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Tag Archives: sex

Holy Smoke: PiL at the Troc

Johnny Lydon

Johnny Lydon

It looks like Johnny Rotten had to sit down through this one. But give the guy a break, he’s nearly 60 and it’s not like he’s treated his body like the temple that other aging rockers like Keith Richards have.

The new Public Image Limited release “Double Trouble” from their album ‘What the World needs Now’ rages against the unreliability of  appliances and a general distaste for cuddling.

If you’re in Philadelphia, get your tickets to see them at the Troc on November 11, you lucky dogs.

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Hey, I could be wrong…

 
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Posted by on August 26, 2015 in Uncategorized

 

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The Hardest Working Organ of the Body

Like the James Brown of the Body

As I started grading the first Pathophysiology Exam on Cardiovascular Function in Health and Disease, the first material I saw was in answer to my questions about the flow of blood through the heart and to the rest of the body. I can’t say that I was happy with the results, but I want to emphasize that this is very basic material that we discussed and outlined in our class, but that I had also assumed was covered in Anatomy and Physiology last semester. After two passes through this material, it should be easily accessible in every student’s mind.

As a reminder of these functions and the flow of blood, here is Khan Academy’s summary of this material:

I believe that that is important foundational material, and you may have a pop quiz on it at any time.

stay on the scene

 
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Posted by on February 21, 2015 in Uncategorized

 

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Poor Science Communication endangers public health

I have a pretty impressive stack of ‘Science’ and ‘Journal of Immunology’ journals stacked on my study desk. Well, they would be impressive if they were not in the ‘To Be Read’ pile.

I had an opportunity to make some headway into this pile today and started reading the 4 October 2013 issue of Science featuring a number of articles about science communication. So far, everything I’ve read has been good, but I just put down a fantastic article by Dan Kahan entitled “A Risky Communication Environment for Vaccines.”

Several aspects of this article make it one of the best I’ve read in some time.

1. Simple, clear writingImage

2. A clear mission of improving public health by insisting on the scientific community to do a better job of talking about its work with the public

3. A novel, data-supported argument exposing how misinformation among scientists leads to misinformation in the public

4. A level-headed explanation of how key decisions should be made in order to obtain the most desirable results (again, increased public health)

It’s widely recognized that Merck made a severe mistake in the marketing and legislative lobbying done to promote mandatory adoption of its HPV vaccine , Gardasil. However, Kahan goes further to illustrate how a very similar vaccine (against Hepatitis B) was previously introduced without a lobbying effort and resulted in widespread adoption of the vaccine without significant resistance from the public. Kahan writes:

Had the HPV vaccine taken this path, it would have followed the uneventful course that marked introduction of the hepatitis B virus (HBV) vaccine into the U.S. public health system. Hepatitis B, like HPV, is sexually transmitted and causes cancer (6). The CDC endorsed universal childhood HBV vaccination—for boys and girls, a much less jarring proposal—in the 1990s. There was no political controversy. Rather, states steadily added the HBV vaccine to mandatory vaccination schedules through the customary mechanism—not high-profile legislative enactments, but guidelines routinely promulgated by public health administrators operating outside the political realm (7).”

Also check out the Podcast Interview with the author, Dan Kahan at ScienceMag.com.

He then goes on to warn against aggressive promotion of vaccines as this can often backfire psychologically and provide fuel for the fire of an anti-vaccine movement. This is exactly what James Colgrove predicted in his Perspective article in the 2006 New England Journal of Medicine when he warned that, “Moves to make the vaccine compulsory are sure to ignite a new round of polarizing debates.” Yet, he goes on to reiterate the importance of (near) universal vaccination in protecting out most vulnerable:

Laws making vaccination compulsory raise unique ethical and policy issues. High levels of herd immunity protect all members of the community, including those who cannot receive vaccines because of medical contraindications. This protection provides a justification for compulsion. The availability of religious or philosophical exemptions mitigates concern about governmental intrusion on individual decision making. Opinions vary, however, about the permissible scope of exemptions. Data show that schools with exemption rates as low as 2 to 4% are at increased risk for disease outbreaks and that children who have been exempted from vaccine requirements have a much greater risk of acquiring infectious diseases than their vaccinated peers.1 Minors have a right to be protected against vaccine-preventable illness, and society has an interest in safeguarding the welfare of children who may be harmed by the choices of their parents or guardians.”

