Health risk analysis from volatile organic compounds and fine particulate matter in the printing industry.

The association between the printing activity and the pollutant exposure of the workers was investigated in five consecutive working days, during 8 h work shift per day. Exposure concentrations of the total volatile organic compound and fine particulate matter were measured in the four voluntary printing factories in Thailand. Two types of the printing process, offset and digital printing, were compared. The 8 h average of particulate matter 2.5 in the field blank, Offset A, Offset B, Offset C printing and Digital printing D was 7.46, 21.51, 44.26, 77.92, and 42.08 µgm-3, respectively. The highest particulate matter level in the Offset printing C, 77.92 µgm-3 was due to the surrounded paper dust in the area. The 8 h average of total volatile organic compounds in field blank, Offset A, Offset B, Offset C printing and Digital printing D was 0.12, 2.68, 5.02, 21.86, and 0.67 ppm, respectively. The highest total volatile organic compound was 21.86 ppm in the Offset printing C because of the high production rate and the application of organic solvents in the cleanup process. Worker's exposure to total volatile organic compound and particulate matter 2.5 in the offset printings was higher than in the digital laser printing. From the health risk evaluation, the workers in offset printings were at risk from total volatile organic compound exposure, Hazard quotient > 1. However, workers exposed to particulate matter exposures were not at risk, Hazard quotient < 1.

Driver exposure to particulate matter in Bangkok.

The aims of this study were to determine the particulate matter with aerodynamic diameters > or = 2.5 microm (PM2.5) and 2.5-10 microm (PM10-2.5) exposure levels of drivers and to analyze the proportion of elemental carbon (EC) and organic carbon (OC) in PM2.5 in Bangkok, Thailand. Four bus routes were selected. Measurements were conducted over 10 days in August (rainy season) 2008 and 8 days in January (dry season) 2009. The mean PM2.5 exposure level of the Tuk-tuk drivers was 86 microg/m3 in August and 198 microg/m3 in January. The mean for the non-air-conditioned bus drivers was 63 microg/m3 in August and 125 microg/m3 in January. The PM2.5 and PM10-2.5 exposure levels of the drivers in January were approximately twice as high as those in August. The proportion of total carbon (TC) in PM2.5 to the PM2.5 level in August (0.97 +/- 0.28 microg/m3) was higher than in January (0.65 +/- 0.13 microg/m3). The proportion of OC in the TC of the PM2.5 in August (0.51 +/- 0.08 microg/m3) was similar to that in January (0.65 +/- 0.07 microg/m3). The TC exposure by PM25 in January (81 +/- 30 microg/m3) remained higher than in August (56-21 microg/m3). The mean level of OC in the PM2.5 was 29 +/- 13 microg/m3 in August and 50 +/- 24 microg/m3 in January. In conclusion, the PM exposure level in Bangkok drivers was higher than that in the general environment, which was already high, and it varied with the seasons and vehicle type. This study also demonstrated that the major component of the PM was carbon, likely derived from vehicles.

Respiratory symptoms and pulmonary function among traffic police in Bangkok, Thailand.

The authors undertook a cross-sectional study of the potential adverse health effects of air pollution in Bangkok, Thailand. During 1998 and 1999, the authors administered lung function spirometry tests and a Thai version of the American Thoracic Society's Division of Lung Diseases (ATS-DLD) respiratory questionnaire to 78 male traffic police and 60 male nontraffic police in Bangkok, as well as to 68 male general police in Ayutthaya province, a rural area in Thailand. No consistent trend of decreased pulmonary function was observed in traffic police. The authors controlled for age, height, and smoking index, after which mean levels of forced expiratory volume in 1 sec and maximal expiratory flow rate in 25% of vital capacity (V25) were significantly lower in Bangkok police than in Ayutthaya police. The prevalence of respiratory symptoms among Bangkok police was slightly higher than among Ayutthaya police. Multiple regression analysis identified age and workplace as statistically significant factors that contributed to the values of forced expiratory volume in 1 sec and V25. This study provided some evidence of an increase in prevalence of obstructive changes in the peripheral airways among traffic police in Bangkok.

