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A Chott

Publications and source records attributed to A Chott.

At least 73 records · Page 4Linked to original sources
PubMed2000

Effect of formalin tissue fixation and processing on immunohistochemistry.

Although immunohistochemistry is routinely performed by many pathology laboratories, its standardization still lags behind. A major cause of variation in the reproducibility of immunohistochemical staining is induced by tissue fixation and, to a lesser degree, tissue processing. This report, stemming from the first meeting of the International Consensus Group on Standardization and Quality Control (ICGSQC) in Nice, France, summarizes the problem and suggests solutions to begin to achieve standardization of fixation and processing. Most laboratories use neutral-buffered formalin (10%) for tissue fixation which introduces cross-links, whereas coagulative fixatives are less popular. Problems with formalin fixation comprise delay of fixation and variations in the duration of the fixation mainly. Solutions to these problems could be to start fixation soon (<30 min) after surgical removal of the tissue and to avoid overfixation (>24-48 hrs). For tissue processing, the most important problem is inadequate tissue dehydration prior to paraffin embedding. This can be prevented by preparing all solutions freshly every week, depending on the volume of tissue processed. If consistently applied, these procedures could eliminate some of the sources of variation in immunohistochemical stains.

Artifacts↗
PubMed2000

Regression of colonic low grade B cell lymphoma of the mucosa associated lymphoid tissue type after eradication of Helicobacter pylori.

BACKGROUND: Lymphoma of the mucosa associated lymphoid tissue (MALT) arising in the stomach has been shown to be related to Helicobacter pylori infection, and total regression of gastric lymphoma after successful eradication of H pylori has consistently been reported. MALT-type lymphoma at other localisations, however, has to our knowledge not been linked to H pylori, and eradication of the bacteria has not been studied for management of such lymphomas. PATIENT/METHOD: A 67 year old man was diagnosed with MALT-type lymphoma simultaneously involving the stomach and the colon descendens. In addition to the presence of MALT-type lymphoma, H pylori associated chronic gastritis was diagnosed, and treatment with clarithromycin, metronidazole, and omeprazole was initiated, resulting in its successful eradication. RESULTS: Follow up performed four months later showed regression of the colonic manifestation, whereas the gastric lymphoma did not respond to antibiotic treatment, as assessed by regular follow up for 14 months, in spite of its restriction to mucosa and submucosa. The patient was therefore treated with oral cyclophosphamide (100 mg a day) resulting in partial remission after seven months of continuous treatment. Because of the presence of residual lymphoma, additional irradiation was performed, which led to complete remission of the gastric lymphoma. The patient remains in complete remission 40 months after diagnosis and 26 months after initiation of treatment. CONCLUSION: In the case of concurrent gastric and intestinal low grade MALT-type lymphoma, H pylori eradication may cause regression of the intestinal lesion.

Aged↗
PubMed2000

ALK expression in extranodal anaplastic large cell lymphoma favours systemic disease with (primary) nodal involvement and a good prognosis and occurs before dissemination.

AIMS: In anaplastic large cell lymphoma (ALCL), the site of origin has been described as an important prognostic factor. Recently, a fusion protein containing anaplastic lymphoma kinase (ALK) was described in systemic nodal ALCL, and shown to be associated with a good prognosis. The aims of this study were to investigate whether the presence of ALK protein differs between ALCL of different sites of origin; to determine whether ALK expression occurs before dissemination to other sites; and, finally, to investigate whether the site of origin remains a prognostic parameter in ALK negative ALCL. METHODS: ALK expression, as detected by immunohistochemistry using the monoclonal antibodies ALK1 and ALKc, was studied in 85 ALCLs from different sites of origin. In 22 patients, ALK expression was studied in multiple biopsies from different sites (including 13 skin, 16 lymph node, and nine other). Overall survival time was analysed using the Kaplan Meier method. RESULTS: ALK expression was found in 20 of 51 systemic ALCLs with (primary) nodal involvement. No ALK expression was found in 15 primary cutaneous, 14 gastrointestinal, and five nasal ALCLs. Multiple and subsequent biopsies of patients showed ALK expression to be identical to that seen in the primary diagnostic biopsy. Kaplan Meier survival curves showed that in ALK negative ALCLs originating from different sites, primary cutaneous cases are associated with an excellent overall survival, whereas the other cases show a comparable five years survival of less than 40%. CONCLUSIONS: If present, ALK expression favours systemic ALCL with (primary) nodal involvement, and can be used in differentiating between extranodal involvement of systemic (nodal) ALCL and primary extranodal ALCL. ALK is expressed consistently in multiple biopsies of a given patient, indicating that the chromosomal abnormality leading to aberrant ALK expression occurs before dissemination to other sites. Finally, in ALK negative non-cutaneous ALCLs, different sites of origin show comparable poor survival.

