Biomedical subjects
Publications and source records attributed to M Zhang.
A new triterpenoid glucoside ecliptasaponin D was isolated from Eclipta alba (L.) Hassk. Its structure was deduced as 3 beta, 16 beta-dihydroxy olean-12-ene-28-oic acid-3 beta-O-beta-D-glucopyranoside, based on spectral analysis and chemical evidences as well as results of hydrolysis.
For exploring cellular immunity disturbances in children with acute lower respiratory infection (ALRI) caused by respiratory syncytial virus (RSV) the level of interleukin-2 (IL-2) soluble interleukin-2 receptor (sIL- 2R), the expression rate of interleukin-2 receptor (IL-2R) on T cells and percentage of T lymphocyte subsets were determined in peripheral blood of 25 acute cases. The results showed that compared acute stage of RSV associated ALRI with recovery stage and control group, the level of peripheral blood IL-2 and expression rates of IL-2R decreased but the level of sIL-2R increased. The level of IL-2 had positive correlation with IL-2R and percentage of CD4+ cells, but had negative correlation with sIL-2R and percentage of CD8+ cells. The plasma sIL-2R level had negative correlation with expression rate of IL-2R, but had a positive correlation with clinical severity. These results suggested that human body had a functional disturbance in cellular immunity when infected with RSV.
It is important for separation and determination of plant growth regulators in the research of plant physiology. A study of the separation of five plant growth regulators, such as abscisic acid (ABA), gibberellic acid (GA), indole-butyric acid (IBA), indole acetic acid (IAA) and naphthaleneacetic (NAA) by micellar electrokinetic chromatography (MEKC) is presented. The effects of pH, SDS concentration, applied voltage and organic additives on migration behavior were investigated. Results showed that satisfactory separation was achieved on optimization of electrophoretic condition: 80 mmol/L SDS, 10 mmol/L borate-phosphate, 5% isopropanol, 18 kV applied voltage, pH 8.0. The SDS concentration and organic additives played an important role in separating plant growth regulators, and the applied voltage and pH gave less effect. The detection limit of ABA, GA, IBA, IAA and NAA were 5.0 x 10(-3), 3.0 x 10(-3), 5.8 x 10(-4), 1.5 x 10(-4) and 1.4 x 10(-4) g/L respectively. Increasing of the SDS concentration or organic additives would change separation factor (alpha) and result an improvement of the resolution of difficult separation pairs ABA-GA and IAA-NAA.
It is of significant importance to isolate lambda(k) form the total absorption cofficient data micro(E) for the analysis of EXAFS spectrum. Generally, least-squares procedure of polynomial spline or B spline was used for removing the smooth sbsorption background, which has been proved to be effective. But it suffers in that the trial of knot points is time-consuming and it is poor in reproducibility. In this paper, a new chemometrics method--wavelet transform analysis was used to separate the lambda(k) and background absorption from micro(E) and it is proved that the technique is a very good method for the analysis of EXAFS spectrum.
Tumor invasion and metastasis are processes poorly understood at the molecular level. Maspin is a serine protease inhibitor (serpin) with tumor-suppressing function in the mammary gland. Maspin gene expression is decreased with malignancy and is lost in metastatic cells. We show in this report that differential expression of maspin in normal and carcinoma-derived mammary epithelial cells is regulated at the transcriptional level. We have identified the Ets and Ap1 sites in the maspin promoter that are active in regulating maspin expression in normal mammary epithelial cells but inactive in tumor cells. The Ets site alone is sufficient to activate transcription in a heterologous promoter, whereas the Ap1 site cooperates with Ets in activation. The enhancing function by Ets and Ap1 elements is decreased in primary tumor cells (21NT) and is abolished in invasive tumor cells (MDA-231). Thus, loss of maspin expression during tumor progression results at least in part from the absence of transactivation through the Ets and Ap1 sites.
BACKGROUND: The human maspin gene encodes a protein in the serine proteinase inhibitor (serpin) family with tumor-suppressing functions in cell culture and in nude mice. In order to examine the role of maspin in an intact mammal, we cloned and sequenced the cDNA of mouse maspin. The recombinant protein was produced and its activity in cell culture was assessed. MATERIALS AND METHODS: Mouse maspin (mMaspin) was cloned by screening a mouse mammary gland cDNA library with the human maspin cDNA probe. Northern blot analysis was used to examine the expression patterns in mouse tissues, mammary epithelial cells, and carcinomas. Recombinant mMaspin protein was produced in E. coli. Invasion and motility assays were used to assess the biological function of mMaspin. RESULTS: mMaspin is 89% homologous with human maspin at the amino acid level. Like its human homolog, mMaspin is expressed in normal mouse mammary epithelial cells and down-regulated in mouse breast tumor cell lines. The expression is altered at different developmental stages in mammary gland. Addition of the recombinant mMaspin protein to mouse tumor cells was shown to inhibit invasion in a dose-dependent manner. As with the human protein, recombinant mMaspin protein also inhibited mouse mammary tumor motility. Deletion in the putative mMaspin reactive site loop (RSL) region resulted in the loss of its inhibitory functions. CONCLUSIONS: mMaspin is the mouse homolog of a human tumor suppressor gene. The expression of mMaspin is down-regulated in tumor cells and is altered at different developmental stages of mammary gland. mMaspin has inhibitory properties similar to those of human maspin in cell culture, suggesting that the homologous proteins play similar physiological roles in vivo.
