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C Kittas

Publications and source records attributed to C Kittas.

At least 73 records · Page 4Linked to original sources

Macrovascular disease of coronaries and cerebral arteries in streptozotocin-induced diabetic rats. A controlled, comparative study.

The aim of this study was to demonstrate the macrovascular disease in streptozotocin-induced diabetic rats and assess any possible differences between the histopatholological changes of the coronaries and cerebral arteries. Hearts and brains were obtained after 4 weeks (short-term experimental diabetes, 10 rats) and 12 weeks (long-term experimental diabetes, 10 rats) of streptozotocin injection. Sham injected, control rats were studied in parallel. Muscular-type arteries of 0.10-0.15 mm were examined and semiquantitatively classified either as normal, or slightly, or moderately, or severely thickened by light microscopy: While the arterial wall appeared normal in all sham-injected rats, a varying degree of hyperplasia of the muscular layer and deposition of fibrinoid material resulting in arterial stenosis was prominent in streptozotocin-injected rats. In the group of short-term diabetes there was a slight thickening of the cerebral arteries in the majority of the rats (8/10 rats), while thickening of the coronaries was moderate (9/10 rats). Further progression of arterial wall thickening in both cerebral and coronary arteries was observed in the long-term diabetic group. The mean severity of lesions was significantly higher in the coronaries than in cerebral arteries, both in the short-term (p < 0.0005) and long-term diabetes (p < 0.02). Moreover, by paired statistics within individual animals, we confirmed that wall thickening was significantly more severe in coronaries than cerebral arteries in both groups. These findings suggest an accelerated progress of macrovascular disease in the heart as compared to the brain in the streptozotocin-induced diabetic rat. Although histopathological changes in humans do not always mirror clinical severity, the differences in the macrovascular disease between heart and brain in experimental diabetes may be relevant to the higher relative risk of myocardial infarction compared to stroke for people with diabetes, as compared to people without diabetes.

Animals↗

Cyst formation after fat injection.

Autologous fat injection has been widely used during the past 20 years to correct contour anomalies. We have been using suction-assisted lipectomy for the past 13 years, and we have used the aspirated fat to correct contour irregularities on several occasions. We present the case of a 44-year-old woman who, after autologous fat transplantation to correct a contour anomaly (depression secondary to a previous operation) at her left groin, developed a large cyst containing pearl-like fat lobules. The cyst was first noticed 3 months postoperatively and was removed under local anesthesia 5 months postoperatively. Histology confirmed that the lobules were mature fat cells.

Adipose Tissue↗

Prognostic implications of proliferating cell nuclear antigen (PCNA), AgNORs and P53 in non-Hodgkin's lymphomas.

We investigated the prognostic value of proliferating cell nuclear antigen (PCNA) and p53 oncoprotein expression and of nucleolar organiser region (NOR) scoring, in relation to classic clinicopathological parameters, in a series of non-Hodgkin's lymphomas (NHL). Paraffin embedded tissue from 91 patients with NHL was stained immunohistochemically with the monoclonal antibodies PC-10 (PCNA) and DO-1 (p53) and histochemically with the AgNOR technique. The median follow-up was 48 (4 to 193) months. The impact of PCNA and p53 expression and of AgNOR number on survival was tested using univariate as well as multivariate analysis, in order to circumvent the heterogeneity in histologic grade, type and therapy. Univariate analysis identified seven variables related to overall survival: histologic type and grade, clinical stage, chemotherapy, p53 labelling index (LI), PCNA LI and AgNOR score, whereas only one parameter i.e. histologic grade influenced disease-free survival. In multivariate analysis stage, PCNA LI and AgNOR score predicted independently overall survival. PCNA was also the only independent predictor of post-relapse survival and histologic grade the most important indicator of disease-free survival. In conclusion, PCNA expression and AgNOR number may be better predictors of overall and post-relapse survival than histologic grade. The latter remains the most valuable prognostic indicator of disease-free survival.

Adolescent↗

Alterations of p16-pRb pathway and chromosome locus 9p21-22 in sporadic invasive breast carcinomas.

