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C Kittas

Publications and source records attributed to C Kittas.

At least 91 records · Page 5Linked to original sources
PubMed1994

Effect of cadmium pretreatment on liver regeneration after partial hepatectomy in rats.

Cadmium is a rare element that is nevertheless widely distributed throughout the biosphere and its toxic effects are becoming potentially more serious due to industrialization. Liver regeneration can be considered as a spectacular example of controlled tissue increase. In this study we examined the effect of cadmium pretreatment, administered 24 h before partial hepatectomy, on the liver regenerative process in rats, at different time intervals. The rate of 3H thymidine incorporation into hepatic DNA and the activity of the enzyme thymidine kinase were used as indices of liver proliferative capacity. Thymidine kinase, the rate-determining enzyme of DNA biosynthesis, was suppressed during the first hours following partial hepatectomy in the liver of cadmium pretreated animals. DNA biosynthesis was also strongly decreased in cadmium pretreated animals, by delaying the first peak of liver regeneration, compared with the partially hepatectomized ones. Biochemical parameters, mitotic index and proliferating cell nuclear antigen staining were also coestimated. The above data suggest that cadmium pretreatment suppressed the hepatic regenerative process, probably due to the inhibition of thymidine kinase.

Animals↗
PubMed1994

Unpigmented intramucosal nevus of palate. An unusual clinical presentation.

A case of unpigmented intramucosal nevus occurring in the palatal mucosa is described. It presented as a nodule and was diagnosed clinically as fibroma. The correct diagnosis was established histologically and immunohistochemically; the importance of this lesion is that it should be considered in the differential diagnosis of oral soft-tissue tumors.

Diagnosis, Differential↗
PubMed1994

p53, c-myc p62 and proliferating cell nuclear antigen (PCNA) expression in non-Hodgkin's lymphomas.

AIMS: To investigate the immunohistochemical expression of p53 protein in non-Hodgkin's lymphomas (NHL) and its relation to that of c-myc p62 oncoprotein and proliferating cell nuclear antigen (PCNA). METHODS: Paraffin wax embedded tissue from 90 non-Hodgkin's lymphomas (72 B cell and 18 T cell) was stained immunohistochemically for p53 protein, c-myc p62 oncoprotein, and PCNA using the monoclonal antibodies DO7, c-myc 1-9 E10, and PC-10, respectively. RESULTS: Of the non-Hodgkin's lymphomas studied, 55 (61%) stained positively for p53 protein. The proportion of positive cases increased from low grade non-Hodgkin's lymphoma and was higher in tumours of T cell origin. The percentage of positive cells (labelling index or LI) was significantly lower in low grade non-Hodgkin's lymphoma, but no difference was established between intermediate and high grade non-Hodgkin's lymphoma. In a large proportion of low grade non-Hodgkin's lymphoma the LI was below 1%. c-myc p62 immunoreactivity was identified in all cases. A significant positive correlation was established between p53 LI and c-myc p62 LI (rs = 0.453) as well as between p53 LI and PCNA LI (rs = 0.338). CONCLUSIONS: p53 immunoreactivity was present in about half the cases of non-Hodgkin's lymphoma and was related to the grade of malignancy and possibly to the B or T cell origin of the tumour. It was also associated with the proliferation state as expressed by PCNA LI and c-myc p62 expression, indicating that the expression of these three cell cycle-related genes might be interrelated.

Antibodies, Monoclonal↗
PubMed1994

B-cell lymphoma of large multilobated type: an immunohistochemical study of 8 cases and review of the literature.

Large multilobated cell lymphomas represent an heterogenous group comprising both B-cell and T-cell subtypes. The correct lineage identification of each subtype cannot be based on morphologic grounds, as it has already been stressed by other authors, and demands the use of immunophenotyping methods. In this study we review the literature and present eight new cases of large multilobated B-cell lymphoma which have been immunophenotyped in paraffin sections with a panel of monoclonal [L26 (CD20), 4KB5 (CD45R), UCHL1 (CD45RO), MT1 (CD43)] and polyclonal (anti-CD3, anti-kappa, anti-lambda) antibodies. We further investigated the expression of c-myc p62 oncoprotein and of proliferating cell nuclear antigen (PCNA) using the monoclonal antibodies c-myc 1-9E10 and PC-10 respectively. In all cases the neoplastic cells were positive for L26 (CD20) and negative for anti-CD3. Five cases were positive for 4KB5 (CD45R) while six cases stained positively for UCHL1 (CD45RO) or MT1 (CD43). Four cases were monoclonal in respect to light chain restriction. Immunoreactivity with c-myc 1-9E10 and PC-10 was observed in all cases. As far as c-myc 1-9E10 is concerned, positive cells constituted more than 45% of the neoplastic population in six cases, whereas in all cases the percentage of PC-10 positive cells was greater than 45%. The staining pattern was nuclear and/or cytoplasmic for c-myc 1-9E10 but solely nuclear for PC-10. The elevated c-myc and PCNA expression are indices of high proliferation rate in this type of lymphoma and may suggest a high malignancy grade.

