Biomedical subjects
Publications and source records attributed to J Crocker.
This report describes the case of an asymptomatic, solitary splenotic nodule in the right ovary, revealed incidentally at histopathological examination. In gynaecological patients, splenosis most often presents as multiple pelvic nodules mimicking endometriosis. Two cases of ovarian splenosis accompanying pelvic and serosal splenotic nodules have been reported previously. However, this is the first documented case of solitary intraovarian splenosis.
Hodgkin's lymphoma (HL) is characterized by the presence of malignant so-called Hodgkin's/Reed-Sternberg (HRS) cells, which display resistance to certain apoptotic stimuli, including a lack of sensitivity to Fas-mediated cell death. However, the mechanisms responsible for their resistance to apoptosis inducers have not been elucidated. Here we confirm that both HL-derived cell lines and the HRS cells of primary HL tissues express Fas ligand (FasL) along with the inhibitory c-FLIP protein. Down-regulation of cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) through the use of specific small inhibitory RNAs (siRNAs) leads to reduced viability of the L428 and L591 HL-derived cell lines. To determine whether endogenous FasL was responsible for the reduction in cell viability observed after down-regulation of c-FLIP, L428 and L591 cells were treated with c-FLIP-specific siRNAs with and without siRNAs directed to FasL. Treatment of these cells with both c-FLIP- and FasL-specific siRNAs in combination restored cell viability to near control levels. Our results provide a mechanism whereby HRS cells are protected from autonomous FasL-mediated cell death while preserving their ability to evade immunosurveillance. Targeting c-FLIP could provide a novel approach to the treatment of HL.
AIMS: To compare the neuropsychological functioning and behaviour of children with non-syndromic end-stage renal disease (ESRD) and sibling controls. METHODS: The study was carried out at two tertiary care paediatric teaching hospitals, in Halifax and Vancouver, Canada. Children with ESRD were on a renal transplant waiting list and either pending dialysis or on dialysis therapy. Twenty two patient-sibling pairs were evaluated. Neuropsychological assessments consisting of measures of intelligence, academic achievement, memory, and motor abilities were carried out. Maternal ratings of behaviour and self-report rating of self-esteem were collected. RESULTS: The Verbal, Performance, and Full Scale IQs of patients with ESRD were significantly lower than the IQs of the sibling controls. The mean differences were 8.6, 11.7, and 10.9 points, respectively. ESRD patients also had significantly more difficulty on measures of fine motor coordination and ability to copy geometric designs than sibling controls. There were no differences between groups on measures of academic achievement, memory, behaviour, or self-esteem. CONCLUSIONS: Although children with ESRD exhibited mild deficits on measures of intelligence and some measures of motor abilities, their neuropsychological outcome was more favourable than earlier reports indicated.
PURPOSE: We compare the tolerability and efficacy of extended release oxybutynin chloride, and immediate release and long acting tolterodine tartrate in children with nonneurogenic diurnal urinary incontinence and symptoms of overactive bladder. MATERIALS AND METHODS: Children with a history of diurnal urinary incontinence were arbitrarily assigned to extended release oxybutynin, immediate release tolterodine or long acting tolterodine. The dose was titrated until effective (onset of complete diurnal urinary continence), maximal recommended dosage was achieved or bothersome anticholinergic side effects developed. An independent observer recorded the dose used, anticholinergic side effects and efficacy of therapy (incidence of urinary frequency, urgency, posturing and urinary incontinence). RESULTS: The study included 86 girls and 46 boys. There were no statistically significant differences among the 3 treatment groups regarding the presence of peripheral or central nervous system anticholinergic side effects. Extended release oxybutynin and long acting tolterodine were significantly more effective at reducing daytime urinary incontinence than immediate release tolterodine (p <0.01 and 0 <0.05, respectively). Extended release oxybutynin was significantly more effective then long acting tolterodine for complete resolution of diurnal incontinence (p <0.05). CONCLUSIONS: Extended release oxybutynin and long acting tolterodine are more effective than immediate release tolterodine in decreasing diurnal urinary incontinence. Extended release oxybutynin chloride is more effective than either immediate or long acting tolterodine for control of daytime urinary incontinence and urinary frequency.
