Search PubMed⌕ Search

Biomedical subjects

J Liang

Publications and source records attributed to J Liang.

At least 235 records · Page 13Linked to original sources

Old-age support system and policy reform in China.

"With the on-going economic transition from the central planned system to a market-oriented system, the population aging process in China is also accelerating, and the support system for the elderly becomes an important issue demanding attention. With data from Chinese national statistics and a regional probability sampling survey in Wuhan Area, two supporting systems for the aged in China are examined in this paper. After a briefing of the population aging process in China, a detailed discussion of the two supporting systems, i.e. the formal and the informal support systems for the aged, including arrangement, operation and funding mechanisms of the systems, is made in terms of policy reform. Then follows an international comparison to highlight features and problems of the Chinese systems. Finally, solutions are proposed for the restructuring of China's pension systems."

Age Distribution↗

[Analysis of factors contributing to low birth weight in Sichuan Province. Cooperating Group for Birth Defects Monitoring].

Data on low birth weight and some potential factors were obtained from an epidemiologic investigation of 111,676 births in Sichuan province during the period from Oct. 1986 to Sep. 1987. There were 8177 (73.22%) cases of low birth weight and 516 (79.89%) dead cases of low birth weight. The results suggest that the occurrence of low birth weight is affected by maternal age, fetal number and living level in rural areas. The incidence of low birth weight delivered by women aged 35 and over is 100.94%; it is 331.53% for twins and 265.96% for triplets. The incidence of low birth weight in rural areas (94.91%) is higher than that in urban areas (59.44%).

Adult↗

[Analyses of the prevalences for neural tube defects and cleft lip and palate in China from 1988 to 1991].

This paper reports the monitoring results of two main categories of birth defects-neural tube defects (NTD) and cleft of lip and palate (CLP) in China during the period of continuous monitoring (1988-1991). The method of hospital-based monitoring was adopted for data collection. From Jan. 1988 to Dec. 1991, a total of 2,750,588 births were monitored, and 28,168 cases of congenital malformations were identified. The prevalence of total birth defects was 102.4 per 10,000. 6885 cases of NTD were identified during this period, the prevalence of NTD being 25.0 per 10,000. The prevalence of NTD varied geographically; it declined gradually from the north to the south of China with the highest rate of NTD in the Taihang Mountain Regions. A total of 4548 cases of CLP were identified, and the provincial prevalence of CLP varied from 11.2 to 25.7 per 10000 with a mean of 16.5 per 10000. The prevalence of NTDs varied seasonally with the peak in winter (January). The sex ratio of NTD was 0.59, the prevalences in female births (32.1 per 10,000) being higher than that in male births (17.4 per 10,000) (P < 0.01). The sex ratio of CLP was 1.33. A significant difference was noted between the sex ratio of cleft palate (0.80) and that of the total cleft lip (1.46) (P < 0.01). The prevalence of NTD in rural areas (44.3 per 10,000) was 3 times as high as that in urban areas (14.4 per 10,000), but no difference in occurrence of CLP was observed between the urban and rural areas (P > 0.05).

China↗

[Changes of fructosamine content and their effects on platelet aggregation of glycosylated modification of low density lipoprotein in vitro].

The changes of fructosamine (FA) in low density lipoprotein (LDL) incubated in different durations and concentrations of glucose, electrophoretic mobility of different degrees of glycosylated modification of LDL, and the effects on platelet aggregation by glycosylated LDL were observed. The results revealed that FA content increased in LDL incubated with glucose and induced glycosylated modification of LDL, and FA content in LDL correlated to the duration of LDL incubated with glucose and also correlated to different concentrations of glucose. There was a positive correlation between electrophoretic mobility and FA content in LDL. The higher of FA content in LDL the higher of platelet aggregation. This study indicated that FA content in LDL reflected the degree of glycosylated modification of LDL, in which the physical, chemical and biological properties were changed.

Fructosamine↗

[Apoptosis of mouse MS-2 fibrosarcoma cells induced by photodynamic therapy with LDL-administered zinc-phthalocyanine].

Photodynamic destruction of MS-2 fibrosarcoma cells in mice induced by LDL-administered Zinc-phthalocyanine and red light irradiation was studied by electron microscopy. The pronounced structural changes such as chromatin condensation, disappearance of nuclear pores, karyopyknosis, karyorrhexis, leakage of chromatin aggregates, autophagocytosis, bleb formation on the cell surface, cytoplasmic vacuolization and cell fragmentation suggest that the tumor cell death was induced by apoptosis. However, its exact mechanism and regulating pathways remain to be further investigated.

