Increased occurrence of PGP 9.5-immunoreactive epidermal Langerhans cells in rat plantar skin after sciatic nerve injury

This study examines the occurrence and distribution of epidermal dendritic cells (DCs) in cryostate sections from plantar skin in normal rats and in rats with a crush injury or neurotomy and suture of the sciatic nerve. The dendritic cells were visualized with antibodies against protein-gene product 9.5 (PGP 9.5). Counts under the fluorescence microscope showed that the occurrence of dendritic cells is increased and that the proportion of dendritic cells in the basal layer is elevated 3 months after sciatic neurotomy and suture but not after a crush lesion. The countings also revealed that the number of cells is elevated as soon as 1 week after neurotomy and suture. Labelling with specific antibodies showed that the dendritic cells examined represent Langerhans cells (LCs). These observations show that there is a neural influence on the occurrence and distribution of PGP 9.5-immunoreactive epidermal Langerhans cells. Whether this influence is direct or indirect remains to be ascertained.     

Rapid detection of the hypertension-associated A1166C polymorphism of the angiotensin II type 1 receptor (AGTR1)

Screening for polymorphisms in the human type 1 angiotensin II receptor locus (AGTR1) has led to the identification of an A1166C transversion in the 3'-untranslated region. This molecular variant, C(1166), has been linked to essential hypertension. We describe here a rapid method for the detection of this point mutation by a simple modification of PCR amplification with allele-specific oligonucleotides (ASO), so as to avoid a hybridization procedure involving either radioactive- or non-radioactive-labeled probes, labeled primers, or restriction typing. The procedure described is convenient for routine clinical laboratory use with manual sample processing and offers the potential for further automation, as well.     

ATM mutations and phenotypes in ataxia-telangiectasia families in the British Isles: expression of mutant ATM and the risk of leukemia, lymphoma, and breast cancer.

We report the spectrum of 59 ATM mutations observed in ataxia-telangiectasia (A-T) patients in the British Isles. Of 51 ATM mutations identified in families native to the British Isles, 11 were founder mutations, and 2 of these 11 conferred a milder clinical phenotype with respect to both cerebellar degeneration and cellular features. We report, in two A-T families, an ATM mutation (7271T-->G) that may be associated with an increased risk of breast cancer in both homozygotes and heterozygotes (relative risk 12.7; P=. 0025), although there is a less severe A-T phenotype in terms of the degree of cerebellar degeneration. This mutation (7271T-->G) also allows expression of full-length ATM protein at a level comparable with that in unaffected individuals. In addition, we have studied 18 A-T patients, in 15 families, who developed leukemia, lymphoma, preleukemic T-cell proliferation, or Hodgkin lymphoma, mostly in childhood. A wide variety of ATM mutation types, including missense mutations and in-frame deletions, were seen in these patients. We also show that 25% of all A-T patients carried in-frame deletions or missense mutations, many of which were also associated with expression of mutant ATM protein.     

Subspecies-specific distribution of intervening sequences in the Bacillus subtilis prophage ribonucleotide reductase genes

A collection of 212 gram-positive bacilli isolated from natural habitats was screened for the presence of intervening sequences (introns and intein-coding sequences) in the SPbeta prophage-related ribonucleotide reductase genes bnrdE and bnrdF. Three novel configurations were identified on the basis of the presence of (i) intervening sequences in bnrdE and bnrdF, and (ii) an ORF in the bnrdE-bnrdF spacer. Analysis of the cell wall genetic determinants as well as of the incorporation of radio-labelled glycerol into cell wall allowed newly and previously identified B. subtilis strains with different configurations of bnrdE/bnrdF intervening sequences to be assigned to one of two subspecies. Strains apparently belonging to the subsp. subtilis contain three intervening sequences many of which are associated with the putative homing endonuclease activity. Strains of the subsp. spizizenii contain only one or two ORF-less group I introns. Introns occupying bnrdF are confined to the subspecies subtilis.     

