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1.
Mol Metab ; 41: 101046, 2020 11.
Article in English | MEDLINE | ID: mdl-32599075

ABSTRACT

OBJECTIVE: Cancer cachexia and muscle loss are associated with increased morbidity and mortality. In preclinical animal models, blocking activin receptor (ACVR) ligands has improved survival and prevented muscle wasting in cancer cachexia without an effect on tumour growth. However, the underlying mechanisms are poorly understood. This study aimed to identify cancer cachexia and soluble ACVR (sACVR) administration-evoked changes in muscle proteome. METHODS: Healthy and C26 tumour-bearing (TB) mice were treated with recombinant sACVR. The sACVR or PBS control were administered either prior to the tumour formation or by continued administration before and after tumour formation. Muscles were analysed by quantitative proteomics with further examination of mitochondria and nicotinamide adenine dinucleotide (NAD+) metabolism. To complement the first prophylactic experiment, sACVR (or PBS) was injected as a treatment after tumour cell inoculation. RESULTS: Muscle proteomics in TB cachectic mice revealed downregulated signatures for mitochondrial oxidative phosphorylation (OXPHOS) and increased acute phase response (APR). These were accompanied by muscle NAD+ deficiency, alterations in NAD+ biosynthesis including downregulation of nicotinamide riboside kinase 2 (Nrk2), and decreased muscle protein synthesis. The disturbances in NAD+ metabolism and protein synthesis were rescued by treatment with sACVR. Across the whole proteome and APR, in particular, Serpina3n represented the most upregulated protein and the strongest predictor of cachexia. However, the increase in Serpina3n expression was associated with increased inflammation rather than decreased muscle mass and/or protein synthesis. CONCLUSIONS: We present evidence implicating disturbed muscle mitochondrial OXPHOS proteome and NAD+ homeostasis in experimental cancer cachexia. Treatment of TB mice with a blocker of activin receptor ligands restores depleted muscle NAD+ and Nrk2, as well as decreased muscle protein synthesis. These results indicate putative new treatment therapies for cachexia and that although acute phase protein Serpina3n may serve as a predictor of cachexia, it more likely reflects a condition of elevated inflammation.


Subject(s)
Acute-Phase Proteins/metabolism , Muscle, Skeletal/metabolism , NAD/metabolism , Serpins/metabolism , Activin Receptors/antagonists & inhibitors , Activin Receptors/drug effects , Activin Receptors/metabolism , Activins/metabolism , Activins/pharmacology , Acute-Phase Proteins/physiology , Animals , Cachexia/metabolism , Cachexia/physiopathology , Cell Line, Tumor , Disease Models, Animal , Male , Mice , Mitochondria/metabolism , Muscle, Skeletal/physiology , Muscular Atrophy/metabolism , Myostatin/metabolism , Oxidative Phosphorylation , Serpins/physiology
2.
J Pediatr Urol ; 15(4): 309-314, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31326327

ABSTRACT

BACKGROUND: Urothelial cell carcinoma (UCC) of the bladder is exceedingly rare in pediatric patients. Limited data are available to guide management in this population. METHODS: The authors systematically searched MEDLINE, Cochrane Library, and Google Scholar (through February 2019) for case reports and series to summarize data regarding presentation, evaluation, management, and follow-up for patients ≤ 18 years diagnosed with UCC of the bladder. Patient-level data were abstracted, and adjusted logistic regression was used to identify factors associated with a combined outcome of recurrence or death. RESULTS: One hundred two articles describing 243 patients from 26 countries met criteria. Average age was 12.5 years, 32.6% were female, 15.3% had medical comorbidities, and 13.2% had known risk factors for bladder cancer. Initial management was transurethral resection in 95.5% of patients, whereas 6.2% required secondary intervention. Tumor stage was TaN0M0 in 86.4% and low grade in 93.4%. Recurrence and death occurred in 8.6% and 3.7%, respectively. Mean time to recurrence or death was 8.6 months (standard deviation [SD] 7.6) for 10.7%. Mean disease free follow-up without recurrence or death was 56.9 months (SD 54.2) for 89.3%. Patients with comorbidities, risk factors, or family history (odds ratio [OR]: 2.4, 95% confidence interval [CI]: 1.02-5.6); ≥TaN0M0 disease (OR: 6.2, 95% CI: 2.5-15.6); and larger tumors at diagnosis (OR: 1.7, 95% CI: 1.2-2.4) had significantly greater adjusted odds of recurrence or death after initial treatment. CONCLUSION: Based on pooled results, disease recurrence or death occurred in 10.7% of pediatric patients and within 9 months for most and within 32 months for all patients. This may suggest that low-grade and stage UCC of the bladder in pediatric patients can be systematically monitored for at least 3 years. However, prospective evaluation of this clinical strategy is warranted.


