Sunday, September 23, 2012

AN APHORISM


There is an aphorism in medical science which says: "You see what you look for; you look for what you know." It can work positively or negatively. If you know something exists but is hidden from view, you may be able to espy clues that thereafter will lead you to it. Thus, discoveries in diagnostic method may be made. On the other hand, if you know something exists in some instances and generalize it to be of significance in all, you may be right--or you may gravely mislead yourself and others.
Williams, Greer. The Plague Killers. Charles Scribners Sons, New York: 1969.

Sunday, September 9, 2012

PROTEIN (MIS)FOLDING

An excellent, insightful lecture by Susan Lindquist on the process of protein folding, prions, and related diseases:

 




Friday, August 24, 2012

PECULIAR SUICIDE

The September 2012 issue of Forensic Science, Medicine, and Pathology contains an interesting article by Hejna, et al., analyzing a case of complex suicide. The article defines complex suicide as one "in which more than one suicide method is applied either simultaneously or successively (one after the other)" and distinguishes complex suicides by two variations: planned, where two or more methods of suicide are combined simultaneously; and unplanned, where a second method of suicide is attempted to compensate for some unsatisfactory aspect of the first, i.e. unbearable pain, or inadequate severity.

This particular case was an instance of planned complex suicide, with the 39 year-old victim employing both a firearm and hanging. While this combination tends to be the most common in planned complex suicides, what makes this case salient is the use of a black-powder derringer. In what was likely an attempt to improve lethality, the gun was loaded with a powder charge far exceeding manufacturer specifications. This resulted in instantaneous death and atypical markings circumscribing the ballistic entrance wound. The effectiveness of the shooting rendered the secondary method of suicide ineffectual, as evidenced by the lack of indicators which are normally present in hanging deaths (such as bleeding into the intevertebral discs).

Hejna, et al. conclude with five key points for forensic investigators to take away from this case:

"1. The combination of hanging and gunshot injury is the most common arrangement involved in primary complex suicides. 
2. Injuries and fatalities resulting from the use of black powder handguns are relatively rare compared to other firearms. 
3. Black powder weapons produce entrance wounds with extensive sooting and powder tattooing (in close range and intermediate range shooting). 
4. The wounds from black powder firearms may have a characteristic sulfurous odor and the soot deposits may have a yellowish color. 
5. The atypical morphology of the entrance wound with extensive back spatter in this presented case was conditioned by the excessively short barrel of the derringer, a higher amount of black powder charge and by artificial incision of the projectile ogive."

 View of the victim as found, with prominent atypical entrance wound. [Hejna, Fig. 2]

"The handgun used– black powder muzzle loading doublebarreled derringer." [Hejna, Fig. 6]



Hejna, Petr; Šafr, Miroslav; Zátopková, Lenka; Straka, Luboš. Complex suicide with black powder muzzle loading derringer. Forensic Science, Medicine, and Pathology (2012) 8: 296-300. 

Sunday, August 19, 2012

POX

I'm through about 25% of Deborah Hayden's book, POX: Genius, Madness, and the Mysteries of Syphilis. Thus far, the work is riveting. Competing theories on the biological evolution and epidemiology of syphilis are weaved throughout a cogent narrative, flavored with notable excerpts from historical records. Apart from the Great Mortality, I can't think of another disease which was so widely personified by poetic mythos and dark imagination as was syphilis. Consider this lurid description by 19th Century French poet Théophile Gautier:

"There is a splendid American pox here, as pure as at the time of Francis I. The entire French army has been laid up with it; boils are exploding in groins like shells, and purulent jets of clap vie with the fountains in the Piazza Navona . . . tibias are exfoliating in extoses like ancient columns of greenery in a Roman ruin . . . lieutenants walking in the streets look like leopards, they are so dotted and speckled with roseola, freckles, coffee-colored marks, warty excrescences, horny and cryptogamic verruccae and other secondary and tertiary manifestations which appear here after a fortnight." [1]





1. Hayden, Deborah. Pox: Genius, Madness, and the Mysteries of Syphilis. Basic Books, New York: 2003. Quoting Claude Quétel: History of Syphilis (1990).

