PubMed Health⌕ Search

Biomedical subjects

S Ruacan

Publications and source records attributed to S Ruacan.

At least 19 recordsLinked to original sources
PubMed1998

Association of tumor washout rates and accumulation of technetium-99m-MIBI with expression of P-glycoprotein in lung cancer.

UNLABELLED: In a prospective study, we correlated the washout rates of 99mTc-sestamibi (MIBI) and the degree of MIBI accumulation with the expression of P-glycoprotein (Pgp) in tumor tissues in a total of 46 patients with lung cancer. METHODS: All patients underwent early (30 min) and delayed (3 hr) MIBI imaging and bronchoscopic biopsy before initiation of chemo- or radiotherapy. The interval between biopsy and imaging varied between 2 and 10 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 Pgp. Normal tissue and tumor washout rates and tumor-to-background ratios were correlated with the level of Pgp expression. RESULTS: There was an inverse correlation between tumor-to-background ratios and the density of Pgp (p = 0.001), whereas there was no appreciable correlation between tumor washout rates of MIBI and the level of Pgp expression (p = 0.414). CONCLUSION: The current data strongly suggest that, although the reduced ability for the tumors to accumulate MIBI correlates well with the increased levels of Pgp expression, tumor washout rates of MIBI do not correlate with the density of Pgp in tumor tissues. Our results also warrant additional research for correlating immunohistological and imaging findings with messenger RNA levels determined by polymerase chain reaction and flow cytometry.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Influence of the heterogeneity of P-glycoprotein expression on technetium-99m-MIBI uptake in breast cancer.

UNLABELLED: We prospectively studied a total of 30 patients with breast cancer to evaluate the relationship between the degree of accumulation of 99mTc-sestamibi (MIBI) and the heterogeneity of p-glycoprotein expression in tumor tissues. METHODS: Twenty patients during initial presentation and 10 patients during post-therapy evaluation underwent contemporaneous 99mTc-MIBI imaging and surgery or biopsy. Immunohistochemical studies were performed on multiple nonconsecutive sections of the same tumor using a p-glycoprotein-specific monoclonal antibody, JSB-1. Tumor-to-background (T/B) ratios were correlated with the level and heterogeneity of p-glycoprotein expression determined by immunohistochemical studies. RESULTS: The T/B ratios were lower for those tumors with strong p-glycoprotein expression (Group 1) than those with strong-to-weak expression (Group 2) or those with weak-to-no expression (Group 3) (1.32 +/- 0.19 and 1.85 +/- 0.56 and 2.86 +/- 1.06, respectively). There was statistically significant difference in T/B ratios between all 3 groups (p < 0.005). Although T/B ratios for Group 1 and Group 3 were clearly distinct from one another with no overlapping values, the values for Group 2 overlapped with those of Group 1 and Group 3. When we evaluated the entire patient group with excluding those with strong-to-weak expression, although the p value remained the same (p < 0.001), we obtained a stronger correlation between T/B ratios and p-glycoprotein expression (r = 0.808 versus 0.735). CONCLUSION: Due to the heterogeneous expression of p-glycoprotein, both immunohistochemistry and 99mTc-MIBI scintigraphy may yield confounding results by contrasting with one another if the presence or absence of p-glycoprotein is not extensively explored. Although our data confirmed that 99mTc-MIBI imaging is useful in the determination of the presence of multidrug resistance in patients with breast cancer, the issue of heterogeneous expression of the antigen should be further investigated when unexpected results are obtained.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Abnormal expression of cripto and p53 protein in endometrial carcinoma and its precursor lesions.

Many oncogenes and tumor suppressor genes are involved in multistep carcinogenesis. Cripto is an epidermal growth factor (EGF) related gene which shares homology with EGF and TGFalpha. The aim of this study was to evaluate the role of abnormal p53 and cripto oncogene expression in endometrial carcinogenesis and progression using a hyperplasia carcinoma sequence model. Ninety-six primary endometrial adenocarcinomas and 30 hyperplastic tissues of which 7 were atypical (AH), were immunohistochemically examined for the presence of cripto and abnormal p53 protein. Immunopositivity was compared in hyperplastic and carcinoma tissues and analysed for conventional clinicopathological prognostic variables such as grade, depth of myometrial invasion, lymphovascular invasion, lymph node metastases and clinical stage. Cripto immunoreactivity was strong in most cases of AH, and endometrial carcinomas revealed 71% overall and 41% strong positivity, while hyperplasias without atypia were weakly stained. There was no correlation between cripto expression and clinicopathological prognosticators. Abnormal p53 was not observed in hyperplasias but AH and carcinomas expressed 14% and 25% overall positivity, respectively. There was a statistically significant correlation between the stage of the disease and abnormal p53 accumulation. Our results suggest that both cripto and p53 may play a role in endometrial carcinogenesis while abnormal p53 expression is an important parameter for disease progression.

