Smokers take note! A new study suggests that people who smoke marijuana for a long time have an increased risk of gum diseases that can lead to tooth loss.

In the study, tobacco users were found to have gum disease as well as reduced lung function, systemic inflammation and indicators of poorer metabolic health.

The study tracked nearly 1,000 New Zealanders from birth to age 38.

"We can see the physical health effects of tobacco smoking in this study, but we don't see similar effects for cannabis smoking," said Madeline Meier, Assistant Professor of Psychology at Arizona State University in the US.

The international research team assessed a dozen measures of physical health, including lung function, systemic inflammation and several measures of metabolic syndrome, including waist circumference, HDL cholesterol (good cholesterol), triglycerides, blood pressure, glucose control and body mass index.

To measure cannabis use, the researchers asked study participants to self-report their use at ages 18, 21, 26, 32 and 38.

However, the study did not find a link between long-term marijuana use and several other health problems associated with cigarette smoking.

"We need to recognise that heavy recreational cannabis use does have some adverse consequences, but overall damage to physical health is not apparent in this study," study co-author Avshalom Caspi, Professor at Duke University in Durham, said.

"Physicians should certainly explain to their patients that long-term marijuana use can put them at risk for losing some teeth," Terrie Moffitt, who is also from Duke University said.

The findings were published in the journal JAMA Psychiatry.

A pinch of poison is good for a body, at least if it is heme, and researchers, including one of Indian-origin, have now found how the body turns this toxin into a nutrient know for its role at the core of hemoglobin, the component of red blood cells responsible for transporting oxygen.

In minuscule amounts, heme works in cells as an essential catalyst called a cofactor and as a signaling molecule to trigger other processes.

"Poor heme management can cause things like Alzheimer's, heart disease, and some types of cancers, so cells have to do a good job of managing how much heme is available," said Amit Reddi, Assistant Professor at Georgia Institute of Technology in the US.

The labile heme serves as a nutrient instead of a poison. But to make sure things stay that way, heme needs to be carefully trafficked through the cell, Reddi said.

"By having biosensors that can monitor heme in cells, we have this new window into how cells make this essential toxin available in carefully sparse concentrations," he said.

The researchers used ratiometric sensor to illuminate heme's movements.

People may recognise heme from its role at the core of hemoglobin, the component of red blood cells responsible for transporting oxygen.

The ionic iron in the heme molecule is what the oxygen molecule sticks to.

In hemoglobin, the heme is embedded tightly in protein, rendering it non-toxic.

For the research, published in the journal Proceedings of the National Academy of Sciences. the team designed a fluorescent sensor molecule to keep tabs on how hem is carefully trafficked through the cell

With heme at very low baseline levels, the sensor lit up bright green and as heme concentration increased, it caused the light to fade out.

Using the heme sensors, the researchers found an enzyme, GAPDH, known for its involvement in breaking down sugar, got tied up in proteins, leaving only a limited amount free for biochemical reactions.

When more labile heme is needed, nitric oxide, a signaling molecule, rapidly released heme from entangling proteins, so it could do jobs such as regulating gene expression.

"Ratiometric fluorescent techniques have been around for a while, but our technique is new, because it specifically senses heme," Reddi said.

"We took a heme binding protein from bacteria and clipped it onto to green fluorescent protein," he explained.

In a finding that could lead to new drugs to treat cancer and autoimmune diseases, researchers, including one of Indian-origin, have discovered a new way of triggering cell death.

Programmed cell death, also called apoptosis, is a natural process that removes unwanted cells from the body. Failure of apoptosis can allow cancer cells to grow unchecked or immune cells to inappropriately attack the body.

The protein known as Bak is central to apoptosis. In healthy cells Bak sits in an inert state but when a cell receives a signal to die, Bak transforms into a killer protein that destroys the cell.

In this study, researcher Sweta Iyer from the Walter and Eliza Hall Institute of Medical Research, Victoria, and colleagues discovered a novel way of directly activating Bak to trigger cell death.

The researchers discovered that an antibody they had produced to study Bak actually bound to the Bak protein and triggered its activation.

"We were excited when we realised we had found an entirely new way of activating Bak," said Ruth Kluck who is also from Walter and Eliza Hall Institute of Medical Research in Australia.

The researchers hope to use this discovery to develop drugs that promote cell death.

"There is great interest in developing drugs that trigger Bak activation to treat diseases such as cancer where apoptosis has gone awry," she said.

"This discovery gives us a new starting point for developing therapies that directly activate Bak and cause cell death," Kluck pointed out.

The researchers used information about Bak's three-dimensional structure to find out precisely how the antibody activated Bak.

The study was published in the journal Nature Communications.

"The advantage of our antibody is that it can't be 'mopped up' and neutralised by pro-survival proteins in the cell, potentially reducing the chance of drug resistance occurring," Kluck said.

Nearly half of all heart attacks may not have classic symptoms, such as chest pain, shortness of breath and cold sweats but are likely to be silent, reveals new research.

A silent heart attack occurs when blood flow to the heart muscle is severely reduced or cut off completely.

"The outcome of a silent heart attack is as bad as a heart attack that is recognised while it is happening," said Elsayed Z. Soliman, director of the epidemiological cardiology research centre at Wake Forest Baptist Medical Centre, in the US.

The findings showed that silent heart attacks are made up 45 percent of all heart attacks.

Also, these are more commonly found in men but are more likely to cause death in women.

Further, the risk of dying from heart disease increases by three times in case of a silent heart attack.

The chance of dying from all other causes rises by 34 percent.

Silent heart attacks are usually detected when patients undergo an electrocardiogram (ECG) -- a process to check heart's electrical activity.

"Doctors need to help patients who have had a silent heart attack quit smoking, reduce their weight, control cholesterol and blood pressure and get more exercise," the researchers noted in the paper published in the journal Circulation.

For the study, the team analysed the records of 9,498 middle-age adults.

For over an average of nine years after the start of the study, 317 participants had silent heart attacks while 386 had heart attacks with clinical symptoms.

Shedding the extra kilos is difficult and keeping it off over years is even harder, but a team of researchers has found one group that has defied the trend of regaining weight.

The research from the University of Colorado Anschutz Medical Campus demonstrated the effectiveness of long-term participation in a national weight-loss program.

The investigators followed over 65,000 overweight or obese people who joined Take Off Pounds Sensibly (TOPS) between 2005 to 2010. In the first year, half of participants in the nonprofit weight-loss support group had significant weight loss.

Of the patients with significant weight loss in the first year who participated in a second year, 80 percent kept off the weight. Each year, during years three to seven, roughly 90 percent of patients who continued participation in the program maintained their weight loss.

The researchers concluded that after one year of significant weight loss, consistent participation in the program helped participants sustain their new healthy weight.

"Maintaining long-term weight loss is a critical challenge in treating obesity and related health problems such as diabetes, high blood pressure and heart disease," said lead author Nia S. Mitchell, adding "Just losing the weight isn't enough. Since the health benefits of weight loss disappear when weight creeps back on, we need more research into effective strategies for maintaining a healthier weight once it is reached."

Mitchell concluded that further studies of the TOPS program should examine which populations will succeed at weight loss and weight-loss maintenance and determine factors that can improve sustainable weight loss and maintenance.