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Biomedical subjects

A Sun

Publications and source records attributed to A Sun.

At least 37 records · Page 2Linked to original sources

[Observation of preventing of bone loss during early postmenopause by percutaneous estradiol in Chinese postmenopausal women].

OBJECTIVE: To investigate the optimal regimen for application of percutaneous estradiol gel in preventing bone loss in Chinese postmenopausal women. METHODS: A 3-year open randomized clinical study was designed. The percutaneous estradiol gel was used in a cyclic regimen combined with micronized progesterone (MP) or medroxyprogesterone acetate (MPA). Sixty healthy women (naturally menopause for 1 to 5 years) were recruited and divided into four groups according to estrogen dosage and two kinds of progestin. All were given for 25 d/month. The cortical bone mineral density (BMD) of right radius was measured by single photon absorptiometry. The trabecular BMD in lumbar vertebrae was measured by quantitative CT. The spine and hip BMD were also measured by dual energy X-ray absorptiometry at baseline, 6, 12, 18, 24 and 36 months, respectively. The bone metabolic markers, scores of menopausal symptoms were also evaluated. RESULTS: Fifty-nine patients (98%) completed 1 year and 56 patients (93%) 2 years, 51 (85%) 3 years of study. The symptoms were alleviated by 80% after 6 months treatment on average. By the end of 24 month, the mean increases of BMD ranged from 4.3% to 7.5% in trabecular bone, and by the end of 36 month 4.2% to 6.2% in the lumbar (L) 2-4, 1.6% to 3.8% in the femur neck, with significant differences (P < 0.05). Comparing the 4 groups with each other, no significant differences (P > 0.05) were found in improvement of symptoms, bone markers and BMD. CONCLUSIONS: Both daily estrogen containing 0.75 mg and 1.5 mg E2 are effective to prevent the early postmenopausal bone loss and improve the menopausal symptoms. During 3 years treatment, the BMD of lumbar increased continuously and the BMD of hip increased in the first 2 years and then plateau.

Administration, Cutaneous↗

Controlling for rater effects when comparing survey items with incomplete Likert data.

The rating scale model (Andrich, 1978) was applied to data from a survey that directed students to rate their satisfaction with college services on a five point Likert scale. Because students used different services, and students were directed to rate only the services they used, the items were differentially exposed to a person factor that we call "pleasability." Differential exposure to pleasability makes items' average rating a biased measure of their performance. In contrast, item parameter estimates in the rating scale model corrected for differential exposure to pleasability. Compared to items' average ratings, item parameter estimates in the rating scale model did a better job of predicting which item received the higher rating when any two items were rated by the same rater.

Adult↗

[The effects of iron supplementation on auditory brain-stem response with iron deficiency anemia in rats].

OBJECTIVE: To evaluate the therapeutic methods of sensorineural hearing loss with iron deficiency anemia and their effects. METHOD: Sixty-eight Wistar rats were randomly divided into 3 groups: Group A (iron deficiency group A) 24 rats, group B (iron deficiency group B) 24 rats and group C (control group) 20 rats. Group A and B were fed with iron deficiency diet for 6 weeks. By analyzing ABR and DPOAE, hearing loss was detected in group A and B. Then, group A was given iron supplementation diet and hyperbaric oxygen therapies, and group B was given iron supplementation diet only. RESULT: The auditory thresholds and period latencies (PL) of I waves of ABR and DPOAE amplitude in 2 kHz and 3 kHz within group A and B were significantly different before and after treatment (P < 0.05). But the effects of treatment between these two groups had not significant differences (P > 0.05). CONCLUSION: It suggested that good results can be obtained by early iron supplementation in iron deficiency hearing loss cases. Hyperbaric Oxygen therapy may not be necessary.

Anemia, Iron-Deficiency↗

[A clinical evaluation on reconstruction in extended partial laryngectomy for transglottic cancer].

OBJECTIVE: Transglottic cancer has been a definite indication for total laryngectomy in decades, compromising function of the larynx. The purpose of this study is to present a new radical surgery of extended partial laryngectomy and reconstruction to restore the essential function of larynx. METHODS: Forty-one cases of transglottic cancer were treated by extended vertical laryngectomy (26/41), extended frontolateral laryngectomy (5/41) and subtotal laryngectomy (10/41); the defects of larynx were reconstructed by rotary door myocutaneous flap in twenty-seven cases, by sternohyoideus flap in seven cases, by osteomuscular flap in five cases and by sternocleidomastoid flap in two cases. RESULTS: The 3 and 5 year survival rates were 85.7% (30/35) and 74.1% (20/27) respectively, those for stage III were 84.6% (22/26) and 76.2% (16/21), for stage IV were 3/4 and 1/2 respectively. All cases resumed acceptable voice, 92.7% (38/41) and enjoyed satisfactory phonation. The over-all decannulation rate was 87.8% (36/41), those with rotary door myocutaneous flap was 96.3% (26/27), with sternohyoideus flap was 5/7, with osteomuscular flap was 4/5 and with sternocleidomastoid flap was 1/2. All patients had normal swallow function. CONCLUSION: Extended partial laryngectomy is a kind of radical operation in selected cases of transglottic cancer. The method of reconstruction with rotary door myocutaneous flap can improve curative effect and the essential functions of the larynx.

