Size-exclusion chromatography purification of high-titer vesicular stomatitis virus G glycoprotein-pseudotyped retrovectors for cell and gene therapy applications

Vesicular stomatitis virus G glycoprotein (VSV-G)-pseudotyped replication-defective retroviral particles are pantropic and amenable to concentration to high titer by ultracentrifugation. These features have allowed development of effective retroviral transduction protocols for stem cells in vitro as well as for tissue engineering in vivo. However, retroparticle ultracentrifugation protocols will also copellet cellular and subcellular debris released from retroviral producer cell lines during vector manufacture. We have analyzed concentrated vector preparations by chromatography and have found that a significant amount of genomic DNA released from producer cells coconcentrates with retroviral particles. In an effort to generate high-purity retroparticle preparations, devoid of subcellular contaminants and contaminating genomic DNA, we have developed a process using size-exclusion chromatography combined with host cell nucleic acid digestion and concentration by ultrafiltration. The procedure allowed for a final recovery of 19 +/- 0.4% infectious viral particles from unfractionated starting material, with an average retroparticle concentration of 7.7 x 10(7) +/- 1.5 x 10(6)/ml. The intact virus is of high purity, >90% as determined by anion-exchange high-performance liquid chromatography. Retroparticle structure appeared intact as determined by negative stain electron microscopy and purified virus was functional and allowed for efficient transduction of primary human bone marrow stromal cells in vitro. In conclusion, we have developed a VSV-G retrovector purification process that can be applied to large-scale retroviral production ideal for cell and gene therapy applications.     

New trends in the management of head and neck cancers

Head and neck cancers affect more than half million person a year worldwide. More than 40% have an advanced stage at diagnosis. The incidence in Lebanon according to the statistics of the Ministry of Public Health was 268 new cases in 2007. The tumors and their treatment modalities have an important impact on the quality of life because they influence communication, breathing and4 swallowing. Treatment modalities are evolving to more conservative approaches for better functional results without impeding survival. We present in this review the state of the art of the management of head and neck cancer in 2011 with emphasis on the most recent advances in the assessment, treatment and follow-up.     

NADPH oxidase inhibition rescues keratinocytes from elevated oxidative stress in a 2D atopic dermatitis and psoriasis model

Emerging evidence suggests oxidative stress plays a role in the pathophysiology of both atopic dermatitis (AD) and psoriasis (PSO). We established in vitro models of AD and PSO skin, and characterized these models in regard to their oxidative stress state. Both AD and PSO model keratinocytes exhibited elevated reactive oxygen species (ROS) levels and accumulated more DNA damage than control cells after oxidative stress induced by 250 µmol/L H₂O₂. Elevated ROS levels and DNA damage accumulation could be inhibited by the NADPH oxidase (NOX) inhibitor diphenyleneiodonium (DPI). Further, immunofluorescence analysis revealed the presence of both NOX1 and NOX4 in keratinocytes. By inhibiting NOX1, stress-related signalling cascades and elevated ROS levels could be abrogated, and survival of AD and PSO cells improved. Taken together, this study reveals that inhibition of NOX inhibition could abrogate elevated oxidative stress in a 2D model of AD and PSO.     

IL-6 Levels,Nutritional Status,and Mortality in Prevalent Hemodialysis Patients

Summary

Background and objectives

The influence of serum IL-6 levels on nutritional status in chronic hemodialysis (HD) patients remains to be elucidated. The present report describes a prospective longitudinal study of IL-6 levels and nutritional parameters to determine whether high IL-6 levels are independently associated with nutritional status over time in a cohort of prevalent hemodialysis patients.

Design, setting, participants, & measurements

85 clinically stable hemodialysis patients (37.6% women), with a mean age of 66.5 ± 10.6 years, were studied after exclusion of patients with BMI < 20 kg/m² and/or serum albumin <35 g/L. IL-6, dietary energy and protein intake, and biochemical markers of nutrition and body composition (anthropometry and bioimpedance analysis) were measured at baseline and at 6, 12, 18, and 24 months following enrollment. Observation of this cohort was continued over 2 additional years.

