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Biomedical subjects

M Poljak

Publications and source records attributed to M Poljak.

At least 37 records · Page 2Linked to original sources
PubMed2000

Proviral HIV-1 DNA in gingival crevicular fluid of HIV-1-infected patients in various stages of HIV disease.

The oral cavity is rarely reported to be a site of human immunodeficiency virus (HIV) transmission, despite detectable virus in saliva and relatively frequent prevalence of periodontal disease in HIV-infected persons yielding increased excretion of mononuclear-cell-enriched gingival fluid. To search for possible sources of HIV in saliva, and using the polymerase chain-reaction technique, we sought the presence and shedding patterns of proviral HIV-1 DNA in gingival crevicular fluid in a group of patients previously determined as HIV-1-seropositive. Periodontal status at the collection sites was monitored by several clinical parameters, including Plaque Index, Gingival Index, probing depth, and clinical attachment loss. Gingival crevicular fluid samples were collected by means of paper points. Proviral HIV-1 DNA was detected in the gingival fluid of 17 out of 35 HIV-1-infected patients. Its detection correlated significantly with higher plasma HIV-1 RNA viral load (p = 0.03) and not with peripheral blood CD4+ cell count, the presence of blood in gingival fluid, or oral lesions. There was a significant correlation between clinical attachment loss at the sites of fluid collection and plasma HIV-1 RNA viral load (p = 0.002), and borderline correlation between the latter and probing depth (p = 0.54) in the group of patients harboring proviral HIV-1 DNA in gingival crevicular fluid. The results of our study suggest that mononuclear cells present in gingival crevicular fluid and harboring proviral HIV-1 DNA could represent a potential source of HIV-1 in the presence or absence of local bleeding, especially in persons with advanced HIV infection and increased loss of clinical attachment.

Adult↗
PubMed2000

Rapid extraction of DNA from archival clinical specimens: our experiences.

The analysis of DNA extracted from archival clinical specimens using polymerase chain reaction represents the basis of a variety of research and diagnostic protocols in medicine. However, the selection of optimal DNA extraction method is critical if such an analysis is to be successful. Recently, we have evaluated a number of rapid DNA extraction protocols in order to find the most suitable method for routine processing of the most common archival materials in pathological and cytological laboratories: paraffin-embedded tissues and Papanicolaou- or Giemsa-stained smears. Our results demonstrate that rapid DNA extraction methods have comparable DNA extraction efficiencies with standard DNA isolation protocols on archival clinical specimens with the exception of Giemsa-stained smears.

Archives↗
PubMed2000

Seroprevalence of HIV-1 subtypes A-E among HIV-1 infected individuals from Slovenia.

To investigate the prevalence of HIV-1 subtypes A-E in Slovenia, 82 HIV-1 infected individuals were tested for the presence of HIV-1 subtype specific antibodies using a research competitive peptide enzyme immuno assay supplied by Boehringer Mannheim. In 74 individuals unambiguous results were obtained. As in other European countries, the majority of Slovenian HIV-1 infected individuals (86.5%) were infected with subtype B. Infections with subtypes C, A, D and E were detected in 8.1%, 2.7%, 1.3% and 1.3% individuals, respectively.

Adolescent↗
PubMed1999

Two- to four-year histological follow-up of gastric mucosa after Helicobacter pylori eradication.

