Preoperative concurrent chemoradiotherapy for stages II-IV oral squamous cell carcinoma: a retrospective analysis and the future possibility of this treatment strategy

This study evaluated survival in 154 patients with stages II-IV oral squamous cell carcinoma (OSCC) treated with preoperative concurrent chemoradiotherapy and assessed the future use of this treatment strategy. 14 patients exhibited advanced stage II, 73 exhibited stage III and 67 exhibited stage IV. All patients received 40Gy irradiation and concurrent cisplatin-based chemotherapy in two courses. Radical surgery was undertaken after 2-6 weeks. The clinical tumour response, histopathologic regression grade, residual tumour grade (RGrade) in the primary tumour and the level of residual pN+ were associated with prognosis. 90% of patients with complete response and 73% of patients with good partial response in the primary tumour were RGrade 0 (no residual tumour cells) or RGrade 1 (viable tumour cells remained within central superficial portion). In patients with complete response in the neck, residual pN+ was only seen in levels IB (8%) and IIA (8%); the higher the level of residual pN+, the lower the survival rate (p<0.0001). This treatment strategy was excellent for stages II-IV OSCC. It may be possible to perform minimally invasive surgery in which the extent of resection in primary tumour and neck is reduced in patients who achieve good response following preoperative chemoradiotherapy.

Establishment of recombinant hybrid-IgG/IgA immunoglobulin specific for Shiga toxin

Shiga toxin 1 produced by enterohaemorrhagic Escherichia coli is an AB(5) toxin that is involved in the life-threatening haemolytic-uraemic syndrome. The B subunits (Stx1B) are cell-binding subunits. We previously established mouse hybridoma cell line producing IgA and IgG monoclonal antibodies (mAbs) against Stx1B. Here, we cloned cDNAs encoding each of the heavy, light and joining (J) chains from the hybridoma cell lines by means of the 5' rapid amplification of cDNA ends (RACE) PCR method. Upon assignment of the variable regions of the heavy and light chains to known germline sequences, we found substantial somatic hypermutation in the complementarity-determining regions in both the IgA and IgG mAbs. We also established a hybrid-IgG/IgA heavy chain having variable regions of the IgG mAb by means of recombinant PCR methods. Upon transient expression of the hybrid-IgG/IgA heavy, IgG-associated light and J chains in COS-1 cells, the translated dimeric hybrid-IgG/IgA bound to immobilized Stx1B, as revealed on ELISA. The production of dimeric hybrid-IgG/IgA was revealed on immunoblot analysis. The dimeric hybrid-IgG/IgA inhibited the binding of digoxigenin-conjugated Stx1B to natural ligands (CD77) displayed on Burkitt's lymphoma cell line Ramos. These results indicate that the replacement of variable regions resulted in the production of more useful recombinant dimeric IgA against Stx1B.

Energy transport in a concentrated suspension of bacteria

Coherent structures appear in a concentrated suspension of swimming bacteria. While transport phenomena in a suspension have been studied extensively, how energy is transported from the individual cell scale to the larger mesoscale remains unclear. In this study, we carry out the first successful measurement of the three-dimensional velocity field in a dense suspension of bacteria. The results show that most of the energy generated by individual bacteria dissipates on the cellular scale. Only a small amount of energy is transported to the mesoscale, but the gain in swimming velocity and mass transport due to mesoscale coherent structures is enormous. These results indicate that collective swimming of bacteria is efficient in terms of energy. This paper sheds light on how energy can be transported toward smaller wave numbers in the Stokes flow regime.

Porcine circovirus type 2 potentiates morbidity of Salmonella enterica serovar Choleraesuis in Cesarean-derived, colostrum-deprived pigs

PROBLEM ADDRESSED

Porcine circovirus type 2 (PCV2) and Salmonella enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) are two leading causes of economic loss in the swine industry. Although S. Choleraesuis infection occurs concurrently with PCV2-associated disease in many swine herds, the pathogenesis of concurrent infection with PCV2 and S. Choleraesuis remains largely undefined.

OBJECTIVE

We investigated the interactions between PCV2 and S. Choleraesuis in 20 Cesarean-derived, colostrum-deprived (CDCD) pigs randomly assigned to 4 groups (n=5 per group).

