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X P Hu

Publications and source records attributed to X P Hu.

At least 19 recordsLinked to original sources
PubMed2005

Functional magnetic resonance imaging and transcranial magnetic stimulation: effects of motor imagery, movement and coil orientation.

OBJECTIVE: To compare fMRI activations during movement and motor imagery to corresponding motor evoked potential (MEP) maps obtained with the TMS coil in three different orientations. METHODS: fMRI activations during executed (EM) and imagined (IM) movements of the index finger were compared to MEP maps of the first dorsal interosseus (FDI) muscle obtained with the TMS coil in anterior, posterior and lateral handle positions. To ensure spatial registration of fMRI and MEP maps, a special grid was used in both experiments. RESULTS: No statistically significant difference was found between the TMS centers of gravity (TMS CoG) obtained with the three coil orientations. There was a significant difference between fMRI centers of gravity during IMs (IM CoG) and EMs (EM CoG), with IM CoGs localized on average 10.3mm anterior to those of EMs in the precentral gyrus. Most importantly, the IM CoGs closely matched cortical projections of the TMS CoGs while the EM CoGs were on average 9.5mm posterior to the projected TMS CoGs. CONCLUSIONS: TMS motor maps are more congruent with fMRI activations during motor imagery than those during EMs. These findings are not significantly affected by changing orientation of the TMS coil. SIGNIFICANCE: Our results suggest that the discrepancy between fMRI and TMS motor maps may be largely due to involvement of the somatosensory component in the EM task.

Adult↗
PubMed2001

Diaquabis(ethylenediamine)copper(II) bis[tris(ethylenediamine)nickel(II)] tris(naphthalene-2,6-disulfonate) tetrahydrate.

The title mixed-metal compound, [Cu(C(2)H(8)N(2))(2)(H(2)O)(2)][Ni(C(2)H(8)N(2))(3)](2)(C(10)H(6)O(6)S(2))(3).4H(2)O, was obtained during investigations of the porous frameworks constructed by amino-coordinated metal complex cations and large organic anions. All three naphthalene-2,6-disulfonate anions and the [Cu(en)(2)(H(2)O)(2)](2+) cation are located on crystallographic inversion centers and assemble into an extended two-dimensional network through intermolecular hydrogen bonds, creating cavities in which the [Ni(en)(3)](2+) cations and water molecules are included.

Journal Article↗
PubMed2001

Norepinephrine transporter (NET) is expressed in cardiac sympathetic ganglia of adult rat.

The sympathetic nervous system plays a cardinal role in regulating cardiac function through releasing the neurotransmitter norepinephrine (NE). In comparison with central nervous system, the molecular mechanism of NE uptake in myocardium is not clear. In present study, we proved that in rat the CNS type of NE transporter (NET) was also expressed in middle cervical-stellate ganglion complex (MC-SG complex) which is considered to control the activity of heart, but not expressed in myocardium. The results also showed that NET expression level in right ganglion was significantly higher than in the left, rendering the greater capacity of NE uptake in right ventricle, a fact which may contribute to the maintenance of right ventricular function under pathologic state.

Animals↗
PubMed2001

Anticipation in familial chronic lymphocytic leukaemia.

Anticipation, a phenomenon in which an inherited disease is diagnosed at an earlier age in each successive generation of a family, has been demonstrated in certain heritable neurological disorders and in multiple myeloma, non-Hodgkin's lymphoma and other haematological neoplasms. The present study was conducted to determine whether anticipation occurs in familial chronic lymphocytic leukaemia (CLL). Fourteen published reports of multigenerational familial CLL were analysed for anticipation, together with 10 previously unreported families with familial CLL, and the difference in disease-free survival between generations was determined. The difference between age at onset for each affected parent-child pair was tested against the null hypothesis that there was no difference in age at onset. The age at onset of the studied cases was also compared with that of the Surveillance Epidemiology and End Results (SEER) Program of the U.S. National Cancer Institute. The median ages at onset in the child and parent generations of all families (51.0 and 72.0 years respectively) were significantly different (P < 0.000001), and the null hypothesis was rejected (P < 0.000001). A significant difference was observed between the ages of onset of the child generation and the SEER population (P < 0.00001), but not between the parent generation and the SEER population. Anticipation characterizes familial CLL.

