Posts tagged science
The story behind DNA’s double helix
The notorious race to uncover the structure of DNA, the molecule of inheritance, began in 1951, when American biologist James Watson arrived at the University of Cambridge. Here he met Francis Crick, an English physicist and the two began building scale models to test their ideas of what DNA’s appearance might be.
Meanwhile, two scientists at King’s College London called Maurice Wilkins and Rosalind Franklin were also studying DNA. They were attempting to crystallise the molecule to make an x-ray pattern of it. They hoped this would provide important clues about its structure.
Although the two institutions were effectively competing against each other, Francis Crick (University of Cambridge) and Maurice Wilkins (King’s College London) communicated regularly. Letters sent from Wilkins to Crick reveal their close personal relationship.
It was Rosalind Franklin’s famous x-ray image, nicknamed ‘Photo 51’, that finally revealed the structure of DNA in May 1952. The pattern appeared to contain ‘rungs’, like those on a ladder, set between two strands. The fuzzy “X” pattern indicated DNA’s helix shape. In early 1953, Wilkins showed Watson the image, seemingly without Franklin’s knowledge.
Recipient of the world’s first human heart transplant, Louis Washkansky, in Groote Schuur Hospital, Cape Town, three days after the surgery, December 6, 1967.
Unfortunately, he died eighteen days after the transplant of pneumonia due to his weakened immune system.
“Domestic weasel” [Ferret] - Mustela putorius
Did you know that ferrets were domesticated over 2500 years ago? They were used in ancient Rome to hunt rabbits, moles, and other ground-dwelling animals, and the verb “ferreting” (as in ferreting out) came from their inquisitive and seeking nature.
Throughout the middle ages, they were used by the nobility and the gentry, but their use during the Renaissance decreased. Until the late-20th century, domestic ferrets were on the decline, but in the mid-1980s, their popularity as pets began to boom. Unfortunately, in some countries, such as New Zealand, feral ferret colonies have destroyed indigenous wildlife. In North America and Northern Europe, however, pet ferrets have continued to stay popular, and wild colonies have not been established thus far.
Double Penis
For those of you wondering if/telling me this post was fake.
Some additional anatomical information can be gleaned from the 1918 text that was not present with the illustrated figure: this man was reported to have two “functionally perfect” organs, though the urethra traveled through one penis, and he ejaculated out the other. Both were capable of maintaining an erection, but it was not as “virile” as an “average male” (presumably meaning neither organ was as stiff as a typical erection).
There were only two testicles, and the “limb” (it was not specified as to whether it was a leg or arm) emerged from the perineum - the region between the genitalia and the anus.
Genito-Urinary Surgery and Venereal Diseases. Edward Martin, Benjamin A. Thomas, and Stirling W. Moorhead, 1918.
Early ether administration methods
Top: Using a drip-cloth to put a woman in labor under anesthesia.
Second: Gauze-filled face-piece used in the same manner as the drip-cloth (by soaking the covering material).
Third: Automatic pressurized ether gas administration mask.
Fourth: Manual ether gas administration mask.
The early anesthesia gasses consisted of nitrous oxide (laughing gas), ether, and chloroform. Ether was the most effective in putting people under, and had the largest therapeutic index (the difference between the recommended dosage and a toxic overdose), but had significant side-effects (such as nausea and vomiting, even before consciousness was regained, resulting in aspiration), and suppressed the autonomic breathing reflex in high enough concentrations.
Today, the only one of the three original anesthetic gasses that is still in use is nitrous oxide. It’s generally used along with local anesthetic, since it is not of the best use in causing complete unconsciousness, but its action on the brain decreases discomfort whilst awake.
Images:
An American Text-Book of Obstetrics for Practitioners and Students. Edited by Richard C. Norris, 1895.
High-Grade Hospital Furniture and Appliances Catalog. Max Wocher & Son, 1905.
Wound closure techniques ca. 1855.
Fig 1. Closure of the wound without sutures, using adhesives and cloth.
Fig 2. Simple interrupted suture.
Fig 3. Simple uninterrupted suture.
