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Biomedical subjects

S Ruacan

Publications and source records attributed to S Ruacan.

At least 55 records · Page 3Linked to original sources
PubMed1997

Solid tumor chemotherapy and in vivo distribution of fluorouracil following administration in poly(L-lactic acid) microspheres.

The physicochemical properties and in vivo distribution of poly(L-lactide) (L-PLA) microspheres containing 5-fluorouracil (5-FU) prepared by a solvent evaporation method were evaluated for potential use in the treatment of liver cancers. Two different molecular weight polymers of L-PLA [L-PLA1 (152,500 Da) and L-PLA2 (52,000 Da)] were used to prepare 5-FU-loaded microspheres. The mean particle size of the microspheres was 3-6 microns, and there was a direct relationship between the mean particle size and the molecular weight of the polymers. The drug release behavior from microspheres exhibited a diffusion mechanism in different dissolution media, with the molecular weight of the polymer being a major factor in controlling the drug release and degradation rates. Following intravenous injection of 99mTc-labeled L-PLA microspheres, with or without 5-FU, or free 5-FU into mice, L-PLA2 microspheres localized mainly in the liver. The disappearance rate of radioactivity from the tissue was very slow in comparison to that of free 5-FU. The results were confirmed by histological examination of liver tissue following administration of fluorescein particles. In addition, growth of a human liver tumor as first transplant generation under the renal capsule of immunocompetent rats and antitumor activity of L-PLA2 microspheres were investigated. Histological examination by optical microscopy showed that there was no neoplastic tissue of the kidney or in other tissues examined after treatment.

Animals↗
PubMed1997

Clinical validation of the influence of P-glycoprotein on technetium-99m-sestamibi uptake in malignant tumors.

UNLABELLED: We prospectively studied 48 patients with either breast cancer (30 patients) or lung cancer (18 patients) to ascertain the relationship between the degree of accumulation of 99mTc-sestamibi and the expression of p-glycoprotein in tumor tissues. METHODS: During initial presentation (37 patients) or post-therapy evaluation (11 patients), the patients underwent contemporaneous 99mTc-sestamibi imaging and biopsy (30 patients) or surgery (18 patients). The interval between surgery/biopsy and imaging varied between 3 and 15 days. All patients had radiologically detectable tumors. Immunohistochemical studies were performed on paraffin sections using a monoclonal antibody, JSB-1, developed against the internal epitope of p-glycoprotein. Tumor-to-background ratios were correlated with the level of p-glycoprotein expression determined by immunohistochemical studies. RESULTS: Our results showed an inverse correlation between the tumor-to-background ratios of 99mTc-sestamibi and the density of p-glycoprotein expression in tumor tissues. The values for the tumor-to-background ratios were significantly lower for those tumors expressing p-glycoprotein at high levels than those with scattered and no expression (p < 0.01 and p < 0.001, respectively). CONCLUSION: Although our results warrant further studies at the molecular level using PCR techniques after the extraction of mRNA, our data strongly suggest that 99mTc-sestamibi imaging is useful to noninvasively determine the presence of multidrug resistance in patients with malignant tumors.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

False positive pleural biopsy and high CA125 levels in serum and pleural effusion in systemic lupus erythematosus.

A 23-year-old female with systemic lupus erythematosus is reported. The clinical features included fever, shortness of breath, lymphadenopathies, hepatosplenomegaly, pleural and pericardial fluids, ANA and Anti-DNA positivity. Pleural biopsy was false positive for malignancy on two occasions. High CA125 levels were detected in both serum and pleural fluid. Following prednisolone treatment, clinical and laboratory findings returned to normal.

Adult↗
PubMed1996

False positive pleural biopsy and high CA125 levels in serum and pleural effusion in systemic lupus erythematosus.

A 23-year-old female with systemic lupus erythematosus is reported. The clinical features included fever, shortness of breath, lymphadenopathies, hepatosplenomegaly, pleural and pericardial fluids, ANA and Anti-DNA positivity. Pleural biopsy was false positive for malignancy on two occasions. High CA125 levels were detected in both serum and pleural fluid. Following prednisolone treatment, clinical and laboratory findings returned to normal.

Adult↗
PubMed1996

Subependymal giant cell astrocytoma associated with tuberous sclerosis: diagnostic and surgical characteristics of five cases with unusual features.

Five children with tuberous sclerosis and intracranial tumors were surgically treated at Neurosurgery Department of Hacettepe University School of Medicine. Two of the five patients presented with the giant cell astrocytoma filling the third ventricle. Direct surgical intervention and tumor removal was carried out in all four patients (three with a total surgical resection and one with a subtotal resection) and cerebrospinal fluid shunting procedure in one. Histopathological examination revealed giant cell astrocytomas in four patients. Postoperatively, one died and the rest four patients survived with minor focal neurologic difficulties. The surgical results and the changing concepts in the treatment of tuberous sclerosis are discussed and the literature is reviewed.

