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Xiang Gao

Publications and source records attributed to Xiang Gao.

At least 37 records · Page 2Linked to original sources
PubMed2006

[Diagnosis and treatment of dysembryoplastic neuroepithelial tumor].

OBJECTIVE: To discuss the diagnosis and treatment of dysembryoplastic neuroepithelial tumor (DNT). METHODS: From November 2001 to February 2005, 18 patients were admitted. The data of the 18 patients were reviewed. RESULT: Epilepsy was the main complaint. There was no mass effect on MRI. Multinodular and specific glioneuronal element was typical in pathological examination, seizure could be controlled by operation. CONCLUSIONS: DNT is benign tumor which could be treated by surgery, total removal of tumor and using intraoperative electrocorticography could improve the result of operation.

Adolescent↗
PubMed2006

Alternative 3' UTR polyadenylation of Bzw1 transcripts display differential translation efficiency and tissue-specific expression.

BZW1 is a conserved regulatory factor for transcriptional control of histone H4 gene at the G1/S transition. In this study, three Bzw1 transcripts were identified in mice with two long forms (approximately 2.9 kb) expressed ubiquitously at low level, and a short transcript of 1.8 kb expressed at high level exclusively in testis. These different transcripts share the same 5' UTR and coding sequence, but differ in the length of 3' UTR by utilizing alternative polyadenylation sites. Different translation efficiencies were observed in the cells transfected with chimeric EGFP-Bzw1 genes tailed with different 3' UTRs. Our results demonstrate that Bzw1 transcripts are alternatively polyadenylated and expressed in tissue-specific pattern.

3' Untranslated Regions↗
PubMed2006

A novel cytochrome P450, zebrafish Cyp26D1, is involved in metabolism of all-trans retinoic acid.

Retinoid signaling is essential for development of vertebrate embryos, and its action is mainly through retinoic acid (RA) binding to its RA receptors and retinoid-X receptors, while the critical concentration and localization of RA in embryos are determined by the presence and activity of retinal dehydrogenases (for RA synthesis) and cytochrome P450 RAs (Cyp26s) (for degradation of RA). Previously, we identified a novel cyp26 gene (cyp26d1) in zebrafish that is expressed in hindbrain during early development. Using reverse-phase HPLC analyses, we show here that zebrafish Cyp26D1 expressed in 293T cells could metabolize all-trans RA, 9-cis RA, and 13-cis RA, but could not metabolize retinol or retinal. The metabolites of all-trans RA produced by Cyp26D1 were the same as that produced by Cyp26A1, which are mainly 4-hydroxy-all-trans-RA and 4-oxo-all-trans-RA. Performing mRNA microinjection into zebrafish embryos, we demonstrated that overexpression of Cyp26D1 in embryos not only caused the distance between rhombomere 5 and the first somite of the injected embryos to be shorter than control embryos but also resulted in left-right asymmetry of somitogenesis in the injected embryos. These alterations were similar to those caused by the overexpression of cyp26a1 in zebrafish embryos and to that which resulted from treating embryos with 1 microm 4-diethylamino-benzaldehyde (retinal dehydrogenase inhibitor), implying that cyp26d1 can antagonize RA activity in vivo. Together, our in vitro and in vivo results provided direct evidence that zebrafish Cyp26D1 is involved in RA metabolism.

Amino Acid Sequence↗
PubMed2006

The negative cell cycle regulator, Tob (transducer of ErbB-2), is involved in motor skill learning.

Tob (transducer of ErbB-2) is a negative cell cycle regulator with anti-proliferative activity in peripheral tissues. Our previous study identified Tob as a protein involved in hippocampus-dependent memory consolidation (M.L. Jin, X.M. Wang, Y.Y. Tu, X.H. Zhang, X. Gao, N. Guo, Z.Q. Xie, G.P. Zhao, N.H. Jing, B.M. Li, Y.Yu, The negative cell cycle regulator, Tob (Transducer of ErbB-2), is a multifunctional protein involved in hippocampus-dependent learning and memory, Neuroscience 131 (2005) 647-659). Here, we provide evidence that Tob in the central nervous system is engaged in acquisition of motor skill. Tob has a relatively high expression in the cerebellum. Tob expression is up-regulated in the cerebellum after rats receive training on a rotarod-running task. Rats infused with Tob antisense oligonucleotides into the 4th ventricle exhibit a severe deficit in running on a rotating rod or walking across a horizontally elevated beam.

