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Biomedical subjects

I Lauder

Publications and source records attributed to I Lauder.

At least 55 records · Page 3Linked to original sources
PubMed1992

Oncogene expression in primary myelodysplasia: correlation with haematological, karyotypic, and clinical progression.

AIMS: To see if the relative expressions of proto-oncogenes that are increased in acute myeloid leukaemia are raised in patients with myelodysplastic syndromes (MDS), and to see if they increase with progression to leukaemia. To note if there is a correlation between morphology, karyotype, and these proto-oncogene expressions and if any one proto-oncogene can predict prognosis. METHOD: Bone marrow from 130 patients was analysed at six monthly intervals over two years for relative mRNA expression of seven oncogenes, karyotype, and morphology. The technique used slot blot hybridisation and densitometric analysis. The results were compared with 14 surgical controls and 30 people with vitamin deficiency anaemia. RESULTS: Six of seven oncogenes showed increased expression which progressed with time, but did not correlate with morphological or karyotypic changes. Expression of four of the seven oncogenes was increased in megaloblastic and iron deficiency anaemia. C-mos showed differences among the five morphological subgroups; it correlated with abnormal location (p = 0.025) and seemed to influence prognosis. CONCLUSION: Increased proto-oncogenes reflect the overall marrow perturbation in MDS. C-mos may reflect persistence of monocyte pathway which confirms marrow stability.

Aged↗
PubMed1992

[Nodular paragranuloma and Epstein-Barr virus: frequency of EBV DNA and clinical relevance].

Studies demonstrating Epstein-Barr virus (EBV) DNA in Hodgkin's disease (HD) provide little information about the EBV-status in the lymphocyte predominant subtype (nodular paragranuloma) which is due to the small number of cases investigated. Therefore we studied 99 typical cases of nodular paragranuloma for the presence of EBV-DNA using the polymerase chain reaction (PCR) technique. Genomic DNA was amplifiable in 71 cases; 29 cases (= 40%) were positive for EBV-DNA (EBNA-1). In situ hybridization revealed EBV-RNA (EBER-1) in L&H cells and in a few lymphocytes. PCR results were correlated to clinical follow-up data and did not show any statistically significant relationship between EBV positivity and survival of the patients.

Adult↗
PubMed1991

Localization of immunoglobulin light chain mRNA expression in Hodgkin's disease by in situ hybridization.

In situ hybridization techniques were used to detect immunoglobulin light chain messenger RNA (mRNA) in 28 formalin-fixed, paraffin-embedded samples of Hodgkin's disease. Cocktails of biotinylated oligonucleotide probes specific for the constant regions of kappa and lambda light chain mRNA were used. None of the Reed-Sternberg cells or their variants in any of the cases studied showed positive staining with either probe, in contrast to normal plasma cells which showed strong staining in the same sections. It was concluded, therefore, that the cytoplasmic immunoglobulin frequently detected within these cells by immunocytochemistry is present not as a result of synthesis, but as a result of some other mechanism.

Hodgkin Disease↗
PubMed1991

Epstein-Barr viral DNA in Hodgkin's disease: amplification and detection using the polymerase chain reaction.

The presence of Epstein-Barr virus (EBV) DNA in biopsy tissues from patients with Hodgkin's disease (HD) was investigated by the polymerase chain reaction (PCR) using primers specific to a sequence within the EBV Bam H1W region. EBV genome was detected in 33 of 57 (58 per cent) cases of HD. Viral DNA was, however, also demonstrated in nine of 24 non-Hodgkin's lymphomas, in three of nine non-neoplastic lymph nodes and in seven of 12 normal peripheral blood samples used as controls. In all cases, the band obtained following PCR was verified using Southern blotting and hybridization with highly specific Bam H1W probes. The results suggest that the technique is sufficiently sensitive to detect EBV in persistent latent infection in B-lymphocytes. Distinction between virus present as a possible aetiological agent of malignancy or as a latent infection is not possible when PCR is used under these conditions. The possible role of EBV as an aetiological agent of HD remains unresolved.

