September 16, 2011
Health Care, Medicine
1,021 Comments
This is a piece taken from HealthBeat to share with our readers. At some time in his life, nearly every man gets exercised about sex. And as many men get older, they wonder if sex is a good form of exercise or if it’s too strenuous for the heart.
Treadmill vs. mattress
To evaluate the cardiovascular effects of sexual activity, researchers monitored volunteers while they walked on a treadmill in the lab and during private sexual activity at home. In addition to 13 women, the volunteers included 19 men with an average age of 55. About three-quarters of the men were married, and nearly 70% had some form of cardiovascular disease; 53% were taking beta blockers. Despite their cardiac histories, the men reported exercising about four times a week, and they reported having sexual activity about six times a month on average.
Researchers monitored heart rate and blood pressure during standard treadmill exercise tests and during “usual†sexual activity with a familiar partner at home. All the sex acts concluded with vaginal intercourse and male orgasm. Disappointingly perhaps, the treadmill proved more strenuous. On an intensity scale of 1 to 5, with 5 being the highest, men evaluated treadmill exercise as 4.6 and sex as 2.7. Sex was even less strenuous for women in terms of heart rate, blood pressure, and perceived intensity of exertion.
Sex as exercise
Men seem to spend more energy thinking and talking about sex than on the act itself. During sexual intercourse, a man’s heart rate rarely gets above 130 beats a minute, and his systolic blood pressure nearly always stays under 170. All in all, average sexual activity ranks as mild to moderate in terms of exercise intensity. As for oxygen consumption, it comes in at about 3.5 METS (metabolic equivalents), which is about the same as doing the foxtrot, raking leaves, or playing ping pong. Sex burns about five calories a minute; that’s four more than a man uses watching TV but it’s about the same as walking the course to play golf. If a man can walk up two or three flights of stairs without difficulty, he should be in shape for sex.
Sex as sex
Raking leaves may increase a man’s oxygen consumption, but it probably won’t get his motor running. Sex, of course, is different, and the excitement and stress might well pump out extra adrenaline. Both mental excitement and physical exercise increase adrenaline levels and can trigger heart attacks and arrhythmias, abnormalities of the heart’s pumping rhythm. Can sex do the same? In theory, it can. But in practice, it’s really very uncommon, at least during conventional sex with a familiar partner.
Careful studies show that fewer than one of every 100 heart attacks is related to sexual activity, and for fatal arrhythmias the rate is just one in 200. Put another way, for a healthy 50-year-old man, the risk of having a heart attack in any given hour is about one in a million; sex doubles the risk, but it’s still just two in a million. For men with heart disease, the risk is 10 times higher — but even for them, the chance of suffering a heart attack during sex is just 20 in a million. Those are pretty good odds.
How about Viagra?
Until recently, human biology has provided unintentional (and perhaps unwanted) protection for men with heart disease. That’s because many of the things that cause heart disease, such as smoking, diabetes, high blood pressure, and abnormal cholesterol levels, also cause erectile dysfunction. The common link is atherosclerosis, which can damage arteries in the penis as well as in the heart.
Sildenafil, vardenafil, and tadalafil  have changed that. About 70% of men with erectile dysfunction (ED) respond to the ED pills well enough to enable sexual intercourse. Sex may be safe for most men with heart disease, but are ED pills a safe way to have sex?
For men with stable coronary artery disease and well-controlled hypertension, the answer is yes — with one very, very important qualification. Men who are taking nitrate medications in any form cannot use ED pills. This restriction covers all preparations of nitroglycerin, including long-acting nitrates; nitroglycerin sprays, patches, and pastes; and amyl nitrate. Fortunately, other treatments for erectile function are safe for men with heart disease, even if they are using nitrates.
Safe sex
Sex is a normal part of human life. For all men, whether they have heart disease or not, the best way to keep sex safe is to stay in shape by avoiding tobacco, exercising regularly, eating a good diet, staying lean, and avoiding too much (or too little) alcohol. Needless to say, men should not initiate sexual activity if they are not feeling well, and men who experience possible cardiac symptoms during sex should interrupt the sexual activity at once.
With these simple guidelines and precautions, sex is safe for the heart — but it should be safe for the rest of the body, too. Sexually transmitted diseases pose a greater threat than sexually induced heart problems. When it comes to sex, men should use their brains as well as their hearts.
[Source HealthBeat: Harvard]
September 10, 2011
Health Care, Medicine
556 Comments
• The regimen for the vaccine is three doses at one and six months apart.
• Longer than recommended intervals between doses do not reduce final antibody concentrations, although protection might not be attained until the recommended number of doses has been administered.(1-5)
• A positive immune response to the vaccine is defined as the development of hepatitis B surface antibody (anti-HBs) at a titer of >10 mIU/mL.
• An interruption in the vaccine schedule does not require restarting the entire series of vaccination or adding extra doses.(6,7)
• If the vaccination schedule is interrupted after the first dose, the second dose should be administered as soon as possible.(8)
• The second and third doses should be separated by an interval of at least two months.
• If only the third dose is delayed, it should be administered when convenient.
• Protective anti-HBs titers may be attained in some after only one or two doses of vaccine, completion of the full course (three doses) is recommended to maximize the anti-HBs titer and duration of protection.
• Anti-HBs titers decrease with time but the duration of protection is long (15 -22 years after the primary vaccination schedule).(9-13) Routine booster injections are not required.(14,15)
• Patients with serologic markers of past HBV infection (anti-HBc and anti-HBs positive) do not need HBV vaccination even if they have low titers of anti-HBs.
• Vaccines should be given intramuscularly since deposition of the vaccine into adipose tissue result in a lower seroconversion rate.(16)
• Deltoid is the preferred site in adults for vaccination.