Animals↗
PubMed2006

Distribution and chemical coding of corticotropin-releasing factor-immunoreactive neurons in the guinea pig enteric nervous system.

Immunofluorescence was used to study immunoreactivity (IR) for corticotropin-releasing factor (CRF) in the guinea pig enteric nervous system. CRF-IR was expressed in both the myenteric and the submucosal plexuses of all regions of the large and small intestine and the myenteric plexus of the stomach. CRF-IR nerve fibers were present in the myenteric and submucosal plexuses, in the circular muscle coat, and surrounding submucosal arterioles. Most of the CRF-IR fibers persisted in the myenteric and submucosal plexuses after 7 days in organotypic culture. CRF-IR was not coexpressed with tyrosine hydroxylase-IR or calcitonin gene-related peptide-IR fibers. The proportions of CRF-IR cell bodies in the myenteric plexus increased progressively from the stomach (0.6%) to the distal colon (2.8%). Most of the CRF-IR myenteric neurons (95%) had uniaxonal morphology; the remainder had Dogiel type II multipolar morphology. CRF-IR cell bodies in the myenteric plexus of the ileum expressed IR for choline acetyltransferase (56.9%), substance P (55.0%), and nitric oxide synthase (37.9%). CRF-IR never colocalized with IR for calbindin, calretinin, neuropeptide Y, serotonin, or somatostatin in the myenteric plexus. CRF-IR cell bodies were more abundant in the submucosal plexus (29.9-38.0%) than in the myenteric plexus. All CRF-IR neurons in submucosal ganglia expressed vasoactive intestinal peptide-IR and were likely to be secretomotor/vasodilator neurons. CRF-IR neurons did not express IR for the CRF(1) receptor. CRF(1)-IR was expressed in neuronal neighbors of those with CRF-IR. Collective evidence suggests that VIPergic secretomotor neurons might provide synaptic input to neighboring cholinergic neurons.

Animals↗
PubMed2006

Meeting adequate intake for dietary calcium without dairy foods in adolescents aged 9 to 18 years (National Health and Nutrition Examination Survey 2001-2002).

BACKGROUND: In the United States, >50% of dietary calcium is provided by milk and milk products. Calcium intakes in the United States are inadequate for many children, and a large proportion do not drink milk or consume dairy products. However, no studies have addressed whether dairy-free diets can provide adequate calcium while meeting other nutrient recommendations. OBJECTIVE: To determine the highest calcium intake for adolescents obtained from dairy-free diets, and to examine the relationship between intakes of calcium-fortified foods, using citrus juice as an example, and maximal calcium intakes. DESIGN: In the National Health and Nutrition Examination Survey 2001 to 2002, 65 females and 62 males, aged 9 to 18 years, reported no intake of dairy. We used linear programming to generate diets with maximal calcium intake, while meeting Dietary Reference Intakes for a set of nutrients, limiting energy and fat intakes, and not selecting food quantities exceeding amounts usually eaten in the population. RESULTS: With food use and energy and fat constraints, diets formulated by linear programming provided 1,150 and 1,411 mg/day of calcium for girls and boys, respectively. With the Dietary Reference Intakes constraints, these decreased to 869 and 1,160 mg/day. When we introduced 1.5 servings of fortified juice to the diets, the highest calcium intake increased to 1,302 mg/day for girls and to 1,640 mg/day for boys. CONCLUSIONS: Adequate intake for calcium cannot be met with dairy-free diets while meeting other nutrient recommendations. To meet the adequate intake for calcium without large changes in dietary patterns, calcium-fortified foods are needed. In addition, greater physical activity and responsible sunlight exposure should be encouraged to promote vitamin D adequacy.

