Comparison of benzene exposure in drivers and petrol stations workers by urinary trans,trans-muconic acid in west of Iran

Motor vehicle traffic is the main emission source of benzene. We undertook this study in order to compare benzene exposure and urinary levels of trans,trans-muconic acid (t,t-MA) in taxi drivers and petrol station workers. Air benzene levels were analyzed with gas chromatography using a Flame Ionization Detector. t,t-MA was extracted from urine and analyzed using high performance liquid chromatography. Significant differences in levels of urinary t,t-MA were found in drivers and petrol station workers when compared to a control group (p<0.05). Correlation coefficients between benzene in air and t,t-MA for petrol station workers and drivers were 0.65 and 0.30, respectively. The concentration of benzene in the breathing zone of petrol station workers was 2-3 times higher than drivers, and also 3 times greater than a threshold level (0.5 ppm) recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). The lowest benzene concentration at which urinary t,t-MA increased to a measurable level was approximately 0.17 ppm. In conclusion our results suggested that high benzene levels are emitted in petrol stations in west Iran. t,t-MA analysis was able to separate those exposed from the non-exposed benzene group when benzene in the breathing zone of subjects was greater than 0.17 ppm.     

上海市汽车加油站职业病危害现况调查及防治对策

目的通过对本市部分区汽车加油站企业职业病危害现状的抽样调查,分析现阶段加油站行业职业卫生工作存在的问题,为职业卫生监管部门制定管理对策提供依据。方法制定加油站职业病危害现状调查表与检测方案,对5个区采用单纯随机抽样抽取50家汽车加油站,每个区县10家,采用问卷方式开展职业卫生管理工作调查,并对每个加油站的环境、作业岗位及油品原料的汽油和苯含量进行采样检测。结果当前汽车加油站开展的职业卫生工作与《中华人民共和国职业病防治法》的要求还存在相当大的差距,职业病危害检测结果个体采样苯浓度超标率5％,油品采样苯含量检出率高达69．7％,且存在超标样品。结论应按照《中华人民共和国职业病防治法》将汽车加油站纳入本市职业病防治监管的范畴,亟需制定“上海市汽车加油站职业卫生操作管理规程”。     

Methodological issues in biomonitoring of low level exposure to benzene

Data from a pilot study on unmetabolized benzene and trans,trans muconic acid (t,t-MA) excretion in filling station attendants and unexposed controls were used to afford methodological issues in the biomonitoring of low benzene exposures (around 0.1 ppm). Urinary concentrations of benzene and t,t-MA were measured by dynamic head-space capillary GC/FID and HPLC, respectively. The accuracy of the HPLC determination of t,t-MA was assessed in terms of inter- and intra-method reliability. The adequacy of urinary t,t-MA and benzene as biological markers of low benzene exposure was evaluated by analysing the relationship between personal exposure to benzene and biomarker excretion. Filling station attendants excreted significantly higher amounts of benzene, but not of t,t-MA, than controls. Adjusting for occupational benzene exposure, smokers excreted significantly higher amounts of t,t-MA, but not of unmetabolized benzene, than nonsmokers. A comparative analysis of the present and previously published biomonitoring surveys showed a good inter-study agreement regarding the amount of t,t-MA and unmetabolized benzene excreted (about 0.1-0.2 mg/l and 1-2 micrograms/l, respectively) per unit of exposure (0.1 ppm). For each biomarker, based on the distribution of parameters observed in the pilot study, we calculated the minimum sample size required to estimate the population mean with given confidence and precision.     

Service station attendants' exposure to benzene and gasoline vapors.

Service station attendants' exposure to benzene, based on 85 TWA results at 7 stations, were well below 1 ppm except one exposure of 2.08 ppm. Short term exposures were 1.21 ppm or less over 15 minutes. Attendants' TWA exposures to total gasoline vapor were 114 ppm or less, with measured 15 minute exposures no higher than 100 ppm during actual filling operations. One station had vapor recovery nozzles; exposures here were below the detectable level (0.01 ppm benzene) on 10% more days than the next lowest station. Still, the magnitude of overall exposures and the degree of reduction indicate that vapor recovery is not needed to control exposures. Some attendants had consistently higher exposures than others. This is felt to be due to work practices, such as standing close to the fill opening, plus local wind conditions around the car as it is filled with gasoline.     

