Extensive N‐methylation of chitosan: evaluating the effects of the reaction conditions by using response surface methodology

The effects of reaction time, concentration of aqueous sodium hydroxide and molar ratio iodomethane/chitosan on the yield of the reaction of chitosan with iodomethane in N‐methyl‐2‐pyrrolidone (NMP) at 25.0 ± 0.1 °C, as well as on the characteristics of the resulting N,N,N‐trimethylchitosan (TMCh), were evaluated by using full‐factorial 2³ design analysis and response surface methodology. This study also aimed to determine the reaction conditions allowing the production of water‐soluble TMCh presenting a high average degree of quaternization and intrinsic viscosity at high reaction yield. ¹H NMR spectroscopy was employed for structural characterization, including the determination of average degrees of acetylation () and quaternization (), while capillary viscometry was used to determine intrinsic viscosity [η]. The results show that when the extensive N‐methylation is carried out for 24 h in NMP/15% NaOH (w/v) employing a lower excess of iodomethane (CH₃I/Ch = 9), water‐soluble highly substituted ( = 46.0%) TMCh ([η] = 213.0 mL g^?1) can be produced in high yield (81.8%). The highly significant mathematical models resulting from this study describe the dependence of the experimental responses on the reaction conditions and allow the characteristics and properties of the resulting TMCh to be defined by properly choosing the reaction conditions. © 2015 Society of Chemical Industry     

Effects of cold rolling process variables on final surface quality of stainless steel thin strip

In cold rolling some surface defects, known as pits, are due to lubricant that, entrapped in the deep valleys of the surface roughness, is nearly incompressible and acts like an inclusion avoiding microcavity elimination. During the rolling process, when specific favorable conditions can be set up, the lubricant may be expelled by the microplasto-hydrodynamic lubrication (MPHL) mechanism and pits may be recovered. In this paper the Λ_m parameter, index of the MPHL, is investigated together with the neutral point position to better understand the practical process recommendations for surface defect recovery. By means of finite element analysis of a Sendzimir’cold rolling process, the sensitivity of these objective functions are studied by means of a design of experiment analysis changing the major process variables like back tension, friction coefficient, reduction parameter, initial thickness, and roll diameter.     

Hydroelastic optimization of a keel fin of a sailing boat: a multidisciplinary robust formulation for ship design

The paper presents a formulation for multidisciplinary design optimization of vessels, subject to uncertain operating conditions. The formulation couples the multidisciplinary design analysis with the Bayesian approach to decision problems affected by uncertainty. In the present context, the design specifications are no longer given in terms of a single operating design point, but in terms of probability density function of the operating scenario. The optimal configuration is that which maximizes the performance expectation over the uncertain parameters variation. In this sense, the optimal solution is “robust” within the stochastic scenario assumed. Theoretical and numerical issues are addressed and numerical results in the hydroelastic optimization of a keel fin of a sailing yacht are presented.     

Identification and functional traits of lactic acid bacteria isolated from Ciauscolo salami produced in Central Italy

Lactic acid bacteria (LAB) from Ciauscolo salami produced in Marche Region of Central Italy, and LAB strains belonging to our laboratory collection were examined for their capability to survive at low pH and bile, to adhere to Caco-2 cells, and for antibiotic resistance. LAB from Ciauscolo were identified by ARDRA and RAPD-PCR. Our study showed that all LAB strains had good adaptation to gastric juice and moderate tolerance to bile. The adhesiveness was variable among strains but significantly lower in LAB from food. Antibiotic resistance was broadly spread among food strains, with level of resistance exceeding 15% for all the antibiotics tested. The resistance determinants erm(B) and tet(M) were found in nine strains of food origin (21.4%) while tet(L) in one strain of our collection (5%). Our work suggests that fermented foods are valuable sources of bacterial strains with functional traits of intestinal lactobacilli. These bacteria may be further studied for their use in probiotic applications.     

Prevalence and growth characteristics of malignant stem cells in B-lineage acute lymphoblastic leukemia

We used a stroma-supported culture method to study the prevalence and growth characteristics of malignant stem cells in acute lymphoblastic leukemia (ALL). In 51 of 108 B-lineage ALL samples, bone marrow-derived stroma not only inhibited apoptosis of ALL cells but also supported their proliferation in serum-free medium. When single leukemic cells were placed in the stroma-coated wells of microtiter plates, the percentage of wells with leukemic cell growth after 2 to 5 months of culture ranged from 6% to 20% (median, 15%; 5 experiments). The immunophenotypes and genetic features of cells recovered from these cultures were identical to those noted before culture. All cells maintained their stroma dependency and self-renewal capacity. Leukemic clones derived from single cells contained approximately 10(3) to 10(6) cells after 1 month of culture; other clones became detectable only after prolonged culture. Cell growth in stroma-coated wells correlated with the number of initially seeded cells (1 or 10; r = .87). However, the observed percentages of positive wells seeded with 10 cells always exceeded values predicted from results with single-cell-initiated cultures (P < .003 by paired t-test), suggesting stimulation of leukemic cell growth by paracrine factors. In conclusion, the proportion of ALL cells with clonogenic potential may be considerably higher than previously thought.     

