This study was supported by the Korea Institute of Science and Technology intramural research grant (2E27513) and the High Value-added Food Technology Development Program (IPET) funded by the Ministry of Agriculture, Food and Rural Affairs (315067-03).

NOTE: The entire experiment must be performed in a clean isolated laboratory maintained at 20 &#176;C with low dust and with minimization of contamination during worm and bacterial handling. For this purpose, experiments must be performed under the flame of an alcohol lamp or using a clean bench.
1. Maintenance of C. elegans and Egg Preparation for the Chemical Test
<ol>
	<li>Maintain C. elegans N2 (var. Bristol) on an NGM agar plate fed with live E. coli OP50 at 20 &#176;C12,13.</li>
	<li>Prepare age-synchronized eggs using either bleach solution treatment5 or the time egg laying method6,14,15. 
	NOTE: Before egg preparation, coat the etoposide-containing NGM plate with heat-inactivated E. coli OP50 as described below. Heat-inactivated E coli OP50 is used to minimize the metabolic activity of E. coli6,16.</li>
</ol>
2. Preparation of Heat-inactivated E. coli OP50 to Feed C. elegans During the Toxicity Test
<ol>
	<li>Prepare 500 mL of double yeast tryptone (DYT) medium as described in Table 1, and inoculate a single colony of E. coli OP50 cultured on a Luria-Bertani (LB) agar plate5.</li>
	<li>Incubate the E. coli OP50 in a shaking incubator for 14 h at 37 &#176;C and 150 rpm.</li>
	<li>After centrifugation for 30 min at 3,220 x g and 20 &#176;C, remove all supernatant DYT medium, and add a pre-mixture of 25 mL of S-buffer, 250 &#181;L of 1 M MgSO4, and 25 &#181;L of 5 mg/mL cholesterol (dissolved in ethanol). All these solutions are sterile.</li>
	<li>Resuspend the bacteria and transfer them to a 50-mL disposable plastic tube.</li>
	<li>For the heat-inactivation, incubate the resuspended E. coli OP50 in a water bath for 30 min at 65 &#176;C.</li>
	<li>Cool down to room temperature and store at 4 &#176;C until use. This can be stored for up to one month.</li>
</ol>
3. Preparation of NGM Plates Containing Either 1% DMSO or 750 &#181;M Etoposide
<ol>
	<li>Prepare two clean 200 mL glass bottles. Add 0.6 g of NaCl, 0.5 g of peptone, 3.4 g of agar, and 195 mL of distilled water, and a magnetic stirrer to one bottle. Add a magnetic stirrer to the other empty bottle.</li>
	<li>Autoclave these two bottles for 15 min at 121 &#176;C, and then cool down the bottles in a water bath for 30 min at 55 &#176;C.</li>
	<li>Add 0.2 mL of 1 M CaCl2, 0.2 mL of 5 mg/mL cholesterol, 0.2 mL of 1 M MgSO4, and 5 mL of 1 M KPO4 (all these solutions are sterile) and then mix them by magnetic stirring on a hot plate at 55 &#176;C.</li>
	<li>Divide the mixed NGM medium into two bottles with the same volume (100 mL each). Next, add 1 mL of DMSO to one bottle, mix it again using the magnetic stirring. Store the other bottle in a water bath at 55 &#176;C until the next step. Aliquot 3 mL of the DMSO-containing medium to each 35 x 10 mm2 Petri dish. Approximately 33 DMSO-containing NGM plates can be made from this step.</li>
	<li>Mix the other bottle using the magnetic stirring, add 1 mL of 75 mM etoposide (stock dissolved in DMSO), mix again, and repeat the aliquot procedure (step 3.4). Approximately 33 etoposide (750 &#181;M)-containing NGM plates can be made from this step. 
	NOTE: In the correlated previous paper6, we tested 0, 250, 500, and 1,000 &#181;M of etoposide. Based on that data, we chose the 750 &#181;M of etoposide dose in this paper.</li>
	<li>Cool down the chemical-containing NGM plates to room temperature by leaving them at room temperature for approximately 3 h, and store them at 4 &#176;C until use. 
