The antithrombotic efficacy of AT-1459, a novel, direct thrombin inhibitor, in rat models of venous and arterial thrombosis.

The antithrombotic efficacy of AT-1459, a novel, direct thrombin inhibitor (Ki = 4.9 nM) was evaluated in rat models of venous thrombosis combined with a bleeding time test and arterial thrombosis. After drugs were given by i. v. bolus injection plus a continuous infusion, the ID50, (a dose that exhibits 50% inhibition of thrombus formation over each vehicle group) values of AT-1459, argatroban, and dalteparin were 0.04 mg/kg plus 0.04 mg/kg/h, 0.1 mg/kg plus 0.4 mg/ kg/h, and 13.0 IU/kg plus 26.0 IU/kg/h, respectively, in the venous thrombosis study. The BT2 (a dose that causes 2-fold prolongation of bleeding time over each vehicle group) values of AT-1459, argatroban, and dalteparin were 0.9 mg/kg plus 0.9 mg/kg/h, 1.0 mg/kg plus 0.6 mg/kg/h, and 345.5 IU/kg plus 691.0 IU/kg/h in the rat tail transection model. The ratios of BT2/ID50 of AT-1459, argatroban, and dalteparin were 22.5, 10.0, and 26.6, respectively. In a rat model of arterial thrombosis induced by topical FeCl2 application, intravenous administration of AT-1459, argatroban, and dalteparin improved the vessel patency significantly (P < 0.01) at 0.6 mg/kg plus 0.6 mg/kg/h, 0.6 mg/kg plus 2.4 mg/kg/h, and 300 IU/kg plus 600 IU/kg/h, respectively. The oral antithrombotic effect of AT-1459 lasted for 6 after administering 30 mg/kg and improved the vessel patency significantly 1 h after administering the same dose in venous and arterial thrombosis models, respectively, with a rapid onset of action. Warfarin also inhibited thrombus weight and improved the vessel patency significantly after oral administration of 0.3 mg/kg for three consecutive days in the same study. The antithrombotic and hemorrhagic effects of all drugs studied were correlated with plasma concentration or clotting times. These results suggest that AT-1459 may be clinically useful as an orally available antithrombotic agent for the prevention of venous and arterial thrombosis.     

Regional bone mass measurement from whole-body dual energy X-ray absorptiometry scan.

There are no data on the relative accuracy and precision of regional bone mass measurement from whole-body dual energy X-ray absorptiometry (DXA) scans in small young subjects. Twelve domestic swine piglets (2550-17,660 g) were scanned on a single-beam and on a fan beam densitometer using each humerus and femur as the region of interest to determine the validity of five different scan modes: two infant whole body (IWB), two spine, and one rat whole body (RWB) scan mode in the determination of regional bone mass measurements. DXA bone mineral content (BMC( measurements from RWB and IWB fan beam and IWB single-beam scans were highly predictive of ash weight (adjusted r2 = 0.98, 0.94, 0.94, respectively). Correlation between left and right limbs was highly significant (p < 0.001 for all comparisons) for ash weight (r = 0.99) and for DXA measurements of BMC (r = 0.92-0.99), area (r = 0.92-0.99), and bone mineral density (r = 0.87-0.99) for all modes of DXA scan. Repeatability (as standard deviation of differences of repeated scans) varied with scan mode and DXA parameters and ranged from 1.5 to 7.6%and from 1.8 to 14.7% for intra-and interoperator, respectively. We conclude that regional DXA measurements from IWB and RWB scans can be assessed accurately and with adequate precision for clinical use in subjects with low bone mass comparable with infants and young children. The RWB scan is useful for research studies. However, appropriate training and documentation of precision errors is needed to minimize repeatability errors.     

Stereotactic body radiotherapy for isolated paraaortic lymph node recurrence from colorectal cancer

AIM: To evaluate the efficacy and complications of stereotactic body radiotherapy in localized paraaortic lymph node recurrence from colorectal cancer. METHODS: From 2003 to 2009, 7 patients with paraaortic lymph node recurrence (1-3 lesions) from colorectal cancer were treated with stereotactic body radiotherapy. Total gross tumor volumes ranged from 4 to 40 mL. The doses were escalated from 36 Gy/patient to 51 Gy/patient and were delivered in 3 fractions. RESULTS: One and 3 year overall survival rates were 100% and 71.4%, respectively, and median survival was 37 mo. Grade Ⅳ intestinal obstruction was reported in 1 of 7 patients. This patient received 48 Gy in 3 fractions with a maximum point dose to the intestine of 53 Gy and V_(45Gy) = 3.6 mL. However, 6 patients received an intestinal maximum point dose of < 51 Gy and V_(45Gy) of < 1 mL, and did not develop any severe complications. CONCLUSION: This pilot study suggests selected paraaortic lymph node recurrence (1-3 closed lesions) that failed to respond to chemotherapy can be potentially salvaged by stereotactic body radiotherapy.     

