CT findings of pulmonary cysts.

Pulmonary cysts are thin-walled radiolucent lesions that may appear in a variety of uncommon disorders known as diffuse cystic lung diseases (DCLD) that essentially includes lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis (LCH), lymphocytic interstitial pneumonia (LIP), Pneumocystis jiroveci pneumonia (PJP), and Birt-Hogg-Dubé syndrome (BHDS). Moreover, they have been reported in several cases of coronavirus disease 2019 (COVID-19). The purpose of this review is to provide a practical approach for evaluating lung cysts when encountered on CT. We describe the imaging findings of DLCD emphasising their differences in terms of shape and distribution of the cysts, as well as their association with other findings such as nodules or ground-glass opacities, which may help in making a confident diagnosis. We also discuss the link between pulmonary cysts and COVID-19.

Using the modified Dixon technique to evaluate incidental adrenal lesions on 3T MRI. / Valoración mediante Dixon modificado de las lesiones suprarrenales incidentales en RM 3T.

OBJECTIVES: To use the mDIXON-Quant sequence to quantify the fat fraction of adrenal lesions discovered incidentally on CT studies. To analyze the relation between the signal loss between in-phase and out-of-phase T1-weighted sequences and the fat fraction in mDIXON-Quant. To compare the sensitivity and specificity of the two methods for characterizing adrenal lesions. MATERIAL AND METHODS: This prospective descriptive study included 31 patients with incidentally discovered adrenal lesions evaluated with 3T MRI using in-phase and out-of-phase T1-weighted sequences and mDIXON-Quant; the fat fraction of the adrenal lesions was measured by mDIXON-Quant and by calculating the percentage of signal loss between in-phase and out-of-phase T1-weighted sequences. RESULTS: The percentage of signal loss was significantly higher in the group of patients with adenoma (61.3% ± 20.4% vs. 5.1% ± 5.8% in the group without adenoma, p<0.005). The mean fat fraction measured by mDIXON-Quant was also higher for the adenomas (26.9% ±10.8% vs. 3.4% ± 3.0%, p<0.005).The area under the ROC curve was 0.99 (0.96 - 1.00) for the percentage of signal loss and 0.98 (0.94 - 1.00) for the fat fraction measured by mDIXON-Quant. The cutoffs obtained were 24.42% for the percentage of signal loss and 9.2% for the fat fraction measured by mDIXON-Quant. The two techniques had the same values for diagnostic accuracy: sensitivity 96% (79.6 - 99.9), specificity 100% (39.8 - 100.0), positive predictive value 100% (85.8 - 100.0), and negative predictive value 80% (28.4 - 99.5). CONCLUSION: The fat fraction measured by the modified Dixon technique can differentiate between adenomas and other adrenal lesions with the same sensitivity and specificity as the percentage of signal loss between in-phase and out-of-phase T1-weighted sequences.

Seroprevalencia de Sífilis en donantes del banco de sangre del Hospital Universitario de Maracaibo: Periodo 2012- 2014 / Seroprevalence associated with Syphilis in donor blood bank of University Hospital of Maracaibo: Period 2012-2014

La sífilis es una enfermedad infectocontagiosa con afectación sistémica, de evolución aguda o crónica, cuyo agente causal es el Treponema pallidum. Su principal mecanismo de transmisión es el contacto sexual sin protección, seguida de riesgo de contagio por transfusión sanguínea. Objetivo: Determinar la seroprevalencia de sífilis en donantes del banco de sangre del Hospital Universitario de Maracaibo, periodo 2012-2014. Metodología: Se realizó un estudio descriptivo, de corte transversal, no experimental que incluyó encuestas con pruebas serológicas confidenciales basada en el principio de ELISA. Se procesaron un total de 45.356 unidades de sangre. El 84,7% (38.414) de los donantes eran hombres y el 15,3% (6.942) mujeres con una edad promedio de 31,1 años. Durante este periodo se observó que la seroprevalencia general de anticuerpos específicos anti- T. pallidum en estos donantes fue de 2,95% lo que equivale a 1.336 casos de serología positiva, representada por individuos en edades comprendidas entre 29-39 años con un 35,1 % (470). El sexo masculino muestra la mayor frecuencia de donantes positivos con un 87,7% (1.172). Todo esto indica la necesidad de hacer un seguimiento longitudinal a largo plazo y de implementar programas de vigilancia epidemiológica.

