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G Karpuzoglu

Publications and source records attributed to G Karpuzoglu.

5 recordsLinked to original sources
PubMed2001

EGFR and p53 expression and proliferative activity in parathyroid adenomas; an immunohistochemical study.

EGFR (epidermal growth factor receptor), p53, and proliferative markers provide some clues as to the formation of several tumours. In this study the mechanism of the genesis of parathyroid adenomas was investigated using immunohistochemistry. Sections of parathyroid adenomas from 12 cases were stained using PCNA (proliferating cell nuclear antigen), EGFR, and p53 immunohistochemistry. Correlations between PCNA LI (labelling index), EGFR expression, p53 expression, age, serum parathormone, Ca and P levels, and tumour diameter were investigated. PCNA LI was 45.8+/-33.1 (mean+/-standard deviation) and all the cases were somewhat positive. Five cases (41.67 %) were EGFR positive. Maximum 10 % of the cells were positive in these cases. All the cases were p53 negative. There was a correlation between PCNA LI and serum parathormone level (r=0.607, p=0.036). According to these results, parathormone synthesis is high when the proliferative activity of parathyroid adenoma is high. Four of the five EGFR-positive patients were below 35 years of age. These data may indicate that formation of parathyroid adenoma in young patients is related to a mechanism involving EGFR. Absence of p53 expression suggests that p53 mutation is not a common component of parathyroid adenomas.

Adenoma↗
PubMed2000

Epithelial membrane antigen and S-100 protein expression in benign and malignant papillary thyroid neoplasms.

Papillary carcinoma of the thyroid is mainly diagnosed with histopathologic features. Classical papillary architectures are important but nuclear change is the essential diagnostic element. Papillary architecture may be seen in benign lesions such as in hyperplastic areas of the follicular neoplasms, multinodular goiter and Grave's disease. Differential diagnosis of papillary carcinoma and papillary hyperplasia is very important for clinical management. Some authors have reported that Epithelial Membrane Antigen (EMA) and S-100 protein expression would be valuable and helpful in identifying papillary neoplasia and distinguishing it from papillary hyperplasia. In this study, EMA and S-100 protein expression of 14 papillary thyroid carcinomas and 13 papillary hyperplasias were studied by using immunohistochemical methods. In 14 papillary carcinomas, 9 showed diffuse and 3 revealed focal S-100 protein nuclear and cytoplasmic immunostaining. Two cases were not stained. All of the 13 papillary hyperplasias were negative for S-100 protein. EMA expression was observed in the apical cytoplasmic location of 11 papillary carcinomas except one case that showed diffuse cytoplasmic staining and one which was negative. In the papillary hyperplasias, 7 revealed both cytoplasmic and apical cytoplasmic staining. One case showed only cytoplasmic staining. Five cases were negative for EMA. The difference in the S-100 protein expression is significant, however immunostaining of EMA is similar in both lesions. We concluded that differential diagnosis of papillary structures in carcinomas and hyperplasias was mainly diagnosed on the histopathologic features but S-100 protein expression could be helpful in difficult cases.

Carcinoma, Papillary↗
PubMedDate not supplied

Multidrug resistant malignant melanoma with intracranial metastasis responding to immunotherapy.

Metastatic malignant melanoma (MM) is well known for its poor response to chemotherapy, radiotherapy, and its remarkable susceptibility to interleukin-2 (IL-2) based immunotherapies. MM with brain metastatis in particular, has 4-5 months life expectancy from metastasis to death. Drug efflux pumps such as P-glycoprotein (P-gp), or drug detoxifying mechanisms e.g. glutathion epsilon S-transferase-pi (GST) are some of the possible multidrug resistance (MDR) mechanisms in MM. Here we report the first P-gp+ MDR MM with brain metastasis in the literature, demonstrating a remarkable response to IL-2, interferon-alpha (IFN), 5-fluorouracil (5FU) regimen. A 41-year old man was admitted with multiple inoperable brain lesions. Biopsies from intracranial and dermal lesions revealed MM. Cisplatin, carmustine, dacarbazine, tamoxifen (CCDT) together with external cranial radiotherapy were administered, and partial response in lesions and symptoms was achieved. However, after the third course of CCDT treatment, he was admitted to the emergency ward with dramatically increased intracranial lesions, and recurring dermal lesions. A biopsy from the recurred lesions revealed that MM cells were P-gp+, but GST. Administration of a IL-2, IFN and 5FU regimen achieved a remarkable decline in the brain lesions with almost total disappearance of symptoms. He was well and capable of doing work for 18 months. Dermal lesions had not recurred since the beginning of immunotherapy. In contrast, another 34-year old man who developed brain metastases after CCDT for MM, was negative for P-gp and GST. Cranial radiotherapy was started and the above mentioned IL-2 based regimen was administered. However, no response was observed. These two cases together with previous studies demonstrating the susceptibility of P-gp+ MDR cancer cell lines to IL-2 activated killer (LAK) cells in this report suggest that P-gp+ MDR MM is probably a good candidate for IL-2 based treatments.

ATP Binding Cassette Transporter, Subfamily B, Mem↗