Adult↗

[Clinical evaluation on second stage reconstruction for laryngostenosis after partial laryngectomy for laryngeal cancer patients].

OBJECTIVE: To present a new method of decannulation for laryngostenosis patients after partial laryngectomy and extended partial laryngectomy, and restoration of the essential functions of larynx and normal neck appearance. METHODS: Nineteen cases of laryngostenosis after partial laryngectomy and extended partial laryngectomy were treated with second stage reconstruction. The patients had been treated by vertical laryngectomy (6/19) using extended vertical laryngectomy (11/19) and frontolateral laryngectomy (2/19). Among these patients, second stage reconstruction of larynx was performed by using rotary door myocutaneous flap (17/19). Stemohyoideus flap (1/19) and sternocleidomastoid flap (1/19). RESULTS: Three and five year-survival rates were 91.7% (11/12) and 3/5, respectively. Over-all decannulation rate was 84.2% (16/19), but 94.1% (16/17) in patients with rotary door myocutaneous flap and 0% (0/2) in both patients with sternohyoideus flap and sternocleidomastoid flap. There were 3 decannulation failures (15.8%). All patients resumed acceptable voice, 94.7% (18/19) enjoyed satisfactory phonation, but 5.3% (1/19) showed severe hoarseness. All except 2 patients returned normal swallow function. The latter 2 patients experienced mild abnormal swallow during eating fluid food in early stage of surgery, but had normal swallow function after 1-2 weeks. CONCLUSION: Functional laryngectomy is a radical operation in selected cases with advanced laryngeal cancer. The second stage reconstruction with bi-pedical rotary door myocutaneous flaps can help decannulation in patients who developed laryngostenosis after partial laryngectomy and extended partial laryngectomy, and restore the essential function of larynx and normal neck appearance.

Adult↗

[Fabrication of allogeneic cartilage with tissue engineering technique and repair of laryngeal cartilage defects in rabbits].

OBJECTIVE: To investigate the fabrication of allogeneic tissue engineered cartilage in predetermined shapes and its ability to repair laryngeal cartilage defects. METHODS: Tissue engineering technique was used to make allogeneic tissue engineered cartilage in predetermined shapes, and then some of them were utilized to repair cartilage defects in the rabbit larynges(n = 12). Finally, the chondrogenesis and reparative effect were studied grossly and histologically at various periods. RESULTS: 1. The gross specimens of 4 weeks after implantation revealed the presence of new hyaline cartilage of approximately the same shapes as original predetermined shapes, which had fair elasticity and support ability. Histological evaluation showed the characteristics of cartilage tissue. 2. Laryngeal cartilage defects were well repaired using allogeneic tissue engineered cartilage in different periods after operation. A few chondrocytes were observed between the reparative areas with tissue engineered cartilage and normal cartilage. Abundant matrices were also detected in the reparative and interfacial areas. No inflammatory cells were found. CONCLUSION: It is possible to regenerate new cartilage in predetermined shapes using tissue engineering technique in allograft animals with immunity. Allogeneic tissue engineered cartilage can be used as reparative material to repair cartilage defect of rabbit larynx.

Animals↗

Unique regio- and stereoselectivity in Pd-catalyzed chlorocarbonylation reaction of 2-phenylethynyl selenides and 2-alkylethynyl selenides. Highly stereoselective synthesis of 2-seleno-3-chloroacrylates

Regio- and stereoselectivity in the chloropalladation carbonylation reaction of different acetylenic selenides in the presence of 0.05 equiv of PdCl2 and 3 equiv of cupric chloride under 1 atm of carbon monoxide affording 2-seleno-3-chloroacrylates were investigated. Opposite stereoselectivities were observed with 2-phenylethynyl selenides and 2-alkylethynyl selenides: the reactions of 2-phenylethynyl selenides afforded (E)-2-seleno-3-chloro-3-phenylacrylates, while the reactions of 2-alkylethynyl selenides gave (Z)-2-seleno-3-chloro-3-alkylacrylates. A chloropalladation carbonylation mechanism for this reaction was proposed. The regio- and stereoselective chloropalladation of the carbon-carbon triple bond in acetylenic selenides affords 1-enylpalladium intermediates, in which the palladium atom connects with the carbon atom bonding with the selenium atom. Carbonylation in the presence of an alcohol affords 2-seleno-3-chloroacrylates.

