A single low-energy, iron-poor supernova as the source of metals in the star SMSS J031300.36-670839.3.

The element abundance ratios of four low-mass stars with extremely low metallicities (abundances of elements heavier than helium) indicate that the gas out of which the stars formed was enriched in each case by at most a few--and potentially only one--low-energy supernova. Such supernovae yield large quantities of light elements such as carbon but very little iron. The dominance of low-energy supernovae seems surprising, because it had been expected that the first stars were extremely massive, and that they disintegrated in pair-instability explosions that would rapidly enrich galaxies in iron. What has remained unclear is the yield of iron from the first supernovae, because hitherto no star has been unambiguously interpreted as encapsulating the yield of a single supernova. Here we report the optical spectrum of SMSS J031300.36-670839.3, which shows no evidence of iron (with an upper limit of 10(-7.1) times solar abundance). Based on a comparison of its abundance pattern with those of models, we conclude that the star was seeded with material from a single supernova with an original mass about 60 times that of the Sun (and that the supernova left behind a black hole). Taken together with the four previously mentioned low-metallicity stars, we conclude that low-energy supernovae were common in the early Universe, and that such supernovae yielded light-element enrichment with insignificant iron. Reduced stellar feedback both chemically and mechanically from low-energy supernovae would have enabled first-generation stars to form over an extended period. We speculate that such stars may perhaps have had an important role in the epoch of cosmic reionization and the chemical evolution of early galaxies.

Vitamin D receptor gene polymorphisms association with the risk of sepsis and mortality.

Association of vitamin D receptor (VDR) gene polymorphisms with sepsis risk and mortality was studied. VDR FokI CC genotype was associated with increased sepsis risk (OR = 13.396, p = .000009) compared to the TT genotype. Results suggest possible role of VDR FokI (rs2228570) as a molecular biomarker of increased sepsis risk.

HMGB1 genetic polymorphisms in oral squamous cell carcinoma and oral lichen planus patients.

OBJECTIVES: This study examined the single nucleotide polymorphisms (SNPs) in high-mobility group box 1 (HMGB1) gene in patients with oral squamous cell carcinoma (OSCC) and oral lichen planus (OLP). MATERIALS AND METHODS: The study was conducted on 93 patients with OSCC, 53 patients with OLP, and 100 controls, all Caucasians of the same ethnicity, matched by age. HMGB1 genotypes for 4 SNPs, 2262G/A (rs1045411), 1177G/C (rs3742305), 3814C/G (rs2249825), and rs4540927, were assessed using TaqMan SNP Genotyping Assays, Applied Biosystems. RESULTS: The HMGB1 1177GG genotype was associated with lymph-node metastasis and tumor stage in OSCCs (P = 0.016 and P = 0.030, respectively). Genotype 1177GG resulted in poorer recurrence-free survival (RFS), P = 0.000. The 1177G/C polymorphism was an independent predictor of RFS compared to GG genotype, P = 0.001. The three polymorphisms were in linkage disequilibrium (LD). The AGC and GGC haplotypes were associated with an increased oral cancer risk, determined over the haplotype odds ratios (HOR = 13.316, P = 0.015, and HOR = 5.769, P = 0.029, respectively). The AGC haplotype was related to erosive OLP progression to OSCC (HOR = 12.179, P = 0.001). CONCLUSIONS: HMGB1 polymorphism 1177G/C could be associated with tumor progression and recurrence-free survival in patients with OSCC. The haplotypes of HMGB1 gene might be associated with susceptibility to OSCC and OLP progression to OSCC.

Association of TLR2, TLR3, TLR4 and CD14 genes polymorphisms with oral cancer risk and survival.

