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Hua Ren

Publications and source records attributed to Hua Ren.

13 recordsLinked to original sources
PubMed2006

High-throughput analysis of chromosome abnormality in spontaneous miscarriage using an MLPA subtelomere assay with an ancillary FISH test for polyploidy.

Chromosome analysis of spontaneous miscarriages is clinically important but is hampered by frequent tissue culture failure and relatively low-resolution analysis. We have investigated replacement of conventional karyotype analysis with a quantitative subtelomere assay performed on uncultured tissue samples, which is based on Multiplex Ligation-Dependent Probe Amplification. This assay is suitable for this purpose as approximately 98% of all observed karyotype abnormalities in spontaneous miscarriages involve copy-number change to one or more subtelomere regions. A pilot study has compared karyotyping and subtelomere analysis on 78 samples. Extensive tissue necrosis accounted for failure of both karyotyping and subtelomere testing in four (5.1%) samples. Excluding these, there were no (0/74) subtelomere test failures compared to 9.5% (7/74) karyotype failures. Twenty-two (30%) whole chromosome aneuploidies and five (6.8%) structural abnormalities were detected using the subtelomere assay. With the exception of three cases of triploidy, all karyotype abnormalities were detected by the subtelomere assay. Following on from this study, a further 100 samples were tested using the subtelomere assay in conjunction with a simple ancillary FISH test using uncultured cells to exclude polyploidy in the event of a normal subtelomere assay result. Except for three necrotic samples, tests results were obtained for all cases revealing 18 abnormalities including one case of triploidy. Taking into consideration the high success rate for the combined MLPA and FISH test results, and the very significant additional advantages of cost-effective, high-throughput batching, and automated, objective analysis, this approach greatly facilitates routine investigation of chromosome abnormalities in spontaneous miscarriage.

Abortion, Spontaneous↗
PubMed2006

Assessment of novel inhibitors of Helicoverpa aminopeptidases as anti-insect agents.

Helicoverpa species present problems worldwide as pests on a variety of agricultural crops. In Australia, the costs of controlling H. armigera (Hübn.) and H. punctigera (Wall.) are a major burden on the cotton industry, and novel mechanisms are continually sought to combat these pests. Potential new targets for insecticides are the digestive proteases of the insect, including the aminopeptidases (APs). A variety of compounds, designed to be similar in structure to known AP inhibitors, were synthesized and screened for activity in inhibiting H. armigera larval growth and AP activity. The most effective compounds in both assays proved to be hydroxamic acids and methylphosphonic acids. Compounds that incorporated both of these groups were also found to have significant potential as control agents. The most inhibitory compounds included valine methylphosphonic acid and a leucine methylphosphonic acid/hydroxamic acid derivative. The valine methylphosphonic acid compound was tested further in vitro, with the aim of producing a new active capable of restricting the viability of Helicoverpa populations on commercial crops.

Aminopeptidases↗
PubMed2006

[Perioperative management for primary tracheal malignant tumors resected under cardiopulmonary bypass].

OBJECTIVE: To retrospectively review the perioperative management for primary tracheal malignant tumors resected under cardiopulmonary bypass. METHODS: The data of 6 patients with primary tracheal malignant tumors who underwent surgery under cardiopulmonary bypass from December 1999 to August 2003 were reviewed. Cardiopulmonary bypass was established through right femoral vessels in 2 patients for emergency operation, through right atrium and ascending aorta in 4 patients. Sleeve tracheal resections in 3 patients, carinal resections and carina reconstructions in 2, and local enucleation in 1 were performed. Respiratory airway was kept patent by coughing and expectorating sputum. RESULTS: All patients' dyspnea were relieved remarkably. The postoperative mechanic ventilation assistance lasted from 10 hours to 7 days. There was no perioperative mortality. CONCLUSION: Resection of primary tracheal malignant tumors with severe tracheal obstruction under cardiopulmonary bypass is practicable. Keeping respiratory airway patent perioperatively is very important and helpful to postoperative recovery.

Adult↗
PubMed2005

High-resolution identification of chromosomal abnormalities using oligonucleotide arrays containing 116,204 SNPs.

