Multilamelled structures from the lungs of patients with pulmonary alveolar proteinosis

Multilamellated structures (MS), which accumulate in the lungs of patients with pulmonary alveolar proteinosis, were examined under the electron microscope. MS, in general, consisted of alternating light and dark lamellae arranged concentrically about membranous vesicles or electron-dense bodies. The darker osmiophilic lamellae consisted of trilaminar membranes 80 to 100 A thick, and the lighter lamellae, which varied from 150 to 300 A in width, appeared amorphous. MS made up 42.6 +/- 12.4% (n = 4) of the total particulate volume present in the pulmonary lavage effluents. MS resembled tubular myelin structures from the lungs of patients, although these latter structures accounted for only 1.6 +/- 2.3% (n = 4) of the total particulate volume. Abnormalities, such as polygonal tubules, irregular tubule dimensions, and large size potential, indicated that tubular myelin structures in the lungs of patients were variable in structure. MS appear to be a form of tubular myelin structure. MS were treated with a variety of disruptive agents and then examined under the electron microscope. Information was obtained about the composition of the MS and the intermolecular forces involved in their three-dimensional organization. Extraction of the MS with acetone or treatment of the structures with phospholipase c resulted in loss of membranes from the structures without a concomitant loss of the intermembranous amorphous material, indicating that phospholipids were a major membrane component. Analysis of phospholipids in the acetone extracts of the MS revealed that the membranes consisted of 45% phosphatidylcholine and that the major fatty acid of the phosphatidylcholine was palmitate (76%). The amorphous material of the intermembranous spaces consisted primarily of protein, since it was destroyed by the proteases trypsin and pronase without loss of the membranes. Reducing agents such as mercaptoethanol and dithiothreitol were disruptive, indicating the importance of disulfide bridges between the protein constituents in maintaining the integrity of the MS. The significance of hydrophobic interactions between the protein constituents was demonstrated by the disruptive action of chaotropic agents according to the sequence KSCN greater than KI greater than KCl. These data indicate that MS consist of phospholipid membranes organized in a protein matrix maintained by intermolecular disulfide bridges and hydrophobic interactions.     

A real-time drawing study of melt-crystallized ultra-high molecular weight polyethylene. Comparison with conventional X-ray results

In the past morphological changes, caused by uni-axial drawing of flexible polymers have been studied mostly under conditions, quite different from the drawing conditions. This could give rise to certain artefacts, leading to mis-interpretations. Up to now very little was known about this possibility. Therefore, X-ray patterns obtained by conventional drawing studies and by real-time X-ray drawing studies are compared in this paper. It will be shown, that although some results on melt-crystallized polyethylene discussed here show indeed small differences, conventional X-ray studies can be used without any problem for qualitative studies. However, studies of deformation phenomena in elastic deformable regions as well as quantitative X-ray studies require real-time measurements.     

Effects of prior polysaccharide vaccination on magnitude, duration, and quality of immune responses to and safety profile of a meningococcal serogroup C tetanus toxoid conjugate vaccination in adults

Extensive use of meningococcal AC polysaccharide (MACP) vaccines has raised concerns about induction of immunologic hyporesponsiveness to C polysaccharide. We investigated the immunogenicity and safety of a meningococcal C-tetanus conjugate (MCC-TT) vaccine in naive adults and prior MACP vaccinees. Laboratory staff (n = 113) were recruited; 73 were naive to meningococcal vaccination, and 40 had previously received > or =1 dose of MACP vaccine. Blood was taken prior to MCC-TT vaccination and 1 week, 1 month, and 6 months later. At each time point, proportions of subjects with serum bactericidal antibody (SBA) titers of > or =8 or > or =128 were similar (P > 0.46); >94% of subjects achieved titers of > or =128 at 1 month. However, the geometric mean titer (GMT) of SBA at 1 month was higher in the naive (1,757; 95% confidence interval [95% CI], 1,102 to 2,803) than in the previously vaccinated (662; 95% CI, 363 to 1,207) group (P = 0.02), and similarly at 6 months (P < 0.001). Conversely, geometric mean concentrations (GMCs) of serogroup C-specific immunoglobulin G (IgG) were significantly higher in the previously vaccinated group pre-MCC-TT and at 1 week; the groups were similar at 1 month, and there was some evidence that the GMC for the previously vaccinated group was higher at 6 months. Qualitative differences in antibodies between groups were demonstrated by using the SBA/IgG ratio, though avidity measures were similar for the two groups throughout the study. MCC-TT was well tolerated, with similar safety profiles in the two groups. Pain in the arm and headache were the most frequently reported events following vaccination. The study shows that MCC-TT is safe and immunogenic in naive and previously MACP-vaccinated adults, though the magnitude and persistence of postvaccination SBA responses in the latter group were lower.     