	NOTE: In the case of light-sensitive chemicals, block out light to minimize the light-induced decomposition. 
	NOTE: Optionally, make a normal NGM plate without chemicals for the egg laying assay, which can be performed using two different chemical treatment conditions as described below.</li>
	<li>Add 100 &#181;L of heat-inactivated E. coli OP50 (as described in section 2) and spread on each NGM plate. Allow to dry overnight in a C. elegans incubator at 20 &#176;C for the chemical test.</li>
</ol>
4. Measurement of C. elegans Growth
<ol>
	<li>Transfer the age-synchronized C. elegans eggs to the NGM plate supplemented with 1% DMSO or 750 &#181;M etoposide.</li>
	<li>Incubate C. elegans in an incubator at 20 &#176;C for 4 days. Observe the worms using a stereo microscope, and take microscopic images every day. Usually 20X magnification (1X objective lens, 2X zoom magnification, and 10X eyepiece lens) is appropriate for the growth observation of C. elegans. Also take a microscopic image of the microscope stage micrometer for the worm size calibration. 
	NOTE: Starvation affects the toxicity test. Therefore, feed with sufficient bacteria or adjust the&#160;transferred C. elegans egg numbers at the beginning. Observe until 3 days to exclude the possibility of starvation.</li>
	<li>Measure the body length of C. elegans treated with DMSO or etoposide at each time point using ImageJ software. 
	NOTE: For each sample measurement, 50 worms are sufficient for the statistical analysis.
	<ol>
		<li>In ImageJ, open the microscope stage micrometer image (&#39;File&#39; &#8594; &#39;Open&#39;). 
		NOTE: The micrometer image and worm images (step 4.2) must be the same magnification.</li>
		<li>Drag a line of 1,000 &#181;m on the micrometer calibration image by using &#39;Straight Line&#39; tool.</li>
		<li>Click &#39;Analyze&#39; &#8594; &#39;Set Scale&#39; and input 1,000 and &#181;m into the &#39;Known distance&#39; box and &#39;Unit of length&#39; box, respectively. Check &#39;Global&#39; and click &#39;OK&#39;.</li>
		<li>Open the worm images (&#39;File&#39; &#8594; &#39;Open&#39;). Draw a line along the feature of each worm by using &#39;Freehand Line&#39; tool. Obtain the body length data by clicking &#39;Analyze&#39; &#8594; &#39;Measure&#39;.</li>
		<li>Repeat these steps for 50 worms.</li>
	</ol>
	</li>
</ol>
5. C. elegans Egg Laying Assay
<ol>
	<li>Incubate the age-synchronized eggs on the NGM plate containing DMSO or etoposide for 64 h (before first birth) until the young adult stage at 20 &#176;C. 
	NOTE: It is optional to use the worms from the growth measurement experiments. It is convenient to do the growth measurement and egg laying assay together.</li>
	<li>Transfer 5 adult worms to the new NGM plates without chemicals (condition 1, chemical treatment within a certain period of time, from eggs to young adult stage) or new NGM plate containing the same chemical pretreatment (condition 2, continuous exposure of chemicals through the overall experimental period), and then incubate them for 24 h. 
	NOTE: It is recommended to make replicates using 3-5 NGM plates for each treatment; these replicates can be used for statistical analysis.</li>
	<li>Transfer to the new NGM plate as described above, and count the number of eggs every day. Count the worms that crawled off, died, and were internally hatched.</li>
	<li>Repeat these steps until the worms lay no more eggs, usually in 5 days.</li>
	<li>Calculate the number of eggs laid per worm from each plate, and sum these values every day for 5 days to determine the total number of eggs laid. 
	NOTE: Exclude the number of worms that crawled off and internally hatched from the calculation.</li>
</ol>