Journal Article↗

Some nutritional and functional properties of defatted wheat germ protein.

Defatted wheat germ protein (DWGP) was isolated by alkaline extraction at pH 9.5 and subsequent isoelectric precipitation at pH 4.0, and its nutritional and functional properties were studied. The results showed that the amino acid content of defatted wheat germ was as high as 26.793 g/100 g, and the contents of eight essential amino acids were all relatively high. The isoelectric point of DWGP was 4.0. When pH >6.0, the DWGP had high solubility with a nitrogen solubility index of 70%. The emulsifying activity and emulsifying stability of DWGP were similar to those of bovine serum albumin and a little higher than those of casein. DWGP had good foaming capacity, but its foaming stability (FS) was not very good. However, the FS of DWGP can be improved through physical, chemical, or enzymatic methods. Moreover, DWGP had excellent water retention (WR); especially at pH 8.0 and a temperature of 70 degrees C, the WR of DWGP was the highest at 229.4%. DWGP offers is a potential source of functional protein isolate for possible food applications.

Chemical Phenomena↗

Dexamethasone for the prophylaxis of radiation-induced emesis: a National Cancer Institute of Canada Clinical Trials Group phase III study.

PURPOSE: To investigate the efficacy of dexamethasone as a prophylactic antiemetic for patients receiving fractionated radiotherapy to the upper abdomen in a randomized controlled trial. PATIENTS AND METHODS: One hundred fifty-four patients planned to receive fractionated radiotherapy to fields involving the upper abdomen (minimum total dose, 20 Gy; minimum number of fractions, five) were randomized to receive prophylactic dexamethasone (2 mg orally three times a day [tid], starting in the morning of first treatment and continuing until after their fifth treatment) or placebo. The primary end point of the study was the proportion of patients free from emesis during the study period. Secondary end points included a quality-of-life assessment using the core questionnaire of the European Organization for Research and Treatment of Cancer and side effects of dexamethasone therapy in this population of patients. RESULTS: Fifty-four (70%) out of 75 patients receiving dexamethasone had complete protection versus 37 (49%) out of 75 patients on placebo (P = .025). Most emetic episodes occurred during the initial phase of treatment. Although there was no difference in global quality of life between the two sets of patients, patients receiving dexamethasone had less nausea and vomiting and less loss of appetite but more insomnia. CONCLUSION: Dexamethasone 2 mg tid seems to be an effective prophylactic antiemetic in this situation. Side effects were acceptable, but there seemed to be no overall effect on global quality of life.

Abdomen↗

Association of HLA-te22 antigen with anti-nuclear antibodies in Chinese patients with erosive oral lichen planus.

The purpose of this study was to determine the frequencies of the presence of serum anti-nuclear antibodies (ANA) and smooth muscle antibodies (SMA) in 76 patients with oral lichen planus (OLP), in 77 patients with other oral mucosal diseases, and in 41 healthy control subjects. HLA phenotypes in some of the patients with OLP and recurrent aphthous ulcers (RAU) were determined to show whether there was an association of HLA antigens with the presence of autoantibodies. Indirect immunofluorescence techniques with mouse liver or stomach as the substrate were used to detect the serum ANA or SMA, respectively. The B lymphocytes isolated from peripheral blood were used for HLA typing by means of a standard microcytotoxicity assay. We found that the positive rate of serum ANA in patients with OLP (29%, p < 0.01), especially in patients with erosive OLP (34%, p < 0.001), was significantly higher than that in the normal control subjects (5%). The frequency of serum SMA in patients with OLP (20%, p < 0.01), in patients with RAU (17%, p < 0.01), or in patients with oral squamous cell carcinomas (41%, p < 0.001) was also significantly higher than that in normal control individuals (0%). In the erosive OLP group, the HLA-Te22 antigen occurred more frequently in patients with positive ANA (75%, p < 0.05) than in those with negative ANA (25%). We conclude that there is an association of HLA-Te22 antigen with ANA in Chinese patients with erosive OLP.

Adolescent↗

Strong association of antiepithelial cell antibodies with HLA-DR3 or DR7 phenotype in patients with recurrent oral ulcers.

