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Background: MATCH (Measuring Analytical Thinking in Clinical Health Care) is an instrument to evaluate clinical reasoning. Aim: To assess MATCH performance in professionals and students with different training in pediatrics. Material and Methods: MATCH was administered to medical students (S), frst (R1) and third (R3) year residents and staff physicians (P). We evaluated the score and time required to achieve it, according to training level in pediatrics. Results: Eighty fve subjects were included (23 S, 28 R1, 17 R3 y 17 P), achieving 37.4 ± 6.0 points, in 25.2 ± 8.5 minutes. There were significant differences in score and time, according to training level. There was a positive correlation between training level and score (Rho = 0.515; p < 0.001), and a negative one between training level and time (Rho = -0.589; p < 0.001). Conclusions: More experienced and trained professionals had a better performance in a clinical analytical thinking test.

Objectives To present a model of decision analysis that allows assessing the trade-off between the short-term risks of performing a carotid endarterectomy and the rate of preventable future events. Methods We used data from a systematic review to define values for a base case and perform a sensitivity analysis. The primary endpoint was a comparison of the fatal and disabling stroke-free survival during a 5-year period in a cohort of hypothetical patients who presented asymptomatic severe carotid stenosis and were treated with either immediate prophylactic carotid endarterectomy or medical treatment alone. Results The difference in estimated fatal and disabling stroke-free survival favoring endarterectomy in patients with asymptomatic severe carotid stenosis is less than 4 days over the course of 5 years. One-way sensitivity analysis demonstrated that if the perioperative rate of death or disabling stroke is greater than 2.1%, then medical treatment is better. A non-surgical strategy is also better if the risk of fatal and disabling stroke with medical treatment is less than 1.09% per year, or if the rate of fatal and disabling stroke beyond 30 days following endarterectomy is greater than 0.51% per year. Conclusions In this model, immediate prophylactic carotid endarterectomy seems to offer a minimum net benefit in terms of fatal or disabling stroke-free survival over a 5-year period, when compared to medical treatment alone.

The so-called stunned myocardium, defined as transitory myocardial contractile dysfunction, has been clearly demonstrated in diverse clinical situations. However, stunned myocardium related to ischemic stroke has been poorly identified. We describe two patients with diagnosis of acute ischemic stroke who developed eletrocardiographic changes, cardiac enzyme increasing levels and myocardial dysfunction secondary to abnormal cardiac wall motion. At the same time the patients developed acute lung injury with rapid resolution, perhaps as a consequence of neurocardiogenic components.

I read with interest the article by Capparelli et al.1 reporting the case of an elderly patient with normal renal function presenting with recurrent episodes of cephalosporin-induced encephalopathy. EEG showed a diffuse slowing without evidence of ongoing epileptiform activity. These authors hypothesized that this neurologic adverse effect could be secondary to the modification that these drugs may produce on the cerebral concentrations of gamma-aminobutyric acid (GABA). The existence of acute confusional states associated with the use of cephalosporins in subjects with variable degrees of renal failure …

The infection of the corneal graft is one of the most serious complications following keratoplasty. In many instances, it can be treated successfully with intensive topical and subconjunctival antibiotics. However, when this therapy is ineffective, a surgical approach must be considered. The usefulness of partial conjunctival flaps that spare the visual axis for managing corneal graft infections is reported.Retrospective review of four cases. All patients were males between 12 and 85 years old. The four abscesses developed in the penetrating corneal graft during the first year after keratoplasty. The organisms found were Propionibacterium acnes, Candida albicans, Staphylococcus aureus, and Streptococcus pneumoniae. After failure of medical therapy, they were operated on using the partial, thick conjunctival flap technique.Resolution of the infection and maintenance of a clear graft was achieved in all patients. The follow-up ranged from 5 to 8 years.The partial conjunctival flap is an effective surgical procedure for the treatment of abscesses in penetrating keratoplasties when medical treatment has failed.

Fungal endocarditis, in particular due to Candida species, requires medical and surgical treatment and amphotericin B is the drug of choice. Caspofungin is an echinocandin very effective against Candida and Aspergillus. We present a patient with Candida tropicalis endocarditis, fluconazol resistant, treated with caspofungin, on a compassional basis as a result of adverse effects with amphotericin B. The patient had a microbiological response.

