Experimental and numerical study of a second-order transition in the behavior of confined self-propelled particles.

In this paper, we conduct experimental investigations on the behavior of confined self-propelled particles within a circular arena, employing small commercial robots capable of locomotion, communication, and information processing. These robots execute circular trajectories, which can be clockwise or counterclockwise, based on two internal states. Using a majority-based stochastic decision algorithm, each robot can reverse its direction based on the states of two neighboring robots. By manipulating a control parameter governing the interaction, the system exhibits a transition from a state where all robots rotate randomly to one where they rotate uniformly in the same direction. Moreover, this transition significantly impacts the trajectories of the robots. To extend our findings to larger systems, we introduce a mathematical model enabling characterization of the order transition type and the resulting trajectories. Our results reveal a second-order transition from active Brownian to chiral motion.

mTOR in Alzheimer disease and its earlier stages: Links to oxidative damage in the progression of this dementing disorder.

Alzheimer's disease (AD) is the most prevalent form of dementia in the elderly population and has worldwide impact. The etiology of the disease is complex and results from the confluence of multiple mechanisms ultimately leading to neuronal loss and cognitive decline. Among risk factors, aging is the most relevant and accounts for several pathogenic events that contribute to disease-specific toxic mechanisms. Accumulating evidence linked the alterations of the mammalian target of rapamycin (mTOR), a serine/threonine protein kinase playing a key role in the regulation of protein synthesis and degradation, to age-dependent cognitive decline and pathogenesis of AD. To date, growing studies demonstrated that aberrant mTOR signaling in the brain affects several pathways involved in energy metabolism, cell growth, mitochondrial function and proteostasis. Recent advances associated alterations of the mTOR pathway with the increased oxidative stress. Disruption of all these events strongly contribute to age-related cognitive decline including AD. The current review discusses the main regulatory roles of mTOR signaling network in the brain, focusing on its role in autophagy, oxidative stress and energy metabolism. Collectively, experimental data suggest that targeting mTOR in the CNS can be a valuable strategy to prevent/slow the progression of AD.

Aberrant protein phosphorylation in Alzheimer disease brain disturbs pro-survival and cell death pathways.

Protein phosphorylation of serine, threonine, and tyrosine residues is one of the most prevalent post-translational modifications fundamental in mediating diverse cellular functions in living cells. Aberrant protein phosphorylation is currently recognized as a critical step in the pathogenesis and progression of Alzheimer disease (AD). Changes in the pattern of protein phosphorylation of different brain regions are suggested to promote AD transition from a presymptomatic to a symptomatic state in response to accumulating amyloid ß-peptide (Aß). Several experimental approaches have been utilized to profile alteration of protein phosphorylation in the brain, including proteomics. Among central pathways regulated by kinases/phosphatases those involved in the activation/inhibition of both pro survival and cell death pathways play a central role in AD pathology. We discuss in detail how aberrant phosphorylation could contribute to dysregulate p53 activity and insulin-mediated signaling. Taken together these results highlight that targeted therapeutic intervention, which can restore phosphorylation homeostasis, either acting on kinases and phosphatases, conceivably may prove to be beneficial to prevent or slow the development and progression of AD.

Isolation, identification and oenological characterization of non-Saccharomyces yeasts in a Mediterranean island.

UNLABELLED: We isolated, identified and characterized yeast strains from grapes, and their fermented musts, sampled in the small island of Linosa, where there are no wineries and therefore the possibility of territory contamination by industrial strains is minimal. By traditional culture-dependent methods, we isolated 3805 colonies, distinguished by molecular methods in 17 different species. Five hundred and forty-four isolates were analysed for the main oenological characteristics such as fermentative vigour with and without sulphites, sugar consumption and production of alcohol, volatile acidity, hydrogen sulphide, glycerol and ß-glucosidase. This analysis identified Kluyveromyces marxianus (seldomly used in winemaking) as the most interesting candidate yeast for the production of innovative wines. SIGNIFICANCE AND IMPACT OF THE STUDY: In recent years, interest is growing for wine production by non-Saccharomyces yeasts, both in research and in the industry. This study describes the yeast population of the grapes in a small-secluded island in the Mediterranean Sea, useful site for the search of new strains. Evaluation of fundamental oenological characters identifies potential best yeasts to assay in experimental vinifications. We also describe, for the first time, 14 new colony morphologies on WL Nutrient Agar, culture medium used to monitor the yeast population dynamics.

