新标准急性下壁心肌梗死ⅡⅢ导联研段抬高STⅢ／Ⅱ〉1对右室心肌梗死的诊断价值

目的：右室心肌梗死心电图诊断新标准的诊断价值。方法：回顾分析23例ⅡⅢ导联ST段抬高的急性下壁心肌梗死心电图，其中17例确诊合并右室心肌梗死，分析急性下壁心肌梗死STⅢ／Ⅱ〉1对右室心肌梗死的临床诊断价值。结果：急性下壁心肌梗死ⅡⅢ导联ST段抬高，STⅢ／Ⅱ〉1对诊断右室心肌梗死的特异性较高。结论：急性下壁心肌梗死ⅡⅢ导联ST段抬高STⅢ／Ⅱ〉1可作为诊断右室心肌梗死的新标准。     

新标准急性下壁心肌梗死ⅡⅢ导联SI段抬高STⅢ/Ⅱ》1对右室心肌梗死的诊断价值

目的:右室心肌梗死心电图诊断新标准的诊断价值.方法:回顾分析23例ⅡⅢ导联ST段抬高的急性下壁心肌梗死心电图,其中17例确诊合并右室心肌梗死,分析急性下壁心肌梗死STⅢ/Ⅱ>1对右室心肌梗死的临床诊断价值.结果:急性下壁心肌梗死ⅡⅢ导联ST段抬高,STⅢ/Ⅱ>1对诊断右室心肌梗死的特异性较高.结论:急性下壁心肌梗死ⅡⅢ导联ST段抬高STⅢ/Ⅱ>1可作为诊断右室心肌梗死的新标准.     

STⅢ／Ⅱ〉1对急性下壁心肌梗死合并右室梗死的诊断价值

急性下壁心肌梗死常合并右室梗死，约占下壁梗死的40％。临床上可根据心电图右侧胸前导联（V3R—V7R）的特征性改变而作出诊断。然而，在大多数医院右侧胸前导联并非常规记录。并且右侧胸前导联ST段抬高时间较短。约55％的患者ST段在发病后10h内降至正常。因此难免有遗漏右室梗死的诊断，有文献报道，下壁心梗时，常规EKG主要反映下壁心电活动的Ⅱ、Ⅲ、avF导联在右室梗死时可有明显变化。并发现下壁心梗ST段抬高STⅢ／Ⅱ〉1，可用于急性下壁心肌梗死合并右室梗死的临床诊断。本文通过回顾性研究我院近10年来下壁梗死合并右室梗死患者STⅢ／Ⅱ〉1并探讨sTⅢ／Ⅱ〉1在诊断右室梗死的临床诊断价值。     

急性下壁心肌梗死邻近部位受累时胸前对应导联ST段改变机制及临床意义的研究

目的研究急性下壁心肌梗死(AIMI)累及邻近部位时，心电图胸前对应导联ST段改变的影响因素及临床意义。方法对118例首次AIMI患者的心电图和临床资料进行比较分析。结果(1)AIMI时心电图下壁各导联(Ⅱ、Ⅲ和aVF)ST段抬高幅度与胸前对应导联ST段改变的相关指标均呈负相关(均P＜0.01)。(2)累及右室(16例)的患者胸前对应导联ST段的改变幅度[V2(0.63±1.82)mm]及与下壁导联ST段抬高的比值(V2/aVF0.84±1.61)，均高于64例单纯下壁梗死组[V2(0.35±1.65)mm，V2/aVF0.29±1.28]；差异尚无显著性(均P＞0.05)。(3)累及侧后壁的患者(38例)胸前对应导联ST段压低幅度[V2(-1.20±1.52)mm]及与下壁导联ST段抬高的比值[V2/aVF(-0.33±1.15)mm]均低于单纯下壁组，且差异均具有显著性意义(P＜0.05)。(4)在除去累及邻近部位梗死的病例，单纯AIMI心电图下壁导联与胸前对应导联ST段改变呈负相关(r=-0.797，P＜0.01)。结论当AIMI累及右室时可使心电图胸前对应导联ST段趋于抬高，而累及侧后壁时则使胸前对应导联ST段进一步降低，故胸前对应导联ST段的改变方向与AIMI累及邻近部位关系密切。     

