Lege Artis Medicinae - 2001;11(02)

Lege Artis Medicinae

FEBRUARY 20, 2001

[The role of steroid hormones in the protection against oxidative stress]

BÉKÉSI Gábor, FEHÉR János

[The incidence of vascular diseases increases in postmenopausal women. This negative trend seems to be controllable favourably by hormone replacement therapy (HRT). Based on the free radical mediated mechanism of atherogenesis the authors try to find the reasons for these observations on the basis of their and others’ data. They consider the increase of activity and amount of neutrophil enzyme myeloperoxydase by certain steroid particulars one of the most important elements of the vasoprotective effect of HRT. This increase diminishes the production of superoxide anion by the inhibition of the NADPH-oxidase enzyme. The observation proved firstly by the authors, that the plasma levels of myeloperoxydase - and so the ability for the inhibition of superoxide anion production by neutrophils - decreases in elderly people, might explain the higher incidence of some free radical mediated illnesses in the elderly. The authors also give a short review of antioxidant effects of steroids in general.]

Lege Artis Medicinae

FEBRUARY 20, 2001

Lege Artis Medicinae

FEBRUARY 20, 2001

[The importance of vitrectomy in the management of diabetic retinopathy in proliferative stage]

BERECZKI Árpád

[Vitrectomy is a closed microsurgical technique, by which intraocular tissue, blood and foreign bodies can be removed through a small incision in the pars plana with an automated suction-cutting device (vitrectom), while maintaining normal or slightly elevated intraocular pressure. This technique requires many accessory instruments (microscope, endoillumination, intraocular instruments, endolaser). The main application of vitrectomy is the treatment of severe complications in diabetes mellitus: diabetic retinopathy in the proliferative stage. Vitrectomy is indicated in diabetic retinopathy for the removal of intraocular bleeding and for the treatment of complications of diabetic proliferative vitreoretinopathy (recurring bleeding, tractional and rhegmatogenous retinal detachment). In the case of intraocular bleeding, early vitrectomy is better than delayed, providing good visus (V: 0,5) in 25% of all patients (based on literature data). In retinal detachment cases of tractional origin, surgery provides satisfactory visus for self-care in 2/3rd of all patients.]

Lege Artis Medicinae

FEBRUARY 20, 2001

[Multidisciplinary medical oncological treatment of colorectal cancer]

LÁNG István

[All stage III. patients and some high risk patients with stage II. colorectal cancer (CRC) should be treated with bolus 5-fluorouracilfolinic acid adjuvant chemotherapy. The usual adjuvant/neoadjuvant treatment for rectal cancer is chemo-radiotherapy. In stage IV. CRC various combinations of 5-fluorouracil, folinic acid, irinotecan or raltitrexed can be used. Patients should be treated in specialised multidisciplinary oncological centers - and, if possible, as participants of clinical trials.]

Lege Artis Medicinae

FEBRUARY 20, 2001

[Gastrointestinal stromal tumor]

GONDA Gábor

[Gastrointestinal stromal tumors were subject of much controversy in the last decades. This type of tumors was delineated from the leiomyoma - leiomyosarcoma group. GISTs show variable histological picture, moreover, they are capable of dual (neurogen and myogen) differentiation as it is proved by immunohistochemical and ultrastructural studies. These tumors have relatively good prognosis, only 10-30% of them is malignant, although it is difficult to predict their behaviour in a given case. The most reliable signs of malignancy - cytological pleoimorphism, high mitotic activity, proliferation index above 10 %, and aneuploid DNA content - are generally accepted. The treatment of choice is excision, but not enucleation. Radical surgery is not necessary, since lymph node metastasis is exceptionally rare. Further investigations revealed electronmicroscopical and immunohistochemical (CD 34, CD 117) similarities of tumor cells and interstitial cells of Cajal (ICC) located in the wall of the bowel. The results of these investigations led to the theory that cells of GIST and ICCs are of the same stem cell origin. Molecular genetic studies are also of great help in the differential diagnosis and in predicting the prognosis of GISTs. Mutations in the c-kit gene can not be detected in leiomyomas, so they are thougt to be specific for GISTs. Mutation of exon 11. of chromosome 4. is observed only in malignant GISTs.]

Lege Artis Medicinae

FEBRUARY 20, 2001

[The clinical importance of HER2 expression in breast cancer]

KAHÁN Zsuzsanna

[HER2 (neu/c-erbB-2) is a member of the EGF receptor family. It is activated without binding a specific ligand that leads to malignant transformation and tumor progression. Overexpression of HER2 is detected in approximately one quarter of human breast cancers. Immunohistochemistry and in situ hybridization (FISH) are the most widely used techniques in studying HER2 expression. HER2 positivity indicates worse outcome in node positive breast cancer and increasing number of studies show unfavourable prognosis in node negative cases as well. Recent data indicate that the knowledge of HER2 status may promote therapeutic decision. The generally applied cyclophosphamide- methotrexate-5-fluorouracil (CMF) polychemotherapy seems to provide no benefit in HER2 positive cases in contrast with HER2 negative breast cancer patients. Interestingly, doseintensive doxorubicin based chemotherapy gives better results in HER2 positive than in HER2 negative tumors. Determination of HER2 expression has great importance before therapeutic application of the humanized antibody trastuzumab (Herceptin). HER2 overexpression usually correlates well with estrogen and progesterone receptor negativity and hormone-resistance, therefore hormonal therapy is not justified for these patients. Some experimental and clinical data indicate that in case of simultaneous HER2 and ER positivity tamoxifen worsens treatment results which may be prevented by the coadministration of tamoxifen and trastuzumab. Emerging experimental and clinical data about HER2 has led to a new stage of individual treatment of breast cancer patients. The knowledge of HER2 status promotes antitumor intervention based on molecular characteristics of breast cancers. Therefore, reliable HER2 tests are needed in the everyday practice.]

Lege Artis Medicinae

FEBRUARY 20, 2001

Lege Artis Medicinae

FEBRUARY 20, 2001

Lege Artis Medicinae

FEBRUARY 20, 2001

Lege Artis Medicinae

FEBRUARY 20, 2001