Genetic Engineer Part 2

I mentioned a link in previous post that crashed my browser. I was referencing an interview between Exxon CEO and Charlie Rose wherein Exxon spoke about their research to genetically engineer algae--the oldest living organism on the planet. Rather than simply use algae as it now exists after how many thousands of years of evolution, they wanted to bio-engineer it so they could profitably make fuel from it. 

I am one of those people who is reluctant to believe that we can do such meddling with 'Mother Nature' safely. I have seen the damage of genetic pollution from promising biotech companies who mess with the gene pool for plants and claim they are the owners of plant species by virtue of their scientific experiments. There is something inherently disrespectful about the presumption that a young understanding of genetic information is somehow superior to the wisdom of natural life, natural species that have adapted slowly and developed in response to environment. We have history of introducing plants and animals across the planet and creating disruptive or invasive species that do not have natural barriers to their unchecked or rampant growth. 

Anyway, I clearly can be viewed as a Luddite or someone against technology but I do understand the hope and fervor of men of science who want to make their mark and leave a legacy and to do things in a big way. I am encouraged by news of individual tinkerers and scientists who devise carburetors that can get 60+ miles per gallon of gas or people who develop cars that run on water or other discoveries that reflect a sensibility and respect for the planet and other life forms. What I hope we guard against as we delve into genetic product development is the propensity to allow entities of scale and economic might to dictate the commercial integration of products that do not serve the highest good but are flawed and allowed to proceed because of the commercial investments made and the objectives of earning profit or gaining market share.

Genetic Engineering

I watched "Life at the Speed of Light" interview with Microbiologist J. Craig Venter after viewing the assigned video "The Frost Interview." Both provide valuable perspectives that when analyzed are very useful to the discussion of bioethics and decisions that are determining the future of life on this planet. The "Life at Speed of--" interview was longer but very informative.

In the Frost Interview, we learn that he was a surfer who went to Vietnam as a corpsman that instilled his desire to study medicine and become a third world doctor. He then started off in a new direction and found his passion in life--biochemistry and research! He later was working at National Institutes of Health (NIH) as a scientist who grew dissatisfied with lack of funding for some research and left to do the work that could and was funded by private sources. Although Frost tries to paint him as an egoist or at least reference allegations of this, I found myself admiring Venter for having the tenacity and self-confidence needed to focus on the achievements he has made, no doubt the critical remarks are at least tinged with professional jealousy and seem to be insignificant to consider when examining the larger magnitude of his work. 

He did state that he does not believe in God, which could be an obvious conclusion for a corpsman in Vietnam at age 21. Still it is a daring statement that engenders disdain or worse among a good segment of the American population. Still, if you can remain neutral on that and just consider the nature of his career and the statements he makes, he is revealing through these interviews that he is orchestrating research and admits to being an adrenaline addict. He learned in Vietnam that life is short and is driven by speed and admits that we have a limited amount of time to accomplish things. He says it would be better if science went a whole lot faster and we should have 10 times the pace of discovery that we do. 

Novartis is a company that makes vaccines, but has long found flu vaccine unprofitable as it takes at least six months if not a whole year to create them using the egg technology system in place for decades. They are working with Venter to create synthetic vaccine, made entirely from digital code that translates DNA; his work on the Human Genome project was foundation for his understanding that DNA and digital code can be interchangeable and that we have been digitizing biology since 1977. He told story of Chinese virus called H7N9 that he created a vaccine for it in just 10-11 hours! He related that Mexican government didn't want it public that Mexico City was source of a new virus and US government didn't want actual samples of it entering the country. Now they can send digital code of virus instead. 

He refers to Asimov who was a biologist before he was a science fiction writer. Venter himself seems to have keen visions and considers that the burgeoning population growth requires that science breakthroughs such as he and his groups are making are needed. He claims that we are evolving socially 1000 times faster than we are evolving biologically and is concerned about the destruction of the environment taking place and says that population pressures will continue unless we devise solutions. 

He says people do not credit Monsanto with creating solutions such as Golden Rice in Africa to keep people from starving. Here I differ with his analysis and support for GMO as benign science. I have to respect him for creating a very secure life for himself and a fascinating career and he is well-spoken. He would be an interesting person to invite to a dinner party!