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Plant Sci. 7, 1667 (2016).</li><li>Kang, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+topoisomerase+inhibitor,+daurinol,+suppresses+growth+of+HCT116+cells+with+low+hematological+toxicity+compared+to+etoposide.">A novel topoisomerase inhibitor, daurinol, suppresses growth of HCT116 cells with low hematological toxicity compared to etoposide.</a> Neoplasia. 13 (11), 1043-1057 (2011).</li><li>Chaudhuri, J., Parihar, M., Pires-daSilva, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+introduction+to+worm+lab:+from+culturing+worms+to+mutagenesis.">An introduction to worm lab: from culturing worms to mutagenesis.</a> J. Vis. Exp. 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The authors have nothing to disclose.

In this article, we describe the toxicity evaluation of chemicals in C. elegans, a soil nematode, using etoposide as a toxicant example. For this purpose, we used two experimental conditions. In the first set, C. elegans were grown on etoposide containing plates from eggs to the young adult stage, and then the worms were allowed to lay eggs on normal NGM plates without chemicals. In the second experimental set, C. elegans were continuously treated with etoposide throughout the whole experimenta...

Toxicological evaluation is essential for the development of pharmaceuticals, nutraceuticals, and cosmeceuticals, as well as the risk assessment of various environmental toxins. The rodent model is one of the most popular in vivo experimental systems for this toxicology study; alternatively, non-mammalian organisms such as C. elegans are also widely used. Non-mammalian toxicological evaluation models are beneficial because of not only animal ethical issues but also their convenience and usefulness considering cost-effectiveness, maintainability, speed, and reproducibility1,2,3,4.
C. elegans, a soil round worm, has been exploited as a model animal in various basic and applied biology and chemistry research. It is a 1 mm long, transparent nematode, which is simply maintained in solid or liquid Nematode Growth Media (NGM) fed with the bacterial strain Escherichia coli OP50. C. elegans has a short life cycle, and wild-type N2 C. elegans lays approximately 300 eggs. Therefore, it is easily propagated to be used as experimental materials3,4,5. C. elegans has also been widely used in the toxicological studies of many drugs and environmental pollutants6,7,8,9.
Because many anticancer drugs target rapidly dividing cancer cells, they can also damage rapidly dividing normal cells such as bone marrow, intestinal epithelium, and hair follicle cells. For example, topoisomerase inhibitory anticancer drugs target the DNA replication process of cancer cells; therefore, they also inhibit rapidly dividing normal cells. Every living organism has topoisomerases, and these topoisomerase inhibitors most likely impact environmental ecosystems6,10,11. Thus, a drug toxicological evaluation platform using a model animal is valuable for both the development of pharmaceuticals and environmental risk assessment.
In this article, we describe the detailed protocols to test the toxicity of etoposide, which is a clinical anticancer agent that targets topoisomerase II, as a model toxic chemical in C. elegans. For this purpose, we will describe the measurement method of body size and the total number of eggs laid in C. elegans treated with etoposide.

<table>
	<tbody>
		<tr>
			<td>Agar</td>
			<td>Affymetrix, USA</td>
			<td>10906</td>
			<td></td>
		</tr>
		<tr>
			<td>Caenorhabditis elegans N2</td>
			<td>Caenorhabditis Genetics Center (CGC)</td>
			<td></td>
			<td>Wild type</td>
		</tr>
		<tr>
			<td>Cholesterol</td>
			<td>Sigma, USA</td>
			<td>C3045</td>
			<td></td>
		</tr>
		<tr>
			<td>Dimethyl sulfoxide</td>
			<td>Sigma, USA</td>
			<td>D2650</td>
			<td></td>
		</tr>
		<tr>
			<td>Escherichia coli OP50</td>
			<td>Caenorhabditis Genetics Center (CGC)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Etoposide</td>
			<td>Sigma, USA</td>
			<td>E1383</td>
			<td></td>
		</tr>
		<tr>
			<td>Image J software (ver 1.4)</td>
			<td>Natinoal Institute of Health, USA</td>
			<td></td>
			<td>https://imagej.nih.gov/ij/</td>
		</tr>
		<tr>
			<td>Microscope camera</td>
			<td>Jenopitk, Progress Gryphax, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Peptone</td>
			<td>Merck, USA</td>
			<td>107213</td>
			<td></td>
		</tr>
		<tr>
			<td>35 &#215; 10 mm Petri dish</td>
			<td>SPL Life Sciences, South Korea</td>
			<td>10035</td>
			<td></td>
		</tr>
		<tr>
			<td>90 &#215; 15 mm Petri dish</td>
			<td>SPL Life Sciences, South Korea</td>
			<td>10090</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereo microscope</td>
			<td>Nikon, Japan</td>
			<td>SMZ800N</td>
			<td></td>
		</tr>
		<tr>
			<td>Yeast extract</td>
			<td>Becton Dickinson, USA</td>
			<td>212750</td>
			<td></td>
		</tr>
	</tbody>
</table>

measuring the effect of chemicals on the growth and reproduction of caenorhabditis elegans

