Atrial natriuretic peptide binding, cross-linking, and stimulation of cyclic GMP accumulation and particulate guanylate cyclase activity in cultured cells

The stimulation of cyclic GMP accumulation and particulate guanylate cyclase activity by atrial natriuretic peptide (ANP) was compared to the affinity and number of ANP receptors in eight cultured cell types. At 100 nM, ANP increased cyclic GMP by 13-fold in bovine adrenal cortical, 35-fold in human lung fibroblast, 58-fold in canine kidney epithelial, 60-fold in bovine aortic smooth muscle, 120-fold in rat mammary epithelial, 260-fold in rat Leydig, 300-fold in bovine kidney epithelial, and 475-fold in bovine aortic endothelial cells. ANP (1 microM) increased particulate guanylate cyclase activity by 1.5-, 2.5-, 3.1-, 3.2-, 5.0-, 7.0-, 7.8-, and 8.0-fold in bovine adrenal cortical, bovine aortic smooth muscle, human lung fibroblast, canine kidney epithelial, rat mammary epithelial, rat Leydig, bovine kidney epithelial, and bovine aortic endothelial cells, respectively. Specific 125I-ANP binding to intact rat Leydig (3,000 sites/cell; Kd = 0.11 nM), bovine aortic endothelial (14,000 sites/cell; Kd = 0.09 nM), bovine adrenal cortical (50,000 sites/cell; Kd = 0.12 nM), human lung fibroblast (80,000 sites/cell; Kd = 0.32 nM), and bovine aortic smooth muscle (310,000 sites/cell; Kd = 0.82 nM) cells was saturable and high affinity. No specific and saturable ANP binding was detected in bovine and canine kidney epithelial and rat mammary epithelial cells. Two ANP-binding sites of 66,000 and 130,000 daltons were specifically labeled by 125I-ANP after cross-linking with disuccinimidyl suberate. The 130,000-dalton ANP-binding sites bound to a GTP-agarose affinity column, and the specific activity of guanylate cyclase was increased by 90-fold in this fraction. Our results demonstrate that the increase in cyclic GMP accumulation and particulate guanylate cyclase activity by ANP does not correlate with the affinity and number of ANP-binding sites. These results suggest that multiple populations of ANP receptors exist in these cells and that only one receptor subtype (130,000 daltons) is associated with particulate guanylate cyclase activity.     

Pharmacokinetics, safety and immunomodulatory effects of human recombinant interleukin-1 receptor antagonist in healthy humans.

A phase I study of human recombinant interleukin-1 receptor antagonist (IL-1ra) was conducted in healthy males between the ages of 18 and 30. Twenty-five volunteers received a single, 3 h continuous intravenous infusion of doses ranging between 1 mg/kg and 10 mg/kg IL-1ra. At 3 h into the infusion, plasma IL-1ra levels were 3.1 micrograms/ml and 29 micrograms/ml for the 1 mg/kg and 10 mg/kg doses, respectively. Post-infusion plasma IL-1ra levels declined rapidly, exhibiting an initial half-life of 21 min and a terminal half-life of 108 min. Clinical, hematological, biochemical, endocrinological and immunomodulatory effects were monitored over 72 h and compared to those of four subjects receiving a 3 h infusion of saline. There were no clinically significant differences between the drug and saline groups in symptoms, physical examinations, complete blood counts, mononuclear cell phenotypes, blood chemistry profiles, serum iron and serum cortisol levels. Peripheral blood mononuclear cells (PBMC) obtained after completion of the IL-1ra infusion synthesized significantly less interleukin 6 ex vivo than PBMC from saline-injected controls. These data suggest that transient blockade of interleukin 1 receptors is safe and does not significantly affect homeostasis.     

Different effects of rain and artificial watering on element zonation patterns in lichen thalli and bark: A study on Physcia biziana (Massal.) Zahlbr. v. leptophylla Ve˘zda

Translocation processes between the inner and outer rings of lichen thalli, as well as between lichens and bark substratum, induce zonation patterns, with a dynamic stratification of pollution history memory which is often affected by the intensity of the atmospheric events. Two experiments of passive biomonitoring are presented, aimed to measure metal concentrations and zonation patterns in lichens and bark, before and after raining events or after a water sprinkling treatment. Ten elements were monitored in the lichen Physcia biziana (Massal.) Zahlbr. v. leptophylla Ve?zda in a moderately polluted area of Campania region (Italy). Element concentrations changed with lichen age, with generally higher concentrations in the older than the younger tissues. Rain and sprinkling had differential effects on lichen and bark: a significant decrease of the overall concentrations was observed after rain in bark, whereas a slight increase was observed in lichen thalli; however, when lichen thalli were just rehydrated with a sprinkling treatment, some elements were found to increase in the younger portions of the thalli and decrease in the older portions. The extent to which zonation patterns account for site “pollution memory” or are affected by the short-term local atmospheric variability is discussed.     

Bone mineral density is inversely related to parathyroid hormone in adolescent girls.

Preventive programs aimed at maximizing peak bone mass as a way of reducing the risk of osteoporotic fractures later in life should take into account the contribution of nutritional factors to bone mass accumulation in young age. The role of calcium and energy intakes on radial mineral density was investigated in 200 healthy girls (aged 11-15 yr) simultaneously evaluating serum changes of insulin-like growth factor-I (IGF-I), parathyroid hormone (PTH) and osteocalcin (OC). Dietary calcium and energy intakes were assessed by a 3-day food record method, bone mineral density (BMD) was performed at ultradistal (ud) and proximal (pr) radial sites using dual energy X-ray absorptiometry. Calcium consumption below the levels suggested by Dietary Reference Intakes in more than 80% of population studied was not related to BMD, which in turn markedly increased in post-compared to premenarcheal girls. Interestingly, in a multiple regression analysis PTH was inversely related to BMD after adjustment for calcium intake, bone age and menarche. Serum IGF-I was positively associated to energy intakes and bone age in girls before menarche, who exhibited the highest values of OC. Our data highlighted the role of food habits in modulating some hormonal response that might influence bone mineral apposition during adolescent age. Low calcium consumption associated to enhanced PTH values, if persisting, could be responsible for reduced rate of gain in bone mineral density. Thus, to optimize bone mineralization during the critical period of rapid body growth adequate intakes of calcium and energy should be recommended.     