OBJECTIVES: The aim of this study is to investigate association between polymorphisms in TLR2, TLR3, TLR4 and CD14 genes or their haplotypes with oral squamous cell carcinomas (OSCC) risk and survival. METHODS: The study was conducted on 93 OSCC patients and 104 cancer-free controls. Polymorphisms were genotyped by real-time PCR or PCR-RFLP method. RESULTS: Significant increase in oral cancer risk was observed in individuals with mutated genotype of TLR3 rs3775291 polymorphism (OR = 1.096, P = 0.036) compared to wild-type. The heterozygous and mutated genotype of TLR3 rs5743312 polymorphism had worse survival in group of patients with stage III tumours (P = 0.043). Multivariate Cox regression analysis revealed that TLR3 rs5743312 polymorphism could be considered as prognostic marker in advanced III stage OSCC (HR = 2.456, P = 0.007), but not independently of nodal status. TLR3 rs3775291 and rs5743312 polymorphisms were in strong linkage disequilibrium. Haplotype TG was associated with worse prognosis in OSCC patients in comparison with common CG haplotype (HR = 1.717, P = 0.042). Interaction among polymorphisms in TLR2, TLR3 and CD14 genes was observed (P = 0.010). CONCLUSIONS: TLR3 rs5743312 polymorphism could be considered as potential predictor of worse overall survival in advanced oral cancer, but not independently of nodal status. Haplotypes in TLR3 gene might be associated with poor prognosis in OSCC patients.

Detection of bacteria and analyses of Chlamydia trachomatis viability in patients with postvenereal reactive arthritis.

Postvenereal reactive arthritis is an inflammatory form of arthritis that commonly develops after urogenital infection, predominantly in human leucocyte antigen-B27-positive men in the third decade of life. In our hospital, patients underwent synovectomy before a 4-month course of antibiotics (ciprofloxacin, tetracycline and roxithromicin). The clinical remission was achieved in approximately 70% patients. At molecular level, the remission was associated with the negative polymerase chain reaction findings of bacteria.

Hypermethylation of RUNX3 but not WIF1 gene and its association with stage and nodal status of tongue cancers.

OBJECTIVES: Recent studies indicate various molecular abnormalities in oral squamous cell carcinomas (OSCC), including DNA methylation of tumor-associated genes. Although promoter hypermethylation of Wnt pathway antagonists RUNX3 (Runt-related transcription factor 3) and Wnt inhibitory factor 1 (WIF1) has been identified as a common event in a number of carcinomas, methylation status and the role of RUNX3 as a possible tumor suppressor in oral and head and neck cancer are yet controversial. The aim of our study is to determine the occurrence of RUNX3 and WIF1 genes hypermethylation and correlation with tumor and host-related factors and prognosis in tongue carcinomas. MATERIAL AND METHODS: In 76 patients with tongue carcinoma, RUNX3 and WIF1 genes promoter hypermethylation analysis was assessed by nested methylation-specific PCR method. RESULTS: Hypermethylation of WIF1 and RUNX3 genes promoters was observed in 35% and 25% of carcinomas, respectively. RUNX3 gene promoter hypermethylation was significantly associated with lymph node involvement (P = 0.013) and tumor stage (P = 0.006), but not with the overall survival. Occurrence of RUNX3 and WIF1 genes comethylation was associated with nodal status (P = 0.058) and tumor stage (P = 0.055). CONCLUSIONS: Our findings indicate that RUNX3 and WIF1 are frequently aberrantly methylated and that RUNX3 promoter methylation could be considered as a potential prognostic marker in tongue carcinoma.

Frequency of BCR-ABL fusion transcripts in Serbian patients with chronic myeloid leukemia.

PURPOSE: The aim of this study was to analyze the occurrence of the most frequent BCR-ABL transcript variants (b3a2, b2a2 and e1a2) in Serbian patients with chronic myeloid leukemia (CML) and compare it with the occurrence reported in other populations. METHODS: We analyzed peripheral blood and bone marrow samples of 136 Serbian patients with CML by RT-PCR and cytogenetic methods. RESULTS: In 100 patients (73.5%) the b3a2 and in 34 (25%) the b2a2 forms of BCR-ABL were detected. One (0.75%) patient was BCR-ABL negative, but in lymphoblastic transformation he expressed the e1a2 [corrected] transcript of BCR-ABL. One (0.75%) patient displayed both b2a2 and b3a2 forms of BCR-ABL. Analysis of this group according to karyotype showed b3a2 predominance (79%) in patients with classic t(9;22); b2a2 was found in 20% and both b2a2 and b3a2 forms in 1%. In variant translocations b3a2 in 65% and b2a2 in 35% of the patients were detected. In contrast, the subgroup with normal karyotype expressed slight predominance of the b2a2 form (50%); b3a2 was found in 43% of the patients and one patient (7%) displayed e1a2. CONCLUSION: Predominance of the b3a2 form in Serbian patients with CML is in concordance with other relevant investigations, conducted mostly on Caucasian ethnic groups, but in contrast to the study performed on the Mestizo ethnic group in Ecuador. Slight predominance of the b2a2 form was also noticed among the patients with normal karyotype.