Subject(s)
Carcinoma, Transitional Cell/therapy , Disease Management , Urinary Bladder Neoplasms/therapy , Urinary Bladder/pathology , Carcinoma, Transitional Cell/diagnosis , Carcinoma, Transitional Cell/epidemiology , Child , Combined Modality Therapy , Disease Progression , Global Health , Humans , Incidence , Risk Factors , Survival Rate/trends , Urinary Bladder Neoplasms/diagnosis , Urinary Bladder Neoplasms/epidemiology
4.
Expert Opin Investig Drugs ; 25(1): 63-72, 2016.
Article in English | MEDLINE | ID: mdl-26560328

ABSTRACT

INTRODUCTION: Cachexia is a syndrome characterized by body weight loss, muscle wasting and metabolic abnormalities, that frequently complicates the management of people affected by chronic diseases. No effective therapy is actually available, although several drugs are under clinical evaluation. Altered energy metabolism markedly contributes to the pathogenesis of cachexia; it can be improved by exercise, which is able to both induce anabolism and inhibit catabolism. AREAS COVERED: This review focuses on exercise mimetics and their potential inclusion in combined protocols to treat cachexia. The authors pay with particular reference to the cancer-associated cachexia. EXPERT OPINION: Even though exercise improves muscle phenotype, most patients retain sedentary habits which are quite difficult to disrupt. Moreover, they frequently present with chronic fatigue and comorbidities that reduce exercise tolerance. For these reasons, drugs mimicking exercise could be beneficial to those who are unable to comply with the practice of physical activity. Since some exercise mimetics may exert serious side effects, further investigations should focus on treatments which maintain their effectiveness on muscle phenotype while remaining tolerable at the same time.


Subject(s)
Cachexia/drug therapy , Drugs, Investigational/therapeutic use , Exercise/physiology , Animals , Cachexia/etiology , Cachexia/physiopathology , Drug Design , Drugs, Investigational/adverse effects , Drugs, Investigational/pharmacology , Energy Metabolism/physiology , Humans , Neoplasms/complications
5.
J Asthma ; 51(7): 743-50, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24654705

ABSTRACT

OBJECTIVE: This study will investigate the reproducibility and influencing factors of exhaled breath temperature measured with the tidal breathing technique in asthmatic patients and healthy children. METHODS: Exhaled breath temperature, fractional exhaled nitric oxide, and spirometry were assessed in 124 children (63 healthy and 61 asthmatic), aged 11.2 ± 2.5 year, M/F 73/51. A modified version of the American Thoracic Society questionnaire on the child's present and past respiratory history was obtained from parents. Parents were also asked to provide detailed information on their child's medication use during the previous 4 weeks. Ear temperature, ambient temperature, and relative-ambient humidity were also recorded. RESULTS: Exhaled breath temperature measurements were highly reproducible; the second measurement was higher than the first measurement, consistent with a test-retest situation. In 13 subjects, between-session within-day reproducibility of exhaled breath temperature was still high. Exhaled breath temperature increased with age and relative-ambient humidity. Exhaled breath temperature was comparable in healthy and asthmatic children; when adjusted for potential confounders (i.e. ambient conditions and subject characteristics), thermal values of asthmatic patients exceeded those of the healthy children by 1.1 °C. Normalized exhaled breath temperature, by subtracting ambient temperature, was lower in asthmatic patients treated with inhaled corticosteroids than in those who were corticosteroid-naive. CONCLUSION: Measurements of exhaled breath temperature are highly reproducible, yet influenced by several factors. Corrected values, i.e. normalized exhaled breath temperature, could help us to assess the effect of therapy with inhaled corticosteroids. More studies are needed to improve the usefulness of the exhaled breath temperature measured with the tidal breathing technique in children.