Fig 4. Interfolded suture, with stabilizing rods. Suture passes under wound and is pulled together despite no stitches over the wound site.
Fig 5. “Suture en zigzags” - Continuous horizontal mattress suture.
Fig 6. Twisted suture. Dieffenbach used this stitch in the early steps of his reconstructive surgery.
Fig 7. Suture needle holder.
Fig 8. Curved suture needles.
Précis iconographique de Médecine Opératoire et d’Anatomie Chirurgicale. Drs. Bernard and Huette, 1854.
Horny growth of the penis
Horny growths on the skin, also known as cornu cutaneum, are keratinous skin tumors, caused by overgrowth of keratin in the dermis. Since they’re avascular (they have no bloodflow), they can be easily removed with a scalpel or sharp razor, but the underlying condition will almost always reappear if the site is not treated with radiation, chemotherapy, or (occasionally) cryotherapy.
Diseases and Surgery of the Genito-Urinary System. Francis Watson, 1908.
Structural anatomy of the human head
Successive frontal slices of adult male, brain removed.
As can be seen in these images, the human skull is a rather complex maze of hollow cavities, thin walls, and hidden structures.
There are four sets of paranasal sinuses in the front of the head: the maxillary sinuses (right below the eyes), frontal sinuses (above the eyes, in the hard part of the forehead), ethmoid sinuses (between/behind the nose and eyes), and the sphenoid sinuses (in the sphenoid bone, under the pituitary gland, in the center of the skull - can be seen in the bottom-most plates).
In addition to those sinuses, you can also see the Eustachian tubes, which connect the ear to the nasopharynx and regulate pressure in the middle ear; the curled nasal concha, which regulate the air flow through our nose, keeping it a relatively constant humidity and temperature; and the falx cerebri, a sickle-shaped sheet of dura mater that divides the right and left hemispheres of the brain.
Studies in the Anatomy and Surgery of the Nose and Ear. Adam E. Smith, 1918.
“While the rarity and beauty of Harvard’s Glass Flowers have won them fame and made them the Harvard Museum of Natural History’s (HMNH) most popular exhibit, the glass animals exist in relative obscurity.”
The glass sea life of the Blaschkas is some of my favorite hand-blown art out there. I regret that I missed the opportunity to see it when it was at the Minnesota Science Museum back in 2006, but it’s still too cool to pass up.
Special Guest post:
“Ew, you have cooties!” is more than just a childish playground taunt; cooties were (and are) a real thing, and a serious problem for much of history.
The term refers to Pediculus humanus corporis, otherwise known as the human body louse. During wartime, body lice were a scourge to soldiers and civilians in crowded conditions, and were a much more dire problem than the other human lice species (head lice and pubic lice, or “crabs”). Cooties carried typhus, a disease that killed over three million people on the former Eastern Front, between 1918 and 1922. De-lousing stations set up on both sides of the conflict kept the cootie from running rampant in Western Europe, but it was still a persistent problem throughout the war. The body louse was most notably found in German concentration camps in WWII, and the typhus carried by Pediculus humanus corporis is what killed both Anne Frank and her sister Margot.
Typhus has plagued humanity for centuries, but cooties have not. The term cootie was first coined by the British army in WWI, and is presumed to be from the Malay word kutu, meaning either biting body louse or dog tick.Today’s post by Arallyn, a humanoid from the third rock from the sun who is fascinated by science and who runs the fantastic blog biomedicalephemera.tumblr.com when she isn’t filling her mind with scientific trivia. Check out her cool blog-I don’t know where she finds her material, but it is spectacular!
Etymology is my friend.
Cooties are not.
Rheumatic heart disease (Rheumatic endocarditis)
A hundred years ago, before we had access to effective antibiotics or preventative care, strep throat (streptococcal pharyngitis), scarlet fever, and other manifestations of Streptococcus pyogenes infection often led to death; sometimes that death was months or years after “recovery” from the disease, but it was directly caused by the reaction of the body’s immune system to the bacterial infection.
