Posts Tagged ‘testicle’

Newer Entries »

Weighing Your Options

Sunday, January 10th, 2010
Bacchus is no longer a role model...

Bacchus is no longer a role model...

What you weigh affects how your sperm play. And your fertility. Overweight men tend to have lower semen volumes, less sperm and more oddly shaped sperm. The same is also true for men who are too thin. So, along with the many other health hazards associated with obesity, add poor semen quality to the list.

Obesity in both sexes is known to be associated with heart disease, diabetes, hypertension, and metabolic syndrome among other nasty conditions that can shorten your life. Typically, obesity is measured with BMI or body mass index, which looks at weight in relation to height. Not a perfect measure, but reasonably accurate. Using this tool, the ideal BMI for men (and women) is considered to be 20-25. A Danish study of 1600 men showed that overweight men with a BMI > 25 had a 22% lower sperm concentration compared with healthy weight men. Interestingly, a BMI of <20 was also associated with poor semen quality. For optimal sperm production, then, it helps to be not too fat and not too thin.

But what about fertility? Is it also affected by obesity? Yup. Another recent study showed that for every 20-pound increase in a man’s weight, there is a 10% increase in the chance of infertility. And this remained true when other factors that might influence the results were accounted for, including obesity status of the women, the man’s age, cigarette smoking, alcohol intake, and solvent and pesticide exposure. In addition, obesity was associated with infertility in both older and younger men.

So what is it about weight that influences men’s sperm production and fertility? One theory is that sex hormone metabolism is altered by changes in weight. Sex hormones are the “fuel” for the engine (testis) to make sperm. Obesity increases fat stores and fat converts male hormones (testosterone) into female hormones (estrogens). Too much estrogen in men is bad for sperm production. Another theory posits that normal 2-degree difference in testis temperature relative to the body is lost with obesity, as excessive fat provides too much insulation and results in overheating. On the other hand, when a man is too thin, he may take on a “catabolic” metabolic state. With a body in “starvation mode,” fertility is not the first thing on its mind and sperm production and fertility suffer.

So, is the epidemic of obesity the reason why sperm counts have been falling in Western countries over the last 50 years? Maybe. But this problem is unique in that it is utterly and entirely preventable. Eat well and in moderation, sleep well and treat your body like a temple. You used to it for your own health; now do it for the health of your future family.

Tags: , , , , , , , , , , , , ,
Posted in male infertility, men's health, sexual health | 2 Comments »

Keeping the Family Jewels Shining

Saturday, January 2nd, 2010
Heirlooms for the species.

Heirlooms for the species.

As a living, breathing being on this good earth, we tend to take things for granted. The ability to have offspring can be one of them. That is, until the day that a serious medical condition like cancer rears it ugly head and puts childbearing at risk. In addition to the sterilizing effect of cancer treatments, the mad rush to treat the disease often marginalizes efforts to preserve fertility. Fire all the canons and check for collateral damage later.

Fertility preservation seeks to protect men, adolescents and children from a common, serious and impactful side effect of cancer treatment: infertility. The goal of fertility restoration is to empower patients who are cured and potentially infertile to bear children. These related fields have burgeoned recently because medical care is now shifting from curing cancer to improving the quality of life among survivors. And without a doubt, for many, fertility is a key quality of life issue at some point. Thankfully, exciting new methods of restoring fertility have already been developed and even newer technologies are under study.

Classic techniques for fertility preservation in men include gonadal shielding and sperm banking. Gonadal shielding uses lead-based devices to protect the testicles from being struck directly by sterilizing radiation treatment. Sperm banking is the process of freezing healthy sperm before cancer treatment begins for later use to conceive. But there is more. For patients who are too young to bank sperm, for those who have precious little time to bank sperm, or for those who have no ejaculated sperm to bank, testis sperm retrieval by biopsy (TESE) or needle aspiration (TESA) for banking is now possible before cancer treatment. In fact, in some cases of testis cancer, it is possible to remove only the cancerous nodule instead of the whole testis, or to freeze sperm from the testicle after it is surgically removed. These are now routine ways to preserve fertility in men.