Subject(s)
Asthma/physiopathology , Body Temperature , Breath Tests , Exhalation , Case-Control Studies , Child , Humans , Nitric Oxide/analysis , Reproducibility of Results , Temperature , Tidal Volume
6.
J Appl Microbiol ; 111(1): 224-32, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21496189

ABSTRACT

AIMS: To investigate the distribution of the genes that encode enterotoxins and the colonization factors (CF) types as well as the antibiotic susceptibility profile of enterotoxigenic Escherichia coli (ETEC) isolated from children from the Brazilian Northeast. METHODS AND RESULTS: We conducted a 3·5-year prospective study that involved 250 children with and 150 without diarrhoea, aged 1-60 months, from low-income families in Teresina/Brazilian Northeast. All samples were assayed for E. coli, enterotoxin and CF genes and antimicrobial susceptibility by microbiological methods and PCR. ETEC strains were isolated from 9·2% children with and 4·0% without diarrhoea. Infection was more common in children aged 6-24 months in rainy months. elt⁺ /CFA/IV⁺ and elt⁺ /CS14⁺ were the most frequent genotypes. Susceptibility to nalidixic acid, ciprofloxacin and gentamicin and resistance to ampicillin, cephalothin and sulfamethoxazole-trimethoprim were common. CONCLUSIONS: elt ⁺isolates and ETEC strains harbouring genes encoding CFA/IV and CS/14 were the most common ETEC found in Brazilian Northeast. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data, the first generated for north-eastern Brazilian children, may be important for the development of an effective vaccine and for facilitation of an empirical choice of antibiotic treatment or prophylaxis for traveller's diarrhoea in the area studied.


Subject(s)
Diarrhea/microbiology , Enterotoxigenic Escherichia coli/isolation & purification , Escherichia coli Infections/microbiology , Bacterial Toxins/genetics , Brazil , Child, Preschool , Diarrhea/drug therapy , Diarrhea, Infantile/drug therapy , Diarrhea, Infantile/microbiology , Enterotoxigenic Escherichia coli/drug effects , Enterotoxigenic Escherichia coli/genetics , Enterotoxigenic Escherichia coli/pathogenicity , Escherichia coli Infections/drug therapy , Escherichia coli Proteins/genetics , Female , Humans , Infant , Male , Prospective Studies , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Virulence Factors/genetics
7.
J Biol Regul Homeost Agents ; 25(4): 627-34, 2011.
Article in English | MEDLINE | ID: mdl-22217994

ABSTRACT

Allergic rhinitis (AR) is characterized by Th2 polarized immune response. Specific immunotherapy modifies this arrangement restoring a physiologic Th1 profile. Sublingual immunotherapy (SLIT) is widely prescribed, but there is no early marker of response. The aim of this study is to investigate possible marker of SLIT effectiveness. Thirty children with mite allergy were studied: 15 were treated with drugs alone, 15 with SLIT and drugs on demand. The study lasted 2 years. Visual analogue scale (VAS) for symptoms and medication score were evaluated. Serum cytokines (IL-2, IL-4, IL-6, IL-8, IL-10, IFN-gamma, MCP-1, and TNF-alpha) were assessed by ELISA before and after 1 and 2 year SLIT. SLIT-treated children obtained a significant improvement of symptoms and a reduction of drug use, whereas children treated with a drug alone did not obtained any change. IL-10 significantly increased, whereas Th2-dependent and pro-inflammatory cytokines significantly decreased. In conclusion, the present study demonstrates that 2-year SLIT is capable of inducing immunologic hyporeactivity to mites.


Subject(s)
Desensitization, Immunologic , Hypersensitivity/therapy , Mites/immunology , Administration, Sublingual , Adolescent , Animals , Child , Cytokines/blood , Female , Humans , Hypersensitivity/immunology , Immunoglobulin E/blood , Male
8.
Article in English | MEDLINE | ID: mdl-21096410

ABSTRACT

The evaluation of the topological properties of brain networks is an emergent research topic, since the estimated cerebral connectivity patterns often have relatively large size and complex structure. Since a graph is a mathematical representation of a network, the use of a theoretical graph approach would describe concisely the topological features of the functional brain connectivity network estimated using neuroimaging techniques. In the present study, we analyze the changes in brain synchronization networks using high-resolution EEG signals obtained during performance of a complex goal-directed visuomotor task. Our results show that the cortical network is more stable when subjects reach the goal than when they fail by hitting an obstacle. These findings suggest the presence of a possible cerebral "marker" for motor actions that result in successful reaching of a target.