The p16-pRb pathway represents a vital cell-cycle checkpoint. In the present study we investigated the alterations of this G1-phase protein pathway using immunohistochemical and molecular methods in a series of 55 breast carcinomas and correlated the findings with clinicopathological features of the patients. Furthermore, we examined its relationship with the status of the chromosomal region 9p21-22 performing a deletion map analysis because there are indications that, in addition to CDKN2 and MTS2/p15(INK4B) tumor suppressor genes (TSGs), this area harbors other TSG(s). Aberrant expression (Ab) of p16 and pRb was observed in 26 (47%) and 16 (29%) of the carcinomas, respectively. A statistical trend pointing out an inverse relationship between p16 and pRb expression was found (p = 0.079). Analysis of the region that encodes for p16 by deletion mapping, a PCR-based methylation assay and PCR-SSCP, revealed that deletions and transcriptional silencing by methylation might represent the main mechanisms of CDKN2/p16(INK4A) inactivation in breast carcinomas. The results of deletion mapping also suggest that another TSG(s) may reside at the 9p21-22 area particularly at the D9S162 loci and that co-deletion of this putative gene with CDKN2/p16(INK4A) may play a role in breast carcinogenesis. In addition, microsatellite instability (MI), a marker of replication error phenotype (RER+), was observed with a frequency of 16% in the area examined and was inversely related with loss of heterozygosity (LOH). Interestingly, most cases with MI at the region encoding for p16 were aggregated in a subgroup of breast carcinomas with no other obvious genetic and/or epigenetic CDKN2/p16(INK4A) alterations. We speculate that there is an additional mechanism of CDKN2/p16(INK4A) inactivation. The relationship of p16 protein level pRb, status, the p16-pRb combined immunoprofiles, and the microsatellite alterations detected at the 9p21-22 locus with the patients' clinicopathological parameters revealed two significant correlations: one between normal pRb expression and lymph node involvement (p = 0.0263), and the other between microsatellite alterations (LOH and or MI) and tumor size (p = 9.2 x 10(-3)). In view of the heterogenous nature of breast cancer, we suggest that in a significant proportion of breast carcinomas, deregulation of the p16-pRb pathway in association with another, as-yet unidentified, TSG(s) of the 9p21-22 region may play a role in initiating or progressing the oncogenic procedure, while in other subgroups, alternative molecules may play this role.

Adult↗

Tuberculosis of the sacroiliac joint.

A 23-year-old woman presented with low back pain of several months' duration. A tuberculous infection of the left sacroiliac joint was diagnosed by closed-needle biopsy. The clinical presentation, radiological features and outcome of this patient are discussed.

Adult↗

Glucocorticoid receptor gene expression during rat embryogenesis. An in situ hybridization study.

Glucocorticoids play an important role in embryonic development. The existence of sufficient amounts of their receptors during rodent embryogenesis has proved to be an absolute necessity for the physiological growth of the animal. We have analyzed the pattern of glucocorticoid receptor gene expression in the rat embryo through embryonic days 12 to 17, by using in situ hybridization histochemistry. Glucocorticoid receptor mRNA is present in the rat liver on embryonic day (E) 12, and by E13 the signal can also be detected in several other tissues, such as the lung, the heart, the mesonephros, the sclerotomes, the thymus and Rathke's pouch. Glucocorticoid receptor gene expression was quite ubiquitous in tissue derivatives of all three germ layers and appeared to vary in intensity within the same tissue during embryogenesis. These variations in the level of receptor gene expression paralleled the developmental stage of each tissue: Intense labelling was detected just prior to the final differentiation step of a structure. Upon differentiation, cell populations highly expressing glucocorticoid receptor gene in the previous stage were found to have reduced amounts of the receptor mRNA. Our results support a morphogenetic role for glucocorticoids during embryogenesis.

Animals↗

A molecular and immunohistochemical study of the MDM2 protein isoforms and p53 gene product in bronchogenic carcinoma.