Monday, August 13, 2012

EERIE EAREY

Today a coworker told me of a story that has recently featured in the news, wherein a Chinese woman checked into Changsha Central Hospital after days of intense irritation and itching in her ear. Further investigation with a video scope revealed that a small jumping spider had taken up residence in the woman's external auditory canal, yielding some pretty neat pictures and endless nightmares for arachnophobes the world over:



This account sparked some mental catalysis, and I began to chatter internally. This is just the proverbial tip of the iceberg; surely Deh interwebs must play host to a plethora of nauseating ear-canal discoveries! And boy do they ever. 

I quickly stumbled upon the ENT USA site, which is both informative and chock-full of revolting photos depicting objects in the ear canal -- objects that, by all rights, should not be there. I've inserted a few, um... favorites (?!) below. 

You've heard of the infamous deer tick, now witness the glory of the EAR tick!
It might not infect you with lyme disease, but it is extremely lethal to your sex life. 


I'm voting to replace the old adage "packed like a can of sardines" with the endearing quip, 
"all tucked-in like a warm bundle of ear maggots." Who's with me?


"This ear ache is killing me! What to do, what to do?... I know!--I'll grab one of my ciprofloxacin tablets, grind it up, and toss the powder in there. That outta make me right as rain!"


That's just a small sample of the fun in the ENT gallery, which includes among many other entries, photos of mastoid fistula, adenocystic carcinoma, and fungal infections of the ear. It's enough to make the most stoic Ferengi go wobbly in the knees with abject horror and despair. Enjoy now, thank me later. 





Friday, August 10, 2012

SMALLPOX IS SUCH A BORING BREAKFAST...

Who hasn't wondered what it would be like to work as a plague doctor -- that secretive scientist who tampers with the biological dark arts, manipulating viral agents to discover new ways of improving delivery, rendering a strain impervious to traditional responses, or selectively tweaking a bug's lethality? It wouldn't be a job for the faint of heart, and I can imagine the paranoia and guilt which accompanied nuclear scientists in the Forties and Fifties might pale in comparison. 
I'm not sure if there will ever be a point where human curiosity is trumped by legitimate danger--a threshold that, being too dangerous to cross, incurs a general consensus response of "screw that!" If such an occassion ever does arise, I suspect it will be rooted in the microscopic. The most dangerous things are invariably very small: a split atom, a bundle of seven structural proteins, a stubbornly self-replicating nanobot with a penchant for ecophagy.     
Certainly, the plague doctors toe this precipice daily, and for them it's business as usual. I'm not sure I'd have the balls to engage in such work, even if I were to pretend I possessed any inclination for it.

"One scientist from Sandakchiev's Vector Laboratories, Deputy Director Sergei Netesov, appeared one day in 1987 at Obolensk with a new idea for plague: he proposed taking the entire viral genome of Venezuelan equine encephalomyelitis (VEE), perforating the plague cell membrane, and planting the virus inside plague cells like another plasmid. At Vector, Netesov had made a career of proposing such devices. Popov, quoting Alibek, identifies Netesov as the originator of the whole concept of chimeras: genetically engineered viruses made of two component parts---smallpox and VEE, smallpox and ebola. Apparently on the strength of these novelties, Netesov had been promoted to deputy director of Vector at Novosibirsk. The name of the program he directed was Okhotnik---Hunter. His proposed plague-VEE chimera, fiendishly simple in design, but ferocious in concept, is probably the first time anyone had proposed putting together a bacterium and a virus. A victim of this chimera would be treated for plague with the appropriate antibiotics, which would kill the plague bacteria. But shattering the bacterial cell walls would release VEE into the lymph or the bloodstream; the invading virus would have already bypassed much of the immune system, and it would make straight for the brain. Within a week or ten days, the victim would be dead of encephalitis." [1]


 1. Orent, Wendy. Plague: the Mysterious Past and Terrifying Future of the World's Most Dangerous Disease. Free Press, New York: 2004.

