Biomedical subjects

L Y Tang

Publications and source records attributed to L Y Tang.

At least 19 recordsLinked to original sources

PubMed2006

Molecular characterization of the developmental gene in eyes: through data-mining on integrated transcriptome databases.

OBJECTIVES: Our aim was to utilize publicly available and proprietary sources to discover candidate genes important for ocular development. DESIGN AND METHODS: The collated information on our 5092 non-redundant clusters was grouped and functional annotation was conducted using gene ontology (FatiGO) for categorizing them with respect to molecular function. The web-based viewer technological platform (H-InvDB) was employed for transcription analyses of in-house high quality fetal eye Expressed Sequence Tags (ESTs). Eye-specific ESTs were also analyzed across species by using EMBEST. RESULTS: According to adult eye cDNA libraries, nucleic acid binding and cell structure/cytoskeletal protein genes were the most abundant among the ESTs of fetal eyes. Using cDNA assembly in H-InvDB, 20 (80%) of the 25 most commonly expressed genes in the human eye are also expressed in extraocular tissues. The crystalline gamma S gene is highly expressed in the eye, but not in other tissues. We used EMBEST to compare human fetal eye and octopus eye ESTs and the expression similarity was low (1.6%). This indicated that our fetal eye library contains genes necessary for the developmental process and biological function of the eye, which may not be expressed in the fully developed octopus eyes. The human fetal eye cDNA library also contained highly abundant eye tissue genes, including alphaA-crystallin, eukaryotic translation elongation factor 1 alpha 1 (EEF1A1), bestrophin (VMD2), cystatin C, and transforming growth factor, beta-induced (BIGH3). CONCLUSIONS: Our annotated EST set provides a valuable resource for gene discovery and functional genomic analysis. This display will help to appreciate the strengths and weaknesses of the different technological platforms, so that in future studies the maximum amount of beneficial information can be derived from the appropriate use of each method.

Animals↗

PubMed2000

The cellular mismatch repair system is able to repair mismatches within MLV retroviral double-stranded DNA at a low frequency.

Eukaryotic cells possess several distinct mismatch repair pathways. A mismatch can be introduced in retroviral double-stranded DNA by a pre-existing mutation within the primer binding site (PBS) of the viral RNA genome. In order to evaluate mismatch repair of retroviral double-stranded DNA, Moloney leukemia virus (MLV)-based vectors with a mutation in their PBS were used to infect mismatch repair-competent as well as mismatch repair-deficient cell lines. If the target cells were capable of repairing the mismatch before an infected cell divided, the mismatch within the PBS could be repaired to the wild-type or mutant PBS. If the target cells were unable to repair the mismatch, half the cells in the colony should contain the mutant PBS while the other half should contain the wild-type PBS. To evaluate these predictions, individual colonies were isolated and analyzed by PCR. Almost all mismatch-deficient cell colonies analyzed (cell lines HCT 116 and PMS2-/-) contained both the wild-type and mutated PBS, therefore, mismatches within retroviral double-strand DNA could not be repaired by the mismatch-deficient cells. In contrast, mismatches in approximately 25% of the mismatch repair-competent cell clones analyzed (cell lines HeLa and PMS2+/+) were repaired, while 75% were not. Therefore, the cellular mismatch repair system is able to repair mismatches within viral double-stranded DNA, but at a low frequency.

Adenosine Triphosphatases↗

PubMed2000

Most retroviral recombinations occur during minus-strand DNA synthesis.

Retroviral RNA molecules are plus, or sense in polarity, equivalent to mRNA. During reverse transcription, the first strand of the DNA molecule synthesized is minus-strand DNA. After the minus strand is polymerized, the plus-strand DNA is synthesized using the minus-strand DNA as the template. In this study, a helper cell line that contains two proviruses with two different mutated gfp genes was constructed. Recombination between the two frameshift mutant genes resulted in a functional gfp. If recombination occurs during minus-strand DNA synthesis, the plus-strand DNA will also contain the functional sequence. After the cell divides, all of its offspring will be green. However, if recombination occurs during plus-strand DNA synthesis, then only the plus-strand DNA will contain the wild-type gfp sequence and the minus-strand DNA will still carry the frameshift mutation. The double-stranded DNA containing this mismatch was subsequently integrated into the host chromosomal DNA of D17 cells, which were unable to repair the majority of mismatches within the retroviral double-strand DNA. After the cell divided, one daughter cell contained the wild-type gfp sequence and the other daughter cell contained the frameshift mutation in the gfp sequence. Under fluorescence microscopy, half the cells in the offspring were green and the other half of the cells were colorless or clear. Thus, we demonstrated that more than 98%, if not all, retroviral recombinations occurred during minus-strand DNA synthesis.

