PubMed Health⌕ Search

Biomedical subjects

J Quan

Publications and source records attributed to J Quan.

At least 19 recordsLinked to original sources
PubMed2005

Association between single nucleotide polymorphisms of estrogen receptor alpha gene and efficacy of HRT on bone mineral density in post-menopausal Japanese women.

BACKGROUND: Although HRT for post-menopausal women can protect against bone loss, variations in bone responses exist. We studied whether single nucleotide polymorphisms (SNP) of the estrogen receptor-alpha (ERalpha) gene contribute to the effect of HRT on lumbar spine bone mineral density (BMD). METHODS: Subjects were 84 post-menopausal women who had been taking HRT for 3 years to treat osteopenia or osteoporosis. Eighteen SNP in the ERalpha gene were characterized by a single nucleotide primer extension assay. RESULTS: Genotyping of the 84 individuals revealed that all SNP were quite common, the minor allele frequency being > or = 20%. A SNP in intron 6 (IVS6+14144) was significantly associated with the response to HRT for the first 3 years after starting treatment (P = 0.043, 0.025 and 0.032 for the first, second and third years respectively). Haplotype analysis revealed that a combination of SNP IVS6+14144 and IVS4+4238 was significantly correlated with the response to HRT; women with haplotype G-G (IVS6 14144-IVS4 4238) showed a significantly higher response (P = 0.014, 0.043 and 0.010 for the first second and third year respectively). CONCLUSIONS: These results suggest that a specific SNP and the haplotype of the selected SNP could be used to predict the effect of HRT on lumbar BMD.

Adult↗
PubMed2001

[Application of fingerprint analysis and computer pattern interpretation in identification and quality evaluation of traditional Chinese medicines].

The fingerprint analysis technique used in the quality control of TCM through identifying charactreristics and evaluating stability is set up with the rapid development of instrument analyses and computer pattern interpretation. There are many kinds of methods for establishment of fingerpirnt of TCM mainly including chromatography, spectroscopic method, x-ray diffraction and molecular biological technique. The methods of computer pattern interpretation in fingerprint of TCM includes fuzzy information analysis, artificial neural networks and gray relational grade cluster.

China↗
PubMed2000

Sexual risk behaviors among heterosexual HIV serodiscordant couples in the era of post-exposure prevention and viral suppressive therapy.

OBJECTIVES: To describe awareness and use of antiretroviral treatments, viral load monitoring, and post-exposure prevention; to assess changing concerns about HIV transmission; and to examine the effect of these advances on sexual behavior in HIV-serodiscordant heterosexual couples. METHODS: Cross-sectional analysis of a baseline sample of 104 couples (n = 208 individuals) from the California Partners Study II, an intervention trial for HIV-serodiscordant couples in California. Questions on sexual practices, viral load testing, HIV treatment, post-exposure prevention, and their effect on sexual behaviors, risk taking and transmission concerns were measured at intake. RESULTS: Over two-thirds of couple members surveyed reported unprotected sex with their partner in the past 6 months. Among seropositive respondents, 37% were taking protease inhibitor therapy, 92% had undergone viral load testing, and of those, 40% said it had ben undetectable at their most recent test. Most respondents, regardless of serostatus, said that viral load testing and awareness of post-exposure prevention had no effect on their condom use. In addition, perceiving that their partner had an undetectable viral load was associated with having protected sex among seronegative subjects (P < 0.05). Seropositive respondent taking protease inhibitors were 2.4 times less likely to report unprotected sex compared with those not taking protease inhibitors (P = 0.05). However, up to 33% of seropositive and 40% of seronegative respondents acknowledged decreased transmission concerns in the light of the new HIV treatments. In comparison with their seropositive partners, seronegative individuals were more likely to acknowledge increased risk taking and decreased HIV transmission concerns (P < 0.05). CONCLUSIONS: New medical advances were not associated with unprotected sex in HIV-serodiscordant couples. However, new treatment options may decrease concerns about HIV transmission, particularly among seronegative partners. Providers should discuss the effect of antiretroviral treatments on sexual transmission risk with their patients. The inclusion of seronegative partners in counseling interventions may decrease risk taking in serodiscordant couples.

Adult↗
PubMed2000

Thymocyte selection is regulated by the helix-loop-helix inhibitor protein, Id3.

E2A, HEB, E2-2, and daughterless are basic helix-loop-helix (bHLH) proteins that play key roles in multiple developmental pathways. The DNA binding activity of E2A, HEB, and E2-2 is regulated by a distinct class of inhibitor HLH proteins, the Id gene products. Here, we show that Id3 is required for major histocompatability (MHC) class I- and class II-restricted thymocyte positive selection. Additionally, H-Y TCR-mediated negative selection is severely perturbed in Id3 null mutant mice. Finally, we show that E2A and Id3 interact genetically to regulate thymocyte development. These observations identify the HLH inhibitory protein Id3 as an essential component required for proper thymocyte maturation.