Thursday, May 17, 2012

WORMBOOK



An excellent online resource for studying C. elegans and other nematodes: 





Thursday, May 10, 2012

GREULICH-PYLE APPLICABILITY

The May 2012 issue of the Journal of Forensic Sciences has an article assessing the Greulich-Pyle method of skeletal age estimation. The study, by Cantekin, et al., analyzed left hand/wrist roentgenograms (x-ray photographs) for a sample of 767 Caucasian eastern Turkish sub-adults, aged 7 through 17, with known chronological age and gender. Although some unacceptably high standard deviations occurred in individual age groups, the difference between bone age mean and chronological age mean for males and females was not statistically significant. These findings reinforce the utility of GP estimation.

"FIG 1--Scatter plot of bone age versus chronological age in girls"


 "FIG 2--Scatter plot of bone age versus chronological age in boys"




Bone Age Assessment: The Applicability of the Greulich–Pyle Method in Eastern Turkish Children
J Forensic Sci, May 2012, Vol. 57, No. 3 doi: 10.1111/j.1556-4029.2011.02035.x
Available online at: onlinelibrary.wiley.com

Saturday, April 28, 2012

LEARNING GIS

I figure that it's about time I get my feet wet with Geographic Information Systems (GIS). The eventual goal is to render original choropleth maps and compile epidemiological data in a graphic and useful way. Below are a couple of very rudimentary maps I authored with ArcGIS Online. The public feature layer sets seem pretty limited, so I'll probably just start making my own once I learn the software and acquire some relevant samples. I'm also playing around with Quantum GIS, GeoDa, and R. Details to follow. 


View Larger Map
Map 1: Greater Cleveland Area, USA Crime Index



View Larger Map
Map 2: Greater Cleveland Area, Populations of Individuals Aged 25+ who Lack College Degree



Saturday, April 14, 2012

EPIVENTURE

The Council of State and Territorial Epidemiologists website has posted a prototype educational module, developed with funding by the CDC, called "EpiVenture: Outbreak Investigation." This software lesson is very similar to proprietary training modules we use in the pharmacy, and it is a very effective tool. The course comprises a mixture of text outlines and terms, with multiple-choice tests and interactive case studies interspersed throughout. I found the prototype version of EpiVenture to be both informative and engaging. Hopefully the CDC/CSTE continue to develop and release new lesson modules for EpiVenture.

Try this self-instructional web course out for yourself:

http://www.cste.org/epiventure/index.html



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Wednesday, April 4, 2012

DEMIRJIAN'S METHOD


One of the most widely used methods of forensic age estimation via dentition was derived in 1973 by Demirjian, Goldstein, and Tanner.[1] Commonly referred to as "Demirjian's Technique," the changes from initial calcium deposition to complete apex are divided into eight observable stages. Each stage is further characterized by up to three additional qualifying criteria (a,b,c). If only criterion (a) is listed, then it must be met. If (a) and (b) are listed, then at least (a) must be satisfied. If (a), (b), and (c) are listed, then both (a) and (b) must be met. Additionally, "at each stage . . . the criteria for the previous stage must be satisfied" [ibid]. The technique is applied to 7 observed teeth, with the individual "score" from each tooth being added. The resulting sum is then referenced on a corresponding conversion chart with ages ranging from 3 to 17 years, in increments of one-tenth. 

