Anti-heart antibodies in postpericardiotomy syndrome: cause or epiphenomenon? A prospective,longitudinal pilot study

OBJECTIVES: To assess the role of anti-heart antibodies (AHA) in postpericardiotomy syndrome (PPS) and the timing of their appearance in relation to the initial manifestations of PPS. DESIGN AND SUBJECTS: Twenty patients who were scheduled to undergo elective coronary artery bypass grafting (CABG) were enrolled in a prospective, longitudinal pilot study. METHODS: Serum was sampled for AHA on the day prior to surgery and at regular intervalsfollowing surgery in all patients. In those who developed PPS, the serum AHA was determined on the day that typical clinical manifestations of PPS appeared and at regular intervals following the onset of PPS. RESULTS: All patients were negative for AHA on the day precedingsurgery. Three(15%) patients developed PPS. Their sera were negative for AHA on the day they were diagnosed as sufferingfrom PPS and the sera became positive for AHA within 14 days from the time of diagnosis. The intensity of immunofluorescence decreased markedly 30 days afterwards and AHA had disappeared within 90days after diagnosis of PPS. The other 17 (85%) patients were negative for AHA prior to surgery and remained so during the six-month postoperative follow-up period. CONCLUSION: The findings of this study suggest that serum AHA may not play a causal role inthe pathogenesis of PPS, but may rather be an epiphenomenon, reflecting an immune response to pericardial and/or myocardial injury.     

Cathepsin L plays an active role in involution of the mouse mammary gland.

Involution of the mammary gland after weaning occurs in two stages. The first stage is reversible, whereas the second stage is characterized by the irreversible collapse of the alveolar structure. A differential display analysis using cDNAs from tissues obtained at various times after forced weaning of pups identified cathepsin L as up-regulated during early involution. Levels of cathepsin L mRNA were dramatically increased within 24 hr after weaning. Cathepsin L protein detected by immunoblot was also increased during involution, reaching near maximal levels by 36 hr after weaning. In situ immunohistochemistry detected pronounced cathepsin L protein in the cytoplasm and cell periphery. Mice treated with a specific inhibitor of cathepsin L exhibited substantially reduced numbers of apoptotic cells at times up to 72 hr after weaning when compared with untreated animals. The cathepsin L inhibitor did not alter levels of cathepsin L detected in immunoblots or influence molecular weight of the cathepsin L species detected. These data suggest that cathepsin L plays a regulatory role early in the process of mammary gland involution.     

Genetic polymorphisms in mouse genes regulating age-sensitive and age-stable T cell subsets

To see whether genetic polymorphisms regulate inter-individual differences in T cell subset levels, we have conducted a genome scan in two populations of mice, bred as the progeny of a cross between CB6F1 females and C3D2F1 males. The data document quantitative trait loci (QTL) with statistically significant effects on CD4, CD8, and CD8 memory T cells, and on subsets of CD4 and CD8 T cells that express P-glycoprotein. Some of the loci detected were robust, in the sense that they produced effects of similar size both in mated female mice, and in a population that included male and female virgin animals. Some of the effects were stable, in that they were apparent at both 8 and 18 months of age, but others were age-specific, showing effects either at 8 or at 18 months but not at both ages. Genes that had an effect on the same T cell subset were in almost all cases additive rather than epistatic, and their combined effects could produce large overall effects, leading in the most dramatic case to a two-fold difference in CD8 memory cells. The analysis also documented two QTL, on chromosomes 4 and 13, that regulate an age-sensitive composite index of T cell subset pattern which has been shown previously to be a predictor of life expectancy in these mice. The analysis thus reveals both subset-specific genes and others which modulate the overall pattern of age-sensitive changes in T cell subset distributions.     

Screening protocol for Torulopsis (Candida) glabrata.

A screening test has been developed for the presumptive identification of Torulopsis (Candida) glabrata from other common clinical isolates of yeast-like fungi. An interlaboratory comparison of a protocol consisting of morphology on cornmeal Tween 80 agar and trehalose fermentation at 42 degrees C was successful in differentiating T. glabrata from other taxa that are frequent or possible clinical isolates. The screening results for 517 clinical yeast isolates, 241 of which were T. glabrata, were compared with their final identification via commercial systems (API20C Yeast Identification System [bioMERIEUX, Hazelwood, Mo.] and Rapid Yeast Identification Panel [Dade Microscan, Sacramento, Calif.]). The trehalose screening test has a sensitivity and a specificity of 97.8 and 95.8%, respectively, and a positive predictive value of 97.4% and a negative predictive value of 96.5%. Overall, the trehalose screen had an efficiency rating of 93.9% for ruling in or out T. glabrata. Since T. glabrata represents a substantial part of the workload in a clinical laboratory, a significant reduction in direct and indirect costs should be realized.     

