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Biomedical subjects

M F Fey

Publications and source records attributed to M F Fey.

At least 127 records · Page 7Linked to original sources

Continuous 5-day infusion of ifosfamide with mesna in inoperable pancreatic cancer patients: a phase II study.

Phase II studies on ifosfamide and mesna in pancreatic cancer have mostly been inconclusive. In all of these studies ifosfamide was administered as an i.v. bolus or by short infusions. Since dose fractionation of ifosfamide over several days increases its therapeutic index, we chose to maximize the dose fractioning by selecting a continuous-infusion schedule (1.75 g/m2 on days 1-5 every 21-28 days, with mesna 60%-100% of the ifosfamide dose up to 12 h after ifosfamide). Since 1987 29 patients (performance status less than or equal to 2) with advanced inoperable adenocarcinoma of the pancreas were studied (8 women and 21 men; median age 58 years: 36-73 years). A total of 25 patients are evaluable for response (1 ineligible; 3 inevaluable: 2 early deaths due to disseminated intravascular coagulation, 1 refusal). One female patient with a complete response on computed tomography scan (after five cycles) but residual liver metastases on surgical exploration survived for 473 days. Three male patients with partial response survived for 205, 335 and 355 days. Six more patients with minor response (3) or no change (3) but significant decrease of tumour marker CA 19-9 had a median survival of 213 days (106-243). Responders seemed to benefit in terms of pain relief and general well-being. The median overall survival of all patients was 148 days (21-473). Haematotoxicity was rarely dose-limiting [median nadirs: white blood cells = 2.1 x 10(9)/l (0.45-6.4), Hb = 10.7 g/dl (7.5-13), platelets = 137 x 10(9)/l (21-411)]. Nausea and vomiting were mild with prophylactic oral metoclopramide. No central nervous system toxicity or urotoxicity was observed. Alopecia was seen in all patients who had received at least two cycles. Continuous infusion of ifosfamide was generally well tolerated and useful for palliation in 10 of 25 patients. A higher dose intensity is recommended.

Adenocarcinoma↗

The polymerase chain reaction: a new tool for the detection of minimal residual disease in haematological malignancies.

The polymerase chain reaction (PCR) is a novel technique for the in vitro amplification of specific short DNA fragments, which permits a selective and up to 10(7) fold enrichment of the target sequence. The method is increasingly being used for the molecular genetic analysis of hereditary, infectious and neoplastic disorders. The use of PCR for the detection of minimal residual disease in particular types of leukaemia or lymphoma, such as chronic myelogenous leukaemia expressing specific BCR/ABL-RNA and follicular non-Hodgkin lymphoma with the chromosomal translocation t(14;18) are reviewed. In acute lymphoblastic leukaemia clone-specific sequences from rearranged antigen receptor genes may be molecular markers suitable for amplification. Although PCR holds great promise for "molecular" staging and follow-up, several technical problems have to be kept in mind, and the clinical relevance of PCR-based evidence of minimal residual disease in haematological malignancies requires further investigation.

False Negative Reactions↗

[Large cell anaplastic lymphomas in the immunocompromised host].

Large cell anaplastic (LCA) lymphomas are a newly defined tumor entity, which has recently been integrated in the updated Kiel classification. The occurrence of CD30+ LCA lymphoma in the setting of renal transplant patients has so far been reported only once. This report describes two LCA lymphomas of B-cell phenotype in renal transplant patients. The clonal evolution and possible etiologic role of Epstein-Barr Virus (EBV) in LCA lymphoma was studied. Our findings give further evidence that clonal evolution of B-cell populations is a second event in lymphomagenesis and is, at least in the cases studied, preceeded by either reactivated latent or primary EBV-infection with clonal EBV proliferation.

Antigens, CD↗

[Diagnostic DNA probes].

