Biomedical subjects

G Huang

Publications and source records attributed to G Huang.

At least 127 records · Page 7Linked to original sources

PubMed1998

Effect of TGF-beta 1 on PDGF receptors expression in human scar fibroblasts.

This study examined the effect of exogenous TGF -beta1 on platelet derived growth factor alpha and beta (PDGF-alpha, beta) receptor expression in human dermal fibroblasts derived from both normal cutaneous tissues (normal skin [NSk]) and (normal scar [NSc]) and abnormal scar (keloid). TGF-beta and PDGF are present in the early phases of wound healing and are implicated in tissue fibrosis. In this study, replicate samples of NSk, NSc and keloid fibroblasts were grown to subconfluency in DMEM/10% FBS followed by replacement of media with DMEM/0.1%FBS for 24 hrs. One group of cells (NSk, NSc and keloid) were exposed to 10 ng/mL of exogenous TGF-beta1 for 24 hours, while the other group was used as control with no exposure to exogenous TGF-beta1. RadioImmunoBinding assays, Western and Northern blot analysis were performed to examine both PDGF-alpha and PDGF-beta receptor expression at the transcriptional and post-transcriptional levels. cDNA receptor probes were synthesized using polymerase chain reaction (PCR) with selected primer sets derived from published sequences. Beta-actin probe was used as a control to confirm that the same quantity of RNA was used for each experimental condition. TGF-beta1 was found to upregulate the expression of PDGF-alpha receptor for keloid fibroblasts but not for NSk or NSc fibroblasts. No effect was observed for TGF-beta 1 on PDGF-beta receptor expression for any of the cell lines examined.

Blotting, Northern↗

PubMed1998

Temperature dependence of outer hair cell nonlinear capacitance.

The temperature dependence of outer hair cell motility-related gating current and capacitance was evaluated under whole-cell voltage clamp. Temperature change caused a shift of these voltage-dependent functions along the voltage axis, with a decrease in temperature causing a negative shift in the voltage at peak capacitance (Vpkcm) of 19.2 mV per 10 degrees C. Gating current kinetics showed only mild temperature dependence, the Q10 being about 1.5. Temperature is speculated to affect outer hair cell (OHC) mechanical gain and frequency response by alterations in lateral membrane viscoelastic properties. Such temperature-dependent effects on the OHC may mediate known temperature effects on in vivo cochlear physiology.

Animals↗

PubMed1998

Risk factors for glioma in adults: a case-control study in northeast China.

A case-control study of risk factors for glioma in adults was carried out in Heilongjiang province in northeast China. Between September 1989 and May 1995, 218 histologically confirmed cases of glioma requiring surgery for tumor removal (139 astrocytoma glioma and 79 other glioma) and 436 controls with non-neoplastic and non-neurological disease were recruited and personally interviewed in the wards of six major hospitals. Controls were matched by sex, age, and area of residence. Occupational, lifestyle, and medical information was obtained through a standardized questionnaire. Use of liquor was associated with cancer risk. Compared with males who never drank liquor, males with total lifetime liquor consumption of less than 1000 liters had an adjusted odds ratio (OR) of 1.60 (95% CI: 0.89-2.88) and for more than 1000 liters, 2.73 (95% CI: 1.06-7.08). Statistically significant associations were also found for diseases related to the brain (OR: 5.75; 95% CI: 1.08-30.47) and trauma to the head requiring medical attention (OR: 4.09; 95% CI: 2.51-10.31). Increased consumption of vegetables and of fruit were each associated with decreased glioma risk. Compared with lowest quartile intake, adjusted risks associated with highest quartile intake were 0.51 (95% CI: 0.29-0.89) for total vegetables and 0.28 (95% CI: 0.16-0.51) for total fruit.

Adult↗

PubMed1998

Immobilization of microalgae for biosorption and degradation of butyltin chlorides.

Since the discovery of their biocidal properties in the 1950s, organotin compounds have found a large spectrum of industrial applications such as wood and textile preservatives, fungicides and pesticides, and antifouling paint on ships and fishing equipment. The fate and environmental impact of butyltins have been the subjects of a large body of research in the last decades. Biosorption and degradation of butyltin compounds by immobilized microalgae chlorella were studied in this paper, aiming to find an alternative way to solve organotin pollution problem. Chlorella emersonii cells were entrapped in a calcium aginate matrix. The cell growth rates, respiratory rate and chlorophyll a content were studied and compared. Results showed that immobilized chlorella had increased respiratory and growth rates, and almost equal chlorophyll a content when compared with free cells. Cell leakage was slight during the 20-day experimental period Cell leakage from the matrix was unrelated to cell growth within the matrix. Immobilized chlorella was applied to deal with butytin contaminated aquatic solutions. Immobilized chlorella had increased degradation rates of tri-, di-, and mono-butyltin chlorides in aquatic solutions, and lower biological accumulation factors on cells, than free cells, which indicates a potential use for tackleing organotin polluted water body.