Subject(s)
Cerebral Cortex/physiology , Electroencephalography/methods , Evoked Potentials/physiology , Models, Neurological , Movement/physiology , Nerve Net/physiology , Visual Perception/physiology , Adult , Computer Simulation , Humans , Male , Neural Pathways/physiology , Task Performance and Analysis , Young Adult
9.
Curr Med Chem ; 17(4): 309-20, 2010.
Article in English | MEDLINE | ID: mdl-20015045

ABSTRACT

The biological activity of peroxisome proliferators (PPs) is mediated by a class of receptors, known as PPARs (PP-Activated Receptor), belonging to the nuclear receptor superfamily. Upon ligand binding, PPARs dimerize with retinoid receptors, translocate to the nucleus, recognize specific PP-responsive elements on DNA and transactivate a number of genes. Several processes are regulated by PPARs, such as mitochondrial and peroxisomal fatty acid uptake and beta-oxidation, inflammation, intracellular lipid trafficking, cell proliferation and death. In addition, PPARs have been proposed to act as tumor suppressors or as tumor promoters, depending on the circumstances. In particular, PPs have been extensively studied for their hepatocarcinogenic action in rodents, most often ascribed to their antiapoptotic action. Recent evidence, however, has been provided about the antiproliferative, proapoptotic, and differentiation-promoting activities displayed by PPAR ligands. The present review will focus on the cytotoxic effects exerted by several PPs, among which clofibrate, on different types of tumor cells, with particular reference to the mechanisms of cell death and to their relevance to cancer induction and progression.


Subject(s)
Clofibrate/pharmacology , Cytotoxins/pharmacology , Disease Progression , Neoplasms/pathology , Peroxisome Proliferators/pharmacology , Animals , Clofibrate/adverse effects , Clofibrate/metabolism , Cytotoxins/metabolism , Cytotoxins/toxicity , Humans , Neoplasms/metabolism , Peroxisome Proliferator-Activated Receptors/metabolism , Peroxisome Proliferators/adverse effects , Peroxisome Proliferators/metabolism
10.
Curr Cancer Drug Targets ; 9(5): 608-16, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19508174

ABSTRACT

Muscle wasting, as occurring in cancer cachexia, is primarily characterized by protein hypercatabolism and increased expression of ubiquitin ligases, such as atrogin-1/MAFbx and MuRF-1. Myostatin, a member of the TGFbeta superfamily, negatively regulates skeletal muscle mass and we showed that increased myostatin signaling occurs in experimental cancer cachexia. On the other hand, enhanced expression of follistatin, an antagonist of myostatin, by inhibitors of histone deacetylases, such as valproic acid or trichostatin-A, has been shown to increase myogenesis and myofiber size in mdx mice. For this reason, in the present study we evaluated whether valproic acid or trichostatin-A can restore muscle mass in C26 tumor-bearing mice. Tumor growth induces a marked and progressive loss of body and muscle weight, associated with increased expression of myostatin and ubiquitin ligases. Treatment with valproic acid decreases muscle myostatin levels and enhances both follistatin expression and the inactivating phosphorylation of GSK-3beta, while these parameters are not affected by trichostatin-A. Neither agent, however, counteracts muscle atrophy or ubiquitin ligase hyperexpression. Therefore, modulation of the myostatin/follistatin axis in itself does not appear sufficient to correct muscle atrophy in cancer cachexia.


