Search PubMed⌕ Search

Biomedical subjects

J Liang

Publications and source records attributed to J Liang.

At least 55 records · Page 3Linked to original sources
PubMed2001

Transitions in functional status among older people in Wuhan, China: socioeconomic differentials.

The vast majority of research on socioeconomic status (SES) and old-age disability is based on data derived from the developed nations. This study evaluates the external validity of current findings by examining old-age disability in China, a developing nation. The direct, indirect, and total effects of SES on disability transitions were ascertained during a 3-year period in a probability sample of 2,943 people aged 60 years or older in Wuhan, China. As SES measures, education and urban residence exert distinct direct and indirect effects on functional transitions with complicated underlying mechanisms. SES has differential effects on functional transitions depending on one's prior functional state. Furthermore, the generally positive effects of SES are partially offset by negative indirect effects

Aged↗
PubMed2001

Social exchange and well-being: is giving better than receiving?

This research examined the effects of giving and receiving assistance on psychological well-being while taking into account other salient dimensions of social support including negative interaction and anticipated support. Structural equation models were evaluated by using data derived from a national probability sample of 1,103 individuals aged 65 years or older. Results indicate that the major dimensions of social support are significantly interrelated, not only directly but also indirectly. Giving and receiving support have both positive and negative consequences on well-being. With reference to the role of reciprocity, the evidence provides some support for the hypothesis of esteem enhancement instead of social exchange and equity theories.

Aged↗
PubMed2001

Pulmonary function response to EDTA, an additive in nebulized bronchodilators.

BACKGROUND: Some nebulized bronchodilator solutions contain additives, such as EDTA, benzalkonium chloride (BAC), or both. OBJECTIVE: Although BAC-induced bronchoconstriction has been well documented in patients with asthma, there is no information on the effects of EDTA on FEV(1) when inhaled in the amounts that would be administered during emergency department treatment of asthma. METHODS: Eighteen subjects with stable asthma and airway responsiveness to methacholine were randomly assigned to inhale up to four 600-microg nebulized doses of EDTA, BAC (positive control), and normal saline (placebo) in a double-blind crossover manner on separate days. FEV(1) was measured 15 minutes after each dose. Treatments were repeated every 20 minutes until FEV(1) decreased by 20% or greater or a maximum of 4 doses were administered. RESULTS: Mean +/- SD maximum percent decrease in FEV(1) was 1.8% +/- 5.8% after EDTA, 16.6% +/- 13.9% after BAC, and 3.6% +/- 8.2% after placebo (P <.001); there was no significant difference between EDTA and placebo. CONCLUSION: The amount of EDTA contained in maximum recommended doses of nebulized bronchodilators does not induce bronchospasm. In contrast, BAC induces clinically important bronchospasm, which could decrease the efficacy of a bronchodilator during an emergency.

Adolescent↗
PubMed2001

Prevalence of otosclerosis in an unselected series of temporal bones.

BACKGROUND: Histologic otosclerosis is a disease process without clinical symptoms or manifestations that can be discovered only by sectioning of the temporal bone at autopsy. Clinical otosclerosis is otosclerosis at a site where it causes conductive hearing loss by interfering with the motion of the stapes or of the round window membrane. Various authors have studied the prevalence of histologic otosclerosis on laboratory collections of temporal bones. Some 12% to 15% of temporal bones with histologic otosclerosis have demonstrated stapedial fixation. Using these figures for calculating the prevalence of clinical otosclerosis gives an extrapolated clinical prevalence of 0.99% to 1.2%. This does not correlate well with the clinical data on otosclerotic families, from which a clinical prevalence of 0.3% has been estimated. OBJECTIVE: To study the prevalence of histologic otosclerosis in an unselected series of temporal bones. STUDY DESIGN: During a 1-year period, 118 consecutive pairs of temporal bones of deceased patients at a tertiary care center were collected to determine the prevalence of otosclerosis. Although histology remains the gold standard for evaluation of otosclerosis, the gross observation of temporal bone slices combined with microradiography was used to screen for otosclerotic lesions more rapidly and with a lower cost/benefit ratio. The temporal bones, which were suspected of having otosclerosis with these techniques, were further analyzed by conventional histology. RESULTS: 2.5% of the 236 temporal bones (or 3.4% of patients) studied demonstrated histologic otosclerosis. CONCLUSIONS: Although the prevalence of 2.5% is much lower than previously published figures on histologic otosclerosis, the extrapolated data (extrapolated clinical prevalence = 0.30% to 0.38%) correlate well with clinical studies of otosclerotic families. The previous studies based on laboratory collections were likely biased by hearing loss or other otologic diseases.

