Search PubMed⌕ Search

Biomedical subjects

G Mikuz

Publications and source records attributed to G Mikuz.

At least 55 records · Page 3Linked to original sources
PubMed1995

Testicular seminomas are aneuploid tumors.

BACKGROUND: Distinct ploidy patterns of germ cell tumors and aneuploidy of classic seminoma are of central importance in a current concept designating seminoma as a stage in tumor evolution preceding all nonseminomatous germ cell tumors. Whereas cytogenetic studies almost constantly revealed numerical chromosomal aberrations in seminomas in line with this pathogenetic model, ploidy determination by DNA cytometry yielded highly controversial results on the frequency of diploid seminomas. EXPERIMENTAL DESIGN: Twenty-two classic seminomas were investigated in a comparative manner by DNA flow and DNA image cytometry on nuclei isolated from fresh as well as formalin-fixed tumors. The cellular composition of the tumors, i.e., the number of neoplastic, interstitial, and lymphoid cells was quantified in each case. RESULTS: Irrespective of the tissue preparation and fixation method, all of the tumors that were analyzed were aneuploid by image cytometry. Diploid cases were only found by flow cytometry. Thus, 1/22 cases from paraffin-embedded and 4/11 cases of native tumors showed a single diploid stemline by flow cytometry, however, they exhibited aneuploidy by image cytometry. The quantity of tumor infiltrating lymphocytes was clearly correlated with false diploidy detected by flow cytometry. CONCLUSIONS: Classic testicular seminomas are aneuploid tumors. Previous reports on diploid cases detected by flow cytometry have most likely been caused by extensive lymphocytic infiltration.

Aneuploidy↗
PubMed1995

Seminomas positive for Epstein-Barr virus by the polymerase chain reaction: viral RNA transcripts (Epstein-Barr-encoded small RNAs) are present in intratumoral lymphocytes but absent from the neoplastic cells.

A possible role of Epstein-Barr virus (EBV) in the pathogenesis of testicular germ cell neoplasms has been suggested repeatedly, but direct evidence for an association of testicular cancer with EBV is lacking. We examined 26 cases of classical seminoma, two spermatocytic seminomas, and 12 cases of nonseminomatous or combined germ cell tumors for the presence and cellular location of EBV with a combined approach using the polymerase chain reaction and nonradioactive in situ hybridization for EBV-encoded small RNAs (EBER1/2). After exclusion of cases without amplifiable DNA, 4/21 (19%) seminomas, but none of the other tumors, were positive for EBV by polymerase chain reaction. In situ hybridization for EBER1/2 showed rare positive lymphocytes, probably latently infected B-cells, in two of these four EBV-positive cases. No EBER-positive tumor cells were found in any of the analyzed tumors. The occurrence of EBV-positive lymphoid cells was not correlated to the frequency of intratumoral lymphocytes, including B-cells, which were present in seminomas in significant numbers. Our study demonstrates the absence of EBV from the neoplastic cells of testicular germ cell tumors and makes a direct role of EBV in the development of these malignancies improbable. Whether the presence of EBER-positive lymphocytes in some seminomas simply reflects the normal occurrence of latently infected cells in lymphoid tissue of seropositive individuals or is influenced by local factors remains to be determined.

Antibodies, Monoclonal↗
PubMed1994

Carcinoma in situ of the testis detected by DNA flow cytometry of testicular fine-needle aspirates.

Testicular carcinoma in situ (CIS) is usually diagnosed histologically on surgical biopsies. The present study was performed to test an alternative approach--DNA flow cytometry (FCM) of testicular fine-needle aspirates (FNA)--for the detection of this lesion. FNAs from 18 cases of testicular germ cell tumors (TGCT) and tumor adjacent parenchyma were analysed by DNA FCM. DNA histograms of all cell nuclei and histograms representing selectively the hyperdiploid compartment were analysed. The presence and extention of CIS were determined by histology and immunohistochemistry. In 16 of 18 cases, CIS was histologically present, whereas aneuploid peaks were detected in only 11 cases in DNA histograms of all cell nuclei. In the analysis of the histograms of the hyperdiploid region, 4 additional cases of CIS could be identified increasing the sensitivity to 15/16 cases (93.8%). In all but one case, the DNA indices of CIS and invasive tumors were identical. The study demonstrates that DNA FCM of testicular FNAs using the described data acquisition and analysis could also be applicable for detection of CIS in a clinical situation.

