scholarly journals REPRODUCING A DETECTION TEST FOR MAGNETIC TAPES DEGRADATION: ACETONE EXTRACTION TEST

2018 ◽  
Author(s):  
Federica Bressan
Keyword(s):  
Acetone Extraction ◽  
Extraction Test

scholarly journals THE LOCALIZATION OF LIPIDS IN HUMAN BLOOD AND BONE MARROW CELLS

Blood ◽  
1950 ◽  
Vol 5 (1) ◽  
pp. 79-88 ◽  
Author(s):  
MARVIN L. BLOOM ◽  
GEORGE B. WISLOCKI
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Ground Substance ◽  
Metabolic Factors ◽  
Baker’S Method ◽  
Sudan Black B ◽  
Specific Granules ◽  
Neutrophilic Leukocytes ◽  
Extraction Test ◽  
Supravital Staining

Abstract By Baker’s method for the staining of lipids, various types of cytoplasmic rods and granules in leukocytes give a positive acid hematein test but are negative after the pyridine-extraction test. According to Baker,8 this combination of results indicates the presence of phospholipids. Some of the rods and granules which are stained appear to be mitochondria, judging from their shape, size and distribution. as well as from the fact that they coincide in all respects with mitochondria demonstrable by supravital staining. Baker8 pointed out that in a great variety of cells his method stained mitochondria, although he did not report having examined leukocytes. In addition to mitochondria, Baker’s method stains the specific granules of the three varieties of granular leukocytes. In the neutrophilic leukocytes, the granules appear gray or black; in some of the eosinophilic leukocytes, they are intensely black, while in others they are unstained although surrounded by stained ground substance; and in the basophilic leukocytes, some of the granules of individual cells are stained while others are not. Provided the method is chemically specific, it follows that the specific granules of these leukocytes contain phospholipids. The appearance of the eosinophils indicates that many of them possess granules composed of protein surrounded by phospholipid, although some of them contain granules with lipid in their interiors. These differences in the eosinophils suggest possible functional stages, related perhaps to the age of the cells or some other metabolic factors. In the monocytes, besides a general stippling of the cytoplasm corresponding to mitochondria, the region of the attraction sphere often contains numerous deeply stained granules. Sudan black B stains both the mitochondria and the specific leukocytic granules in a manner similar to Baker’s method. However, certain slight differences were noticed. Platelets were brought out moderately distinctly by the acid hematein procedure, whereas in sudan black preparations they were barely visible. A variability was noted in the staining of the granules of the eosinophilic leukocytes in Baker’s method, in contrast to the uniformity of their staining with sudan black. This difference should perhaps be interpreted as indicating that the eosinophilic granules contain other lipid substances besides phospholipids. Mitochondnia, in whatsoever type of leukocyte they are observed, appear to stain more deeply and distinctly by Baker’s method than with sudan black, a circumstance suggesting that mitochondria are very rich in phospholipids.

In Vitro Cytotoxicity Testing of Wood-Based Biomorphic SiC Ceramics

2005 ◽  
Vol 284-286 ◽  
pp. 581-584 ◽  
Author(s):  
Alejandro de Carlos ◽  
Jacinto P. Borrajo ◽  
Julia Serra ◽  
Pio González ◽  
Sara Liste ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
In Vitro Cytotoxicity ◽  
Cellular Activity ◽  
Sic Ceramics ◽  
Cellular Attachment ◽  
Sic Ceramic ◽  
Extraction Test ◽  
Innovative Material ◽  
In Vitro Performance

The aim of this study was to test the in vitro cytotoxicity of wood-based biomorphic Silicon Carbide (SiC) ceramics, using MG-63 human osteoblast-like cells. This innovative material has been recently developed and it exhibits unique mechanical properties towards their application in biomedical technology. In the solvent extraction test the SiC ceramic extracts had almost no effect on cellular activity even at 100% concentration. A similar behaviour was found for Ti6Al4V and bioactive glass, used as reference materials. The results of the cell morphology and the cellular attachment response have also demonstrated that the in vitro performance of these biomorphic SiC ceramics is qualitatively comparable to that produced by titanium alloy and bioactive glass, which seems very promising.

