Progress on the mechanism of n-hexane induced toxic effects in vitro and in vivo / 中华劳动卫生职业病杂志

Hexane is a widely used organic solvent in industry, and chronic hexane poisoning is the main occupational toxic lesion in China. In particular, axonal and myelin lesions in the distal thick fibers of the peripheral nervous system may be caused by 2, 5-hexanedione (2, 5-HD), an intermediate metabolite of n-hexane in humans. Hexane has toxic effects not only on the nervous system but also on the liver, kidneys, and reproductive organs. In this paper, we review the progress of research on the mechanism of n-hexane toxic neuropathy.

Composition, Antioxidant and Anti-inflammatory activities of Hexane and Methanol extracts of Acmella uliginosa from Terai region of Uttarakhand

Abstract Acmella uliginosa, an edible herb belonging to Asteraceae family, was collected from the Terai region of Uttarakhand, India. Methanol and hexane extracts of the whole plant were prepared using soxhlet apparatus. The GC-MS analysis of plant extracts identifies 22 and 35 major compounds of methanol and hexane extracts which comprises of 74.21% and 73.20% of the total composition of extracts, respectively. The major compound in hexane was 2, 4-heptadienal (7.99%) whereas trans, trans-9, 12-octadecadienoic acid propyl ester (16.96%) was major compound in methanol extract. The extracts were evaluated for antioxidant and anti-inflammatory properties. Methanol extract showed higher free radical scavenging and reducing power activities with IC50 value 153.82±1.69 µg/mL and RP50 value of 152.28±0.41 µg/mL, respectively. The metal chelating activity was higher in hexane extract as compared to methanol extract i.e., 62.08±0.25 µg/mL. The anti-inflammatory activity assessed by its ability to inhibit denaturation was higher in methanol having IB50 value 87.33±0.15 µg/mL. The total phenolic content (TPC), total flavonoid content (TFC) and ortho-dihydric phenol content (ODP) of methanol and hexane extracts were also evaluated. TPC, TFC and ODP was higher in methanol extract having value of 122.23±0.22, 35.01±0.29 and 8±0.86 mg/mL, respectively. Acmella uliginosa, might be considered as a natural source for antioxidant and anti-inflammatory properties

O monitoramento comportamental como medida de exposição ocupacional e ambiental de agentes tóxicos / Behavioral monitoring as a measure of occupational and environmental exposure to toxic agents

Resumo Introdução: o comportamento, como uma função biológica do organismo, pode ser tomado como objeto de estudo da neuropsicologia, já que parte do propósito dessa ciência é identificar, caracterizar e compreender as variáveis que o afetam, como a exposição crônica a agentes tóxicos. Objetivo: sustentar a ideia de que o comportamento humano pode ser utilizado como medida de identificação e avaliação da exposição ambiental e ocupacional de toxicantes. Métodos: este ensaio se apoia em revisão assistemática de literatura da área de toxicologia comportamental. Resultados: buscou-se caracterizar a abordagem comportamental como uma alternativa de mensuração em estudos epidemiológicos e apresentar algumas medidas e técnicas de avaliação neurocomportamentais. Discute-se a importância da padronização das baterias neurocomportamentais e suas limitações, além de exemplificar o seu uso potencial na triagem toxicológica com solventes (hexano). Conclusão: argumentou-se em favor da importância da toxicologia comportamental como área de interesse da saúde ocupacional, assim como da utilização de avaliações comportamentais na detecção precoce e prevenção de agravos à saúde dos trabalhadores, de modo a oferecer subsídios para o desenvolvimento de processos de produção mais seguros.

Abstract Introduction: behavior, as a biological function of the organism, can be studied by neuropsychology, as this science seeks to identify, characterize, and understand the variables that affect it, such as exposure to toxic agents. Objective: to support the idea that human behavior can be used as a measure to identify and evaluate environmental and occupational exposure to toxic agents. Methods: based on a non-systematic literature review in the field of behavioral toxicology. Results: we sought to characterize the behavioral approach as a measurement alternative for epidemiological studies and presented some neurobehavioral measures and evaluation techniques. We discussed the importance and limitations of standardizing neurobehavioral test batteries and exemplified their potential use in toxicological screening with solvents (hexane). Conclusion: behavioral toxicology is an important field of study for occupational health. Behavioral evaluations can be used for early detection and prevention of occupational injuries, in order to offer subsidies for safer production processes development.

