Biomedical subjects

X Xing

Publications and source records attributed to X Xing.

At least 37 records · Page 2Linked to original sources

PubMed2000

The ets protein PEA3 suppresses HER-2/neu overexpression and inhibits tumorigenesis.

Because HER-2/neu overexpression is important in cancer development, we looked for a method of suppressing the cell transformation mediated by HER-2/neu overexpression. We have identified that the DNA-binding protein PEA3, which is encoded by a previously isolated gene of the ets family, specifically targeted a DNA sequence on the HER-2/neu promoter and downregulated the promoter activity. Expression of PEA3 resulted in preferential inhibition of cell growth and tumor development of HER-2/neu-overexpressing cancer cells. This is a new approach to targeting HER-2/neu overexpression and also provides a rationale to the design for repressors of diseases caused by overexpression of pathogenic genes.

3T3 Cells↗

PubMed2000

[Bone marrow transplantation for beta-thalassemia major].

OBJECTIVE: To examine the feasibility of bone marrow hematopoietic stem cell transplantation for thalassemia major. METHODS: Bone marrow transplantation was performed on a 4-year-old patient with beta-thalassemia major, whose gene mutation was CD41-42/654. The donor was his brother. In the 850ml bone marrow, the nucleated cells were 5.6x10(8)/kg, CD(+)(34) cells 7.8 x 10(6)/kg, and colony-forming-unit-granulocyte-macrophages(CFU-GM) 5.7x10(5)/kg. HLA was one site mismatched, while RBC type matched. Pre-transplant conditions included Busulfan 16mg/kg, cyclophosphamide 200mg/kg and lymphoglobuline 88mg/kg. Cyclosporine and methotrexate were used for prevention of graft-versus-host disease(GVHD). RESULTS: After transplantation, the patient had grade II acute GVHD and cytomegalovirus(CMV) interstitial pneumonia; he was cured. White blood cells(WBC) and neutrophil granulocytes recovered to 1.1 x 10(9)/L and 0.4 x10(9)/L respectively on day 14 post transplantation. WBC was 4.5 x 10(9)/L on day 18, and descended for a time during treating interstitial pneumonia with Ganciclovir. Platelet(Plt) exceeded 50 x 10(9)/L on day 86 and recovered to normal 5 mothers and a half post transplantation. Hb reached 106g/L on day 128. The patient received the last blood transfusion on day 103. Before transplantation, the patient had to receive 200ml blood infusion per month for maintaining Hb 60-90g/L; after transplantation, his Hb kept up >110g/L for 6 months without blood transfusion. The gene type had changed to donor's CD41-42/N heterozygen. CONCLUSION: This is the first report on successful transplantation of bone marrow stem cell for thalassemia major in China, suggesting a new way to treat the disease and to expand the use of BMT. For treatment of CMV interstitial pneumonia post-transplantation, Ganciclovir should be dose enough and be used for at least 2 months.

Child, Preschool↗

PubMed2000

Cell culture of biopsied endometriomas after danazol/hormonal therapy: a study of growth features and fertility effects.

The growth features of cells from endometriomas biopsied from patients who had been treated with Danazol or with hormones have not been studied in vitro. Danazol is a versatile drug and despite its recognised efficacy in controlling endometriosis, little is known about is cytotoxicity and mechanism of action. Culture of the biopsied endometriomas permitted qualitative cytotoxic assessments by way of comparison with cultured normal uterine endometrial cells treated in vitro with Danazol. The growth characteristics were studied in monolayer and collagen gel cultures. Cytopathology was characterised by light and electron microscopy. Since endometriosis is associated with infertility in women, data from in vitro fertilisation (IVF) were analysed with respect to treatment modalities as compared with cases suffering fallopian occlusion. Danazol reduced pregnancy chances. Two factors may be responsible: (a) altered follicle development resulting in poor oocyte quality (b) reduced nidation because of long-lasting endometrial cytotoxicity. The experimental findings reported here support the latter explanation. Consequently, Danazol therapy should be conditional; patients wishing to achieve pregnancy should preferably receive hormonal therapy.

Cells, Cultured↗

PubMed2000

[Review on research of plant nutrient use efficiency].