Toxicological evaluation is crucial for understanding the effects of chemicals on living organisms in basic and applied biological science fields. A non-mammalian soil round worm, Caenorhabditis elegans, is a valuable model organism for toxicology studies due to its convenience and lack of animal ethics issues compared with mammalian animal systems. In this protocol, a detailed procedure of toxicological evaluation of chemicals in C. elegans is described. A clinical anticancer drug, etoposide, which targets human topoisomerase II and inhibits DNA replication of human cancer cells, was selected as a model testing chemical. Age-synchronized C. elegans eggs were exposed to either dimethyl sulfoxide (DMSO) or etoposide, and then the growth of C. elegans was monitored every day for 4 days by the stereo microscope observation. The total number of eggs laid from C. elegans treated with DMSO or etoposide was also counted by using the stereo microscope. Etoposide treatment significantly affected the growth and reproduction of C. elegans. By comparison of the total number of eggs laid from worms with different treatment periods of chemicals, it can be decided that the reproductive toxicity of chemicals on C. elegans reproduction is reversible or irreversible. These protocols may be helpful for both the development of various drugs and risk assessment of environmental toxicants.

The treatment of etoposide (24-96 h) significantly retarded the growth of C. elegans. After 96 h of incubation, etoposide-treated worms grew to 0.86 mm in body length, while the vehicle-treated worms grew to 1.04 mm (Figure 1). Growth retardation was also apparently observed under stereo microscope observation (Figure 2). We started to see eggs from the vehicle-treated worms at 72 h of incubation. On the other hand, eggs...

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Measuring the Effect of Chemicals on the Growth and Reproduction of Caenorhabditis elegans

A basic protocol to evaluate the toxicity of chemicals in a model animal, Caenorhabditis elegans, is described. The method is convenient and useful for the development of pharmaceuticals as well as for the risk assessment of various environmental pollutants.

Measuring the Effect of Chemicals on the Growth and Reproduction of Caenorhabditis elegans

Toxicological evaluation is crucial for understanding the effects of chemicals on living organisms in basic and applied biological science fields. A ...

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16.8K Views.  Korea Institute of Science and Technology. A basic protocol to evaluate the toxicity of chemicals in a model animal, Caenorhabditis elegans, is described. The method is convenient and useful for the development of pharmaceuticals as well as for the risk assessment of various environmental pollutants.

Video: Measuring the Effect of Chemicals on the Growth and Reproduction of Caenorhabditis elegans

Measuring the Strength of Mice

Kondziela7 devised the inverted screen test and published it in 1964. It is a test of muscle strength using all four limbs. Most normal mice easily score maximum on this task; it is a quick but insensitive gross screen, and the weights test described in this article will provide a finer measure of muscular strength.
There are also several strain gauge-based pieces of apparatus available commercially that will provide more graded data than the inverted screen test, but their cost may put them beyond the reach of many laboratories which do not specialize in strength testing. Hence in 2000 a cheap and simple apparatus was devised by the author. It consists of a series of chain links of increasing length, attached to a "fur collector" a ball of fine wire mesh sold for preventing limescale build up in hard water areas. An accidental observation revealed that mice could grip these very tightly, so they proved ideal as a grip point for a weight-lifting apparatus. A common fault with commercial strength meters is that the bar or other grip feature is not thin enough for mice to exert a maximum grip. As a general rule, the thinner the wire or bar, the better a mouse can grip with its small claws.
This is a pure test of strength, although as for any test motivational factors could potentially play a role. The use of scale collectors, however, seems to minimize motivational problems as the motivation appears to be very high for most normal young adult mice.

Deficits in muscular strength occur in many clinical conditions such as motor neuron disease. The inverted screen and weight lifting tests described here measure strength in mice almost exclusively, with minimal influence of factors such as coordination.

Kondziela7 devised the inverted screen test and published it in 1964. It is a test of muscle strength using all four limbs. Most normal mice easily score ...

Immunohistochemical Staining of B7-H1 (PD-L1) on Paraffin-embedded Slides of Pancreatic Adenocarcinoma Tissue