Gender-differences in disease distribution and outcome in hospitalized elderly: data from the REPOSI study.

BACKGROUND AND PURPOSE: Women live longer and outnumber men. On the other hand, older women develop more chronic diseases and conditions such as arthritis, osteoporosis and depression, leading to a greater number of years of living with disabilities. The aim of this study was to describe whether or not there are gender differences in the demographic profile, disease distribution and outcome in a population of hospitalized elderly people. METHODS: Retrospective observational study including all patients recruited for the REPOSI study in the year 2010. Analyses are referred to the whole group and gender categorization was applied. RESULTS: A total of 1380 hospitalized elderly subjects, 50.5% women and 49.5% men, were considered. Women were older than men, more often widow and living alone or in nursing homes. Disease distribution showed that malignancy, diabetes, coronary artery disease, chronic kidney disease and chronic obstructive pulmonary disease were more frequent in men, but hypertension, osteoarthritis, anemia and depression were more frequent in women. Severity and comorbidity indexes according to the Cumulative Illness Rating Scale (CIRS-s and CIRS-c) were higher in men, while cognitive impairment evaluated by the Short Blessed Test (SBT), mood disorders by the Geriatric Depression Scale (GDS) and disability in daily life measured by Barthel Index (BI) were worse in women. In-hospital and 3-month mortality rates were higher in men. CONCLUSIONS: Our study showed a gender dimorphism in the demographic and morbidity profiles of hospitalized elderly people, emphasizing once more the need for a personalized process of healthcare.

In vivo protective effect of ferulic acid against noise-induced hearing loss in the guinea-pig.

Ferulic acid (FA) is a phenolic compound whose neuroprotective activity was extensively studied in vitro. In this study, we provided functional in vivo evidence that FA limits noise-induced hearing loss. Guinea-pigs exposed to acoustic trauma for 1 h exhibited a significant impairment in auditory function; this injury was evident as early as 1 day from noise exposure and persisted over 21 days. Ferulic acid (150 mg/kg i.p. for 4 days) counteracted noise-induced hearing loss at days 1, 3, 7 and 21 from noise exposure. The improvement of auditory function by FA was paralleled by a significant reduction in oxidative stress, apoptosis and increase in hair cell viability in the organ of Corti. Interestingly in the guinea-pig cochleae, the neuroprotective effect of FA was functionally related not only to its scavenging ability in the peri-traumatic period but also to the up-regulation of the cytoprotective enzyme heme oxygenase-1 (HO-1); in fact, FA-induced improvement of auditory function was counteracted by the HO inhibitor zinc-protoporphyrin-IX and paralleled the time-course of HO-1 induction over 3-7 days. These results confirm the antioxidant properties of FA as free-radical scavenger and suggest a role of HO-1 as an additional mediator against noise-induced ototoxicity.

The heme oxygenase/biliverdin reductase pathway in drug research and development.

The heme oxygenase/biliverdin reductase (HO/BVR) axis catalyzes the degradation of heme, but this system and its by-products, carbon monoxide (CO) and bilirubin, have also been shown to exert cytoprotective effects by activating pro-survival pathways and scavenging free radicals. Naturally occurring substances that upregulate the inducible isoform of HO (HO-1) have therefore been proposed as potential new drugs for the treatment of free radical-induced disease. A number of existing drugs have also been shown to regulate the HO/BVR system, and this capacity is considered an additional mechanism for their therapeutic activity. However, upregulation of the HO/BVR axis is not always beneficial for cells: the heme depletion and accumulation of CO and bilirubin it causes are potentially toxic. Therefore, new pharmacological modulators of HO/BVR activity must act in a dose-dependent manner. This would allow dose titration to achieve a desired pharmacologic effect without producing toxicity. Unfortunately, this goal is more complicated than it seems because toxicity has to be defined in terms of each of the main products of heme metabolism. Furthermore, sensitivity to the therapeutic/toxic effects of these products is likely to be tissue- or cell-type specific. The solution may lie in the use of novel drug-delivery systems that allow targeted delivery of low doses of the HO/BVR modulator to selected tissues.

