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C Kittas

Publications and source records attributed to C Kittas.

142 records · Page 8Linked to original sources
PubMedDate not supplied

Experimental inoculation of laboratory animals with samples collected from sarcoidal patients and molecular diagnostic evaluation of the results.

Studies on the implication of mycobacteria in the pathogenesis of sarcoidosis have generated conflicting results. In an attempt to further elucidate the etiology of the disease, we obtained broncho-alveolar lavage (BAL) samples from sarcoidal patients, which were subsequently used for intra-tracheal inoculation of a group of rabbits. Patients were characterized as sarcoidal on the grounds of clinical, radiographic, histological and microbiological testing. Four months following inoculation, lung and alveolar lymph node specimens were collected from the animals and were examined by means of histology and microbiology, as well as by a polymerase chain reaction (PCR) assay, targeted to DNA sequences of the Mycobacterium tuberculosis and Mycobacterium avium complexes. All of the twenty five BAL-inoculated rabbits revealed evidence of lobar pneumonia, with thirteen developing lesions of non-caseous granulomatous inflammation, similar to those observed in sarcoidal patients. Microbiological cultivation of lung and alveolar lymph node material, Zihl-Neelsen staining of corresponding tissue sections and PCR analysis of extracted DNA yielded no evidence of mycobacterial infection. Identical processing of biopsies originating from the martyrs, formerly inoculated with drinking water or disinfected BAL, revealed no pathological signs. Our findings suggest that BAL samples from patients with sarcoidosis may carry an agent that produces a disease characterized by similar histological lesions in rabbits. However, culture, and PCR, could not identify this agent as a member of Mycobacterium tuberculosis, or Mycobacterium avium complexes.

Adult↗
PubMedDate not supplied

A new rare allele at the CGG repeat polymorphism in the first intron of human c-H-ras gene.

We have examined a region in the first intron of the human c-H-ras gene containing a CGG repeat. This region was previously shown to be variable in length. The length variation was attributed to the presence of the CGG repeat after estimation of its electrophoretic mobility. In the present report we have characterized in detail this region by PCR-RFLP and automated sequencing, in a total of 102 histologically normal tissues from unrelated individuals affected by lung and breast cancer. Four alleles were detected and analysis of their internal sequence showed that the length alterations of this region were due to the presence of 5, 6, 8 and 9 CGG triplets respectively. The last three occur most often (44.1%, 34.8%, 20.6% respectively) and coincide with three previously reported alleles (Riggins et al, Hum Mol Genet 9: 775, 1992). The fourth allele consisting of 5 repeats is a rare one (0.5%), whilst alleles with 7, and a previously reported one suggested to comprise 11 repeats (1%) were not present in our cohort. This polymorphism coincides in position with an element that was previously shown to possess regulatory activity.

Alleles↗
PubMedDate not supplied

Alterations of the 16q22.1 and 16q24.3 chromosomal loci in sporadic invasive breast carcinomas: correlation with proliferative activity, ploidy and hormonal status of the tumors.

BACKGROUND: Breast cancer is characterized by complex genetic alterations found in multiple chromosomal regions, most commonly losses of 17p, 16q, 8p and others. A number of tumor suppressor genes mapped on these loci have been investigated in mammary tumors, whereas other gene products are of unclear function and await identification. MATERIALS AND METHODS: We analyzed the loss of heterozygosity (LOH) of two chromosomal loci: a. 16q24.3 using the genetic markers D16S303, D16S3026 and D16S3407 and b. 16q22.1, the locus of E-cadherin gene, using the microsatelite markers D16S503, D16S752 and D16S512, in a series of 63 sporadic invasive breast carcinomas consisting of 56 ductal, 4 lobular and 3 tumors of mixed type. Our findings were correlated with proliferative activity, ploidy and hormonal status of the tumors. RESULTS: Fourteen (22.2%) tumors demonstrated LOH of 16q24.3. Allelic imbalance of the 16q22.1 locus was found in 19 of 61 informative cases (31%) and commonly coexisted with LOH of 16q24.3. A significant association was observed between LOH of D16S752 and the absence of progesterone receptors in tumor cells (p = 0.005). CONCLUSIONS: LOH of 16q24.3 and 16q22.1 are frequent genetic alterations in breast cancer and they do not seem to correlate with tumor cell proliferation or ploidy. The statistical association between LOH of 16q24.3 and progesterone receptors need to be further investigated in larger series.

