Micro News

San Francisco Microscopical Society

Spring 2020 (Volume 15, #2)

When Social Flatworms Dine Together

Brian Whyte will present WHEN SOCIAL FLATWORMS DINE TOGETHER at a future date. Unable to make his scheduled presentation on September 17, 2019, we were pleased to present Brian Whyte at the Tuesday, March 17, 2020 SFMS General Membership Meeting at the Randall Museum, but the event has been postponed due to COVID-19. 

President's Message

By Hank Fabian, SFMS President

Greetings members,

At the January SFMS General Membership Meeting I was elected president by the members attending that interesting meeting. The editor of Micro News, our newsletter, has asked me to introduce myself to the many members who were not in attendance so here goes. 

I got my first microscope when I was eight or nine years old. I don’t recall asking for it. It may be that my mother thought that if spent time staring into ocular lenses it would be an easy way of keeping track of me. It worked and it helped me developed an interest in microscopy at an early age. In the beginning, I was a single cell, a zygote, like all of you. I soon progressed into a morula, then a blastocyst, and eventually I made it to college. 

Did I mention I grew up on a farm? My parents also owned a greenhouse and floral business, so I was surrounded by life and had, in retrospect, an ideal childhood, apart from having to grow up, go to school, and eat my vegetables. Everything was fair game for my microscope.  (Nice transition if I don’t say so myself. Toot! toot!)

The first day of college more or less shaped my life for the next four years. “What are you majoring in”, my roommate asked. To my astonishment, the answer I just blurted out was “I don’t know.”  He responded: “I’m majoring in speech and theatre.”

I had been on the debate team in high school.  Hell, I could do that. The next thing I knew, I was in plays, then doing the lead in plays, because no one else was very good, with the exception of my friend, Miguel Gomez, who became a high school principle. Occasionally I now see someone I knew in a commercial, a sit com, or playing a bit part in a movie.  Thank God, I minored in biology!

I had a tiny, tiny scholarship and relied on my parents who sold part of the farm to send my sister and me to school. Money was running out. I was a hippie because that was the best way to live cheaply, but eventually I had to face the music. There was no way I could afford to get a second degree. There was nothing left to do but apply to graduate school and I knew exactly what I wanted to major in:  fisheries! Oddly enough the Fisheries Department at Colorado State University welcomed me with open arms. I paid my $5.00 entrance fee and waited for my official acceptance. It never came. I drove five hours to Fort Collins, Colorado to speak to the admissions people, aka the scum of the earth.  “You never sent in your application fee” the bureaucrat told me.

After what seemed like endless rounds of yes-I-did, no-you-didn’t, she finally checked.  “Oh, here it is!” she laughed.” Well, I’m afraid the deadline has past, but you can apply next year.” Now at 21, a year is significant portion of your life. What was I going to do for a year? 

Thankfully, I landed a job working for the Pawnee National grasslands as a field tech, but only for the summer. One day my housemate informed me that he had been accepted to grad school in the Agronomy department, and that there was a fully paid position open for anyone willing to study Methionine in Pinto Beans. I was the only one who applied for it and so, ipso facto, I was in a master’s degree program, studying crop genetics. That degree landed me a job in Moscow, Idaho, where I developed pea varieties for the next seven years. It was my first real job, but my boss was a bully and ignorant about anything I was doing. Eventually I had enough and quit. 

I was sick of research and sick of genetics. While a couple of my varieties proved to be extremely successful (toot toot) the work had totally consumed my life and I was glad to be out of it. So I went back to school to study Native American religion. I loved that! I even worked with the Hopis one summer and made some great friends but when I left, they asked me not to write anything about them for fear they would be ostracized by the tribe. It had happened before; so much for a thesis. I promised not to continue my program. Instead, I decided to do what my father had done. I built a greenhouse to grow wholesale cut flowers.

