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D H Wright

Publications and source records attributed to D H Wright.

At least 55 records · Page 3Linked to original sources
PubMed1997

Tissue preparation for immunocytochemistry.

AIMS: To investigate the effect of tissue preparation on immunostaining and to establish whether there is a standard tissue preparation schedule that allows optimal demonstration of all antigens. METHODS: Blocks of tonsil were subjected to variations to a standard fixation, processing, and section preparation schedule. The sections were stained with five antibodies-L26 (CD20), UCHL1 (CD45RO), CD3, vimentin, and anti-kappa light chain--using the streptavidinbiotin immunostaining technique. When further investigation was necessary, other tissues and antibodies were used and where weak immunostaining was obtained the use of microwave pretreatment to improve staining was tested. RESULTS: Several factors involved in fixation were found to affect immunoreactivity. These included the duration, pH, and type of fixative used. In tissue processing only temperature and the duration of the dehydration and wax infiltration steps affected immunoreactivity. Of all the factors investigated, the temperature and duration of the section drying had the greatest effect. In contrast, long term storage of cut sections before immunostaining had no effect on the reactivity of the antibodies tested. Antibodies were found to be affected by alterations to tissue preparation by varying degrees, UCHL1 and vimentin being the most susceptible to changes in fixation and L26 to changes in processing. Where weak staining occurred, microwave pretreatment was generally found to eliminate the problem. CONCLUSIONS: There is no standard tissue preparation schedule for the optimal demonstration of all antigens. Factors involved in all aspects of tissue preparation can affect immunoreactivity, so it is important that precise details of the preparation schedule are given when reporting immunocytochemical studies, rather than using the general term "routinely fixed and processed".

Histocytological Preparation Techniques↗
PubMed1997

Oligoclonal populations of T and B cells in a case of angioimmunoblastic T-cell lymphoma predominantly infiltrated by T cells of the VB5.1 family.

AIMS: Immunohistological and molecular characterisation of a case of peripheral T-cell lymphoma (PTCL) of angioimmunoblastic T-cell lymphoma (AILD) type. METHODS: Frozen and paraffin wax sections of the diagnostic lymph node were stained with a panel of T- and B-cell lineage monoclonal antibodies. DNA was isolated from the paraffin wax embedded biopsy material for T-cell receptor (TCR) and immunoglobulin (Ig) PCR amplification, and resultant PCR products were cloned and sequenced. RESULTS: Immunohistological analysis of the presenting lymph node was consistent with an extensive infiltrate of pleomorphic CD3+CD8+ lymphocytes. Most (>80%) of these infiltrating CD3+ cells were also positive for the TCR VB5.1 gene family product, and were shown to be oligoclonal by TCRB PCR amplification and sequencing. Three oligoclones of B cells were also demonstrable by PCR amplification with Ig heavy chain primers and sequencing, a finding at variance with the diagnosis of AILD. CONCLUSIONS: These data demonstrate the complexity and heterogeneity of PTCL which require extensive histological examination and molecular characterisation.

Aged↗
PubMed1997

Enteropathy associated T cell lymphoma.

Enteropathy associated T cell lymphoma (EATCL) is the most serious complication of coeliac disease. HLA genotyping shows that patients with EATCL have the coeliac disease associated DQA1*0501, DQB1*0201 phenotype. Other HLA-DR/DQ alleles that may be associated with adult onset coeliac disease appear to represent additional risk factors for lymphoma development. Increased numbers of small intestinal intraepithelial cytotoxic T cells are found in the small intestinal mucosa of patients with coeliac disease and in the enteropathic bowel of patients with EATCL. The neoplastic cells of EATCL have the immunophenotype of intraepithelial cytotoxic T cells and may exhibit epitheliotropism. Analysis of T cell receptor genes and immunohistochemistry have shown that the intestinal mucosa distant from the tumour contains clonal populations of small T cells, often of the same clone as the high grade T cell lymphoma. Most cases of chronic ulcerative enteritis are probably part of the same disease process. The ulceration seen in chronic ulcerative enteritis and in enteropathy associated T cell lymphoma may be due to the release of cytolytic enzymes by cytotoxic T cells and tumour cells. These findings suggest that EATCL arises in the setting of coeliac disease and evolves from intraepithelial lymphocytosis through low grade lymphoma to a high grade tumour, possibly under antigen drive from gliadin peptides. These peptides may be presented to the intraepithelial cytotoxic T cells directly by epithelial cells bearing the coeliac disease associated HLA-DQ alleles.