Luckily, these great articles about scientific communication are freely available on the website links above.

It’s embarrassing that a (admittedly fantastic) comic like Calvin and Hobbes can communicate more in one page that many scientists can over the course of their entire careers. Bill Waterson asks, “Is it sometimes valuable to give up just a little freedom if all society can work better because of it? …”

Ethicshobb

 
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Posted by on November 9, 2013 in Uncategorized

 

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HPV Vaccine Success in Australia

The April 18, 2013 edition of the British Medical Journal contained the results of Australia’s new campaign to vaccinate young women against the Human Papillomavirus (HPV), associated with genital warts and an increased incidence of cervical cancer. This news was brought to my attention by a Slate article by Phil Plait discussing the politics of vaccination and how they get particularly how when the vaccine in question is against a STD. I suggest you read that article if you have any interest in exploring that hot-button topic and how it goes head-to-head-against an abstinence-only policy.

Although those questions intrigue me, I simply want to point out the data behind HPV and how the new vaccines are dramatically effective. First, I think it’s important to examine just who has HPV.

ImageAccording to the CDC’s report on HPV, approximately 79,000,000+ people in the USA have HPV. That’s a pretty high number given that the Jul 2011 US census reported that the US population is only 311,591,917 – and about 70 million of those people are under 17, the average age the Kinsey Institute reports that kids lose their virginity. Let’s call it half of Americans who have had sex, also have HPV – this estimate agrees with the CDC’s data on HPV.

ImageThere are a number of different HPV viruses and some of them are more dangerous than others. Of the ~40 strains of HPV, two of them (6 and 11) are responsible for most genital warts, but are not associated with cancer, whereas two different strains (16 and 18) are linked to the majority of cervical cancer cases. Gardasil, a quadrivalent vaccine made by Merck, protects against all four of these strains, while Cervarix is a bivalent vaccine made by GlaxoSmithKline and protects against strains 16 and 18.

In 2007, Australia began offering free vaccinations against HPV for girls 12-13 years old. Fortunately, the vaccine being offered was the Merck vaccine, so the efficacy of the vaccine could be readily tracked by using genital warts as an indicator rather than having to wait to measure cervical cancer rates at a much later time point. The caveat is that this trial assumes that the reduction in genital warts accurately models an expected reduction in cervical cancer, despite the two conditions resulting from different strains of the virus. I’m comfortable with this assumption, but I do think that caveat needs to be kept in mind.

So, what are the results? It’s been five years. According to estimates from the US population, these girls should be starting to have sex now. Are they getting genital warts?

“In the vaccination period, the proportion declined dramatically by 92.6%, to 0.85% in 2011”

Image Further, not only are fewer vaccinated girls developing genital warts, but it looks like the vaccination campaign in also benefiting unvaccinated girls as well (although this is an assumption about causality on my part). 

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Remember, not ALL genital warts are caused by the four strains in the vaccine – and, these vaccines will only work on people who have not caught HPV already.

   Altogether, this looks to be a whoppingly successful campaign – one that the US should strongly consider mimicking.

 

 

 

 
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Posted by on May 3, 2013 in Uncategorized

 

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Why Sex is Fun, Chapter 2

Chapter 2 is lowering my expectations of this book. It remains somewhat interesting and well researched, but for a book titled ‘ Why Sex is Fun’, an extended discussion of why males of most species abandon their sex partners to raise their young alone is not exactly what I was hoping for.

I wasn’t expecting penthouse forum, but I guess I was expecting some discussion of why sex is fun.

Nevertheless, I will certainly continue reading and reporting on my progress here.

