The Relationship between Photoluminescence Emissions and Photocatalytic Activity of CeO2 Nanocrystals.

In this work, we focus on understanding the morphology and photocatalytic properties of CeO2 nanocrystals (NCs) synthesized via a microwave-assisted solvothermal method using acetone and ethanol as solvents. Wulff constructions reveal a complete map of available morphologies and a theoretical-experimental match with octahedral nanoparticles obtained through synthesis using ethanol as solvent. NCs synthesized in acetone show a greater contribution of emission peaks in the blue region (∼450 nm), which may be associated with higher Ce3+ concentration, originating shallow-level defects within the CeO2 lattice while for the samples synthesized in ethanol a strong orange-red emission (∼595 nm) suggests that oxygen vacancies may originate from deep-level defects within the optical bandgap region. The superior photocatalytic response of CeO2 synthesized in acetone compared to that of CeO2 synthesized in ethanol may be associated with an increase in long-/short-range disorder within the CeO2 structure, causing the Egap value to decrease, facilitating light absorption. Furthermore, surface (100) stabilization in samples synthesized in ethanol may be related to low photocatalytic activity. Photocatalytic degradation was facilitated by the generation of ·OH and ·O2- radicals as corroborated by the trapping experiment. The mechanism of enhanced photocatalytic activity has been proposed suggesting that samples synthesized in acetone tend to have lower e'─h· pair recombination, which is reflected in their higher photocatalytic response.

Assessing the molecular basis of transferable quinolone resistance in Escherichia coli and Salmonella spp. from food-producing animals and food products.

Enterobacteriaceae resistant to quinolones frequently arise in animals, being easily disseminated through the food-chain. The aim of this study was to investigate the presence of plasmid-mediated quinolone resistance (PMQR) determinants in Salmonella spp. (n=183) and Escherichia coli (n=180) isolates, collected from food-producing animals and food products among swine, poultry, rabbits and cattle. All isolates were subjected to antimicrobial susceptibility testing and molecular screening of PMQR determinants. ß-Lactamase-encoding genes, and the quinolone resistance determining region (QRDR) of gyrA, gyrB, parC and parE genes were also investigated in PMQR-positive isolates. Plasmid characterization was performed by conjugation, followed by replicon-typing. Genetic relatedness of PMQR-positive E. coli was examined by Multilocus Sequence Typing, while Salmonella was previously serotyped. The association of mobile genetic elements and PMQR was investigated through PCR mapping assays. Overall, 4.1% (15/363) isolates harbored qnrB2 (n=3), qnrB19 (n=3), and qnrS1 (n=9) genes. All but one isolate presented one to four mutations in QRDR of gyrA or parC genes, which is consistent with the range of MIC values detected (0.19-64 mg/L) for ciprofloxacin; 60% (9/15) of qnr-harboring isolates were non-susceptible to ß-lactam antibiotics which was justified by the presence of ß-lactamases from TEM (TEM-1, n=8; TEM-135, n=1) and SHV (SHV-108, n=1) families. Analysis of mobile genetic elements revealed that qnr genes were detected nearby relevant genetic elements like intI1, ISEcl2, IS26 and ISCR1 and enclosed in diverse Inc. type plasmids. This study illustrated the existence of Qnr-producing E. coli and Salmonella from food-producing animals, associated to specific mobile elements that might mediate their transference between species and among distinct settings.

[GADA persistence and detectable C peptide in patients with long standing diabetes mellitus type 1]. / Implicações clínicas da persistência de anti-GAD positivo e peptídeo C detectável em pacientes com diabetes melito tipo 1 de longa duração.

OBJECTIVE: The aim of this study was to evaluate if GADA+ and detectable CP had any influence in other autoimmune diseases, glycemic control, and risks of retinopathy in diabetes mellitus type 1 (T1DM) lasting longer than 3 years of duration. SUBJECTS AND METHODS: Fifty T1DM subjects were interviewed, performed fundoscopic examination, and measured CP before and after glucagon, HbA1C, and GADA. RESULTS: GADA+ (n = 17) had a higher frequency of other autoimmune diseases when compared to GADA (p = 0.02). Detectable CP was also associated with a higher prevalence of these diseases (p = 0.03), although, retinopathy was not influenced by either one. Detectable CP had no influence in the glycemic control (mean HbA1C) (p = 0.28). However, insulin daily doses were lower in this group (0.62 vs. 0.91 U/kg/day; p = 0.004). CONCLUSION: Although not recommend as a marker of other autoimmune diseases, GADA+ seems to be not only a pancreatic autoimmunity signal. Detectable CP may also have some promising influence in detecting these diseases. Neither influenced the presence of retinopathy, but insulin daily requirements were smaller when CP was present.

