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Biomedical subjects

H Dai

Publications and source records attributed to H Dai.

At least 19 recordsLinked to original sources
PubMed2026

[Tafluprost/timolol fixed-dose combination versus tafluprost monotherapy for open-angle glaucoma and ocular hypertension: a multicenter, randomized, double-blind, parallel-group trial].

Objective: To evaluate the efficacy and safety of a preservative-free tafluprost/timolol maleate fixed-dose combination compared with preservative-free tafluprost monotherapy in Chinese patients with open-angle glaucoma (OAG) or ocular hypertension (OHT). Methods: This was a multicenter, randomized, double-blind, parallel-controlled clinical trial conducted across 25 centers, including the Eye & ENT Hospital of Fudan University, from January 2019 to November 2022. Patients diagnosed with OAG or OHT who required enhanced intraocular pressure (IOP) reduction after a 4-week washout period were enrolled. Participants were randomized 1&#x2236;1 to receive either tafluprost/timolol or tafluprost once daily for 3 months. The primary endpoint was the change from baseline in mean diurnal IOP (the average of measurements at 8:00, 10:00, and 16:00) at Month 3. Secondary endpoints included IOP changes at individual time points and the proportion of responders achieving predefined IOP reduction thresholds. Safety was assessed via the incidence of adverse events (AEs). Analysis of covariance (ANCOVA) using the Markov Chain Monte Carlo (MCMC) method was employed for the primary endpoint; superiority was established if the upper limit of the 95% confidence interval (CI) was<0 mmHg (1 mmHg=0.133 kPa). Continuous variables in secondary endpoints were compared using ANCOVA, and responder rates were analyzed using Fisher's exact test. Results: A total of 219 patients were enrolled (tafluprost/timolol group: n=110; tafluprost group: n=109). The primary efficacy analysis set included 215 patients (tafluprost/timolol: n=107; tafluprost: n=108). Baseline characteristics were well-balanced between the two groups. The majority of patients were male [127 (59.1%)] with a mean age of (44.80&#xb1;15.71) years at screening. At Month 3, the mean diurnal IOP reduction from baseline was (6.56&#xb1;3.44) mmHg in the tafluprost/timolol group and (5.36&#xb1;2.94) mmHg in the tafluprost group. After adjusting for baseline IOP, the between-group difference was -1.312 mmHg (95%CI: -2.010 to -0.696); as the upper limit was<0 mmHg, tafluprost/timolol demonstrated superior IOP-lowering efficacy to tafluprost. Responder rates for IOP reductions of&#x2265;15%,&#x2265;25%, and&#x2265;30% were significantly higher in the tafluprost/timolol group (P=0.016, 0.028, and 0.032, respectively). The incidence of ocular AEs was 20.0% (22/110) in the tafluprost/timolol group and 26.6% (29/109) in the tafluprost group. The most common AE was conjunctival hyperemia, occurring in 2.7% (3/110) and 8.3% (9/109) of the groups, respectively. Conclusion: Compared with preservative-free tafluprost monotherapy, the tafluprost/timolol combination provides significantly greater IOP reduction in patients with OAG and OHT, while maintaining a favorable safety profile.

Humans↗
PubMed2006

Neutralizing IL-7 promotes long-term allograft survival induced by CD40/CD40L costimulatory blockade.