Adolescent↗
PubMed1991

Demonstration of insulin and glucagon mRNA in routinely fixed and processed pancreatic tissue by in-situ hybridization.

Human insulin and glucagon mRNA were identified in routinely processed pancreatic tissue by non-radioactive in-situ hybridization using digoxigenin-labelled oligonucleotide probes. Cocktails of synthetic oligonucleotides complementary to human insulin and glucagon mRNA were labelled with digoxigenin using terminal deoxynucleotidyl transferase (Tdt). Specific hybrids were detected with alkaline phosphatase-labelled anti-digoxigenin antibody and visualized by BCIP-nitroblue tetrazolium indicator substrate. The results showed highly sensitive and specific staining of islet cells on a range of routinely formalin-fixed and paraffin-embedded tissues. Post-mortem pancreatic tissue from adults and stillborn neonates yielded acceptable signals as long as tissue morphology was well preserved. Preliminary investigations using pancreatic endocrine cell tumours gave clear easily interpretable signals which were comparable to conventional immunostaining. The application of this technique promises to be of value in the investigation of pancreatic disease.

Adult↗
PubMed1991

The expression of parathyroid hormone messenger RNA in normal and abnormal parathyroid tissue.

The distribution and expression of preproparathyroid hormone (PTH) mRNA were investigated in parathyroid tissue from 57 parathyroidectomy specimens. PTH mRNA was detected by in situ hybridization using digoxigenin-labelled oligonucleotide probes. Cell morphology was seen to correlate with PTH mRNA expression. Strong expression of PTH mRNA was confined to cells which on haematoxylin and eosin staining had large vesicular nuclei. These included both vacuolated and non-vacuolated cells. Chief cells with small dark nuclei and scanty cytoplasm had little or no expression. In both adenoma and chief cell hyperplasia, the striking difference from normal was the greatly increased proportion of cells expressing PTH mRNA. In adenomas, the rim of uninvolved parathyroid tissue showed PTH mRNA expression similar to that of normal parathyroid. In hyperplasia, there was frequently concordance of staining within individual nodules. The findings establish morphological criteria for activity of parathyroid tissue and support current concepts of the different pathogenesis of hyperplasia and adenoma. The expression of PTH mRNA in oxyphil change and parathyroid carcinoma was also investigated.

Humans↗
PubMed1991

The clinical relevance of plasma viscosity in Hodgkin's disease.

The erythrocyte sedimentation rate has previously been identified as an important prognostic factor in Hodgkin's disease. The plasma viscosity has replaced the ESR measurement in many laboratories, but doubts exist about its clinical relevance. In this study plasma viscosity at presentation/diagnosis was studied in 107 patients with Hodgkin's disease. A multivariate analysis of factors influencing prognosis and relapse-free survival identified plasma viscosity and number of disease sites as being highly significant. The risk of relapse increases initially with a rise in plasma viscosity, but after a value of about 2.0 mPa.s no further increase in risk is observed. When all of the prognostic factors are made available to the proportional hazards model, treatment modality and plasma viscosity are selected as the best set for predicting time to first relapse. This study demonstrates that measurement of plasma viscosity at presentation is an important prognostic factor in Hodgkin's disease, in terms of predicting outcome or risk of relapse.

Adult↗
PubMed1991

High-grade T-cell lymphoma following treatment with cyclosporin A.

A 47-year-old man with persistent severe oropharyngeal ulceration developed a high-grade T-cell lymphoma soon after commencing treatment with cyclosporin A. Using Southern blotting to identify T-cell beta-chain gene rearrangements, evidence of clonal restriction was found both in blood and lymph node DNA samples. Two BamH1 rearranged bands were demonstrated in both samples. In the blood a 16 Kb band predominated, with a weaker 28 kb band. In the lymph node sample this pattern was reversed. The findings suggest that a bi-clonal population of T-lymphocytes or clonal evolution of an existing T-cell monoclone had developed, and that cyclosporin contributed to the emergence of a high-grade T-cell lymphoma.