The concept of nutrient use efficiency is the central to the understanding of ecosystem function. We reviewed the concept of nutrient use efficiency and resorption, its expression and calculation, affecting factors and biochemical basis, we also analyzed the current problems in the studies of nutrient use efficiency, and pointed out the directions for future research work of this field.

Absorption↗

PubMed2000

[Beta-diversity of Stipa communities in Inner Mongolia Plateau].

The beta-diversity characteristics of four Stipa communities (S. baicalensis, S. grandis, S. krylovii and S. klemenzii) were studied using comparable plots methods. As a measurement of species turnover within communities, Whittacker's index(beta ws) was size-dependent, and reduced gradually with the increasing quadrat size. Under the same scale, beta ws indices of the communities were similar. Cody's index (beta c) was also affected by sampling size. beta c increased initially as quadrat size enlarged, then stabilized over the size of 0.5 m2 for S. baicalensis and S. grandis communities, and 2 m2 for S. krylovii and S. klemenzii communities. S. baicalensis community had the highest Cody index, while S. klemenzii community had the lowest one. In most cases, the within-community distance interval had a relatively high effect on Cody index; From S. baicalensis to S. klemenzii community, the functional group diversities of forbs, perennial bunch and rhizome grasses decreased greatly, the diversity of intermediate xerads reduced significantly, and the diversity of xerads increased firstly, and then declined for S. klemenzii community. The changes in species composition of four Stipa communities could give a reflection to the degrees of community replacement along ecological gradients, and Cody indices between the communities reduced gradually. The Morisita-Horn similarity coefficient between S. baicalensis and S. grandis community was significantly higher (0.72) than those between S. grandis and S. krylovii communities (0.55), and between S. krylovii and S. klemenzii communities(0.42).

China↗

PubMed2000

[Cytologic and histopathologic examinations of fine-needle aspirates of pancreatic mass].

OBJECTIVE: To evaluate the usefulness in diagnosis of pancreatic mass by histopathologic and cytologic examinations of fine-needle aspirates obtained under ultrasonic guidance. METHODS: In 83 patients with pancreatic mass, percutaneous fine-needle aspiration was performed under ultrasound guidance. The fluid aspirates were examined cytologically and tissue fragments examined histopathologically. The findings were compared. RESULTS: The rate of accuracy, sensitivity, and specificity of cytologic examination was 98.8%, 98.3% and 100% respectively, and that of histopathologic diagnosis was 95.1%, 93.2% and 100%, respectively. There was no false positive. CONCLUSION: Both histopathologic and cytologic examinations of fine-needle aspirates of pancreatic mass are sensitive and accurate enough for the diagnosis of pancreatic diseases. They can be used with complementarity.

Biopsy, Needle↗

PubMed2000

[Effects of alfacalcidol on osteoporosis in ovariectomized rats].

OBJECTIVE: To investigate the effects of alfacalcidol on osteoporosis in rats induced by ovariectomy (OVX). METHODS: Fifty-three virgin female Wistar rats of six months old were divided into 6 groups: (1) rats in baseline group (base) were sacrificed what 6 months before OVX, and those in the other 5 groups were either bilaterally OVX or sham-operated (sham) as follows: (2) Sham; (3) OVX baseline (OVXb); (4) OVX end (OVXe); (5) OVX + 17beta-estradiol 20 microgram/kg.(-1) SC. (O + E); and (6) OVX + alfacalcidol 0.1 microgram/kg.(-1) oral (O + VD). Rats in OVXb group were sacrificed 6 weeks after OVX and the others were sacrificed 14 weeks after surgery. Alfacalcidol (TEVA, Israel) was fed orally at 6 weeks after OVX and lasted for 8 weeks. Urine and serum samples were collected before sacrifice to determine the bone turnover markers. The right tibia was processed undecalcified for histomorphometric analysis, and the right femur was prepared for pQCT scanning and bone biomechanical measurement with indentation test. RESULTS: Treatment of OVX rats with alfacalcidol (O + VD) increased tibial cancellous bone volume in histomorphometric analysis (12.0% +/- 1.1% vs 5.8% +/- 1.3%, P < 0.01). pQCT scanning showed that trabecular BMC and BMD were sharply elevated in O + VD group compared with OVXe group, increased 109.2% and 133.1% respectively (P < 0.01). In consistency with these changes in mechanical competency of cancellous bone in distal femur, maximal load was enhanced in O + VD group compared with OVXe group (21.3% +/- 4.0% N vs 7.9% +/- 1.9% N, P < 0.05). All these changes in O + VD group were similar to those in 17beta-estradiol treatment group (O + E). Serum calcium concentration increased in O + VD group. Histomorphometric and biochemical indices of bone resorption reduced in O + VD group. CONCLUSION: Alfacalcidol effectively prevent bone loss in OVX rats and restore partly the trabecula, with evidenced increasing density, contents as well as maximal loads of cancellous bone, and reduce bone resorption.