Analyzing the prevalence of key occupational hazards in 56 printing enterprises in Shenzhen City / 中国职业医学

@# Objective To investigate the prevalence of the occupational hazard of organic solvent and noise in printing and Methods record medium production enterprises in Longgang District of Shenzhen City. A total of 56 printing and record medium production enterprises were selected as the study subjects by judgmental sampling method to analyze the worksite Results survey of occupational health and the key occupational hazard factors. There were 256 organic solvent samples ， detected in 56 enterprises which included a total of 148 terms and 1 358 categories of volatile constituents. The top three （ ）， - （ ） （ ） volatile constituents were toluene 35.5% n hexane 25.7% and methanol 23.8% . The top three detected samples of the （ ， ， ， ， - ， ，- ， eight key chemical occupational hazard factors benzene toluene xylene ethylbenzene n hexane 1 2 dichloroethane ） ， - ， trichloroethylene and chloroform were toluene n hexane and ethylbenzene. In the workplace air toluene was the most risk ， factor of occupational hazard factors in enterprise and in sample detection while no trichloromethane was detected. The toluene in workplace air was found to exceed the national standard with the rate of 2.6%. It showed that 27.9% of the work sites were found occupational noise hazard which was over national standard in the 10 key work sites. Only 64.3% and 57.1% enterprises - performed occupational hazard factors detection and occupational health examination. Both none or invalid toxicant proof - facilities accounted for 33.9% of the enterprises. Both none or invalid noise proof facilities accounted for 78.6% of the Conclusion ， - enterprises. The occupational hazards factor of toluene n hexane and noise were serious in printing and record ， medium production enterprises in Longgang District of Shenzhen City and the occupational health management was imperfect. The occupational regulation should be enhanced in this industry.

Antibacterial activity of plant essential oils against indigenously characterized methicillin-resistant Staphylococcus aureus (MRSA)

@#Plant essential oils were evaluated for antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA). The isolates (n=03) were procured from Institute of Microbiology, UVAS Lahore, Pakistan. After biochemical and 16S rRNA gene-based PCR characterization, accession numbers were retrieved from NCBI i.e. MW344063.1, MW344064.1 and MW344065.1. These isolates exhibited molecular positivity by multiplex PCR for mecA, coa and eta toxin genes. Moreover, these isolates exhibited resistance to cefoxitin, ampicillin, amoxicillin, penicillin, amoxicillin clavulanate, ciprofloxacin, erythromycin and gentamicin. The antibiotic resistant isolates were evaluated for antimicrobial activity of plant essential oils. The highest zone of inhibition (mean ZOI±S.D.) was measured for Cinnamomum verum (22.67±1.52 mm) followed by Eucalyptus globulus (18.67±2.51 mm) and Syzygium aromaticum (12.67±2.51 mm). Lowest mean MIC value (0.33±0.11 mg/mL) was recorded for E. globulus. Eucalyptus globulus was processed for fractionation by column chromatography and n-hexane, chloroform, n-hexane + chloroform and ethyl-acetate fractions were evaluated for antibacterial activity. Lowest mean MIC (10.04±5.80 mg/mL) was recorded for E. globulus n-hexane fraction. Cell survival percentage of BHK21 cell line was 51.7% at 54.87mg/mL concentration of E. globulus n-hexane fraction. Through gas chromatography-mass spectrometry (GC-MS) analysis of n-hexane fraction, benzene was found abundant (29.9%) as active compound. It was concluded that E. globulus n-hexane fraction exhibited significantly promising results against MRSA.

Effect of lyciumbarbarum polysaccharide on sex hormone and ovarian estrogen receptor in rats exposed to n-hexane / 中国职业医学