BACKGROUND: Previous studies showed that antiepithelial cell antibodies (anti-ECA) were present in 71% (15/21) of patients with recurrent oral ulcers (ROU) and that there was a strong association of human leukocyte antigen (HLA)-DRw9 with ROU in Chinese patients. In this study, we assessed anti-ECA in a larger group of Chinese patients with ROU (n = 88) in order to further investigate the association of anti-ECA with HLA-DR and -DQ antigens. METHODS: The anti-ECA in the sera of ROU patients were detected by an indirect immunofluorescence technique with rat esophagus as the substrate, and the HLA-DR and -DQ antigens in ROU patients were typed by a standard microcytotoxicity assay using Terasaki's oriental tray. RESULTS: The rate of anti-ECA positivity was significantly higher (p < 0.0001) in ROU patients (68%) than in healthy control subjects (0%). Furthermore, the rate of anti-ECA positivity in patients with major or minor oral ulcers (72%) was significantly higher (29%) than that in patients with herpetiform ulcers (p < 0.05). There was a significant increase in the frequency of DR3 or DR7 antigen expression (p < 0.0001, pc [p corrected] < 0.001, relative risk [RR] = 4.3, etiologic fraction = 0.41) in anti-ECA-positive ROU patients compared with the corresponding frequencies in healthy control subjects. There was also a significant increase in the frequency of DR7 or DRw9 antigen expression (p < 0.005, pc < 0.05, RR = 4.7, etiologic fraction = 0.45) compared to healthy controls. CONCLUSIONS: Because only DR3 or DR7 antigen occurred more frequently in anti-ECA-positive than in anti-ECA-negative ROU patients (p < 0.0007, pc < 0.05, RR = 19.6, etiologic fraction = 0.51), we concluded that the gene coding for DR3 or DR7 antigen may contribute to the presence of anti-ECA in Chinese patients with ROU.

Adolescent↗

Expression of interleukin-2 receptor by activated peripheral blood lymphocytes upregulated by the plasma level of interleukin-2 in patients with recurrent aphthous ulcers.

This study used flow cytometry to determine the peripheral blood lymphocyte subsets and a sandwich enzyme immunoassay to measure the plasma levels of interleukin-2 (IL-2) and soluble IL-2 receptor (sIL-2R) in 34 patients in different stages of recurrent aphthous ulcers (RAU) and in 32 age/sex-matched normal control subjects. In the exacerbation stage of RAU, a significant increase in the percentages of CD3+ (p < 0.001), CD4+ (p < 0.001), CD4+ IL-2R+ (p < 0.001), CD8+ IL-2R+ (p < 0.01) and IL-2R+ cells (p < 0.001), in the CD4+/CD8+ (p < 0.01) and CD4+/CD3+ CD8+ ratios (p < 0.01), and in the plasma level of IL-2 (p < 0.001) was found in the patients as compared with the levels in the normal control subjects. However, in the post-exacerbation stage of RAU, there was a significant decrease in the percentage of CD4+ cells (p < 0.05) and in the CD4+/CD8+ (p < 0.01) and CD4+/CD3+ CD8+ ratios (p < 0.001), as well as a significant increase in CD8+ cells (p < 0.001) in the patients, as compared with the levels in the normal control subjects. Because the CD4+, CD4+ IL-2R+ and CD8+ IL-2R+ cell counts and the plasma level of IL-2 increased simultaneously in the patients in the exacerbation stage of RAU, we suggest that the markedly increased plasma level of IL-2 may have been secreted by the increased number of activated CD4+ cells, and that the expression of IL-2R by activated peripheral blood lymphocytes was upregulated by the plasma level of IL-2 in patients with RAU. In addition, the increase and then decrease of the CD4+/CD8+ ratio in the RAU patients and the increased number of CD4+ IL-2R+ and CD8+ IL-2R+ activated T cells in the RAU patients support the role of cell-mediated cytotoxicity in the immunopathogenesis of RAU.

Adolescent↗

[Application of high frequency radiosurgical knife in the treatment of cervical diseases].