Adjuvants, Immunologic↗

PubMed2000

[Study on risk factors of breast cancer among urban women in China].

OBJECTIVE: Breast cancer is the most common malignant neoplasm in women all over the world. It is necessary to establish monitoring methods and to identify risk factors. METHODS: Six cities including Beijing, Shanghai, Tianjin, Chongqing, Wuhan and Guangzhou were chosen as the sample areas. 2 100 cases with 1:1 matched controls were interviewed with a uniformed questionnaire. Conditional logistic regression and cluster analysis were used for multivariate analysis. RESULTS: The common risk factors for the combined data of the six cities were high educational level (OR: 1.17), high body mass index (OR: 1.51), high intake of milk products (OR: 1.49), high intake of eggs (OR: 1.14), psychological depression (OR: 2.78), history of benign breast diseases (OR: 2.24), old age at marriage (OR: 1.42), dysmenorrhea (OR: 1.22), short duration of lactation (OR: 1.17). Among these factors, different cities had different ORs, as high educational level (OR: 1.20 - 1.61), high body mass index (OR: 1.40 - 22.36), high intake of milk products (OR: 1.64 - 3.39), depression (OR: 1.60 - 10.50), history of benign breast diseases (OR: 1.73 - 19.44). Some statistically significant correlations existed in different cities such as early age at menarche, old age at marriage, long menstrual periods, high intake of meat, eggs, sea food and passive smoking were risk factors. Some risk factors varied between premenopausal and postmenopausal women. Beijing, Wuhan and Chongqing were clustered as the same group in cluster analysis, so did Shanghai and Tianjin, but Guangzhou could not be grouped with other cities. CONCLUSION: Some common risk factors for breast cancer did exist in the six cities, but there were varieties in different areas which showed different places would have their own characteristics. Thus, careful study of risk factors, especially in the selection of variables and data analysis need to be carried on.

Breast Neoplasms↗

PubMed2000

[Tissue engineering of skin].

OBJECTIVE: To review the recent progresses on tissue engineering of skin. METHODS: Recent original articles about tissue engineering of skin were extensively reviewed, which focused on the progresses and major problems concerning the epidermal substitutes, dermal substitutes, cultured-epidermal composite skin graft. RESULTS: Most investigators had come to conclusion that the optimal skin substitute should provide for immediate reconstruction of both the lost epidermis and dermis. The research was mainly focused on how to transplant epidermal cells immediately, preserve their activity and function, and develop the extracellular matrix which could effectively accelerate the function of transplanted cells, induce vascular growth from the wound bed, could be biodegradable, no toxicity and no danger of carrying pathogen. CONCLUSION: The major research trends of tissue engineering of skin should be focused on the study of immediate transplantation of epidermal cells, accelerate wound healing and developing extracellular matrix of dermis.

Cell Transplantation↗

PubMed2000

[Changes of the responses of arterioles to noradrenaline, acetylcholine and nitroglycerin after limb ischemia-reperfusion].