Absorption↗

PubMed1998

Dynamic stability of glenohumeral joint during scapular plane elevation.

OBJECTIVE: To investigate the muscle-controlled dynamic stability of the glenohumeral joint through X-ray fluoroscopy in active and passive shoulder elevation in scapular plane. METHODS: Sixty healthy volunteers were collected in this study, including 23 men and 37 women, with an average age of 28.4 years. Passive and active shoulder elevation in scapular plane were observed under X-ray imaging. In 18 subjects, X-ray films were taken when the shoulder elevated in scapular plane from 0 degree to 150 degrees with a 30 degrees interval at each stage in both active and passive movements. The angles between the pivot of the humerus and the glenoid surface (GHA) during the active and passive motion were calculated and analyzed. Manual examination was also applied in the same manner. RESULTS: The pivot of the humerus had a tendency to be vertically closer to the glenoid surface in the active elevation than in the passive elevation. The differences of GHA between the active and passive motion at 0 degree, 30 degrees, 60 degrees, 90 degrees, 120 degrees and 150 degrees elevation were 4.55 degrees +/- 0.37 degree, 5.44 degrees +/- 1.16 degrees, 6.50 degrees +/- 1.50 degrees, 4.94 degrees +/- 0.82 degree, 4.50 degrees +/- 0.40 degree and 1.44 degrees +/- 0.68 degree, respectively. Manual examination found the angle between the scapula and the humerus tended to be larger in the active motion than in the passive motion. CONCLUSION: The active coordination of the muscles around the shoulder is beneficial to the dynamic stability of the glenohumeral joint.

Adolescent↗

PubMed1998

[Mechanism for the formation of F-V curve configuration analysed with tangent time constant and wave-speed theory in normal adolescents].

To understand the distribution of F-V curve configuration and the characteristics of tangent time constant (tau t), and to explore the mechanical mechanism for the formation of F-V curve configuration, we measured the tau t of high, mid, low lung volumes (tau t75, tau t50, tau t25) from F-V curves in 728 normal adolescents aged 8-19. The results showed that the distribution of the concave type was the highest among 4 types of F-V curve configuration with a range of 40%-70%. Its tau t features were tau t75 > tau t50 > tau t25 and magnitude of tau t75 > 1s. Then the concave type and its tau t features were called "adolescent fashion". Contrastedly, the distribution of the convex type was the lowest, only 4%-22%. The mechanical mechanism responsible for the formation of the concave type was analysed with the wave-speed theory. During the growth of adolescents, the lung elastic pressure and driving pressure increase with age. The diameters of airways increase, especially those of the peripheral airways with profuse branches. These changes lead to a decrease of resistance. Therefore, the critical flow (Vc) or wave-speed flow (Vmax) of peripheral airways is raised, and the flow there-in could hardly be limited. Thus the choke point (CP) will stay in trachea for a longer period, leading to the elongation of the plateau towards the tail or the concavity of the curve towards the volume axis and hence the formation of the concave type.

Adolescent↗

PubMed1998

[Characteristics of F-V curve configuration and its tangent time constants and its wave-speed mechanism in normal humans above 50 years old].

To understand the characteristics of F-V curve configuration and its tangent time constant (tau 1) in normal humans above 50 years old, the tau 1 at high, mid, low lung volumes (tau 175, tau 150, tau 125) were measured from F-V curves for 135 normal humans aged 50-84. The results showed that the convex type was the most frequent one (40%-75%) among the 4 types of F-V curve and its tau 1 characteristics were tau 175 > tau 150 < tau 125 and magnitude of tau 175 < 1s; on the other hand, the concave type was the least frequent one (0.18%). These suggested that the convex type and its tau 1 characteristics might be the changes in senility. Further, the mechanical mechanism for the convex type of F-V curve configuration was explored.

Age Factors↗

PubMed1998

[Determination of airway resistance with the interruption technique in 300 normal adolescents].

The airway resistance (Raw) was determined with interruption technique in 300 normal adolescents aged 12 to 19 years on the RM-6000 polygraph system. FVC, V75, V50, V25 were also measured. The regression equations of expiratory and inspiratory resistances were built with multiple stepwise regression analysis on the IBM-PC/XT computer with age, height and FVC as independent variables. The results showed that both expiratory and inspiratory resistances decreased with age and negatively correlated with height and FVC, but FVC, V75, V50, V25 increased with age. These reflected that Raw declined with the growth and development of the lung and airway proportionally. This fact is correspondent with some international investigations. The rules and regression equations of Raw variation during the growth of adolescents for Chinese presented in this paper can be put to use in public health and clinical work.