Aneuploidy↗
PubMed1994

In vitro investigations of interphase and metaphase argyrophilic nucleolar organizer regions and cellular proliferation in the human urothelial cancer cell line HOK-1.

Detailed investigation of cell growth and nucleolar organizer region associated argyrophilic proteins (Ag-NORs) is necessary to assess a possible impact of Ag-NOR quantification on the diagnosis and prognosis of tumours. In this study, cellular proliferation of the transitional-cell carcinoma cell line HOK-1 was modulated over a period of 11 days by starvation and subsequent medium addition. Proliferation was determined daily by DNA flow cytometric estimation of S-phase fraction (SPF) and mitotic index (MI) calculation. The number and area of interphase Ag-NORs were quantified by automated image analysis daily and the number of Ag-NOR bearing chromosomes in metaphase was counted. In interphase nuclei, Ag-NOR area showed a highly significant correlation with SPF (p < 0.0001) whereas interphase Ag-NOR number showed significant correlation with MI (p < 0.05). A positive relationship between the number of Ag-NOR bearing chromosomes in metaphases and cellular proliferation was also observed. There is variability in Ag-NOR quantity during interphase and metaphase depending on growth conditions in vitro. Correlations of the number of interphase Ag-NORs with the MI on one hand and Ag-NOR area with SPF on the other provide further evidence that distribution and quantity of Ag-NORs are strongly influenced by the cell cycle phase within the structural-functional unit of the nucleolus.

Carcinoma, Transitional Cell↗
PubMed1994

Detection of intralesional calcium by intracoronary ultrasound depends on the histologic pattern.

This study was designed to examine the accuracy of intravascular ultrasound in detecting different histologic types of calcium pattern in human coronary artery atherosclerotic lesions. Previous studies have shown that calcium deposits in atherosclerotic lesions may occur in various forms and that intravascular ultrasound is a sensitive technique to detect calcium in atherosclerotic lesions. However, there has been no distinction between varying image representations of calcium and different histologic patterns of intralesional calcific deposits. Calcific lesions have an important clinical impact on the outcome of intracoronary transcatheter therapy, and the varying types of calcium may also play a role in the guidance of intracoronary interventions. Fifty fresh coronary vessel segments were studied by intracoronary ultrasound imaging and the images compared with the corresponding histologic sections. With intracoronary ultrasound imaging, calcium was defined as bright echo with corresponding sharp edged shadowing in the distal field. Three different histologic types of calcification were defined, and the sensitivity and specificity of the detection by intravascular ultrasound were determined for each type. Dense calcified plaques (type 1) were found 18 cases, microcalcification (small flecks of calcium) with single calcium fleck size < or = 0.05 mm (type 2) in 12 cases, and combination of calcified plaque surrounded by small calcium flecks (type 3) in 3 cases. In 17 (34%) coronary vessel segments, histologic analyses detected no calcium. Intracoronary ultrasound correctly detected 16 (89%) of 18 cases of type 1 calcification, 2 (17%) of 12 type 2, and all 3 (100%) type 3. Sensitivity for detection of type 1 and 3 calcification was 90%, with specificity of 100%.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium↗
PubMed1994

Quantification of spermatogenesis by dual-parameter flow cytometry.

OBJECTIVE: To investigate the usefulness of dual-parameter flow cytometry of testicular fine-needle aspirates for the quantification of spermatogenesis. Immunofluorescence staining for vimentin was introduced to discriminate vimentin-negative germ cells from vimentin-positive stromal cells. The results of flow cytometry were compared with testicular morphology and immunohistochemistry in cases of regular and disturbed germ cell maturation. DESIGN: Testicular fine-needle aspiration and surgical biopsy were performed in 50 autopsy cases. The fine-needle aspirates were double stained for the intermediate filament vimentin by indirect immunofluorescence and DNA propidium iodide and analyzed by flow cytometry. Surgical biopsies were examined by light microscopy. The distribution of vimentin-positive cells was evaluated by immunohistochemistry. RESULTS: A comparison of morphology and flow cytometric analysis yielded characteristic quantitative distribution patterns of the different germ cell and somatic cell populations in regular and disturbed spermatogenesis. All three ploidy compartments of the germ epithelium correlated with high statistical significance with the respective histologic diagnoses. Moreover, a marked quantitative increase of stromal cells could be demonstrated in spermatogenetic disorders. CONCLUSIONS: The simultaneous analysis of the cellular DNA content and the intermediate filament vimentin by flow cytometry enables a detailed investigation of spermatogenetic disorders. Quantitative changes of the relationships between germ cells and somatic cells can be selectively investigated.