[The following is best resurrection of entry that was lost and not saved when I launched another tab to get this link on algae and refused to allow cookies; it crashed my browser and the work was not saved!]

http://www.bloomberg.com/news/2013-05-21/exxon-refocusing-algae-biofuels-program-after-100-million-spend.html

DESIGNER BABIES
http://www.foxnews.com/on-air/special-report-bret-baier/2014/02/27/all-star-panel-debate-over-designer-babies-heats

George Will and other panelists weigh in on the gap or lag time between bioethics and laws with the frontiers of genetic science that have been introduced virtually without such beneficial discussions as a society. Designer babies refers to the idea that parents will soon have the ability to choose not only the sex of their child, but to preselect for intellectual or athletic aptitude as well as desired physical features such as height, or whatever vanity is projected and available for child shoppers using a menu from businesses offering not just genetic counseling but genetic modifications that could involved the mitochondria of a "third parent" with all that entails. 

In fact, the debate about surrogate mothers has not kept it from taking place, and the "fertility clinics' around the globe collect DNA and sperm and created the infamous "Octo-Mom' mother of an octet (eight babies) whose vanity and need for attention outweighed the very practical considerations of raising eight babies on top of her pre-existing family as a single mother. 

The examples of commercial application of science-engineered discoveries that have not been vetted by society in terms of discussion of the ethical dimensions of the applications and the legal framework to keep up with such rapid and unfamiliar and some might say radical changes have history of having a lengthy gap of more than 10 years. 

Given that in my lifetime we have traveled from surrogate moms to the cloning of Dolly the sheep, to the commercial introduction of cloned pigs to the US pork market for humans is evidence that the companies will take the risks and not wait for the laws to tell them if and how they can proceed. Maybe other countries do things differently and decide what research or developments can be introduced, but here in America, money -private money-funds research that develops discoveries that then goes to market and if there is any oversight by civic leaders and the legal system, it happens decades afterwards.

We have cell phone technology that is ubiquitous well before the studies were even contemplated to determine the physical risks of the EM radiation. And then, when such questions and research threaten to undermine profits, companies handily hire teams of PR people to refute the validity of the findings and keep innocent consumers in the dark as long as possible. We can expect this behavior of commercial interests when we consider any and all future genetic or biotech "advancements" that are essentially brought to market via justifications to correct problems but generally create a dozen problems that did not exist before.

Flip-Coin

This quick sketch represents the genetic traits of the 16-year-old daughter of the sampled couple 

	Allele(s) from Mother	Allele(s) from Father	Genotype	Phenotype
Sex of child:	XX	XY	XX	Female
Face shape	R	r	Rr	Round
Chin Shape (I)	v	v	vv	less prominent
Chin Shape (II)	R	r	Rr	round
Cleft chin
Skin color	ABcD	aBcd	AaBBccDd	Medium Brown
Hair type	C	c	Cc	Wavy Hair
Widow’s Peak	w	w	ww	absent
Eyebrows (I)	b	B	Bb	bushy eyebrows
Eyebrows (II)	N	N	NN	not connected
Eyebrow color	h	H	Hh	same as hair
Eyes distance apart	e	E	Ee	average distance
Eyes size	E	E	EE	large eyes
Eyes shape	a	a	aa	round
Eyes slant	H	H	HH	horizontal
Eyelashes	L	L	LL	long
Eye color	Abcd	ABcD	AABbccDd	light brown
Mouth size	M	m	Mm	average
Lips	L	L	LL	thick
Protruding lower lip	h	H	Hh	slightly protruding
Dimples	D	D	DD	dimples
Nose size	n	N	Nn	average
Nose shape	R	r	Rr	rounded
Nostril shape	R	r	Rr	rounded
Earlobe Attachment	F	F	FF	free
Freckles on checks	f	f	ff	freckle-free
Hair color	ABCD	abCD	AaBbCCDD	dark brown

Genome # 11

ANON2; BULN2

Summary

The protein encoded by this gene is a member of the nerve growth factor family. It is induced by cortical neurons, and is necessary for survival of striatal neurons in the brain. Expression of this gene is reduced in both Alzheimer's and Huntington disease patients. This gene may play a role in the regulation of stress response and in the biology of mood disorders. Multiple transcript variants encoding distinct isoforms have been described for this gene. [provided by RefSeq, Jan 2009]

Cell Cycle Mitosis Lab

Journal questions:

1. Based on your data and observations, what are some of the differences between normal cells and cancer cells?
   
   Cancerous cells seem to have fewer cells in Interphase than normal cells, if the sampling for this lab is any indication. Those cancerous cells also seem to have more cells in the prophase, metaphase, and anaphase than normal cells. All three of the cancerous cells in this lab (lung, stomach and ovary) had one cell in the slides that was in the telophase whereas non of the corresponding normal cell slides had a cell in the telophase.
   