Magnetic resonance pancreatography: comparison of two- and three-dimensional sequences for assessment of intraductal papillary mucinous neoplasm of the pancreas

The purpose was to compare two-dimensional (2D) magnetic resonance pancreatography (MRP) with 3D MRP to evaluate intraductal papillary mucinous neoplasm (IPMN). Thirty-four patients (22 men, 12 women; age range, 45–80 years) with IPMN (n = 40) were examined with MRP on 2D and 3D sequences. Two readers independently reviewed the images to assess the overall image quality, artifacts, lesion location, communication with main pancreatic duct, and potential for malignancy. The readers assigned their confidence level (1–5) for predicting ductal communication of the lesion. The results of MRP were compared with endoscopic retrograde pancreatography and surgical and histopathologic findings. Studies obtained with 3D MRP were of significantly higher technical quality than those obtained with 2D MRP. Although 3D MRP showed higher area under the ROC curve (Az) values for predicting ductal communication of the lesion, there was no statistical significance between Az values of 2D and 3D MRP (Az for 2D = 0.821, 0.864 for readers 1 and 2, respectively, and Az for 3D= 0.964, 0.921). Accuracies for discriminating benign from malignant lesions were 70 and 67.5% (reader 1 and 2, respectively, for 2D) and 62.5 and 80.1% (3D). 3D MRP showed superior image quality to that of 2D MRP but did not increase the diagnostic accuracy for predicting ductal communication of the lesion.     

High insulin levels in newly diagnosed breast cancer patients reflect underlying insulin resistance and are associated with components of the insulin resistance syndrome

Background High insulin levels have been associated with poor outcomes in breast cancer. Our goal was to investigate whether hyperinsulinemia was associated with insulin resistance in a cohort of newly diagnosed locoregional breast cancer patients and to examine associations of hyperinsulinemia with the broader insulin resistance syndrome (IRS). Methods Five hundred and four women with T1-3, N0-1, M0 breast cancer provided fasting blood that was analyzed for glucose, insulin and lipids. They underwent anthropomorphic measurements and provided information on diet, exercise and sleep. Relationships of insulin with three validated indices of insulin resistance and with attributes of the IRS were examined. Results High insulin levels were strongly correlated with insulin resistance calculated using the three indices of insulin resistance/sensitivity (Spearman r = 0.83–0.98). Hyperinsulinemia was also associated with other components of the IRS (obesity, high waist–hip ratio, lipid profile). Conclusions High insulin levels in women with locoregional breast cancer reflect the presence of insulin resistance and are associated with other components of the IRS. These observations have implications for the development of therapies that target hyperinsulinemia in early stage breast cancer and for the long-term management of breast cancer survivors.     

An efficient liposomal gene delivery vehicle using Sendai F/HN proteins and protamine

By means of a simple mixing procedure, we have constructed cationic Sendai virosomes consisting of fusogenic viral F/HN proteins and cationic lipids. Sendai virus F/HN proteins were purified by Triton X-100 treatment and sequential centrifugation, and then quantitatively added to cationic liposomes. The presence of HN proteins is essential for hemolytic activity of Sendai virus as well as efficient gene transfection. The amount of detergent added for purification of F/HN proteins was also crucial for hemolytic activity. The relevance of F/HN proteins in the gene-transfer capability of the cationic Sendai F/HN virosomes (CSVs) was verified by heat inactivation of the F/HN proteins, and cell-binding competition. DNA condensation by protamine sulfate was able to further enhance the transfection efficiency and serum resistance of CSV. The enhanced transfection efficiency of protamine-condensed DNA-encapsulating cationic Sendai F/HN virosomes (PCSVs) may result from specific and efficient cell binding mediated by F/HN proteins and efficient DNA encapsulation by protamine. The DNA condensation by protamine was crucial for systemic in vivo gene transfer by CSVs. The PCSVs exhibited a higher gene expression in various organs, especially the liver, compared to DOTAP/Chol lipoplexes. These results demonstrate the potential for the use of PCSV as gene delivery vehicles for systemic gene transfer.     