An unusual case of bilateral acute endophthalmitis in association with the HLA-DQ5 histocompatibility antigen is reported. A 35-year-old woman with high myopia and cataracts in both eyes underwent phacoemulsification procedures performed in separate sessions using different viscoelastic substances and following the same strict prophylactic measures. After each surgical procedure, she developed S. epidermidis acute endophthalmitis in the right eye and Propionibacterium acnes acute endophthalmitis in the left eye; both were successfully treated with capsular bag irrigation and intracameral vancomycin (1 mg/0.1 mL). She tested positive for the HLA-DQ5 (DQ1), DQ2 antigen. The question is raised as to whether the HLA-DQ5 histocompatibility antigen may be a predisposing factor for both staphylococcal and P. Acnes acute endophthalmitis. A multicenter prospective study is proposed to identify this HLA antigen in all patients scheduled for cataract surgery who have a history of postoperative endophthalmitis in the fellow eye.

The most frequent postoperative complication in extracapsular cataract surgery is opacification of the posterior capsule. The purpose of this study was to correlate the frequency of capsular opacification with each kind of senile cataract. A total of 566 eyes with cataracts were studied. They had been operated on between 1980 - and 1990 using the extracapsular, intercapsular, and phacoemulsification techniques. Our results confirm that senile complete cataracts (mature cataracts) had a significantly lower tendency to produce postoperative capsular opacification than other cataract types (nuclear, cortical, posterior subcapsular).

A bullet located in the interventricular septum is shown in frontal (A) and right lateral (B) chest radiography and in an echocardiogram (C; RA indicates right atrium; RV, right ventricle; LA, left atrium; and LV, left ventricle. …

Six hundred and thirty-one patients with hemolytic uremic syndrome (HUS) were treated from 1960 to 1992; 19 (3%) were familial cases, of which 9 were classified as concomitant (including twins), 6 as non-concomitant, and 4 as recurrent. In the recurrent group there were 15 HUS episodes, 10 being concomitant in 2 patients. Prodromal diarrhea was present only in concomitant and non-concomitant cases. Patients with recurrences were sisters from a single family. Concomitant and non-concomitant cases had clinical features, course, and age similar to typical endemoepidemic forms of HUS, in which an association with verocytotoxin-producing Escherichia coli has been reported. There may be a genetic determinant in concomitant cases; these occurred outside the season during which endemoepidemic forms are typically detected. In patients with recurrent disease a genetic factor which may lead to the development of the disease when triggered by viral infections is likely.

Thirty-four hemolytic uremic syndrome (HUS) patients and ninety-five family members were studied to determine the frequency of infection with verocytotoxin-producing Escherichia coli (VTEC) in household contacts using three diagnostic criteria: VTEC strains isolation and characterization, detection of free fecal VT (FVT) and VT-neutralizing antibodies (VT-NAbs). Gastrointestinal tract symptoms occurred in one to six family members in 8 (23.5%) of the index cases, the week before admission to hospital or simultaneously. The control group consisted of 34 children with acute gastroenteritis who did not develop HUS. Cumulative evidence of VTEC infection was found in 13 (38.2%) of 34 HUS patients, in 30 (31.6%) of 95 family members and in 10 (29.4%) of 34 control children. The serotypes of VTEC isolated were O157: H7 and O25: H2. The prevalent VT type was VT2 in VTEC and FVT; and VT1 in VT-NAbs. Both parents had the same infection rate by fecal toxin or serological data (11.1% FVT, 32% VT-NAbs). These were higher than those detected in siblings (6.2% FVT, 23.5% VT-NAbs) and grandparents (0% FVT, 18% VT-NAbs). Of 16 patients without evidence of infection, 3 had household contacts with FVT and 13 with VT-NAbs. Our results show the wide dissemination of VTEC in the population of Argentina and that family members of HUS patients are usually infected. Therefore, person-to-person transmission may play an important role in the high incidence of HUS in our country.

For many years, the evolution of Argentina's healthcare system has been influenced by political and economic instability. Inflation and hyperinflation have led to anarchic development of both health administration systems and hospitals. Critical care grew in a similar manner, resulting in a mix of500 critical care units with very different levels of technology and trained personnel. Cost-containment policies have been implemented mainly by health administration systems. Public institutions (university and large provincial and county hospitals) have suffered hard budget cuts that have resulted in a decrease in the quality of care and the loss of trained human resources. Union organizations, which cover the healthcare costs of60% of the population, implemented a low reimbursement policy that resulted in low standards of care for critically ill patients. The country's private hospital system is extremely heterogenous, ranging from little, simple institutions with a 20- to 30-bed capacity to great private institutions with international standards of care. Cost-containment efforts have been sporadic and isolated, and statistical data to analyze the results are lacking. In order to formulate a strategy of cost-containment in the near future, accreditation and categorization of critical care units and human resources training are being implemented by health authorities and the Argentine Society of Critical Care Medicine.