Adolescent↗
PubMed1996

Factors influencing the distribution of metastases and survival in metastatic breast carcinoma.

A total of 370 patients with metastatic breast, carcinoma who had been followed at Hacettepe Oncology Department between 1980 and 1991 were retrospectively analyzed for the factors influencing the distribution of metastases and survival. Median age was 47 years. Radical or modified radical mastectomies were performed in 199 (53.8%). Infiltrative ductal carcinoma was the most common pathologic subtype (69.4%). In 191 patients who were evaluated for estrogen receptor (ER) status, 101 (52.9%) were positive and 90 (47.1%) were negative. The distribution of first metastases did not differ between the soft tissue, bone, and visceral sites. The second, third, and fourth metastases were more common in visceral sites (p < 0.05). ER and menopausal status did not affect distribution. Mortality rate was significantly lower in the group having the first metastasis to the bone (p < 0.05). Of interest, first metastases were predominantly found in visceral sites in patients having radical or modified radical mastectomies (p < 0.05). Response to therapy, presence of initial metastases, axillary status, and age were the important factors influencing the overall survival in univariate analysis, whereas response to therapy, ER status, age, and presence of initial metastases were the important factors according to the multivariate analysis.

Adult↗
PubMed1995

Lymphangiomatosis of bone. A case report.

Primary lymphangioma is a disease of unknown aetiology in which lytic lesions occur in the long bones, pelvis, spine and skull. A case in a girl, 4 years of age, is presented.

Bone Neoplasms↗
PubMed1994

Morphological assessment in pinealectomy and foetal pineal gland transplantation in rats: Part I.

The effects of pineal gland, an endocrine organ known to affect the physiology of various organs and systems including the hypothalamo-hypophyseal axis, on the morphological characteristics of target organs were investigated in rats after pinealectomy and foetal pineal gland transplantation to a subpial cortical area close to the pinealectomized region. It was demonstrated that weight gain was significantly slower in pinealectomized male rats (p < 0.01); pituitary gland weight was lower in the pinealectomized group (p < 0.01) and transplantation had no effect on the weight of this organ; weight of adrenal gland and testis were lower after pinealectomy (p < 0.01) but restored back to control levels after transplantation; the mitotic activity in seminiferous tubules increased with pinealectomy and returned back to control indexes after transplantation. Research on hypothalamic catecholaminergic content revealed a diminished histofluorescence in pinealectomized rats which showed a potentiated restoration after transplantation. The innervation of the pineal gland was studied by anterograde and retrograde injections of Wheat Germ Agglutinin Horse Radish Peroxidase from superior cervical ganglion and pineal gland, respectively. It was demonstrated that cell bodies were traced both at the transplanted tissue and hypothalamus. In view of these data, the multifunctional and a probable high level homeostatic harmony regulator essence of pineal gland is discussed.

Adrenal Glands↗
PubMed1994

Non-Hodgkin's lymphomas in Turkey: eighteen years' experience at the Hacettepe University.

In this retrospective study, 470 patients with non-Hodgkin's lymphoma (NHL) who had been followed in the Hacettepe University Medical Oncology Department between 1973 and 1990, were evaluated to establish their epidemiologic, clinical and therapeutic characteristics. Out of 470 patients, 302 (62.2%) were male and 168 (37.8%) were female. The ages ranged from 16 to 85, with a median of 44 years. Constitutional symptoms were present in 46.4% of the patients. According to the Working Formulation, low, intermediate, and high-grade lymphomas comprised 33.4%, 54.9%, and 12.7%, respectively. The most common extranodal presentation was gastrointestinal. The chemotherapy regimens most commonly used were CVP (cyclophosphamide, vincristine, prednisone), BCNOP (bleomycin, cyclophosphamide, mitoxantrone, vincristine, prednisone), CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) and CHOP-Bleo (cyclophosphamide, doxorubicin, vincristine, prednisone, bleomycin). The response rates and the survival figures attained with these regimens were not statistically significantly different (P > 0.05). In the Cox multivariate model, pathologic grade, leukopenia, responsiveness to chemotherapy, bone marrow involvement and age were the important factors influencing the disease-free survival, while responsiveness to chemotherapy, age, presence of constitutional symptoms, pathologic grade, extranodal presentation and stage were the important factors influencing the overall survival. The distribution of NHL according to grade and stage was similar to that in western societies, while constitutional symptoms and lymphomas of the small intestine including immunoproliferative small intestinal disease were more common in Turkey.

Adolescent↗
PubMed1994

[Mesoblastic nephroma in adults: a clinical case].

