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Biomedical subjects

J Lopez

Publications and source records attributed to J Lopez.

161 records · Page 9Linked to original sources

Melanotic neuroectodermal tumor of infancy: review of the literature and report of case.

A characteristic case of melanotic neuroectodermal tumor of infancy is reported and the literature regarding this lesion is reviewed. The case reported shows the salient features of previously described melanotic neuroectodermal tumors of infancy; it occurs in infants of less than 1 year of age; it most commonly arises from bone (jaws and skull), has distinctive gross and histologic features, is benign, and is cured by total local excision. Since the teeth in the mandible and maxilla are undergoing development about the time that this tumor occurs, it is not surprising to find tooth buds in close proximity to the expanding neoplastic mass. When odontogenic rests are found in association with the lesion, it must be assumed that it is a collision of the two structures and not that the odontogenic epithelium is the origin for the lesion as previously thought. This is especially true since odontogenic epithelium is not found in the tumor when it occurs outside the jaws. This is the type of lesion that will most probably first be noticed by a dentist and should be managed by the oral surgeon. It is important to note that proper advice regarding future dental problems should be given to the parents of the infant. Such possibilities as crowding or absence of the deciduous or permanent teeth, malocclusion, and possible malformation of the remaining maxillary ridge should be explained. Close dental follow-up is mandatory since recurrence is possible.

Female↗

Xeroradiography in dentistry.

Extensive review of the literature reveals that the diagnostic benefits of xeroradiography in medicine are rapidly being recognized. It is viewed with particular interest by clinicians managing neoplasms of the laryngopharyngeal, mammary, and joint regions. Xeroradiography is a definite aid in cephalometric analysis. Examples of use have been presented. The main disadvantage of xeroradiography in dentistry is that of slow-speed developing in comparison with that of our current silver halide films. This becomes significant when dealing with intraoral films. However, the only disadvantage that we have experienced with xerocephalometrics is that of head orientation. Because our radiology department is not equipped with a wall mount for proper alignment along the horizontal and vertical planes, the head position must be estimated with a plumb line. Very often, therefore, the head may be tipped in one direction or another. This, however, is not difficult to correct. I have noted several definite advantages that include: --Sharp, clear-cut contrast (because of the edge effect), which enhances image quality. --Simplified viewing (no need for view boxes). --Less radiation than that required for conventional radiographs. Because of the benefit of multiple-tissue diagnosis on one radiograph, there is no need to take multiple radiographs to record tissues of different densities, with the possible exceptional of special situations in tomography. --Dry, automatic processing, therefore, eliminating the need for mixed chemicals and darkroom. --Less cost to produce a xeroradiograph than a conventional radiograph because of the lower cost of materials and equipment (for example, no darkroom requirement). The Russian investigators reported an eightfold reduction in cost. Xeroradiography (from Greek word xeros meaning dry) is a radiographic process in which the quality is critically dependent on the potential of the surface charge on the plate, the amount of radiation exposure, and the conditions of development, all of which must be carefully controlled. This technique is gaining general acceptance. Special courses are being offered to teach technicians this process. I believe we have come on a new horizon in diagnostic radiography. Only through further investigation and research will we be better able to delineate the exact role of xeroradiography in dentistry.

Humans↗

Three years' experience with implanted pacemakers.

At the University Hospital, Saskatoon, over the last three years, pacemakers have been inserted in 40 patients with complete or incomplete heart block. Fourteen of the patients were females and 26 were males. The average age was 65 years; 12 were over 80 years of age, and the youngest patient was 8 years of age. In none was the heart block due to operation. Thirty-three patients are still alive and well. There have been seven deaths three early and four late. One patient died because of a "runaway" pacemaker, and two as a result of infection persisting around the pacemaker. Twenty-nine Medtronic pacemakers were used and 14 Atricor pacemakers; currently we favour the latter instrument.

Adams-Stokes Syndrome↗

A recruitment-based rheological model for mechanical behavior of soft tissues.

When lung tissue is subjected to finite deformations, phenomena appear that can only be described using nonlinear models. This paper considers the lung as a material composed of two elements, a continuous phase that acts uninterruptedly and a second phase composed of fiber elements that are recruited progressively into the mechanical process. Each individual fiber participates in the mechanical response of the set only when the deformation is above a certain value. A nine-parameter model was designed adopting standard viscoelastic elements both for the matrix and for each of the fibers. The mechanical behavior of the lung can be reproduced by a fitting process with standard numerical procedures in both dynamic-mechanical measurements and stress relaxation processes. Mechanical stress relaxation tests and dynamic-mechanical measurements have been carried out on subpleural parenchymal strips from rat lung. The model permits the reproduction of lung behavior in both types of measurements. The results show a recruitment ratio that decreases with deformation and the nonparticipation of the parallel matrix fraction in the lung's mechanical response so that a uniaxial transmission of force in the lung occurs via the recruited elements and the matrix series.

Animals↗

Airway maintenance in patients with long-term endotracheal intubation.

Long-term endotracheal intubation in seriously ill patients is frequently complicated by nosocomial infection of the tracheobronchial tree, especially with aerobic gram negative bacilli. A further complication is drying of pulmonary secretions unless the medical gases given are humidified. The performance characteristics of humidifying system used in spontaneously breathing, intubated patients is described. This system possesses the potential to decrease infection, provides physiologic humidification without nebulization, and, by avoiding air dilution, allows the administration of a precisely regulated FIO2.

