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Biomedical subjects

M Benson

Publications and source records attributed to M Benson.

136 records · Page 8Linked to original sources

The SJL/J mouse: a new model for spontaneous age-associated amyloidosis. I. Morphologic and immunochemical aspects.

A high incidence of spontaneous amyloidosis is described in SJL/J mice. Amyloid was detected as early as 30 weeks of age and the incidence rose to 90 per cent by 60 weeks of age. Amyloid deposits were most prominent in the perifollicular zones of the spleen and the lobular areas of the liver. Ultrastructural analysis revealed rigid, nonbranching fibrils indistinguishable from those observed in casein-induced murine amyloidosis. On the other hand, immunochemical studies indicated that amyloid deposits in SJL/J mice differ from those found in casein-treated CBA mice with respect to size, amino acid content, and antigenic properties. Since the SJL/J mouse also develops spontaneous reticulum cell tumors and serum M components, it appears to be a useful model for study of the pathogenesis of amyloidosis and its relationship to aging, neoplasia, and certain B-cell dyscrasias.

Age Factors↗

Disaster triage: START, then SAVE--a new method of dynamic triage for victims of a catastrophic earthquake.

Triage of mass casualties in situations in which patients must remain on-scene for prolonged periods of time, such as after a catastrophic earthquake, differs from traditional triage. Often there are multiple scenes (sectors), and the infrastructure is damaged. Available medical resources are limited, and the time to definitive care is uncertain. Early evacuation is not possible, and local initial responders cannot expect significant outside assistance for at least 49-72 hours. Current triage systems are based either on a shorter time to definitive care or on a longer time to initial triage. The Medical Disaster Response (MDR) project deals with the scenario in which specially trained, local health-care providers evaluate patients immediately after the event, but cannot evacuate patients to definitive care. For this type of scenario, a dynamic triage methodology was developed that permits the triage process to evolve over hours or even days, thereby maximizing patient survival and resulting in a more efficient use of resources. This MDR system incorporates a modified version of "Simple Triage and Rapid Treatment" (START) that substitutes radial pulse for capillary refill, coupled with a system of secondary triage termed, "Secondary Assessment of Victim Endpoint" (SAVE). The SAVE triage was developed to direct limited resources to the subgroup of patients expected to benefit most from their use. The SAVE assesses survivability of patients with various injuries and, on the basis of trauma statistics, uses this information to describe the relationship between expected benefits and resources consumed. Because early transport to an intact medical system is unavailable, this information guides treatment priorities in the field to a level beyond the scope of the START methodology. Pre-existing disease and age are factored into the triage decisions. An elderly patient with burns to 70% of body surface area is unsalvageable under austere field conditions and would require the use of significant medical resources-both personnel and equipment-and would be triaged to an "expectant area." Conversely, a young adult with a Glasgow Coma Scale score of 12 who requires only airway maintenance would use few resources and would have a reasonable chance for survival with the interventions available in the field, and would be triaged to a "treatment" area. The START and SAVE triage techniques are used in situations in which triage is dynamic, occurs over many hours to days, and only limited, austere, field, advanced life support equipment is readily available. The MDR-SAVE methodology is the first systematic attempt to use triage as a tool to maximize patient benefit in the immediate aftermath of a catastrophic disaster.

Abdominal Injuries↗

Increase of the soluble IL-4 receptor (IL-4sR) and positive correlation between IL-4sR and IgE in nasal fluids from school children with allergic rhinitis.

Soluble cytokine receptors (SCR) can either act as inhibitors, by competitively inhibiting cytokines from binding to their membrane-bound receptors, or as enhancers, by serving as cytokine carriers. We have previously found that the levels of the Th2 cytokines interleukin (IL)-4, IL-5, IL-6, and IL-10 were positively correlated to eosinophils and IgE in nasal fluids from 60 children with seasonal allergic rhinitis. In this study, nasal fluids were reexamined to analyze IL-4sR, IL-6sR, IL-1 beta, TNF-alpha, IL-1sR2, TNF-sR1, and TNFsR2 in relation to eosinophils, neutrophils, ECP, and IgE. In allergic patients IL-4sR increased significantly during the pollen season, and weak, but positive correlations with IgE and eosinophils were found (r = 0.45, P < 0.001 and r = 0.4, P < 0.001 respectively). By contrast, none of the other SCR showed increases or correlations with IgE. However, positive correlations between IL1 beta, TNF-alpha, IL-6sR, IL-1sR2, TNF-sR1, TNF-sR2, and either neutrophils or ECP were found. Also, in healthy controls, these cytokines and their receptors were positively correlated to neutrophils or ECP. Thus, increased levels of the soluble IL-4 receptor, as well as IgE, were specifically associated with allergic rhinitis, whereas all other SCR correlated with either inflammatory cells or their products, in both allergic and healthy subjects. These results may suggest that SCR in vivo act as cytokine enhancers, rather than inhibitors.

Adolescent↗

A prospective comparative clinical analysis of the first-generation knee replacements: polycentric vs. geometric knee arthroplasty.

A prospective study of 119 polycentric and 92 geometric knee replacements was performed to determine and compare the clinical effectiveness of these two prostheses. All kneex were followed for a minimum of 2 years and a mean time of 3 1/2 years (2--6 years). Data were collected using a specially designed proforma for subsequent computer analysis. Failure occurred in 11% of the polycentric and in 16% of the geometric knees. Males (8 of 47) and patients with osteoarthritic knees (22 of 68) failed most frequently. Both prostheses provided excellent relief of pain, the same degree of flexion and improvement in flexion contracture. However, walking, function, alignment, stability, muscle strength and patellar mobility varied as to the degree of improvement and the type of prosthesis. Present results with prosthetic knee replacement using a completely new operative technique can be used as a basis for comparison with other contemporary and future arthroplasty designs.

Adolescent↗

An immunoassay for anti-neuronal antibodies associated with involuntary repetitive movement disorders.

Tourette's syndrome (TS) is a complex neurobehavioral disorder emerging in childhood and is characterized by motor and vocal tics of at least one year in duration. In a portion of patients with TS, environmental (non-genetic) factors may either have an etiologic role or act to modulate the phenotype. One possible environmental factor may be antibodies to central nervous system cells, as sera from several children diagnosed with either TS or Sydenham's chorea contained anti-neuronal antibodies. Using enriched membrane preparations isolated from HTB-10 neuroblastoma cells, a sensitive and specific assay was developed for the determination of human anti-neuronal antibodies associated with involuntary repetitive movement disorders. This assay exhibited between-run and within-run precision of 11.3 percent and 5.9 percent, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of this assay for the diagnosis of TS and TS or chorea are 79.1 percent, 61.2 percent, 61.6 percent, 78.8 percent, and 71.1 percent, 60.9 percent, 68.6 percent, and 63.6 percent, respectively. In addition, there was a significant difference (p < 0.0001) between the mean optical density in the patients with TS and children determined to be clinically "normal".

Autoantibodies↗