Syphilis is an infectious disease with systemic involvement, chronic or acute evolution, whose causal agent is Treponema pallidum. Its main mechanism of transmission is unprotected sexual contact, followed by risk of transmission by blood transfusion. Objective: To determine the seroprevalence associated with syphilis in blood bank donors at the Universitario Hospital of Maracaibo during the period 2012-12014. Methodology: A non-experimental descriptive study, cross-sectional surveys that included confidential serological tests based on the principle of ELISA to detect anti-T. pallidum antibodies was performed. A total of 45,356 units of blood were processed. 84.7% (38,414) of donors were men and 15.3% (6,942) women with an average age of 31.1 years. During this period it was observed that the specific overall seroprevalence of anti- T. pallidum in these donors was 2.95% which is equivalent to 1,336 cases of positive serology, represented by individuals 29-39 aged 35,1% (470). The male shows increased frequency of positive donors with 87.7% (1,172). All this indicates the need for a long-term longitudinal follow and implement epidemiological surveillance programs.

Molecular modeling of the full-length human TRPV1 channel in closed and desensitized states.

The transient receptor potential vanilloid subtype 1 (TRPV1) is a member of the TRP family gated by vanilloids, heat, and protons. Structurally, TRPV1 subunits have a modular architecture underlying different functionalities, namely stimuli recognition, channel gating, ion selectivity, subunit oligomerization, and regulation by intracellular signaling molecules. Considering modular organization and recent structural information in the ion channel field, we have modeled a full-length TRPV1 by assembly of its major modules: the cytosolic N-terminal, C-terminal, and membrane-spanning region. For N-terminal, we used the ankyrin repeat structure fused with the N-end segment. The membrane domain was modeled with the structure of the eukaryotic, voltage-gated Kv1.2 K+ channel. The C-terminus was cast using the coordinates of HCN channels. The extensive structure-function data available for TRPV1 was used to validate the models in terms of the location of molecular determinants of function in the structure. Additionally, the current information allowed the modeling of the vanilloid receptor in the closed and desensitized states. The closed state shows the N-terminal module highly exposed and accessible to adenosine triphosphate and the C-terminal accessible to phosphoinositides. In contrast, the desensitized state depicts the N-terminal and C-terminal modules close together, compatible with an interaction mediated by Ca2+ -calmodulin complex. These models identify potential previously unrecognized intra- and interdomain interactions that may play an important functional role. Although the molecular models should be taken with caution, they provide a helpful tool that yields testable hypothesis that further our understanding on ion channels work in terms of underlying protein structure.

Phosphorus removal from aqueous solution using iron coated natural and engineered sorbents.

New filtration materials covered with metallic oxides are good adsorbents for both cation and anion forms of pollutants. Sfax is one of the most important industrial towns in Tunisia. Its phosphate manufacture in particular is causing considerable amounts of water pollution. Therefore, there is a need to find out a new way of getting rid of this excessive phosphate from water. This work is aimed to examining the potential of three sorbent materials (synthetic iron oxide coated sand (SCS), naturally iron oxide coated sand (NCS) and iron oxide coated crushed brick (CB)) for removing phosphate ions from aqueous solutions. According to our literature survey CB was not used as adsorbent previously. Phosphate ions are used here as species model for the elimination of other similar pollutants (arsenates, antimonates). Optical microscope and scanning electron microscope (SEM) analyses were used to investigate the surface properties and morphology of the coated sorbents. Infra-red spectroscopy and X-ray diffraction techniques were also used to characterize the sorbent structures. Results showed that iron coated crushed brick possess more micro pores and a higher surface area owing to its clay nature. The comparative sorption of PO4(3-) from aqueous solutions by SCS, CB and NCS was investigated by batch experiments. The estimated optimum pH of phosphate ion retention for the considered sorbents was 5. The equilibrium data were analysed using the Langmuir and Freundlich isotherms. The sorption capacities of PO(4)3- at pH 5 were 1.5 mg/g for SCS, 1.8 mg/g for CB and 0.88 mg/g for NCS. The effect of temperature on sorption phenomenon was also investigated. The results indicated that adsorption is an endothermic process for phosphate ions removal. This study demonstrates that all the considered sorbents can be used as an alternative emerging technology for water treatment without any side effect or treatment process alteration.