Cell Line↗

PubMed1999

Development of a Chinese chronic illness-related stress inventory for primary care.

This study evaluates the construct validity and internal consistency of a Chronic Illness-Related Stress Inventory (CRSI) for primary care Chinese patients and studies the relationship between chronic illness-related stress and sociodemographic characteristics and indices of disease severity. A total of 301 patients were interviewed using a structured questionnaire. The responses to the CRSI were divided into a frequency scale and a severity scale. Six factors including physical integrity and discomfort, psychosocial function and economic burdens, self-fulfillment and daily life, sexual function, self-esteem, and diet limitations were obtained for each CRSI scale. Except for the last factor, all other factors and the scale as a whole for both scales have a Cronbach alpha of > 0.90. The results of the convergent and discriminant validity analysis were promising. In addition, chronic illness-related stress was related to insurance status and the self-perceived severity of disease.

Adult↗

PubMed1999

Mortality trends of elderly people in Taiwan from 1974 to 1994.

BACKGROUND: the hypothesis that disability and death will eventually be compressed to a period late in life needs empirical confirmation. OBJECTIVES: we have examined the secular trends of life expectancy and common causes of death in the aged population of Taiwan. METHOD: we compared the life expectancy, causes of death and probability of death for people at birth, at age 65 and at age 85 for both sexes from 1974 to 1994 using data from Taiwan government statistics. RESULTS: there has been a substantial gain in life expectancy, especially for men age 85 and over, in the past 20 years. . Mortality due to stroke, ischaemic heart disease, hypertension and chronic pulmonary disease has declined. There has been a steep increase in cancer deaths and deaths associated with diabetes mellitus. Tuberculosis and injury-related deaths have declined but pneumonia deaths have increased. For elderly people, the probability of dying from cancer and ischaemic heart disease increased with time. However, the probability of dying from stroke decreased. Although there was a decrease in probability of deaths associated with falls, there was an increase of deaths due to 'frailty' (as judged by falls, pneumonia and septicaemia). CONCLUSIONS: cancer is a major cause of death in the elderly population of Taiwan. This rapidly expanding elderly population seemed to suffer from poorer health in the later period of their life.

Aged↗

PubMed1998

Screening of depression in patients with chronic medical diseases in a primary care setting.

BACKGROUND: Patients with chronic medical diseases may have depression that is not recognized by their primary care physicians. OBJECTIVES: We aimed to examine the application of Zung's Self-Rating Depression Scale (SDS) in the screening of depression in primary care patients with chronic medical diseases in a Chinese population. METHODS: We studied 268 patients with chronic medical diseases in the Family Medicine Outpatient Clinic using a structured questionnaire including basic demographic data, a Chinese version of the SDS and a rating for the self-perceived severity of physical condition. The severity of chronic medical diseases was assessed by the authors using the Duke University Severity of Illness Scale from a chart audit. Fifty patients were randomly selected for a diagnostic interview according to the DSM-IV criteria. The construct validity and internal consistency reliability, sensitivity and specificity of the SDS were examined. RESULTS: The results revealed that the SDS has good construct validity and internal consistent reliability in the evaluation of depression in Chinese patients with chronic medical diseases. A cut-off point of 55 had a sensitivity of 66.7% and a specificity of 90.0%. Depressed patients reported more cognitive symptoms than depressed affect and physical symptoms. Female patients had more severe depressed affect than male patients, but males had more prominent diurnal variation of mood than females. CONCLUSIONS: We concluded that SDS can be a good screening tool for depression in Chinese patients with chronic medical diseases. Owing to constraints in the expression of sexual desire in the Chinese, elderly subjects tended to report loss of libido in the response to the SDS.

