Fever-like temperature impacts on Staphylococcus aureus and Pseudomonas aeruginosa interaction, physiology, and virulence both in vitro and in vivo.

BACKGROUND: Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) cause a wide variety of bacterial infections and coinfections, showing a complex interaction that involves the production of different metabolites and metabolic changes. Temperature is a key factor for bacterial survival and virulence and within the host, bacteria could be exposed to an increment in temperature during fever development. We analyzed the previously unexplored effect of fever-like temperatures (39 °C) on S. aureus USA300 and P. aeruginosa PAO1 microaerobic mono- and co-cultures compared with 37 °C, by using RNAseq and physiological assays including in vivo experiments. RESULTS: In general terms both temperature and co-culturing had a strong impact on both PA and SA with the exception of the temperature response of monocultured PA. We studied metabolic and virulence changes in both species. Altered metabolic features at 39 °C included arginine biosynthesis and the periplasmic glucose oxidation in S. aureus and P. aeruginosa monocultures respectively. When PA co-cultures were exposed at 39 °C, they upregulated ethanol oxidation-related genes along with an increment in organic acid accumulation. Regarding virulence factors, monocultured SA showed an increase in the mRNA expression of the agr operon and hld, pmsα, and pmsß genes at 39 °C. Supported by mRNA data, we performed physiological experiments and detected and increment in hemolysis, staphyloxantin production, and a decrease in biofilm formation at 39 °C. On the side of PA monocultures, we observed an increase in extracellular lipase and protease and biofilm formation at 39 °C along with a decrease in the motility in correlation with changes observed at mRNA abundance. Additionally, we assessed host-pathogen interaction both in vitro and in vivo. S. aureus monocultured at 39οC showed a decrease in cellular invasion and an increase in IL-8-but not in IL-6-production by A549 cell line. PA also decreased its cellular invasion when monocultured at 39 °C and did not induce any change in IL-8 or IL-6 production. PA strongly increased cellular invasion when co-cultured at 37 and 39 °C. Finally, we observed increased lethality in mice intranasally inoculated with S. aureus monocultures pre-incubated at 39 °C and even higher levels when inoculated with co-cultures. The bacterial burden for P. aeruginosa was higher in liver when the mice were infected with co-cultures previously incubated at 39 °C comparing with 37 °C. CONCLUSIONS: Our results highlight a relevant change in the virulence of bacterial opportunistic pathogens exposed to fever-like temperatures in presence of competitors, opening new questions related to bacteria-bacteria and host-pathogen interactions and coevolution.

Fever-like temperature impacts on Staphylococcus aureus and Pseudomonas aeruginosa interaction, physiology, and virulence both in vitro and in vivo.

Background: Staphylococcus aureus and Pseudomonas aeruginosa cause a wide variety of bacterial infections and coinfections, showing a complex interaction that involves the production of different metabolites and metabolic changes. Temperature is a key factor for bacterial survival and virulence and within the host, bacteria could be exposed to an increment in temperature during fever development. We analyzed the previously unexplored effect of fever-like temperatures (39°C) on S. aureus USA300 and P. aeruginosa PAO1 microaerobic mono- and co-cultures compared with 37°C, by using RNAseq and physiological assays including in-vivo experiments. Results: In general terms both temperature and co-culturing had a strong impact on both PA and SA with the exception of the temperature response of monocultured PA. We studied metabolic and virulence changes on both species. Altered metabolic features at 39°C included arginine biosynthesis and the periplasmic glucose oxidation in S. aureus and P. aeruginosa monocultures respectively. When PA co-cultures were exposed at 39°C they upregulated ethanol oxidation related genes along with an increment in organic acid accumulation. Regarding virulence factors, monocultured SA showed an increase in the mRNA expression of the agr operon and hld, pmsα and pmsß genes at 39°C. Supported by mRNA data, we performed physiological experiments and detected and increment in hemolysis, staphylxantin production and a decrease in biofilm formation at 39°C. On the side of PA monocultures, we observed increase in extracellular lipase and protease and biofilm formation at 39°C along with a decrease in motility in correlation with changes observed at mRNA abundance. Additionally, we assessed host-pathogen interaction both in-vitro and in-vivo . S. aureus monocultured at 39°C showed a decrease in cellular invasion and an increase in IL-8 -but not in IL-6- production by A549 cell line. PA also decreased its cellular invasion when monocultured at 39°C and did not induce any change in IL-8 or IL-6 production. PA strongly increased cellular invasion when co-cultured at 37°C and 39°C. Finally, we observed increased lethality in mice intranasally inoculated with S. aureus monocultures pre-incubated at 39°C and even higher levels when inoculated with co-cultures. The bacterial burden for P. aeruginosa was higher in liver when the mice were infected with co-cultures previously incubated at 39°C comparing with 37°C. Conclusion: Our results highlight a relevant change in the virulence of bacterial opportunistic pathogens exposed to fever-like temperatures in presence of competitors, opening new questions related to bacteria-bacteria and host-pathogen interactions and coevolution.

