Does the AD7c-NTP locus encode a protein?

AD7c-NTP, the only known protein entirely encoded by tandem and nested cassettes of Alu repetitive elements, is reportedly over-expressed in brains of Alzheimer's disease patients [de la Monte et al., J. Clin. Invest. 15 (1997)]. Based on these findings a commercial diagnostic assay ("7c Gold"/"AlzheimAlert" ) has been developed. We analyzed the published cDNA sequence and compared it to corresponding EST clones as well as the genomic sequences of human and chimpanzee. We come to the conclusion that the existence of the gene and in particular the predicted protein is inconsistent with EST and genomic data. Previously published data need to be reassessed.     

Cystatins, thyropins and inhibitors homologous to propeptides of cysteine proteases

Protein inhibitors of proteolytic enzymes play an important role in regulating the activity of endogenous proteases and in host defense mechanisms against pathogens preventing the deleterious effects of exogenous proteases. In recent years a great interest in protein inhibitors of cysteine proteases has increased due to the extensive growth of knowledge about the contribution of cysteine proteases to pathological processes associated with many human diseases, as well as due to prospects for treatment of these disorders which may arise from the thorough understanding of their inhibitory mechanisms. This paper reviews the most important aspects of three families of cysteine protease inhibitors: cystatins, thyropins and inhibitors homologous to propeptides of cysteine proteases. Special attention is given to structural bases of the interactions between the inhibitors and their target enzymes. The paper presents a general characterization of the families according to the MEROPS classification of protease inhibitors, pointing out new members.     

Molecular mechanisms of biotoxicity of homocysteine--facts and hypotheses

In the article, the main pathways of homocysteine metabolism are described, i.e. transsulfuration to cysteine and glutathione, as well as remethylation to methionine. Furthermore, formation of homocysteine thiolactone through editing mechanism with methionyl t-RNA syntethase and unusual reactivity of thiolactone against lysine epsilonNH2 groups of proteins as well as calcium dependent enzymatic hydrolysis of thiolactone are discussed. The effects of oxidative stress related to homocysteine are also reviewed. Finally, possible links of homocysteine to NO and arginine metabolism are discussed, including ADMA (N(G),N(G)-dimethylarginine). The links between metabolism of homocysteine, adenosine and other nucleosides are emphasized. In conclusion, the N-homocysteilation of proteins with thiolactone changing enormously their properties seems to be the main reason of biotoxicity of homocysteine during atherosclerosis and other diseases.     

Antibacterial and antifungal lysozyme-type activity in Cameraria ohridella pupae

Lysozyme-type antibacterial and antifungal activity in pupae of Cameraria ohridella was studied. Activity against Micrococcus luteus and Bacillus megaterium was detected in pupae extract. Also antifungal activity from C. ohridella pupae extract directed against Saccharomyces cerevisiae strain W 303 was shown. During immunoblotting two bands in pupae extract, with molecular mass of about 15 and 28 kDa were recognized by antibodies directed against HEWL. After acid electrophoresis followed by bioautography of the extract, two lytic zones showing lysozyme-type activity against M. luteus were observed. Two bacteria: Gram-positive Aerococcus viridans and Gram-negative Aeromonas salmonicida ssp. masoucida were isolated from pupae of C. ohridella. Their activity against M. luteus, B. megaterium, and S. cerevisiae W303 was detected. After immunoblotting with antibodies against HEWL, also two proteins from bacterial suspensions of A. viridans and A. salmonicida were detected, about 15 and 28 kDa.     

Mutator phenotype resulting from DNA polymerase IV overproduction in Escherichia coli: preferential mutagenesis on the lagging strand

We investigated the mutator effect resulting from overproduction of Escherichia coli DNA polymerase IV. Using lac mutational targets in the two possible orientations on the chromosome, we observed preferential mutagenesis during lagging strand synthesis. The mutator activity likely results from extension of mismatches produced by polymerase III holoenzyme.     

Clinical trials using autologous bone marrow and peripheral blood-derived progenitor cells in patients with acute myocardial infarction

This paper discusses the current data concerning the results of major clinical trials using bone marrow-derived and peripheral blood-derived stem/progenitor cells in treatment of patients with acute myocardial infarction (AMI) and depressed left ventricular ejection fraction. In all major trials (TOPCARE-AMI, BOOST), the primary outcome measure was increase in left ventricular systolic function (LVEF) and left ventricle remodeling. The most consistent finding is the significant increase in LVEF. Some trials suggest also reduction of left ventricular remodeling. Although the absolute LVEF increase is small (6-9%), it may substantially contribute to the improvement of global LV contractility. None of the studies in AMI patients treated with intracoronary infusion of progenitor cells revealed excess risk of arrythmia, restenosis or other adverse effects attributable to the therapy. The exact mechanism of improved myocardial contractile function remains unknown, however, there are several possible explanations: therapeutic angiogenesis improving the blood supply to the infarct border zone, paracrine modulation of myocardial fibrosis and remodeling (e.g. inhibition of myocyte apoptosis) and transdifferentiation of stem/progenitor cells into functional cardiomyocytes. No study showed the superiority of the particular subpopulation of autologous progenitor cells in terms of left ventricular function improvement in AMI. In fact, most of the clinical trials used the whole population of mononuclear bone marrow-derived progenitor cells, peripheral blood derived progenitor cells (endothelial progenitors).     