Photoaffinity labelling of Plasmodium falciparum proteins involved in phospholipid transport.

Erythrocytes infected with mature-stage malaria parasites accumulate phospholipids from exogenous sources. We show that the transport of N-(7-nitrobenzy-2-oxa-1,3-diazol-4-yl)-1,2- dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (N-NBD-DPPE), from the erythrocyte membrane to the intracellular malaria parasite, is dependent upon metabolic energy. A photoreactive phospholipid analogue, N-[125I]iodo-4-azidosalicylamidyl-1, 2-dilauryl-sn-glycero-3-phosphatidylethanolamine (N-125I-ASA-DLPE), has been synthesised and used in an attempt to identify proteins involved in phospholipid trafficking in malaria-infected erythrocytes. This photoreactive probe was found to preferentially label a protein with an apparent molecular weight of 22 kDa. Photolabelling of the 22-kDa protein was enhanced upon ATP depletion of malaria-infected erythrocytes.

Inhibition of wheat embryo calcium-dependent protein kinase and other kinases by mangostin and gamma-mangostin.

The hull of the fruit of the mangosteen tree (Garcinia mangostana) contains four inhibitors of plant Ca(2+)-dependent protein kinase. Two of these inhibitors have been purified and identified as the xanthones 1,3,6-trihydroxy-7-methoxy-2,8-bis(3-methyl-2-butenyl)-9H- xanthen-9-one (mangostin) and 1,3,6,7-tetrahydroxy-2,8-bis(3-methyl-2-butenyl)- 9H-xanthen-9-one (gamma-mangostin). Both xanthones also inhibit avian myosin light chain kinase and rat liver cyclic AMP-dependent protein kinase. This is the first report of inhibition of plant and animal second messenger-regulated protein kinases by plant-derived xanthones.

Inhibition of myosin light chain kinase, cAMP-dependent protein kinase, protein kinase C and of plant Ca(2+)-dependent protein kinase by anthraquinones.

A variety of anthraquinone (anthracene-9,10-dione) derivatives inhibits rat brain Ca(2+)- and phospholipid-activated protein kinase C (PKC) of which the most potent inhibitors are mitoxantrone (1,4-dihydroxy-5,8-bis[2-(hydroxyethylamino)-ethylamino]-9,10- anthracenedione) (IC50 4 microM) and quinalizarin (1,2,5,8-tetrahydroxy-anthraquinone (IC50 4 microM). Anthraquinone derivatives with less polar substitution in positions 1 to 4 and 5 to 8 are less effective as inhibitors of PKC. Wheat germ Ca(2+)-dependent protein kinase (CDPK) assayed with a myosin light chain-based peptide substrate is much less sensitive to inhibition by anthraquinones, the most effective anthraquinone inhibitors being the 1,2,4-trihydroxy (IC50 14 microM), 1,8-dihydroxy-3-methyl (IC50 56 microM) and 1,2,5,8-tetrahydroxy (IC50 65 microM) derivatives. Ca(2+)-calmodulin-dependent myosin light chain kinase (MLCK) is inhibited by a range of di-, tri- and tetrahydroxylated anthraquinones (IC50 values 2 to 53 microM), the most potent inhibitors being the more polar compounds, namely mitoxantrone (IC50 2 microM) and emodin (1,3,8-trihydroxy-6-methylanthraquinone) (IC50 8 microM). Mitoxantrone interacts with calmodulin as determined from abolition of Ca(2+)-dependent fluorescence enhancement of dansyl-calmodulin (IC50 4 microM). A range of anthraquinone derivatives inhibits the catalytic subunit of cAMP-dependent protein kinase (cAK). In a number of cases compounds acting as potent inhibitors of MLCK (such as mitoxantrone and emodin) are very poor inhibitors of cAK and vice versa.

