Analysis of PTEN Gene Mutations in Korean Patients With Cowden Syndrome and Polyposis Syndrome

PURPOSE PTEN (phosphatase and tensin homologue deleted in chromosome 10) is a candidate tumor suppressor gene. Mutations of this gene are responsible for PTEN hamartoma tumor syndromes, including Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, Proteus syndrome, and Proteus -like syndromes. Recently, PTEN mutations were identified in several human neoplasms. We analyzed the DNA of various organs and lesions in Korean patients with Cowden syndrome, their family members, and patients with familial adenomatous polyposis for germline or somatic PTEN mutations.METHODS The 11 patients included in this study were 5 patients with Cowden syndrome, 4 of their family members, and 2 patients with familial adenomatous polyposis. Deletions and mutations in exons 1 to 9 of the PTEN gene were evaluated by polymerase chain reaction-single strand conformation polymorphism and sequencing analysis in esophageal acanthosis, gastric polyps, colonic polyps, skin lesions, and peripheral blood mononuclear cells. To exclude common polymorphisms, 240 controls were tested.RESULTS All patients with Cowden syndrome showed several to numerous polyps in the gastrointestinal tract. A missense mutation at codon 217 (GTC to GAC, Val to Asp) in exon 7 was identified in one Cowden syndrome patient, and a nonsense mutation at codon 211 (TGC to TGA, Cys to stop) in exon 6 was identified in a second patient. Identical mutations were found in all tissue samples, including colonic polyps, from each patient. No PTEN mutations were found in their family members or in any patient with familial adenomatous polyposis. None of tested controls contained a mutation.CONCLUSIONS We have identified two new germline PTEN mutations in Korean patients with Cowden syndrome. Mutations in the introns and regulatory regions of the PTEN gene may be present in additional patients with Cowden syndrome and polyposis syndrome.Supported by a grant (Grant number 2003-261) from the Asan Institute for Life Sciences, Seoul, Korea.Reprints are not available.Presented at the meeting of International Gastrointestinal Bioregulation Conference, Hyogo, Japan, March 27, 2004.     

Pseudomonas aeruginosa possesses homologues of mammalian phenylalanine hydroxylase and 4 alpha-carbinolamine dehydratase/DCoH as part of a three-component gene cluster.

Pseudomonas aeruginosa possesses a multigeneoperon that includes phenylalanine hydroxylase (PhhA; phenylalanine4-monooxygenase, EC 1.14.16.1). phhA encodes PhhA (M(r) = 30,288), phhB (M(r) =13,333) encodes a homologue of mammalian 4 alpha-carbinolaminedehydratase/homeodomain protein transregulator, and phhC encodes an aromaticaminotransferase (M(r) = 43,237). The reading frames specifying phhB and phhCoverlap by 2 bases. The P. aeruginosa PhhA appears to contain iron and is pterindependent. Unlike the multimeric mammalian hydroxylase, the native P. aeruginosaenzyme is a monomer. The P. aeruginosa PhhA is homologous with mammalian PhhA,tryptophan hydroxylase, and tyrosine hydroxylase. Expression of PhhA from itsnative promoter required phhB. This may suggest a positive regulatory role forphhB, consistent with the dual catalytic and regulatory roles of thecorresponding mammalian homologue.     

突击量氯磷定治疗急性有机磷农药中毒致呼吸肌麻痹76例观察

目的 比较突击量与非突击量氯磷定方案对急性有机磷农药中毒（ＡＯＰＰ）致呼吸肌麻痹（ＲＭＰ）的治疗效果。方法 对７６例ＡＯＰＰ致ＲＭＰ闰人,根据救治时头３ｄ是否应用突击量氯磷定方案或近似突击量氯磷定方案,将病人分为两组。Ａ组３０例,平均年龄２８．９岁。每天氯磷定用量≥１０．０ｇ,平均１１．４ｇ。Ｂ组病人４６例,平均年龄３０．７岁。每天氯磷定用量〈１０．０ｇ,平均６．３ｇ。结果 Ａ组病人自主呼吸恢复时     