Adult↗
PubMedDate not supplied

HER-2/neu overexpression in breast cancer: an immunohistochemical study including correlations with clinicopathologic parameters, p53 oncoprotein and cathepsin-D.

PURPOSE: To evaluate the relationship between HER-2/neu overexpression and standard as well as investigational prognostic factors in Greek females with invasive breast carcinoma. MATERIALS AND METHODS: Paraffin-embedded tumor sections from 128 consecutive primary breast cancer patients were screened for HER-2/neu oncoprotein (p185) overexpression by immunohistochemistry using the polyclonal antibody A 0485. The relationship between HER-2/neu staining and other established markers of prognosis were examined using both a univariate and a multivariate analysis. RESULTS: HER-2/neu overexpression was detected in 46.1% of tumors. No statistical correlation was found between HER-2/neu and age, tumor diameter, histologic type, nodal status, tumor grade, stage, estrogen and progesterone receptor status or cathepsin-D. A significant correlation was noted between HER-2/neu and p53 overexpression in the total sample (p=0.014) as well as in node-positive patients (p=0.026). In those groups, HER-2/neu and p53 co-expression was found in 19.5% and 21.6% of cases, respectively. In node-negative patients, HER-2/neu overexpression did not correlate with any other marker. CONCLUSION: HER-2/neu overexpression seemed to correlate only with p53 oncoprotein.

Biomarkers, Tumor↗
PubMedDate not supplied

Expression of HLA-DR is reduced in tumor infiltrating immune cells (TIICs) and regional lymph nodes of non-small-cell lung carcinomas. A putative mechanism of tumor-induced immunosuppression?

BACKGROUND: Deregulation of MHC class II molecules consists of a favorable mechanism of tumor evasion from immune surveillance. Among these molecules, HLA-DR antigens are the predominant ones in cancer. In the present study we sought to investigate the ability of tumor infiltrating immune cells (TIICs) to express HLA-DR antigen in the primary tumor site and reactive regional lymph nodes (LNs) in non small cell lung cancer (NSCLC). MATERIALS AND METHODS: Material consisting of 60 NSCLCs with corresponding regional LNs was studied by immunohistochemistry for human leukocyte antigen D-region related (HLA-DR) expression. Control reactive LNs, regional to several different malignant and non-malignant disorders, were also included in the study. RESULTS: Primary tumor site investigation revealed positive HLA-DR cancer cells in 22% of cases, whereas TIICs rarely expressed HLA-DR antigens. The lack of HLA-DR expression in TIICs was gradually attenuated as the distance from the primary tumor site decreased. Regional LN investigation showed that all follicles (paracapsular and deep cortical ones) were HLA-DR-negative in 60% of the LNs; in the remaining 40%, the paracapsular follicles remained negative, while all deep cortical ones were positive. Interestingly, LNs possessing only HLA-DR-negative follicles were more proximal to the primary tumor site compared to those that had only the paracapsular follicles negative. All control reactive LNs, regional to several distinct malignant and non-malignant disorders, were found to be HLA-DR-positive. CONCLUSION: The impairment of HLA-DR expression, detected both in neoplastic and by-stander immune cells, may justify the immunosuppression observed in NSCLC. This phenomenon may be due to a putative soluble factor in the tumor environment secreted by cancer cells.

Carcinoma, Non-Small-Cell Lung↗
PubMedDate not supplied

[Oral Kaposi's sarcoma as the first sign of AIDS].

Kaposi's sarcoma is a multicentric malignant neoplasm probably of endothelial origin. Four forms of Kaposi's sarcoma are now recognised. AIDS-Kaposi's sarcoma is the most common malignant neoplasm associated with HIV-infection. About 20% of patients with HIV infection develop Kaposi's sarcoma and half on of them appear oral lesions. The oral mucosa may be the first or the only site of the tumor. In this paper a rare case of oral Kaposi's sarcoma which was the first sign of AIDS in a 43-years old homosexual man is presented.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Expression of proliferating cell nuclear antigen (PCNA) and nucleolar organizer regions (NORs) in multiple myeloma.

We have studied 72 cases of multiple myeloma (MM) bone marrow trephine biopsies using the monoclonal antibody PC-10 and the colloid silver nitrate method for identification of proliferating cell nuclear antigen (PCNA) and nucleolar organizer regions (NORs), respectively. PC-10 and AgNOR scores were statistically significantly different between low versus intermediate and low versus high grade of malignancy (P < 0.001), whereas their difference was not significant between intermediate and high grade. A strong correlation was identified between these two proliferation-associated indices in each histological grade. There is evidence that the proliferative state of myelomas belonging to the intermediate grade is approximately the same as that observed in high grade (blastic) ones.

