Clostridium difficile infection in cancer patients with hospital acquired diarrhea at the teaching hospitals in Iran: Multilocus sequence typing analysis (MLST) and Antimicrobial resistance pattern.

BACKGROUND: This study aimed to investigate the phenotype and genotype characterization of Clostridium difficile isolates among cancer patients with hospital-acquired diarrhea in 4 teaching hospitals in Isfahan, Iran. STUDY DESIGN: This was a cross sectional study conducted on adult (>18 years old) between April 2015 and May 2017. METHODS: Over two years, 67 diarrheic fecal samples were collected. C. difficile isolates were characterized according to the presence of toxin genes and antibiotic resistance. Multilocus sequence typing (MLST) was performed to evaluate the genetic relationships between different lineages of toxigenic strains. RESULTS: Seven toxigenic and 12 non- toxigenic strains were detected among stool samples. Patients with a history of previous surgery during hospitalization were more than 7 times likely to develop Clostridium difficile infection (CDI). All isolates were susceptible to metronidazole, vancomycin and fusidic acid. Toxigenic C. difficile strains were divided into 3 different sequence types. The detected types were ST-54, ST-2 and ST-37, while none of the isolates was identified as ST-1 or ST-11. CONCLUSIONS: This is the first description of the MLST analysis of C. difficile strains isolated from cancer patients in Iran. All of the studied population were exposed to multiple antibiotics and chemotherapeutic agents. Further research and clinical studies are recommended in the treatment through good antimicrobial stewardship and prevention of C. difficile infection in all healthcare settings.

Deep eutectic-water binary solvent associations investigated by vibrational spectroscopy and chemometrics.

Investigation of the behaviour of deep eutectic solvents (DESs) as novel green solvents in the presence of other solvents is of great interest. In this study the behaviour of a common natural DES, namely choline chloride-glycerol deep eutectic solvent (GDES), was studied in the presence of water. A detailed study of the association of the two solvents was performed by integration of two vibrational spectroscopic methods (FTIR and Raman spectroscopy) followed by multivariate analysis. Moreover, a binary mixture of glycerol (Gly) as one of the liquid constituents of GDES and water was explored under the same conditions. A quintuplet and ternary systems were resolved for GDES-water and Gly-water probes, respectively, using multivariate analysis of global data (multi-technique and multi-experiment data arrangements). The results confirmed that in the presence of water the GDES showed different behaviour from its components. Therefore, a DES can be introduced as an independent solvent with its unique properties. Also, different H-bond interaction energies of GDES and its pure components in the presence of water were shown by theoretical calculations based on a density functional theory framework. To investigate the effects of water on the structure of GDES, molecular dynamics (MD) simulations of GDES-water liquid mixtures were performed at 0.9 mole fraction of water.

Effects of type of binder and conducting phase on the performance of solid-state electrochemiluminescence composites.

The electrochemiluminescence (ECL) of tris(2,2-bipyridyl)ruthenium [Ru(bpy)3 ](2+) has received much attention. By immobilizing [Ru(bpy)3 ](2+) on an electrode surface, solid-state ECL has several advantages over solution-phase ECL, such as reduced amounts of costly reagent and a simplified experimental design. Herein, different types of solid-state ECL sensors were fabricated and the performances of paraffin oil and two ionic liquids (ILs) as the binders were compared for the construction of solid-state ECL. Scanning electron microscopy (SEM), CCD camera, UV-vis, fluorescence spectroscopy, electrochemistry and ECL were applied to characterize and evaluate the performance of the solid-state composites. According to the obtained results, Ru-graphite/IL octyl pyridinium hexaflurophosphate (OPPF6 ) was introduced as a new solid-state ECL with excellent properties such as simple preparation, low background current, fast electron-transfer rate and good reproducibility and stability. Moreover, for a study of the effect of carbon structure on the performance of the electrode, graphite was replaced by multi-walled carbon nanotubes (MWCNTs) and Ru-MWCNT/OPPF6 was constructed and its efficiency was compared with Ru-graphite/OPPF6 composite electrode.

Postrhinoplasty acne formation: a case-control study.

