Biomedical subjects

Z Yang

Publications and source records attributed to Z Yang.

At least 163 records · Page 9Linked to original sources

PubMed2001

Proinflammatory properties of the human S100 protein S100A12.

S100 proteins represent a new class of chemoattractants. Here we extend earlier evidence for the proinflammatory properties of human S100A12. A12 induced migration of monocytoid cells, with optimal activity at 10(-10) M and potency of >10(-9) M C5a. Neutrophils were poorly responsive, and lymphocyte migration was not affected. Actin polymerization in monocytoid cells was accompanied by a sustained [Ca(2+)]i flux of a magnitude comparable with C5a. A12 elicited a transient infiltration of neutrophils (4-8 h) and more delayed recruitment of monocytes (8-24 h) in vivo. A12 (approximately 70 nM) was present in synovial fluid (SF) from rheumatoid arthritis patients, and synovium contained A12-positive neutrophils in the sublining and interstitial region, often surrounding the perivasculature but rarely in the synovial lining layer, although some macrophages were positive. The A12 gene was transiently up-regulated in monocytes by tumor necrosis factor alpha (6 h); induction by lipopolysaccharide (LPS) was sustained (12-48 h). A12 may contribute to leukocyte migration in chronic inflammatory responses.

Actins↗

PubMed2001

Taking the pulse of Internet pharmacies.

Like most businesses, online pharmacy companies will only be successful if they make sure customers are satisfied with the service they receive. But what attributes of service quality lead to satisfaction and dissatisfaction? This study identified 19 Internet pharmacy service quality dimensions in three categories: (1) product cost and availability, (2) customer service, and (3) the online information system. Our analysis uncovered attributes that tend to determine consumer satisfaction and points out ways to improve overall service quality in the Internet pharmacy arena.

Consumer Behavior↗

PubMed2001

Dimeric S100A8 in human neutrophils is diminished after phagocytosis.

S100A8 is a major cytoplasmic protein of neutrophils and monocytes/macrophages and has been associated with myeloid cell differentiation and activation. Little is known about its functions or mechanisms of release from neutrophils. We have developed a monoclonal antibody to murine S100A8, which cross-reacts with human S100A8. This antibody, which recognizes the homodimeric form of the protein, detects its expression specifically in human neutrophils and is reactive in formalin-fixed, paraffin-embedded tissues. Using this antibody as well as a commercially available antibody to human S100A8, we show that phagocytic activation of neutrophils, in vivo in acute appendicitis and in vitro following phagocytosis of opsonized zymosan, is characterized by loss of cytoplasmic immunoreactivity for S100A8. In vitro, phagocytosis is associated with rapid diminution of immunostaining without loss of viability. Loss of immunoreactivity for S100A8 may serve as a marker of localized neutrophil activation in tissues.

Acute Disease↗

PubMed2001

[Effects of attenuated measles virus on hepatitis B virus in vivo and in vitro].

OBJECTIVE: To observe the effects of attenuated measles virus on hepatitis B virus replication inside and outside the body. METHODS: Patients with chronic hepatitis B virus replication were chosen, and attenuated measles viruses were inoculated in them and observed twice every week for a total of 48 weeks. The changes of CD4+, CD8+, IFN-gamma, IL-2, HBeAg and HBV DAN were observed. Also the changes of the HBVM were observed when adding the measles virus in suspension of the 2.2.15 cells. RESULTS: The average ratio of CD4+ and CD8+ before the treatment was 1.05 +/- 0.19 and it rose to 1.47 +/- 0.18 after follow up for 48 weeks. Then, compared with the ratio before the treatment, the difference was significant(t = 5.36, P < 0.01). After inoculating the measles virus for two weeks, IFN-gamma and IL-2 increased. Although the total average ratio had not great difference, IL-2 level of 26.3% of the cases elevated 5 times higher in the second week, as compared with the control group, there was a great difference (chi 2 = 12.07, P < 0.005). The results of the examination of the HBeAg before treatment was 317, 35 +/- 151.75, but became 139.17 +/- 166.66 after observing for 48 weeks(t = 2.16, P < 0.05). The positive ratio of HBV DNA before the treatment was 100% and become 63.16% after treatment. Thus the ratio difference is significant(chi 2 = 10.08, P < 0.005). However, no such ratio difference was found in the control group. When adding the attenuated measles virus in suspension of 2.2.15 cell, the HBsAg and HBeAg decreased. CONCLUSION: When the measles virus and hepatitis B virus infect the cases in an overlapping way, the latter may be interfered by change of the cell immunity status of the body of the former, and measles virus may have direct interference effects on hepatitis B virus.