Integrative Analysis of Hereditary Nonpolyposis Colorectal Cancer: the Contribution of Allele-Specific Expression and Other Assays to Diagnostic Algorithms

The identification of germline variants predisposing to hereditary nonpolyposis colorectal cancer (HNPCC) is crucial for clinical management of carriers, but several probands remain negative for such variants or bear variants of uncertain significance (VUS). Here we describe the results of integrative molecular analyses in 132 HNPCC patients providing evidences for improved genetic testing of HNPCC with traditional or next generation methods. Patients were screened for: germline allele-specific expression (ASE), nucleotide variants, rearrangements and promoter methylation of mismatch repair (MMR) genes; germline EPCAM rearrangements; tumor microsatellite instability (MSI) and immunohistochemical (IHC) MMR protein expression. Probands negative for pathogenic variants of MMR genes were screened for germline APC and MUTYH sequence variants. Most germline defects identified were sequence variants and rearrangements of MMR genes. Remarkably, altered germline ASE of MMR genes was detected in 8/22 (36.5%) probands analyzed, including 3 cases negative at other screenings. Moreover, ASE provided evidence for the pathogenic role and guided the characterization of a VUS shared by 2 additional probands. No germline MMR gene promoter methylation was observed and only one EPCAM rearrangement was detected. In several cases, tumor IHC and MSI diverged from germline screening results. Notably, APC or biallelic MUTYH germline defects were identified in 2/19 probands negative for pathogenic variants of MMR genes. Our results show that ASE complements gDNA-based analyses in the identification of MMR defects and in the characterization of VUS affecting gene expression, increasing the number of germline alterations detected. An appreciable fraction of probands negative for MMR gene variants harbors APC or MUTYH variants. These results indicate that germline ASE analysis and screening for APC and MUTYH defects should be included in HNPCC diagnostic algorithms.     

Multiple-chromosome sex systems in the darkling beetles Blaps gigas and Blaps gibba (Coleoptera, Tenebrionidae)

We have studied mitotic and meiotic chromosomes in the males of two species of Blaps: B. gigas and B. gibba. Karyological characteristics such as the occurrence of a multivalent configuration at diakinesis and two types of metaphase-II spreads support the notion that multiple-chromosome sex systems involving five chromosomes in B. gigas and eight chromosomes in B. gibba have developed in these species. Results obtained by means of silver staining and C-banding techniques suggest that the complex sex systems occurring in B. gigas and B. gibba may have originated from exchanges of terminal ribosomal genes among the Y chromosome and some autosomes.     

Susceptibility to erbB-induced erythroblastosis is a dominant trait of 151 chickens.

Rous-associated virus-1 (RAV-1)-induced erythroblastosis results from proviral insertions into or viral transductions of the c-erbB region of the epidermal growth factor gene. Most chickens develop low incidences (less than 5%) of RAV-1-induced erythroblastosis. However, an inbred line of chickens (151) suffers high incidences (approximately 80%) of RAV-1-induced erythroblastosis. Analysis of 151, K28, and (K28 X 151) X K28 chickens for susceptibility to RAV-1-induced erythroblastosis revealed that susceptibility to RAV-1-induced erythroblastosis is a dominant trait of line 151 chickens. Analysis of 151 X K28 and K28 chicks for susceptibility to the induction of erythroblastosis by two new c-erbB-transducing viruses (avian erythroblastosis virus strains AEV-5005 and AEV-5009) revealed that susceptibility to transformation by new c-erbB-transducing viruses is also a dominant trait of 151 chickens. We think it is likely that both of these dominant traits are encoded by the same gene or genes. Our hypothesis is that this gene (or genes) potentiates the ability of the transmembrane and cytoplasmic domains of the epidermal growth factor receptor to transform cells.     

Non-coding RNAs and heme oxygenase-1 in vaccinia virus infection

Small nuclear RNAs (snRNAs) are <200 nucleotide non-coding uridylate-rich RNAs. Although the functions of many snRNAs remain undetermined, a population of snRNAs is produced during the early phase of infection of cells by vaccinia virus. In the present study, we demonstrate a direct correlation between expression of the cytoprotective enzyme heme oxygenase-1 (HO-1), suppression of selective snRNA expression, and inhibition of vaccinia virus infection of macrophages. Hemin induced HO-1 expression, completely reversed virus-induced host snRNA expression, and suppressed vaccinia virus infection. This involvement of specific virus-induced snRNAs and associated gene clusters suggests a novel HO-1-dependent host-defense pathway in poxvirus infection.     

The cytotoxic,neurotoxic, apoptotic and antiproliferative activities of extracts of some marine algae on the MCF-7 cell line

We investigated the cytotoxic, neurotoxic, apoptotic and antiproliferative effects of extracts from Petalonia fascia, Jania longifurca and Halimeda tuna on the MCF-7 breast cancer cell line. J. longifurca extracts were more toxic than those of P. fascia and H. tuna. The algal extracts showed significant toxic effects at different dilutions. The toxic effects were due to increased oxidative stress and resulted in apoptosis. Algal toxicity may exert negative effects through the food chain or by direct interaction. Algal toxicity also has potential for cancer therapy. The toxic effects that we observed may be especially important for therapy for breast tumors.