Mutation of the human genome ranges from single base-pair changes to whole-chromosome aneuploidy. Karyotyping, fluorescence in situ hybridization, and comparative genome hybridization are currently used to detect chromosome abnormalities of clinical significance. These methods, although powerful, suffer from limitations in speed, ease of use, and resolution, and they do not detect copy-neutral chromosomal aberrations--for example, uniparental disomy (UPD). We have developed a high-throughput approach for assessment of DNA copy-number changes, through use of high-density synthetic oligonucleotide arrays containing 116,204 single-nucleotide polymorphisms, spaced at an average distance of 23.6 kb across the genome. Using this approach, we analyzed samples that failed conventional karyotypic analysis, and we detected amplifications and deletions across a wide range of sizes (1.3-145.9 Mb), identified chromosomes containing anonymous chromatin, and used genotype data to determine the molecular origin of two cases of UPD. Furthermore, our data provided independent confirmation for a case that had been misinterpreted by karyotype analysis. The high resolution of our approach provides more-precise breakpoint mapping, which allows subtle phenotypic heterogeneity to be distinguished at a molecular level. The accurate genotype information provided on these arrays enables the identification of copy-neutral loss-of-heterozygosity events, and the minimal requirement of DNA (250 ng per array) allows rapid analysis of samples without the need for cell culture. This technology overcomes many limitations currently encountered in routine clinical diagnostic laboratories tasked with accurate and rapid diagnosis of chromosomal abnormalities.

Chromosome Aberrations↗
PubMed2005

[Surgical treatment of chronic pulmonary thromboembolism].

OBJECTIVE: To evaluate the perioperative management and safety of pulmonary thromboendarterectomy for chronic pulmonary thromboembolism. METHODS: From March 1999 to March 2004, 12 patients with chronic pulmonary thromboembolism received thromboendarterectomy. The operation was performed under cardio-pulmonary bypass with low flow or circulative arrest and deep hypothermia. The clinical data of the 12 cases were reviewed retrospectively. RESULTS: Pulmonary pressure immediately decreased 20 to 40 mm Hg (1 mm Hg = 0.133 kPa) after operation in 6 cases. Various degrees of postoperative pulmonary edema happened in 8 cases. One patient died at the 19th day after operation due to severe lung infection and pulmonary re-embolism. Eleven patients were followed-up for 2 months to 5 years, the clinical symptom and routine daily activity were improved after surgery. CONCLUSION: Pulmonary thromboendarterectomy is an effective treatment for chronic pulmonary thromboembolism. It is very important to management of postoperative reperfusion injury and pulmonary edema. A key point to enhance the safety of surgical treatment for chronic pulmonary thromboembolism is preoperative correct evaluation and indication selection.

Adult↗
PubMed2005

BAC-based PCR fragment microarray: high-resolution detection of chromosomal deletion and duplication breakpoints.

The introduction of molecular techniques in conjunction with classical cytogenetic methods has in recent years greatly improved the diagnostic potential for chromosomal abnormalities. In particular, microarray-comparative genomic hybridization (CGH) based on the use of BAC clones promises a sensitive strategy for the detection of DNA copy-number changes on a genomewide scale, offering a resolution as high as >30,000 "bands" (as defined by the number of BACs within the currently highest-density BAC array) [Ishkanian et al., 2004]. We have tested the possibility of further increasing this resolution using PCR fragments generated from individual BAC clones. Using this approach, we have efficiently defined the proximal and distal breakpoints in two cytogenetic cases, one duplication and one deletion, to within 5-20 kb. The results support the potential use of BAC-based PCR fragments to further improve the resolution of the microarray-CGH strategy by an order of magnitude.

Chromosome Aberrations↗
PubMed2005

Detection of cryptic subtelomeric chromosome abnormalities and identification of anonymous chromatin using a quantitative multiplex ligation-dependent probe amplification (MLPA) assay.