Effects of coffees before and after special treatment procedure on cell membrane potentials in stomach cells.

Coffee, one of the most excessively used beverages worldwide, commences the risk of gastroesophageal reflux (GER), which may lead to gastric ulcers and increase the risk of gastric cancer. Many attempts have been made by the coffee industry to diminish the irritating effect on mucosa by means of altering the extraction methods concerning gerbic acids and the roasting processes. This paper describes the effect of differently produced coffees involving two brands of Darboven and two brands of other coffee roasters. The aim of this study was to prove the results of gastric potential measurements we found in literature by using human AGS gastric epithelial cells (human adenocarcinoma). All four coffee extracts tested differentially affected the membrane resting potential of AGS cells. Coffees no. 1 and no. 2 depolarized the cells, presumably by increasing the cation entry into the cytosol. In marked contrast, coffee no. 4 hyperpolarizes the cells, possibly by H(+) extrusion and/or Cl(-) influx, suggesting that this coffee might increase acidity in the stomach, which might negatively affect the stomach, especially in people with gastroesophageal reflux symptoms. Overall, our data suggest that different roasting methods of coffees affect the membrane potentials of AGS stomach cells, resulting in increased influx of H+ possibly resulting in decreased stomach acidity and thus reducing GER. These results are in good accordance with clinical pharmacological results from potential difference measurements in healthy volunteers we found in the literature.

Evaluation of bromate ions level introduced by sodium hypochlorite during post-disinfection of drinking water.

During the last ten years, interest concerning the occurrence of bromate in drinking water has grown due to its potential carcinogenicity and the new regulations. One source of bromate in finished water is due to its presence in the sodium hypochlorite solutions used for the disinfection of water. In fact, the brine solutions used for the production of sodium hypochlorite contain bromide ions in varying degrees that subsequently generate a certain quantity of bromate ions. Bromate concentrations ranging from 82 to 857 mg l(-1) (0.5-7.4 mg BrO3-/ g Cl2) have been found in commercial solutions of sodium hypochlorite used by Société Anonyme Gestion des Eaux de Paris (SAGEP), a company that produces drinking water for Paris, France. In addition, the chlorine concentration of the hypochlorite solution can decrease during storage, consequently the added amount of bromate increases for a given applied dose of chlorine.

An ATP-based method for monitoring the microbiological drinking water quality in a distribution network.

The titration of adenosine triphosphate (ATP) by bioluminescence permits rapid evaluation of the quantity of viable micro-organisms present in a water sample. During two sampling campaigns, Société Anonyme de Gestion des Eaux de Paris (SAGEP) tested a new extraction and titration system of bacterial ATP in the Paris drinking water distribution network. As far as the entire set of results of analyses of water in the network is concerned there is a linear relationship between log [ATP] and log(HPC-R2A/ml). Furthermore, as regards the drinking water originating from treatment of surface waters, some of the results obtained indicate a slight change as regards the Paris network in the microbiological quality. This is certainly linked to the distance travelled from the production location as well as to a reservoir effect observed on a site. Conversely, no change is apparent with regard to waters of underground origin. Lastly, despite changes in temperature and chlorine residual, no significant influence has been observed, essentially because of the very low density of culturable bacteria.

Salmonid viral haemorrhagic septicaemia virus: fusion-related enhancement of virus infectivity by peptides derived from viral glycoprotein G or a combinatorial library.

To search for enhancers and/or inhibitors of viral haemorrhagic septicaemia virus (VHSV, a salmonid rhabdovirus) infectivity, a total of 51 peptides from a pepscan of viral envelope protein G, a recombinant peptide from protein G (frg11) and 80 peptide mixtures from an alpha-helix-favoured combinatorial library were screened. However, contrary to what occurs in many other enveloped viruses, only peptides enhancing rather than inhibiting VHSV infectivity were found. Because some of the enhancer pepscan G peptides and frg11 were derived from phospholipid-binding or fusion-related regions identified previously, it was suggested that enhancement of virus infectivity might be related to virus-cell fusion. Furthermore, enhancement was significant only when the viral peptides were pre-incubated with VHSV at the optimal low pH of fusion, before being adjusted to physiological pH and assayed for infectivity. Enhancement of VHSV infectivity caused by the pre-incubation of VHSV with peptide p5 (SAAEASAKATAEATAKG), one of the individual enhancer peptides defined from the screening of the combinatorial library, was independent of the pre-incubation pH. However, it was also related to fusion because the binding of p5 to protein G induced VHSV to bypass the endosome pathway of infection and reduced the low-pH threshold of fusion, thus suggesting an alternative virus entry pathway for p5-VHSV complexes. Further investigations into VHSV enhancer peptides might shed some light on the mechanisms of VHSV fusion.

