Estudio descriptivo de las alteraciones en pruebas de neuroimagen en pacientes con cefalea en un ámbito ambulatorio / Descriptive study of the alterations in neuroimaging tests in patients with headache in an outpatient setting

Introducción: Los estudios disponibles ofrecen una guía limitada acerca del uso de la neuroimagen en pacientes con cefalea en el ámbito ambulatorio. El objetivo de este estudio fue describir y analizar la frecuencia y el porcentaje de alteraciones en neuroimagen en pacientes valorados por cefalea en una consulta de neurología, así como determinar qué datos de alarma clínicos (red flags) se asocian con mayor frecuencia a estas alteraciones. Pacientes y métodos: Realizamos un estudio observacional, descriptivo y transversal de una serie de pacientes con cefalea de la consulta de neurología del Hospital Universitario de Móstoles a los que se les realizó una prueba de neuroimagen. ResultadosSe incluyó a 279 pacientes en el estudio (190 mujeres y 89 hombres). Ningún paciente sin datos de alarma clínicos presentó alteraciones graves en la neuroimagen y, de los que presentaban datos de alarma clínicos (219 pacientes), sólo el 2,3% (cinco pacientes) presentó alteraciones graves. Los dos datos de alarma clínicos que se asociaron de forma significativa a una mayor probabilidad de alteraciones graves en la neuroimagen fueron la cefalea que se desencadena o empeora significativamente con cambios posturales o maniobras de Valsalva y la cefalea crónica diaria desde su inicio. Conclusiones: La prevalencia de alteraciones significativas en neuroimagen en pacientes con cefalea en un ámbito ambulatorio fue baja, incluso en presencia de datos de alarma clínicos, por lo que la utilidad de estos datos de alarma parece ser menor en un contexto ambulatorio. Podría ser razonable intentar reducir el uso de la neuroimagen en pacientes con cefalea en el ámbito ambulatorio.(AU)

Introduction: Available studies provide limited guidance on the use of neuroimaging in patients with headache in the outpatient setting. The aim of this study was to describe and analyse the frequency and the percentage of neuroimaging abnormalities in patients evaluated for headache in a neurology clinic, as well as to determine which red flags are most commonly associated with these abnormalities. Patients and methods: We conducted an observational, descriptive and cross-sectional study of a series of patients with headache from the neurology department of the Hospital Universitario de Móstoles who underwent a neuroimaging test. Results: A total of 279 patients (190 women and 89 men) were included in the study. No patient without any red flags had severe abnormalities in the neuroimaging study and, of those with red flags (219 patients), only 2.3% (five patients) displayed severe abnormalities. The two red flags that were significantly associated with an increased likelihood of severe neuroimaging abnormalities were headache that is triggered or significantly worsened by postural changes or Valsalva manoeuvres and chronic daily headache since onset. Conclusions: The prevalence of significant neuroimaging abnormalities in headache patients in an outpatient setting was low, even in the presence of red flags, and so their utility appears to be lower in an outpatient setting. It may be reasonable to try to reduce the use of neuroimaging with headache patients in the outpatient setting.(AU)

[Descriptive study of the alterations in neuroimaging tests in patients with headache in an outpatient setting]. / Estudio descriptivo de las alteraciones en pruebas de neuroimagen en pacientes con cefalea en un ámbito ambulatorio.

