Co-localization of the inwardly rectifying potassium ion channel, Kir2.2, and the substance P receptor in single locus coeruleus neurons.
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Biomedical subjects
Publications and source records attributed to J H Pringle.
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AIM: To investigate vascular endothelial growth factor (VEGF) mRNA expression in glomerular disease in the context of heavy proteinuria. METHODS: Non-radioisotopic in situ hybridisation was performed using a cocktail of 12 deoxyoligonucleotides complementary to VEGF mRNA labelled during solid phase synthesis with 2,4-dinitrophenyl. Archival renal biopsies were studied from cases of minimal change nephropathy, membranous nephropathy, diabetic nephropathy, and controls, matched for age, sex, race, and storage time. Hybrid detection used NBT/BCIP colorimetric development. RESULTS: More VEGF mRNA positive glomerular cells per unit cross sectional diameter were seen in minimal change nephropathy (mean (SEM), 19.35 (1.5)) compared with controls (12.6 (1.73)), p < 0.01. In contrast, fewer were seen in diabetic nephropathy (5.93 (0.97)) compared with controls (9.97 (1.25)), p < 0.03. Analysis of membranous nephropathy (10 (1.62)) showed no difference from controls (10.98 (1.51)), NS. In addition, in minimal change nephropathy there was a significant correlation between 24 hour protein excretion at the time of biopsy and the number of VEGF mRNA cells per glomerulus (r = 0.08, p = 0.01). CONCLUSIONS: Using non-radioisotopic in situ hybridisation, VEGF mRNA is almost exclusively expressed by visceral glomerular epithelial cells. Abnormal numbers of cells are seen in both minimal change and diabetic nephropathy. As VEGF exists in a number of functionally distinct isoforms, further study of qualitative VEGF isoform expression in diagnostic groups is indicated.
Chlorambucil and prednisolone, two commonly used drugs in the treatment of chronic lymphocytic leukemia (CLL), induce apoptosis in CLL cells. We have investigated the involvement in this apoptotic cell death of caspases, which cleave critical cellular substrates thereby acting as the executioners of the apoptotic process. Induction of spontaneous or chlorambucil/prednisolone-induced apoptosis of freshly isolated B-CLL cells in culture resulted in the activation of the 'effector' caspases, -3 and -7, but generally not of caspase-2. Activation of caspases-3 and -7 was accompanied by the proteolysis of the DNA repair enzyme, poly (ADP-ribose) polymerase. Induction of apoptosis was also accompanied by the processing of caspase-8, the extent of which varied between patients. Induction of apoptosis and processing of all the caspases was inhibited by the cell permeable caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethyl ketone (Z-VAD.fmk). Our results demonstrate a key role for the activation and processing of caspases in the execution phase of apoptosis in CLL cells. Apoptosis of CLL cells resulted in the selective activation of some but not all caspases. Our results suggest that the dysregulation of apoptosis observed in CLL may be due to the signalling leading to the activation of caspases rather than a deletion of pro-caspases. High levels of caspase-8 in CLL cells in conjunction with low levels of CD95 receptor may offer new therapeutic opportunities for the treatment of CLL.
The use of reverse transcription (RT) PCR for relative quantitation of gene transcripts relies on the reproducibility of the individual RT, PCR and product measurement steps. Semi-competitive RT-PCR (RT-cPCR) uses an internal competitor template in the PCR step to improve quantitation. We have surveyed the reproducibility of RT, PCR, RT-cPCR and measurement, amplifying the glyceraldehyde-3-phosphate dehydrogenase "housekeeping" gene from isolated renal glomeruli. We used an enzyme-linked immunosorbent assay (ELISA) to quantify PCR products. We also report our PCR-based method for constructing a competitor DNA identifiable independently of the native product. Our results show that the entire RT-PCR and ELISA process had a standard deviation (SD) of less than 10% (n = 10). This compared to an SD of less than 13% (n = 10) in PCR and ELISA. The SD for ELISA alone was less than 11% (n = 10). RT-cPCR quantitation gave an SD of approximately 15% (n = 10). These results support the use of standard RT-PCR for the relative quantitation of mRNA. RT-cPCR is also suited to relative quantitation, but it is also independent of the amplification saturation curve and permits the identification of differences in cellularity between samples.