Towards targeted epigenetic therapy of cancer.

Increasing number of publications in the last 10 years implicated that cancer development depends, except genetic alterations, also on inheritable gene expression patterns that are not bound to DNA sequence alterations. These epigenetic mechanisms manifest mostly through changes in chromatin packing and in localized gene promoter changes that influence the transcription of the genes involved in carcinogenesis. These changes are mitoticaly inheritable and potentially reversible, providing large possibilities of epigenetic therapy of cancer. So far this therapy lacks specificity of targeting certain genes. Instead, epigenetic therapy attempts either to reactivate or to silence genes that are important for the cancer progress. Epigenetic therapy of cancer is based mostly on the usage of inhibitors of DNA methyltransferases (DNMTs), histone deacetylase (HDAC) inhibitors and anti-micro-RNA therapy. Developments that involve integration of the latest technological advances, such as whole genome microarray expression profiling, help identify mechanisms of action of epigenetic drugs, leading to development of second generation of epi-drugs which would have greater specificity and efficacy. The obtained results are promising, leaving great possibilities for improvement of cancer therapy.

TP53 mutations in breast cancer: association with ductal histology and early relapse of disease.

PURPOSE: This study aimed to investigate the incidence of core domain TP53 mutations in Serbian breast cancer patients in view of their possible correlation with prognostic parameters, tumor characteristics and clinical disease course. METHODS: 145 breast cancer patients were included. Data on clinical disease course were available for 100 patients including 30 node-negative and 70 node-positive patients. After surgery, node-positive patients underwent adjuvant chemotherapy, mostly CMF. TP53 mutations were detected by PCR-SSCP. RESULTS: 31 mutations were found in 27/145 patients including 4/59 node-negative patients and 23/83 node-positive patients (4 double mutations). 26/31 TP53 mutations were found in patients with invasive ductal carcinoma and only 2 in patients with invasive lobular carcinoma. The presence of TP53 mutations was correlated with clinical disease course in premenopausal node-positive patients (n=70). 11/20 patients with TP53 mutations relapsed. Within the first 24 months of follow-up, significantly shorter disease-free intervals were observed in TP53-mutated patients. CONCLUSIONS: TP53 mutations correlated only with nodal status and ductal histology. The significance of the predominant distribution of TP53 mutations in tumors with a ductal histology for the aggressive behavior of these tumors has yet to be proved, since the favorable biological features of tumors with a lobular histology do not result in a better prognosis. Early relapse in mutated-TP53 carriers may support data on its predictive value with respect to adjuvant CMF.

Expression of programmed cell death proteins in patients with chronic myeloid leukemia.

PURPOSE: Chronic myelogenous leukemia (CML) is a malignant myeloproliferative disease developing out of pluripotent hematopoietic stem cells that contain the fusion Bcr-Abl gene. The mechanisms that lead to these changes at molecular level are still unknown as are the mechanisms that increase the proliferative capacity of these cells. Disorders that occur in the process of apoptosis represent one of the possible molecular mechanisms that bring about disease progress. In our study we analyzed the presence of mutated (mut) p53 gene and the amplification of Bax proteins in patients with CML. PATIENTS AND METHODS: This study included 30 patients with CML (23 in chronic phase, 7 in blast transformation). Using immunohistochemistry with alkaline phosphatase / anti-alkaline phosphatase (APAAP) method we analyzed the expression of cell death proteins p53 and Bax in mononuclear bone marrow cells. Polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) method was used to analyze the presence of mut p53 gene in mononuclear peripheral blood cells. Reverse transcription-polymerase chain reaction (RT-PCR) method was used to analyze the presence of Bcr-Abl in peripheral blood cells. RESULTS: High expression of Bax protein was detected in all analyzed patients, but no significant differences were noticed among them. No mut p53 gene was detected in any of the analyzed samples. Bcr-Abl b3a2 protein form was detected in all patients with variant translocations. CONCLUSION: Lack of mut p53 product in the peripheral blood and bone marrow cells in patients with CML suggests that this gene plays no important role in disease pathology. Increased level of Bax protein expression is an essential characteristic of CML cells but it is not related with the clinical stage of disease.