Adolescent↗
PubMed2001

Initiation and regulation of water deficit-induced abscisic acid accumulation in maize leaves and roots: cellular volume and water relations.

Water deficit-induced ABA accumulation in relation to cellular water relations was investigated in maize root and leaf tissues. While polyethylene glycol (PEG) treatment led to a significant increase of ABA content in both root and leaf tissues, ethylene glycol (EG), a permeable monomer of PEG, had no effect on ABA accumulation at similar or much lower osmotic potentials. A rapid and massive accumulation of ABA in leaf tissues occurred at a specific threshold of PEG 6000 concentration, about 20% (w/v), and closely coincided with the start of the tissue weight loss and the obvious decrease of cellular osmotic potential. Pretreatment with EG lowered the cell sap osmotic potential and also lowered the capability of both root and leaf tissues to accumulate ABA in response to further air-drying or PEG treatment. When samples were dehydrated and incubated under pressure, a method to maintain high water potential and pressure potential during dehydration, ABA accumulation was similar to those dehydrated and incubated under atmospheric pressure. Such results suggest that both the absolute water potential and pressure potential per se had no direct effects on the dehydration-induced ABA accumulation. The results have provided evidence that the initiation of ABA accumulation is related to the weight loss of tissues or changes in cellular volume rather than the cell water relation parameters, and the capability of ABA accumulation can be regulated by cellular osmotic potential.

Abscisic Acid↗
PubMed2001

[What characteristics have the elderly who contact friends at hospitals?].

PURPOSES: The purposes of this study are to examine two points; 1) What effects do regular visits to hospitals have on the existence of friend?. and 2) Do the elderly use hospitals as substitutes for other meeting places or independent of other places?. METHODS: Data concerning 2,447 older adults were obtained from a national survey for the elderly aged 60 and over, conducted in 1996. 1) To examine effects of regular visits to hospitals on friends, friendships as a dependent variable, regular visits to hospitals as a confounding variable, and some two way-interaction terms as independent variables were entered in logistic regression analysis. 2) To analyze relationships between hospitals and other meeting places, correspondence analyses and logistic regression were used. 3) Existence of friends whom the elderly contact at hospitals as a dependent variable, existence of friends whom they meet at other places as a confounding variable, and some two way-interaction terms as independent variables were entered in logistic regression analysis. 3) Relationships between clinics and other meeting places were also analyzed using correspondence analyses and logistic regression. RESULTS: 1. Although regular visits to hospitals did not have a significant direct impact on existence of friends, the respondents with low activities of daily living who regularly visits hospitals were more likely to have friends than ones did not visits hospitals. 2. The respondents who meet friends at hospitals were also more likely to have contacts with friends at community centers for the elderly or community organization. 3. The respondents who meet friends at clinics had similar characteristics to those who meet friends at hospitals. CONCLUSIONS: Regular visits to hospitals may contribute to maintain contacts with friends, especially in the elderly with low ADL. The elderly may use hospitals as meeting places with friends independent of other places. Hospitals may have similar functions to what clinics as meeting places with friends.

Activities of Daily Living↗
PubMed2001

Simian virus 40 large tumor antigen forms specific complexes with p53 and pRb in human brain tumors.

