Biomedical subjects

X Zhao

Publications and source records attributed to X Zhao.

At least 451 records · Page 25Linked to original sources

PubMed1997

[The study of women's bone density in Beijing].

Bone mass of 434 healthy women aged from 20-65 years was measured at both distal and mid-radius of the non-dominant arm by using a single-photon absorptiometer (SPA) with an 241Am source (model SD-1000), and bone density and related factors were studied. The bone density in women reached the peak value around 40 years old and the bone loss began around 45 years old. Bone loss was accelerated after menopause, with faster speed in trabecular bone than in cortical bone. The effect of menopause on bone loss was more significant than the effect of advancing age. Among 174 menopausal women, 9.8% had fractures. The bone density of postmenopausal women with history of bone fracture was lower than that of those without fracture. The results of this study suggest that the measurement of bone density can be used to predict the risk of osteoporotic fractures.

Absorptiometry, Photon↗

PubMed1997

[Study on standard of patch test for cosmetic allergens].

39 allergens, chemical ingredients commonly used in cosmetics in China, were tested. The safe concentration of allergens was determined in experiments on animals. On the basis of the above results and referring to the literature, the concentration of allergens used in patch test for human was designed and the patch test was carried out on 10 volunteers by routine method. Finally the concentration which gave no reaction in all 10 volunteers was verified in patients with eczema or contact dermatitis. The rate of positive reactions for each allergen was raged from 0 to 12% with an average 3.4%, According to the results of three above mentioned experiments the series of allergen standards for patch test was established. It is used as an appendix to the document for diagnostic criteria and principles of management of consmetic diseases.

Allergens↗

PubMed1997

[A study on the mechanism of taurine postponing the aging process of human fetal brain neural cells].

The relationship between taurine and aging of brain neural cells was studied by using primary human fetal brain neural cells cultured in serum-free medium. The results indicated that the activity of superoxide dismutase (SOD) was significantly higher in taurine added group than the control group cultured for 6, 9 and 15 days (P < 0.05). With different taurine levels, the SOD activities of 50 mg/L and 200 mg/L taurine groups were significantly higher than the control group cultured for 6 days (P < 0.05). After 3-day culture, the activity of glutathione peroxidase (GSH-Px) in the taurine added group was significantly higher than the control group (P < 0.05). The membrane lipid fluidity of neural cells decreased with time in control group, but was stable in the group treated with taurine. The fluidity was more stable in the groups treated with 50, 200 and 400 mg/L groups cultured for 6 days, compared with the control group (P < 0.05 or 0.01). The present study showed that taurine is necessary for maintaining membrane lipid fluidity of neural cells in proper levels, and plays an important role in postponing the aging process of brain neural cells.

Brain↗

PubMed1997

[A study on the relationship between bone mineral content and the tissue calcium level in rats].

The relationship of bone mineral density (BMD) and bone mineral content (BMC) of femur bone with the tissue and blood calcium contents was studied with 98 Wistar rats (15-week old). The results indicated that the body length, body weight, bone width, BMC, BMC/weight, BMD/weight and BMD/length in male were markedly different from those in female animals. The BMD of alive rats was significantly correlated with the total calcium intake, length, weight and calcium retention rate (P < 0.05). BMC was significantly related to sex, length, weight, liver calcium content and total calcium intake. Multiple regression analysis indicated that the animal body length, weight, total calcium intake and calcium content in heart were positively correlated with the BMD of alive animals. The animal body length and plasma calcium content were positively correlated with BMD of separated bones after the animals were sacrificed. The present results indicated that the BMC and BMD of alive rats could reflect the calcium status and bone mineral accumulation in the body because of the significant correlation with the growth rate, calcium retention rate, muscle and plasma calcium contents, but not with the separated bone BMD or BMC.

Animals↗

PubMed1997

[Evaluation on the method to test the sex-improve function and its key points].