Prognostic significance of TP53 mutations in oral squamous cell carcinoma with human papilloma virus infection.

PURPOSE: The aim of this study was to analyze the prognostic impact of mutated TP53 in patients with oral squamous cell carcinoma (OSCC) whose tumors were infected with human papillomavirus (HPV). METHODS: Thirty-two HPV-positive OSCC patients were included. Most of them were clinically classified as stage III (n=29). All patients underwent postoperative radiotherapy (follow-up from 12 to 60 months, median 32). There were 21 relapses. DNA was isolated by phenol extraction from tumor tissue. HPV DNA (type 16, 18, 31, 33) was detected in genomic DNA of the tumors by the PCR-PAGE method. TP53 mutations (exons 4-8) were detected by the PCR-SSCP method. RESULTS: A statistically significant difference in the number of relapses in HPV-infected (13/21) versus HPV-infected and TP53-mutated (8/8) patients was observed. Patients with both TP53 mutation and HPV infection had a significantly shorter disease-free interval than patients with HPV infection only (median 6 versus 31 months, respectively). CONCLUSIONS: TP53 mutations are associated with a higher risk of relapse and contribute to an even worse prognosis of patients with OSCC when the tumors are HPV infected. The shorter disease-free interval in patients with TP53 mutations indicates that the response to postoperative radiotherapy may be influenced by TP53 status. The presence of both HPV infection and TP53 mutations may define a particular group of tumors with a more aggressive phenotype in advanced OSCC.

Detection of t(14;18), P53 and RAS gene mutations and quantification of residual disease in patients with B-cell non-Hodgkin's lymphoma.

UNLABELLED: PCR analysis has been demonstrated as a valuable tool for detection of minimal residual disease (MRD) in lymphoid malignancies. However, the finding that patients with evidence of MRD sometimes remain in long-lasting remission directs further investigations toward biology of residual disease and/or quantification of MRD level. The study included 40 B-NHL patients--13/40 patients with high- (HG) and 27/40 with low-grade (LG) lymphoma. Seven patients achieved partial clinical remission (PR) and 33 patients achieved complete clinical remission (CCR) after chemotherapy. Peripheral blood samples were analyzed for MRD at up to ten follow-up points while samples of MRD+ patients and patients who achieved partial clinical response after therapy were further analyzed for the presence of t(14;18) and P53 and RAS genes mutations. The level of MRD was quantified in eight patients by PCR-limiting dilution method. RESULTS: MRD was found in 13/33 patients (12 LG and 1 HG) who achieved CCR. The incidence of relapse was significantly higher in MRD+ vs. MRD- B-NHL patients (Fisher's exact test, p = 0.0083). In the LG group the incidence of relapse between MRD+ and MRD-patients was not significantly different. In the HG group MRD was detected in only one patient who subsequently relapsed. Significant difference in DFI between MRD+ and MRD- patients was not observed. Concerning MRD+ patients in CCR and patients who achieved PR, t(14;18) was found in six patients (4 relapsed). In the same group of patients P53, K- and N-RAS mutations were not found. H-RAS mutations were found in six patients--3 relapsed and 3 remain in CCR. The calculated number of IGH copies ranged from 4800 to 44,000. Our results demonstrated positive correlation between MRD-positivity and incidence of relapse in B-NHL patients, but could not indicate significance of P53 and RAS mutations for evaluation of residual clone malignancy. The study implies that MRD level, measured at one follow-up point, does not correlate with clinical outcome. The measurement of MRD level sequentially, at different follow-up points, seems to be a better parameter for the prediction of disease course.