Tyrosine phosphorylation of the inactivating peptide of the shaker B potassium channel: a structural-functional correlate.

A synthetic peptide patterned after the sequence of the inactivating "ball" domain of the Shaker B K(+) channel restores fast (N-type) inactivation in mutant deletion channels lacking their constitutive ball domains, as well as in K(+) channels that do not normally inactivate. We now report on the effect of phosphorylation at a single tyrosine in position 8 of the inactivating peptide both on its ability to restore fast channel inactivation in deletion mutant channels and on the conformation adopted by the phosphorylated peptide when challenged by anionic lipid vesicles, a model target mimicking features of the inactivation site in the channel protein. We find that the inactivating peptide phosphorylated at Y8 behaves functionally as well as structurally as the noninactivating mutant carrying the mutation L7E. Moreover, it is observed that the inactivating peptide can be phosphorylated by the Src tyrosine kinase either as a free peptide in solution or when forming part of the membrane-bound protein channel as the constitutive inactivating domain. These findings suggest that tyrosine phosphorylation-dephosphorylation of this inactivating ball domain could be of physiological relevance to rapidly interconvert fast-inactivating channels into delayed rectifiers and vice versa.

Determination of chlorinated pesticides in water by SPME/GC.

Solid-phase microextraction (SPME) followed by gas chromatography (GC) coupled with an electron capture detector has been applied for the analysis of chlorinated pesticides in water. Molecule adsorption on 100 microm polydimethylsiloxane (PDMS) fibers was activated by immersion of the whole fiber-sample system in an ultrasonic bath. The good reproducibility, low detection limits and wide linear ranges obtained encourage the use of this technique in water control.

Arginine-rich peptides are blockers of VR-1 channels with analgesic activity.

Vanilloid receptors (VRs) play a fundamental role in the transduction of peripheral tissue injury and/or inflammation responses. Molecules that antagonize VR channel activity may act as selective and potent analgesics. We report that synthetic arginine-rich hexapeptides block heterologously expressed VR-1 channels with submicromolar efficacy in a weak voltage-dependent manner, consistent with a binding site located near/at the entryway of the aqueous pore. Dynorphins, natural arginine-rich peptides, also blocked VR-1 activity with micromolar affinity. Notably, synthetic and natural arginine-rich peptides attenuated the ocular irritation produced by topical capsaicin application onto the eyes of experimental animals. Taken together, our results imply that arginine-rich peptides are VR-1 channel blockers with analgesic activity. These findings may expand the development of novel analgesics by targeting receptor sites distinct from the capsaicin binding site.

Pseudoaneurysm in the mitral-aortic intervalvular fibrosa. A cause of mitral regurgitation.

Left ventricular outflow tract pseudoaneurysm is an uncommon but potentially catastrophic complication of aortic valve surgery, aortic valve endocarditis or chest trauma. We describe a case of a left ventricular outflow tract pseudoaneurysm 1 month after an aortic valve replacement that caused a systolic compression of mitral valve and a severe regurgitation. The diagnosis was confirmed using transoesophageal echocardiography, magnetic resonance image and intraoperative endoscopy. Surgical repair of the pseudoaneurysm corrected the mitral regurgitation.

The 26-mer peptide released from SNAP-25 cleavage by botulinum neurotoxin E inhibits vesicle docking.