Subject(s)
Cachexia/drug therapy , Follistatin/metabolism , Histone Deacetylase Inhibitors , Hydroxamic Acids/pharmacology , Muscles/drug effects , Muscular Atrophy/metabolism , Myostatin/metabolism , Valproic Acid/pharmacology , Animals , Cachexia/complications , Cachexia/pathology , Colonic Neoplasms/complications , Disease Models, Animal , Drug Evaluation, Preclinical , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Glycogen Synthase Kinase 3/antagonists & inhibitors , Glycogen Synthase Kinase 3 beta , Hydroxamic Acids/therapeutic use , Mice , Mice, Inbred BALB C , Muscles/metabolism , Muscular Atrophy/complications , Muscular Atrophy/drug therapy , Neoplasm Transplantation , Ubiquitin-Protein Ligases/metabolism , Valproic Acid/therapeutic use
11.
Biochem Pharmacol ; 77(2): 169-76, 2009 Jan 15.
Article in English | MEDLINE | ID: mdl-18983831

ABSTRACT

Peroxisome proliferators (PPs) are a class of compounds that exert their nominal effects through the peroxisome proliferator-activated receptors. PPs, among which clofibrate (CF), have been extensively studied for their hepatocarcinogenic properties in rodents, generally ascribed to their antiapoptotic action. However, previous results demonstrated that various PPs may also have apoptogenic properties. CF, in particular, promptly induces a massive apoptotic death in cell lines established from murine or human hepatomas and from breast or lung cancers as well. The present study was aimed at elucidating the apoptotic pathway(s) triggered by CF in AH-130 cells. The results show that CF-induced cell death is completely blocked by the poly-caspase inhibitor z-VAD-fmk and that caspases 3, 8, and 9 are early activated. Consistently, cytochrome c is released from mitochondria, and CF cytotoxicity is inhibited by cyclosporine A, partially at least. In addition, the occurrence of endoplasmic reticulum (ER) stress is suggested by the observation that the levels of phosphorylated eIF2alpha and JNK increase in CF-treated cells, while the caspase 2 precursor protein levels are concurrently reduced. Finally, some degree of calpain activation also takes place, as suggested by the appearance of fodrin cleavage products. The present findings demonstrate that CF-induced apoptosis in the Yoshida AH-130 cells basically is a caspase-dependent process that involves more than a single mechanisms. Activation of the intrinsic apoptotic pathway and ER stress both play a major and concurrent role, while calpain activation seems to have only a marginal part in the process.


Subject(s)
Apoptosis/drug effects , Clofibrate/pharmacology , Amino Acid Chloromethyl Ketones/pharmacology , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/physiopathology , Caspase 3/metabolism , Caspase 8/metabolism , Caspase 9/metabolism , Cell Death/drug effects , Cell Line, Tumor , Cysteine Proteinase Inhibitors/pharmacology , Humans , Liver Neoplasms/pathology , Liver Neoplasms/physiopathology
12.
Eur J Clin Invest ; 38(7): 531-8, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18578694

ABSTRACT

BACKGROUND/AIMS: Myostatin belongs to the transforming growth factor-beta superfamily and negatively regulates skeletal muscle mass. Its deletion induces muscle overgrowth, while, on the contrary, its overexpression or systemic administration cause muscle atrophy. The present study was aimed at investigating whether muscle depletion as occurring in an experimental model of cancer cachexia, the rat bearing the Yoshida AH-130 hepatoma, is associated with modulations of myostatin signalling and whether the cytokine tumour necrosis factor-alpha may be relevant in this regard. MATERIALS AND METHODS: Protein levels of myostatin, follistatin (myostatin endogenous inhibitor) and the activin receptor type IIB have been evaluated in the gastrocnemius of tumour-bearing rats by Western blotting. Circulating myostatin and follistatin in tumour hosts were evaluated by immunoprecipitation, while the DNA-binding activity of the SMAD transcription factors was determined by electrophoretic-mobility shift assay. RESULTS: In day 4 tumour hosts muscle myostatin levels were comparable to controls, yet follistatin was reduced, and SMAD DNA-binding activity was enhanced. At day 7, both myostatin and follistatin increased in tumour bearers, while SMAD DNA-binding activity was unchanged. To investigate whether tumour necrosis factor-alpha contributed to induce such changes, rats were administered pentoxifylline, an inhibitor of tumour necrosis factor-alpha synthesis that partially corrects muscle depletion in tumour-bearing rats. The drug reduced both myostatin expression and SMAD DNA-binding activity in day 4 tumour hosts and up-regulated follistatin at day 7. CONCLUSIONS: These observations suggest that myostatin pathway should be regarded as a potential therapeutic target in cancer cachexia.