Litiasis coledociana: resultados de la colangiografa intraoperatoria en nuestro medio / Choledocholithiasis: results of the intraoperative cholangiography in our community

The term choledocholithiasis refers to a condition when a gallstone or gallstones become lodged within any duct of the bile system. We can find pigment gallstones, cholesterol gallstones and mixed. During surgery to remove the gallbladder you may have a procedure called intraoperative cholangiogram to look for gallstones that may be in the common bileduct. Stones in the bile ducts are classified as either primary (arising the novo), secondary (migrating from the gallbladder), recurrent (reforming after biliary tract surgery) or retained (overlooked at the time of surgery). The prevalence of choledocholithiasis in patients with simptomatic gallbladder lithiasis can be a reason for enlargement of the hospital stay, and eventually in the complexity on the prevented surgical procedure. Our aim was to investigate its prevalence in our Hospital, and the results with the empoyement of the intraoperative cholangiography accordin to our surgical protoco, and the recognized guideliness from other Centers. The results obtained are discused

Biopsia del ganglio centinela en melanomas en nuestro medio / Sentinel node biopsy in patients with melanomas

A sentinel node biopsy is a procedure in which the sentinel lymph node is identified, removed and examined to determine whether cancer cells are present. It´s used most commonly in evaluating breast cancer and melanoma. The sentinel nodes are the first few lymph nodes into which a tumor drains. The sentinel nodes are removed and analyzed in a laboratory. Melanoma is a tumor of melanocyte origin. There is a considerable evidence that early recognition and surgical removal of melanoma makes this a highly curable cancer. Because early detection of melanoma results in a high frequency of cure it is important to recognize the lesion in the earliest stages. Malignant melanoma is a type of cancer that develops from the pigment-containing cells known as melanocytes, and is the most aggressive and life-threatening skin cancer. Sentinel node biopsy is a surgical procedure to determine whether cancer has spread beyond a primary tumor into the lymphatic system. Removal and examination of the sentinel lymph node to which cancer cells are likely to spread from the primary tumor, are supposed to be an useful tool to prevent early this spread. In this paper the authors present their experience with the management of this procedure.

A master dynamic flow diagram for the shear thickening transition in micellar solutions.

The shear thickening behavior of dilute micellar solutions of hexadecyltrimethylammonium-type surfactants with different counterions (tosylate, 3- and 4-fluorobenzoate, vinylbenzoate and salicylate) and of n-alkyltetradecylammonium bromide (CnTAB), with n = 14, 16 and 18, is examined here. These solutions undergo a shear thickening transition due to the formation of shear-induced structures (SISs) in the shear range studied. Here we report a relationship between the shear thickening intensity and the differences in the hydrophobicity of counterions according to the Hofmeister-like anion series, which leads to a master flow diagram. This master flow diagram is produced by plotting a normalized shear thickening intensity (Iη - 1)/(Imax - 1) versus CD/CD,max, where Iη is the shear-thickening intensity, defined as the largest viscosity obtained in the shear-thickening transition (STT) at a given surfactant concentration CD divided by the Newtonian viscosity η0, and Imax is the largest intensity value obtained in the STT at a surfactant concentration CD,max. The master flow diagram is built using several cetyltrimethylammonium-type surfactants with different counterions, according to a Hofmeister-like series, and by n-alkyltetradecylammonium bromide surfactants with different alkyl chain lengths.

