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Stephen Hamilton-Dutoit

Publications and source records attributed to Stephen Hamilton-Dutoit.

13 recordsLinked to original sources
PubMed2007

Immunohistochemical detection of 3 viral infections in paraffin-embedded tissue from mink (Mustela vison): a tissue-microarray-based study.

Immunohistochemical (IHC) assays were developed and tested for the detection of 3 viral infections in archived paraffin-embedded mink tissue. Specimens had been obtained from mink with diagnoses of acute Aleutian disease (AD), mink parvoviral enteritis (MVE), or canine distemper (CD) made by means of routine diagnostic procedures. To improve the efficiency and reduce the costs of IHC analyses, tissue microarray (TMA) technology was used. Representative cores 2 mm in diameter from each tissue specimen and from positive- and negative-control specimens were collected in a TMA block. Immunohistochemical reactions to viral antigens were assessed and graded. Positive reactions were found in 91% of the 32 specimens from mink with AD, 53% to 80% of the 60 specimens from mink with MVE, and all 66 of the specimens from mink with CD. To validate the use of TMAs, the IHC methods were applied to whole-mount paraffin-embedded sections of 10 of the positive specimens for each disease, together with whole-mount sections of small intestine and lung tissue from 2 healthy mink. The IHC grading of the TMA cores and the whole-mount sections from the same animal corresponded completely. These results suggest that IHC demonstration of viral antigen allows rapid and reliable diagnosis of the 3 viral infections in mink and is a potential supplement to histologic diagnostic procedures. The TMA technique proved useful for screening large numbers of samples for expression of specific viral antigens, while reducing overall costs.

Aleutian Mink Disease↗
PubMed2005

Epstein-Barr virus-associated familial Hodgkin lymphoma: paediatric onset in three of five siblings.

We report familial Hodgkin lymphoma (FHL) in a family with five children, of which three were human leucocyte antigen (HLA) class I identical. These three siblings were diagnosed with Epstein-Barr virus (EBV)-positive Hodgkin lymphoma within a 6-year period. All three were treated with chemo- and/or radiotherapy and are presently in complete remission. None of the children had evidence of overt immunodeficiency or autoimmune disease. This case contributes to the existing material on FHL and implies a role for both HLA class I antigens and EBV infection of the tumour cell population in the pathogenesis of some cases of FHL.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Laser-assisted microdissection of membrane-mounted tissue sections.

Biological tissues (in particular those affected by disease) are inherently complex mixtures of different cell types and matrices. This heterogeneity can complicate the interpretation of molecular biological studies performed on whole-tissue extracts if the precise cellular origin of the molecules being tested is not known. Laser-assisted microdissection (LAM) has emerged as a leading histological technique for obtaining samples enriched for specific target cell populations or tissue components for subsequent molecular (especially polymerase chain reaction-based) analysis. This method allows the identification and study of target-specific molecular alterations in heterogeneous specimens, and enables more accurate detection and quantification of target molecules. In this chapter, we focus on tissue microdissection performed with an ultraviolet laser system and describe protocols for the basic procedure and for handling of the samples.

Animals↗
PubMed2005

Laser-assisted microdissection of membrane-mounted sections following immunohistochemistry and in situ hybridization.

Laser microbeam microdissection (LMM) is an increasingly important histological technique for obtaining homogeneous cell populations and tissue components in order to analyze target-specific changes in genes, gene expression, and proteins. The quality of data obtained with LMM is heavily dependent on the precision with which the target for microdissection can be identified. Since no cover slip is used during LMM, tissue morphology is poor compared with traditional light microscopy. This hampers morphological recognition of targets for microdissection in routinely stained sections and can be a limiting factor in the use of this technique. Immunohistochemistry (IHC) and in situ hybridization (ISH) can improve the identification of specific cell populations in situ in tissue sections, but there are a number of problems in applying these methods to slides prepared for LMM. In this chapter, we present optimized protocols that allow IHC to be performed for detecting a wide range of antigens in conjunction with LMM, both on formalin-fixed paraffin-embedded and on frozen sections. In addition, we present a quick, versatile protocol for performing ISH on archival material suitable for LMM.