BACKGROUND: Some lymphomas express natural killer (NK)-cell markers such as the neural cell adhesion molecule, which is recognized by the CD56 antibody. These lymphomas may present in the skin, but do not represent a homogeneous group. The new World Health Organization classification of lymphoma/leukaemia recognizes several types of NK/T-cell neoplasm, including blastic NK-cell lymphoma, which characteristically presents with cutaneous lesions. OBJECTIVES: To describe the clinical, pathological and molecular features in six cases of CD56+ lymphoma with cutaneous presentation. METHODS: The clinical, histopathological and immunophenotypic features of six patients were reviewed. In addition, in situ hybridization (ISH) to identify Epstein-Barr virus (EBV) mRNA, and polymerase chain reaction analysis to identify the presence of a clonal population of T cells or B cells were performed on lesional skin. RESULTS: All patients presented with widespread nodules and plaques, which in five cases were a characteristic purple colour. Four patients developed disseminated disease, three with neurological involvement. These four patients died between 14 and 46 months following diagnosis (median 30 months). In four of six cases the histopathological and immunohistological features were in keeping with a blastic NK-cell lymphoma. No clonal immunoglobulin heavy chain (IgH) or T-cell receptor (TCR) gene rearrangement was detected in the four cases consistent with an origin from NK cells. A further case fitted the criteria for an extranodal NK/T-cell lymphoma of nasal type and was also the only case to show evidence of EBV mRNA by ISH. A clonal T-cell population was identified in the final case. This patient also exhibited molecular evidence of a clonal B-cell population and a t(14;18) translocation confirmed by sequence analysis. CONCLUSIONS: Our data confirm that NK-cell lymphomas presenting in the skin are a heterogeneous group, and that in the U.K., blastic NK-cell lymphoma is more common than extranodal NK/T-cell lymphoma of nasal type. These lymphomas pursue an aggressive course, with rapid development of disseminated disease, and resistance to chemotherapy. Detailed immunophenotyping is needed to distinguish the different types. Our molecular data indicate that blastic NK-cell lymphoma cases lack clonal TCR/IgH gene rearrangements consistent with an NK-cell origin. Our ISH findings indicate that EBV plays a pathogenetic role only in extranodal NK/T-cell lymphoma of nasal type.
The renin-angiotensin system is an important regulator of blood pressure, and blockade of this system improves blood pressure in obesity and type 2 diabetes. Recently, components of the system have been described in adipose tissue. However, to date no study has investigated the influence of varying insulin concentrations on angiotensinogen (AGT) protein expression in human subcutaneous abdominal fat. Isolated subcutaneous adipocytes were treated with insulin (1-1000 nm) for 48 h. As part of the studies, a novel AGT antibody was developed and validated by Western blotting and immunohistochemistry. Western blotting was performed on the protein extracted from the adipocytes treated with insulin to determine AGT expression. Increasing doses of insulin raised AGT protein expression in a dose-dependent manner (control 1.0 +/- 0.0 (mean +/- s.e.) - protein expression standardized relative to control; 1 nm insulin: 2.64 +/- 0.0.32 upward arrow ***; 100 nm insulin: 4.37 +/- 0.57 upward arrow ***; 1000 nm insulin: 6.50 +/- 0.97 upward arrow ***; ***p < 0.001, n = 3). In conclusion, increasing insulin doses stimulates AGT production. In this study, protein analysis suggests that hyperinsulinaemia may be an important factor in obesity-related hypertension.
Epstein-Barr virus has been associated with a proportion of typical gastric adenocarcinomas. Here we report that the prevalence of Epstein-Barr virus in gastric adenocarcinomas from the United Kingdom is one of the lowest in the World. Gastric adenocarcinoma is another tumour whose association with Epstein-Barr virus varies with the population studied.