Fertility restoration for men has also seen real advances lately. Sperm “mapping” is an innovation that I developed for men who survive cancer treatment but have no sperm in the ejaculate. It non-invasively and non-surgically deciphers whether there are small numbers of mature sperm in the testis, too few to get into the ejaculate, but usable nonetheless. In men who sustain nerve injury from cancer surgery and who are unable to ejaculate, a special medical instrument can produce an ejaculate for fertility purposes in a process termed electroejaculation. Techniques such as these are valuable tools to help men deemed “sterile” after cancer treatment to become fathers.

One of the most exciting areas of fertility restoration involves stem cell technology. Yes, the “promise” that we have all heard about stem cells curing disease will likely find its way into the fertility field as well. In pre-pubertal boys with cancer, ejaculated sperm is not present. Despite this, it may be possible to freeze the early stem cells from the testicles of boys before sterilizing treatment. After thawing, these “adult” stem cells may later be used to create sperm after further growth in a Petri dish or after transplantation back into the same individual. Also on the horizon is our ability to take skin cells from a sterile man, convert them into an embryonic-like stem cells and then “drive” these cells to become mature sperm in a dish–a true “artificial testicle.” So, with the belief that hope can cure misery, the world of science has taken fertility research from science fiction to reality. Not convinced? Stay tuned!

Tags: , , , , , , , , , , , , , , , , ,
Posted in male infertility, men's health, testis cancer | 4 Comments »

A Short History of the Y Chromosome

Tuesday, September 22nd, 2009
The Y chromosome: diminutive but cool.

The Y chromosome: diminutive but cool.

Among the many chromosomes in a man’s body, the smallest one with the largest personality has to be the Y chromosome. With it, you are a male; without it, you are a female, with few exceptions. More than any other chromosome, it really defines who you are.

The Y chromosome controls other traits as well: hairy ears, tooth enamel, and stature to name a few. But for the longest time, the Y chromosome was also considered home to a lot of “junk DNA” that we thought had no purpose. We now know that much of this DNA has a purpose and that the Y is the home of many important male fertility genes.

Before its association with male fertility, the Y chromosome was widely considered a genetic black hole, a chromosome that evolved as a broken remnant of the X chromosome. We knew that the “maleness” gene was on the Y and a few other genes. However, since the Y chromosome has been fully undressed as a result of the human genome project, we now know that it is very unique, even special, and that it evolves in its own special way to keep men men.

The Y chromosome, and its neighbor the X chromosome, evolved into “sex” chromosomes hundreds of millions of years ago. This is important because many species do not have a chromosome for each sex like we do. Some species become male or female based simply on the environment in which they find themselves. Imagine that! A boy in the Artic but a girl in the Caribbean. At first, the original sex chromosomes probably evolved as a pair of two X chromosomes. Then, 150 million years ago, the Y chromosome made its break from the X chromosome. Basically, it stopped associating with it and this led to our current X-Y system of sex determination. I guess this is when men really became men.

As it works now, the single Y chromosome has no partner with which to swap genes when sperm are made (at a normal rate of 1200 sperm/heartbeat!) This “swap meet” of genes that occurs when new sperm are formed is an important repair process for the 22 other chromosomes and is absolutely critical for our evolution as a species. In fact, this is the source of our evolution. So, now that the Y chromosome has become isolated and less of a team player, is it doomed to extinction? More importantly, are men are doomed to extinction?  

So how does the Y chromosome survive and repair itself, living alone in isolation while the world is changing around it? Well, we now know that it manages very well on its own, thank you. And this has probably been true for about 5 million years. Although it no longer swaps genes with the X chromosome, from which it came, the human Y chromosome is able to swap genes with itself to discard bad genes. It’s called gene conversion and no other chromosome does it. Just the Y. How uniquely male.

Basically, essential Y chromosome genes are arranged in a series of eight “palindromes,” or mirror image sequences, each of which folds like a hairpin in which its two arms come together. Then the “DNA checkers” compare the two arms for any differences and convert a mutation back to the correct sequence, thus saving the Y’s genes from mutational decay. So, the older “junk DNA” thought to exist on the Y chromosome is now known to represent DNA that it critical for its survival. One man’s junk is another man’s treasure. And so it goes, the Y lives on, and men do too.