OBJECTIVE: To study the role of simian virus 40 (SV40) early region gene coding product large tumor antigen (Tag) expression and the interaction between Tag and tumor suppressors p53 and pRb in human brain tumorigenesis. METHODS: Tag was investigated by immunoprecipitation followed by silver staining and Western blot in 65 cases of human brain tumors and 8 cases of normal brain tissues. Tag-p53 and Tag-pRb complexes were screened in 18 and 15 Tag positive tumor tissues, respectively. RESULTS: Tag was found in all 8 ependymomas and 2 choroid plexus papillomas, 90% of pituitary adenomas (9/10), 73% of astrocytomas (11/15), 70% of meningiomas (7/10), 50% of glioblastomas multiforme (4/8), 33% of medulloblastomas (2/6). 5 oligodendrogliomas, 1 pineocytoma, and 8 normal brain tissues were negative for Tag. Tag-p53 complex was detected in all 18 Tag positive tumors. Tag-pRb complex was found in all 15 Tag positive tumors. CONCLUSION: SV40 Tag is expressed in human brain tumors and can form specific complexes with tumor suppressors p53 and pRb. The inactivation of p53 and pRb due to the formation of Tag-p53 and Tag-pRb complexes may be an important mechanism in the etiopathogenesis of human brain tumors.

Animals↗
PubMed2001

[The characteristics of multifocal electroretinogram in normal subjects in China].

OBJECTIVE: To test the characteristics of multifocal ERG in normal Chinese subjects and to provide reference values in clinical application. METHODS: The multifocal ERGs by using VERIS 4.0 visual evoked response imaging system were tested for 42 subjects (48 eyes). Their ages ranged from 11 to 67 years (mean, 40.7 years). The stimulative visual angles subtended plus minus 26.6 horizontally and plus minus 22.1 vertically. Burian-Allen contact lens electrode was used to record the responses from 103 retinal locations in 8 min (16 segments). RESULTS: With age increasing, the latencies of N(1) wave and P(1) wave delayed, there were statistically significant differences of the latencies between < 50 year group and greater-than-or-equal 50 year group (t > 2.01, P < 0.05), and the amplitude densifies of N(1) wave and P(1) wave decreased with wide inter-individual variation. The amplitude densities of N(1) wave and P(1) wave were greatest at the central fovea, they were (44.88 plus minus 13.30) nV/deg(2), (70.90 plus minus 17.77) nV/deg(2) respectively, the densities reducing towards more peripheral location. The amplitude sum of N(1) wave at the upper retina were greater than that at the lower retina, and the amplitude densities and sums of N(1) wave and P(1) wave at superior-temporal quadrant were greater than that at inferior-nasal quadrant. CONCLUSION: Our results suggest multifocal ERG be able to reflect the visual function at different retinal locations correctly and objectively and provide normal reference limits.

Adolescent↗
PubMed2001

[Change of cone's motion perception in patients with primary open angle glaucoma].

OBJECTIVE: To assess the change of cone's motion perception in primary open angle glaucoma (POAG). METHODS: Equi-luminance random dots moving test was used to determine the change of motion perception of blue, green and red cones in 51 eyes with POAG. To isolate the three kinds of cones, the blue, green and red visual targets were displayed on the yellow, purple and blue-green background respectively. RESULTS: The direction discrimination thresholds of motion perception from blue, green and red cones were all damaged in POAG compared to that of the normal group, and among them the blue cone was the most obviously damaged. CONCLUSIONS: These findings indicate that cone's motion perception, especially the blue cone's, may reveal pre-clinical visual nerve damage in POAG.

Adolescent↗
PubMed2001

[Improved retrosigmoid approach operation in the treatment of trigeminal neuralgia].

