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Biomedical subjects

X Ge

Publications and source records attributed to X Ge.

At least 37 records · Page 2Linked to original sources
PubMed2001

[The efficiency of algae removal from drinking water by ferrate].

This paper studied the efficiency of algae removal by ferrate from two kinds of raw water which were collected from Donghu and Tiegang reservoir respectively. The experimental results showed that the removal efficiency of algae reached about 95% only through PAC coagulation when the raw water was extracted from Donghu reservoir in which most of algae was Chlorella. But dealing with Tiegang raw water in which the majority of algae were Oscillatoria, terrate was used as pre-oxidant coupling with PAC coagulation not only using PAC to flocculate and the efficiency of algae removal could be up to 97.85%. However this treatment method using ferrate as pre-oxidant overmatched the traditional method prechlorination for algae removal.

Eukaryota↗
PubMed2000

A calmodulin-related protein that suppresses posttranscriptional gene silencing in plants.

Posttranscriptional gene silencing (PTGS) is an ancient eukaryotic regulatory mechanism in which a particular RNA sequence is targeted and destroyed. The helper component-proteinase (HC-Pro) of plant potyviruses suppresses PTGS in plants. Using a yeast two-hybrid system, we identified a calmodulin-related protein (termed rgs-CaM) that interacts with HC-Pro. Here we report that rgs-CaM, like HC-Pro itself, suppresses gene silencing. Our work is the first report identifying a cellular suppressor of PTGS.

Agrobacterium tumefaciens↗
PubMed2000

Iridoids from Dunnia sinensis.

A plumieride type iridoid glucoside, dunnisinoside, and a non-glucosidic iridoid, dunnisinin, were isolated from the leaves of Dunnia sinensis. Their structures were established by 1D and 2D NMR and FABMS experiments.

Anti-Inflammatory Agents↗
PubMed2000

Expression and changes of HSP70 in the rat forebrain subjected to gamma knife (100Gy) irradiation targeted on the caudate putamen and survived for different times.

Forebrain heat shock protein 70 (HSP70) immunohistochemical reactivity was investigated in rats subjected to gamma knife irradiation focusing on the right caudate putamen nucleus. The forebrain sections of all experimental animals were processed with anti-HSP70 antiserum and then by avidin-biotin peroxidase complex immunohistochemistry after gamma ray irradiation with a dose of 100Gy and they each survived for different times (from 30 min to 30 days). Some neurons, glial cells, and endothelial cells were HSP70-like immunoreactivity (HSP70-LI) positive. HSP70-LI was mainly distributed in the target area of irradiation, as well as in non-target regions, e.g. the cortex, hippocampus, and hypothalamus, etc. The expression and change of HSP70-LI from 3 h to 30 days after irradiation followed the following rules: (1) Within 3 to 24 h, the dilated vessels with HSP70-LI endothelial cells were found at first, and a few lightly stained HSP70-LI neurons and glias were observed in the target and non-target regions; (2) In 3-7 days, darkly stained HSP70-LI neurons and glias were apparently increased and formed an expression peak. From 14 to 30 days, HSP70-LI cells were distinctly decreased and became weakly stained or negative. These results suggested that although the irradiation target of the gamma knife was localized, the response to irradiation occurred extensively.

Animals↗
PubMed2000

External aperture of the vestibular aqueduct in Meniere's disease.

OBJECTIVE: To study the relationship of the length of the external aperture of the vestibular aqueduct and the ratio of the summating potential and action potential (SP:AP) in patients with Meniere's disease. STUDY DESIGN: Retrospective case study. SETTING: Neurotology referral center. PATIENTS: Fifty-four patients with Meniere's disease and nine control subjects without Meniere's disease. INTERVENTION: The external aperture of the vestibular aqueduct was measured from a three-dimensional surface reconstruction computed tomography scan. Transtympanic electrocochleography was performed on patients with Meniere's disease. MAIN OUTCOME MEASURE: The length of the external aperture of the vestibular aqueduct in the Meniere's disease ears was related to the SP:AP ratio in the Meniere's disease ears and compared with controls. RESULTS: The average length of the external aperture was 3.79 +/- 2.92 mm in Meniere's disease ears and 5.35 +/- 1.73 mm in the control ears (p < 0.05). An enlarged SP:AP ratio was found in 95% of ears in the group with nonvisible external apertures of the vestibular aqueduct, 91% of ears in the <5 mm group, 58% of ears in the 5-7 mm group, and 29% of ears in the >7 mm group (chi-square = 24.814; p = 0.000). CONCLUSIONS: The length of the external aperture of the vestibular aqueduct in patients with Meniere's disease is significantly shorter than in those without Meniere's disease. Endolymphatic hydrops, evidenced by an enlarged SP:AP ratio, was related to the length of the external aperture of the vestibular aqueduct. The shorter the external aperture, the more often the SP:AP ratio was enlarged. A short or nonvisible external aperture of the vestibular aqueduct is a predisposing factor to the development of Meniere's disease.