The mating-test with normal mouse is one of the methods built to test wheather the type of sexual function improvement food could improve the sexual function. Through controlling the influence factor of the experiment such as the most suitabke mating time, the weights of mating mice, the mating temperature and the mating cage, and through making the female mice in different sexual response circle to be in the same, we got quite good results. The authors' study affirms the availability and dependability of the sexual function experiment method set by the authors' intitute.

Animals↗

PubMed1997

[The experimental study on absorption and utilization of calcium from oyster shell powder mixed with fruit juice].

A new kind of calcium powder was prepared from the shell of oyster and the bones of other sea lives, in which fruit juice was mixed. This calcium powder and other four different forms of calcium (i.e., active calcium, gluconate, lactate, and phosphate) were fed to 4 groups of Wistar rats for 30 days. 3 days calcium metabolism test was done. The absorption and retention rates of calcium powder were 69.2% and 95.1% in the experimental group, which were higher than those in other calcium supplement groups (P < 0.05). The weight of femurs and the total calcium content of femurs had significantly increased in calcium powder group (P < 0.05). These findings indicated that calcium from calcium powder, which was prepared from sea lives and mixed fruit juice was more effective.

Animals↗

PubMed1997

[Survey on nutritional knowledge, attitude and practice among the residents in Beijing, Guangzhou and Shanghai].

A survey on nutritional knowledge, attitude and practice (K-A-P) was carried out among 965 residents aged between 20 and 50 and randomly selected in Beijing, Guangzhou and Shanghai. The results showed that subjects' knowledge level was not high, and their knowledge scores were significantly correlated with their education levels (r = 0.3011, P < 0.010). Subjects aged above 35 had a higher knowledge level than that of younger ones. Subjects from three cities held a positive and favorable attitude towards the acquisition of nutritional knowledge, reasonable dietary pattern and healthy diet habits. Results of food frequency survey indicated that the consumption of rice/flour, meat/poultry, vegetables, fruits, milk and milk products was relatively high. In addition, 89.5%, 78.8% and 47.8% of subjects selected newspaper, TV and broadcast as their main sources of nutritional information respectively. This survey provided basis on content and method for future nutrition education.

Adult↗

PubMed1997

[Hepatocyte apoptosis in chronic viral hepatitis and its relationship with viral and Fas antigen expression].

To study the apoptosis of hepatocytes and its relationship with viral and Fas antigen expression in viral hepatitis, we detected apoptosis of liver cell and the expression of viral and Fas antigens in liver tissues of patients with chronic hepatitis B and/or C virus infection by using in situ end-labelling and immunohistochemical methods, respectively. 25 of 31 cases were detected end-labelling positive cells in their liver. The stained cells scattered in hepatic lobules, and also located in some necrosis areas and in bile duct epithelium. The apoptosis index was higher in patients with high histological active index (HAI) and in patients with viral antigen(s) positive in their liver than that in patients with low HAI and in patients without viral antigen, respectively. Apoptosis occurred in antigen positive and negative cells. There was no significant difference of apoptosis index between Fas antigen positive and negative group. These results indicated that both the infected and uninfected liver cells could occur apoptosis in patients with viral hepatitis. Further study on the mechanism of liver cell apoptosis is needed.

Adult↗

PubMed1997

[Effects of captopril on the myocardial performances and hemodynamics after cardiac arrest].

UNLABELLED: The effects of cardioplegia and reperfusional blood containing 4.6 mumol/L captopril (CPL) on the myocardial performances and hemodynamics of canine heart under hypothermic extracorporeal circulation were studied. Twenty four mongrel dogs were divided randomly into 3 groups. CONTROL GROUP: Only modified St. Thomas cardioplegia was used. CPL group: St. Thomas cardioplegia containing CPL 4.6 mumol/L was used and the same concentration of captopril in the circulatory blood was established before releasing the cross clamp. CPL + phenylephrine group: The concentration was the same as the CPL group, with an additional dose of phenylephrine (2 micrograms/kg) into the oxygenator and abdominal coarctation. The results revealed that the coronary blood flow and left ventricular contractility and relaxation indices of CPL group were significantly improved than those of the control group, and increasing the systemic and pulmonary vascular resistence had no effect on the cardiac function protected by captopril. It is suggested that captopril could ameliorate the recovery of myocardial performences by inhibitting myocardial and systemic renin-angiotensin system and scavenging free radicals.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1997

[The prognostic values of FCM determination of primary tumor and axillary lymph node of the patients with breast cancer].

