Effect of lymphocyte mediators on macrophages in vitro. A correlation of morphological and cytochemical changes

Sephadex purified PPD and Con A induced mediator rich fractions (MRF) were applied to guinea-pig macrophages cultured in vitro. At varying times after the addition of the MRF, cells were removed from culture for morphological study and for cytochemical tests. Respiratory enzyme activity and lysosomal acid phos-phatase activity were estimated and the former was quantitated using an integrating microdensitometer. Early changes, 1 hr after MRF contact, were observed and subsequent alterations in activity up to 48 hr after the addition of MRF were also seen. These changes have been related to the inhibition of migration and subsequent `activation' of the macrophages which has been observed morphologically at times up to 3 weeks after MRF addition.

It is suggested that alterations in the cytochemistry of the macrophages after MRF contact could help explain changes in the behaviour of the cells under these experimental conditions.

     

The newer unconventional indications of permanent pacemakers

In recent years, the indications for permanent pacemakers have expanded. The interest has focussed on hypertrophic cardiomyopathy, dilated cardiomyopathy and a new entity called hypertensive hypertrophy with cavity obliteration (HHCO). Pacemaker therapy is establishing itself for the prevention of atrial fibrillation. Pacing for neurocardiogenic syncope with newer pacing mode has encouraging datas. Pacemaker for long QT syndrome, after cardiac transplant and for haemodynamic improvement in occasional cases of first degree atrio-ventricular block is getting attention. The AHA and ACC guidelines updated in 1998 for implantation of cardiac pacemakers, now include several of these newer indications.     

Water-clear cell adenoma of the parathyroid gland: a rare entity

Water-clear cell hyperplasia is a rare but well-documented cause of primary hyperparathyroidism. Parathyroid adenomas of water-clear cell type are exceptionally rare, and only five case reports are available at present in the medical literature. We report an additional case of water-clear cell adenoma of the parathyroid gland, and the differential diagnoses are discussed.     

Linkage analysis of SLE susceptibility: confirmation of SLER1 at 5p15.3

We detected a novel susceptibility gene, SLER1, for systemic lupus erythematosus (SLE) at 5p15.3.(1) This finding was based on a selected subgroup of SLE families, where two or more family members have had alleged rheumatoid arthritis (SLE-RA). The main objective of this study was to replicate the linkage at 5p15.3 based on an independent data set of 88 SLE-RA families. Heterogeneity in the genetic model led us to use a nonparametric allele-sharing method. Since our a priori hypothesis of linkage at 5p15.3 was fixed, we genotyped six markers at the linked region. Our new results replicate the initial linkage at 5p15.3 (Zlr=2.58, P<0.005, LOD=1.45). Moreover, evidence of linkage was sustained when analysis was restricted to the subset of SLE families who had 3 or more individuals with alleged RA (Zlr=3.32, P=0.008, LOD=2.40) The results of our previous findings, together with these new results, confirm the SLER1 linkage at 5p15.3. Our results also demonstrate the utility of clinically defined subgroup analysis for detecting susceptibility loci for complex genetic diseases, such as SLE.     

An improved method for utilization of peptide substrates for antibody characterization and enzymatic assays

Synthetic peptides have become an important tool in antibody production and enzyme characterization. The small size of peptides, however, has hindered their use in assays systems, such as Western blots, and as immunogens. Here, we present a facile method to improve the properties of peptides for multiple applications by ligating the peptides to intein-generated carrier proteins. The stoichiometric ligation of peptide and carrier achieved by intein-mediated protein ligation (IPL) results in the ligation product migrating as a single band on a SDS-PAGE gel. The carrier proteins, HhaI methylase (M.HhaI) and maltose-binding protein (MBP), were ligated to various peptides; the ligated carrier-peptide products gave sharp, reproducible bands when used as positive controls for antibodies raised against the same peptides during Western blot analysis. We further show that ligation of the peptide antigens to a different thioester-tagged carrier protein, paramyosin, produced immunogens for the production of antisera in rabbits or mice. Furthermore, we demonstrate the generation of a substrate for enzymatic assays by ligating a peptide containing the phosphorylation site for Abl protein tyrosine kinase to a carrier protein. This carrier-peptide protein was used as a kinase substrate that could easily be tested for phosphorylation using a phosphotyrosine antibody in Western blot analysis. These techniques do not require sophisticated equipment, reagents, or skills thereby providing a simple method for research and development.