Biopsy, Needle↗
PubMed1994

Rapid detection of mycobacterial DNA in clinical samples by multiplex PCR.

Triplex-polymerase chain reaction technique (PCR) was developed for the detection and identification of mycobacterial DNA sequences in uncultured clinical samples. A 123 bp fragment corresponding to a specific Mycobacterium tuberculosis sequence complex, a 383 bp DNA fragment encoding for part of the 65 kD mycobacterial surface antigen, and a 268 bp fragment of the human beta-globin gene to demonstrate the presence of suitable DNA were amplified by triplex PCR. To demonstrate the applicability of this method, 206 alcohol-fixed, paraffin-embedded sputum samples from 47 patients with culture-proven tuberculosis were investigated. Of 206 samples, 157 were PCR positive, resulting in correct diagnosis of tuberculosis in 46 of 47 (97.8%) patients. Furthermore, 165 alcohol-fixed, auramin-stained sputum smears were examined in a blind trial. Triplex PCR revealed tuberculosis in 20 of 21 samples from patients with tuberculosis. In comparison, cultures were positive in 20 of 21 samples, and acid-fast organisms were found by microscopy in 18 of 21 samples. We conclude that triplex PCR is a rapid and sensitive technique for the detection of mycobacterial DNA in uncultured clinical samples and offers equivalent sensitivity (95.2%) and specificity (98.6%) as do culture methods.

Base Sequence↗
PubMed1994

Bronchoalveolar lavage: results of sequential, selective techniques in viable murines.

The purpose of this study was to develop an optimal technique for performing sequential bronchoalveolar lavage (BAL) in a murine animal model. Two general anesthetic regimens and four operative techniques of BAL were tested. Anesthesia by intraperitoneal injection of ketamine hydrochloride (100 mg/kg body wt) resulted in death for four of ten subjects, whereas inhalation of diethyl ether led to death for one of ten subjects. BAL using a balloon catheter under bronchoscopic guidance was comparable with postmortal lavage, tolerated better, and resulted in superior cell retrieval with respect to cell differential (macrophages: 95 +/- 2.3; lymphocytes: 3 +/- 1.2; polymorphonuclear lymphocytes [PNL]: 1.2 +/- 1.4) compared with two other techniques using a bent metal tube/polyethylene tubing combination (macrophages: 19.3 +/- 27.4; lymphocytes: 3.8 +/- 4.3; PNL: 35.5 +/- 35.5) and a bronchoscope/polyethylene tubing combination (macrophages: 11.1 +/- 25.5; lymphocytes: 0.7 +/- 1.0; PNL: 55.8 +/- 41.0). The BAL fluid contained significantly more alveolar macrophages and fewer PNL and epithelial cells (p = 0.0001, p = 0.0025, p = 0.02, respectively). We conclude that the technique using a balloon catheter under bronchoscopic guidance during inhalation of diethyl ether is the procedure of choice and results in a representative sample of BAL.

Anesthesia↗
PubMed1994

Sequential quantification of AgNOR area and number during silver staining by means of an image analysing system.

Standardized AgNOR staining protocols are required to compare results obtained by means of image analysis systems (IAS) in different laboratories. In order to investigate the staining kinetics of the NOR silver staining, we evaluated automatically the area and number of AgNORs of a human transitional-cell carcinoma cell line (HOK-1) by IAS at one minute intervals over a total staining period of 30 minutes. Results showed a constant increase (standard error of estimate: 0.001; R squared: 0.8) of the AgNOR area reaching a plateau after 10 minutes followed by further area increase. In contrast, in all experiments a pronounced variability in the AgNOR number (standard error of estimate: 0.042; R squared: 0.75) was noted, reflecting the aggregation of silver stained spots. Thus the evaluation of the AgNOR area yielded reliable and easily reproducible results, whereas the assessment of the AgNOR number by means of an automated IAS was associated with a marked variability.