Animals↗

Biological activity assays of cell-free reassembled nuclei--injecting cell-free reassembled nuclei into unfertilized eggs can induce the eggs to cleave and reconstitute asters, and the injected nuclei undergo cell cycle changes.

Nucleus may reassemble spontaneously in cell-free mixture of HeLa metaphase chromosomes, Xenopus egg extracts and ATP-regenerating system, and the nucleus shows some biological activities. It is found that, after being injected into unfertilized mature eggs, the cell-free reassembled nuclei can cause the eggs to cleave and reconstitute asters in their cytoplasm, and the injected nuclei undergo changes in response to cell cycle regulators stored in the eggs, and that reinjecting cytostatic factors (CSF) into the eggs can stabilize the eggs in mitotic phase, cause the nuclei disassembly and chromatin condensation to chromosomes.

Animals↗

[Effect of olbetam on hyperlipidemia in NIDDM].

The effect of Olbetam on serum lipid and lipoproteins was studied in 30 diabetic patients with hyperlipidemia in four weeks trial. The dose of Olbetram was 500 mg/d. The results showed serum concentrations of TC, TG, and VLDL-C were decreased while HDL-C especially HDL2-C increased significantly after treatment. There were no significant changes in FBG, blood creatinine and urine acid. This result suggests Olbetam can improve dyslipidemia in NIDDM and was well tolerated by all patients.

Adult↗

[Determination of tuberculostearic acid for diagnosis of tuberculous meningitis with negative culture of tubercle bacillus].

Tuberculostearic acid, a structural component of Mycobacterium tuberculosis, was identified by gas chromatography in cerebrospinal fluid from 44 out of 59 patients with tuberculous meningitis. Tuberculostearic acid was found in the cerebrospinal fluid of 5 patients out of 112 with non-tuberculous meningitis or non-infectious disorders. The results showed the test had a sensitivity of 74.6% and a specificity of 95.9%. Detection of tuberculostearic acid in cerebrospinal fluid is a rapid, sensitive and specific test for tuberculous meningitis.

Adolescent↗

[Clinical application of silica ball implant enclosed by an autologous reversal sclera in patients with enucleation].

PURPOSE: To observe the effects of improved silica ball implantation enclosed by autologous reversal sclera. METHODS: After the enucleation of eye balls, we reversed, cleared the autologous sclera, enclosed the silica ball and implanted it in the operative eye. RESULTS: 30 cases with enucleation were implanted the prosthetic eyes. The follow-up period was 6 months to 3 years. The prosthetic eyes had the motility of 10 degrees to 25 degrees and the empty socket syndrome was effectively prevented. CONCLUSION: The sargical method can overcome the defect that prosthetic eyes cannot rotate after being implanted and has got satisfactory cosmetic effects.

Adolescent↗

Prediction of peptide affinity to HLA DR molecules.

A method to quantitatively predict peptide binding to HLA DRB1*0401, B1*0101, and B1*1501 has been developed using a dataset of the relative contributions of each of the naturally occurring amino acids in the context of a simplified peptide backbone. The prediction assumed that the relative role of each of the peptide sidechains could be treated independently and could be measured by assaying each of the twenty naturally occurring amino acids at the central eleven positions of a 13 residue peptide previously shown to contain the minimal requirements for high affinity binding to HLA DR proteins. Three separate databases were generated. They were shown to have predictive value when tested on a set of 13 unrelated peptides known to bind the DR proteins with a wide range of apparent affinity. The DRB1*0401 database was tested further by analyzing myelin basic protein. All 13 amino acid peptides containing a hydrophobic amino acid at the third position were synthesized and assayed for binding purified DRB1*0401. In every case, the measured affinity correlated with the predictive values within the experimental error of the assays. Finally, the ability to predict peptide binding to MHC class II molecules was shown to help in identifying T cell determinants. The specificity of DRB1*0401 restricted T cell hybridomas against human serum albumin corresponded to two peptides, predicted, and shown to bind the class II protein with high affinity.

Amino Acid Sequence↗

Effect of an intracerebroventricularly administered vasopressin V1 antagonist on blood pressure and heart rate in deoxycorticosterone-salt hypertensive rats.

