Human gene mutations. Gene symbol: HRPT2. Disease: Hyperparathyroidism Jaw-tumor syndrome.
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Biomedical subjects
Publications and source records attributed to J Chen.
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PURPOSE OF INVESTIGATION: To evaluate women with cytological high-grade squamous intraepithelial lesions (HGSIL) who received standard colposcopic evaluation and direct diagnostic large loop electric excision for the transformation zone (LLETZ) to determine the feasibility of using LLETZ alone (ie, skipping the colposcopic examination). METHODS: From May 1999 to May 2001, 70 women, with the mean age of 49.58 years (range, 20-82 years) and with cervical HGSIL categorized by the Bethesda system were all evaluated by colposcopic evaluation and LLETZ. Cases with a satisfactory colposcopy examination were classified as group A and those with an unsatisfactory colposcopy examination were classified as group B. "Over-treatment" was determined if the women did not need further LLETZ for evaluation or management. "Under-treatment" was determined if treatment might be potentially inadequate or invasive cancer could be ruled out during a satisfactory colposcopic evaluation. RESULTS: Group A consisted of ten women who were evaluated satisfactorily by colposcopy and group B consisted of 30 women who were not evaluated satisfactorily by colposcopy. Overall 8.6% of the patients (6/70) were considered "over-treated". The rate of over-treatment was 10.0% (4/40) in group A compared with 6.7% (2/30) in group B. In contrast, overall 10% of the patients (7/70) were considered "under-treated". The rate of under-treatment was 10% (1/40) in group A compared with 10% (3/30), in group B. The positive predictive values of group A and B were 90.6% and 88.0%, respectively. The negative predictive values were 33.2% and 40%, respectively. CONCLUSION: Direct diagnostic and therapeutic LLETZ for the management of cervical HGSIL may be a better alternative to colposcopy. This method of treatment avoids the possibility of under-treatment and is associated with an acceptable over-treatment rate, especially for postmenopausal women with cytological HGSIL. LLETZ has a good diagnostic accuracy with minimal morbidity and, most importantly, may help reduce patient anxicty, although further studies are needed to directly examine this effect.
OBJECTIVE: To examine the profile and referral pattern of patients attending an out-patient pain management service in Hong Kong. DESIGN: Prospective cross-sectional survey. SETTING: Regional public hospitals, Hong Kong. PATIENTS: All patients attending out-patient pain management clinics in the New Territories East public hospitals between 1 September and 31 December 2002. MAIN OUTCOME MEASURES: Demographic profiles, referring specialty, pain diagnosis, pain sites, duration and severity of pain, treatment modality, litigation, compensation, and social welfare status. Data were collected using a standardised questionnaire. RESULTS: Two hundred and forty-eight patients were interviewed. Most patients (70%) were middle-aged, with 21% over 60 years. Seventy-nine percent of patients were referred to the clinics either from orthopaedic surgeons (64.1%), general and other surgeons (14.9%), or general practitioners (3.6%). The median (range) duration of pain was 2.3 (0.08-26.7) years. The most common pain diagnoses were musculoskeletal back pain (46.4%) and neuropathic pain (27.8%). A total of 11.3% of the patients had two pain diagnoses, while 40.7% complained of pain in more than one location. Pain in the limbs was the most frequent complaint followed by the head, neck, and back. Approximately 38% of patients had tried four or more treatment modalities. Oral medication was the most common method (86.7%) of pain-relief treatment. More than half of the patients had also tried physiotherapy and traditional Chinese medicine. Approximately 37% of the patients were unemployed, while 31% were receiving social security subsidy. Eighty-six patients had pain associated with a work-related injury, and of these patients, 80% were involved in compensation claims. CONCLUSIONS: The profile of patients referred to the pain management clinics was complex. Patients were mainly referred from specialists. The economic implication in this group of patients is likely to be significant as many patients utilised multiple treatment modalities, were unemployed and on social welfare benefits, and were involved in compensation and litigation proceedings.