The need to detect clinically significant segmental aneuploidies beyond the range of light microscopy demands the development of new cost-efficient, sensitive, and robust analytical techniques. Multiplex ligation-dependent probe amplification (MLPA) has already been shown to be particularly effective and flexible for measuring copy numbers in a multiplex format. Previous attempts to develop a reliable MLPA to assay all chromosome subtelomeric regions have been confounded by unforeseen copy number variation in some genes that are very close to the telomeres in healthy individuals. We addressed this shortcoming by substituting all known polymorphic probes and using two complementary multiplex assays to minimize the likelihood of false results. We developed this new quantitative MLPA strategy for two important diagnostic applications. First, in a group of cases with high clinical suspicion of a chromosome abnormality but normal, high-resolution karyotypes, MLPA detected subtelomeric abnormalities in three patients. Two were de novo terminal deletions (del(4p) and del(1p)), and one was a derivative chromosome 1 from a maternal t(1p;17p). The range of these segmental aneuploidies was 1.8-6.6 Mb, and none were visible on retrospective microscopy. Second, in a group of six patients with apparently de novo single-chromosome abnormalities containing anonymous chromatin, MLPA identified two cases with simple intrachromosomal duplications: dup(6p) and dup(8q). Three cases showed derivative chromosomes from translocations involving the distal regions of 9q and 4q, 5p and 11q, and 6q and 3p. One case showed a nonreciprocal, interchromosomal translocation of the distal region of 10p-7p. All abnormalities in both groups were confirmed by fluorescence in situ hybridization (FISH) using bacterial artificial chromosomes (BACs). This quantitative MLPA technique for subtelomeric assays is compared with previously described alternative techniques.

Adolescent↗
PubMed2005

Thromboendarterectomy for chronic pulmonary thromboembolism.

OBJECTIVE: To evaluate the improving reliability and safety of thromboendarterectomy and perioperative management for chronic pulmonary thromboembolism. METHODS: The clinical data of 12 cases with chronic pulmonary thromboembolism, who underwent thromboendarterectomy assisted by low flow or circulation arrest with deep hypothermia, were reviewed retrospectively. RESULTS: Pulmonary artery pressure decreased 20 to 40 mmHg immediately after surgical procedures in 9 cases. The postoperative pulmonary edema at various degrees happened in 12 cases, among them, 1 died of severe lung infection and pulmonary re-embolism at 19 days postoperation. Computed tomography pulmonary angiography and angiography of 11 cases indicated that the original obstruction of pulmonary artery disappeared. During the follow-up period of 2 months to 5 years, the clinical symptoms and activity was improved. CONCLUSION: Thromboendarterectomy is an effective treatment for chronic pulmonary thromboembolism. The outcome of the surgical procedure needs to be further investigated and followed up regularly according to an evaluative system, because it might be influenced by multiple factors.

Adult↗
PubMed2004

Improved testing for CMT1A and HNPP using multiplex ligation-dependent probe amplification (MLPA) with rapid DNA preparations: comparison with the interphase FISH method.

Charcot-Marie-Tooth disease type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsies (HNPP) are the two most common peripheral neuropathies, with incidences of about 1 in 2,500. Several techniques can be used to detect the typical 1.5-Mb duplication or deletion associated with these respective conditions, but none combines simplicity with high sensitivity. MLPA is a new technique for measuring sequence dosage. We have assessed its performance for the detection of the specific 1.5-Mb duplication/deletion by prospectively testing 50 patients referred with differential diagnoses of CMT or HNPP. Probes were designed to evaluate the TEKT3, PMP22, and COX10 genes within the CMT1A/HNPP region. We have compared the results with our existing fluorescence in situ hybridization (FISH) assay, which was performed in parallel. There was concordance of results for 49 patients. Of note, one patient showed an intermediate multiplex ligation-dependent probe amplification (MLPA) result with an abnormal FISH result, which is consistent with mosaicism. The assay works equally well with either purified DNA or rapid DNA preparations made by direct cell lysis. The use of the latter significantly reduces the cost of the assay. MLPA is a sensitive, specific, robust, and cost-effective technique suitable for fast, high-throughput testing and offers distinct advantages over other testing methods.