METHODS AND APPROACH

Pigs in the dual-infected and PCV2-infected groups were inoculated intranasally with PCV2 at 5 weeks of age, and pigs in the dual-infected and S. Choleraesuis-infected groups were inoculated intranasally with S. Choleraesuis at 7 weeks of age. Pigs in the control group served as uninfected controls.

RESULTS

After S. Choleraesuis inoculation, severe clinical signs, reduction of weight gain, and severe microscopic lung lesions were observed in dual-infected pigs compared to those in other groups. In addition, the pigs in the dual-infected group shed significantly (P=0.002) higher quantities of S. Choleraesuis in feces 12 days after S. Choleraesuis inoculation, and S. Choleraesuis was recovered from more tissues in this group 14 days after S. Choleraesuis inoculation.

CONCLUSIONS

These results indicate that prior PCV2 infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of S. Choleraesuis in infected pigs. Therefore, dual infection of pigs with PCV2 and S. Choleraesuis may increase clinical effects of salmonellosis in the field.

Comparison between spring network models and continuum constitutive laws: application to the large deformation of a capsule in shear flow

A capsule is a liquid drop enclosed by a solid, deformable membrane. To analyze the deformation of a capsule accurately, both the fluid mechanics of the internal and external fluids and the solid mechanics of the membrane must be solved precisely. Recently, many researchers have used discrete spring network models to express the membrane mechanics of capsules and biological cells. However, it is unclear whether such modeling is sufficiently accurate to solve for capsule deformation. This study examines the correlations between the mechanical properties of the discrete spring network model and continuum constitutive laws. We first compare uniaxial and isotropic deformations of a two-dimensional (2D) sheet, both analytically and numerically. The 2D sheet is discretized with four kinds of mesh to analyze the effect of the spring network configuration. We derive the relationships between the spring constant and continuum properties, such as the Young modulus, Poisson ratio, area dilation modulus, and shear modulus. It is found that the mechanical properties of spring networks are strongly dependent on the mesh configuration. We then calculate the deformation of a capsule under inflation and in a simple shear flow in the Stokes flow regime, using various membrane models. To achieve high accuracy in the flow calculation, a boundary-element method is used. Comparing the results between the different membrane models, we find that it is hard to express the area incompressibility observed in biological membranes using a simple spring network model.

Pharmacokinetics and pharmacodynamics of dapagliflozin, a novel selective inhibitor of sodium-glucose co-transporter type 2, in Japanese subjects without and with type 2 diabetes mellitus

AIMS

Dapagliflozin, a selective, orally active inhibitor of the renal sodium-glucose co-transporter type 2 (SGLT2) is in development for the treatment of type 2 diabetes mellitus (T2DM). Here, the pharmacokinetics (PK) and pharmacodynamics (PD) of dapagliflozin were evaluated in healthy Japanese subjects and in Japanese subjects with T2DM.

METHODS

Two studies were conducted: a single-ascending dose (SAD) study (2.5-50 mg) in 32 healthy subjects and a multiple-ascending dose (MAD) study (2.5-20 mg QD for 14 days) in 36 subjects with T2DM. Safety and tolerability were assessed in both studies. Single and multiple dose PK of dapagliflozin and its inactive major metabolite, dapagliflozin 3-O-glucuronide, and PD (urinary glucose parameters) were characterized. Plasma glucose parameters were assessed over 14 days in the MAD study.

RESULTS

No serious adverse events or discontinuations due to adverse events occurred in either study. In healthy and T2DM subjects, dapagliflozin was rapidly absorbed with a time to maximum plasma concentration of 0.5-1.3 h. Systemic exposure of dapagliflozin and dapagliflozin 3-O-glucuronide, measured by maximum plasma concentration and area under the plasma concentration-time curve, increased proportional to dose. On a molar basis, systemic exposure to dapagliflozin 3-O-glucuronide was similar to parent dapagliflozin. There was a dose-related increase in the amount of glucose excreted in the urine (SAD and MAD), which was associated with dose-related decreases in plasma glucose parameters in subjects with T2DM (MAD).

CONCLUSIONS

Dapagliflozin was well tolerated and showed predictable dose-proportional PK and PD parameters in both healthy and T2DM Japanese subjects.