OBJECTIVE: To investigate the effect of n-hexane on the level of sex hormones and expression of estrogen receptor(ER) in rats and the protective effect of Lyciumbarbarum polysaccharide(LBP) on n-hexane-induced reproductive toxicity. METHODS: Based on factorial design model of 4×2, specific pathogen free adult female SD rats were divided into control group and low-, medium-and high-n-hexane exposure groups, and each group was divided into non-LBP intervention and LBP intervention sub-group. There were 8 subgroups with 6 rats in each group. On the first day, the rats in the 4 groups were given intraperitoneal injection of n-hexane at 0, 675, 1 350 and 2 700 mg/kg body weight, respectively. On day 2-4, the rats in the non-LBP intervention subgroup were given intragastric administration of 0.9% sodium chloride solution, and the rats in the LBP intervention subgroup were given intragastric administration of LBP at 50 mg/kg body weight once a day. On the fifth day, all animals were sacrificed, and the levels of follicle stimulating hormone(FSH), luteinizing hormone(LH), estradiol, progesterone were detected by enzyme linked immunosorbent assay. The mRNA expression of Erα, Erβ and G protein coupled estrogen receptor 1(Gper1) was detected by real time fluorescence polymerase chain reaction, and the expression of ERα, ERβ and GPER1 protein was detected by Western blotting. RESULTS: i) In the absence of LBP intervention(i.e. simple n-hexane exposure), there was no significant difference in the level of serum FSH, LH, estradiol and progesterone in the 4 groups(P>0.05). The relative expression of Erβ mRNA in ovary of low dose group decreased, while the relative expression of proteins of ERα and GPER1 increased(P<0.05) when compared with the control group. The relative expression of Erα mRNA and GPER1 protein in the ovary of medium-and high-dose groups increased(P<0.05), while the relative expression of Erβ, Gper1 mRNA and ERβ protein decreased(P<0.05). The relative expression of ERα protein in ovary of high-dose group increased(P<0.05). ii) At the same dose of n-hexane exposure, the relative expression of Erα mRNA in ovary of rats in low dose group increased(P<0.05), while the relative expression of ERβ and GPER1 protein decreased in LBP intervention group compared with the no LBP intervention group(P<0.05). The relative expression of ERα and GPER1 protein in ovary of medium dose group increased(P<0.05), while the relative expression of Gper1 mRNA and GPER1 protein in ovary of high dose group decreased in LBP intervention group compared with the no LBP intervention group(P<0.05). CONCLUSION: n-Hexane can up-regulate the expression of ERα and GPER1 in rat ovary, but has no significant effect on female endocrine system. LBP may play a protective role in female reproductive system by up-regulating the expression of ERα and GPER1.

Study on the effect of diallyl sulfide on peripheral nerve injury in n-hexane intoxicated rats / 中华劳动卫生职业病杂志

Objective@#To investigate the antagonistic effect of diallyl sulfide (DAS) against peripheral nerve injury induced by n-hexane in rats.@*Methods@#A total of 68 adult male Wistar rats were selected, among which 50 were randomly selected and divided into blank control group, DAS control group (100 mg/kg·bw) , n-hexane model group, low-dose DAS intervention group (50 mg/kg·bw) , and high-dose DAS intervention group (100 mg/kg·bw) . A rat model of peripheral nerve injury was established by n-hexane exposure, and the rats were treated with DAS at different doses. The changes in pyrrole adducts and behavior were observed, a metabolic analysis was performed for serum pyrrole adducts, and the intervention effect was evaluated. The remaining 18 rats were randomly assigned to the n-hexane model group, the low-dose DAS intervention group, and the high-dose DAS intervention group, with 6 rats in each group, as satellite groups used for the toxicokinetic analysis of serum pyrrole adducts.@*Results@#Compared with the blank control group, the n-hexane model group and low-and high-dose DAS intervention groups had a significant reduction in body weight since week 2 (P<0.01) . Compared with the n-hexane model group at the end of the experiment at week 7, the high-dose DAS intervention group had a significantly higher body weight (P<0.05) , while there was no significant difference in body weight between the n-hexane model group and the low-dose DAS intervention group (P>0.05) . The n-hexane model group developed gait abnormality at week 2 of poisoning, while the low-and high-dose DAS intervention groups developed gait abnormality at weeks 3 and 5 of poisoning, respectively. At the end of the experiment, the n-hexane model group and the low-and high-dose DAS intervention groups had a significantly higher gait score than the blank control group (P<0.01) . At the end of the experiment, the n-hexane model group and the low-dose DAS intervention group had significantly shorter latency in rotarod test than the blank control group (P<0.01) , while there was no significant difference in latency between the DAS control group and the high-dose DAS intervention group (P>0.05) . Compared with the n-hexane model group, the low-and high-dose DAS intervention groups had a significant increase in latency in rotarod test (P<0.01) . Compared with blank control group, the n-hexane model group and the low-dose DAS intervention group had a significant increase in mean nerve conduction velocity (P<0.01) , while there was no significant difference between the blank control group and the DAS control group or high-dose DAS intervention group (P>0.05) , and compared with the n-hexane model group, the low-and high-dose DAS intervention groups had a significant increase in nerve conduction velocity (P<0.01) . Compared with the blank control group at the end of the experiment at week 7, the n-hexane model group and the low-and high-dose DAS intervention groups had significant increases in the concentration of pyrrole adducts in serum, urine, and hair (P<0.01) , while there was no significant difference between the blank control group and the DAS control group (P>0.05) , and the high-dose DAS intervention group had a significantly lower concentration of pyrrole adducts in serum, urine, and hair than the low-dose DAS intervention group (P<0.05) . Serum pyrrole adducts reached the peak level at 9-12 hours and then started to decrease. Compared with the n-hexane model group, the high-and low-dose DAS intervention groups had a significantly shorter half-life period of serum pyrrole adducts (P<0.01) . Compared with the n-hexane model group, the high-and low-dose DAS intervention groups had a significant reduction in the area under the curve of serum pyrrole adducts (P<0.05) .@*Conclusion@#DAS can antagonize peripheral nerve injury induced by n-hexane.