   ---

2. When studying cell division in tissue samples, scientists often calculate a mitotic index, which is the ratio of dividing cells to the total number of cells in the sample. Which type of tissue would have a higher mitotic index, normal tissue or cancerous tissue? Explain.
   
   Cancerous cells would have a higher mitotic index than normal cells because they exhibit a higher rate of dividing cells than normal tissue cells.
   

   ---

3. Different types of normal tissues in the human body have different mitotic indices. From the following list, which normal tissues would you expect to have the highest mitotic index: muscle, skin, kidney, or lung? Explain your answer.
   
   Because various tissues of the body are replaced or renewed in cycles that are not identical, we see different mitotic indices; the mitotic index is a measurement of the cell division and that reveals the cycles inherent to that tissue group. Our skin regenerates more quickly than kidney tissue or muscle tissue for example. Because of this shorter life cycle, we would see a higher mitotic index for skin cells.

Review of other Blogs

After clicking to view a few blogs, my first impression is that I am ever the person who loves writing. I love learning and playing with ideas as well as writing to provide and exchange understandings. One observation is that we all do process information differently and respond differently even in the shared context of reading the written assignment instructions. Our answers reflect this; no two responses were alike!

I loved the way that Melanie's blog used blue color on the font to ease readability. No question it is organized and easy to grasp what information she provided in response to the assigned questions. In general, I appreciate that each blog has different color schemes and images.

I find that I wish I knew how to adjust and create Ariel as the default font. I am constantly highlighting and selecting Ariel because it defaults to a serif font such as Times New Roman. If I wasn't fighting this, I might have managed to spend time and adopt Melanie's font color decision which lends so much to both readability and organization of information.

Brain Tricks

After visiting http://braintricks.org/index.php , I lost at least 20 minutes of my life trying without success to figure out the visual clue for why moving one section of an image changed the number of people (drawn in caricature) from 12 to 13 or 13 to 12. Our visual center and its inherent processes are fascinating in their implications. Can we trust that we are seeing what really is there, and is there a there? Given quantum mechanics and the phenomena that what is seen depends on vantage point and whether you are looking at "it" or not suggests that no two people possible can share the exact same view. That's right, two people standing right next to each other watching a parade will each have different observations and will relate them differently as well. This means a lot when law enforcement interviews people who "witness" a crime. 

Well, on to the assignment.... I scored 100 percent correct on the color blindness test, http://braintricks.org/test_score.php. 

I then did the color perception test which asks people to look at the center cross. I quickly was able to see the green dot phasing or cycling through each position on the "clock" face, creating a ghostly green glow around each of the previously magenta dots. In the time I allowed, I was not able to see only the green dot or to have the magenta dots disappear altogether.

 

Having seen this before, I gravitated to see how quickly I would find the hidden human face in the image above. Do you see it?  Did you see it right away or was it a delayed response? I found it quickly. 

My next choice was the audio test that asked for use of a headset. I put on a headset and discovered that the references for left and right were  not congruent with my experience so I flipped the headset so that what was on one ear was now on the other and in fact, the references in the audio track were congruent. When the barber said he was positioning the clippers or the electric razor next to the right ear, that is where I heard it.

Forming a hypothesis about why I may see something that isn't there, the brain can be fooled to not see something that is there due to a structure in the brain so perhaps there is a structure that similarly explains why I may see something that isn't there. Sometimes a brain injury accounts for people who do not see a full face when looking at others.

Since a hypothesis must be tested, I will suggest that I can see something that isn't there due to the image staying on my retina longer, as when a person shifts their eyes and quickly the image of what they were gazing at persists for a moment or two longer. I imagine that this is a standard tactic in movie making cinematography to fool us into believing that a person was stabbed or fell off a cliff.