Though the Demirjian method worked well with the original French Canadian subject sample, more recent studies have questioned its effectiveness when applied to sample groups of varied descent. A 2007 study by Tunc and Koyuturk revealed that the technique was less accurate with regard to sampled Turkish children, who   displayed more advanced dental maturity.[2] 
A 2001 article using Belgian children as the sample group confirmed popular findings that the Demirjian method has a tendency to result in over-estimation of age, but employed new adaptations to the scoring system to achieve an increase in accuracy.[3] 

The Demirjian technique remains a well-regarded forensic tool for determining age in sub-adults. As with all estimation methods, there is a discernible margin of error, but overall the technique still provides advantages over other dentition methods, especially those based on tooth eruption, which can be highly influenced by health and environmental factors. It should be remembered that in practical application, a synthesis of various age-estimation methods generally yields the best overall results.    


REFERENCES:

1. Demirjian, A., et al. A New System of Dental Age Assessment. Human Biology 45(2): 211. 1973.

2. Tunc, E.S.; Koyuturk, A.E. Dental age assessment using Demirjian's method on northern Turkish
    children. Forensic Science International. 175(1): 23-26. 2008.
   http://www.mendeley.com/research/dental-age-assessment-using-demirjians-method-on-northern-turkish-
   children/

3. Willems G., et al. Dental Age Estimation in Belgian Children: Demirjian’s Technique Revisited.
  Journal of Forensic Science 46(4): 893-895. 2001.
  http://www.kuleuven.be/fortand/MFO/articles/01_JFS_Willems_demirjian.pdf 



Sunday, April 1, 2012

HAITI

Haiti, with all of its misfortune -- the atrocious sanitary conditions, profound socioeconomic disparity, and recent natural disasters -- serves as an ideal case study for epidemiologists. The U.N.'s ongoing role there provides an example of how organizational interaction can severely affect the health of a population, for better or worse.   

Global Failures on a Haitian Epidemic

Infectious Diseases of Haiti (E-Book)


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Tuesday, March 27, 2012

SOME PITHY TITLE ALLUDING TO WINDS OF CHANGE, BLA BLA BLA

I haven't been posting as much as I would like, but some exciting developments are underway. I'm currently finishing my last semester as an Anthropology/Linguistics undergrad, and have decided to forego law school to pursue an MPH in Epidemiology. Of course, this rather recent decision means my plans have been eviscerated. Instead of the LSAT, I need to prepare (rather tardily) for the GRE, and I'm scrambling to put my admissions material together in time to meet application deadlines. All this on top of composing my senior project on Native land rights in the Americas. Still, I haven't been this excited about the future for years, and I'm standing firmly behind my gut feeling on this decision. Though I'm versed in some rudimentary science  and statistics through formal coursework and personal study, I've got a long path ahead of me. As I immerse myself in this academic pursuit, expect the postings to reflect continued exploration of subjects like biostatistics, public health concerns, and infectious diseases, in addition to the topics already covered. I'm not sure where this new direction will spit me out, but I'm certain it will be one hell of an interesting ride!

Friday, March 16, 2012

NEW HUMAN SPECIES?


A new PLoS ONE journal article studies recently-discovered humanoid remains which may be an evolutionary offshoot of Homo sapiens. The skeletons, discovered in caverns in the South-west of China, feature large jaws  (absent chin) and molars, eminent brow ridges, robust bone structure, and flat faces. Caches of fossilized remains from giant prehistoric deer suggest that venison comprised a significant portion of these early humans' diet. The big question now is one of taxonomy: will the "red deer cave people" be classified as a phenotypic anomaly, or a new human species? 

Read the full journal article here:
Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians

Related secondary sources:
National Geographic
Live Science


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Wednesday, February 29, 2012

MUMMIES OF GUANAJUATO

The Museo de las Momias in Guanajuato, Mexico, features a 56-body collection of incredibly well-preserved mummies. Most of the mummies date to around 1833, when they were "accidentally" interred during an outbreak of disease, most likely cholera. The collection has captivated artists and writers, including Werner Herzog and Ray Bradbury. The latter wrote of his visit, "The experience so wounded and terrified me, I could hardly wait to flee Mexico. I had nightmares about dying and having to remain in the halls of the dead with those propped and wired bodies. In order to purge my terror, instantly, I wrote 'The Next in Line.' One of the few times that an experience yielded results almost on the spot."