Forty-one bronchogenic carcinomas were investigated for expression of MDM2 protein isoforms and their relationship to p53 protein levels and p53 gene alterations using molecular and immunohistochemical techniques. The findings were correlated with the pathological features of the carcinomas. MDM2 protein was overexpressed in 26 cases (63 percent). Western blot analysis with two monoclonal antibodies, 1B10 and IF2, revealed three MDM2 protein isoforms, p90, p57 and p76/74. p90 and p57 are capable of interacting with p53 protein, while p76/74 is not. Various patterns of MDM2 isoforms were seen. Although no correlation between the patterns and pathological features was observed, lymph node metastases were more frequent in the cases with MDM2 overexpression (P < 0.005). In 3 out of 17 specimens of normal lung tissue examined, there was a low level of expression of p90. Molecular analysis revealed that MDM2 overexpression was a consequence of increased transcription rather than MDM2 gene amplification. p53 protein was overexpressed in 21 cases (51 percent) and p53 gene alterations (mutations + allelic deletions) were detected in 23 patients (56 percent). A high degree of concordance (76 percent) between p53 mutations and p53 staining was noticed (P < 10(-5)). p53 gene alterations were significantly associated with lymph node disease (P < 0.01). MDM2 and p53 proteins were simultaneously detected in 21 cases (51 percent), of which 17 (42 percent) showed p53 and MDM2 overexpression. The latter group was positively correlated with p53 mutations (P < 0.05). A strong correlation between MDM2/p53 co-expression and lymph node metastases was observed (P < 0.001). The findings suggest that MDM2 overexpression is a common event in bronchogenic carcinoma. The selective expression of some MDM2 isoforms in neoplastic tissue and not in the surrounding normal areas underscores the pathological role of the various MDM2 products. Finally, the coexistence of MDM2 protein(s) and p53 aberrations (mutations and/or overexpression) in a subset of lung carcinomas may be indicative of a 'gain of function' phenotype, with more aggressive characteristics.

Blotting, Northern↗

Bile canaliculi are defective in hepatic involvement of organ failure and recovery of liver function is due to their secondary regeneration.

OBJECTIVE: To investigate the morphological changes in the liver in patients with organ failure and hyperbilirubinemia and to correlate them to the outcome. DESIGN: A case series prospective study. SETTING: Intensive care units of two general hospitals. PATIENTS: Twelve patients in organ failure with predominant hepatic involvement, aged 16 to 69 years (mean 56 years). INTERVENTIONS: Liver biopsy was performed on all patients 3-15 days after organ failure. A second biopsy was also performed on all four surviving patients, as well as on 3 patients just before death at a mean time of 16 days (6-32) and 31 days (14-55), respectively, after the first biopsy. The samples were studied by electron microscopy and findings were assessed according to Rappaport's designation. MEASUREMENTS AND MAIN RESULTS: In the first biopsy it was shown that in zone III there was complete degeneration of bile canaliculi and hepatocytes in contrast to zone I. The grade of histological severity for zone III is positively correlated to the bilirubin concentration (p = 0.001). In the specimens from the second biopsy, it was shown that numerous, newly formed secondary bile canaliculi per 20 consecutive hepatocytes had developed in zone III in the surviving patients, whereas there was a complete absence of such canaliculi in the patients who died (mean +/- SD: 9.6 +/- 3.2 vs 0). CONCLUSIONS: It appears that the destruction of primary bile canaliculi is a striking anatomical defect in patients with organ failure and impaired bilirubin excretion. The restoration of liver function coincides with adequate formation of new secondary bile canaliculi in zone III, giving credence to the hypothesis that this formation is an important structural change responsible for the improvement in liver function.

Bile Canaliculi↗

Hepatic stimulator substance administration enhances regenerative capacity of hepatocytes in cadmium-pretreated partially hepatectomized rats.

The liver is of central importance in the metabolism of essential and toxic metals such as cadmium (Cd). Cd pretreatment suppressed the regenerative capacity of hepatocytes, which normally occurs 24 hr after partial hepatectomy, due to the inhibition of the activity of the enzyme thymidine kinase. The effect of hepatic stimulator substance (HSS) administration (10, 20, and 40 mg protein/kg body weight) on hepatocyte proliferation was investigated in Cd-pretreated partially hepatectomized rats. HSS administration partly restored the suppressed hepatocyte DNA biosynthesis in Cd-pretreated partially hepatectomized rats. The hepatocyte mitotic activity and the percentage of proliferating cell nuclear antigen-positive nuclei were in accordance with the liver proliferative status. The administration of HSS did not affect in a statistically significant manner the activity of the enzyme thymidine kinase in Cd-pretreated partially hepatectomized rats. It is suggested that the administration of HSS ameliorates the diminished hepatocyte regenerative response to partial hepatectomy in this model of acute liver injury, due to Cd intoxication.