Adolescent↗
PubMed2006

Microfilament-binding properties of N-terminal extension of the isoform of smooth muscle long myosin light chain kinase.

Myosin light chain kinases (MLCK) phosphorylate the regulatory light chain of myosin II in thick filaments and bind to F-actin-containing thin filaments with high affinity. The ability of short myosin light chain kinase (S-MLCK) to bind F-actin is structurally attributed to the DFRXXL regions in its N-terminus. The long myosin light chain kinase (L-MLCK) has two additional DFRXXL motifs and six Ig-like modules in its N-terminal extension. The six Ig-like modules are capable of binding to stress fibers independently. Our results from the imaging analysis demonstrated that the first two intact Ig-like modules (2Ig) in N-terminal extension of L-MLCK is the minimal binding module required for microfilament binding. Binding assay confirmed that F-actin was able to bind 2Ig. Stoichiometries of 2Ig peptide were similar for myofilament or pure F-actin. The binding affinities were slightly lower than 5DFRXXL peptide as reported previously. Similar to DFRXXL peptides, the 2Ig peptide also caused efficient F-actin bundle formation in vitro. In the living cell, over-expression of 2Ig fragment increased "spike"-like protrusion formation with over-bundled F-actin. Our results suggest that L-MLCK may act as a potent F-actin bundling protein via its DFRXXL region and the 2Ig region, implying that L-MLCK plays a role in cytoskeleton organization.

Actins↗
PubMed2006

alpha-Tocopherol intake and plasma concentration of Hispanic and non-Hispanic white elders is associated with dietary intake pattern.

alpha-Tocopherol from foods has been associated with protection against several chronic diseases and maintenance of immune function. However, most people do not meet current recommendations for intake. We examined alpha-tocopherol intake and plasma concentration in a representative sample of Puerto Rican and Dominican older adults (n = 447) and in neighborhood-matched non-Hispanic whites (n = 155). A validated food frequency questionnaire was used to assess dietary intake. Mean dietary intakes of alpha-tocopherol were 6 mg in both ethnicities. Only 4.7% of women and 7.9% of men met the estimated average requirement (12 mg/d) for vitamin E from food alone. Top sources of alpha-tocopherol for Hispanics included oils and milk, and for non-Hispanic whites they were ready-to-eat breakfast cereal and sweet baked products. Mean plasma alpha-tocopherol concentrations were 24.5 micromol/L for Hispanics and 25.8 micromol/L for non-Hispanic whites (P > 0.05). Plasma alpha-tocopherol was positively associated with alpha-tocopherol intake (P = 0.003), and significance remained after adjusting covariates and after exclusion of supplement users (P for trend = 0.008). We identified the following 5 dietary patterns by cluster analysis: 1) fruit and breakfast cereal, 2) starchy vegetables, 3) rice, 4) milk and milk products, and 5) sweets. Those following the sweets pattern had the lowest plasma alpha-tocopherol relative to those following the fruit and breakfast cereal or milk patterns (P < 0.05 for all), although they had similar intakes. A large proportion of these elders (>90%) have inadequate intake of alpha-tocopherol, and plasma concentrations were associated with intake patterns.

Aged↗
PubMed2006

The maximal amount of dietary alpha-tocopherol intake in U.S. adults (NHANES 2001-2002).