My timing couldn’t have been worse.  Shortly after I grew the plants the doors were open to imports from Columbia and other countries who could sell cut flowers cheaper than I could grow them.  With my life back in the proverbial toilet vortex,    I went back to school—a community college. I could be a nurse!  Why not?  That’s close to biology and it pays well--but first the prerequisites. I took anatomy, physiology and microbiology and did well in all the classes.  Soon, I was tutoring, and then, out of the blue, I was asked to teach a physiology class. “You have a master’s degree,” they told me. “Yeah, but I’m no physiologist. I just took your course!” They were desperate for someone to teach at their satellite campus and assured me I could do it. So, I did.  That course got me hooked on teaching.

Within a year I had been hired full time. Just before I got tenure, I managed to make the VP mad and I was let go. That occurred in the same year I was nominated for teacher of the year. Go figure. There was no use arguing because they had an iron clad excuse:  An agronomist has no business teaching human anatomy and physiology. Strange they didn’t think of that before. 

These events made me sick of education and I decided to go into physical therapy. I only applied to one school, the Mayo Clinic. Mayo sent me a typed letter explaining that I had been one of twenty-five candidates chosen to interview for two positions. The odds were not that great, but why not give it a shot?  When I arrived, I discovered the secretary had made a typo and I was up against not twenty-five but 250 fellow candidates. Many of them were already physicians. I had some fun at the interview, but did not get in. On the same day of my rejection letter from Mayo (no typos) I got a full ride scholarship for a unique program at Idaho State University. My mission, should I decide to accept it, was for the Doctor of Arts degree in Biology. The DA is like a PhD, but for generalists not specialists. This was ideal.

I failed to mention to you that I had also applied for this degree because one of my friends had told me about it, and I thought, why not?  For the next three years I studied hard and became Dr. H. Fabian at the ripe of old age of forty-seven.

In graduate school I was teaching again, and equally hooked on that profession.  Never mind the bureaucrats. I would learn how to handle them later. That was wishful thinking.

I fell in love with a beautiful woman, moved to the Bay Area where she worked as a nurse, did freeway flying for two years (that means I worked at multiple schools as an adjunct), and eventually landed a full time job at Merritt College where I worked for the next sixteen years. At Merritt I served as chair for five years, then stepped down with the suggestion that we do a rotating chair. That did not happen. I also created more courses than I care to count as well as four programs with considerable help from my colleagues: Microscopy, Genomics, Histology and Master Naturalist. I have always believed that novelty creates opportunity, but not everyone shares this idea. I also discovered a new physical law that I called the Peralta Effect.  Simply put, “All energy toward improvement is met by an equal or greater force of resistance.”  After sixteen years I’d had enough.

I’ve learned a few things in life.  Never work for a bully, a Nazi or an idiot.  When you have a good boss treasure him or her because they are so rare. Don’t be afraid to stand up for what you believe even though there will often be consequences. Leave when necessary. Avoid between meal treats and brush often with Crest. Remember as twenty doors slam shut, the draught usually forces open another one. You’ll be amazed what’s on the other side. 

That’s my nut-case life in a nutshell. I could write more, but why give James Mitchener a run for his money? If you are ever in need of sleep, please feel free to read it again.

The editor asked me to also write about my vision.  With glasses, it’s 20/20, the same as hindsight.  It would be remiss of me not to say that my vision is your vision, so please share your ideas with me and the board. It is an honor to be your president, but I promise you my vision is not that of several past chancellors, where their vision was to be the chancellor and that’s the end of that.

My first idea is to do more outreach to the community. We have been invited to participate at the Exploratorium in April [editor's note: now postponed due to the pandemic]. Let’s see about doing something at my retirement community in Rossmoor. Let’s make some You Tube videos on how to maintain a microscope, how to prep a slide, etc.  

That’s the short list. My favorite quote is from Linus Pauling, “The best way to have a good idea is to have a lot of ideas.” The phone lines are open. My cell: (925) 286-1801.

