Efficacy of rifaximin in the different clinical scenarios of hepatic encephalopathy. / Eficacia de la rifaximina en los diferentes escenarios clínicos de la encefalopatía hepática.

Hepatic encephalopathy is a frequent complication in patients with cirrhosis of the liver and is associated with a high mortality rate. Costs attributed to the management of patients with cirrhosis are especially high due to complications, such as hepatic encephalopathy, given that they increase the number of days of hospital stay. Different drugs are currently used to treat hepatic encephalopathy, and the main ones are lactulose, L-ornithine L-aspartate (LOLA), and certain antibiotics, especially rifaximin-α (RFX). Even though many of them have been shown to be effective to greater or lesser degrees, it is important to understand the differences between them, so that every patient receives individualized treatment and the best option is chosen, in accordance with the different clinical scenarios. Thus, the aim of the present study was to analyze the evidence on the advantages and disadvantages of the individual or combined use of the 3 main treatments for hepatic encephalopathy, specifically taking into consideration their different degrees of efficacy, their impact on quality of life, prophylaxis, and cost reduction.

Bowel symptoms in patients that receive proton pump inhibitors. Results of a multicenter survey in Mexico. / Síntomas intestinales en pacientes que reciben inhibidores de bomba de protones (IBP). Resultados de una encuesta multicéntrica en México.

INTRODUCTION: Proton pump inhibitors (PPIs) have been associated with small intestinal bacterial overgrowth (SIBO), which increases with prolonged PPI use, and SIBO has been associated with irritable bowel syndrome (IBS). OBJECTIVE: The aim of the present study was to study the prevalence of bowel symptoms in patients treated with PPIs in Mexico. METHODS: Gastroenterologists in 36 cities surveyed patients treated with PPIs, utilizing an ad hoc questionnaire to determine the presence of bowel symptoms and IBS. RESULTS: Two hundred and fifteen physicians interviewed 1,851 patients. PPI indications were gastritis (48.8%), gastroesophageal reflux (38.5%), peptic ulcer (6.2%), and others (6.5%). A total of 77.5% of the patients received treatment for ≤6 months and 11.9% for ≥1 year. Symptoms were reported in 92.3% of the patients: abnormal bowel habits (90%), bloating (82%), abdominal pain (63%), flatulence (58%), and abdominal discomfort (53%). A total of 67.5% of the patients fit the Rome III criteria for IBS. Symptoms presented in 55.9% of the patients before PPI intake and in 44.1% of the patients after PPI use (P<.005). Constipation (63.8%) predominated in the former, and diarrhea (56.5%) in the latter (P<.0001). The treatments prescribed for managing those symptoms were antispasmodics, antibiotics, prokinetics, and antiflatulents, but patients stated greater satisfaction with antibiotics (mainly rifaximin) (P<.0001). CONCLUSION: The association of PPIs with bowel symptoms and IBS is frequent in Mexico. Diarrhea and bloating predominate, and antibiotics produce the greatest treatment satisfaction, suggesting that SIBO or dysbiosis is the cause of the PPI-related bowel symptoms. However, that remains to be confirmed.

Effect of chemical structure on the subglass relaxation dynamics of biobased polyesters as revealed by dielectric spectroscopy: 2,5-furandicarboxylic acid vs. trans-1,4-cyclohexanedicarboxylic acid.

The chemical structure-dynamics relationship for poly(trimethylene 2,5-furanoate) and poly(trimethylene 1,4-cyclohexanedicarboxylate) was investigated via dielectric spectroscopy and compared with that of poly(trimethylene terephthalate) in order to evaluate the impact on the subglass dynamics of the chemical nature of the ring. Further comparison was accomplished with the neopentyl glycol containing counterparts: poly(neopentyl 2,5-furanoate) and poly(neopentyl 1,4-cyclohexanedicarboxylate). Our study reveals a multimodal nature of the subglass ß process. For the more flexible polymers (containing cyclohexane rings) three modes for the ß process were detected. The faster mode was assigned to the relaxation of the oxygen linked to the aliphatic carbon, the slower one to the link between the aliphatic ring and the ester group, and the third mode to the aliphatic ring. For stiffer polymers (containing aromatic rings), the local modes appear more coupled. This effect is more evident in the polymers with the furan ring where essentially a single ß mode can be resolved.

Susceptibility to rifaximin and other antimicrobials of bacteria isolated in patients with acute gastrointestinal infections in Southeast Mexico. / Susceptibilidad a la rifaximina y otros antimicrobianos de bacterias aisladas en pacientes con infecciones gastrointestinales agudas en el sureste de México.

