Diagnostic performances of various gray-scale, color Doppler, and contrast-enhanced ultrasonography findings in predicting malignant thyroid nodules.

BACKGROUND: Ultrasonography is the most frequently used clinical tool for the identification, assessment, and follow-up of thyroid nodules. The purpose of this research was to evaluate the value of diagnostic ultrasonography indicators, to obtain rankings of the most valuable indicators in the differential diagnosis of thyroid nodules, and to analyze the optimal diagnostic points and clinical values. METHODS: One hundred forty-four patients with 172 thyroid nodules underwent preoperative ultrasonography examinations, including gray-scale ultrasonography (GSUS), color Doppler ultrasonography (CDUS), and contrast-enhanced ultrasonography (CEUS). Fourteen indicators of thyroid nodules on GSUS, CDUS, and CEUS were selected to evaluate all thyroid nodules. The differences between the benign and malignant thyroid nodules in all indicators were analyzed by the chi-squared test; the diagnostic ultrasonography values were obtained by logistic regression; and the optimal diagnostic points were explored by receiver operating characteristic curve analysis. RESULTS: Of the 172 thyroid nodules that were surgically removed, 78 were benign and 94 were malignant. Ten indicators of GSUS and CEUS showed significant differences between the benign and malignant nodules (p<0.05), whereas four CDUS indicators had no value. The rankings of the valuable indicators were obtained according to their odds ratios (ORs). The top four indicators were ring enhancement and homogeneity of enhancement on CEUS, and microcalcification and halo on GSUS. These indicators were the most valuable, with ORs of greater than 20 in the differential diagnosis of benign and malignant thyroid nodules. The other six indicators-the relative arrival time of the nodule on CEUS, interior echogenicity on GSUS, peak interior echogenicity on CEUS, shape on GSUS, peak peripheral echogenicity on CEUS, and orientation on GSUS-were also valuable, with ORs less than 20. The areas under the receiver operating characteristic curves for GSUS, CEUS, and the combination of GSUS and CEUS in the diagnosis of thyroid nodules were 0.936, 0.910, and 0.966, respectively. Five positive features of the 10 valuable indicators on GSUS and CEUS defined the cut-off for the diagnosis of malignant thyroid nodules, with a sensitivity of 89.4% (84/94), specificity of 93.6% (73/78), and accuracy of 91.3% (157/172). CONCLUSIONS: The ring enhancement and homogeneity of enhancement of thyroid nodules on CEUS and the microcalcification and halo on GSUS were the four most valuable indicators in the differential diagnosis of thyroid nodules. Conjoint analysis of specific features of thyroid nodules on GSUS and CEUS could enhance the diagnostic value of thyroid nodules.

[Rectal stenosis following procedure for prolapse and hemorrhoids].

OBJECTIVE: To evaluate stenosis of the lower rectum following PPH with special respect to potential predictive factors or stenotic events. METHODS: A retrospective analysis of 554 consecutive patients, which underwent PPH from July 2000 to December 2004 was performed. RESULTS: Only patients with follow-up check were evaluated, thus the analysis includes 489 patients (489/554, 88.3%) with a mean follow-up of (324 +/- 18) days. Rectal stenosis was observed in 12 patients (12/489, 2.5%), the median time to stenosis was 89 - 134 (125 +/- 5) days. All the patients complained of obstructive defecation and underwent strictureplasty with electrocautery or balloon dilation through colonoscopy. A statistical analysis revealed that patients with stenosis had significantly more often prior sclerosis therapy for hemorrhoids (58.3% vs. 20.0%, P = 0.02) and severe postoperative pain (25.0% vs. 6.7%, P = 0.003). Other factors, such as gender (P = 0.32), prior surgery for hemorrhoids (P = 0.11), histological evidence of squamous skin (P = 0.77) or revision (P = 0.53) showed no significance. CONCLUSION: Rectal stenosis is an uncommon event after PPH. Early stenosis will occur within the first four months after surgery. The majority of the stenosis can be cured through colonoscopy surgery. The predictive factors for stenosis are previous sclerosis therapy for hemorrhoids and severe postoperative pain.