Implicações clínicas da persistência de anti-GAD positivo e peptídeo C detectável em pacientes com diabetes melito tipo 1 de longa duração / GADA persistence and detectable C peptide in patients with long standing diabetes mellitus type 1

OBJETIVO: Avaliar se anti-GAD positivo e PC detectável se correlacionam com a presença de outras doenças autoimunes, com controle glicêmico e com risco de retinopatia no diabetes melito tipo 1 (DMT1) > 3 anos de duração. PACIENTES E MÉTODOS: Cinquenta sujeitos com DMT1 foram entrevistados, realizaram fundoscopia e dosaram PC pré e pós-glucagon, HbA1C e anti-GAD. RESULTADOS: Pacientes anti-GAD+ (n = 17) apresentaram maior frequência de doenças autoimunes em relação aos demais (p = 0,02). PC detectável (n = 11) também foi associado ao aumento dessa prevalência (p = 0,03), porém nenhum dos dois parâmetros influenciou na presença de retinopatia diabética. PC detectável não influenciou no controle glicêmico (HbA1C média) (p = 0,28), porém as doses diárias de insulina foram mais baixas (0,62 vs. 0,91 U/kg/dia; p = 0,004) neste grupo. CONCLUSÃO: Apesar de não ser um marcador para outras doenças autoimunes, o anti-GAD+ parece ser não só um sinalizador de autoimunidade pancreática. PC detectável também parece ter papel promissor na detecção dessas comorbidades. Ambos não interferiram na presença de retinopatia, entretanto, o PC detectável se relacionou a menores necessidades de insulina.

OBJECTIVE: The aim of this study was to evaluate if GADA+ and detectable CP had any influence in other autoimmune diseases, glycemic control, and risks of retinopathy in diabetes mellitus type 1 (T1DM) lasting longer than 3 years of duration. SUBJECTS AND METHODS: Fifty T1DM subjects were interviewed, performed fundoscopic examination, and measured CP before and after glucagon, HbA1C, and GADA. RESULTS: GADA+ (n = 17) had a higher frequency of other autoimmune diseases when compared to GADA (p = 0.02). Detectable CP was also associated with a higher prevalence of these diseases (p = 0.03), although, retinopathy was not influenced by either one. Detectable CP had no influence in the glycemic control (mean HbA1C) (p = 0.28). However, insulin daily doses were lower in this group (0.62 vs. 0.91 U/kg/day; p = 0.004). CONCLUSION: Although not recommend as a marker of other autoimmune diseases, GADA+ seems to be not only a pancreatic autoimmunity signal. Detectable CP may also have some promising influence in detecting these diseases. Neither influenced the presence of retinopathy, but insulin daily requirements were smaller when CP was present.

Relationship between bolus transit and LES-relaxation studied with concurrent impedance and manometry.

BACKGROUND/AIMS: Neuromuscular mechanisms regulating esophageal bolus transport are well studied. However, detailed data about the relationship between bolus transit and lower esophageal sphincter (LES)-relaxation during conventional motility testing are still lacking. METHODOLOGY: We performed systematic studies in 25 normal subjects, employing a catheter that integrates the two techniques impedancometry and manometry in a single instrument for simultaneous recording and analysis of the relationship between bolus transit and LES relaxation after swallowing saline or yogurt. RESULTS: 195 swallows were analyzed. LES relaxation occurred frequently later than UES relaxation. The mean latency between bolus entry into the esophagus and LES relaxation was 3.6 +0.2 sec. Two types of swallow-induced LES relaxation were observed: (a) LES relaxation preceding bolus transit (46 cases or 24%) and (b) LES relaxation occurring during bolus transit (149 cases or 76%). In the later case, during 114 (76%) cases of this deglutition, the position of the bolus was very close to the LES. CONCLUSIONS: During deglutition, LES relaxation seems to be modulated by bolus transit and occurs predominantly upon arrival of the bolus in the distal esophagus.

Impedance characteristics of esophageal motor function in achalasia.

Detailed data on patterns of esophageal bolus transport in patients with achalasia are still lacking. To study these we applied the novel technique of multichannel intraluminal impedance measurements. Ten patients with achalasia were studied using a 16 channel system. Liquid and semisolid boluses of 10 mL were applied with the patients in a supine position. Patterns of bolus transport were determined and analyzed as compared to results obtained from 20 healthy subjects. The healthy subjects featured a unique typical primary peristalsis pattern independent of bolus viscosity. In contrast, achalasia patients demonstrated different impedance characteristics, including: (i) significantly lower baseline esophageal impedance during the resting state as compared with healthy volunteers (999 omega +/- 108 versus 2749 omega +/- 113); (ii) failed bolus transport through the esophagus in all cases; (iii) impedance evidence of luminal content regurgitation in 35% of the swallows (iv) impedance evidence of pathological air movement within the proximal esophagus during deglutition in 38% of the swallows, so called air trapping. Thus, impedance characteristics of achalasia have been defined and can be attributed to known symptoms of achalasia. They can be used as basic findings for further classification of pathological bolus transports in other esophageal motility disorders.

