Biomedical subjects

I Lauder

Publications and source records attributed to I Lauder.

At least 37 records · Page 2Linked to original sources

PubMed1995

Increased dimeric IgA-producing B cells in tonsils in IgA nephropathy determined by in situ hybridization for J chain mRNA.

The origin of mesangial IgA deposits in IgA nephropathy (IgAN) remains obscure. A significant proportion of deposited immunoglobulin is dimeric (J chain-positive). Previous studies of J chain expression within lymphoid tissue in IgAN have utilized antibodies which other investigators have found to be non-specific. To address this problem, we have developed and in situ hybridization (ISH) method for the detection of J chain mRNA within IgA plasma cells. Tonsils from 12 patients with IgAN and 12 controls were studied using (i) non-isotopic ISH for J chain mRNA, and (ii) combined immunofluorescence (IF) and fluorescent ISH. J chain mRNA-positive cells were identified in germinal centres, and within the subepithelial and interfollicular zones. A greater number of J chain mRNA-positive cells were found in the germinal centres of patients (mean 57.7 +/- 4.6 cells/10(5) micron2) compared with controls (mean 36.9 +/- 3.5 cells/10(5) micron2) (P < 0.001). Combined IF and fluorescent ISH showed a greater proportion of J chain mRNA-positive interfollicular IgA cells in patient tonsils (32 +/- 3.4%) compared with controls (21 +/- 2.3%; P < 0.02). These results indicate a shift towards dimeric IgA production in the tonsils in IgAN. In addition, the finding of excess numbers of J chain-positive Iga-negative cells within germinal centres suggests that an abnormality may be present at the B cell differentiation stage before IgA switching. These results further highlight immune abnormalities within the tonsil as a central feature of abnormal polymeric IgA biology in this common form of glomerulonephritis.

Adolescent↗

PubMed1995

Combination of Hodgkin's disease and diffuse large cell lymphoma: an in situ hybridization study for immunoglobulin light chain messenger RNA.

It is not clear whether the rare combination of Hodgkin's diseases with non-Hodgkin lymphomas are true composite lymphomas or differentiation stages of one tumour cell clone. We used in situ hybridization and immunohistochemistry for the demonstration of immunoglobulin light chains in order to investigate the relationship between the two lymphoma components. In three cases of nodular lymphocyte predominance Hodgkin's disease combined with diffuse large B-cell lymphoma the Hodgkin cells, as well as the tumour cells in the diffuse large B-cell lymphoma, showed the same messenger RNA for one light chain. Thus, using in situ hybridization in nodular lymphocyte predominance Hodgkin's disease combined with diffuse large B-cell lymphoma in a small number of cases a possible genetic relationship between the two components could be shown. In nodular sclerosis combined with diffuse large B-cell lymphoma, in situ hybridization did not support a common clonal origin of both tumour parts. However, a unique clonal derivation cannot be excluded by the techniques applied.

Hodgkin Disease↗

PubMed1995

Thrombocytopenia following autologous bone marrow transplantation: evidence for autoimmune aetiology and B cell clonal involvement.

Thrombocytopenia outlasting anaemia and neutropenia is a well recognised sequel of autologous bone marrow transplantation (BMT) but the pathogenesis remains unclear. Autoimmune destruction of platelets has been suggested as a possible mechanism. We studied 5 patients who had undergone autologous BMT and were found to have persistent thrombocytopenia (< 150 x 10(9)/l) 6 months from transplantation with a normal haemoglobin level and granulocyte count. Apart from a mild reduction in the megakaryocyte numbers in one case, no other quantitative or qualitative defects of the megakaryocyte lineage were present to explain the peripheral thrombocytopenia. Two cases had positive anti-platelet autoantibodies. Immunoglobulin heavy chain gene rearrangement studies of peripheral blood and bone marrow mononuclear cells using the polymerase chain reaction showed evidence of clonal rearrangement in one of the two cases with positive anti-platelet autoantibodies. Our results support the previous reports that anti-platelet antibody-mediated destruction of platelets may play a role in the pathogenesis of post-autologous BMT thrombocytopenia. Furthermore, the demonstration of a clonal B cell expansion in one of the cases with anti-platelet antibodies suggests an aetiological link between clonal B cells, autoantibody production and thrombocytopenia.

Adult↗

PubMed1995

Changes in serum lipoprotein(a) and lipids during treatment of hyperthyroidism.