Animals↗
PubMed2004

Fas ligand expression in metastatic renal cell carcinoma during interleukin-2 based immunotherapy: no in vivo effect of Fas ligand tumor counterattack.

PURPOSE: It has been hypothesized that tumor cells expressing Fas ligand (FasL) might be able to counterattack and neutralize tumor-infiltrating lymphocytes. We assessed the effect of FasL tumor counterattack on the clinical outcome of interleukin-2 (IL-2)-based immunotherapy in metastatic renal cell carcinoma. EXPERIMENTAL DESIGN: Tumor core needle biopsies were obtained before IL-2-based immunotherapy in 86 patients and repeated within the first cycle in 57 patients. Tumor cells expressing FasL and intratumoral lymphocyte subsets expressing CD4, CD8, CD56, and CD57 were analyzed by immunohistochemistry. RESULTS: At baseline, negative FasL staining in tumor cells was seen in 10 of 86 (12%) biopsies, whereas intense FasL staining was seen (a) in fewer than 10% of tumor cells in 26 (30%) biopsies; (b) in 11 to 50% of tumor cells in 25 (29%) biopsies; (c) in 51 to 90% of tumor cells in 18 (21%) biopsies; and (d) in >90% of tumor cells in 7 (8%) biopsies. On treatment, tumor FasL expression did not change from baseline levels. Moreover, tumor FasL expression was not correlated with objective response or survival whereas the absolute number of CD4(+), CD8(+), CD56(+), and CD57(+) cells per mm(2) tumor tissue at baseline was significantly higher in responding patients compared with nonresponding patients (P = 0.01, P = 0.008, P = 0.015, and P < 0.001, respectively). During the first course of immunotherapy, the absolute number of CD4(+), CD8(+), and CD57(+) cells per mm(2) tumor tissue was significantly higher in responding patients compared with nonresponding patients (P = 0.034, P < 0.001, and P < 0.001, respectively). However, no correlation was observed between the number of intratumoral lymphocytes and tumor FasL expression level. CONCLUSION: These observations do not support the hypothesis that FasL tumor "counterattack" has an effect on the clinical outcome in metastatic renal cell carcinoma during IL-2-based immunotherapy.

Adult↗
PubMed2004

Real-time quantitative PCR of microdissected paraffin-embedded breast carcinoma: an alternative method for HER-2/neu analysis.

We studied the feasibility of using real-time quantitative PCR to determine HER-2 DNA amplification and mRNA expression in microdissected formalin-fixed, paraffin-embedded breast tumors and compared this with standard immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) methods. Study cases (27 carcinomas and 3 ductal breast carcinoma in situ (DCIS) cases) showed varying Her-2 expression as determined by IHC (HercepTest). In carcinomas, there was a good correlation between HER-2 DNA amplification and strong HER-2 protein expression detected by FISH and IHC, respectively. A single DCIS case was amplified in FISH, but not in IHC. Both HER-2 gene amplification and expression could be quantified in microdissected paraffin-embedded tumors using real-time PCR, DNA and RNA being successfully detected in 146 of 150 (97%) and 141 of 150 (94%) samples, respectively. PCR analysis for HER-2 DNA amplification using the LightCycler HER2/neu DNA Quantification kit (Roche Molecular Biochemicals, Mannheim, Germany) correlated fairly well with IHC and FISH. All IHC HER-2 3+ tumors were amplified according to the kit, as was the FISH-amplified DCIS case. DNA-PCR identified five additional tumors as being amplified. Interestingly, all these scored 2+ with the HercepTest, but were negative using FISH. We believe that real-time quantitative PCR analysis of HER-2 DNA amplification following microdissection represents a useful supplementary or perhaps even an alternative technique for establishing HER-2 status in paraffin-embedded tumors.