Age of Onset↗
PubMed2001

ERS transform for the automated detection of bronchial abnormalities on CT of the lungs.

The identification of bronchi on Computed Tomography (CT) images of the lungs provides valuable clinical information in patients with suspected airways diseases including bronchiectasis, emphysema, or constrictive obliterative bronchiolitis. The automated recognition of the airways is, therefore, an important part of a diagnosis aid system for resolving potential ambiguities associated with intensity-based feature extractors. On CT images, near-perpendicular cross sections of bronchi normally appear as elliptical rings and this paper presents a novel technique for their recognition. The proposed method, the edge-radius-symmetry (ERS) transform, is based on the analysis of the distribution of edges in local polar coordinates. Pixels are ranked according to local edge (E) strength, radial (R), uniformity and local symmetry (S). A discrete implementation of the technique is provided which reduces the computational cost of the ERS transform by using a geometric approximation of the intensity patterns. The identification of the adjacent pulmonary vessels with template matching then allows for the automated measurement of bronchial dilatation and bronchial wall thickening. Computationally, the method compares favorably with other methods such as the Hough transform. Noise-sensitivity of the technique was evaluated on a set of synthetic images and nine patients under investigation for suspected airways disease. Agreement for the automated scoring of the presence and severity of bronchial abnormalities was demonstrated to be comparable to that of an experienced radiologist (kappa statistics kappa > 0.5 ).

Bronchial Diseases↗
PubMed2001

[Qi deficiency and blood stasis and circulatory renin-angiotensin system as well as plasminogen activator inhibitor activity in rats with cardiac qi deficiency syndrome].

OBJECTIVE: To explore the relationship between cardiac Qi deficiency Syndrome and effect of circulatory renin-angiotensin system (RAS) and endogenous fibrinolytic system in rats with heart failure (HF). METHODS: Plasma RAS levels and plasminogen activator inhibitor (PAI-1) activity were measured in 2 groups of rats: the sham-operated group (Group A) and the HF with Heart Qi deficiency Syndrome model group (Group B) established by making arteriovenous fistula. Using radioimmunoassay and chromatography, plasma renin activity (PRA) and angiotensin II (Ang II) levels and PAI-I activity were determined before, immediately after and 30 days after the surgical operation respectively. RESULTS: After the operation was completed in Group B the left ventricular dysfunction revealed, left ventricular systolic pressure decreased and end diastolic pressure increased (P < 0.05), PRA and Ang II level and PAI-1 activity increased significantly, as compared with those in Group A and before modeling (P < 0.05). With cardiac function improved, the plasma PRA, Ang II level and PAI-1 activity lowered in Group B comparing with those immediately after modeling (P < 0.05). CONCLUSION: The activation of RAS is associated with the endogenous fibrinolyticim balance, and play an important role in endogenous fibrinolytic system dysfunction in HF with Heart Qi deficiency Syndrome and Qi deficiency-blood stasis, which was helpful to explain that cause of hypercoagulant state in HF patients and increase the risk of suffering from embolism-thrombotic diseases, and might be the pathogenetic basis of Heart Qi deficiency induced Qi deficiency-blood stasis.

Animals↗
PubMed2000

Age of onset evidence for anticipation in familial non-Hodgkin's lymphoma.

