Human Exposure to Metals: Levels in Autopsy Tissues of Individuals Living Near a Hazardous Waste Incinerator

The concentrations of a number of metals were determined in the brain, bone, kidney, liver, and lung of 20 autopsied subjects who had lived, at least 10 years, in the neighborhood of a hazardous waste incinerator (HWI) in Tarragona (Catalonia, Spain). Results were compared with those obtained in 1998 (baseline survey) and previous surveys (2003 and 2007). Arsenic, Be, Ni, Tl, and V showed concentrations below the corresponding detection limits in all tissues. Cadmium showed the highest levels in the kidney, with a mean value of 21.15 μg/g. However, Cd was found below the detection limit in the brain and bone. Chromium showed similar concentrations in the kidney, brain, and lung (range of mean values, 0.57–0.66 μg/g) and higher in the bone (1.38 μg/g). In turn, Hg was below the detection limit in all tissues with the exception of the kidney, where the mean concentration was 0.15 μg/g (range, <0.05–0.58 μg/g). On the other hand, Mn could be detected in all tissues showing the highest levels in the liver and kidney (1.45 and 1.09 μg/g, respectively). Moreover, Pb showed the highest concentrations in bone (mean, 1.39 μg/g; range, <0.025–4.88 μg/g). Finally, Sn could be detected only in some tissue samples, reaching the highest values in the bone (0.17 μg/g). The current metal levels in human tissues from individuals living near the HWI of Tarragona are comparable and of a similar magnitude to previously reported results corresponding to general populations, as well as those of our previous surveys.     

镉在黑斑蛙组织的积累与分布

研究民镉暴露实验中黑斑蛙不同器官组织对镉的吸收积累,并对其在不同器官组织中的分布规律进行了分析。结果表明：镉在黑斑蛙器官组织的积累具有选择性,主要积累在肠和肝脏中,其次是皮肤、肌肉,而骨骼中没有积累。     

镉诱导金属硫蛋白在华溪蟹组织中的表达

采用体外暴露染毒法,研究了不同浓度与时间条件下,镉诱导河南华溪蟹(Sinopotamon henanense)金属硫蛋白(metallothionein,MT)在肝胰腺、肌肉、鳃和卵巢中的表达差异。镉浓度分别为0、14·5mg/L、29mg/L和58mg/L;处理时间依次为1d、3d和5d。利用镉血红蛋白饱和法和火焰原子吸收分光光度法(AAS)测定MT的蛋白含量。结果显示,用不同的染毒浓度和处理时间,镉在组织中诱导产生MT的含量有较大差异,其中肝胰腺MT的诱导量最大,变化规律也最明显;肌肉中也有较大量MT的表达;而鳃和卵巢MT的诱导量均较低。此外,本文分析了镉的浓度与时间梯度对诱导MT表达的影响与毒性效应机制。结论:组织不同,染毒浓度及时间不同,镉诱导MT的表达也不同,具有一定的组织差异性和规律性。     

流行性出血热病人尸检材料中的病毒包涵体

应用抗流行性出血热病毒多克隆及单克隆抗体结合敏感的方法在尸检组织切片上进行了免疫细胞化学染色,多克隆抗体可清楚地显示出尸检组织中病毒抗原阳性的包涵体结构。依光镜下染色的形态特点不同,可将包涵体分为四个类型即小泡型、大泡型、多泡型和实心型。单克隆抗体染色进一步证实,实心型及空泡型包涵体呈“N”抗原阳性,少数组织中空泡状包涵体也呈“G2”抗原阳性。病毒包涵体的出现可作为该病毒在人体细胞内感染及复制的形态学证据。     

Calcium Decreases Cadmium Concentration in Root but Facilitates Cadmium Translocation from Root to Shoot in Rice

Journal of Plant Growth Regulation - Understanding cadmium (Cd) accumulation in rice is important for the development of plant-based strategies for crop safety. Cd and calcium (Ca) are antagonistic...     