B7-H1/PD-L1, a member of the B7 family of immune-regulatory cell-surface proteins, plays an important role in the negative regulation of cell-mediated immune responses through its interaction with its receptor, programmed death-1 (PD-1) 1,2. Overexpression of B7-H1 by tumor cells has been noted in a number of human cancers, including melanoma, glioblastoma, and carcinomas of the lung, breast, colon, ovary, and renal cells, and has been shown to impair anti-tumor T-cell immunity3-8.
Recently, B7-H1 expression by pancreatic adenocarcinoma tissues has been identified as a potential prognostic marker9,10. Additionally, blockade of B7-H1 in a mouse model of pancreatic cancer has been shown to produce an anti-tumor response11. These data suggest the importance of B7-H1 as a potential therapeutic target. Anti-B7-H1 blockade antibodies are therefore being tested in clinical trials for multiple human solid tumors including melanoma and cancers of lung, colon, kidney, stomach and pancreas12.
In order to eventually be able to identify the patients who will benefit from B7-H1 targeting therapies, it is critical to investigate the correlation between expression and localization of B7-H1 and patient response to treatment with B7-H1 blockade antibodies. Examining the expression of B7-H1 in human pancreatic adenocarcinoma tissues through immunohistochemistry will give a better understanding of how this co-inhibitory signaling molecule contributes to the suppression of antitumor immunity in the tumor's microenvironment. The anti-B7-H1 monoclonal antibody (clone 5H1) developed by Chen and coworkers has been shown to produce reliable staining results in cryosections of multiple types of human neoplastic tissues4,8, but staining on paraffin-embedded slides had been a challenge until recently13-18. We have developed the B7-H1 staining protocol for paraffin-embedded slides of pancreatic adenocarcinoma tissues. The B7-H1 staining protocol described here produces consistent membranous and cytoplasmic staining of B7-H1 with little background.

Immunohistochemical Staining of B7-H1 PD-L1 on Paraffin-embedded Slides of Pancreatic Adenocarcinoma Tissue

B7-H1 (PD-L1) and its binding to PD-1 provide a major tumor-induced immunosuppressive signal in the tumor&#x2019;s microenvironment. An immunohistochemical staining technique to characterize the expression and localization of B7-H1 in pancreatic adenocarcinoma is described here.

B7-H1/PD-L1, a member  of the B7 family of immune-regulatory cell-surface proteins, plays an important  role in the negative regulation of cell-mediated ...

Measuring Frailty in HIV-infected Individuals. Identification of Frail Patients is the First Step to Amelioration and Reversal of Frailty

A simple, validated protocol consisting of a battery of tests is available to identify elderly patients with frailty syndrome. This syndrome of decreased reserve and resistance to stressors increases in incidence with increasing age. In the elderly, frailty may pursue a step-wise loss of function from non-frail to pre-frail to frail. We studied frailty in HIV-infected patients and found that ~20% are frail using the Fried phenotype using stringent criteria developed for the elderly1,2. In HIV infection the syndrome occurs at a younger age.
HIV patients were checked for 1) unintentional weight loss; 2) slowness as determined by walking speed; 3) weakness as measured by a grip dynamometer; 4) exhaustion by responses to a depression scale; and 5) low physical activity was determined by assessing kilocalories expended in a week's time. Pre-frailty was present with any two of five criteria and frailty was present if any three of the five criteria were abnormal.
The tests take approximately 10-15 min to complete and they can be performed by medical assistants during routine clinic visits. Test results are scored by referring to standard tables. Understanding which of the five components contribute to frailty in an individual patient can allow the clinician to address relevant underlying problems, many of which are not evident in routine HIV clinic visits.

Frailty syndrome is commonly seen in the aged and reflects multi-system physiological change. However, with reduced functional reserve and resilience frailty is also known to be common in the HIV infected population. This study outlined an easily administered screening test to identify HIV patients with frailty. When significant components of frailty are identified, clinicians will be able to focus on amelioration of the problem and promote reversion to the pre-frail state.

A simple, validated protocol consisting of a battery of tests is available to identify elderly patients with frailty syndrome. This syndrome of decreased ...

The Influence of Liver Resection on Intrahepatic Tumor Growth

The high incidence of tumor recurrence after resection of metastatic liver lesions remains an unsolved problem. Small tumor cell deposits, which are not detectable by routine clinical imaging, may be stimulated by hepatic regeneration factors after liver resection. It is not entirely clear, however, which factors are crucial for tumor recurrence.
The presented mouse model may be useful to explore the mechanisms that play a role in the development of recurrent malignant lesions after liver resection. The model combines the easy-to-perform and reproducible techniques of defined amounts of liver tissue removal and tumor induction (by injection) in mice. The animals were treated with either a single laparotomy, a 30% liver resection, or a 70% liver resection. All animals subsequently received a tumor cell injection into the remaining liver tissue. After two weeks of observation, the livers and tumors were evaluated for size and weight and examined by immunohistochemistry.
After a 70% liver resection, the tumor volume and weight were significantly increased compared to a laparotomy alone (p &#60;0.05). In addition, immunohistochemistry (Ki67) showed an increased tumor proliferation rate in the resection group (p &#60;0.05).
These findings demonstrate the influence of hepatic regeneration mechanisms on intrahepatic tumor growth. Combined with methods like histological workup or RNA analysis, the described mouse model could serve as foundation for a close examination of different factors involved in tumor growth and metastatic disease recurrence within the liver. A considerable number of variables like the length of postoperative observation, the cell line used for injection or the timing of injection and liver resection offer multiple angles when exploring a specific question in the context of post-hepatectomy metastases. The limitations of this procedure are the authorization to perform the procedure on animals, access to an appropriate animal testing facility and acquisition of certain equipment.