BACKGROUND: Acne formation is a common dermatological problem which, if left untreated, may lead to severe facial scars, a consideration that may be particularly important for patients who seek cosmetic surgery. Postrhinoplasty acne development has not yet been discussed in the literature. We therefore decided to evaluate the occurrence of acne in nasal plastic surgery in a case-control study. SUBJECTS & METHODS: One hundred and twenty patients were selected for this case-control study and were then assigned to case and control groups, each consisting of 60 patients. None of the participants was a known case of acne and those with any specific skin condition were excluded from the study. The cases were patients whose external nasal structures had been affected by the procedure; the control group consisted of matched patients who were candidates for closed septoplasty. After the operation, acne formation was evaluated in all participants and a comparison was made between cases and controls looking at the surgical method employed, and at the patients' personal and family backgrounds. RESULTS: Twelve patients, all from the case group, developed postsurgical acne; all these patients had undergone open rhinoplasty. Age, gender, family history for acne and recent medication use prior to the surgery showed no significant correlation with acne formation. CONCLUSION: The incidence of acne after nasal plastic surgery was significantly higher than in the control group, especially when the method of surgery was open rhinoplasty.

Olfactory function after nasal plastic surgery.

OBJECTIVE: Nasal plastic surgery is a common procedure, which may cause complications. Many patients are concerned about possible changes in the ability to smell. This study aimed to investigate the impact of nasal surgery, by itself, on the sense of smell in a group of patients with minimal endonasal pathologies and no pre-operative olfactory alterations. METHODOLOGY: In this prospective study from January 2009 until January 2011, we evaluated post-rhinoplasty olfactory changes in a series of 100 rhinoplasty candidates. Olfactory evaluation was performed both subjectively and objectively. The subjective evaluation contained a 0-to-100 Visual Analogue Scale and a five-choice qualitative questionnaire; while, the objective evaluation was performed using the same odor variant of the University of Pennsylvania Smell Identification Test (UPSIT40). Then, the results were analyzed by age, sex, operation method, symptoms, and time-interval groups. RESULTS: Subjective and objective scoring revealed no significant change in terms of postsurgical olfactory outcome. According to subjective grading, 26 patients had improvement, 61 had no change, and 13 had deterioration of the smell sense. Closed rhinoplasty resulted in a better smell outcome after surgery according to the Visual Analogue Quantitative Score (P = 0.034). CONCLUSION: Rhinoplasty does not appear to significantly change the preexisting olfactory status.

Transient threshold shift after gunshot noise exposure.

BACKGROUND: Many people, such as soldiers, are routinely exposed to gunshot noise during target practice. It is suspected that this high-intensity noise may affect audition through repeated Transient Threshold Shifts (TTS); it can also mechanically alter auditory components such as waves. This study investigates the scope of gunshot noise from the AK-47 rifle (Kalashnikov) and the impact on the shooters' audition. METHODS: Forty soldiers (80 ears) were recruited in this study. They were all young and being exposed to gunshot noise for the first time. Gunshot characteristics were measured before exposure. The soldiers underwent auditory evaluation with Pure Tone Audiometry (PTA) and Oto-Acoustic Emission (OAE) once before exposure and immediately (less than one hour) after exposure. RESULTS: The AK-47 gunshot noise pressure level varied between L(AIm) = 73.7 dBA to L(AIm) = 111.4 dBA. Fourteen participants had subclinical hearing impairment in their pre-exposure evaluation; this number increased to 16 after the exposure. Six months post-exposure and later, the number of cases with impairment had fallen to eight (improvement in 50%). Both pre- and post-exposure OAE results were within normal values, while PTA results indicated a significant threshold alteration only at 6 kHz. CONCLUSION: The results of this study confirm that exposure to gunshot noise with no ear protection can represent a significant hazard for auditory function, especially at higher frequencies.

Interaction of anionic dyes and cationic surfactants with ionic liquid character.

