Biomedical subjects

M Poljak

Publications and source records attributed to M Poljak.

At least 19 recordsLinked to original sources

PubMed2006

Efficiency of three surgical procedures in eliminating high-risk human papillomavirus infection in women with precancerous cervical lesions.

PURPOSE OF INVESTIGATION: To establish the efficiency of laser vaporization (LV), large loop excision of the transformation zone (LLETZ) and cold knife conization, done for precancerous cervical lesions, in eliminating high-risk human papillomavirus (HPV) infection. Additionally, we determined whether the same HPV genotype persisted after surgery. METHODS: A total of 214 women were tested for HPV infection by the Hybrid Capture II (HCII) test prior to surgery. HPV-positive women were followed by HCII test ten months after surgery. In persistently HPV-positive women, HPV genotypes were determined by PCR - PGMY09/PGMY11. RESULTS: The HCII test showed elimination of HPV infection after LV, LLETZ and cold knife conization in 67.6%, 86.3%, and 100% (p < 0.05) of women, respectively. In seven (38.9%) women a different HPV genotype was found to be present after surgery, the corrected efficiency thus being 79.4%, 92.7% and 100% (p = NS), respectively. CONCLUSIONS: The three analyzed surgical procedures are effective in eliminating high-risk HPV infection. HPV testing is useful at follow-up, since it can identify a small proportion of women requiring close surveillance and potential treatment.

Adult↗

PubMed2005

Acute fatty liver of pregnancy -- an underlying condition for herpes simplex type 2 fulminant hepatitis necessitating liver transplantation.

The infrequent occurrence of herpes simplex virus (HSV) hepatitis in healthy women in comparison with the high prevalence of HSV infections suggests that, in addition to deranged immunity, an underlying condition in the liver might be necessary to develop HSV hepatitis. We report the case of a 28-year-old pregnant woman in the 28 (th) week of gestation. Following HSV type 2 infection of the uterine cervix, acute liver failure developed, necessitating urgent liver transplantation. In addition to fulminant HSV type 2 hepatitis, the explanted liver also showed the histological features of acute fatty liver of pregnancy. The presented case suggests a possible pathogenetic role of acute fatty liver of pregnancy in the development of fulminant HSV hepatitis following recurrent infection with HSV in healthy pregnant women. We believe that early histopathological diagnosis, followed by specific antiviral treatment and liver transplantation in selected patients may improve the clinical outcome of otherwise almost uniformly fatal HSV hepatitis.

Adult↗

PubMed2005

Expression of human telomerase catalytic protein in gallbladder carcinogenesis.

BACKGROUND: Telomerase catalytic subunit (hTERT) gene re-expression is a rate limiting step for the activity of telomerase, a key enzyme implicated in cellular immortalisation and transformation. AIMS: To determine the potential role of hTERT protein in gallbladder carcinogenesis. MATERIAL/METHODS: hTERT protein was analysed by means of immunohistochemistry in 89 gallbladder tissue samples: 16 normal epithelia, 14 reactive hyperplasias, 15 low grade dysplasias, 16 high grade dysplasias, and 28 adenocarcinomas. At least 200 nuclei were assessed for each slide and the mean number of positive signals for each nucleus was expressed as the hTERT index. RESULTS: The mean hTERT index increased progressively with the degree of gallbladder epithelial abnormalities: from 0.03 in normal epithelia, 0.04 in hyperplastic epithelia, 0.25 in low grade dysplasia, 0.82 in high grade dysplasia, to 0.93 in adenocarcinoma. Statistical analysis revealed that three different groups of gallbladder epithelial changes can be distinguished according to the number of hTERT signals for each nucleus: (1) normal and regenerative gallbladder epithelium, (2) low grade dysplasia, and (3) high grade dysplasia and adenocarcinoma (p < 0.001). CONCLUSIONS: The occasional presence of hTERT protein in normal and regenerative gallbladder mucosa reflects their regenerative capacity. Nevertheless, significantly higher hTERT indices in low and high grade dysplastic epithelia and in gallbladder adenocarcinomas are probably a consequence of hTERT re-expression--an early event in the multistep process of gallbladder carcinogenesis.