Advances in molecular biology have had a tremendous impact on our understanding of the pathogenesis of hereditary disorders, tumours and infectious diseases. It is anticipated that recombinant DNA technology will gradually assume an important role as a diagnostic tool in medicine, since at least some of the techniques are now ready for routine use in the clinical laboratory. The most lucrative application (and hence the most competitive market) for DNA probes will be the detection of bacteria, viruses and other microbiological organisms by nucleic acid hybridization techniques. The value of recombinant DNA technology for prenatal diagnosis and carrier detection in genetic disorders is now firmly established. Analysis of DNA and RNA obtained from tumours may provide diagnostic information of practical relevance in carefully selected cases. It is, however, unlikely to challenge the established value of the more "traditional" diagnostic tools such as histopathology and immunophenotyping.

Bacteria↗

Assessment of clonality in human tumors: a review.

The various methods of determination of the clonality of human tumors are described. There are three major approaches based on X-chromosome inactivation analysis, lymphocyte analysis, and somatic mutation analysis. For each of these approaches there are established methods and more recent methods based on DNA analysis. The increasing number of methods available increases the scope of clonality determination to most tumors. All the methods have inherent advantages and disadvantages, and these are discussed in relation to their clinical application.

Chromosome Deletion↗

A PvuII restriction fragment length polymorphism of the glucose-6-phosphate dehydrogenase gene is an African-specific marker.

The site of a PvuII restriction fragment length polymorphism (RFLP) of the human glucose-6-phosphate dehydrogenase (G6PD) gene has been located in intron V, 60 bp upstream of G6PD exon VI. A population survey shows this RFLP to be specific for African populations, with frequencies of the rarer allele (PvuII type 2 site present) of 0.32-0.40 in Kenyans, Nigerians, Zambians, and West Indians. This allele has not been found in the European, Asian and Middle Eastern populations studied. Such population-specific markers may be useful in the study of population affinities and may provide insight into prehistoric migrations of peoples.

Black People↗

Immunogenotyping with antigen receptor gene probes as a diagnostic tool in childhood acute lymphoblastic leukaemia.

13 cases of childhood acute lymphoblastic leukaemia (ALL) were studied combining cell surface marker analysis with immunogenotyping by Southern blot hybridisation with a panel of antigen receptor gene probes. The immunophenotypes were unequivocal: 7 patients had B-phenotype and 6 patients T-phenotype ALL. In several patients immunogenotypes were not fully consistent with the respective phenotypes. For example, 2 B-cell precursor ALL had rearranged TCR beta chain genes and 2 T-ALL rearrangement of Ig heavy-chain genes. All cases showed clonal rearrangement or deletions within the TCR delta gene locus. TCR delta gene rearrangements might, therefore, serve as markers of clonality but not of B- or T-lineage in immature lymphoid neoplasms. We conclude that in current diagnostic practice immunogenotyping is a supplement rather than an alternative to immunophenotyping by surface marker analysis.

Adolescent↗

[DNA fingerprints and hypervariable regions: genetic marker with many application potentials in medicine and biology].

DNA polymorphisms are based on variations in the nucleotide sequences of the DNA within a given population and are transmitted from parents to offspring by Mendelian inheritance. Most of these mutations are phenotypically silent. Two different types of DNA polymorphisms are restriction fragment length polymorphisms and highly variable regions (HVRs), the latter with many different alleles at a given locus. Molecular probes for HVRs (or DNA minisatellites) can detect a great number of cross-hybridising fragments dispersed throughout the genome. The polymorphic patterns of these fragments are completely individual-specific, hence termed DNA "fingerprints". DNA "fingerprinting" has been shown to be a powerful tool for establishing family relationships, for example in paternity disputes, and for the positive identification of individuals in forensic medicine. The technique may be used to document marrow engraftment in patients who have undergone allogeneic bone marrow transplantation. DNA "fingerprinting" is a new method of assessing clonality in human tumours by identifying clonal somatic mutations in the tumour DNA. Cloning of individual DNA "fingerprint" fragments yields locus-specific HVR probes which, due to their high rate of heterozygosity, are ideal for linkage analysis and prenatal diagnosis in single gene disorders. This is exemplified by adult polycystic kidney disease, which has been found by a 3'alpha-globin-HVR probe to be closely linked to the alpha-globin-gene cluster on chromosome 16p. Locus-specific HVR probes have been used for the molecular diagnosis of clonal chromosomal deletions or loss of heterozygosity at particular loci in a large variety of tumours. These findings are the basis for the identification of anti-oncogenes or putative tumour-suppressor genes in the human genome.