OBJECTIVE: To investigate the indication, resection scope of loop electrosurgical excision procedure (LEEP) and pathological characteristics. METHODS: 176 cases with abnormal cytological and colposcopical findings, including cervical intraepithelial neoplasia (CIN) and atypical squamous cells of undermined significance (ASCUS), were studied. Conization of cervix was performed in 63 cases of > or = CIN2, of which 33 cases with LEEP and 30 by traditional electrosurgical knife (TEK) as controls. Cervical biopsy was performed in 113 cases of CIN1 and ASCUS, of which 60 cases by LEEP and 53 by cervical biopsy forceps (CBF) as controls. RESULTS: Three months after conization of cervix the cytological persistent rate of disease was 6.1% in LEEP group and 6.7% in TEK group (P > 0.05). The operation duration of LEEP is (5.0 +/- 0.5) min, and is much shorter than TEK [(15.0 +/- 0.4) min]. The bleeding and recovery time of the cervix are also shorter (P < 0.01). Three months after cervical biopsy the cytological persistent rate of diseases was only 1.7% in LEEP group, significantly less than that in CBF group (35.8%). CONCLUSION: LEEP is indicated to conization of cervix of CIN2-3 and cervical biopsy of CIN1 and ASCUS. It is safe and time-saving. The optimal depth of cervical conization and biopsy was 7 mm and 4 mm respectively in the cervix, and 15 mm and 4 mm respectively in the cervical tube. It can offer intact sample for pathological diagnosis, and has special value for detecting cervical microinvasive carcinoma and local minor carcinoma.

Female↗

[Application of mitotic index and proliferating cell nuclear antigen index in monitoring the change of rat endometrium after administration of estrogen and progestin].

OBJECTIVE: To investigate the mitotic index (MI) and proliferating cell nuclear antigen (PCNA) index in monitoring the rat endometrium during estrogen and progestin administration. METHODS: One hundred and sixty Sprague-Dolly rats were randomly divided into seven groups. The 1st and 2nd group were normal estrous (E) and ovariectomized (OVX) control. The other groups received estradiol (E2V) only or combined with medroxyprogesterone(MPA) which imitated the clinical regimen in different dosage and different time before sacrificed. Uteri sections were stained with HE and immunohistochemical procedures to detect mitosis and PCNA. RESULTS: The MI and PCNA index were similar in the luminal and glandular cells. Both markers were low in the two control groups and increased with the E2V dosage in the treatment group. But if E2V was given for 1 to 21 days, the MI increased during the first 3 days and then dropped to low level and kept to the end. PCNA index increased in the first 3 days and decreased to a low level on the 4th day and then increased gradually to a high level until the last day. In the continuous regimen, both markers decreased as the MPA dosage increased. In the cyclic regimen, The MI reached to a significant low level nearly to zero in almost each ratio. Addition of MPA for 10 days, PCNA index at the ratio of 1:4.0 could be reduced to a low level and addition for 5 days, PCNA index in each subgroup was still as high as the positive control even though the dosage of MPA increased several times to 1:8.0. CONCLUSIONS: This study suggests that PCNA index can reflect both the effect of estrogen and progestogen. PCNA index is better than mitotic index in reflecting the change of endometrium.

Animals↗

A role for intracellular calcium in tight junction reassembly after ATP depletion-repletion.

The integrity of the tight junction (TJ), which is responsible for the permeability barrier of the polarized epithelium, is disrupted during ischemic injury and must be reestablished for recovery. Recently, with the use of an ATP depletion-repletion model for ischemia and reperfusion injury in Madin-Darby canine kidney cells, TJ proteins such as zonula occludens-1 (ZO-1) were shown to reversibly form large complexes and associate with cytoskeletal proteins (T. Tsukamoto and S. K. Nigam, J. Biol. Chem. 272: 16133-16139, 1997). In this study, we examined the role of intracellular calcium in TJ reassembly after ATP depletion-repletion by employing the cell-permeant calcium chelator 1, 2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-AM (BAPTA-AM). Lowering intracellular calcium during ATP depletion is associated with significant inhibition of the reestablishment of the permeability barrier following ATP repletion as measured by transepithelial electrical resistance and mannitol flux, marked alterations in the subcellular localization of occludin by immunofluorescent analysis, and decreased solubility of ZO-1 and other TJ proteins by Triton X-100 extraction assay, suggesting that lowering intracellular calcium potentiates the interaction of TJ proteins with the cytoskeleton. Coimmunoprecipitation studies indicated that decreased solubility may partly result from the stabilization of large TJ protein-containing complexes with fodrin. Although ionic detergents (SDS and deoxycholate) appeared to cause a dissociation of ZO-1-containing complexes from the cytoskeleton, sucrose gradient analyses of the solubilized proteins suggested that calcium chelation leads to self-association of these complexes. Together, these results raise the possibility that intracellular calcium plays an important facilitatory role in the reassembly of the TJ damaged by ischemic insults. Calcium appears to be necessary for the dissociation of TJ-cytoskeletal complexes, thus permitting functional TJ reassembly and paracellular permeability barrier recovery.

Adenosine Triphosphate↗