As I said above, chapter 2 parses the involvement of each parent in the rearing of offspring and finds (unsurprisingly) that this directly correlates with two things:

  1. Certainty of paternity
  2. Energy investment in making each offspring vs the ability of this offspring to survive in the absence of care.
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Paternity Testing

Together, these considerations account for why males of many (but not all) species tend to be dead-beats. Given the low cost of sperm production and the ability to reproduce with a number of females concurrently, coupled with the lack of assurance that any given child is the male’s own, it pays to remain uninvolved in raising any one specific (potential) offspring.

Several exceptions to the rule are presented and a few good considerations that must be made to actually weigh against the low cost of sperm – just because it’s cheap to make one doesn’t mean one is enough. And sometimes women aren’t that eager to have sex with you just because you have sperm. – Amazing!

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Male penguins incubating eggs while mom is away

 

 
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Posted by on January 29, 2013 in Uncategorized

 

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Why is sex fun? Chapter 1

whyfun I’ve decided to start a sort of online book discussion as a way of reflecting on a book that I just picked up and will be reading this spring semester. In the two classes I teach, I am reading Neil Shubbin’s ‘Your Inner Fish’ (General Biology) and Paul Offit’s ‘Vaccinated’ (Microbiology). I’m sure that I will discuss these from time to time here, but there is another book that I just got in the mail yesterday that I’ve been meaning to read for some time, Jared Diamond’s ‘Why Sex is Fun’. This author may be familiar to you for some of his other works including ‘Guns, Germs and Steel’ which I have to get onto my reading list as well. But for now, I’ll go with what I have.

Please feel free to enter into the conversation at any time; I would love to hear your thoughts. Also, I should say that my approach will probably be just to cherry-pick ideas from each chapter for discussion, but don’t let that restrict your comments.

The Animal with the weirdest sex life…

Diamond’s book starts out reminding us just how unique our (human) sex lives are from other species on the planet. He highlights our desire for privacy, couple pairing, having sex when it is improbable or impossible to reproduce, etc. The question he poses is ‘Why did we evolve to be so different?’

One of the first things I noticed was the way he highlighted how females of many other species “solicit sex only during those fertile days, are sexually unattractive or less attractive to males on other days because they lack the arousing signals.”

This quote made me immediately think of an article I read about several years ago that points in the other direction, illustrating how humans are not exempt from their baser animal instincts. This article suggested that humans too had pheromonal or other cues that made women more ‘attractive’ to men during the ovulating stage of their menstrual cycle. The way this was tested was by analyzing the tips received by female strippers during different times in their cycle. The data were published in Evolution and Human Behavior Volume 28, Issue 6 , Pages 375-381, November 2007.

Here’s the breakdown:

$335 per shift while ovulating

$260 per shift during the luteal phase after ovulation

$185 per shift while menstruating

(by the way, these were five hour shifts )

One other idea I wanted to touch on briefly was the discussion of menopause. This is indeed fairly unique to humans, however it is difficult to assess whether this is an adaptive response to anything or if it just happens without any direct rationale and has only become apparent in recent human history because of increasingly long lifespans. A recent article about whales might point to Diamond having something here though. It turns out that these are only three (?) species known to go through menopause. These are humans and two species of whales, including the killer whales. Last year, a fantastic study came out showing the importance of post-menopausal females in pods of these whales as evidenced by longer lifespans of male whales with surviving mothers. I encourage you to check out this article here.

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(ps – this was also to see if legitimately having ‘sex’ as a keyword would have a noticeable effect on my blog stats)

 
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Posted by on January 10, 2013 in Uncategorized

 

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HHMI site

I just completed a survey on the HHMI website that introduced me to some of their resources that I have not yet explored. One that I thought was relevant to our current work is on chromosomes, genes and sex determination. It can be found here.

 

Follow this link to the BioInteractive Animation Page where you can find the animations of DNA Replication, Transcription and Translation (among others) that we watched and discussed in class.

 
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Posted by on November 28, 2012 in Uncategorized

 

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Making Better Babies – A pragmatic solution to a problem and the ethical firestorm it provokes

Let’s say you are a young person thinking about having a baby, but you know there is a genetic disease in your family that worries you. It’s a reasonable concern that people have recognized for some time. There have always been diseases to concern parents, but technology is changing how we think about and face these concerns.