Celiac Disease↗
PubMed1996

A study of accessory cells in the acquired lymphoid tissue of helicobacter gastritis.

This paper presents a description of the patterns of distribution of accessory cells in helicobacter gastritis and low-grade gastric MALT lymphomas. The use of gastric resection specimens afforded abundant, well-orientated lymphoid tissue. Fifteen cases were selected from patients with MALT lymphomas, three with gastritis alone, and six histologically normal controls. A panel of antibodies working in paraffin-embedded tissue, identifying differing accessory cells, was used. These comprised antibodies to HLA class II (WR18), acid cysteine proteinase inhibitor (ACPI), CD68 (PGM1), Factor XIIIa, S100 protein, CD23 (BU38), CD106 (V-CAM1), CD55 (BRIC 128), and CD21 (1F8). CD68-positive macrophages in the gastritis cases were abundant in the superficial mucosa. Factor XIIIa also identified dendritic cells at deeper sites but these were absent from both the acquired and the neoplastic lymphoid tissue. Antibodies to both S100 protein and ACPI stained dendritic cells localized to areas within and adjacent to the lymphoid tissue only. S100 protein-positive cells were concentrated in close contact with glandular epithelium immediately above the germinal centres, while ACPI-positive dendritic cells were identified, especially around the more blastic reactive follicles, in the intervening space between the germinal centres and the overlying epithelium. Similar patterns of organization were also seen in the areas of mucosal lymphoma. The follicular dendritic markers revealed overlapping but distinct sub-populations within the germinal centres which appeared to alter depending on the activity of the germinal centres. While both ACPI and CD55 stained the germinal centre dendritic reticulum cell networks only, CD21 and CD106 also stained the mantle dendritic cells. The proportion staining with CD23, which stains dendritic reticulum cells within the centrocyte-rich areas of the germinal centres only, was greatest in the more quiescent germinal centres. Similar patterns of staining were also seen in germinal centres within the gastric MALT lymphomas. It is proposed that the sub-populations of dendritic cells staining with S100 protein and ACPI may facilitate helicobacter antigen delivery to the germinal centres. The follicular dendritic cells then promote a sustained B-cell response to the luminal pathogen.

Antigen Presentation↗
PubMed1996

Accessory cells in Crohn's disease of the terminal ileum.

We present a study which describes the immunophenotype and distribution of accessory cells in 13 resections of terminal ileum from patients with Crohn's disease. A panel of antibodies working in paraffin-embedded tissue was employed and these included PGM1 (CD68), S-100 protein, WR18 (HLA class II), factor XIIIa and acid cysteine proteinase inhibitor. This study revealed a heterogeneity of accessory cell populations which was profoundly influenced by local inflammatory and repair mechanisms. Both acid cysteine proteinase activity and S-100 protein positive cells are identified in more actively inflamed areas. The acid cysteine proteinase activity positive dendritic cell population was particularly numerous in ulcer bases. S-100 protein positive dendritic cells had a more limited distribution in close proximity to the epithelium in inflamed but otherwise intact mucosa adjacent to the areas of ulceration. PGM1 revealed normal distribution of macrophages within histologically uninvolved areas and, in addition, also stained granulomas and large numbers of dendritic cells in the inflamed, ulcerated and scarred areas. Factor XIIIa positive dendritic cells were especially numerous in areas of active scarring where they co-localized with PGM1 positive cells. They were largely absent from the more superficial ulcerated areas. HLA class II was strongly expressed on mononuclear inflammatory and dendritic cells. The strength of epithelial staining for HLA class II reflected the intensity of adjacent inflammation, except on ulcer-associated epithelium which consistently showed up-regulation independent of the severity of the inflammatory process. This study shows that localized alterations in the accessory cell distribution in Crohn's disease correlate with different states in the evolution of the inflammatory and repair process of the disease. The more acute lesions are associated with recruitment of acid cysteine proteinase activity and S-100 protein positive dendritic cells while factor XIIIa stained dentritic cells are especially numerous in areas of scarring.