INTRODUCTION: Available studies provide limited guidance on the use of neuroimaging in patients with headache in the outpatient setting. The aim of this study was to describe and analyse the frequency and the percentage of neuroimaging abnormalities in patients evaluated for headache in a neurology clinic, as well as to determine which red flags are most commonly associated with these abnormalities. PATIENTS AND METHODS: We conducted an observational, descriptive and cross-sectional study of a series of patients with headache from the neurology department of the Hospital Universitario de Mostoles who underwent a neuroimaging test. RESULTS: A total of 279 patients (190 women and 89 men) were included in the study. No patient without any red flags had severe abnormalities in the neuroimaging study and, of those with red flags (219 patients), only 2.3% (five patients) displayed severe abnormalities. The two red flags that were significantly associated with an increased likelihood of severe neuroimaging abnormalities were headache that is triggered or significantly worsened by postural changes or Valsalva manoeuvres and chronic daily headache since onset. CONCLUSIONS: The prevalence of significant neuroimaging abnormalities in headache patients in an outpatient setting was low, even in the presence of red flags, and so their utility appears to be lower in an outpatient setting. It may be reasonable to try to reduce the use of neuroimaging with headache patients in the outpatient setting.

TITLE: Estudio descriptivo de las alteraciones en pruebas de neuroimagen en pacientes con cefalea en un ámbito ambulatorio.Introducción. Los estudios disponibles ofrecen una guía limitada acerca del uso de la neuroimagen en pacientes con cefalea en el ámbito ambulatorio. El objetivo de este estudio fue describir y analizar la frecuencia y el porcentaje de alteraciones en neuroimagen en pacientes valorados por cefalea en una consulta de neurología, así como determinar qué datos de alarma clínicos (red flags) se asocian con mayor frecuencia a estas alteraciones. Pacientes y métodos. Realizamos un estudio observacional, descriptivo y transversal de una serie de pacientes con cefalea de la consulta de neurología del Hospital Universitario de Móstoles a los que se les realizó una prueba de neuroimagen. Resultados. Se incluyó a 279 pacientes en el estudio (190 mujeres y 89 hombres). Ningún paciente sin datos de alarma clínicos presentó alteraciones graves en la neuroimagen y, de los que presentaban datos de alarma clínicos (219 pacientes), sólo el 2,3% (cinco pacientes) presentó alteraciones graves. Los dos datos de alarma clínicos que se asociaron de forma significativa a una mayor probabilidad de alteraciones graves en la neuroimagen fueron la cefalea que se desencadena o empeora significativamente con cambios posturales o maniobras de Valsalva y la cefalea crónica diaria desde su inicio. Conclusiones. La prevalencia de alteraciones significativas en neuroimagen en pacientes con cefalea en un ámbito ambulatorio fue baja, incluso en presencia de datos de alarma clínicos, por lo que la utilidad de estos datos de alarma parece ser menor en un contexto ambulatorio. Podría ser razonable intentar reducir el uso de la neuroimagen en pacientes con cefalea en el ámbito ambulatorio.

Increased Lung Immune Metabolic Activity in COVID-19 Survivors.

PURPOSE: We quantified lung glycolytic metabolic activity, clinical symptoms and inflammation, coagulation, and endothelial activation biomarkers in 2019 coronavirus disease (COVID-19) pneumonia survivors. METHODS: Adults previously hospitalized with moderate to severe COVID-19 pneumonia were prospectively included. Subjects filled out a questionnaire on clinical consequences, underwent chest CT and 18 F-FDG PET/CT, and provided blood samples on the same day. Forty-five volunteers served as control subjects. Analysis of CT images and quantitative voxel-based analysis of PET/CT images were performed for both groups. 18 F-FDG uptake in the whole-lung volume and in high- and low-attenuation areas was calculated and normalized to liver values. Quantification of plasma markers of inflammation (interleukin 6), d -dimer, and endothelial cell activation (angiopoietins 1 and 2, vascular cell adhesion molecule 1, and intercellular adhesion molecule 1) was also performed. RESULTS: We enrolled 53 COVID-19 survivors (62.3% were male; median age, 50 years). All survivors reported at least 1 persistent symptom, and 41.5% reported more than 6 symptoms. The mean lung density was greater in survivors than in control subjects, and more metabolic activity was observed in normal and dense lung areas, even months after symptom onset. Plasma proinflammatory, coagulation, and endothelial activation biomarker concentrations were also significantly higher in survivors. CONCLUSION: We observed more metabolic activity in areas of high and normal lung attenuation several months after moderate to severe COVID-19 pneumonia. In addition, plasma markers of thromboinflammation and endothelial activation persisted. These findings may have implications for our understanding of the in vivo pathogenesis and long-lasting effects of COVID-19 pneumonia.