Adolescent↗
PubMed1993

A comparative assessment of proliferating cell nuclear antigen, c-myc p62, and nucleolar organizer region staining in non-Hodgkin's lymphomas: a histochemical and immunohistochemical study of 200 cases.

Proliferating cell nuclear antigen (PCNA) and c-myc p62 oncoprotein are two nuclear proteins expressed in proliferating and transformed cells. They can be recognized immunohistochemically in paraffin sections by the monoclonal antibodies PC-10 and c-myc 1-9E10, respectively. On the other hand, nucleolar organizer regions (NORs) are loops of DNA that carry the r-RNA genes and can be visualized in paraffin sections as black dots (AgNORs) using a silver impregnation method. It has been suggested that the mean number of AgNORs may reflect the cellular kinetics of a tumor. We independently examined 200 cases of non-Hodgkin's lymphomas using the monoclonal antibodies PC-10 and c-myc 1-9E10, as well as the AgNOR method. Our study shows a very significant correlation between PCNA, c-myc expression, and AgNOR count on the one hand and histologic grade on the other (P < .001), although a significant overlap among the three grades exists. PC-10, c-myc 1-9E10, and AgNOR scores are all shown to be linearly related, even though significant discrepancies were observed, and the correlation is stronger between PCNA and AgNORs (PCNA v c-myc p62, r = .551; PCNA v AgNORs, r = .746; c-myc p62 v AgNORs, r = .529; P < .001). A remarkable finding is that the intermediate group of lymphomas is heterogeneous as far as the proliferative rate is concerned: diffuse large cell cleaved/non-cleaved lymphomas (category G of the Working Formulation) are characterized by a significantly higher proliferative index, as evidenced by the elevated PCNA, c-myc p62, and AgNOR scores, in comparison with the other types of intermediate-grade lymphomas (P < .001). However, the proliferative rate is lower than that of the high-grade lymphomas (PCNA, P < .05; c-myc p62, P < .001; AgNORs, P < .005). No significant difference exists between B-cell and T-cell lymphomas except for the higher expression of c-myc p62 in intermediate-grade B-cell lymphomas, obviously due to the higher proliferative rate of diffuse large cell lymphomas. Based on our findings, it appears that the combination of PCNA, c-myc p62, and AgNORs provides an accurate estimate of the proliferative rate of non-Hodgkin's lymphomas in paraffin sections. Clinical studies may show whether this information has prognostic value independent of histologic classification. In addition, our results suggest that category G (diffuse large cell) lymphomas may belong to a malignancy grade higher than the intermediate grade, a suggestion consistent with their more aggressive biologic behavior.

Antigens, Neoplasm↗
PubMed1992

Hodgkin's disease involving the gingiva in AIDS.

Non-Hodgkin lymphomas are a recognised complication of AIDS and may involve the oral cavity. However, no case of Hodgkin's disease affecting the oral cavity in AIDS appears to have been recorded. We report a male homosexual with AIDS and Hodgkin's lymphoma, who presented with gingival involvement.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Silver-binding nucleolar organizer regions in benign and malignant prostatic lesions.