Histochemical and Morphological Studies of the Lipids in Oogenesis. I. Periplaneta americana

1958 ◽  
Vol s3-99 (47) ◽  
pp. 315-332
Author(s):  
VISHWA NATH ◽  
BRIJ L. GUPTA ◽  
BACHAN LAL
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Periplaneta Americana ◽  
Lipid Synthesis ◽  
Active Role ◽  
Lipid Bodies ◽  
Acetone Extraction ◽  
Morphological Studies ◽  
Carbohydrate Complex

1. Three kinds of lipid bodies have been described in the oogenesis of the cockroach, Periplaneta americana (i) L1 bodies, present in the earliest oocyte, which persist till the oocyte measures approximately mm and contain phoapholipids only, possibly having more lecithint than cephalins; (ii) L2bodies, which first arise in the oocyte measuring 0.4 mm and have a complete or incomplete sheath of phoapholipida surrounding a medulla of triglycerides (rather highly saturated); (iii) L3 bodies, which are the only type of lipids present in the oocytea measuring more than 0.65 mm and consist of triglycerides only (rather highly saturated). 2. Some of the larger L3 bodies give a ‘ringed’ or ‘crescentic’ appearance in Sudan black when used at room temperatures (12° C to 40° C) but appear mostly solid when this colouring agent is used at 6o° C. 3. Mitochondria, which remain as fine granules throughout the course of oogenesis, contain proteins and phospholipids. They seem to have some lipids which are masked normally but are unmasked after acetone extraction, with a resulting increase in sudanophilia. 4. Yolk globules appear in the oocytes meaauring approximately 0.5 mm. They contain a protein-carbohydrate complex. 5.The bacterioid objects described by earlier workers have been shown to contain phospholipids and free fatty acids. They possibly play an active role in the lipid synthesis of the cell.

scholarly journals Determination of Fat in Raw and Processed Milks by the Gerber Method: Collaborative Study

2001 ◽  
Vol 84 (5) ◽  
pp. 1499-1508 ◽  
Author(s):  
Dick H Kleyn ◽  
Joanna M Lynch ◽  
David M Barbano ◽  
M Jeffrey Bloom ◽  
Martin W Mitchell ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Reference Method ◽  
Fat Content ◽  
Interlaboratory Study ◽  
Test Portion ◽  
Ether Extraction ◽  
Whole Milk ◽  
Relative Standard ◽  
Extraction Test ◽  
Fat Level

Abstract The Gerber method is used worldwide as a simple and rapid method for determining fat in raw and processed milks. However, the volume of the test portion used in the method has not been internationally agreed upon. A collaborative study was conducted to evaluate performance of the Gerber method using either a weighed test portion (11.13 g) or by a 10.77 mL test portion delivered by pipet. For each method, laboratories received 10 test samples: 5 raw and 5 pasteurized homogenized milks, 2 of which were blind duplicate pairs. Eleven and 10 laboratories participated in the evaluation of aliquot addition by weight and pipet, respectively. Mojonnier ether extraction (Method 989.05) was used as the reference method. Interlaboratory study statistics were similar between methods of test portion addition and between raw and processed materials; therefore, summary interlaboratory study statistics were pooled. The fat content of milk samples ranged from 0.96 to 5.48%. Absolute reproducibility and repeatability were not affected by fat level, and pooled statistical performance (invalid and outlier data removed) was (g fat/100 g milk) sr = 0.026, sR = 0.047, r = 0.074, and R = 0.132. Relative standard deviations increased with decreasing fat content, and were summarized by fat level: 1–2% fat milk, mean = 1.437, RSDr = 1.809%, RSDR = 3.271%; 2–6% fat milk, mean = 4.156, RSDr = 0.626%, RSDR = 1.131%. Compared with ether extraction, test results by the Gerber method were slightly lower (0.02% fat) using a weighed test portion and significantly lower (0.06% fat) using a 10.77 mL volume addition by pipet. A trend toward underestimating fat content at lower fat concentrations (1–2% fat) was observed with the weighed test portion but not when a pipet was used. The Associate Referee recommends that the Gerber method using a weighed test portion be adopted as First Action with applicability limited to whole milk.