The interactions of an imidazolium based ionic liquid (IL), namely 1-dodecyl-3-methylimidazolium chloride [C12 mim][Cl] with two sulfonated anionic dyes, azocarmine G and methyl orange, are studied spectrophotometrically in both acidic and basic media. ILs (with some surface active character) can interact with the above dyes and cause considerable shifts in their spectra. These interactions are then compared with some surfactant-dye interactions. Evolving factor analysis (EFA) and multivariate curve resolution-alternating least squares (MCR-ALS) are used for complete resolution of the measured spectrophotometric data. The concentration and spectral profiles of all species were calculated without any assumption of the chemical models. The spectral variation of dye solutions as a function of IL concentrations below and above the critical aggregation concentration (CAC) is analyzed using MCR-ALS as a soft-modeling technique. The ion pair formation constants between ILs and dyes were calculated using the obtained concentration profiles.

Novel synchronization of discrete-time chaotic systems using neural network observer.

This paper presents a new approach to solve the synchronization problem of a large class of discrete chaotic systems. The chaotic systems can be reformulated as an appropriate class of linear parameter varying (LPV) systems. The synchronization problem for this class of nonlinear systems is revisited from a control perspective and it is argued that the problem can be viewed as an observer design problem. Then, based on the LPV representation, a neural network observer-based approach is proposed to solve the synchronization problem. The simulation results show the advantages of combining the LPV techniques and the neural networks to determine the appropriate observer gain within the context of chaotic system synchronization.

Impact of anti-tuberculosis therapy on plasma zinc status in childhood tuberculosis.

This study compared plasma zinc levels in 15 children with active pulmonary tuberculosis, 15 malnourished children and 15 healthy children. Mean plasma zinc concentrations in children with tuberculosis (71.7 microg/dL) were not significantly different than the other 2 groups (72.5 and 76.9 microg/dL). The zinc status of the children with tuberculosis was evaluated after 2 months and 4 months of DOTS therapy. The serum zinc level during anti-tuberculosis therapy decreased after 1 month and then recovered to the initial level after 4 months of treatment.

Super RLuc8-sFv; a new luciferase-labeled probe for detection of human CD4+ cells.

The human immunodeficiency virus (HIV) destroys CD4+ lymphocytes and monitoring these cells is one of the best techniques for studying HIV infection. In the present study a novel bioluminescent probe, super RLuc8-sFv, is developed in order to detect human CD4+ cells by fusion of an anti-human CD4 sFv to the C-terminus of super RLuc8. The results indicate that the probe can bind to CD4+ cells via its sFv domain; also it emits visible light through its signalling domain. Super RLuc8-sFv provides a new gateway for detection of human CD4+ cells using luminometric-based assays and may reduce the difficulties involved in, and the cost of, HIV-related diagnostic tests.

Simultaneous spectrophotometric determination of Fe(III), Al(III) and Cu(II) by partial least-squares calibration method.

A spectrophotometric method for simultaneous determination of Fe(III), Al(III) and Cu(II) using Alizarin Red S as a chelating agent was developed. The parameters controlling behavior of the system were investigated and optimum conditions were selected. A partial least-squares multivariate calibration method was used for the analysis of ternary mixtures of Fe(III), Al(III) and Cu(II) over the range of 450-6000, 140-4000 and 450-15000 ng ml(-1), respectively. Absorbance data were taken between 400 and 800 nm. Applying this method to simultaneous determination of these metal ions in several synthetic alloy solutions with total relative standard error of less than 5% validated the proposed method.

Primary and acquired drug resistance in childhood tuberculosis.

This study determined the resistance pattern of Mycobacterium tuberculosis to 4 first-line anti-tuberculosis drugs in children with pulmonary tuberculosis at the Iranian National Research Institute of Tuberculosis and Lung Diseases from 1999 to 2004. There were 350 children with positive cultures over the study period: 7 (2%) were resistant to at least one of the 4 anti-tuberculosis drugs. Primary resistance was detected in 4 cases and secondary resistance in 3 cases. Most cases (6) were among Afghan refugees. Resistance to rifampicin both in primary and secondary resistances was high, showing that children in the Islamic Republic of Iran face the threat of drug-resistant tuberculosis transmission.

Increased expression of an endopeptidase (gamma-EGE/IDE) hydrolyzing beta-endorphin during differentiation and maturation of bone marrow macrophages.