A psychosocial taxonomy of patients with diabetes: validation in a primary care setting.

AIMS: The aims of this study were (i) to extend a psychosocial taxonomy of patients with diabetes to a primary care setting, and (ii) to validate the taxonomy using more sophisticated clustering methods across an array of psychological dimensions independent of demographic and medical variables. METHODS: In a cross-sectional study, 111 adults with Type 2 diabetes seen in a primary care setting completed the Multidimensional Diabetes Questionnaire and the Brief Symptom Inventory (BSI). They also provided diabetes-specific self-report measures along with HbA(1c). RESULTS: Four psychosocial patient profiles were identified using model-based cluster analysis in a US primary care setting. The four profiles represent a replication of two and refinement of a third profile found previously in French-speaking patients at diabetes education centres. Validation of the profiles using the BSI was replicated for depression and extended to other psychological dimensions. The validity and distinctiveness of the four psychosocial profiles were independent of demographic and diabetes-specific medical variables. CONCLUSION: Replication and extended validation of the psychosocial taxonomy into primary care may allow healthcare workers to supplement medical treatments with psychosocial interventions that can improve outcomes for patients with diabetes that are practical, individually tailored, and cost-effective.

Assessment and treatment of depression following myocardial infarction.

Approximately 65 percent of patients with acute myocardial infarction report experiencing symptoms of depression. Major depression is present in 15 to 22 percent of these patients. Depression is an independent risk factor in the development of and mortality associated with cardiovascular disease in otherwise healthy persons. Persons who are depressed and who have pre-existing cardiovascular disease have a 3.5 times greater risk of death than patients who are not depressed and have cardiovascular disease. Physicians can assess patients for depression by using one of several easily administered and scored self-report inventories, including the SIG E CAPS + mood mnemonic. Cognitive-behavior therapy is the preferred psychologic treatment. Selective serotonin reuptake inhibitor antidepressants are the recommended pharmacologic treatment because of the relative absence of effects on the cardiovascular system. The combination of a selective serotonin reuptake inhibitor with cognitive-behavior therapy is often the most effective treatment for depression in patients with cardiovascular disease.

Interleukin-1alpha and collagenase activity are elevated in chronic wounds.

Interleukin-1-alpha (IL-1alpha) is a member of a family of proinflammatory polypeptide mediators that has been shown in vitro to stimulate collagenase production. Collagenase is a proteolytic enzyme classified as one of the matrix metalloproteinases (MMP-1) that specifically recognizes and cleaves collagen. Therefore, the objective of this study was to compare the levels of these two proteins in chronic wounds as possible factors in the pathogenesis of chronic wounds. Fluids from 10 chronic wounds were collected before and after a 1-week treatment with a hydroactive dressing (Cutinova cavity). In addition, fluids were collected from 20 acute wounds for comparison. IL-1alpha and MMP-1 levels were quantified using sandwich ELISA. Collagenase activity was measured using a radiolabeled collagen as substrate. Clinically, the chronic wounds showed decreased area (-21.0 cm2) and reduced volume (-134.5 cm3) by 4 weeks after treatment with the hydroactive dressing. There were no significant differences in the protein concentrations between acute wound fluids (21.0 +/- 3.0 mg/ml) and chronic wound fluids before and after treatment with the hydroactive dressing (18.3 +/- 5.5 and 25.2 +/- 7.6 mg/ml, respectively). Levels of IL-1alpha in the acute wound fluids were low (0.019 pg/mg), whereas in the chronic wound fluid before treatment they had been significantly elevated (44.9 + 21.8 pg/mg). Following treatment with the hydroactive dressing, the IL-1alpha levels dropped to 10.3 + 3.3 pg/mg (p < 0.05). Collagenase activity was not detectable in acute wound fluid, elevated in pretreatment chronic wounds (12.9 + 3.4 units), and decreased in chronic wounds after treatment (11.4 + 3.3 units). This study correlated clinical healing of chronic wounds with biochemical changes in the ulcer microenvironment. As the chronic wounds began to heal, there was a significant decrease in the IL-1alpha levels and collagenase activity, thus suggesting that these two proteins may contribute to the lack of healing characteristic of chronic wounds.

