Comparative fasting bioavailability and pharmacokinetic properties of 2 formulations of glucosamine hydrochloride in healthy Chinese adult male volunteers

Glucosamine (CAS 66-84-2) hydrochloride is an amino monosaccharide indicated for the treatment of arthrosis, especially osteoarthritis of the knee joint. This study was conducted to assess and compare the pharmacokinetic (PK) properties, bioavailability of a newly developed dispersible tablet formulation (test) of glucosamine hydrochloride with those of an established branded capsule formulation (reference) in healthy Chinese adult male volunteers.This single-dose, randomized, open-label, 2-period crossover study was conducted in 18 healthy Chinese adult male volunteers under fasting condition. Plasma samples were collected at pre-specified times over a 12-h period following administration in each period and analyzed the plasma glucosamine concentrations by Liquid Chromatography coupled with Tandem Mass Spectrometry (LC/MS/MS) method. The mean (SD) PK parameters of Cmax, Tmax, AUC0-12, and AUC0-∞ after administration of the test and reference formulations were, respectively, as follows: Cmax, 907.01 (444.22) vs. 944.40 (429.89) ng/mL, Tmax, 3.03 (0.95) vs. 3.30 (0.99) hours, AUC0-12, 2891.41 (1352.30) vs. 2889.69 (925.48) ng/mL/h, and AUC0-∞, 3029.90 (1321.36) vs. 3091.87 (870.36) ng/mL/h. The mean (SD) t1/2 was 1.10 (0.52) hours for the test formulation and 1.50 (1.17) hours for the reference formulation. On ANOVA, neither period nor sequence effects were observed for any PK properties. The relative bioavailability of the test formulation was 98.3% assessed by AUC0-12. The 90% CIs of glucosamine for the log-transformed ratios of Cmax, AUC0-12, and AUC0-∞ were 78.4-113.9%, 80.8-108.5% and 80.8-105.8%, respectively, meeting the predetermined criteria for bioequivalence of SFDA.

SU-E-J-205: Modeling Fiducial Marker Movement in Prostate

PURPOSE

To understand fiducial marker movement in prostate and to improve prostate patient positioning with fiducial markers.

METHODS

Patient planning CT and positioning CBCT were retrospectively analyzed. CBCT images were automatically registered to the corresponding CT ones based on their bony structures in Eclipse. The coordinates of the markers in the CT and CBCT were recorded. The status of bladder and rectum fillings, and gas in rectum were indexed into four levels and recorded. An algorithm was developed to optimally register the (three) fiducial markers in CBCT with those in the CT so that only the information on prostate deformation and marker migration remained. A mathematical model was built to estimate the marker migration and the relative contribution to the deformation from the status change of bladder and rectum.

RESULTS

The registration error from our optimal registration algorithm indicates the minimal patient setup error by using fiducial markers. The results from our analyzed 3 patients were average(standard deviation) = 1.10(0.40), 1.27(0.67) and 0.62(0.38) mm, but there were some fractions when the registration errors were over 2 mm. From our mathematical model, it was found that the marker migration could be as large as 2.9 mm. If 2 mm tolerance is required in such as SBRT, then soft tissue based registration may be more appreciated when the optimal registration error is greater than 2 mm or from the date when the migration is greater than 2 mm because the migrated marker may not change the location thereafter. In addition, for one investigated patient, the relative contribution to the deformation from the bladder, rectum filling and gas in the rectum is 0.43:0.31:0.26. More patient data are in analysis, and other interesting results will be reported.

CONCLUSIONS

Fiducial marker migration can be over 2 mm. The migration will Result in a conclusion that small registration error does not mean good patient positioning.

Changes in cortical bone response to high-fat diet from adolescence to adulthood in mice

Diabetic obesity is associated with increased fracture risk in adults and adolescents. We find in both adolescent and adult mice dramatically inferior mechanical properties and structural quality of cortical bone, in agreement with the human fracture data, although some aspects of the response to obesity appear to differ by age.

INTRODUCTION

The association of obesity with bone is complex and varies with age. Diabetic obese adolescents and adult humans have increased fracture risk. Prior studies have shown reduced mechanical properties as a result of high-fat diet (HFD) but do not fully address size-independent mechanical properties or structural quality, which are important to understand material behavior.

METHODS

Cortical bone from femurs and tibiae from two age groups of C57BL/6 mice fed either HFD or low-fat diet (LFD) were evaluated for structural and bone turnover changes (SEM and histomorphometry) and tested for bending strength, bending stiffness, and fracture toughness. Leptin, IGF-I, and non-enzymatic glycation measurements were also collected.