Autoanalysis↗
PubMed1994

Teratoma of the umbilical cord. Case report with review of the literature.

Teratomas of the umbilical cord are very rare lesions. We found only five cases in the literature from 1887 to 1993, the latest reported in 1985. We report a case of a 10 x 7 x 5-cm mass located just at the end of an omphalocele in the umbilical cord of a full-term baby. The mass exhibited something like a cranial and a caudal pole, and tissues of all three germinal layers could be found, but there were no skeletal structures. Therefore, this lesion was diagnosed as a teratoma of the umbilical cord. We review the literature and discuss the relationship between the teratoma of the umbilical cord and the holoacardius amorphus.

Adult↗
PubMed1993

[Non-urothelial tumors of the urinary tract].

Only about 2% of the urinary tract are not of urothelial origin. Our knowledge of their morphology and biology is mainly based on single case reports, and therefore apart from a few exceptions very poor. Generally, the most often affected site is the urinary bladder (79.2%), followed by the urethra (12.7%), pelvis (4.9%) and ureter (3.2%). The urinary bladder also is the only organ in which all different histological types of these tumors were described. According to their histogenesis non-urothelial tumors (NUT) can be classified by the following main groups: soft tissue tumors, mixed epithelial and non epithelial tumors (carcinosarcomas), neuroendocrine carcinomas, carcinoids, malignant lymphomas, malignant melanomas and extragonadal germ cell tumors. Moreover some very interesting tumor-like lesions, like malakoplakia and inflammatory pseudosarcoma, mainly occur in this region. About 75% of all NUT of the urinary tract belong to the soft tissue tumors. Rhabdomyosarcomas in children and leiomyomas and -myosarcomas in adults are the more frequent histological types. Leiomyosarcomas can easily be confused with other tumor types or even with inflammatory pseudotumors. The use of immunohistochemistry to achieve a correct diagnosis is mandatory but not always successful. A relatively frequent tumor occurring in the bladder of young adults is the paraganglioma (pheochromocytoma), which usually produces typical symptoms of catecholamine excess. Carcinosarcomas of the urinary bladder contain both epithelial and mesenchymal components. They have to be distinguished from collision tumors (coexistent but separate carcinoma and sarcoma), spindle cell transitional carcinomas as well as from carcinomas with osseous or cartilaginous metaplasia. Carcinoids and neuroendocrine carcinomas developed from the neuroendocrine cells scattered all over the transitional epithelium of the bladder. Neuroendocrine carcinomas of the bladder are also called "oat cell carcinomas" since they show the same histological features and immunoreactivity as the oat cell carcinomas of the lung. They share also the same poor prognosis. The affection of the urinary tract in generalized malignant lymphomas and leukemias occur in more than 30% of cases. Lymphomas, primarily localised in the urinary bladder are, however, extremely rare. The most frequent ones are low grade non Hodgkin lymphomas, although 3 cases of Hodgkin disease and a few cases of primary extramedullary plasmacytoma of the bladder have been reported, too.(ABSTRACT TRUNCATED AT 400 WORDS)

Carcinoma↗
PubMed1993

[Proliferative activity and p53 expression in transitional cell carcinoma of the urinary bladder].

Mutations of the p53 gene are important mechanisms in malignant transformation and are associated with dysregulation of normal cell growth. In the present study the expression of mutated p53-protein and proliferating cell nuclear antigen (PCNA) was investigated in a series of 31 human transitional cell carcinomas (TCC) by immunohistochemistry (IHC). The number of PCNA-positive cells and the pattern of expression was distinct in normal urothelium being confined to the basal cell layer. In dysplastic urothelium and in Carcinoma in situ (CIS) PCNA-immunoreactive nuclei were irregularly distributed throughout all layers. In tumor cell complexes the pattern of PCNA-immunoreactivity was different in papillary and primary infiltrating TCCs. Densitometric quantification of the intensity of the PCNA-reactivity using image analysis revealed an increase from normal to dysplastic urothelium and from dysplastic urothelium to invasive tumors. 21/31 (68%) of the tumors and tumor-associated CIS showed overexpression of p53 varying in percentage, pattern and reaction intensity. The percentage of PCNA-positive cells was higher in tumors overexpressing p53. Double IHC showed colocalization of both molecules in a significant proportion of tumor cells suggesting a link of p53 overexpression and the abnormal proliferative activity. The present results show that p53 over-expression is found in a significant percentage of TCCs and indicate a close association with a defective growth regulation resulting in increased PCNA-levels and enhanced cellular proliferation.

