Fc-gamma receptor-ligand interactions enhance macrophage GSIB4-binding activity

Activated macrophages have an increased ability to bind the lectin Griffonia simplicifolia-IB4 (GSIB4). Since macrophages readily use the Fc-receptor (FcR) during several immunologic and inflammatory processes, it is important to determine whether interactions with this moiety affect GSIB4-binding ability. Peritoneal macrophages cultured in vitro with Fc fragments of immunoglobulin G (IgG), whole IgG, or heat-aggregated IgG demonstrate an increase in this function. Conversely, treatment of macrophages with (Fab')2 fractions alone has no direct effect on this activity. Although the GSIB4-binding response is minimally expressed by normal macrophages, it is more markedly apparent on macrophages from LPS-treated animals. In both cases, however, pretrypsinization of the cells renders them refractory to IgG-mediated induction of the GSIB4-binding response. Moreover, macrophages cultured independently with IgG subclasses 1, 2a, or 3 demonstrate that the magnitude of their response to this signal is directly associated with the type of subclass used. Although each subclass enhanced the response, in this study interactions with IgG2a produced the best results. Overall, however, the greatest GSIB4-binding activity is generated when FcRs are crosslinked by aggregated IgG rather than simply bound by independent monomeric interactions at the FcRs. This suggests that the event of appropriately interacting with the FcRs amplifies the GSIB4-binding function. Such a mechanism could play a key role in coordinating the humoral, cell-mediated, and innate responses of the immune system.     

Malignant fibrous histiocytoma of the larynx

Malignant fibrous histiocytomas of the upper respiratory tract are rare, aggressive, mesenchymal neoplasms. There have been sporadic cases reported in the English language literature. This paper reports the case of a subglottic malignant fibrous histiocytoma in a 26-year-old female. A review of the important clinical-pathological features of this type of tumor is presented. The treatment of choice appears to be wide surgical resection of the tumor. Although the published experience is small, it appears that tumors of the subglottic space are characterized by a younger patient population and a better prognosis than those of the larynx.     

Evaluating the capacity to work of the mentally ill

This study explored the relationship between psychiatric symptomatology and the functional capacity to work. Subjects were diagnosed using DSM-III criteria and were grouped into categories of psychotic or nonpsychotic, and disabled or nondisabled, in regard to adjudication for mental impairment from the Social Security Administration (SSA). There were significant relationships between disability status and work capacity, in the direction of better performance for the nondisabled subjects. This finding reflected concordance between the evaluation procedure used in the study and the SSA's disability determination process. There was considerable overlap in work performance among subjects, however, suggesting that a functional assessment of work capacity might improve disability determination in certain cases. Results suggested that these work assessments might be as short as one or two days.     

Foot-ulcer prevention in the elderly diabetic patient.

Diabetic foot ulceration is frequently the result of repetitive trauma, foot deformity, malfunction, or ill-fitting footwear. The failure of such ulcers to heal is most often a consequence of the failure to provide protection from continuing trauma. Risk evaluation of the diabetic patient, with appropriate correction or accommodation of deformity or mechanical pressure, can be expected to reduce the incidence of serious infection secondary to ulceration.     

Discounting of delayed rewards in opioid-dependent outpatients: exponential or hyperbolic discounting functions?

Recent theories of substance abuse have used value discounting of delayed rewards to partly explain the decision to take drugs. Normative-economic theory holds that an exponential function describes the effects of delay on discounting, whereas the matching law posits a hyperbolic discounting function. The ability of these functions to describe 18 human heroin-dependent individuals' monetary- and heroin-reward delay-discounting functions was assessed. In the 1st condition, participants chose between immediate and delayed hypothetical monetary rewards. Delayed rewards were $1,000, and the immediate reward amount was adjusted until choices reflected indifference. In the 2nd condition, participants chose between immediate and delayed heroin (the delayed amount was that which each participant reported he or she could purchase with $1,000). The hyperbolic function produced significantly higher R2 values and significantly lower sums of squared error values. Consistent with previous findings, delayed heroin rewards were discounted at a significantly higher rate than were delayed monetary rewards.     

Characterization of Orbiviruses of the Kemerovo serogroup: Isolations and serological comparisons

Summary Nine Orbiviruses of the Kemerovo serogroup were isolated from ticks collected in seabird colonies situated in the U.K., Faeroe Islands, Norway, Morocco and California, U.S.A. Comparison by serological tests with previously reported members of the Kemerovo serogroup demonstrated that viruses isolated from the hard tick,Ixodes uriae, were members of the Great Island subgroup, whereas viruses from soft ticks,Argas monolakensis andOrnithodoros maritimus, belonged to the Chenuda subgroup. Members of the Chenuda group differed from the Great Island group in their ability to produce plaques inXenopus cell cultures and in the time taken to produce clinical signs in infected mice.