Exposure to benzene and urinary concentrations of 8-hydroxydeoxyguanosine, a biological marker of oxidative damage to DNA.

OBJECTIVES--Benzene is an established animal and human carcinogen. The mechanism of benzene toxicity, particularly its leukaemogenic effect, is not fully understood. The modified base 8-hydroxy-deoxyguanosine (8-OHdG) is a sensitive marker of the DNA damage due to hydroxyl radical attack at the C8 of guanine. This damage, if left unrepaired, has been proposed to contribute to mutagenicity and cancer promotion. We conducted this biomonitoring study with the aim of evaluating the association between excretion of 8-OHdG and level of exposure to benzene and other aromatic compounds among occupationally exposed people. METHODS--A random sample of 65 filling station attendants from Rome, Italy was studied for personal exposure to benzene, toluene, and xylenes, and excretion of 8-OHdG. Information about age, length of employment, smoking habits, and diagnostic exposure to x rays was collected by questionnaire. An average yearly level of exposure to benzene and methylbenzenes was calculated for each filling station attendant on the basis of about seven repeated personal samples collected during one year. A spot sample of 20 ml of urine was collected from each worker. Concentrations of 8-OHdG were determined by high performance liquid chromatography (HPLC) with coupled columns. RESULTS--A mean (SD) concentration of 1.36 (0.49) mumol of 8-OHdG/mol of creatinine was measured. A significant correlation was found between urinary 8-OHdG and exposure to benzene (r = 0.34). In a multiple regression analysis relating the concentration of urinary 8-OHdG with the age, length of employment, smoking, diagnostic exposure to x rays and personal exposure to benzene, an increase of 0.15 mumol/mol creatinine in urinary 8-OHdG/unit increase in the natural logarithm of the average yearly benzene concentration was estimated. CONCLUSION--This study shows a dose-response effect between personal exposure to benzene and urinary 8-OHdG concentration; further studies are needed to clarify the biological significance of 8-OHdG as a marker of cancer risk.     

Exposure to Volatile Organic Compounds in an Ethanol and Gasoline Service Station

The present study was conducted to determine the VOCs concentrations in a service station located in a residential and commercial area in the city of Rio de Janeiro. This is, to our knowledge, the first published determination in Brazil, where both ethanol and ethanol-blended gasoline are used. Electro polished, stainless steel, evacuated canisters were used for sampling. The analysis was performed by gaschromatography with flame ionization detection (CG-FID) and by gas chromatography–mass spectrometry (CG–MS). A total of 80 and 56 compounds were determined in samples collected at the service station and control location, respectively. The most abundant compounds at the service station were in order of decreasing concentration (units: μg m⁻³): 2-methylbutane (1,715.7), 2-methylbut-1-ene (1,043.2), isobutene (758.8), 2-methylprop-1-ene (703.7), 2-methylpentane (492.1), pentadi-1,3-ene (189.7), toluene (157.0), benzene (144.5), but-2-ene (126.3) and m,p-xylene (123.2). A mean concentration of 144.5 μg m⁻³ was determined for benzene, this value is about ten times the concentration determined in the control location in this work and about 70 times the value determined in other locations of Rio de Janeiro using charcoal cartridges for the sampling. The mean benzene/toluene ratios are 0.92 and 0.31 in the service station and control location, respectively. Since in Brazil service station workers are employed to fill customer’s cars (self-service is not commonly used) the possible risk of cancer of these workers should be evaluated in a future study.     