Adolescent↗
PubMed2000

Myelosarcoma of the cavernous sinus in a nonleukemic patient--case report.

Myelosarcomas are rare, solid extramedullary tumors composed of granulocyte precursors in most cases associated with leukemia. A 38-year-old nonleukemic female presented with a myelosarcoma of the cavernous sinus. After surgical removal of the cavernous sinus tumor she was treated by chemotherapy and whole brain radiation therapy. Despite this aggressive therapy, she died 4 months after surgical intervention.

Adult↗
PubMed1999

Treatment of hairy cell leukemia with cladribine (2-chlorodeoxyadenosine).

Hairy cell leukemia is a rare lymphoproliferative disorder resistant to conventional chemotherapeutic agents. Recently, the purine analogue cladribine (2-chlorodeoxyadenosine, 2-CdA) was introduced for the treatment of this disease. We report on 14 patients with hairy cell leukemia who were treated with 2-CdA at our department between 1993 and 1997. The patients received a single cycle of 2-CdA at a dose of 0.07 or 0.09 mg/kg/day by continuous infusion, over a seven-day period. Five patients were previously untreated, while the others had received prior treatment with interferon-alpha (seven patients), interferon-alpha and splenectomy (one patient) or interferon-alpha, splenectomy and pentostatin (one patient). Six patients achieved complete remission, three a good partial response and three partial remission. Two patients did not respond to treatment and one of them died from septicemia in aplasia. Relapse of the disease occurred in two patients. Side effects such as fever (WHO grade 2) and/or neutropenia (WHO grade 4) were noted in eight patients. Thus, 2-CdA is an effective treatment of hairy cell leukemia that can induce long lasting remissions in both, previously treated and untreated patients.

Adult↗
PubMed1999

Improved treatment results in childhood B-cell neoplasms with tailored intensification of therapy: A report of the Berlin-Frankfurt-Münster Group Trial NHL-BFM 90.

In study NHL-BFM 90, we investigated whether the serum lactate dehydrogenase (LDH) concentration and early response are useful markers for stratification of therapy for childhood B-cell neoplasms in addition to stage, if the outcome of patients with abdominal stage III and LDH >/=500 U/L can be improved by high-dose (HD) methotrexate (MTX) at 5 g/m(2) instead of intermediate-dose (ID) MTX at 500 mg/m(2) in the preceding study 86; whether 2 therapy courses are enough for patients with complete resection; and whether combined systemic and intraventricular chemotherapy is efficacious for central nervous system-positive (CNS(+)) patients. After a cytoreductive prephase, treatment was stratified into 3 risk groups: patients in R1 (completely resected) received 2 5-day courses (ID-MTX, dexamethasone, oxazaphorins, etoposide, cytarabine, doxorubicin, and intrathecal therapy), patients in R2 (extra-abdominal primary only or abdominal tumor and LDH <500 U/L) received 4 courses containing HD-MTX, and patients in R3 (abdominal primary and LDH >/=500 U/L or bone marrow/CNS/multilocal bone disease) received 6 courses. Incomplete responders after 2 courses received an intensification containing HD-cytarabine/etoposide. Patients with no or necrotic tumor thereafter received 3 more courses; 6 patients with viable tumor received autologous bone marrow transplantation. From April 1990 through March 1995, 413 evaluable patients were enrolled (R1, 17%; R2, 40%; and R3, 43%). The 6-year event-free survival (pEFS) was 89% +/- 2% for all and 100%, 96% +/-2%, and 78% +/- 3% in R1, R2, and R3, respectively. The pEFS of patients with abdominal stage III and LDH >/=500 U/L was 81% +/- 4% as compared with 43% +/- 10% in study 86. Of 26 CNS(+) patients, 5 died early, but only 3 relapsed.

Adolescent↗
PubMed1999

Hyperfibrinolysis in a case of myelodysplastic syndrome with leukemic spread of mast cells.