Adult↗

PubMed1997

Self-rated health and mortality in Chinese institutional elderly persons.

The relationship between self-rated health (SRH) and subsequent mortality was examined in a cohort of 411 Chinese elderly individuals living in institutions. SRH was assessed by a global health rating, by comparing health with others of the same age, and by perception of recent physical condition. Covariates including age, sex, daily activity function, instrumental daily activity function, cognitive function, self-reported visual acuity, urinary function, number of chronic conditions, number of medications, and history of falls were controlled by the Cox proportional hazard model. Elderly people who rated their global health as "fair or poor" had increased mortality compared to those in the "good" category (RR = 6.00; 95% CI 1.39-25.1) and a borderline significant increase in mortality risk for those who rated themselves in the "average" category (RR = 4.05; 95% CI 0.93-17.70). Elderly people who compared their health with others of the same age as "worse or worst" and "similar" had an RR of 2.75; 95% CI of 0.64-11.83 and RR of 2.40; 95% CI of 0.64-8.96, respectively. Elderly people who rated their physical symptoms as "moderate or severe" and "slight" had an RR of 2.54; 95% CI 0.65-9.80 and RR of 1.05; 95% CI 0.32-3.41, respectively. Age, institutional factors, and history of multiple falls were associated with an increased risk of mortality. We concluded that only the global health rating has direct predictive power for mortality in institutionalized elderly people.

Activities of Daily Living↗

PubMed1997

Prostaglandin E2 increases the skeletal response to mechanical loading.

The study tested the influence of prostaglandin E2 (PGE2) on the skeletal response to increased in vivo mechanical loading through a four-point bending device. One hundred and twenty Sprague-Dawley female rats (6 months old, 354 +/- 34 g) were divided into 12 groups to accommodate all possible combinations of doses of loads (25, 30, or 35 N) and PGE2 (0, 0.1, 0.3, or 1 mg/kg). Rats received subcutaneous injections of PGE2 daily and in vivo loading of the right tibia every Monday, Wednesday, and Friday for four weeks. Histomorphometric analysis of the periosteal and endocortical surfaces following in vivo dual fluorochrome labeling was performed on both the loaded region of the right tibial diaphysis and a similar region of the left tibial diaphysis. Without PGE2, the threshold for loading to stimulate bone formation was 30 N (peak strain 1360 mu epsilon) at the periosteal surface and 25 N (peak strain 580 mu epsilon) at the endocortical surface. Without loading, the minimum dose of PGE2 to stimulate bone formation at all surfaces was 1 mg/kg/day. When 1 mg/kg/day PGE2 was combined with the minimum effective load, an additive effect of PGE2 and loading on bone formation was observed at the endocortical surface, but a synergistic effect was noted at the periosteal surface. No combined effect of ineffective doses of loading and PGE2 was found. A synergistic effect at peak strains of approximately 1625 mu epsilon on the periosteal surface could suggest either the involvement of locally produced growth factors or autoregulation of endogenous synthesis of PGE2 by exogenously administered PGE2.

Animals↗

PubMed1997

Study of simplified measures for malaria surveillance in the late consolidation phase in China.

This paper presents the results of a study on simplified surveillance methods conducted in 23 pilot counties in 11 provinces and municipalities in China where reside 15 million people and malaria control has been in the late consolidation phase. Two simplified surveillance Schemes (A and B) taking treatment of clinical cases as the main measure were implemented in 1992-1994. The rate of annual blood examination for case detection was 1.0% in pilot Scheme A, while in areas of scheme B it was 0.3%. The implementation of both Scheme A and Scheme B, simplified or without treatment of infection foci and management of mobile populations, acquired satisfactory effects against malaria. Consequently, malaria incidence was declining steadily, only a few indigenous and introduced cases were detected. The parasite rate in residents and the IFA positive rate in children were very low. The results of pilot studies and cost-effectiveness analysis indicated that Scheme B is effective, rational and economic, and can be implemented to replace the routine surveillance measures in areas where malaria has been at the late consolidation phase in China.