Interference of fixatives and fixation period on the morphologic analysis of ovarian preantral follicles.

Ovine ovarian fragments (3 × 3 × 1 mm) were fixed in neutral buffered formalin (NBF), Carnoy's solution (CAR), Davidson's solution (DAV), or paraformaldehyde (PFA) for 12 h or 24 h. After this fixation time, each fragment was prepared for histological analysis. Although fixative and fixation period did not affect follicular and stromal cells density, the percentages of morphologically normal primordial and primary follicles was affected by the fixative type and period of fixation. Paraformaldehyde was not indicated as a fixative for ovarian fragments. Formalin was a suitable fixative only when the period of fixation was 12 h, while Carnoy was efficient after a fixation period of 24 h. In conclusion, the most indicated fixative for the morphological evaluation of ovarian preantral follicles was DAV, regardless of the fixation period, that is 12 or 24 h.

Antimicrobial resistance in companion animals - Veterinarians' attitudes and prescription drivers in Portugal.

Antimicrobial resistance transmitted from companion animals is a threat to public health increased by the pet's relationship with humans. This study aims to understand the attitude and drivers of antimicrobial (AM) prescription among companion animal veterinarians in Portugal and identify actions to combat antimicrobial resistance (AMR). This cross-sectional study is based on a questionnaire with 417 respondents representing the Portuguese veterinary population. The results allowed grouping the respondents according to the attitude of prescription. Two types of veterinarians were identified: those who prefer to prescribe treatments based on the animals' signs and their own experience - empirical-oriented type - and those who refer to a guidance protocol to assist the prescription decision - protocol-oriented type. Respondents working in hospitals displayed a positive association with the use of guidance protocols. Efficacy was the main driver of prescription for both groups, suggesting that no matter the attitude in prescribing, the veterinarian's aim is achieving positive clinical results. Most respondents prefer empirical-oriented prescriptions, declare the absence of protocols for the prudent use of AM at the workplace and do not refer to AMR issues nor the need for hygiene reinforcement measures with owners. Owners are less likely to request AMs from veterinarians aged over 43 years old. It was discovered that communication between owners and veterinarians about risks associated with AMR was poor and must be improved and the adoption of a national guideline for the adequate use of AM directed for companion animals would be beneficial.

[Radiographic measurement of the acetabular angle for early diagnosis of hip development dysplasia]. / Medición radiográfica del ángulo acetabular para el diagnóstico temprano de la displasia del desarrollo de la cadera.

BACKGROUND: In order to avoid sequelae in the development dysplasia of the hip the treatment should be early; The acetabular angle corresponds to the inclination of the roof of the acetabulum. Stanisvljevic indicates that to properly measure the acetabular angle, the hips should be placed in abduction. Question: What is the magnitude of the difference in radiographic measurement of the acetabular angle between the anteroposterior projections of pelvis in neutral position and with abduction of hips? METHODS: 916 radiographic measurements were taken by contrasting the neutral position against those of hip abduction, of patients in our clinic attended between April 1, 2010 and March 31, 2013. RESULTS: T tests were performed for means of two matched samples and a hypothetical difference of the mean of 0.0000 was obtained and the Pearson correlation coefficient for right hip was 0.74427531 and for the left 0.73779866. Using a proposed table of normality of the Acetabular angle according to age, the area was obtained under the curve in a distribution Tgl457 = 0.650 with P = 0.516. The index acetabular in neutral position and with abduction of hips is similar with high statistical significance, according to the analysis of correlation of Pearson. Based on the ROC curve, the acetabular index in frog position has a high sensitivity and specificity. DISCUSSION: Therefore, the measurement of the acetabular index in position with hip abduction, has high reliability to achieve a correct diagnosis.