Because of suggestions that thyroid hormones modulate serum lipoprotein(a) [Lp(a)] concentration, we evaluated prospectively the serial changes of serum Lp(a), measured as apolipoprotein(a) [apo(a)], and other lipoproteins in 40 subjects with hyperthyroidism treated with radioactive iodine (RAI) therapy. Hyperthyroid patients had lower (P < 0.001) concentrations of apo(a), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and apo B, but higher apo A-I concentrations compared with age-matched controls [geometric mean (range)]; apo(a) 81 (17-614) vs 187 (17-1808 IU/L): TC 4.07 +/- 0.8 vs 5.22 +/- 1.00 mmol/L (mean +/- SD); LDL-C 2.47 +/- 0.89 vs 3.40 +/- 0.88 mmol/L; HDL-C 1.05 +/- 0.33 vs 1.24 +/- 0.34 mmol/L; apo B 0.66 +/- 0.23 vs 1.13 +/- 0.34 g/L, and apo A-I 2.07 +/- 0.42 vs 1.46 +/- 0.28 g/L, respectively. Euthyroidism was associated with normalization of serum TC, LDL-C, and apo B within 1 month of treatment. However, apo(a) required 4 months to normalize, and HDL-C and apo A-I were still abnormal 6 months after RAI. Serum apo(a), TC, LDL-C, and apo B were negatively correlated with serum thyroxine (T4), free thyroxine index, and triiodothyronine (T3) and positively correlated with thyrotropin during the transitional period from hyperthyroidism to euthyroidism. Parallel changes of these lipoproteins and thyroid hormones were also observed after treatment of hyperthyroidism. In conclusion, thyroid hormones do modulate lipoproteins, particularly Lp(a). The delay in normalization of apo(a) but not LDL suggests an effect on apo(a) production rather than on LDL removal.

Adult↗

PubMed1994

Expression of J chain mRNA in duodenal IgA plasma cells in IgA nephropathy.

Glomerular IgA in IgA nephropathy (IgAN) is at least in part polymeric, and is thought to derive from the mucosal IgA system in view of the association between mucosal infection and haematuria in this condition. To investigate this hypothesis, an in situ hybridization (ISH) technique was developed for the detection of J chain mRNA, the expression of which has been correlated with the secretion of high level polymeric immunoglobulin (pIg). Endoscopic duodenal biopsies from ten patients and matched controls were examined by: (i) two color immunofluorescence (IF); (ii) ISH; and (iii) combined ISH and IF, to permit simultaneous identification of plasma cell type. IF revealed a reduction in the percentage of IgA plasma cells (P < 0.02) and increased absolute numbers of IgG cells (P < 0.02) in patient biopsies. ISH demonstrated fewer J chain mRNA expressing plasma cells (P < 0.005) with lower signal intensity (P < 0.002) in patients' biopsies compared with controls. Combined ISH and IF confirmed a reduction in J chain mRNA-positive IgA plasma cells in the patient biopsies (P < 0.02). The reduction in J chain mRNA expression in duodenal IgA plasma cells in IgAN argues against the gastrointestinal lamina propria as the source of glomerular pIgA.

Adult↗

PubMed1994

Mesothelial cell inclusions within mediastinal lymph nodes.

The presence of mesothelial cell inclusions within mediastinal lymph nodes is an extremely rare occurrence with apparently only two previously reported cases. We report a single case with immunohistochemistry and transmission electron microscopy. A study of 318 mediastinal nodes from 80 patients using haematoxylin and eosin and immunohistochemistry is reported with the observation of no further positive cases. A review of the literature concerning nodal inclusions found at other anatomical sites aids discussion on the aetiology of this type of nodal inclusion.

Adult↗

PubMed1994

Liver regeneration: a comparison of in situ hybridization for histone mRNA with bromodeoxyuridine labeling for the detection of S-phase cells.