Adult↗

PubMed1997

[The epidemiologic value of polymerase chain reaction to the diagnosis of brucellosis patients].

PCR was used to test fifty-four brucellasis patients and thirty-six healthy people as controls, who were all from Man Tang Chuan and Yi He communities, Sui De county, Shan Xi Province, where brucellosis out-break was occurred in 1996. The diagnostic titres of SAT for brucellasis patients was set 1:100++. The positive rates of PCR in patients and controls were 75% and 65.7% respectively, comparing with the positive rates of RBPT 96.3% and 30.6% in the same two groups. At the same time, we also detected eight people who had received immunization one month to thirty-two years ago, with positive rates for PCR and RBPT 100% and 87.5% respectively. The results showed that there was no significant diversity of PCR results among acute, subacute and chronic brucellosis patients. It was revealed that the serological results were related to the course of disease, but the results came out of PCR method which was used to detect target DNA was not influenced by the course of disease.

Animals↗

PubMed1996

Functional characterization of prostaglandin E2 inducible osteogenic colony forming units in cultures of cells isolated from the neonatal rat calvarium.

Prostaglandin E2 (PGE2) increases the number of mineralized nodules that form in cultures of rat calvarial (RC) cells. The purpose of our study was to characterize PGE2-inducible osteogenic colony forming units (CFU-Os) by determining their number, the cell populations from which they were released, their specific responsive period to PGE2, and their proliferating and differentiating characteristics under the stimulation of PGE2. Limiting dilution analysis was used to determine the number of PGE2-inducible CFU-Os. Sequential digestion of intact rat parietal bones with collagenase isolated 5 subpopulations of RC cells that were used to estimate the cell populations where PGE2-inducible CFU-Os resided. The responsive period of PGE2-inducible CFU-Os to PGE2 was evaluated by treating cultures of mixed RC cells for all possible combinations of days 1-10, 11-20, and 21-30. PGE2 effects on proliferation and differentiation of CFU-Os were evaluated by comparing the DNA synthesis and AP activity in subpopulations I and IV on days 3, 6, and 9. Results showed: (1) PGE2-inducible CFU-Os represent 0.27% of cells in the mixed RC population, (2) the majority of determined and PGE2-inducible CFU-Os were found in the subpopulations released during the 60-100 min digestion periods, (3) the response of PGE2-inducible CFU-Os is limited to the first 10 days of culture, and (4) PGE2-stimulated nodule formation is associated with an early increase in DNA synthesis and a sustained increase in alkaline phosphatase activity. We conclude that, functionally, PGE2-inducible CFU-Os are slowly proliferating AP negative cells primarily found in the subpopulations III-V. PGE2 stimulates them to proliferate and become AP+, and function as determined CFU-Os to form mineralized nodules in vitro.

Alkaline Phosphatase↗

PubMed1996

The use of enzyme-digested soybean residue for feeding common carp.

This experiment was an attempt to use the soybean residue derived from the production of "soy milk". The residue contains about 18% protein, 70% carbohydrates and 7.5% lipid as fish feed for rearing common carp, Cyprinus carpio. There were 4 types of diets: (1) soybean residue, (2) soybean residue digested with Papain, (3) soybean residue (64%) mixed with beef liver (34%) and (4) same mixture as (3) but digested with Papain. The results indicate that the percentage increase in weight and length of fish feeding with beef liver supplemented diets was higher than those feeding with soybean residue alone. This was possibly due to the fact that beef liver was able to supplement the nutrient deficiency in soybean. The two types of feeds (2 and 4) digested with Papain also yielded significantly better fish growth in terms of weight and length gains, than their counterparts without digestion. Furthermore, the water turbidity of the tanks added with digested feeds was significantly less, as Papain was able to hyrolyse the protein substrates suspended in the water, and thus lowered the turbidity.

Animal Feed↗

PubMed1995

Prostaglandin E2 administration prevents bone loss induced by orchidectomy in rats.

