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Biomedical subjects

N Rooney

Publications and source records attributed to N Rooney.

At least 19 recordsLinked to original sources
PubMed2001

Epidemiological studies of human and animal Salmonella typhimurium DT104 and DT104b isolates in Ireland.

A total of 122 human and animal Salmonella Typhimurium DT104 isolates and 6 epidemiologically related DT104b isolates from human and animal products were analysed by pulsed-field gel electrophoresis (PFGE). Genomic DNA was subjected to macrorestriction with three enzymes, SpeI, SfiI and XbaI. A total of 14 restriction fragment length polymorphism (RFLP) profiles were identified when the PFGE patterns from the three enzymes were combined. The majority of isolates (81.2%) exhibited the same RFLP profile. Six animal DT104 isolates, susceptible to enrofloxacin and resistant to naladixic acid, were identified from the antibiotic susceptibility test. Four of these isolates had a different PFGE profile from the common RFLP. In addition, 4 of the 6 isolates were geographically clustered in one region. It was concluded that there was one predominant strain of S. Typhimurium DT104 in Ireland and that the potential and selection pressures for emergence of fluoroquinolone-resistant isolates were present.

Animals↗
PubMed2001

Epstein-Barr virus infection in paediatric liver transplant recipients: detection of the virus in post-transplant tonsillectomy specimens.

AIMS: Post-transplant lymphoproliferative disease (PTLD) is an important and serious complication in transplant patients. Recent studies have suggested that quantitative assessment of Epstein-Barr virus (EBV) infection in transplant patients might help to identify those at risk of developing PTLD. Therefore, tonsils from paediatric liver transplant recipients were studied for evidence of EBV infection. METHODS: Tonsils were studied by in situ hybridisation for the detection of the small EBV encoded nuclear RNAs (EBERs). The phenotype of EBV infected cells was determined by double labelling in situ hybridisation and immunohistochemistry. The expression of viral latent and lytic antigens was determined by immunohistochemistry. Tonsils from patients without known immune defects were studied as controls. RESULTS: Tonsils from transplant patients showed pronounced follicular hyperplasia and minor paracortical hyperplasia. In situ hybridisation revealed variable numbers of EBV infected B cells in the tonsils from transplant patients (range, 2-1000/0.5 cm(2); mean, 434/0.5 cm(2); median, 105/0.5 cm(2)). Lower numbers were detected in the control tonsils (range, 1-200/0.5 cm(2); mean, 47/0.5 cm(2); median, 9/0.5 cm(2)). The latent membrane protein 1 (LMP1) of EBV was not detected and there were only rare cells in two cases showing expression of the EBV encoded nuclear antigen 2 (EBNA2). There was no evidence of lytic infection. None of the patients developed PTLD within a follow up period of up to five years. CONCLUSIONS: These data indicate that tonsillar enlargement in paediatric liver transplant patients does not necessarily imply a diagnosis of PTLD. Furthermore, the presence of increased numbers of EBV infected cells in tonsils from liver transplant recipients by itself does not indicate an increased risk of developing PTLD.

Antigens, Viral↗
PubMed2000

Lack of evidence for an involvement of Epstein-Barr virus infection of synovial membranes in the pathogenesis of rheumatoid arthritis.

OBJECTIVE: To test the hypothesis that Epstein-Barr virus (EBV) infection of cells within the synovial membrane contributes to the pathogenesis of rheumatoid arthritis (RA). METHODS: Biopsy samples of synovial membrane from 37 patients with RA and from 51 patients with other joint diseases were studied for evidence of EBV infection using in situ hybridization specific for the EBV-encoded RNAs (EBERs). Latent membrane protein 1 (LMP1) and the lytic-cycle BZLF1 protein were detected by immunohistochemistry. RESULTS: Rare EBER-positive B lymphocytes were detected in 7 RA biopsy samples. EBV was not detectable in any other cells. Expression of the LMP1 and BZLF1 proteins of EBV was not observed in any of the samples. No EBV infection was detected in synovial membranes from patients with other joint diseases. CONCLUSION: Our data indicate that EBV infection is not directly involved in the pathogenesis of RA. Any contribution of EBV to the pathogenic process leading to RA is likely to be indirect.

Adult↗
PubMed2000

Oral mucosal non-Hodgkin's lymphoma--a dangerous mimic.