A high incidence of tumor recurrence after resection of liver metastases remains an unsolved problem. The illustrated mouse model may be useful to investigate the reasons for such recurrences. It combines a liver resection model with intrahepatic tumor cell injection for the first time.

The high incidence of tumor recurrence after resection of metastatic liver lesions remains an unsolved problem. Small tumor cell deposits, which are not ...

Phosphorus-31 Magnetic Resonance Spectroscopy: A Tool for Measuring In Vivo Mitochondrial Oxidative Phosphorylation Capacity in Human Skeletal Muscle

Skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity, which is critically important in health and disease, can be measured in vivo and noninvasively in humans via phosphorus-31 magnetic resonance spectroscopy (31PMRS). However, the approach has not been widely adopted in translational and clinical research, with variations in methodology and limited guidance from the literature. Increased optimization, standardization, and dissemination of methods for in vivo 31PMRS would facilitate the development of targeted therapies to improve OXPHOS capacity and could ultimately favorably impact cardiovascular health. 31PMRS produces a noninvasive, in vivo measure of OXPHOS capacity in human skeletal muscle, as opposed to alternative measures obtained from explanted and potentially altered mitochondria via muscle biopsy. It relies upon only modest additional instrumentation beyond what is already in place on magnetic resonance scanners available for clinical and translational research at most institutions. In this work, we outline a method to measure in vivo skeletal muscle OXPHOS. The technique is demonstrated using a 1.5 Tesla whole-body MR scanner equipped with the suitable hardware and software for 31PMRS, and we explain a simple and robust protocol for in-magnet resistive exercise to rapidly fatigue the quadriceps muscle. Reproducibility and feasibility are demonstrated in volunteers as well as subjects over a wide range of functional capacities.

Phosphorus-31 Magnetic Resonance Spectroscopy: A Tool for Measuring In Vivo Mitochondrial Oxidative Phosphorylation Capacity in Human Skeletal Muscle

This work demonstrates the feasibility of an in vivo phosphorus-31 magnetic resonance spectroscopy (31PMRS) technique to quantify mitochondrial oxidative phosphorylation (OXPHOS) capacity in human skeletal muscle.

Skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity, which is critically important in health and disease, can be measured in vivo ...

Turbidimetry on Human Washed Platelets: The Effect of the Pannexin1-inhibitor Brilliant Blue FCF on Collagen-induced Aggregation

Turbidimetry is a laboratory technique that is applied to measure the aggregation of platelets suspended in either plasma (platelet-rich plasma, PRP) or in buffer (washed platelets), by the use of one or a combination of agonists. The use of washed platelets separated from their plasma environment and in the absence of anticoagulants allows for studying intrinsic platelet properties. Among the large panel of agonists, arachidonic acid (AA), adenosine di-phosphate (ADP), thrombin and collagen are the most frequently used. The aggregation response is quantified by measuring the relative optical density (OD) over time of platelet suspension under continuous stirring. Platelets in homogeneous suspension limit the passage of light after the addition of an agonist, platelet shape change occurs producing a small transitory increase in OD. Following this initial activation step, platelet clots form gradually, allowing the passage of light through the suspension as a result of decreased OD. The aggregation process is ultimately expressed as a percentage, compared to the OD of platelet-poor plasma or buffer. Rigorous calibration is thus essential at the beginning of each experiment. As a general rule: calibration to 0% is set by measuring the OD of a non-stimulated platelet suspension while measuring the OD of the suspension medium containing no platelets represents a value of 100%. Platelet aggregation is generally visualized as a real-time aggregation curve. Turbidimetry is one of the most commonly used laboratory techniques for the investigation of platelet function and is considered as the historical gold standard and used for the development of new pharmaceutical agents aimed at inhibiting platelet aggregation. Here, we describe detailed protocols for 1) preparation of human washed platelets and 2) turbidimetric analysis of collagen-induced aggregation of human washed platelets pretreated with the food dye Brilliant Blue FCF that was recently identified as an inhibitor of Pannexin1 (Panx1) channels.