A liquid chromatographic-mass spectrometric (LC-MS) assay was developed and validated for the determination of loratadine in human plasma using reversed-phase HPLC combined with electrospray ionization (ESI) mass spectrometry. The analysis involved a simple liquid-liquid extraction. The organic extract was then evaporated and the residue was reconstituted in mobile phase. The reconstituted solution was injected into an HPLC system and was subjected to reverse-phase HPLC on a 5-microm ODS-3 column at a flow-rate of 0.2 ml/min. The mobile phase comprised of acetonitrile-ammonium acetate (pH 4.0; 0.02 M, using formic acid to adjust) using gradient elution. Loratadine was detected in the single ion monitoring (SIM) mode. Standard curves were linear over the concentration range of 0.2-100 ng/ml. The mean predicted concentrations of the quality control (QC) samples deviated by less than 10% from the corresponding nominal values; the intra-assay and inter-assay precision of the assay were within 12% relative standard deviation. The extraction recovery of loratadine was more than 80%. The validated assay was applied to a pharmacokinetic study of loratadine in human plasma following the administration of a single loratadine tablet (40 mg).
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Previous studies have shown that L-arginine (L-Arg) administration to apoE-/-/iNOS-/- double knockout mice (dKO) on a Western diet paradoxically results in an increase in atherosclerotic lesion size. We hypothesized that the potential beneficial effects of L-Arg could be offset, in part, by the byproducts of L-Arg catabolism, especially the atherogenic risk factor, homocysteine. In the kidney, L-Arg is converted to L-ornithine and guanidinoacetate (GAA) by L-arginine-glycine amidinotransferase. The efficient transmethylation of GAA by an S-adenosyl-methionine (SAM)-dependent methyltransferase in liver yields creatine and S-adenosylhomocysteine (SAH), which is readily hydrolyzed to homocysteine and adenosine. We, therefore, measured total plasma homocysteine in the dKO mice and control mice. We found that L-Arg supplementation caused a 37% increase in total plasma homocysteine (tHcy) levels in dKO mice compared to controls not treated with L-Arg (5.2+/-2.2 vs 3.8+/-1.5 microM Hcy, p<0.04). In a liver cell line, HepG2, addition of 10 and 50 microM GAA in the presence of 50 microM L-methionine (L-Met) increased tHcy production by approximately 1.47 (p<0.0001) and 2.3-fold (p<0.0001), respectively. In the presence of additional 100 microM L-Met, baseline homocysteine production was elevated by 20% (p<0.005), and 10 and 50 microM GAA augmented homocysteine production by an additional 1.88- (p<0.0001) and 3.4-fold (p<0.001), respectively, compared with 50 microM L-Met. These data suggest that increased concentrations of a methyl acceptor, such as L-Arg-derived GAA, drives SAM-dependent-methylation and consequent homocysteine formation. Furthermore, L-Met levels can also influence homocysteine production likely by regulating the synthesis of the methyl donor SAM. Epidemiological studies have suggested that homocysteine is a graded risk factor. In animal models, modestelevations of homocysteine can cause endothelial dysfunction and augment atherosclerosis. Our data suggest that L-arginine supplementation may contribute to vascular injury and atherogenesis under some circumstances by elevating homocysteine levels.
Degenerate primers for RT-PCR were designed and used to amplify genome fragments ( c. 750 nt in the coat protein-ORF6 region) of allexiviruses from a total of 28 garlic samples from 24 provinces in China. Many samples contained more than one distinct sequence. A total of 60 different sequences were obtained. Phylogenetic analysis and two-way comparisons were used to assess the status of the sequences and to re-examine the criteria for distinguishing species within the genus. Most of the sequences could be allocated to either Garlic virus D or Garlic virus X on the basis of sequence similarity but some appeared to be intermediate between existing species. There were no sequences of Garlic virus C or Shallot virus X. A comparison with the related genera Carlavirus, Foveavirus and Potexvirus suggests that the published allexivirus species demarcation criteria may have been drawn too tightly and should be re-examined.