OBJECTIVE: To explore the surgical method which can raise the treatment effect and reduce the complication occurrence of cerebellopontine angle (CPA) operation by retrosigmoid approach. METHOD: Have improved the retrosigmoid approach in the skin incision, the hole position of bone, the intracranial operation skills and the duramatral suture, etc. By the improved retrosigmoid approach, we used partial sensory rhizotomy (PSR) to cure 54 cases with trigeminal neuralgia (TN). RESULT: 52 cases got satisfactory treatment effect and no complication appeared. In the other 2 cases, the trigeminal nerve was not found in CPA. CONCLUSION: The CPA operation by retrosigmoid approach is dangerous relatively, it usually can cause some serious complication. But improved retrosigmoid approach can expose CPA sufficiently and is convenient to operate. On the other hand, it can decrease intracranial unexpected hemorrhage and complication occurrence.

Adult↗
PubMed2001

[Expression of the chiA gene from Serratia marcescens in both strain E26 and strain NG13, nitrogen-fixing bacteria associated with rice root].

A 1.8 kb HinfI fragment carrying the chitinase gene (chiA) from Serratia marcescens was cloned into the expression vector pKK223-3 and the plasmid pMC71A, yielded the plasmid pKChiA and the plasmid pMChiA respectively. Both plasmid pKChiA and plasmid pMChiA were used to transform to the Enterobacter cloacae strain E26 and the Klebsiella oxytoca strain NG13, two nitrogen-fixing bacteria associated with rice root. The chiA gene could be highly expressed in the ChiA+ transformants of the strain E26 or the strain NG13. Cell location determination of the expressed chitinase showed that the enzyme existed not only in cell periplasm and cytoplasm, but also in extracellular broth. When the cultures were in the aftor logarithmic growthe phase, the distribution of the enzyme activity in extracellular broth, periplasm and cytoplasm were 23%-28%, 45%-51% and 21%-32%, respectively. The molecular weight of chitinase expressed in the ChiA+ transformants was 58 kD by SDS-PAGE analysis. The stability of the plasmid pMChiA in the transformants was better than that of the plasmid pKChiA.

Chitinases↗
PubMed2001

[The measurement of multifocal electroretinography].

PURPOSE: Discussing the testing procedure of multifocal electroretinography(ERG). METHODS: The testing procedure of 131 multifocal ERG records was reviewed. RESULTS: Some variable factors existed in the measurement of multifocal ERG. These factors included the subject's co-operation, the mounting of electrode, the fixation of tested eye and adjustment of focus. The good records of multifocal ERG depend upon the skill of the operator. CONCLUSION: The testing procedure of multifocal ERG must be standardized so as to ensure the reliability and repeatability of the results.

Adult↗
PubMed2001

Motion perception of short-wavelength sensitive cones in glaucoma using random dots moving.

PURPOSE: To determine whether motion perception of short-wavelength sensitive(SWS) cones is capable of predicting primary open angle glaucoma(POAG) optic neuropathy. METHODS: Motion perceptions of SWS cones were isolated by Blue random dot stimulus displayed on the Yellow background, then the detecting displacement threshold of motion perception from SWS cone in POAG was measured, and compared with the age-matched normal group. RESULTS: The detecting displacement thresholds of motion perception from SWS cones in 8 sites of 15 degrees were all elevated in POAG compared with the normal group. CONCLUSION: These findings suggest that motion perception of SWS cones may reveal preclinical visual nerve damage in early POAG.

Adolescent↗
PubMed2001

[Correlations of Ki-67 expression and histopathologic characteristics in uveal melanomas].

PURPOSE: To investigate the relations between the cellular proliferation and histopathologic variables in paraffin embedded uveal melanomas with the using of the monoclonal antibody Ki-67 as a proliferation marker. METHODS: Fifty-seven enucleated eyes were included for histopathological study and Ki-67 immunostaining. All these eye globes were enucleated between 1988 and 1997 without prior treatment. RESULTS: The score of Ki-67 index ranged from zero to 4.89%, mean (0.75 +/- 1.02) %. The mean score of Ki-67 was significantly higher in large tumors (P = 0.007) or in tumors that contained epithelioid cells (P = 0.037) when compared to medium size tumors or to spindle cell type tumors. There was a significant difference of the distribution of epithelioid cell and spindle cell when compared histologic cell type with tumor size (chi 2 = 4.528, P < 0.05). Higher proportions of large tumors were found in epithelioid cell group. No significant correlation was found between the Ki-67 index and tumor location, scleral extension and age. CONCLUSION: The Ki-67 index is significantly correlated with the histologic cell type and tumor size.