We describe a straightforward method for the isolation of washed platelets from human blood followed by agonist-induced platelet aggregation measurements by turbidimetry. As an example we apply this method for studying the aggregation response of human platelets to collagen after a pre-incubation with the Pannexin1 channel inhibitor Brilliant Blue FCF.

Turbidimetry is a laboratory technique that is applied to measure the aggregation of platelets suspended in either plasma (platelet-rich plasma, PRP) or ...

A Primary Human Trophoblast Model to Study the Effect of Inflammation Associated with Maternal Obesity on Regulation of Autophagy in the Placenta

Maternal obesity is associated with an increased risk of adverse perinatal outcomes that are likely mediated by compromised placental function that can be attributed to, in part, the dysregulation of autophagy. Aberrant changes in the expression of autophagy regulators in the placentas from obese pregnancies may be regulated by inflammatory processes associated with both obesity and pregnancy. Described here is a protocol for sampling of villous tissue and isolation of villous cytotrophoblasts from the term human placenta for primary cell culture. This is followed by a method for simulating the inflammatory milieu in the obese intrauterine environment by treating primary trophoblasts from lean pregnancies with tumor necrosis factor alpha (TNF&#945;), a proinflammatory cytokine that is elevated in obesity and in pregnancy. Through the implementation of the protocol described here, it is found that exposure to exogenous TNF&#945; regulates the expression of Rubicon, a negative regulator of autophagy, in trophoblasts from lean pregnancies with female fetuses. While a variety of biological factors in the obese intrauterine environment maintain the potential to modulate critical pathways in trophoblasts, this ex vivo system is especially useful for determining if expression patterns observed in vivo in human placentas with maternal obesity are a direct result of TNF&#945; signaling. Ultimately, this approach affords the opportunity to parse out the regulatory and molecular implications of inflammation associated with maternal obesity on autophagy and other critical cellular pathways in trophoblasts that have the potential to impact placental function.

Presented here is a protocol for sampling of human placental villous tissue followed by isolation of cytotrophoblasts for primary cell culture. Treatment of trophoblasts with TNF&#945; recapitulates inflammation in the obese intrauterine environment and facilitates the discovery of molecular targets regulated by inflammation in placentas with maternal obesity.

Maternal obesity is associated with an increased risk of adverse perinatal outcomes that are likely mediated by compromised placental function that can be ...

Measuring the Effects of Bacteria and Chemicals on the Intestinal Permeability of Caenorhabditis elegans

In living organisms, intestinal hyperpermeability is a serious symptom that leads to many inflammatory bowel diseases (IBDs). Caenorhabditis elegans is a nonmammalian animal model that is widely used as an assay system due to its short lifespan, transparency, cost-effectiveness, and lack of animal ethics issues. In this study, a method was developed to investigate the effects of different bacteria and 3,3'-diindolylmethane (DIM) on the intestinal permeability of C. elegans with a high-throughput image analysis system. The worms were infected with different gut bacteria or cotreated with DIM for 48 h and fed with fluorescein isothiocyanate (FITC)-dextran overnight. Then, the intestinal permeability was examined by comparing the fluorescence images and the fluorescence intensity inside the worm bodies. This method may also have the potential to identify probiotic and pathogenic intestinal bacteria that affect intestinal permeability in the animal model and is effective for examining the effects of harmful or health-promoting chemicals on intestinal permeability and intestinal health. However, this protocol also has some considerable limitations at the genetic level, especially for determining which genes are altered to control illness, because this method is mostly used for phenotypic determination. In addition, this method is limited to determining exactly which pathogenic substrates cause inflammation or increase the permeability of the worms' intestines during infection. Therefore, further in-depth studies, including investigation of the molecular genetic mechanism using mutant bacteria and nematodes as well as chemical component analysis of bacteria, are required to fully evaluate the function of bacteria and chemicals in determining intestinal permeability.

Measuring the Effects of Bacteria and Chemicals on the Intestinal Permeability of Caenorhabditis elegans

This protocol describes how to measure intestinal permeability of Caenorhabditis elegans. This method is helpful for basic biological research on intestinal health related to the interaction between intestinal bacteria and their host and for screening to identify probiotic and chemical agents to cure leaky gut syndrome and inflammatory bowel diseases.