ANTECEDENTES: Para evitar secuelas en la displasia del desarrollo de la cadera el tratamiento debe ser temprano; el ángulo acetabular corresponde a la inclinación del techo del acetábulo. Stanisavljevic indica que para medir adecuadamente el ángulo acetabular se deben colocar las caderas en abducción. Pregunta: ¿cuál es la magnitud de la diferencia de la medición radiográfica del ángulo acetabular entre las proyecciones anteroposterior de pelvis en posición neutra y con abducción de caderas? MÉTODOS: Se tomaron 916 mediciones radiográficas comparando las de posición neutra contra las de abducción de caderas, de pacientes atendidos en consulta externa entre el 1 de Abril de 2010 y el 31 de Marzo de 2013. RESULTADOS: Se realizaron pruebas t para medias de dos muestras emparejadas y se obtuvo una diferencia hipotética de las medias de 0.0000 y el coeficiente de correlación de Pearson para cadera derecha fue 0.74427531 y para la izquierda 0.73779866. Usando una tabla propuesta de normalidad del ángulo acetabular según edad, se obtuvo el área bajo la curva en una distribución tgl457 = 0.650 con p = 0.516. El índice acetabular en posición neutra y con abducción de caderas es similar con alta significancia estadística, según el análisis de correlación de Pearson. Con base en la curva ROC, el índice acetabular en posición de rana tiene una alta sensibilidad y especificidad. Por tanto, la medición del índice acetabular en posición con abducción de caderas, tiene alta confiabilidad de lograr un diagnóstico correcto.

Nuevas tecnologías en el tratamiento del tabaquismo / New technologies in tobacco treatment

Resumen La mHealth, se refiere al uso de dispositivos móviles como una herramienta de telemedicina, ideal para la promoción, prevención y control de enfermedades. En Chile, un 84,1% de la población tiene acceso a internet y un 80% de los accesos son a través de dispositivos móviles, esto convierte a internet y la telefonía móvil en herramientas particularmente atractivas para intervenciones en salud. Los estudios que implican intervenciones a través de mensajes de texto para el apoyo a la cesación tabáquica no son directamente extrapolables a nuestro país ya que la mayoría provienen de países desarrollados y de habla inglesa, motivo por el cual es necesario desarrollar y evaluar intervenciones adecuadas para nuestra población.

mHealth, refers to the use of mobile devices as a telemedicine tool, ideal for promotion, prevention and control of diseases. In Chile, 84.1% of the population has access to the Internet and 80% of accesses are through of mobile devices, this makes the internet and mobile telephony particularly attractive tools for health interventions. Studies involving interventions through text messages to support smoking cessation are not directly extrapolated to our country since most of them come from developed and English-speaking countries, which is why it is necessary to develop and evaluate appropriate interventions for our population.

Efecto del pre-procesamiento del EEG en el Análisis por Componentes Independientes: reducción del artefacto del implante coclear en los Potenciales Evocados Auditivos / Effect of EEG pre-processing on Independent Component Analysis: reduction of cochlear implant artifact in Auditory Evoked Potentials

Resumen: El Análisis por Componentes Independientes (ICA, Independent Component Analysis) es una herramienta muy utilizada para eliminar los artefactos comunes del EEG, sin embargo existe poca bibliografía sobre el impacto que tienen etapas de pre-procesamiento de esta señal sobre el desempeño del ICA. En este trabajo se comparó el efecto de aplicar dos filtros digitales diferentes, pasabajas y pasabanda, en una etapa de procesamiento previa a ICA, para remover específicamente el artefacto de un implante coclear en registros de Potenciales Evocados Auditivos. Se analizaron señales de 10 sujetos usuarios de implante coclear y en 5 de estos registros con el pre-filtrado pasabajas se obtuvieron los mayores valores del índice de la Relación Señal Interferencia, utilizado para evaluar la calidad de la separación. El mayor efecto al remover el artefacto del implante coclear se nota en los electrodos T4 y T6, que corresponde a la zona donde los sujetos tienen colocado su implante (área temporal derecha).