Animals↗

Analysis of somatic mutations at human minisatellite loci in tumors and cell lines.

Hypervariable human minisatellite loci show a substantial level of germline instability, and spontaneous mutation rates to new length alleles have been measured directly by pedigree analysis. We now show that mutation events altering the number of minisatellite repeat units are not restricted to the germline, but also arise in other tissues. Mutant alleles can be detected at a very low frequency in lymphoblastoid cell lines and at much higher frequencies in clonal tumor cell populations, most particularly in gastrointestinal adenocarcinomas. Mutant alleles in these tumors are usually present at a dosage equal to or greater than that of the progenitor allele, indicating that most or all of the tumor cells carry the same clonally derived mutant allele. As with germline mutation, the incidence of somatic mutations in tumors varies from locus to locus, with the same locus showing the highest level of germline and somatic instability. Most length changes, as those in the germline, are of only a few repeat units; however, very large changes are also observed, implying that such mutations can occur in the absence of meiosis.

DNA Mutational Analysis↗

Clonal allele loss in gastrointestinal cancers.

Using a panel of DNA probes for hypervariable DNA regions we screened 52 gastrointestinal carcinomas for clonal allele losses on chromosomes 1, 5, 7, 12, 16 and 17. A total of 24/35 informative cases of colorectal cancers showed loss of constitutional heterozygosity at a locus on chromosome 17p, while 9/31 cases informative for a locus on 5q showed allele loss. Loss of sequences at 5q was linked to allele loss at 17p with a single exception. In gastric cancers loss of heterozygosity most frequently occurred at 1q (5/10 tumours) and at 12q (6/11 tumours). Gastrointestinal tumours show consistent chromosomal losses and the loci involved are different in gastric and colorectal cancers.

Adenocarcinoma↗

[DNA analysis in the assessment of leukemia].

In 5 cases of leukaemia and in two other cases where a diagnosis of leukaemia was considered, no definitive classification was made by morphology, cytochemistry, patterns of surface markers and/or cytogenetics. Therefore, genotyping was performed by DNA analysis of leukaemic cells. Somatic rearrangements in leukaemic cell DNA of immunoglobulin and T cell receptor genes, and of the breakpoint cluster region on chromosome 22 involved in the Philadelphia chromosome translocation, proved to be useful DNA markers to confirm or refute particular types of leukaemia.

Antigens, Differentiation↗

Absence of immunoglobulin and T-cell receptor gene rearrangements in myelodysplastic syndromes and acute nonlymphocytic leukemias.

The arrangement of the immunoglobulin and T-cell receptor genes has been analysed in 72 cases of primary myelodysplastic syndrome and 17 cases of acute nonlymphocytic leukemia. DNA was extracted from bone marrow aspirates, digested with at least two restriction enzymes, and hybridised with probes for the joining region of the immunoglobulin heavy chain gene, the constant region of the T-cell receptor beta chain gene, and the joining region of the T-cell receptor gamma chain gene. All cases showed germline arrangements of the immunoglobulin and the T cell receptor genes. Thus, true interlineage infidelity, myeloid to lymphoid, is a rare occurrence in myelodysplasia and in myeloid leukemias.

Acute Disease↗

Molecular diagnosis of haematological neoplasms.

DNA analysis has become of practical value in the diagnosis and classification of leukaemias and lymphomas. This is exemplified by the study of lymphoproliferative disorders using immunoglobulin and T-cell receptor gene probes for the determination of clonality and cell lineage. Chromosomal analysis with DNA probes is now a useful complementary approach to cytogenetics. For example, the study of particular lymphomas or chronic myelogenous leukaemia with DNA probes hybridising to specific chromosomal breakpoints allows the detection of chromosomal translocations at a genomic level. Chromosomal loss in neoplastic cells can be detected by DNA probes in individual heterozygous for particular restriction fragment length polymorphisms, most efficiently by locus-specific hypervariable region probles. These techniques will enable progress to be made in the understanding of the biology of remission and disease progression in haematological malignancies.

DNA↗