Rapid sample preparation for determination of iron in tissue by closed-vessel digestion and microwave energy.

1988 ◽  
Vol 34 (6) ◽  
pp. 1128-1130 ◽  
Author(s):  
D B Van Wyck ◽  
R B Schifman ◽  
J C Stivelman ◽  
J Ruiz ◽  
D Martin
Keyword(s):  
Bovine Liver ◽  
Dry Weight ◽  
Close Correlation ◽  
Microwave Energy ◽  
National Bureau ◽  
Tissue Preparation ◽  
Closed Vessel ◽  
Tissue Samples ◽  
Mouse Tissues ◽  
Analytical Recovery

Abstract We developed a rapid acid-digestion method for preparing tissue samples for iron determination. Specimens were digested in nitric acid and hydrogen peroxide under high temperature and pressure in closed Teflon vessels, with microwave energy. Analysis for iron in 25- to 250-mg portions of digested bovine liver powder (National Bureau of Standards Certified Reference Material no. 1577a) showed excellent linearity ([predicted] = 1.007[actual] - 0.166 micrograms per sample) and analytical recovery (98%). Precision (CV) was 5.4% when iron content was 10 micrograms per sample. Assaying split samples of mouse tissues, we found a close correlation between iron concentrations obtained with closed vs open vessels ([closed] = 0.878[open] + 68 micrograms/g, r = 0.994, range 400-4600 micrograms/g dry weight). In contrast to time-consuming conventional procedures for tissue dissolution, closed-vessel digestion with microwave energy dramatically shortens time for tissue preparation, minimizes use of caustic acid, reduces risk of sample loss or contamination, and yields accurate and reproducible results.

Micro-quantity tissue digestion for metal measurements by use of a microwave acid-digestion bomb.

1989 ◽  
Vol 35 (3) ◽  
pp. 488-490 ◽  
Author(s):  
J R Nicholson ◽  
M G Savory ◽  
J Savory ◽  
M R Wills
Keyword(s):  
Nitric Acid ◽  
Reference Material ◽  
Microwave Digestion ◽  
Absorption Spectrometry ◽  
Bovine Liver ◽  
Dry Weight ◽  
Acid Digestion ◽  
Tissue Samples ◽  
Dry Ashing ◽  
Tissue Digestion

Abstract We describe a simple and convenient method for processing small amounts of tissue samples for trace-metal measurements by atomic absorption spectrometry, by use of a modified Parr microwave digestion bomb. Digestion proceeds rapidly (less than or equal to 90 s) in a sealed Teflon-lined vessel that eliminates contamination or loss from volatilization. Small quantities of tissue (5-100 mg dry weight) are digested in high-purity nitric acid, yielding concentrations of analyte that can be measured directly without further sample manipulation. We analyzed National Institute of Standards and Technology bovine liver Standard Reference Material to verify the accuracy of the technique. We assessed the applicability of the technique to analysis for aluminum in bone by comparison with a dry ashing procedure.

scholarly journals Interannual and Spatial Variability of Cyanotoxins in the Prespa Lake Area, Greece

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 357
Author(s):  
Valentini Maliaka ◽  
Miquel Lürling ◽  
Christian Fritz ◽  
Yvon J.M. Verstijnen ◽  
Elisabeth J. Faassen ◽  
...  
Keyword(s):  
Water Quality ◽  
Spatial Variability ◽  
Spatial Heterogeneity ◽  
Dry Weight ◽  
Ecosystem Functions ◽  
Lake Area ◽  
Total Chlorophyll ◽  
Tissue Samples ◽  
Cyanobacteria Blooms ◽  
Prespa Lake

The Prespa Lakes area in Greece—comprised partly of lake Great and lake Lesser Prespa and the Vromolimni pond—has a global importance for biodiversity. Although the waters show regular cyanobacteria blooms, assessments of water quality threats are limited. Samples collected in 2012 revealed scattered and low microcystin (MC) concentrations in Great Prespa (<0.2 μg MC L−1) whereas considerable spatial heterogeneity in both total chlorophyll (2.4–93 µg L−1) and MC concentrations (0.04–52.4 µg MC L−1) was detected in Lesser Prespa. In 2013, there was far less spatial variability of MC concentrations in Lesser Prespa (0.4–1.53 µg L−1), however in 2014, increased concentrations were detected near the lakeshore (25–861 µg MC L−1). In Vromolimni pond the MC concentrations were on average 26.6 (±6.4) µg MC L−1 in 2012, 2.1 (±0.3) µg MC L−1 in 2013 and 12.7 (±12.5) µg MC L−1 in 2014. In 2013, no anatoxins, saxitoxins, nor cylindrospermopsins were detected in Lesser Prespa and Vromolimni waters. Tissue samples from carps, an otter and Dalmatian Pelicans contained 0.4–1.9 µg MC g−1 dry weight. These results indicate that cyanotoxins could be a threat to the ecosystem functions of particularly Lesser Prespa and Vromolimni.

