By Claudio Pairoba
 |
| Estela Albanesi standing by the poster presented during the symposium |
Human papilloma viruses cause visible lesions known as warts. They can also produce another type of lesions, less visible, described as intraepithelial. These lesions require a specific approach due to their distinctive features.
Estela Albanesi has a degree in Biochemical Sciences and presented a
poster in the recent symposium on HPV that took place in the city of Rosario. Their research
focuses on the photodynamic diagnostic and treatment of intraepithelial lesions
caused by HPV. She explains it in
more detail.
Which are the available
treatments for lesions produced by HPV?
Currently, they are surgically removed with scalpel or using carbon
dioxide lasers, which vaporize water eliminating affected areas. Electro
scalpels are also used.
I know that therapies with niobium particles are also an option. The
drawback is that these particles need to be removed from the body. Active
research is currently underway to develop methods to accomplish this.
Which is the goal of your
research team?
We propose a new technology using the characteristic fluorescence of
tissues. We use a spectrofluorometer with a 2-mm laser tip to touch the skin
and obtain a specific spetrum. Pre-neoplastic or neoplastic tissues display a
spectrum different from normal tissue.
For example, we show the results obtained working with a case of
parotid neoplasia. The area was defined applying infrared thermography and the
light intensity released by tissues in response to thermography is different whether
tissues are healthy or not.
This process is used as a diagnostic tool.
Which
are other applications for infrared thermography?
This technique is extremely useful to control temperature during
photodynamic treatments since marked increases can be observed causing
discomfort to patients. To avoid this, on and off periods are applied.
What other techniques can
be applied?
Another approach uses a photosensitizer, which is absorbed in higher
levels by tumor cells compared to normal ones. By using blue light, tumor cells
can be detected even before changes are visible.
If we apply laser therapy, sick cells implode as a result of free
radicals produced by the interaction among the photosensitizer, oxygen and light.
After a period of time, the treated area recovers its normal appearance.
Have you been able to
apply this treatment to patients?
We had the case of a female patient with a 10-year lesion. Her
surgeon considered that breast removal was the only option available since intraepithelial
lesions would not heal.
Considering this, we decided to apply laser therapy. The most
superficial layers were peeled off and new blood vessels were detected. Next,
we performed another screening using a diferent laser intensity and
intraepithelial lesions healed.
Based on these results, we consider to be on the right track for the
diagnosis and treatment of this type of lesions. Spectrophotometry is highly
promising
In summary, these
techniques can be applied ether for diagnosis or treatment.
Definitely. We are currently exploring to link fotosensitizers to
HPV-specific molecules.
The research team is also formed by María Eugenia Etcheverry, Agustina
Corti, Horacio Poteca and Mario Garavaglia. Researchers belong to different
organizations such as Hospital Zonal de Agudos Ricardo Gutierrez de La Plata, Facultad de Cs.Exactas de la Universidad Nacionalde La Plata,
Centro Médico Láser, Instituto Médico Mater Dei de La Plata and Centro deInvestigaciones Ópticas (CCT-CONICET, CIC).