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Friday, February 24, 2012

MY FRIEND DAHMER

Cleveland's own Derf Backderf has penned a new graphic novel which is certain to draw the interest of those fascinated by psychology and serial killers alike. My Friend Dahmer reflects upon Derf's own interactions with an adolescent Jeffrey Dahmer, the latter's growing pains, and the horrific consequences of human frailty. 


"MY FRIEND DAHMER is the haunting, new graphic novel by Derf Backderf, an award-winning cartoonist and comix creator. In these pages, Backderf tries to make sense of the iconic monster who he shared the same school hallways, cafeterias, libraries, and compulsive car rides. What emerges is a surprisingly sympathetic portrait of a disturbed young man struggling helplessly against the ghastly urges bubbling up from the deep recesses of his psyche. The Dahmer recounted here, universally regarded as an inhuman monster by the rest of the world, is a lonely oddball who, in reality, is all too human. A shy kid who is sucked inexorably into madness while the adults in his life fail to notice. 
 We all know what Dahmer did, but in MY FRIEND DAHMER, Backderf provides, from his unique vantage point, profound (and at times, even strangely comic) insight into how, and more importantly, why Jeffrey Dahmer transformed from a high school nerd into a depraved fiend as notorious as Jack the Ripper. 

In MY FRIEND DAHMER, Derf comes as close as anyone yet has to explaining the seemingly unexplainable phenomenon of one Jeffrey Dahmer, Revere High School, Class of 1978."

You can pre-order a copy HERE.

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Wednesday, February 22, 2012

SALIVA AS A PREDICTOR OF AGE


Promising research now shows that DNA Methylation of human saliva can be utilized to predict a person's age with a modest degree of accuracy. No doubt the technique will improve with refinement and ongoing technological advances. Inferential methods like this are invaluable, because they allow forensic investigators to build a suspect's profile without having to rely on database matches (as is the case with fingerprints, DNA, etc.).

Read a summary of the research here:

Then check out the genuine research publication on PLoS ONE:

ABSTRACT:
From the moment of conception, we begin to age. A decay of cellular structures, gene regulation, and DNA sequence ages cells and organisms. DNA methylation patterns change with increasing age and contribute to age related disease. Here we identify 88 sites in or near 80 genes for which the degree of cytosine methylation is significantly correlated with age in saliva of 34 male identical twin pairs between 21 and 55 years of age. Furthermore, we validated sites in the promoters of three genes and replicated our results in a general population sample of 31 males and 29 females between 18 and 70 years of age. The methylation of three sites—in the promoters of the EDARADD, TOM1L1, and NPTX2 genes—is linear with age over a range of five decades. Using just two cytosines from these loci, we built a regression model that explained 73% of the variance in age, and is able to predict the age of an individual with an average accuracy of 5.2 years. In forensic science, such a model could estimate the age of a person, based on a biological sample alone. Furthermore, a measurement of relevant sites in the genome could be a tool in routine medical screening to predict the risk of age-related diseases and to tailor interventions based on the epigenetic bio-age instead of the chronological age.
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HERE WE GO AGAIN


Visitors to Flesh and Bones will no doubt have noticed that the author has been on lengthy hiatus; Alas, life waits for no man. Pending graduation and a fairly easy final semester now leave me with some much-appreciated spare time, and new posts will be arriving in short order. 

I'll be simultaneously authoring my other latest blogging endeavor, Olio / Etcetera, and I encourage anyone interested to check it out and subscribe. The blog is an eclectic collection of my researches and clippings, mental blurbs, book excerpts, academic work, essays, and photography. The underlying theme, if any, is "man the animal." Special emphasis will be placed on history, anthropology and language systems, but any subject is fair game. Enjoy, and thank you for your interest!

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