Serum magnesium, ambulatory blood pressure, and carotid artery alteration: the Ohasama study

BACKGROUND

To investigate the associations of 24-h ambulatory blood pressure (ABP) and serum magnesium level (sMg) with risk of carotid artery alteration in a general population.

METHODS

sMg and ABP, monitored every 30 min, were measured in 728 subjects (mean age, 67 years) from the Japanese general population. The extent of carotid artery alteration was evaluated according to mean common carotid intima-media thickness (IMT) and the presence of focal carotid plaque. To determine the association of sMg and carotid artery alteration, analysis of covariance (ANCOVA) (for adjusted mean IMT) or multiple logistic regression analysis (for odds ratio (OR) for the presence of carotid plaques) was used.

RESULTS

Lower sMg was significantly associated with mean IMT (P = 0.004) and risk of ≥2 carotid plaques (P = 0.03) after adjusting for possible confounding factors, including 24-h ABP (systolic), creatinine clearance (Ccr) (estimated using the Cockcroft-Gault equation), and serum minerals (sodium, potassium, calcium, and inorganic phosphorus). Even when 24-h ABP values were within normal range (<130/80 mm Hg), lower sMg levels (<2.2 mg/dl) were significantly associated with mean IMT (P = 0.007) and risk of ≥2 carotid plaques (OR, 2.14; 95% confidence interval, 1.18-3.85; P = 0.01).

CONCLUSIONS

Both 24-h ABP and lower sMg were closely and independently associated with risk of carotid artery alteration. Further investigations are needed to examine the relationship between sMg levels and the incidence of cardiovascular disease.

Adipose differentiation-related protein regulates lipids and insulin in pancreatic islets

The excess accumulation of lipids in islets is thought to contribute to the development of diabetes in obesity by impairing beta-cell function. However, lipids also serve a nutrient function in islets, and fatty acids acutely increase insulin secretion. A better understanding of lipid metabolism in islets will shed light on complex effects of lipids on beta-cells. Adipose differentiation-related protein (ADFP) is localized on the surface of lipid droplets in a wide range of cells and plays an important role in intracellular lipid metabolism. We found that ADFP was highly expressed in murine beta-cells. Moreover, islet ADFP was increased in mice on a high-fat diet (3.5-fold of control) and after fasting (2.5-fold of control), revealing dynamic changes in ADFP in response to metabolic cues. ADFP expression was also increased by addition of fatty acids in human islets. The downregulation of ADFP in MIN6 cells by antisense oligonucleotide (ASO) suppressed the accumulation of triglycerides upon fatty acid loading (56% of control) along with a reduction in the mRNA levels of lipogenic genes such as diacylglycerol O-acyltransferase-2 and fatty acid synthase. Fatty acid uptake, oxidation, and lipolysis were also reduced by downregulation of ADFP. Moreover, the reduction of ADFP impaired the ability of palmitate to increase insulin secretion. These findings demonstrate that ADFP is important in regulation of lipid metabolism and insulin secretion in beta-cells.

Particle-based methods for multiscale modeling of blood flow in the circulation and in devices: challenges and future directions. Sixth International Bio-Fluid Mechanics Symposium and Workshop March 28-30, 2008 Pasadena, California

A major computational challenge for a multiscale modeling is the coupling of disparate length and timescales between molecular mechanics and macroscopic transport, spanning the spatial and temporal scales characterizing the complex processes taking place in flow-induced blood clotting. Flow and pressure effects on a cell-like platelet can be well represented by a continuum mechanics model down to the order of the micrometer level. However, the molecular effects of adhesion/aggregation bonds are on the order of nanometer. A successful multiscale model of platelet response to flow stresses in devices and the ensuing clotting responses should be able to characterize the clotting reactions and their interactions with the flow. This paper attempts to describe a few of the computational methods that were developed in recent years and became available to researchers in the field. They differ from traditional approaches that dominate the field by expanding on prevailing continuum-based approaches, or by completely departing from them, yielding an expanding toolkit that may facilitate further elucidation of the underlying mechanisms of blood flow and the cellular response to it. We offer a paradigm shift by adopting a multidisciplinary approach with fluid dynamics simulations coupled to biophysical and biochemical transport.

