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At least 19 recordsLinked to original sources

Diagnostic molecular pathology.

Molecular pathology, defined broadly as the use of nucleic acid probes to diagnose and study disease, is an emerging discipline of growing importance and promise. Utilizing the principles of nucleotide base-pairing for specific hybridization between a DNA or RNA probe and its complementary target sequence, molecular diagnostic techniques are finding ever-increasing applications across the entire spectrum of human disease. These include infectious diseases (using DNA probes for viruses, bacteria, and parasites), neoplastic diseases (through detection of gene rearrangements, tissue-specific gene transcription, and oncogene activation), hereditary diseases (by screening for specific mutated genes or linked DNA polymorphisms), and the differentiation of individuals from one another by "DNA fingerprinting" (for purposes of donor recipient identification in transplants, paternity testing, or forensic investigations). This review surveys the current applications in each of these areas, along with the most important techniques now being used: Southern blotting, in situ hybridization, and the polymerase chain reaction. Finally, the impact of these powerful new methodologies on the entire field of diagnostic pathology is discussed.

Humans↗

Treatment failure and margin status in head and neck cancer. A critical view on the potential value of molecular pathology.

Molecular pathology may demonstrate tumour cells not detected by histology. The idea has emerged that these cells influence the prognosis negatively and that their detection will lead to more appropriate treatment and improved patient survival. We theorized that tumour cells at surgical margins overlooked by the pathologist should demonstrate their clinical significance by causing recurrences at the primary site in the patients reported to have tumour-free margins by histology. To assess this assumption, we investigated the prognostic influence of the histologically determined status of the surgical margins. The material that formed the basis of this study consisted of 394 patients that underwent resection for their primary tumour during the years 1990-1995. In 207 patients, initial treatment was complete as assessed by conventional histopathological examination of the surgical specimen. In 187 patients, initial treatment was incomplete, defined as tumour in or close to the margin, or mild, moderate or severe dysplasia or in situ cancer at the margin. Causes for treatment failure were recorded for both groups separately. In the group with tumour-free margins, 16.9% had a second primary head and neck cancer, 8.2% had a second tumour in the lung, 10.6% had recurrent disease in the neck, 2.9% had distant metastasis, and 3.9% had local recurrence at the same site as the primary cancer. For the group without tumour-free margins, these figures were the following: second primary in the head and neck area: 17.1%, second primary in the lung: 7.0%, recurrent disease in the neck: 11.8%, distant metastasis: 8.0% and local recurrence at the primary site: 21.9%. Local recurrences were rare in patients in which the pathologist reported the resection to be complete. Although there may be tumour cells in surgical margins that evade histological detection, their clinical impact appears to be almost negligible.

Carcinoma, Squamous Cell↗

[Molecular pathology: applications of molecular biology in pathological anatomy].

The rapid development of molecular biology techniques as well as recent progress in the understanding of genetic and molecular basis of human diseases have had enormous impact in the practice of clinical pathology. Since new diagnostic (molecular) tools are now available, the concept of Molecular Pathology is emerging. Molecular Pathology is defined by the use of molecular biology techniques and the type of specimens that are involved in its practice, basically ARN and ADN, extracted from cytological and tissue specimens. Although most methods used in molecular pathology and their applications are still under investigation and clinical validation they have great potential in several areas of pathological diagnosis, particularly on infectious and neoplastic diseases. Introduction of these techniques in pathology laboratories in our country should significantly enhance the diagnostic and research skills in the field.

Genetic Techniques↗

[From Virchow's cellular pathology to modern molecular pathology].

Evolution of Virchow's cellular pathology into molecular biology and molecular pathology due to achievements of cytology, biochemistry (histochemistry), immunology (immunomorphology) and genetics as well as new opportunities opened by integration of these disciplines (electron histochemistry, immunohistochemistry, immunogenetics, etc.).

History, 19th Century↗

Goals and objectives for molecular pathology education in residency programs. The Association for Molecular Pathology Training and Education Committee.