Assessment of copper accumulation in archived liver specimens from cats

2020 ◽  
pp. 1098612X2096135
Author(s):  
Punyamanee Yamkate ◽  
Randi M Gold ◽  
Panagiotis G Xenoulis ◽  
Katja Steiger ◽  
David C Twedt ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Hepatic Steatosis ◽  
Dry Weight ◽  
Reference Interval ◽  
Copper Accumulation ◽  
Zonal Distribution ◽  
Tissue Samples ◽  
Hepatic Copper ◽  
Liver Copper ◽  
Flame Atomic Absorption

Objectives The aim of this study was to assess hepatic copper concentrations and zonal distribution in cat liver specimens. Methods For this study, 121 archived, formalin-fixed, paraffin-embedded liver specimens from cats were used. Tissue sections were stained for copper with rhodanine and scored from 0 (no copper accumulation) to 5 (panlobular copper accumulation). The tissue specimens were then deparaffinized and hepatic copper concentrations were measured using flame atomic absorption spectroscopy. Results Tissue samples were categorized into four groups based on histopathologic findings: (1) no significant histopathologic hepatic changes (n = 66); (2) hepatic steatosis (n = 18); (3) inflammatory or infectious disease (n = 24); and (4) neoplasia (n = 13). Of the 121 specimens, 13 (11%) stained positive for copper, with three having a score ⩾3. Thirty-seven specimens (31%) had copper concentrations above the reference interval ([RI] <180 µg/g dry weight liver). Copper concentrations in cats with hepatic inflammatory or infectious disease were significantly higher than cats with hepatic steatosis ( P = 0.03). Copper-staining score and concentration were positively correlated ( rs = 0.46, P <0.001). Conclusions and relevance Despite the fact that 31% of specimens had copper concentrations above the RI, only 11% showed positive copper staining and only 2.5% had a score ⩾3. Our findings suggest that hepatic copper concentrations greater than the upper limit of the RI are relatively common in cats. Further studies to determine the factors that influence hepatic copper staining in cats and to establish contemporary RIs for hepatic copper in healthy cats are warranted.

scholarly journals Age Prediction of Human Based on DNA Methylation by Blood Tissues

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 870
Author(s):  
Jiansheng Zhang ◽  
Hongli Fu ◽  
Yan Xu
Keyword(s):  
Dna Methylation ◽  
Pearson Correlation ◽  
Close Correlation ◽  
Gradient Boosting ◽  
Tissue Samples ◽  
Regression Methods ◽  
Cpg Sites ◽  
Testing Dataset ◽  
Age Related ◽  
Better Than

In recent years, scientists have found a close correlation between DNA methylation and aging in epigenetics. With the in-depth research in the field of DNA methylation, researchers have established a quantitative statistical relationship to predict the individual ages. This work used human blood tissue samples to study the association between age and DNA methylation. We built two predictors based on healthy and disease data, respectively. For the health data, we retrieved a total of 1191 samples from four previous reports. By calculating the Pearson correlation coefficient between age and DNA methylation values, 111 age-related CpG sites were selected. Gradient boosting regression was utilized to build the predictive model and obtained the R2 value of 0.86 and MAD of 3.90 years on testing dataset, which were better than other four regression methods as well as Horvath’s results. For the disease data, 354 rheumatoid arthritis samples were retrieved from a previous study. Then, 45 CpG sites were selected to build the predictor and the corresponded MAD and R2 were 3.11 years and 0.89 on the testing dataset respectively, which showed the robustness of our predictor. Our results were better than the ones from other four regression methods. Finally, we also analyzed the twenty-four common CpG sites in both healthy and disease datasets which illustrated the functional relevance of the selected CpG sites.

Comparison of Various Tissue-Preparation Techniques for Cryosectioning of Frozen Mouse Tissues

2009 ◽  
Vol 32 (4) ◽  
pp. 186-189 ◽  
Author(s):  
Lee Hui Ling ◽  
Susan Mary Rogers ◽  
Vanessa Tay ◽  
Gino V. Limmon ◽  
Zheng Dahai ◽  
...  
Keyword(s):  
Tissue Preparation ◽  
Mouse Tissues ◽  
Preparation Techniques

Hydride Generation and Condensation Flame Atomic Absorption Spectroscopic Determination of Antimony in Raw Coffee Beans and Processed Coffee