The presence and regulated expression of peptidase activity is a powerful mechanism with the potential to terminate or alter receptor recognition, cell membrane signal transduction, and physiological responses of immune cells to exogenous opioid peptides. In this study, the expression of an endopeptidase that hydrolyzes beta-endorphin to gamma-endorphin and other peptide products was investigated during in vitro differentiation and maturation of recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) -derived, bone marrow-derived macrophages. In freshly isolated intact isolated mouse bone marrow cells the rate of beta-endorphin hydrolysis is undetectable (<0.1 nmol beta-endorphin hydrolyzed/h/10[6] cells). However, total intracellular beta-endorphin hydrolytic activity was increased significantly to 20.0 +/- 1.7 nmol/h/10(6) cells in the mature mouse macrophages derived in vitro by culture with rGM-CSF. rGM-CSF-derived macrophages expressed significantly higher levels of both protein and mRNA for the major beta-endorphin endopeptidase, gamma-endorphin-generating enzyme/insulin-degrading enzyme (gamma-EGE/IDE). Moreover, this enzymatic activity appears to be responsible for cleavage of exogenous beta-endorphin by intact rGM-CSF-derived macrophages or peritoneal macrophages to generate gamma-endorphin and other peptide products.

Delayed primary repair of intrathoracic esophageal perforation: is it safe?

The management of intrathoracic esophageal perforation with delayed diagnosis is a subject of controversy. Because of the obvious advantages of primary repair as a simple single-stage operation, this technique was preferentially used to treat 18 of 22 consecutive patients with esophageal perforation. These patients were stratified into three groups according to the time interval between perforation and repair: group A, less than 6 hours, five patients (28%); group B, 6 to 24 hours, six patients (33%); and group C, more than 24 hours, seven patients (39%). Group A patients were older (p < 0.05) and group B had fewer iatrogenic perforations (B, 17%; A, 80%; C, 57%, p < 0.1). Additional tissue was used to buttress the repair site in all three groups (A, 3/5 patients, 60%; B, 4/6 patients, 67%; C, 6/7 patients, 86%; p = not significant). In seven patients (39%), a fundic wrap was used to reinforce the site of primary repair. The outcomes of the three groups were analyzed. Group A had the lowest proportion of postoperative leaks (A, 0/4 patients, 0%; B, 4/6 patients, 67%; C, 5/6 patients, 83%; p < 0.05) and postoperative morbidity (A, 2/5 patients, 40%; B, 6/6 patients, 100%; C, 6/7 patients, 86%; p < 0.1). However the increased incidence of leak and morbidity did not lead to an increase in mortality. One death occurred in each group, with an overall mortality of 17% (A, 1/5 patients, 20%; B, 1/6 patients, 17%; C, 1/7 patients, 14%; p = not significant). We conclude that in the era of advanced intensive care capabilities, primary repair of intrathoracic esophageal perforation can be safely accomplished in most patients regardless of the time interval between perforation and operation. Leakage at the suture site is common unless primary repair is carried out without delay. Postoperative leakage, however, is usually inconsequential and does not necessarily result in an adverse outcome.

A dramatic change in the interaction of Cu(II) with bio-peptides promoted by SDS--a model for complex formation on a membrane surface.

The extent of complex formation between Cu(II) and many biologically active oligopeptides has been shown to change significantly in the presence of SDS micelles, a recognized model for cell lipid membranes. Protonation constants of peptides can be increased by up to 2 log unit, especially when they contain hydrophobic side chains. Metal complex formation is generally less extensive and the conformations of peptides can be altered dramatically when compared to those in simple aqueous solution.

Kinetic-spectrophotometric determination of sulfide by its reaction with resazurin.

A sensitive, rapid and selective method for the determination of sulfide based on its reaction with resazurin at pH 7 is described. The method is simple and has the great advantage of being free from interference of other sulfur anions and thus sulfide can be easily determined at trace levels in the presence of other sulfur compounds. The method has been applied to some synthetic samples and a spring water sample. The importance of sulfide compounds in biological processes has been widely demonstrated [1]. However, most of the methods used so far are either not sensitive enough or require complicated and expensive instruments; or are subjected to interferences from other sulfur compounds. Therefore, more sensitive, simple and selective methods are still required.