The role of rat Crry, a complement regulatory protein, in proliferation of thymocytes

In our previous work we showed that 3F10 monoclonal antibody (mAb), which recognizes the rat complement receptor 1-related/gene protein y (Crry), induces homotipic aggregation of thymocytes. In this work we studied the effect of 3F10 mAb on proliferation of rat thymocytes stimulated with concanavalin A (ConA) or by cross-linking the T cell receptor (TCR) by anti-alphabetaTCR mAb (R73), in vitro, and the mechanisms involved in the process. Our results show that 3F10 mAb stimulates proliferation of total thymocytes triggered by suboptimal concentrations of ConA or TCR cross-linking, in a dose-dependent manner. Maximal stimulation was observed using 10 microg/ml and 20 microg/ml of 3F10 mAb, respectively. The 3F10-induced stimulation of thymocytes proliferation in the presence of ConA, that was followed by increased production of interleukin-2 (IL-2), up-regulation of the expression of IL-2 receptor alpha (IL-2Ralpha) and was inhibited by anti-CD11a and anti-CD18 mAbs. Purified thymocytes did not respond by proliferation to 3F10 mAb, either alone or in combination with R73 mAb or ConA. Proliferation of these cells was achieved only in the presence of OX-6+ antigen-presenting cells (APC) and additional signals transmitted by TCR or ConA. These results suggest that Crry is involved in the LFA-1 dependent proliferation of thymocytes, a phenomenon that has not been recognized so far.     

Analysis of common CFTR polymorphisms 5T, M470V and R75Q in healthy Serbian population

Three common CFTR polymorphisms, 5T, M470V and R75Q, have been shown to be relatively frequent in Serbian patients with monosymptomatic CF disorders. Since there is a variation in distribution of common polymorphisms among different populations, it was important to compare their frequencies in patients with the frequencies in healthy population in order to assess the possible role of these polymorphisms in the monosymptomatic CF disorders. Samples obtained from 100 healthy Serbian individuals were analyzed for the presence of CFTR 5T, M470V and R75Q variants by PSM, RFLP and DGGE methods, respectively. Allele 5T was present in two individuals, giving the allelic frequency of 1% (2/200 alleles). The frequency obtained for allele M470 was 45% (90/200 alleles), while V470 allele was present with the frequency of 55% (110/200 alleles). Polymorphism R75Q was present in two individuals, with allelic frequency of 1% (2/200 alleles). Our study has shown that the frequencies of two common polymorphisms, 5T and M470V, differ significantly in Serbian population in comparison with other South European populations. Since it appears that Serbian population has a specific distribution of studied CFTR gene variants, it would also be interesting to analyze other common variants of this gene in our population. Such data can also be potentially useful as anthropogenetic markers in population studies.     

B-type natriuretic peptide predicts new-onset atrial fibrillation in patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention

The predictive value of B-type natriuretic peptide (BNP) with respect to the occurrence of new-onset atrial fibrillation (AF) in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (PCI) is unknown. The aim of this study was to evaluate whether BNP has a predictive value for the occurrence of new-onset AF in patients with STEMI treated by primary PCI. In 180 patients with STEMI treated by primary PCI, BNP concentrations were measured 24h after chest pain onset. The Receiver Operating Characteristic analysis was performed to identify the most useful BNP cut-off level for the prediction of AF. The patients were divided into the two groups according to calculated cut-off level: high BNP group (BNP≥720 pg/mL, n=33) and low BNP group (BNP<720 pg/mL, n=147). The incidence of AF was 5.0%, and occurred more frequently in high BNP group (7/33, 21.2%) than in low BNP group (2/147, 1.4%), (p<0.001). Patients with high BNP were older (p=0.017), had more often anterior wall infarction (p=0.015), higher Killip class on admission (p=0.038), higher peak troponin I (p=0.002), lower left ventricular ejection fraction (p=0.029) than patients with low BNP. After multivariate adjustment, BNP was an independent predictor of AF (OR 3.70, 95% CI 1.40-9.77, p=0.008). BNP independently predicts the occurrence of new-onset AF in STEMI patients treated by primary PCI.     

Ubiquitin‐specific protease‐like 1 (USPL1) is a SUMO isopeptidase with essential,non‐catalytic functions

Isopeptidases are essential regulators of protein ubiquitination and sumoylation. However, only two families of SUMO isopeptidases are at present known. Here, we report an activity‐based search with the suicide inhibitor haemagglutinin (HA)‐SUMO‐vinylmethylester that led to the identification of a surprising new SUMO protease, ubiquitin‐specific protease‐like 1 (USPL1). Indeed, USPL1 neither binds nor cleaves ubiquitin, but is a potent SUMO isopeptidase both in vitro and in cells. C13orf22l—an essential but distant zebrafish homologue of USPL1—also acts on SUMO, indicating functional conservation. We have identified invariant USPL1 residues required for SUMO binding and cleavage. USPL1 is a low‐abundance protein that colocalizes with coilin in Cajal bodies. Its depletion does not affect global sumoylation, but causes striking coilin mislocalization and impairs cell proliferation, functions that are not dependent on USPL1 catalytic activity. Thus, USPL1 represents a third type of SUMO protease, with essential functions in Cajal body biology.