Antigen-Presenting Cells↗
PubMed1996

Accessory cells in physiological lymphoid tissue from the intestine: an immunohistochemical study.

We report a study of the organization of accessory cell populations, in normal mucosal lymphoid tissue from small intestine (8 cases), large intestine (6) and appendix (9) using a panel of monoclonal antibodies and polyclonal antisera in paraffin-embedded tissue. Two populations were identified in dome areas, one positive for acid cysteine proteinase inhibitor and HLA class II (WR18) only and the second positive for S-100 protein, CD68, and WR18 and negative for acid cysteine proteinase inhibitor and factor XIIIa. Superficial colonic mucosal and small intestinal villous tip macrophages stained positively with CD68 and WR18 only, while deeper cryptal and submucosal populations exhibited additional positivity for factor XIIIa, but both populations were negative for acid cysteine proteinase inhibitor and S-100 protein. Germinal centre macrophages were positive for CD68, WR18 and acid cysteine proteinase inhibitor and negative for factor XIIIa, and S-100 protein. T zone dendritic cells included a population which stained positively for S-100 protien, WR18 and were negative for factor XIIIa, CD68 and acid cysteine proteinase inhibitor, an immunophenotype typical of interdigitating dendritic reticulum cells. This distribution of phenotypically identifiable accessory cell subpopulations was apparent at all three sites examined. We suggest that the specialized subpopulations of dendritic cells staining for S-100 protein and for acid cysteine proteinase inhibitor which are restricted to the dome areas, may have a potential role in the transfer of antigen across the epithelium to the germinal centres, while factor XIIIa appears to identify a tissue macrophage population with a potential role in stromal modulation distant from direct antigen challenge.

Antigen-Presenting Cells↗
PubMed1996

Lorazepam stability in parenteral solutions for continuous intravenous administration.

OBJECTIVE: To determine the stability of lorazepam over a 24-hour period when prepared in polyvinyl chloride (PVC) bags at initial concentrations of 0.08 and 0.5 mg/mL. DESIGN: Each concentration was studied at room (21 degrees C) and refrigerator (4 degrees C) temperatures in dextrose 5% (D5W) and NaCl 0.9% solutions. Duplicate test solution admixtures were prepared for each lorazepam concentration, diluent, and temperature. At 0, 1, 4, 8, and 24 hours, duplicate samples were obtained for visual inspection, pH determination, and concentration determination by stability-indicating, reverse-phase HPLC analysis. Compared with baseline, peaks for lorazepam degradation products were not found on any of the study chromatograms. RESULTS: In D5W and NaCl 0.9% solutions, lorazepam loss in excess of 10% by HPLC analysis occurred for concentrations of 0.08 and 0.5 mg/mL at 1 and 4 hours, respectively. CONCLUSIONS: These data suggest that significant loss of lorazepam occurs as the probable result of sorption to PVC bags when admixed in both D5W and NaCl 0.9% solutions at 21 and 4 degrees C.

Chromatography, High Pressure Liquid↗
PubMed1995

Heterogeneous expression of Epstein-Barr virus latent proteins in endemic Burkitt's lymphoma.

Epstein-Barr virus (EBV)-infected cells may sustain three distinct forms of virus latency. In lymphoblastoid cell lines, six EBV-encoded nuclear antigens (EBNA1, 2, 3A, 3B, 3C, -LP), three latent membrane proteins (LMP1, 2A, 2B), and two nuclear RNAs (EBERs) are expressed. This form of latency, termed latency III, is also encountered in some posttransplant lymphoproliferative disorders. In EBV-positive cases of Hodgkin's disease, the EBERs, EBNA1, and the LMPs are expressed (latency II), whereas in Burkitt's lymphoma (BL) only the EBERs and EBNA1 have been detected (latency I). We have studied the expression of EBV proteins in 17 cases of EBV-positive endemic BL by immunohistology. Expression of LMP1 was seen in variable proportions of tumor cells in two cases and EBNA2 was detected in some tumor cells in three other cases. Also, the BZLF1 trans-activator protein was expressed in a few tumor cells in 6 cases, indicating entry into the lytic cycle. A phenotypic drift from latency I to latency III has been observed previously in some BL cell lines. Our results suggest that a similar phenomenon may occur in BL in vivo and indicate that the operational definition of EBV latencies is not easily applied to human tumors.