We developed an in situ hybridization technique for measurement of proliferative cell numbers through detection of histone mRNA in routinely fixed, paraffin-embedded tissue sections. Histone gene expression is coordinated with the cell cycle, and the increase in expression during S-phase permits unambiguous identification of cells undergoing DNA replication. Histone mRNAs were identified in routinely processed rat liver tissue by non-isotopic in situ hybridization with digoxigenin-labeled oligonucleotide probes. Specific hybrids were detected with alkaline phosphatase-labeled anti-digoxigenin antibody and visualized by BCIP-nitroblue tetrazolium indicator substrate. Unequivocal cytoplasmic labeling was observed in various cell types in the liver remnant during the first 72 hr after a two-thirds partial hepatectomy. The spatial and temporal patterns of histone labeling were almost identical to those obtained by staining with an antibody to bromodeoxyuridine. The identification of histone mRNA appears to be a reliable marker of the S-phase fraction, a technique with the further advantage that the tissue does not have to be first exposed to a nucleotide analogue. Hence, retrospective studies are possible. The probes can be applied to human and animal cells and tissues because the nucleotide sequences of histone genes are conserved.

Animals↗

PubMed1993

In situ correlation of synthesis and storage of parathormone in parathyroid gland disease.

The distribution and expression of parathyroid hormone (PTH) were investigated in normal and abnormal parathyroid tissue. PTH was detected using a monoclonal antibody with specificity for the 44-68 region of the PTH molecule. Prominent reactivity for PTH was seen in normal parathyroid with a granular pattern of staining. Active parathyroid tissue (adenoma and hyperplasia) showed much less reactivity for PTH, although there was prominent reactivity in the normal tissue around adenomas. Comparison of expression of PTH with that of parathormone mRNA showed a reciprocal pattern in normal tissue and, to a less marked extent, in abnormal tissue. Parathyroid carcinoma in particular had coinciding areas of PTH and PTH mRNA expression. Oxyphil cells had little or no PTH expression, except in the associated 'colloid' in some cases. The findings indicate an inverse relationship between storage and cellular synthesis of PTH, this being more marked in physiological than in pathological conditions of the parathyroid.

Adenoma↗

PubMed1993

Clinical necropsy rates during the 1980s: the continued decline.

The trends in necropsy rates during the 1980s in three groups of British teaching hospitals in Leicester, Manchester, and Sheffield were compared in a retrospective study. The clinical necropsy rates declined in all three cities: in Leicester, from 16 to 10 per cent; in Manchester, from 14 to 8 per cent; and in Sheffield from 18 to 11 per cent. The medico-legal and overall necropsy rates showed variable trends between the cities. Specific events and changes in organization during the review period were correlated with the changing trends. The observed trends emphasize the continued decline in clinical necropsy rates over the last decade and illustrate the importance of monitoring differential necropsy rates.

Autopsy↗

PubMed1993

Demonstration of light chain mRNA in Hodgkin's disease.

The lineage of Hodgkin and Reed-Sternberg cells is still unclear. Detection of both immunoglobulin light chains in Hodgkin and Reed-Sternberg cells by immunohistochemistry is a well-known phenomenon. However, up to now, in situ hybridization techniques have failed to demonstrate light chain messenger(m) RNA in Hodgkin and Reed-Sternberg cells. In this investigation, we have analysed 26 cases of Hodgkin's disease (nodular lymphocyte predominant Hodgkin's disease, mixed cellularity, and nodular sclerosis type) using digoxigenin-labelled oligonucleotide probes for kappa and lambda light chains by in situ hybridization. In nearly half of the cases of nodular lymphocyte predominant Hodgkin's disease and in one case of mixed cellularity type, mRNA for only one light chain could be clearly demonstrated in the lymphocytic and histiocytic cells, Hodgkin, and Reed-Sternberg cells. These results support the idea that at least some cases of Hodgkin's disease are B-cell neoplasms.

Hodgkin Disease↗

PubMed1993

Flow cytometric quantitation of sequence-specific mRNA in hemopoietic cell suspensions by primer-induced in situ (PRINS) fluorescent nucleotide labeling.