急性下壁心肌梗死合并右室梗死的心电图特征

目的 探讨常规导联心电图对急性下壁合并右室心肌梗死的诊断价值。方法 入院即刻描记常规12导联心电图并加作V3R～V5R、V7～V9导联，入院第1天每8小时描记1次心电图，第2～3天每24小时描记1次心电图；ST段测定以J点后0．08s为起始点，抬高或压低〉1mm为阳性标准，制定测量指标：（1）Ⅲ导联ST段抬高幅度大于U导联ST段抬高幅度；（2）V2导联ST段压低与avF导联ST段抬高幅度之比≤50％；（3）V1～V6ST段抬高呈递减性或V1ST段抬高而V2ST段压低。结果 三个指标对诊断急性下壁合并右室心肌梗死的敏感性、特异性分别为87％和88％、83％和92％、54％和85％。结论 常规导联心电图对急性下壁合并右室心肌梗死具有诊断价值。     

急性下壁心肌梗死V1导联ST段抬高的临床意义

目的：探讨V1导联ST段抬高在急性下壁心肌梗死中的临床意义。方法：对68例急性下壁心肌梗死进行回顾性分析。结果：23例有V1导联ST段抬高,其余45例表现为V1导联ST段压低或无改变,其中在V1导联ST段抬高组合并右室梗死14例（62％）,显著高于非V1导联ST段抬高组9例（21％）;心肌酶谱V1导联ST段抬高组CK峰值（2430±410）U较非V1导联ST段抬高组（1528±369）U明显增高。心律失常合并症26例,其中V1导联ST段抬高组12例,非V1导联ST段抬高组14例。其中5例病人住院期间死亡。V1导联ST段抬高组3例,非V1导联ST段抬高组2例。结论：V1导联ST段抬高作为下壁心肌梗死合并右室梗死的诊断条件。敏感性和特异性分别达59％和80％。下壁心肌梗死中V1导联ST段抬高者具有较高的CK峰值及严重心律失常发生率。     

急性下壁心肌梗死冠状动脉造影与心电图的对比研究（附89例分析）

目的探讨急性下壁心肌梗死（AIMI）时体表心电图对梗死相关动脉（IRA）的判断价值。方法选择2004年1月-2007年12月急性下壁心梗患者89例,对其心电图Ⅱ、Ⅲ导联ST段抬高比值及I、AVL、V4R导联ST段偏移进行分析并与冠状动脉造影的结果比较。结果89例中,右冠状动脉（RCA）为IRA者67例（75.3％）,左回旋支（LCX）22例（24.7％）;STⅢ／STⅡ抬高比值〉1,STaVL、ST1压低,STv4R抬高≥0.5mm,提示IRA为RCA;而STⅢ／STⅡ抬高比值≤1,STavL、ST1抬高,提示LCX为IRA。结论心电图中STⅢ／STⅡ抬高比值,STaVL、ST1及STv4R变化可作为AIMI患者IRA的临床判断指标。     

急性下壁合并右心室心肌梗死的诊断

单纯右室心肌梗死（fight ventficular myocardial infarction RVMI）不常见（2．4％），多数与左室下壁或后壁合并存在，发生率高达43．0％（平均19．0％），但临床诊断率仅为7．7％～23％。右心导联心电图对右室心肌梗死具有诊断价值，但由于右心导联为非常规导联，并且右室壁比左室壁薄、电位低、显示困难，同时右室导联ST段升高时间短暂，这是既往文献报道发生率低的原因。本文旨在探讨常规12导联心电图中ST V2压影ST AVF抬高〈0．5及ST Ⅲ抬高／STⅡ抬高〉1对急性下壁心肌梗死合并右室心肌梗死诊断意义。现将实验结果报告如下：     