Benzene exposure assessment for use of a mineral spirits-based degreaser

This study examines benzene emissions from the use of a metal parts washer ("degreaser") supplied with a mineral spirits solvent containing either 9 or 58 ppm benzene. Air samples were obtained during a one-hour session of relatively vigorous parts cleaning activity using a degreaser station equipped with wet brush and sprayer attachments and a compressed air hose. Two methods were utilized to assess airborne benzene levels: U.S. EPA TO-14 (summa stainless steel canister) and NIOSH 1501 (charcoal tube). Overall, both methods provided similar results, excepting detection limit differences. The first simulation was performed with recycled solvent (9 ppm benzene in solvent) showing average one-hour airborne benzene levels < or =33 ppbv in the worker's breathing zone and directly above the parts cleaning tank. Average airborne benzene concentrations 18 inches away from the tank were below 2 ppbv during the 60-minute cleaning protocol. The second simulation with benzene-spiked recycled solvent (58 ppm benzene) showed airborne benzene levels averaging 500 ppbv measured over the 60-minute cleaning period in the worker's breathing zone and directly above the tank, while average concentrations 18 inches from the tank perimeter were 63 ppbv. The data indicate that average and peak exposures to airborne benzene were roughly proportional to the solvent benzene content, although the brief peak exposures exhibited greater variance probably related to aerosol generation associated with the use of the brush and/or spraying attachment. Under this selected upper bound exposure simulation, we found that cleaning parts using a recycled mineral spirits-based solvent in an open warehouse setting did not result in exposures in excess of the current occupational exposure limit of 0.5 ppm averaged over 8 hours for solvent benzene content between 9 and 58 ppm.     

GIS-based assessment of cancer risk due to benzene in Tehran ambient air

Objectives

The present study aimed to assess the risk of cancer due to benzene in the ambient air of gas stations and traffic zones in the north of Tehran. The cancer risk was estimated using the population distribution data for benzene levels and the unit risk for benzene proposed by the United States Environmental Protection Agency (US EPA).

Material and Methods

Sixteen sampling locations were monitored, once every week, during 5 April 2010 to 25 March 2011.

Results

The results showed that the mean annual benzene concentration was 14.51±3.17 parts per billion (ppb) for traffic zones and 29.01±1.32 ppb for outside gas stations. The risk calculated was 1026×10^?6 for gas station 27 and 955×10^?6 for gas station 139.

Conclusions

According to our results, the annual benzene level in Tehran ambient air is 2 to 20 times higher than the respective value specified in International Standard (1.56 ppb). Moreover, the results showed a notable increase of cancer risks, ranging from 10% to 56%, for the vicinity population close to the gas stations in comparison to the vicinity population in the traffic zones.     

Customer exposure to MTBE, TAME, C6 alkyl methyl ethers, and benzene during gasoline refueling.

We studied customer exposure during refueling by collecting air samples from customers' breathing zone. The measurements were carried out during 4 days in summer 1996 at two Finnish self-service gasoline stations with "stage I" vapor recovery systems. The 95-RON (research octane number) gasoline contained approximately 2.7% methyl tert-butyl ether (MTBE), approximately 8.5% tert-amyl methyl ether (TAME), approximately 3.2% C6 alkyl methyl ethers (C6 AMEs), and 0.75% benzene. The individual exposure concentrations showed a wide log-normal distribution, with low exposures being the most frequent. In over 90% of the samples, the concentration of MTBE was higher (range <0.02-51 mg/m3) than that of TAME. The MTBE values were well below the short-term (15 min) threshold limits set for occupational exposure (250-360 mg/m3). At station A, the geometric mean concentrations in individual samples were 3.9 mg/m3 MTBE and 2. 2 mg/m3 TAME. The corresponding values at station B were 2.4 and 1.7 mg/m3, respectively. The average refueling (sampling) time was 63 sec at station A and 74 sec at station B. No statistically significant difference was observed in customer exposures between the two service stations. The overall geometric means (n = 167) for an adjusted 1-min refueling time were 3.3 mg/m3 MTBE and 1.9 mg/m3 TAME. Each day an integrated breathing zone sample was also collected, corresponding to an arithmetic mean of 20-21 refuelings. The overall arithmetic mean concentrations in the integrated samples (n = 8) were 0.90 mg/m3 for benzene and 0.56 mg/m3 for C6 AMEs calculated as a group. Mean MTBE concentrations in ambient air (a stationary point in the middle of the pump island) were 0.16 mg/m3 for station A and 0.07 mg/m3 for station B. The mean ambient concentrations of TAME, C6 AMEs, and benzene were 0.031 mg/m3, approximately 0.005 mg/m3, and approximately 0.01 mg/m3, respectively, at both stations. The mean wind speed was 1.4 m/sec and mean air temperature was 21 degreesC. Of the gasoline refueled during the study, 75% was 95 grade and 25% was 98/99 grade, with an oxygenate (MTBE) content of 12.2%.     