Animals↗

Immunohistochemical and molecular evaluation of the mdm-2 gene product in bronchogenic carcinoma.

In this study, we investigated immunohistochemically the expression of mdm-2 protein in 93 surgically resected bronchogenic carcinomas. The findings were correlated with p53 protein detection status and clinicopathologic data (histologic type, differentiation grade of the lesions, lymph node metastases, and smoking history of the patients). Thirty of the 93 immunohistochemically examined specimens were subjected to Northern blot and differential polymerase chain reaction analysis to look into the mechanism of mdm-2 overexpression. Finally, we studied the concordance between p53 immunohistochemical positivity and p53 gene alterations as assessed by the single-strand conformation polymorphism technique. Seventy-three (78%) and 67 (72%) of 93 carcinomas showed nuclear immunoreactivity for mdm-2 and p53 proteins, respectively. We observed a high degree of concordance (75%) between p53 mutations and p53 immunolabelling, which was even higher in the specimens with p53 positively in more than 50% of the cells (90%). Despite the high percentage of mdm-2 and p53 expression, the two molecules were simultaneously detected in 50 (54%) of 93 cases. Forty-two (84%) of the 50 cases were accompanied by p53 mobility shifts, which indicated mutations. Interestingly, statistical analysis revealed an almost significant correlation between the carcinomas with mdm-2/p53 coexpression and lymph node disease (P = 0.058), which indicated a possible "gain of function" phenotype. In addition, absence of reactivity for both proteins was statistically more frequent in the patients without lymph node disease (P = 0.006). The mdm-2-positive/p53-negative immunohistochemical profile was more often seen in adenocarcinomas (P = 0.003), especially in well-differentiated ones (P = 0.02), than in other histologic types of lung cancer, which suggested a p53-independent pathway of mdm-2 overexpression. Molecular analysis showed that mdm-2 overexpression was a consequence of increased transcription rather than of mdm-2 gene amplification. The smoking history of the patients was strongly related to p53 (P = 10(-4)) even in the group of adenocarcinomas (P = 0.012). No correlation was observed between cigarette consumption and mdm-2 immunoreactivity.

Adenocarcinoma↗

Cystadenolymphoma of the parotid gland an immunohistochemical study of the epithelial component of twenty cases.

Carcinoembryonic antigen, epithelial membrane antigen, Keratin, Desmin, Vimentin, CD30, lysozyme, alpha 1-antitrypsin, alpha 1-antichymotrypsin, S-100 protein, somatostatin and glucagon were looked for using immunohistochemical methods in the epithelial component of 20 parotid gland cystadenolymphomas and 20 normal parotid glands. Carcino-embryonic antigen, ephithelial membrane antigen, S-100 protein, and somatostatin were found in the epithelial cells of most of the cystadenolymphomas. In normal parotid tissue, carcinoembryonic antigen, epithelial membrane antigen, Keratin, alpha 1-antitrypsin, alpha 1-antichymotrypsin, and S-100 protein were found in all three types of ductal cells, somatostatin only in intercalated and striated ductal cells, and lysozyme only in acinar and intercalated ductal cells. Desmin and CD30 were found in the epithelial component of seven of the 20 tumors versus none of the 20 normal parotid glands. Glucagon and Vimentin were negative both in tumor epithelial cells and in normal parotid ductal cells. Our results support the theory that cystadenolymphomas arise from epithelial cells. The presence of lysozyme in the epithelial tumor cells and in the intercalated ductal cells of normal parotid tissue suggest that cystadenolymphomas may arise from the intercalated ducts. The presence of S-100 and somatostatin may indicate that the tumor derives from neuroendocrine structures, but further studies are needed to clarify this point.

Adenolymphoma↗

Molecular analysis of p53 gene in laryngeal premalignant and malignant lesions. p53 protein immunohistochemical expression is positively related to proliferating cell nuclear antigen labelling index.