Adolescent↗
PubMed1995

HLA-DRB, -DQA, and -DQB polymorphism in celiac disease and enteropathy-associated T-cell lymphoma. Common features and additional risk factors for malignancy.

CD is a gluten-sensitive enteropathy, strongly associated with expression of the DQA1*0501, DQB1*0201 genotype. CD patients have an increased risk of malignancy, particularly EATCL. However, it is controversial as to whether adults with EATCL represent a subgroup of patients with CD or should be regarded as a distinct entity. To investigate the genetic relationship between CD and EATCL, HLA class II DRB1, DQA1, and DQB1 typing of peripheral blood, frozen or paraffin-embedded biopsy tissue obtained from Caucasian patients with CD (n = 91) or EATCL (n = 47) was performed by PCR-SSOP typing. Genotype frequencies were compared with those observed in 151 unrelated control individuals. A total of 83 (91%) of 91 CD patients were of DQA1*0501, DQB1*0201 genotype (pc < 10(-6), RR = 522.2), compared with 40 (93%) of 43 EATCL patients (pc < 10(-6), RR = 44.2) with amplifiable DNA versus 35 (23%) of 151 controls. DRB1*03 frequencies were also elevated in both patient groups (79 of 91 in CD [87%; pc < 10(-6), RR = 24.5] and 38 of 40 in EATCL [95%; pc < 10(-6), RR = 70.7]) compared with controls (32 of 151, 21%). These results confirm previous studies of HLA associations in CD and also suggest that EATCL arises in individuals with the DQA1*0501, DQB1*0201 CD-predisposing genotype. However, the frequency of DRB1*03,04 heterozygotes was significantly increased in the EATCL group (16 of 40, 40%) compared with both control individuals (3 of 151, 2%; pc < 10(-6), RR = 32.9) and uncomplicated CD patients (6 of 91, 7%; pc = 0.04, RR = 9.4).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

The major complications of coeliac disease.

Neoplasms constitute the major complication of coeliac disease, and high-grade T-cell lymphoma of the small intestine (enteropathy-associated T-cell lymphoma) is the most common neoplasm in this category. HLA genotyping indicates that in patients with enteropathy-associated T-cell lymphoma have the coeliac disease associated DQA1*0501, DQB1*0201 phenotype, although additional HLA-DR/DQ alleles may represent risk factors for lymphoma development. Molecular biological and immunohistochemical studies have shown that the intestinal mucosa distant from the tumour contains clonal populations of small T cells, often of the same clone as the high-grade T-cell lymphoma. These findings suggest that enteropathy-associated T-cell lymphoma arises in the setting of coeliac disease and evolves from reactive intraepithelial lymphocytes through a low-grade lymphocytic neoplasm to a high-grade tumour, which is usually the cause of the presenting symptoms. Most cases of chronic ulcerative enteropathy (ulcerative jejunitis) are probably part of the same disease process. If the ulceration occurs at a time when the neoplastic T-cells are of a low grade, morphological recognition of tumour cells in the ulcers may be impossible. Carcinoma of the pharynx and oesophagus, and adenocarcinoma of the small intestine, are increased in frequency in patients with coeliac disease. The increased risk of carcinoma of the oesophagus may be related to vitamin A deficiency. A number of reports have indicated an increased prevalence of various types of chronic hepatitis in patients with coeliac disease, but no coherent view of the cause of this association has emerged. Similarly, patients with coeliac disease have been reported to have various forms of fibrosing lung disease of uncertain causation. In recent years, there have been several reports, mainly from Italy, of a syndrome of epilepsy and bilateral brain calcification occurring in coeliac patients. The pathogenesis of this condition is not known and its prevalence in other communities is uncertain. Splenic atrophy occurs frequently in patients with coeliac disease and is related to the severity of the disease and degree of dietary control. Splenic atrophy predisposes to infection with capsulated bacteria, although mortality studies indicate that infection with these organisms is not a major cause of death in patients with coeliac disease.

Brain↗
PubMed1995

Preclinical studies with the anti-CD19-saporin immunotoxin BU12-SAPORIN for the treatment of human-B-cell tumours.

