Updates: My Blogger template designs

I always need a creative outlet to express myself. Not that vet school and Sapna Magazine don't keep me busy enough -- it's just nice to have a variety sometimes. To that end, and I've decided to launch a line of free blogger templates!

I'm creating the templates with stock images that can be downloaded for free. I'm so excited! My first release will be the design above, which will probably go public in June. After that, I may crank out 3-4 designs over the summer.

Stay tuned!
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Updates: my article on saving tigers

You can now read my article on tiger endangerment online at www.sapnamagazine.com. Wildlife conservationists agree that tiger endangerment is a critical issue. Mainstream media intermittently picks up on problems such as these (for example, the April 13, 2009 cover of TIME Magazine features a Sumatran tiger).

My Sapna Magazine article features interviews that I conducted via email with some of the top experts in tiger conservation, including Dr. Ullas Karanth. In 2007, Dr. Karanth was awarded the Getty Award for Conservation Leadership -- an honor that has been given to the likes of Jane Goodall. Also featured in my article are Dr. Ron Tilson, Chairman and Director of the Tiger Foundation, and Dr. Mahendra Shrestha, Director of the Save the Tiger Fund, among others.

My article was published in 2007; the online version features a brief 2009 update. I will be working on a more comprehensive update this summer.

I first stumbled upon (and was first disturbed by) the notion of a human-induced age of extinction in Scott Weidensaul's book The Ghost with Trembling Wings. The recent TIME Magazine feature falls in step with this theory, saying that we are creating "a new age of extinction."

From TIME.com:
"There have been five extinction waves in the planet's history — including the Permian extinction 250 million years ago, when an estimated 70% of all terrestrial animals and 96% of all marine creatures vanished, and, most recently, the Cretaceous event 65 million years ago, which ended the reign of the dinosaurs. Though scientists have directly assessed the viability of fewer than 3% of the world's described species, the sample polling of animal populations so far suggests that we may have entered what will be the planet's sixth great extinction wave. And this time the cause isn't an errant asteroid or megavolcanoes. It's us."
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Notebook: Anesthesia

Injectable anesthetics: rapidly acting anesthetics (examples: thiopental, propofol, etomidate, ketamine); slow acting (examples: potent opioids, neuroleptanalgesics)

BARBITUATES
- mechanism of action: allosteric modulation of the GABA A receptor
- increase in average duration of GABA-activated Cl- ion channel openings

Other mechanisms of action -- keywords for CNS: interaction w/ central Ca2+ and Na+ channels, glutamate and nicotinic ACh receptors. Depression of autonomic ganglia. keywords for PNS: block ACh effects at nicotinic synapses, inhibition of transmembrane Ca2+ fluxes

What do barbituates do?
- gradually depress the CNS (anesthesia)
- (don't provide analgesia)
- decrease EEG activity
- decrease cerebral blood flow
- decrease intracranial pressure
- provide anticonvulsive activity

Undesired effects of barbituates?
- central respiratory depression (i.e. hypoventilation)
- cardiovascular depression
- decrease in cardiac output
- decrease in arterial blood pressure
- may cause tachyarrhythmias
- decrease in renal blood flow
- decrease in hematocrit
- decrease in white blood cells
- perivascular injection may cause thrombophlebitis

Pharmacokinetics: How are barbituates eliminated?
- metabolized in the liver; conjugated with glucuronic acid
- renal excretion

Case in point: thiopental (pentothal)
- indicated for brief surgeries/ exams, neurosurgical patients with increased intracranial pressure, induction of general anesthesia, immediate control of convulsions

PHENOLS
- unrelated to barbituates
- main mechanism of action:
- allosteric modulation of GABA A receptor

What do phenols do?
- gradually depress CNS
- intravenous deep sedation
- non-hypnotic CNS effects:
- decrease cerebral blood flow
- decrease intracranial pressure
- antiemetic effects
- can be used for general anesthesia
- decrease EEG activity
- no analgesia

Undesired effects of phenols?
- respiratory system
- central respiratory system depression
- bronchodilation
- inhibition of laryngeal reflexes
- cardiovascular system
- hypotension
- transient excitatory effects

IMIDAZOLE (ETOMIDATE)
- good for inducing anesthesia in high-risk patients
- mechanism of action: allosteric modulation of GABA A receptor
- no analgesic effects
- decrease in EEG activity
- decrease in cerebral blood flow
- decrease in intracranial pressure
- cons: occasional CNS excitatory effects, hemolysis, pain, inhibition of adrenal steroid genesis