Cell Division↗
PubMedDate not supplied

Expression of C-myc p62 oncoprotein in multiple myeloma: an immunohistochemical study of 180 cases.

The immunohistochemical expression of C-myc p62 oncoprotein was investigated using the immunoperoxidase method and the monoclonal antibody (Mab) MYC 1-9E10 in bone marrow paraffin sections. 180 cases of multiple myeloma (MM) were studied. C-myc expression was found to correlate well with the grade of malignancy, type of myeloma and tumor cell burden (p < 0.001). A relationship was also observed between C-myc p62 and IgA-secreting myelomas. It was found that intermediate grade myelomas are heterogeneous as far as C-myc expression is concerned. Our findings strongly suggest that C-myc might be involved in myelomutagenesis. The evaluation of its expression in MM may be helpful in determining the grade of malignancy and possibly the biological behaviour of this tumor.

Antibodies, Monoclonal↗
PubMedDate not supplied

A rapid method for the screening and typing of high risk HPVs using molecular biology techniques.

To date over 60 different human papilloma virus (HPV) types have been described and novel HPV genomes are still being identified. The identification and taxonomy of papilloma viruses has become increasingly complex However, some types, especially HPV-16, -18 and to a lesser extent HPV-31 and -33, which are found in a high proportion of invasive cervical cancers and their metastases, are classified as high risk types For preventive reasons it is important to identify and classify the different HPV types in clinical specimens. Many of the methods used until recently are cumbersome. In this paper we use molecular biology techniques which permit a rapid screening and typing of high risk HPVs in clinical specimens. The screening procedure is based on the very sensitive method of polymerase chain reaction. Using a set of general primers derived from the E1 open reading frame, which anneal to a large variety of human papilloma virus DNA, we can classify samples into positive or negative for the presence of HPV sequences in a single step. The typing of the high risk HPV types is achieved by restriction enzyme analysis using the endonuclease Alu I which cleaves each high risk HPV type at different sites, thus permitting the easy identification of each type after agarose gel electrophoresis.

Base Sequence↗
PubMedDate not supplied

C-erbB-2 oncoprotein expression in operable non-small cell lung cancer.

Although c-erbB-2 oncoprotein immunohistochemical expression has been thoroughly studied in a variety of human tumors, its prognostic significance remains unclear. Moreover, differences in assessment criteria further complicate the evaluation of c-erbB-2 as a prognostic marker. In the present study we examined the expression of c-erbB-2 protein in 107 patients suffering from operable (T 1,2-N0, 1 staged) non-small cell lung cancer (30 adenocarcinomas and 69 squamous cell carcinomas) treated with surgery alone. A 3-7 year of follow up (median 45 months) was available for all patients. Paraffin embedded sections were stained with the NCL-CB11 monoclonal antibody using the immunoperoxidase technique. Analysis was based on cytoplasmic reactivity as membrane staining was impossible to assess against this background. Strong positive cytoplasmic staining was identified in 20/107 (19%) of cases, weak in 30/107 (20%) and negative in 57/107 (53%). Results were correlated with patient variables (age,sex) and tumor parameters (T,N-stage, grade, histology, Ki67 proliferation index, p53 and EGFR expression). C-erbB-2 expression was not related to any of these factors. Although c-erbB-2 defined a worse prognosis, univariate analysis of survival did not confirm any statistically significant difference between the c-erbB-2 staining groups (p=0.5). T,N-stage were the only statistically significant prognostic variables. Any contribution of c-erbB-2 to the development of tumour aggressive behaviour in non-small cell lung cancer requires assessment in the specific subgroups of patients.

Adenocarcinoma↗
PubMedDate not supplied

Human papillomaviruses in cervical cancer: II. Application of PCR and in situ hybridization and HPV significance.

Human papillomaviruses especially type 16 and 18 are associated with cervical cancer. These viruses encode transforming proteins which are capable of binding and form complexes with p53 protein. Tumour-tissue samples from women with cervical cancer as well as normal controls were analysed for the presence of HPV and the expression of p53 by in situ hybridization and PCR analysis. The results showed that HPV 16 and 18 predominated in all pathological conditions and that p53 expression was related to the presence of certain types of HPV. The significance of HPV in cervical carcinoma is well demonstrated.