Memory T cells are somewhat resistant to immunosuppresion. They therefore pose a threat to inducing long-term allograft survival. IL-7 is essential for memory T-cell generation. Here, we investigated whether neutralizing IL-7 promotes allograft survival. We found that neutralizing IL-7 alone did not significantly prolong allograft survival. However, blocking both IL-7 and CD154 signaling synergistically prolonged allograft survival. In contrast, neutralizing IL-2 failed to further prolong allograft survival induced by CD40/CD154 costimulatory blockade. Allospecific memory CD8+ T-cell generation was severely impaired under the treatment of anti-IL-7 plus anti-CD154 Ab while administering recombinant IL-7 enhanced CD8+ memory generation even under donor-specific transfusion plus anti-CD154 Ab treatment. Neutralizing IL-7, but not IL-2, together with blocking CD154 synergistically suppressed the proliferation of naïve/effector CD8+ T cells infiltrating grafts. Nevertheless, neutralizing IL-7 did not alter regulatory T-cell generation while neutralizing IL-2 suppressed their generation. Hence, targeting IL-7 represents a new strategy to prolong allograft survival by acting on both naïve and memory T cells. Long-term allograft survival may be achieved by neutralizing IL-7 plus CD40/CD154 blockade, since CD40/CD154 costimulatory blockade prevents acute rejection while neutralizing IL-7 suppresses the generation of memory T cells that persist and mediate late or chronic rejection.

Animals↗
PubMed2005

Hydrogenation of single-walled carbon nanotubes.

Towards the development of a useful mechanism for hydrogen storage, we have studied the hydrogenation of single-walled carbon nanotubes with atomic hydrogen using core-level photoelectron spectroscopy and x-ray absorption spectroscopy. We find that atomic hydrogen creates C-H bonds with the carbon atoms in the nanotube walls, and such C-H bonds can be completely broken by heating to 600 degrees C. We demonstrate approximately 65 +/- 15 at % hydrogenation of carbon atoms in the single-walled carbon nanotubes, which is equivalent to 5.1 +/- 1.2 wt % hydrogen capacity. We also show that the hydrogenation is a reversible process.

Journal Article↗
PubMed2005

No common denominator for breast cancer lymph node metastasis.

The axillary lymph node status is the most powerful prognostic factor for breast cancer patients to date. The molecular mechanisms that control lymph node metastasis, however, remain poorly understood. To define patterns of genes or gene regulatory pathways that drive breast cancer lymph node metastasis, we compared the gene expression profiles of 15 primary breast carcinomas and their matching lymph node metastases using microarrays. In general, primary breast carcinomas and lymph node metastases do not differ at the transcriptional level by a common subset of genes. No classifier or single gene discriminating the group of primary tumours from those of the lymph node metastases could be identified. Also, in a series of 295 breast tumours, no classifier predicting lymph node metastasis could be developed. However, subtle differences in the expression of genes involved in extracellular-matrix organisation and growth factor signalling are detected in individual pairs of matching primary and metastatic tumours. Surprisingly, however, different sets of these genes are either up- or downregulated in lymph node metastases. Our data suggest that breast carcinomas do not use a shared gene set to accomplish lymph node metastasis.

Adult↗
PubMed2004

Measurement of the flux of ultrahigh energy cosmic rays from monocular observations by the High Resolution Fly's Eye experiment.

We have measured the cosmic ray spectrum above 10(17.2) eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode. We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors. We fit the spectrum to a model consisting of galactic and extragalactic sources.

Journal Article↗
PubMed2003

Effects of diltiazem on platelet activation and cytosolic calcium during percutaneous transluminal coronary angioplasty.

AIMS: To evaluate effects of diltiazem on platelet hyper-reactivity in situations associated with endothelial injury and their possible relationship to cytosolic calcium concentration. METHODS: Blood samples were collected at seven time points from 35 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) who received combined diltiazem and aspirin/ticlopidine therapy or aspirin/ticlopidine therapy alone. Platelet expression of glycoprotein IIb/IIIa and P-selectin, production of thromboxane B(2), and cytosolic calcium concentration were measured, respectively, by whole blood flow cytometry, radioimmunoassay, and fluorospectrophotometry. The effects of diltiazem of different concentrations on expression of glycoprotein IIb/IIIa and P-selectin were also studied in vitro in blood samples from patients with chronic stable angina. RESULTS: Of the two treatments, aspirin/ticlopidine therapy did not prevent an acute increase of expression of glycoprotein IIb/IIIa and P-selectin and plasma thromboxane B(2) five minutes and 10 minutes after first inflation and 10 minutes after PTCA, whereas combined diltiazem and aspirin/ticlopidine therapy had a significant inhibitory effect. In the group receiving aspirin/ticlopidine therapy, there was a short term increase of platelet [Ca(2+)](i) immediately after PTCA which was significantly reduced by diltiazem treatment. Expression of glycoprotein IIb/IIIa and P-selectin was significantly inhibited in vitro by diltiazem in the concentration of 200 ng/ml or higher, but not 50 ng/ml. CONCLUSIONS: Combined diltiazem and aspirin/ticlopidine therapy significantly inhibited platelet activation that continued in the presence of conventional aspirin/ticlopidine treatment. Antiplatelet effects of diltiazem were probably a consequence of reduction of platelet [Ca(2+)](i) and may only be achieved in higher than therapeutic concentrations.