I could test this by staring intently, as I did in the above illusion test, at a particular object--my cell phone--and then quickly shifting my eyes to the space on the table near the cell phone and see if the ghostly image of my cell phone will appear. To form a theory, I would have to do this under controlled conditions, allowing for others to perform the test and then measuring their responses as well before determining if the evidence supports my hypothesis. 

I have wondered about the ability of law enforcement to train themselves to be observant as they drive by, scanning for the unusual, the patterns that suggest crime, or the ability to elicit accurate information and assessment of that information for problem-solving duties. Sometimes I test my observation skills. I am beginning a new career in Asian medicine which relies on various skills, including powers of senses such as smell, vision, and touch to provide clues to the practitioner. Becoming aware of the sensory impressions literally at our fingertips as well as the scents that people carry and the sounds and sights that constantly are in our environments is a valuable exercise. it is not hard for people to smell if another has recently smoked a cigarette or eaten a meat sandwich or to detect the scent of their personal care products and cologne. It can be hard to train one's attention on one sound when another sound is more strident, or louder. It can be hard to find the right pressure to detect nuances in someone's pulse but using our senses and respecting the statements that people make about their experience of reality is what we work with. If they say they feel pins and needles in their legs, and we do not see any, well, we take in that information and seek other inputs as we work with people to resolve their concerns.  

Conversely, trusting what we see that is not seen by others has value as well. Each of us has acuity that can vary according to genetics, awareness and state of alertness, and training or acceptance of sensory perceptions. Training oneself to not allow the brain to filter in ways it may choose to on an automatic basis is a challenge, but can deepen one's practice and yield interesting options. 

Sheep Brain dissection

1. The brain of the sheep when compared to the human brain is similar in having delineated structures such as the cerebellum, the pineal gland and thalamus, and the sheep's brain even has hemispheric lobes with ventricles. The orientation of the sheep's brain is much more elongated than for that of a human brain. Another difference, which may take a moment to fully appreciate, is that the size of the olfactory bulb is much larger in the sheep's brain. As a herd animal, sheep survival often relies on the ability to detect the scents of predators. The sheep brain is also lacking the characteristic folds and large size of the human cerebrum, which explains why, so far, sheep are not hired at call centers to resolve problems that require complex language skills and decision making.
2. The "dura mater" is the outermost layer of the membranes or meninges that protect the brain and also encases the spinal cord. Its outer side rests against the skull itself while its inner side is next to the arachnoid meninges. The dura mater part is the slick, gray lining wrapped about the brain that is only slightly opaque and seems to act like cellophane to keep the moist brain tissues moistened with cerebrospinal fluid which serves "as a liquid shock absorber around the brain and spinal cord." [Johnson, Michael D. Human Biology Concepts and Issues. 2014. Print] 
3.  The bumps of the cerebrum, which are known as "gyri" and the grooves, which are termed "sulci" create a larger surface area while maintaining the most compact profile possible. Accordion folding is a natural design that engineers are adopting to enable storage of greater amounts of data. Brain tissues in this region process memories, reasoning, and perform higher functions that require or derive from this anatomical design. 
4.  Dark spider web tissues clinging to the surface structures of the sheep brain are part of the blood vessel network that provide a nourishing level of oxygen to the brain, which is vital for the functions that support life. The interior brain tissues are bathed not in blood but in cerebrospinalfluid (CSF) that circulates and can be found in the ventricles. This helps to regulate the brain in such a way that typically, but not always, keeps blood-borne pathogens and drugs from interfering with brain function.
5.  Examining the dissection of the sheep brain allows us to compare and think about the role of the pineal gland. In the sheep, like the human, this endocrine gland serves to regulate sleep patterns.Melatonin is a hormone that this gland can make or secrete so that humans and mammals get sleepy and can then perform a number of rejuvenating tasks during sleep. People who work the graveyard shifts are fighting their pineal gland's native intelligence that guides us for rest at night and alertness during the daytime hours. The pineal gland works in concert with other endocrine glands to regulate sex drive and other important functions. Flouridation of water in the drinking water supplies is reportedly having an adverse affect on human pineal glands. Research suggests a causational link between flouridation and calcification of the pineal gland in humans, which obviously lessens functionality. While one can certainly find reasons to support flouridation and it was originally propagated as a way to reduce dental caries in children, calcification of the pineal gland is no small risk.  There are a number of indications that radiation from cell phone use is also playing a role in diminished pineal gland function and disturbed sleep patterns. While our species will evolve and adapt to environmental influences over time, individual organisms will suffer in terms of function according to their genetic or constitutional predispositions and their exposure to environmental influences.