Tags: , , , , , , , , ,
Posted in Uncategorized | 6 Comments »

The Ailing Male Pill

Thursday, August 6th, 2009
What shape will the male pill take?

What shape will the male pill take?

A male birth control pill certainly sounds like a good idea. But after 25 years and millions of dollars of research, there’s still no pill. We put a man on the moon faster than we’ve invented a male pill.

The question isn’t really whether it can be done, because it can. The production of sperm is linked to testosterone levels in the body. When testosterone levels are too high, the body stops producing sperm. Witness the testis shrinking (atrophy) that occurs with anabolic steroid use. Such pills have been tested, and are successful. One problem, though, is that the ability of hormone-based male pills to work perfectly (which they really need to do) varies with a man’s ethnicity. Works for some, but not all. This issue alone may prove fatal for the male hormone pill.

Besides this, there is a litany of concerns regarding the physical side effects of a hormone-based male pill. Immediate concerns have been a big issue in past trials- adult acne, weight gain, moodiness and the like. But what about possible long term effects? The female contraceptive pill has been linked with higher rates of heart disease and breast and liver cancer in women. Although not completely comforting, at least we know these issues in women. But little to no research has addressed similar issues with long term “pill” use in men.

Despite all of this, there is still a healthy interest in a male birth control pill. Studies have shown that men in committed relationships are more interested than single men in a pill– no surprise here. Single men are interested in using condoms for the added bonus of protection against STDs. A male birth control pill might also be a better contraceptive alternative for men who want more control over family planning than that offered by vasectomy. That said, there is still the eternal question of whether or not a pill would sell successfully– would women, in the end, trust their partners to be consistent and compliant in taking the pill? The answer to this question varies from couple to couple, but to get a sense of things, ask yourself how often you fail to take something as simple and uneventful as a daily multivitamin to get an idea of the magnitude of this problem.

There simply aren’t enough options for male contraception on the market today. The main ones are abstinence, rhythm method, withdrawal, condoms, and vasectomy. Given this lineup, there is certainly room for more, and more reliable, contraceptives for men. One thing seems reasonable clear: given the safety and effectiveness of vasectomy, and fact that daily compliance is not needed to keep it effective, anything new has to be this good or better. How about a truly reversible vasectomy? Or a long term, implantable hormonal device? In the end, these are likely to become tasty alternatives to a male pill.

Tags: , , , , , , , , ,
Posted in men's health | 1 Comment »

Infertility: Window into Men’s Minds

Monday, July 13th, 2009

It's true...it hurts to be infertile. Like any other disease.

It's true...it hurts to be infertile. Like any other disease.

Recently, sitting face to face with an infertile patient, I asked him what the first thing was that came to his mind after being told that he had no sperm count. After a short silence in which his eyes gazed downward and then back again toward me, he stated, quietly “I thought it might be the end of my family lineage.”

Facing a diagnosis of infertility is one of the loneliest experiences a man can have, as evidenced by a study I recently co-authored with Drs. James Smith and Patty Katz at UCSF. Published in The Journal of Sexual Medicine this week, it found that men with a diagnosis of male infertility suffer intense negative sexual, personal and social strains that might be considered typical for other medical illnesses, including cancer. It affects not only their self esteem, but their sexual confidence and sexual function. Think about it. Men find the inability to sire children a real and palpable blow to their manhood and self-identity. The impact of this diagnosis is easily comparable to the mortal challenge associated with a cancer diagnosis. Infertility causes an immense strain to their relationships both with their partners and socially. Adding to the strain, this diagnosis is as taboo as syphilis or AIDS. The ramifications for the rest of his life are significant, especially if his lifelong assumption was that having kids is normal, expected, eventually, would not be a problem. Infertility is often one big secret that is kept from the rest of the world, making the patient, and his partner, feel isolated and desperate.