The current study was designed to determine the maximal amount of alpha-tocopherol intake obtained from food in the U.S. diet, and to examine the effect of different food group intakes on this amount. Data from 2138 men and 2213 women aged >18 y were obtained from the National Health and Nutrition Examination Survey (NHANES) 2001-2002. Linear programming was used to generate diets with maximal alpha-tocopherol intake, with the conditions of meeting the recommended daily allowances or adequate intakes for a set of nutrients, sodium and fat recommendations, and energy limits, and that were compatible with the observed dietary patterns in the population. With food use and energy constraints in models, diets formulated by linear programming provided 19.3-24.9 mg alpha-tocopherol for men and women aged 19-50 or >50 y. These amounts decreased to 15.4-19.9 mg with the addition of the sodium, dietary reference intake, and fat constraints. The relations between maximal alpha-tocopherol intake and food group intakes were influenced by total fat restrictions. Although meeting current recommendations (15 mg/d) appears feasible for individuals, dramatic dietary changes that include greater intakes of nuts and seeds, and fruit and vegetables, are needed. Careful selection of the highest vitamin E source foods within these groups could further increase the likelihood of meeting the current recommended daily allowance.

Adult↗
PubMed2006

The 2005 USDA Food Guide Pyramid is associated with more adequate nutrient intakes within energy constraints than the 1992 Pyramid.

The USDA issued the Food Guide Pyramid (FGP) to help Americans choose healthy diets. We examined whether adherence to the 1992 and 2005 FGP was associated with moderate energy and adequate nutrient intakes. We used data for 2138 men and 2213 women > 18 y old, from the 2001-2002 U.S. National Health and Nutrition Examination Survey (NHANES). Quadratic programming was used to generate diets with minimal departure from intakes reported for the NHANES 2001-02. We examined the effect of the number of servings/d of Food Pyramid groups set at 1992 and at 2005 FGP recommendations for 1600, 2200, and 2800 kcal (1 kcal = 4.184 kJ) levels. We calculated energy and nutrients provided by different FGP dietary patterns. Within current U.S. dietary practices, following the 1992 FGP without sodium restriction may provide 200 more kcal than recommended for each energy level. Although it can meet most of old nutrient recommendations (1989), it fails to meet the latest dietary reference intakes, especially for the 1600 kcal level. The 2005 FGP appears to provide less energy and more adequate nutrient intakes, with the exception of vitamin E and potassium for some groups. However, without discretionary energy restriction, Americans are at risk of having excessive energy intake even if they follow the 2005 FGP food serving recommendations. Our analysis suggests that following the 2005 FGP may be associated with lower energy and optimal nutrient intake. Careful restriction of discretionary calories appears necessary for appropriate energy intakes to be maintained.

Animals↗
PubMed2006

Histopathological study of five cases with sporadic meningioangiomatosis.

We report five cases of sporadic meningioangiomatosis, three males and two females, ranging in age from 12 to 36 years at diagnosis. The lesion was found incidentally by MRI after a head trauma in one case; the other four subjects had a seizure disorders, which improved following surgical resection of the cortical lesions. Grossly, the lesionectomy specimens were of a whitish color and firm consistency. Histological examination revealed that the lesions were confined to the cortex with focal involvement of the overlying leptomeninges, and revealed unifying features of meningioangiomatosis, such as proliferating microvessels with perivascular cuffs of spindle-cell proliferation within the cortex. Two cases had numerous calcifications; one was associated with a prominent fibrocalcifying component. Immunostaining results were variable among the cases. Only vimentin was consistently positive. Some of the spindle cells were weak positive for EMA in two cases. Immunoreactions with anti-CD34 detected within the cytoplasm of the spindle cells were observed in three of the five cases. The Ki-67 proliferation index of all the cases was very low, less than 0.1%. Neurofibrillary tangles were identified in only one of the five cases using the Bodian and immunostaining methods. These findings indicate that meningioangiomatosis lesions show a wide range of clinicopathological features, making diagnosis difficult. A histopathological spectrum and differential diagnoses were discussed with a review of the literature. Since this lesion is a distinct clinicopathological entity and hamartomatous in nature, it is important to make a correct diagnosis in order to avoid further aggressive treatment.

Adolescent↗
PubMed2006

Report on the first Chinese family with Gerstmann-Sträussler-Scheinker disease manifesting the codon 102 mutation in the prion protein gene.