In a 2- to 4-year prospective study, the reversibility of gastritis after Helicobacter pylori eradication was analysed. Sixty-three H. pylori-positive, chronic duodenal ulcer patients were studied after the successful eradication of bacteria in the period from 1990 to 1993. H. pylori eradication was obtained by triple antimicrobial regimens (colloidal bismuth subcitrate, amoxycillin, and metronidazole) applied for at least 14 days. The criteria for eradication were the absence of bacteria from two antral and two body of stomach biopsies stained with haematoxylin, eosin, and Warthin Starry, and a negative antral biopsy culture. The same diagnostic procedures were repeated, at regular follow-up endoscopies, each year for up to 4 years. Neutrophil-granulocyte infiltration of gastric mucosa disappeared in 2 months after bacterial eradication. Mononuclear cellular infiltration was disappearing with statistical significance up to the second year and normal mucosa was observed in the majority of patients in the fourth year of follow-up. Degeneratively changed lymphoid aggregates were also present in the fourth year in the antrum (12.5 per cent of patients) and in the body of stomach (14 per cent of patients). There was no significant change in antral intestinal metaplasia during the 4 years of follow-up. Antral atrophy declined significantly in the period from 1 to 3 years of follow-up. In conclusion, 3-4 years are needed for gastric mucosa to become normal after H. pylori eradication, although some residual lymphoid aggregates persist even after that period.

Adult↗
PubMed1999

Prevalence of hepatitis C and G virus infections among intravenous drug users in Slovenia and Croatia.

The prevalence of hepatitis C virus (HCV) and hepatitis G virus (HGV) infections was assessed in 115 Slovenian and 102 Croatian intravenous drug users (IVDUs). HCV and HGV infections were detected in 60 (52.2%) and 61 (53.0%) Slovenian IVDUs and in 70 (68.6%) and 39 (38.2%) Croatian IVDUs, respectively. The established prevalence of both HCV and HGV infection in Croatian IVDUs are the lowest found to date among IVDUs. HCV positive Slovenian and Croatian IVDUs were significantly older and reported longer duration of the intravenous drug use in comparison with HCV negative IVDUs. In contrast, no significant differences in both parameters were found among HGV-positive and -negative IVDUs.

Adult↗
PubMed1999

Comparative evaluation of first- and second-generation digene hybrid capture assays for detection of human papillomaviruses associated with high or intermediate risk for cervical cancer.

In the present study we comparatively evaluated the first- and second-generation Digene Hybrid Capture assays for detection of human papillomaviruses (HPV) associated with high or intermediate risk for cervical cancer in cervical specimens. Concordant results were obtained with 468 of 483 (96.8%) specimens. All 15 specimens which gave repeatedly discordant results were positive by the second-generation test only, and 14 of them tested PCR positive. The enhanced sensitivity of the second-generation assay is mainly a result of the reformulation of hybridization reagents and, to a lesser extent, a result of the addition of new HPV probes.

Cervix Uteri↗
PubMed1998

Human papillomavirus infection in esophageal carcinomas: a study of 121 lesions using multiple broad-spectrum polymerase chain reactions and literature review.

To elucidate the putative role of human papillomavirus (HPV) infection in the etiology of esophageal cancer, 121 formalin-fixed, paraffin-embedded specimens originating from a non-high-incidence area for this carcinoma, from Slovenia, were screened for HPV infection using eight different polymerase chain reactions (PCR). Three different HPV consensus primer sets and four primer sets specific for HPV types 6, 16, and 18 failed to detect HPV DNA sequences in any of the tumor samples. Fragments of human beta-globin gene that served as internal controls were successfully amplified from 120 of 121 specimens. Our study confirms the opinion that most esophageal cancers originating from non-high-incidence geographic areas of this cancer are not associated with HPV infection. According to the studies reviewed, it is likely that HPV infection plays a much more significant role in esophageal carcinogenesis in those areas of the world with a high incidence of ESCC.

Aged↗
PubMed1998

Simple one-tube reverse transcription-polymerase chain reaction protocol containing anticontamination procedure for detection of GB virus C/hepatitis G virus RNA.

A simple one-tube reverse transcription-polymerase chain reaction protocol for detection of GB virus C/hepatitis G virus (GBV-C/HGV) RNA in serum samples containing anticontamination uracil-N-glycosylase procedure was developed. Amplification products were detected in a standard microtiter plate format using a commercial PCR ELISA kit (Boehringer Mannheim, Germany). Complete agreement between the results of a novel method and the previously determined GBV-C/HGV RNA status was obtained on 131 serum samples (76 GBV-C/HGV RNA positive and 55 GBV-C/HGV RNA negative samples). The novel method provides the potential for automated, simple, rapid and accurate routine detection of GBV-C/HGV RNA in diagnostic virological laboratories.