[Differential diagnosis of esophageal motor disorders based in characteristics of dysphagia]. / Diagnóstico diferencial dos distúrbios motores esofagianos pelas características da disfagia.

BACKGROUND: Dysphagia is one of principal symptoms of esophageal disorders and its characterization is important for diagnosis and management of patients. Anamnesis is useful for differentiating organic and functional dysphagia, but data are lacking about dysphagia characterization among different motor disorders. OBJECTIVES: To evaluate if it is possible the distinction among esophageal motor disorders according to their manometric diagnosis, based on dysphagia characteristics. PATIENTS AND METHODS: Dysphagia characteristics (relation with bolus, frequency and localization) of 133 patients submitted to esophageal manometry were reviewed and analysed. All patients had barium swallow studies and/or endoscopy in order to exclude organic lesions. RESULTS: Esophageal manometry was abnormal in 85% of the patients. Characteristics of dysphagia were compared among groups of patients with achalasia, esophageal spastic disorders, non-specific esophageal motor disorders and with normal test. The precise distinction among groups based solely on characteristics of dysphagia was not possible, however some aspects could point to one or another group. In achalasia patients, dysphagia for both solid food and liquids, constant and felt in substernal area, was more frequent in relation to every other group. Intermittent dysphagia was more frequent in patients with spastic disorders. Characteristics of dysphagia in patients with non-specific esophageal motor disorders were similar to those observed in the group with normal test, frequently referred in the neck. CONCLUSION: Characteristics of dysphagia were ancillary to presume the diagnosis of these motor disturbances, however esophageal manometry is necessary for the correct diagnosis in patients with functional dysphagia.

Lower esophageal sphincter pressure in idiopathic achalasia and Chagas disease-related achalasia.

The most important etiologies of achalasia are idiopathic and related to Chagas' disease. The lower esophageal sphincter pressure (LESP) in idiopathic achalasia (Id Ach) is higher compared with a healthy group, but there are different reports in Chagasic achalasia (Ch Ach). We compared the LESP of patients with both forms of achalasia and a control group. The LESP of 213 achalasia patients without previous treatment and 32 healthy volunteers were assessed. In 126 patients, the etiology could be demonstrated using serologic tests (Id Ach, 94 and Ch Ach, 32). The LESP of 213 patients was 31.86+/-14.18 mmHg and in the control group was 17.92+/-7.03 mmHg (P < 0.0001). The LESP in Id Ach and Ch Ach was 33.28+/-13.63 mmHg and 23.5+/-12.09 mmHg (P < 0.0001), respectively. Only the Id Ach group achieved statistical difference in relation to the control group (P < 0.0001). In conclusion, the LESP of Id Ach patients was higher than in Ch Ach patients and the control group, but there was no LESP difference between the Ch Ach and control groups.

Manometric findings of esophageal motor disorders in 240 Brazilian patients with non-cardiac chest pain.

Two hundred and forty Brazilian patients with chest pain and normal cardiac evaluation were submitted to computerized esophageal manometry. Endoscopic examination and/or swallow barium studies had excluded obstructive lesions. Motor disorders were found in 63% of patients; non-specific motors disorders and hypotensive lower esophageal sphincter were the most common. The finding of nutcracker esophagus in only 6% of the patients is a quite different rate from what has been previously described in the literature. Esophagitis was observed at endoscopy in 13.4% of the patients, hiatus hernia in 19.7% and peptic gastric or duodenal ulcer in 4.9%. It should be emphasized that after excluding pain as being of cardiac origin an abnormal manometry result points to the esophagus as the probable site of origin of the pain; esophageal investigation is important for establishing proper treatment for these patients.

Effects of severe protein restriction in levels of parasitemia and in mortality of mice acutely infected with Trypanosoma cruzi.

Adult mice were submitted to different degrees of protein restriction for five weeks (4.75, 9.5, 14.25 and 19% of protein in isocaloric diets with normal content of mineral and vitamins), being subsequently infected with two strains of Trypanosoma cruzi: 10(5) trypomastigotes of Y strain or 10(4) trypomastigotes of CL strain. The same diet was maintained for all animals and the infection was followed up by evaluation of blood parasites, mortality and intensity of lesions in the heart and skeleton muscle. Only severe protein restriction (4.75%) induced decrease in resistance to the infection with both the Y and CL strains of T. cruzi, which resulted in higher parasitemia and mortality. The inflammatory lesions in heart and skeleton muscle were less extensive in groups with severe protein restriction despite the increased number of parasite in muscle cells. Depression of immune mechanisms could be responsible for the reduced resistance and reduced inflammatory reaction after T. cruzi infection in severely protein restricted animals.