Increasing knowledge of the molecular basis of disease and advances in technology for analyzing nucleic acids and gene products are changing pathology practice. The explosion of information regarding inherited susceptibility to disease is an important aspect of this transformation. Pathology residency programs are incorporating molecular pathology education into their curricula to prepare newly trained pathologists for the future, yet little guidance has been available regarding the important components of molecular pathology training. We present general goals for pathology training programs for molecular pathology education. These include recommendations to pathology residents for the acquisition of both basic knowledge in human genetics and molecular biology and specific skills relevant to microbiology, molecular oncology, genetics, histocompatibility, and identity determination. The importance of residents gaining facility in integrating data gained via nucleic acid based-technology with other laboratory and clinical information available in the care of patients is emphasized.

Communicable Diseases↗

Specimen collection and storage for diagnostic molecular pathology investigation.

The success of the newest discipline in the diagnostic clinical pathology laboratory, molecular pathology, is dependent on proper collection and storage of both the original and processed (nucleic acid) specimen. This issue will grow in importance as test volumes increase in the diagnostic molecular pathology laboratory. This review is a distillation of a literature review by the Patient Preparation and Specimen Handling Committee of the College of American Pathologists. It describes specific collection, storage, and anticoagulant or preservative requirements based on the diagnostic molecular technique and/or specimen type used for analysis. This review serves as a guide for clinical laboratories interested in appropriate collection and storage of specimens to be used in nucleic acid-based analysis.

DNA↗

Pathological anatomy and molecular pathology.

The incidence of malignant mesotheliomas in Germany has increased since about the mid 1980s, and a further increase is expected until about 2020 due to the peak in asbestos processing in Germany between 1965 and 1980. About 90% of the mesotheliomas recorded in the files of the German Mesothelioma Registry in Bochum are asbestos-related and therefore possibly due to an occupational exposure. In 2003, 717 mesotheliomas were newly diagnosed at the German Mesothelioma Registry. Mesotheliomas are very heterogeneous in terms of histological appearances and of prognosis. At present, the diagnostic gold standard is conventional histology in combination with additional immunohistochemical analysis. We were not able to confirm a promising report that described telomerase reverse transcriptase catalytic subunit (TERT) for the differentiation between reactive and neoplastic mesothelial lesions, which can be extremely difficult. DNA cytometric analysis may also help differentiate between reactive and neoplastic mesothelial lesions. There are some characteristic patterns of chromosomal imbalances as detectable by comparative genomic hybridization (CGH), but at present, specific chromosomal or genetic defects that give rise to a mesothelioma are not known. A reliable pathological diagnosis is the basis for therapeutic, prognostic, and medicolegal consequences. In general, it can be achieved by thoracoscopic inspection with specifically directed biopsy. Furthermore, a description of the peculiarities of each mesothelioma by the pathologist might be the key to a more individual therapy in the future.

Asbestos↗

[Molecular pathological diagnosis of cancer].

Molecular biological analysis plays an important role for understanding of cancer pathogenesis. For example, accumulation of oncogene and anti-oncogene changes is necessary for cancer development. Molecular pathology is defined as a study field examining clinical materials using molecular biological technique. Even though mechanisms of cancer development and progression has much complexity, molecular pathological findings give a crucial information on clinical medicine, as Ki-ras point mutation and certain allelic loss may convert colon adenoma into carcinoma. Overexpression of EGF/receptor in gastric cancer is a biologic marker for high malignancy. More accumulation of molecular pathological informations will provide a new approach for prospective molecular diagnosis.

Adenocarcinoma↗

Molecular pathology of tumor metastasis. II. Molecular staging and differential diagnosis.