Adenocarcinoma↗

PubMed2005

Human papillomavirus infection in relation to mild dyskaryosis in conventional cervical cytology.

PURPOSE OF INVESTIGATION: To establish the prevalence and distribution of high-risk human papillomavirus (HPV) genotypes in Slovene women with repeat mild dyskaryosis, and to evaluate three molecular methods for the detection of HPV that could be used as a complementary method to cervical cytology. METHODS: In this prospective study 148 women with three subsequent cervical cytologic tests within two years showing mild dyskaryosis were enrolled. HPV infection was determined using three molecular tests: Hybrid Capture II and two variants of polymerase chain reaction (PCR-PGMY11/PGMY09 and PCR-CPI/CPIIG). RESULTS: HPV was detected in 17 of the 45 women aged < or =30 years and in 21 of the 103 women aged >30 years (37.8% vs 20.4%, p = 0.04). The most common genotype was HPV 16 detected in eight (21.1%) women, the next were HPV 53 and HPV 51, each detected in five (13.2 %) women. The three molecular methods matched in 92.9%. CONCLUSION: Low prevalence of HPV infections indicates that cervical screening programmes in Slovenia are overburdened with mild dyskaryosis. Repeat cytology is not reliable; HPV testing might be useful as a complementary method.

Adult↗

PubMed2005

Role of human papillomavirus testing in reducing the number of surgical treatments for precancerous cervical lesions.

PURPOSE OF INVESTIGATION: To determine whether the addition of the Hybrid Capture II (HC II) test (Digene Corp., Gaithersburg, MD, USA) to cytological, colposcopical and histological results could reduce the number of surgical treatment procedures for precancerous cervical lesions. METHODS: Surgical treatment of precancerous cervical lesions was performed in 181 women. Priorly, the women were tested for high-risk human papillomavirus (HPV). Sensitivity, specificity, positive and negative predictive value were calculated to assess the performance characteristics of HC II in the detection of cervical intraepithelial neoplasia grade 2 or worse (CIN 2+) and grade 3 or worse (CIN 3+). RESULTS: Eighty (44.2%) women had a histological result < CIN 2; 117 (64.6%) women had < CIN 3. Fifty-three (29.3%) women with < CIN 2 tested HPV negative; 69 (38.1%) women with < CIN 3 tested HPV negative (p < 0.05). The sensitivity of HC II for detecting CIN 2+ and CIN 3+ was 76.2% and 87.5%, respectively. CONCLUSION: A high proportion of women were overtreated probably due to cytological and histological overestimations. HPV testing would reduce the number of unnecessary surgical treatments and should be used as an additional screening tool.

Adult↗

PubMed2005

Retrospective and prospective evaluation of the Amplicor HPV test for detection of 13 high-risk human papillomavirus genotypes on 862 clinical samples.

BACKGROUND: Persistent infection with a subgroup of at least 15 high-risk human papillomavirus (HPV) genotypes is considered as a necessary although insufficient etiological factor in the development of cervical carcinoma. As a consequence, HPV testing has recently become an important part of the cervical carcinoma screening and detection algorithms. AIM OF THE STUDY: To evaluate the analytical performance of a recently developed polymerase chain reaction (PCR)-based Amplicor HPV test (Roche Molecular Systems) in comparison with the Hybrid Capture 2 HPV DNA test (hc2) (Digene Corporation) for the detection of 13 high-risk HPV genotypes. Inhouse consensus PGMY09/PGMY11 and CPI/IIg PCRs targeting two different HPV genes coupled with HPV genotyping were used as an HPV internal reference standard. MATERIALS AND METHODS: In the retrospective evaluation, 550 cervical scrape specimens with previously established HPV status were included. Additionally, 312 cervical scrape specimens were tested prospectively for the presence of 13 high-risk HPV genotypes by both hc2 and Amplicor HPV test. RESULTS: In the retrospective evaluation, the Amplicor HPV test results agreed almost completely with the HPV internal reference standard results. In the prospective evaluation performed on 312 samples, the concordant Amplicor and hc2 results were obtained in 85.9% of samples tested. CONCLUSION: In our hands, the Amplicor HPV test demonstrated high analytical sensitivity and specificity. The higher analytical specificity of Amplicor in comparison to that of hc2 can be considered clinically useful. Prospective studies with clinical endpoints are urgently needed to assess the clinical utility of the higher analytical sensitivity of the Amplicor HPV test for primary HPV screening and triaging patients with ASC-US.