May your days be full of the best resolution,
Hank Fabian, President, SFMS

Worms: Platyhelminth, Nematodes and Annelids

By Henry Schott

There are many worms in the environment and in some regions, if only the worms remained suspended in space and all other material disappeared or became invisible, you could say with some certainty that here was a dog, and there was a lawn, and the horses, invisible but identified by the worms in their gut, were grazing in this invisible meadow identified by the worms in the soil. The fish in the river or ocean, the other organisms in the mud or between the coral fronds would also be identifiable by their associated worm populations. Solitary, communal or parasitic, worms are found wherever there is enough moisture to support their lifestyle.

Three general body plans with a great variety of modifications permit us to categorize the worms. Flatworm varieties form the Phylum Platyhelminthes. (Greek platy meaning broad or flat and helminth, a worm. Since these worms do not have a true body cavity in which other organs can be found, they have the most primitive body plan of the three Phyla. A good example that can be found in most freshwater ponds is planaria, 4 to 10 mm long, containing a digestive system that reaches all parts of its body. Tapeworms also belong to this phylum and are mostly composed of reproductive segments formed near the head end, or scolex, and are pushed further back  as the worm produces new reproductive segments, each continuing to grow and evolve.

Phylum Nematoda, the roundworms, contains over 10,000 species and estimates range into several hundred thousands. With bilateral symmetry and three tissue layer construction, ectoderm, mesoderm and endoderm, these worms have a body cavity, here called a pseudocoelom because it is not completely lined with mesoderm.  This cavity is filled with fluid that serves as a hydroskeleton that produces a characteristic thrashing motion when longitudinal muscles contract. A complete digestive system with mouth and anus is also characteristic of these worms. Widely parasitic, the largest live in whales were they reach length of 7 meters. 

An important laboratory research animal is the soil dwelling Caenorhabditis elegans, consisting of about 1,000 cells (1-3 mm long) used in a wide variety of experiments involving genetics and/or nutritional research. Consider for a moment what a complex set of reactions such a limited number of cells must accomplish in order to carry out the many chemical reactions necessary to support life processes.

Nematodes have an exterior covering called a cuticle. It is a product of the epidermis and is not cellular. In order for the organism to grow it must shed this cuticle and produce a new larger one. 

The Annelids (Phylum Annelida) include the familiar earthworm. Since these worms live below ground, they must burrow tunnels through the soil. They do this by ingesting soil particles that contain organic material from which they extract by digestion the nutrients they need. The body consists of a series of segments that are like rings each forming a compartment containing two excretory organs. A dorsal and a ventral blood vessel forming a closed circulatory system circulates blood through the body. At the anterior portion of the worm enlarged blood vessels form a heart that contract to pump the blood. While each worm has both male and female reproductive structures (they are hermaphrodites) they mate and cross-fertilize. 

If you explore the seashore tidepools you may have seen polychaets, segmented worms that have paired paddle-like appendages with stiff bristles that help the organism move and exchange gasses with the surrounding water. These annelids are often six inches long. 

A third annelid group are the leeches. Most eat small invertebrates. They can be found in slow moving streams and ponds. Using a sucker shaped mouth, they slit the skin having secreted an anesthetic and an anticoagulant. Having gorged on blood they can then survive for month without eating again. 

Worms are eminently successful having developed both parasitic and free-living species.

iBiology: Cell Biology Flipped Course

The Cell Biology Flipped Course is built around a model where students watch iBiology videos as homework, with assignments to guide them, and then use classroom time for in-depth discussions and problem-based learning. The Cell Biology Flipped Course was first developed in collaboration with Professor Jonathan Scholey at the University of California – Davis and offered in 2013 to senior undergraduate biology majors. It was offered again in the spring of 2019 by UC Davis Professors Kassandra Ori-McKenney and Rick McKenney. Below, you will find all of the course materials including the seminars, discussion questions, and assignments. To access the assignment materials you must register as an educator.
 
Sessions: (1): Origins of Life, (2): Organization of Cytoplasm, (3): G-proteins, (4): Vesicle Trafficking, (5): Cell Motility, (6): Cytoskeletal Motor Proteins, (7): Cell Division, (8): Protein Kinases, (9): Cell Cycle.