OBJECTIVE: To explore the mechanism of microvascular spasm after limb ischemia-reperfusion. METHODS: The rabbit hindlimb normothermic tourniquet ischemia model was employed. The tendon on the dorsum of the foot was exposed for observation of microvessels. The responses of arterioles on tendon surface to topical application of 10(-6) mol/L noradrenaline (NE) (a vasoconstrictor), 10(-6) mol/l acetylcholine(Ach) (an endothelium-dependent vasodilator) and 10(-4) mol/L nitroglycerin(NTG) (an endothelium-independent vasodilator) were observed at the period of ischemia and following 30 minutes of reperfusion after 2 hours and 5 hours of ischemia by use of intravital microscopy. RESULTS: No significant changes in the responses of arterioles to NE, Ach and NTG were noted following 30 minutes of reperfusion after 2 hours of ischemia compared with pre-ischemia. The constrictor responses of arterioles to NE were still not significantly altered following 30 minutes of reperfusion after 5 hours of ischemia, however, the dilation responses to Ach and NTG were significantly decreased (to Ach P < 0.01; to NTG, P < 0.05). CONCLUSION: Reperfusion after 5 hours of ischemia significantly impairs both the endothelium-dependent and endothelium-independent vasodilation, meanwhile preserves constrictor responses to NE, these may contribute to the genesis of the vasospasm in ischemia reperfusion.

Acetylcholine↗

PubMed2000

[Effects of 1 alpha(OH)D3 on trabecular and cortical bone in ovariectomized rats].

OBJECTIVE: To study the pharmaceutical effects of 1 alpha(OH)D3 on trabecular and cortical bone in ovariectomized (OVX) rats. METHODS: 41 female Wistar rats of six months old were randomly divided into 5 groups: (1) Baseline control; (2) Sham control; (3) 6 weeks after OVX (OVXb); (4) 14 weeks after OVX (OVXe); (5) OVX + 0.1 microgram/(kg.d) 1 alpha(OH)D3 (O + VD), treatment started 6 weeks after OVX and lasted 8 weeks. Histomorphometry analysis of tibia, peripheral quantitative computed tomography (pQCT) scanning of femur, bone biomechanical test and serum and urinary biochemical parameters were determined. RESULTS: The levels of bone turnover indexes increased in OVX rats, OVX also resulted in reducing of trabecular, bone mass and biomechanical properties. The ratio of urinary deoxypyridinoline crosslink/creatinine was decreased by 67.0% in O + VD group compared with OVXe group 67.0% [(43.50 +/- 11.20) nmol.L-1/mmol.L-1 vs(131.80 +/- 14.90) nmol.L-1/mmol.L-1, P < 0.01]. Percent trabecular area (Cn-BV/TV) was increased by 89.8% in O + VD group compared with OVXe group (11.03 +/- 0.73 vs 5.81 +/- 1.29, P < 0.05). Trabecular bone mineral content and density were increased by 77.3% and 91.3% compared with OVXe respectively (P < 0.05). Although cancellous maximal load and stiffness increased in O + VD group, but no statistical significance. 1 alpha(OH)D3 also enhanced polar moment of inertia (PMI) and maximal load of cortical bone in femur compared with OVXe (23.70 +/- 1.63 vs 18.23 +/- 1.41, P < 0.01 and 171.69 +/- 9.92 vs 147.58 +/- 11.29, P < 0.05 respectively). CONCLUSION: 1 alpha(OH)D3 inhibited the higher bone turnover induced by OVX, increased trabecular bone in proximal tibia and bone mass in distal femur. 1 alpha(OH)D3 also improved the mechanical properties of cortical bone in femur.

Animals↗

PubMed1999

Normal changes in spinal bone mineral density in a Chinese population: assessment by quantitative computed tomography and dual-energy X-ray absorptiometry.

This study was designed to determine age- and gender-based normative values for spinal bone mineral density (BMD) in a Chinese population. In addition, we compared our data with those of other countries and populations. Four hundred and forty-three healthy Chinese subjects, aged 10-79 years (189 males, mean age 46.9 years; 254 females, mean age 45.7 years) were recruited for BMD assessment. BMD was measured by quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA), including posteroanterior DXA (PA-DXA), lateral DXA (L-DXA) and midlateral DXA (mL-DXA). For both genders, BMD values peaked in the 10-19 year age group when measured by QCT, and in the 30-39 year age group when measured by PA-DXA. BMD values decreased with age after reaching peak bone density in males and females for all measurements, except for PA-DXA in males. Male BMD values by DXA tended to increase beginning with the 60-69 age group through the 70-79 age group whether by PA-DXA, or L-DXA and mL-DXA. However, male QCT data showed stable BMD values among these two older groups. Comparative results showed female QCT data were higher in the 20-39 age group and lower after the 40-49 age group compared with American females. The peak BMD value by PA-DXA in Chinese females was reached in the same age group as American and European females and was similar in magnitude (p > 0.05). However, the peak BMD value for Chinese females was reached earlier and was significantly higher than that observed in Japanese females (p < 0.001). We conclude that the age group in which the peak BMD values are reached is different depending on the technique used, as is the calculated age-related rate of bone loss. It can be speculated that such differences reflect different timing for bone maturation in cancellous and cortical bone.