The immunotoxin BU12-SAPORIN was constructed by covalently coupling the single-chain ribosome-inactivating protein saporin to the anti-CD19 monoclonal antibody BU12 via a disulphide linker using the heterobifunctional reagent SPDP. The immunoreactivity and specificity of BU12-SAPORIN was identical to that of unmodified native BU12 antibody. BU12-SAPORIN was selectively cytotoxic in vitro in a dose-dependent manner for the CD19+ human common acute lymphoblastic leukaemia (cALL) cell line NALM-6 but exhibited no toxicity for the CD19- T-cell acute lymphoblastic leukaemia (T-ALL) cell line HSB-2. The survival of severe combined immunodeficient (SCID) mice with disseminated NALM-6 leukaemia was significantly prolonged compared with sham-treated control animals by a course of therapy with BU12-SAPORIN but not with the irrelevant anti-CD7 immunotoxin HB2-SAPORIN. BU12-SAPORIN had no therapeutic effect in SCID mice with disseminated CD19- HSB-2 leukaemia. These preclinical studies have clearly demonstrated the selective cytotoxicity of BU12-SAPORIN for CD19+ target cells both in vitro and in vivo. This, taken together with the lack of expression of the CD19 molecule by any normal life-sustaining tissue and its ubiquitous and homogeneous expression by the majority of cALL and B-NHL cells, provides the rationale for undertaking a phase I trial of systemic therapy with BU12-SAPORIN.

Animals↗
PubMed1995

Low-grade B-cell lymphomas of the splenic marginal zone: a clinicopathological and immunohistochemical study of 14 cases.

We have studied 14 cases of low-grade, splenic marginal zone, B-cell non-Hodgkin's lymphoma. The clinical presentation in all cases was with splenomegaly and, in 10 cases, circulating neoplastic lymphoid cells in the peripheral blood with involvement of bone marrow. In all cases the splenic white pulp was hyperplastic with expansion of marginal zones and varying degrees of infiltration of germinal centres by neoplastic cells. The cells were a mixture of medium sized lymphocytes with moderate amounts of cytoplasm and finely dispersed nuclear chromatin, together with occasional blast cells with small nucleoli. Satellite red pulp aggregates of tumour cells centred on small epithelioid cell clusters were seen in all cases. These appear to be a characteristic and diagnostically important feature of splenic marginal zone lymphoma. The tumour cells expressed CD20, CD45RA, bcl-2 and the antigens detected by MB2. All cases expressed IgM with light chain restriction. In addition, IgD was expressed in four cases. The follicular dendritic cell network was disrupted in those follicles which were infiltrated by tumour cells. A network of stromal myoid cells, at the periphery of the marginal zone, identified by expression of alpha-smooth muscle actin, was preserved. Alpha-smooth muscle actin positive dendritic cells were also seen within and around satellite tumour nodules in the red pulp.

Aged↗
PubMed1995

Acromial angle on radiographs of the shoulder: correlation with the impingement syndrome and rotator cuff tears.

OBJECTIVE: This study was undertaken to determine the reproducibility of measurements of an acromial angle on radiographs and to correlate those measurements with the presence of the impingement syndrome and rotator cuff tears. MATERIALS AND METHODS: Ninety-nine shoulders in 95 patients who had an arch radiograph and had undergone shoulder arthroscopy were included in this retrospective study. The acromial angle was measured on the arch view of the shoulder independently by three observers who were blinded to the name, history, and arthroscopic results. The angle was measured at the intersection of lines drawn along the inferior cortex of the anterior and posterior portions of the acromion. Interobserver variability was determined by the intercorrelation coefficient (a test of reproducibility of quantitative measurements). The average of the three measurements for each patient was correlated with the preoperative diagnosis and the arthroscopic findings. RESULTS: A correlation was found between increasing severity of cuff disease as determined on arthroscopy and increasing acromial angle (p < .01). In 67 patients (70 shoulders) with impingement, patients with a full-thickness tear (29%) accounted for 43% of those with an angle of 30 degrees or greater. The average acromial angle for patients with impingement was greater than that for either patients with instability or patients with trauma (p < .05 for both). An angle of 25 degrees or greater was measured in 63% of patients with impingement but in only 18% of those with instability. The average acromial angle in patients with impingement and an intact rotator cuff was also greater than the average angle in patients with instability (p = .001). The interobserver variability had an intercorrelation coefficient of 0.90. CONCLUSION: The acromial angle is an objective and fairly reproducible measure of anterior acromial shape. The angle is useful in identifying patients with a greater likelihood of having a rotator cuff tear and in distinguishing patients with primary impingement from those with instability.