TCRgamma gene rearrangement analysis in skin samples and peripheral blood of mycosis fungoides patients.

BACKGROUND: Diagnosing mycosis fungoides (MF) can be challenging in the early stage of the disease because histopathological features may simulate a variety of benign inflammatory skin diseases. Assessment of T-cell clonality was found to be useful in diagnosis and follow-up of patients. OBJECTIVE: In this study, PCR-based TCRgamma gene rearrangement analysis was performed in skin and peripheral blood samples of patients with MF treated at the two largest referral centers in Serbia, and the results obtained were correlated with clinical and follow-up data. METHODS: Skin and peripheral blood samples were obtained with informed consent from 37 patients treated at the Department of Dermatology of the Military Medical Academy and the Medical Center of Serbia from 2001 to 2006. The median time of follow-up was 4 years. Multiplex PCR was used for TCRgamma gene rearrangement analysis in skin and peripheral blood samples. Clonality results were correlated with the clinical data and disease course data. RESULTS: Monoclonality was detected in skin samples of 30/37 patients (81%), in 2/5 patients with large-plaque parapsoriasis (LPP), in 28/32 (88%) patients with histologically proven MF, and in 1/16 (6%) patients with benign inflammatory dermatoses. A monoclonal pattern in both skin and peripheral blood was detected in 7/16 (44%) patients in the late stage of the disease, and in 1/7 (14%) patients in the early stage of the disease. A dominant clone was found in both skin and peripheral blood in 1/4 patients in remission, 2/5 with a stable disease, and 4/9 (44%) with disease progression. CONCLUSION: TCR-gamma gene rearrangement analysis can be regarded as a useful adjunct to diagnosis of epidermotropic lymphoproliferative disorders. The presence of a dominant clone in both the skin and peripheral blood was more frequently detected in late stages and in patients with disease progression, confirming the usefulness of clonality detection by TCR-gamma gene rearrangement analysis in follow-up of patients with primary cutaneous T-cell lymphomas.

Successful treatment of extranodal Hodgkin's lymphoma in a patient with longstanding hairy cell leukemia.

Purine analogs, particularly pentostatin and cladribine, are highly effective in hairy cell leukemia (HCL). Both of these drugs induce responses in approximately 80-95% of patients. However, it is not yet determined if treatment with these drugs can induce second malignancies. Hodgkin's lymphoma is very rare as a second malignancy and there are only 3 reported cases concerning the association of this lymphoma with HCL. We describe a patient with longstanding HCL in complete remission after cladribine, in whom extranodal Hodgkin's lymphoma appeared 8 years after the diagnosis of HCL. Magnetic resonance imaging revealed diffuse intra-osseal neoplastic infiltration of the corpora of the whole spinal column and extra-osseal propagation from the fifth thoracic vertebra into the spinal canal with spinal cord compression. Histological and immunohistochemical analysis of the extradural tumor, which was completely excised, disclosed nodular sclerosis Hodgkin's lymphoma with typical Reed-Sternberg cells that were positive for CD30, CD15, bcl-6, Ki67, p53, EBV LPM-1 and IgG, and negative for CD45, CD20, DBA44, kappa, lambda light chains and IgM. In addition, immunohistochemical analysis of the bone marrow in 1999 showed infiltration with positivity for IgM and negative for kappa light chains and IgG. These findings (expression of different immunoglobulins and light chains on the cells) suggest an independent origin of these 2 B-cell neoplasms. After neurosurgery the patient received 6 courses of the MP-ABVD protocol and achieved a complete remission, which has lasted 16 months thus far.

Analysis of T-cell clonality pattern in tumor samples of breast cancer patients.