BACKGROUND: Carbonic anhydrase IX has been linked to cancer development and progression. AIM: To analyse carbonic anhydrase IX expression and anhydrase inhibition in pancreatic cancer and to correlate these findings with p53 expression and microvessel density. MATERIALS AND METHODS: Seventy-seven pancreatic cancers were examined (43 males, 34 females; mean age, 64 years). The anti-carbonic anhydrase IX M75 antibody was used for immunohistochemistry and Western blot analysis. Microvessels were visualized using the anti-CD34 antibody, and p53 expression in cancer cells was assessed with a specific anti-p53 antibody. Quantitative polymerase chain reaction was performed in order to assess carbonic anhydrase IX mRNA levels in the pancreas. Furthermore, pancreatic cancer cell lines were treated with acetazolamide, a carbonic anhydrase inhibitor. RESULTS: In the normal pancreas, carbonic anhydrase IX immunoreactivity was observed at the basolateral membrane of ductal cells in 24 cases (31%). Carbonic anhydrase IX expression was found at the membrane and in the cytoplasm of pancreatic cancer cells in 16 pancreatic cancers (21%). Carbonic anhydrase IX expression was independent of the localization, stage, size, metastases and differentiation of the tumour. p53 expression was significantly more frequent in poorly differentiated cancers (P=0.0323); however, p53 expression and microvessel density were independent of carbonic anhydrase IX expression. Overall, carbonic anhydrase IX expression was not altered in pancreatic cancers vs. adjacent normal pancreatic tissue as assessed by Western blot and quantitative polymerase chain reaction analysis. However, incubation of pancreatic cancer cell lines with acetazolamide led to a significant inhibition of cell proliferation in AsPC-1 and PANC-1 pancreatic cancer cells. CONCLUSION: Carbonic anhydrase IX expression is observed in both ductal epithelial and cancer cells of the pancreas. Although the expression of carbonic anhydrase IX in pancreatic cancer is not associated with angiogenesis or advanced disease, it may well be a target for carbo-anhydrase inhibitors in a subset of pancreatic cancers.
Degenerate primers were used to amplify virus sequences from imported lilies in Zhejiang province, China. Two viruses, Lily mottle virus (LMoV, genus Potyvirus) and Lily symptomless virus (LSV, genus Carlavirus) were detected, purified and completely sequenced from a mixed infection in a plant raised from bulbs imported from the Netherlands. The sequence of LMoV was 9644 nt long and encoded a polyprotein of 3095 amino acids with a calculated M(r) of 351.0 kDa that had only 45.1-54.4% identity to other completely sequenced potyviruses. Phylogenetic analysis of the complete polyproteins of members of the genus demonstrated that LMoV was distantly grouped with LYSV, BYMV and ClYVV. Two partial LMoV sequences from different cultivars were identical to one another and very similar (98.3% identical nucleotides) to the corresponding region of the complete sequence. Analysis of the coat protein sequences of LMoV isolates revealed two subgroups, corresponding to the earlier "Tulip breaking virus lily strain" and "Tulip band breaking virus" isolates. Our newly-determined isolates showed an extremely close relationship to the first of these. The LSV sequence was 8393 nucleotides long and had the typical carlavirus genome organization. The ORF1 protein was most closely related to that of Blueberry scorch virus (57.2% identical amino acids). Sequences of 1796 nt at the 3'-end of three additional LSV isolates from different cultivars were very similar (>98% identical nucleotides) to the corresponding region of the complete sequence. This is the first report of complete sequences for LMoV and LSV.