Endoscopic otoplasty in the rabbit model: effect of mechanical abrasion on ear cartilage deformation.

The purpose of this study was (1) to introduce an endoscopic technique for performing otoplasty; (2) to compare the durability of folding with scoring, sutures, or abrasion; and (3) to study the histologic changes associated with three techniques. Thirteen adult New Zealand White rabbits (26 ears) were divided into three otoplasty groups: bent cartilage (nine ears), cut cartilage (nine ears), or endoscopic abrasion of cartilage (eight ears). In all three groups, the ears were folded using external mattress sutures, with a transverse 180-degree fold. Sutures were removed at 1 to 6 weeks, and the ears followed for 4 weeks postoperatively. Ear-folding angles were followed weekly from suture removal to 4 weeks postoperatively. After sacrifice, the ear cartilage was harvested for histologic analysis. The ears were maintained in a 180-degree ventral fold by splinting sutures, which were removed at various times. Four weeks after suture removal, the mean ear angles were 13 degrees in the bent (control) group, 84 degrees in the cut group, and 132 degrees in the abraded group. The differences between the abraded and cut versus bent groups were significant (p = 0.0001 and 0.0073, respectively). There was no significant difference between the abraded versus cut groups. Histologic analysis showed perichondrial thickening on the convex surface in all of the groups. Fibrocartilage was produced in the cut and abraded groups. Based on histologic observation, the repair cartilage in the cut group was more fibrous, whereas that in the endoscopic group was more abundant with marked degenerative changes in the central zone. A new method of percutaneous endoscopic otoplasty in the rabbit model is described. This study showed that endoscopic otoplasty produced folding that was well maintained during the study period.

Hyaluronic acid inhibits fetal platelet function: implications in scarless healing.

Platelets are important for the initiation of inflammation in adults, but the role of fetal platelets in fetal wound healing is unclear because fetal dermal wounds heal with a minimal inflammatory response and lack of excessive scarring. Because fetal tissue is abundant in glycosaminoglycans (GAGs), predominantly hyaluronic acid (HA), this study was designed to test the hypothesis that HA inhibits the reactivity of platelets and thus contributes to the minimal scarring characteristic of fetal tissue repair. Platelets were isolated from 10 fetal pigs at day 80 of gestation (term, 115 days) and exposed to 0.5 mg/mL of arachidonic acid, an agent shown in prior studies to evoke maximal aggregation and degranulation of fetal platelets. The ability of HA at 0.1 and 0.5 mg/mL to inhibit this response was determined. The presence of HA resulted in a dose-dependent reduction in platelet aggregation at 180 seconds (control, 99.7 +/- 0.3%; HA [0.1 mg/mL] 91.7 +/- 3.8%; and HA [0.5 mg/mL] 48.5 +/- 9.0%; P < .005 v control). The onset of aggregation was also significantly delayed by 0.5 mg/mL of HA (13.5 +/- 2.5 seconds) compared to control (2.9 +/- 0.7 seconds), P < .05. No significant diminution of platelet aggregation could be achieved by the addition of other GAGs at similar concentrations. HA also significantly impaired the release of platelet-derived growth factor (PDGF)-AB from fetal platelets. The authors conclude that HA, the predominant GAG in fetal dermal matrix, inhibits platelet aggregation and cytokine release. This inhibition of platelet aggregation and resultant inflammatory response may explain, in part, the minimal inflammation and scarless healing characteristic of fetal dermal repair.

Collagen induces cytokine release by fetal platelets: implications in scarless healing.