Intensive care practices in brain death diagnosis and organ donation.

We conducted a multicentre study of 1844 patients from 42 Spanish intensive care units, and analysed the clinical characteristics of brain death, the use of ancillary testing, and the clinical decisions taken after the diagnosis of brain death. The main cause of brain death was intracerebral haemorrhage (769/1844, 42%), followed by traumatic brain injury (343/1844, 19%) and subarachnoid haemorrhage (257/1844, 14%). The diagnosis of brain death was made rapidly (50% in the first 24 h). Of those patients who went on to die, the Glasgow Coma Scale on admission was ≤ 8/15 in 1146/1261 (91%) of patients with intracerebral haemorrhage, traumatic brain injury or anoxic encephalopathy; the Hunt and Hess Scale was 4-5 in 207/251 (83%) of patients following subarachnoid haemorrhage; and the National Institutes of Health Stroke Scale was ≥ 15 in 114/129 (89%) of patients with strokes. Brain death was diagnosed exclusively by clinical examination in 92/1844 (5%) of cases. Electroencephalography was the most frequently used ancillary test (1303/1752, 70.7%), followed by transcranial Doppler (652/1752, 37%). Organ donation took place in 70% of patients (1291/1844), with medical unsuitability (267/553, 48%) and family refusal (244/553, 13%) the main reasons for loss of potential donors. All life-sustaining measures were withdrawn in 413/553 of non-donors (75%).

Relación entre el valor del ratio elastográfico y la clasificación citológica de Bethesda en la patología tiroidea / Relationship between the value of elastography ratio and the cytological classification of Bethesda in thyroid pathology

Objetivo: Presentar nuestra experiencia en la categorización de la patología tiroidea, a través de la utilización de parámetros ecográficos de malignidad y elastografía con medición del ratio de la deformación tisular, y la correlación de los hallazgos obtenidos con la clasificación citológica de Bethesda. Materiales y métodos: Se llevó a cabo un estudio prospectivo y observacional, entre septiembre de 2012 y abril de 2013, que incluyó 137 nódulos tiroideos. Se excluyeron 10 casos Bethesda III-IV. Se realizó ecografía, power Doppler, visualización de micropartículas (Micropure) y elastografía con medición del ratio elastográfico, así como también punción aspirativa con aguja fina guiada por ecografía (con el citólogo presente), utilizando la clasificación Bethesda. Los estudios fueron hechos por el mismo operador con un ecógrafo Toshiba Aplio 400 y los datos estadísticos se evaluaron con el programa IBM SPSS Statistics 20. Resultados: Se estudiaron 127 nódulos en pacientes con una edad promedio de 59±16 anos. El 82% de los casos ocurrió en mujeres. Ciento veinte nódulos (94%) fueron clasificados como Bethesda II. La media elastográfica para Bethesda I-II fue de 1,94±2,12 vs. 7,07±5,46 para V-VI (p: 0,048). El punto de corte elastográfico ≤ 2 (87 de 127) presentó una sensibilidad del 85,7% y una especificidad del 81,7% para predecir Bethesda asociada a patología benigna, con un valor predictivo negativo (VPN) del 99% y un valor predictivo positivo del 15%. Conclusiones: El ratio elastográfico permitió descartar la patología tiroidea maligna con valores ≤ 2 y un VPN del 99%, mejorando la selección de los pacientes a punzar. El incremento del ratio elastográfico se asoció a una mayor probabilidad de patología maligna, aunque no se pudo establecer un valor de corte debido al bajo número de casos con Bethesda V-VI.

