Teeth could regrow, say scientists; more news

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Teeth could regrow, say

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November 21 2004 at 10:59AM

 

Sydney - Stem cells exist inside the teeth and could be harnessed to

allow the organ to repair itself, Australian researchers said on Sunday.

 

Biologist Stan Gronthos told national broadcaster ABC that dental stem

cells could be harvested and stored in liquid nitrogen, ready for use to

repair damaged or diseased teeth.

 

" It's a complex organ and it's got many tissues associated with it so

it's going to take a lot of study to actually try and form a living tooth in

an animal, " he said.

 

" At the moment technology is at the stage where we can probably repair

portions of the tooth. " - Sapa-dpa

 

 

 

 

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Asian study to help refine genetic map

 

Asian study to help refine genetic map

November 20 2004 at 02:52PM

 

Just how similar are the Japanese and Indonesians, apart

from being Asians?

 

Although their physical appearances highlight a range of

differences, their genetic make-up could reveal more similarities than their

looks suggest, scientists said this week at the launch of an unprecedented

study on the genetic profile of Asians.

 

The scientists, from a range of research institutes across

the region, said the study could reveal Asia's migratory patterns and

explain the susceptibility of different Asian societies to illnesses such as

childhood leukaemia and diabetes.

 

" If you look from Korea to Indonesia and India to Japan,

you find huge human variations yet to be understood, " said Edison Liu,

executive director of the Genome Institute of Singapore.

 

" We don't have enough understanding of how different we

are or how similar we are. this initiative is to identify that and to refine

future studies, " Liu said.

 

Scientists said the latest initiative will improve the

findings of the Human Genome Project, a 13-year project completed last year,

which first sequenced the complete human genome and found human DNA to be

99,9 percent identical, with the 0,1 percent variation accounting for all

the differences between individuals.

 

" Although we know the difference in our genetic make-up is

only 0,1 percent, we know very little about the genetic factors that make us

different, " said Liu.

 

The Asian genome study, a project spanning populations in

17 Asian countries, will also allow scientists to compare genetic maps and

find out if people prone to certain illness have a common characteristic in

their DNA set.

 

" By looking at our genetic differences, it gives us a

roadmap of where to examine the genome when we want to study a disease, "

said Liu, one of the scientists speaking at the Human Genome Organisation

Asia-Pacific conference in Singapore.

 

Genetic mapping, widely seen as a major scientific

milestone, has gained prominence in the medical field in the past few years

as researchers uncover genetic links to various illnesses.

 

Findings so far have led drug manufacturers to look into

personalised medicine, a new therapy that matches drugs to a patient's

genetic make-up, and customises treatments for various diseases.

 

" What we believe is that the differences between human

beings provide a basis on how they have a disease and how they respond to

therapies, " said Liu.

 

 

 

November 20 2004 at 02:52PM

 

 

 

 

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Increase in risk of oral cancer in SA

November 22 2004 at 10:34AM

 

Blood used in hospitals should be screened for the human herpes

virus 8, a recently discovered virus which leads to Kaposi's sarcoma,

particularly in HIV and Aids patients, the Medical Research Council has

recommended.

 

Kaposi's sarcoma was the leading cancer in many central, east

and southern African countries, with rates " rapidly increasing " in South

Africa, the MRC warned in its 2004 annual report.

 

Other data from the MRC's cancer epidemiology research group

showed that the percentage of lung cancer cases that could be ascribed to

occupational environments (about 40 percent) was higher in a South African

study than had been previously found in developed countries.

 

About 3 500 patients were studied to measure the association of

lung cancer and occupation, with increased risks found among miners and

workers in chemical industries.

 

'HIV-positive individuals were 3,5 times more likely to

develop cancer of the vulva'

In addition, 2 910 patients were examined to measure the

association between HIV-infection and a number of socio-demographic

characteristics.

 

Alcohol consumption was found to be an important risk factor for

HIV infection, probably due to its promotion of sexual risk-taking

behaviour.

 

" HIV-positive individuals were 3,5 times more likely to develop

cancer of the vulva than HIV-negative individuals, " read the report.

 

Data from a case-control study were also analysed to determine

the risk factors for cervical cancer among black women, with the results yet

to be published.

 

The association between hormonal contraceptive use and breast

cancer was also investigated, with risks associated with the use of

injectable progesterone contraceptives - widely used among black women since

the 1970s - of particular interest.

 

The team also investigated the relationship between antibodies

against six herpes viruses and seven different cancer groups: oral,

cervical, prostate, Hodgkin's lymphoma, non-Hodgkin's lymphoma, multiple

myeloma and leukaemia.

 

" The results showed a statistically significant increasing risk

of oral cancer with increasing quantities of antibodies against the HHV-6

herpes virus, " said the annual report.

 

Prostate cancer was found to be the most common cancer in males

of all population groups during 1996-97 and evidence suggested that

environmental factors could play a role.

 

The emphasis of the cancer epidemiology research group was on

the leading cancers affecting South Africans, namely prostate, cervix,

breast, oesophagus and lung, as well as cancers that were rapidly increasing

among the population, such as Kaposi's sarcoma.

 

The group focuses on major and emerging causes of the disease,

such as tobacco, infectious agents, alcohol, occupational environment and

hormonal factors. - Sapa