PURPOSE AND METHODS: A large body of experimental evidence has confirmed that different tumors, including breast carcinomas, can stimulate specific T-cell-mediated immune responses. In this study we have analyzed patterns of T-cell clonality in tumor samples of 54 breast cancer patients classified as lymph node negative, N0 (n=16), or lymph node positive, N+ (n=38). The clonality of T-cells was analyzed by the PCR-PAGE method. RESULTS: Monoclonal/oligoclonal (M/O) T-cell populations were found in 15 breast cancer patients, nine N+ and six N0. In all analyzed groups (N+ + N0, N+, N0) the incidence of relapse was not significantly different between patients with M/O and patients with polyclonal T-cells. Comparison of disease-free interval (DFI) between patients divided according to the presence of TCRgamma monoclonality/oligoclonality showed a marginally significant difference only in the group of N+ patients within the first 24 months of follow-up. Patients with a M/O T-cell population had a shorter DFI than patients with a polyclonal T-cell population. This difference was not observed when the complete follow-up period was considered in the same group of patients. Furthermore, there was no significant difference in overall survival (OS) between patients with M/O and patients with polyclonal T-cells. CONCLUSION: Our results imply that tumor infiltrating T-cells are usually polyclonal. The pattern of T-cell clonality does not correlate with the incidence of relapse and the duration of DFI and OS in the analyzed groups of breast cancer patients, excluding N+ patients with M/O T-cells who had a shorter DFI in the first 24 months of follow-up. This observation suggests that polyclonal T-cell populations may provide a broader spectrum of T-cell-mediated antitumor response.

Ionizing radiation-induced expression of the genes associated with the acute response to injury in the rat.

Total-body irradiation of rats with doses ranging from an LD10/30 to an LD100/30 induced a dose-dependent increase in the concentration of serum protein associated with the acute response to the irradiation. However, this increase was reached at a later time and was not as pronounced as described previously during the typical acute phase of the response found experimentally (A. Koj, in Structure and Function of Plasma Proteins, Vol. 1, pp. 73-131, Plenum Press, London, 1974). The greatest increase in the serum concentrations of acute-phase proteins was found from the third to the seventh days postirradiation. At these times, the serum concentrations of alpha 2-macroglobulin, haptoglobin, fibrinogen and cysteine protease inhibitor were raised from two- to fivefold, whereas alpha 1-acid glycoprotein was increased sixfold. Incorporation of [35S]methionine into total serum and acute-phase proteins indicated that the increase in the concentration of the acute-phase proteins was preceded by their de novo synthesis in the liver. The results that were obtained by dot-blot analysis showed that the basic course of change in the relative mRNA concentrations in the liver for the acute-phase proteins examined correlated with the changes in their protein concentrations in the serum; only the relative increase in the concentration of alpha 1-acid glycoprotein mRNA was significantly lower than the increase in proteins in the serum, suggesting that a fraction of the serum alpha 1-acid glycoprotein had an extrahepatic origin. On the basis of these results we concluded that total-body irradiation increased the expression of acute-phase protein genes.

Re-establishment of homeostasis and the acute-phase proteins.

The stimulation of transcription of acute-phase protein (APP) genes in the liver is incorporated in the complex interchange of cytokines, growth factors and glucocorticoid hormones that are released during the systemic defence reaction in response to trauma. Through the broad spectrum of their activities, this heterogeneous group of circulating proteins assists the injured organism in restoring homeostasis by assuming a protective role. APPs accomplish this by inactivating vasoactive, proteolytic and cytotoxic molecules liberated from damaged tissues and accumulating phagocytic cells, and by participating in a feedback control mechanism that prevents an overload by the organisms' immune response. APP synthesis represents a non-specific response of the liver, in so much as different types of trauma elicit the production of the same proteins. However, data obtained from different laboratory models and clinical observations revealed a certain relationship between the severity and type of trauma and the magnitude of activation of APP gene expression. The observed variations of the overall pattern of APP synthesis point to the existence of different interplays between humoral and cellular mediators capable of adjusting the production of individual proteins to suit different traumas. Hence, changes in the serum concentrations of some APPs have been shown to be useful in monitoring complications such as infection or sepsis after surgery or trauma, and predicting the clinical course of malignant and other diseases. Of the APPs studied in humans, information obtained on CRP and SAA has in particular proved to be a useful indicator of the progression of different pathological states.

Early inflammatory cytokine and acute phase protein response under the stress of thermal injury in rats.