INTRODUCTION: Enteropathogenic bacteria isolated in Mexico City have shown a high rate of resistance to different antibiotics, with the exception of rifaximin (RIF). RIF is a nonabsorbable antibiotic that reaches high fecal concentrations (≈ 8,000µg/g). Susceptibility to antimicrobials can vary in different geographic regions. AIM: To study the susceptibility to rifaximin and other antimicrobials of enteropathogenic bacteria isolated in patients with acute diarrhea in the southeastern region of Mexico. MATERIAL AND METHODS: A total of 614 strains of bacteria isolated from patients with acute diarrhea from 4 cities in Southeast Mexico were analyzed. An antibiogram with the following antibiotics was created: ampicillin (AMP), trimethoprim/sulfamethoxazole (T-S), neomycin (NEO), furazolidone (FUR), ciprofloxacin (CIP), chloramphenicol (CHL), and fosfomycin (FOS), assessed through the agar diffusion method at the standard concentrations recommended by the Clinical and Laboratory Standards Institute (CLSI) and the American Society for Microbiology (ASM), and RIF, assessed through microdilution at 4 concentrations. RESULTS: The bacteria were Escherichia coli (55%), as the majority, in all its pathogenic variants, Shigella (16.8%), Salmonella (15.3%), Aeromonas (7.8%), and less than 5% Campylobacter, Yersinia, Vibrio, and Plesiomonas. The accumulated overall susceptibility to RIF was 69.1, 90.8, 98.9, and 100% at concentrations of 100, 200, 400, and 800µg/ml, respectively. Overall susceptibility to other antibiotics was FOS 82.8%, CHL 76.8%, CIP 73.9%, FUR 64%, T-S 58.7%, NEO 55.8%, and AMP 23.8%. Susceptibility to RIF at 400 and 800µg was significantly greater than with the other antimicrobials (P<.001). CONCLUSIONS: The data of the present study were similar to those of a previous study carried out in Mexico City: susceptibility to RIF in > 98% of the bacterial strains and a high frequency of resistance to several common antimicrobials.

Susceptibility of bacteria isolated from acute gastrointestinal infections to rifaximin and other antimicrobial agents in Mexico.

BACKGROUND: Bacterial resistance may hamper the antimicrobial management of acute gastroenteritis. Bacterial susceptibility to rifaximin, an antibiotic that achieves high fecal concentrations (up to 8,000µg/g), has not been evaluated in Mexico. OBJECTIVE: To determine the susceptibility to rifaximin and other antimicrobial agents of enteropathogenic bacteria isolated from patients with acute gastroenteritis in Mexico. MATERIAL AND METHODS: Bacterial strains were analyzed in stool samples from 1,000 patients with diagnosis of acute gastroenteritis. The susceptibility to rifaximin (RIF) was tested by microdilution (<100, <200, <400 and <800µg/ml) and susceptibility to chloramphenicol (CHL), trimethoprim-sulfamethoxazole (T-S), neomycin (NEO), furazolidone (FUR), fosfomycin (FOS), ampicillin (AMP) and ciprofloxacin (CIP) was tested by agar diffusion at the concentrations recommended by the Clinical & Laboratory Standards Institute and the American Society for Microbiology. RESULTS: Isolated bacteria were: enteropathogenic Escherichia coli (E. coli) (EPEC) 531, Shigella 120, non-Typhi Salmonella 117, Aeromonas spp. 80, enterotoxigenic E. coli (ETEC) 54, Yersinia enterocolitica 20, Campylobacter jejuni 20, Vibrio spp. 20, Plesiomonas shigelloides 20, and enterohemorrhagic E. coli (EHEC 0:157) 18. The overall cumulative susceptibility to RIF at <100, <200, <400, and <800µg/ml was 70.6, 90.8, 99.3, and 100%, respectively. The overall susceptibility to each antibiotic was: AMP 32.2%, T-S 53.6%, NEO 54.1%, FUR 64.7%, CIP 67.3%, CLO 73%, and FOS 81.3%. The susceptibility to RIF <400 and RIF <800µg/ml was significantly greater than with the other antibiotics (p<0.001). CONCLUSIONS: Resistance of enteropathogenic bacteria to various antibiotics used in gastrointestinal infections is high. Rifaximin was active against 99-100% of these enteropathogens at reachable concentrations in the intestine with the recommended dose.

Flat-on lamellae in spin-coated, stable films of poly(propylene azelate).

