Sharapova through as seeds tumble

Former world number one Maria Sharapova showed the seeded players the way with a superb win at the Pan Pacific Open as more big names fell by the wayside. The Russian, unseeded as she makes her way back after injury, thrashed Sam Stosur 6-0 6-1 to reach the last 16.

Earlier, third seed Elena Dementieva went down 6-2 6-7 (3-7) 6-1 to Kateryna Bondarenko in Tokyo . And there was more bad news for tournament organisers when Caroline Wozniacki retired through illness. The Danish fourth seed, who finished runner-up at the US Open earlier this month, trailed Aleksandra Wozniak 5-0 when she withdrew.

"I've been sick all week," said the 18-year-old. "Before I left already I was feeling sick and I haven't practiced, and today I felt 'OK, I will try to play.'

"I thought I was able to play but as soon as I just got the pulse up a little bit I started to feel ill. There was no chance. I tried my best, it wasn't possible for me today, so I retired. I just try to get better and try to be 100% for Beijing ."

Top seeds Dinara Safina and Venus Williams, along with fifth seed Svetlana Kuznetsova, lost on day one and the tournament has been decimated of its leading players. Others to struggle on Tuesday were sixth seed Vera Zvonareva, who lost 3-6 6-4 6-2 to fellow Russian Alisa Kleybanova, and 13th seed Nadia Petrova, who went down 6-2 6-2 to Magdalena Rybarikova of Slovakia.

But seventh seed Jelena Jankovic came through a tough encounter to beat Sabine Lisicki of Germany 6-3 4-6 6-2. Eighth seed Victoria Azarenka of Belarus thrashed China 's Jie Zheng 6-1 6-1, and 14th seed Marion Bartoli beat fellow Frenchwoman Aravane Rezai 6-4 6-2.

Olympic champion Dementieva blamed some questionable line calls and fatigue for her loss to a player she had not conceded a set to in four previous meetings. "There were way too many bad calls from the chair umpire today," she said. "I'm surprised they don't have a challenge system at such a big event."

Dementieva lost in the second round at the US Open, while Ukrainian Bondarenko is currently at a career-high 33 in the rankings after reaching the quarter-finals at Flushing Meadows. "I played way too many matches in the US Open series," said Dementieva. "I would have liked to have an extra week to get refreshed for this event. I just didn't have the energy."

Sharapova returned to the tour in May after nine months out with a serious shoulder injury and has climbed back up the rankings to her current position of 25th. However, the Russian has reached just one final in that time and has not won a tournament since Amelia Island in April, 2008.

"I just want to finish the year on a good note," said Sharapova. "I served smart. It was definitely a good day at the office all around."

Source : bbc news

Social isolation 'worsens cancer'

Social isolation may make cancer more deadly, US research on mice suggests. Researchers found the social environment can modify the biology of the disease - and lead to significant differences in outcome. Female mice stressed because they were separated from their mothers developed more and larger mammary gland tumours than more contented animals.

The University of Chicago study appears in the journal Cancer Prevention Research. Previous research has suggested that social support can improve health outcomes for patients with breast cancer, while social isolation has been linked to an increased risk of death from several chronic diseases. The Chicago team worked with mice genetically predisposed to mammary gland cancer.

They found changes in the activity of genes that play a role in tumour growth in the stressed animals, suggesting that they may have been directly influenced by surging levels of stress hormones. The researchers said more work was needed to pin down exactly which cell types are affected.

New treatments

But researcher Dr Suzanne Conzen said the study raised hopes of new ways to block cancer growth. She said: "Given the increased knowledge of the human genome we can begin to objectively identify and dissect the specific alterations that take place in cancer-prone tissues of individuals in at-risk environments and that will help us to better understand and implement cancer prevention strategies."

Dr Caryn Lerman, editor of the journal, said: "This study uses an elegant preclinical model and shows that social isolation alters expression of genes important in mammary gland tumour growth." Professor Thea Tlsty, of University of California San Francisco , said it had long been known that psychological factors could influence disease, but not how.

She said the study added to growing evidence that chemicals circulating in the blood - such as stress hormones - could influence the development of cancer by turning genes on and off within cells with the potential to turn malignant.

Previous work has also suggested that depression can have a negative effect on cancer prognosis. Oliver Childs, of the charity Cancer Research UK , warned against drawing any firm conclusions. He said: "These experiments were carried out in mice, so certainly do not prove that the stress caused by social isolation causes cancer to get worse in humans.

"It is now widely recognised that stress plays a part in illness, but no-one really knows how much and there is no good evidence from controlled studies that stress contributes to cancer progression."

source : bbc news