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Osteoporosis is a highly prevalent and multifactorial disease whose main manifestation is the appearance of fragility or low-impact fractures. The most frequent locations of osteoporotic fractures occur at the vertebrae, femoral, distal end of the radius and humerus. Osteoporotic vertebral fracture deserves special mention among them due to its prevalence, importance as it often goes unnoticed and medium-long term consequences are: pain, deformity, disability and deterioration in quality of life. In this review we will focus on the classification and initial evaluation of the patient with osteoporosis, estimation of risk factors, laboratory and imaging studies for an adequate assessment using simple radiography, dual densitometry and magnetic resonance imaging. We will also address the main aspects of the differential diagnosis, treatment and prevention of vertebral fragility fracture, briefly reviewing the main therapeutic agents currently used for its prevention and treatment.

La osteoporosis es una enfermedad muy prevalente y multifactorial cuya principal manifestación es la aparición de fracturas por fragilidad o bajo impacto. Las localizaciones más frecuentes de la fractura osteoporótica ocurren a nivel vertebral, femoral, extremo distal del radio y húmero. Especial mención entre ellas merece la fractura vertebral osteoporótica por su prevalencia, importancia, al pasar muchas veces desapercibida, y consecuencias a medio-largo plazo: dolor, deformidad, discapacidad y deterioro de la calidad de vida. En esta revisión nos centraremos en la clasificación y en la evaluación inicial del paciente con osteoporosis, estimación de los factores de riesgo, estudios de laboratorio e imagen para una valoración adecuada mediante radiografía simple, densitometría dual y resonancia magnética. Abordaremos, asimismo, los principales aspectos del diagnóstico diferencial, tratamiento y prevención de la fractura vertebral por fragilidad, revisando sucintamente los principales agentes terapéuticos que se utilizan en la actualidad para su prevención y tratamiento.

Patent ductus arteriosus is treated according to its indications conservatively with medications or by surgical closure; the latter was traditionally performed by an open technique, then later, the percutaneous approach was developed for selected cases and finally, in recent years, it has been done by thoracoscopic surgery with success challenging percutaneous results. However, at our hospital, this had not been tried before. We present the case of a female patient who met the ideal criteria for this procedure to be performed and in whom it was successfully accomplished without complications; hence our report, motivated by the historical importance and as a baseline for future cases.

La polimialgia reumática y la arteritis de células gigantes pueden suponer una emergencia médica en la que el retraso en su correcto diagnóstico y manejo terapéutico pueden asociar complicaciones graves.

The relationship between psoriasis and associated diseases has drawn particular interest in recent years. To provide appropriate management of psoriasis from an early stage, it is necessary to include prompt diagnosis of concomitant disease and to prevent and treat any comorbidity found. Such an integrated approach also serves to ensure that the drugs used to treat associated diseases do not interfere with the management of psoriasis, and vice versa.

Abstract: Introduction: Experimental models of osteoporosis in rabbits are useful to investigate anabolic agents because this animal has a fast bone turnover with predominant remodelling over the modelling processes. For that purpose, it is necessary to characterize the densitometric values of each type of bony tissue. Objective: To determine areal bone mass measurement in the spine and in trabecular, cortical and subchondral bone of the knee in healthy and osteoporotic rabbits. Design: Bone mineral content and bone mineral density were measured in lumbar spine, global knee, and subchondral and cortical bone of the knee with dual energy X-ray absorptiometry using a Hologic QDR-1000/W densitometer in 29 skeletally mature female healthy New Zealand rabbits. Ten rabbits underwent triplicate scans for evaluation of the effect of repositioning. Osteoporosis was experimentally induced in 15 rabbits by bilateral ovariectomy and postoperative corticosteroid treatment for 4 weeks. Identical dual energy X-ray absorptiometry (DXA) studies were performed thereafter. Results: Mean values of bone mineral content at the lumbar spine, global knee, subchondral bone and cortical tibial metaphysis were: 1934±217 mg, 878±83 mg, 149±14 mg and 29±7.0 mg, respectively. The mean values of bone mineral density at the same regions were: 298±24 mg/cm2, 455±32 mg/cm2, 617±60 mg/cm2 and 678±163 mg/cm2, respectively. Bone mineral content and bone density of healthy rabbits followed a normal distribution at the four skeletal regions studied. Precision after triplicate repositioning yielded a coefficient of variation ranging from 2.6% to 3.8%. The least significant change ranged between 7.3% and 10.7%. Bone mineral density measured at the four different skeletal regions correlated significantly. Bone mineral density in osteoporotic rabbits was significantly lower in the four regions studied than that in controls, rendering a T-score of, respectively, −2.0±1.1 in the lumbar spine, −2.2±2.1 in the global knee, −1.9±0.6 in the subchondral bone, and −5.7±3.1 in the cortical tibia (P<0.05). Conclusions: DXA is a reliable and precise method to evaluate the bone mass in rabbits. Our results also suggest that subchondral bone is a bone of mixed densitometric characteristics with marked cortical bone predominance.