Antigens, CD↗
PubMed1991

In situ hybridisation in perspective.

In the introduction to this review two questions were posed: is the technology associated with ISH ready for general use, and will the method become an important investigative tool? With the exception of the demonstration of some single and low copy sequences, non-radioactive ISH is now sufficiently developed and simplified to make it a routine technique. It is also clear that ISH will continue to have an important research role. In diagnostic pathology the technique is already providing valuable information and the present decade should see the development of many more diagnostic applications.

Genome, Human↗
PubMed1990

Demonstration of Epstein-Barr viral DNA in formalin-fixed, paraffin-embedded samples of Hodgkin's disease.

The presence of Epstein-Barr virus (EBV) DNA in formalin-fixed, paraffin-embedded samples of Hodgkin's disease (HD) was investigated by Southern blot hybridization using a specific EBV Bam H1W fragment probe. DNA from 16 samples of HD in children and young adults was compared with that from ten samples in adults older than 45 years. A further eight cases of DNA extracted from fresh samples of HD were also studied, in order to compare the results obtained with fresh and fixed tissue samples. Hybridization was demonstrated in 15 of the 34 cases of HD studied in contrast to 3 or the 34 control specimens of non-Hodgkin's lymphoma, non-neoplastic lymph nodes, and carcinomas. No differences between the two age groups compared were found. The results of this study suggest that there is a definite association between EBV and HD, although the exact nature of this association remains to be established. It has also been shown that DNA of sufficient quality for the detection of EBV DNA can be extracted from formalin-fixed, paraffin-embedded material, and that comparable results can be obtained using DNA extracted from fresh and fixed tissue.

Adolescent↗
PubMed1990

In situ hybridization of immunoglobulin light chain mRNA in paraffin sections using biotinylated or hapten-labelled oligonucleotide probes.

An in situ hybridization technique has been developed for the detection of immunoglobulin light chain mRNA in routine pathology specimens. The method detects kappa or lambda constant region sequences using a cocktail of synthetic oligonucleotide probes labelled with biotin or fluorescein 5-isothiocyanate (FITC) reporter molecules. The probes were labelled at flanking sites chemically by primary amine directed acylation and by 'homopolymer tailing' with terminal deoxynucleotidyl transferase using non-radioactive nucleotide analogues. The mRNA was unmasked in the formalin-fixed tissue sections by digestion with varying concentrations of proteinase K, and the hybrids were demonstrated using alkaline phosphatase with either a streptavidin/biotin based four-stage system or an anti-FITC antibody based detection system. Alkaline phosphatase was visualized using a Fast Red naphthol-capture method and the sections were counterstained with haematoxylin. The results confirm that the method is specific for kappa or lambda mRNA and show that specific mRNAs can be detected in routine formalin-fixed sections using non-radioactive techniques with retention of good morphology. The method reliably detects light chain mRNA in cells expressing secretory immunoglobulin. The protocol can also be applied to tissue rich in endogenous biotin by using hapten-labelled probes.

Biotin↗
PubMed1990

Zonal distribution of immunoglobulin-synthesizing cells within the germinal centre: an in situ hybridization and immunohistochemical study.

Immunohistologic studies have shown that synthesis of cytoplasmic immunoglobulin (cIg) is a normal function of some follicle centre cells (FCCs). The mechanisms regulating this synthesis of immunoglobulin and its function within the germinal centre are still poorly understood. In this study we applied a recently developed in situ hybridization method for the detection of kappa and lambda light chain mRNA to reactive lymph nodes and tonsils in order to investigate further the immunoglobulin-synthesizing cells of the germinal centre. FCCs containing detectable levels of light chain mRNA corresponded closely to cells containing cIg. The detection of light chain mRNA rather than its immunoglobulin product was found to be an advantage in that problems associated with the detection of extracellular immunoglobulin were eliminated. This was most apparent in germinal centres where the absence of 'network' immunoglobulin led to the observations that immunoglobulin-synthesizing FCCs are predominantly small centrocytes and that in a proportion of germinal centres they localize in that part of the light zone closest to the dark zone. This zonal distribution of immunoglobulin-synthesizing FCCs raises the possibility of further functional and micro-environmental subcompartments within the light zone.