急性下壁心肌梗死伴与不伴右室梗死心电图对比分析

目的：探讨急性下壁心肌梗死伴与不伴右室梗死在常规心电图上的鉴别诊断。方法：选择2007—01／2008—12同期住院的急性下壁心肌梗死患者87例，其中单纯急性下壁心肌梗死45例，伴右室梗死42例。比较两组患者STⅢ↑〉STⅡ↑、STⅠ、aVL↓≥0．1mV、STaVR、vⅠ↑等9项心电图指标。结果：STⅢ〉STⅡ、qⅠ、aVL、V5、V6消失；STv1～v5↑逐渐减小；STv2↓＋／STaVF↑〈50％，合并房室传导阻滞等心律失常五项指标，两组比较差异显著（P〈0．05）。STI、aVL↓≥0．1mV、STaVR↑、STaVR↓、STV1↑四项指标，两组比较无统计学差异（P〉0．05）。结论：急性下壁心肌梗死患者伴有STⅢ↑〉STⅡ↑、q1,aVL、V5、V6消失、STv1～v5↑逐渐减小、STv2↓／STaVF↑〈50％心电图改变时，高度提示急性下壁心肌梗死伴有右室梗死。     

心电图对急性下壁合并右室心肌梗死的诊断价值

急性右室心肌梗死（RMI）单独出现者少见,多合并其他部位心肌梗死,以急性下壁心肌梗死（ARVI）合并RMI患者最为常见,据报道约50％。ARVI患者合并ARVI者住院期间病死率及并发症发生率明显增加。本研究对我院收治的AIMI病例进行分析,旨在探讨STV4R抬高≥1mm、STⅢ抬高幅度≥STⅡ抬高幅度、STV1抬高幅度〉STV2抬高幅度（ECG）在AIMI合并RMI的诊断价值。     

Evaluation of the use of salivary lead levels as a surrogate of blood lead or plasma lead levels in lead exposed subjects

We conducted a study to evaluate the use of parotid salivary lead (Pb-saliva) levels as a surrogate of the blood lead (Pb-B) or plasma lead levels (Pb-P) to diagnose lead exposure. The relationship between these biomarkers was assessed in a lead exposed population. Pb-saliva and Pb-P were determined by inductively coupled plasma mass spectrometry, while in whole blood lead was determined by graphite furnace atomic absorption spectrometry. We studied 88 adults (31 men and 57 women) from 18 to 60 years old. Pb-saliva levels varied from 0.05 to 4.4 μg/l, with a mean of 0.85 μg/l. Blood lead levels varied from 32.0 to 428.0 μg/l in men (mean 112.3 μg/l) and from 25.0 to 263.0 μg/l (mean 63.5 μg/l) in women. Corresponding Pb-Ps were 0.02–2.50 μg/l (mean 0.77 μg/l) and 0.03–1.6 μg/l (mean 0.42 μg/l) in men and women, respectively. A weak correlation was found between Log Pb-saliva and Log Pb-B (r=0.277, P<0.008), and between Log Pb-saliva and Log Pb-P (r=0.280, P=0.006). The Pb-saliva/Pb-P ratio ranged from 0.20 to 18.0. Age or gender does not affect Pb-saliva levels or Pb-saliva/Pb-P ratio. Taken together, these results suggest that salivary lead may not be used as a biomarker to diagnose lead exposure nor as a surrogate of plasma lead levels at least for low to moderately lead exposed population.     

Blood lead level and lead exposure of industrial workers in suburban Tokyo

Blood lead concentrations were determined at intervals between 1975 and 1980 from two groups of industrial workers, a group of highway repairmen, and workers from a lead-using electrical manufacturing plant in suburban Tokyo. The average blood lead content of the highway repairmen ranged from 9.6 ± 3.2 to 11.5 ± 4.7 μg/100 mol. The blood lead content of every factory worker employed as such for over 5 years was at least twice that of the highway repair crew members. Among the factory workers, variations in blood lead levels were greater between the workers in any given sampling period than those of an individual worker over the 5-year study period. The high, steady blood levels in the factory workers were attained within 6 months of employment.     