RESULTS

In both young and adult mice fed on HFD, femoral strength, stiffness, and toughness are all dramatically lower than controls. Inferior lamellar and osteocyte alignment also point to reduced structural quality in both age groups. Bone size was largely unaffected by HFD, although there was a shift from increasing bone size in obese adolescents to decreasing in adults. IGF-I levels were lower in young obese mice only.

CONCLUSIONS

While the response to obesity of murine cortical bone mass, bone formation, and hormonal changes appear to differ by age, the bone mechanical properties for young and adult groups are similar. In agreement with human fracture trends, adult mice may be similarly susceptible to bone fracture to the young group, although cortical bone in the two age groups responds to diabetic obesity differently.

Encoding a superantigen by Staphylococcus aureus does not affect clinical characteristics of infected atopic dermatitis lesions

BACKGROUND

Bacterial infection with Staphylococcus aureus is a known trigger for the worsening of atopic dermatitis (AD). Staphylococcal superantigens have been theorized to make a potential contribution to this worsening of AD seen with infection.

OBJECTIVES

We sought to assess whether encoding a superantigen by S. aureus affects the inflammatory characteristics of impetiginized AD skin lesions.

METHODS

Fifty-two children with clinically impetiginized lesions of AD which were positive for S. aureus were enrolled in this study. A lesion was graded clinically using the Eczema Area and Severity Index (EASI), and then wash fluid was obtained from the lesion for quantitative bacterial culture, and measurement of bacterial products lipoteichoic acid and staphylococcal protein A and cytokines. The staphylococcal isolate was tested for antibiotic susceptibilities and the presence of a superantigen.

RESULTS

Fifty-four per cent (28 of 52) of the staphylococcal isolates encoded a superantigen. The presence of a superantigen had no significant effect on EASI score, amounts of bacterial products or inflammatory cytokines in the AD lesion.

CONCLUSIONS

These studies suggest that the expression of a superantigen by S. aureus alone does not play an important role in the increased skin inflammation associated with staphylococcal infection in childhood AD.

Two HTS options for a 600 MHz insert of a 1.3 GHz LTS/HTS NMR magnet: YBCO and BSCCO

In 2008, the Phase 3 program to complete a 1.3 GHz (30.5 T) NMR magnet started at the Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology. It comprises two sub-phases, 3A and 3B. In Phase 3A, a 600 MHz high temperature superconductor (HTS) insert magnet (H600) will be designed, constructed, and operated in the bore of a 500 MHz low temperature superconductor (LTS) background magnet. This will be followed by Phase 3B, in which the H600 will be combined with a 700 MHz LTS background magnet to complete a 1.3 GHz NMR LTS/HTS magnet. This paper presents and discusses design issues for two conductor options for H600: BiSCCO-2223 (Bi2223) and coated-YBCO or its variants, here designated as YBCO. For each conductor option, we focused on the following issues: 1) elastic and thermal properties; 2) critical current vs. field performance; 3) splice and index heat dissipations; 4) mechanical and thermal stresses; and 5) protection.

An Inhibitor of ADAMs (a Distintegrin and Metalloproteinase) Overcomes HER3-Mediated Resistance to Trastuzumab and Lapatinib

Background: Inhibitors of HER-2/neu and EGF receptors such as trastuzumab, lapatinib, and erlotinib have demonstrated clinical efficacy but not all HER-2/neu or EGFR positive tumors respond and many that initially respond develop resistance. Ligand mediated HER-3 signaling results in tumor growth and survival and is a proposed mechanism of resistance to trastuzumab and lapatinib. Proteolytic cleavage of both ErbB ligands and receptors has been shown to be a critical event that results in ErbB pathway activation. Cleavage is necessary for the generation of soluble, functionally active forms of ErbB ligands and in the case of HER-2/neu, cleavage results in a shed extracellular domain (ECD) and a membrane bound fragment (p95) that contains a kinase domain with significant constitutive activity. In addition, it has been shown that the preferential association between HER3 and p95 can further activate the pathway. Both ErbB ligand and HER-2/neu cleavage are mediated by the ADAM family of proteases. Further, we have previously shown that the ADAM protease inhibitor, INCB7839, provides synergistic inhibition of HER2+ breast cancer cell line growth when combined with either trastuzumab or lapatinib. Materials and Methods: The HER-2 overexpressing BT-474 human breast cancer cell line was treated with either lapatinib or trastuzumab in the presence or absence of the HER-3 ligand, heregulin, and the effects on cell growth measured. The effects of the ADAM protease inhibitor INCB7839 in this system were also examined. Results: The addition of heregulin overcame the anti-proliferative effects of both lapatinib and trastuzumab on the growth of the BT-474 cell line in vitro. Addition of INCB7839 synergized with lapatinib or trastuzumab and importantly, restored the anti-proliferative effects of these agents in the presence of heregulin. Further, pretreatment of BT-474 cells with INCB7839 for 6 days, which we have previously shown completely eliminates the presence of the p95 form of HER2, amplified these effects, presumably by eliminating p95 before stimulating the cells with heregulin. Discussion: Together, these results confirm that heregulin can overcome the anti-proliferative effects of both trastuzumab and lapatinib as previously reported. Prevention of p95 formation by ADAM protease inhibitors appears to restore the anti-proliferative effects of both trastuzumab and lapatinib when heregulin/HER3 signaling occurs, negating a proposed mechanism of resistance to these agents in the clinic. These results suggest that combining an ADAM inhibitor with targeted inhibitors of the ErbB family can overcome HER-3-mediated resistance and enhance the clinical efficacy of approved HER2-targeted agents in the clinical setting. INCB7839 is currently under clinical investigation in combination with trastuzumab for women with metastatic breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3138.