Adeloye M.B., B.S., C.P., F.R.C.S, Adelola and Felson M.D., Benjamin, “Incidence of Normal Pineal Gland Calcification in Skull Roentgenograms of Black and White Americans” American Journal of Roentgenology November 1974. Web. 5 April 2014 http://www.ajronline.org/doi/abs/10.2214/ajr.122.3.503


     6.    Ventricles are cavities or spaces within an organ such as the brain or heart through  which fluids are circulated. 

     7.     The cerebellum structure of the brain sits like a rock outcropping above the brain stem region at the back or base of the skull. Dancers, runners, and every person who enjoys fine motor skills can thank this part of their brains for providing us with balance and abilities to exhibit graceful, fluid and rapid physical movements. Alcohol has an adverse effect on this function, and the uncoordinated and sloppy movements so characteristic of people who have had too much to drink attest to the important job the cerebellum does for us.

     8.    The Thalamus and the Hypothalamus each perform important functions. They are neighbors in the center of the brain; the thalamus is larger and receives sensory information that it relays to the cerebrum. The hypothalamus actually is located under the thalamus and similarly monitors sensory signals such as what we see, smell, taste or hear. If our bodies feel cool or warm, the hypothalamus is going to be involved in modulating for homeostasis. When we recognize a hunger pang or sensation of being thirsty, the hypothalamus has been active.

     9.   The spinal cord, which is protected by the spinal column of bone vertebrae discs, has nerve tracts or bundles of axons on its outer borders. The mylenated wrapping for this is called white matter. Western science has alternately termed the non-mylenated structures of the spinal cord ( the neurons and neuroglial cells near the center of the spinal cord) as gray matter.  

   10.     I think I am very much surprised that my revulsion for anatomical dissection images has quietly abated. My revulsion for the sensory impressions of formaldyhyde however, is still strong and I do appreciate being able to observe and learn about brain structures without that assault on my senses.

Histology Dissection Lab

 Nervous System Histology and Dissection Lab

Peripheral Nerve Histology (Microanatomy)

The differential staining in Slide 1 shows the different layers in peripheral nerve. Connective tissue stains blue. Outside the nerve, loose connective tissue combined with adipose cells is called epineurium. The next layer of connective tissue, denser and ensheathing different bundles of nerve fibers is called perineurium (dark Purplish-­blue in the slide). Delicate connective tissue called endoneurium surrounds each nerve fiber and appears as delicate blue fibers. The nerve fiber itself stains pink and is seen as a cylinder in the center of myelin with a lighter pink stain. The nerve fiber is labeled A (for axon) and the myelin is labeled M. A Node of Ranvier (R) is also visible.

1. Western science developed using Latin as the language root for terminology to create classification systems. Using just the three terms in bold in the paragraph above, we see a prefix of epi-, peri-, and endo- used to describe the structural elements in the slide of a nerve fiber. This coding system is helpful and consistent to describe the intricate structures of anatomy so that scientists, healthcare professionals and students can have a common naming convention and simplify complexities by establishing or seeing patterns. In this slide, the "epineurium" denotes the uppermost or outermost layer resting "upon" the other layers; the "perineurium" term--which means around--is used to describe the tissue that surrounds each nerve fiber, and "endoneurium," which uses the Latin prefix of "endo" means "within" or "inside," so we can clearly learn that something labeled as "endoneurium" is referring to the interior portion of a structure. 

2. Looking at the way that nervous tissue and muscle tissue is bundled, we can say that muscle fibers are ensheathed into fascicles like the strands of twine may be bound to create a rope or cable--except the fibers are sheathed without the braiding quality we can see in ropes and cables. One can also imagine that each fascicle contains strands of muscle fibers similar to the box of spaghetti pasta noodles. The fascicles provide a structural support that protects from injury and actually contributes to the movement process.