Botulinum neurotoxin E (BoNT E) cleaves SNAP-25 at the C-terminal domain releasing a 26-mer peptide. This peptide product may act as an excitation-secretion uncoupling peptide (ESUP) to inhibit vesicle fusion and thus contribute to the efficacy of BoNT E in disabling neurosecretion. We have addressed this question using a synthetic 26-mer peptide which mimics the amino acid sequence of the naturally released peptide, and is hereafter denoted as ESUP E. This synthetic peptide is a potent inhibitor of Ca2+-evoked exocytosis in permeabilized chromaffin cells and reduces neurotransmitter release from identified cholinergic synapses in in vitro buccal ganglia of Aplysia californica. In chromaffin cells, both ESUP E and BoNT E abrogate the slow component of secretion without affecting the fast, Ca2+-mediated fusion event. Analysis of immunoprecipitates of the synaptic ternary complex involving SNAP-25, VAMP and syntaxin demonstrates that ESUP E interferes with the assembly of the docking complex. Thus, the efficacy of BoNTs as inhibitors of neurosecretion may arise from the synergistic action of cleaving the substrate and releasing peptide products that disable the fusion process by blocking specific steps of the exocytotic cascade.

[Association between myocardial infarction and angiotensin converting enzyme gene polymorphism in young patients]. / Asociación entre polimorfismo inserción/deleción del gen codificador de la enzima conversiva de la angiotensina e infarto de miocardio en pacientes jóvenes.

BACKGROUND: Different studies have shown a relationship between an insertion-deletion polymorphism of the angiotensin converting enzyme (ACE) gene and the risk of ischemic heart disease, although there are no data on this association in the Spanish population. MATERIALS AND METHOD: We have studied three groups of patients: I, healthy volunteers (n = 56, mean age 36.20 +/- 4.20 years); II, patients having presented an acute myocardial infarction (MI) < or = 50 years (n = 59, mean age 42.30 +/- 5.30 years), and III, patients with MI over the age of 50 years (n = 60, mean age 66.36 +/- 9.47 years). In all patients the genotype ACE gen was determined by an assay based on the polymerase chain reaction. RESULTS: The distribution of the ACE genotype between the three groups were not significative. Comparing the ratio of DD/II-DI in groups II and III there were 26/33 versus 15/45 (p = 0.02864). There was no difference in the smoking, hypercholesterolemia and hypertension between groups II and III; there were only differences in familial history of ischemic heart disease; diabetes mellitus was more prevalent in the III group. A multivariate analysis showed that smoking familial history of ichemic heart disease, hypercholesterolemia and DD genotype were more prevalent in young patients (OR 3.92, 2.85, 2.36 and 1.77), whereas diabetes mellitus was more prevalent in the group of older patients. There were no differences in the ACE genotype with respect to infarct location or gender. CONCLUSIONS: In our population DD ACE genotype is associated with MI in young patients, although smoking, family history and hypercholesterolemia show a more powerful association.

Selected peptides targeted to the NMDA receptor channel protect neurons from excitotoxic death.

Excitotoxic neuronal death, associated with neurodegeneration and stroke, is triggered primarily by massive Ca2+ influx arising from overactivation of glutamate receptor channels of the N-methyl-D-aspartate (NMDA) subtype. To search for channel blockers, synthetic combinatorial libraries were assayed for block of agonist-evoked currents by the human NR1-NR2A NMDA receptor subunits expressed in amphibian oocytes. A set of arginine-rich hexapeptides selectively blocked the NMDA receptor channel with IC50 approximately 100 nM, a potency similar to clinically tolerated blockers such as memantine, and only marginally blocked on non-NMDA glutamate receptors. These peptides prevent neuronal cell death elicited by an excitotoxic insult on hippocampal cultures.

Inmunodiagnostico de la toxoplasmosis: hemaglutinación indirecta e inmunoanalisis enzimatico IgM e IgG / Immunodiagnosis of the toxoplasmosis: indirect hemagglutination IgM and IgG enzime linked immunosorbent assay

En el presente trabajo se compararon los métodos de Hemaglutinación Indirecta (HAI) e Inmunoanálisis Enzimático (ELISA, IgM e IgG) para investigar anticuerpos antitoxoplasma en 54 muestras sanguíneas. Los resultados obtenidos muestran una concordancia del 62.96 por ciento entre HAI y ELISA. IgM y del 83.33 por ciento entre HAI y ELISA. IgG. El análisis estadístico mediante el chi cuadrado, reveló que hubo significancia cuando se compararon todos los títulos de HAI a partir de 1:2 con todos los índices de ELISA. IgM, esta significancia no puede establecer la superioridad de un método sobre el otro, debido: a. La utilización del "kit" comercial ELISA. IgM que solo detecta este tipo de anticuerpo; b. La detección por HAI de IgM e IgG; c. La presencia de anticuerpos inespecíficos de HAI y ELISA. IgG reveló que no hubo diferencias, lo cual nos indica que la discordancia entre ambos métodos no es estadísticamente significante

[A comparison of 2 clinical laboratory methods in the diagnosis of bacterial vaginosis]. / Comparación de 2 métodos de laboratorio clínico en el diagnóstico de la vaginosis bacteriana.

