Ragweed presence in Trieste: clinical and aerobiological data

Summary Studies on ragweed have been carried out in the province of Trieste (Northern Italy) in which it is becoming widespread. The floristic records, the increasing amount of airborne pollen monitored and the relevant skin reactivity are reported. This phenomenon, though still at the beginning, is actually showing an upward trend due to man's intervention over wider and wider areas which as a consequence become suitable for the settlement of these anthropophitic species. The aerobiological data are compared to the skin reactivities of allergic subjects.     

Storage mites sensitivity and allergic respiratory disease

Summary In order to evaluate the frequency of skin sensitivity to Storage Mites and the role of such sensitization in respiratory allergic disease in workers with occupational exposure to stored items we studied 217 dock workers, 93 farmers and 104 white collars.From the results of skin prick tests the sensitization to sole Storage Mites appears significantly higher among people working in docks or farms, compared with a control group. This confirms the role of the working environment in inducing sensitization to Storage Mites. Rhinitis and asthma however affect nearly always (27/29 cases) people with an associated sensitization to House Dust Mites. Further studies are needed to define the allergenic importance of Storage Mites in working environments.     

Plasma lipids and lipoproteins and the prevalence of risk for coronary heart disease in Canadian adults. Canadian Heart Health Surveys Research Group.

OBJECTIVE: To report population reference values for blood lipids, to determine the prevalence of lipid risk factors and to assess their association with other risk factors. DESIGN: Population-based cross-sectional surveys. Survey participants were interviewed at home and provided a blood sample at a clinic. All blood lipid analyses were done in the Lipid Research Laboratory, University of Toronto. The laboratory is standardized in the National Heart, Lung Blood Institute-Centres for Disease Control Standardization Program. SETTING: Nine Canadian provinces, from 1986 to 1990. PARTICIPANTS: A probability sample of 26,293 men and women aged 18 to 74 was selected from the health insurance registers for each province. Blood samples were obtained from 16,924 participants who had fasted 8 hours or more. OUTCOME MEASURES: Concentration of total plasma cholesterol, triglycerides and high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol in blood samples from fasting participants. MAIN RESULTS: Of the study population, 46% had total plasma cholesterol levels above 5.2 mmol/L, 15% had LDL-cholesterol levels above 4.1 mmol/L, 15% had triglyceride levels above 2.3 mmol/L and 8% had HDL-cholesterol levels below 0.9 mmol/L. Total plasma cholesterol, LDL-cholesterol and triglyceride levels rose with age in men to a maximum in the 45-54 age group; in women there was little change with age up to ages 45 to 54, at which time the level of each of these lipids increased appreciably. The age-standardized prevalence of obesity was positively associated with elevation of total plasma cholesterol. CONCLUSION: The results suggest the need for a multifactorial approach in health promotion efforts to lower blood cholesterol levels and reduce other risk factors in the population. A considerable number of adults were found to be at risk at all ages in both sexes. In the short term, men aged 34 and older and women aged 45 and older might benefit most from prevention programs.     

Isolation and expression of linked zinc finger gene clusters on human chromosome 11q

Proteins that share conserved "zinc finger" motifs represent a class of DNA-binding proteins that have been shown to play a fundamental role in regulating gene expression and to be involved in a number of human hereditary and malignant disease states. We have isolated, characterized, and mapped zinc finger-encoding genes specific to human chromosome 11q to investigate their possible association in the molecular pathogenesis of several disease loci mapped to this chromosome. An arrayed chromosome 11q cosmid library was screened using a degenerate oligonucleotide corresponding to the H/C link consensus sequence of the Drosophila Kruppel zinc finger gene, resulting in the isolation of six putative zinc finger genes. Three of the genes (ZNF123, ZNF125, and ZNF126) were analyzed and shown to contain tandemly repeated zinc finger motifs of the C2-H2 class. All three novel genes were found to be expressed in normal adult human tissues, although the tissue-specific pattern of expression differs markedly. Isolated zinc finger genes were regionally mapped on chromosome 11 using fluorescence in situ suppression hybridization and demonstrated clustering of the genes at 11q13.3-11q13.4 and 11q23.1-11q23.2. Analysis of in situ hybridization to interphase nuclei demonstrated a maximum distance of 1 Mb separating distinct finger genes. This analysis defines two linked multigene families of zinc finger genes to chromosome bands associated with a high frequency of specific translocations associated with malignancies.     

Effect of potassium humate on apple cv. ‘Golden Delicious’ cultured in vitro

The effects of humic substances on in vitro culture of Golden Delicious apple are reported. Potassium humate (KH) when used in proliferation showed a negative interaction with BA while it enhanced rooting when IBA was not present in the culture medium. In the presence of IBA, KH increased root number and reduced root growth. The highest concentration tested, 500 mg l^-1, caused a drastic reduction in root system development. 50 mg l^-1 KH hastened rooting and plants grew more rapidly when transferred to soil.     