We report a case of a child who developed Hemolytic Uremic Syndrome in whom two Shiga-like toxin (SLT)-producing Escherichia coli strains of different serotypes and genotypes, were simultaneously isolated from stools. In addition, one of these strains represented a new toxin producing serotype. Strain 1 belonged to serotype O157: H7, biotype D, produced SLT II and was susceptible to all antibiotics tested. This strain hybridized with gene probes for SLT II, fimbrial adhesion (EHEC factor) and attaching and effacing factor (eae). Strain 2 belonged to serotype 025: K2: H2, produced SLT II and had a multiresistant antibiotic susceptibility pattern. This strain hybridized with the EHEC gene probe but not with SLT I, SLT II and eae gene probes. Free fecal SLT II cytotoxin was detected in stools of the child and his father, suggesting that the infection may have been acquired from a household contact. Fil: Rivas, Marta. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Microbiología; Argentina. Fil: Voyer, L. Hospital General de Niños Pedro de Elizalde; Argentina. Fil: Leardini, Nelida. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Microbiología; Argentina. Fil: de Mena, María F. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Microbiología; Argentina. Fil: Wainsztein, Raquel. Hospital General de Niños Pedro de Elizalde; Argentina. Fil: Callejo, Raquel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Microbiología; Argentina. Fil: Prado, Valeria. Universiad de Chile. División Ciencias Médicas Oriente; Chile. Fil: Tous, Monica. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Microbiología; Argentina. Fil: Binsztein, Norma. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Microbiología; Argentina.

We report a case of a child who developed Hemolytic Uremic Syndrome in whom two Shiga-like toxin (SLT)-producing Escherichia coli strains of different serotypes and genotypes, were simultaneously isolated from stools. In addition, one of these strains represented a new toxin producing serotype. Strain 1 belonged to serotype O157: H7, biotype D, produced SLT II and was susceptible to all antibiotics tested. This strain hybridized with gene probes for SLT II, fimbrial adhesion (EHEC factor) and attaching and effacing factor (eae). Strain 2 belonged to serotype 025: K2: H2, produced SLT II and had a multiresistant antibiotic susceptibility pattern. This strain hybridized with the EHEC gene probe but not with SLT I, SLT II and eae gene probes. Free fecal SLT II cytotoxin was detected in stools of the child and his father, suggesting that the infection may have been acquired from a household contact.

Falls in gastric intramucosal pH (pHi) are associated with morbidity and mortality in patients admitted to intensive-care units (ICU). We tested the hypothesis that ICU outcome can be improved by therapy guided by changes in pHi and aimed at improving systemic oxygen availability. We studied 260 patients admitted to ICUs with APACHE II scores of 15-25. After insertion of a gastric tonometer, each patient was randomly assigned to a control or protocol group within the admission pHi category (normal = 7.35 or higher; low = below 7.35). The control groups were treated according to standard ICU practices. The protocol groups received, in addition, treatment to increase systemic oxygen transport or to reduce oxygen demand, whenever the pHi fell below 7.35 or by more than 0.10 units from the previous measurement. The protocol was used, because pHi fell, in 67 (85%) of the protocol group with normal pHi on admission. There were no significant differences between protocol and control groups in demographic characteristics, admission blood gases or haemoglobin concentration, number or type of organ system failures, or the intensity of ICU care. For patients admitted with low pHi, survival was similar in the protocol and control groups (37% vs 36%), whereas for those admitted with normal pHi, survival was significantly greater in the protocol than in the control group (58% vs 42%; p less than 0.01). Therapy guided by pHi measurements improved survival in patients whose pHi on admission to ICU was normal. pHi-guided resuscitation may help improve outcome in such patients by preventing splanchnic organ hypoxia and the development of a systemic oxygen deficit.

An unusual case of spontaneous corneal perforation of acute hydrops in the left eye of a 21-year-old man is presented. The patient had a history of atopic diseases. To evaluate the status of the other eye, corneal topographic analysis was performed. This confirmed a subclinical keratoconus in the fellow eye and the association with atopy, eye rubbing, and rapid progression of the ectasia leading to perforation.

La calidad de un hormigón de cemento portland se considera satisfactoria si se verifican determinadas características en sus diversos estados. Las más importantes son las siguientes: trabajabilidad, cohesión, resistencia, impermeabilidad y durabilidad. Los conocimientos actuales sobre el tema permiten dimensionar las estructuras con un grado de seguridad adecuado, que puede quedar invalidado como consecuencia de acciones agresivas. En este trabajo se analizan los efectos de la acción de los agentes atmosféricos o agresivos, naturales o artificiales, sobre el hormigón, y las soluciones adecuadas, desde el punto de vista tecnológico, para evitar o reducir al mínimo las mismas. The quality of a concrete from portland cement, is considered satisfactory, if certain given characteristics are checked in its various states. The most important of these, are; workability, cohesion, resistance, impermeability and durabi1ity. Current knowledge on the subject allows to dimension structures with an adequate degree of security that may, notwithstanding, be invalidated as a consequence of aggresive actions. In this work, the effects of the action of atmospheric or aggresive agents, whether natural or man-made, upon concrete, and the adequate solutions from the technological point of view, are analyzed with the purpose of avoiding or minimizing them.