Acromion↗
PubMed1995

Bucket-handle tears of the medial and lateral menisci of the knee: value of MR imaging in detecting displaced fragments.

OBJECTIVE: A bucket-handle tear of a meniscus is a longitudinal tear with an attached fragment displaced away from the meniscus. Several MR findings of bucket-handle tears have been reported previously. However, the sensitivity of MR for detecting the displaced fragment is unknown. We determined the sensitivity of MR for detecting a displaced bucket-handle tear and determined how the sensitivity varied with tears of different sizes. We also evaluated whether the three findings of a displaced fragment differed in frequency between medial and lateral tears. MATERIALS AND METHODS: We retrospectively evaluated the MR examinations of 39 patients with arthroscopically proven bucket-handle tears for signs of a displaced meniscal fragment. Thirty-two patients had medial meniscal bucket-handle tears, and seven had lateral tears. Two observers evaluated each examination independently, with discrepancies resolved by consensus of a third reader. Each observer evaluated for three findings of a bucket-handle tear: a double posterior cruciate ligament sign, a flipped meniscus sign, or a fragment in the intercondylar notch. A double posterior cruciate ligament sign is present when the meniscal fragment is displaced anterior to the posterior cruciate ligament, resembling two ligaments. A flipped meniscus sign occurs when the fragment is flipped anteriorly so the anterior horn of the meniscus appears to be enlarged. We tested for differences between menisci in the sensitivity for each sign using Pearson's chi-squared test or Fisher's exact test. We compared the sensitivity of MR for identifying fragments when the tear involved one third, two thirds, or the entire meniscus using Spearman's rank correlation. RESULTS: Overall sensitivity for a displaced fragment was only 0.64. When the bucket-handle tear involved the entire meniscus, the displaced fragment could be seen in 84% of the menisci. The double posterior cruciate ligament sign was seen in 53% of the medial and none of the lateral bucket-handle tears (p = .01). The flipped meniscus sign was noted in 44% of medial and 29% of lateral menisci (p = .68), and a fragment was identified in the intercondylar notch in 66% of medial and 43% of lateral menisci (p = .40). CONCLUSION: MR is sensitive for detecting meniscal fragments in large bucket-handle tears, but is less so in small tears. The flipped meniscus sign and presence of a fragment in the notch were comparably useful findings of a displaced fragment in both medial and lateral menisci. The double posterior cruciate ligament sign was noted only in medial bucket-handle tears.

Adult↗
PubMed1995

Study of the immunohistochemistry and T cell clonality of enteropathy-associated T cell lymphoma.

Specimens from 23 patients with enteropathy-associated T cell lymphoma were studied by immunohistochemistry after antigen retrieval. Specimens from 14 of these patients were investigated for the presence of clonal T cell gene rearrangements in both the tumor and the adjacent enteropathic intestine by the polymerase chain reaction. Primers for T cell receptor beta and gamma genes were used in a combination that permits the identification of approximately 90% of T cell receptor rearrangements. Clonal rearrangements of the T cell receptor were found in 13 of the 14 tumors studied. Specimens of enteropathic bowel resected with the tumor, but showing no morphological or immunohistochemical evidence of tumor involvement, showed clonal T cell receptor gene rearrangements in 11 cases. In 10 of these, the amplified DNA was of the same molecular weight in the enteropathic bowel as in the corresponding tumor. In 2 cases, sequencing the polymerase chain reaction product showed identical T cell receptor gene rearrangements in the tumor and in the adjacent intestine. Uniform staining for p53 was seen in 22 of the 23 tumors. In 9 of 19 cases studied, collections of small lymphocytes in the enteropathic bowel expressed p53. In all but one of these specimens, a clonal rearrangement of the T cell receptor genes was identified. We interpret these findings as support for the concept that enteropathy-associated T cell lymphoma arises on a background of gluten-sensitive enteropathy with evolution of neoplastic T cell clones from the reactive T cell population present in the enteropathic bowel.

Adult↗