Analysis of Variance↗
PubMed1992

Deoxyribonucleic acid flow cytometry and semiquantitative histology of spermatogenesis: a comparative study.

OBJECTIVE: To compare deoxyribonucleic acid (DNA) flow cytometry with a semiquantitative histologic method for the assessment of spermatogenesis and to investigate the influence of various preparative techniques on the results of DNA measurements. DESIGN: Testicular tissue from 52 autopsies was examined for spermatogenesis by DNA flow cytometry and by conventional semiquantitative histology. Flow cytometry was performed on single nuclei suspensions from fine needle aspiration biopsies, resuspended imprints, as well as on specimens obtained by mechanical disaggregation of surgical biopsies of the same testis. RESULTS: In all cases, flow cytometry revealed a characteristic distribution pattern of haploid (n), diploid (2n), and tetraploid (4n) cells independent of the preparation technique used. The percentage of haploid cells of the testes showed statistically highly significant correlations (P = 0.0002) with the results of semiquantitative histology. Fine needle aspiration biopsy always contained more haploid cells compared with resuspended imprints and mechanically disaggregated samples. CONCLUSION: Our results confirm the suitability of DNA flow cytometry as a fast and reliable quantitative method for the assessment of spermatogenesis and demonstrate its optimal feasibility in combination with fine needle aspiration biopsy.

Adult↗
PubMed1992

Relationship between quantity of silver stained nucleolar organizer regions associated proteins (Ag-NORs) and population doubling time in ten breast cancer cell lines.

Using a one-step silver staining technique ten human breast cancer cell lines were investigated, determining by means of automated image analysis the mean area of Ag-NORs per nucleus, the total number of Ag-NORs, and the so-called "scattered" and "clustered" Ag-NORs. These parameters were statistically correlated with the population doubling time (PDT) of the various carcinoma cell lines of this series. Our results show that the mean area of Ag-NORs per nucleus (p less than 0.001) is highly significantly correlated to the PDT, whereas all other parameters were less or not significant. It is concluded that the assessment of the area of Ag-NORs by automated image analysis is a simple and reliable method for the determination of cell duplication rates.

Breast Neoplasms↗
PubMed1992

Morphometry and prognosis in cancer of the pancreatic head.

The histological slides of 39 cases of cancer of the pancreatic head were analysed using an interactive image analyser system. Some 14 cases were classified as periampullary, 25 as ductal pancreatic cancer. All cases had undergone radical tumor resection according to Whipple's procedure. Morphometric data, tumor size and metastatic nodal involvement were correlated to prognosis. Univariate statistical analysis showed that the classical differentiation between ductal and periampullary cancer was a weaker prognosticator than morphometric variables. In fact, multivariant statistical analysis showed that the morphometric variable irregularity was the best prognosticator (p = 0.0001). No other variable added significant prognostic information. Irregularity is a newly developed variable describing the nuclear shape corrected for roundness. We conclude that morphometry can be of essential prognostic information for the clinician in cancer of the pancreatic head.

Carcinoma, Intraductal, Noninfiltrating↗
PubMed1992

Graft replacement of post-traumatic thoracic aortic aneurysm: results without bypass or shunting.

From 1986 to 1991 13 cases of post-traumatic thoracic aneurysm were treated at our department. All patients had apparent thoracic injury at the time of trauma, and their mean age was 35 years. The mean time between trauma and operation was 3 years and six patients were asymptomatic. In all patients the diagnosis was made by computed tomography and angiography and all post-traumatic thoracic aneurysms were located at the aortic isthmus. No spinal cord protection by bypass or shunting was used during surgery and the clamp-and-repair method with a mean clamping time of 38 min was used in all 13 patients. No renal or neurological complications were observed postoperatively and there were no hospital deaths. The data of 202 patients who had been operated upon for post-traumatic thoracic aneurysms since 1981 have been reviewed with regard to the relationship between spinal cord protection and the incidence of postoperative paraplegia. Different methods of spinal cord protection were used in 121 patients resulting in paraplegia rate of 1.6%. In 81 patients the clamp-and-repair method was used and no case of paraplegia was observed in this group.

Adult↗