• Longer needles should be used in overweight individuals.
• Hepatitis B vaccine is effective not only in preventing HBV infection but also in preventing the sequelae of chronic HBV infection.
• It is the first example that cancer can be prevented by vaccination.
References
1. Wiström J, Ahlm C, Lundberg S, et al. Booster vaccination with recombinant hepatitis B vaccine four years after priming with one single dose. Vaccine 1999;17:2162.
2. Zechowy R, Rubin LG. Effect of the time interval between the first and second doses of hepatitis B vaccine on the antibody titer achieved after the third dose. Child Hos Q 1997;9:67.
3. Middleman AB, Kozinetz CA, Robertson LM, et al. The effect of late doses on the achievement of seroprotection and antibody titer levels with hepatitis b immunization among adolescents. Pediatrics 2001;107:1065.
4. Halsey NA, Moulton LH, O’Donovan JC, et al. Hepatitis B vaccine administered to children and adolescents at yearly intervals. Pediatrics 1999;103:1243.
5. Heron LG, Chant KG, Jalaludin BB. A novel hepatitis B vaccination regimen for adolescents: two doses 12 months apart. Vaccine 2002;20:3472.
6. Saito K. Introductory remark of Dr. Rokuzo Kobayashi’s achievements. Keio J Med 2002;51 Suppl 2:2.
7. Hepatitis B vaccine: What you need to know. Available at: www.cdc.gov/vaccines/pubs/vis/downloads/vis-hep-b.pdf (Accessed on October 20, 2009).
8. Hoofnagle JH. Toward universal vaccination against hepatitis B virus. N Engl J Med 1989;321:1333.
9. Liao SS, Li RC, Li H, et al. Long-term efficacy of plasma-derived hepatitis B vaccine: a 15-year follow-up study among Chinese children. Vaccine 1999;17:2661.
10. Lin HH, Wang LY, Hu CT, et al. Decline of hepatitis B carrier rate in vaccinated and unvaccinated subjects: sixteen years after newborn vaccination program in Taiwan. J Med Virol 2003;69:471.
11. Yuen MF, Lim WL, Chan AO, et al. 18-year follow-up study of a prospective randomized trial of hepatitis B vaccinations without booster doses in children. Clin Gastroenterol Hepatol 2004;2:941.
12. McMahon BJ, Bruden DL, Petersen KM, et al. Antibody levels and protection after hepatitis B vaccination: results of a 15-year follow-up. Ann Intern Med 2005;142:333.
13. Zanetti AR, Mariano A, Romanò L, et al. Long-term immunogenicity of hepatitis B vaccination and policy for booster: an Italian multicentre study. Lancet 2005; 366:1379.
14. Lu CY, Chiang BL, Chi WK, et al. Waning immunity to plasma-derived hepatitis B vaccine and the need for boosters 15 years after neonatal vaccination. Hepatology 2004;40:1415.
15. Jan CF, Huang KC, Chien YC, et al. Determination of immune memory to hepatitis B vaccination through early booster response in college students. Hepatology 2010;51:1547.
16. Shaw FE Jr, Guess HA, Roets JM, et al. Effect of anatomic injection site, age and smoking on the immune response to hepatitis B vaccination. Vaccine 1989;7:425.
September 9, 2011
Health Care, Medicine, Social Health Community
1,531 Comments
Enterobacteriaceae isolates carrying a novel MBL gene, the New Delhi metallo-beta-lactamase (NDM-1) was first described in December 2009 in India with Klebsiella pneumoniae (1). Later, it was described in patients who had traveled to and undergone procedures in India and Pakistan (2). Cases were also reported in Asia, Europe, and North America (2-4). Isolates have also included E. coli and Enterobacter cloacae (2).
Risk factors
- Recent treatment with carbapenem
- Indwelling urinary or venous catheters
- Severe illness (5)
- NDM-1 can inactivate all beta-lactams except aztreonam.
Salient points
1.   It is an important emerging resistant pathogen (6).
2.    NDM1 isolates are susceptible to colistin or tigecycline
3.   The susceptibility is short-lived.
4.    NDM-1 has been identified in public water supplies in India (7)
References
- Yong D, Toleman MA, Giske CG, et al. Characterization of a new metallo-beta-lactamase gene, bla(NDM-1), and a novel erythromycin esterase gene carried on a unique genetic structure in Klebsiella pneumoniae sequence type 14 from India. Antimicrob Agents Chemother 2009;53:5046.
- Kumarasamy KK, Toleman MA, Walsh TR, et al. Emergence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemiological study. Lancet Infect Dis 2010;10:597.
- Centers for Disease Control and Prevention (CDC). Detection of Enterobacteriaceae isolates carrying metallo-beta-lactamase – United States, 2010. MMWR Morb Mortal Wkly Rep 2010;59:750.
- Sidjabat H, Nimmo GR, Walsh TR, et al. Carbapenem resistance in Klebsiella pneumoniae due to the New Delhi Metallo-β-lactamase. Clin Infect Dis 2011;52:481.
- Deshpande P, Shetty A, Kapadia F, et al. New Delhi metallo 1: have carbapenems met their doom? Clin Infect Dis 2010;51:1222.
- Nordmann P, Poirel L, Toleman MA, Walsh TR. Does broad-spectrum {beta}-lactam resistance due to NDM-1 herald the end of the antibiotic era for treatment of infections caused by Gram-negative bacteria? J Antimicrob Chemother 2011;66:689.
- Walsh TR, Weeks J, Livermore DM, Toleman MA. Dissemination of NDM-1 positive bacteria in the New Delhi environment and its implications for human health: an environmental point prevalence study. Lancet Infect Dis 2011;11:355.