Adult↗

PubMed2001

[Stress-strain properties of the tissue-engineered cartilage].

This study was conducted to investigate the biomechanical properties of tissue-engineering cartilage. The compressive modulus of the collagen-chondrocyte constructs that had been cultured in vivo for 16 weeks and the centrifuge-tube-cultured cartilage in vitro were measured with 5% strain. The results showed that the compressive moduli of the centrifuge-tube-cultured cartilage at the 4th, 8th, 12th and 16th weeks were 0.352 MPa, 0.653 MPa, 0.233 MPa and 0.262 MPa respectively. The top modulus among them was at the 8th week. The compressive modulus of the neocartilage engineered by the collagen-chondrocyte constructs in vivo for 16 weeks was 10.668 MPa and reached the same order of magnitude as human fetal articular cartilage, but it is still under that of the human fetal articular cartilage actually. The culture methods should be developed further though the dynamic alteration of the compressive modulus of the centrifuge-tube-cultured neocartilage is in accord with that of the GAG/DNA content ratio of the neocartilage.

Animals↗

PubMed2001

Myocardial ischemic preconditioning in rodents is dependent on poly (ADP-ribose) synthetase.

BACKGROUND: Activation of the nuclear enzyme poly (ADP-ribose) synthetase (PARS) in response to oxidant-mediated DNA injury has been shown to play an important role in the pathogenesis of reperfusion injury. Here we investigated the role of PARS in myocardial ischemic preconditioning (IPC). MATERIALS AND METHODS: Mice with or without genetic disruption of PARS and rats in the absence or presence of the PARS inhibitor 3-aminobenzamide underwent coronary occlusion and reperfusion with or without IPC. RESULTS: Both poly(ADP-ribose) synthetase (PARS) deficiency and ischemic preconditioning (IPC) induced protection from reperfusion injury, attenuated inflammatory mediator production, and reduced neutrophil infiltration when compared to the response in wild-type mice. Surprisingly, the protective effect of IPC not only disappeared in PARS-/- mice, but the degree of myocardial injury and inflammatory response was similar to the one seen in wild-type animals. Similarly, in the rat model of IPC, 3-aminobenzamide pretreatment blocked the beneficial effect of IPC. Myocardial NAD+ levels were maintained in the PARS-deficient mice during reperfusion, while depleted in the wild-type mice. The protection against reperfusion injury by IPC was also associated with partially preserved myocardial NAD+ levels, indicating that PARS activation is attenuated by IPC. This conclusion was further strengthened by poly(ADP-ribose) immunohistochemical measurements, demonstrating that IPC markedly inhibits PARS activation during reperfusion. CONCLUSIONS: The mode of IPC's action is related, at least in part, to an inhibition of PARS. This process may occur either by self-auto-ribosylation of PARS during IPC, and/or via the release of endogenous purines during IPC that inhibit PARS activation during reperfusion.

Animals↗

PubMed2001

[The genotype analysis of glucose-6-phosphate dehydrogenase deficiency in Yunnan province].

OBJECTIVE: To identify glucose-6-phosphate dehydrogenase (G6PD) gene mutations in 23 patients with G6PD deficiency and to gain further understanding of the molecular and genetic background of G6PD gene in Yunnan province, China. METHODS: The mutations located in exons 2-12 and in parts of introns of G6PD gene were analyzed by amplification refractory mutation system(ARMS), natural and mis-match primer PCR/restrict enzyme, polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP ) analysis and automatic DNA sequencing. RESULTS: Among these 23 samples, 5 different point mutations in G6PD gene were identified, and they constituted 5 genotypes. There were 7 Han and 3 Dai patients with G487A mutation, 7 cases with both intron 11 T93C and C1311T mutations, 4 cases with intron 5 636 or 637 T-->del mutation, 1 case with G871A mutation, and 1 case with G487A/T93C/C1311T mutation. Two haplotypes, 93C/1311T and 93C/1311T/487A were identified in Yunnan. A strong association was observed between C1311T and the Nla III restriction site produced by intron 11 T93C. The findings of the investigators on IVS-5 636 or 637T-->del in Chinese, on G871A in mainland of China, and on G487A in the Han people of Yunnan have not been reported previously. CONCLUSION: G6PD deficiency is very heterogenous in Yunnan; G487A is one of the common mutations in that province and may be of different origins. Possibly IVS-11 T93C mutation is of non-African origin. IVS-11 T93C and C1311T might jointly result in G6PD deficiency. The above data on G6PD gene mutation types could be useful for clinical diagnosis, prevention of G6PD deficiency, and researches in the origin and migration of minorities in Yunnan or other regions.