Regulated production of mature insulin in rat hepatoma cells: insulin production is up-regulated by dexamethasone and down-regulated by insulin.

We engineered an artificial beta cell line that produces an up-regulation of insulin in response to dexamethasone, and a down-regulation in response to insulin. A regulatory secretion system was devised by placing proinsulin cDNA containing genetically engineered furin endoprotease cleavage sites and a regulatory promoter for phosphoenolpyruvate carboxykinase (PEPCK), and an insulin expressing retrovirus vector (pN-PEPCK-mINS) was constructed and transfected into Hepa1-6 cells. The levels of insulin in culture medium and expression of insulin gene was estimated by radioimmunoassay and reverse transcription-polymerase chain reaction (RT-PCR), respectively. The clone (Hepa1-6/INS21), which secreted the highest level of insulin (10.79 microIU/106 cells per day), was selected for the regulation experiment. Compared with the non-treated Hepa1-6/INS21 cells, insulin production was augmented 3.6-fold by the addition of 10-7 M of dexamethasone. Addition of exogenous insulin to the culture medium decreased insulin mRNA expression remarkably on RT-PCR results, while dexamethasone increased insulin gene expression at the transcriptional level. The data indicated that genetically engineered Hepa1-6 cells could synthesize process and secrete insulin in a physiological manner.

[Imatinib mesylate STI571 therapy for five patients with advanced gastrointestinal stromal tumors].

OBJECTIVE: To explore the therapeutic effect of STI571(imatinib mesylate) on advanced gastrointestinal stromal tumors (GISTs). METHODS: Clinical data of 5 cases with advanced GISTs were analyzed retrospectively. RESULTS: The expression of c- kit (CD117) was detected by immunohistochemical method in five patients with advanced GISTs . All patients failed to systematic chemotherapy or radiofrequency and operation because of extensive and multiple metastases (4 cases underwent 1 to 3 times of exploratory surgery). Tumor size was markedly decreased one to six months after STI571 given without serious drug- related side effects. CONCLUSIONS: STI571 is an effective chemotherapy for advanced unresectable or metastatic GISTs. Inhibitor of the Kit signal- transduction pathway is a promising regimen that is different from conventional chemotherapy for advanced GISTs.

[In vitro evidence for pancreatic lineage: Ngn3 positive cells are endocrine progenitors derived from cultured islets].

OBJECTIVE: Further studies have been conducted to evaluate the roles of Ngn3 in adult islet maintenance and renewal. METHODS: Islets were isolated from 6 - 8 week old male C57BL/6 mice. After common bile duct cannulation, the pancreas was resected and digested in collagenase V (2.5 mg/ml). Islets were then handpicked and 10 - 12 islets were plated in 60 mm culture dish and cultivated with RPMI-1640, which contained 12.5 mmol/L HEPES, 5.2 mmol/L glucose and 2% fetal bovine serum (FBS). Islet cells were analyzed by immunocytochemistry methods for A6, insulin, glucagon, nestin, Ngn3 and 5-bromo-2'-deoxy-uridine (BrdU). RESULTS: The results of these studies indicated that less than 15 percent of proliferated islet cells were Ngn3 expressing cells, in which about one third of the Ngn3 positive cells co-expressed A6. The existence of Ngn3 in cultured islet cells is consistent with the results from other's findings both in embryogenesis and adult islet studies. A significant finding of our study is that the existence of A6 and Ngn3 co-expressing cells in the cultured islet. A6 is a marker for identifying bile duct epithelial cell oriented hepatic progenitor cells. Islet-derived A6 cells are possibly born in the adult pancreatic duct and migrate into islets. A6 cells co-express Ngn3 when these cells commit to endocrine lineage within the islets. More interestingly, islet-derived A6 positive cells have the potential to transdifferentiate into hepatic cells. CONCLUSION: The presence of Ngn3(+) and A6(+) cells in the cultured islets suggests that the four established islet cell types arise from a common endocrine lineage residing within the adult islets. A6 and Ngn3 are useful markers for understanding intra-islet adult stem cell lineages in our future studies. This approach may allow for significant advances in understanding the IPC proliferation and differentiation, and open the possibility of using intra-islet adult stem cells for diabetes treatment.