In previous studies the authors demonstrated that unlike adult platelets, fetal platelets respond poorly to collagen. When platelets make contact with the exposed collagen at the site of injury, the result is activation, aggregation, and degranulation with the release of cytokines and growth factors. This sequence of events is well characterized in adult wounds, which heal with an acute inflammatory response and dense scar formation. In sharp contrast, fetal dermal wounds heal without an acute inflammatory response and minimal scar formation. Therefore, the aim of this study was to test the hypothesis that collagen, abundant at the site of dermal injury, is a poor inducer of cytokine release by fetal platelets. This could explain, in part, the minimal inflammation accompanying fetal dermal wound healing. Platelet suspensions from six fetal Yorkshire swine at day 80 of gestation (term, 114 days) were exposed to either arachidonic acid, 0.5 mg/mL, collagen, 0.19 mg/mL, or saline. The release into plasma of transforming growth factor-beta (TGF-beta 1), and platelet-derived growth factor (PDGF)-AB effected by these agents was determined by enzyme-linked immunosorbent assays. Transmission electron microscopy (TEM) was used to correlate the biochemical findings with ultrastructural changes and showed that arachidonate-treated platelets were aggregated and devoid of granules. In contrast, collagen-treated platelets had undergone conformational changes but showed only a moderate change in the quantity and homogeneity of their secretory granules compared with saline-treated controls. There was a significant increase in TGF-beta 1 release into plasma after treatment with collagen (6.64 +/- 0.36 ng/mL) and arachidonate (7.64 +/- 0.77 ng/mL) compared with saline (4.74 +/- 0.36 ng/mL), P < .05. Likewise, PDGF-AB release was significantly higher after collagen (0.22 +/- 0.02 ng/mL) and arachidonate treatment (0.44 +/- 0.04 ng/mL) compared with saline (0.09 +/- 0.02 ng/ mL), P < .05. The authors conclude that fetal platelets actually do release cytokines in response to contact with collagen despite poor aggregation. Therefore, impaired aggregation to collagen cannot solely explain the minimal inflammation after fetal wounding.

[Ambulatory phlebectomy with Müller procedure in the treatment of lower limb varices. Indications, technique and long-term results]. / La flebectomia ambulatoriale sec. Müller nel trattamento delle varici degli arti inferiori. Indicazioni, tecnica e risultati a distanza.

The authors report the results of more than five years experience of phlebectomies, according to Müller's method, performed both in general anesthesia during stripping operations and in local practice. The results confirmed the validity of this complementary surgical treatment for its radicality, execution simpleness and best respect for aesthetics.

Partial purification of a high molecular weight hepatocyte growth stimulating factor from normal calf serum.

A heparin-binding protein, acting as a potent hepatocyte growth stimulating factor (HGSF) was extracted and partially purified from normal calf serum. HGSF stimulated DNA synthesis and proliferation in primary cultures of adult Balb/c mouse hepatocytes and in two liver-derived epithelial cell lines (C6 and C2.8) plated at low cell density in serum-free medium in the absence of epidermal growth factor. HGSF was non-dialyzable in M(r) 50,000 cutoff membranes, and was purified after chromatofocusing on PBE94 resin, (NH4)2SO4 precipitation (80% salt concentration) of the active fractions eluted at pH 5.7, flow chromatography and elution through Sephacryl S300 HR and HA-Ultrogel columns. The hepatotrophic activity was eluted with a protein fraction that was concentrated approximately 40,000 fold over the starting material. The effect was half maximal at approximately 50 ng/ml on adult hepatocytes in primary culture, HGSF had a molecular weight of 90,000-110,000 by gel filtration, was unstable on heat-treatment and was completely inhibited after trypsin digestion and after reduction with dithiothreitol. HGSF did not stimulate growth in Balb/c 3T3 fibroblasts. When injected into partially (40%) hepatectomized Balb/c mice, HGSF increased hepatic DNA synthesis 2 to 4-fold over the background stimulation, at 20 hours after the hepatectomy.

Expression and inducibility of drug-metabolizing enzymes in novel murine liver epithelial cell lines and their ability to activate procarcinogens.