Flaviviridae↗
PubMed1998

DNA extraction from archival Giemsa-stained bone-marrow slides: comparison of six rapid methods.

The ability of six rapid DNA extraction procedures to provide DNA for the polymerase chain reaction from archival Giemsa-stained bone marrow slides was tested on 120 samples. Boiling in distilled water, freeze-thaw method, boiling in 10% Chelex-100 resin solution, proteinase K/Tween 20/NP-40 method coupled with simplified phenol/ chloroform/isoamyl alcohol protocol or salting-out procedure using saturated NaCl and modification of commercial QIAamp procedure (Qiagen. Chatsworth, Calif.) gave DNA extraction efficiencies of 50%, 70%, 85%, 95%, 100% and 100%, respectively. Our results demonstrate that rough DNA extraction methods have decreased efficiencies compared to complete DNA extraction protocols and that the latter are required to ensure highly reproducible results from archival Giemsa-stained bone marrow slides.

Azure Stains↗
PubMed1998

Detection of human papillomaviruses in tissue specimens.

During the past decade, molecular methods based on the detection of viral DNA have become a key tool for the detection of human papillomaviruses (HPVs) in tissue. The methods can be divided into two groups: those in which tissue destruction is unavoidable for the detection of HPV DNA, and those in which the detection of viral DNA is performed in a way that allows tissue morphology preservation. Polymerase chain reaction is currently the most sensitive method for HPV detection and an excellent research tool. However, because of frequent contamination problems and lack of standardization, it is not readily applicable to diagnostic laboratories. The recent improvements in in situ hybridization have made it possible for this method to become the most appropriate method for routine detection of HPVs in tissue. At present, however, the use of at least two independent HPV DNA detection methods is indispensable for accurate determination of HPVs.

DNA, Viral↗
PubMed1998

Prevalence of hepatitis G virus infection in Slovenian hemodialysis patients as determined by the detection of viral genome and E2 antibodies.

The prevalence of hepatitis G virus (HGV) infection was assessed by the detection of viral genome and HGV E2 antibodies in hemodialysis patients from a dialysis unit with the highest prevalence of hepatitis C virus infection in Slovenia. HGV RNA was detected in 7 (11.9%) and HGV E2 antibodies in 20 (33.9%) of 59 hemodialysis patients. One patient had detectable HGV RNA as well as HGV E2 antibodies in her serum sample at the time of the study. The total prevalence of HGV infection was 44.1%. Our results clearly indicate that the mere detection of HGV RNA in serum samples would seriously underestimate the real prevalence of HGV infection in hemodialysis patients. Therefore, when assessing the prevalence of HGV infection in hemodialysis patients, detection of both antibody and nucleic acid is requisite.

Adult↗
PubMed1998

Seroprevalence of human T cell leukaemia/lymphoma virus type I (HTLV-I) in pregnant women, patients attending venereological outpatient services and intravenous drug users from Slovenia.

To establish current seroprevalence of human T cell leukaemia/lymphoma virus type I (HTLV-I) infection in some low- and high-risk populations from Slovenia, 10,369 and 869 serum samples collected during Slovenian 1994 unlinked surveys of human immunodeficiency viruses seroprevalence in pregnant women and patients attending venereological outpatient services, respectively, and 219 serum samples collected from Slovenian intravenous drug abusers during 1995 and 1996, were screened for the presence of anti-HTLV-I antibodies using commercial particle agglutination test Serodia HTLV-I (Fujirebio, Tokyo, Japan). Only one sample obtained from a pregnant woman was found repeatedly positive in the screening test. Presence of anti-HTLV-I antibodies in the reactive sample was undoubtedly confirmed with supplemental Western blot test. The prevalence of antibodies to HTLV-I in the Slovenian population might be somewhere between one in 10,000 (0.01%) and one in 15,000 (0.0066%), which is similar or even higher to prevalence rates in other European countries.