Thin films (5-500 nm thick) of the linear aliphatic polyester (3,7) poly(propylene azelate) (PPAz) were prepared by spin-coating of CHCl(3) polymer solutions with different polymer concentrations. The morphology and structure of the spin-coated thin films were investigated by atomic force microscopy (AFM) and by grazing incidence wide-angle X-ray scattering (GIWAXS) techniques. AFM revealed the continuous nature of the flat, spherulitic films which are stable against dewetting even for polymer coatings as thin as 15 nm. GIWAXS patterns revealed a high crystal orientation of the films. A sharp reflection on the meridian whose spacing is related to the polymer chain unit length (c-axis) supports the presence of flat-on lamellae morphology in the whole range of film thicknesses investigated. The flat-on lamellae morphology is also supported by AFM images. A triclinic unit cell with the c*-axis perpendicular to the substrate is proposed for PPAz. The repulsion of the long aliphatic spacer by the Si-substrate is invoked as the main reason for the flat-on morphology observed.

Structure and morphology of thin films of linear aliphatic polyesters prepared by spin-coating.

Thin films, with thicknesses from 10 to 400 nm of linear aliphatic polyesters (X, Y), based on propylenediol (X = 3) and on dicarboxylic acid of different chain length (Y = 2, 3, and 4 CH(2) units) were prepared by spin coating of CHCl(3) polymer solutions with different polymer concentrations. Morphology and structure of the spin coated thin films were investigated by atomic force microscopy (AFM) and by grazing incidence X-ray scattering techniques at small, (GISAXS) and wide angles (GIWAXS). AFM revealed a strong dewetting for all three polymers for coatings thinner than 100 nm. The polymer films are clearly semicrystalline for thicknesses higher than 50 nm. GIWAXS of the thicker films revealed their oriented crystalline nature. An edge-on-lamellae morphology is clearly shown by the AFM-phase images even for relatively thin films. SAXS with the beam parallel to the sample plane also support the presence of lamellae perpendicular to the substrate. The use of a mu-beam helped to interpret the GIWAXS patterns and allowed to obtain oriented WAXS patterns from melt solidified filaments. Thus, a crystal chain packing is proposed for the three polymers and consequently the indexing of the observed reflections. Accordingly, the polymer chains lie parallel to the substrate being the bc plane of the monoclinic crystal unit cell parallel to the substrate.

Magnetic resonance imaging in the preoperative assessment of Mayer-Rokitansky-Kuster-Hauser syndrome.

PURPOSE: We evaluated the accuracy of magnetic resonance imaging (MRI) in young women with primary amenorrhoea with suspected Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome (congenital absence of both vagina and uterus and presence of normal ovaries). MATERIALS AND METHODS: Fifty-eight women (age range 14-30 years, mean 20.9) with primary amenorrhea were studied with MRI performed with a 1.0-T superconducting magnet (Philips NT Intera). All patients were examined in the supine position using a phased-array coil (four channels). Turbo spin-echo T2-weighted images were acquired in the sagittal, axial and coronal planes with the following parameters: TR 4,750-6,686, TE 100-120, FOV 350-375, 4- to 5-mm sections with a 0.4- to 0.5-mm intersection gap and NSA 6. T1-weighted images were acquired in the axial and coronal planes (TR 470, TE 15, FOV 350, 4-mm sections with a 0.6-mm intersection gap, NSA 3). Two experienced radiologists evaluated all the examinations in consensus to assess the presence, position and morphology of vagina, uterus, ovaries and kidneys and any pelvic abnormalities. MRI results were judged on the basis of laparoscopic findings in 41 patients. RESULTS: MRKH syndrome was confirmed in 56 patients with 100% sensitivity and specificity. MRI identified bilateral Müllerian buds in 34/56 (61%) and unilateral in 10/56 (18%) patients. MRI sensitivity was 81.42%, and there was good agreement with laparoscopy (k=0.55) and full agreement in the identification of cavitation between MRI and intraoperative sonography. Both ovaries were visualised in 54 patients, with regular morphology in 46 (82.1%), polycystic in 10 (17.8%), pelvic in 47 (83.6%) and extrapelvic in eight (14.5%). We found associated abnormalities of the upper urinary tract in six patients (solitary kidney in four and ptosis in two). CONCLUSIONS: MRI is a useful diagnostic tool in the preoperative evaluation of MRKH syndrome and is less expensive and invasive than laparoscopy. Strong cooperation between radiologists and surgeons is highly recommended.

Evidence of early stage precursors of polymer crystals by dielectric spectroscopy.