Subject(s)
Cachexia/metabolism , Muscle, Skeletal/metabolism , Muscular Atrophy/metabolism , Signal Transduction/physiology , Transforming Growth Factor beta/metabolism , Analysis of Variance , Animals , Blotting, Western , Cachexia/genetics , Disease Models, Animal , Male , Muscular Atrophy/genetics , Myostatin , Rats , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/genetics , Transforming Growth Factor beta/genetics , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
13.
J Robot Surg ; 1(3): 213-5, 2007.
Article in English | MEDLINE | ID: mdl-25484965

ABSTRACT

In laparoscopic prostatectomies, vesicourethral anastomotic leaks may result in significant morbidity because of the chemical and metabolic derangements created by urine within the peritoneal cavity. To date, minimal data are available on this problem. Herein we present our experience with urine leaks after RALP. Over a period of 24 months, 135 men underwent RALP. Any drainage creatinine greater than two times the serum creatinine was considered as an anastomotic leak. According to our criteria, 20% of the first 110 patients developed an anastomotic leak. The patients were analyzed in two groups, those with and without leaks. In the two groups, there was no statistically significant difference in age, height, weight, prostate volume and pre-op hemoglobin. The patients with leaks did have higher rate of prior abdominal surgery (50 vs. 36%), higher average pre-operative PSA values (7.6 vs. 6.1), higher rates of multiple biopsies (27 vs. 17%) and a higher average BMI (29.6 vs. 27.8). Intraoperative differences included an average of 30 min longer operative time and 66 cm(3) higher average EBL in patients with leaks. The transfusion rate was higher in the leak group at 18 vs. 1% in the no leak group. Recovery tended to be longer in patients with leaks, with hospital stays of an average of 3.6 days longer. The most common indication for prolonged hospitalization was ileus, which 55% of patients with leaks developed. Management included placing the catheter on mild traction, continuous antibiotics and taking the drain-off suction with caution to monitor the signs of a worsening ileus. In the last 25 patients, we revised our anastomotic technique. We now include posterior tailoring of the bladder neck prior to the vesicourethral anastomosis when the bladder neck is enlarged. This facilitates a water-tight anastomosis. Using this technique, we have yet to see the anastomotic leak. In RALPs, anastomotic leaks can lead to ileus formation and longer hospital stays. These leaks are associated with a higher average blood loss and transfusion rate. Management should focus on prevention. Since we have incorporated posterior bladder neck tailoring with the anastomosis, the problem has been markedly reduced.

14.
J Chem Phys ; 124(16): 164903, 2006 Apr 28.
Article in English | MEDLINE | ID: mdl-16674166

ABSTRACT

We analyze the time decay of small amplitude density perturbations in systems of highly packed Brownian hard rods, relaxing towards a uniform density distribution. The results of Brownian dynamics simulations and those of the deterministic dynamic density functional (DDF) theory, are contrasted with a new theoretical approach beyond the DDF assumptions. We characterize dynamical correlation modes which, having the lowest relaxation time, determine the late time evolution of the system. The spectrum of possible time decays has a continuous band structure, with pockets of discrete values, near the minima of the DDF results, where the validity of that theory appears to be well established.

15.
Phys Rev E Stat Nonlin Soft Matter Phys ; 70(2 Pt 1): 021505, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15447494

ABSTRACT

Density functional theory is used to study colloidal hard-rod fluids near an individual right-angled wedge or edge as well as near a hard wall, which is periodically patterned with rectangular barriers. The Zwanzig model, in which the orientations of the rods are restricted to three orthogonal orientations but their positions can vary continuously, is analyzed by numerical minimization of the grand potential. Density and orientational order profiles, excess adsorptions, as well as surface and line tensions are determined. The calculations exhibit an enrichment [depletion] of rods lying parallel and close to the corner of the wedge (edge). For the fluid near the geometrically patterned wall, complete wetting of the wall-isotropic liquid interface by a nematic film occurs as a two-stage process in which first the nematic phase fills the space between the barriers until an almost planar isotropic-nematic liquid interface has formed separating the higher-density nematic fluid in the space between the barriers from the lower-density isotropic bulk fluid. In the second stage, a nematic film of diverging film thickness develops upon approaching bulk-isotropic-nematic coexistence.

