In vivo Junin virus-mouse macrophages interaction

The role of mononuclear phagocytic cells in extraneural infection of the mouse with Junin virus (JV) was studied. Endpoint susceptibility (4 days of life) was evaluated by intraperitoneal (i.p.) inoculation of suckling mice. By means of immunofluorescence (IF) and C3 receptor assays, it was found that macrophages were permissive to viral replication in vivo and fostered the recruitment of inflammatory cells as evidenced by the absence of C3 marker. In support, in vitro infection failed to induce alterations of this receptor. Throughout, both in vivo and in vitro, there were no signs of C3-mediated phagocytosis. Silica treatment had no effect on either resistance or susceptibility, suggesting that the "macrophage-barrier" failed to hinder or favour the course of disease. Differences with other JV models are discussed.     

The Electron Microsopic Features of Sinus Histiocytosis with Massive Lymphadenopathy: A Study of 11 Cases

Eleven cases of sinus histiocytosis with massive lymphadenopathy (SHML) involving lymph nodes were studied electron microscopically. Histiocytes were the most conspicuous element of the infiltrate. They could be divided into small and large forms, although transitions were apparent among them. Most of the small histiocytes were located in the medullary cords. The large histiocytes were predominantly seen within sinuses and were subdivided into two types on the basis of their appearance. The most distinctive feature of these histiocytes was the presence of lymphocytes, plasma cells, and neutrophils within their cytoplasm. Other cells present in the infiltrate were lymphocytes, plasma cells, and occasional neutrophils and mast cells. Blood vessels were prominent throughout. Virus particles, bacteria, and Langerhans granules were consistently absent. No morphologic clues were provided by this study as to the etiology of this disorder.     

Affiliation to mature B cell repertoire and positive selection can be separated in two distinct processes

Using an 'oligoclonal' model, we have previously shown that mice transgenic for a mu chain (H3) and deficient for kappa chain expression display a mature B cell repertoire largely dominated by the H3/lambda1 pair, while the four H3/lambda available combinations can be observed in the immature B cell compartment. This led us to propose the existence of a positive selection process. To test this hypothesis, we have introduced the SJL lambda locus coding for a defective lambda1 chain (lambda1(s)) that creates a dysfunctional Ig receptor complex during B cell differentiation. Our results show that the lambda1(s) defect impairs the development of mature B cells when the H3-mu transgene insert is present in the hemizygous state. This suggests that the Gly --> Val substitution present in the C(lambda)1(s) chain at position 155 is sufficient to abrogate the selection of the H3/lambda1 pair. Unexpectedly, when the H3-mu transgene array is present in a homozygous state in lambda1(s) mice but not in 'wild-type' lambda1 mice (lambda1(+)), a significant number of mature B cells expressing all H3/lambda combinations can be developed. These results indicate that the overriding H3/lambda1 dominance observed in lambda1(+) mice is due to a positive selection process and not to a negative selection of other H3/lambda combinations. They also show that the export of B cells to the periphery can be controlled by the expression of the mu chain.     

Allotypic restriction of the expression of MOPC460 idiotope after immunization with either anti-2,4-dinitrophenyl (DNP) or anti-idiotypic antibodies

The MOPC460 idiotype is expressed in mice with the IghCa allotypic haplotype after anti-2,4-dinitrophenyl (DNP) immunization. We have previously shown that two monoclonal syngeneic anti-idiotypic antibodies (IDM 92-13 and IDM 41-27) define two distinct idiotopes (the 460.92 and the 460.41) on the M460 idiotype. The current study demonstrates that only one idiotope (460.92) is recurrently expressed after antigen immunization in IghCa positive mice and also that, immunization against the monoclonal anti-idiotypic molecules induces the synthesis of 460.92 idiotope positive anti-DNP antibodies. However, the detection of such molecules is only possible when animals with the IghCa allotypic haplotype are immunized with the IDM 92-13 molecules. Immunization of mice with either of the two monoclonal anti-idiotypic antibodies never results in the synthesis 460.41 positive molecules. Therefore, whatever protocol of immunization used, the expression of 460.92 was allotypic restricted.     