Abstract: Independent Component Analysis (ICA) is an algorithm used to remove artifacts from the EEG. However, there is little current literature about the impact of preprocessing stages of this signal on the performance of ICA. In this paper the effect of applying two different digital filters - lowpass and bandpass -, in a pre-processing step to ICA, was compared. This to remove the cochlear implant artifact from the Auditory Evoked Potentials. Recordings from 10 cochlear implant users were analyzed. In 5 of these records using the pre-lowpass filtering, the highest Signal Interference Ratio (SIR) was obtained; this index was used to assess the quality of ICA separation. The greatest effect of removing the cochlear implant artifact is noted in both T4 and T6 electrodes, which correspond to the area where the subjects have placed their implants (right temporal area).

Substratos, concentrações de ácido indolbutírico e tipos de miniestacas no enraizamento de melaleuca (Melaleuca alternifolia Cheel) / Substrates, indolebutyric acid levels and types of minicuttings on the rooting of tea tree (Melaleuca alternifolia Cheel)

Melaleuca alternifolia tem como produto principal o óleo essencial extraído das folhas devido às propriedades antifúngicas e antibacterianas. Pouco se tem relatado sobre a propagação desta espécie, sendo a miniestaquia uma alternativa para a propagação vegetativa de clones superiores visando à implantação de campo de produção. Este trabalho teve como objetivo avaliar o efeito de diferentes substratos, concentrações de AIB, e tipo de miniestaca, no enraizamento de Melaleuca alternifolia. No primeiro experimento foram testados os substratos, areia de granulometria média, Plantmax HT®, Golden-Mix® e vermiculita. No segundo experimento foram avaliadas diferentes concentrações de AIB (0, 500, 1000 e 2000 mg L-1), em dois tipos de miniestacas (apical e mediana). As miniestacas foram confeccionadas com 5 cm de comprimento, mantidas em casa de vegetação com nebulização intermitente, e, após 45 dias do plantio, foram avaliadas as porcentagens de miniestacas enraizadas, com calos e não responsivas, o número de raízes formadas por miniestaca e o comprimento das três maiores raízes (cm). O substrato Golden-Mix® e as miniestacas coletadas da porção apical do ramo submetidas ao tratamento com 500 mg L-1 de AIB apresentaram maior porcentagem de enraizamento e melhor qualidade do sistema radicial.

Melaleuca alternifolia has as major product the essential oil extracted from its leaves due to its antifungal and antibacterial properties. There are scarce reports about the propagation of this species, and minicutting is an alternative for vegetative propagation of superior clones in order to establish a production field. This study aimed to evaluate the effect of different substrates, IBA levels and types of minicuttings on the rooting of Melaleuca alternifolia. In the first experiment, the following substrates were tested: medium sand, Plantmax HT®, Golden-Mix® and vermiculite. In the second experiment, different IBA levels (0, 500, 1000 and 2000 mg L-1) were tested for two minicutting types (apical and medium). Minicuttings were prepared with 5 cm length and were kept in a greenhouse with intermittent mist; then, at 45 days after planting, we evaluated: the percentages of rooted minicuttings, with callus and non-responsive, the number of roots per minicutting and the length of the three longest roots. The substrate Golden-Mix® and the minicuttings collected from the apical part of the branch and treated with 500 mg L-1 IBA presented the largest rooting percentage and the best root system quality.

