Occurrence of the t(2;5)(p23;q35) in non-Hodgkin's lymphoma

Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study.     

Dural sinus thrombosis: study using intermediate field strength MR imaging

The magnetic resonance (MR) images of six patients with thrombosis of a dural sinus were reviewed. The diagnosis had been verified by computed tomographic scans in three patients and arteriograms in two; in the sixth patient, only MR imaging was used to confirm the clinical syndrome. In all patients, high-intensity signal was seen from the thrombus within the affected dural sinus on all echoes. This persistent signal intensity allowed intravascular clot to be distinguished from normal causes of increased signal such as flow-related enhancement (entry phenomenon) and even-echo rephasing. MR imaging demonstrated the cause of the thrombosis in three patients: two were secondary to adjacent tumors, and one was secondary to unsuspected mastoiditis. Complications such as infarction were also demonstrated. Using MR imaging, one can easily and safely diagnose thrombosis of a dural sinus. MR should be the imaging method of choice in patients suspected of having thrombosis of a dural sinus.     

Cardiac Surgery in Nonagenarians

A bstract Objectives and Background : The purpose of this study was to document our initial experience with patients 90 years of age and older and to determine whether cardiac surgery is justified in this age group. Cardiac surgery in octogenarians has proven to be a successful and worthwhile procedure. A small group of nonagenarians with severe coronary artery disease (CAD) and aortic valve disease refractory to medical therapy have been considered for surgery. Methods : Fourteen patients aged 90 or more underwent cardiac surgery for symptomatic CAD or aortic valvular disease refractory to medical therapy. Eight patients underwent isolated coronary artery bypass grafting (CABG) and six patients underwent aortic valve replacement (AVR). All patients were in NYHA Class IV preoperatively. Results : Hospital mortality occurred in one patient (7%). Hospital morbidity occurred in 10 patients (71%) and included 7 cardiac, 5 neurological, 1 gastrointestinal, 1 infectious, and 1 pulmonary event. All survivors left the hospital symptomatically improved. The mean length of stay was 26 days. Four CABG patients went on to die at a mean of 2 years and 2 months, and 3 remain alive at a mean of 2 years and 4 months. Three AVR patients expired at a mean of 3 years and 4 months, and 3 remain alive at 4 years and 1 month. Conclusions : Cardiac surgery in carefully selected nonagenarians is justified and can be performed with acceptable results.     

Clinical MR imaging with a Helmholtz-type surface coil

Limited-field-of-view radio-frequency receiver antennas provide improved near-field sensitivity for magnetic resonance imaging by decreasing the antenna volume. The Helmholtz-type surface coil, consisting of two flat rings, is an organ-encompassing antenna that takes advantage of this principle to yield an improved signal-to-noise ratio (S/N). The coil was tested in a group of 50 patients and 16 healthy volunteers. Images obtained with the Helmholtz coil demonstrated quantitatively superior S/N of 2.2-fold or greater than that of comparison body coil images, as well as qualitatively superior anatomic resolution.     

Immunolocalization of the Inducible Nitric Oxide Synthase Isoform in Human Fetal Membranes

PROBLEM: Nitric oxide (NO) synthesized by fetal membranes may protect the fetus from maternal infection or immune challenge or have a tocolytic effect on myometrium. The sites of synthesis and enzymes responsible for NO production in human fetal membranes remain unidentified. METHOD OF STUDY: Fetal membranes were obtained from four groups of patients: term (>37 weeks gestation) or preterm (<37 weeks gestation), both either in labor or not in labor. Frozen sections of membrane rolls were immunostained for inducible (iNOS) and endothelial (eNOS) nitric oxide synthase isoforms and the monocyte/macrophage marker CD14. RESULTS: Positive iNOS immunostaining was found in fibroblasts of amnionic and chorionic mesenchyme and in decidual macrophages identified by CD14 from all four groups of tissues. No iNOS immunostaining was seen in amnion epithelium or chorion trophoblast. Very intense iNOS staining was seen with evidence of monocyte/macrophage invasion of membranes. eNOS immunostaining was only found in decidual vascular endothelium. CONCLUSIONS: Constitutive expression of iNOS in decidual macrophages and fetal membrane fibroblasts may form an immune barrier against maternal insult. In chorioamnionitis, macrophage recruitment and NO expression may be part of the maternal immune response.     