Nerve tissues are bundled, though their structure differs considerably from muscle tissues. Nerve tissues or "axons" are bundled in a myelin sheath that enables swift relay of electrical impulses to muscle tissues. Acting like an insulator, bio-electrical impulses can travel efficiently with this shield, thus saving the body's energy by not needing the active transport process (ATP) to do their work. 

3. The dark blue and purplish ares on the slide are the perineurium or the connective tissue that is around the nerve fibers.

 

 A. Node of Ranvier, indicated on the slide above by white gaps in intervals in between Schwann cells along an axon; these are unmyelinated spaces, that is, not covered by the insulating sheath., where the axon is exposed.

  B. Axon- represented by the deeper mauve pink with an elongated smooth appearance are the section of the neurons which carry electrical impulses, or bio-electric messages to the terminals where they inform muscles cells.

  C. Myelin Sheath is represented by the textured pink boundaries to either side of the axons described above. This sheath is generated by the Schwann cells along the axon.

  D. Endoneurium is the structure that is represented by blue fibers in the diagram above. The  endoneurium is the loosely connective tissue matrix that holds the neurons and blood vessels in formation inside the myelin sheath.  

Slide 3 Question:
To diagnose a nerve disease, what could the lipids tell you?

The lipids stained by the dye indicate health of the myelin sheath that can be damaged. If  a view of these lipids show deformities, gaps where the insulating blanket doesn't quite cover the neurons, this could indicate onset of multiple sclerosis.

Fasicles shown in diagram to left are like the casing on a sausage, holding the neurons in packages.

Perineurium represents the white boundary zones which have a denser quality that the interior tissues.

Endoneurium, which refers to what is inside, is what surrounds the neurons-the loose matrix located inside the fasicles.

Axons are the superhighway lane that is labeled on the above diagram.

Myelin Sheath, labeled above, is again what protective barrier the Schwann cells produce to increase the speed of electrical impulses.

Virtual Pathology Lab

Data Table

Below is a captured screen shot of the Virtual Pathology exercise case for Mononucleosis

 

Journal Questions 

 

1--In what ways do normal red and white blood cells differ?

When comparing red and white blood cells, we can differentiate based on several characteristics, such as: quantity, function, composition, and origin from the stem cells.

·        QUANTITY

Looking first at the quantities found in a person having a normal blood count, the red far outnumber the white blood cells. White blood cells (WBC) together with platelets comprise just one (1) percent of a given volume of whole blood compared to a 44 percent level of red blood cells (RBC).

·        FUNCTION

Under the right conditions, RBC are the’ worker ants of the blood’ that contain millions of proteins that tirelessly transport oxygen. In fact, a single red blood cell “can carry up to 1.2 billion molecules of oxygen.” [Human Biology textbook, p. 145] To a far lesser degree, the RBC in the blood transport carbon dioxide from the tissues.

WBC are designed to fight infection and protect the body when injured. These are the warriors of the bloodstream, the samurai who defend against invaders and have a short lifespan. They sense a threat and emit chemicals that create more WBC, calling in reinforcements when needed. Sometimes the new WBC come from the storehouse of the spleen and sometimes they are generated from the bone marrow. The WBC basically scour the body and “dine” on fungi, bacteria and parasites.

There are two types of WBC: granular and agranular. Neutrophils are the largest percentage of granular WBC and are the first responders to the scene. Other granular WBC called Eosinophils are able to act like the Lilliputians in Gulliver’s Travels who swarm and secure a larger giant. In this case, rather than stake to the ground, they use enzymes to digest unwelcome parasites. They also are responsible for chemical reactions that modulate allergic reactions in the body. A third type of granulocyte is known as the Basophils, which release histamine and help to bathe injured tissue in plasma released from nearby blood vessels.  

·        COMPOSITION

WBC are larger than RBC and are translucent-primarily because they lack hemoglobin and contain nuclei; red blood cells do not have a nucleus.

·        ORIGIN FROM STEM CELLS

Mature red blood cells, also called “erythrocytes,” derive from erythroblasts created from stem cells.  The clever design that cast out the nucleus gives the mature RBC a unique dimpled shape that makes it flexible and able to squeeze into tiny blood vessels.