DNA Probes, HPV↗

PubMed2004

Human telomerase catalytic subunit gene re-expression is an early event in oral carcinogenesis.

AIMS: Detection of telomerase catalytic subunit (hTERT) mRNA has been used as a surrogate marker for estimation of telomerase activity. The exact role and timing of telomerase re-activation, a key enzyme implicated in cellular immortalization and transformation, in the multistep process of oral carcinogenesis is still unknown. The aim was to test the hypothesis that (i) quantitative rather than qualitative differences exist in the level of hTERT mRNA expression between normal oral mucosa, different grades of oral epithelial abnormalities and squamous cell carcinomas of the oral cavity, and that (ii) hTERT gene re-expression is an important, probably early event in oral carcinogenesis. METHODS AND RESULTS: The relative quantity of hTERT mRNA was analysed in 45 frozen oral epithelia representing different morphological stages of oral carcinogenesis classified according to the Ljubljana classification and in 37 oral squamous cell carcinomas, using a commercially available LightCycler Telo TAGGG hTERT Quantification kit. hTERT mRNA was not detected in normal or reactive hyperplastic oral epithelia, but was present in 43% of atypical hyperplasias (premalignant lesions), 60% of intraepithelial carcinomas and 68% of oral squamous cell carcinomas. Statistical analysis revealed two groups of oral epithelial changes, with significant differences in the levels of hTERT mRNA expression: 1, normal and reactive hyperplastic oral epithelium, and 2, atypical hyperplasia, intraepithelial carcinomas and squamous cell carcinomas. CONCLUSION: These data suggest that hTERT gene re-expression represents an early event in the multistep process of oral carcinogenesis, already detectable at the stage of precancerous oral epithelial changes. Nevertheless, other genetic aberrations appear to be necessary for progression of oral epithelial abnormalities towards invasive squamous cell carcinoma.

Carcinoma, Squamous Cell↗

PubMed2003

The IgG antibody profile to various antigen regions of hepatitis C virus differs in oral fluid and serum of patients with chronic hepatitis C.

Antibodies to hepatitis C virus (HCV) can be detected not only in serum but also in oral fluid. The aim of the study was to determine IgG antibody reactivity directed to six antigen regions of HCV in oral fluid and to evaluate the significance of the antibody pattern in oral fluid compared to serum. Oral fluid and serum samples of 32 HCV viremic patients were collected to detect antibodies to six antigen regions incorporated as antigen bands into modified commercial updated third generation line immuno-assay. Compared to serum, a significantly lower cumulative antibody response and reactivity to five HCV antigens was found in oral fluid. The significantly highest prevalence of oral fluid reactivity was recorded with antigen C1 (78%), whereas in serum the most significantly frequent reactivity was detected with antigen NS3 (100%). The absence of antibody reactivity with antigen E2 was similar in both body fluids. The discrepancy in antibody pattern to HCV antigens between oral fluid and serum indicates the possible existence of local viral replication, viral mutants, viral inhibitors in oral cavity and, most probably, leakage of the muco-vascular barrier.

Adult↗

PubMed2003

Human papillomavirus DNA in oral squamous cell carcinomas and normal oral mucosa.