Dielectric spectra of the polyester poly(propylene succinate) were measured upon crystallization. For this model aliphatic polyester the alpha and beta relaxations appear simultaneously and are well resolved in the experimental frequency window. During isothermal crystallization, this fact allows one to use the beta relaxation to characterize the crystalline structural development while the alpha relaxation provides information about the evolution of the amorphous phase dynamics. In this way structure development and dynamics evolution can be characterized by a single experiment during the crystallization process. The unambiguous analysis of the dielectric loss clearly supports the existence of precursors of crystallization in the induction period.

Hemodynamic and oxidative stress profile after exercise in type 2 diabetes.

This study investigated the effect of an acute bout of exercise (>85% VO2Max) on biochemical, hemodynamic and oxidative stress variables in sedentary and physically active subjects with type 2 diabetes (T2D). Blood measurements were taken before and after a treadmill test on 12 sedentary non-diabetes subjects (ND), 12 sedentary type 2 diabetes (T2S) and 9 physically active T2D subjects (T2DA). T2DS subjects before and after the treadmill test showed a higher plasma glucose (123.2 +/- 19.0 mg/dL versus 108.9 +/- 16.8 mg/dL, p < 0.001), HbA1C (8.7 +/- 2.4% versus 7.3 +/- 1.2%, p < 0.001) and body fat% (21.3 +/- 5.7% versus 34.6 +/- 4.5%, p < 0.001) than T2DA subjects. T2DA had higher VO2Max (37.7 +/- 3.5 versus 29.5 +/- 3.2, p < 0.05), time on treadmill (22.3 +/- 2.1 min versus 16.1 +/- 2.1 min, p < 0.05), hemoglobin (17.9 +/- 0.9 g/dL, p < 0.05) and lower blood pressure levels in comparison to ND and T2DS subjects. Thiobarbituric acid substances (TBARS) in T2DS were higher than in T2DA subjects (0.27 +/- 0.1 nmol/mL versus 0.21 +/- 0.1 nmol/mL, p < 0.05). Glutathione (GSH) levels were similar among the groups. Physically active type 2 diabetes subjects had a more favorable biochemical, hemodynamic and oxidative stress profile than sedentary subjects. The coexistence of a poor cardiopulmonary performance and high oxidative stress environment can determine a profile of high risk for serious cardiovascular events in patients with diabetes.

Effects of inter- and intra-observer variability on echocardiographic measurements in awake cats.

The objective of this study was to determine intra- and inter-observer variability of echocardiographic measurements in awake cats. Four observers with different levels of experience in echocardiography performed 96 echocardiographic examinations in four cats on four different days over a 3-week period. The examinations were randomized and blinded. The maximum within-day and between-day CV values were 17.4 and 18.5% for inter-ventricular septal thickness in diastole, 18.7 and 22.6% for left ventricular free-wall thickness in diastole, 9.8 and 14.9% for left ventricular end-diastolic diameter, 20.8 and 15.2% for left ventricular end-systolic diameter, and 21.2 and 18.4% for left ventricular shortening fraction. The maximum within-day CV values were most often associated with the least competent observer (i.e. the graduate student) and, the minimum CV values with the most competent observer (i.e. the associate professor in cardiology). A significant interaction between cat and observer was also evidenced. Thus, the most competent observer could not be replaced by any of the other observers.

[Prescription of exercise in the diabetic patient]. / Acerca de la prescripción de ejercicio en el paciente diabético.

There is a broad epidemiologic evidence related with the increase of the incidence and prevalence of diabetes mellitus type 2 throughout the world, especially in Western populations, at rates considered epidemic. Cerebrovascular disease and myocardial infarction are two of the most important complications of this disease and they have very high social and economic consequences. Treatment of this disease is directed good metabolic control, diminishing toward obtain co-morbidity, and reducing acute and chronic diabetic complications. Diet, hypoglycemic drugs or insulin, and programs of physical activity are used for this purpose. This document presents some thoughts on the difficulties related with the prescription of physical exercise in the diabetic patient and a brief proposal to solve those problems in the clinical practice.

Oxidative stress, acute and regular exercise: are they really harmful in the diabetic patient?

Oxidative stress has been involved in the pathogenic process of a variety of diseases including diabetes mellitus. The production of oxidative reactive products has been involved in biochemical changes in bio-molecules that might produce tissue damage directly related to some of the main vascular complications in the diabetic patient. On the other hand, exercise, paradoxically, is a well-recognized model of oxidative stress and also an important therapeutic tool in diabetes management. Therefore, the relationship between oxidative stress and exercise in diabetic patients implies an interesting biochemical paradox due to some of the negative effects of exercise principally by the increase of oxidative species in plasma. The effect of oxidative stress during an acute exercise and after an aerobic training period on those patients remains unknown and needs to be studied.