Benzene exposure monitoring of Tunisian workers

To monitor benzene exposure and to check reliability of urinary trans,trans-Muconic Acid (t,t-MA) as a bio-marker of benzene exposure in local conditions, a study was conducted on 30 Tunisian exposed workers (20 tanker fillers and 10 filling station attendants). The analyses were carried out on environmental air and urinary t,t-MA before (t,t-MAA) and at the end of work shift (t,t-MAB). 20 nonoccupationally exposed subjects were also investigated. The average value of environmental benzene concentration was 0.17 ppm. The differences between t,t-MAA and t,t-MAB concentrations and between t,t-MAB and t,t-MA measured in controls (t,t-MAC) were both significant (p < 0.001). Benzene air concentrations were well correlated with t,t-MAB: R = 0.76. In the nonexposed group, average t,t-MA concentrations is significantly higher among smokers than nonsmokers (P < 0.02). Analysis of urinary t,t-MA offers a relatively simple and suitable method for benzene exposure monitoring.     

Evolution of occupational exposure to environmental levels of aromatic hydrocarbons in service stations

During refuelling, people may easily be exposed to extremely high levels of gasoline vapour for a short time, although such exposure takes on more importance in the case of service station attendants. The volume of gasoline sold in refuelling operations and the ambient temperature can significantly increase the environmental level of benzene, toluene and xylene (BTX) vapours and, subsequently, the occupational risk of service station attendants. This is especially true in the case of benzene, the most important component of gasoline vapours from a toxicological point of view. The European Directive 98/70/EC, limiting the benzene composition of gasoline, and 94/63/EC, concerning the use of vapour recovery systems in the delivery of gasoline to services stations, were applied in Spain from January 2000 and 2002, respectively. In addition, a new limit value for occupational exposure of 3.25 mg/m(3) was fixed for benzene in Directive 97/42/EC, applied from June 2003. However, recent years have seen the growing use of diesel as well as of unleaded and reformulated gasoline. In this study, we analyse the differences found between air concentration levels of BTXs in 2000 and 2003, analysing samples taken from the personal breathing-zone of occupationally exposed workers in service stations. The results are compared with those obtained in a similar study carried out in 1995 (before the new regulations came into force). The study was carried out in two phases. The first phase was carried out in 2000, after application of the new legal regulation limiting the benzene concentration in gasoline. In this case, an occupationally exposed population of 28 service station attendants was sampled in July, with a mean ambient temperature of 30-31 degrees C. In the second phase, 19 exposed subjects were sampled in July 2003, one of the warmest months in recent years with mean temperatures of 35-36 degrees C during the time of exposure monitoring. The results were then compared with those obtained in 1995, for similar summer weather conditions (environmental temperature between 28 and 30 degrees C). A significant relationship between the volume of gasoline sold and the ambient concentration of aromatic hydrocarbons was found for each worker sampled in all three of the years. Furthermore, a significant decrease in the environmental levels of BTXs was observed after January 2000, especially in the case of benzene, with mean time-weighted average concentrations for 8 h of 736 microg/m(3) (range 272-1603) in 1995, 241 microg/m(3) (range 115-453) in 2000 and 163 microg/m(3) (range 36-564) in 2003, despite the high temperatures reached in the last mentioned year.     

Environmental exposure to volatile organic compounds among workers in Mexico City as assessed by personal monitors and blood concentrations.