Adolescent↗

PubMed1998

[Gonadotropin releasing hormone and its receptor in the tissue of human hepatocellular carcinoma].

OBJECTIVE: To provide the basis for studying the relationship between gonadotropin releasing hormone(GnRH) and the regulation of hepatocarcinoma cell proliferation and differentiation, we observed the localization and distribution of GnRH and its receptor(GnRH-R) in various differentiated hepatocarcinoma tissues. METHODS: GnRH and its receptor were detected in 33 hepatocellular carcinoma(HCC) by immunohistochemical SABC technique. RESULTS: GnRH and its receptor had the same distributive pattern in hepatocarcinoma cells. The positive signal was found mainly on the surface and in the cytoplasm of hepatoma cells, with enhanced staining in the cytoplasm surrounding the nucleus; no positive signal was revealed in the nucleus. The GnRH positive rate (94%; 16/17) of edmondson grade I-II HCC was higher than that of grade III HCC (50%; 5/10) and grade IV HCC(17%; 1/6), (P < 0.05 and P < 0.001 respectively). In grades I-II HCC GnRH-R positive rate was 88% (15/17), which was higher than 17% (1/6) in grade IV HCC (P < 0.01). Although GnRH and GnRH-R positive rates in every grade HCC were lower than those in their related peri-cancerous tissues, the differences were not significant (P > 0.05). CONCLUSION: The expression of GnRH and GnRH-R in the tissues of hepatocarcinoma is related to their degree of differentiation.

Carcinoma, Hepatocellular↗

PubMed1998

[The effect of cytokines on the activation of T cells induced by B7-1-transfected leukemia cells].

OBJECTIVE: To observe the effects of IL-12, IFN-gamma, IL-10 on the B7-1 expression of B7-1 transfected leukemia cells (K562 and HL-60) and on the IL-2 and IFN-gamma expression and production in the peripheral blood mononuclear cells(PBMC) induced by B7-1 transfected K562 and HL-60 cells. METHODS: RT-PCR and ELISA techniques were used to assay the expression and production of IFN-gamma and IL-2. RESULTS: IFN-gamma and IL-12 increased the expressions of B7-1, IL-2 and IFN-gamma, but IL-10 inhibited all the expressions. CONCLUSION: IFN-gamma, IL-10 and IL-12 affected the expression and production of IFN-gamma and IL-2 possibly by affecting the B7-1 expression.

B7-1 Antigen↗

PubMed1998

[Culture of mycobacterium tuberculosis of gastric juice collected through different ways in diagnosis of pulmonary tuberculosis in children].

OBJECTIVE: To explore the value of culture of Mycobacterium tuberculosis through gastric juice specimens in diagnosis of patients with pulmonary tuberculosis in children. METHOD: Sputum, early morning vomited gastric juice (MVG), the other time vomited gastric juice (OVG) and early morning gastric lavage (MGL) were collected from 46 children with suspected pulmonary tuberculosis. All the specimens were processed to culture for Mycobacterium tuberculosis using pyruvate media, and the results were compared. RESULT: Of the 46 cases, Mycobacterium tuberculosis was found in 4 sputum samples (9%), 15 MGL samples (33%), 12 MVG samples (26%) and 2 OVG samples (4%). CONCLUSION: Collecting gastric juice through different methods for culture of Mycobacterium tuberculosis is specific for diagnosis of paediatric pulmonary tuberculosis.

Adolescent↗

PubMed1998

[Pathogenetic study of femoral head necrosis caused by cortical steroid].

OBJECTIVE: To study cortical steroid caused femoral head necrosis. METHODS: We designed an experimental animal model of femoral head necrosis through cortical steroid administration. Lipid analyses of blood samples were made and examined specimens from livers and femoral heads were studied with HE, TEM methods. RESULTS: Cortical steroid resulted in dearrangement of fat metabolism, lipid change of liver and hyperlipemia. CONCLUSION: The pathogenesis of femoral head necrosis is due to fatty degeneration of osteocytes.

Animals↗

PubMed1998

[Histological and electron microscopic study of rotator cuff tear].

OBJECTIVE: To understand the changes of rotator cuff during tear and observe the pathologic and ultramicroscopic structure of rotator cuff. METHOD: Histological and ultra thin slides of samples of 36 cases of rotator cuff were made. RESULT: The degeneration of rotator cuff happened in synovium side, and then extended to the middle and deep sides of tendon. The deep side of cuff tendon could degenerate without synovium. The repair of tendon could be achieved with two types of healing. CONCLUSION: It would be difficult to achieve full repair when complete tear and deep side tear occurred to the rotator cuff.

Adult↗

PubMed1998

[Cellular apoptosis, proliferation and bcl-2 Bax expression in colorectal carcinoma and their association with tumor prognosis].