SFMS Meeting Reports

General Membership Meeting Report, January 21, 2020 
By the time I arrived at the Randall Museum at 7: PM, Myron had set up the microscopes and our speaker for the evening, Damon Tighe, had covered a table with various models of magnifiers that could be attached to a camera or that were self-sufficient magnifiers, some with batteries for added illumination. Particularly easy to use, was a large plastic clip with a lens mounted at one end that could be clamped on your cell phone and stored handily by clipping it to the brim of your hat. 

The power-point presentation was very much to the point consisting of pictures taken with various magnifiers while on field trips. The evening was well attended and there were fruitful conversations and plenty of time to make use of the instruments on display. A number of Foldscopes were given away to anyone who wanted to try to assemble these famous cardboard microscopes. Look at the You Tube video before trying to do this puzzle. It will save you time and frustration.

SFMS Board Meeting Report, February 22, 2020
This was the first meeting of the board under the new leadership of President Hank Fabian. Present were Myron Chan, Treasurer, Theresa Halula, Recording Secretary and Eric Weinstein, Communicating Secretary. The agenda provided the structure for the meeting. The treasurer reported that we had $17,541.42 funds available. PayPal funds are not included. A second signature required by the bank will be that of Hank Fabian.

The presentation by Bryan Whyte on March 17, 2020, was approved. The May 19 meeting presenter is being researched and will be discussed at the board meeting to be held March 28, at 11a m at 20 Drake Lane [editor's note: postposed due to COVID-19]. Members are welcome. Various events were discussed where the society participates by invitation. Hank will report doing an outreach program at Rossmore. “Bug Day”at the Randall will take place on April 25 from 10 to 2 PM [editor's note: postponed due to COVID-19]. We will participate if we have volunteers. Call 925-286-1801 to help work the microscopes. The meeting adjourned after about an hour and a half.                              
HS

The Small Intestine, With the Area of a Football Field

By Henry Schott

This essay involves enjoying a multimedia experience. Use your computer to listen and see powerful graphics.

In the November 2019 issue of Micro News, I proposed to describe the epithelial tissue of the small intestine in the next issue. (See page 6, in the last paragraph.)  I should have been more cautious and have used the phrase “in some future issue”. This is that future issue. Perhaps it will add a modicum of new information to your knowledge. 

Whether you are reading this after breakfast, lunch or dinner, chances are good that your small intestine is busy harvesting nutrients from your recent meal and passing them to the liver through the bloodstream. It is the peculiar arrangement and behavior of the epithelium tissue layer that makes this possible. 

Absorbing enough nutrients to make us efficient energy consuming organisms requires that food be reduced to small molecules able to cross the membranes of epithelial tissue even if this requires in some cases transport molecules. While there are a variety of processes by which molecules are moved from the lumen of the small intestine to the blood stream, these would be insufficient if the surface area were restricted to a flat sheet lining the small intestine. One possible way to increase the surface area is to provide folds of tissue that extend into the lumen as is found in some simpler organisms such as the earthworms. Even though we have such folds, doubling or tripling the absorptive area is not enough for our need. The evolutionary solution was to develop small projections that were covered with a layer of epithelium and contained a capillary network as well as an open-ended vessel that is part of the lymphatic system and is called a lacteal. Its function is to drain the interstitial (between the cells) lymphatic fluid that would otherwise alter the hemostatic pressure and cause swelling. 

To the naked eye, the small intestinal surface looks velvety but microscopically they reveal millions of tiny fingerlike projections increasing the surface area enormously. These villi are covered by epithelial columnar cells that have one free border, the apical region, exposed to the lumen of the small intestine. This border is also called a brush border because the cell membrane there is composed of microvilli forming a vast surface for each cell through which fluids and molecules pass.

As food particles pass over the villus they will carry away these terminal epithelial cells so that they must be replaced. We now know that cells at the tip migrate there from lower down. This is accomplished by the process of cell division but where does this take place? Mitotic figures are not seen in the epithelial cells of the villus but their migration from cells within the glands at the base of the villi is well understood. The intestinal glands open through a pore at the base of the villi. What do these glands and the cells look like? 