Benzene, an important component in gasoline, is a widely distributed environmental contaminant that has been linked to known health effects in animals and humans, including leukemia. In Mexico City, environmental benzene levels, which may be elevated because of the heavy traffic and the poor emission control devices of older vehicles, may pose a health risk to the population. To assess the potential risk, portable passive monitors and blood concentrations were used to survey three different occupational groups in Mexico City. Passive monitors measured the personal exposure of 45 workers to benzene, ethylbenzene, toluene, o-xylene and m-/p-xylene during a work shift. Blood concentrations of the above volatile organic compounds (VOCs), methyl tert-butyl ether, and styrene were measured at the beginning and the end of a work shift. Passive monitors showed significantly higher (p > 0.0001) benzene exposure levels among service station attendants (median = 330 microg/m3; range 130-770) as compared to street vendors (median = 62 microg/m3; range 49-180) and office workers (median = 44 microg/m3, range 32-67). Baseline blood benzene levels (BBLs) for these groups were higher than those reported for similar populations from Western countries (median = 0.63 microg/L, n = 24 for service station attendants; median = 0.30 microg/L, n = 6 for street vendors; and median = 0.17 microgr;g/L, n = 7 for office workers). Nonsmoking office workers who were nonoccupationally exposed to VOCs had BBLs that were more than five times higher than those observed in a nonsmoking U.S. population. BBLs of participants did not increase during the work shift, suggesting that because the participants were chronically exposed to benzene, complex pharmacokinetic mechanisms were involved. Our results highlight the need for more complete studies to assess the potential benefits of setting environmental standards for benzene and other VOCs in Mexico.     

通信机房作业环境空气污染及特征研究

目的 了解通信作业环境空气的污染状况,为制定防治措施提供依据。方法 选择某通信站的一个地面站、两个地下站共9个作业环境,应用气体传感器、沉降法以及气相色谱－质谱联用技术,现场测定了一氧化碳、二氧化碳、可吸入颗粒物（IP）、细菌总数、二氧化氮、二氧化硫、硫化氢以及4种苯系物等11项空气污染指标。结果 地面站污染物浓度范围分别为：二氧化碳：0.053-0.055%,一氧化碳：2.06-3.31mg/m^3;可吸入颗粒物：未检出－0.08mg/m^3;细菌总数：414－1007CFU／^3;苯：未检出－ 33.48mg/m^3;甲苯：9.75-29.40mg/m^3;乙苯：2.84-6.00mg/m^3;二甲苯：7.82-20.21mg/m^3;地下站污染物浓度范围分别为：二氧化碳：0.032-0.107%,一氧化碳：未检出－34.47mg/m^3;可吸入颗粒物：未检出-0.04mg/m^3;细菌总数：847－1391CFU／m^3;甲苯：16.54-345.54mg/m63;乙苯：未检出－6.29mg/m^3;二甲苯：10.90-313.87mg/m^3;二氧化氮：0.32-0.67mg/m^3;硫化氢：未检出－0.78mg/m^3;二氧化硫：未检出-1.26mg/m^3;苯未检出。结论 通信机房特别是地下作业环境存在空气污染问题,而以苯系物为代表的VOCs 污染应引起重视。     

Evaluation of personal exposure to monoaromatic hydrocarbons

OBJECTIVES: To evaluate the personal exposure of members of the general public to atmospheric benzene, toluene, and the xylenes, excluding exposure from active smoking. METHOD: 50 volunteers were equipped with active air samplers for direct measurement of personal exposure to monoaromatic hydrocarbons (MAH) and an activity diary was completed during each sampling period. Exposures were also estimated indirectly by combining activity data with independent measurements of hydrocarbon concentrations in several microenvironments. RESULTS: Personal exposure were generally well in excess of those which would be inferred from outdoor measurements from an urban background monitoring station. A wide range of sources contribute to exposure, with indoor and in car concentrations generally exceeding those measured at background outdoor locations. Environments contaminated with tobacco smoke were among those exhibiting the highest concentrations. Personal exposures determined indirectly from activity diaries/microenvironment measurements were well correlated with those determined directly with personal samplers. Personal 12 hour daytime exposures to benzene ranged from 0.23-88.6 ppb (mean 3.81 ppb), with 12 hour night time exposures of 0.61-5.67 ppb (mean 1.94 ppb) compared with an annual average concentration of 1.18 ppb at the nearest suburban fixed site monitoring station. The excess of personal exposure over fixed site concentrations was greater for benzene and toluene than for the xylenes. CONCLUSION: A wide range of sources contribute to personal exposures to monoaromatic hydrocarbons with exposure duration being as important a determinant of total exposure as concentrations. Exposures generally exceed those estimated from concentrations measured by background fixed point monitors. Microenvironment sampling combined with activity diary information can provide satisfactory estimates of personal exposure to these compounds.