Evaluation of Antimicrobial Activities of Fractions of Plant Parts of Pterocarpus santalinoides

Aims: The study aims to investigate the antimicrobial activities of the leaves, seeds, bark, and root of Pterocarpus santalinoides plant. Study Design: Agar well diffusion and Agar well dilution methods were used to test the preliminary antimicrobial and minimum inhibitory/bactericidal/fungicidal concentrations respectively of Pterocarpus santalinoides plants. Place and Duration of Study: Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Agulu Campus, Nigeria, between February – October, 2017. Methodology: Primary extraction and fractionation of the plant parts were undertaken with methanol, butanol, ethyl acetate, and n-hexane. Agar diffusion method for the primary antimicrobial screening on Muller-Hinton agar (bacteria) and Sabouraud dextrose agar (fungi) were used to assess the antimicrobial activities of the sixteen (16) samples on some microbial isolates namely Salmonella typhi, Escherichia coli, Candida albicans, Aspergillus niger, Microsporon canis, and Trichophyton rubrum. The minimum Inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC) and percentage inhibition diameter growth (PIDG) of the samples that yielded positive activity were also evaluated. Results: Twelve (12) samples exhibited inhibitory activity on at least one or more of the test isolates. The MIC range observed for the extracts and fractions that yielded positive activity was 12.5 – 100 mg/ml. The n-hexane fraction of the plant root indicated the best value of 12.5 mg/ml against M. canis. The best MBC/MFC value of 25 mg/ml was observed with the ethyl acetate fraction of the bark (against E. coli and M. canis) and the n-hexane fraction of the root (against M. canis). The result showed S. typhi to be the most sensitive organism to the metabolites of P. santalinoides. Extended-spectrum activity was observed with the ethyl acetate fraction of the bark against three (3) of the test isolates namely S. typhi, E. coli and M. canis. The determination of PIDG values for the test organisms against the plants’ extracts/fractions showed that crude methanol extract (28.57%) and ethyl-acetate fraction (0.14%) of the leaves, butanol fraction (0.14%) of the root (all against S. typhi) were the most potent test samples. Conclusion: The results indicated that the plant parts may have potential medicinal values and confirmed its use in traditional medicine.

Chlorella sorokiniana and Chlorella minutissima exhibit antioxidant potentials, inhibit cholinesterases and modulate disaggregation of ß-amyloid fibrils

BACKGROUND: Microalgae are aquatic chlorophyll-containing organisms comprising unicellular microscopic forms, and their biomasses are potential sources of bioactive compounds, biofuels and food-based products. However, the neuroprotective effects of microalgal biomass have not been fully explored. In this study, biomass from two Chlorella species was characterized, and their antioxidant, anticholinesterase and anti-amyloidogenic activities were investigated. RESULTS: GC­MS analysis of the extracts revealed the presence of some phenols, sterols, steroids, fatty acids and terpenes. Ethanol extract of Chlorella sorokiniana (14.21 mg GAE/g) and dichloromethane extract of Chlorella minutissima (20.65 mg QE/g) had the highest total phenol and flavonoid contents, respectively. All the extracts scavenged 2,2-diphenyl-1-picrylhydrazyl, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) and hydroxyl radicals. The highest metal chelating activity of the extracts was observed in the ethanol extracts of C. minutissima (102.60 µg/mL) and C. sorokiniana (107.84 µg/mL). Furthermore, the cholinesterase inhibitory activities of the extracts showed that ethanol extract of C. sorokiniana (13.34 µg/mL) exhibited the highest acetylcholinesterase inhibitory activity, while dichloromethane extract of C. minutissima (11.78 µg/mL) showed the highest butyrylcholinesterase inhibitory activity. Incubation of the ß-amyloid protein increased the aggregation of amyloid fibrils after 96 h. However, ethanol extract of C. sorokiniana and C. minutissima inhibited further aggregation of Aß1­42 and caused disaggregation of matured protein fibrils compared to the control. This study reveals the modulatory effects of C. sorokiniana and C. minutissima extracts on some mediators of Alzheimer's disease and provides insights into their potential benefits as functional food, nutraceutics or therapeutic agent for the management of this neurodegenerative disease.