Anticipation, a phenomenon in which an inherited disease is diagnosed at an earlier age in each successive generation of a family, has been demonstrated in certain neurological and haematological disorders. This study was conducted to determine whether anticipation occurs in familial non-Hodgkin's lymphoma (NHL). Eleven published reports of multigenerational familial NHL were analysed for evidence of anticipation, together with 18 previously unreported families with familial NHL. Differences in disease-free survival between generations were determined. The difference between age at onset for each affected parent-child pair was tested against the null hypothesis that there was no difference in age at onset. These analyses were also performed separately using only parent-child pairs with age of onset > 25 years to avoid ascertainment bias. In addition, the age at onset distribution of the studied cases was compared with that of the Surveillance Epidemiology and End Results (SEER) Program using data for 1973-98. The median ages at onset in the child and parent generations of all families (48.5 and 71.3 years respectively) and in the selected pairs (52.5 and 71.5 years respectively) were significantly different (P < 0.000002 and P < 0.000001 respectively). The null hypothesis was rejected for all (P < 0.000001) as well as selected pairs (P < 0.000003). A significant difference was observed between the ages of onset of the child generation and the SEER population (P < 0.009), but not between the parent generation and the SEER population. Anticipation occurs in familial NHL, which suggests a genetic basis for it.

Age of Onset↗
PubMed2000

Toxicity and residual effectiveness of insecticides on insecticide-treated spheres for controlling females of Rhagoletis pomonella (Diptera: Tephritidae).

This study evaluated the toxicity of five technical-grade insecticides of four different classes to apple maggot females, Rhagoletis pomonella (Walsh), following a 10-min exposure period in insecticide-coated glass jars, with or without a feeding stimulant (sucrose) present. According to LC90 values for toxicity by ingestion and tarsal contact, imidacloprid was 1.5 times more toxic than dimethoate or abamectin, diazinon was less toxic, and phloxine B (a phototoxic dye) least toxic. Based on LC90 values for tarsal contact alone, dimethoate was 2.3, 4.0, and 18.4 times more toxic than imidacloprid, abamectin, and diazinon, respectively. Contact alone with phloxine B caused no mortality. When exposure was assessed using spheres coated with a latex paint mixture containing sucrose and formulated dimethoate (Digon 400 EC) or imidacloprid (Provado 1.6 F) at concentrations ranging from 5 to 70 g (AI)/cm2, both insecticides showed reduced effectiveness compared with toxicities from glass jar tests, with Digon two times more toxic than Provado. After exposure to artificial rainfall and retreatment with sucrose, Digon- and Provado-treated spheres exhibited greatest residual effectiveness, with diazinon-treated spheres less effective. Spheres treated with formulated abamectin (Agri-Mek 0.15 EC) at 1.0% (AI) performed only slightly better than phloxine B-treated spheres, which completely lost effectiveness after exposure to rainfall. Spheres treated with formulated imidacloprid (Merit 75 WP) at 1.5% (AI) showed equal or better residual efficacy in killing apple maggot flies (> 80% mortality, shorter lethal duration of feeding) over a 12-wk exposure period to outdoor weather than spheres treated with Digon at 1.0% (AI) after both types were retreated with sucrose. Our results indicate that imidacloprid is a promising safe substitute for dimethoate as a fly killing agent on lure-kill spheres. Imidacloprid formulated as Merit 75 WP had greater residual efficacy than imidacloprid formulated as Provado 1.6 F.

Animals↗
PubMed1999

Quantification of ribonucleotide reductase expression in wild-type and hydroxyurea-resistant cell lines employing in situ reverse transcriptase polymerase chain reaction and a computerized image analysis system.