Adolescent↗
PubMed1998

Prevalence of mutant CCR5 allele in Slovenian HIV-1-infected and non-infected individuals.

A 32 bp deletion in the CCR5 gene designated CCR5 delta 32 has been identified recently as the cellular basis for resistance to human immunodeficiency virus type 1 (HIV-1) in some individuals which remained non-infected despite a repeated exposure to this virus. The prevalence of this deletion was examined by polymerase chain reaction (PCR) on 51 HIV-1-infected and 385 non-infected individuals from all parts of Slovenia. 84.4% of the the HIV-1-infected and 83.2% of the non-infected individuals were homozygous for wild type CCR5, and 19.6% and 16.3%, respectively, were heterozygous. No homozygous mutant genotype was observed among the HIV-1-infected patients. Of the non-infected individuals, 2 women (0.5%) were found to harbour the CCR5 delta 32/CCR5 delta 32 genotype only, which is, to the best of our knowledge, the lowest prevalence of this particular genotype found among Caucasians to date.

Adolescent↗
PubMed1997

Evaluation of the automated COBAS AMPLICOR hepatitis C virus PCR system.

To evaluate the reliability and feasibility of the automated Roche COBAS AMPLICOR PCR system for routine detection of hepatitis C virus (HCV) RNA, a total of 405 serum samples previously tested by an in-house nested PCR and manual Roche AMPLICOR microwell plate HCV test were examined. Complete concordance was found between the results with the HCV COBAS AMPLICOR system and the previously determined HCV RNA status. The automated HCV COBAS AMPLICOR system provides the clinical microbiology laboratory with a specific and sensitive PCR method for rapid and reliable detection of HCV RNA.

Automation↗
PubMed1997

Molecular evidence for nosocomial spread of two different hepatitis C virus strains in one hemodialysis unit.

The highest prevalence of hepatitis C virus (HCV) infection among hemodialysis patients in Slovenia was found in a small dialysis unit with old equipment and room shortage, where the first anti-HCV-positive patient was detected in 1990. In 1992 and 1993, an additional 8 and 7 patients seroconverted, respectively. Genotyping analyses among 15 HCV RNA-positive patients showed quite unusual HCV genotype distribution for our country: genotypes 2 and 3 were determined in 9 and 6 patients, respectively. Sequence analysis of the 270-bp part of the NS-5 region was carried out in 12 patients. In 6 patients infected with subtype 2c and in 4 patients infected with subtype 3a, very similar sequences were obtained, forming two distinct clusters in the phylogenetic tree. In 2 patients infected with subtype 2c, viral strains were neither related to the main 2c strain nor to each other. Phylogenetic analysis unequivocally confirmed simultaneous nosocomial spread of two different HCV strains in one hemodialysis unit. The study confirmed that implementation of rigorous hygienic routines and introduction of separate rooms and machines for HCV-infected patients are important measures for effective control of HCV infection in a hemodialysis environment.

Cross Infection↗
PubMed1997

Human papillomaviruses: a study of their prevalence in the epithelial hyperplastic lesions of the larynx.

This study investigated the prevalence of human papillomavirus (HPV) infection in various laryngeal epithelial hyperplastic lesions using the Kambic classification from simple hyperplasia to invasive squamous cell carcinoma. For detection of HPV infection polymerase chain reaction (PCR) with 3 different HPV consensus primer sets and in situ hybridization were used. The presence of the HPV DNA was detected in only 2 of the 88 specimens tested: HPV type 6 was detected in 1 case of simple hyperplasia and HPV type 16 in 1 case of invasive squamous cell carcinoma. In conclusion, our study suggests that most laryngeal epithelial hyperplastic lesions are not associated with HPV infection and that other pathogenic mechanisms are more important in the etiology of these lesions.

Carcinoma, Squamous Cell↗