Aged↗
PubMed2001

Quantum interference and ballistic transmission in nanotube electron waveguides.

The electron transport properties of well-contacted individual single-walled carbon nanotubes are investigated in the ballistic regime. Phase coherent transport and electron interference manifest as conductance fluctuations as a function of Fermi energy. Resonance with standing waves in finite-length tubes and localized states due to imperfections are observed for various Fermi energies. Two units of quantum conductance 2G(0) = 4e(2)/h are measured for the first time, corresponding to the maximum conductance limit for ballistic transport in two channels of a nanotube.

Electron Transport↗
PubMed2001

[Predictive value of combined application of umbilical artery color Doppler velocimetry, nonstress testing and ultrasonography in monitoring umbilical cord entanglement].

OBJECTIVE: To explore the predictive value of combined application of umbilical artery color Doppler flow monitoring (CDFI), nonstress testing (NST) and ultrasonography in monitoring umbilical cord entanglement. METHODS: 1 860 cases of pregnant women between gestational ages of 37 approximately 42 weeks were studied 1 approximately 2 weeks before delivery by CDFI, nonstress testing (NST) and ultrasonography to monitor umbilical cord entanglement. RESULTS: The prevalence rate of umbilical cord entanglement was 23.23% (432/1 860). Positive predictive value and negative predictive value were 95.4 % (412/432) and 98.6% (1 408/1 428) respectively. The rate of accuracy was 97.8% (1 820/1 860). The rate of fetal distress among the fetuses with umbilical cord round the body or four limbs was 85.29% (23/34) and the incidence of cesarean section in this group was 88.28% (30/34). The rate of fetal distress among the fetuses with umbilical cord round the neck was 13.06% (52/398) and the incidence of cesarean section in this group was 44.94% (178/398). The rates of fetal distress and cesarean section were significantly higher in the group with umbilical cord around the body or four limbs than in the group with umbilical cord around the neck (chi(2) = 107.27 and 23.76 respectively, P < 0.001). The systolic/diastolic (S/D) ratio was basically in normal ranges in the group with the umbilical cord round the neck. In cardiotopography (CTG), umbilical cord entanglement mainly showed variable deceleration (VD), early deceleration (ED), nonreaction on NST, and late deceleration (LD) on oxytocin challenge test (OCT). Prolonged fetal heart rate deceleration (PD) could be seen in the group with umbilical cord around the body or four limbs. CONCLUSION: The combined application of umbilical artery color Doppler velocimetry, nonstress testing and ultrasonography have an important auxiliary value in monitoring umbilical cord entanglement. It remarkably increases the positive predictive rate as a valuable reference for the choice of delivery form.

Adult↗
PubMed2001

Experimental annotation of the human genome using microarray technology.