Adolescent↗

PubMed2001

[Factors allowing continuous working of female nurses in the People's Republic of China--survey of 15 hospitals in 5 areas].

PURPOSE: Few investigations have been conducted on working, childcare and home education among female nurses (nurses) in the People's Republic of China (P.R. of China). The purpose of this study was to clarify the factors allowing continued working of female nurses. METHODS: The subjects were nurses from 15 hospitals in 3 provinces and 2 autonomous areas. They were surveyed by questionnaire regarding their childcare and home education. In was distributed by the Ministry of Health in the P.R. of China and the data were collected between February and April in 1996. RESULTS: A total of 4,284 (80.0%) questionnaires were collected. 1. About 60% of the nurses began working when they were 15 to 19 years old. The average length of service was 13.9 years. 2. Their professional position correlated directly with their years of service. 3. 4.3% of them had not continued working. 4. The nurses entrust their children to day-care institutions (61.2%) or grandparents (22.3%) during the daytime, and to the father (66.3%) or the grandparents (19.5%) during the night. 5. 17.6% of them have experienced being away from home for more than one month due to their job. 6. 66.8% of the nurses have experienced more than one month official trip, and had children under 14 years old at the time. They entrusted their children to day-care institutions (34.1%), to the father (29.2%) and grandparents (25.3%) during the official trip. CONCLUSIONS: In summary, most nurses are employed when they are young and go on working as nurses. It is possible for them to continue their work after marriage, childbirth, and while they are bringing up their children. The high rate of working woman, sufficient nursery schools and family cooperation in housework can be pointed out as main factors that enable them to continue their work.

Adolescent↗

PubMed2001

[Childcare and home education in families of female nurses in the People's Republic of China--survey of 15 hospitals in 5 areas].

PURPOSE: The purpose of this study was to investigate the actual conditions of childcare and home education among families of female nurses in the P. R. of China. METHODS: The subjects were nurses from 15 hospitals in 3 provinces and 2 autonomous areas. They were surveyed by questionnaire regarding their childcare and home education. It was distributed by the Ministry of Health in the P. R. of China and data were collected between February and April in 1996. RESULTS: A total of 4284 (80.0%) questionnaires were collected. 1. The age of the subjects was between 18 and 62 years old with a mean of 32.9 +/- 9.0 (SD) years 71.4% of them had husbands, whose ages were between 23 and 71 years old, the mean age being 38.3 +/- 8.4 (SD) years. The family types were 63.2% nuclear family and 33.7% extended family, with 3.1% being single. 65.1% of the subjects had children, whose mean number was 1.1 +/- 0.4 (SD). Firstborn children were 49.9% girls and 50.1% boys. 2. The most popular method of infant nutrition was breast-feeding, utilized by 60.1%. The highest rate (67.8%) was in the age group of 25 to 29 years old (P < 0.01). 3. The practice of "swaddling" (wrapping the child so as not to allow movement) was more common in the over 40 year old age group than the under 40 year old group (P < 0.01). Swaddling-practice showed significant differences by area. 4. The rates for children who helped with housework were 50.3% for girls and 46.7% for boys. 5. A number of children between 7 and 18 years old were studying English privately. 6. The greatest expectation of the subjects, for their children aged between 7 and 18 years old, was to study. CONCLUSIONS: 1. Infant nutrition showed significant differences between generations, and swaddling-practice differed with the generation and the area. 2. Although girls help their parents more than boys in Japan, boys and girls equally helped their parents in the P. R. of China. 3. Concerning the topics of private learning and parents expectations, the results were similar to those in Japan.

Adolescent↗

PubMed2001

[Emissions of biogenic sulfur gases from wheat fields].

Emission rates of carbonyl sulfide (COS), carbon disulfide (CS2) and dimethyl sulfide (DMS) to the atmosphere from wheat fields treated with different fertilizers were measured by using the closed chamber method. The results showed that the emission rate of COS, CS2 and DMS was affected by wheat growth and COS was absorbed by the plants. DMS and CS2 were the predominant sulfur gases emitted from these fields. The diurnal variations of emission rates of COS and CS2 were obvious. The sulfur flux in the plot treated with organic fertilizer was higher than that in the other plots. The sulfur fluxes from different plots were in the range of -1.40 to 0.79 mg.m-2.

Air↗

PubMed2001

[Effects of surface pattern of polymers on adhesion characteristics of transformed human embryonic tendon cells].