The authors found a female patient aged 33-years with dementia and cerebellar ataxia rapidly progressing for a year. EEG tracings were abnormal but without features of typical CJD. The patient died 13 months after the onset of illness. Biopsy of her cerebral cortex showed moderate spongiform changes, neuronal loss and gliosis. Numerous deposits of eosinophilic substance amorphous or in the shape of Kuru plaques were disclosed in the cerebral cortex. All deposits stained strongly with monoclonal 3F4 antibody to human prion protein. Genetic studies disclosed the Pro to Leu point mutation at codon 102 with a 102 Leu-129 Met in the PrP gene. Codon 129 was heterozygous for Met/Val, and codon 219 was homozygous for Glu/Glu. It was established; moreover, that the patient's grandfather had a similar disease and died at age 48 and the patient's brother died after a 10-year long neurological disease diagnosed as hereditary cerebellar ataxia. On the basis of clinical, neuropathological and genetic findings, the authors diagnosed the Gerstmann-Sträussler-Scheinker disease, a familial prion disease with an autosomal dominant character. This is the first report on this disease in China.

Adult↗
PubMed2006

Stable skin-specific overexpression of human CTLA4-Ig in transgenic mice through seven generations.

Skin graft rejection is a typical cellular immune response, mainly mediated by T cells. Cytotoxic T lymphocyte associated antigen 4-immunoglobin (CTLA4-Ig) extends graft survival by blocking the T cell co-stimulation pathway and inhibiting T cell activation. To investigate the efficacy of CTLA4-Ig in prolonging skin graft survival, human CTLA4-Ig (hCTLA4-Ig) was engineered to overexpress in mouse skin by transgenesis using the K14 promoter. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot assay indicated that the expression of CTLA4-Ig remained skin-specific and relatively constant compared to the internal control protein, AKT, through seven generations. The presence and concentration of the hCTLA4-Ig protein in transgenic mouse sera was determined by enzyme-linked immunosorbent assay (ELISA), and the results indicated that the serum CTLA4-Ig concentration also remained constant through generations. Survival of transgenic mouse skins grafted onto rat wounds was remarkably prolonged compared to that of wild-type skins from the same mouse strain, and remained comparable among all seven generations. This suggested that the bioactive hCTLA4-Ig protein was stably expressed in transgenical mice through at least seven generations, which was consistent with the stable skin-specific CTLA4-Ig expression. The results demonstrated that the transgenic expression of hCTLA4-Ig in skin driven by the K14 promoter remained constant through generations, and a transgenic line can be established to provide transgenic skin with extended survival reproducibly.

Abatacept↗
PubMed2006

A kinetic spectrophotometric method for the determination of nitrite by stopped-flow technique.

A novel and highly sensitive stopped-flow kinetic spectrophotometric method for the determination of nitrite, based on monitoring the variation in the absorbance of the intermediate within a very short period, has been developed. The optimum conditions for various parameters on which the reaction of nitrite with perphenazine depends, were investigated. It was found that the initial reaction rate increased linearly with increasing nitrite concentration in the range from 1.0 x 10(-8) to 6.0 x 10(-6) M. The detection limit was calculated to be 4.8 x 10(-9) M. This method was used for the determination of nitrite in natural and drinking-water with satisfactory results. The influence of cationic, non-ionic and anion surfactants was also studied in this work.

Anions↗
PubMed2006

[The effects of EPHPH on acoustic brainstem response threshold and its relative factors of senile model rats].