Ribonucleotide reductase (RR) is the enzyme responsible for converting nucleoside diphosphates to deoxynucleoside diphosphates, ensuring a balanced supply of deoxyribonucleotides for DNA synthesis. Expression of RR is tightly regulated, but it is affected by exogenous agents, such as hydroxyurea (HU), which inactivates the tyrosyl free radical on the small subunit of RR, R2. We have previously employed in situ reverse transcriptase (RT)-PCR to estimate expression of R2 in wild-type and HU-resistant human colon carcinoma cell lines and to correlate altered expression of R2 with changes in cell size and morphology. The current studies were undertaken to render this methodology more quantitative. Both wild-type and resistant cells were grown on partitioned glass slides and analyzed with in situ RT-PCR. Because both wild-type and resistant cells were analyzed under a single cover slip, protease digestion, reverse transcription, PCR, and color development were all performed under identical conditions. Images were analyzed with NIH Image 1.59 software. There was a highly significant correlation between expression of R2 and cell size for both sensitive and resistant cells (P = 0.0001, for both). When cell size was compared either with expression of R2 or cell shape, however, these correlated only in wild-type cells (P = 0.001 and 0.0001, respectively). These data demonstrate that normal cell growth in the unperturbed wild-type cell line was closely linked to expression of R2, whereas in the resistant variants which overexpress R2, these correlations were absent, suggesting that HU resistance is related to loss of linkage between R2 expression and cell growth and confirming previous data relating overexpression of R2 with multiple other changes in the cell growth repertoire. Thus, we have demonstrated for the first time a quantitative application of in situ RT-PCR.

Base Sequence↗
PubMed1998

Controlled release of sugar and toxicant from a novel device for controlling pest insects.

A novel biodegradable device, designed for long-lasting residual effectiveness of feeding stimulant (sugar) and insecticide (dimethoate) against apple maggot files and other insects, was formulated. The device is an 8-cm diameter fruit-mimicking sphere, consisting of 42-50% sugar entrapped in a mixture of gelatinized corn flour and wheat flour in the presence of glycerin, and coated with a layer of latex paint containing dimethoate and sugar. We found that the outer layer of paint prevents cracking of the sphere upon drying and creates a barrier to control the release of both sugar and dimethoate. Releases of each ingredient were screened first by chemical analysis and then by bioassays in the laboratory and in field cages against apple maggot flies. Chemical analysis demonstrated strong potential for controlled release of water-soluble feeding stimulant and water-insoluble insecticide measured as a function of the amount of rainfall and duration of exposure time. Field results showed greater than 70% insecticidal activity after 11 weeks of sphere exposure in an orchard. This device has the potential to be used for a variety of insect-control applications through manipulating its shape, color and texture into forms known to be attractive to target insects, and by employing various toxicants designed to be effective against such insects.

Animals↗
PubMed1998

Impact of histology on the treatment outcome of metastatic or recurrent renal cell carcinoma.

Among 107 renal cell carcinoma (RCC) patients with histopathologic subtype diagnosis who were treated at Albert Einstein Cancer Center with cytokines over a 10-year period, seven patients had sarcomatoid histology, 63 had clear cell carcinoma, and 10 patients had mixed histology (sarcomatoid and clear cell). Regardless of their histology, patients with a disease free interval of 2 years or more had significantly better survival. None of the patients with sarcomatoid histology responded to therapy. However, several patients with mixed and clear cell histology achieved partial or complete responses following high dose Interleukin-2 (IL-2) therapy. The median survival of patients with sarcomatoid histology was the shortest (13.8 months), whilst that of patients with mixed and clear cell histology was much longer (34.8 months and 39.1 months, respectively). This result was statistically significant in both univariate and multivariate survival analysis (P < 0.001 and P < 0.01, respectively). Patients with mixed and clear cell histology had no significant difference in survival, and their median survival combined was significantly longer than that of patients with sarcomatoid histology (P < 0.0001 in univariate analysis, P < 0.01 in multivariate analysis). This study suggests that survival with a diagnosis of RCC is predicted by tumor histology and disease free interval, and this impacts on the ability to respond to standard therapy. Patients with mixed and clear cell histology respond to cytokine therapy. Other therapies should be sought for patients with sarcomatoid RCC.

Adenocarcinoma, Clear Cell↗
PubMed1998

Anticipation in familial plasma cell dyscrasias.