Effects of surface pattern of polymers on adhesion characteristics of transformed human embryonic tendon cells (THETCs) have been examined by using a micropipette aspiration technique, which is a cellular mechanical method. The results showed that the adhesion characteristics of THETCs depend on the surface pattern of polymers, and the adhesion force of THETCs to porous films is higher than that to non-porous films and fibers. The adhesion force bears relationships with the aperture of porous films and has a stronger dependence on the large aperture (150-500 microns) than on the small aperture (< 150 microns) of porous films. The adhesion force of THETCs to fibers is increased slightly with the diameter of fibers (P > 0.05). These demonstrate that the tissue-engineered tendon scaffolds made of porous polymer foam with specially designated aperture, or of polymer fiber with specially designated diameter, may serve as a good attachment substrate for THETCs.

Biopolymers↗

PubMed2001

[Expression of c-fos protein in brain and lung in ovalbumin sensitized rats].

OBJECTIVE: c-fos expression and its distribution in brain and lung of ovalbumin sensitized and challenged rats were investigated. METHODS: Asthma rat model sensitized and challenged by ovalbumin was established. c-fos expression was detected with immunohistochemical ABC and image analysis methods. RESULTS: c-fos positive staining increased significantly in both brain and lung in asthmatic group as compared with normal control. (P < 0.01). c-fos positive products were mainly concentrated in frontal and parietal cortex, forebrain limbic system (cingulated cortex, piriform cortex and central amygdaloid nucleus), paraventricular thalamic nucleus, hypothalamic paraventricular nucleus, supraoptic nucleus, lateral hypothalamic area, periventricular hypothalamic nucleus, nucleus of solitary tract, area postrema and ventrolateral medulla. No distinct gathering area of c-fos protein was found in the cerebellum. CONCLUSION: It is suggested that neuroimmunomodulation may play a role in the pathogenesis of asthma and c-fos protein might be involved in the neuroimmunomodulation.

Animals↗

PubMed2001

[Significance on expressions of Annexin-I and its correlative gene proteins in endometrial hyperplasia, atypical hyperplasia and endometrial carcinoma].

OBJECTIVE: To investigate expression of Annexin-I in various endometrial lesions and its significance in differential diagnosis of endometrial borderline lesions. METHODS: We collected 37 specimens with different endometrial lesions, and reclassified them according to China and FIGO's standard, which included 12 cases of endometrial hyperplasia (EH), 10 cases of atypical hyperplasia (ATH) and 15 cases of endometrial carcinoma (EC). Immunohistochemical staining for AX-I, c-erbB-2, p53 protein, ER, PR, EGF and IGF were performed by LSAB. RESULTS: The results showed that for AX-I, 1 cases of EH was weakly positive and others were negative; 9 cases of ATH showed strong positivity in the cytoplasm and the cell membrane, and 1 weakly positive; 7 cases of EC were positive and 8 negative. c-erbB-2 was expressed in 9 cases of ATH and 1 was negative. Expressions of EGFR, ER and PR were strong in all cases, but IGFR was negative in almost all cases. P53 expression was higher in EC than in ATH. CONCLUSIONS: AX-I expression suggests that (1) AX-I protein may play an important role in the pathogenesis of cancer, the expression decreased and disappeared after malignant change. (2) High expression for AX-I can be used to differentiate ATH and EC. In addition, c-erbB-2 expression appeared to parallel the expression of AX-I in both ATH and EC, but in ATH it was higher than that in EC.

Annexin A1↗

PubMed2001

[Allelopathy in sustainable development of agriculture].

Allelopathy in agriculture was summarized. For sustainable development of agriculture, inhibitions and simulations of allelopathy as some new measures were put forward and suggested to apply reasonably and effectively, so as to improve some techniques about crop straws returning into soil, cultivation measure, crop rotation and bio-control of weeds and insect pests.

Agriculture↗

PubMed2001

[Emission of volatile sulfur gases from Chinese paddy soils].

In the paper, emission of volatile sulfur gases from paddy soil was discussed in a growth period of paddy rice by constructing a field sampling system. The result showed that COS, CS2, DMS and DMDS were mainly emitted from paddy soil. The order of emission fluxes was 81.11, 6.33 and 10.71 mg.(m2.a)-1. Sulphur emission fluxes of Chinese paddy soil was 0.013662 Tg/a, and those of world paddy soil was 0.07992 Tg/a.

Oryza↗

PubMed2001

[A clinical study on the effects of delayed rapid fluid resuscitation on the blood circulation during postburn shock stage].