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BACKGROUND/AIMS: CD40, a member of the tumour necrosis factor (TNF) receptor family, is expressed on a variety of haematopoietic cells and is crucial in orchestrating both humoral and cellular immune responses. CD40 is also expressed on some carcinoma cells, where its function remains largely unknown. This study investigated the effects of CD40 ligation on ovarian carcinoma cell growth and apoptosis and on cytokine production, in addition to the role of the NF-kappa B and JNK signalling pathways. METHODS: CD40 expression was measured in epithelial ovarian carcinoma (EOC) biopsies by immunohistochemistry and in EOC cell lines by flow cytometry. To examine the effects of CD40 ligation on cell growth recombinant soluble CD40 ligand was used to stimulate EOC cell lines and growth was measured by MMT assays. Cytokine production was measured by enzyme linked immunosorbent assays interleukin 8 (IL-8) gene transcription was estimated by means of reverse transcription polymerase chain reaction. The integrity of the CD40 signalling pathway in those cell lines that did not produce cytokines in response to CD40 ligation was assessed by the detection of the transcription factor NF-kappa B by an electrophoretic mobility shift assay. To investigate the defect in the NF-kappa B pathway the phosphorylation status of I kappa B alpha was determined by an antibody specific to phosphorylated I kappa B alpha and dissociation of the I kappa B alpha-p65 complex was assessed by co-immunoprecipitation. RESULTS: CD40 is expressed in primary ovarian carcinoma biopsies and EOC cell lines. CD40 ligation resulted in growth inhibition in most of these carcinoma cell lines and was also found to promote apoptosis, with this last effect only being evident in early passage EOC cells. CD40 ligation also induced significant IL-6 and IL-8 production in most of the EOC cell lines examined and it was confirmed for IL-8 that this effect was regulated at the transcriptional level. NF-kappa B activation in response to CD40 ligation was found in three of the EOC cell lines and specific defects in the CD40 induced NF-kappa B pathway were identified in two cell lines. However, CD40 engagement induced JNK activation in all the EOC cell lines. CONCLUSIONS: These data suggest that the CD40 pathway is functional in ovarian carcinoma cells and highlight the need for further studies to provide insight into the role of CD40 in the carcinogenic process and the possible exploitation of this pathway for novel therapeutic approaches.
In the past 10 years, molecular biology has found major applications in pathology, particularly in oncology. This has been a field of enormous expansion, where pure science has found a place in clinical practice and is now of everyday use in any academic unit. This demystified review will discuss the techniques used in molecular pathology and then provide examples of how these can be used in oncology.
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Approximately 40% of Hodgkin's disease (HD) cases carry EBV in the malignant Hodgkin-Reed Sternberg (H-RS) cells, with expression of viral latent membrane proteins (LMPs) 1 and 2. These viral proteins are targets for CTLs in healthy EBV carriers, and their expression in EBV-associated HD raises the possibility of targeting them for a CTL-based immunotherapy. Here we characterize the CTL response to EBV latent antigens in both the blood and tumor-infiltrating lymphocytes of HD patients using two approaches: (a) in vitro reactivation of CTLs by stimulation with the autologous EBV-transformed lymphoblastoid cell line; and (b) an enzyme-linked immunospot assay to quantify frequencies of CTLs specific for known LMP1/2 epitopes. We detected EBV-specific CTLs in blood and biopsy samples from both EBV-negative and EBV-positive HD patients. However, as in healthy EBV carriers, LMP-specific CTL precursors occurred only at low frequency in the blood of HD patients, and with the exception of one EBV-negative HD case, were undetectable in the tumor. These data give rise to two considerations: (a) they may explain why EBV-positive tumor cells persist in the presence of an existing EBV-specific immune response; and (b) they provide a rationale for selectively boosting/eliciting LMP-specific CTL responses as a therapy for EBV-positive HD.