The most important product of the sequencing of a genome is a complete, accurate catalogue of genes and their products, primarily messenger RNA transcripts and their cognate proteins. Such a catalogue cannot be constructed by computational annotation alone; it requires experimental validation on a genome scale. Using 'exon' and 'tiling' arrays fabricated by ink-jet oligonucleotide synthesis, we devised an experimental approach to validate and refine computational gene predictions and define full-length transcripts on the basis of co-regulated expression of their exons. These methods can provide more accurate gene numbers and allow the detection of mRNA splice variants and identification of the tissue- and disease-specific conditions under which genes are expressed. We apply our technique to chromosome 22q under 69 experimental condition pairs, and to the entire human genome under two experimental conditions. We discuss implications for more comprehensive, consistent and reliable genome annotation, more efficient, full-length complementary DNA cloning strategies and application to complex diseases.

Algorithms↗
PubMed2001

Yersinia enterocolitica O9 as a possible barrier against Y. pestis in natural plague foci in Ningxia, China.

A survey of Yersinia spp, as related to plague control, was made in Haiyuan of Ganning loess plateau plague focus, Yanchi of Inner Mongolia plateau plague focus, and Yinchuan city, as a control area, in Ningxia, China. In Haiyuan, where the main plague reservoir was Mongolian ground squirrel (Citellus alaschanicus) living in the prairie, Y. enterocolitica O9 was frequently isolated from pigs, dogs, rodents living in and around houses, but only rarely from hare and Mongolian ground squirrel. In Yanchi, where the main plague reservoir was Mongolian gerbil (Meriones unguiculatus) living in the prairie and Y. pestis, which was isolated from rodents up to 1991, Y. enterocolitica O9 was sometimes isolated from pigs and rodents. In all areas, some strains of Y. enterocolitica O3 and Y. pseudotuberculosis serotypes 3 and 4b were also isolated from pigs, dogs, and from rodents. We propose that an epidemiological link exists between the prevalence of Y. pestis and Y. enterocolitica O9 in domestic and rodents living in these areas in China. The residential area in Haiyuan may be protected against Y. pestis by the domestic animals and rodents which acquired cross-protection against Y. pestis by infection with Y. enterocolitica O9, but this is not the case in the Yanchi district.

Animals↗
PubMed2001

Expression profiling using microarrays fabricated by an ink-jet oligonucleotide synthesizer.

We describe a flexible system for gene expression profiling using arrays of tens of thousands of oligonucleotides synthesized in situ by an ink-jet printing method employing standard phosphoramidite chemistry. We have characterized the dependence of hybridization specificity and sensitivity on parameters including oligonucleotide length, hybridization stringency, sequence identity, sample abundance, and sample preparation method. We find that 60-mer oligonucleotides reliably detect transcript ratios at one copy per cell in complex biological samples, and that ink-jet arrays are compatible with several different sample amplification and labeling techniques. Furthermore, results using only a single carefully selected oligonucleotide per gene correlate closely with those obtained using complementary DNA (cDNA) arrays. Most of the genes for which measurements differ are members of gene families that can only be distinguished by oligonucleotides. Because different oligonucleotide sequences can be specified for each array, we anticipate that ink-jet oligonucleotide array technology will be useful in a wide variety of DNA microarray applications.

Cells, Cultured↗
PubMed2001

Fibroblast growth factor receptor 3 (FGFR3) - analyses of the S249C mutation and protein expression in primary cervical carcinomas.

Fibroblast growth factor receptor 3 (FGFR3) seems to play an inhibitory role in bone development, as activating mutations in the gene underlie disorders such as achondroplasia and thanatophoric dysplasia. Findings from multiple myeloma (MM) indicate that FGFR3 also can act as an oncogene, and mutation of codon 249 in the fibroblast growth factor receptor 3 (FGFR3) gene was recently detected in 3/12 primary cervical carcinomas. We have analysed 91 cervical carcinomas for this specific S249C mutation using amplification created restriction site methodology (ACRS), and detected no mutations. Immunohistochemistry was performed on 73 of the tumours. Reduced protein staining was seen in 43 (58.8%) samples. Six of the tumours (8.2%) revealed increased protein staining compared with normal cervical tissue. These patients had a better prognosis than those with reduced or normal levels, although not statistically significant. This report weakens the hypothesis of FGFR3 as an oncogene of importance in cervical carcinomas.