Antibody-Producing Cells↗
PubMed1990

Automated immunochemistry.

A prototype immunostainer, featuring totally enclosed slide chambers, a reagent carousel and a microcomputer controlled fluid transfer system, was developed. The machine offers total flexibility in choice of primary and detection reagents for each slide and has been successfully used for the immunochemical demonstration of a variety of antigens in paraffin wax and blood smear preparations. It is considerably cheaper to use than manual immunochemistry and will be even cheaper in a production version currently under development.

Equipment Design↗
PubMed1989

In situ hybridization demonstration of poly-adenylated RNA sequences in formalin-fixed paraffin sections using a biotinylated oligonucleotide poly d(T) probe.

An in situ hybridization technique has been developed for assessing poly(A)+ RNA preservation in routine pathology specimens. The method detects poly-adenylated RNA sequences in tissue sections using a biotinylated polydeoxythymidine (poly d(T)) probe. The probe was prepared from single-stranded 25-30 base oligo d(T) and was biotinylated using the enzyme terminal deoxynucleotide transferase with biotin-11-dUTP and dTTP in the ratio 1:4. The hybridization protocol uses varying concentrations of proteinase K to unmask mRNA sequences and the biotin-labelled hybrids are demonstrated after hybridization under standard conditions by the application of streptavidin and biotinylated alkaline phosphatase. Alkaline phosphatase was visualized using a Fast Red naphthol-capture method and the sections were counterstained with haematoxylin. The results have confirmed that the method is specific for poly(A)+ RNA and shows that poly(A)+ RNA can be demonstrated in routine formalin-fixed sections using non-radioactive techniques with retention of morphology. It also provides a means of optimizing the hybridization conditions for specific mRNA probes and produces a staining pattern demonstrating the relative level of poly(A)+ RNA per cell which may reveal new information about cell activity and tissue function.

Base Sequence↗
PubMed1989

In situ hybridization detection of light chain mRNA in routine bone marrow trephines from patients with suspected myeloma.

A method for the detection of immunoglobulin light chain mRNA by situ hybridization has been applied to routine bone marrow trephines, from patients suspected of having multiple myeloma. The principle aim was to define monoclonal populations even in cases lacking a paraprotein or an obvious atypical plasma cell proliferation. The expression of light chain mRNA in plasma cells in routine bone marrow trephines from 14 patients with suspected myeloma was studied. Plasma cells in the marrow ranged from 4% to 99%. Clonal populations based on light chain restriction were delineated in 12 patients, using biotinylated probes to kappa and lambda mRNA and visualized using an alkaline phosphatase/fast red naphthol capture method. Normal tonsil and bone marrow trephines were used as controls. In situ hybridization was found to be a specific, safe and rapid technique. It could be applied to both fixed and fresh tissue. It was found to lack the background staining of interstitial immunoglobulin, particularly in sclerotic cases, which is so often encountered with immunocytochemistry. Additionally, this technique will type plasma cell neoplasms (undetected by routine immunocytochemistry) in post-transcriptional block or non-secretory myeloma.

Bone Marrow↗
PubMed1989

A retrospective study of follicular lymphomas.

Sixty-four cases of follicular lymphoma followed-up for 10 years have been studied. The influence of age, sex, histological appearance, immunophenotype and T-cell content on prognosis has been examined. Initial evaluation indicated that increasing age, relatively low numbers of intrafollicular T-cells and absence of mantle zones around the neoplastic follicles were associated significantly with mortality. Multiple regression analysis with adjustment for age and sex was performed and the only significant variable was then found to be the histological grade.

Antibodies, Monoclonal↗