To elucidate the putative etiologic role of human papillomaviruses (HPV) in oral carcinogenesis, a comparative study was carried out on 62 tissue specimens of oral squamous cell carcinoma (OSCC) and on 62 specimens of histologically normal oral mucosa obtained from the individuals who matched the subjects with OSCC in age, gender, localization of obtained tissue specimens, drinking and smoking habits. Internal control amplification showed that amplifiable DNA was recovered from 59/62 and 61/62 tissue samples of OSCC and normal oral mucosa, respectively. The amplification with two different HPV L1 and one HPV E6 consensus primer sets showed the presence of the HPV DNA genotypes 16, 33, 58 in 5/59 (8.4%) OSCC specimens and HPV genotypes 11, 16, 31, 68 in 4/61 (6.6%) tissue samples of normal oral mucosa tested. In the study in which a comparative examination of the presence of HPV DNA was for the first time performed on the tissue samples of the patients with OSCC and the age- and gender-matched control subjects there was no significant difference in the prevalence of HPV DNA among both study groups. Our results suggest that occasional findings of HPV DNA in OSCC tissue specimens may be the result of an incidental HPV colonization of oral mucosa, rather than of viral infection, and that HPVs play a limited role in the etiopathogenesis of the majority of OSCC.

Adult↗

PubMed2002

Soil radon monitoring in the Krsko Basin, Slovenia.

In order to support the safe operation of the Krsko Nuclear Power Plant (Westinghouse, 676 MWe PWR), the seismotectonic structure of the Krsko basin has been thoroughly investigated. As part of a wider study, a study on radon in soil gas was started in April 1999. Combined barasol detectors buried in six boreholes, two along the Orlica fault and four on either side of it, measure and record radon activity, temperature and pressure every 60 min. The results have been evaluated and the possibility of a correlation with seismic activity is discussed. Correlation between radon concentration and barometric pressure has been observed for all barasols. Preliminary results show that, at one location, the correlation coefficient between radon and barometric pressure changed sign before earthquakes.

Journal Article↗

PubMed2002

Low prevalence of hepatitis C virus infection among human immunodeficiency virus type 1-infected individuals from Slovenia and Croatia.

The prevalence of hepatitis C virus (HCV) infection in the population of human immunodeficiency virus 1 (HIV-1)-infected individuals from Slovenia and Croatia was determined. One hundred and sixty-six out of a total of 188 Slovenian HIV-1-infected individuals and 120 subjects who were randomly chosen out of a total 342 Croatian HIV-1 antibodies-positive individuals were tested for HCV infection. Detection of HCV antibodies was carried out by a third generation enzyme-linked immunoassay (ELISA) and the positive samples were additionally tested by a third generation immuno-blot assay. Additionally, the presence of HCV RNA was determined in all serum samples by a qualitative polymerase chain reaction (PCR). Twenty-four (14.5%) out of 166 Slovenian and 18 (15.0%) out of 120 Croatian HIV-1-infected individuals were HCV antibodies-positive. Nineteen out of 24 (79.2%) Slovenian and 13 out of 18 (72.2%) Croatian anti-HCV positive individuals were also viremic. HCV RNA was not detected in any of 244 HCV antibodies-negative/HIV-1-infected individual from both countries. A significant difference in the prevalence of HCV infection between blood (77.8% in Slovenia and 66.7% in Croatia) and sexual exposure risk groups (1.6% in Slovenia and 6.6% in Croatia) was found in both countries. In a study carried out on the highest proportion of entire population of HIV-1-infected individuals from a certain country or geographic region, Slovenia and Croatia were identified as countries with the second and third lowest prevalence of HCV infection among HIV-1/HIV-2 infected individuals worldwide.

Croatia↗

PubMed2001

Second-generation Hybrid capture test and Amplicor monitor test generate highly correlated hepatitis B virus DNA levels.

The performance of the Digene Hybrid Capture II HBV DNA Test HC II and the Roche Cobas Amplicor Monitor Test (Cobas-HBV) was evaluated on 252 serum samples. One hundred and seventy-three samples were HBV DNA positive and 75 HBV DNA negative by both assays. Four samples were HBV DNA positive by Cobas-HBV only. Linear regression analysis showed that the HBV DNA concentrations obtained from both assays were significantly related (n=173, r=0.976, P<0.0001). The results of the study show that Hybrid capture II and Cobas-HBV could be used equally in the management for patients with chronic HBV infection.

Automation↗

PubMed2001

Comparative evaluation of semiautomated COBAS AMPLICOR hepatitis B virus (HBV) monitor test and manual microwell plate-based AMPLICOR HBV MONITOR test.