scholarly journals Leveraging Extraction Testing to Predict Patient Exposure to Polymeric Medical Device Leachables Using Physics-based Models

2020 ◽  
Vol 178 (1) ◽  
pp. 201-211
Author(s):  
Paul Turner ◽  
Robert M Elder ◽  
Keaton Nahan ◽  
Anne Talley ◽  
Saloni Shah ◽  
...  
Keyword(s):  
Medical Device ◽  
Chemical Constituents ◽  
A Priori ◽  
Exposure Dose ◽  
Test Results ◽  
Animal Testing ◽  
Patient Exposure ◽  
Extraction Test ◽  
Routine Basis

Abstract Toxicological risk assessment approaches are increasingly being used in lieu of animal testing to address toxicological concerns associated with release of chemical constituents from polymeric medical device components. These approaches currently rely on in vitro extraction testing in aggressive environments to estimate patient exposure to these constituents, but the clinical relevance of the test results is often ambiguous. Physics-based mass transport models can provide a framework to interpret extraction test results to provide more clinically relevant exposure estimates. However, the models require system-specific material properties, such as diffusion (D) and partition coefficients (K), to be established a priori for the extraction conditions. Using systems comprised high-density polyethylene and 4 different additives, we demonstrate that these properties can be quantified through standard extraction testing in hexane and isopropyl alcohol. The values of D and K derived in this manner were consistent with theoretical predictions for these quantities. Based on these results, we discuss both the challenges and benefits to leveraging extraction data to parameterize physics-based exposure models. Our observations suggest that clinically relevant, yet still conservative, exposure dose estimates provided by applying this approach to a single extraction measurement can be more than 100 times lower than would be measured under typical aggressive extraction conditions. However, to apply the framework on a routine basis, limiting values of D and K must be established for device-relevant systems either through the aggregation and analysis of more extensive extraction test data and/or advancements in theoretical and computational modeling efforts to predict these quantities.

scholarly journals In Vitro and In Vivo Testing to Determine Cd Bioaccessibility and Bioavailability in Contaminated Rice in Relation to Mouse Chow

2019 ◽  
Vol 16 (5) ◽  
pp. 871 ◽  
Author(s):  
Shuo Sun ◽  
Xiaofang Zhou ◽  
Zhian Li ◽  
Ping Zhuang
Keyword(s):  
Mineral Content ◽  
Significant Negative Correlation ◽  
Chow Group ◽  
Oral Bioaccessibility ◽  
Significant Difference ◽  
Extraction Test ◽  
In Vivo Testing ◽  
Distribution In Organs

A combination of an in vitro physiologically based extraction test (PBET) and an in vivo mouse model was used to determine Cd oral bioaccessibility and estimate bioavailability in Cd-contaminated rice. The PBET found lower Cd bioaccessibility in the intestinal stage (40–50%) than in the gastric stage (93–98%) for both rice and mouse chow. No significant difference was found in Cd bioaccessibility between contaminated rice and Cd-amended mouse chow in the gastric or gastrointestinal phase (except for rice 1). The result of the in vivo bioassay revealed that Cd absorption in the kidney or liver of mice fed with contaminated rice were significantly higher than in the mouse chow group containing an equal Cd concentration. Correlation analysis between concentrations of different elements in mouse chow or rice and Cd concentrations in mice kidney or liver showed that Fe, Ca, Cu, and Zn had significant negative correlation (r2 > 0.7, p < 0.01). These results suggest that nutritional elements in the diet could affect Cd absorption and distribution in organs and that different food matrices may result in unequal Cd health risks at an equal Cd concentration due to the specific mineral content of food.

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