Absorptiometry, Photon↗

PubMed1999

[Orbital fat preservation and orbicularis muscle flap suspension for lower eyelid pouches].

OBJECTIVE: This is to introduce the experience in the treatment of lower eyelid pouches by orbital fat preservation and orbicularis oculi muscle flap suspension techniques. METHODS: From Sept. 1996 to May 1997, thirty patients with lower eyelid pouches were treated using Hamra's procedure. During the operation, the arcus marginalis was incised. The orbital fat was released and advanced beyond the infraorbital rim and sutured. A lateral-based orbicularis oculi muscle flap was created, and its pedicle was repositioned to the periosteum of the upper lateral orbital rim in a superiomedial direction. RESULTS: A total of 26 patients were available for postoperative follow-up for 3 to 8 months (mean 5.6 months). Of them one patient developed unilateral lower eyelid ectropion due to flabby reposition of the orbicularis oculi muscle flap. The rest obtained excellent cosmetic results without complications. CONCLUSION: This new method has following advantages: 1. The lower eyelid pouches and the infraorbital rim show that may be corrected simultaneously: 2. Sunken eyelids and scleral show that may follow fat removal in conventional lower blepharoplasty can be effectively avoided. 3. "Cheek lift" and a youthful eyelid-cheek complex contour can be obtained.

Adult↗

PubMed1999

[The study of new bio-membrane-bred epidermal cell grafts].

OBJECTIVE: The human epidermal cells were bred on a kind of bio-membrane, the bio-brane, in engineering a kind of new epidermal substitute, the bio-membrane bred cell graft. METHODS: Fresh and frozen grafts of biomembrane bred epidermal cells were transplanted into the full-thickness wounds of nude mice and those received simple Bio-brane were served as control. The wounds of the two groups were observed daily and biopsy was taken on the 3, 5, 7, 10, 21 and 35 days respectively. RESULTS: Epidermal cells could be cultured in vitro on the bio-membrane reaching the sub-saturated state of 60 to 70 percents. The bio-membrane after being grafted the epidermal cells continued to proliferate and differentiate to form a layer of new epidermis. There was no difference between the fresh and the frozen bio-membranes. CONCLUSION: Bio-membrane bred with epidermal cells could be a kind of ideal epidermal substitute.

Animals↗

PubMed1999

[Bone mineral analysis of whole body in 292 normal subjects assessed by dual X-ray absorptiometry].

OBJECTIVE: To understand whole body bone mineral changes in normal subjects. METHODS: Bone mineral was measured by dual X-ray absorptiometry (DXA) in 292 normal subjects aged 10-79, including 152 females and 140 males. They were divided into age-groups by decade. RESULTS: In males, peak value ages of total bone mineral content(TBMC), total bone mineral density(TBMD), anteroposterior spine BMD(L2-4 BMD) were in the 30-39, 20-39, 20-29 age-groups respectively. In females, they were all in the 30-39 age-group. Peak values of TBMC, TBMD, L2-4BMD were higher in males than those in females. Loss of bone mineral for females was more pronounced than that for males. There was a tendency of increased BMD among the 70-79 age-group for males. Loss of L2-4 BMD was more pronounced than TBMD. CONCLUSIONS: This study provides the normal bone mineral data of whole body for males and females, and the characteristic of changes.

Absorptiometry, Photon↗

PubMed1999

[Evaluation of the risk of vertebral fracture predictable with quantitative tibial ultrasound velocity test in postmenopausal women].