Imaging microdomain Ca2+ in muscle cells

Ca2+ ions passing through a single or a cluster of Ca2+-permeable channels create microscopic, short-lived Ca2+ gradients that constitute the building blocks of cellular Ca2+ signaling. Over the last decade, imaging microdomain Ca2+ in muscle cells has unveiled the exquisite spatial and temporal architecture of intracellular Ca2+ dynamics and has reshaped our understanding of Ca2+ signaling mechanisms. Major advances include the visualization of "Ca2+ sparks" as the elementary events of Ca2+ release from the sarcoplasmic reticulum (SR), "Ca2+ sparklets" produced by openings of single Ca2+-permeable channels, miniature Ca2+ transients in single mitochondria ("marks"), and SR luminal Ca2+ depletion transients ("scraps"). As a model system, a cardiac myocyte contains a 3-dimensional grid of 104 spark ignition sites, stochastic activation of which summates into global Ca2+ transients. Tracking intermolecular coupling between single L-type Ca2+ channels and Ca2+ sparks has provided direct evidence validating the local control theory of Ca2+-induced Ca2+ release in the heart. In vascular smooth muscle myocytes, Ca2+ can paradoxically signal both vessel constriction (by global Ca2+ transients) and relaxation (by subsurface Ca2+ sparks). These findings shed new light on the origin of Ca2+ signaling efficiency, specificity, and versatility. In addition, microdomain Ca2+ imaging offers a novel modality that complements electrophysiological approaches in characterizing Ca2+ channels in intact cells.     

Expression of p21(WAF1) and p53 and polymorphism of p21(WAF1) gene in gastric carcinoma

AIM: To investigate the relationship between expression of p21(WAF1) and p53 gene, and to evaluate the deletion and polymorphism of p21(WAF1) gene in gastric carcinoma (GC). METHODS: Expression of p21 and p53 proteins, and deletion and polymorphism of p21 gene in GC were examined by streptavidin-peroxidase conjugated method (SP) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) respectively. RESULTS: The expression of p21 and p53 was found in 100% (20/20) and 0% (0/20) of normal gastric mucosae(NGM), 92.5% (37/40) and 15.0% (6/40) of dysplasia (DP) and 39.8% (43/108) and 56.5% (61/108) of GC, respectively. The positive rate of p21 in GC was lower than that in NGM and DP (P<0.05), while the positive rate of p53 in GC was higher than that in NGM and DP (P<0.05). p21 and p53 were significantly expressed in 63.3% (19/30) and 36.7% (11/30), 35.0% (14/40) and 77.5% (31/40), 26.7% (4/15) and 80.0% (12/15), 30.8% (4/13) and 30.8% (4/13), and 20.0% (2/10) and 30.0% (3/10) of well-differentiated, poorly-differentiated, undifferentiated carcinomas, mucoid carcinomas and signet ring cell carcinomas. The expression of p21 in well-differentiated carcinomas was significantly higher than that in poorly-differentiated, un-differentiated, mucoid carcinomas and signet ring cell carcinomas (P<0.05). Contrarily, The expression of p53 was increased from well-differentiated to poorly-differentiated and un-differentiated carcinomas (P<0.05). The expression of p21 and p53 in paired primary and metastatic GC (35.3% and 70.6%) was different from non-metastatic GC (62.5% and 42.5%) markedly (P<0.05). The expression of p21 in invasive superficial muscle (60.0%) was higher than that in invasive deep muscle or total layer (35.2%) (P<0.05) and was higher in TNM stages I (60.0%) and II (56.2%) than in stages III (27.9%) and IV (22.2%) (P<0.05), whereas the expression of p53 did not correlate to invasion depth or TNM staging (P>0.05). The exoression patterns of p53+/p21-, and of p53-/p21+ were found in 5.0% and 82.5% of DP. There was a significant correlation between expression of p21 and p53 (P<0.05). But there was no significant correlation between expression of both in GC (P>0.05). There was no deletion in exon 2 of p21 gene in 30 cases of GC and 45 cases of non-GC, but polymorphism of p21 gene at exon 2 was found in 26.7% (8/30) of GC and 8.9% (4/45) of non-GC, a significant difference was found between GC and non-GC (P<0.05). There was no significant relation between p21 expression of polymorphism (37.5%, 3/8) and non-polymorphism (45.5%, 10/22) in GC (P>0.05). CONCLUSION: The loss of p21 protein and abnormal expression of p53 are related to carcinogenesis, differentiation and metastasis of GC. The expression of p21 is related to invasion and clinical staging in GC intimately. The expression of p21 protein depends on p53 protein largely in NGM and DP, but not in GC. No deletion of p21 gene in exon 2 can be found in GC. The polymorphism of p21 gene might be involved in gastric carcinogenesis.There is no significant association between polymorphism of p21 gene and expression of p21 protein.     