 

     

Myeloproliferative disorders due to the use of gasoline as a solvent: report of three cases

BACKGROUND: Health effects of occupational exposure to benzene are currently a problem, despite the fact that preventive measures have been in existence in Italy for more than 40 years. OBJECTIVES: To describe three recent cases of severe haematological disease presumably induced by an occupational exposure to benzene. Exposure occurred as a result of contact with ordinary automobile petrol used as a solvent-degreaser for metal parts. METHODS: Clinical diagnosis was performed using standard immuno-phenotypic and morphological criteria; the hypothesis of an occupational origin was derived from analysis of the occupational histories. RESULTS: The first case was a 59 year-old blacksmith suffering from acute myeloid leukaemia (AML) FAB M2, who had used petrol for 36 years to degrease the forged metal parts before painting them. The second was a 53 year-old mechanic with AML FAB M3 who had used petrol for 15 years to degrease mechanical parts of tanker motors. The third was an 82 year-old car mechanic suffering from idiopathic myelofibrosis since the age of 75, who had used petrol to degrease mechanical car motor parts for 42 years. In all three cases, the environmental hygiene measures necessary to limit inhalation or skin contact were not followed and, at times, in the case of the two mechanics, the petrol was siphoned by mouth; so there was substantial exposure to the 1-5% benzene present in the petrol. Latency of the disease was between 30-50 years from start of exposure, and between 3-17 years following cessation of exposure. CONCLUSION: The cases described indicate that the myelotoxic effects of benzene are still a problem. They were the consequence of improper use of petrol, due to total misinformation of the risks involved in such use. It is not possible to ascertain whether the cases presented are a casual aggregation or if the use of petrol as a solvent is more common than is normally believed; in the latter case two questions must be asked: is a "normal" occupational history able to discover such an uncommon risky condition of exposure? If it cannot, how many cases of benzene-related diseases escape aetiological diagnosis? It is not possible to provide precise answers but efforts should be made to improve the quality of information about the risks of petrol. Furthermore, in all cases of haematological disease potentially related to benzene, any form of contact with petrol, even if uncommon, should be carefully researched.     

Gasoline and vapor exposures in service station and leaking underground storage tank scenarios.

Exposure to gasoline and gasoline vapors from service station operations and leaking underground storage tanks is a major health concern. Six scenarios for human exposure were examined, based primarily on measured air and water concentrations of total hydrocarbons, benzene, xylenes, and toluene. Calculated mean and upper limit lifetime exposures provide a tool for assisting public health officials in assessing and managing gasoline-related health risks.     

某油藏计量转运站职业病危害现况

[目的]调查某油藏计量转运站（简称计转站）职业病危害,提出改进措施,保护劳动者健康。[方法]采用职业卫生现场调查、职业病危害因素检测等方法进行综合评价。[结果]该计转站运行中的主要职业病危害因素有硫化氢、非甲烷总烃、苯、甲苯、二甲苯、甲烷、甲醇和噪声,各职业病危害因素浓度或强度均低于国家职业接触限值;化学毒物防护设施、噪声控制设施、高温防护设施基本可行,具有一定的防护效果。职业卫生管理、职业健康监护及个人使用的职业病防护用品等职业病防护措施基本符合《工业企业设计卫生标准》的要求。[结论]该计转站运行过程中的职业病危害控制措施基本可行、有效,不会对人体健康产生不良影响。     