We modified a technique of RNA detection based upon primed in situ labeling of RNA (PRINS) to quantitate poly(A) and histone mRNA in HL60 cell suspensions by flow cytometry. The direct PRINS technique was used to label poly(A) mRNA, based upon the incorporation of fluoresceinated nucleotides into cDNA chains generated by reverse transcription from the site of oligo(dT) primer-specific annealing on the poly(A) template. By this method, poly(A) fluorescent signals of up to 20-fold above background were obtained when primer concentrations were saturating. Nonspecific binding of the fluorochrome-conjugated nucleotide proved to be the greatest source of background fluorescence in cell suspensions. This was considerably reduced by preincubation of the cells in lysine and an excess of cold nucleotides prior to the PRINS reaction. The application of indirectly fluoresceinated antibodies to the FITC moiety of the conjugated nucleotide (indirect PRINS) enhanced detection of a fluorescent signal generated from cells by the direct PRINS technique after stringent histone priming. Cell cycle analysis, based upon DNA histograms obtained after PRINS labeling, showed the histone fluorescence to be primarily in S-phase cells of an exponentially growing population. Confocal laser scanning microscopy revealed good retention of cellular architecture, with cytoplasmic localization of poly(A) and histone mRNA fluorescence and heterogeneous mRNA expression among cells. Our modified PRINS labeling of RNA represents a useful advance in the precise quantitation of RNA species in cell suspension by flow cytometry.

Flow Cytometry↗

PubMed1993

The glycosylphosphatidylinositol-anchored lymphocyte antigen CDw52 is associated with the epididymal maturation of human spermatozoa.

The CAMPATH-1 (CDw52) antigen is a small glycosylphosphatidylinositol (GPI) anchored glycoprotein with a mature peptide comprising only 12 amino acids. It is abundantly expressed on human lymphocytes and is an unusually good target for complement-mediated cell lysis. The immunosuppressive and lymphocyte-depleting effects of CAMPATH-1 antibodies are being tested in a variety of diseases. Here we show that the antigen is also expressed at a high level in the male reproductive system, being found in the epididymis, seminal vesicle, seminal plasma and on the surface of mature (but not testicular) spermatozoa. Its possible transfer from epithelial cells in the epididymis to maturing sperm may represent a novel method of acquisition of cell surface antigens. In the presence of human complement, CAMPATH-1 antibodies inhibited the motility of washed sperm. However, seminal plasma blocks antibody binding and can protect sperm from this cytotoxic effect.

Antigens, CD↗

PubMed1993

Effect of antibiotics on sputum inflammatory contents in acute exacerbations of bronchiectasis.

We studied the changes in sputum neutrophil chemotactic activity (NCA) and elastolytic activity (EA) in acute exacerbations of bronchiectasis before and after treatment with oral antibiotics. Twelve patients who chronically produced sputum were assessed in the stable state, and when they subsequently developed symptoms of acute exacerbations, prior to initiation of antibiotics, during 2 weeks of antibiotics, and at 2 and 6 weeks after stopping antibiotics. NCA was measured using modified Boyden's technique with multiwell chemotaxis chamber, and EA with N-succinyl-trialanine-p-nitroanilide as elastase substrate. All 12 patients had NCA (49.3 +/- 8.69% FMLP response) and EA (50.5 +/- 17.1 mU per 100 microliters) in their sputum in the stable state. At acute exacerbation, there was significant increase in NCA (P < 0.001) and EA (P < 0.05). All responded clinically after 1 week of antibiotics, and this was associated with a decrease in NCA and EA back to the levels in stable state. A further week of antibiotics did not result in further decline of NCA or EA. Three patients had another acute exacerbation clinically between 2-6 weeks after stopping antibiotics and their NCA and EA rose again. In the other nine patients, both NCA and EA at 2 and 6 weeks post-treatment were similar to pre-exacerbation levels. Our findings suggest that short course antibiotics effectively control the upsurge in inflammatory activity in acute exacerbations, but has little effect on chronic airway inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1993

Detection of immunoglobulin heavy chain gene rearrangements in Hodgkin's disease using PCR.

AIM: To detect clonal rearrangements of the immunoglobulin (Ig) heavy chain gene in Hodgkin's disease tissue using the polymerase chain reaction (PCR). METHODS: DNA extracted from 36 samples of Hodgkin's disease was analysed using PCR and primers from conserved sequences in the variable (VH) and joining (JH) regions. RESULTS: Clonal rearrangement was detected only in one case. Evidence of clonal immunoglobulin gene rearrangement had been detected previously in this case using conventional Southern blot analysis. CONCLUSIONS: The sensitivity of the two techniques is equivalent and clonal Ig heavy chain gene rearrangements are rare in Hodgkin's disease.

Base Sequence↗

PubMed1993

Analysis of antigen receptor genes in Hodgkin's disease.