16.
Phys Rev E Stat Nonlin Soft Matter Phys ; 68(6 Pt 1): 061407, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14754204

ABSTRACT

The dynamic density functional (DDF) theory and standard Brownian dynamics simulations (BDS) are used to study the drifting effects of a colloidal particle in a polymer solution, both for ideal and interacting polymers. The structure of the stationary density distributions and the total induced current are analyzed for different drifting rates. We find good agreement with the BDS, which gives support to the assumptions of the DDF theory. The qualitative aspect of the density distribution are discussed and compared to recent results for driven colloids in one-dimensional channels and to analytical expansions for the ideal solution limit.


Subject(s)
Colloids/chemistry , Polymers/chemistry , Kinetics , Models, Statistical , Normal Distribution
17.
Braz. j. med. biol. res ; 35(1): 31-38, Jan. 2002. ilus, tab
Article in English | LILACS | ID: lil-304190

ABSTRACT

The objective of the present study was to determine the possible prognostic factors which may explain the difference in the survival of patients with cystic fibrosis (CF) with and without meconium ileus. Over a period of 20 years, 127 patients with CF, whose diagnosis was confirmed by typical clinical characteristics and altered sweat chloride levels, were studied retrospectively. The patients were divided into two groups: group 1 consisted of patients who presented CF and meconium ileus (N = 9), and group 2 consisted of patients with CF without meconium ileus (N = 118). The characteristics studied were based on data obtained upon admission of the patients using a specific protocol. Demographic, clinical, nutritional and laboratory data were obtained. The genotype was determined in 106 patients by PCR. Survival was analyzed using the Kaplan-Meier method. The median follow-up period was 44 months. A statistically significant difference was observed between the groups studied regarding the following variables: age at diagnosis and weight and height z scores. The presence of meconium ileus was associated with an earlier diagnosis; these patients had greater deficits in height and weight at the time of diagnosis and at the end of the study. The estimated probability of survival for patients with CF without meconium ileus was 62 ± 14 percent and for those with meconium ileus 32 ± 18 percent. Patients with CF and meconium ileus presented a poor nutritional status at diagnosis and a lower survival rate compared to the general CF population


Subject(s)
Humans , Female , Male , Infant, Newborn , Infant , Cystic Fibrosis/complications , Meconium , Intestinal Obstruction/etiology , Chi-Square Distribution , Cystic Fibrosis/genetics , Cystic Fibrosis/mortality , Follow-Up Studies , Prognosis , Retrospective Studies
18.
Braz J Med Biol Res ; 35(1): 31-8, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11743612

ABSTRACT

The objective of the present study was to determine the possible prognostic factors which may explain the difference in the survival of patients with cystic fibrosis (CF) with and without meconium ileus. Over a period of 20 years, 127 patients with CF, whose diagnosis was confirmed by typical clinical characteristics and altered sweat chloride levels, were studied retrospectively. The patients were divided into two groups: group 1 consisted of patients who presented CF and meconium ileus (N = 9), and group 2 consisted of patients with CF without meconium ileus (N = 118). The characteristics studied were based on data obtained upon admission of the patients using a specific protocol. Demographic, clinical, nutritional and laboratory data were obtained. The genotype was determined in 106 patients by PCR. Survival was analyzed using the Kaplan-Meier method. The median follow-up period was 44 months. A statistically significant difference was observed between the groups studied regarding the following variables: age at diagnosis and weight and height z scores. The presence of meconium ileus was associated with an earlier diagnosis; these patients had greater deficits in height and weight at the time of diagnosis and at the end of the study. The estimated probability of survival for patients with CF without meconium ileus was 62 +/- 14% and for those with meconium ileus 32 +/- 18%. Patients with CF and meconium ileus presented a poor nutritional status at diagnosis and a lower survival rate compared to the general CF population.