Objectives: We present our experience in the categorization of thyroid pathology using the sonographic parameters of malignancy and elastography with measurement elastography strain ratio, to evaluate the relationship between the results found and the Bethesda classification. Materials and methods: Prospective observational study, included 137 thyroid nodules studied between September 2012- April 2013. We excluded 10 cases with Bethesda categories III-IV. Ultrasonography, Doppler, Micropure, elastogrphy strain ratio between the lesion and the normal tissue, fine needle aspiration cytology (FNAC),were the diagnosis methods used. The pathologist was always present and the cytological classi fication of Bethesda was used. All study was made by the same physician used Toshiba Aplio 400 ultrasound unit. Results were analyzed with IBM SPSS Statistics 20. Results: We studied 127 nodules in patients 59±16 years old, 82% were female; 120 were Bethesda II (94%). The average strain ratio for nodules Bethesda I-II was 1.94±2.12 vs. 7.07±5.46 for those nodules Bethesda V-VI (p:0,048). This means that an elastography strain ratio ≤ 2 (87 of 127 nodules) has a sensibility of 85.7% and a specificity of 81.7% of predicting Bethesda associated with benign pathology with a negative predictive value (NPV) of 99% and a positive predictive value of 15%. Conclusion: The elastography strain ratio allowed to discard malignant nodules with strain ratio ≤ 2 with a NPV of 99% improves the selection of patients for FNAC. The increment in the elastography strain ratio was associated to a higher possibility of malignant thyroid pathology, being unable to determine a limit value due to the low amount of cases with nodules Bethesda V-VI.

Ultrasound diagnosis of three cases of Mondor's disease.

OBJECTIVE: To describe clinical features and ultrasound findings of three cases of a little-known and relatively infrequent entity in daily clinical activity, which is often unnoticed and under-reported: penile Mondor's disease or superficial penile veins thrombophlebitis. METHODS: We are reporting the cases of three patients aged 33, 25 and 39 years who were referred to our department, the first case with suspicion of inguinal hernia, the second one to rule out testicular pathology because of pubic and perineal discomfort, and the third one for painful induration of the dorsal region of the penis. The three patients underwent Doppler-ultrasound examination (Toshiba®, using a 13-18MHz linear transducer) to establish definitive diagnosis, and had a favorable evolution with conservative management. RESULTS: Ultrasound examination revealed: Case 1. Penile superficial dorsal vein and lateral superficial veins thrombosis. Case 2. Thrombosis of the right branch of the superficial dorsal vein and its perineal distal connections. Case 3. Penile superficial dorsal vein thrombosis. Definitive diagnosis of the three cases was Mondor's disease. CONCLUSIONS: Mondor's disease is an often under-reported entity in daily clinical activity. Doppler-ultrasound findings (echogenic material within veins, lack of any response after compression by the transducer and absence of color flow) confirm de diagnosis. This disease has a favorable evolution and functional prognosis. Knowledge of Mondor's disease by echographists is basic to avoid false-negative results in radiologic examination.

Effects of electrolyte concentration and counterion valence on the microstructural flow regimes in dilute cetyltrimethylammonium tosylate micellar solutions.

The shear thickening behavior and the transition to shear thinning are examined in dilute cetyltrimethylammonium tosylate (CTAT) micellar solutions as a function of surfactant concentration and ionic strength using electrolytes with different counterion valence. Newtonian behavior at low shear rates, followed by shear thickening and shear thinning at higher shear rates, are observed at low and intermediate surfactant and electrolyte concentrations. Shear thickening diminishes with increasing surfactant concentration and ionic strength. At higher surfactant or electrolyte concentration, only a Newtonian region followed by shear thinning is detected. A generalized flow diagram indicates two controlling regimes: one in which electrostatic screening dominates and induces micellar growth, and another, at higher electrolyte and surfactant concentrations, where chemical equilibrium among electrolyte and surfactant counterions controls the rheological behavior by modifying micellar breaking and reforming. Analysis of the shear thickening behavior reveals that not only a critical shear rate is required for shear thickening, but also a critical deformation, which appears to be unique for all systems examined, within experimental error. Moreover, a superposition of the critical shear rate for shear thickening with surfactant and electrolyte concentration is reported.