Prochymosin expression in Bacillus subtilis

Prochymosin (PC) sequence was cloned in Bacillus subtilis using two kinds of plasmid constructions. In plasmid pSM316 the cDNA was inserted to obtain the intracellular expression of the enzyme. The enzyme turned out to be expressed in an insoluble form which could be converted to native enzyme under proper denaturing and refolding conditions. The levels of intracellular expression of PC were further enhanced by modifying the 5' region of the gene in a way that a two-cistron expression system was created. For the PC secretion, the cDNA was fused to the subtilisin leader sequence and expressed under the control of the B. subtilis neutral protease promoter. A properly folded PC was secreted by the cells, although to low levels.     

Studies of ionizing radiation as a promoter of neoplastic transformation in vitro

The induction of malignant transformation was examined in a standard promotion protocol in which BALB/3T3 cells were incubated continuously with tritiated water (3HOH) following acute treatment with various doses of either X-rays or benzo(a)pyrene (BP). In no case was there any evidence that protracted exposure to ionizing radiation from 3HOH enhanced the yield of transformants induced by the primary carcinogen over that predicted if the effects of the two agents were additive.     

Isolation and characterization of noncleavable (Ind-) mutants of the LexA repressor of Escherichia coli K-12.

The LexA repressor of Escherichia coli represses a set of genes that are expressed in the response to DNA damage. After inducing treatments, the repressor is inactivated in vivo by a specific cleavage reaction which requires an activated form of RecA protein. In vitro, specific cleavage requires activated RecA at neutral pH and proceeds spontaneously at alkaline pH. We have isolated and characterized a set of lexA mutants that are deficient in in vivo RecA-mediated cleavage but retain significant repressor function. Forty-six independent mutants, generated by hydroxylamine and formic acid mutagenesis, were isolated by a screen involving the use of operon fusions. DNA sequence analysis identified 20 different mutations. In a recA mutant, all but four of the mutant proteins functioned as repressor as well as wild-type LexA. In a strain carrying a constitutively active recA allele, recA730, all the mutant proteins repressed a sulA::lacZ fusion more efficiently than the wild-type repressor, presumably because they were cleaved poorly or not at all by the activated RecA protein. These 20 mutations resulted in amino acid substitutions in 12 positions, most of which are conserved between LexA and four other cleavable proteins. All the mutations were located in the hinge region or C-terminal domain of the protein, portions of LexA previously implicated in the specific cleavage reactions. Furthermore, these mutations were clustered in three regions, around the cleavage site (Ala-84-Gly-85) and in blocks of conserved amino acids around two residues, Ser-119 and Lys-156, which are believed essential for the cleavage reactions. These three regions of the protein thus appear to play important roles in the cleavage reaction.     

Cytogenetics of the European plethodontid salamanders of the genus Hydromantes (Amphibia,Urodela)

A karyological analysis was carried out on different European species of the genus Hydromantes (Plethodontidae). All the species examined share the same chromosome number (2n=28) and, with the exception represented by pair XIV, morphologically similar karyotypes. While the karyotypes display a similar distribution — mainly centromeric and pericentric — of C-heterochromatin, quantitative variations in pericentric heterochromatin are observed among species. In the continental species Hydromantes italicus and ambrosii as well as in the eastern Sardinian species imperialis, flavus and specie nova, pair XIV consists of heteromorphic sex chromosomes of the XX/XY type. It is proposed that the differentiation of the Y might have taken place through the occurrence of a structural rearrangement, such as a pericentric inversion, starting from a hypothetical, homomorphic pair XIV. A sex-related heteromorphism is not found in the western Sardinian species H. genei. A further karyological differentiation among these species concerns the position of the nucleolus organizing region (NOR), which is located on chromosome XII (H. italicus and ambrosii) or on chromosome X, close to the centromere (H. genei, H. imperialis and H. specie nova), or in an intercalary position (H. flavus). The location and the number of the 5 S DNA sites have been conserved during species divergence. On the basis of these karyological data, as well as of results obtained through a preliminary restriction enzyme analysis of the ribosomal and genomic DNAs, the phyletic relationships among the European Hydromantes species are discussed.     

Kinetic properties of cyanase

Cyanase is an inducible enzyme in Escherichia coli that catalyzes the hydrolysis of cyanate. Bicarbonate is required for activity, perhaps as a substrate, and the initial product of the reaction is carbamate, which spontaneously breaks down to ammonia and bicarbonate [Anderson, P. M. (1980) Biochemistry 19, 2882]. The purpose of this study was to characterize the kinetic properties of cyanase. Initial velocity studies showed that both cyanate and bicarbonate act as competitive substrate inhibitors. A number of monovalent anions act as inhibitors. Azide and acetate appear to act as competitive inhibitors with respect to cyanate and bicarbonate, respectively. Chloride, bromide, nitrate, nitrite, and formate also inhibit, apparently as the result of binding at either substrate site. Malonate and several other dicarboxylic dianions at very low concentrations display "slow-binding", reversible inhibition which can be prevented by saturating concentrations of either substrate. The results are consistent with a rapid equilibrium random mechanism in which bicarbonate acts as a substrate, bicarbonate and cyanate bind at adjacent anion-binding sites, and both substrates can bind at the other substrate anion binding site to give a dead-end complex.