Study confirms Parkinson's-pesticides link

NEW YORK (Reuters Health) — Results of a family-based, "case-control" study support a relationship between exposure to pesticides and the development of Parkinson's disease (PD).

Prior studies have shown that people with Parkinson's disease are over twice as likely to report being exposed to pesticides as people without the disease, but few studies have looked at this association in people from the same family or have assessed associations between specific classes of pesticides and Parkinson's disease.

In their study of 319 Parkinson's patients and more than 200 unaffected relatives, Dr. Dana Hancock from Duke University, Durham, North Carolina and colleagues found that the Parkinson's patients were 61 percent more likely to report direct pesticide application than were healthy relatives.

Both insecticides and herbicides — most notably organochlorines, organophosphorus compounds, chlorophenoxy acids/esters, and botanicals — significantly increased the risk of Parkinson's disease, the researchers report in the online journal BioMedCentral (BMC) Neurology.

"Further investigation of these specific pesticides and others may lead to identification of pertinent biological pathways influencing Parkinson's disease development," the investigators suggest.

It's also worth noting, they say, that "the strongest associations between Parkinson's disease and pesticides were obtained in families with no history of Parkinson's.

"This finding suggests that sporadic Parkinson's cases may be particularly vulnerable to the toxic effects of pesticides, but the possibility of pesticides influencing risk of Parkinson's in individuals from families with a history of PD cannot be ruled out."

Bone biopsy can help treat diabetic foot infection

NEW YORK (Reuters Health) — A biopsy of the bone can help doctors determine what antibiotic is the best to use in treating diabetic patients with serious foot infections, according to findings published in the journal Diabetes Care. This approach may help patients avoid surgery.

Due to circulation problems and decreased nerve sensation, diabetics are at increased risk for foot injuries that can go unnoticed. What may start as a simple blister can soon spiral into a serious skin infection, including one that extends down to the bone, referred to as osteomyelitis.

"The question of surgical versus nonsurgical treatment for diabetic patients with osteomyelitis of the foot remains subject to debate," Dr. Eric Senneville, of Dron Hospital, Tourcoing, France, and colleagues write. It has usually been though that these infections could not be successfully treated without removing a portion of the infected bone.

In the present study, the authors reviewed the medical records of 50 diabetic patients who were treated without surgery for osteomyelitis of various foot bones at 9 French diabetic foot centres. Among the various research questions addressed was whether a bone biopsy was better than a simple skin swab to determine the best antibiotic to combat the infection.

On average, the study subjects were 62 years old and had been diabetic for about 16 years. The average wound duration was 20 weeks, and the average duration of antibiotic treatment was 11.5 weeks. Overall, 22 patients (44 percent) underwent bone biopsy-based therapy, and 28 (56 percent) had swab-based therapy.

Success was defined as the absence of any sign of infection at the initial or a contiguous site at least one year after the end of treatment.

After an average follow-up of 12.8 months, success was achieved in 18 (81.8 percent) patients treated on the basis of bone culture results and in 14 (50 percent) of patients with swab-based therapy, the researchers report.

"Our results provide arguments for recommending the use of bone biopsy in diabetic patients treated nonsurgically for osteomyelitis of the foot," the team concludes.

Kidney cancer may be linked to multiple myeloma

NEW YORK (Reuters Health) — For the first time, researchers have evidence of an association between renal cell carcinoma and multiple myeloma, a type of blood cancer, one that "cannot be explained by random incidence alone," they say.

"I think general oncologists as well as myeloma and renal cancer physicians should be aware of this association," Dr. Mohamad A. Hussein of the H. Lee Moffitt Cancer and Research Institute in Tampa, Florida, noted in comments to Reuters Health.

Renal cell carcinoma begins in the kidney cells and although it may progress slowly, it is very resistance to chemotherapy. Multiple myeloma, which may also progress slowly, is likewise resistant to treatment.

It begins in the blood's plasma cells, a type of white blood cell that is part of the immune system. Over time, myeloma cells build up in bone marrow and then in the solid parts of bone.

In a review of data from patients referred to the Cleveland Clinic between 1990 and 2005, Hussein and colleagues identified 1,100 patients with multiple myeloma, 2,704 with renal cell carcinoma, and 8 with both types of cancer.

In four of the eight patients, renal cell carcinoma was diagnosed three to 46 months after the multiple myeloma diagnosis. In the remaining four, renal cell carcinoma was diagnosed one to 108 months before the multiple myeloma. Seven of the eight patients were first diagnosed with renal cell carcinoma on the right side.

"The probability of this association was much higher than that expected in the general population," the researchers note in the medical journal BJU International. "No clear treatment-related, environmental, genetic or immune-mediated common factors can fully explain this association."