Charcot-Marie-Tooth Disease↗
PubMed2004

Non-invasive imaging of coronary artery with 16-slice spiral computed tomography.

OBJECTIVE: To evaluate the value of 16-slice spiral CT in the demonstration of coronary artery and in the diagnose of coronary artery stenosis. METHODS: Plain and enhanced CT scans were performed with a 16-slice CT scanner (Sensation 16, Siemens, Germany) in 230 patients with suspected coronary heart disease (CHD). Parameters of the plain scan were: 120 kV, 133 mA, slice collimation 16 mm x 1.5 mm, rotation time 0.42 seconds, increment 1.5 mm, and slice width 3 mm. Parameters of the enhanced scan were: 120 kV, 500 mA, slice collimation 16 mm x 0.75 mm, rotation time 0.42 seconds, increment 0.5 mm, and slice width 1 mm. Enhanced CT scan was performed with a rapid intravenous injection of 100 mL iothalamate meglumine (Ultravist) (370 mgI/mL) or Omnipaque (350 mgI/mL) and 30 mL 0.9% NaCl chaser bolus at a flow rate of 3.5 mL/s. Calcium scoring with plain scan images and two and three dimensional reconstruction with enhanced scan images were made in all cases, among which 30 cases underwent conventional coronary angiography. Demonstration of coronary arteries and their stenosis were evaluated and the factors that might influence the image quality were analyzed. RESULTS: Coronary calcium scores were calculated and coronary artery was demonstrated in our study. In the evaluation of image quality with volume rendering technique (VRT) images, 78.3% of the images were of the first class, 12.2% the second class, and 9.6% the third class. Multi-planar reconstruction (MPR) and maximal intensity projection (MIP) were better than VRT in the demonstration of small branches. The image quality was related to the heart rate, with or without arrhythmia, and breath-hold ability of patients. Comparative study of the stenosis of coronary arteries in 30 cases showed that the sensitivity and specificity of 16-slice coronary CT angiography (CTA) to diagnose significant stenosis were 95.8% and 94.8% respectively. CONCLUSION: As a non-invasive and quick method, 16-slice coronary CTA is sensitive and specific to diagnose the stenosis of coronary arteries and can be used as a screening method in the diagnosis of CHD.

Coronary Angiography↗
PubMed2003

[Coronary angiography with sixteen-slice spiral CT: an initial study].

OBJECTIVE: To evaluate the scanning technique and primary clinical value of sixteen-slice spiral CT coronary angiography. METHODS: Plain and enhanced sixteen-slice spiral CT imaging was performed in 69 patients, including 64 cases of suspected coronary heart disease and 5 cases of coronary stent. Calcium scoring with plain scan images and MPR, MIP and VRT reconstruction with enhanced scan images were made in all cases, among which 10 underwent conventional coronary angiography. The demonstration and stenosis of coronary arteries were evaluated. The factors influencing the image quality were analyzed. Additional MPR and MIP reconstruction of slices perpendicular to the stent and virtual endoscopy of stent were made in 7 stents of the 5 cases of coronary stent. The patency of the stents was evaluated. RESULTS: A four-step scanning procedure was devised. Coronary calcium score could be got by plain scanning with sixteen-slice spiral CT angiography. All of the primary, most of the secondary and tertiary, and part of the fourth level branches of coronary artery could be shown isotropically with MPR, MIP and VRT reconstruction images of enhanced scanning. MPR and MIP were better than VRT in demonstrating small branches. Evaluated by VRT image, the image quality of 79.7% of the patients were first class, 10.1% second class, and 10.1% third class. The image quality was correlated to the contrast concentration in the root of aorta, heart rate, existence or absence of arrythmia, and the patient's breath-holding ability. Stenosis of coronary arteries was evaluated by sixteen-slice spiral CT imaging in 10 cases, with a result comparable to that by conventional coronary angiography. The stents were well shown, six stents being evaluated as patent, while one not. CONCLUSION: Sixteen-slice spiral CT coronary angiography is a noninvasive, simple and good method. Coronary calcium score and coronary artery stenosis can be evaluated with one study. The patency of stents can also be evaluated.

Adult↗