Angiotropic lymphoma, also known as intravascular lymphomatosis, is characterised by widespread intravascular proliferation of malignant lymphoid cells, usually without evidence of focal disease. A case of a 52 year old man referred for investigation of a two year history of pyrexia of unknown origin, skin rash and multiple organ failure is described. Angiotropic lymphoma was seen in gastric, colonic and skin biopsy specimens, and review of an earlier skin biopsy specimen showed similar morphological features. In contrast to previous cases which showed B or T cell differentiation, immunohistochemical examination was positive for histiocyte markers. Molecular studies showed no evidence of immunoglobulin heavy chain gene or T cell receptor gene rearrangement. The patient responded to combination chemotherapy, comprising cyclophosphamide, doxorubicin, etoposide, and prednisolone. This case highlights the fact that advanced lymphoma may be present without evidence of focal disease and that the diagnosis may be missed easily both clinically and histologically.
AIMS: To visualise directly numerical chromosomal aberrations and polyploidy in both Hodgkin and Reed Sternberg (HRS) cells and background cells from cases of Hodgkin's disease using in situ hybridisation. METHODS: Non-isotopic DNA in situ hybridisation was applied to interphase cell nuclei of Hodgkin's disease within routine paraffin embedded tissue sections. Two a satellite DNA probes, specific for chromosomes 3 and 12, were used to evaluate the feasibility of this approach. Double labelling with immunocytochemical detection of the CD30 antigen was used to identify HRS cells. Cytogenetic normal diploid and triploid placental tissue served as controls. RESULTS: The eight cases of Hodgkin's disease investigated displayed frequent polysomy, while the majority of background cells showed disomy signals. CONCLUSIONS: Numerical chromosomal aberrations were detected in HRS cells from eight cases of Hodgkin's disease by in situ hybridisation. These data show that in Hodgkin's disease HRS cells frequently display polyploidy compared with background cells and are, therefore, probably the only neoplastic component in this disease. Correlations between polysomy and tumour type or grade could not be made from these data owing to the limited number of cases examined and to problems with interpreting data from truncated nuclei.
AIM: To determine the optimum form of labelling and the most efficient reporter molecule for non-radioisotopic in situ hybridisation (ISH). METHODS: Nine deoxyoligonucleotides complementary to histone mRNA were synthesised and labelled either enzymatically or during solid-phase synthesis with the reporter molecules digoxigenin, 2,4-dinitrophenyl (DNP), or alkaline phosphatase. Pooled deoxyoligonucleotide cocktails were then used in non-radioisotopic ISH detection of histone mRNA in human tonsil. Hybrid detection was by nitroblue tetrazoleum/5-bromo-4-chloro-3-indolyl phosphate colorimetric development. RESULTS: The use of a spacer in 3' enzymatic labelling and when labelling with alkaline phosphatase significantly increased ISH signal. The 3' and 5' labelling of oligonucleotides with triple DNP groups during solid-phase synthesis produced the strongest signal as determined by the highest cell signal intensity and shortest development time. CONCLUSIONS: 3' and 5' solid-phase labelling with triple DNP groups produced the best labelling for non-isotopic ISH using deoxyoligonucleotide cocktails.
A method has been developed by which single human glomeruli may be plucked from fresh renal biopsies under direct vision, followed by separation of mRNA using oligo-dT-linked paramagnetic beads. The mRNA was amplified by reverse transcription and polymerase chain reaction (RT-PCR). Primers for a variety of human and rat proteins have been developed. The quantity of the amplified cDNA was measured by an enzyme-linked immuno-sorbent assay (ELISA), where biotinylated forward strands of DNA were captured, probed with a fluorescein-conjugated DNA oligomer, and then assayed with an enzyme-linked anti-fluorescein antibody. The cDNA-linked beads are reported to be stable and can be reused with different primer sets, thus forming a "bank' of samples from cases with defined glomerular disorders, which can be used to address new questions as they arise. Using rat glomeruli, a method has been devised which permits at least partial separation of epithelial cell mRNA from mesangial and endothelial cell mRNA.