COPD in Chinese nonsmokers

Little is known about chronic obstructive pulmonary disease (COPD) in Chinese nonsmokers. The present study aimed to investigate the profiles of COPD among nonsmokers based on the Chinese Epidemiological Survey of COPD (CESCOPD). In the CESCOPD, 20,245 subjects aged 40 yrs or older were interviewed with questionnaires and spirometry tests. Subjects with a post-bronchodilator forced expiratory volume in one second (FEV(1))/forced vital capacity (FVC) ratio of <0.70 were identified as having COPD. Data of 12,471 nonsmokers and 1,024 smoking COPD patients were analysed in the current study. The overall prevalence of COPD among nonsmokers was 5.2% (95% confidence interval 4.8-5.6). Being male, of advanced age, lower body mass index (BMI) and lower educational level, having exposure to environmental tobacco smoke, coal and/or biomass smoke, poor ventilation in the kitchen, a family history of respiratory disease and recurrent childhood cough were all independently associated with a higher risk of having COPD among nonsmokers. Nonsmokers with respiratory symptoms without airflow limitation showed a somewhat different pattern of risk factors. Nonsmokers with COPD were less likely to present with chronic productive coughs and lower BMI, while more likely to have received a physician diagnosis of asthma and respiratory diseases in childhood, than smokers with COPD. Chronic obstructive pulmonary disease is prevalent among Chinese nonsmokers, and nonsmoking chronic obstructive pulmonary disease may have different profiles from smoking chronic obstructive pulmonary disease.

Meta- and pooled analyses of the effect of glutathione S-transferase M1 and T1 deficiency on chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a complex polygenic disease in which gene-environment interactions are very important. A number of studies have investigated the genotypes of glutathione S-transferase M1 and T1 (GSTM1 and GSTT1) in relation to COPD susceptibility in different populations. However, the results of individual studies have been inconsistent.

METHODS

To address the inconsistent findings in studies of the association of the polymorphism of the GSTM1 and GSTT1 genes with susceptibility to COPD, we performed a meta-analysis of the published data. We searched the Medline database for case-control studies published from 1966 to July 2008. Data were extracted and pooled, and ORs were calculated with their 95%CIs.

RESULTS

Twelve eligible studies comprising 1697 patients with COPD and 1867 controls were included in the meta-analysis. The pooled result showed that the GSTM1 deficiency was associated with risk of COPD (OR 1.46, 95%CI 1.16-1.83). Subgroup analysis supported the results in smoking and non-Asian populations, but not in Asian populations. The GSTT1 deficiency was not associated with risk of COPD.

CONCLUSIONS

The GSTM1 gene is a genetic contributor to overall COPD susceptibility in non-Asian populations, and the GSTT1 gene is not associated with COPD.

Measurement of the toughness of bone: a tutorial with special reference to small animal studies

Quantitative assessment of the strength and toughness of bone has become an integral part of many biological and bioengineering studies on the structural properties of bone and their degradation due to aging, disease and therapeutic treatment. Whereas the biomechanical techniques for characterizing bone strength are well documented, few studies have focused on the theory, methodology, and various experimental procedures for evaluating the fracture toughness of bone, i.e., its resistance to fracture, with particular reference to whole bone testing in small animal studies. In this tutorial, we consider the many techniques for evaluating toughness and assess their specific relevance and application to the mechanical testing of small animal bones. Parallel experimental studies on wild-type rat and mouse femurs are used to evaluate the utility of these techniques and specifically to determine the coefficient of variation of the measured toughness values.