OBJECTIVE: To determine the sensitivity, the specificity, and positive and negative predictive values of two laboratory methods used to diagnose bacterial vaginosis; Gram stain and the Gardnerella vaginalis culture, in comparison with the clinical sings of vaginal discharge; homogeneous secretion, pH > 4.7, positive amine test and the presence of clue cells. DESIGN: A prospective, comparative and crossover type. SETTING: This study was carried out in the Health Center "Dr. José Castro Villagrana" SSA, situated in Tlalpan, México City. From January, 1992 to July, 1996. PARTICIPANTS: 3,142 women, from 16 to 55 years old with cervicovaginitis diagnosis, without previous treatment and sexual active life history. RESULTS: By means of clinical criterion (33.1%), it was diagnosed 1,041 women with bacterial vaginosis. Statistical differences were not found between the culture and Gram stain in the presence or no-presence of bacterial vaginosis diagnosed by clinical criterion (p = 0.33) The clue cells were the best predictor of bacterial vaginosis. CONCLUSIONS: The differences between both methods analysed were minimal and they didn't have statistical value so that, it is proposed the Gram stain as diagnostic method of bacterial vaginosis based on factors like speed, reproductiveness and low cost.

A peptide that mimics the C-terminal sequence of SNAP-25 inhibits secretory vesicle docking in chromaffin cells.

Excitation-secretion uncoupling peptides (ESUPs) are inhibitors of Ca2+-dependent exocytosis in neural and endocrine cells. Their mechanism of action, however, remains elusive. We report that ESUP-A, a 20-mer peptide patterned after the C terminus of SNAP-25 (synaptosomal associated protein of 25 kDa) and containing the cleavage sequence for botulinum neurotoxin A (BoNT A), abrogates the slow, ATP-dependent component of the exocytotic pathway, without affecting the fast, ATP-independent, Ca2+-mediated fusion event. Ultrastructural analysis indicates that ESUP-A induces a drastic accumulation of dense-core vesicles near the plasma membrane, mimicking the effect of BoNT A. Together, these findings argue in favor of the notion that ESUP-A inhibits ATP-primed exocytosis by blocking vesicle docking. Identification of blocking peptides which mimic sequences that bind to complementary partner domains on interacting proteins of the exocytotic machinery provides new pharmacological tools to dissect the molecular and mechanistic details of neurosecretion. Our findings may assist in developing ESUPs as substitute drugs to BoNTs for the treatment of spasmodic disorders.

Tyrosine phosphorylation modulates the activity of clostridial neurotoxins.

Clostridial neurotoxins' metalloprotease domain selectively cleaves proteins implicated in the process of synaptic vesicle fusion with the plasma membrane and, accordingly, blocks neurotransmitter release into the synaptic cleft. Here we investigate the potential modulation of these neurotoxins by intracellular cascades triggered by environmental signals, which in turn may alter its activity on target substrates. We report that the nonreceptor tyrosine kinase Src phosphorylates botulinum neurotoxins A, B, and E and tetanus neurotoxin. Protein tyrosine phosphorylation of serotypes A and E dramatically increases both their catalytic activity and thermal stability, while dephosphorylation reverses the effect. This suggests that the biologically significant form of the neurotoxins inside neurons is phosphorylated. Indeed, in PC12 cells in which tyrosine kinases such as Src and PYK2 are highly abundant, stimulation by membrane depolarization in presence of extracellular calcium induces rapid and selective tyrosine phosphorylation of internalized light chain, the metalloprotease domain, of botulinum toxin A. These findings provide a conceptual framework to connect intracellular signaling pathways involving tyrosine kinases, G-proteins, phosphoinositides, and calcium with the action of botulinum neurotoxins in abrogating vesicle fusion and neurosecretion.