Genetic and phenotypic architecture of metabolic syndrome-associated components in dyslipidemic and normolipidemic subjects: the GEMS Study

Atherogenic dyslipidemia, manifest by low HDL-cholesterol and high TG levels, is an important component of ATP-III defined metabolic syndrome. Here, we dissected the phenotypic and genetic architecture of these traits by assessing their relationships with other metabolically relevant measures, including plasma adipo-cytokines, highly sensitive C-reactive protein (hsCRP) and LDL particle size, in a large family data set (n=2800) and in an independent set of dyslipidemic cases (n=716) and normolipidemic controls (n=1073). We explored the relationships among these phenotypes using variable clustering and then estimated their genetic heritabilities and cross-trait correlations. In families, four clusters explained 61% of the total variance, with one adiposity-related cluster (including hsCRP), one BP-related cluster, and two lipid-related clusters (HDL-C, TG, adiponectin and LDL particle size; apoB and non-HDL-C). A similar structure was observed in dyslipidemic cases and normolipidemic controls. The genetic correlations in the families largely paralleled the phenotype clustering results, suggesting that common genes having pleiotropic effects contributed to the correlations observed. In summary, our analyses support a model of metabolic syndrome with two major components, body fat and lipids, each with two subcomponents, and quantifies their degree of overlap with each other and with metabolic-syndrome related measures (adipokines, LDL particle size and hsCRP).     

Serum nuclear factor IB as a novel and noninvasive indicator in the diagnosis of secondary hyperparathyroidism

BackgroundChronic renal failure (CRF) referred to chronic progressive renal parenchymal damage caused by various causes, with metabolite retention and imbalance of water, electrolyte, and acid‐base balance as the main clinical manifestations. Secondary hyperparathyroidism (sHPT) was a common complication in maintenance hemodialysis patients with CRF. Nuclear factor IB (NFIB) was a newly found tumor suppressor gene in various cancers. The present study aimed to illustrate the role of NFIB in sHPT clinical diagnosis and treatment response.MethodsA retrospective, case‐control study, including 189 patients with sHPT and 106 CRF patients without sHPT, compared with 95 controls. Serum NFIB and 1,25(OH)₂D₃ levels were measured by RT‐qPCR and ELISAs, respectively. ROC analysis was conducted to verify the diagnostic value of NFIB in sHPT. Spearman''s correlation analysis was conducted to verify the association between NFIB and bone mineral density (BMD) scores. After 6 months of treatment, the variance of NFIB and 1,25(OH)₂D₃ in different groups was recorded.ResultsThe expression of NFIB was significantly lower in serum samples from sHPT and non‐sHPT CRF patients, compared to controls. Clinicopathological information verified sHPT was associated with NFIB, parathyroid hormone (PTH), serum calcium, serum phosphorus, time of dialysis, and serum 1,25(OH)₂D₃ levels. Spearman''s correlation analysis illustrated the positive correlation between NFIB levels and BMD scores. At receiver operator characteristic (ROC) curve analysis, the cutoff of 1.6508 for NFIB was able to identify patients with sHPT from healthy controls; meanwhile, NFIB could also discriminate sHPT among CRF patients as well (cutoff = 1.4741). Furthermore, we found that during 6 months of treatment, NFIB levels were gradually increased, while PTH and serum P levels were decreased.ConclusionsSerum NFIB was a highly accurate tool to identify sHPT from healthy controls and CRF patients. Due to its simplicity, specificity, and sensitivity, this candidate can be proposed as a first‐line examination in the diagnostic workup in sHPT.     

Thromboelastography (TEG) in normal pregnancy and its diagnostic efficacy in patients with gestational hypertension,gestational diabetes mellitus,or preeclampsia

BackgroundThromboelastography (TEG) provides global assessment of hemostatic function and has been recommended to monitor potential coagulopathies during pregnancy in which hypercoagulable state is favored. In present study, we established the reference intervals (RIs) of the TEG parameters (R, K, MA, and α‐angle) with Chinese pregnant women of third trimester. In addition, we examined the diagnostic efficacies of the TEG parameters in the patients diagnosed of gestational hypertension (GH), gestational diabetes mellitus (GDM), or preeclampsia (PE).MethodsWith specified including and excluding criteria, non‐pregnant controls, healthy pregnant women, and pregnant women with GH, GDM, or PE had their venous blood drawn at Beijing Obstetrics and Gynecology Hospital, followed by TEG tests performed in the clinical laboratory.ResultsThe RIs determined with the healthy pregnant women (in third trimester) for R, K, MA, and α‐angle were 4.0‐7.7, 1.2‐3.2, 51.9‐70.1, and 41.4‐74.4, respectively. When compared with the healthy pregnancy group, the K value was significantly decreased in GH patients but increased in PE patients; MA was significantly lower in the PE group. In the receiver operating characteristic curve (ROC) analyses, K value was able to efficiently distinguish normal pregnancy from the GH patients, with an AUC of 0.86 which is far better than those of R (AUC = 0.57) and MA (AUC = 0.56). For the PE patients, the AUC of MA (0.69) was significantly greater than that of R (0.50).ConclusionsThromboelastography may provide more accurate experimental basis for monitoring coagulation functions especially in pregnant women with complications of GH and PE.