In living organisms, intestinal hyperpermeability is a serious symptom that leads to many inflammatory bowel diseases (IBDs). Caenorhabditis elegans is a ...

Effect of Artificial Tear Formulations on the Metabolic Activity of Human Corneal Epithelial Cells after Exposure to Desiccation

Artificial lipid-containing tear formulations are developed to reduce tear evaporation by the restoration of a deficient tear lipid layer. Artificial tear formulations that prevent cell desiccation will result in ocular surface protection and the maintenance of cell metabolic activity. During dehydration, cells undergo the process of loss of metabolic activity and subsequently cell death. This work describes a method for assessing the efficacy of artificial tear formulations. The metabolic dye (i.e., alamarBlue) changes from a low fluorescent molecule resazurin to a fluorescent molecule resorufin in viable cells. The biological performance of an artificial tear formulation is measured as the ability of the formulation to (a) maintain cell viability and (b) provide cell protection from desiccation. Growth media and saline are used as controls for the cell viability/desiccation tests. Cells are incubated with test solutions for 30 min and then desiccated for 0 or 5 min at 37 &#176;C and 45% relative humidity. Cell metabolic activity after initial exposure and after cell desiccation is then determined. The results show the comparative effects of eye drop formulations on cell metabolic activity and desiccation protection. This method can be used to test dry eye formulations that are designed to treat individuals with evaporative dry eye.

The purpose of this protocol is to evaluate if different artificial tear formulations can protect human corneal epithelial cells from desiccation using an in vitro model. After exposure to artificial tear formulations and desiccation, human corneal epithelial cells are assessed for metabolic activity.

Artificial lipid-containing tear formulations are developed to reduce tear evaporation by the restoration of a deficient tear lipid layer. Artificial tear ...

Quantification of Optic Nerve Cross Sectional Area on MRI: A Novel Protocol using Fiji Software

Optic nerve assessment is an important aspect of glaucoma diagnosis and follow-up. This project describes a protocol for a unified methodology of optic nerve cross-sectional assessment and quantification using 3 T MRI for image acquisition and ImageJ's Fiji software for image processing quantification. Image acquisition was performed using 3 T MRI, with proper instructions for the patient to ensure straight fixation during imaging. A T2-weighted fat suppressed sequence was used. A coronal cut taken 3 mm behind the globe and perpendicular to the optic nerve axis should be uploaded to the software. Using the threshold function, the white matter area of the optic nerve is selected and quantified, thus, eliminating inter-individual measurement bias. We also described the normal limits for the optic nerve cross-sectional area according to age, based on previously published literature. We used the described protocol to assess optic nerve of a suspected glaucoma patient. The optic nerve cross-sectional area was found to be within the normal limits, a finding further confirmed via optical coherence tomography of the optic nerve.

We provided a detailed protocol for a standardized method of optic nerve assessment and quantification using MRI, utilizing a widely available imaging sequence, and open access software for image analysis. Following this standardized protocol would provide meaningful data for comparison between different patients and different studies.

Optic nerve assessment is an important aspect of glaucoma diagnosis and follow-up. This project describes a protocol for a unified methodology of optic ...

Measuring the Effect of Chemicals on the Growth and Reproduction of Caenorhabditis elegans

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Measuring the Strength of Mice

Immunohistochemical Staining of B7-H1 (PD-L1) on Paraffin-embedded Slides of Pancreatic Adenocarcinoma Tissue

Measuring Frailty in HIV-infected Individuals. Identification of Frail Patients is the First Step to Amelioration and Reversal of Frailty

The Influence of Liver Resection on Intrahepatic Tumor Growth

Phosphorus-31 Magnetic Resonance Spectroscopy: A Tool for Measuring In Vivo Mitochondrial Oxidative Phosphorylation Capacity in Human Skeletal Muscle

Turbidimetry on Human Washed Platelets: The Effect of the Pannexin1-inhibitor Brilliant Blue FCF on Collagen-induced Aggregation

A Primary Human Trophoblast Model to Study the Effect of Inflammation Associated with Maternal Obesity on Regulation of Autophagy in the Placenta

Measuring the Effects of Bacteria and Chemicals on the Intestinal Permeability of Caenorhabditis elegans

Effect of Artificial Tear Formulations on the Metabolic Activity of Human Corneal Epithelial Cells after Exposure to Desiccation

Quantification of Optic Nerve Cross Sectional Area on MRI: A Novel Protocol using Fiji Software