This study was undertaken in order to investigate the molecular nature of the p53 gene in 19 laryngeal squamous cell carcinomas and dysplasias. Moreover, we have examined the possible relationship between proliferating cell nuclear antigen (PCNA) expression and p53 protein detection status in 42 laryngeal premalignant and malignant lesions in which 14 of the 19 samples used in the molecular study were included. p53 gene analysis was performed with the single-strand conformation polymorphism technique. PCNA was stained with the peroxidase/antiperoxidase immunohistochemical method using the monoclonal antibody PC-10. Data from previous work concerning p53 expression was used. We found that 9 of 12 of the immunohistochemically p53 positive (+) cases had mutations in exons 5 or 6. In the remaining immunohistochemically p53(+) and p53 negative (-) specimens there was no indication of sequence alterations. Furthermore, we did not observe any deletions in the chromosomal region 17p31.1 which encodes exons 4-8 of the p53 gene. The PCNA labelling index (LI) increased progressively with p53 protein detection status (percentage of cells immunohistochemically positive for p53). The difference between the group with the higher percentage of p53(+) cells and the others was statistically significant. These data show that although there is a discrepancy between immunohistochemical demonstration of p53 and molecular analysis, a large proportion of the former harbours the mutant form of the protein. In addition, p53 overexpression is positively correlated with PCNA LI, a finding which accompanies tumour progression.

Base Sequence↗

Heat shock protein 70 and HLA-DR molecules tissue expression. Prognostic implications in colorectal cancer.

PURPOSE: The expression of 70,000-Da heat shock protein (HSP 70) and HLA-DR molecules on cancer cells influences immunologic mechanisms that may be of some prognostic significance. The purpose of this study was to examine the relationship among immunohistochemical HSP 70, HLA-DR expression, and clinicopathologic tumor variables, as well as patient survival in a series of 128 colorectal carcinomas. METHOD: A three-step immunoperoxidase staining technique was undertaken for detection of both markers. RESULTS: Of the examined carcinomas 77.3 percent were HSP 70-positive and 74.2 percent were HLA-DR-positive. Increased HSP 70-positive expression correlated significantly with low differentiation (P < 0.05), showed a tendency to characterize advanced stages of disease, and was clearly associated with worse overall survival (P < 0.05). The highest rate of HLA-DR positivity was demonstrated in early stages and was significantly associated with more favorable prognosis (P < 0.001). HSP 70-positive/HLA-DR-negative patients had worse overall survival compared with the rest (P < 0.001). CONCLUSIONS: The resulting opposite effects on prognosis of examined markers seem to be related to different pathophysiologic functional roles on tumor immunology.

Adolescent↗

Retinoic acid affects basement membrane formation of the seminiferous cords in 14-day male rat gonads in vitro.

The vitamin A derivative retinoic acid (RA) has been previously shown to have teratogenic effects and an ability to modulate cell differentiation in vivo and in vitro. In this study bilateral testicular primordia with the mesonephroi attached were isolated from rat fetuses at 14.5 days of gestation. The gonads were cultured on agar-coated grids in a synthetic medium. RA was added to male rat embryonic gonad cultures at a final concentration of 10(-6) M for 3 h. Two types of controls were prepared: (1) by omitting RA from the culture medium (alcohol controls) and (2) by using plain medium (untreated controls). When applied to gonad cultures RA was found to affect basement membrane development and disturb the general appearance of the tissue. All controls exhibited normal morphology. In order to evaluate the morphological changes observed due to the RA treatment, constituents of the basement membrane, laminin and collagen IV, were localized immunohistochemically at the light microscope level. Basement membrane was also studied at the electron microscope level in control and RA-treated cultures. We propose that one of the effects RA has on rat testicular morphogenesis is the irreversible suppression of seminiferous cord basement membrane formation and the disruption of normal testicular morphogenesis.

Animals↗

Expression of bcl-2 and p53 proteins in nasopharyngeal carcinoma. Absence of correlation with the presence of EBV encoded EBER1-2 transcripts and latent membrane protein-1.

