Category: Biology

Tissue Microarrays 

Tissue Microarrays 

Tissue Microarrays

09/02/17

“What is a Tissue Microarray?”

 

Tissue microarray is a recently-implemented pathological tool that provides high-throughput, multiplex analysis of different tissues and cells at the same time on a single histological slide. A single microarray actually consists of tissue samples that have been extracted from different paraffin donor blocks and re-introduced into a single paraffin block, at different array points.

This way, over a thousand tissue core samples can be analyzed simultaneously and cellular components such as DNA, RNA and proteins can be analyzed under similar standardized conditions, using the same diagnostic reagents on a single histological slide.
This technology facilitates the study of large sets of formalin-fixed, paraffin-embedded tissues both in prospective and retrospective sense.
What is so great about this technique is that it allows for maximal preservation and use of limited tissue resources. It provides a way to work around the rigid guidelines that back up the obtaining of human tissue. This way, scarce resources are used effectively.
Tissue microarray is commonly employed in immunohistochemistry, oncology analysis, and fluorescent in-situ hybridization.
History

One of the previous forms of tissue microarray was the multi-tumor “sausage” tissue block developed by Dr. Hector Battifora in 1986. The block consisted of a number of tissue samples thrown for the analysis of a single protein. Wan et al made an improvement to this technique in 1990: they used a 16-gauge needle to manually remove cores from tissues blocks and arranged them in a multi-tissue straw in a way they could identify the organ origin of the blocks. This was named accordingly as the “checkerboard tissue block”.

The final changes that made tissue microarray what it is today were made by J. Kononen and his collaborators in 1998.They developed a regular sample size by using a 4mm skin biopsy punch to remove a core from its donor block and recognize its position before transferring to the recipient block. This was how the more precise sampling technique of tissue microarray was born.

Procedure

The sampling technique in tissue microarray usually involves a hollow needle used to remove tissue cores as small as 0.6 mm in diameter from different organ regions of
interest. These tissue cores are then inserted into a recipient paraffin block in a precisely spaced, array pattern. This recipient block can then be cut into 5μm sections using a microtome. These sections are then mounted independently on microscopic  slides and are subjected to histological analysis. A single microarray block can be cut up into sections ranging from 100-500 in number, depending on the thickness of the block.

A variation in this procedure is seen in frozen tissue array in which up to 50 different sample cores, 2mm in diameter, of fresh frozen tissue are arrayed in a recipient block. The block is cut up in sections by a cryostat and then it follows the normal procedure of being mounted on a microscopic block and subjected to standard tissue analysis.

Tissue Microarray and Cancer

Tissue microarray has been recently implemented in the analysis of molecular markers in oncology research. It has been instrumental in tumor staging and in identifying new diagnostic and prognostic markers and targets in various human
cancers. It has a range of potential applications in basic research, prognostic oncology, and drug discovery. This technology has the potential to significantly accelerate cancer research.

 

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Pathogens

Pathogens

Pathogens

07/18/17

“What do we term the activator of a disease?”
Disease is one of the most important studies in Biology. And diseases are caused when a vector carries the disease with it. However, what exactly do we term the activator that is carried? Well, after much debate, Biologists have settled with the definition of a pathogen to describe such organisms. Viruses, bacteria, protozoa, prions, and fungus are commonly pathogens, as well as other micro-organisms

What can walking can do for you?

What can walking can do for you?

What can walking can do for you?

07/16/17

“So what can walking do for you?”

 

 

  • Do you ever feel a bit gloomy or sad? Well, maybe all you need is a nice brisk walk. Studies have shown that taking time for a nice brisk walk can activate the release of chemicals which work to boost your mood and make you happier. (Rosenberg, Yael 2016)
  • Would you like to feel smarter? According to research by the Beth Israel Deaconess Medical Center, individuals that commit to a regular workout stimulate the growth of nerve development. (Goldstein, Lev 2016)
  • Want to prevent or reduce the risk of developing heart disease? Since walking is an anaerobic exercise, your heart will be strengthened by it. And with a stronger heart, you will be able to better resist the development of heart issues such as heart disease (Rosenberg, Yael 2016)
  • Want to lose weight? Nearly any type of exercise will cause you to lose weight. Through walking, you can burn off those calories that you have been holding in for a long time, allowing for a healthier weight range. (Goldstein, Lev 2016)
  • Do you ever just want to relieve yourself of some stress? Walking is cardiovascular in nature and can commence stress reducing endorphins to develop and takes your mind off the harmful things in life. (Rosenberg, Yael 2016)

 

 

References

 

Goldstein, Lev. “The Benefits of Walking.” Beth Israel Deaconess Medical Center. Beth Israel Deaconess Medical Center, 29 June 2016. Web. 22 June 2017.