Mast cells (MC) are multipotent hemopoietic effector cells producing diverse mediators like histamine, heparin, or tissue type plasminogen activator. We report a 75-year-old male patient with myelodysplastic syndrome (MDS) of recent onset (3 months' history) associated with a massive leukemic spread of immature tryptase+ MC (tentative term: myelomastocytic leukemia). The patient presented with pancytopenia, bleeding, hypofibrinogenemia, and an increased cellular tryptase level. Moreover, an excessive elevation of plasmin-antiplasmin complexes (9,200 ng/ml; normal range: 10-150), an elevated D-dimer, and an increase in thrombin-antithrombin III complexes were found. The identity of the circulating MC was confirmed by immunophenotyping (CD117/c-kit+, CD123/IL-3R alpha-, CD11b/C3biR-), biochemical analysis (cellular ratio [ng:ng] of tryptase to histamine >1), and electron microscopy. Bone marrow (bm) examination showed trilineage dysplasia (17% blasts), 30% diffusely scattered MC, and a complex karyotype. No dense, compact MC infiltrates (mastocytosis) were detectable in bm sections. Despite hyperfibrinolysis and mediator syndrome (flushing, headache), the patient received remission induction polychemotherapy (DAV) followed by two cycles of consolidation with intermediate dose ARA-C (2 x 1 g/m2/day on days 1, 3, and 5). He entered complete remission after the first chemotherapy cycle without evidence of recurring MDS. Moreover, in response to chemotherapy, the hyperfibrinolysis and mediator syndrome resolved, and the circulating c-kit+ MC disappeared. We suggest consideration of polychemotherapy as a therapeutic option in patients with high-risk MDS of recent onset, even in the case of MC lineage involvement.

Aged↗
PubMed1999

Hematopoietic donor chimerism and graft-versus-myeloma effect in relapse of multiple myeloma after allogeneic bone marrow transplantation.

A large group of patients relapsing after allogeneic bone marrow transplantation (BMT) have obtained remission after infusion of leukocytes from their original donor, suggesting a graft-versus-myeloma effect. However, side effects such as graft-versus-host disease and myelosuppression are severe, and sometimes fatal, complications of this therapeutic approach. Previously we demonstrated that patients with leukemia who lack donor hematopoiesis in relapse after BMT experience severe and lasting aplasia after infusion of donor leukocytes. In two patients - one with extramedullary and one with marrow relapse after a sex-mismatched transplantation - we analyzed hematopoietic chimerism by cell sorting and bone marrow cultures. CD34-positive cells, CD4-CD8-positive cells, committed progenitors, and LTC-IC were of donor origin, as demonstrated by two-color fluorescence in situ hybridization (FISH). Additionally, in relapse complete donor T-cell chimerism was seen. In contrast, plasma cells were of recipient origin in the patient who had a relapse in the bone marrow. Both patients were treated with infusions of donor leukocytes from their original donor. Neither patient suffered myelosuppression, and one achieved a stable complete remission.

Adult↗
PubMed1999

Tyrosine kinases expressed in vivo by human prostate cancer bone marrow metastases and loss of the type 1 insulin-like growth factor receptor.

An important biological feature of prostate cancer (PCa) is its marked preference for bone marrow as a metastatic site. To identify factors that may support the growth of PCa in bone marrow, expression of receptor and nonreceptor tyrosine kinases by androgen-independent PCa bone marrow metastases was assessed. Bone marrow biopsies largely replaced by PCa were analyzed using reverse transcriptase-polymerase chain reaction amplification with degenerate primers that amplified the conserved kinase domain. Sequence analyses of the cloned products demonstrated expression of multiple kinases. Expression of the receptor and nonreceptor tyrosine kinases, alpha platelet-derived growth factor receptor and Jak 1, respectively, was confirmed by immunohistochemistry. In contrast, the type 1 insulin-like growth factor receptor, thought to play a role in PCa development, was lost in metastatic PCa. These results implicate several specific growth factors and signaling pathways in metastatic androgen-independent PCa and indicate that loss of the type 1 insulin-like growth factor receptor contributes to PCa progression.

Bone Marrow Neoplasms↗
PubMed1999

Positron emission tomography with fluorine-18-2-fluoro-2-deoxy-D-glucose (F18-FDG) does not visualize extranodal B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT)-type.

BACKGROUND: On the basis of promising data on the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (F18-FDG) whole body positron emission tomography (WB-FDG-PET) in the staging of patients with lymphoma, we initiated a pilot series to evaluate the role of WB-FDG-PET in the staging of extranodal B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. PATIENTS AND METHODS: We examined ten consecutive patients with histologically-verified MALT-type lymphomas of various origin before initiation of therapy. Nine patients had low-grade lymphomas (five cases of gastric lymphoma, two patients with lymphoma arising in the lung, one parotid and one lacrimal gland lymphoma), while one patient had a high-grade gastric lymphoma arising from a low-grade background. Two patients had stage EI, seven had stage EII disease, and one presented with stage EIII. WB-FDG-PET scans were performed 40 min following the injection of 300-380 MBq of F18-FDG. The PET scans were correlated with extensive conventional staging including ophthalmologic investigation, otolaryngologic examination, gastroscopy, endosonography, enteroclysis, colonoscopy, CT of thorax and abdomen, and bone marrow biopsy. RESULTS: WB-FDG-PET documented no lymphoma in any of the 10 patients studied, as no focal tracer uptake was demonstrated in either gastric or extragastric lesions or in involved lymph nodes, irrespective of histologic grading. In three patients the scan showed a false negative result with respect to the MALT lesions but showed focal tracer uptake indicating tumor spread, which, however, was ruled out by further follow-up and biopsy, respectively, and was thus rated false positive. Due to these results, the study was discontinued prematurely after the first ten patients. CONCLUSIONS: These discouraging results indicated that WB-FDG-PET is not useful for staging and follow-up of MALT-type lymphoma, and should therefore not be included in the clinical decision making process.