Familial myeloma was described as early as 1925; however, the causative factors are unknown. Studies of families with other familial haematological malignancies demonstrate anticipation. Five new families are described in which plasma cell dyscrasias occurred in parent and child generations (six such pairs), and data were pooled with those of 16 other families (with 20 parent-child pairs affected) recorded in the literature. Disease-free survival for parent and child generations were each estimated and differences in the disease-free survival between generations were tested by the log-rank and signed rank methods. In all six previously unreported parent-child pairs with plasma cell dyscrasia and in 18/20 such pairs found in the literature, the disease occurred at an earlier age in the child generation. The median age of onset of myeloma in the parent and child generations of all 26 pairs was 71 years (95% CI 67-78 years) and 50 years (95% CI 45-55 years), respectively (P<0.0001). The ages of onset of malignant plasma cell dyscrasias in the parent and child generations of these families compared with patients in the general population were significantly different for the child generation (P<0.005) but not for the parent generation. It would appear that anticipation occurs in familial myeloma.

Adult↗
PubMed1997

Urinary estrogen metabolites and breast cancer: a case-control study.

Preliminary studies suggest that the estrogen metabolite 16 alpha-hydroxyestrone is associated with breast cancer, whereas 2-hydroxyestrone is not. However, epidemiological studies evaluating this relationship and taking established risk factors for breast cancer into account are lacking. The purpose of this study was to examine the association of the ratio of the urinary estrogen metabolites (2-hydroxyestrone and 16 alpha-hydroxyestrone) and of the individual metabolites with breast cancer. A spot urine sample, a brief history, and clinical data were collected from breast cancer cases (n = 42) and from women coming to the hospital for a routine mammogram or attending a free breast cancer screening (n = 64). 2-Hydroxyestrone and 16 alpha-hydroxyestrone were measured by enzyme immunoassay, and the estrogen metabolite ratio (EMR; 2-hydroxyestrone:16 alpha-hydroxyestrone) was computed. Cases and controls were similar in terms of age (mean age of cases, 53.8 +/- 15.1 years, versus 54.2 +/- 10.4 years for controls; P = 0.9) and demographics. Mean EMR was not associated with breast cancer overall (1.67 +/- 0.80 versus 1.72 +/- 0.66; P = 0.7). However, in postmenopausal women, the mean EMR was significantly lower in cases compared to controls (1.41 +/- 0.73 versus 1.81 +/- 0.71; P = 0.05). The multivariate adjusted odds ratios for the intermediate and lowest tertiles of the EMR relative to the highest among postmenopausal women were 9.73 (95% confidence interval, 1.27-74.84) and 32.74 (95% confidence interval, 3.36-319.09), respectively. The test for trend was highly significant (P = 0.003). Analyses of the individual metabolites indicated that 16 alpha-hydroxyestrone was a strong risk factor. The EMR did not show any consistent associations with age, race/ethnicity, age at first birth, parity, body mass index, family history of breast cancer, smoking, or alcohol intake. These data suggest a strong, inverse association of the EMR and a strong positive association of 16 alpha-hydroxyestrone with breast cancer in postmenopausal women. Larger studies are needed to confirm these results and to assess the relationship of the EMR and of the individual metabolites with breast cancer, with attention to menopausal status and clinical factors and with adjustment for known breast cancer risk factors.

Adult↗
PubMed1996

[Analysis of nucleotide level of human erythrocytes in patients with liver-fire exuberance syndrome].

Level of erythrocytes in 30 patients with Liver-Fire Exuberance Syndrome (LFES) was observed, and that of 30 healthy persons was determined in the meantime as control by high-performance liquid chromatography. It was found that the adenosine triphosphate in erythrocytes of LFES patients was lower and level of adenosine monophosphate was higher than that of healthy persons. While, the levels of adenylate pool and energy load ratio were lower than that of control. These results showed the metabolism was exuberant, the energy consumption increased and the energy storage reduced in patients of LFES.

Adenosine Monophosphate↗
PubMed1995

Identifying adults at increased risk of coronary disease. How well do the current cholesterol guidelines work?

