with best correction. The following formula was generated by multiple linear regression model: Visual outcome = 0.963775 - 0.0896543 x (type of injury). CONCLUSION: Pediatric ocular trauma may cause severe visual impairment and occurs most frequently at the age of 4 to 8 years. The visual outcome is mainly associated with the type of injury.

Adolescent↗
PubMed1997

[A survey on mother's nutritional knowledge-attitude on the feeding of young child in Guangdong province].

A survey on mother's nutrition knowledge-attitude on the feeding of young child was conducted in Guangdong province in 1995 among 414 mothers of 0 to 18 months old children. The results showed that the nutritional knowledge-attitude level of the mothers was low in both city and township. Only 51% of them had qualified level. The level of general nutritional concepts and the nutritional knowledge-attitude during weaning period were significantly lower than that of breastfeeding and follow-weaning. It suggests that the promotion of nutritional education in the feeding of young children is urgent in Guangdong province especially in township and rural area. It is necessary to focus on the improvement of nutritional knoweledge in weaning period and general nutrition concepts.

Breast Feeding↗
PubMed1997

[Primary and secondary structure of 3'--end of the large subunit ribosomal RNA of silkworm Attacus ricini and evolution implications as inferred from the gene sequence].

The DNA sequence of the 3'-end of LSu-rRNA coding region of silkworm Attacus ricini was determined. By comparisons with the corresponding sequence of H. sapiens, X. leavis, H. momus, A. albopictus, D. melanogaster, C. elegants, S. pombe, M. musculus and M. racemosus, we found that the coding sequence we obtained is very conserved. Phylogenetic tree inferred by Neighbor-joining Method showed that the rate of evolution of insects was much faster than vertebrate. In addition, the secondary structure has also worked out it is highly conserved.

Animals↗
PubMed1997

[Effects of composite blood-activating decoction on adhesive function of bone marrow stroma cells in radiation injured mice].

OBJECTIVE: To evaluate the effect of commonly used "blood activating and stasis-removing" Chinese herbal drugs on adhesive function of bone marrow stroma cells in acute radiation injured mice. METHODS: After irradiation by 8 Gy 60Co gamma-ray, each mouse was intraperitoneally injected immediately with 0.2 ml 100% composite blood-activating decoction (CBAD) twice a day for 6 days. On the 7th day, the femura were taken and the bone karyocyte (BMC) suspension was made. According to long term bone marrow culture procedure, on the 12th day, the fibroblastic colony forming units were counted, and on the 28th day, the adhesion of culture stroma cells to normal murine BMC was observed. RESULTS: The adhesion of culture stroma cells to normal murine BMC was 67.8 +/- 17.2% in normal group, while in CBAD group, it was 55.8 +/- 10.5%. The difference was insignificant (P > 0.05). In the control group, the value was 47.7 +/- 13.6%, which was significantly lower than that in normal group (P < 0.02). CONCLUSION: The commonly used "blood-activating and stasis-removing" Chinese herbal drugs can enhance the adhesive function of bone marrow stroma cells in acute radiation injured mice.

Animals↗
PubMed1997

[Detection of human cytomegalovirus infection in blood donor population by the polymerase chain reaction].

Samples of peripheral blood from 76 different donors were detected for the presence of human cytomegalovirus (HCMV) DNA by polymerase chain reaction (PCR). The results showed that HCMVs were present in 39 out of 76 blood donors which reached an infection positive rate of 51.3%. In addition, the sensitivity and specificity on PCR were tested, it also indicated that the sensitivity can reach the level of 5fg.microliter-1. The method is simple, rapid, highly sensitive and specificity. It can be considered as a diagnostic measure in clinical detection of HCMV.

Blood Donors↗
PubMed1996

p53 mutations in bladder tumors from arylamine-exposed workers.

In this study we compared the frequency and pattern of p53 mutations in 34 bladder tumors from people with high-level occupational exposure to arylamines to those in 30 bladder tumors from people without such exposure. No differences were observed for p53 mutations between the two groups. The frequency of mutation was similar at 47% for arylamine-exposed individuals and 53% for unexposed individuals and showed a similar pattern of mutation, with GC to AT transitions accounting for the majority of the mutations in both groups. This finding suggests that arylamine exposure does not leave a mutational "footprint" in the p53 gene. However, compared to other tumors, bladder tumors from both exposed and unexposed individuals had a high frequency of multiple mutations and it is interesting that these mutations were highly concordant. We suggest that one explanation of this pattern of mutations could be from decreased DNA repair fidelity within tumor cells. The frequency of mutation in p53 is closely linked to tumor grade and stage and so may be a late event in the development of bladder tumors.

Aged↗