[Profiling by LC-MS and LC-MS/MS with Electrospray source (ESI) of extracts from three organs of Thymelaea hirsuta L.] / Profilage par LC-MS et LC-MS/MS avec source Electrospray (ESI) des extraits de trois organes de Thymelaeahirsuta L.

Algeria, by its geographical position, is home to an exceptional biodiversity occupied by important medicinal plants. Thymelaea hirsuta, endemic species is a medicinal plant used in Algerian folk medicine for the treatment of various diseases. This work focused on the phytochemical study by liquid chromatography coupled with mass spectrometry (LC-MS) with Electrospray source (ESI) of aqueous extracts from flowers, leaves and twigs. The phytochemical results show that the different organs, more particularly the flowers constitute a privileged source of biologically active molecules belong to the family of polyphenols in which the subfamilies of hydroxycinamic acids (ferulic acid, caffeic acid, chlorogenic acid, feruloylquinic acid…), coumarins (esculetin, scopoletin, sphondine, rutarensin…) and flavonoids (Isochamaejasmine, kaempferol, apigenin…). This study confirms, scientifically, the traditional use of this plant and reveals its interest in the context of industrial pharmaceutical exploitation.

Does job stress affect injury due to labor accident in Japanese male and female blue-collar workers?

To clarify whether job stressors affecting injury due to labor accidents differ between Japanese male and female blue-collar workers, the Job Content Questionnaire (JCQ), assessing dimensions of job stressors based on the demand-control-support model, was applied to 139 blue-collar workers in a manufacturing factory. Of them, 24 male and 15 female workers suffered from injuries at work. In the female workers with the experience of work injury, the job demand score and job strain index (i.e., the ratio of job demand to job control) of the JCQ were significantly higher and the score of coworker support was significantly lower, than those in the female workers without the experience. High job demand (or, high job strain and low coworker support) was significantly related to work injury in all the female workers. Between the male workers with and without work injury, however, there was no significant difference in any job stressors. This pilot study suggests that high job strain (specifically, high job demand), as well as low coworker support, are important factors affecting work injury in Japanese female blue-collar workers. Further research with a large number of male blue-collar workers will be required to seek other factors that may be associated with work injury.

Blood lead levels in copper smelter workers in Japan.

Lead exposure of workers in a Japanese copper smelter was assessed by determining lead levels in blood, air and flue cinder at the copper smelting processes. All the samples were analyzed for lead by atomic absorption spectrometry. Mean lead levels of air were highest at the anode department followed by the converter, smelter and blend departments. The mean level of blood lead of the workers in the anode department was also the highest among the four smelting departments. The mean blood lead levels of the workers in each department were positively correlated with their air lead levels (r = 0.99, p < 0.01). This study indicates therefore that workers in copper smelters have been exposed to lead in their workplace. Though this finding has already been reported in preceding studies, the Ordinance on Prevention of Lead Poisoning in Japan has not included copper smelter into its target job categories if their lead concentration in the raw material is less than 3%. The limitation of the present Ordinance which defines the targets by the types of job and not by the actual exposure, is discussed.

[Subjective pain and tenderness in low back among care workers in relation to work load and daily life].

Five hundred and fifty-two care-workers aged 20 to 60 years, who worked at six custodial-care homes, were examined to clarify the relationship between subjective pain and tenderness in the low back, together with the factors affecting occupational low back pain. Subjects who were diagnosed as having tenderness in the low back by one medical practitioner at the time of health examinations, and those who reported the presence of low back pain in self-rating questionnaires were defined as those with "objective" and "subjective" low back pain, respectively. Complaints concerning workloads and daily life, as well as musculoskeletal and systemic symptoms, were inquired of in the self-rating questionnaires; the former complaints were compiled into four factors representing "environmental load at work," "physical load at work," "mental load at work," and "daily life" by the factor analysis. The corresponding rates in subjective and objective low back pains were 67.0% in 188 male care workers and 70.9% in 364 female care workers. In males and females, "physical load at work" was positively related to subjective low back pain (P < 0.05) with the use of the multiple logistic regression analysis including all the causal and confounding factors. Musculoskeletal symptoms in females were also positively related to subjective and objective low back pain (P < 0.05). These data suggest that subjective low back pain clearly reflects the problem of occupational low back pain as a whole, and that low back pain is mainly related to the physical load at work in care workers.

Effects of fractionated x-irradiation on the Ly-6--Ril-1--Pol-5 region.