Audiometry, Evoked Response↗
PubMed2000

Parenting practices and adolescent depressive symptoms in Chinese American families.

This study examined parenting practices and adolescent depressive symptoms among Chinese Americans. First, confirmatory factor analyses revealed that self-reported parenting practices by mothers and fathers and adolescent perception of parenting practices loaded adequately on three subscales: Inductive Reasoning, Monitoring, and Harsh Discipline. Second, parents' depressive symptoms were related to disrupted parenting practices, which, in turn, were significantly related to the negative evaluation of these behaviors by the adolescents. Adolescents' perceptions of such parenting practices were significantly associated with their depressive symptoms. Third, the relationships were robust even after parental income, education, and generation status were statistically controlled. Overall, the relationships between parenting practices and adolescent depressive symptoms among Chinese Americans seemed to echo those found among European Americans.

Adolescent↗
PubMed2000

Lung development following diaphragmatic hernia in the fetal rabbit.

Diaphragmatic hernia was created in 39 rabbit fetuses on day 23 of gestation. Fifteen fetuses underwent a sham thoracotomy (SHAM). Thirty-nine non-operated littermates served as internal controls (CTR). Fetuses were harvested by Caesarean section on days 25, 27, 29 and 30 of gestation. Pulmonary response was evaluated by lung to body weight ratio (LBWR), morphometry, and density of type II pneumocytes. No difference was found between CTR and SHAM fetuses at term. CDH fetuses had smaller lungs (LBWR 0.014 +/- 0.004 versus 0.030 +/- 0.04 in CTR, P < 0.0001), a less complex acinus [mean terminal bronchial density (MTBD) 1.786 +/- 0.408 versus 0.917 +/- 0. 188, P < 0.0001], thicker alveolar septa [mean wall transection length (LMW) 0.0221 +/- 0.008 versus 0.0142 +/- 0.002, P = 0.0003], and a lower type II cell count (144.5 +/- 19.33 versus 216.2 +/- 27.85 per high power field, P < 0.0001). The differences in MTBD and LMW were significant from gestational day 25 onwards, and the differences in type II cell count from day 27 onwards. Surgical diaphragmatic hernia in rabbit fetuses in the late pseudoglandular phase reproduces many features of the pulmonary hypoplasia associated with human congenital diaphragmatic hernia, including the delayed maturation. The effects are present within 2 days following experimental diaphragmatic hernia and progress over time.

Animals↗
PubMed2000

Cognitive abilities in adolescent-limited and life-course-persistent criminal offenders.

T. E. Moffitt's (1993a) hypothesis that adolescent-limited criminal offenders will have higher scores on tests of cognitive ability than life-course-persistent offenders was tested with 12 tests of cognitive ability given to a large and diverse sample of delinquent juveniles whose arrest records were collected over 20 years. This is the first investigation to empirically evaluate this proposal with longitudinal data obtained from a sample for a long enough time to distinguish life course patterns of crime. This study provided only partial support for Moffitt's hypothesis because the results varied by ethnicity. We found relatively consistent support for the hypothesis for Caucasians and Hispanics but no support for the hypothesis for African Americans. These findings are interpreted in terms of differences in developmental contexts for individual ethnic groups.

Adolescent↗
PubMed2000

[Changes of plasma renin activity and angiotensin II levels in women with polycystic ovary syndrome].