Carcinoma↗
PubMed1998

Prognostic factors in renal cell carcinoma.

In this study we evaluated some morphological and clinical prognostic factors in 166 patients with renal cell carcinoma (RCC). Patients' ages, sex and localization of the tumor had no effect on survival. Tumor diameter and the weight of the nephrectomy specimen revealed prognostic value. Stage of the tumor, especially the presence of metastasis, is the most important prognostic factor for RCC (p < 0.001). Tumor grade had prognostic value (p = 0.0146). The survival difference between cell types was not significant (p > 0.05). Renal vein invasion, the presence of pseudocapsules and tumor in the intravascular space, mitotic rate, the presence and the number of lymphocytes and macrophages, along with the presence of calcifications had no prognostic value (p > 0.05). The presence of necrotic areas was significant (p = 0.0102). The patients with "infiltrative growth pattern" showed poorer prognosis than patients with "pushing type growth pattern", regardless of the existence of a pseudo capsule (p = 0.0045).

Adenocarcinoma, Clear Cell↗
PubMed1997

Posterior deviation of left ventricular outflow tract septal components without ventricular septal defect.

OBJECTIVE: To describe 11 patients with narrowing of the left ventricular outflow tract caused by angular posterior deviation of both the outlet septum and the upper part of trabecular septum, which was diagnosed by cross sectional echocardiography in all and confirmed by angiocardiography in seven. RESULTS: Four patients had a subaortic systolic pressure gradient ranging from 23 to 70 mm Hg by Doppler echocardiography; cardiac catheterisation showed a significant (60 and 104 mm Hg) systolic pressure gradient in two. In four cases aortic regurgitation and two tricuspid pouches were shown by Doppler echocardiography, angiocardiography, or both. Four cases had a ridge at the angulation point on echocardiographic examination. Three patients were operated on for systolic pressure gradients of the left ventricular outflow tract and one for severe aortic regurgitation. There was proliferation of collagen-rich fibrous tissue in the subendocardial region on histopathological examination of the myectomy material. A ventricular septal defect had been diagnosed previously by contrast echocardiography in one patient; thus ventricular septal defects may close spontaneously over a period of time including fetal life. A subaortic ridge was detected in one patient at follow up. CONCLUSIONS: Deviation of the outlet and trabecular septa should be considered as a cause of ventricular outflow tract obstruction even when no ventricular septal defect is present.

Adolescent↗
PubMed1997

Multiple bilateral chondromatous hamartomas of the lung. A rare entity mimicking metastatic carcinoma.

Multiple chondromatous hamartomas are extremely rare and we have not found any bilateral presentation in the literature. We report the case of a 47-year-old woman presenting with a cough, chest pain and dyspnea. Chest x-ray and computed tomography revealed multiple and bilateral pulmonary nodules. A metastatic carcinoma was considered, but the open lung biopsy revealed a chondromatous hamartoma of the lung. The pathogenesis of hamartomas is discussed and the recent literature is reviewed.

Biopsy, Needle↗
PubMed1997

The role of cytokines in Henoch Schonlein purpura.

Serum levels of tumor necrosis factor (TNF) and interleukin(IL-1) were studied in 20 HSP patients, in the acute phase and after remission, by ELISA technique. Skin biopsies obtained during the acute phase both from a lesion and from unaffected skin, as well as during remission, were immunostained for TNF, IL-1, and IL-6. The mean age of the patients was 9.8 (5-13). Mean serum TNF levels during the acute phase and remission were 14.0 +/- 8.9 pg/ml, and 6.8 +/- 2.4 pg/ml, respectively (p < 0.05). Serum TNF levels in patients with renal involvement (18.8 +/- 10.2 pg/ml) were significantly higher than in those without (10.8 +/- 6.5 pg/ml) (p < 0.05). Serum levels of IL-1 in the acute phase and remission were undetectable. All specimens showed leukocytoclastic vasculitis. Immunohistochemical studies revealed TNF, and a less intense IL-1 and IL-6 staining in the nucleated epidermal layer, with a granular, intracellular pattern. Staining was significantly increased in the affected skin during the acute phase. These results suggest that TNF, IL-1, and IL-6 may play a role as a mediator of inflammation in HSP.

Adolescent↗
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↗