OBJECTIVE: To assess the accuracy of lipid screening strategies to identify individuals at increased risk of coronary heart disease mortality. PATIENTS: The 15% random sample of adults recruited into the Lipid Research Clinic Prevalence and Follow-up Studies, which included 3678 men and women aged 35 to 74 years. Total plasma cholesterol levels, lipoprotein fractions, and other coronary risk factors at study entry were compared with subsequent coronary heart disease mortality (mean follow-up, 12.2 years). MAIN OUTCOME MEASURES: The areas under receiver operating characteristic curves for blood lipids, lipid ratios, the screening guidelines proposed by the National National Cholesterol Education Program, those of the Canadian Consensus Conference on Cholesterol, and a coronary risk model that used Framingham data. MAIN RESULTS: The current National Cholesterol Education Program guidelines (area under the curve, 0.74) were significantly (P = .03) more accurate than the old National Cholesterol Education Program guidelines (area, 0.72). The ratio of total plasma cholesterol level to high-density lipoprotein cholesterol level (area, 0.72) was as accurate as current National Cholesterol Education Program guidelines. The coronary risk model (area, 0.85) was superior (P < .003) to all other screening maneuvers. Compared with the current National Cholesterol Education Program guidelines, the risk model demonstrated superior test sensitivity (70% vs 45%) with only slightly reduced specificity (82% vs 86%). CONCLUSION: The ratio of total plasma cholesterol level to high-density lipoprotein cholesterol level is as accurate as current American screening guidelines. Future guidelines should better incorporate high-density lipoprotein cholesterol levels and nonlipid risk factors to target high-risk individuals accurately.

Adult↗
PubMed1994

Effect of retinoic acid and interferon alpha on granulocyte-macrophage colony forming cells in chronic myeloid leukemia: increased inhibition by all-trans- and 13-cis-retinoic acids in advanced stage disease.

Granulocyte-macrophage colony forming units (CFU-GM) from patients with advanced stage chronic myelogenous leukemia (CML), i.e. in blastic crisis (BC) or accelerated phase (AP), were inhibited by all-trans-retinoic acid (tRA) approximately 1000-fold more potently than those from chronic phase (CP) CML patients (median IC50 = 10(-9) M tRA for six CML-AP/BC cases vs > 10(-6) M tRA for seven CML-CP cases). A similar activity pattern was observed for the stereoisomer 13-cis-RA (cRA). There was no apparent correlation of CFU-GM retinoid sensitivity with cloning efficiency or other colony characteristics. Interferon alpha-2a (INF alpha) alone strongly inhibited CFU-GM growth in all four CML-AP/BC cases (IC50 < or = 250 IU/ml) and three out of seven CML-CP cases (IC50 < or = 500 IU/ml), but there was little or no interactive effect between various concentrations of tRA and INF alpha (50 IU/ml) on CFU-GM from either CML-AP/BC or CML-CP cases. These results suggest that CML-AP/BC CFU-GM have some intrinsic molecular alteration(s) which markedly enhances their responsiveness to tRA and cRA, which may be clinically exploitable.

Adult↗
PubMed1991

Bayesian image processing in magnetic resonance imaging.

In the past several years, image processing techniques based on Bayesian models have received considerable attention. In our earlier work, we developed a novel Bayesian approach which was primarily aimed at the processing and reconstruction of images in positron emission tomography. In this paper, we describe how the technique has been adopted to process magnetic resonance images in order to reduce noise and artifacts, thereby improving image quality. In this framework, the image is assumed to be a statistical variable whose posterior probability density conditional on the observed image is modeled by the product of the likelihood function of the observed data with a prior density based our prior knowledge. A Gibbs random field incorporating local continuity information and with edge-detection capability is used as the prior model. Based on the formalism of the posterior density, we can compute an estimate of the image using an iterative technique. We have implemented this technique and applied it to phantom and clinical images. Our results indicate that the approach works reasonably well for reducing noise, enhancing edges, and removing ringing artifact.

Algorithms↗