AIM: To analyse the configuration of the antigen receptor genes in Hodgkin's disease. METHODS: DNA extracted from 45 samples of Hodgkin's disease was analysed using Southern blotting and DNA hybridisation, using probes to the joining region of the immunoglobulin heavy chain gene, the constant region of kappa immunoglobulin light chain gene, and the constant region of the beta chain of the T cell receptor gene. RESULTS: A single case of nodular sclerosing disease showed clonal rearrangement of the immunoglobulin heavy and light chain genes, all other samples having germline immunoglobulin genes. The nature of the clonal population in the diseased tissue is uncertain, because the intensity of the rearranged bands did not correlate with the percentage of Reed-Sternberg cells present. The T cell receptor genes were in germline configuration in all the samples. CONCLUSIONS: Antigen receptor gene rearrangement is a rare finding in unselected cases of Hodgkin's disease.

Adult↗

PubMed1993

Response analysis in histopathology external quality assessment schemes.

AIMS: To develop a computerised method for analysing the results of histopathology external quality assessment (EQA) schemes which can provide confidential personal reports to individual participating pathologists. METHODS: A program was developed using the OMNIS database system, running on Apple Macintosh or IBM compatible computers. RESULTS: The program produces a general report of participants' responses to each case, and a choice of two types of personal report. One of these provides a list of the participant's diagnoses with a list of the most popular (Consensus) diagnoses for comparison. The other provides automatically calculated scores for the pathologist's performance along with simple statistical evaluation. The scores can be calculated by comparison with the consensus of the group or with correct diagnoses if they are known. A histogram indicating the distribution of performance within the group can be produced. The program can accept uncertainty in the form of differential diagnosis lists from participants. Potentially dangerous diagnostic errors can be identified and handled separately. Participants are identified only by code numbers and confidentiality can easily be enforced. The program is currently being used in the national renal pathology EQA scheme and in the local general histopathology scheme in the East Midlands. CONCLUSIONS: This program offers solutions to problems which have bedevilled the organisers of histopathology EQA schemes. It offers confidential advice to pathologists and will help to identify areas where an individual might benefit from continuing career grade medical education. It raises the possibility of the development of nationally agreed standards of performance in the reporting of pathological specimens, and it may be applicable to other specialties where textual reports are produced.

Confidentiality↗

PubMed1992

Vimentin expression by Reed-Sternberg cells in Hodgkin's disease.

The expression of vimentin in Reed-Sternberg cells in 61 samples of Hodgkin's disease (HD) was examined using an avidin-biotin-peroxidase complex technique. Forty biopsies (66%) expressed vimentin, and expression was seen in all subtypes of HD. No immunophenotypic differences between vimentin-positive and vimentin-negative cases were noted. The significance of such expression is unclear, but may be related to the alterations in growth and differentiation that are typical of neoplastic cells.

Hodgkin Disease↗

PubMed1992

Simultaneous in situ hybridisation of native mRNA and immunoglobulin detection by conventional immunofluorescence in paraffin wax embedded sections.

AIMS: The development of a technique for simultaneous in situ hybridisation for native mRNA and conventional immunofluorescence for cytoplasmic antigens in routine pathology specimens. METHODS: Cocktails of synthetic deoxyoligonucleotides coding for immunoglobulin J chain and kappa light chain were 3' end labelled enzymatically with digoxigenin using terminal deoxynucleotidyl transferase. Native mRNA sequences were "unmasked" using proteolytic digestion with proteinase K and hybrid detection was achieved with an alkaline phosphatase labelled anti-digoxigenin antibody. Alkaline phosphatase was visualised with Fast red/naphthol AS-MX phosphate. Fluorescein isothiocyanate (FITC) conjugated anti-isotype antibodies were used simultaneously at the detection stage to identify the isotype production by individual plasma cells in endoscopic duodenal biopsy specimens. RESULTS: The IgA plasma cells of the lamina propria were identified by immunofluorescence and hybrids were detected in the anticipated plasma cell population by Fast red visualisation. The reaction product was visible in bright field or ultraviolet illumination which allowed FITC and Fast red labels to be visualised together under ultraviolet light at 490 nm. Dual labelled cells were clearly visible. Morphology was well preserved throughout. CONCLUSIONS: This technique permits the demonstration of specific mRNA species in cells expressing immunoglobulin. It combines all the advantages of non-radioactive synthetic oligonucleotide probes and conventional immunofluorescence techniques in routine formol-saline fixed and paraffin wax embedded sections with good retention of morphology.

Antigens↗