Untreated Streptococcus infections can lead to an autoimmune cross-reaction to the body’s own tissues. One of these autoimmune responses is rheumatic fever. In this condition, the heart and joints are attacked, causing them to grow vegetations (see the opened heart above) which impede blood flow and free movement of the large joints. Rheumatic fever also causes what’s known as “St. Vitus’ Dance” (chorea minor), which causes uncontrolled movements and muscle twitching, which can further impair quality-of-life and productivity.
While rheumatic fever is rare in the developed world (and almost always caught early when it does occur), it’s still painfully common in places like South-East Asia and Sub-Saharan Africa. People (largely children) who develop it often don’t know until symptoms begin to seriously manifest themselves, when the growths have reached a point where they have the potential to soon completely block the heart valves. At this point, the only cure for the patient is open-heart surgery - something that’s incredibly hard to come by in the developing world. Over 300,000 people still die of this condition every year.
Keif Davidson recently released an Academy Award-nominated short documentary called “Open Heart”, following eight Rwandan children to the Salam Center in Northern Sudan. This well-built and impressively staffed charitable hospital is run by Emergency, an Italian NGO. For the children that can get there, open-heart surgery and all follow-up visits are provided for free. It’s an impressive and touching film, and the passion of the filmmaker and of the surgeons is hard to ignore.
If Streptococcal infections are treated, rheumatic fever almost never develops. But if it does, early treatment can mean that those afflicted with the condition can live happy and productive lives, and may never develop the life-threatening heart conditions associated with it. There are currently efforts to disseminate antibiotic availability for Streptococcal infections, and a mobile team is now being organized to screen for early rheumatic fever in the field. Prevention and early treatment is much cheaper for everyone, and hopefully both of these efforts will be successful in decreasing the number of people who must trek far from home for any chance at all of treatment.
Illustration: Researches on Rheumatism. F.J. Poynton and Alexander Paine, 1914.
Poster: “Open Heart” Film. Directed by Keif Davidson, in Association with Stories Of Change A Project Of and supported by the Skoll Foundation. 2013.
When the cure is worse than the disease…
No. 97: Metallic stomatitis sores, concurrent with re-emergence of syphilitic mucous papules. Caused by mercuric injections.
No. 98: Bullous Erythema multiforme brought on by arseno-benzene injections. Patient had nine injections of mercury and eleven of arseno-benzene, and presented his rash two-and-a-half months later. His urine had much protein in it and showed signs of acute yellow atrophy of the liver. He was given three more injections of arseno-benzene and apparently recovered?
No. 99: “Typical” presentation of nails after acute arsenical dermatitis, after the rash has disappeared.
There were many recorded deaths from the “cure” for syphilis, often from infection of open wounds caused by reactions to the deadly poisons that people were ingesting to try and avail themselves of an illness that, if anything, would probably have killed them much more slowly…
Venereal Diseases: Their Clinical Aspect and Treatment. J. E. R. McDonagh, 1921.
Left: Pathological bone loss from gunshot wound. 2.5 inches lost. Ends of bones partially healed and injured bone reabsorbed due to significant delay in reaching surgical hospital (one fortnight on the battlefront after gunshot - external splinting and sanitation only).
Right: Inlay sliver fixation graft in same case. Held in place with kangaroo sutures. Engaging both ends of ulnar fragment.
Orthopedic and Reconstruction Surgery, Industrial and Civilian. Fred H. Albee, 1919.
1. Top Center: “Trough” battery cell
2. Top Right: “Column” battery cell
3. Central Figure: “Pneumatic machine”
The glass bell on this contraption is known as the the “passive component” of this pneumatic circuit. Where an automatic gas compressor would be found today (the set of chambers and cranks to the right), is a manual gas compressor, vacuum chamber, and pressure gauge.
Steam age physics demonstrators are too cool-looking to not want to play with.
Dictionnaire universel d’histoire naturelle. Charles Dessalines d’Orbigny, 1837.
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A blog for all biological and medical ephemera, from the age of Abraham through the era of medical quackery and cure-all nostrums. Featuring illustrations, history, and totally useless trivia from the diverse realms of nature and medicine.
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