Human Anatomy at Colby

Lizzy Gorence: The JanPlan A&P Experience

February 14th, 2014 · Comments Off on Lizzy Gorence: The JanPlan A&P Experience

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Taking the JanPlan Anatomy and Physiology course at Colby College over the past month has been an experience that I would consider not only unique to liberal arts colleges with a January program, but distinctive within the Colby environment as well. Yes, as an anatomy and physiology student of Dr. Klepach’s, pupils are given the opportunity to tour the new Maine General facilities in Augusta with a third-year medical student, to dissect a pig heart, and to apply biological sciences to fine arts in the gorgeous Colby museum. However fascinating and wonderful these experiences may have been, they could likely be replicated in similar courses at other schools. What I found most unique about the Colby Anatomy and Physiology course as a senior about to embark on her final semester of undergraduate study, was that Dr. Klepach gave us students his permission to do poorly (at least in the quantifiable sense) on assignments. Sometimes he even predicted that we would! As long as we were engaged during class and dedicated to learning the material, Dr. K. reassured us that our final grades would reflect our work and that we would have more fulfilling experiences overall.

Admittedly, this approach was initially very hard for me to stomach, and I suspect that some (or many) of my classmates shared my discomfort. As a Colby student, I’ve grown accustomed to finding academic success in the form of a percentage marked in red pen on my assignments, which is usually directly proportional to the amount of time I spend on the third floor of Miller Library. Usually, with a number of notable exceptions, I’ve been able to hammer through difficult material at Colby simply by staying up late with it, sleeping in on it, or sometimes simply putting it off until the pressure really sets in. Essentially, my learning process in college thus far has been based on repetition and revisiting material. However, as any mule can attest, we students are not afforded the same luxury of ruminative study time during JanPlan as we enjoy during the fall and spring semesters. Instead, over the month of January each year, Colby students are immersed in a single subject of their choosing, in which we are given a sort of crash course.

While many of my fellow seniors chose to pursue an independent study or to plow through a Wharton novel every day, I, along with eighteen compatriots (including some very brave first years), chose to undertake Anatomy and Physiology during the month of January. Before the course, I had no clue just how quickly a month could zip by. Sure, one single month sounds like a short amount of time to learn about the structure and function of the human body, but I still felt pretty confident at the outset of Dr. K.’s A&P class. I was bolstered by my own fading memories of my high school Anatomy class and the widespread belief that JanPlan classes are so-called “jokes,” and are engineered to allow their students ample skiing time.

My false confidence was shattered fairly quickly after I received my first quiz grade under 50%. Even though Dr. K. reassured us that the material was very challenging and that none of us should be discouraged to receive grades we weren’t accustomed to, it was pretty unnerving. Over time however, I was able to detach myself from my Colby-conditioned urge to pursue a number grade, and began to focus more on the process itself. Ultimately, human anatomy and physiology is a subject that cannot be thoroughly covered, and its information cannot be wholly retained in the span of one month. It took me a short while to accept this, but thankfully Dr. K. had been cognizant of it long before we started class on January 6th. He was constantly reminding us, his students, that our goal during JanPlan should be to absorb as much information as we could, and to whet our appetites for future study of the human body. After all, medical students spend years learning about topics to which I’ve already experienced some brief exposure. For me that was pretty awesome, and totally inspiring.

Coming into my final January at Colby, I hadn’t expected to be surprised by my JanPlan course. I had the sort of been-there-done-that attitude that comes from spending three and a half years at a small liberal arts college in a small town. Instead, over January I experienced a class that was challenging in a different sense from the other courses offered at Colby. I was asked to step out of my comfort zone not only when dissecting a pig heart, but when thinking about my own learning process and my performance in the class. Anatomy and Physiology was stimulating, inspiring, and yes, sometimes pretty stressful (sorry, Dr. K.!), but I think it prepared me for life beyond Colby College in a sense that many of my other courses have not.