Thirty-six transvesical or transurethral prostatectomy cases were selected from the histopathology files of the Laiko General Hospital. Among the 36 cases, there were 10 with benign prostatic hyperplasia (8 patients having distinct areas of adenosis) and 26 cases of prostatic adenocarcinoma (6 grade I, 13 grades II and III and 7 grade IV carcinomas). From each case, silver-binding nucleolar organizer regions (AgNORs) have been counted in sections of routinely processed paraffin-embedded tissue blocks. The mean AgNOR count per case was calculated. For the cases of prostatic hyperplasia, the mean AgNOR count was found to be 2.95 +/- 0.42, for adenosis 3.45 +/- 0.56, for grade I adenocarcinoma 4.97 +/- 0.74, for grades II and III 7.31 +/- 0.81 and for grade IV adenocarcinomas 11.41 +/- 1.68. This difference in the mean AgNOR count was found to be of statistical significance (p < 0.001) between adenosis and grade I adenocarcinomas and between grade II and III and grade IV adenocarcinomas. It appears that AgNOR counting may prove to be of benefit in differentiating between some benign and malignant prostatic lesions and that it might provide information concerning the biological behavior of prostatic adenocarcinomas.

Adenocarcinoma↗
PubMed1992

Correlation of colposcopy and histology in cervical biopsies positive for CIN and/or HPV infection.

The purpose of our study was the investigation of colposcopic findings in 108 patients with histologically proved CIN and/or HPV infection in colposcopically directed cervical punch biopsies. The chi square test with Yates' correction was used for the statistical analysis. In 82 cases there were histological changes suggestive of HPV infection, 91 cases showed CIN while in 65 cases CIN was superimposed on HPV infection. The sensitivity of colposcopy was 89% for the detection of CIN and 61% for HPV. In 45% of CIN cases colposcopy underdiagnosed the CIN level, especially in more severe lesions (level II or higher, P < 0.001). We have also observed that the HPV-related colposcopic findings significantly increased the probability of underdiagnosing CIN (P < 0.05). Our results suggest that biopsy is always necessary in order to establish the diagnosis and determine the severity of CIN, especially if the colposcopist suspects HPV infection. We have also shown that many cases of HPV infection are not detected by colposcopy, because they are masked by the coexisting CIN.

Colposcopy↗
PubMed1992

Tuberculosis associated hemophagocytic syndrome complicated with severe bone marrow failure and disseminated intravascular coagulation.

Tuberculosis associated hemophagocytic syndrome (HPS) has recently been recognized as a benign reactive histiocytic proliferation with marrow hemophagocytosis. To our knowledge, only five autopsy documented cases have previously been reported. We present here a unique case of the disorder complicated by severe bone marrow failure and disseminated intravascular coagulation. The possible mechanisms of these complications are discussed and it is concluded that the immunological disturbances usually occurring in miliary tuberculosis could play a role in the pathogenesis of HPS.

Aged↗
PubMed1989

Glycosaminoglycans in urine, articular and periarticular tissues in streptozotocin diabetes in rats.

Experimental data support the hypothesis that insulin deficiency increases the degradation of glycosaminoglycans (GAGs) and decreases their synthesis. The purpose of this study was to investigate the effect of streptozotocin-induced experimental diabetes on mucopolysaccharide content of the articular and periarticular tissues as well as on the urine GAGs excretion. In two groups (A and B) of ten white Wistar rats, experimental diabetes was induced after administration of streptozotocin in a dose of 65 and 45 mg/kg of body weight, respectively. The animals of group A (short term diabetes) and B (long term diabetes) were sacrificed on the 8th and 87th day of the experimental procedure respectively. GAGs were determined in urine specimens collected before and on the 8th day in group A and before and on 3rd, 8th, 16th, 23rd, 36th, 52nd, 71st and the 87th day in group B. At the end of the experiment articular and periarticular tissue specimens were examined for changes in their mucopolysaccharides content and compared to a group of five animals of the same age and dietary conditions (control group, C). We found a marked increase (P less than 0.001) of urine GAGs excretion during streptozotocin-induced diabetes as compared to the respective values before the experiment in both groups, while in group B a positive relationship (P less than 0.001) between 24 hour urine GASGs excretion, and the duration of diabetes was observed. The histochemistry of the articular and periarticular tissues revealed marked decrease in GAGs content, as well as hardening of the tendons.

Animals↗
PubMed1989

Intraepithelial lumina in urothelial bladder neoplasms. A histochemical, immunohistochemical and electron microscopy study.