Cross Infection↗

Early enteral nutrition in critically ill patients with a high-protein diet enriched with arginine, fiber, and antioxidants compared with a standard high-protein diet. The effect on nosocomial infections and outcome.

BACKGROUND: This study was designed to evaluate the effects of a high-protein formula enriched with arginine, fiber, and antioxidants compared with a standard high-protein formula in early enteral nutrition in critically ill patients. METHODS: For this study, 220 patients were enrolled in a prospective, multicenter, single-blind, randomized trial in 15 Spanish intensive care units (ICUs). The primary end-points were the incidence density rates of nosocomial infections, ICU and hospital length of stay, ICU and in-hospital mortality, and mortality at 6-month follow-up. RESULTS: The patients in the control and study groups had similar baseline characteristics. The study group had a lower incidence of catheter-related sepsis (0.4 episodes/1000 ICU days) than the control group (5.5 episodes/1000 ICU days), with a relative risk (RR) of 0.07 (95% confidence interval [CI] 0.01 to 0.54, p < .001). There were no differences in the incidence of ventilator-associated pneumonia, surgical infection, bacteremia, or urinary tract infections between the 2 groups. ICU mortality (16% in the study group versus 21% in the control group; RR 1.5, CI 95% 0.7 to 2.9) and in-hospital mortality (21% in the study group versus 30% in the control group; RR 1.6, CI 95% 0.9 to 3) were similar without differences in survival at 6-month follow-up (75% in the study group versus 68% in the control group, p = .15). Patients in the study group who were treated for 2 or more days showed a strong trend for better survival at 6-month follow-up (76% in the study group versus 67% in the control group, p = .06). Medical patients treated with the study diet had better survival than medical patients in the control group (76% in the study group versus 59% in the control group, p < .05). CONCLUSIONS: Critically ill patients fed a high-protein diet enriched with arginine, fiber, and antioxidants had a significantly lower catheter-related sepsis rate than patients fed a standard high-protein diet. There were no differences in mortality or ICU and hospital length of stay. The subgroup of patients fed the study diet for >2 days showed a trend toward decreased mortality.

Adult↗

Genetic variability and microdistribution of Triatoma infestans genotypes and Trypanosoma cruzi clones in Arequipa region (Peru).

The genetic variability of Triatoma infestans and Trypanosoma cruzi populations was studied by isoenzyme analysis in two distinct areas of Arequipa province (Peru); one, Santa Rita de Siguas, being an endemic area for Chagas' disease, the second, Arequipa, recently infected. Analysis of T. infestans genetic variability indicates, (i) temporal stability of genotypes found in Santa Rita de Siguas, (ii) high genetic differences between Arequipa and Santa Rita de Siguas populations suggesting minor contact between them, (iii) multiple origin of the T. infestans population in Arequipa, and (iv) poor dispersal capacity of T. infestans: the panmictic unit could be reduce to a house. Parasite isoenzyme analysis was performed in 29 Peruvian stocks of T. cruzi, mainly isolated from bugs taken in a single locality, Santa Rita de Siguas. The results show, (i) a high genetic polymorphism, (ii) nine different multilocus genotypes were detected and clustered in two different clades, (iii) most of the parasite isolates pertained to one of the clade and were genetically similar to those analyzed 12 years before. This sample allowed the study of the mating system of T. cruzi in strict sympathic conditions and gave more strength to the hypothesis of the clonal structure of T. cruzi populations.

Animals↗

Group protocol to mitigate disaster stress and enhance social support in adolescents exposed to Hurricane Hugo.

Literature reports that cognitive understanding and social support can mitigate stress in both adults and adolescents. As a subcomponent of the Carolina Adolescent Health Project (CAHP), this research evaluated the efficacy of a Cognitive Social Support (CSS) group protocol designed to mitigate the disaster stress of adolescents who had been exposed seriously to Hurricane Hugo. A purposive sample of 259 students participated in and evaluated the CSS. This article reports the specific structure, content, process, rationale, and cost of the CSS. Evaluations indicated that 82% of the students evaluated the small-group component of the CSS as "very good" or "excellent," while 70% rated the large-group component as "very good" or "excellent."

Adolescent↗

Bladder retraining.

Explore the source record for details and available documents.

Humans↗

[Interest and limit of a free light chain immunoassay in serum and urine for the diagnosis and the follow-up of monoclonal dysglobulinemia].

This work aims to define the interest and the limits of free light chain (FLC) determination in serum and urine for the investigation of monoclonal gammopathies. Based on the study of nine typical cases extracted from laboratory practice, the authors demonstrate the interest of this determination for the diagnosis and the monitoring of FLC and non secretory myelomas. This test is also useful for the evaluation of response to chemotherapy and the early detection of relapses in intact immunoglobulin multiple myelomas. These results are discussed in the light of the literature with a special emphasis on AL amyloidosis and monoclonal gammapathy of undetermined significance (MGUS). Finally the authors underline some limitations leading to an overestimation of the results in certain patients together with the difficulty to interpret data when a renal damage is associated.

Aged↗