High fruit intake is associated with a lower risk of future hypertension determined by home blood pressure measurement: the OHASAMA study

We investigate associations of fruit and vegetable intake with the risk of future hypertension using home blood pressure in a general population from Ohasama, Japan. We obtained data from 745 residents aged ≥35 years without home hypertension at baseline. Dietary intake was measured using a validated 141-item food frequency questionnaire, and subjects were then divided into quartiles according to the fruit and vegetable intake. Home hypertension was defined as home systolic/diastolic blood pressure of ≥135/85 mm Hg and/or the use of antihypertensive medication. During a 4-year follow-up period, we identified 222 incident cases of home hypertension. After adjustment for all putative confounding factors, the highest quartile of fruit intake was associated with a significantly lower risk of future home hypertension (odds ratio 0.40, 95% confidence interval 0.22-0.74, P=0.004). In conclusion, this study, based on home blood pressure measurement, suggests that higher intake of fruit is associated with a lower risk of future home hypertension.

Factors affecting efficacy in patients with genotype 2 chronic hepatitis C treated by pegylated interferon alpha-2b and ribavirin: reducing drug doses has no impact on rapid and sustained virological responses

Reducing the dose of drug affects treatment efficacy in pegylated interferon (Peg-IFN) and ribavirin combination therapy for patients with hepatitis C virus (HCV) genotype 1. The aim of this study was to investigate the impact of drug exposure, as well as the baseline factors and the virological response on the treatment efficacy for genotype 2 patients. Two-hundred and fifty patients with genotype 2 HCV who were to undergo combination therapy for 24 weeks were included in the study, and 213 completed the treatment. Significantly more patients who achieved a rapid virological response (RVR), defined as HCV RNA negativity at week 4, achieved a sustained virological response (SVR) (92%, 122/133) compared with patients who failed to achieve RVR (48%, 38/80) (P < 0.0001). Multivariate logistic-regression analysis showed that only platelet counts [odds ratio (OR), 1.68; confidence interval (CI), 1.002-1.139] and RVR (OR, 11.251; CI, 5.184-24.419) were independently associated with SVR, with no correlation being found for the mean dose of Peg-IFN and ribavirin for RVR and SVR. Furthermore, in the stratification analysis of the timing of viral clearance, neither mean dose of Peg-IFN (P = 0.795) nor ribavirin (P = 0.649) affected SVR in each group. Among the patients with RVR, the lowest dose group of Peg-IFN (0.77 +/- 0.10 microg/kg/week) and ribavirin (6.9 +/- 0.90 mg/kg/day) showed 100% and 94% of SVR. Hence, RVR served as an important treatment predictor, and drug exposure had no impact on both SVR and RVR in combination therapy for genotype 2 patients.

Reduced risk of hepatocellular carcinoma after interferon therapy in aged patients with chronic hepatitis C is limited to sustained virological responders

This study was undertaken to investigate the effect of interferon (IFN) monotherapy on the risk of hepatocellular carcinoma (HCC) in aged-patients with chronic hepatitis C. Seven hundred and twenty-five patients with histologically proven chronic hepatitis C were enrolled in this retrospective cohort study; 531 received IFN monotherapy for 6 months between 1992 and 1995, and 157 were collected as a historical control. The effect of IFN therapy on the development of HCC was compared between the patients with chronic hepatitis C under 60 years old (non-aged group, n = 531) and those 60 and over (aged group, n = 194). A stepwise Cox proportional-hazards regression analysis in the non-aged group revealed that IFN therapy (risk ratio 0.52, 95% CI 0.33-0.81, P = 0.004), older age (P = 0.001), and higher histological stage (P < 0.001) were independent factors associated with the development of HCC. In the aged-group, only higher histological stage (P = 0.002) and male gender (P = 0.011), but not IFN therapy (risk ratio 0.77, 95% CI 0.42-1.40, P = 0.386), were identified as independent risk factors for HCC, although HCC was significantly reduced when sustained virological response (SVR) was obtained (risk ratio 0.23, 95% CI 0.08-0.64, P = 0.005). In conclusion, inhibitory effect of IFN on development of HCC in the patients with chronic hepatitis C aged 60 and over was limited to the patients achieving SVR when treated with 6 months-IFN monotherapy.