The objects of this study were to investigate whether prostaglandin E2 (PGE2) can prevent orchidectomy (ORX)-induced cancellous bone loss in growing male rats, and to determine the differential effects of PGE2 on sham-operated (sham) and ORX male rats. Fourteen-week-old Sprague-Dawley male rats were divided into groups of basal, vehicle-treated sham, PGE2-treated sham, vehicle-treated ORX, and PGE2-treated ORX rats for either 3 or 9 weeks. PGE2 was given at 6 mg/kg body weight daily by subcutaneous injection. Static and dynamic cancellous bone histomorphometry were performed on double-fluorescent labeled undecalcified proximal tibial metaphyseal sections. No effect was observed by ORX on body weight or longitudinal bone growth rate when compared with sham-operated controls. However, androgen deficiency caused significant increases in percent eroded perimeter, mineral apposition rate, and bone turnover (bone-volume-referent-bone formation rate), which resulted in a significant decrease in trabecular bone number, increase in trabecular separation, and a nonsignificant decrease in trabecular bone area by 3 weeks of ORX. After 9 weeks of ORX, trabecular bone area and number were significantly decreased, and trabecular separation, percent eroded perimeter, and the index of bone turnover (bone-volume-referent-bone formation rate) remained significantly increased while the index of bone formation (tissue-volume-referent-bone formation rate) was nonsignificantly decreased when compared with sham controls. When 6 mg PGE2/kg/day was given for 3 and 9 weeks, similar anabolic effects were observed in sham and ORX rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1993

[An investigation on the freshwater crab as the host of Paragonimus in Hunan province].

Through an investigation of the freshwater crabs in 39 counties of Hunan province, 20 species of fresh water crabs were found as the intermediate hosts of Paragonimus. They belong to three genus and two families, in which 10 are new species (including 4 new subspecies). Besides, the natural infection with lung fluke metacercariae was also observed in some of the fresh water crabs.

Animals↗

PubMed1992

Restoring and maintaining bone in osteopenic female rat skeleton: I. Changes in bone mass and structure.

This experiment contains the crucial data for the lose, restore, and maintain (LRM) concept, a practical approach for reversing existing osteoporosis. The LRM concept uses anabolic agents to restore bone mass and architecture (+ phase) and then switches to an agent with the established ability to maintain bone mass, to keep the new bone (+/- phase). The purpose of this study was to learn whether switching to an agent known chiefly for its ability to maintain existing bone mass preserves new bone induced by PGE2 in osteopenic, estrogen-depleted rats. The current study had three phases, the bone loss (-), restore (+), and maintain (+/-) phases. We ovariectomized (OX) or sham ovariectomized (sham-OX) 5.5-month-old female rats (- phase). The OX rats were treated 5 months postovariectomy with 1-6 mg PGE2 per kg/day for 75 days to restore lost cancellous bone mass (+ phase), and then PGE2 treatment was stopped and treatment began with 1 or 5 micrograms/kg of risedronate, a bisphosphonate, twice a week for 60 days (+/- phase). During the loss (-) phase, the cancellous bone volume of the proximal tibial metaphysis in the OX rat fell to 19% of initial and 30% of age-matched control levels. During the restore (+) phase, the cancellous bone volume in OX rats doubled. When PGE2 treatment was stopped, however, and no special maintenance efforts were made during the maintain (+/-) phase, the PGE2-induced cancellous bone disappeared. In contrast, the PGE2-induced cancellous bone persisted when the PGE2 treatment was followed by either a 1 or 5 micrograms treatment of risedronate per kg given twice a week for 60 days during the maintain (+/-) phase. The tibial shaft demonstrated very little cortical bone loss during the loss (-) phase in OX rats. The tibial shaft cortical bone fell some 8%. During the restore (+) phase, new cortical bone in OX rats increased by 22%. When PGE2 treatment was stopped and nothing was given during the maintain (+/-) phase, however, all but the PGE2-induced subperiosteal bone disappeared. In contrast, when PGE2 treatment was stopped and 1 micron risedronate per kg twice a week for 60 days was administered during the maintenance (+/-) phase, the PGE2-induced subperiosteal bone and some of the subendocortical bone and marrow trabeculae persisted.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗

PubMed1992

Prostaglandin E2 alleviates cyclosporin A-induced bone loss in the rat.