Assessing the contribution from lead in mining wastes to blood lead

Lead has been recognized for years as an environmental pollutant of concern for young children. Nonetheless, many children in the United States still experience high body burdens of lead. Reducing exposure to lead must include an assessment of all potential sources of lead and a definition of routes of exposure. In this paper, the relationships between soil lead and blood lead concentrations in residents in communities with high soil lead concentrations resulting from past mining and ore processing (milling) activities are compared to those derived from studies in urban communities or communities with operating smelters. The impact of mine waste-derived lead in soil (usually in the form of lead sulfide) on blood lead is less than that for lead in soil derived from smelter, vehicle, or paint sources. Possible reasons for a reduced impact of lead sulfide on blood lead in children in mining communities include the following: lead from mining sources contributes less to lead in the immediate environment of children than lead from other sources; mine wastes typically are of larger particle size, which decreases the bioavailability of lead in the gastrointestinal tract; and lead sulfide is absorbed less in the gastrointestinal tract compared to other lead species. A reduced impact of mine waste-derived lead on blood lead may be important from a regulatory point of view. Expensive cleanup actions for lead-contaminated soils in mining communities based on acceptable soil lead concentrations derived from smelter or urban communities may be questionable in terms of reducing blood lead in children.     

The ecotoxicology of lead shot and lead fishing weights

Lead shot ingestion is the primary source of elevated lead exposure and poisoning in waterfowl and most other bird species. For some species (e.g. Common Loons, Gavia immer), lead sinker ingestion is a more frequent cause of lead poisoning. In freshwater environments where recreational angling activity and loon populations co-occur, lead poisoning from ingestion of small (<50 gram) lead sinkers or jigs accounts for 10–50% of recorded adult loon mortality, depending on the locations studied. Lead shot ingestion occurs in waterfowl, and in a wide variety of non-waterfowl species, including upland game birds, shorebirds, raptors, and scavengers. Where it has been explicitly studied in Canada and the US, lead poisoning mortality of bald (Haliacetus leucocephalus) and golden eagles (Aquila chrysactos) from eating prey animals with lead shot embedded in their tissues accounts for an estimated 10–15% of the recorded post-fledging mortality in these raptorial species. In addition to environments that experience hunting with lead shot, clay target shooting ranges, especially those in which the shotfall zones include ponds, marshes, lakes, rivers, beaches, or other aquatic-type environments, create a significant risk of shot ingestion and poisoning for waterbirds. Metallic lead pellets deposited onto soils and aquatic sediments are not chemically or environmentally inert, although tens or hundreds of years may be required for total breakdown and dissolution of pellets. Functional, affordable non-toxic alternatives to lead shot and sinkers are being currently produced, and additional such products are being developed. Several countries have successfully banned the use of small lead sinkers, and of lead shot for waterfowl and other hunting, also for clay target shooting, using a phasing-out process that gives manufactures, sellers, and users adequate time to adjust to the regulations.     

羧甲基壳聚糖钙对染铅小鼠治疗性排铅作用的研究

目的观察羧甲基壳聚糖钙对染铅小鼠排铅作用及其抗氧化能力的影响。方法小鼠随机分组，饮用醋酸铅水溶液建立小鼠铅中毒模型。然后灌胃受试物，连续30d后，采血，取肝脏、全脑、股骨，用原子吸收分光光度计测定其铅、钙含量。同时测定小鼠肝组织中的抗氧化指标。结果羧甲基壳聚糖钙能显著降低染铅小鼠血液、全脑、肝脏、股骨铅含量，降低染铅小鼠肝脏中MDA水平，显著升高SOD、GSH—Px、T—AOC活性，增加股骨钙含量。结论羧甲基壳聚糖钙能显著促进染铅小鼠排铅，增强抗氧化能力，还具有一定的补钙功效．     

Bone lead mobilization in lactating mice and lead transfer to suckling offspring

Drinking water containing 200 μg/ml lead (labeled with ²¹⁰Pb) was provided to adult female mice for 105 days prior to the date of mating or for 105 days prior to mating and during the periods of gestation and lactation (160 days total exposure). During lactation there was an increased rate of lead elimination from adult mice exposed prior to mating compared to nonlactating female mice. The magnitude of the additional lead elimination during lactation was similar to the magnitude of the decrease in femur ash weights during lactation. These data support the hypothesis that lead mobilization during lactation is the result of bone mineral mobilization. Approximately 3% of the lead body burden of mothers exposed to lead prior to mating was retained in litters of suckling pups as a result of lead transferred in milk. The magnitude of lead mobilized from maternal bone during lactation was not increased by a diet which was moderately calcium deficient. Continuous ingestion of lead by mothers during lactation significantly increased the net transfer of lead to suckled pups. Lead transferred from mother to offspring during lactation greatly exceeded transfer during gestation for all treatment groups. These data indicate that both prior and current maternal lead exposure should be considered in assessing potential lead exposure of suckling infants.     