Efeito dos ácidos naftaleno acético e indolilbutírico no enraizamento de estacas de jambolão [Syzygium cumini (L. ) Skeels] / Effect of naphthaleneacetic acid and indolebutyric acid on rooting of jambul [Syzygium cumini (L. ) Skeels] cuttings

O jambolão propaga-se normalmente por sementes o que acarreta variabilidade nas plantas descendentes e um problema quando o objetivo é a formação de pomar comercial. O desenvolvimento de protocolo de propagação vegetativa por meio da estaquia possibilitaria a reprodução de todas as características da planta matriz, uniformidade nas populações e facilidade de propagação. O presente trabalho teve por objetivo avaliar o efeito dos ácidos naftaleno acético (ANA) e indolilbutírico (AIB) no enraizamento de estacas de jambolão. Estacas da região mediana dos ramos foram confeccionadas com 12 cm de comprimento, cortadas em bisel na base e reto acima da última gema axilar, mantendo-se um par de folhas reduzidas à metade. As bases das estacas foram imersas por 10 segundos em soluções aquosas contendo ANA ou AIB nas concentrações de 0, 500, 1.000 e 1.500 mg L-1. Para o plantio foram utilizadas bandejas plásticas contendo areia de granulometria média. As estacas foram mantidas em casa-de-vegetação com nebulização intermitente e após 120 dias do plantio, foram avaliadas as variáveis: porcentagem de estacas enraizadas, com calos, vivas (não enraizadas e sem calos) e mortas, comprimento das três maiores raízes (cm) e número de raízes formadas por estaca. Os melhores resultados de enraizamento foram verificados com 1.000 mg L-1 para ambos os fitorreguladores testados. A porcentagem de enraizamento foi ligeiramente superior com a utilização de ANA quando comparada ao AIB.

Jambul usually propagates by seeds, which causes variability in the descendant plants and represents a problem in the formation of commercial orchards. The development of a protocol for vegetative propagation by cuttings would enable the reproduction of all features of the Mother plant, uniformity in populations and easy propagation. The aim of this work was to evaluate the effect of naphthaleneacetic acid (NAA) and indolebutyric acid (IBA) on rooting of jambul cuttings. Twelve-cm-long cuttings from the median region of branches were prepared through bevel cut in the base and right cut above the last axillary bud, keeping one pair of halved leaves. Cutting bases were immersed for 10s in aqueous solutions containing NAA or IBA at 0, 500, 1000 and 1500 mg L-1 concentrations. Plastic trays containing medium sand were used in the planting. The cuttings were kept in a greenhouse under intermittent nebulization and, at 120 days after planting, the following variables were evaluated: percentage of rooted, with calluses, alive (not-rooted and without calluses) and dead cuttings; length of the three largest roots (cm); and number of roots per cutting. The best rooting was observed by using 1000 mg L-1 of both tested plant growth regulators. Rooting percentage was slightly higher under NAA relative to IBA.

Echocardiographic, electrocardiographic and blood pressure changes induced by icodextrin solution in diabetic patients on peritoneal dialysis.

The use of icodextrin as an osmotic agent in solutions for peritoneal dialysis (PD) has important cardiovascular effects related with better control of extracellular volume. Among them, reduction of arterial pressure and an improvement in echocardiographic parameters stand out. In diabetic patients, icodextrin has additional potential advantages related with better metabolic control. In a multicenter, open-label randomized controlled trial, the effects of icodextrin solutions were compared to glucose solutions on echocardiographic, electrocardiographic, and blood pressure changes in diabetic patients on PD. Two phases were noted in the follow-up. In the early phase (6 months), reduction in ambulatory blood pressure (ABP) and left ventricular end diastolic diameter were found in the icodextrin group. These changes correlated with changes in body fluids. In the late phase (12 months), a trend towards baseline values in ABP was seen. Changes in inferior vena cava diameter and in low frequency R-R variability spectral analysis in the icodextrin group suggest that icodextrin increases circulating blood volume and sympathetic tone, probably by accumulation of icodextrin metabolites in the bloodstream and improvement in diabetic neuropathy as a result of lower peritoneal glucose absorption. The effects of icodextrin in diabetic patients were related to better fluid management and metabolic control.