CYCLOHEXANONES
- ketamine, tiletamine. "dissociative anesthesia"
- loss of consciousness
- catalepsy
- maintenance of protective reflexes
- skeletal muscle movements
- mechanism of action: blocks NMDA receptor
- decrease in central glutamatergic activity
- provides analgesia and anesthesia

INHALANT ANESTHETICS
- inhalant anesthetic dose required to maintain an appropriate surgical plane of anesthesia is lower in older animals than in younger animals
- the speed of upake of inhalant anesthetics into the blood is inversely related to blood solubility and cardiac output
- inhalant anesthetics commonly cause vasodilation and negative inotropic effects
- they suppress the effects of excitatory neurotransmitters such as glutamate and ACh within the CNS
- inhalant anesthetics: degree of hepatic metabolism (ranked highest to lowest) is sevoflurane > isoflurane > desflurane > nitrous oxide
- the minimal alveolar concentration (MAC) of an anesthetic agent prevents gross purposeful movement in 50% of subjects exposed to a supramaximal noxious stimulus.

Isoflurane
- causes more significant cardiovascular depression than sevoflurane.

Sevoflurane
- sevoflurane is less potent than isoflurane
- sevoflurane allows for more rapid adjustment of anesthetic depth during anesthesia than does isoflurane
- In general, renal toxicity is not a common problem with sevoflurane.
- sevoflurane is more lipid soluble than desflurane

Desflurane
- desflurane is a halogenated ether
- desflurane has a more pungent odor and irritates airways more than sevoflurane does
- recovery of anesthesia from desflurane is faster than from isoflurane
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Updates: Marine Symposium 2-18-2009

Next Wednesday, February 18, please join us at the University of Pennsylvania School of Veterinary Medicine Hill Pavilion Auditorium for an experience in marine conservation education.

Dr. Enric Sala, PhD -- a National Geographic Explorer -- along with Dr. Alonso Aguirre, DVM, PhD -- co-founder of the Consortium for Conservation Medicine -- will be dazzling us with their speaking abilities. Check out the flyer at left (designed by yours truly)! And check out our facebook group as well.

Details below:

Join us for a UPenn “Year of Evolution” event focused on the critical issue of marine species conservation – recent groundbreaking discoveries and innovative solutions to save our oceans. Famed marine researchers and explorers will share their findings and recount their global adventures, tracking and protecting endangered marine species.

Featured speakers:

ENRIC SALA, PhD, National Geographic Explorer, Pew Marine Conservation Fellow, and key player in the recent establishment of the largest marine reserve in the world.

ALONSO AGUIRRE, DVM, PhD, co-founder of the Consortium for Conservation Medicine, leading expert in marine mammal and sea turtle conservation.

Presented by Special Species Club, EcoVet, and IVSA, with generous sponsorship from Merial, the Office of the Provost, and Public Health Club.

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Updates: Blogging about a Blog

Sapna Magazine has a blazing blog going lately! Vaishali Rao, our director of communications, is currently our resident blogger -- and she's been posting on a diverse array of interesting topics.

Recent topics have explored fashion, politics, consumerism and the arts. For example, who knew that Britney Spears hired a Bollywood-inspired choreographer for her Circus world tour? The blog also put a spotlight on the success of South Asian American supermodel Lakshmi Menon. (Check out Menon's model bio on New York Magazine's website.)

The following is an excerpt from the Sapna blog:

Britney chose Indian choreographer, Rujuta Vaidya, trained by famous Bollywood choreographer Saroj Khan, to help her hit her moves.

“Britney was not used to the Bollywood style of dance but she is a fast learner and she picked it up well. I know she was excited about doing it because she is the one who selected us,” Rujuta told a New York-based website.

Can she pull it off? Or will it look like more of a Circus than it's supposed to?

Visit www.sapnamagazine.com and scroll down to "the Sapna blog" to read more!
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Notebook: Hemostasis -- Coagulation

The following notes were taken during a 2-hour lecture by Dr. Urs Giger, DipACVIM.

Brief introductory discussion on the molecular level:
- activation of protein C.
- in order to be functional, protein C has a cofactor (protein S)
- both protein C and protein S are vitamin-K-dependent factors.
- complex of protein C and S will inhibit factors 5 and 7
- complex will also activate the inhibitor of plasminogen activator.
- this is a very regulated system that has to be balanced.
- Imbalances will lead to either a tendency to bleed or a tendency to thombose.