I have seen this distress in my practice, day in and day out, for years. Finally, through this study, some proof has surfaced that male infertility is one of the toughest challenges a man can face in life. The funny thing is, male infertility is not as uncommon as one might think. It affects 10% to 15% of reproductive aged couples worldwide. About half as common as diabetes. But far more silent a disease than diabetes. The bright side is that it is treatable in many cases.

So what should men do if they have a diagnosis of infertility? First, get information so that you can make decisions and get control of the situation. You need to “own” it, and this is a great start. Learn through websites such as ASRM.org and SSMR.org, or TheTurekClinic.com and see a urologist or specialist. Also, talk openly with your partner and people you trust, and get the support that you need. Decide with your partner who needs to know about this and who doesn’t. Keep the lines of communication open with your partner, as this can be the most significant threat your relationship will ever see. Keep doing the things that you do best, as these are not likely the cause of infertility and can keep the balance in your life. Importantly, take time to “blow off” stress through exercise, sports, yoga, massage or whatever works for you. Maintain that critical balance as you tackle this issue like you have tackled others, and as you will tackle future issues.

Tags: , , , , , ,
Posted in male infertility | No Comments »

No Men. Just Sperm.

Thursday, July 9th, 2009

Does this look like a real sperm? Do you believe in UFO's?

Does this look like a real sperm? Do you believe in UFO's?

We saw it coming. We created stem cells from testis tissue and published it earlier this year and I mentioned previously that it should be possible to do the opposite and create sperm from stem cells. Well, as announced yesterday from a research group in Britain, that possibility is closer to becoming a reality. Sperm created in a Petri dish. Artificial sperm.

Published yesterday in the journal Stem Cells and Development, this is being hailed by the press as “breakthrough” research. Now call me cautious, or call me a stem cell biologist, but I get suspicious when that term is used to describe medical research. More on that later. The technique, discovered by a team of biologists at the University of Newcastle in England and led by Dr. Karim Nayernia, purports to have created actual moving sperm from human embryonic stem cells. Not in a testicle, but in a laboratory dish. This group has some amount of “street cred” as they had previously published a paper in which mouse embryonic stem cells were used to produce in a dish. In fact, these sperm were injected into mouse eggs, formed mouse embryos and baby mice. However, a close look at the small print reveals the mouse pups all had “growth abnormalities” and died after birth.

Now back to being Mr. Cautious. If you look closely at the figures and video in the human paper, you might not be convinced that these are actual sperm. Pictures are a little too fuzzy. Kind of UFO-like. Could they really be neurons instead of sperm? Also, the sperm neither look nor move quite like what we would expect with normal sperm. Finally, some of the “reporter” genes that are used to classify the genetic origin of the cells are not working all that perfectly. Why didn’t the researchers provide more convincing evidence of the universally recognized elements of a sperm including the acrosome, midpiece with mitochondria and characteristic axonemal structure? Oh, and where are the controls?

There is no doubt that Dr Nayernia will face scrutiny for this work, as he has before. And this is all good. Because if the scientific world believes that it is true, then this is an amazing feat of science with enormous potential. For such acceptance to occur, a confirmatory study by another group will likely be necessary. Maybe ours, as we are investigating the same concept but in a radically different and much more feasible way—by trying to create an entire artificial testicle instead.

There are other meaty issues surrounding this research. Is it safe? Is it practical? Remember how inefficient it was to clone Dolly the lamb? Inefficiency runs rampant in any reproductive process. As an example, say that you discovered that humans can reproduce through sex and tried to license the process. With a 20% efficiency rate, you would probably be denied the license. On the other hand, if it is really true, this work has demonstrated the enormous potential of embryonic stem cells, as making a sperm is about as complex a process of cellular transformation that you will find in the body. Making bone, cartilage or heart cells should be much easier. Will it ever get to the point in which a healthy child might be conceived in this way? If that happens, then I might start thinking more about the real role of man in mankind. But not sooner. After all, if men become redundant in the reproductive process, who will replace men’s uncanny knack for opening jars?

Tags: , , , , , , , ,
Posted in male infertility | 24 Comments »

Newer Entries »