Effects of n-hexane on the serum level of three neurotoxicity biomarkers in rat / 中国职业医学

OBJECTIVE: To observe the effect of n-hexane subchronic exposure on the serum level of neuron specific enolase(NSE), neurofilament light chain protein(NF-L) and nerve growth factor(NGF) in rat, and to explore the feasibility of using NSE, NF-L and NGF as biomarkers of n-hexane neurotoxicity. METHODS: Specific pathogen free male SD rats were randomly divided into control group and low-, medium-and high-dose exposure groups, with 6 rats in each group. Rats in the low-, medium-and high-dose exposure groups were given n-hexane solution at doses of 168, 675 and 2 700 mg/kg body mass, respectively, while rats in the control group were gavaged with 0.9% sodium chloride solution, once a day, 5 days a week for 6 weeks. At week 0, 2, 4, and 6 of exposure, the body mass of the rats was weighed, the gait scores were performed, and the serum levels of NSE, NF-L, and NGF were detected.RESULTS: Body mass, gait score and serum levels of NSE and NF-L in rats were statistically significant in terms of the n-hexane exposure dose and exposure time(P<0.01). At the 6 th week of n-hexane exposure, the body mass of the three dose exposure groups was lower than that of the control group(P<0.05), and the gait score was higher than that of the control group(P<0.05). Moreover, the abnormal gait of the rats showed a dose-effect relationship with the increasing n-hexane poisoning dose. At week 2, 4 and 6, the serum levels of NSE and NF-L in these three dose exposure groups were higher than that in the control group(P<0.05). In addition, the serum level of NF-L in rats in the medium-and high-dose exposure groups increased with the n-hexane exposure time increasing and showed a time-effect relationship(P<0.05). The level of serum NGF in rats was statistically significant in the main effects of n-hexane dose and duration of exposure(P<0.05). The serum NGF level in the high-dose exposure group was lower than that in the control group, the low-dose and medium-dose exposure groups(P<0.05). NGF level in serum of rats at week 6 was lower than that at week 0, 2 and 4(P<0.05). CONCLUSION: Both NSE and NF-L in serum can be used as biomarkers for the early effect of n-hexane on peripheral nerve injury. The feasibility of using serum NGF as a biomarker for the early effect of n-hexane on peripheral nerve injury warrants further investigation.

Determination of 2,5-hexanedion in urine by liquid-liquid extraction-gas chromatography / 中国职业医学

OBJECTIVE: To establish a method for rapid determination of 2,5-hexanedion in urine by liquid-liquid extraction-gas chromatography. METHODS: Two mL of urine simple was acidified using 100 μL of hydrochloric acid. Anhydrous sodium sulfate 0.5 g was added for salting out. Extraction was carried out using 1 mL of chromatographic grade ethyl acetate vortex, separated by Rtx®-WAX chromatographic column, and detected with flame ionization detector. RESULTS: The good linear range of 2,5-hexanedion was 0.25-15.00 mg/L. The correlation coefficient was 0.999 7. The detection limit was 0.08 mg/L and the minimum detection concentration was 0.25 mg/L. The average recovery rate was 93.0%-110.0%. The within-run relative standard deviation(RSD) was 1.9%-5.4% and the between-run RSD was 5.0%-11.2%. CONCLUSION: This method is simple, sensitive and accurate, which is suitable for detecting urine 2,5-hexanedion in occupational n-hexane exposed workers and suspected patients with occupational chronic n-hexane poisoning.

P0 protein promotes the expression of INF-γ and IL-10 in peripheral blood of n-hexane neuropathy patients / 中华劳动卫生职业病杂志

Objective@#To study the changes of monocyte cytokines in peripheral blood of n-hexane neuropathy patients induced by P0 protein, and to explore the role of autoimmunity in n-hexane neuropathy patients.@*Methods@#In May 2018, 5 patients with peripheral neuropathy diagnosed as n-hexane poisoning were selected as case group in Shenzhen Prevention and Treatment Center for Occupational Disease in 2017. 6 workers exposure to n-hexane and 6 workers without n-hexane exposure were selected as contact group and control group. Peripheral blood mononuclear cells(PBMC) were isolated from venous blood.@*Results@#The number of spots produced by INF-γ and IL-10 increased after stimulation with P0 protein in case group, and the positive rate was significantly higher than control group and the contact group.@*Conclusion@#Autoimmunity induced by P0 protein may be involved in the occurrence of myelin sheath damage in n-hexane neuropathy patients.