When an animal has a clotting problem, we need to know if the problem is primary or secondary. Problems may be acquired (any time, any age) or hereditary (for example, von Willebrand disease and hemophilia).

When an animal presents, ask the owner if there is a possibility of rodenticide problem.

During the physical exam, characterize bleeding.

COAGULOPATHIES: Problems with Secondary Hemostasis
- use a diagnostic test to assess hemostasis
- cuticle bleeding time: assesses overall hemostasis. Not standardized, painful.
- this method doesn't differentiate between problems with primary and secondary.
- "an absolute must" for every patient: blood smear evaluation
- look for platelets; if absent, ask yourself: is this a true thrombocytopenia?

Additional diagnostic testing
- do this prior to treatment (most situations -- unless patient is critically ill)
- why? b/c any treatment you do may change these results.
- Citrate tube: Tube contains 3.2% citrate solution that is added to the blood.
- Remember, without calcium, there is no coagulation
- The citrate is in a molar form, so calcium binding is a reversible process.
- (An EDTA sample chelates calcium and therefore is irreversible.)
- To perform the test, the tube must contain 9 parts blood and 1 part citrate.

- Collection technique is very important:
- if technique is incorrect, you may activate the coagulation pathway
- this may leave to shortened coagulation time.

- Activated Coagulation Time
- uses surface activation
- does not involve extrinsic clotting pathway
- does not require instrumentation
- does not require anything but the tube containing diatomaceous earth
- use vacuutainer; once first drops of blood are in the tube, start the timer
- when it is filled, pull it off; make sure there is good hemostasis
- mix by gently rotating the tube in your hands
- results: if there are no platelets, the actual clotting time will be prolonged.

[2nd HOUR OF LECTURE]

Partial Thromboplastin Time (laboratory PTT/aPTT)
- reactants: calcium, PTT activator (phospholipid), plasma
- phospholipids need to be added b/c plasma lacks platelets
- results are given in unit time, not in percent or in amount of protein
- in a way, it's assessing the same systems as ACT (intrinsic & common pathways)

Prothrombin Time (laboratory PT)
- assesses the extrinsic and common pathways
- reactants: calcium, tissue factor, plasma
- assay can be done within an hour; results are very reliable.

Protein Induced by Vitamin K Antagonism or Absence (PIVKA test)
- important for the main reason of anticoagulative rodenticides
- similar or identical to PT
- it is NOT specific for rodenticide poisoning.
- no reason to do this anymore. (PT test gives the same information)
- note: PTT test is most useful.

Fibrin degradation
- two ways to estimate fibrinogen:
- Thrombin Time (TT)
- not affected by rodenticides
- Plasma Fibrinogen Quantity

Thromboelastography
- overall hemostatic evaluation
- can predict thrombotic tendency
- can suggest fibrinolytic activity

Extra notes on hemostasis:
- Heparin is a very good coagulation inhibitor.
- Remember, you CANNOT DO coagulation tests with serum.
- The difference between serum and plasma: COAGULATION FACTORS -- mainly FIBRINOGEN.
- Schistocytes (spelling?) are seen when there are fibrin strands in a blood vessel.

Note to self: See Dr. Giger's lecture handout and complete the table on the second to last page.

TRANSFUSION MEDICINE
- indication for transfusion: anemia
- plasma may need to be given, or a combination of plasma and RBCs

Blood types are genetic markers on RBC surfaces; these are species specific and may differ between individuals.

Note to self: See more info on transfusion medicine in Dr. Giger's lecture handout.
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Opinions: the Aerial Gunning of Wolves

For years now, the Defenders of Wildlife has been sending me alerts on the brutal killing of wolves in Alaska. I've always opposed the savagery that's been documented in bloody photos and videos, but not until today did a classmate make me think: Why is Alaska doing this? What is the motivation? Does the wolf population need to be managed, and if so, why?

Even if the wolf populations are in need of management, there needs to be a humane way to control their populations. However, she inspired me to do some digging.

My research yielded the following: Wolves are being targeted because they are killing their natural prey, caribou and moose, in their Alaskan homeland. A natural prey-predator relationship that the governor wants to stop? Why? There's got to be a motive... And here it is.