Factors that control the reactivity of the interface cysteine of triosephosphate isomerase from Trypanosoma brucei and Trypanosoma cruzi.

The amino acid sequences and X-ray structures of homodimeric triosephosphate isomerase from the pathogenic parasites Trypanosoma brucei (TbTIM) and Trypanosoma cruzi (TcTIM) are markedly similar. In the two TIMs, the side chain of the only interface cysteine (Cys14) of one subunit docks into loop 3 of the other subunit. This portion of the interface is also markedly similar in the two enzymes. Nonetheless, Cys14 of TcTIM is nearly 2 orders of magnitude more susceptible to the thiol reagent methylmethane thiosulfonate (MMTS) than Cys14 of TbTIM. The causes of this difference were explored by measuring the second-order rate constant of inactivation by MMTS (k(2)) under various conditions. At pH 7.4, k(2) in TcTIM is 70 times higher than in TbTIM. The difference decreases to 30 when the amino acid sequence of loop 3 and adjoining residues of TbTIM are conferred to TcTIM (triple mutant). The pK(a) values of the thiol group of the interface cysteine of TcTIM and the triple mutant were 0.7 pH unit lower than in TbTIM. Because this difference could account for the different sensitivity of the enzymes to thiol reagents, we determined the k(2) of inactivation at equal levels of ionization of their interface cysteines. Under these conditions, the difference in k(2) between TcTIM and TbTIM became 8-fold, whereas that of the triple mutant to TbTIM was 1.5 times. The substrate analogue phosphoglycolate did not modify the pK(a) of the thiol group of the interface, albeit it diminished the rate of its derivatization by MMTS. In the presence of phosphoglycolate, under conditions in which the interface cysteines of the enzymes had equal levels of protonation, the difference in k(2) of TcTIM and TbTIM became smaller, whereas k(2) of the triple mutant was almost equal to that of TbTIM. Thus, from measurements of the reactivity of the interface cysteine in various conditions, it was possible to obtain information on the factors that control the dynamics of a portion of the dimer interface.

Staphylococcal peritonitis in continuous ambulatory peritoneal dialysis: colonization with identical strains at exit site, nose, and hands.

To evaluate the relationship of nasal or skin Staphylococcus carrier status with identical strains and the development of staphylococcal peritonitis, 59 consecutive peritonitis episodes in patients using a twin-bag system for continuous ambulatory peritoneal dialysis from a single dialysis center were prospectively studied. Dialysate samples and exit-site, nose, and nail swabs from patients and their dialysis partners were obtained on the same day for culture. When bacteria belonging to the same species of the Staphylococcus genus were isolated from dialysate and at least one extraperitoneal anatomic site, pulsed-field gel electrophoresis typing was performed. The bacterial strains isolated from catheter exit site, nose, or nails of each patient and his or her dialysis partner were classified as identical or different. Twenty-seven of the 59 peritonitis episodes (46%) were caused by staphylococci. Nineteen of these 27 patients carried the same Staphylococcus species causing the peritonitis episode at the exit site, nose, or nails, but only 17 patients (63%) carried an identical strain. Four of 5 dialysis partners carried the same Staphylococcus species causing the peritonitis episode at nose or nails, but the strain was identical for only 3 dialysis partners (60%). Four patients and 1 dialysis partner carried unrelated strains of the Staphylococcus species causing the peritonitis episode. The most frequently colonized site with strains identical to that causing the peritonitis episode was the catheter exit site, followed by nose and nails. This finding may be clinically relevant because eradication of Staphylococcus aureus colonizing the catheter exit site may be more important and have a greater likelihood of success than maneuvers directed to more distant locations.

Derivatization of the interface cysteine of triosephosphate isomerase from Trypanosoma brucei and Trypanosoma cruzi as probe of the interrelationship between the catalytic sites and the dimer interface.