Mantle cell lymphoma disguised as marginal zone lymphoma

We report a case of mantle cell lymphoma histologically indistinguishable from marginal zone lymphoma. An 83-year-old man presented with a 9.0-cm, slowly enlarging axillary mass. Microscopically, the neoplastic process was largely interfollicular, surrounding residual follicular centers, some of which had discernible small lymphocyte mantles. Overall, the morphologic pattern was highly suggestive of marginal zone lymphoma. However, flow cytometric and immunohistochemical results, including cyclin D1 positivity, revealed an immunophenotype that fit with mantle cell lymphoma. The differential diagnosis of mantle cell lymphoma is broad, and it is well known that mantle cell lymphoma can assume a number of histologic appearances, including, infrequently, that of more indolent B-cell non-Hodgkin lymphomas. Although not pathognomonic, cyclin D1 positivity is highly specific for mantle cell lymphoma and is key in distinguishing these clinically dissimilar malignant lymphomas. In recent years, detection of cyclin D1 has expanded the recognizable histologic spectrum of mantle cell lymphoma.     

Differences in leisure-time physical activity levels between blacks and whites in population-based samples: The Minnesota heart survey

Energy expenditure in leisure-time physical activity (LTPA) was measured using the Minnesota LTPA Questionnaire in 35- to 74-year-old black and white residents of Minneapolis-St. Paul, Minnesota. Estimates of the geometric mean LTPA energy expenditure were 129 and 204 kcal per day for black and white men (p<.05) and 91 and 123 kcal per day for black and white women (p<.05). The percentage of individuals expending 2000 kcal or more per week in LTPA was significantly lower in black men than white men (25 vs. 35%; p=.01) but was not different in black versus white women (18 vs. 17%). Although black men and women reported greater occupational physical activity than their white counterparts, LTPA and job activity were unrelated in all race and sex groups. In both races, LTPA energy expenditure declined with age. LTPA increased with level of formal education, and the largest LTPA difference between blacks and whites was observed in those who had a high-school diploma or less. Blacks had lower participation rates than whites in most of the individually assessed physical activities. Additional research is needed on the determinants and promoters of LTPA in population subgroups.The research was funded by National Heart, Lung, and Blood Institute Research Grant R01 HL 23727 and National Research Award T32 HL 07328-10.     

Evolution of a near-triploid karyotype in a secondary erythroleukemia

We report a case of erythroleukemia (EL;FAB M6), preceded by a myelodysplastic phase, in a 50-year-old male 8 years after treatment for Hodgkin's lymphoma. Cytogenetic analysis of bone marrow at time of diagnosis of EL revealed three cell lines: 1) 28 of 53 cells (53%) were hypodiploid, 43,XY,-5,-7,-12; 2) 23 of 53 cells (43%) were near-triploid, stemline 67-69,XY,+2,del(5)(q11.2),+del(5)(q11.2),+6,-7,+8,-9,-11,-12,+15,-16,der (17)t (17;?) (p11.2;?),-18,-20,-20,+22,+r, + mar (relative to a complete triploid cell); 3) 2 of 53 cells (4%) were normal 46,XY. The relative monosomies of 5, 7, and 12 in both abnormal lines suggest that the near-triploid line evolved from the hypodiploid line. A single hypodiploid cell with both del(5) and der(17) chromosomes that appeared identical to those in the near-triploid line suggests that polyploidization occurred after these structural rearrangements. While EL is not characterized by any well-defined structural abnormality, reported cases are frequently hypodiploid, with occasional cases of polyploidization, as in our patient, EL in adults without previous neoplasia or recognized mutagenic exposure has been shown to have loss or deletion of chromosomes 5 and 7, also characteristic of myelodysplastic syndromes and secondary leukemia. Our patient had a relative lack of chromosomes 5 and 7 in both abnormal clones, as well as a del(5)(q11) in the near-triploid line. This case of EL clearly demonstrates the evolution of a complex near-triploid line from a hypodiploid line, with chromosome abnormalities typical of both EL and secondary leukemia.     

Immunogenicity and antigenicity of chimeric picornaviruses which express hepatitis A virus (HAV) peptide sequences: evidence for a neutralization domain near the amino terminus of VP1 of HAV.

We evaluated the antigenic characteristics of chimeric picornaviruses created by inserting peptide sequences from hepatitis A virus (HAV) capsid proteins into the B-C loop of VP1 of Sabin strain type 1 poliovirus (PV-1). Fifteen viable chimeras were generated. Each retained the ability to be neutralized by polyclonal PV-1 antisera. Two chimeras (H15 and H2) stimulated production of low levels of HAV neutralizing antibodies in immunized rabbits or mice, although in both cases only a small fraction of immunized animals produced this response. The H15 chimera, which contains residues 13-24 of HAV VP1, elicited HAV neutralizing antibodies in three of nine rabbits and at least one of seven immunized mice. These results indicate that a neutralization domain exists in this region of VP1. However, human sera with high titers of antibodies to HAV failed to neutralize or immunoprecipitate this chimera, suggesting the absence of a significant antibody response to this neutralization domain following natural infection. Sera from rabbits immunized with H15 that did not develop HAV neutralizing antibodies contained antibodies reactive with the HAV peptide segment expressed by the H15 virus, indicating substantial differences in the specificities of antibodies elicited by this peptide segment among individual immunized rabbits. The H15 peptide insert was an effective antigen, as indicated by a high level of sensitivity of the H15 chimera to neutralization by a related anti-peptide antibody which was itself devoid of HAV neutralizing activity. One of 16 rabbits immunized with the H2 chimera (residues 101-108 of HAV VP1) developed HAV neutralizing antibodies, confirming both the presence and the highly conformational nature of a neutralization antigenic site involving these residues of HAV.