Reports of T-cell lymphomas in the oral cavity are rare. Most have presented as a persisting ulcerated swelling. This paper reports two men, one of whom presented with a short history of increasing facial swelling and pain apparently related to a lower premolar tooth, and the other who had recurrent oral ulceration in several sites over a period of years. These types of cases are likely to present initially to general dental practitioners.

Aged↗
PubMed1999

CD79a detected by ZL7.4 separates chronic lymphocytic leukemia from mantle cell lymphoma in the leukemic phase.

Both B-cell chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) are characterized by a lymphoproliferation of neoplastic CD5+ B-cells, but an accurate differential diagnosis between these two malignancies is vitally important for guiding treatment options. Because CD79a has been identified as a pan-B marker, we intended to use it in place of CD19 to identify B-cells and to use CD23 to distinguish between CLL and MCL in the leukemic phase. Anti-CD79a (clone ZL7.4) was used to detect the Igalpha/mb1 protein in fresh CD5+ B-lymphocytes by dual-channel flow cytometry. Expression of CD19 and CD23 were similarly assessed. As expected, CD19 was expressed in all specimens, whereas CD23 expression was zero in 3/4 MCLs, weak in 1/4 MCLs, and 2/8 CLLs (10-19%) and stronger in 6/8 CLLs (> or =45%). However, although all the CD19+/CD5+ cells of MCL expressed high CD79a levels, CD79a expression was negligible or absent in 8/8 CLL specimens (mean positivity for CD79a = 2.41 +/- 2.71%). CD79a (ZL7.4) levels may provide a more reliable distinction than CD23 levels between CLL and MCL. If these results hold up in a larger series, we recommend that the ZL7.4 antibody should be considered in routine marker panels for CLL and low-grade lymphoma.

Aged↗
PubMed1999

The incorporation of a stent-graft into the porcine aorta and the inflammatory response to the endoprosthesis.

The fate of a non-sutured anastomosis and the inflammatory response to an endoprosthesis in a porcine aorta was determined. Self-expanding aorto-aortic endovascular prostheses were deployed into the infrarenal aorta of Large White pigs by the transfemoral route, in accordance with Home Office regulations. Animals were followed up at intervals to 1 year. The aortas were explanted and specimens were subjected to light microscopy. Thirteen animals, mean weight 103 kg, underwent placement of a prosthesis. There was early evidence of a neointima at 4 weeks and a well-developed neointima by 12 weeks, with complete incorporation of the endoprosthesis. The early acute inflammatory reaction seen at 4 weeks had become chronic by 12 and was largely absent by 26 weeks. There was no evidence of atypia. Complete incorporation of the non-sutured anastomosis is seen in this model. The acute inflammatory reaction to the prosthesis seen at 4 weeks had largely subsided by 26 weeks.

Acute Disease↗
PubMed1999

A long-term follow-up of cognitive, emotional, and behavioural sequelae to Reye syndrome.

Eighteen adolescents who had survived Reye syndrome (RS) in early childhood were assessed on cognitive, emotional, and behavioural variables in a second follow-up study tracking this group. Siblings were used as controls. The entire group with RS had survived with no obvious neurological damage at the first follow-up study. Indeed, current findings suggested that long-term cognitive, emotional, and behavioural functioning was comparable to siblings in approximately half of the group with RS. However, two factors were associated with a less favourable outcome. Cognitive, emotional, and behavioural functioning were significantly poorer in the subgroup of survivors whose illness had occurred in the first year of life. In addition, loss of consciousness, although the association with poor outcome was not as noticeable, was also associated with relative deficits on some scales of cognitive ability. Many of these deficits had not been obvious at the first follow-up and the importance of neurodevelopmental factors are considered. Finally, the implications of these findings for research and interventions in RS and other such encephalopathies are discussed.

Adolescent↗
PubMed1998

Expression of inducible nitric oxide synthase activity in human colon epithelial cells: modulation by T lymphocyte derived cytokines.