1982 ◽  
Vol 65 (5) ◽  
pp. 1146-1149
Author(s):  
Roy W Kuennen ◽  
Mark H Hahn ◽  
Fred L Fricke ◽  
Karen A Wolnik
Keyword(s):  
Atomic Absorption ◽  
Inductively Coupled Plasma ◽  
Hydride Generation ◽  
Dry Weight ◽  
Atomic Emission ◽  
Standard Reference Materials ◽  
National Bureau ◽  
Total Acid ◽  
Flame Atomic Absorption ◽  
Coffee Beans

Abstract A method was developed for determining Sb at nanogram per gram levels in raw coffee beans and processed coffee. The procedure uses either total acid digestion or extraction with 6M HCl followed by hydride generation/condensation with subsequent revolatilization of stibine (SbH3) and detection by flame atomic absorption spectroscopy. The lowest quantifiable level, based on a 2 g (dry weight) sample, is 2 ng Sb/g. The results of recoveries on spiked samples, precision studies on composited coffee samples, and the analysis of National Bureau of Standards Standard Reference Materials demonstrate the reliability and accuracy of the procedure. Sb concentrations in coffee samples were verified by neutron activation analysis and inductively coupled plasma atomic emission spectroscopy. Advantages of the method compared with the AOAC colorimetric procedure and hydride generation without condensation are discussed.

scholarly journals Distribution of Dopamine in 35 Subregions of the Rat Caudate-Putamen: A High Performance Liquid Chromatography with Electrochemical Detection Analysis

1982 ◽  
Vol 9 (4) ◽  
pp. 421-427 ◽  
Author(s):  
Thérèse Di Paolo ◽  
Michel Daigle ◽  
André Dupont
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Electrochemical Detection ◽  
High Performance ◽  
Major Axis ◽  
Tissue Preparation ◽  
Caudate Putamen ◽  
Tissue Samples ◽  
Analytical Technique ◽  
Detection Analysis

SUMMARY:Topographical variations in the endogenous content of dopamine were studied in the rat caudate-putamen. For this purpose, a high performance liquid chromatography with electrochemical detection procedure for the determination of norepinephrine, epinephrine and dopamine in nervous tissue samples is described. Tissue preparation required only homogenization in acidic solution and centrifugation prior to application to the chromatograph. Detection limits in the low picogram range were found for the catecholamines separated. This assay was used in combination with a micropunch dissection technique. The performance of this analytical technique is illustrated by the detailed mapping of dopamine content in 35 subregions of the rat caudate-putamen. The distribution of dopamine varies along the major axis of the nucleus.

scholarly journals Endothelin receptor antagonist improves donor lung function in an ex vivo perfusion system

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
K. Walweel ◽  
K. Skeggs ◽  
A. C. Boon ◽  
L. E. See Hoe ◽  
M. Bouquet ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Partial Pressure ◽  
Ex Vivo ◽  
Weight Ratio ◽  
Dry Weight ◽  
Lung Damage ◽  
Endothelin Receptor ◽  
Donor Pool ◽  
Ex Vivo Lung Perfusion ◽  
Tissue Samples

Abstract Background A lung transplant is the last resort treatment for many patients with advanced lung disease. The majority of donated lungs come from donors following brain death (BD). The endothelin axis is upregulated in the blood and lung of the donor after BD resulting in systemic inflammation, lung damage and poor lung graft outcomes in the recipient. Tezosentan (endothelin receptor blocker) improves the pulmonary haemodynamic profile; however, it induces adverse effects on other organs at high doses. Application of ex vivo lung perfusion (EVLP) allows the development of organ-specific hormone resuscitation, to maximise and optimise the donor pool. Therefore, we investigate whether the combination of EVLP and tezosentan administration could improve the quality of donor lungs in a clinically relevant 6-h ovine model of brain stem death (BSD). Methods After 6 h of BSD, lungs obtained from 12 sheep were divided into two groups, control and tezosentan-treated group, and cannulated for EVLP. The lungs were monitored for 6 h and lung perfusate and tissue samples were processed and analysed. Blood gas variables were measured in perfusate samples as well as total proteins and pro-inflammatory biomarkers, IL-6 and IL-8. Lung tissues were collected at the end of EVLP experiments for histology analysis and wet-dry weight ratio (a measure of oedema). Results Our results showed a significant improvement in gas exchange [elevated partial pressure of oxygen (P = 0.02) and reduced partial pressure of carbon dioxide (P = 0.03)] in tezosentan-treated lungs compared to controls. However, the lungs hematoxylin–eosin staining histology results showed minimum lung injuries and there was no difference between both control and tezosentan-treated lungs. Similarly, IL-6 and IL-8 levels in lung perfusate showed no difference between control and tezosentan-treated lungs throughout the EVLP. Histological and tissue analysis showed a non-significant reduction in wet/dry weight ratio in tezosentan-treated lung tissues (P = 0.09) when compared to control. Conclusions These data indicate that administration of tezosentan could improve pulmonary gas exchange during EVLP.