OBJECTIVE: To investigate predicting value of increased risk of vertebral fracture associated with reduction of tibial ultrasound velocity (SOS) test in postmenopausal women. METHODS: 193 menopausal women aged(54.4 +/- 7.3) years were included in our study. Post menopausal period of these subjects were (16.0 +/- 7.8) years. These participants received tibial ultrasound speed (SOS) test, DEXA for lumbar 2-4, femoral neck wards triangle and trochant, as well as SPA for 1/3 and 1/10 of distal forearm. Vertebral fracture was determined by radiograph of lateral lumbar and thoracic spine. RESULTS: 54 subjects were found at least one vertebral deformation, and no vertebral deformation was found in other 139 subjects. Tibial SOS was significantly lower in subjects with than without vertebral fracture [(3,651.9 +/- 188.3) vs (3,731.3 +/- 140.8), P < 0.01], The similar results were also found in BMD. The analysis of logistic regression showed: odds ratio (OR) of SOS to vertebral fracture was 1.86(P < 0.01) when 1 standard deviation of SOS changed. It was lower than OR of BMD by DEXA(2.25-3.28, all P < 0.001), and similar with OR of BMD by SPA (1.50-1.96). CONCLUSIONS: Low SOS was associated with presence of vertebral fracture in postmenopausal women. SOS could predict the risk of vertebral fracture, 86% of the risk of vertebral fracture increased when 1 standard deviation of SOS reduced.

Aged↗

PubMed1998

Preclinical and clinical study of HER-2/neu-targeting cancer gene therapy.

Cationic liposomes have been used in many gene therapy approaches. The advantages of low toxicity, lack of immunological response, and easy preparation using cationic liposomes make multiple administrations possible, which may overcome the disadvantage of low transfection efficiency. Cationic liposomes, therefore, provide a promising procedure for delivering a therapeutic gene into cancer patients. Amplification or overexpression of the HER-2/neu oncogene is frequently found in breast and ovarian cancers and correlates with poor clinical prognosis. We have found that the adenovirus 5 E1A and the nontransforming simian virus 40 (SV40) large-T antigen mutant can inhibit HER-2/neu overexpression and reverse the HER-2/neu-mediated malignant phenotypes. By using the cationic liposome 3beta[N-(N',N'dimethylamino)ethanecarbamoyl]-cholesterol (DC-Chol), we successfully transferred E1A and/or large-T mutant into established orthotopic breast and ovarian cancer models. The survival of a treated group of mice was significantly prolonged and the expression of HER-2/neu oncogene was down-regulated in vivo. A subsequent toxicity assay indicated that no significant toxicity was associated with the liposome-DNA complex administration even when we used ten times the dose needed to achieve a therapeutic effect. Based on these data, a phase I clinical trial of DC-Chol-mediated E1A gene therapy for ovarian and breast cancers that overexpress HER-2/neu has been initiated in our institute. In this article, we will review the development of HER-2/neu-targeting gene therapy using cationic liposomes.

Journal Article↗

PubMed1998

DNA ligase gene disruptions can depress viral growth and replication in poxvirus-infected cells.

Poxvirus-encoded DNA ligases are assumed to play a role in viral DNA replication; however mutational inactivation of vaccinia ligase has not been reported to affect viral growth rates in culture. This communication re-examines this surprising aspect of poxviral biology using both Shope fibroma virus (SFV) and vaccinia virus. SFV and vaccinia ligase deficiencies create essentially identical phenotypes. In particular, ligase-deficient SFV strains are mildly UV sensitive and etoposide resistant, phenotypes previously shown to characterize ligase-deficient vaccinia strains. Moreover, we find that ligase mutations can inhibit the growth of both SFV and vaccinia virus in vitro. The poor growth observed in the absence of a viral ligase is correlated with a two- to tenfold reduction in viral and extragenomic DNA synthesis. This phenotype is host dependent. No differences in viral growth or DNA yield were seen when vaccinia strains were cultured on rabbit (SIRC) cells, but ligase deficiencies reduced growth and DNA yields when vaccinia was plated on BSC-40 cells or SFV on SIRC cells. Despite these replicative defects, mutational inactivation of SFV ligase produced no detectable increase in the number of viral DNA breaks and had no effect on virus-catalyzed extragenomic DNA recombination or UV repair. We conclude that poxviral ligases do play a role in viral DNA replication, but the replicative defect is obscured in some cell lines.

Animals↗