Results

IL-6 levels increased with time in both unadjusted (linear estimate: 2.57 ± 0.44 pg/ml per 2 yrs; P = 0.001) and adjusted models (linear estimate: 2.35 ± 0.57 pg/ml per 2 yrs; P = 0.049). Significant reductions of daily energy intake, laboratory markers (albumin, transferrin, cholesterol, creatinine), and body composition (fat mass) with higher IL-6 levels were observed over the duration of the longitudinal observation period. However, none of the studied parameters were associated with changes in IL-6 levels over time (IL-6-by-time interactions were NS). Furthermore, cumulative incidences of survival were correlated with the baseline serum IL-6 levels (P = 0.004 by log-rank test). Finally, for each pg/ml increase in IL-6 level, the hazard ratio for death from all causes was 1.06 (95% CI 1.01 to 1.10) after adjustment for demographic and clinical parameters.

Conclusions

Our results suggest that higher serum IL-6 levels are associated with all-cause mortality without additional changes in clinical and laboratory markers of nutritional status in clinically stable HD patients.     

Spontaneous rupture and hemorrhage of hepatic focal nodular hyperplasia in lobus caudatus

In general, focal nodular hyperplasia lesions of the liver have a benign natural course; the majority of cases remain asymptomatic and complications are rare. We report a case of spontaneous rupture and hemorrhage of focal nodular hyperplasia, which is extremely rare in the literature. A 35-year-old woman was admitted with severe upper abdominal pain and unstable hemodynamic status. No major abdominal trauma was noted. Radiology findings suggested a diffuse hemoperitoneum. Emergent surgical exploration showed a hemoperitoneum due to the rupture of a hepatic mass lesion in segment I. Suture of the rupture was undertaken with success. After this lifesaving emergent surgery, further investigations, including ultrasound, contrast-enhanced computed tomography, and magnetic resonance imaging, were undertaken, and a 5.7 × 9.8 × 6.4-cm focal nodular hyperplasia lesion was identified in segment I. Two weeks after the first surgical hemostasis, surgical removal of segment I, including the mass, was performed. The postoperative course was uneventful. Pathological evaluation confirmed the nature of focal nodular hyperplasia. The patient remains asymptomatic without evidence of recurrence 3 years and 6 months after surgery. To our knowledge, this is the firstcase of spontaneous rupture and hemorrhage of focal nodular hyperplasia that needed two consecutive surgical operations.     

Factors affecting birth weight in Kuwait. Part I, Maternal, dietary and socioeconomic factors.

The aim of this study was to determine the effect of maternal nutrition, vitamin supplementation and socioeconomic status on infants birth weight in Kuwait. The weight of 1995 newborn Kuwaiti infants was recorded shortly after delivery. Data on mothers' bodyweight just before pregnancy, height, weight gain during pregnancy and vitamin intake were recorded. Mothers were interviewed to collect data in family income, educational level and employment during pregnancy. The results show that mean birth weight in Kuwait (3.50 Kg) compares favourably with any country. The birth weight was affected by several factors. Maternal body weight, height and weight gain during pregnancy were positively correlated with birth weight. The results also show that the intake of vitamin supplement during pregnancy did not have a significant inference on birth weight. Obese mothers consuming a reducing diet delivered babies with birth weight slightly above normal. The results show that mothers from high income families had heavier babies when compared with a low income group. On the other hand, educated and employed mothers were more liable to have slightly smaller babies when compared with illiterate or unemployed mothers.     

Can a Single-Use and Patient-Specific Instrumentation Be Reliably Used in Primary Total Knee Arthroplasty? A Multicenter Controlled Study

Background

The aim of this controlled multicenter study is to evaluate the clinical and radiologic outcomes of primary total knee arthroplasty (TKA) using single-use fully disposable and patient-specific cutting guides (SU) and compare the results to those obtained with traditional patient-specific cutting guides (PSI) vs conventional instrumentation (CI).

Qualitative research on adolescent pregnancy: a descriptive review and analysis

This study examined qualitative research on adolescent pregnancy to determine designs and methods used and to discover emergent themes across studies. Most of the 22 studies reviewed were described as qualitative or phenomenological by design and included samples comprising either African-American and Caucasian participants or African-Americans exclusively. Based on analysis of the collective primary findings of the sample articles, four themes were identified: (a) factors influencing pregnancy; (a) pregnancy resolution; (c) meaning of pregnancy and life transitions; and (d) parenting and motherhood. Overall, the studies revealed that most adolescent females perceive pregnancy as a rite of passage and a challenging yet positive life event. More qualitative studies are needed involving participants from various ethnic backgrounds, on males' perceptions relative to adolescent pregnancy and fatherhood, and about decision-making relevant to pregnancy resolution, intimacy, and peer relationships.