Animals↗
PubMed2000

Tobramycin solution for inhalation reduces sputum Pseudomonas aeruginosa density in bronchiectasis.

We conducted a placebo-controlled, double-blind, randomized study to evaluate the microbiological efficacy and safety of inhaled tobramycin for treatment of patients with bronchiectasis and Pseudomonas aeruginosa. Patients were randomly assigned to receive either tobramycin solution for inhalation (TSI) (n = 37) or placebo (n = 37), which was self-administered twice daily for 4 wk and followed by 2-wk off-drug. At Week 4, the TSI group had a mean decrease in P. aeruginosa density of 4.54 log(10) colony-forming units (cfu)/g sputum compared with no change in the placebo group (p < 0.01). At Week 6, P. aeruginosa was eradicated in 35% of TSI patients but was detected in all placebo patients. Investigators indicated that 62% of TSI patients showed an improved medical condition compared with 38% of placebo patients (odds ratio = 2.7, 95% confidence interval [CI] 1.1 to 6.9). Tobramycin-resistant P. aeruginosa strains developed in 11% of TSI patients and 3% of placebo patients (p = 0.36). The mean percent change in FEV(1) percent predicted from Week 0 to Week 4 was similar for the TSI and placebo groups (p = 0.41). More TSI-treated patients than placebo patients reported increased cough, dyspnea, wheezing, and noncardiac chest pain, but the symptoms did not limit therapy. Additional study is warranted to further evaluate TSI in bronchiectasis patients.

Administration, Inhalation↗
PubMed2000

[Effects of epimedium on the expression of interleukin-6 messenger ribonucleic acid in bone of ovariectomized rat].

OBJECTIVE: To investigate the effects of the traditional herb-epimedium on the expression of interleukin-6 (IL-6) mRNA in bone of ovariectomized rat. METHODS: Forty female rats were randomly allocated into 4 groups, 10 in each: ovariectomized (OVX) group, sham operation group, OVX followed by epimedium (group 3) or nilestriol (group 4) for 3 months respectively. All rats were then sacrificed, and total RNA were directly isolated from their right tibia. Interleukin-6 mRNA expression was detected by relative semiquantitative reverse transcription-polymerase chain reaction technique. Lumbar bone mineral density (BMD) was measured by dual-energy X ray absorptiometry before sacrifice. RESULTS: The BMD of epimedium group was significantly higher than that in the OVX group (P < 0.05). On the contrary, the IL-6 mRNA expression level of epimedium group was significantly lower than that in the OVX group (P < 0.01), but higher than those in the sham and nilestrial group (P < 0.01). CONCLUSIONS: IL-6 may play a role in the pathogenesis of postmenopausal teoporosis. Epimedium can inhibit the expression of IL-6 mRNA, which may contribute to its anti-resorptive effect.

Animals↗
PubMed2000

Bereavement support. The occupational health nurse's role when death comes to work.

1. Providing bereavement support for grieving employees can positively impact their adjustment and productivity. 2. Good bereavement care follows the nursing process approach: assessment, analysis, planning (goal setting), intervention/implementation, and evaluation. It acknowledges the five dimension of optimal health, and incorporates them into the nursing process. 3. The occupational health nurse, as clinician and advisor, can provide care to the bereaved individual and guidance to the manager and coworkers about the grief process and how to interact with the grieving employee. 4. Grief work is necessary for healing. The occupational health nurse can play a valuable role in facilitating the work by offering clinical support, a "safe" place for the grieving employee to talk about the death, referrals to the Employee Assistance Program or other professional support, and education about the process.

Adaptation, Psychological↗
PubMed1999

Corneal topographical changes following strabismus surgery.

PURPOSE: To study corneal topographical changes after strabismus surgery. METHODS: Computer-aided corneal topography was used in 43 strabismus patients (45 eyes) one or two days prior to and six or seven days after strabismus surgery. The spherical and cylindrical equivalents were calculated based on the simulated keratometry. RESULTS: After the surgery, only the changes at 3 mm in the inferior quadrant were statistically significant. The changes at 3 mm in the rest quadrants and the changes at 7 mm were not significant. Significant changes in spherical equivalent were found post-operatively. Neither the horizontal nor the vertical meridional equivalent showed significant changes after surgery. CONCLUSIONS: The results of corneal topographical changes following strabismus surgery in our preliminary study indicated the little effect of strabismus surgery on corneal curvature and corneal astigmatism.

Adolescent↗
PubMed1998

Preparative separation of alkaloids from the root of Sophora flavescens Ait by pH-zone-refining counter-current chromatography.

pH-Zone-refining counter-current chromatography was applied to the separation of alkaloids from a crude extract of the root of Sophora flavescens Ait using a multilayer coil planet centrifuge. After methyl tert.-butyl ether and water were equilibrated, triethylamine (10 mM) was added to the organic phase as a retainer and hydrochloric acid (5-10 mM) to the aqueous phase as an eluter. The separation was performed by eluting the aqueous phase while the organic phase was used as the stationary phase. From 1.0 g of the crude extract, sophocarpine (170 mg) and matrine (600 mg) were separated within 4.5 h at high purity of over 98%.