Mesoblastic nephroma is the most common renal tumor in infancy but is infrequent in the adult. It has a typical histological pattern but its histogenesis is unknown. We report a case of mesoblastic nephroma in an eighteen year old man who was treated by conservative surgery.

Adolescent↗
PubMed1993

Does gastric adenocarcinoma develop after the treatment of gastric lymphoma?

Two adult patients with the diagnosis of gastric lymphoma who developed adenocarcinoma of the stomach 8 years after the treatment are presented. Both patients were treated by subtotal gastrectomy followed by irradiation of 4,000-4,500 cGy to the epigastric region and six courses of chemotherapy (vincristine, cyclophosphamide, prednisolone). In our review of the literature, 16 cases of gastric adenocarcinoma following the treatment of gastric lymphoma were found and listed with details. The factors influencing the development of this secondary carcinoma, mainly those treatment related are discussed. The possible role of both radiotherapy and chemotherapy in shortening the latent period for the development of stump carcinoma is emphasized.

Adenocarcinoma↗
PubMed1993

Arterial bridging for repair of peripheral nerve gap: a comparative study.

A new experimental model was designed in which the regeneration of rat femoral nerve across a 8 mm excised gap was investigated after insertion of the distal and proximal stumps into the anatomically and functionally intact femoral artery (AIAB). This model was compared with groups of free artery and autologous nerve grafting. After a period of 12 weeks, a histological and electrophysiological analysis was carried out, which demonstrated that the AIAB and autologous nerve grafting group had a significantly higher percentage of regeneration compared with the free artery-graft group. The nerve regeneration and intraneural vascular reconstruction that occurred within AIAB group were more successful than those that occurred in the artery and nerve-grafting groups.

Anastomosis, Surgical↗
PubMed1993

Topical effect of bromocriptine on rat-transplanted human prolactinomas.

In prolactinoma surgery, especially in macro-adenomas, it is not always possible to remove the tumour totally. Cell remnants may cause a regrowth and continue hypersecretion. In order to find out whether tumour remnants could be destroyed by local application of bromocriptine, a research model has been designed. First, prolactin secreting pituitary tumours, removed during surgery, were implanted bilaterally into the brain tissue of rats. In eight rats, the viability of tumour transplants was proven histopathologically and their prolactin secretion was shown immunocytochemically. In a second step, on eight rats, sterile bromocriptine solution was applied topically to the tumour transplants on one side. The other side served as control. Histopathological examination of these treated tissues revealed fibrosis. Immunocytochemical analysis showed no secretory activity. Ultrastructural investigations also revealed evidence of degeneration of the treated cells. The natural course of the transplanted tumour tissues of the other side, as a control group, was also observed during the same 55-day period.

Animals↗
PubMed1993

Struma ovarii.

OBJECTIVE: To review the clinicopathological experience of patients with benign and malignant struma ovarii. METHOD: A retrospective institutional analysis of 2 patients with malignant and 14 patients with benign struma ovarii, treated during a period of 20 years. RESULT: The patients with struma ovarii constituted 1.0% of all ovarian neoplasms in our institution (16/1501). Four percent of the germ cell tumors were calculated to be of struma ovarii (16/382). The stages of the malignant cases were recorded as 1A and 1C. Besides detection at early stage, a biologically low grade tumor was encountered as well. Although 5 of the patients had goitre, none of them had hyperthyroidism. None of the patients had a bilateral tumor. However, in 2 patients, a serous cystadenoma and dermoid cyst were found in the contralateral ovaries. The preoperative and intraoperative diagnosis of malignant struma ovarii proved to be difficult since 2 patients subjected to radical surgery according to suspicious frozen section reports in this series later were found to be benign struma ovarii. CONCLUSION: The low metastatic potential and slow progression rate of malignant struma ovarii support conservative surgery especially in young patients who have not yet completed their families.

Adolescent↗
PubMed1993

Synovial sarcoma in the neck.

Synovial sarcomas are very uncommon and highly malignant tumours. This uncommon malignant tumour of mesenchymal origin may rarely present in the neck. Since 1954, nearly 80 cases of synovial sarcoma, located in the head and neck region have been reported. Synovial sarcoma is most prevalent in adolescents and young adults between 15 and 40 years of age. In this report we present a case of synovial sarcoma in the neck of a 10-year-old patient.

Child↗
PubMed1993

Ameloblastic fibrosarcoma.

A case of an ameloblastic fibrosarcoma in the mandible is described. The primary tumor was seen in a 5-year-old child. In spite of repeated surgical interventions, the tumor recurred three times within a one and a half year period, but not metastases have been observed. The difficulties in arriving at a correct diagnosis for this rare tumor involving the mandible are discussed. The treatment of choice seems to be radical surgery.

Child, Preschool↗