OBJECTIVE: To investigate the relationship between cellular apoptosis, proliferation and bcl-2/bax expression in the tissue of colorectal carcinoma and biological behavior of the tumor. METHOD: The apoptotic cells index (AI) in situ were identified by the terminal deoxynucleotidyl transfer-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistologic staining for Ki-67 proliferation index (KI), bcl-2/bax protein expression was performed on archival material from 77 adenocarcinomas. RESULT: The mean AI and KI were 5.3/45.4 in early stage cancer, 5.6/48.7 in non-metastatic cancer, 6.6/55.3 in advanced cancer and 8.9/60.1 in cancer with distant metastasis respectively. There was a positive relationship between the AI and KI in each specimen. bcl-2 and bax was expressed as 54.5%, 74% in carcinoma and highly differentiated carcinoma. In the univariate analysis, significantly longer survival time was observed in the subgroup of bcl-2 positive carcinoma with low AI. In the multivariate analysis, tumor stage, tumor type, KI, and bcl-2 expression were independent risk factors for prognosis. CONCLUSION: The data indicate that abnormally exchanged AI/KI, bcl-2/bax expression appears to be an event associated with tumor progression and apoptosis might also reflect the proliferative activity of human colorectal carcinoma.

Apoptosis↗

PubMed1998

[Studies on structure modification and structure-activity relationship of new taxoids derived from sinenxan a].

In order to develop new taxol analogues with possible antitumor properties, sinenxan A (SIA), a new biosynthetic taxoid, was chemically modified, mainly by esterification of C14-OH with taxol-like side-chain acids. Twenty-one new taxoids thus formed were tested on three kinds of cell lines. Their activities are far below those of taxol. The SAR of SIA derivatives partly agree with that of taxol and can be roughly discerned.

Antineoplastic Agents, Phytogenic↗

PubMed1998

[Observation on the infectivity of different densities of Plasmodium vivax to Anopheles sinensis].

AIM: To study the infectivity of different densities of P. vivax to An. sinensis. METHODS: Venous blood samples from 38 volunteers artificially infected with P. vivax of South-Yunnan collected at the time of initial parasitaemia, primary attack and relapse, were used to infect Anopheles sinensis by feeding on parasitaemia blood in vitro. The finding of oocysts in the mid-gut of the mosquito by microscope was taken as criteria of positive infection. RESULTS: P. vivax in the initial parasitaemia did not infect the mosquito. In the cases of primary attack, when the density of parasite was more than 100/microliter blood, the infectivity and intensity rose with the prolongation of the course of the disease and the increase in the density of the parasite. The infectivity of the P. vivax in the relapse cases was higher than in the primary attack cases, the mosquitoes could be infected at a parasite density of 1/microliter blood. The mosquitoes acquired a higher infection rate, a higher positive rate of mosquito mid-gut and a higher oocyst index in the primary attack cases whose parasite density were higher than 1,000/microliter blood and in the relapse cases whose parasite density were higher than 100/microliter blood. CONCLUSION: The P. vivax in the period of clinical attack was one of the most dangerous period of the spread of malaria. The cases of relapse were the more dangerous infective sources in malaria transmission.

Adult↗

PubMed1998

[Determination of trace Pb, Cu and Cd in environmental sample by slotted-tube atom-trapping atomic absorption spectrometry].

The optimal measuring conditions of slotted-tube atom-trapping atomic absorption spectrometry of Pb, Cu and Cd were examined in detail. The results show that the characteristic concentrations measured after trapping for 1min under definite conditions were 1.82 x 10(-3), 1.26 x 10(-3) and 6.7 x 10(-5) mg/L for Pb, Cu and Cd, respectively. Thus slotted tube atom-trapping AAS yields increase in sensitivety for Pb, Cu and Cd by 110, 39 and 150 fold, respectively, in comparison with the conventional FAAS. Trace elements Pb, Cu and Cd in earth surface water, tea and hair were determined by slotted tube atom-trapping. Satisfactory results were obtained.

English Abstract↗

PubMed1998

[GFAAS determination of trace Cr(III) and Cr(VI) after its separation by coprecipitation-floatation with aluminium hydroxide].

A method for determination of trace Cr(III) in natural water and drinking water by GFAAS after separation by coprecipitation-floatation with Al(OH)3 has been studied. Cr(VI) was determined also after being reduced by FeSO4. Conditions of Cr(III) floatation such as pH, the amount of floatation agent and coprecipitator-Aluminium added, the flow rate of nitrogen gas, the floatation time etc. were discussed. The influence of coexisting elements was investigated. The detection limit is 0.027 microg/L (n = 15). For Cr(III) concentration level of 0.5 microg/L, the RSD is 3.4% and the recovery of Cr(III) is 96.0-104.0%.

Aluminum Hydroxide↗