OBJECTIVE: To test the hypothesis that the formation of ectopic germinal center (GC)-like structures in Sjögren's syndrome (SS) is associated with the ectopic expression of the constitutive lymphoid tissue-homing chemokines B cell-attracting chemokine 1 (BCA-1; or, CXCL13) and stromal cell-derived factor 1 (SDF-1; or, CXCL12). METHODS: Immunohistochemical and immunofluorescence analysis was used to determine the expression of the constitutive chemokines BCA-1 (CXCL13) and SDF-1 (CXCL12) in salivary glands from 5 SS patients and 3 non-SS patients. In addition, the expression of their respective receptors (CXCR5 and CXCR4) was examined on infiltrating lymphocytes. Human tonsil was used as a positive control for secondary lymphoid tissue. RESULTS: BCA-1 (CXCL13) was expressed within lymphoid aggregates in SS, which shared many structural features with GCs in tonsil. BCA-1 (CXCL13) was completely absent in control biopsy samples from patients who did not have SS. High levels of BCA-1 (CXCL13) were also found on endothelial cells in salivary glands from SS patients. Diseased SS tissue was infiltrated by CXCR5-expressing B cells which organized into GC-like clusters. In complete contrast, SDF-1 (CXCL12), a constitutive chemokine involved in leukocyte retention within lymphoid tissue, was expressed by epithelial cells in both diseased and control samples. The chemokine receptor for SDF-1, CXCR4, was expressed on T cells that accumulated in a periductal distribution in diseased tissue. CONCLUSION: The ectopic expression of BCA-1 (CXCL13) on endothelial cells and within GC-like structures, together with the strong expression of SDF-1 (CXCL12) on ductal epithelial cells, is a unique feature of inflamed glands in SS. By creating a local microenvironment supportive of focal B cell aggregation and differentiation, with structural features that are remarkably similar to GCs, BCA-1 (CXCL13) and SDF-1 (CXCL12) may contribute to the excessive production of high-affinity, class-switched autoantibodies and to the high incidence of B cell lymphomas classically associated with SS.
The tumour necrosis factor receptor-associated factors (TRAFs) 1 and 2 participate in the signal transduction of various members of the tumour necrosis factor receptor (TNFR) family, including TNFR1, TNFR2, CD40, CD30, and the Epstein-Barr virus (EBV)-encoded latent membrane protein-1 (LMP1). Previous in situ hybridization studies have demonstrated TRAF1 transcripts in the malignant cells of the majority of Hodgkin's disease (HD) tumours, where the expression of TRAF1 was higher in EBV-associated tumours than in their EBV-negative counterparts. In order to determine whether TRAF1 and also TRAF2 were expressed at the protein level in HD and whether there was any relationship to EBV status, immunohistochemistry has been used to detect these proteins in a series of HD specimens. TRAF1 protein was detected more frequently in Hodgkin/Reed-Sternberg (HRS) cells from EBV-positive tumours than in their EBV-negative counterparts. This difference was statistically significant (p=0.01). In contrast, TRAF2 expression by HRS cells appeared to be independent of EBV status. Using a sequential labelling approach, co-localization of LMP1 with either TRAF1 or TRAF2 was also demonstrated in HRS cells from EBV-positive tumours.
Lipomas of the retropharyngeal region are rare, slow-growing tumours that attain a large size before producing symptoms such as dysphagia and dyspnoea. Clinical diagnosis may be difficult. However computed tomography or magnetic resonance imaging is the investigation of choice and helps in definitive diagnosis preoperatively, although final histological confirmation is essential. Surgery is the treatment of choice. In the following paper we report a case of retropharyngeal lipoma presenting with dysphagia which was managed surgically with complete amelioration of symptoms.
Research on self-esteem has focused almost exclusively on level of trait self-esteem to the neglect of other potentially more important aspects such as the contingencies on which self-esteem is based. Over a century ago, W. James (1890) argued that self-esteem rises and falls around its typical level in response to successes and failures in domains on which one has staked self-worth. We present a model of global self-esteem that builds on James' insights and emphasizes contingencies of self-worth. This model can help to (a) point the way to understanding how self-esteem is implicated in affect, cognition, and self-regulation of behavior; (b) suggest how and when self-esteem is implicated in social problems; (c) resolve debates about the nature and functioning of self-esteem; (d) resolve paradoxes in related literatures, such as why people who are stigmatized do not necessarily have low self-esteem and why self-esteem does not decline with age; and (e) suggest how self-esteem is causally related to depression. In addition, this perspective raises questions about how contingencies of self-worth are acquired and how they change, whether they are primarily a resource or a vulnerability, and whether some people have noncontingent self-esteem.
There is a constant balance in cancer cells between division and death. The malignant phenotype is associated with a continuing cell cycle or 'immortalization'. Telomeres, structures that cap the chromosomes, are related to cell longevity and are regulated by a ribonucleoprotein called telomerase. This review describes the possible roles of telomeres and telomerase in the malignant process.