某地铁站竣工耐室内化学性污染物监测与评价

目的对深圳某地铁站竣工时站厅、站台、室内空气化学性污染物进行卫生监测与评价,预防和控制污染物可能对乘客健康的危害。方法根据该地铁站厅、站台面积,采用随机抽样方法,每天分上、下午对室内空气化学性污染物进行连续3天的检测。结果12种化学性污染物3天检测结果的均值均无超标;站厅站台的PM10、站厅的苯、站台的TVOC合格率分别为85．O％、78．8％、91．7％、96.3％,其他污染物各检测点合格率均为100％;站厅和站台CO、CO2、SO2、NO2,站厅的甲醛,站台的笨、二甲苯的含量明显低于深圳市2004年18个地铁站的平均水平（P〈．05）。结论该地铁站竣工时站厅站台受化学性污染物污染的程度较轻,可能与改善通风和使用环保材料有关。     

Esophageal cancer complicated by acute myelofibrosis--report of an autopsy case

An autopsy case of esophageal cancer complicated by myelofibrosis was studied. A 62-year-old Japanese patient with esophageal cancer, received surgical treatment and then splenectomy. The resected spleen was normal in appearance. Five months later he received radiation therapy for the cancer. After the therapy, his blood profile revealed thrombocytopenia and leukoerythroblastosis, and the bone marrow punctures were dry tap. He died of disseminated fungal infections at eleven months after the first operation. An autopsy of the patient revealed a striking increase in the megakaryocytes and a moderate increase in the reticulin fibers in the bone marrow. Myeloid metaplasia was noted in the lymph nodes, kidneys, and other organs and tissues, although the lymph nodes were not grossly swollen. These findings suggest esophageal cancer complicated by acute myelofibrosis. This it the first case report on esophageal cancer complicated by acute myelofibrosis.     

Novel method in diagnosis of chronic myeloproliferative disorders--detection of JAK2 mutation

Chronic myeloproliferative disorders are clonal hematopoietic stem cell disorders characterized by proliferation of one or more myeloid cell lineages in the bone marrow. The WHO classification describes six major groups of chronic myeloproliferative disorders, as follows: chronic myeloid leukemia, chronic neutrophilic leukemia, chronic eosinophilic leukemia, polycythemia vera, essential thrombocythemia and chronic idiopathic myelofibrosis. The diagnosis of chronic myeloid leukemia and certain types of chronic eosinophilic leukemia are based on the detection of fusion genes (in chronic myeloid leukemia the BCR/ABL fusion gene, and in chronic eosinophilic leukemia the FIP1L1-PDGFRalpha gene). On the other hand molecular markers for polycythemia vera, essential thrombocythemia and chronic idiopathic myelofibrosis were lacking, making it difficult to identify these disorders clearly. The authors investigated the incidence of the newly identified somatic point mutation V617F of the Janus-2 tyrosine kinase in patients with polycythemia vera, essential thrombocythemia and myelofibrosis. Janus-2 kinase is a cytoplasmic, non-receptor protein-tyrosine kinase with a key role in signal transduction from multiple hematopoietic growth factor receptors. The mutant protein is constitutively phosphorylated and is able to activate its downstream signaling pathways in the absence of any cytokine, thereby contributing to the pathogenesis of chronic myeloproliferative disorders. The authors investigated DNA samples from 132 patients with chronic myeloproliferative disorders. The V617F mutation was detected by allele-specific polymerase chain reaction, and the patients were genotyped by a DNA tetra-primer amplification refractory mutation system assay. Approximately 73% of polycythemia vera, 60% of essential thrombocythemia and 67% of myelofibrosis showed the JAK2 V617F mutation. Using the amplification refractory mutation system assay, the frequency of homozygotes was 17.5% in polycythemia vera, 5.4% in essential thrombocythemia and 0% in myelofibrosis. The authors established an effective polymerase chain reaction based method for the identification of JAK2 mutation in the routine oncohematologic diagnostics.