Subject(s)
Cystic Fibrosis/complications , Intestinal Obstruction/etiology , Meconium , Chi-Square Distribution , Cystic Fibrosis/genetics , Cystic Fibrosis/mortality , Female , Follow-Up Studies , Humans , Infant , Infant, Newborn , Male , Prognosis , Retrospective Studies , Survival Rate
19.
Braz. j. med. biol. res ; 34(11): 1415-1420, Nov. 2001. ilus, tab
Article in English | LILACS | ID: lil-303311

ABSTRACT

The objective of the present study was to determine the efficacy of detection of antigliadin immunoglobulins G and A (IgG and IgA) for the diagnosis of celiac disease in a developing country, since other enteropathies might alter the levels of these antibodies. Three groups were studied: 22 patients with celiac disease (mean age: 30.6 months), 61 patients with other enteropathies (mean age: 43.3 months), and 46 patients without enteropathies (mean age: 96.9 months). Antigliadin IgG and IgA ELISA showed sensitivity of 90.9 and 95.5 percent, respectively. With the hypothetical values of prevalence ranging from 1:500 to 1:2000 liveborns, the positive predictive value varied from 8.5 to 2.3 percent for IgG and from 4.8 to 1.1 percent for IgA. Considering the patients without enteropathies, specificity was 97.8 and 95.7 percent for IgG and IgA, respectively. In patients with other enteropathies, specificity was 82.0 and 84.1 percent, respectively. When patients with and without other enteropathies were considered as a whole, specificity was 88.8 and 91.6 percent, respectively. The specificity of positive IgG or IgA was 93.5 percent in children without enteropathies and 78.7 percent in the presence of other enteropathies. The negative predictive value for hypothetical prevalences varying from 1:500 to 1:2000 liveborns was 99.9 percent. Thus, even in developing countries where the prevalence of non-celiac enteropathies is high, the determination of serum antigliadin antibody levels is a useful screening test prior to the jejunal biopsy in the investigation of intestinal malabsorption


Subject(s)
Child , Child, Preschool , Infant , Female , Humans , Male , Autoantibodies , Celiac Disease/diagnosis , Immunoglobulin A , Immunoglobulin G , Analysis of Variance , Autoantibodies , Biopsy , Case-Control Studies , Developing Countries , Celiac Disease/immunology , Enzyme-Linked Immunosorbent Assay , Immunoglobulin A , Immunoglobulin G , Intestinal Diseases , Jejunum , Biomarkers , Organizational Case Studies , Predictive Value of Tests , Sensitivity and Specificity , Statistics, Nonparametric
20.
Braz J Med Biol Res ; 34(11): 1415-20, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11668350

ABSTRACT

The objective of the present study was to determine the efficacy of detection of antigliadin immunoglobulins G and A (IgG and IgA) for the diagnosis of celiac disease in a developing country, since other enteropathies might alter the levels of these antibodies. Three groups were studied: 22 patients with celiac disease (mean age: 30.6 months), 61 patients with other enteropathies (mean age: 43.3 months), and 46 patients without enteropathies (mean age: 96.9 months). Antigliadin IgG and IgA ELISA showed sensitivity of 90.9 and 95.5%, respectively. With the hypothetical values of prevalence ranging from 1:500 to 1:2000 liveborns, the positive predictive value varied from 8.5 to 2.3% for IgG and from 4.8 to 1.1% for IgA. Considering the patients without enteropathies, specificity was 97.8 and 95.7% for IgG and IgA, respectively. In patients with other enteropathies, specificity was 82.0 and 84.1%, respectively. When patients with and without other enteropathies were considered as a whole, specificity was 88.8 and 91.6%, respectively. The specificity of positive IgG or IgA was 93.5% in children without enteropathies and 78.7% in the presence of other enteropathies. The negative predictive value for hypothetical prevalences varying from 1:500 to 1:2000 liveborns was 99.9%. Thus, even in developing countries where the prevalence of non-celiac enteropathies is high, the determination of serum antigliadin antibody levels is a useful screening test prior to the jejunal biopsy in the investigation of intestinal malabsorption.


Subject(s)
Autoantibodies/blood , Celiac Disease/diagnosis , Immunoglobulin A/blood , Immunoglobulin G/blood , Analysis of Variance , Autoantibodies/immunology , Biomarkers/blood , Biopsy , Case-Control Studies , Celiac Disease/blood , Celiac Disease/immunology , Child , Child, Preschool , Developing Countries , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Infant , Intestinal Diseases/blood , Intestinal Diseases/diagnosis , Intestinal Diseases/immunology , Jejunum/pathology , Male , Predictive Value of Tests , Sensitivity and Specificity , Statistics, Nonparametric
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