Exposure to p-phenylendiamine in hairdressing parlours

Summary The purpose of this study is to verify and assess, in working conditions, the respiratory exposure to PPD of hairdressing parlour personnel. Several air samples collected in a hairdressing parlour during the time required for 8 applications of dyeing products containing PPD 2.52% have been analyzed. Tests are also carried out by extracting air immediately above the bowls containing the dyeing products, both at room temperature and at 37°C. PPD was assessed by means of HPLC. Only air sampled directly on bowls at 37°C has shown a level of 1 g, corresponding to an environmental release of PPD equivalent to 8 applications of dyeing products. On the basis of these experimental data, the PPD concentration in the air according to the parlour volume and to the supposed air exchanges has been calculated. Our results show a substantial insignificance of the concentration of PPD released in the environmental air during normal operations of hair dyeing: authors are of the opinion that hairdressers can't be truly considered as a PPD-asthmatic risk category like other workers exposed to PPD dust dispersed in the air of their working environment.     

Survey of allergic respiratory symptoms in grain terminal workers in the Port of Genoa

Summary Fifty workers from two grain elevator terminals were examined to evaluate the prevalence of respiratory symptoms and their relationship with grain dust exposure.Fifty per cent of subjects complained of respiratory symptoms (rhinitis, asthma, chronic cough and dyspnea on exertion). In 34% of the workers the ventilatory function revealed some abnormalities (slight or moderate obstruction).Twenty-two (44%) showed a positive cutaneous reaction to one or more of the allergens tested, mostly towardsDermatophagoides and storage mites. The self-measurement of PEF over 14 days in 27 workers, showed significant differences between symptomatic and asymptomatic subjects. In particular, the results obtained from the cutaneous reactions could suggest a bronchial hypereactivity, worsened by the working exposure to dusts. The monitoring of PEF appears to be a simple and useful method for investigating the relationship between respiratory symptoms and the working environment.     

Glyoxylate Cycle Enzymes in Peroxisomes Isolated from Petals of Pumpkin (Cucurbita sp.) during Senescence

The activities of the two unique enzymes of the glyoxylate cycle,isocitrate lyase (EC 4.1.3.1 [EC] ) and malate synthase (EC 4.1.3.2 [EC] ),were undetectable in petals of pumpkin (Cucurbita sp. AmakuriNankin) until the end of blooming, but they appeared duringsenescence. The activity of catalase (EC 1.11.1.6 [EC] ) increased,glycolate oxidase (EC 1.1.3.1 [EC] ) activity did not change, whilehydroxypyruvate reductase (EC 1.1.1.81 [EC] ) activity peaked at fullblooming stage and declined thereafter. After fractionationof cellular organelles on a sucrose density gradient, we detectedisocitrate lyase and malate synthase activities in peroxisomalfractions only from petals at the senescing stage. Northernblot analysis revealed that malate synthase mRNA increased duringpetal senescence. Citrate synthase (EC 4.1.3.7 [EC] ) and malate dehydrogenase(EC 1.1.1.37 [EC] ) activities were also present, while aconitase(EC 4.2.1.3 [EC] ) was not detectable in peroxisomal fractions. Moreoverthe presence of 3-hydroxyacyl-CoA dehydrogenase (EC 1.1.1.35 [EC] )and urate oxidase (EC 1.7.3.3 [EC] ) in the peroxisomal fractionsfrom senescing petals indicates that peroxisomes could be involvedboth in the ß-oxidation pathway and in the purinecatabolism during petal senescence. (Received May 25, 1991; Accepted September 25, 1991)     

The chemical characterization of melanin contained in substantia nigra of human brain

The pigment of substantia nigra human brain has been extracted by a mild procedure consisting of washes with phosphate buffer, methanol and incubation with SDS-proteinase. Pyrolisis gas chromatography mass spectrometry infrared spectrometry, termogravimetric analysis and elemental analysis were the techniques used for the chemical characterization. An indole moiety bound to a sulfur containing amino acid and to palmitic acid were the main aspects found in the structure. The presence of a 7% inorganic component was observed. This probably contains Fe, Cu, Zn and Cr which are also relevant, for the formation and the role of melanin in substantia nigra neurons. The fatty acid moiety is chemically bound to the indole structure as it was not eliminated by repeated methanol washing. The same situation occurs for the sulfur containing gropu. Considering these data and the most abundant molecules present in substantia nigra the precursor of neuromelanin seems to be a cysteinyl-cethecol, to which is then bound a palmityl group.     