Aims-To investigate the immunohistochemical expression of bcl-2 and p53 proteins in nasopharyngeal carcinomas in relation to the expression of the Epstein-Barr virus (EBV) encoded EBER messenger RNAs (mRNAs) and latent membrane protein-1 (LMP-1).Methods-Formalin fixed, paraffin wax embedded tissue from 44 nasopharyngeal carcinomas (NPCs) was stained by immunohistochemistry for p53, bcl-2 and LMP-1 proteins and by RNA in situ hybridisation for EBER mRNAs.Results-The tumours were divided histologically into 13 cases of keratinising squamous cell NPC (KNPC), 15 cases of non-keratinising squamous cell NPC (NKNPC) and 16 cases of undifferentiated NPC (UNPC). Bcl-2 expression was observed in five of 15 NKNPC cases and in six of 16 UNPC cases; p53 expression was observed in one of 13 KNPC, two of 15 NKNPC and four of 16 UNPC cases. EBER 1-2 transcripts were detected in five of 15 NKNPC and nine of 16 UNPC cases, while LMP-1 expression was observed in one of 16 UNPC cases. All 13 KNPCs were EBV and bcl-2 negative. No correlation was found between the presence of EBER 1-2 transcripts and the detection of bcl-2 or p53 proteins, or both, in NPC cells.Conclusions-The expression of bcl-2 and p53 proteins may be associated with the level of the tumour cell differentiation in NPC. In addition, in view of the important role of the bcl-2 protein in the inhibition of apoptosis, the expression of bcl-2 protein may contribute to tumour cell survival in a proportion of NPCs. Furthermore, in the light of previous findings that the p53 gene in most UNPCs is in the wild-type configuration, mechanisms other than mutation may be responsible for stabilisation of the p53 protein in UNPCs.

Journal Article↗

Histological and functional changes in the salivary glands in thalassaemia major.

Oral salivary secretion and oral histology in 15 multi-transfused adult thalassaemia homozygotes was studied. Iron stores of minor salivary glands were also histochemically determined. Salivary secretion in multi-transfused thalassaemia patients was subclinically decreased, but no clear correlation was evident between salivary secretion impairment and salivary gland destruction by iron deposition, lymphocyte infiltration and fibrosis. The underlying mechanism remains to be determined.

Adolescent↗

Expression of p53 protein in laryngeal squamous cell carcinoma and dysplasia: possible correlation with human papillomavirus infection and clinicopathological findings.

In order to evaluate the expression of p53 protein in 28 premalignant and 40 malignant squamous cell proliferations of the larynx and its relationship to tobacco consumption, human papillomavirus infection and differentiation grade of the lesions, p53 expression was examined by means of a microwave post-fixation immunohistochemical method using the PAb 240 and PAb 1801 monoclonal antibodies. HPV infection was assessed by non-isotopic in situ hybridization (NISH) and polymerase chain reaction (PCR). A large proportion of carcinomas (77.5%) and dysplasias (61%) expressed p53. No difference was found between differentiation grades of the lesions regarding p53 detection (P > 0.1), but moderate or intense p53 expression was more frequent in the carcinomas (P < 0.05). A statistical correlation was found between cigarette consumption and both p53 detection and p53 staining intensity (P < 0.05 in each case). HPV study revealed HPV 16 and 18 infection only in carcinomas. The frequency was 28% and the physical state of the virus as demonstrated by NISH was integration into the genome. We observed an inverse relationship between HPV infection and p53 expression (P = 0.006). Our findings suggest that p53 overexpression is a common and early event which increases in frequency with progression of laryngeal squamous cell carcinoma. The expression of p53 is influenced by tobacco and high-risk types of HPV.

Base Sequence↗

Proliferating cell nuclear antigen (PCNA) expression in regenerating rat liver after partial hepatectomy.

Proliferating cell nuclear antigen (PCNA) is a nuclear protein maximally elevated in the S phase of proliferating and transformed cells and is recognized by the monoclonal antibody PC-10 in paraffin tissue sections. The liver regenerative process after partial hepatectomy in rats was estimated with the in vivo incorporation of [3H]thymidine into liver DNA and the liver thymidine kinase activity. The expression of PCNA in rat liver after partial hepatectomy was performed by immunohistochemical staining with PC-10 in paraffin embedded tissues, at different time intervals up to 240 hr. Proliferating cell nuclear antigen expression, [3H]thymidine incorporation into DNA, and liver thymidine kinase activity exhibited marked oscillations during the liver regenerative process. A close relationship was demonstrated among DNA synthesis, thymidine kinase activity, and PC-10 score. Our results suggest that PC-10 monoclonal antibody may be used as a worthwhile proliferation index in the evaluation of the rate of liver regeneration in rats.

Animals↗