Low-artifact intravascular devices: MR imaging evaluation

Flow-phantom magnetic resonance (MR) imaging, with use of both spin-echo (SE) and gradient-echo (GRE) techniques at 1.5 T, was performed on the percutaneous Greenfield (beta-III titanium alloy [TMA wire]), Amplatz (MP32-N alloy), and Simon nitinol filters and TMA wire facsimiles of the bird's nest, Gunther, new retrievable, and Amplatz vena caval filters. SE imaging allowed detection of thrombi as small as 5 X 5 mm trapped within the percutaneous Greenfield, Simon nitinol, and TMA-wire facsimile filters; with the MP32-N Amplatz filter, a larger volume of thrombus (10 X 20-mm clots) was necessary for clot detection. GRE imaging allowed detection of intraluminal tilting of the percutaneous Greenfield and facsimile Amplatz (TMA-wire) filters. GRE imaging was useful for demonstrating postfilter turbulence due to clots, which was greatest for the Amplatz filter. Imaging of facsimile vascular devices made of tantalum or TMA wire did not cause the severe "black-hole" MR artifacts typical of the stainless-steel devices. SE and GRE imaging were very useful for determining caval patency in two patients with previously placed Mobin-Uddin filters. Noninvasive MR evaluation of blood vessels in the presence of a variety of low-artifact intravascular devices appears feasible.     

Evolutionary variants of simian virus 40: characterization of cloned complementing variants.

Three evolutionary variants of simian virus 40 (SV40), cloned by complementation with temperature-sensitive SV40 mutants, have been mapped by restriction endonuclease analysis and by electron microscopic heteroduplex mapping. One of the variants contains a deletion of most of the “late” region of the genome, and the other two contain nonidentical deletions within the “early” region. Each of the variants has a distinctive duplication of a DNA segment which includes the initiation site for DNA replication. Based on the physical maps of these genomes, a recombinational mechanism is suggested for the generation of variants; once generated, encapsidatible molecules with duplications of the replication initiation site would have a selective growth advantage. One variant contains one of its two initiation sites close to the site where SV40-DNA replication normally terminates. In this variant, however, replication appears to terminate 180° from the initiation point. Therefore, unlike initiation, termination of SV40-DNA replication is probably not sequence specific.     

Evolutionary variants of simian virus 40: cloned substituted variants containing multiple initiation sites for DNA replication.

Two cloned evolutionary variants of simian virus 40 (SV40) containing substitutions of cellular DNA have been characterized by restriction endonuclease analysis, electron microscopic heteroduplex mapping, and DNA-DNA hybridization. Each variant genome is made up of a small, tandemly repeated segment of DNA consisting of cellular DNA and that portion of the SV40 genome containing the initiation signal for viral DNA replication. Cellular DNA sequences are different in the two variants, indicating that recombination between cell DNA and SV40-DNA can occur at more than one site. However, one end of the SV40 segment (0.68 SV40 map-units) is the same in each variant. The data suggest that substituted variants arise by integration of SV40-DNA into cellular DNA followed by excision of a small substituted genome which is subsequently amplified to a size compatible with encapsidation; the presence of multiple initiation signals in each molecule results in selective replication.     

Social Determinants and COVID-19 in a Community Health Center Cohort

Associations between social determinants of health (SDOH), demographic factors including preferred language, and SARS-CoV-2 detection are not clear. We conducted a retrospective cohort study among those seeking testing for SARS-CoV-2 at a multi-site, urban community health center. Logistic regression and exact matching methods were used to identify independent predictors of SARS-CoV-2 detection among demographic, SDOH, and neighborhood-level variables. Of 1,361 included individuals, SARS-CoV-2 was detected among 266 (19.5%). Logistic regression demonstrated that SARS-CoV-2 detection was less likely in White participants relative to Hispanic participants (adjusted odds ratio [aOR] 0.18, 95% confidence interval [CI] 0.05–0.46). and more likely in patients who prefer Spanish relative to those that prefer English (aOR 2.04, 95% CI 1.43–2.96). No observed SDOH predicted SARS-CoV-2 detection in adjusted models. A robustness analysis using a matched subset of the study sample produced findings similar to those in the main analysis. Preferring to receive care in Spanish is an independent predictor of SARS-CoV-2 detection in a community health center cohort.