The role of the arginine-glycine-aspartic acid-directed cellular binding to type I collagen and rat mesenchymal cells in colorectal tumour differentiation

The relationship between the adhesion of five human colorectal carcinoma cell lines to extracellular matrix (ECM) proteins, namely type I collagen, type IV collagen, fibronectin, laminin and basement membrane extract (Matrigel), and the ability of these cells to express morphological differentiation when grown in a basement membrane extract (Matrigel) or on normal rat mesenchymal cells has been examined. Two cell lines, SW1222 and HRA-19, organised into glandular structures, with well-defined polarity when cultured on both substrata as well as in three-dimensional (3D) collagen gel culture as previously shown. The remaining three cell lines (SW620, SW480 and HT29) grew as loose aggregates or as they would normally grow on tissue culture plastic. Addition to the culture medium of a hexapeptide, containing the cell-matrix recognition sequence arginine-glycine-aspartic acid (RGD), inhibited attachment and glandular formation of SW1222 and HRA-19 when these cells were grown on living mesenchymal cells, but not in Matrigel. The morphological differentiation of HRA-19 cells in 3D-collagen was also inhibited by the same RGD-containing peptide, as previously shown for SW1222 cells. Attachment of the remaining three cell lines was inhibited on mesenchyme but not in Matrigel, further supporting the specificity of the peptide effect on epithelial-mesenchymal binding. In conclusion we have shown that colorectal tumour cells are able to bind ECM proteins and that the cellular binding is an essential step in the induction of the morphological differentiation seen on living mesenchymal cells, in basement membrane extracts and in type I collagen gel.(ABSTRACT TRUNCATED AT 250 WORDS)     

Isolation and partial characterization of a protein kinase NII from wheat germ chromatin

A protein kinase, type NII, has been purified from wheat germ chromatin. The enzyme, which uses both ATP and GTP as phosphoryl donors, catalyzes the phosphorylation of casein, phosvitin and E. coli RNA polymerase, but not of histone proteins. Polypeptide bands at 46 kDa, 37 kDa and 25 kDa were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Autophosphorylation of the 25 kDa subunit was observed following incubation of the purified kinase with (-³²P)ATP and (-³²P)GTP.     

Analysis of X-chromosome inactivation and presumptive expression of the Wiskott-Aldrich syndrome (WAS) gene in hematopoietic cell lineages of a thrombocytopenic carrier female of WAS

Summary We report on a thrombocytopenic female belonging to a pedigree with the Wiskott-Aldrich syndrome (WAS). Restriction fragment length polymorphism (RFLP) analysis with probe M27, closely linked to the WAS gene, demonstrated that she is a carrier of WAS. Both small-sized and normal-sized platelets were present, suggesting that, unlike the vast majority of WAS carriers, she does not manifest nonrandom X-chromosome inactivation in the thrombopoietic cell lineage. Study of X-chromosome inactivation by means of RFLP and methylation analysis demonstrated that the pattern of X-chromosome inactivation was nonrandom in T lymphocytes, but random in granulocytes. While this is the first complete report on the occurrence of thrombocytopenia in a carrier female of WAS as the result of atypical lyonization, it also suggests that expression of the WAS gene occurs at (or extends up to) a later stage than the multipotent stem cell along the hematopoietic differentiation pathway.     

Leaf water potential and leaf conductance during the growing season in almond trees under different irrigation regimes

Seasonal changes in leaf water potential (Φ) and leaf conductance (g₁) were determined in almond trees under different irrigation regimes. The development of water stress in the rainfed treatment induced a specific seasonal dynamics of Φ values and an important reduction in g₁ values. A decrease in g₁ values occurred independently of the irrigation treatment through the growing season. No statistically significant differences were obtained in g₁ values within the drip irrigated treatments.