 

Rosenberg, Yael. “Improve Your Mood: Walking Helps Beat the Blues.” Beth Israel Deaconess Medical Center. Beth Israel Deaconess Medical Center, 21 Apr. 2016. Web. 22 June 2017.

Pseudoscience in health marketing

Pseudoscience in health marketing

Pseudoscience in health marketing

07/15/17

“How can we identify pseudoscience in health marketing?”

 

People become sick from time to time. And when people become sick with an unknown illness, they often become desperate for anything that sounds like a cure. And as such, malignant individuals will try to take advantage of people’s confusion and lack of knowledge. So to save your health, time, and money, here are some warning signs for pseudoscience in health marketing

 

 

  • Claims of being “natural”

 

Many pseudoscientific health products try to justify their existence with the claim of being “natural”. (Senapathy, Kavin 2017) Supposedly, being composed of natural ingredients means that this product is safe and healthy for use and works better than the “artificial” industrial alternatives. However, just because something is natural or comes from a plant does not mean that it has any useful qualities. Uranium and parasitic fungi are natural but don’t offer anything good for us

 

  1. Claims of being based on “ancient knowledge”

Since pseudoscience marketers are often unable to explain their products using modern scientific theories, they will often retort that their material is based on “ancient” or “forgotten” knowledge/wisdom (Ernst, Edzard 2013). However, previous generation’s knowledge of the natural and social world was often flawed (see geocentric universe, flat earth, and racial “science”) and are not a substitute for the fruits of current empirical endeavors.

 

  1. Claims of being “untestable”

Testability of a hypothesis is one of the most important aspects of the scientific method. (Thompson, Bruce 1997) If something can not be tested, then it can not be accepted as a scientific phenomenon and must be avoided until such procedures are possible

 

  1.   Claims of being a wide ranging cure

Since pseudoscience plays on the fears of ordinary people, vendors will often make bold claims about the healing powers of their product. However, such claims are usually unfounded, and if one logically thinks about it, if these items were so useful wouldn’t they be selling like hot cakes? For more info, look up “too good to be true” (Gauch, Hugh G. 2003)

 

  1. Claims of conspiracy

When pressed to explain their lack of widespread success, alternative health marketers will often retort that there is a “conspiracy” to keep them down. These are usually a desperate attempt to rationalize their product’s niche nature, and never based on reality. (Gauch, Hugh G. 2003)

 

References

 

Ernst, Edzard. “Thirteen Follies and Fallacies about Alternative Medicine.” EMBO Reports 14.12 (2013): 1025-026. Web.

 

Gauch, Hugh G. (2003). Scientific Method in Practice. Cambridge University Press. ISBN 9780521017084. LCCN 2002022271.

 

Senapathy, Kavin. “Your Logical Fallacy Is Appeal To Nature: These 5 Natural Toxins In Food Have Caused Real Harm.” Forbes. Forbes Magazine, 30 Apr. 2017. Web. 22 June 2017.

 

Thompson, Bruce. “Appeal to Mystery.” Ad Hominem – Abusive. Palomar College, 08 Nov. 1997. Web. 22 June 2017.

Vectors (epidemiology)

Vectors (epidemiology)

Vectors (Epidemiology)

07/14/17

 

“What organisms carry diseases to others?”
Diseases are everywhere, whether it be in plants, animals, or fungi. However, what is the term for organisms that transmit diseases? Well, after many years of study, Epidemiologists have termed organisms that transmit diseases vectors (Kind of like the mathematical construction found in physical and engineering sciences). Any organisms can be a vector, including humans!

Malaria

Malaria

Malaria

07/12/17

“What is Malaria?”

 

Mosquitos spread all sorts of diseases. However, one of their more infamous ones is known as Malaria. Malaria is characterized by high fevers, chills, and muscle pain. Malaria can be treated with medicines, but are not always effective due to possible bio-resistance by certain strands of the Malaria parasite. Malaria is commonly found in Asia, Latin America, and Africa

Parasites

Parasites

Parasites

07/07/17

“Do some organisms require the suffering of another to survive?”

 

One of the most important factors for the survival of organisms is to be able to obtain nutrients. Some obtain it through absorbing sunlight, some through consuming other creatures. And all organisms also need a habitat  (a place to live). But some organisms are quite special in the fact that their living food source and habitat are one in the same. Specifically, they live by stealing nutrients from a hosting animal. These animals are known as parasites and can be found all over the world, from mites on your hairs to tapeworms in a stomach