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The Human Microbiome, Healthcare-associated Infections, and Probiotic Therapy

February 14th, 2014 · Comments Off on The Human Microbiome, Healthcare-associated Infections, and Probiotic Therapy

By Lizzy Gorence

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Within the human body lives a diverse and abundant population of microorganisms. These microbes populate the surface and deep layers of the skin, the saliva and oral mucosa, the conjunctiva, the urogenital tract, and most significantly, the gastrointestinal tract. Although still not entirely understood and catalogued, studies conducted through the Human Microbiome Project (HMP), an initiative of the National Institute of Health, have revealed the presence of many thousands of species of bacteria, fungi, and archaea, which populate the human host.  In fact, HMP studies indicate that there are at least ten times as many bacteria as human cells in the body, and that microorganisms account for approximately 1-3% of total body mass.

But we are in a human anatomy and physiology class, not a microbiology class, so why do we care? Well, without the presence and diverse composition of these microbial populations our own human cells would be unable to carry out the vital processes about which we’ve learned throughout the JanPlan term. Examining the mutually beneficial nature of the human-bacterial relationship is one of the central goals of the Human Microbiome Project. While the human microbiota varies in abundance, composition, and size among individuals, it is similarly vital for every human’s health and survival. Imbalances in our gut microbiota can have serious implications for our overall health because many bacteria in the digestive tract are able to break down certain nutrients that humans otherwise could not digest. Additionally, certain microbes that are ubiquitous in the gastrointestinal tract, such as Clostridium difficile, are also opportunistically pathogenic.

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C. difficile causes illness in the human host when granted a competitive advantage over their cohabitating organisms. It usually gains this advantage in the bodies of people getting medical care, who may have taken an antibiotic that targeted an organism that competes with C. difficile for nutrition. It can also be transmitted through feces and is commonly transferred between patients on the hands of healthcare providers. Thus, C. difficile infections are categorized as healthcare-associated infections (HAI). While most types of HAIs are declining, C. difficile remains at historically high levels. When C. difficile populations increase to pathogenic proportion, the infection causes cases of diarrhea and intense abdominal pain linked to 14,000 American deaths annually. An estimated $3 billion in excess healthcare costs annually are spent on managing C. difficile infections. Therefore, finding effective and affordable treatment for this particular HAI is imperative.

Traditionally, when we think of treatments for infectious disease, we think of antibiotics. However, our developing understanding of the human microbiome has led many to believe that probiotic therapies will be just as (if not more) effective in the treatment of infections like Clostridium difficile. Personally, I’ve always found the concept of fecal transplantation completely fascinating. Once you move past the “ick factor,” it’s an incredibly effective and fairly intuitive treatment. By transplanting bacterial fecal flora from a healthy donor to an ailing recipient via enema, the competitive environment of the healthy gastrointestinal tract is restored. At the Mayo Clinic, the fecal transplantation program yields a 90% cure rate for C. difficile infections. While the practice of fecal transplantation has been streamlined over the 50 years since its introduction, companies like Rebiotix, out of Minnesota, seek to further standardize the treatment.

This small biotechnology company has developed a microbiota suspension that can be easily preserved, ordered on demand, and administered by medical professionals. In addition to sufferers of C. difficile, the Rebiotix treatment can potentially be effective for those afflicted by Crohn’s disease, Ulcerative Colitis, or Metabolic Syndrome. While their RBX2660 suspension is currently in phase 2 of its clinical trial, the product is poised to enter the market in early 2016. While products like this are still rare, and may seem foreign to those who grew up associating antibiotics with treatment and bacteria with illness, probiotic treatments represent a new understanding of the human body and the organisms it harbors. By augmenting microbial populations, probiotic treatments harness their power, and use it to improve the health of the host.

 

References:

 

  1. “Human Microbiome Project.” National Institutes of Health. NIH, n.d. Web. 27 Jan. 2014.
  2. “Clostridium Difficile Infection.” Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 01 Mar. 2013. Web. 27 Jan. 2014.
  3. “Clinical Updates.” Quick, Inexpensive and a 90 Percent Cure Rate. Mayo Clinic, n.d. Web. 26 Jan. 2014.
  4. “Powerful Therapy, Delivered.” About Clostridium Difficile Infection. Rebiotix, n.d. Web. 27 Jan. 2014.