OBJECTIVE: To investigate changes of plasma renin activity(PRA) and plasma angiotensin II (PANG II) in women with polycystic ovary syndrome(PCOS). METHODS: We chose thirty PCOS women as trial group and thirty normal menstrual women as control. PRA and PANG II levels during follicularphase(FP) of the two groups were measured by radioimmunoassay. RESULTS: PRA and PANG II increased in women with PCOS as compared with the normal FP. The increment of PRA and PANG II in PCOS women of high testosterone levels was correlated with serum luteinizing hormone/follicle-stimulating hormone and testosterone concentration. CONCLUSION: The elevated PRA and PANG II suggest an enhanced functional activity of ovarian renin angiotensin system in PCOS, and which may play a role in the pathologenesis of PCOS.

Adult↗
PubMed2000

[A new method to evaluate the eustachian tube function].

OBJECTIVE: To study the practicality of a new method to evaluate eustachian tube function. METHOD: We acquired the tympanogram of 30 normal persons (60 cases) by means of classical tympanometry, Toynbee test and valsalva maneuvre respectively, the peak point of each tympanogram was P1, P2 and P3 corresponding P1 -P2 > 10 daPa or Pmax-Pmin > 15 daPa was accepted as normal. RESULT: 70% cases were accepted normal, whose peak point shifted obviously. CONCLUSION: The method is a simple, objective and practical one; If the peak point shifts obviously, the function of ET is normal; On the contrary, if the function of ET may be abnormal, other tests should be performed.

Acoustic Impedance Tests↗
PubMed2000

[The evaluation of eustachian tube function in patients suffered from SOM with C type curve].

OBJECTIVE: To explore eustachian tube (ET) function in patients suffered from SOM with C type curve. METHOD: To test the tympanogram following toynbee test and valsalva manoeuvre respectively. The shift of peak point was quantified and the results were compared with normal subjects. RESULT: ET dysfunction was found in 52.38% of the patients, it was observed in 30% of the normal subjects (P < 0.05). CONCLUSION: ET dysfunction is one of the causes of SOM with C type curve, but not the only cause.

Acoustic Impedance Tests↗
PubMed2000

[Activities of superoxide dismutase in Xanthomonas oryzae pv. oryzae and its induction].

The activities of superoxide dismutase(SOD) in Xanthomonas oryzae pv. oryzae were determined to demonstrate the correlation of SOD activities with the bacterial virulence. In liquid culture, SOD activities of the tested strains reached the maxima at the end of lag phase and then declined. The virulent strain PXO99A showed higher SOD activities than the avirulent strain PXO99A (pBUavr Xa10.F1). Analysis on the subcellular location indicated that SOD activities detected from the cytoplasm and periplasm were over 70% and 20%-30% of the total, respectively. Treatment of the bacterial culture for 1 h with exogenous O2- at concentration of 50-800 mumol/L induced SOD activities of both the strains. The treatment with 200 mumol/L resulted in the highest SOD activities. The effect of exogenous O2- on SOD induction was more significant in 12 h-culture than in 24 h-culture, and more notable for the virulent strain PXO99A. The treatment with exogenous O2- resulted in significantly decreased survival rate off both the strains. The decreases of survival rate were greater in 24 h-culture than in 12 h-culture, and more significantly for the virulent strain than for the avirulent one.

Oryza↗
PubMed2000

[The study of the distortion product emission in the people with hypertriglyceride].

OBJECTIVE: To study the change of the amplitude and latency of the distortion product emission (DPOAE) in the people with hypertriglyceride. METHOD: The DPOAE amplitude and latency of 30 people with hypertriglyceride and 18 normal was acquired with ILO-V5. RESULT: Although the hearing threshold of pure tone was not affected, but DPOAE amplitude of the people with hypertriglyceride was significantly decreased with the normal people, the changes of latency was not significantly affected. CONCLUSION: The cochlea of patient with hyperlipidemia may be damage in its early-stage. The generating mechanism of DPOAE latency and amplitude may be different.

Adult↗
PubMed2000

[Determination of trace tin in aluminum alloy by ICP-AES].

A method for the determination of trace tin in aluminum alloy by ICP-AES is proposed. The sample is dissolved in the acid mixture of HCl, HNO3, and a little HF is added dropwise. By fuming with sulfuric acid, the sample is then dissolved in HCl media for the determination of tin. Two sensitive wavelengths of tin in ultra-violet region are selected as analytical lines. The results are in accordance with spectrophotometric and FAAS methods, and a standard reference material of aluminum alloy is also analyzed with satisfactory results. The method is simple, rapid and sensitive, It can be used for the determination of trace tin in aluminum alloys.