Biomarkers, Tumor↗
PubMed2001

[The abnormal changes of apolipoprotein(s) in patients with type 2 diabetes mellitus].

OBJECTIVE: To investigate the changes of the apolipoproteins(apoA I, A II, B100, C II, C III, E) in patients with type 2 diabetes mellitus. METHODS: The levels of fasting plasma glucose(FBG), insulin, TG, TC, apoA I, A II, B100, C II, C III, E were all measured in 127 non-diabetic subjects and 143 type 2 diabetic patients (20 associated with coronary heart disease (CHD) and 66 associated with hypertriglyceridemia(HTG), 55 associated with hypercholesterolemia). RESULTS: In male type 2 diabetic patients, the levels of FBG, WHR and apoC II were significantly higher (P < 0.05) and apoA I, A II levels were significantly lower (P < 0.05) than those in male non-diabetic subjects. In female type 2 diabetic patients, the levels of FBG, BMI, WHR, TG significantly elevated while HDL-C, apoA I, A II levels significantly decreased as compared with those in female non-diabetic subjects. In type 2 diabetic group, the levels of WHR, FBG and TG in HTG patients were elevated significantly as compared with those without HTG, and the levels of HDL-C, apoA I and apoA II were decreased; the levels of WHR, TG, TC, apoB100, C II, C III, E in patients with HTC were significantly higher than those whose cholesterol levels were normal. In patients with CHD, the levels of fasting insulin, apoB100, apoC II and apoE were significantly higher than those in patients without CHD, and the levels of HDL-C and apoA II were decreased significantly. CONCLUSION: Abnormal changes of apo(s) in type 2 diabetes mellitus may be a cause of type 2 diabetes associated with HTG and CHD.

Adult↗
PubMed2001

[The mechanism of protective effects of enalapril on experimental diabetic nephropathy of rats].

OBJECTIVE: To elucidate the mechanisms of renoprotective effects of ACEI on diabetic animals and patients. METHODS: STZ-induced diabetic rats were treated with Enalapril and the levels of urine protein, TGF-beta and AGEs in renal tissue were measured and compared. RESULTS: The results of TGF-beta quantitation and AGE fluorescence of Enalapril treatment group rats were the same as those of diabetic control rats. CONCLUSION: Suppression of TGF-beta overexpression or AGEs accumulation was not implicated in the mechanisms of renoprotective effects of ACEI.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2001

[Analysis on the sex ratios at birth for deliveries in hospitals in China from 1987 to 1992].

OBJECTIVE: To estimate the sex ratios at birth (SRB) for livebirths in hospitals in China. METHODS: Data were collected by the birth defects monitoring network. The livebirths with gestation of 28 weeks or over delivered in hospitals of 30 provinces, municipalities and autonomous regions all over the country from 1987 to 1992 were analyzed and used for calculating the SRB. RESULTS: The high male bias in SRB was observed in the data from most areas, and there was an upward trend of SRB, especially in rural areas. The SRB for livebirths in the hospitals of urban areas was normal from 1987 to 1989, and rose to 108.9 in 1992. The SRB for rural areas was high and was 109.9 in 1987, and rose to 111.8 in 1992. The SRB for livebirths given by the mothers under 20 years of age and coming from lower educational background was higher than that for others. The SRB for higher parities was even higher. CONCLUSION: The SRB in China is high; this is possibly related to sex-preference. Under-reporting of female neonates and "missing females" are not the main causes of the rising SRB.

China↗