A potyvirus isolated from Pinellia ternata in China was characterised and shown to be related to Soybean mosaic virus (SMV). The virus was pathogenic on P. ternata and some soybean cultivars, whereas the local soybean SMV isolate HH5 did not infect P. ternata. Western blot experiments demonstrated a serological relationship between the virus from Pinellia, SMV and Watermelon mosaic virus (WMV). The complete nucleotide sequences of the Pinellia virus (isolate P-1, 9735 nt) and of the Chinese soybean SMV isolates HH5 (9585 nt) and HZ (9588 nt) were determined. A 1733 nt sequence at the 3'-terminus of a second isolate from Pinellia (isolate P-2) was also determined. The predicted polyprotein of isolate P-1 has 83% amino acid (aa) identity with those of published SMV sequences. In many parts of the genome, aa identity was about 90% but it was much lower in the P1 protein region (24-29%), where it more closely resembled Dasheen mosaic virus (62%). The partial sequence of isolate P-2 had 91% nt identity to P-1 and both isolates resembled a recent sequence in the public databases (AF469171) wrongly named Zantedeschia mosaic virus. The two complete SMV soybean sequences had 93-95% nt identity with those of the previously sequenced isolates and >97% amino acid identity. Phylogenetic analysis and comparisons of coat proteins suggest that the Pinellia, WMV and SMV potyviruses should probably be treated as strains of the same species.
AIMS/HYPOTHESIS: To estimate the prevalence of diagnosed and undiagnosed diabetes and impaired fasting glucose in the general adult population of China. METHODS: The International Collaborative Study of Cardiovascular Disease in ASIA, conducted from 2000 to 2001, included a nationally representative sample of 15 540 adults, aged 35 to 74 years. An overnight fasting blood specimen was collected to measure serum glucose and information on history of diabetes and use of hypoglycaemic medications was obtained by a standard questionnaire. Undiagnosed diabetes (fasting glucose > or =7.0 mmol/l) and impaired fasting glucose (6.1-6.9 mmol/l) were defined using the American Diabetes Association criteria. RESULTS: Prevalence of self-reported diagnosed diabetes, undiagnosed diabetes, and impaired fasting glucose in Chinese adults were 1.3%, 4.2%, and 7.3%, respectively. Overall, 5.2% or 12.7 million men and 5.8% or 13.3 million women in China aged 35 to 74 years had diabetes (self-reported diagnosis plus undiagnosed diabetes). The age-standardized prevalence of diabetes was higher in residents of northern compared to southern China (7.4% vs 5.4%, p<0.001) and in those living in urban compared to rural areas (7.8% vs 5.1%, p<0.001). CONCLUSIONS/INTERPRETATION: Our results show that the prevalence of diabetes in the adult population in China is much higher than previously reported. Three out of every four diabetes patients are undiagnosed, indicative of a lack of population-based screening programmmes and a relatively rapid and recent increase in incidence of diabetes. These results indicate that diabetes has become a major public health problem in China and underscore the need for national strategies aimed at prevention and treatment of diabetes.
We observe a narrow enhancement near 2m(p) in the invariant mass spectrum of pp pairs from radiative J/psi-->gammapp decays. No similar structure is seen in J/psi-->pi(0)pp decays. The results are based on an analysis of a 58 x 10(6) event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit-Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m(p) at M=1859(+3)(-10) (stat)+5-25(syst) MeV/c(2) and the total width is Gamma<30 MeV/c(2) at the 90% confidence level. These mass and width values are not consistent with the properties of any known particle.
Helical tomotherapy (HT) is a novel treatment approach where the ring gantry irradiation geometry of a helical CT scanner is combined with an intensity-modulated megavoltage x-ray fan beam. An inverse treatment planning system (TomoTherapy Inc., Madison) was used to optimize the treatment plans for ten randomly selected prostate patients. Five different sets of margins (2, 5, 7.5 and 10 mm uniform 3D margins and a non-uniform margin of 5 to 10 mm) were employed for the prostate (GTV2) and seminal vesicles (GTV1). The dose distribution was evaluated in targets, rectum, bladder and femoral heads. HT plans are characterized by a rapid dose fall off around the target in all directions resulting in low doses (less than 30% of the dose at ICRU reference point) to the femurs in all cases. Up to a margin of 5 mm for target structures, it was always possible to satisfy the requirements for dose delivery set by RTOG protocol P-0126. Using a 'class solution', HT plans require minimal operator interaction and result in excellent sparing of normal structures in prostate radiotherapy.