OBJECTIVE: Acupuncture is known to enhance gastric motility. Electrical acustimulation has been shown to reduce gastric tachyarrhymia in vection-induced motion sickness. The aim of this study was to investigate the effect of electrical stimulation of acupuncture points on gastric myoelectrical activity in healthy humans. METHODS: Nine healthy native Chinese were studied. Gastric myoelectrical activity was recorded using surface electrogastrography (EGG). The EGG recording was made in the fasting state, in a study period during which acupuncture points were electrically stimulated continuously, and in a recovery period after stimulation. The percentage of regular slow waves was assessed by computing the percentage of 2 to 4 cycles per minute slow waves in the EGG. RESULTS: Electrical stimulation significantly increased the percentage of regular slow waves, which was sustained in the recovery period. The increase of the regular slow wave activity resulted from the normalization of arrhythmia. CONCLUSION: Electrical stimulation of acupuncture points may enhance the regularity of gastric myoelectrical activity and may be an option for treatment of gastric dysrhythmia.
CT and MR imaging can play an important role in the diagnosis of lung cancer. Evaluation of a solitary pulmonary nodule is usually carried out using CT. High-resolution CT is useful in the morphologic diagnosis of a solitary pulmonary nodule. The enhancement characteristics of a pulmonary nodule in contrast-enhancement CT can be a method of distinguishing benign and malignant nodules. MR imaging is superior to CT in contrast resolution and multidirectional imaging capability. Contrast-enhancement MR imaging can describe the enhancement characteristics of the pulmonary lesion better than contrast-enhancement CT. The extent of chest wall and mediastinal invasion of lung cancer can be better shown using MR imaging than CT.
This article addresses briefly the measurement of multidimensional outcomes and costs for major depression. We emphasize the importance of measuring outcomes in a variety of domains, including the broader issues of improvement or decline in functioning and impairment based on domains known to be affected by major depression. We emphasize the importance of measuring the economic costs of illness, both the direct total health care costs and indirect costs. Direct costs include mental health treatment costs and all other health care costs. Indirect costs include such varied factors as lost wages for the depressed individual and caregiver burden. We demonstrate the usefulness and importance of using these measures with several examples from our own research.
OBJECTIVE: To report the efficacy and outcomes of transcervical resection of the endometrium (TCRE) in treatment of menorrhagia. METHODS: 400 patients with menorrhagia due to fatigue causes who had failed in medical therapy and did not desire pregnancy and surgery underwent TCRE under hysteroresectoscope. Among them, 72 patients with submucous uterine myoma less than 5cm in diameter had their myoma resected simultaneously, 366 cases were followed up postoperatively for 3 months to 4 years. RESULTS: TCRE was performed successfully except 16 cases, giving a success rate of 95.6%. Three cases sustained uterine perforation. During follow-up, 146 cases (41.7%) became amenorrhea, 119 (34.0%) had only spotting. The remaining 85 (24.3%) had normal periods. 78.3% of the cases who previously had dysmenorrhea had relieved their pain. Long-term complications were recurrent abnormal uterine bleeding (22 cases 13 of them had a second operation), hematometra (5) and adenomyosis (4 cases). CONCLUSION: TCRE is an effective procedure in treating menorrhagia and small submucous uterine myoma.
OBJECTIVE: To demonstrate the efficacy of intracytoplasmic sperm injection (ICSI) in treatment male infertility and idiopathic fertilization failure. METHODS: 31 couples received intracytoplasmic sperm injections because of severe oligo-astheno-teratospermia or idiopathic infertility. Ovarian stimulation was achieved by conventional protocol. Transvaginal ultrasound-guided oocyte collections were done 36 hours after hCG injection. Only matured oocytes were selected for microinjection. RESULTS: 237 oocytes were treated by intracytoplasmic sperm injection; normal fertilization and cleavage occurred in 132 of 213 oocytes which were survived (62.0% normal fertilization rate). From 1995 to 1996, clinical pregnancies were achieved in 8 cases (25.8%). The first ICSI baby was delivered on October 3, 1996. CONCLUSION: Intracytoplasmic sperm injection has improved the results of IVF-ET treatment in male and idiopathic infertility.
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DNA in the liver, kidney, testes, etc. was amplified with semi-random polymerase chain reaction (PCR) in Wistar male rats exposed to ethylene oxide (EtO) for various times and in control rats with hemoglobin gene-specific primer to study the damage effects of EtO on DNA molecule. Results showed that inhalation of 800 mg/m3 of EtO for six to nine weeks could cause damage to DNA in the liver, kidney and testes, etc. to various extent, with the most serious damage to DNA in the testes.
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The treatment of the bone defect of the distal part of the radius included repair of the bone defect and restoration of the function of the wrist joint. Since 1979, three operative methods were used to treat 13 cases, and they were grafting of the vascularized fibula by anastomrsis fibular vessels, grafting of upper part of fibular with lateral inferior genicular artery and grafting vascularized scapula flap. Follow-up had been carried out from 1 to 10 years. The result was satisfactory. The discussion included the repair of the defect of the middle or distal part of the radius, the operative methods, main attentions and indications. It was considered that it should be based on the length of bone defect while the operative method was considered.
A novel 15-subunit complex with the capacity to remodel the structure of chromatin, termed RSC, has been isolated from S. cerevisiae on the basis of homology to the SWI/SNF complex. At least three RSC subunits are related to SWI/SNF polypeptides: Sth1p, Rsc6p, and Rsc8p are significantly similar to Swi2/Snf2p, Swp73p, and Swi3p, respectively, and were identified by mass spectrometric and sequence analysis of peptide fragments. Like SWI/SNF, RSC exhibits a DNA-dependent ATPase activity stimulated by both free and nucleosomal DNA and a capacity to perturb nucleosome structure. RSC is, however, at least 10-fold more abundant than SWI/SNF complex and is essential for mitotic growth. Contrary to a report for SWII/SNF complex, no association of RSC (nor of SWI/SNF complex) with RNA polymerase II holoenzyme was detected.
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