Rheological behavior of surfactant-based precursors of silica mesoporous materials.

The linear and non-linear viscoelastic behaviors of polymer-like micellar solutions of cetyltrimethylammonium tosilate (CTAT) with added NaOH and tetraethyl orthosilicate (TEOS) to produce precursors of mesoporous materials are studied. The effect of TEOS/CTAT (T/C) ratio at fixed CTAT concentration, CTAT concentration at fixed T/C and aging time are reported. The systems show increasingly larger deviations from near-Maxwell behavior upon increasing T/C ratio, CTAT concentration and aging. Moreover, in steady and unsteady shear-flow, shear banding develops between two critical shear rates, which tend to fade as the T/C ratio and aging increase. The Granek-Cates model is employed to analyze linear viscoelastic behavior. The Bautista-Manero-Puig (BMP) model is used here to reproduce the steady and transient nonlinear rheology of these systems. We explain these results in terms of the changes in inter-macromolecular interactions that arise out of the presence of colloidal additives in the viscoelastic gel. The ordered mesoporous materials were identified by X-ray diffractometry (XRD) and high-resolution transmission electron microscopy.

14 years of experience with the artificial urinary sphincter in children and adolescents without spina bifida.

PURPOSE: The efficacy of the artificial urinary sphincter to treat sphincteric incontinence in pediatric patients with spina bifida has been clearly reported. The possibility of maintaining spontaneous voiding has usually been the main reason for prosthetic device surgery. We reviewed our experience with the artificial urinary sphincter in patients without spina bifida who had had previous surgery of the bladder neck or proximal urethra. MATERIALS AND METHODS: From 1990 to 2004, 112 children and adolescents underwent implantation of an AMS 800 artificial urinary sphincter. Of the patients 19 males and 4 females (20.5%) between ages 4 and 17 years (mean 8.1) had no spina bifida. Instead there were bladder exstrophy in 12 patients, anorectal malformation with a rectourethral or vesical fistula in 7 and epispadias in 4. A bladder neck cuff between 5.5 and 7.5 cm, and a 61-70 balloon were used in all patients. RESULTS: Only 1 patient was lost to followup. In 22 patients (95.6%) mean followup was 80 months (range 4 to 155). Three sphincters in patients with exstrophy were removed because of erosion and/or infection 5, 49 and 60 months after initial surgery, respectively. A total of 19 sphincters remained in place (86.3% survival rate) with 5 revisions (26.3%) because of the pump (2), the cuff (2) or balloon fluid leakage. In this group 13 patients (68.4%) voided spontaneously and 6 (31.6%) performed clean intermittent catheterization, although 3 also voided spontaneously. Overall continence was good in 87% of patients because 2 were still incontinent at night. CONCLUSIONS: The artificial urinary sphincter is a good long-term solution to urinary incontinence secondary to sphincter incompetence despite multiple previous surgeries of the bladder neck or proximal urethra. Patients with bladder exstrophy and many previous bladder procedures are more exposed to complications such as erosion compared with patients with epispadias or anorectal malformation. The high percent of patients maintaining spontaneous voiding and the good rate of continence are the most important benefits of this type of surgical option for sphincter incompetence.

Fasting plasma ghrelin levels increase progressively after biliopancreatic diversion: one-year follow-up.

BACKGROUND: The role of ghrelin in weight control after surgery is not clear. We examined plasma ghrelin and leptin levels in patients with morbid obesity undergoing biliopancreatic diversion (BPD) of Scopinaro. METHODS: 30 adult patients (27 females, 3 males), undergoing elective BPD were recruited from the Hospital Surgery Service. Fasting blood samples for biochemical determinations were drawn before surgery and 1, 3 and 12 months after BPD. Human plasma ghrelin was measured by RIA. RESULTS: During the study period, weight, BMI and serum leptin levels decreased significantly at all sample points compared to preoperative values. Ghrelin plasma levels increased during the study, with statistical significance at 3 months and 1 year after surgery compared with preoperative levels. While leptin changes correlated with changes in BMI, no correlation was found between ghrelin and leptin or BMI changes. CONCLUSION: Plasma ghrelin levels could be decreased in obese patients as a compensatory mechanism to their nutritional state, but our results do not support the postulated beneficial role of ghrelin in the 1-year weight loss after BPD. They rather suggest that weight loss somehow stimulates ghrelin secretion, even in the absence of part of the stomach.