The acute inflammatory response associated with thermal injury was examined in rats. The appearance of mediators of inflammation in the systemic circulation, including cytokines interleukin-1 (IL-1), tumor necrosis factor (TNF) and interleukin-6 (IL-6) and acute phase proteins were assessed during initial 72 h following thermal injury. Increased levels of activity were noted for all three cytokines, but with a different time-course. While serum IL-1 activity was elevated throughout the 3-day period of observation, the levels of serum TNF activity were enhanced after 12 h and on days 1 and 3 following scalding injury. The values of IL-6 were already increased one hour after thermal injury and increased progressively up to day 1 following scalding. Alpha2-macroglobulin and haptoglobin levels were increased 12 h after thermal injury, rising further on days 1 and 3. Positive correlation was found between the time-course of increased serum IL-6 activity and alpha2-macroglobulin, as well as between TNF and haptoglobin in the serum.

p53 and c-myc alterations in patients with non-small cell lung carcinoma in Serbia.

PURPOSE: To determine the incidence of c-myc amplification and p53 mutations in patients with stage I, II and III of histologically confirmed non-small cell lung cancer (NSCLC) of different histological subtypes: adenocarcinomas (AC), squamous cell carcinomas (SCC), large cell carcinomas (LCC) and adeno-squamous carcinomas (AC-SCC) and of histological grade (G) 2 and 3. MATERIALS AND METHODS: DNA was isolated from 41 frozen tumor samples by standard phenol-chloroform extraction. Amplification of c-myc gene was determined by the differential polymerase chain reaction (PCR) method, followed by polyacrylamide gel electrophoresis, and mutations in exons 5, 6, 7 and 8 p53 gene were detected by the PCR single-strand conformation polymorphism (SSCP) method. RESULTS: c-myc gene amplification was found in 2 of 41 (4.9%) analyzed tumors and both amplifications were found in stage III tumors. Mutations in the p53 gene were found in 19 of 41 (46.3%) of the analyzed tumors. SCC and LCC were more likely to contain mutations in p53 gene (68.4% and 66.7%, respectively). CONCLUSION: Our results indicate that p53 mutations are common in NSCLC with higher incidence in SCC compared with other histological subtypes. Since the mutations are more frequent in early-stage NSCLC, it appears that mutations in p53 gene could be an early event in lung carcinogenesis. On the other hand, c-myc amplification is a rare event in NSCLC and occurs in the late phase of development of this type of lung cancer.

Distribution of high-risk HPV types in Yugoslav women with cervical neoplasia.

PURPOSE: The purpose of this study was to determine the frequency of high-risk types of human papillomavirus (HPV) infection, namely type 16, 18, 31 and 33, among Yugoslav women diagnosed with different grades of squamous intraepithelial lesion (SIL), as well as to investigate the relationship between HPV infection and age, parity, age at first intercourse, number of sexual partners and residence of the patients, all of which are considered risk-factors. PATIENTS AND METHODS: DNA was isolated from cervical swabs of 72 women using phenol/chloroform/isoamylalcohol extraction. Detection of HPV DNA in patients' genomic DNA was performed using the polymerase chain reaction (PCR) method with type-specific primer pairs, and amplification products were analyzed using 2% agarose and 10% polyacrylamide gel electrophoresis. RESULTS: Thirty out of 72 (41.7%) patients with cervical intraepithelial neoplasia (CIN) were HPV-positive and 8 of them were double positives. HPV31 was the most frequent high-risk HPV type in this group of patients (13.9%). Eighty percent of the high-grade SIL (HSIL) patients were HPV-positive and 38.8% of the low-grade SIL (LSIL) patients were HPV-positive. Compared to HPV-negative women, the HPV-positive ones were younger, had started sexual activity earlier, and overall had more sexual partners. CONCLUSION: Our study showed that oncogenic HPV types are responsible for the transition of LSIL to HSIL, and for its further progression to an invasive carcinoma of the cervix. Thus, HPV typing should become a widely used method for identifying women with increased risk for developing HSIL and invasive cervical cancer. We also concluded that sexual behavior is connected with the frequency of HPV infection. Henceforth, introduction of prophylactic measures could reduce the incidence of HPV infected women in our country.