Molecular Pathology of Tumor Metastasis With the development of non-invasive methods, diagnosis of metastasis from various solid malignancies has become a routine task for diagnostic pathology. However, the differential diagnosis between primary and metastatic cancers and the precise identification of various metastatic cancer types requires the coordinated use of various morphological (light- and electron microscopic-), immunological and molecular techniques. The detection of the lymphatic spread of the primary tumor may now based on the sentinel lymph node technology while the identification of the hematogenous progression may be based on the analysis of the peripheral blood and the bone marrow. More and more frequently these techniques employ highly sensitive immunological and molecular techniques. Accordingly, clinical staging is now confronted with the results of molecular staging, where the only techniques which are able to detect cancer cells are immunocytochemistry or nucleic acid-based methodology. Although several clinical studies have provided evidences for the impact of the immunocytochemistry-based identification of micrometastases on the survival of patients with various type of cancers, none of these methods have become part of standard diagnostic protocols. Although more sensitive molecular techniques are being introduced to identify micrometastasis, their clinical significance is yet unknown. Multicentric clinical trials are now warranted to establish the clinical impact of molecular staging in various cancer types. Without the integration of these methods into the prognostic/predictive pathological protocols it is difficult to envision significant improvement in the results of cancer therapy.

Diagnosis, Differential↗

Epidemiology and molecular pathology at crossroads to establish causation: molecular mechanisms of malignant transformation.

Epidemiology is a very reliable science for the identification of carcinogens. Epidemiological studies require that the effect, cancer in this case, has already occurred, when of course it would be more desirable to identify potential carcinogenic substances at an earlier stage before they have caused a large number of malignancies and thus become identifiable by epidemiological studies. In the past 30 years, molecular pathology (which includes chemistry, biochemistry, molecular biology, molecular virology, molecular genetics, epigenetics, genomics, proteomics, and other molecular-based approaches) has identified some key alterations that are required for cellular transformation and malignancy. Agents that specifically interfere with some of these mechanisms are suspected human carcinogens. It can be stated that tumor formation requires the following steps: (1) inactivation of Rb and p53 cellular pathways; (2) activation of Ras and/or other growth promoting pathways; (3) inactivation of phosphatase 2A that causes changes in the phosphorylation and activity of several cellular proteins; (4) evasion of apoptosis; (5) telomerase activation or alternative mechanisms of cellular immortalization; (6) angiogenic activity; and (7) the ability to invade surrounding tissues and to metastasize. Here, we review the molecular mechanisms of cellular transformation. The integration of this knowledge with classical epidemiology and animal studies should permit a more rapid and accurate identification of human carcinogens.

Cell Cycle↗

Coxsackie B3 myocarditis in 4 cases of suspected sudden infant death syndrome: diagnosis by immunohistochemical and molecular-pathologic investigations.

Immunohistochemical and molecular-pathologic techniques have improved the diagnosis of myocarditis as compared with conventional histologic staining methods done according to the Dallas criteria. Most investigations were carried out on adults, and only a few authors investigating childhood deaths applied these modern methods, used for diagnosing myocarditis. We report on four children under one year of age, who suddenly died without prodromal symptoms. Their deaths were attributed to SIDS (sudden infant death syndrome). Immunohistochemical (LCA, CD68, CD45R0, MHC-class-II-molecules, VP1-capsid-protein of enteroviruses) and molecular-pathologic (RT-PCR) investigations, however, suggested that death was caused by a coxsackie-B3-myocarditis. In the future, these methods should be used for investigating cases with suspicion of SIDS.

Biomarkers↗

Molecular pathology of prostate cancer.

The molecular pathology of prostate cancer is complex; not only are multiple genes involved in its pathogenesis, but additional environmental factors such as diet and inflammation are also involved. The exhaustive research into prostate cancer to date has demonstrated a complex interaction of multiple genes and environmental factors, some of which may be more important in individual prostate cancer cases. This is an exciting era, with the emergence of new investigative tools such as DNA microarray technology and the application of the field of proteomics to the study of human cancers. Knowledge of genetic changes underlying the initiation, development, and progression of prostate cancer is accumulating rapidly. With increasing knowledge, it may be possible to distinguish indolent from aggressive prostate tumours by molecular fingerprinting. This review discusses the most consistently reported molecular pathological findings in hereditary and sporadic prostate cancer, together with new concepts and technologies.

Chromosome Aberrations↗