OBJECTIVE: To explore the protocol for the quick correction of postburn shock in case of delayed resuscitation. METHODS: Twenty burn patients inflicted with 40% or bigger TBSA burn, and who were in shock due to delayed admission to hospital, were enrolled in the study. The patients were treated by delayed rapid fluid resuscitation. The amount of infused fluid and urine output was observed. The indices of hemodynamics and oxygen metabolism, i.e. arterial blood pressure (BP), pulmonary arterial pressure (PAP), pulmonary arterial wedge pressure (PAWP), central venous pressure(CVP), cardiac output (CO), pulmonary vascular resistance (PVR), systemic vascular resistance (SVR), oxygen delivery (DO2), oxygen consumption (VO2), oxygen extraction (O2ext), lactic acid (LA) and base deficit (BD) were monitored at the shock stage(1 approximately 48 PBHs). RESULTS: The amount of rapid fluid infusion within 2 hours after admission accounted for (38.8 +/- 6.1)% of the amount calculated with the formula (The Third Military Medical University burn shock fluid infusion formula) for the 1st 24 PBHs. When the amount of prehospital infusion was added, the amount would be (48.3 +/- 5.0)% of the amount for the 1st 24 PBHs. The real amount of the infusion for the 1st 24 PBHs was (31.4 +/- 14.3)% more than that of the formula amount, and the real infused fluid amount for the 2nd 24 PBHs was (3.2 +/- 7.2)% more than that of the formula amount. After rapid fluid infusion, there exhibited remarkable increase in urine output, CO and DO2 with evident decrease in SVR, LA and BD. Furthermore, PAWP, PAP and CVP remained within normal range even though PVR increased significantly after rapid fluid infusion. CONCLUSION: In case of shock or compulsory delayed resuscitation, rapid fluid resuscitation during early postburn stage was beneficial with critical hemodynamic monitoring. The amount of delayed rapid fluid infusion was much increased than routine. Hemodynamic indices such as CO, PAP, PAWP and CVP were employed as the guidelines for delayed rapid resuscitation with reference to some clinical indices such as serum LA, blood gas analysis and urine output.

Adolescent↗

PubMed2001

[The effects of resuscitation with hypertonic saline solution on the postburn pulmonary injury in scalded dogs].

OBJECTIVE: To explore the preventive and curative effects of resuscitation with hypertonic saline solution on postburn pulmonary injury in scalded dogs. METHODS: Mongrel dogs inflicted by 40% TBSA III degree scald were employed as the model. Sixteen dogs were randomly divided into two groups with 8 in each group, i.e. hypertonic saline solution group (H group) and isotonic saline solution (N group). The changes in cardiac output (CO), cardiac index (CI), pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) were determined within 48 postburn hours (PBHs). Pulmonary tissue samples were obtained for the measurement of pulmonary water and hydrocarbon (C2 H4 and C2 H6) contents. Bronchoalveolar lavage fluid (BALF) was harvested for white blood cell (WBC) counting and classification and for the detection of the changes in PLA2 activity and LTC4 content. RESULTS: Compared to those in N group, the CO and CI in H group increased significantly while the pulmonary water content, the hydrocarbon content, the WBC count, and PLA2 activity and LTC4 content in BALF all decreased obviously. CONCLUSION: Hypertonic saline solution might be beneficial in the management of early postburn pulmonary injury.

Animals↗

PubMed2001

Sodium channels in the apical membrane of human nasal epithelial cells.

OBJECTIVE: To study the electrophysiological properties of sodium channels in the apical membrane of human nasal epithelial cells. METHOD: Nasal epithelial cells of human inferior turbinate from patients with obstructive sleep apnea syndrome were cultured in serum free medium on collagen gel-coated membranes at an air-liquid interface and studied by a patch clamp technique. RESULTS: In cell-attached patches, a typical single channel current with a conductance of 21.09 pS and reversal potential of -50.96 were recorded. The permeability ratio PNa/PK was more than 5.80. In the presence of 10(-4) mmol/L amiloride in the pipette, the incidence of sodium channels decreased from 26.67% to 5.13%. This revealed that a population of channels were inhibited by amiloride at a dose of 10(-4) mmol/L. Ca2+ at dose of 10(-3) mmol/L did not influence the incidence of sodium channels. There was no obvious association between voltage and the open probability of the channels. CONCLUSIONS: Our results indicate that most Na+ channels in cell-attached patches of human nasal epithelial cells are amiloride-sensitive and Na+ selective. Only a few channels are amiloride-insensitive. The channels were not activated by extracellular Ca2+ and the open probability followed a voltage-independent manner.

Amiloride↗