Effects of n-hexane on learning and memory and the expressions of nerve growth factor mRNA and nerve growth factor receptor mRNA of brain tissue in mice exposed to N-hexane / 中华劳动卫生职业病杂志

Objective@#To Effects of n-hexane on learning and memory and the expressions of nerve growth factor (NGF) mRNA and nerve growth factor receptor (NGFR) mRNA of brain tissue in mice exposed to N-hexane.@*Methods@#40 Kunming mice were randomly divided into low-dose group, meddle-dose group, high-dose dose group and control group, with 10 mice in each group. All the groups were orally exposed to n-hexane in different doses: low-dose group with 43.5 mg/kg, middle-dose group with 86.5 mg/kg and high-dose group with 173.0 mg/kg, 1 time per day for 20 d. After the poisoning, the Y-arm test and the expressions of NGF mRNA and NGFR mRNA and the concentrations of NGF and NGFR in the brain tissues of each group were measured.@*Results@#In the first Y-arm test, there existed a significant difference in correct reaction rate generally in all groups (P<0.05), and correct reaction rate in the middle-dose group and the high-dose group were low significantly compared with that in the control group(P<0.05). In the second Y-arm test, there existed a significant differences in total electric shock time and correct reaction rate generally in all groups (P<0.01), and the total electric shock time prolonged significantly and the correct response rate decreased significantly in 3 dose groups compared with those of the control group(P<0.05). The expression levels of NGF mRNA in brain tissues of low, meddle and high dose-groups were 0.81±0.66, 0.67±0.37 and 0.69±0.26, and the expression levels of NGFR mRNA were 1.22±0.42, 1.98±0.84 and 2.01±2.01, respectively. Compared with the control group, the expressions of NGF mRNA in the 3 dose groups decreased significantly (P<0.05), and the expression of NGFR mRNA in middle-and high-dose groups increased significantly (P<0.05). The concentrations of NGF in brain tissues of low,meddle and high dose-groups were 39.97±7.24 ng/L, 39.26±7.88 ng/L,31.70±8.21 ng/L,and the concentrations of NGFR were 17.37±6.82 ng/L,21.37±7.16 ng/L, 22.46±7.70 ng/L, respectively. Compared with the control group, the concentrations of NGF in high-dose groups decreased significantly(P<0.05), and the concentrations of NGFR in middle-and high-dose groups increased significantly (P<0.05).@*Conclusion@#N-hexane exposure can result in decrease of learning and memory in mice, which may be related to abnormal expression of NGF mRNA and NGFR mRNA in brain tissue.

Simultaneous detection of 45 kinds of common organic compounds in workplace air by gas chromatography / 中国职业医学

OBJECTIVE: To explore the feasibility of simultaneous detection of 45 kinds of common organic compounds in workplace air by solvent desorption-gas chromatography method.METHODS: A total of 45 kinds of common organic compounds such as benzene,1,2-dichloroeyhane,n-hexane and trichloroethylene in workplace air were collected with activated carbon tube and desorbed with carbon disulfide,separated by capillary chromatographic column,and detected with flame ionization detector.RESULTS: There was good linear relationship in the selected range.The correlation coefficients was 0.999 92-0.999 99.The detection limit was 0.03-0.30 mg/L and the minimum detectable concentration range was 0.01-0.20 mg/m~3( sample volume was 3.00 L).The average desorption efficiencies was 75.4%-105.7%.The within-run and between-run relative standard deviations were 0.4%-6.7% and 1.8%-7.9%,respectively.The sampling efficiency was 91.9%-100.0%.CONCLUSION: The method is simple,high sensitivity and good precision,which can be used for simultaneous detection of 45 kinds of common coexisting organic compounds in workplace air.