Breast Neoplasms↗
PubMed2003

Characteristics of Hodgkin's lymphoma after infectious mononucleosis.

BACKGROUND: Infectious mononucleosis-related Epstein-Barr virus (EBV) infection has been associated with an increased risk of Hodgkin's lymphoma in young adults. Whether the association is causal remains unclear. METHODS: We compared the incidence rates of Hodgkin's lymphoma in two population-based Danish cohorts of patients who were tested for infectious mononucleosis: 17,045 with serologic evidence of having had acute EBV infection, and 24,614 with no such evidence. We combined the cohort of patients who had serologically verified infectious mononucleosis with a cohort of 21,510 Swedish patients with infectious mononucleosis (combined total, 38,555). Biopsy specimens of Hodgkin's lymphomas occurring during follow-up in this combined cohort were tested serologically for the presence of EBV. Using this information, we modeled the relative risk of EBV-negative and EBV-positive Hodgkin's lymphoma in different periods after the diagnosis of infectious mononucleosis and estimated the median incubation time for mononucleosis-related EBV-positive Hodgkin's lymphoma. RESULTS: Only serologically confirmed infectious mononucleosis was associated with a persistently increased risk of Hodgkin's lymphoma. Sixteen of 29 tumors (55 percent), obtained from patients with infectious mononucleosis, had evidence of EBV. There was no evidence of an increased risk of EBV-negative Hodgkin's lymphoma after infectious mononucleosis. In contrast, the risk of EBV-positive Hodgkin's lymphoma was significantly increased (relative risk, 4.0; 95 percent confidence interval, 3.4 to 4.5). The estimated median incubation time from mononucleosis to EBV-positive Hodgkin's lymphoma was 4.1 years (95 percent confidence interval, 1.8 to 8.3). CONCLUSIONS: A causal association between infectious mononucleosis-related EBV infection and the EBV-positive subgroup of Hodgkin's lymphomas is likely in young adults.

Adolescent↗
PubMed2003

[Nonalcoholic steatohepatitis--a "new" hepatic disease].

Non-alcoholic fatty liver disease (NAFLD) is one of the most common hepatic disorders in the Western world. Non-alcoholic steatohepatitis (NASH) may occur in a subset of NAFLD patients and is an increasingly recognised clinicopathologial hepatic disorder. NASH may have significant impact on the healthcare system as it is associated with the metabolic syndrome comprising insulin resistance, obesity, hypertension, and type 2 diabetes mellitus. NASH can progress to liver fibrosis, cirrhosis and chronic hepatic failure and eventually to the need for a liver transplantation. The present review deals with the epidemiological features of NASH, describes a two-step pathogenesis with hepatic lipid accumulation (NAFLD) followed by the development of steatohepatitis (NASH). A strategy for establishing a diagnosis of NASH is presented including the indication for liver biopsy. The treatment of NASH may comprise different modalities from diet, weight loss, and exercise to pharmacological treatment to improve insulin resistance and drugs with antioxidant effects.

Denmark↗
PubMed2003

[Nonalcoholic steatohepatitis. Three case reports].

Non-alcoholic steatohepatitis (NASH) may develop in a subset of patients with non-alcoholic fatty liver disease (NAFLD). NASH is strongly associated to the metabolic syndrome with insulin resistance and obesity. NASH can progress to liver fibrosis, cirrhosis and chronic hepatic failure and eventual need for a liver transplantation. Three case stories are presented with characteristic clinical and histopathological changes.

Adult↗
PubMed2003

The myofibroblast is the predominant plasminogen activator inhibitor-1-expressing cell type in human breast carcinomas.