Alloys↗
PubMed1999

Attenuation of morphine tolerance and dependence in scopolamine-treated rats.

Morphine tolerance and dependence were investigated in scopolamine-treated rats. The results showed that scopolamine treatment (up to 2 mg/kg) did not affect basal line or morphine-induced latency in the tail-flick test but significantly increased the escape latency in the Morris water-maze task. Co-administration of scopolamine could considerably attenuate development of morphine tolerance and naloxone-precipitated withdrawal syndrome. Pretreatment of scopolamine for 7 days prior to morphine administration also significantly reduced the tolerance and withdrawal symptoms. Scopolamine treatment was further shown to attenuate morphine-induced conditioned place preference, an indicator of morphine psychological dependence. The present study demonstrated the attenuation of morphine tolerance and dependence in scopolamine-treated animals, probably related to scopolamine-produced learning and memory impairment.

Analgesics, Opioid↗
PubMed1999

Administration of the tris salt of alpha-tocopheryl hemisuccinate inactivates CYP2E1, enhances microsomal alpha-tocopherol levels and protects against carbon tetrachloride-induced hepatotoxicity.

A series of tocopherol compounds were examined for their capacity to protect against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Of the tocopherol compounds tested in our study, only the tris salt of d-alpha-tocopheryl hemisuccinate (TS-tris) protected against CCl4-induced hepatotoxicity. The administration of d-alpha-tocopherol (alpha-T) and the nonhydrolyzable tocopherol ether, d-alpha-tocopheryloxybutyrate tris salt (TSE-tris), failed to protect against CCl4-induced hepatotoxicity. TS-tris was the only tocopherol which significantly decreased CYP2E1 activity after 18 h. This decrease in CYP2E1 activity is likely to limit the activation of CCl4 and protect against CCl4-induced hepatotoxicity. Our results also suggest that TS-tris protection against CCl4-induced hepatotoxicity correlates with the enhanced capacity of TS-tris to deliver alpha-T and increase the antioxidant status of hepatocytes. TSE-tris did not increase cellular alpha-T levels, while administration of TS-tris produced large increases in alpha-T levels in liver homogenates as well as in liver nuclei, microsomes, mitochondria and plasma membranes. This enhanced ability to deliver tocopherol equivalents to parenchymal liver cells may be related in part to the ability of TS-tris to form liposomes in aqueous solutions. TS-tris administration protected against CCl4-induced microsomal lipid peroxide formation and inactivation of the microsomal enzyme glucose-6-phosphatase (G6Pase). Supplementation of animals with alpha-T protected against microsomal lipid peroxide formation but not against the inactivation of G6Pase. Based on our findings, we propose that high cellular levels of alpha-T protect against CCl4-induced hepatotoxicity by scavenging CCl4 radicals as well as protecting against lipid peroxidation. Our results do not support the importance of microsomal lipid peroxidation as an early event in acute CCl4-induced hepatic necrosis.

Alanine Transaminase↗
PubMed1999

Adjustment problems and emerging personality characteristics from early to late adolescence.

This 6-year longitudinal study extended earlier findings of contextual influences on adolescent adjustment problems by examining relationships between adolescent emotional and behavioral problems and late adolescent personality among more than 400 youths who were followed from 7th grade to the last year of high school. Results suggest that psychological distress and behavioral problems experienced during the adolescent years (7th-10th grades) are significantly related to personality structure during the final year of high school (12th grade). Psychological distress in adolescence was primarily related to the Multidimensional Personality Questionnaire (MPQ) superfactors of negative and positive emotionality, whereas delinquency and substance use problems were primarily related to the MPQ superfactor of constraint. These relationships remained significant even when personality characteristics in 9th grade were taken into account. That is, emotional and behavioral problems predicted change in personality traits during the adolescent years. Moreover, both initial level and change in distress and problem behaviors were predictive of late adolescent or early adult personality. This finding suggests that personality formation is a dynamic process, dependent on the growth or decline, as well as the magnitude of earlier developmental problems. Because earlier research has shown that these developmental problems are affected by both distal and proximal environmental contexts as well as by the formative nature of adolescence, intervention efforts aimed at the reduction of maladjustment and the enhancement of healthy personality development should target early adolescent social contexts. Other theoretical implications of the findings also are discussed.

Adjustment Disorders↗