Hyperventilation as a specific test for diagnosis of coronary artery spasm

Xanthomas may be associated with benign or malignant lymphoproliferative diseases, often with associated hypergammaglobulinema. In human immunodeficiency virus type 1 (HIV-1) disease, there is a high lymphoproliferative rate despite the immunodeficiency and increased cell death. We report three HIV-1-positive patients with facial papular xanthomatosis eruptions associated with hypergammaglobulinema, and an immunoglobulin A (IgA) gammopathy. Histopathologic features include lipid-laden macrophages, extracellular nuclear dust with phagocytosized nuclear debris, and hyalinization with areas of hyaline necrosis of collagen fibers. These distinctive papular xanthomas may be a marker of HIV-1 disease and of a pattern of immunodysregulation, immunodeficiency, and lymphoid proliferation seen in HIV-1 disease.     

A hidden immunoglobulin G2 in patients with rheumatoid arthritis detected by nuclear magnetic resonance

OBJECTIVE: The ratios of immunoglobulin (Ig) G1 and IgG2 in patients with rheumatoid arthritis (RA) were examined by nuclear magnetic resonance (NMR) and the results were compared to data obtained by ELISA. METHODS: The IgG of 11 patients with RA were prepared with a DE-52 column and the specific signals for IgG1 and IgG2 were measured by NMR. The ratios of IgG1 and IgG2 were determined by the intensity of this signal. The samples were also measured by ELISA. RESULTS: The ratios of IgG2 in patients with RA measured by NMR were increased significantly compared to controls. However, there were no significant differences in the data determined by ELISA. Thus, a discrepancy exists in the analysis of IgG2 ratios between NMR and ELISA methods. CONCLUSION: There was a discrepancy in the IgG2 ratios of patients with RA between NMR and ELISA methods, and we attribute this to a conformational difference in IgG2 in patients with RA.     

Intrathoracic tracheal reconstruction with a collagen-conjugated prosthesis: evaluation of the efficacy of omental wrapping

Reconstructions of the intrathoracic trachea in 24 dogs were done with the use of 50 mm long collagen-conjugated tracheal prostheses. Omental wrapping was also done in 14 of the dogs (omentopexy group) to evaluate the efficacy of this option in comparison with results in the other 10 dogs (control group). All 24 dogs had uneventful postoperative courses and were killed at 4 weeks or 3, 6, or 12 months after the operation. Better epithelialization and fewer complications, such as mesh exposure and luminal stenosis, were observed in the omentopexy group than in the control group. Angiography and analysis of regenerated blood vessels revealed that vessel ingrowth had started within 4 weeks and that vessel formation reached its maximal point within 6 to 12 months in the omentopexy group. In contrast, revascularization of the subepithelial region in the control group was poor even after 3 months, and vessel formation continued for as long as 12 months. The differences between the two groups were considered to be mainly a result of the speed of blood vessel ingrowth into the regenerated mucosa. We conclude that our prosthesis can be used safely for intrathoracic tracheal reconstruction and that omental wrapping is a useful supplementary method that reduces the occurrence of complications.     

Involvement of CD40 ligand-CD40 and CTLA4-B7 pathways in murine acute graft-versus-host disease induced by allogeneic T cells lacking CD28

The blockade of B7, using B7 antagonists such as anti-CD80 and/or -CD86 mAbs or CTLA4Ig in vivo, has been shown to induce an efficient suppression of T cell-mediated immune responses in allograft, allergy, and autoimmune models. However, this treatment does not result in complete tolerance. In this study, we examined CD28-B7-independent activation pathways in the pathogenesis of graft-vs-host disease (GVHD) using allogeneic T cells from CD28-deficient mice. Acute GVHD was induced in the absence of CD28 on donor T cells and its manifestations were obvious in the lymphoid tissues. The CD28-independent GVHD was significantly improved by treatment with anti-CD40 ligand (CD40L) mAb. In contrast, treatment with anti-CD80 plus anti-CD86 mAbs exacerbated the clinical manifestations of GVHD and increased the T cell response against host alloantigen, resulting in the expression of CTLA4, CD40L, and CD25 on splenic T cells. These data suggested that the CD40L-CD40 pathway significantly contributed to the CD28-independent pathogenesis of acute GVHD, whereas the CTLA4-B7 pathway acted protectively in the development of GVHD. These results imply that selectively blockading CD28, instead of disrupting both CD28 and CTLA4, would be a better therapeutic strategy for GVHD. Additionally, the simultaneous use of CD40 antagonists may be advantageous.     

Effect of transfection with a superoxide dismutase expression plasmid on xanthine/xanthine oxidase-induced cytotoxicity in cultured rat lung cells

We inserted human Cu, Zn-superoxide dismutase (hSOD) cDNA into the eukaryotic expression plasmid (pRc/CMV) under the control of the cytomegalovirus promoter. The hSOD expression plasmid (pRc/CMV-SOD) was transfected in L2 cells by mean of lipofection. The intracellular SOD activity in pRc/CMV-SOD transfected cells (CMV-SOD cells) was about twice that in host cells. However the level of extracellular SOD activity was similar in CMV-SOD and host cells. When exposed to xanthine (X)/xanthine oxidase (XO) to generate active oxygen species, significantly more CMV-SOD cells than host cells survived. The production of lipid peroxidation in host cells significantly increased in the presence of X/XO, but that in CMV-SOD cells did not change. Thus, transfection with SOD gene effectively prevented X/XO-induced cytotoxicity. The results indicated that increasing the level of intracellular SOD activity protected cells against extracellular superoxide anion stress.     

Photoconductivity analysis of chromium and oxygen-related levels in semi-insulating GaAs

Semi-insulating GaAs doped with different amounts of Cr and oxygen has been characterized by extrinsic photocon-ductivity spectra at room temperature. The shape of the spectrum depends on the amount of Cr and oxygen dopant. It is interpreted by the two-level model which assumes the lattice relaxation effect at the Cr and oxygen-related levels. The height of the photoconductivity hump around 0.9 eV depends on the concentration ratio of Cr to oxygen; the larger the ratio is, the higher the hump is.     

Regulation of tissue plasminogen activator production in cultured human fetal mesangial cells

This study was designed to determine the persistence of culturable bacteria versus DNA in the presence of a middle ear effusion in a chinchilla model of otitis media. Cohorts of animals were either infected with an ampicillin-resistant Haemophilus influenzae strain or injected with a tripartite inoculum consisting of freeze-thawed Streptococcus pneumoniae; pasteurized Moraxella catarrhalis; and DNA from H influenzae. The H influenzae-infected animals displayed culture positivity and polymerase chain reaction positivity through day 35. In the chinchillas infected with the low-copy number inocula of S pneumoniae, DNA was not detectable after day 1 from the co-inoculated pasteurized M catarrhalis bacteria or the purified H influenzae DNA; however, amplifiable DNA from the live low-copy number bacteria persisted through day 21 even though they were not culture-positive past day 3. These results demonstrate that DNA, and DNA from intact but nonviable bacteria, does not persist in an amplifiable form for more than a day in the presence of an effusion; however, live bacteria, while not culturable, persist in a viable state for weeks.