The tumor level of plasminogen activator inhibitor-1 (PAI-1) is an informative biochemical marker of a poor prognosis in several cancer types. However, the tumor biological functions of PAI-1 and the identity of PAI-1-expressing cells are controversial. With the aim of immunohistochemically localizing PAI-1 in formalin-fixed, paraffin-embedded invasive ductal breast carcinoma samples, we raised new polyclonal antibodies against PAI-1 from different expression systems. The antibodies were affinity purified by absorption on immobilized preparations of PAI-1 different from those used for immunization. The specificity of the antibodies was ensured by immunoblotting analysis. In immunohistochemistry, the staining pattern obtained with the antibodies showed a good correlation with the PAI-1 mRNA expression pattern. In all 25 cases analyzed, PAI-1 immunoreactivity was predominantly localized in fibroblast-like cells. Double-immunofluorescence analyses showed co-expression of PAI-1 and alpha-smooth muscle actin in these cells, suggesting that they are myofibroblasts. PAI-1 was also seen in some myoepithelial cells surrounding occasional foci of ductal carcinoma in situ (9 of 25), some endothelial cells (8 of 25), some cancer cells (3 of 25), and some mast cells (6 of 25). In conclusion, we have provided a robust immunohistochemical procedure for detection of PAI-1 and shown that the majority of the PAI-1-expressing cells in invasive ductal breast carcinomas are myofibroblasts.

Actins↗
PubMed2002

Identifying distinct classes of bladder carcinoma using microarrays.

Bladder cancer is a common malignant disease characterized by frequent recurrences. The stage of disease at diagnosis and the presence of surrounding carcinoma in situ are important in determining the disease course of an affected individual. Despite considerable effort, no accepted immunohistological or molecular markers have been identified to define clinically relevant subsets of bladder cancer. Here we report the identification of clinically relevant subclasses of bladder carcinoma using expression microarray analysis of 40 well characterized bladder tumors. Hierarchical cluster analysis identified three major stages, Ta, T1 and T2-4, with the Ta tumors further classified into subgroups. We built a 32-gene molecular classifier using a cross-validation approach that was able to classify benign and muscle-invasive tumors with close correlation to pathological staging in an independent test set of 68 tumors. The classifier provided new predictive information on disease progression in Ta tumors compared with conventional staging (P < 0.005). To delineate non-recurring Ta tumors from frequently recurring Ta tumors, we analyzed expression patterns in 31 tumors by applying a supervised learning classification methodology, which classified 75% of the samples correctly (P < 0.006). Furthermore, gene expression profiles characterizing each stage and subtype identified their biological properties, producing new potential targets for therapy.

Disease Progression↗
PubMed2002

[Detection of human herpes virus 8 in Kaposi sarcoma using polymerase chain reaction and single stranded probe in situ hybridization with a tyramide signal amplification system].

OBJECTIVE: To study the relationship between Kaposi's sarcoma (KS) and human herpes virus 8 (HHV8; Kaposi's sarcoma-associated herpes virus), and to develop an in situ hybridization (ISH) technique effective for clinical pathological diagnosis. METHODS: Polymerase chain reaction (PCR) technique was used to synthesize a digoxigenin-labeled single stranded DNA probe specific for HHV8 open reading frame 72 cyclin D homolog gene encoded mRNA as the probe accompanying with a tyramide signal amplification system (TSA) for ISH assay. Totally 20 formalin-fixed and paraffin-embedded samples from 14 cases of KS from Danish patients were collected for HHV8 detection. In order to compare the result obtained, all of these cases were checked simultaneously using PCR technique. RESULTS: HHV8 was detected in 10 of 14 (71%) KS cases, of which 8 cases were positive for HHV8 by both ISH and PCR. In ISH, HHV8 hybridization signal was seen as a dot or patch located in the nuclei of both the neoplastic spindle cells and the endothelial cells. HHV8 was found in lesions in all the stages of KS including early patch, plaque and late nodular or tumor lesions, as well as in the primary and metastatic lesions. All the control cases showed a relevant positive or negative results. CONCLUSIONS: The results further confirmed that there is a strong association between Kaposi's sarcoma and HHV8. The ISH technique with single stranded probe and TSA would be helpful in clinical pathological diagnosis for HHV8 infected diseases, such as KS, primary effusion lymphoma and multicentric Castleman's disease.

Adolescent↗