BACKGROUND: Nitric oxide (NO) synthesis and inducible nitric oxide synthase (iNOS) expression are increased in colonic biopsy specimens from patients with ulcerative colitis, but the cellular source of NO production is not known. AIMS: To examine the distribution of iNOS in human colonic mucosa and to explore the ability of T lymphocyte derived cytokines to regulate iNOS expression and activity in human colonic epithelial cells. METHODS: iNOS expression was examined using immunohistochemistry in colonic biopsy samples from 12 patients with ulcerative colitis and three with infectious colitis and compared with 10 normal controls. In vitro iNOS expression and activity were determined in HT-29 cell cultures; nitrite levels were measured using a fluorescent substrate, iNOS mRNA expression by northern blot analysis, and iNOS protein expression by western blot analysis. RESULTS: No iNOS expression was detected (10 of 10) in non-inflamed mucosa derived from normal controls. In 11 of 12 cases of newly diagnosed ulcerative colitis, iNOS protein was expressed in the epithelial cells, while no other positive cells were found in the lamina propria. Similar iNOS labelling was found in colonic biopsy samples from patients with infectious colitis in the acute phase, but when re-examined in samples from patients in total remission, no iNOS staining was observed. Both interleukin (IL)-13 and IL-4, but not IL-10, are potent inhibitors of iNOS expression and activity induced by an optimal combination of cytokines, namely IL-1 alpha, tumour necrosis factor alpha and interferon gamma. CONCLUSIONS: The data suggest that the epithelium is the major source of iNOS activity in ulcerative colitis and that IL-13 and IL-4 may act as intrinsic regulators of NO generation in intestinal inflammation.

Acute Disease↗
PubMed1998

Air weapon fatalities.

AIMS: To describe characteristics of a series of people accidentally and deliberately killed by air powered weapons. METHODS: Five cases of fatal airgun injury were identified by forensic pathologists and histopathologists. The circumstances surrounding the case, radiological examination, and pathological findings are described. The weapon characteristics are also reported. RESULTS: Three of the victims were adult men, one was a 16 year old boy, and one an eight year old child. Four of the airguns were .22 air rifles, the other a .177 air rifle. Two committed suicide, one person shooting himself in the head, the other in the chest. In both cases the guns were fired at contact range. Three of the cases were classified as accidents: in two the pellet penetrated into the head and in one the chest. CONCLUSIONS: One person each year dies from an air powered weapon injury in the United Kingdom. In addition there is considerable morbidity from airgun injuries. Fatalities and injuries are most commonly accidents, but deliberately inflicted injuries occur. Airguns are dangerous weapons when inappropriately handled and should not be considered as toys. Children should not play with airguns unsupervised.

Accidents↗
PubMed1997

Epstein-Barr virus infection and malignant lymphomas in liver transplant recipients.

Post-transplant lymphoproliferative disease (PTLD) is a major cause of death and disease in transplant patients. We describe 4 cases with histologically confirmed malignant lymphoma arising in the Birmingham liver transplant programme between 1982 and 1995. One was an EBV-positive diffuse large B-cell lymphoma, 2 were EBV-positive Burkitt's lymphomas and the 4th was an EBV-negative Burkitt's lymphoma. Immunohistochemistry revealed expression of the EBV-encoded latent membrane protein LMP1 and of the BZLF1 trans-activator protein in 2 cases each, whereas the virus-encoded nuclear antigen EBNA2 was not detectable. All available post-transplant biopsies from the 3 patients with EBV-associated lymphoma were then studied to test whether the detection of EBV-positive cells in liver allograft biopsies could be used to identify patients at risk for the development of PTLD. Two patients showed infrequent EBV-positive cells in liver allograft biopsies up to 14 months before the occurrence of lymphoma and a marked increase in the number of such cells at the time of lymphoma diagnosis. Multiple biopsies from the 3rd patient did not reveal any EBV-carrying cells in the entire post-transplant period. Our results demonstrate a low incidence of PTLD in the Birmingham liver transplant programme. The PTLDs were morphologically high-grade malignant lymphomas. Only 3 cases were associated with EBV infection, and these showed heterogeneous patterns of EBV latent protein expression. Our results also suggest that the examination of liver allograft biopsies using EBER in situ hybridisation is not an appropriate method for identifying patients at risk of developing PTLD.

Adult↗
PubMed1997

Immunohistochemical detection of the Epstein-Barr virus-encoded latent membrane protein 2A in Hodgkin's disease and infectious mononucleosis.