Comparative evaluation of the semiautomated COBAS AMPLICOR hepatitis B virus (HBV) MONITOR Test (COBAS-HBV) and manual AMPLICOR HBV MONITOR Test (AMPLICOR-HBV) on 208 serum samples revealed no significant difference in the sensitivities of the two assays. Twenty samples tested HBV DNA negative and 183 samples tested HBV DNA positive by both assays. Three samples tested positive by COBAS-HBV only and two samples tested positive by AMPLICOR-HBV only. HBV DNA concentrations determined by the two assays were significantly related (n = 183, r = 0.97, P < 0.0001), which indicates that COBAS-HBV could replace AMPLICOR-HBV. The major inconvenience of COBAS-HBV is the required performance of appropriate predilutions of high-titer samples in order to extend the narrow dynamic range of the assay.

Automation↗

PubMed2001

Detection of hepatitis C virus RNA from gingival crevicular fluid and its relation to virus presence in saliva.

BACKGROUND: To search for a possible source of hepatitis C virus (HCV) in saliva, the presence and shedding patterns of HCV in gingival crevicular fluid (GCF) and saliva of HCV viremic patients were assessed based on clinical, biochemical, histological, virological, and oral health parameters. METHODS: Saliva and GCF samples of 50 HCV viremic patients were collected to detect HCV RNA by a modified commercial polymerase chain reaction (PCR) assay. Clinical oral examination was performed and periodontal status at the collection sites was monitored. The results were correlated to specified parameters. RESULTS: HCV RNA was detected in 59% (29/49) of the GCF specimens and in 35% (17/48) of the saliva specimens. In saliva specimens, HCV RNA was detected only in cases which also had detectable HCV RNA in the GCF samples (P=0.00002) and was significantly related to the presence of blood in saliva (P=0.03). Higher, but not significant, values of oral clinical parameters at the sites of fluid collection were found in GCF specimens harboring HCV RNA. In GCF specimens with no blood detected, HCV RNA was more often present in cases with higher plasma viral load (P=0.05). CONCLUSIONS: The results suggest that besides blood, the other most probable source of HCV in saliva is GCF. Unknown endogenous HCV inhibitory mechanisms in the oral cavity may explain the discrepancies in HCV appearance between saliva and GCF. The results provide a biologic basis for further investigation of the role of HCV in the pathogenesis of periodontal disease.

Adult↗

PubMed2001

Influenza vaccination of human immunodeficiency virus 1-infected patients receiving antiretroviral therapy.

In 13 human immunodeficiency virus 1 (HIV-1) infected patients receiving a highly active antiretroviral therapy (HAART) annual influenza vaccination was conducted. It was hoped that HAART would prevent a post-vaccination increase in HIV-1 load and potential adverse effects. Only two patients had an increased viral load on day 14 post vaccination (p.v.). At 6 months p.v., the majority of the patients had a significantly increased CD4 cell count and a significantly decreased viral load. This indicates that HAART can protect patients from adverse consequences of influenza vaccination. The production of antibodies to the influenza A and B viruses in the HIV-infected patients was substantially lower than that in healthy persons. We propose that HIV-positive patients receiving HAART should be subjected to annual influenza vaccination.

Adult↗

PubMed2000

The Ljubljana classification: a practical strategy for the diagnosis of laryngeal precancerous lesions.

There is no internationally accepted classification of epithelial hyperplastic laryngeal lesions (EHLL). The majority of current classifications follow criteria similar to those commonly used for cervical epithelial lesions. However, the different etiology of laryngeal cancer and its particular clinical and histologic features necessitate a grading system more appropriate to this region. The Ljubljana classification of EHLL was devised in 1971 to cater to this requirement. Detailed criteria for histologic grading in this classification were formulated by a working group on EHLL of the European Society of Pathology in 1999. The system recognizes four grades: simple and abnormal hyperplasia are benign categories; atypical hyperplasia ("risky" epithelium) is potentially malignant, and carcinoma in situ actually malignant. The main features by which the proposed grading system differs from other classifications are: 1. the distinction between benign and potentially malignant lesions; 2. the positive separation of carcinoma in situ from atypical hyperplasia; 3. the lack of prognostic significance for any surface keratin layer. The eventual outcome of EHLL patients so graded justifies the proposal for separating the lesions into a benign group, showing malignant transformation in only 0.9% of cases, from a potentially malignant group showing malignant transformation in 11% of cases. For diagnostically difficult cases, supplementary techniques such as those using morphometry, immunohistochemical and molecular biology are advised to improve the accuracy of diagnosis and predictions of their biological behavior.