Using Flow cytometry, we determined the ploidy and SPF on the primary tumor and axillary lymph node of 58 patients with breast cancer. Follow up for 5 years evealed that 23 patients had recurrence. 21 of them died. We conclude that the patients with aneuploid and high SPF have a higher relapce rate than those with diploid and low SPF, especially in those with advanced stage tumor or metastatic lymph node. It seems that ploidy and SPF of primary tumors affect more strong the prognosis of the patient than those of axillary lymph node. The probable cause of the recurrence of diploid tumor patients suggest post operation treatment for the patients with aneuploid cancer.

Adult↗

PubMed1997

[A preliminary study on the effect of estrogen on nasal mucosal hyperreactivity].

To understand the mechanism of the effect of estrogen on nasal mucosal hyperreactivity, animal models (guinea pigs) with different levels of estradiol (E2) were observed as follows: 1. effect of the change of E2 levels on E2 receptors (E2R) content in nasal mucosa; 2. effect of E2 level changes on histamine content in nasal mucosa and on nasal mucosal eosinophil and mast cell counts; 3. effect of E2 on release of cytokine IL-6 from macrophages. The results showed that high level of E2 might reduce the E2R content and eoinophil count but no significant effect on mast cells count and histamine content. The secretion of IL-6 from the macrophages was suppressed by E2 within concentration range of 3.13-50 micrograms/L. It was suggested that estradiol may play a complicated role in nasal mucosal hyperreactivity.

Animals↗

PubMed1997

[Transsphenoidal microscopic removal of invading pituitary adenoma].

Eighteen cases of invading pituitary adenoma were removed via the approach of transsphenoidal microscopical operation. Among them 4 cases had insulin dependent diabetes. The pituitary adenoma were near-totally removed in 15 cases, partially removed in 3, and 10 cases were treated by supplement radiotherapy postoperatively and 5 cases by oral bromocriptin postoperatively. The average time of follow-up was 3.8 years. There were 3 cases(16.6%) had postoperative recurrence of the tumor which were finally cured by transfrontal craniotomy. The feasibility of the transsphenoidal microscopic approach for the invading pituitaty adenoma was discussed.

Adenoma↗

PubMed1997

[Scanning electron microscopic changes of maxillary sinus mucosa before and after functional endoscopic sinus surgery].

We attempted to evaluate postoperative maxillary sinus mucosal changes in 20 maxillary sinuses of 16 patients who underwent functional endoscopic sinus surgery (FESS). Ciliated area of the maxillary sinus mucosa and ostium of maxillary sinus were quantitatively observed by scanning electron microscope and image analysis before and after FESS. In the present study, the number of preoperative ciliated cells of maxillary sinus mucosa and ostium was significantly reduced, goblet cells and microvillous cells were increased, and squamous cell metaplasia observed in part of the maxillary sinuses. Many damaged ciliated cells tend to recover and ciliated area significantly increased at 6-12 months after the surgery. The results showed that the damaged ciliated epithelium could return to normal by the improvement of ventilation and drainage of the maxillary sinus following FESS.

Adolescent↗

PubMed1997

[The development of light-curing soft denture liner].