We describe two new monoclonal antibodies specific for the Epstein-Barr virus (EBV)-encoded latent membrane protein 2A (LMP2A) that are suitable for the immunohistochemical analysis of routinely processed paraffin sections. These antibodies were applied to the immunohistochemical detection of LMP2A in Hodgkin's disease (HD). LMP2A-specific membrane staining was seen in the Hodgkin and Reed-Sternberg (HRS) cells of 22 of 42 (52%) EBV-positive HD cases, but not in 39 EBV-negative HD cases. In lymphoid tissues from patients with acute infectious mononucleosis (IM), interfollicular immunoblasts were shown to express LMP2A. This is the first demonstration of LMP2A protein expression at the single-cell level in EBV-associated lymphoproliferations in vivo. The detection of LMP2A protein expression in HD and IM is of importance in view of the proposed role of this protein for maintaining latent EBV infection and its possible contribution for EBV-associated transformation. Because LMP2A provides target epitopes for EBV-specific cytotoxic T cells, the expression of this protein in HRS cells has implications for the immunotherapeutic approaches to the treatment of HD.

Animals↗
PubMed1996

Changes in Bcl-2 and p53 expression in recurrent B-cell lymphomas.

The aim of this study was to investigate the changes involved in the evolution of nine cases of recurrent B-cell lymphomas. Using the polymerase chain reaction (PCR) on formalin-fixed, paraffin-embedded tissue from both the primary and the recurrent lymphoma of each case, monoclonality was demonstrated in every tumour. In all nine cases, the recurrent lymphoma was shown to belong to the same clone as the primary lymphoma. Eight of these cases were then investigated by immunohistochemistry for changes in Bcl-2 and p53 expression. Five out of eight of the primary lymphomas showed Bcl-2 overexpression. Two of the three cases initially negative for Bcl-2 expression became positive in the recurrence. One out of eight of the primary lymphomas was positive for p53 expression. Of the seven negative cases, one became positive for p53 expression in the recurrence. Both of the p53-positive cases showed high-grade histology. This study shows that Bcl-2 overexpression is probably an important early event in the development of B-cell lymphomas, although it may occur as a post-neoplastic event. p53 mutation is probably more important as a late event and may be associated with high-grade transformation.

Gene Expression Regulation, Neoplastic↗
PubMed1995

Non-Hodgkin's lymphoma, coeliac disease, and Epstein-Barr virus: a study of 13 cases of enteropathy-associated T- and B-cell lymphoma.

A group of 166 patients with coeliac disease was followed for a period of up to 25 years. During this time, 17 patients developed intestinal tumours that were diagnosed as lymphoma, of which 15 cases were available for review. Eleven of the lymphomas were of T-cell type (enteropathy-associated T-cell lymphoma, EATL) and two were of B-cell type. Two cases were reclassified as undifferentiated carcinoma. The interval between the diagnosis of enteropathy and the onset of lymphoma varied from less than 2 months in four patients to more than 5 years in seven. Seven of the T-cell and both B-cell lymphomas were investigated for the presence of Epstein-Barr virus (EBV) by in situ hybridization (ISH) using probes against Epstein-Barr virus-encoded RNAs (EBERs) and by immunohistochemistry with EBV-specific monoclonal antibodies. All EATL cases were negative, suggesting that EBV is not an important factor in these cases. In one of the B-cell cases, EBV was detectable by ISH and immunohistochemistry in most tumour cells in the mesenteric lymph nodes, but not in any of the tumour cells in the primary ileal tumour, indicating that in this case EBV infection was a late event in the neoplastic process. These results show that lymphoma may develop any time after the onset of coeliac disease and that in our cases of EATL, EBV was not an important factor. In some cases of EBV-related neoplasia, virus infection may be a late event.

Adult↗
PubMed1995

The use of the polymerase chain reaction in the diagnosis of B-cell lymphomas from formalin-fixed paraffin-embedded tissue.