Cyclosporine A (CsA) administered to the male and female rat produces high-turnover osteopenia. Prostaglandins have both bone-resorbing and bone-forming properties, but administration of prostaglandin E2 (PGE2) to the rat in vivo produces a net increase in cancellous bone. To investigate the effects of PGE2 on CsA-induced alteration in bone mass, 43 male Sprague-Dawley rats (9 weeks old) were administered 15 mg/kg of CsA by oral gavage and/or 6 mg/kg of PGE2 by subcutaneous injection daily for 21 days according to the following protocol: group A was an age-matched control; group B received CsA only; group C received PGE2 only; and group D received CsA and PGE2. Serum was assayed on days 0, 7, 14, and 21 for bone gla protein (BGP), PTH, and 1,25-dihydroxyvitamin D [1,25-(OH)2D]. A computerized image analysis system was used for bone histomorphometry of the proximal tibial metaphysis after double tetracycline labeling. Compared to control animals (group A), treatment with CsA alone (group B) and PGE2 alone (group C) significantly elevated BGP levels. Combination therapy (group D) resulted in BGP levels that were significantly higher on days 7 and 14 than with either agent alone. 1,25-(OH)2D was significantly elevated in the CsA group only (group B). Therapy with CsA alone (group B) resulted in a significant osteopenia. The concurrent administration of PGE2 with CsA (group D) alleviated the altered bone mass induced by CsA alone by adding a significant amount of additional bone. This report confirms and extends the current knowledge of the different effects of CsA and PGE2 on bone mineral metabolism and demonstrates that PGE2 can alleviate the deleterious effects of CsA on bone.

Administration, Oral↗

PubMed1992

Prostaglandin E2 prevents disuse-induced cortical bone loss.

The object of this study was to determine whether prostaglandin E2 (PGE2) can prevent disuse (underloaded)-induced cortical bone loss as well as add extra bone to underloaded bones. Thirteen-month-old retired female Sprague-Dawley breeders served as controls or were subjected to simultaneous right hindlimb immobilization by bandaging and daily subcutaneous doses of 0, 1, 3, or 6 mg PGE2/kg/d for two and six weeks. Histomorphometric analyses were performed on double-fluorescent labeled undecalcified tibial shaft sections (proximal to the tibiofibular junction). Disuse-induced cortical bone loss occurred by enlarging the marrow cavity and increasing intracortical porosity. PGE2 treatment of disuse shafts further increased intracortical porosity above that in disuse alone controls. This bone loss was counteracted by enhancement of periosteal and corticoendosteal bone formation. Stimulation of periosteal and corticoendosteal bone formation slightly enlarged the total tissue (cross-sectional) area and inhibited marrow cavity enlargement. These PGE2-induced activities netted the same percentage of cortical bone with a different distribution than the beginning and age-related controls. These findings indicate the PGE2-induced increase in bone formation compensated for the disuse and PGE2-induced bone loss, and thus prevented immobilization-induced bone loss.

Analysis of Variance↗

PubMed1991

Intrapartum amnioinfusion for replacement of meconium-stained-amniotic-fluid to prevent meconium aspiration syndrome.

The presence of meconium-stained amniotic-fluid (MSAF) during labor in cephalic presentation is a potentially ominous sign of fetal distress and, a direct cause of meconium aspiration syndrome (MAS). The authors designed a new method of intrapartum amnioinfusion for replacement (IAR) of the MSAF with normal saline solution. A total of 177 parturients with MSAF were studied from July 1986 to January 1987. Seventy-three cases receiving IAR treatment were analysed and 104 cases treated routinely served as controls. The newborn infants receiving IAR treatment had a significantly lower incidence of neonatal asphyxia (P less than 0.001) and MAS (P less than 0.05). No neonatal death occurred in the treated group; whereas, three infants died in the controls. There was no significant difference in puerperal morbidity between these two groups. The results of this study suggest that IAR might be a hopeful and effective treatment for parturients with MSAF in reducing the incidence of MAS.

Amnion↗