In this study, a visible light-curing soft denture liner was developed, and 6 methacrylate polyurethane elastomer and a diluent were synthesised, their effect on tensile strength, compression set, Shore A hardness, absorption and solubility were also investigated. The results showed that the elastomer made of polyethylene adipate or polybutylene ether glycol possessed the highest tensile strength and hardness, the elastomer made of polypropylene ether glycol showed low tensile strength and low shore A hardness, the elastomer made of hydroxyl-terminated liquid polybutadiene rubber had a moderate tensile strength and hardness.

Denture Liners↗

PubMed1997

[Preparation of monoclonal antibodies to barley yellow mosaic virus].

Using hybridoma techniques, six hybridoma celllines: 4D6, 4D4, 4F10, 3H6, 3H8 and 4E9 secreting monoclonal antibodies to Shanghai Isolate of Barley yellow mosaic virus (BaYMV) were prepared by fusion between myeloma cells NS-1 and spleen cells of BALB/C mouse immunized with BaYMV. The subclasses of monoclonal antibodies obtained belong to IgG2a. The cross-reaction test with different viruses (SMV, TMV and three isolates of TuMV) showed that six monoclonal antibodies were specific to BaYMV. The titers of six monoclonal antibodies to BaYMV in their cell cultured supernatauts were 1:1-5 x 10(4), and that of 4F10 in ascitic fluid was 1:6.4 x 10(5) by using indirected ELISA test respectively.

English Abstract↗

PubMed1997

[Simulation of a decoupling generalized predictive control algorithm for temperature-humidity system].

A decoupling generalized predictive control algorithm was presented in this paper. This algorithm was proposed to control the temperature-humidity system of a practical air-conditioning environmental chamber. By introducing absolute humidity as an intermediate variable, temperature and humidity of the system can be decoupled. Then the two decoupled systems are controlled by generalized predictive control (GPC) algorithm at different sample rates. Many simulation experiments demonstrated the effectiveness of the algorithm. Besides, decoupling of temperature and humidity will be extremely helpful to the application of GPC on the real system. This is also the effective method to control the temperature and humidity system.

Air Conditioning↗

PubMed1997

[9-cis retinoic acid induces apoptosis in HL-60 cells].

OBJECTIVE: To investigate the apoptosis of HL-60 cells induced by 9-cis retinoic acid (9-cis RA), and illustrate the possible molecular mechanism. METHODS: Apoptosis was detected by morphological observation, DNA electrophoresis and flow cytometric cell cycle analysis. Bcl-2 expression was detected by flow cytometry. RESULTS: 9-cis RA initiated apoptosis of HL-60 cells after inducing them irreversibly commited to differentiation. Bcl-2 was downregulated during the differentiation and apoptosis process. 9-cis RA was more potent than all-trans retinoic acid (ATRA) did in inducing terminal differentiation associated apoptosis and in downregulation of Bcl-2 expression. CONCLUSION: 9-cis RA can induce apoptosis in HL-60 cells. Downregulation of Bcl-2 expression appears to play an important role in the apoptosis of the differentiated leukemic cells.

Alitretinoin↗

PubMed1997

[Bone mineral content and its influence factors of children aged 0-16 in a city and village].

The radial and ulnar bone mineral content (BMC) was measured by single-photon absorptiometry, and the effects of multiple independent variables on BMC and bone width (BW) were explored using multiple regression analysis in 332 rural and city children aged 0-16 years in Henan province from 1994 to 1995. BMC, BW, BMC/BW and forearm length increased with age increasing, and the BMC in city children aged 0-6 years was higher than that in rural children. Radial BMC was positively related to BW in the measured sites. Age, body weight and height (or length) all had significantly positive and independent effects on radial BMC in both groups. The positive correlation of radial BMC with age was observed, however, the ratio of radial BMC to body weight was negative correlation. The BW in measured site and forearm length increased with ages. After adjusted for body size, there were no significant effects of sex, age and body weight on radial BW except height (length). This study shows that overall body size rather than adiposity is the important factor for bone BMC, so that it is needed to consider several variables, for example, BMC, BMD, BMC/body weight and BMC/age.

Absorptiometry, Photon↗