The glands are named the crypts of Lieberkühn and are simple pits lined with undifferentiated cells consisting of Paneth and argentaffin cells. They proliferate by mitosis passing upward through the pore and move up the side of the villus where they differentiate into columnar absorptive epithelium or into mucous producing goblet cells. Their migration has been researched by Krndija et al. and reported in Science 16 August 2019, p. 705. The research report is introduced by an article by Marnix Jansen in the same issue on p 642 on which the following material is based. 

Direct observation of explants, thin slices of living mouse intestinal tissue removed from the organism, permitted measurement of changes in cell density and migratory speed. The idea that it is the reproduction of cells in the crypt that pushes the cells up along the sides of the villus is only true for the migration through the pore and the lower part of the villus. After that there is active migration facilitated by actin molecules, a cytoskeletal molecule that is functionally important in cell shape and migration. Small protrusions containing actin were observed in the base of intestinal columnar epithelial cells. They are called lamellipodia and involve actin polymerization that causes the cell basal surface to act like little feet allowing the cell to crawl up the villus. Constrained by tight junctions between these cells, they must move in concert with other columns of cells forming a sheet on the surface of the villus. Overcrowding of cells at the tip of the villus results in extrusion of the cells from the epithelial sheet. The recognition that cell migration toward the villus tip is due to the effect of actin-protein complexes within the epithelial absorptive columnar cell is a new revelation, replacing the purely passive migration held for many years. Actin plays several roles in cells and its function in muscle cells is well understood where it interacts with myosin to bring about shortening of the muscle structure. 

At this point in our review of this functional subunit of the small intestine I recommend that you view the YouTube presentation in iBiology by Hans Clevers entitled Discovery and Characterization of Adult Stem Cells and Organoids. This deals with what takes place in the crypt and the subsequent growth of the epithelium. It is the first of three presentation that further explore this subject and is well worth exploring. 

The modern study of the growth of the epithelial coating of the gut has solved some of the mysteries of diseases of digestion and has demonstrated the rapid turnover of the coating of the villi that occurs in six days or less. The columnar epithelium with its brush-border is unique in having a surface area that when combined with that of all the cells coating the vast number of villi approaches that of a football field. Its proper functioning is required for our survival and good health.

Fig 2. Villi and crypts.
Photo from: https://meded.ucsd.edu/hist-img-bank/index.htm

Election of 2020 SFMS Officers

Following the procedures identified in our constitution, the attending members at the January General Membership Meeting held an election for officers to serve through the current year and into the January 2021. We were fortunate to have several volunteers but some were aware that they might not be able to serve the whole year so we elected two extra members who may act as substitutes for the five officers required by the constitution. The following members were elected:

President: Hank Fabian, of Walnut Creek, CA (925) 286-1801
Vice President: Taylor Bell, of Oakland CA
Treasurer: Myron Chan, of San Francisco, CA
Recording Secretary: Theresa Halula, Berkeley, CA
Communication Secretary: Eric Weinstein, of Berkeley, CA
Member at Large #1: Bill Hill, of Fairfax, CA
Member at Large #2: James Forslind, of Alamo, CA
You can contact any board member by using the following number: (925) 286-1801. Your message will be forwarded to the president or to the identified board member.

Radiation Absorbing Fungi

Chernobyl, the site of the worlds worst nuclear disaster, is in the Ukraine. Russia build a giant concrete sarcophagus around it to contain the radioactive structure but the land for miles around the power plant is radioactive and people are not allowed to live there. Experiments are being conducted to test if Cryptococcus neoformans, a fungus recently found to block radiation, can be used to clean up the area. The fungus contains melanin, which absorbs radiation and turns it into chemical energy. The fungus can decompose radioactive materials such as hot graphite debris from the Chernobyl explosion. Astronauts are testing melanin to see if it can protect against radiation encountered in space travel.
(San Francisco Chronicle, Friday, February 14, 2020. by Steve Newman: Earthweek: a diary of the planet.)

What We Know*

The S. F. Microscopical Society