The water jet as a new tool for endoprosthesis revision surgery--an in vitro study on human bone and bone cement

In revision surgeries of endoprostheses, the interface between implant and bone cement or bone must be loosened. Conventional tools have many disadvantages because of their size and limited range. Taking advantage of the selective and athermic cutting process, a plain water jet is already used in order to cut soft tissues. This study investigates the possibilities of both a plain and an abrasive water jet as cutting tools for revision surgery. Samples of the mid-diaphysis of human femora and bone cement (CMW3) were cut with a plain water jet (PWJ) and an abrasive water jet (AWJ) at two different jet-to-surface angles (30 degrees,90 degrees ) and at five different pressure levels (30, 40, 50, 60, 70 MPa). For a PWJ a selective pressure range was identified, where only bone cement was cut. Injecting a bio-compatible abrasive (lactose) to the jet stream resulted in significantly higher cut depths in both materials. Material removal in bone was significantly less at the smaller jet-to-surface angle for both techniques. No clear selectivity between bone and bone cement was observed for application of the AWJ. However, the material removal rate was significantly higher for bone cement than for bone at all pressure levels. The results indicate that an AWJ might be an alternative tool for cement removal. The possibility for localised cutting at interfaces could be an advantage for revision of a non-cemented prosthesis.     

Stress and glucocorticoid inhibit apical GLUT2-trafficking and intestinal glucose absorption in rat small intestine

We have proposed a new model of rat intestinal sugar absorption in which high glucose concentrations promote rapid insertion of GLUT2 into the apical membrane, so that absorptive capacity is precisely regulated to match dietary intake. Construction and building work during expansion and refurbishment of our department permitted opportunistic experiments on the effects of building-induced stress on the GLUT2 component of absorption. In fed rats perfused with 75 m m glucose in vivo , stress rapidly inhibited glucose absorption 36.4 ± 3.0% compared with control rats. Selective inhibition of the GLUT2 component with phloretin demonstrated that stress inhibited the GLUT2 component by 42.8 ± 3.8%, which correlated with a corresponding diminution in apical GLUT2 levels: the SGLT1 component and its level were unaltered by stress. Effects of stress were reversed by the administration in drinking water of metyrapone, which inhibits 11-β-hydroxylase. Injection of dexamethasone into control rats 60 min before perfusion resulted in absorption and transporter properties indistinguishable from stressed rats. Our data are consistent with the view that stress activates the hypothalamus–pituitary–adrenal (HPA) axis, causing release of glucocorticoid. The ensuing inhibition of GLUT2 trafficking and absorption seems necessary to prevent enhanced intestinal delivery of glucose to the circulation from antagonizing the essential stress response of glucorticoid in mobilizing peripheral energy stores for emergency purposes.     

European seroepidemiology network 2: Standardisation of assays for seroepidemiology of varicella zoster virus.

BACKGROUND: The aim of the European Sero-Epidemiology Network (ESEN2) is to harmonise the serological surveillance of vaccine-preventable diseases in Europe. OBJECTIVE: To allow comparison of antibody prevalence in different countries by standardising results into common units. STUDY DESIGN: For varicella zoster virus (VZV), a reference laboratory established a panel of 148 samples, characterised by indirect enzyme-immunoassay (ELISA), indirect immunofluorescence, and complement fixation test. Fifty-seven samples were also studied by the fluorescence antibody to membrane antigen test. The geometric mean of the antibody activity (GMAA) obtained from four ELISA determinations was used to characterise each sample of the panel as positive (GMAA: >100 mIU/ml), equivocal (GMAA: 50-100 mIU/ml) or negative (GMAA: <50 mIU/ml) for antibody to VZV (anti-VZV). Thirteen laboratories, using five different ELISA tests, tested the panel. RESULTS: Agreement with the reference laboratory was above 85% in all cases, and the R(2) values obtained from regression analysis of the quantitative results were always higher than 0.87. Finally, the regression equations could be used to convert national values into a common unitage. CONCLUSION: This study confirmed that results for anti-VZV obtained by different ELISA methods can be converted into common units, enabling the comparison of the seroprevalence profiles obtained in the participant countries.     