It is well known that peripheral vasopressin (VP) is essential for the development and maintenance of DOC-salt hypertension. It is, however, still unclear whether central VP is involved in this type of hypertension. Therefore, the aim of this study was to clarify the role of central VP in the regulation of blood pressure in DOC-salt hypertension. In order to examine this issue, three series of investigations were performed. First, a novel vasopressin V1 antagonist (OPC21268) was administered intravenously to DOC-salt hypertensive rats, and mean arterial blood pressure (MABP) and heart rate (HR) were recorded. Second, the concentration of VP in the perfusate of microdialysis of cerebrospinal fluid (CSF) was determined in DOC-salt hypertensive and control rats. Finally, intracerebroventricular (i.c.v.) administration of a V1 antagonist was performed in DOC-salt hypertensive rats to determine the central mechanism of hypertension. Intravenous administration of a V1 antagonist had no effect on MABP and HR. There was no difference in VP in the perfusate of CSF between DOC-salt hypertensive and control rats. I.c.v. administration of a V1 antagonist significantly decreased MABP and HR in a dose-dependent manner in DOC-salt hypertensive rats (P < 0.05-0.01). These results suggest that central VP is involved in the maintenance of DOC-salt hypertension, and the mechanism is, in part, mediated by upregulation of the V1 receptor.

Animals↗

The pKa of the protonated Schiff bases of gecko cone and octopus visual pigments.

A visual pigment is composed of retinal bound to its apoprotein by a protonated Schiff base linkage. Light isomerizes the chromophore and eventually causes the deprotonation of this Schiff base linkage at the meta II stage of the bleaching cycle. The meta II intermediate of the visual pigment is the active form of the pigment that binds to and activates the G protein transducin, starting the visual cascade. The deprotonation of the Schiff base is mandatory for the formation of meta II intermediate. We studied the proton binding affinity, pKa, of the Schiff base of both octopus rhodopsin and the gecko cone pigment P521 by spectral titration. Several fluorinated retinal analogs have strong electron withdrawing character around the Schiff base region and lower the Schiff base pKa in model compounds. We regenerated octopus and gecko visual pigments with these fluorinated and other retinal analogs. Experiments on these artificial pigments showed that the spectral changes seen upon raising the pH indeed reflected the pKa of the Schiff base and not the denaturation of the pigment or the deprotonation of some other group in the pigment. The Schiff base pKa is 10.4 for octopus rhodopsin and 9.9 for the gecko cone pigment. We also showed that although the removal of Cl- ions causes considerable blue-shift in the gecko cone pigment P521, it affects the Schiff base pKa very little, indicating that the lambda max of visual pigment and its Schiff base pKa are not tightly coupled.

Animals↗

Social networks, social support, and mortality among older people in Japan.

This study examined the effects of social networks and social support on the mortality of a national probability sample of 2,200 elderly Japanese persons during a three-year period. The direct and indirect effects of social relationships were assessed by using hazard rate models in conjunction with ordinary least squares regressions. Among the five measures of social relationships, social participation is shown to have a strong impact on mortality, and this effect remains statistically significant when other factors are considered. Social participation, social support, and feelings of loneliness are found to have indirect effects on the mortality of the Japanese elders through their linkages with chronic diseases, functional status, and self-rated health. On the other hand, marital status and social contacts are not shown to have statistically significant effects on the risk of dying, either directly or indirectly.

Aged↗

The relationship of chronic diseases and health status to the health services utilization of older Americans.

OBJECTIVE: To study simultaneously the relationships among chronic diseases and physical health status as they affect health services utilization of older adults. DESIGN: Secondary analysis of a large, cross-sectional health interview survey, the Supplement on Aging of the 1984 National Health Interview Survey, using multiple equation methods to evaluate disease-specific impacts on physical health status, the direct impact of specific diseases on utilization of physician services and hospital care, and the indirect impact of specific diseases on utilization, mediated through physical health status. PARTICIPANTS: A total of 11,497 people aged 65 and older, representing a complex, multistage sample of the noninstitutionalized, older adult population of the United States. MEASUREMENTS: Predictor variables included specific chronic diseases (hypertension, arthritis, diabetes, cancer, and atherosclerotic heart disease), self-rated health status, and total number of disabilities. Control variables included age, gender, race, education, social integration. Outcome variables were physician visits and hospital stays. MAIN RESULTS: It was shown that different diseases have different relative impacts on physical health status, probability of utilization, and amount of utilization, if any, and different chronic diseases have a different mix of direct and indirect effects on utilization. CONCLUSION: The impact of chronic disease on health services utilization in a community-dwelling population is not a simple or direct relationship. Diseases vary according to their impact on different types of utilization, their impact on the probability of any health services use versus the amount of use, and on how much their effect on utilization is mediated through health status.

Aged↗