Alkaloids↗
PubMed1998

Multidimensional counter-current chromatographic system and its application.

A multidimensional counter-current chromatographic system was set up for the first time with two sets of high-speed counter-current chromatography instruments. This system was successfully applied to the preparative separation of isorhamnetin, kaempferol and quercetin from crude flavone aglycones of Ginkgo biloba L. and Hippophae rhamnoides L. with a two-phase solvent system composed of chloroform-methanol-water (4:3:2, v/v/v).

Antiviral Agents↗
PubMed1998

Masoprocol (nordihydroguaiaretic acid): a new antihyperglycemic agent isolated from the creosote bush (Larrea tridentata).

An ethnomedically-driven approach was used to evaluate the ability of a pure compound isolated from the creosote bush (Larrea tridentata) to lower plasma glucose concentration in two mouse models of type 2 diabetes. The results indicated that plasma glucose concentration fell approximately 8 mmol/l in male C57BL/ks-db/db or C57BL/6J-ob/ob mice following the oral administration of masoprocol (nordihydroguaiaretic acid), a well known lipoxygenase inhibitor. The decline in plasma glucose concentration following masoprocol treatment in the mice was achieved without any change in plasma insulin concentration. In addition, oral glucose tolerance improved and the ability of insulin to lower plasma glucose concentrations was accentuated in masoprocol-treated db/db mice. These data raise the possibility that masoprocol, or other lipoxygenase inhibitors, represents a new approach to the pharmacological treatment of Type 2 diabetes.

Animals↗
PubMed1998

Cryptolepis sanguinolenta: an ethnobotanical approach to drug discovery and the isolation of a potentially useful new antihyperglycaemic agent.

Evidence has been published that a wide array of plant-derived active principles, representing numerous classes of chemical compounds, demonstrate activity consistent with their possible use in the treatment of patients with Type 2 diabetes mellitus (DM). Despite these interesting observations, to date, metformin is the only ethical drug approved for treatment of Type 2 DM derived from a medicinal plant. Why is this so, given the fact that higher plants are such a potential source of new drugs? The answer to this rhetorical question may lie in the reliance of most pharmaceutical companies on random, in vitro, mechanism-based, high throughput screening in the initial phases of plant drug research. In this article we describe an alternative pathway to discovery of drugs for the treatment of Type 2 DM: on based on an ethnomedical approach, involving ethnobotany and traditional medicine. In particular, we present evidence that cryptolepine, an indoloquinolone alkaloid isolated from Cryptolepis sanguinolenta, significantly lowers glucose when given orally to a mouse model of diabetes. The antihyperglycaemic effect of cryptolepine leads to a significant decline in plasma insulin concentration, associated with evidence of an enhancement in insulin-mediated glucose disposal. Finally, cryptolepine increases glucose uptake by 3T3-L1 cells. These data permit us to conclude that an ethnobotanical approach to drug discovery can identify a potentially useful drug for the treatment of Type 2 DM.

Adipose Tissue↗
PubMed1998

Nongenetic mouse models of non-insulin-dependent diabetes mellitus.

The purpose of the study was to develop a mouse model of non-insulin-dependent diabetes mellitus (NIDDM) that closely simulates the metabolic abnormalities of the human disease and is also cost-effective compared with the genetic models currently available. For this purpose, insulin resistance was induced in male C57BL/6J or Institute of Cancer Research (ICR) mice by feeding diets enriched in either fructose or fat, and hyperglycemia was induced by injecting these mice with a dose of streptozotocin (STZ) that does not cause diabetes in chow-fed mice. In the case of C57BL/6J mice, insulin levels initially increased in response to the fructose- and fat-enriched diets and then decreased to levels comparable to or still higher than those in chow-fed mice following STZ injection. Associated with the decrease in insulin levels following STZ, fat-fed and fructose-fed C57BL/6J mice became significantly hyperglycemic, reaching values of 388 +/- 38 and 366 +/- 58 mg/dL, respectively. In contrast, neither plasma glucose nor insulin concentrations changed in chow-fed mice injected with an identical amount of STZ. Essentially identical findings were seen before and after STZ injection in fat-fed compared with chow-fed ICR mice. Although a direct comparison was not made, sensitivity to the diabetogenic effects of STZ appeared to be greater in fat-fed ICR compared with fat-fed C57BL/6J mice. Finally, plasma glucose decreased when mice with these experimental models of NIDDM were treated with either metformin or tolbutamide. Given these results, it seems reasonable to suggest that the combination of dietary-induced insulin resistance and relatively low-dose STZ results in mouse models that should be of use in studying the pathophysiology of NIDDM or in evaluating therapeutic compounds for the treatment of NIDDM.

Animals↗