Lymphatic metastases to level IIb in hypopharyngeal squamous cell carcinoma

OBJECTIVES: To evaluate the prevalence of level IIb lymph node (LN) metastasis and to identify potential clinical risk factors when level IIb metastatic diseases are present in patients with clinically node-negative (N0) and node-positive (N+) necks with hypopharyngeal squamous cell carcinoma (HPSCC). This will provide a basis for determining whether this region can be excluded in elective or therapeutic neck dissection in patients with HPSCC. DESIGN: Prospective analysis of a case series. SETTING: University hospital. PATIENTS: Fifty patients with HPSCC who underwent surgical treatment for a primary lesion and simultaneous neck dissection from January 1998 to February 2004. MAIN OUTCOME MEASURES: The incidences and clinical risk factors for level IIb LN metastasis and regional recurrence according to the presence or absence of pathologic LN involvement in level IIb. RESULTS: A total of 93 neck dissections were analyzed in this study. Of these dissections, 59 (63%) were elective and 34 (37%) were therapeutic. Three percent (2 of 59) of all N0 necks and 32% (11 of 34) of all N+ necks had level IIb LN metastases. Level IIb nodal metastases were significantly more prevalent in N+ necks (P=.007) than in N0 necks and in the presence of other positive LNs (P=.01) than in the absence of other positive LNs. Of the 35 patients with pathologic LNs, the regional recurrence rate was significantly higher in cases with positive level IIb LNs (33% [4 of 12]) than without (4% [1 of 23]; P=.04). CONCLUSIONS: Level IIb LN pads may be preserved during elective neck dissection in the treatment of patients with clinically N0 necks with HPSCC. This area should be removed during therapeutic neck dissection in the treatment of clinically N+ necks.     

Bone, lean and fat mass of newborn twins versus singletons

AIM: Twin gestations are associated with disturbed fetal growth. The aim of this study was to compare body composition measurements of twins to those of singletons. METHODS: Anthropometric and dual energy X-ray absorptiometry (DXA) measurements were performed in twins and in matched singleton neonates. There were 48 pairs of twins in which 76 infants were appropriate for gestational age (AGA) with birth weights between the 10th and 90th percentile and 20 were small for gestational age (SGA) with birth weights <10th percentiles. Each AGA twin was matched as closely as possible for birth weight to an AGA singleton. Each SGA twin was matched with two cohorts of AGA singletons: one with similar birth weight and one with similar gestation. RESULTS: For AGA twins and their singleton cohort matched for birth weights, profile analysis using repeated measure analysis of variance showed that there were no significant differences in bone, fat and lean mass either as absolute values or as percentage of total weight. This was also the case for body composition of SGA twins compared to singletons matched for birth weight. In contrast, SGA twins have significantly lower absolute amounts of lean with tendency to lower fat and bone mass. CONCLUSION: For clinically normally grown neonates, with comparable weight, the body composition with respect to bone, fat and lean mass components are similar regardless whether they are products of singleton or twin pregnancies.     

Conservation and Variability of West Nile Virus Proteins

West Nile virus (WNV) has emerged globally as an increasingly important pathogen for humans and domestic animals. Studies of the evolutionary diversity of the virus over its known history will help to elucidate conserved sites, and characterize their correspondence to other pathogens and their relevance to the immune system. We describe a large-scale analysis of the entire WNV proteome, aimed at identifying and characterizing evolutionarily conserved amino acid sequences. This study, which used 2,746 WNV protein sequences collected from the NCBI GenPept database, focused on analysis of peptides of length 9 amino acids or more, which are immunologically relevant as potential T-cell epitopes. Entropy-based analysis of the diversity of WNV sequences, revealed the presence of numerous evolutionarily stable nonamer positions across the proteome (entropy value of ≤1). The representation (frequency) of nonamers variant to the predominant peptide at these stable positions was, generally, low (≤10% of the WNV sequences analyzed). Eighty-eight fragments of length 9–29 amino acids, representing ~34% of the WNV polyprotein length, were identified to be identical and evolutionarily stable in all analyzed WNV sequences. Of the 88 completely conserved sequences, 67 are also present in other flaviviruses, and several have been associated with the functional and structural properties of viral proteins. Immunoinformatic analysis revealed that the majority (78/88) of conserved sequences are potentially immunogenic, while 44 contained experimentally confirmed human T-cell epitopes. This study identified a comprehensive catalogue of completely conserved WNV sequences, many of which are shared by other flaviviruses, and majority are potential epitopes. The complete conservation of these immunologically relevant sequences through the entire recorded WNV history suggests they will be valuable as components of peptide-specific vaccines or other therapeutic applications, for sequence-specific diagnosis of a wide-range of Flavivivirus infections, and for studies of homologous sequences among other flaviviruses.