Gene expression of tumor necrosis factor alpha and TNF-receptors, p55 and p75, in nonalcoholic steatohepatitis patients.

The main objective of this study was to analyze the pathogenic role of the tumor necrosis factor alpha (TNF-alpha) system in the development of nonalcoholic steatohepatitis (NASH). Fifty-two obese patients were studied. We investigated: (1) the expression of mRNA of TNF-alpha and their p55 and p75-receptors by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) in hepatic and adipose tissues; and (2) the relationship between TNF-alpha, p55, and p75 and the severity of NASH. Obese patients without NASH were the control group. A remarkable increase in the expression of mRNA of TNF-alpha was found in patients with NASH in hepatic tissue (0.65 +/- 0.54) and in peripheral fat (0.43 +/- 0.45); in the control samples, the mRNA expression was 0.28 +/- 0.32, P <.007, and 0.26 +/- 0.22, P <.018, respectively. Furthermore, we found a significant increase in the mRNA levels of p55 receptor (2.42 +/- 1.81 vs. 1.56 +/- 1.17; P <.05); however, the mRNA expression of the p75 receptor was similar in both patients. Those patients with NASH with significant fibrosis presented an increase in the expression of mRNA TNF-alpha in comparison with those with a slight or nonexistent fibrosis. An overexpression of TNF-alpha mRNA is found in the liver and in the adipose tissue of NASH patients. The levels of mRNA-p55 are increased in the liver tissue of NASH patients. This overexpression is more elevated in patients with more advanced NASH. These findings suggest that the TNF-alpha system may be involved in the pathogenesis of NASH.

Are there predictive factors of severe liver fibrosis in morbidly obese patients with non-alcoholic steatohepatitis?

BACKGROUND: Non-alcoholic steatohepatitis (NASH) is a clinicopathological entity characterized by the presence of steatosis and lobular and/or portal inflammation with or without fibrosis. Patients with non-alcoholic fatty liver and fibrosis on liver biopsy have increased liver-related deaths. METHODS: 181 wedge liver biopsies, taken at the time of bariatric surgery from patients with a mean body mass index (BMI) of 47, were studied. In all cases, the liver biopsy was performed without knowledge of the patient's clinical and biochemical data, which were then examined with univariate and multivariate analysis. RESULTS: Diagnosis of NASH was established in 105 patients (91%); 74 patients (70%) showed mild steatosis, 20 (19%) had moderate inflammation and fibrosis, and 11 (10%) had steatosis with severe fibrosis. None of the liver biopsies showed cirrhosis. Age was the only independent predictor of moderate and severe fibrosis (p = 0.001). CONCLUSIONS: Since only age was a predictor of moderate or severe fibrosis, and no clinical or biochemical abnormalities detected slowly progressive hepatic fibrosis, liver biopsy is the only means of detecting progression to more advanced liver disease in a NASH patient.

[Risk of transmission of cholera by fish products: regional perspective in South America]. / Riesgos de transmisión del cólera por productos pesqueros: perspectiva regional en Sudamérica.

Cholera returned to South America in January 1991, after almost a century of absence. The hygienic status of the countries affected, aggravated by economic and political difficulties, allowed the disease to spread rapidly. In Peru, fishery products were incriminated from the outset, although without conclusive evidence. However, epidemiological and laboratory findings in other countries have confirmed the transmission of the disease by these products. The authors discuss the effects of the recent cholera epidemic on the trade and consumption of fishery products in countries of South America. The actual risk of cholera transmission by food and in particular by the consumption of fishery products is discussed, and a basis for conducting an accurate evaluation of these risks is proposed. Finally, the authors summarise the measures recommended to prevent the transmission of cholera by fishery products.