Assessment of lead in cosmetic products

There have been a number of recent reports in the media and on the internet about the presence of lead in brand-names lipsticks. This has drawn our attention to assess the safety of various cheap brands of cosmetics sold at 2-riyals stores in Saudi market that are imported from countries where safety regulations are poorly enforced as well as they lack perfect conditions for manufacturing. Lead contents were determined in 26 and eight different brands of lipsticks and eye shadows using the Zeeman atomic absorption spectrophotometer coupled to graphite tube atomizer after an acid digestion procedure. Lead was detected in all the studied samples. The median (25th–75th percentile) lead content in 72 lipsticks samples was 0.73 (0.49–1.793) PPM wet wt. in the range of 0.27–3760 PPM wet wt. There were four brands of lipsticks with lead content above the FDA lead limit as impurities in color additives (20 PPM). The FDA does not set a limit for lead in lipstick. Three of them were extremely high points and considered outliers. The median (25th–75th percentile) lead contents in pressed powder eye shadow was 1.38 (0.944–1.854) PPM wet wt. (n = 22) in the range of 0.42–58.7 PPM wet wt. One brand was above 20 PPM the US FDA’s lead limit as impurities. The overall results indicate that lead in lipsticks and eye shadows are below the FDA lead limit as impurities and, thus, probably have no significant toxicological effects. Nevertheless, few brands had lead content above 20 PPM that might put consumers at the risk of lead poisoning. Lead is a cumulative, and applying lead-containing cosmetics several times a day or every day, can potentially add up to significant exposure levels. Pregnant and nursing mothers are vulnerable population because lead passes through placenta and human milk and affect fetus or infant’s developments. Our findings call for an immediate mandatory regular testing program to check lead and other toxic metals in lipsticks and other cosmetic products imported to Saudi Arabia in order to curtail their excess and safeguard consumer health.     

Monensin potentiates lead chelation efficacy of MiADMSA in rat brain post chronic lead exposure

The present study evaluates combination therapy with a chelating agent, MiADMSA and a Na⁺ ionophore, monensin against sub-chronic lead toxicity in rats. Animals were exposed to 0.1% lead in drinking water for 16 weeks and then treated with either MiADMSA at 50 mg/kg body weight, or monensin at 10 mg/kg, or both in combination for a period of 5 days was administered. Biomarkers indicative of oxidative stress like ROS, GSH, GSSG and TBARS demonstrated lead-induced toxic manifestations in blood, kidney and brain. Antioxidants like SOD, catalase and glutathione peroxidase along with specific lead biomarker, blood ALAD were also severely depleted in lead intoxicated animals. Serum parameters and histopathological findings supported the said results. MiADMSA treatment during both mono- and combination therapy with monensin, restored the antioxidant status and recovered biochemical and haematological variables due to lead. However, monensin alone was not found to be effective in the given scenario. Interestingly, combination therapy in its ability to revert lead-induced overall systemic toxicity was only found at par with the MiADMSA monotherapy except for its chelation potential. Monensin given in combination with MiADMSA potentiated its lead chelation ability especially from brain, along with maintaining the normal copper concentrations in the organ unlike MiADMSA monotherapy.     

Effect of food intake on blood lead concentration in workers occupationally exposed to lead

Results from a cross-sectional study showed the concentration of lead in the blood of male workers, aged 20-55 years, occupationally exposed to lead in a steel factory, to be negatively correlated with the daily nutritional content of dietary fiber, iron and vitamin B1 (thiamine) intake. Furthermore, in experiments with rats injected subcutaneously with lead acetate, lead levels in blood and femur of animals on a vitamin-rich laboratory chow were lower than those fed a general laboratory chow. Moreover, in the group fed the vitamin-rich chow, lead excretion in feces increased, while excretion in urine did not. These results suggest that lead excretion from the body may be increased by a high intake of nutrients such as thiamine, iron and fiber, that lead excretion in feces via bile may be enhanced by a large intake of vitamins such as thiamine and that accordingly the lead concentration in the blood of the workers is reduced.