Detection of VEGF-Axxxb Isoforms in Human Tissues

Vascular Endothelial Growth Factor-A (VEGF-A) can be generated as multiple isoforms by alternative splicing. Two families of isoforms have been described in humans, pro-angiogenic isoforms typified by VEGF-A₁₆₅a, and anti-angiogenic isoforms typified by VEGF-A₁₆₅b. The practical determination of expression levels of alternative isoforms of the same gene may be complicated by experimental protocols that favour one isoform over another, and the use of specific positive and negative controls is essential for the interpretation of findings on expression of the isoforms. Here we address some of the difficulties in experimental design when investigating alternative splicing of VEGF isoforms, and discuss the use of appropriate control paradigms. We demonstrate why use of specific control experiments can prevent assumptions that VEGF-A₁₆₅b is not present, when in fact it is. We reiterate, and confirm previously published experimental design protocols that demonstrate the importance of using positive controls. These include using known target sequences to show that the experimental conditions are suitable for PCR amplification of VEGF-A₁₆₅b mRNA for both q-PCR and RT-PCR and to ensure that mispriming does not occur. We also provide evidence that demonstrates that detection of VEGF-A₁₆₅b protein in mice needs to be tightly controlled to prevent detection of mouse IgG by a secondary antibody. We also show that human VEGF₁₆₅b protein can be immunoprecipitated from cultured human cells and that immunoprecipitating VEGF-A results in protein that is detected by VEGF-A₁₆₅b antibody. These findings support the conclusion that more information on the biology of VEGF-A₁₆₅b isoforms is required, and confirm the importance of the experimental design in such investigations, including the use of specific positive and negative controls.     

Continuous In Vivo Monitoring of the Oxygen Concentration in Tissues

Biophysics - Abstract—The kinetics of delayed fluorescence and phosphorescence of xanthene dyes in mouse tissues under the pulse-periodic excitation of molecules was studied in vivo and in...     

Matrix Metalloproteinases of Normal Human Tissues

This review considers biochemical properties of the family of matrix metalloproteinases (MMPs) of normal human tissues and the involvement of these enzymes in morphogenesis. Four main MMP subfamilies are characterized, and a group of other MMPs is described. Data on mechanisms of activation and inhibition of MMPs in certain tissues during various physiological processes (embryogenesis, angiogenesis, tissue growth and involution) are considered. Information about tissue inhibitors of MMP is presented, and the ability of these inhibitors to regulate the activity of MMPs is analyzed.     

Cadmium Alters the Concentration of Fatty Acids in THP-1 Macrophages

Fatty acid composition of human immune cells influences their function. The aim of this study was to evaluate the effects of known toxicant and immunomodulator, cadmium, at low concentrations on levels of selected fatty acids (FAs) in THP-1 macrophages. The differentiation of THP-1 monocytes into macrophages was achieved by administration of phorbol myristate acetate. Macrophages were incubated with various cadmium chloride (CdCl₂) solutions for 48 h at final concentrations of 5 nM, 20 nM, 200 nM, and 2 μM CdCl₂. Fatty acids were extracted from samples according to the Folch method. The fatty acid levels were determined using gas chromatography. The following fatty acids were analyzed: long-chain saturated fatty acids (SFAs) palmitic acid and stearic acid, very long-chain saturated fatty acid (VLSFA) arachidic acid, monounsaturated fatty acids (MUFAs) palmitoleic acid, oleic acid and vaccenic acid, and n-6 polyunsaturated fatty acids (PUFAs) linoleic acid and arachidonic acid. Treatment of macrophages with very low concentrations of cadmium (5–200 nM) resulted in significant reduction in the levels of arachidic, palmitoleic, oleic, vaccenic, and linoleic acids and significant increase in arachidonic acid levels (following exposure to 5 nM Cd), without significant reduction of palmitic and stearic acid levels. Treatment of macrophages with the highest tested cadmium concentration (2 μM) produced significant reduction in the levels of all examined FAs: SFAs, VLSFA, MUFAs, and PUFAs. In conclusion, cadmium at tested concentrations caused significant alterations in THP-1 macrophage fatty acid levels, disrupting their composition, which might dysregulate fatty acid/lipid metabolism thus affecting macrophage behavior and inflammatory state.     