A molybdenum - sulfur - cadmium interaction in sheep

1997 ◽  
Vol 48 (2) ◽  
pp. 147 ◽  
Author(s):  
G. M. Smith ◽  
C. L. White
Keyword(s):  
Control Diet ◽  
Dietary Treatment ◽  
Basal Diet ◽  
Dry Weight ◽  
Fresh Weight ◽  
Tissue Samples ◽  
Cd Accumulation ◽  
Treatment Groups ◽  
Pre Treatment ◽  
Treatment Concentration

We determined the effects of increased dietary concentrations of molybdenum and sulfur on the accumulation and tissue concentrations of cadmium in sheep, and compared them with effects on copper. Forty sheep, each weighing approximately 40 kg, were adjusted for 3 weeks to a basal diet of 80% wheaten chaff and 20% lupin seed containing (per kg dry weight) 0·016 mg Cd, 0·45 mg Mo, 3·4 mg Cu, and 1·9 g S. On Day 0 of treatment, 8 sheep were killed and the tissues analysed for trace minerals to provide a baseline value. The remaining sheep were divided into 4 dietary treatment groups: control (basal diet plus 4 mg Cd/kg), +Mo (control diet plus 15 mg Mo/kg), +S (control diet plus 4 g S/kg), +Mo+S (control diet+15 mg Mo+4 g S/kg). The treatment period lasted 80 days, after which sheep were killed for tissue samples. Sulfur alone reduced the accumulation of Cd in liver, kidney, and muscle by 60% compared with control sheep (P < 0·05). Molybdenum alone reduced Cd accumulation by 40% in liver and muscle (P < 0·05) and 30% in kidney (P = 0·09). When provided together (+Mo+S), the effect was equivalent to feeding with Mo alone, showing that Mo blocked the effect of S. Cadmium concentrations in whole kidneys for the 4 respective treatments were 6·40 ± 0· 7, 2·8 ± 0·3, 4·5 ± 0·8, and 5·0 ± 0·5 mg/kg fresh weight. The pre-treatment concentration was 0·7 ± 0·2 mg/kg. For Cu in blood and tissues, the effects of Mo and S treatment were consistent with the thiomolybdate hypothesis, and were quite different from those seen for Cd. Copper concentrations in whole kidney for the 4 treatments were 4·1 ± 0·1, 3·5 ± 0·2, 4·7 ± 0·3, and 22·4 ± 3·9 mg/kg fresh weight. The pre-treatment concentration was 4·1 ± 0·3 mg/kg. The results show that increased dietary levels of Mo and S reduce the accumulation of Cd in tissues, and the mechanisms of action differ from those involving Cu.

Attenuation of hyperoxic lung injury by the 21-aminosteroid U-74389G

1995 ◽  
Vol 78 (5) ◽  
pp. 1635-1641 ◽  
Author(s):  
S. Tasaka ◽  
A. Ishizaka ◽  
T. Urano ◽  
K. Sayama ◽  
F. Sakamaki ◽  
...  
Keyword(s):  
Lung Injury ◽  
Lung Tissue ◽  
Guinea Pigs ◽  
Weight Ratio ◽  
Dry Weight ◽  
Endothelial Damage ◽  
Lung Water ◽  
Tissue Samples ◽  
Cell Accumulation ◽  
Hyperoxic Lung Injury

Hyperoxic lung injury is attributable to oxygen radicals produced under hyperoxic conditions. The 21-aminosteroid (AS), U-74389G, is a potent antioxidant. We examined the effect of U-74389G on lung injury in guinea pigs during exposure to 90% O2 for 48 h. We injected either vehicle or 10 mg/kg of U-74389G 30 min before the O2 exposure and injected the same dose 12, 24, and 36 h later. We performed two series of experiments after exposure. In the first series, we measured the clearance rate of 99mTc-labeled dialdehyde starch (DAS) from the lungs as an index of pulmonary epithelial damage in three experimental groups consisting of 1) control (n = 6) O2 alone (n = 6), and 3) O2 + AS (n = 6). In the second series, pulmonary endothelial injury was estimated by using 28 guinea pigs divided into four experimental groups consisting of 1) control (n = 8), 2) AS alone (n = 5), 3) O2 alone (n = 6), and 4) O2 + AS (n = 9). In the second series, we measured the wet-to-dry weight ratio (W/D) as an index of lung water and the concentration ratio of 125I-labeled albumin in lung tissue and bronchoalveolar lavage (BAL) fluid compared with plasma (T/P and BAL/P, respectively) as indexes of pulmonary endothelial damage. Cell accumulation in BAL fluid and lung tissue samples was also assessed in the second series.(ABSTRACT TRUNCATED AT 250 WORDS)

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