In this study the use of the polymerase chain reaction (PCR) to detect monoclonality in B-cell lymphoid proliferations in archival formalin-fixed paraffin-embedded tissue was assessed. Using consensus primers against the framework 3 (FR 3) region of the immunoglobulin heavy chain gene (IgH), PCR analysis was performed on 29 low grade B-cell non-Hodgkin's lymphomas. Cases of benign lymphoid hyperplasia served as polyclonal controls. Sequenced cases of acute lymphoblastic leukaemia served as positive controls. In the lymphomas, monoclonality could be demonstrated in 18 of 29 (62%) cases. Only five of 11 (45%) follicle centre cell lymphomas were positive by this method whilst the success rate for the remainder was 13 of 18 (72%). None of the polyclonal controls gave false positive results although occasional non-specific dominant bands were present which disappeared on repeating the experiments. These results show that this method will identify monoclonality in 62% of low grade B-cell non-Hodgkin's lymphomas in archival material. The success rate is increased to 72% if follicle centre cell lymphomas are excluded. Thus, this method is a useful adjunctive test to aid diagnosis in lymphoid infiltrates when standard morphology and immunohistochemistry are equivocal.

Base Sequence↗
PubMed1994

Primary breast lymphoma with skin involvement arising in lymphocytic lobulitis.

Primary breast lymphoma is a rare tumour which has recently been associated with pre-existing lymphocytic lobulitis. We report a patient with lymphocytic lobulitis in whom the lymphoma recurred in the contra-lateral breast 5 years after the initial presentation, to be followed shortly afterwards by skin involvement. This progression illustrates the relationship between extra-nodal lymphomas and underlying autoimmune disease and the homing of lymphomas to related sites.

Breast Neoplasms↗
PubMed1994

Latent Epstein-Barr virus infection in cottontop tamarins. A possible model for Epstein-Barr virus infection in humans.

The association of Epstein-Barr virus (EBV) with a growing number of human malignancies underlines the importance of efforts aimed at preventing the infection with this potential carcinogen and of establishing animal models for human virus-associated tumors. Cottontop tamarins have been used in EBV vaccine studies because virus infection regularly induces lymphomas similar to those seen in human immunocompromised individuals. In recent years, several vaccines based on the gp340/220 envelope protein of EBV have been developed and shown to prevent the development of EBV-associated lymphomas in this model. Using in situ hybridization and immunohistology, we have characterized EBV infection in one nonimmunized and three immunized animals after challenge with a standard tumorigenic dose of EBV. In the nonimmunized animal, EBV-infected lymphoid cells were detected in numerous tissues showing no obvious lymphoma infiltration. Surprisingly, variable numbers of virus-carrying cells were also found in all three immunized animals that were protected against the development of virus-associated lymphoma. This observation demonstrates that vaccination does not induce sterilizing immunity against EBV infection in this model. Double labeling suggested a B cell phenotype of the majority of these cells. EBV infection of nonlymphoid cells was not observed. Analysis of viral gene expression in immunized animals suggested a restricted form of virus latency different from that seen in EBV-driven lymphomas in nonimmunized cottontop tamarins. These results raise the possibility that immunized cottontop tamarins protected against the development of EBV-driven lymphoma or animals exposed to a sublymphomagenic dose of virus may serve as a model for EBV infection in humans.

Animals↗
PubMed1993

Overexpression of p53 in Hodgkin's disease: lack of correlation with Epstein-Barr virus infection.

Recent work has shown that p53 gene mutations are frequently found in Epstein-Barr virus (EBV)-positive and EBV-negative cases of Burkitt's lymphoma but not in EBV-associated undifferentiated nasopharyngeal carcinomas (NPCs). Similar viral gene expression patterns are observed in undifferentiated NPCs and in EBV-positive cases of Hodgkin's disease (HD), suggesting that the contribution of the virus to the pathogenesis of these malignancies may also be similar. We have analysed 116 cases of HD for EBV association and for immunohistologically detectable overexpression of p53. p53 overexpression was detected in the tumour cell population of 37 (32 per cent) of the cases. Fifteen cases showed p53-specific labelling of more than 40 per cent of tumour cells; in six of these, virtually all tumour cells were stained. In eight cases, between 5 and 40 per cent of tumour cells were labelled, and in another 14 cases, less than 5 per cent of tumour cells expressed detectable amounts of p53. EBV-positive HD cases were found in all groups with different levels of p53 overexpression as well as amongst p53-negative cases. While a more detailed analysis of the p53 gene in HD is required, these data show that overexpression of p53 in HD is heterogeneous and that there is no simple correlation between EBV infection and p53 overexpression.

Gene Expression↗