[Oxidative stress. Should it be measured in the diabetic patient?]. / El estrés oxidativo. Es necesario medirlo en el paciente diabético?

Oxidative stress has been defined as a loss of counterbalance between free radical or reactive oxygen species production and the antioxidant systems, with negative effects on carbohydrates, lipids, and proteins. It is also involved in the progression of different chronic diseases and apoptosis. Diabetes mellitus is associated to a high oxidative stress level through different biochemical pathways, i.e. protein glycosylation, glucose auto-oxidation, and the polyol pathway, mainly induced by hyperglycemia. Oxidative stress could also be involved in the pathogenesis of atherosclerotic lesions and other chronic diabetic complications. Measurement of oxidative stress could be useful to investigate its role in the initiation and development processes of chronic diabetic complications and also to evaluate preventive actions, including antioxidative therapy. Different attempts have been made to obtain a practical, accurate, specific, and sensitive method to evaluate oxidative stress in clinical practice. However, this ideal method is not currently available to date and the usefulness of the current methods needs to be confirmed in daily practice. We suggest quantifying oxidated and reduced glutation (GSSG/GSH) and the thiobarbituric reactive substances (TBARS) with currently alternatives. Currently available alternative methods while we await better options.

PET supports the hypothesized existence of a male sexual brain algorithm that may respond to treatment combining psychotherapy with virtual reality.

Could a brain circuit exist, verifiable using positron emission tomography (PET), that links coitus and its dysfunctions, such as impotence? Could re-establishing normal sexual functioning be linked with the normalization of some sort of altered brain metabolism utilizing a therapeutic project that uses psychodynamic psychotherapy integrating virtual reality (VR)? A Brain PET Scan and a self-administered sexual activity questionnaire were given to 11 heterosexual patients affected by impotence due to psychological causes, both before and approximately 6 months after a cycle of psychodynamic psychotherapy. Seven randomly-selected patients received psychotherapy with VR technology using the Optale Method. PET data, used to indicate glucose consumption in various brain areas, were compared with data from normal patients, and a statistical analysis was run. Alterations in cerebral metabolic functioning were displayed in the following areas: frontal cortex, nucleus caudatus, and thalamus. The seven patients who received psychotherapy with VR technology "normalized" in these same areas and attained satisfactory sexual performance. The existence of a male sex algorithm may be hypothesized that links the frontal cortex, nucleus caudatus, and thalamus, and explains its action on cortical motor areas and/or on the medial preoptic area of the hypothalamus, which may respond to treatment combining psychotherapy with VR.

Risk factors for steroid diabetes in rheumatic patients.

BACKGROUND: Steroid induced diabetes (SDM) has been known for a long time, but its pathophysiological mechanisms as well as its predisposing factors remain unknown. METHODS: In order to investigate the different factors related to the development of steroid diabetes (SDM) in patients with rheumatic diseases, we studied 27 patients with SDM, and 27 age- and sex-matched controls who also received therapy with glucocorticoids. In every case, family history of DM, body mass index, associated treatment, steroid dose and treatment duration were studied; fasting serum insulin, "C" peptide, growth hormone and glucagon levels were measured. RESULTS: All of the patients received prednisone. Cumulated prednisone dose was the only factor significantly associated with the development of SDM. Patients with SDM had a cumulated dose of 26.6 +/- 28 g (M +/- SD), while the control group received 11.6 +/- 11 g (p < 0.02) (odds ratio, 6.35). Serum insulin levels were not significantly different, but insulin/glucose ratio was lower in SDM (0.104 +/- 0.05) than in the control group (0.163 +/- 0.07) (p < 0.05). CONCLUSIONS: These findings suggest that high cumulated prednisone dose may induce DM regardless of another hereditary or personal predisposing factor.

[Treatment of diabetic neuropathy]. / Tratamiento de la neuropatía diabética.

Diabetic polyneuropathy is a complication, that affects most patients with longstanding diabetes mellitus, deteriorating their quality of life. In the last few years, new therapeutic approaches have been developed that can improve symptoms and neurologic function, and which may prevent and in some cases stop nerve damage, and even, promote nerve fiber regeneration. These treatments are supported by several investigations in animals and humans: a) thigh glycemic control (insulin), b) aldose reductase inhibition (tolrestat), c) prevention of protein glycation (amino-guanidine), d) improvement of nerve ischemia (vaso-dilators, gamma-linolenic acid), and e) administration of neurotrophic factors (gangliosides). Most evidence support the usefulness for glycemic control. Early treatment is suggested, because marked nerve fiber loss is present in advanced neuropathy.