Value of right ventricular ejection fraction in predicting short-term prognosis of patients with severe chronic heart failure

BACKGROUND: The prognosis of chronic heart failure has been studied extensively, but factors predicting short-term outcome in patients with severe chronic heart failure are still poorly defined, and the current indications for heart transplantation as a treatment for end-stage heart failure need on objective analysis. METHODS: Purpose of the study was to identify the determinants of short-term prognosis in a group of 142 consecutive ambulatory patients (mean age 49.8 +/- 11 years). Referred for heart transplantation because of severe chronic heart failure, the patients were admitted with left ventricular ejection fraction markedly depressed and had had symptoms in spite of an optimal standardized medical therapy for at least 1 month. Baseline clinical and instrumental evaluation included right-sided heart catheterization with a flow-directed multilumen thermodilution catheter, which enables determination of pressures, cardiac output, right ventricular volumes, and ejection fraction. RESULTS: Most patients were in New York Heart Association class III (61%) and IV (24%), and the hemodynamic profile was characterized by mean left ventricular ejection fraction of 20.2% +/- 6%, cardiac index of 2.13 +/- 0.6 l/min/m2, pulmonary capillary wedge pressure of 23.1 +/- 11 mm Hg, right atrial pressure of 7.9 +/- 6 mm Hg, right ventricular ejection fraction of 23.2% +/- 12.4%. During a mean follow-up of 11.1 +/- 9.4 months, 33 patients underwent transplantation (23.4%), 41 died (28.8%), and 68 were still alive (47.8%). There was a substantial overlap in left ventricular ejection fraction between patients divided on the basis of outcome, whereas right ventricular ejection fraction was significantly lower in patients who died or underwent transplantation. Cox multivariate analysis showed three independent prognostic variables: cause (p = 0.03), heart failure score (p = 0.001), and right ventricular ejection fraction (p = 0.000). Short-term survival (10 months) was significantly (p = 0.000) different in patients with > or = 24% or < 24% right ventricular ejection fraction. Statistical analysis identified right ventricular ejection fraction as the single variable to be highly correlated with an increased risk of early death. CONCLUSIONS: This study suggests that right ventricular function is a crucial determinant of short-term prognosis in severe chronic heart failure. Statistical analysis identified right ventricular ejection fraction, determined by thermodilution during right-sided heart catheterization, as the single most important predictor of short-term prognosis in a large cohort of patients who had symptoms in spite of a standardized, optimized, multipharmacologic treatment. The variable allows a useful risk stratification in patients with severe chronic heart failure and uniformly depressed left ventricular ejection fraction and provides guidance in the assessment of indications and timing for transplantation.     

Afterload mismatch-related problems after "domino" heart transplantation

The heart transplants with domino technique, which uses donor hearts from heart-lung recipients, increases the pool of donors, provides the advantage of shortening the ischemic time and makes suitable hearts for patients with pulmonary hypertension. The present study aimed to characterise the pre- and post-transplant clinical and hemodynamic profiles of patients that underwent domino transplant in Pavia. METHODS: Between 1991 and 1992, 9 heart transplants were performed with the domino procedure at I.R.C.C.S. Policlinico S. Matteo of Pavia. Domino donors (6 with primary pulmonary hypertension, 2 with Eisenmenger's syndrome due to atrial septal defect, 1 with cystic fibrosis) underwent electrocardiographic, echocardiographic, chest roentgenogram studies, and right heart catheterization and coronary angiography (for donor older than 40). Domino recipients, 6 males and 3 females with a mean age of 44 years, had dilated cardiomyopathy (4 cases), coronary artery disease (4 cases) and valvular heart disease (1 case) (group 1). Seven of the 9 cases entered the study; 2 were excluded: one because had undergone heterotopic transplantation, the other had received the heart from another country and therefore the graft had suffered from a very long ischemic time. Controls group consisted of 12 patients who had consecutively undergone cardiac transplantation with non-domino donors during the same period (group 2). Immunosuppression was similar in both groups, and consisted of a combination of cyclosporin A, azathioprine and corticosteroids, plus a 7-day-course of antithymocyte globulin. Hemodynamic and echocardiographic controls were performed at 2, 3 and 4 weeks (short-term control) and at 2 and 6 months (mid-term control) after surgery. RESULTS: Domino donors (39 +/- 12.5 years) had significantly higher mean right ventricular end-diastolic diameter and lower left ventricular diameter than normal mean values. Domino recipients had significantly higher mean pulmonary arteriolar resistances than controls; mean ischemic time was also significantly lower in group 1 than in group 2. Short- and mid-term controls after surgery in group 1 showed persistently higher systemic vascular resistances and pulmonary vascular resistances and lower cardiac output than in group 1. Two patients developed an early and unexpected increase in pulmonary wedge pressure accompanied by severe paroxysmal nocturnal dyspnea and mitral regurgitation. In all cases, the left ventricles were relatively inadequate; the combination of low cardiac output and of high systemic vascular resistances favoured the occurrence of an afterload mismatch condition that was worsened by chronic hypoxia. This condition must be known and expected in these patients after transplantation in order to provide timely and effective treatment to potentially life-threatening left ventricular failure episodes. IN CONCLUSION, the subset of transplanted patients that receives domino donors may develop left-side afterload mismatch which, combined with low cardiac output, with high systemic vascular resistances and with the effects of chronic hypoxia originally suffered by the heart, may cause sudden and unexpected left-side heart failure which has to be timely recognised and managed. Although hemodynamic adaptation of this patients is highly problematic, it does not limit the value of the domino procedure.     