A detailed infrared spectroscopy analysis in the 2500 to 3800 cm−1region has been used to study the formation of species in samples of iron oxides embedded in silica xerogel matrix. We report the presence of α, β, and γ forms of iron oxyhydroxides as intermediate species in the formation of α-Fe2O3, γ-Fe2O3and ε-Fe2O3starting from three different iron precursors: iron nitrate, iron chloride and nanometric Fe particles prepared by chemical reduction. Our results show that under thermal dehydration α and γ forms of iron oxyhydroxides transform into hematite and maghemite, respectively, whereas the β form transform to the ε-Fe2O3without going through an intermediate iron oxide phase.

We report a study using X-ray diffraction, refinement Rietveld, IR absorption spectroscopy and vibrating sample magnetometry of the formation of particles of Ni-Zn ferrites embedded in a xerogel SiO2matrix. Initial solutions were prepared mixing TEOS, distilled water, ethanol, and three different nitrates: iron, nickel and zinc. A molar ratio H2O:TEOS:Et-OH of 11.66:1.0:4.0 was used in all solutions. Formation of Ni0.5Zn0.5Fe2O4as well as structural modifications of the SiO2matrix induced by these particles are discussed. Ni-Zn crystals having dimensions varying from 4 to 16.5 nm have been synthesized by a suitable heat treatment schedule at temperatures varying from 700 to 1100°C. The coercivity values for different heat-treated samples are found in the range 11–193 Oe, which are significantly larger than those presented by bulk Ni-Zn ferrites.

In this work we report composites of γ-Fe2O3/SiO2and α-Fe2O3/SiO2starting from three different iron precursors: iron nitrate, iron chloride and nanometric Fe particles prepared by aqueous chemical reduction. The composite samples were prepared by the sol-gel method and were ground in order to produce powders, heat treated at different temperatures under atmospheric conditions. The powder samples were characterized by X-Ray diffraction, IR absorption, and UV-visible spectroscopy. A specific composite can be produced depending on the temperature used for reaction.

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Method for calculating bulk viscosity is described. This method relies on the results of the revised Enskog theory for hard-sphere fluid mixtures and the use of the temperature and density-dependent diameter of Mansoori-Canfield and Rasaiah-Stell to model each species of the real mixtures. Using this method the predicted values of the bulk viscosity of several mixtures of hydrocarbons and noble gases were calculated. These results are mainly predictive.

Abstract.: Osteoporosis is a common disease among patients undergoing transplantation. Its prevalence and complications have been well described in solid organ recipients, especially kidney, liver, and heart. However, studies in bone marrow transplantation (BMT) are scarce. Among the mechanisms invoked in the pathogenesis of BMT osteoporosis are the baseline disease, the use of immunosuppressive drugs and, more remarkably, secondary hypogonadism. We present a study of 27 women who underwent BMT, all of them suffering ovarian failure. We studied different biochemical markers of bone formation/resorption and also evaluated the presence of osteopenia/osteoporosis by dual energy X-ray absorptiometry (DXA) of the lumbar spine. Osteopenia was observed in nine patients (33%) and osteoporosis in another five (18%), according to the World Health Organization criteria. We also detected a subgroup showing elevation of several bone turnover biochemical markers, indicating high osseous remodeling. A remarkable increase in urine hydroxyproline/creatinine was detected in 95% of cases, although an explanation is lacking. We outline a reasonable therapeutic approach for osteoporosis in BMT emphasizing the need to monitor these patients after transplantation.

TO THE EDITOR. —We have read with great interest the article by Desnoyers et al1 in the July 1984 issue of the Archives referring to a case of pulmonary hemorrhage (PH) in systemic lupus erythematosus (SLE).Although we consider that the case reported is most interesting, we disagree with these authors on several points. We herein discuss a similar patient whom we have studied recently.2 In our case, the patient died as a consequence of two episodes of massive PH.We think that the patient described by Desnoyers et al probably also had two episodes of PH and that the first episode went unnoticed because it was attributed to a mycoplasmal pneumonia and because the anemia was presumed to be due to gastrointestinal tract bleeding. We believe that a guaiac-positive stool is not sufficient evidence to account for such severe gastrointestinal tract bleeding. Otherwise, hemolytic anemia associated with