Aged↗
PubMed1999

Immunophenotypic characterization of human bone marrow endosteal cells.

In order to determine the relationship between bone marrow (bm) endosteal cells (EDC) and hemopoietic progenitors, we have analyzed the immunophenotype of EDC using various antibodies (Ab) against mesenchymal antigens. The Ab were applied on paraffin sections of normal bm (iliac crest, n=17; talus, n=1; phalanx, n=1), myeloregenerative bm (after chemotherapy), and hematologic disorders (acute myeloid leukemia (AML), n=8; chronic myeloid leukemia (CML), n=6; myelodysplastic syndromes (MDS), n=14; severe aplastic anemia (SAA), n=4; essential thrombocythemia (ET), n=2; idiopathic (primary) osteomyelo-fibrosis (IMF), n=1; polycythemia vera (PV), n=1). In normal bm, EDC were found to react with Ab against vimentin, tenascin, alpha-smooth muscle actin, osteocalcin, CD51, and CD56, but did not react with Ab against CD3, CD15, CD20, CD34, CD45, CD68, or CD117. An identical phenotype of EDC was found in AML, MDS, SAA, ET, IMF, PV, myeloregenerative bm, and peripheral bones lacking active hemopoiesis (talus, phalanx). In patients with CML, EDC reacted with Ab to CD51, but did not react with Ab to CD56. Based on their unique antigen profile, EDC were enriched from normal bm by enzyme digestion and cell sorting. However, these enriched cells (CD56+, CD45-, CD34-) did not give rise to hemopoietic cells under the culture conditions used, i.e. in the presence of the growth factors IGF-1, bFGF, SCF, IL-3, and GM-CSF Together, our data do not support the hypothesis that EDC are totipotent mesenchymal progenitors giving rise to hemopoietic cells.

Antigens, CD↗
PubMed1999

Frequent allelic imbalance but infrequent microsatellite instability in gastric lymphoma.

Specific defects in DNA repair pathways are reflected by DNA microsatellite instability (MSI) and play an important role in carcinogenesis. Reported frequencies in gastric non-Hodgkin's lymphomas (NHL) vary from 14% to as high as 90%. Another form of genetic instability in tumours is allelic imbalance (AI) due to loss or gain of genetic material at a specific chromosomal region. This might point to the presence of a tumour suppressor gene or oncogene. We examined both MSI and AI in 26 gastric lymphomas (10 low-grade and 13 high-grade MALT lymphomas and three cases lacking MALT features and categorised as diffuse large B cell lymphoma (DLCL)). Tumour components and normal cells (epithelium, muscle) were microdissected from paraffin-embedded resection samples. Contrary to other studies we did not observe frequent MSI when investigating 18 different loci distributed over 12 chromosomes. Microsatellite instability of a single locus was found in 1/10 (10%) low-grade MALT lymphomas and 2/13 (15%) high-grade MALT lymphomas. These data indicate that DNA mismatch repair genes do not play a role in the pathogenesis of these lymphomas. Allelic imbalance was detected in 60% (6/10) of low-grade MALT lymphomas, in 62% (8/13) of high-grade MALT lymphoma and in 67% (2/3) of DLCL. In high-grade lymphomas more loci showed AI (one to seven loci, with a mean of 2.5 loci per case) than in the low-grade lymphomas (one to two loci, with a mean of 1.3 loci per case), possibly reflecting an increased genomic instability.

DNA Mutational Analysis↗
PubMed1999

Aberrant esophageal HLA-DR expression in a high percentage of patients with Crohn's disease.