Triptorelin acetate administration in early pregnancy: case reports and review of the literature

OBJECTIVE: The report estimates the treatment costs, cost-offset effects, and cost-effectiveness of Collaborative Care of depressive illness in primary care. STUDY DESIGN: Treatment costs, cost-offset effects, and cost-effectiveness were assessed in two randomized, controlled trials. In the first randomized trail (N = 217), consulting psychiatrists provide enhanced management of pharmacotherapy and brief psychoeducational interventions to enhance adherence. In the second randomized trial (N = 153). Collaborative Care was implemented through brief cognitive-behavioral therapy and enhanced patient education. Consulting psychologist provided brief psychotherapy supplemented by educational materials and enhanced pharmacotherapy management. RESULTS: Collaborative Care increased the costs of treating depression largely because of the extra visits required to provide the interventions. There was a modest cost offset due to reduced use of specialty mental health services among Collaborative Care patients, but costs of ambulatory medical care services did not differ significantly between the intervention and control groups. Among patients with major depression there was a modest increase in cost-effectiveness. The cost per patient successfully treated was lower for Collaborative Care than for Usual Care patients. For patients with minor depression. Collaborative Care was more costly and not more cost-effective than Usual Care. CONCLUSIONS: Collaborative Care increased depression treatment costs and improved the cost-effectiveness of treatment for patients with major depression. A cost offset in specialty mental health costs, but not medical care costs, was observed. Collaborative Care may provide a means of increasing the value of treatment services for major depression.     

IL-2 adenovector-transduced autologous tumor cells induce antitumor immune responses in patients with neuroblastoma

In many different murine models, the immunogenicity of tumor cells can be increased by transduction with a range of immunostimulatory genes, inducing an immune response that causes regression of pre-existing unmodified tumor cells. To investigate the relevance of these animal models to pediatric malignancy, we used autologous unirradiated tumor cells transduced with an adenovirus-IL-2 to immunize 10 children with advanced neuroblastoma. In a dose-escalation study, we found that this tumor immunogen induced a moderate local inflammatory response consisting predominantly of CD4(+) T lymphocytes, and a systemic response, with a rise in circulating CD25(+) and DR+ CD3(+) T cells. Patients also made a specific antitumor response, manifest by an IgG antitumor antibody and increased cytotoxic T-cell killing of autologous tumor cells. Clinically, five patients had tumor responses after the tumor immunogen alone (one complete tumor response, one partial response, and three with stable disease). Four of these five patients were shown to have coexisting antitumor cytotoxic activity, as opposed to only one of the patients with nonresponsive disease. These results show a promising correlation between preclinical observations and clinical outcome in this disease, and support further exploration of the approach for malignant diseases of children.     

Regulation of delta opioid receptors by delta9-tetrahydrocannabinol in NG108-15 hybrid cells

In this study we employed the neuroblastoma x glioma NG 108-15 cell line as a model for investigating the effects of long-term activation of cannabinoid receptors on delta opioid receptor desensitization, down-regulation and gene expression. Exposure of NG 108-15 cells to (-)-delta9-tetrahydrocannabinol (delta9-THC) reduced opioid receptor binding, evaluated in intact cells, by approximately 40-45% in cells exposed for 24 h to 50 and 100 nM delta9-THC and by approximately 25% in cells exposed to 10 nM delta9-THC. Lower doses of delta9-THC (0.1 and 1 nM) or a shorter exposure time to the cannabinoid (6 h) were not effective. Down-regulation of 6 opioid receptors was not observed in cells exposed for 24 h to pertussis toxin (PTX) and then treated for 24 h with 100 nM delta9-THC. In cells that were exposed for 24 h to the cannabinoid, the ability of delta9-THC and of the delta opioid receptor agonist [D-Ser2, Leu5, Thr6]enkephalin to inhibit forskolin-stimulated cAMP accumulation was significantly attenuated. Prolonged exposure of NG 108-15 cells to 100 nM delta9-THC produced a significant elevation of steady-state levels of delta opioid receptor mRNA. This effect was not observed in cells pretreated with PTX. The selective cannabinoid receptor antagonist SR 141716A blocked the effects elicited by delta9-THC on delta opioid receptor desensitization, down-regulation and gene expression; thus indicating that these are mediated via activation of cannabinoid receptors. These data demonstrate the existence, in NG 108-15 cells, of a complex cross-talk between the cannabinoid and opioid receptors on prolonged exposure to delta9-THC triggered by changes in signaling through Gi and/or G0-coupled receptors.