Here's an old clip from the Seattle Times (December 8, 1992):

We Should Learn From Alaska's Big, Bad Wolf Mistake
by John A. Baden, Ph.D. and Robert Ethier

KILLING WOLVES is a dramatic and highly controversial wildlife management practice. Alaska has recently proposed this as a way to boost caribou, moose, and deer populations for tourists and hunters.

But many people find gunning wolves from airplanes offensive and are outraged.

The logic underlying the killing seems clear, but the issues are complex. Wolves do kill caribou, elk and moose - especially their young. Reducing wolf populations should increase the numbers of these ungulates, but by how much? There are bitter disputes among scientists over the size of predator impact upon prey populations. Read full article

In a nutshell, it seems that these wolves are being killed so that hunters can come in and have lots of caribou and moose to kill? So... The wolves are being killed because they're doing as nature intended... So that hunters can come in and fulfill a disgusting blood lust for the thrill of the chase?

My research is far from over on this issue, so there will be more updates to come. But I maintain: Even if population management is warranted, there are more humane methods that can be used. After all, hunting by aerial gunning has been illegal in the United States since 1972, and with good reason.

Humane methods of population control will be detailed in a future post.
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Notebook: Electrocardiography 3

These notes were taken during a lecture by Dr. Meg Sleeper, veterinary cardiologist.

- Ectopic beats come from outside the sinus node; they can be either early or late.
- Junctional beat is the same as an AV nodal beat
- Junctional escape vs. ventricular escape

BASIC ECG CLASSIFICATION
- aberrant conduction (the conduction path is abnormal)
- bundle branch block (RBBB) occurs commonly.
- right bundle branch block occurs most commonly.
- left bundle branch block is more often associated with structural heart dz.
- arrythmia (either of supraventricular or ventricular origin)

2 differentials for a wide QRS complex:
- ventricular aberrant beat (a ventricular complex)
- block in conduction (blockade through conduction through the ventricles)
- with a RBBB, you see negative deflection

SUPRAVENTRICULAR CARDIAC RHYTHMS

Classification of conduction defects
1st degree: prolonged PR interval (slower than normal conduction through the AV node
- can be caused by fibrosis of the AV node, or certain drugs (i.e. digoxin)

2nd degree type 1 or Wenchebach: some of the P waves don't get through. Unconducted p waves typically occur as the R to R interval is lenghtening. May see subtle lengthening of the PR interval.
- in a dog where this is physiologic, increasing sympathetic tone will cause this to go away (i.e., running the dog in the hallway for a bit)

2nd degree type 2: P wave that is not followed by a QRS complex. Most typically it is progression of AV disease or fibrosis. (If this animal is exercised, the rhythm won't go away.)

3rd degree: complete AV block. Nothing is conducting down. It may seem that the P waves are very regular on their own and the QRS complexes are very regular on their own; however, the regularity of the two may not seem to be related. T waves are wider than normal with discordant QRS complexes.

Asides:
Remember, the first heart sound is caused by closure of the mitral valve. Premature beats are usually very loud b/c they occur when the valve is wide open.

Summation occurs when two cardiac events appear on the ECG paper at the same time.

If a QRS is not very wide, it may be coming from the AV node.

Case example: Dog has been fainting; ECG shows a sinus bradycardia with a ventricular escape beat. Atropine an be given as a diagnostic test (Atropine Response Test).

If the pattern goes away in response to atropine, the pattern is a sinus tachycardia. (A normal dog would also respond this way.) This means that the heart can respond normally when vagal tone goes away. For some reason this dog has abnormally high vagal tone. Note: If the dog had not presented for fainting, and the atropine response test caused the pattern to go away, this dog probably would not need to be treated.

Sinus rhythm is common in cats but pretty rare in dogs. Sinus arrhythmia is common in dogs. Remember, an arrhythmia is not necessarily abnormal. Sinus tachycardia is a normal response to pain, fever, stress, fear, etc.; this is a way the sinus node responds to elevated sympathetic tone.

Supraventricular tachycardia is also known as paroxysmal atrial tachycardia. If vagal tone is increased, does this slow down gradually or abruptly? -- To answer this question, the carotid sinuses or eyeballs are pressed as a (tentative) diagnostic test (this doesn't always work). If the pressure is released and the pattern resumes abruptly, the pattern is a supraventricular tachycardia. If the pattern resumes gradually, it is a sinus tachycardia.

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