OBJECTIVE: The effect of EPHPH on aged deafness and its mechanism was explored by observing the effects of EPHPH on acoustic brainstem response threshold (ABRT), malondialdehyde (MDA), superoxide dismutase (SOD), total-nitrogen monoxide (NOS) and typing-nitrogen monoxide (iNOS) in cochleae tissues of senile model rats. METHOD: ABRT value was measured by induced potentiometer, MDA was measured by TBA colorimetry, SOD was determined by nitrite method, NOS and iNOS was determined by spectrophotometry in cochleae tissues of senile model rats that separately administered by gavage the alcoholic extract from 2.16, 4.32 or 8.64 g x kg(-1) x d(-1) PHPH once a day for 6 months. RESULT: ABRT value and MDA content notably increased, activities) of SOD, NOS and iNOS notably decreased in cochlear tissues of senile model rats from control. It indicated on relative analysis that relativity between ABRT value ascent and MDA ascent showed positive, relaxivities between ABRT value ascent and activity descents of SOD, NOS and iNOS showed all negative. It differently resisted ABRT value ascent and MDA ascent in cochlear tissues that senile model rats separately administered the alcoholic extract from 2.16, 4.32 or 8.64 g x kg(-1) x d(-1) PHPH whose relaxivities between quantity and efficiency showed all negative. It differently inhibited activity descents of SOD, NOS and iNOS in cochlear tissues that senile model rats separately administered various doses of EPHPH whose relaxivities between quantity and efficiency showed all positive. CONCLUSION: EPHPH may relieve the degree of aged deafness and its mechanism may be connected with eliminating oxygen free radicals and increasing the activities of SOD, NOS and iNOS in cochleae of natural senile rats.

Aging↗
PubMed2006

[Real-time and non-invasive temperature monitoring of thermotherapy using MRI].

High-intensity focused ultrasound (HIFU) thermotherapy is a promising technique for local tumor destruction of solid organs. Temperature is the important parameter which impacts the curative effects of thermotherapy. For safety and efficiency reasons, it is necessary to monitor the temperature changes inside body in real-time, non-invasively and precisely. Recently MRI methods employed for temperature monitoring during HIFU therapy have been paid more and more attentions to. This paper introduces the general principles of non-invasive temperature monitoring using MRI. The authors also review the development of this technique and point out some problems that need to be solved.

Animals↗
PubMed2006

[Erythropoietin enhances the therapy potency of autologous bone marrow stromal cells in a rat heart infarction model via phosphatidylinositol-3-kinase/Akt pathway].

OBJECTIVES: Erythropoietin (EPO) induces angiogenesis and inhibits apoptosis through the phosphatidylinositol-3-kinase/Akt (PI3-K/Akt) pathway. Transplantation of mesenchymal stromal cells (MSC) has been shown to improve heart perfusion and function post myocardial ischemia. We investigated whether EPO enhances the therapeutic potency of MSC transplantation in rats with experimental myocardial infarction (MI). METHODS: Wistar rats were divided into four groups (n=8 each): myocardial infarction (MI) group, EPO group, MSC group and MSC-EPO group. MI was made by ligating the anterior descending coronary artery. MSC was injected in the infarcted area immediately after ligation in MSC group and MSC-EPO group. EPO (3000 U/kg) was administered i.p. in EPO group and MSC-EPO group for 3 days post MI and on the 14th to 16th day post MI. Cardiac function was measured by echocardiography at 2 and 21 days after MI. MI size was measured, and the level of phosphorylated Akt was assessed by Western blot and immunohistology at 21 days post MI. RESULTS: LVEF was significantly lower at 21 days than that at 2 days in MI group while significantly increased in other 3 groups, especially in MSC-EPO group at 21 days than that at 2 days. MI size was significantly lower (20.7%+/-2.3% vs. 24.0%+/-2.3%, 26.0%+/-0.9%, 28.1%+/-1.5%, all P<0.05), capillary density was significantly higher (12.95+/-2.11 vs. 10.78+/-0.99, 10.43+/-1.52 and 6.31+/-0.69, all P<0.05) in MSC-EPO group at 21 days than that in other groups and the ratio of phosphorylated Akt to total Akt measured by Western blot was also significantly higher in MSC-EPO group than other groups (0.36 vs. 0.32, 0.31 and 0.28, all P<0.05). Compared to other groups, Bcl-2 was significantly up-regulated and Bax down-regulated in MSC-EPO group. CONCLUSION: Our results demonstrated that MSC transplantation and EPO infusion could improve cardiac function and EPO enhances the therapeutic potency of MSC transplantation via PI3-K/Akt pathways.

Animals↗