 

 

 

Tags: Human Health

Grand Rounds: 49-Year-Old Male with Adenocarcinoma of the Rectum and Novel Bacterial Therapy

January 29th, 2014 · Comments Off on Grand Rounds: 49-Year-Old Male with Adenocarcinoma of the Rectum and Novel Bacterial Therapy

By: Cameron, Lizzy, & Cody

Adenocarcinoma is cancerous disease that originates in mucus-secreting glandular tissues, most commonly in the lungs, pancreas, prostate, esophagus, colon/rectum. 95% of all colorectal cancers (CRC) are adenocarcinomas. Three months prior to diagnosis, the patient (Male, 49 years) notes blood in his stool. He went to his primary physician who found his physical examination to be normal. His father had colonic polyps, and his paternal grandmother had colon cancer in her 80s. Although family history of CRC is most significant in first degree family members, his father’s history of polyps may suggest a hereditary CRC predisposition in the patient. Six weeks before the patient’s presentation at MGH, he noted decreased stool caliber, and prolonged presence of blood and mucus in his feces. He went to see a gastroenterologist who performed a colonoscopy and discovered an exophytic mass 15 cm from the anal verge and 2 polyps in the descending colon.

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At higher magnification, small infiltrating glands in desmoplastic stroma are diagnostic of moderately differentiated adenocarcinoma. The depth of invasion cannot be assessed from this small biopsy specimen.

Biopsy of the mass revealed dense stroma covered by villiform dysplastic epithelium, with stromal hypertrophy and small infiltrating glands, a characteristic that is indicative of moderately-differentiated adenocarcinoma. An axial CT image of the abdomen/pelvis revealed a rectal mass causing abrupt narrowing of the rectal lumen (3.2×3.1×6.8 cm). An MRI image showed the rectal mass extending through the muscularis propria and into the outer layer (serosa) of the colon. Ultrasonography-guided fine-needle aspiration and core biopsy of the inguinal lymph node determined that the cancer had not spread into the lymph node and was still limited to the colon (although locally advanced). Final diagnosis of the case was moderately differentiated, invasive rectal adenocarcinoma (Stage IIA).

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An axial image from the CT study with oral and intravenous contrast material that was performed at the other hospital  shows a soft-tissue density in the rectum causing abrupt narrowing of the rectal lumen

The patient’s rectal cancer is advanced, and as such the first major treatment decision is whether to resect immediately or use preoperative (neoadjuvant) chemotherapy, radiation, and/or postoperative chemoradiation. The team of doctors recommended preoperative chemoradiation therapy with fluorouracil and radiation therapy. Stage I rectal cancer is often successfully treated with resection, but advanced rectal cancer cases such as Stage II or III typically need multiple treatment modalities (e.g. radiation). Lynch syndrome is an autosomal dominant disorder, and in this case is likely the cause of his colorectal cancer. According to the Amsterdam criteria, this patient did not qualify as having lynch syndrome. However, the Bethesda guidelines, which are more sensitive to subtle cases of Lynch syndrome, did suggest Lynch syndrome. Between 50 and 70% of people with Lynch Syndrome develop colon cancer in their lifetime, and the risk of syndrome is 50% to immediate family members–making clinical diagnosis important not only for the patient but for immediate family members as well. Postoperative treatment was complicated by a Superficial femoral-vein thrombosis which was treated with a 6 month course of heparin. The take down of his ileostomy was successful, with colon function being restored. He is now alive without recurrence more than 4 years after resection, and undergoes annual endoscopic surveillance and visits his doctor biannually.

Scientists at Chonnam National University in South Korea have developed a way to selectively attach flagellar bacteria to polystyrene microbeads. The team modified Salmonella typhimurium with a selectively BSA (bovine serum albumin) pattered PS (polystyrene) microbead. S. typhimurium has been shown to aggregate around quiescent or necrotic tumors due to chemoattraction to tumor cell lysates and spheroids. The attached microbead can release the therapeutic compound inside of the tumor. The bacteria are also useful in detecting metastases and small tumors. One of the most significant challenges of chemotherapeutic treatments is the continuous, specific delivery of optimal quantities of drugs to target cells – which would allow the bacteriobot to shine in efficiency and selectivity of drug delivery. The advancement of this treatment could mean that a total colectomy may not be necessary if the cancer recurs in the colon. The treatment also could help eliminate the negative gastrointestinal issues associated with chemotherapy by reducing general cytotoxicity and negative body response to treatment.

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Tags: Grand Rounds