Female↗
PubMedDate not supplied

K-ras mutation in Greek patients with poorly and moderately differenciated tumours of the lower intestinal tract.

The K-ras protooncogene is activated via mutations in approximately 40% of primary colorectal adenocarcinoma. This finding suggests that these genetic alterations are important events in the genesis of colon cancer and should be correlated with other parameters in order to infer some conclusions relevant to the etiology and the pathogenesis of this type of cancer. In our study we examined whether the incidence of K-ras mutations detected in 23 samples with colorectal adenocarcinomas, was related to different anatomical sites within the lower intestinal tract (transverse colon, descending colon and rectosigmoid region) and also the correlation between K-ras mutations and depth of invasion, level of tumour cell differentiation and metastasis to the regional lymph nodes. For this study the critical regions for the activation of the K-ras protooncogene were amplified by the PCR technique and the particular sequences analysed, after their membrane transfer, by differential hybridization with selected synthetic oligonucleotides. Our results demonstrated that 39% of the adenocarcinomas examined contained point mutations, and 66.6% of these were located in the second position of K-ras codon 12, whereas the other 33.3% were located in the second position of codon 13. 77.8% of the mutations were located at the rectosigmoid region and the relevance of the mutations was higher in poorly differenciated tumours. The depth of invasion was associated with the presence of a mutation whereas no correlation was found between the presence of a mutation anb the regional lymph node metastasis.

Adult↗
PubMedDate not supplied

Multiplex PCR assay for the detection of mycobacterial DNA sequences directly from sputum.

Time consuming classical diagnostic tests and the increasing incidence of tuberculosis epidemics have rendered the need for new more sensitive diagnostic tools, urgent. This study explored the possibility of a direct and rapid method for the identification and characterization of pathogenic typical and atypical species of mycobacteria from sputum, based on a multiplex PCR assay. Gene bank search on the mycobacterial genome revealed specific sequences that fulfilled the above set criteria. Two pairs of primers were used to amplify a 243 bp fragment of the gene encoding the immunogenic protein MPB 64 and a 133 bp fragment of the gene encoding the 65-KDa mycobacterial antigen. The first pair of primers was selected among others, to detect specifically bacteria of the M. tuberculosis complex, whereas the second, to detect in addition to the latter, those of the M. avium-intracellular complex. Our mutiplex PCR assay, detected and identified correctly, all the mycobacterium tuberculosis and M. avium-intracellulare complex strains provided on pure culture as controls with a sensitivity of 10(-3) colony forming units. Furthermore, by performing our assay on 55 sputum samples from patients with positive culture and Ziehl-Neelsen staining, we identified mycobacterial DNA sequences in all--39 samples with M. tuberculosis complex and 16 with M. avium-intracellulare complex. Out of 300 sputum specimens from patients with clinical evidence of tuberculosis, 149 were positive by our method (95 M. tuberculosis and 54 M. avium-intracellulare complex) whereas 157 samples (95 M. tuberculosis complex, 59 M. avium-intracellulare complex, 1 M. xenopi, and 2 that could not be positively identified) were culture positive and only 95 Ziehl Neelsen positive. These findings suggest that the method described can be applied on sputum, and can identify in one step strains of the M. tuberculosis and M. avium-intracellulare complex and has effectivness comparable to culture methodologies.

DNA Primers↗
PubMedDate not supplied

Immunohistochemical detection of p53 protein in HPV positive oral lesions.

Oral cancer provides a unique model system for the study of the multistep nature of cancer. The influence of viruses and tumor suppressor gene inactivation are of major importance in this HPVs are small oncogenic viruses which are implicated in epithelial carcinogenesis, and p53 is a tumor suppressor gene with a central role in the prevention of genomic injury. p53 protein detection is usually a synonym for p53 mutation. This study was designed to determine the immunohistochemical detection of p53 protein in HPV positive oral squamous cell carcinomas and hyperplastic oral lesions. p53 was detected in 50% (5/10) of HPV positive hyperplastic oral lesions and in 59.41% (22/39) of oral squamous cell carcinomas. These results indicate that HPV and p53 protein alterations frequently coexist in the lesions of our study and suggest that p53 mutation may be an early genetic event in oral carcinogenesis. Moreover, this coexistance reveals that other environmental carcinogens have a more prominent role in oral carcinogenesis, one that overrides the action of HPV.

Carcinoma, Squamous Cell↗