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AIM: To investigate the possible role of the systemic IgA immune system in the pathogenesis of IgA nephropathy METHODS: J chain mRNA expression in the IgA cells of the bone marrow was studied. Bone marrow trephine biopsy specimens from seven patients with IgA nephropathy and seven matched controls were examined by (1) non-isotopic in situ hybridisation (ISH) and (2) combined immunofluorescence and non-isotopic ISH to identify the plasma cell type. Serum polymeric IgA was also determined using standard high pressure liquid chromatography and sandwich enzyme linked immunosorbent assay. RESULTS: Non-isotopic ISH revealed a similar number of J chain mRNA positive cells/unit length in biopsy specimens from patients (16.5 +/- 2.7 cells/mm) and controls (17.7 +/- 2.4 cells/mm). Combined immunofluorescence and ISH revealed a greater proportion of J chain mRNA positive IgA cells in patients (7.6 +/- 1.45%) compared with controls (3 +/- 0.8%). Serum polymeric IgA was similar in both patients (91 +/- 22 mg/l) and controls (77 +/- 24 mg/l). CONCLUSION: These data suggest that excess production of dimeric IgA occurs in the bone marrow in IgA nephropathy.
Aim-To investigate whether clinical features of non-Hodgkin's lymphomas, at the time of first biopsy, correlate with studies of cell proliferation and cell death as well as with the level of bcl-2 expression.Methods-Bcl-2 expression, determined by immunocytochemistry, was compared with cell proliferation, measured using in situ hybridisation for histone mRNA, and cell death by apoptosis, measured using in situ end labelling for DNA cleavage.Results-Histone mRNA staining gave a labelling index of 30% of cells for reactive germinal centres, 5.2-13.5% of cells for low grade non-Hodgkin's lymphoma and 12.1-50.5% of cells for high grade non-Hodgkin's lymphoma. In situ end labelling gave a labelling index of 5.0-10.0% of cells for reactive germinal centres, 1.0-3.7% of cells for low grade non-Hodgkin's lymphoma and 4.7-13.5% of cells for high grade non-Hodgkin's lymphoma. There was a positive correlation between apoptotic index and proliferation index. More cases of low grade than high grade non-Hodgkin's lymphoma expressed bcl-2. There was no correlation between apoptotic index and bcl-2 expression for high grade non-Hodgkin's lymphoma.Conclusions-The molecular mechanisms controlling cell proliferation and death in non-Hodgkin's lymphoma are complex, probably involving a range of genes, including bcl-2. A better understanding of resistance to cell death is needed if the clinical goal of tailoring cancer treatment to individual tumours is to be achieved.
The patterns of expression of mRNA encoding decidualization-associated protein (DAP) in the rat uterus from early, mid-, and late stages of pregnancy were examined by in situ hybridization to provide an insight into the function of DAP during pregnancy. Parallel studies were performed on rat uteri during the oestrous cycle and oil-induced deciduomata. DAP transcripts were absent in virgin uteri and during the day of implantation (day 5), low in early gestation tissues (days 8, 9) and high during midgestation (days 10-14). Expression of mRNA encoding DAP was first detected on day 8 of pregnancy in decidual cells of the lateral decidual glycogen wing areas. On day 9, mRNA encoding DAP was found in the same area as on day 8 as well as in the outer layer of cells in the antimesometrial decidua adjacent to the myometrium termed the fibrinoid capsula. On days 11 and 12, expression appeared in the decidual cells of the mesometrial decidua, and was particularly strong around the ectoplacental cone and blood vessels that were invaded by the trophoblast. By day 13 and throughout the remainder of pregnancy, expression occurred in the mesometrial decidua and metrial gland. No signal was observed in granulated metrial gland cells. mRNA encoding DAP was also found in the smooth circular muscle coat adjacent to the mesometrial decidua. A similar pattern and cellular localization of expression of mRNA encoding DAP expression was detected during the development of the deciduomata, artificially induced in the absence of a conceptus. The spatial and temporal patterns of expression correlated with a possible role for DAP in mediating fetal-maternal interactions and the establishment of the placental structure.