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A Downs Syndrome Karyotype

Once upon a time these was little more to do but cross your fingers and hope for a good result. Then chromosomal testing (Karyotyping) of a developing fetus became possible allowing parents to know what is happening inside the womb. Getting this information was not without risk, and even with the results in hand, would-be parents are faced with terrible choices. The way we dealt with this test in our family was to not have it done. We really wanted a baby and thought that  that having test results would not change our behavior. So we chose not to be put in a position of having to make that choice. It was what worked for us, but we also didn’t have specific concerns other than the fact that we were getting older.

Following the advent of chromosomal tests, it became possible to test the DNA of a fetus for specific, known problems. For example, If caner runs in the family, you could check to see if the baby’s p53 gene was normal. Having one or more bad copy of this gene dramatically raises the probability of developing cancer relatively early in life. Today, this is something we can know for certain.

But there are several sources of DNA in us. We typically think of the vast amount of DNA carried in the form of linear chromosomes that are packaged inside the nucleus of our cells. This is definitely the lion’s share of the DNA passed from one generation to the next, but there is another source as well: The Mitochondria. You may have learned about these organelles (little organs) as the ‘Powerhouse of the Cell’ for its role in generating much of the energy (ATP) your cells need to do their jobs. These organelles have a strange history in us. It is thought that many eons ago those things that are now mitochondria inside our cells were once free living organisms (possibly parasites, possibly a bigger cell’s dinner). However it happened these microbes were taken inside of our cells, but not digested as food or harmful enough to kill the host either.

Powerhouse

Why am I talking about this? Because those organelles still carry remnants of their former selves. They still have their own protein-making machinery and even their own DNA. This DNA isn’t large, but it does carry genes coding for vital proteins. And this is how we get back to our original story, because sometimes these mitochondrial genes are no good. If these genes aren’t right, they can’t make healthy, functional proteins. If they can’t make good proteins, then the host cell and the while organism can die.

Interestingly, all the mitochondria in every cell of your body came from your mother. This is one place where dad makes no contribution. Even though sperm have mitochondria, they don’t get incorporated into the new zygote, only those from the egg will remain.

Enter The Future of Fertility Medicine

Recent developments have shown that it is possible to replace the unhealthy mitochondria with healthy versions from a donor cell to make good eggs that can be fertilized and result in a healthy child. This was the subject of an excellent review in Nature and also discussed on the Nature Podcast this week. So how many parents is that? One mom, one dad and one mitochondria donor (I guess this could conceivably come from dad, but I just don’t know). This procedure has been done successfully with non-human primates, but so far not with humans.

So, pursuing a simple line of work aimed at helping parents make healthy babies is suddenly possible and suddenly a great ethical question. Have you ever seen Gattaca? If not, go out and watch it. I was sure this film was going to be miserable and be a poor representation of science, but I was totally wrong. They ask the same questions in that film that we are beginning to face in real life:

This isn’t the first time people have thought about this

When does Medicine become tampering with life? And does it matter? Don’t we want healthier, more able bodied people? Is it wrong to replace bad genes? What constitutes ‘bad’?

Personally, I don’t believe that there are universally right and wrong answers to these questions. Even if we decide that there are some less desirable consequences for mankind, that doesn’t mean that we wouldn’t do it. Much of plastic surgery isn’t really necessary and some might call it a perversion of medicine, but that doesn’t stop tons of people from getting it.

 
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Posted by on October 24, 2012 in Uncategorized

 

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An overview of Cell Cycling in Humans

Consider Leonardo here, who is going to be making sperm cells via meiosis. In this figure we’re tracking n number, chromosome number and c number with every division. Note that because we are following human cells – the n number always remains 23. However, the ‘ploidy’ will change between haploid(n) and diploid(2n) and c number will change between 1,2 or 4 depending on ploidy and whether the chromosomes have one or two chromatids.

Once sex cells(sperm) are formed, we see the combination of sperm and egg during fertilization to form a zygote which restores the diploid condition. Then this cell goes into cycle many times over going through mitosis again and again as the organism grown from zygote into a full grown person.

 
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Posted by on October 11, 2012 in Uncategorized

 

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