Carcinoma in Situ↗

PubMed2000

Genetic analysis of wild-type Dobrava hantavirus in Slovenia: co-existence of two distinct genetic lineages within the same natural focus.

Genetic analysis was performed of wild-type (wt) Dobrava hantavirus (DOB) strains from Slovenia, the country where the virus was first discovered and where it was found to cause haemorrhagic fever with renal syndrome (HFRS), with a fatality rate of 12%. Two hundred and sixty mice of the genus APODEMUS:, trapped in five natural foci of DOB-associated HFRS during 1990-1996, were screened for the presence of anti-hantavirus antibodies and 49 APODEMUS: flavicollis and four APODEMUS: agrarius were found to be positive. RT-PCR was used to recover partial sequences of the wt-DOB medium (M) and small (S) genome segments from nine A. flavicollis and one A. agrarius. Sequence comparison and phylogenetic analysis of the Slovenian wt-DOB strains revealed close relatedness of all A. flavicollis-derived virus sequences (nucleotide diversity up to 6% for the M segment and 5% for the S segment) and the geographical clustering of genetic variants. In contrast, the strain harboured by A. agrarius showed a high level of genetic diversity from other Slovenian DOB strains (14%) and clustered together on phylogenetic trees with other DOB strains harboured by A. agrarius from Russia, Estonia and Slovakia. These findings suggest that the DOB variants carried by the two species of APODEMUS: in Europerepresent two distinct genetic lineages.

Animals↗

PubMed2000

Chromosomes 7,17 polysomies and overexpression of epidermal growth factor receptor and p53 protein in epithelial hyperplastic laryngeal lesions.

PURPOSE: To visualize directly a sequence of genetic changes underlying the entire spectrum of epithelial hyperplastic laryngeal lesions (EHLL) and laryngeal cancer by the use of non-isotopic in situ hybridization (ISH) for chromosomes 7 and 17 in correlation with overexpression of p53 protein and epidermal growth factor receptor (EGFR). The specific aim was to compare the results and prognostic significance between the two types of EHLL: isolated, mainly atypical hyperplasia or risky epithelium, and EHLL associated with squamous cell carcinoma (SCC). PATIENTS AND METHODS: 59 tissue specimens of EHLL obtained from 34 patients, graded according to the Ljubljana classification into simple (SH), abnormal (AbH) and atypical hyperplasia (AtH), and carcinoma in situ (CIS) were included in the study. Non-fluorescent ISH for chromosomes 7 and 17 was performed by biotinylated alpha-satellite DNA probes. Immunohistochemical staining for EGFR and p53 protein was analyzed on the same tissue samples. RESULTS: Polysomy for both chromosomes increased in correlation with progressive grades of EHLL. The most important finding was the statistically significant difference in chromosome copy numbers between the isolated AtH and AtH associated with SCC. Overexpression of EGFR and p53 protein was found in 61 (36/59) and 52% (31/59) of cases, respectively. The immunoreactivity for both markers increased with the grade of lesions, but the staining pattern was not so uniform in isolated EHLL. On the other hand, the immunoreactivity was expressed more constantly in EHLL adjacent to SCC. CONCLUSIONS: Numerical changes in chromosomes 7 and 17 might be associated with an upregulation of EGFR and p53 genes, and could contribute to critical events in laryngeal carcinogenesis. For daily practice, the cytogenetic and immunohistochemical analyses could be of assistance in distinguishing between low- and high-risk groups of AtH. However, the isolated forms of atypical hyperplasia need considerable further study by evaluating genetic changes with the described methods regarding their ultimate transformation to carcinoma.

Adult↗