Inhibition of rat liver cyclic AMP-dependent protein kinase by flavonoids.

Rat liver cyclic AMP-dependent protein kinase catalytic subunit (cAK), assayed using the synthetic peptide substrate, LRRASLG, is inhibited by a range of plant-derived flavonoids. In general, maximal inhibitory effectiveness (IC50 values 1 to 2 microM) requires 2,3-unsaturation and polyhydroxylation involving at least two of the three flavonoid rings. 3-Hydroxyflavone (IC50 value 4 microM), 3,5,7,2',4'-pentahydroxyflavone (IC50 = 10 microM) and 5,7,4'-trihydroxyflavone (IC50 = 7 microM) represent somewhat less active variations from this pattern. Flavonoid O-methylation or O-glycosylation greatly decreases inhibitory effectiveness, as does 2,3-saturation. Various flavonoid-related compounds, notably gossypol (IC50 = 10 microM), also inhibit cAK. Flavonoids and related compounds are in general much better inhibitors of cAK than of avian Ca(2+)-calmodulin-dependent myosin light chain kinase or of plant Ca(2+)-dependent protein kinase. Tricetin (IC50 = 1 microM) inhibits cAK in a fashion that is non-competitive with respect to both peptide substrate and ATP (Ki value 0.7 microM). When histone III-S is used as a substrate, inhibition of cAK requires much higher flavonoid concentrations.

Inhibition of wheat embryo calcium-dependent protein kinase and avian myosin light chain kinase by flavonoids and related compounds.

Avian myosin light chain kinase (MLCK) is inhibited by a range of plant-derived flavonoids. Maximal inhibition requires 2,3-unsaturation and polyhydroxylation of two of the three flavonoid rings. Phosphorylation of a synthetic myosin light chain-related peptide by wheat embryo Ca(2+)-dependent protein kinase (CDPK) is also inhibited by a range of flavonoids but phosphorylation of histone preparation III-S by wheat CDPK is not inhibited by flavonoids. The structural requirements for inhibition of wheat CDPK by flavonoids are more stringent than for inhibition of avian MLCK. Potent flavonoid inhibitors of wheat CDPK are unsaturated in 2,3 position, have hydroxyl groups in positions 3' and 4' and an additional hydroxyl in the chromone ring. Flavonoid glycosylation or methylation can abolish inhibition. A number of other naturally occurring plant phenolics including chalcones and gossypol also inhibit avian MLCK and wheat CDPK. Gossypol binds to calmodulin, abolishing Ca(2+)-dependent enhancement of dansyl-calmodulin fluorescence.

Identification of urinary metabolites and quantitative measurement of creatinine by a proton nuclear magnetic resonance spectrometry.

1H-NMR spectra of 60 human urine specimens were recorded without pretreatment by a JEOL FX 90 Q spectrometer operating at 89.55 MHz. The signals of the methyl protons of creatinine (3.04 +/- 0.02 ppm) were observed in all spot fasting morning urine samples collected from 7 healthy persons, 10 patients with nephrotic syndrome and 43 patients with diabetes mellitus. The concentrations of creatinine measured by NMR spectroscopy (Y) and the chemical assay based on the Jaffe reaction (X), over the range of 19-190 mg/dl, were compared by the least-squares linear regression analysis (Y = 6.7799 + 0.6717 X). The mean urinary creatinine concentration by NMR spectroscopy appeared to be lower than that obtained by the Jaffe reaction at the normal and high normal levels. In the urine of 20 diabetic patients with an average blood glucose of 251.30 +/- 50.26 (SD) mg/dl typical spectra of the multiple large signals of glucose protons at position from 3.13 +/- 0.04 to 4.04 +/- 0.12 (SD) ppm were shown. Moreover, some urinary metabolites and amino acids spectra were occasionally detected at one time.