Study on the determination of pyrrole adduct content in hair samples / 中华劳动卫生职业病杂志

Objective@#To find out a method to determine the pyrrole adducts in the hairs.@*Methods@#Collected the hair from common people and rats, defatted after completely washed, steeped the hair in different concentration of 2, 5-hexandione to build hair model containing pyrrole adducts; dissolved the hair and determined the concentration of pyrrole adducts.@*Results@#(1) . The combination of 0.72 mol/L of sodium hydrate and 2% tyrisin could dissolve the hair, and the digestion liquid could react with the Ehrlich's reagent showing fuchsia color; (2) . The color could maintain longer after adding more ethanol; (3) . More pyrrole adducts would be produced by the increasing the concentration of 2, 5-dihexandione (P<0.01) ; (4) . Concentration of pyrrole adducts in n-hexane treated hair showed no difference compared with control (P>0.05) .@*Conclusion@#the method could be used to determine the concentration of pyrrole adducts in hair exposed to n-hexane

Influence of n-hexane on vascular endothelial active substances in brain tissue in mice / 中华劳动卫生职业病杂志

Objective@#To investigate the influence of n-hexane on vascular endothelial active substances in brain tissue in mice and its significance.@*Methods@#A total of 48 healthy Kunming mice were randomly divided into high-dose exposure group, middle-dose exposure group, low-dose exposure group, and control group, with 12 mice in each group. All groups except the control group were exposed to n-hexane via static inhalation (0.035 g/L, 0.018 g/L, and 0.009 g/L for the high-, middle-, and low-dose exposure groups, respectively) 4 hours a day for 21 days. the mice in the control groups were not exposed to n-hexane. After the exposure, the lev-els of endothelin-1 (ET-1) , nitric oxide (NO) , and angiotensin II (Ang II) in brain tissue were measured in all groups.@*Results@#There were significant differences in the levels of ET-1, NO, and Ang II between the three ex-posure groups and the control group (P<0.05). Compared with the control group, the high-and middle-dose expo-sure group had significant increases in the levels of ET-1 and Ang II and the high-dose exposure group had a sig-nificant reduction in the level of NO (P<0.05 or P<0.01).@*Conclusion@#n-Hexane can affect the vascular endothe-lial active substances in brain tissue in mice, and the changes and imbalance in vascular endothelial active sub-stances may be one of the reasons for central nervous system impairment caused by n-hexane.

Comparison of therapeutic effects between comprehensive therapy and routine therapy in treatment of occupational chronic n-hexane poisoning / 中国职业医学

OBJECTIVE: To evaluate the therapeutic effects between comprehensive therapy and routine therapy in treatment of occupational chronic n-hexane poisoning. METHODS: By randomized controlled trial,116 cases with occupational chronic n-hexane poisoning were divided into two groups: the control group( n = 58) and the treatment group( n = 58). Subjects in the control group were given vitamin B_(12) and vitamin B_1 for neural nutrition; and Danshen and deproteinized calf blood extractive injection for activating blood circulation to dissipate blood stasis. Subjects in the treatment group were treated with comprehensive treatment including traditional Chinese and Western medicine,which including mouse nerve growth factor,acupuncture,physical therapy( infraredtherapy,microwave irradiation therapy),Chinese medicine steamingwashing and comprehensive rehabilitation therapy for a period of 12 weeks in addition to the conventional treatment. The curative effect and adverse reactions of both groups were observed after 12 weeks,and the treatment results and hospital stay were followed up. RESULTS: Before treatment,no significant differences( P > 0. 05) were noted in both groups in scores of neurological symptoms,signs,activities of daily living and neurogenic damage indexes of electroneuromyography[including motor digital latency( MDL),motor nerve conduction velocity( MCV),sense nerve conduction velocity( SCV) of median nerve,ulnar nerve,sural nerve or common peroneal nerve; and the detection of lengthen MDL,shorten MCV and SCV]. After treatment,patients in both groups got better in terms of the above indicators( P < 0. 05),with larger extend of improvement noted in the treatment group than in the control group( P < 0. 05). No obvious adverse reactions were noted in the 2 groups. Hospital stay of patients in the treatment group was about 2 months shorter than that in the control group( P < 0. 05). CONCLUSION: The therapeutic effects of comprehensive therapy on occupational chronic n-hexane poisoning are obviously better than routine therapy,which is an effective and safe therapeutic method.