All of the granular leukocytes (WBC) such as neutrophils, eosinophils and basophils, originate from stem cells by way of “myeloblasts”.

There are two agranular leukocytes (WBC), with the Monocyte originating from the Monoblasts, and the Lymphocytes originating from the Lymphoblasts.  

2. Which type of white blood cell would you expect to be most common in a normal blood smear?

Neutrophils are most commonly found in a normal blood smear

 

3. A differential count of white blood cells from a patient gave the absolute number of lymphocytes as 8000 per mm3 and the total number of white blood cells as 12,000 per mm3. Calculate the percentage of lymphocytes in this sample of white blood cells. Is this a normal or abnormal percentage? Explain your answer.

A normal range of lymphocytes is the 20 to 40 percentile, so this an example of an abnormally high percentage, in the neighborhood of 67 percent.  

4. Describe the difference between a communicable disease and an inherited disease. Use examples you have studied in this exploration to support your description.

  

Essentially, the difference between a communicable disease and an inherited disease is that you can pass a communicable disease to others primarily through vectors such as parasites, viruses, or bacteria via physical contact; transmission often occurs through exposure to blood, saliva, fluid from the mucous membranes of the lungs and airways, and other body fluids. 

Inherited diseases are of course transmitted via the genetic roulette of procreation, but having a genetic variation that fits the definition of a disease is dependent on the cellular matrix unique to offspring and mutations in genetic code that persist generation to generation. 

For example, research shows that people with chronic myelogenous leukemia, which is one of those rare diseases characterized by the bone marrow factories being overrun by abnormal and inefficient white blood cells, have an abnormal chromosome as the causal factor. However, the boundary zone for leukemia origin between communicable and inherited is fuzzy; environmental exposures and even viral infections are thought to be the causal factors in some cases.

The person cannot maintain the homeostasis and intricate symphony of balances that normally keep white blood cell production in the proportion needed for good health and a strong immune system.

 

5. Why are white blood cells in a stained blood smear usually counted at low power under a microscope? Explain your answer.

White blood cells are large elements in a given blood sample so it would be like taking a close up photo of a giraffe and only seeing a spot on the neck if you use the high power. Use the low power magnification when examining a stained blood smear of white blood cells and you can see and count their numbers much like a camera with a wider lens will be able to capture not just the spot, but the entire neck of the giraffe as well as the head, body and legs.

6. Why is the presence of a larger than normal number of neutrophils indicative of an infection? Explain your answer.

Neutrophils are the first line of defense and as such, they aggressively outnumber and basically engulf a foreign body or invader such as bacteria or virus before it can spend much time or do much damage. When they mass, this is a sure sign of an infection, of the immune system working as designed to thwart what does not belong.

7.  Why would you not expect to see tissue macrophages in a blood smear? Explain your answer.

Macrophages are a type of large white blood cell that are like the trash trucks that come by to remove the red blood cells that reached their expiration date of 120 days. The liver and spleen are where old RBC get destroyed. Much like the neutrophils engulf foreign bacteria or viruses, the macrophages engulf the no longer useful RBC and digest them. It’s a process called “phagocytosis” and it’s a housekeeping duty our bodies perform at the cellular level.

Blood smears are a snapshot of what is going on in the bloodstream. Since the old red blood cells are more or less sequestered in the liver and spleen for this housekeeping, the macrophages typically won’t be visible in a blood smear.  

1.28.2014 FORWARD

GRANULAR VIEWS

It is late, but I am getting familiar with blogging tools and experimenting in the spirit of the course. I look forward to viewing the virtual microscope that our instructor mentioned in her most recent video. I enjoy reading and learning so I have become attached to the name of Nidaba, which according to online references, has something to do with a Sumerian goddess of writing, learning and the harvest.

I will want to learn more about that. I have always been attracted to the pleasures of writing and yet, oddly enough, this is my first blog--as a student. Finding an online biology course this semester was looking like a dim prospect right up until I managed to spot one seat left and dared to inquire by email if I might be a late registrant.

Once I determine the option of keeping this blog from going viral, I will post additional comments for classmates. I am certainly not interested in following comments from anyone in the virtual world led to this blog by bots and the practice of indexing for search engines.