心肌肌钙蛋白T在病毒性心肌炎心肌组织中的表达及意义

目的:了解病毒性心肌炎心肌组织中肌钙蛋白T的表达情况,探讨病毒性心肌炎时心肌结构蛋白损伤的机制及意义。方法:运用免疫组化和计算机图像分析技术,观察13例明确性病毒性心肌炎和17例界限性病毒性心肌炎尸检心脏标本中心肌肌钙蛋白T的表达与分布。结果:在正常对照的心肌组织中,蛋白成强阳性表达,分布均匀,未见缺染。在明确性心肌炎及14例界限性心肌炎心肌组织中都存在着不同程度的蛋白表达缺染或脱失。缺染的范围及分布与病毒性心肌炎病变特点基本一致,但其范围往往小于炎症细胞浸润范围。计算机图像分析和数据统计结果显示缺染区域的心肌肌钙蛋白T表达量要明显小于其周边区域和正常心肌细胞(P＜0．01)。结论:病毒性心肌炎患者的心肌损害要早于炎症细胞的浸润,病毒的作用可能是心肌肌钙蛋白T脱失的主要因素。心肌肌钙蛋白T的免疫组化检查可以作为一种有效的手段,来辅助病毒性心肌炎的病理学诊断。     

Cadmium and Other Metal Levels in Autopsy Samples from a Cadmium-Polluted Area and Non-polluted Control Areas in Japan

This study was initiated to examine accumulation of cadmium (Cd) and other metals in kidney and liver in autopsy samples and to compare the levels between those in an area with heavy Cd exposure and those in no-polluted areas in Japan. Data on Cd and other metals in kidney (cortex and medulla) and liver in 95 cases (87 women and eight men; the exposed) in a Cd-polluted area and 43 cases (21 women and 22 men; the controls) in non-polluted areas were cited from 15 previous publications to be summarized together with six unpublished cases. Cd levels in kidney cortex and medulla were significantly lower in the exposed (31.5 and 23.8 μg/g wet tissue as GM, respectively) than in the controls (82.7 and 36.4 μg/g, respectively), whereas Cd levels in liver was higher in the exposed (60.2 μg/g) than in the controls (8.1 μg/g). Exposed women had lower Cd in the cortex (29.9 μg/g) and medulla (22.7 μg/g) than exposed men (55.4 and 38.1 μg/g, respectively) as well as in cortex of control women (92.9 μg/g). Comparison with worldwide data other than Japan for non-exposed populations [19.1, 9.3, and 1.3 μg/g in cortex, medulla, and liver, respectively, as the inverse variance-weighted averages (IVWA) of GM values for each of 22 reports] suggests that the levels for the non-exposed Japanese (123.3, 33.5, and 3.9 μg/g as IVWA) tended to be higher than the levels in other countries, possibly reflecting high dietary Cd intake in the past.     

Seasonal Variation in Human Salivary Cortisol Concentration

Measurement of cortisol concentration can contribute important information about an individual's ability to adjust to various environmental demands of both physical and psychosocial origin. However, one uncertainty that affects the possibilities of correctly interpreting and designing field studies is the lack of observations of the impact of seasonal changes on cortisol excretion. For this reason, the month‐to‐month changes in diurnal cortisol concentration, the awakening cortisol response (ACR), maximum morning concentration, and fall during the day were studied in a group of 24 healthy men and women 32 to 61 yrs of age engaged in active work. On one workday for 12 consecutive months, participants collected saliva at four time points for determination of cortisol: at awakening, +30 min, +8 h, and at 21:00 h. Data were analyzed by a repeated measures design with month (12 levels) and time‐of‐day (4 levels) as categorical predictors. Cortisol concentrations were analyzed on a log scale. The diurnal pattern of cortisol was similar across months (interaction between month and time of day: p>0.4). The main effects of month and time‐of‐day were statistically significant (p <0.001). Highest concentrations were observed in February, March, and April, and lowest concentrations were observed in July and August. There were no statistically significant effects in any of the other measures, or between men and women. In conclusion, a seasonal variation in salivary cortisol concentrations was detected in an occupationally active population. Thus, seasonal variation needs to be taken into account when designing and evaluating field studies and interventions and when making comparisons across studies.