The investigators point out that interleukin-6 supports the growth and expansion of both types of cancer. Interleukin-6 is a "cytokine" that normally enhances the body's immune response to disease and infection.

"I think the take-home message," Hussein said, "is that after active therapy for myeloma, if the kidney lesion does not clear — especially if it is affecting the right kidney — renal cell cancer should be considered."

In this study, when myeloma was the first malignancy diagnosed, "the renal cell carcinoma was at a very early stage and therefore surgical exploration is critical."

Saliva test may speed heart attack diagnosis

NEW YORK (Reuters Health) — A simple saliva test may one day be used in ambulances, restaurants, neighbourhood drug stores, or other places in the community to quickly tell if a person is having a heart attack.

"Proteins found in the saliva have the ability to rapidly classify potential heart attacks," Dr. John T. McDevitt, a biochemist at the University of Texas at Austin, told Reuters Health.

McDevitt and colleagues developed a nano-bio-chip sensor that is biochemically programmed to detect sets of proteins in saliva capable of determining whether or not a person is currently having a heart attack or is at high risk of having a heart attack in the near future.

With the saliva heart attack diagnostic test, a person spits into a tube and the saliva is then transferred to credit card-sized lab card that holds the nano-bio-chip containing a standard battery of cardiac biomarkers. The loaded card is inserted like an ATM card into an analyser that determines the patient's heart status in as little as 15 minutes.

In a study involving 56 people who had a heart attack and 59 healthy "controls" who did not, "we found that our test could distinguish between heart attack patients and controls with about the same diagnostic accuracy" as that of standard blood tests, McDevitt noted in an interview with Reuters Health.

Many heart attack patients, especially women, experience nonspecific symptoms, or have normal EKG readings, making timely diagnosis difficult, McDevitt explained.

"In our small trial, we had about one third of the patients with these... silent heart attacks on EKG."

These patients need to go the emergency department and have their blood drawn and tested for enzymes that are indicative of a heart attack, "which could take an hour to an hour and a half."

The saliva test could be used in conjunction with the EKG and "aid in rapidly diagnosing heart attacks that are silent on EKG," McDevitt said, adding that larger and more refined studies are planned.

Sharing bed with wife helps men's sleep apnea Rx

NEW YORK (Reuters Health) — Men with sleep apnea are more likely to stick with their overnight treatment if their wives stay in bed with them rather than flee their snoring, a small study suggests.

In obstructive sleep apnea (OSA), soft tissues in the throat temporarily collapse during sleep, causing repeated stops and starts in breathing. Major symptoms include loud snoring and daytime fatigue caused by poor sleep.

The most effective therapy for OSA is continuous positive airway pressure, or CPAP, which involves wearing a facemask through which the CPAP device delivers pressurised air to keep the airways open overnight. Despite the effectiveness of CPAP, however, the therapy's cumbersome nature makes many OSA sufferers reluctant to use it regularly.

The new findings, based on a study of ten married couples, included a husband with CPAP and a wife without the condition.

The study found that on nights the couples slept separately, the husbands wore the CPAP device for at least 4 hours 43 percent of the time. On nights when couples slept together, however, husbands met this treatment goal three quarters of the time — a "dramatic difference," Dr. Rosalind Cartwright, of Rush University Medical Center in Chicago, told Reuters Health.

She reports the findings in the Journal of Clinical Sleep Medicine.

Clinicians who treat sleep apnea have long sought ways to improve patients' CPAP compliance. "But we have not been able to find a good way to do it," Cartwright said.

While having couples sleep in the same bed sounds like a simple solution, she pointed out that OSA affects both partners, and many spouses resort to leaving the room so they can get a good night's sleep. Of the ten couples in Cartwright's study, four were regularly sleeping apart before the husband began CPAP therapy.

At the study's outset, all couples spent a night in the sleep lab so their sleep quality could be monitored by polysomnography. The husbands then began CPAP treatment. Over the next two weeks, the couples kept sleep logs documenting whether they slept together each night; and data downloaded from the CPAP machine was used to gauge the husbands' compliance with the therapy.

In general, Cartwright found, the findings showed that a husband was more likely to use the device when he shared the bed with his wife.

In a second sleep lab study done 2 weeks into the husbands' CPAP therapy, Cartwright also found that the men's sleep had improved, as had their scores on a standard measure of quality of life.

Their wives' quality of life scores, in contrast, had not improved, and were actually lower than those of their husbands.

Many wives of men with OSA, Cartwright explained, become "fragile sleepers," waking often during the night to get their snoring husband to turn over onto his side, or to make sure he is still breathing.

Some wives, after years of listening to their husband gasp for air in his sleep, become conditioned to waking up to check on him.

Not surprisingly, it may take longer than two weeks for women to break these patterns and sleep soundly, according to Cartwright.

"So," she said, "we need to encourage wives to stick with it and stay in the bed."