A well-recognized complication of Sjögren's syndrome (SS) is the development of malignant lymphoma, with a risk 44 times that of the general population. Although a few clinical signs may indicate the onset of lymphoma, there are few reliable laboratory markers which predict the development of neoplasia. A non-isotopic in situ hybridization technique has been applied to routinely processed labial salivary gland (LSG) biopsies of patients under investigation for SS. Serial section of 70 LSGs were examined for a kappa and gamma immunoglobulin light chain mRNA using digoxigenin-labelled oligonucleotide probes. As controls, 39 biopsies from non-SS-associated sialadenitis were also examined. Sections were analysed using computer-assisted quantification to determine the percentage of kappa-expressing cells in each case. The range of kappa expression in the SS group was 24.1-93.4 percent and in the non-SS group 48.3-75.4 per cent. Light chain restriction was found in 13/70 (18.6 percent) cases from the SS group but in no cases of the control group. Of the SS cases showing restriction, 4/13 (30.7 percent) have subsequently developed extrasalivary gland lymphoma. Two patients not showing light chain restriction in LSG have subsequently developed lymphoma. The positive predictive value of this test to identify patients at risk of lymphoma was 30.7 percent with a detection rate (sensitivity) of 66.7 percent and a false-positive rate of 14.1 per cent(specificity 85.9 percent). This study has identified a high prevalence of light chain restriction in labial gland biopsies of patients with SS and provides objective quantitative criteria to identify those patients at greater risk of lymphoma development.
We describe a case report of a 21-year-old male with fatal Epstein-Barr virus-associated haemophagocytic syndrome. Virus is detected in multiple organs by polymerase chain reaction and in the tissue-specific cells of those organs by in situ hybridisation. It is suggested that organ failure may be a direct response to infection.
To distinguish reactive versus neoplastic monocytoid B-cell (MBC) proliferations, the clonality of MBC was examined in paraffin-embedded tissues by in situ hybridization (ISH) of immunoglobulin (Ig) light chain messenger RNA (mRNA) with sensitive oligonucleotide probes in 26 cases. They included 13 cases of lymphadenitis with MBC reaction and 13 cases of nodal (n = 8) and extranodal (n = 5) monocytoid B-cell lymphoma (MBCL). Two cases represented a composite lymphoma showing a centroblastic-centrocytic and MBCL component. The clonality of MBC infiltrates could be demonstrated in 16 of 26 (61.5%) cases by immunostaining for Ig light chains and in all (100%) cases by ISH. Neoplastic MBC usually expressed a faint-to-moderate light chain restriction of mRNA, whereas some MBC (10% to 30% of total MBCL population) showed a strong positivity irrespective of plasmacytoid differentiation as indicated by Ig immunostaining (present in 9 of 13 cases). Reactive MBC expressed a faint kappa and lambda light-chain mRNA positivity. Five percent to 20% of total reactive MBC showed also a strong positivity for both Ig light chain mRNA, although only a minor part of these cells (7 of 13 cases) expressed polyclonal Ig by immunohistochemistry. These results indicate that (1) both reactive and neoplastic MBC can differentiate into plasma cells; and (2) a relatively high percentage of reactive and neoplastic MBC show a detectable mRNA transcription, but not a corresponding Ig synthesis. Either the Ig detection is not sensitive enough or these cells might be in an early differentiation phase, where the Ig production has not yet started.
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.
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.
Sjögren's syndrome (SS) is an autoimmune disease characterised by a generalised lymphoproliferation. Patients have an increased risk of developing lymphomas which are usually of the type associated with mucosa-associated lymphoid tissue (MALT). Histological examination of the minor salivary glands of the lower lip is a common and useful diagnostic test for SS but has not been able to provide information with regard to potential malignant change. In this study, a sensitive in situ hybridisation technique for the detection of kappa and lambda immunoglobulin light-chain mRNA was applied to labial salivary glands of 14 patients with SS. 7 cases showed light chain restriction, in 5 cases this was kappa(kappa:lambda ratio > 8.0) and in 2 it was lambda(kappa:lambda ratio < 0.6). Of these 7, 5 developed lymphomas--4 were low grade lymphomas of MALT type and the fifth patient died of disseminated lymphoma. The finding of light chain restriction in lip minor salivary glands is strong evidence of a monoclonal population of B-cells at this site. It is concluded that in patients with SS who develop lymphomas, dissemination of malignant cells may result in detectable disease in the minor salivary glands. Determination of kappa:lambda ratios in labial minor salivary glands may thus provide important prognostic information.