An antigen processing polymorphism revealed by HLA-B8-restricted cytotoxic T lymphocytes which does not correlate with TAP gene polymorphism

In previous studies of antigen presentation through HLA-B27, we identified a healthy person whose lymphoblastoid cells do not present three B27-restricted viral epitopes to specific cytotoxic T lymphocytes (CTL), despite adequate cell surface expression of HLA-B2702 of normal sequence. Similar findings were observed in all members of his family sharing the HLA-A3-B2702 haplotype. The original donor, NW, carries HLA-B8 on his other class I haplotype, which his daughter, HW, has inherited. We now report a failure to present an HLA-B8-restricted epitope from influenza nucleoprotein following viral infection of NW cells, although exogenous added peptide is still presented normally. However, cells from HW, which do not carry the A3-B2702 haplotype, present the expected epitope after viral infection. Another B8-restricted epitope, from human immunodeficiency virus-gag, is presented equally well by both cell lines when infected with gag-vaccinia. This antigen processing phenotype does not correlate with any of the known human TAP-1 and TAP-2 polymorphisms.     

Nuclear organization of centromeric domains is not perturbed by inhibition of histone deacetylases

It is well established that modification of lysines in histone molecules correlates with gene expression and chromatin structure. It is not known whether this operates entirely at a local level, e.g. through the recruitment of specific proteins, or whether histone modifications might impact on more long-range aspects of chromatin organization. There is a distinctive organization of chromatin within the nucleus and the chromatin at the nuclear periphery of mammalian cells appears to be hypoacetylated. Previously it had been suggested that inhibition of histone deacetylases by TSA causes a gross remodeling of nuclear structure, specifically the recruitment of centromeric heterochromatin to the nuclear periphery. Here, we have quantified the nuclear organization of histone modifications and the localization of centromeric domains in human cells before and after TSA treatment. TSA alters the nuclear distribution of histone acetylation, but not that of histone methylation. TSA elevates levels of histone acetylation at the nuclear periphery but we see no alteration in the position of centromeric domains in the nuclei of treated cells. We conclude that the distinctive nuclear localization of centromeric domains is independent of histone acetylation.     

Plasma-cell dyscrasia with polyneuropathy. The spectrum of POEMS syndrome.

BACKGROUND. The POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome and osteosclerotic myeloma (polyneuropathy and sclerotic bone lesions) may both be manifestations of plasma-cell dyscrasia, but the interrelation of these diseases is not clear. We therefore set out to define the clinical spectrum of disease in patients with plasma-cell dyscrasia and polyneuropathy who have the complete or incomplete form of the POEMS syndrome or osteosclerotic myeloma. METHODS. Among 2714 patients with plasma-cell dyscrasia who were identified between 1973 and 1989, we reviewed the cases of those with polyneuropathy and plasma-cell dyscrasia who fulfilled the criteria for the POEMS syndrome or osteosclerotic myeloma. RESULTS. Thirty-eight patients (1.4 percent) with a median age of 51 years were identified, 22 of whom were male. By definition, all had polyneuropathy (37 combined sensorimotor, and 1 primarily motor). Other findings included osteosclerotic bone lesions (82 percent), skin abnormalities (58 percent), lymphadenopathy (42 percent), papilledema (37 percent), peripheral edema (29 percent), hepatomegaly (24 percent), splenomegaly (21 percent), and ascites (11 percent). Thirty-three patients (87 percent) had an abnormal M protein in serum or urine (17 had IgA lambda, and 12 IgG lambda). Five patients fulfilled all the criteria for the POEMS syndrome. The estimated five-year survival in the 38 patients was 60 percent, which was significantly better than the 20 percent survival in 869 patients with multiple myeloma (P < 0.05). The clinical course was similar among the patients with the complete form of the POEMS syndrome and those with the incomplete form. CONCLUSIONS. Plasma-cell dyscrasia with polyneuropathy is a rare multisystem disease that often presents with osteosclerotic bone lesions. The differentiation of the POEMS syndrome from so-called osteosclerotic myeloma with peripheral neuropathy appears to have no clinical value.