One-stage primary repair of distal esophageal perforation using fundic wrap.

Esophageal leak following primary repair of esophageal perforation is a serious complication that can lead to severe mediastinitis and sepsis. Complete diversion with esophageal exclusion or resection is designed to minimize further mediastinal contamination. However, this approach is not necessarily associated with less morbidity or mortality. Furthermore, a second stage operation is required to restore esophageal continuity. From 1986 to 1994, we performed a one-stage primary repair of the distal esophagus in seven patients with either iatrogenic (n = 5) or spontaneous (n = 2) perforations and reinforced the repair by a fundic wrap. One patient underwent an additional modified Heller myotomy for achalasia. Delay between perforation and operation was less than 6 hours in 3 patients, 6 to 24 hours in 2 patients, and greater than 24 hours in 2 patients. Only one patient (14%) developed a small esophageal leak that spontaneously resolved with adequate mediastinal drainage, intravenous antibiotics, and aggressive nutritional support. One patient (14%), whose repair was delayed by 12 hours, died postoperatively of profound sepsis. This patient was moribund from sepsis preoperatively, and postmortem examination of the esophagus revealed no evidence of esophageal leak. Esophageal continuity was maintained in all patients. The median length of stay was 21 days (range, 15-58 days). We conclude that primary reinforced repair of esophageal perforation using a fundic wrap is an effective method of treatment for distal esophageal perforation, even when the repair is delayed by more than 24 hours.

Flow injection analysis of sulphite by gas-phase molecular absorption UV/VIS spectrophotometry.

A flow injection gas-phase molecular absorption spectrophotometric method is described for the determination of sulphite in aqueous solution. The sulphite solution, 200 microl, is introduced into a stream of distilled water. The carrier stream containing a sulphite zone is reacted, in the first mixing coil, with a stream of sulphuric acid (1 M). The evolved sulphur dioxide is purged to the segments of nitrogen flow through the second mixing coil. The gaseous phase is separated from the liquid stream by the use of a purpose built gas-liquid separator and then is swept into a purpose built flow-through cell. The absorbance of the gaseous phase is measured at 200 nm using a UV/VIS spectrophotometer. Up to 440 microg of sulphite is determined. The limit of detection is 0.8 microg and the R.D.S. for the determination of 70 and 220 microg of sulphite are 1.02 and 0.76%, respectively. Up to 40 samples h(-1) can be analyzed. The effect of several anions and cations on the determination of sulphite was studied and the results showed that the method is relatively free from interferences. The proposed method was applied to the determination of sulphite in a synthetic sample, water sample and lemon juice.

Kinetic spectrophotometric determination of traces of sulfide.

A method for the determination of sulfide based on the addition reaction of sulfide with magenta at pH 7 and 25 degrees C is described. The decrease in absorbance of magenta at 540 nm, its lambda(max), over a fixed time is proportional to the concentration of sulfide over the range of 25-2500 ng ml(-1). The limit of detection was found to be 15 ng ml(-1). Ten replicate analysis of a sample solution containing 1.5 mug ml(-1) sulfide gave a relative standard deviation of 0.8%. The effects of various cations and anions on sulfide determination have been reported and procedures for removal of interferences have been described.

Kinetic spectrophotometric determination of ascorbic acid by reduction of toluidine blue.

A simple kinetic method is described for the determination of ascorbic acid. The procedure is based on the reduction of toluidine blue with ascorbic acid. The rate of reaction is followed by measuring the decrease in absorbance of toluidine blue (lambda(max) = 600 nm) as a result of its decolorization upon reduction by ascorbic acid. Ascorbic acid in the range of 3-35 microg/ml was determined using slope and fixed time methods of analysis, while the variable time method allowed the determination of 5-50 microg/ml of ascorbic acid. The percent relative standard deviation of the method varied from 0.78 to 1.32% depending on the kinetic method used. The high sensitivity of the method also allows determination of low levels of ascorbic acid in some fruits and vegetables such as dew melon, water melon, parsley and coriander.