Intraepithelial lumina observed in 12 urothelial bladder neoplasms were studied histochemically, immunohistochemically and ultrastructurally. Both intercellular and intracytoplasmic lumina could be demonstrated showing an alcianophilic margin and containing non-sulphated acid mucins. The presence of secretory component (SC) was identified in neoplastic urothelial cells around or adjacent to intercellular lumina as well as in cells with intracytoplasmic lumina. The cells surrounding intercellular lumina revealed ultrastructurally tight junctions, microvilli and a prominent glycocalyx while cellular remnants were found quite often within the lumen. As similar histochemical, immunohistochemical and ultrastructural characteristics are also expressed in surface umbrella cells of normal urothelium it is suggested that a focal differentiation of neoplastic urothelial cells towards surface umbrella-like cells takes place and that this process is intimately related to the formation of lumina.

Carcinoma↗
PubMed1989

Alterations in pancreatic B-, A- and D-cell populations following administration of corticosteroids. Immunocytochemical study in rats.

Prednisolone was administered to two groups of rats for 2 or 4 weeks, respectively. A third group served for control. Serum glucose and insulin levels were measured, and changes in population size along with alterations in staining density of the intracellular granules in pancreatic B-, A- and D-cells were assessed. Two weeks of prednisolone treatment induced significant increases in the staining density of the intracellular granules of B- and D-cells as well as the population size of A-cells, while significant hyperglucosaemia and hyperinsulinaemia were observed. Four weeks of prednisolone administration induced significant increases in population size of B- and D-cells and significant decrease in the population size of A-cells, while hyperglucosaemia and hyperinsulinaemia were even greater. It is concluded that corticosteroids cause an increase in pancreatic B-cell activity and, eventually A-cell numerical atrophy by altering the glucose metabolism. The changes in activity of D-cells possibly reflect functional adaptation to increased B-cell activity.

Animals↗
PubMed1988

Fundic, antral and pancreatic D-cell population changes following oophorectomy and sex hormone administration in guinea pigs. Experimental immunocytochemical study.

Twelve female guinea pigs were given estradiol and another 12 testosterone for 18 days. A third group of 15 animals underwent oophorectomy and a group of 8 animals served as controls. Gastric and pancreatic D-cells were quantitated in all four groups. Oophorectomy and androgens significantly increased and estrogens significantly decreased gastric D-cell populations. Additionally, estrogens significantly decreased D-cell population in pancreatic islets. It is concluded that the alterations in gastric and pancreatic D-cell populations, which are induced by sex hormone administration and oophorectomy, possibly reflect a hormonal adaptive attempt to restore gastric secretory functions within the normal range.

Animals↗
PubMed1988

Immunohistochemical study of sex steroid hormones in primary liver cancer.

Paraffin-embedded tissue sections from 29 patients with primary liver carcinomas were retrospectively studied for the presence of estradiol and testosterone using the peroxidase-antiperoxidase (PAP) technique. Twenty-seven hepatomas and two cholangiomas were treated with antiestradiol and antitestosterone primary serum. Estradiol was detected in 17 cases and testosterone in 11 cases of hepatomas. The two cases of cholangiocarcinoma were positive for estradiol and negative for testosterone. The immunohistochemical reaction in the tumor cells was mainly cytoplasmic and in a few cases both cytoplasmic and intranuclear. The positivity of the reaction in the tumour cells was compared with that of the adjacent non-neoplastic liver tissue and bile duct cells. Our findings were also analyzed in relation to tumor differentiation and the age and sex of the patients.

Adult↗
PubMed1988

B-chronic lymphocytic leukemia. Disease progression in 150 untreated stage A and B patients as predicted by bone marrow pattern.

Previous studies have shown that the pattern of bone marrow (bm) involvement in B-CLL patients is the single most important prognostic factor. In the present study we analyse the disease progression observed in 45 out of 150 untreated stages A and B, B-CLL patients in relation to their pattern of bm involvement. The mean treatment free period was 45 months (10-130). The distribution of bm patterns and disease progression in our series was as follows: in stage A, Bm patterns diffuse in 24 cases (21.8%); in stage B: in 21 cases (52.5%). Disease progression from stage A to stage B or C and from stage B to stage C was found 50% of the A and B-diffuse patients as compared to 10% of the A and B-nondiffuse. The mean period during which this progression occurred was 18 months for the stages A and B with a diffuse pattern and 59 months for the stages A and B with a nondiffuse pattern. No differences could be observed in the nondiffuse group when our patients were analysed on the basis of nodular, interstitial and mixed pattern of bm involvement. All progressed patients required therapy. These findings support our previous observations, and present further evidence that in B-CLL patients with a diffuse pattern of bm disease at diagnosis, treatment should be initiated independently of their clinical stage.

Adult↗