Clinical analysis on occupational chronic n-hexane poisoning cases / 中国职业医学

OBJECTIVE: To collect,analyze and summarize the clinical characteristics of occupational chronic n-hexane poisoning cases reported in the literatures published in domestic open public periodicals in order to provide evidence for the revision of GBZ 84 Diagnostic Criteria of Occupational Chronic n-Hexane Poisoning. METHODS: By the bibliometrics method,the databases of CNKI,VIP and WANFANG were used to retrieve literatures on the occupational chronic n-hexane poisoning published from 1990 to 2014. The literatures with detailed clinical data were screened and selected for summary and analysis. RESULTS: A total of 68 reference literatures meeting the inclusion criteria were chosen in 25 years of domestic publication. These literatures reported 1 027 cases of occupational n-hexane poisoning,including 165 males and 862 females. The median of age was 28. 3( 13. 0-59. 0) years. Most of the cases had a disease incubation period of 2. 0-10. 0months. The diagnostic classification was made in 817 cases( 79. 6%),with mild,moderate and severe chronic n-hexane poisoning in 418,241 and 158 cases,respectively. The n-hexane levels in workplace air were reported in 736 cases( 71. 7%),91. 8%( 676 /736) of which had exceeded the national occupational exposure limit. Chronic n-hexane poisoning was mainly characterized by peripheral nerve damage,626 cases( 61. 0%) had feeling and movement disorders,256 cases( 24. 9%) had movement disorder and 145 cases( 14. 1%) had feeling disorders. The clinical characteristics of these disorders were bilaterally symmetric feeling or movement disorders in distal limbs. The nerve-electromyography examination showed the neurogenic damage,which was parallel with the severity of patients' condition and could be detected at early stage of illness. The gas chromatography was used to detect the 2,5-hexanedione level of 156 cases( 15. 2%) of patients and the positive detection rate was 50. 6%( 70 /156). Currently,there was no specific medication or other therapy for treatment of chronic n-hexane poisoning. The comprehensive therapy which mainly include nerve restoration was the general therapy method. Addition of mouse nerve growth factor to the conventional therapy had significant treatment effects. The therapeutic effect was reported in 954 cases with the recovery rate of 83. 6%( 798 /954),and the complication in nervous system was observed in 156 cases who were not cured. CONCLUSION: The main clinical manifestation of chronic n-hexane poisoning is peripheral neuropathy. The nerve-electromyography is the most important diagnostic method. Currently,comprehensive therapy is used with good prognosis in the patients.

Effect of Hexane Extract of Galla Rhois on Inflammatory Alveolar Bone Loss

One of functions of Galla Rhois (GR) is reportedly an anti-inflammatory effect on the several inflammatory diseases. However, an effect of GR related to periodontitis has not been investigated. In the present study, we examined the effect of the hexane extract of Galla Rhois (GR-H) on periodontitis. Cytotoxicity was assessed by MTS analysis using human gingival fibroblast (hGF) cells. Experimental periodontitis was induced by injecting E.coli LPS into the palatal gingiva maxillary molar thrice weekly for 3 weeks (LPS group). GR-H diluted in 1xPBS was orally administrated using a syringe at 30 mg/kg body weight and 100 mg/kg body weight once a day (GR-H group). GR-H effect on the alveolar bone loss (ABL) was digitized with a micro-CT. GR-H treatment at concentrations exceeding 0.5 mg/ml showed cytotoxic effect in hGF cells. The micro-CT among groups were presented for the different distances from cemento-enamel junction (CEJ) to alveolar bone crest (ABC). The results indicated an inhibitory effect on alveolar bone loss for orally administered GR-H in a model of LPS-induced periodontitis.

Comparative Study of the Physicochemical Properties and Fatty Acid Composition of Some Indigenous Spices in Nigeria.

Aim: This study evaluates the physicochemical properties and fatty acid composition of “Gbafilo” (Uapaca guineesis), “Omilo” (Parinari excelsa), “Country onion” (Afrostyax lepidphyllus), and “Taiko” (Zanthoxyllum zanthoxylloids). Methods: The oil was extracted using n-hexane in a soxhlet apparatus and evaluated for their physical and chemical properties. Fatty acids profile was determined by Gas Chromatography (GC). Results: The Refractive Index, Specific gravity and Oxidative stability values range between 1.44- 1.46, 0.930-.0970, 40-72hr, respectively; While Iodine, Acid, Ester and Saponification values range between 94.14-105.20 I2/100g, 2.58-19.25mgKOH/g, 164.28-231.14mgKOH/g and 170.92-233.72mgKOH/g, respectively. Oleic acid was the predominant fatty acid in Omilo (92.98%) and Country onion (72.73%); While palmitic acid was predominant in Gbafilo (30.45%) and Taiko (28.09%). Linoleic acid was present only in Country onion (12.84%) and Omilo (2.04%). Conclusion: These results suggest that the oil from these spices have potentials for use as food supplements and industrial raw materials in addition to their traditional use as condiments.