In the interface of homodimeric triosephosphate isomerase from Trypanosoma brucei (TbTIM) and Trypanosoma cruzi (TcTIM), one cysteine of each monomer forms part of the intersubunit contacts. The relatively slow derivatization of these cysteines by sulfhydryl reagents induces progressive structural alterations and abolition of catalysis [Garza-Ramos et al. (1998) Eur. J. Biochem. 253, 684-691]. Derivatization of the interface cysteine by 5, 5-dithiobis(2-nitrobenzoate) (DTNB) and methylmethane thiosulfonate (MMTS) was used to probe if events at the catalytic site are transmitted to the dimer interface. It was found that enzymes in the active catalytic state are significantly less sensitive to the thiol reagents than in the resting state. Maximal protection against derivatization of the interface cysteine by thiol reagents was obtained at near-saturating substrate concentrations. Continuous recording of derivatization by DTNB showed that catalysis hinders the reaction of sulfhydryl reagents with the interface cysteine. Therefore, in addition to intrinsic structural barriers, catalysis imposes additional impediments to the action of thiol reagents on the interface cysteine. In TcTIM, the substrate analogue phosphoglycolate protected strongly against DTNB action, and to a lesser extent against MMTS action; in TbTIM, phosphoglycolate protected against the effect of DTNB, but not against the action of MMTS. This indicates that barriers of different magnitude to the reaction of thiol reagents with the interface cysteine are induced by the events at the catalytic site. Studies with a Cys14Ser mutant of TbTIM confirmed that all the described effects of sulfhydryl reagents on the trypanosomal enzymes are a consequence of derivatization of the interface cysteine.

[Human papillomavirus infection in women with and without abnormal cervical cytology]. / Infección por el virus del papiloma humano en mujeres con y sin citología cervical anormal.

This study sought to define the prevalence rates of human papillomavirus (HPV) infection and cytologic abnormalities in 3,257 sexually active females 13 to 45 years of age, undergoing routine cervical cytologic screening in the outpatient clinic of an urban hospital. One hundred and fifty patients (4.6%) showed cytologic evidence of cervical human papillomavirus infection (abnormal Pap). We selected a control group (n = 150) with negative cervical cytologic smears. Cells collected were analysed for HPV-DNA by PCR amplification method with probes for HPV types 6.11, 16.18 and 33. The HPV-DNA was detected in 21/300 (7.0%). The prevalence of cervical HPV-DNA types among women with negative cytology was 5.3% (8/150) and 8.6% (13/150) among women with abnormal Pap. The risk of HPV infection seems to be related with age at first intercourse, younger age and number of sexual partners. We did not find relation with the use of oral contraceptives smoking and history of prior sexually transmitted disease.

[Morphological study of the hepatocyte in cirrhotic patients treated with phenobarbital]. / Estudio morfológico del hepatocito en cirróticos tratados con fenobarbital.

The authors report on a comparative study of light and electron microscopy in the diagnosis of tissue obtained in 21 percutaneous liver biopsies in patients known to have cirrhosis. Using light microscopy twelve patients were ascertained to have post-necrotic cirrhosis and twelve had Laennec's cirrhosis. All of these patients were given phenobarbital, 65 mg. every twelve hours, during twenty-one days. A control group of five patients received placebos. With electron microscopic methods, in all of the cirrhotic patients both before and after treatment with phenobarbital, the authors observed bands of fibrous tissue made up of collagen fibers and fibroblasts which originate in the portal spaces and in the Kupffer cells. This makes up the mesenchymal reaction to the liver cell damage, which in the long run proves to be more important than liver cell regeneration. Phenobarbital treatment resulted in hyperplasia of the agranular endoplasmic reticulum in liver cells. The authors agree with other authors that this is related to metabolic activity of enzymes acting on extraneous drugs and chemical substances.