Four novel nontransformed epithelial cell lines, isolated from fetal or adult mouse liver, were tested: (a) to determine the profile of xenobiotic metabolizing enzymes; (b) to evaluate the inducibility of the polysubstrate (cytochrome P-450-dependent) monooxygenase system by various classes of inducers; and (c) to assess the capacity of the cells to metabolize structurally different procarcinogens. With regard to the phase I pathway, the cells expressed various P-450 (class IA, IA2, IIB, IIE1, IIIA) and flavin adenine dinucleotide-containing monooxygenase-dependent bio-transformation enzyme activities at levels (in lines C2.8 and C6) comparable with those present in murine adult liver preparations. The expression of various P-450s was demonstrated also by immunoprecipitation assays using rabbit polyclonal antibodies. For the phase II pathway, cells expressed substantial levels of glutathione S-transferase, glutathione S-epoxide transferase, and UDP-glucuronosyltransferase. Low expression of epoxide hydrolase was observed. Induction of P-450 function by sodium phenobarbital, beta-naphthoflavone, isosafrole, ethanol, and pregnenolone 16 alpha-carbonitrile, monitored using specific P-450-linked activities, was considerably elevated (over 5-fold in class IIB with the C2.8 and C6 cell lines). The most competent C2.8 and C6 cell lines were able to activate benzo(a)pyrene, cyclophosphamide, dimethylnitrosamine, diethylstilbestrol, and 2-naphthylamine as shown by the significantly increased frequencies of mitotic gene conversion, mitotic crossing-over, and point [reverse] mutation in the diploid D7 strain of Saccharomyces cerevisiae after 4 [cyclophosphamide], 24 [benzo(a)pyrene,2-naphthylamine, dimethylnitrosamine] or 48 [diethylstilbestrol], h of exposure in the presence of 3 x 10(6) cells/flask. The degree of conservation and the inducibility of representative oxidative and postoxidative reactions in the novel epithelial cell lines C2.8 and C6, together with their ability to activate a wide spectrum of procarcinogens, offers a means to study the potential of chemicals for inducing DNA damage in short-term genotoxicity testing. In addition the cells may be suitable for analyzing the metabolic disposition of compounds and the multistage process of carcinogenesis.

Screening for depression: use of patient questionnaires.

Despite the prevalence of depression, it is consistently underdiagnosed. As a result, many depressed patients fail to receive adequate treatment and may experience serious consequences, including suicide. Various screening instruments have been developed to identify depression in patients whose symptoms might go unrecognized. Despite the risks associated with screening, many benefits may result. These include increased recognition of depression, alteration of treatment plans and improved clinical outcome.

"Effort" thrombosis of the axillary and subclavian vein associated with cervical rib and oral contraceptives in a young woman athlete.

"Effort" thrombosis, also called the Paget-Schroetter syndrome or primary thrombosis of the upper extremity, has been well documented in the literature. However, in our review of the United States, Canadian, and British literature, we found only 52 cases in which it was related to sports participation. We report a case of axillary and subclavian vein "effort" thrombosis in a young woman athlete, who was predisposed to thrombosis by all three postulates of the Virchow triad: namely, (1) stasis caused by constriction from a cervical rib, (2) increased coagulability as a result of oral contraceptive use, and (3) vessel wall injury because of competitive softball participation. Of the available therapeutic plans, we believe that athletes with "effort" thrombosis should have aggressive treatment that is initiated as early as possible to prevent swelling, tingling numbness, easy fatigue of the arm, and pain on prolonged use of the affected extremity.

Nicardipine and propranolol in the treatment of essential hypertension.

Two hundred thirty-four patients with supine diastolic blood pressure of between 95 and 114 mm Hg were enrolled into a double-blind, randomized, parallel, multicenter trial. The patients were randomized to either nicardipine 30 mg tid, propranolol 40 mg tid, or nicardipine 30 mg tid and propranolol 40 mg tid for six weeks. Two hundred six patients yielded data for analyses. Of the 28 not included, seven had missing data, whereas the remaining 21 were excluded because they either failed to meet inclusion criteria or were noncompliant at endpoint. Both nicardipine and propranolol as monotherapies and in combination achieved statistically significant, (P less than .01), supine diastolic blood pressure reduction relative to baseline. The combination of nicardipine and propranolol showed a greater reduction in supine diastolic and systolic measurements than either of the monotherapies. Nicardipine produced greater blood pressure reductions one hour after dosing, whereas the propranolol treatment tended to produce slightly greater blood pressure decreases eight hours after dose. The combination always resulted in the greatest blood pressure reduction, independent of time after dose. Adverse experiences were reported by 26% of patients in the nicardipine-treated group, most often transient vasodilatory effects, by 17% of the propranolol-treated patients, and by 18% of the combination-treated group. This study demonstrated at the doses studied that nicardipine alone produced equivalent blood pressure reductions to those obtained by propranolol alone, but that the combination of these two drugs produced greater reductions in blood pressures than either of the monotherapies.