Post traumatic brain perfusion SPECT analysis using reconstructed ROI maps of radioactive microsphere derived cerebral blood flow and statistical parametric mapping

Background  

Assessment of cerebral blood flow (CBF) by SPECT could be important in the management of patients with severe traumatic brain injury (TBI) because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia), or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets.     

Initial evaluation of a continuous speech recognition program for radiology

The aims of this work were to measure the accuracy of one continuous speech recognition product and dependence on the speaker's gender and status as a native or nonnative English speaker, and evaluate the product's potential for routine use in transcribing radiology reports. IBM MedSpeak/Radiology software, version 1.1 was evaluated by 6 speakers. Two were nonnative English speakers, and 3 were men. Each speaker dictated a set of 12 reports. The reports included neurologic and body imaging examinations performed with 6 different modalities. The dictated and original report texts were compared, and error rates for overall, significant, and subtle significant errors were computed. Error rate dependence on modality, native English speaker status, and gender were evaluated by performing ttests. The overall error rate was 10.3 +/- 3.3%. No difference in accuracy between men and women was found; however, significant differences were seen for overall and significant errors when comparing native and nonnative English speakers (P = .009 and P = .008, respectively). The speech recognition software is approximately 90% accurate, and while practical implementation issues (rather than accuracy) currently limit routine use of this product throughout a radiology practice, application in niche areas such as the emergency room currently is being pursued. This methodology provides a convenient way to compare the initial accuracy of different speech recognition products, and changes in accuracy over time, in a detailed and sensitive manner.     

Leukemic transformation in patients with the 5q- alteration: analysis of the behavior of the 5q- clones in preleukemic to leukemic phases

Serial cytogenetic studies have been performed in four patients with myelodysplastic syndromes. In all four a 5q- alteration was present, but with a different pattern of presentation. One patient presented 5q- as the only alteration since diagnosis; two patients acquired this alteration during the course of the disease; and the fourth showed a 5q- plus other alterations since the first cytogenetic study. Likewise, three of the four patients showed a clone with trisomy 8 and without 5q-. According to these observations and others from the literature with similar cytogenetic behavior, we have analyzed the following points: 5q- as a primary event and as the only alteration, 5q- as a secondary event, 5q- plus other alterations, and presence of cytogenetically different clones. Analysis of these points suggests that the 5q- alteration can represent an early mutation conferring a slow capacity of expansion to the affected clones, with the possibility of cytogenetic evolution during the progression of the disease (about 30% of the patients). Likewise, the association of trisomy 8 clones with 5q- clones can be a nonrandom event.     

Schizophreniform disorder: a diagnostic dilemma

The DSM-III diagnostic criteria for schizophreniform disorder, mainly based on duration of symptoms, are insufficient to furnish a good treatment strategy. In recent literature, schizophreniform disorder has been grouped either with the schizophrenias or with the affective disorders. Scandinavian researchers have described two other groups of psychotic disorders that resemble schizophreniform disorder. These are the reactive psychosis and the cycloid psychosis. They were found to be different from the schizophrenias and the affective disorders. "Good prognosis" schizophrenia, which has been extensively studied and reported in the literature, is clinically very similar to schizophreniform disorder. The relatively consistent data collected in patients with good prognosis schizophrenia may provide the basis for the additional diagnostic criteria needed in DSM-III schizophreniform disorder.     

Genomic and Pathologic Findings for Prototheca cutis Infection in Cat

Severe nasal Prototheca cutis infection was diagnosed postmortem for an immunocompetent cat with respiratory signs. Pathologic examination and whole-genome sequencing identified this species of algae, and susceptibility testing determined antimicrobial resistance patterns. P. cutis infection should be a differential diagnosis for soft tissue infections of mammals.