Al intensificarse en los últimos años las grandes obras en nuestro país y principalmente en lo referente a la construcción de diques y presas, se encaró en el LEMTT la puesta en marcha de un equipo de permeabilidad, que hasta el presente es el único en el país. Con esto se posibilita la obtención de coeficientes de permeabilidad en hormigones sin necesidad de recurrir por este ensayo a otros países. En este trabajo se vuelcan antecedentes bibliográficos y los ensayos sobre diferentes tipos de hormigones, pudiendo con los resultados obtenidos dar algunas pautas sobre conveniencias de razones agua-cemento, tipos de cemento y uso de aditivos, en la obtención de hormigones de bajos coeficientes de permeabilidad. In view of the increment of many civil engineering works of top level, including large dams, bridges and hydraulic structures, and for obtain the coefficient of permeability in concretes, LEMIT has tested a permeability equipment, the first one operating in this country. Results are given related to different types of concretes. According to them, it is possible to determine the more convenient water/cement ratio, the types of cement and the use of additives for the obtention of a low coefficient of permeability. Bibliographic references are given.

La incidencia del peso propio sobre las cargas actuantes en estructuras de hormigón simple o armado es de tal importancia, que se han estudiado modernamente hormigones estructurales livianos, lo que influye no sólo en la reducción del peso propio sino en mayor rapidez en la construcción, especialmente la prefabricación, menores costos de transporte, posibilidad de empleo de equipos más pequeños, etc. En este trabajo, luego de la presentación de antecedentes bibliográficos, se dan los resultados obtenidos, en los hormigones preparados con arena natural de río y arcillas expandidas por cocción, de fabricación nacional. The incidence of his own weight on the load that affect concrete structures is so important that now light structural concrete is studied, as a contribution to reduce his own weight and also to give more celerity to the constructions works, specialy in the préfabrication industry, lower cost of transport, use of small equipment, etc. In this paper, after the bibliographical references, the results obtained with concretes prepared using natural river sand and Argentine expanded calcinated clays, are presented.

El estudio de elementos de tan vasta aplicación como el hormigón armado o el pretensado, requiere un conocimiento amplio de los materiales que lo componen. En este trabajo se ha tratado de volcar en la forma más explícita posible, las características, normas de aplicación y detalles constructivos de los aceros que se fabrican en el país. Se destaca además la importante función que cumple el LEMIT en el otorgamiento de los Certificados de Empleo de los aceros de producción nacional y su vigencia, condición ésta indispensable para poder utilizarlos en las obras públicas provinciales. Este trabajo está destinado en especial a los proyectistas, inspectores y directores de obra. For the study of materials so useful as the prestressed and reinforced concretes, it is necessary a wide knowledge of the materials employed. In this paper it has been outlined the characteristics, the forms of application and other details referring to the steels that are made in the country. It has been pointed the role* of LEMIT, which gives the Useful Certificates for the domestic steels employed in public works in the Buenos Aires Province. This paper is specially prepared for technicians, supervisors and managers of civil works.

Considerando la necesidad creciente de utilizar cementos puzolánicos en hormigones, el LEMIT ha iniciado un estudio para la obtención de puzolanas artificiales, por tratamiento térmico de arcillas provenientes de las formaciones sedimentarias de la Serie de La Tinta en el sistema de Tandilia y de las sierras Australes de la Provincia de Buenos Aires. Para le realización del trabajo, se efectuó un muestreo representativo de arcillas; se procedió luego a su activación a diversas temperaturas. Las muestras así tratadas, se estudiaron por difracción de Rayos X, lo que permitió seguir las transformaciones de la estructura de las arcillas. Finalmente se realizaron ensayos de acuerdo a normas vigentes para este tipo de materiales. Las muestras ensayadas cumplen con los requisitos exigidos en las mismas. The increasing need for the use of pozzolanic cements has induced the LEMIT to start a research for obtaining artificial pozzolans by thermic treatment of clays from sedimentary sequences of the La Tinta Series and Southern Hills of Buenos Aires Province. After a representative sampling, clays were activated at different temperatures and then studied bv X-Ray diffraction to determine transformations of clay structures. Tests were also carried out in accordance with prevailing norms. The results obtained are highly satisfactory, as most treated samples fulfill the specifications of the norms.