Adult↗
PubMed2001

Longitudinal changes in pulmonary function and respiratory symptoms in cotton textile workers. A 15-yr follow-up study.

To evaluate the chronic effects of exposure to cotton dust, a 15-yr follow-up study in cotton textile workers was performed in Shanghai, China from 1981 to 1996. Testing occurred four times during the 15-yr period. The achieved follow-up rates were 76-88% of the original 447 cotton textile workers, and 70-85% of the original 472 silk textile workers (as a control group). Identical questionnaires, equipment, and methods were used throughout the study. The prevalence of byssinosis increased over time in cotton workers, with 15.3% at the last survey versus 7.6% at the baseline, whereas no byssinosis was found in silk workers. More workers in the cotton group consistently reported symptoms than in the silk group, although symptom reporting varied considerably from survey to survey. Cotton workers had small, but significantly greater, adjusted annual declines in FEV(1) and FVC than did the silk workers. Years worked in cotton mills, high level of exposure to endotoxin, and across-shift drops in FEV(1) were found to be significant determinants for longitudinal change in FEV(1), after controlling for appropriate confounders. Furthermore, there were statistically significant associations between excessive loss of FEV(1) and byssinosis, chest tightness at work, and chronic bronchitis in cotton workers. Workers who consistently (three or four of the surveys) reported byssinosis or chest tightness at work had a significantly greater 15-yr loss of FEV(1). We conclude that long-term exposure to cotton dust is associated with chronic or permanent obstructive impairments. Consistent reporting of respiratory symptoms, including byssinosis and chest tightness at work, is of value to predict the magnitude and severity of chronic impairments in textile workers.

Adult↗
PubMed2001

[Changes in respiratory and circulatory function during sequential invasive-noninvasive mechanical ventilation].

OBJECTIVE: To investigate the change of respiratory and circulatory function in COPD during sequential invasive-noninvasive mechanical ventilation. METHODS: 12 COPD patients with type II respiratory failure were ventilated via endotracheal intubation. When pulmonary infection was under control (the appearance of "PIC Window"), all patients were extubated and received mask ventilation. The parameters of hemodynamics oxygenation and esophageal pressure were measured during endotracheal ventilation and mask ventilation (3 hrs after extubation). RESULTS: The change of respiratory and circulatory parameters were not significantly different between invasive mechanical ventilation and noninvasive mechanical ventilation (P > 0.05). CONCLUSION: The respiratory and circulatory function of COPD patients remained stable during sequential invasive-noninvasive mechanical ventilation.

Adult↗
PubMed2001

[Study on the immunologic function of lymphocyte in cord blood].

OBJECTIVE: To explore immunologic function of T lymphocytes in human cord blood (HUCB) and provide theoretical basis for clinical application of HUCB. METHODS: Immunophenotype and co-stimulated molecules were detected by flow-cytometry using a panel of double labelled McAb, intracellular cytokines (interferon-gamma, interleukin-4) secreted by T lymphocytes by micro-culture of whole blood, and CD25 expression of T lymphocyte by PHA stimulation. T lymphocytes from adult peripheral blood (PB) were used as control. RESULTS: There are a higher CD4+/CD8+ ratio of T subset and a lower percentage of CD8+ lymphocytes in HUCB than that in adult PB (P < 0.01), and more than 90% of HUCB T-cells co-expressed CD45RA naive antigen which was significant higher than the percentage in adult PB (P < 0.01). The percentages of IFN-gamma and IL-4-producing CD4+ and CD8+ T cells from HUCB were lower than that of the control group. T cells in HUCB were able to be activated by PHA, but the phases of activation differed from adult PB T cells. CONCLUSIONS: It suggested that the low ability to secret cytokines and high percentage of naive T cells might be responsible for the decreased incidence of acute and chronic GVHD and provided possible explanation for the clinical result in HUCB transplantation. T cells in HUCB is a potential resource of adoptive immunotherapy.

Cytokines↗