Gynecomasty as a first sign of adrenal carcinoma--case report

We present a case of 50 year-old man with feminizing adrenal carcinoma. He was admitted to the hospital because of weakness and one year history of gynecomastia and high blood pressure. Examinations revealed a large left adrenal mass and increased levels of estradiol. Patient underwent adrenalectomy and followed by mitotan therapy as the result of histopathological examination was adrenocortical carcinoma. One year after operation patient stays free from the recurrence of the disease and his estradiol, androstendion and DHEA levels are below the detection limits. We report this case because feminizing adrenal carcinoma is a very rare but serious disease and gynecomastia that could be its manifestation is quite frequent symptom in men's population and thus it could easily be missed. In every case of gynecomastia related to estradiol excess feminizing tumors of testis and adrenal gland should be ruled out.     

Macroprolactin in subjects with hyperprolactinaemia: clinical observations and relations between free PRL and PRL complexed with IgG

In some patients with hyperprolactinaemia a large portion of circulating prolactin is bound to authologous gammaglobulin and therefore it is called macroprolactin or Big-Big-Prolactin (BB-PRL). THE AIM: of the study was to select patients with predominance of macroprolactin and to learn more about the natural course of this disorder, in particular about the possible dependence of the presence of clinical features from the amount of circulating "free" PRL level, and also to search whether the quantitative proportions of both forms of PRL are stable or they change parallel to changes of the total serum PRL level. MATERIAL AND METHODS: We identified 58 patients with hyperprolactinaemia, in whom BB-PRL consisted>or=60% of the total PRL concentration. The predominance of macroprolactin was settled using the well accepted method of polyethylene glycol (PEG) precipitation of large m.w. serum proteins, followed by contemporary immunoradiometric measurement of the total and free PRL levels, and calculation of BB-PRL. Repeating such measurements during the long term observation lasting 6-66 months (mean 33 months), which was possible in 18 our patients (13--with idiopathic hyperprolactinaemia and 5--with pituitary adenoma), we could analyze the relations between both forms of PRL during the specific treatment, after it's cessation and, in few cases--during pregnancy. Apart of that, in 18 patients selected from 53 with idiopathic hyperprolactinaemia, we analyzed the shortterm alterations in the ratio between free and complexed PRL during the metoclopramide PRL stimulation test. RESULTS AND CONCLUSIONS: 1. In hyperprolactinaemic patients with predominance of BB-PRL, there was no direct correlation between the presence of clinical features and the concentration of residual "free" PRL. 2. During the long-term observation, in spite of moderate changes in the total PRL concentration induced by the treatment or it's cessation (excluding pregnancy), the ratio of "free" PRL and BB-PRL remained stable. 3. During the short time of metoclopramide stimulation test, there was a marked rise mainly of the total and "free" PRL concentrations, and, in some tested subjects, the predominance of BB-PRL was lost temporally for 1 to 2 hours.     

Positive effects of DHEA therapy on insulin resistance and lipids in men with angiographically verified coronary heart disease--preliminary study

OBJECTIVES: The aim of this study was to analyze the influence of DHEA therapy on insulin resistance (FIRI, FG/FI) and serum lipids in men with angiographically verified coronary heart disease (CHD). MATERIAL AND METHODS: The study included thirty men aged 41-60 years (mean age 52+/-0.90 yr) with serum DHEA-S concentration<2000 microg/l, who were randomized into a double-blind, placebo-controlled, cross-over trial. Subjects completed the 80 days study of 40 days of 150 mg oral DHEA daily or placebo, and next groups were changed after 30 days of wash-out. Fasting early morning blood samples were obtained at baseline and after each treatment to determine serum hormones levels (testosterone, DHEA-S, LH, FSH estradiol and IGF-1) and also metabolic profile (total cholesterol, LDL-cholesterol, triglicerides, HDL-cholesterol, insulin, glucose, fasting insulin resistance index--FIRI and FG/FI ratio). RESULTS: Administration of DHEA was associated with 4.5-fold increase in DHEA-S levels. Relative to baseline DHEA administration resulted in a decrease in insulin levels by 40% (p<0.005) and fasting insulin resistance index (FIRI) by 47% (p<0.004). Also total cholesterol levels and LDL-cholesterol levels decreased significantly (from 222.9+/-6.6 mg/dL to 207.4+/-6.6 mg/dL and from 143.9+/-6.9 mg/dL to 130.5+/-6.0 mg/dL respectively; p<0.05). Glucose levels dropped significant below baseline values after DHEA (p<0.001). Estrogen levels significantly increased after DHEA (p<0.05). While changes of serum concentrations of testosterone, LH, FSH, IGF-I, HDL-cholesterol, triglycerides were not statistical significant. Tolerance of the treatment was good and no adverse effects were observed. CONCLUSIONS: DHEA therapy in dose of 150 mg daily during 40 days in men with DHEA levels<2000 microg/l decreased total cholesterol concentration, insulin and glucose levels and fasting insulin resistance index (FIRI). This therapy may be a beneficial against CHD risk factors.