Our laboratory has focused on defining, localizing, and understanding the mode of action of genes involved in fractionated x-irradiation (FXI) leukemia in susceptible and restraint mouse strains. We have described the genetic and molecular evidence suggesting the existence of multiple independent loci involved in FXI-induced leukemogenesis. These studies indicated that one of these, Ril-1, a locus on the distal portion of chromosome 15, is the major locus influencing susceptibility to the disease. Our data unequivocally place Ril-1 in the gene complex Ly-6--Ril-1--Sis--H-30--Pol-5. Ril-1 appears to be closest to Ly-6 and Sis. We report that in FXI-induced leukemias there are hypomethylation changes in the Ly-6 region as compared to normal thymocytes. In contrast, Sis was found to be hypermethylated and not expressed. In addition, we have noted DNA rearrangements in the Ly-6--Pol-5 region in the majority of tumors examined using the Ly-6 and spleen focus-forming virus (SFFLV) molecular probes. Increased expression of Ly-6 and other surface markers encoded in this region has been noted in FXI-induced thymomas.

Murine thymomas induced by fractionated-X-irradiation have specific T-cell receptor rearrangements and characteristics associated with day-15 to -16 fetal thymocytes.

We report here that specific T-cell receptor rearrangements were observed in fractionated-X-irradiation-induced murine leukemias. Consistent gamma-chain rearrangements, limited beta-chain rearrangements, and no detectable alpha-chain rearrangements were observed. Gene expression studies revealed that, in comparison with normal thymus tissue, expression of alpha T-cell receptor genes was lower in the thymomas, beta expression was much higher but approximately equal to that of normal thymocytes, and gamma expression was significantly increased. After coupling these data with those from analyses using reagents against other surface markers, such as Lyt-2, L3T4, H-2, IL-2R and MEL-14, we concluded that the target T cells for fractionated-X-irradiation-induced transformation resemble fetal thymocytes from days 15 and 16 of gestation.

Positioning of nucleosomes reconstituted with xeroderma pigmentosum and normal histones.

Positioning of nucleosomes was examined in a reconstituted system using a plasmid DNA and histones from normal human and xeroderma pigmentosum, complementation group A (XPA), lymphoblastoid cells. The present studies indicate that the arrangement of nucleosomes, composed of normal human histones, in a region near the SV40 origin of replication on the plasmid DNA, is nonrandom. The alignment of nucleosomes in this region was not affected by the presence of histone H1. No difference in nucleosome positioning was observed when the nucleosomes were composed of histones from XPA cells.

Comparison of histones in normal and xeroderma pigmentosum lymphoblastoid cells.

Histones from normal human and xeroderma pigmentosum, complementation group A (XPA), lymphoblastoid cells were compared both quantitatively, qualitatively and for binding affinity for DNA. Electrophoretic examination of the histones showed that all five major histone species were present in both cell groups and that there were no quantitative differences between normal and XPA histones. Binding affinity to [3H] mammalian DNA of the histones was determined. No significant differences were observed in binding of either normal or XPA histones to DNA.

Enhancement of two apurinic/apyrimidinic endonuclease activities from normal but not xeroderma pigmentosum lymphoblastoid cells by nucleosome structure.

The influence of nucleosomes on the activity of two chromatin-associated apurinic/apyrimidinic (AP) DNA endonuclease activities, pIs 9.2 and 9.8, from normal and xeroderma pigmentosum, complementation group A (XPA), lymphoblastoid cells was examined. These AP endonuclease activities were studied on non-nucleosomal and nucleosomal plasmid pWT830/pBR322 DNA which had been reconstituted with core (H2A, H2B, H3, H4) or total (core plus H1) histones from normal or XPA cells. Both nucleosomal and non-nucleosomal DNA was rendered partially AP by alkylation with 12.5 mM methyl methanesulfonate, followed by heating it at 70 degrees C, to produce approximately three AP sites per DNA molecule. The activities of both normal lymphoblastoid AP endonuclease activities on nucleosomal AP DNA, reconstituted with core histones, was approximately 2.5 times greater than that on non-nucleosomal AP DNA. When histone H1 was added to the system, this increase was reduced. XPA AP endonuclease activities, on the other hand, did not show any increase in activity on nucleosomal AP DNA reconstituted with core histones. These differences between normal and XPA endonuclease activities on AP nucleosomal DNA were the same regardless of whether histones from normal or XPA cells were used in the reconstituted system.