Esophageal histology is not well studied in patients with Crohn's disease (CD). We, therefore, analyzed the histologic and immunohistologic appearance of esophageal mucosa in CD. Biopsy specimens taken from the esophagus of 57 consecutive patients with known CD of the large and/or small bowel, of 200 Crohn's-free controls, of 15 cases with ulcerative colitis, and of 5 cases with viral esophagitis were evaluated. In controls, most patients had either HLA-DR negative esophageal epithelium or showed focal or diffuse basal staining. HLA-DR expression of all epithelial layers (transepithelial staining) was observed in only four (2%) control subjects, in one case with herpes esophagitis, but not in patients with ulcerative colitis. In contrast, transepithelial HLA-DR expression was found in 19 (33%) patients with CD (p < 0.0001). In CD patients, it was associated with a significantly increased epithelial content in T-cells (CD3+, TIA-1+, granzyme B+), B-cells (CD79a+), natural killer cells (CD57+), and macrophages (CD68+). There was no correlation with either histological findings elsewhere in the upper gastrointestinal tract or with laboratory findings, symptoms, CDAI, or medication. Transepithelial esophageal HLA-DR expression is common in CD. Immunohistochemistry may prove useful in supporting the histologic diagnosis of CD in staging procedures, for initial diagnosis as well as in doubtful cases.

Adolescent↗
PubMed1999

Combined polymerase chain reaction approach for clonality detection in lymphoid neoplasms.

The present study analyzes the efficiency of a combination of four immunoglobulin heavy chain (IgH) gene polymerase chain reaction (PCR) primer systems and a multiplex T-cell receptor gamma chain (TRG) gene PCR for detection of clonality in 409 samples (234 paraffin sections, 175 bone marrow aspirates) of different lymphomas. Using the four IgH PCR systems together, clonality was detected in all samples of B-cell chronic lymphocytic leukemias, hairy cell leukemias, common acute lymphoblastic leukemias, and Burkitt-like B-cell lymphomas. Clonality was detected in all bone marrow aspirates with lymphoplasmacytoid immunocytoma, mantle cell lymphoma, marginal zone B-cell lymphoma, and unclassifiable low-grade B-cell lymphomas. The combined IgH gene PCR approach allowed clonality detection in 78.2% of myelomas, 75% of Burkitt lymphomas, 74.4% of diffuse large B-cell lymphomas, 68.7% of follicular center lymphomas, 50% of posttransplant lymphomas, 28.6% of anaplastic large cell lymphomas, 29% of T-cell lymphomas, and 18.8% of Hodgkin diseases. The combination of the four IgH gene primer systems with the multiplex TRG gene PCR allowed detection of clonality in 84.2% of B-cell neoplasms, 92.1% of T-cell non-Hodgkin lymphomas, and 18.8% of Hodgkin diseases, which was much more efficient than single PCR protocols.

Clone Cells↗
PubMed1999

Evidence of T cell receptor beta-chain patterns in inflammatory and noninflammatory bowel disease states.

T cell activation, as defined by expression of relevant cell surface molecules, such as the interleukin-2 receptor (CD25), is increased in many chronic relapsing diseases, including inflammatory bowel disease (IBD). These T cells are generally activated through contact of their clonotypic T cell receptor (TCR) with a peptide antigen presented by a major histocompatibility complex molecule. One of the putative antigenic contact sites for the TCR is the third complementarity determining region (CDR3) of the TCR beta-chain variable region (TCRBV). Therefore, analysis of the TCRBV CDR3 provides insight into the diversity of antigens encountered by a given T cell population. This study evaluated the TCRBV CDR3 usage of the activated intestinal lymphocytes from human subjects with IBD, diverticulitis (inflammatory control), and a normal tissue control. Public patterns, as demonstrated by shared TCRBV CDR3 amino acid sequences of activated intestinal T cell subpopulations, were observed. In particular, a public pattern of TCRBV22, a conserved valine in the fifth position, and use of TCRBJ2S1 or TCRBJ2S5 was present in three of four Crohn's disease subjects while not present in the ulcerative colitis subjects. However, the private patterns of TCRBV CDR3 region amino acid sequences were far more striking and easily demonstrated in all individuals studied, including a normal noninflammatory control. Thus we conclude that selective antigenic pressures are prevalent among an individual's activated intestinal lymphocytes.

Amino Acid Sequence↗
PubMed1999

Persisting bone marrow aplasia following interferon-alpha combined with ara-C for chronic myelogenous leukemia.

A 37-year-old man with a newly diagnosed chronic myelogenous leukemia received induction therapy with hydroxyurea and interferon-alpha, and maintenance therapy with low-dose ara-C and interferon-alpha. Subsequent to a rapid hematological remission, a continuously aggravating pancytopenia with bone marrow aplasia developed which persisted after withdrawal of maintenance therapy. Bone marrow examination exhibited aplastic areas and residual hematopoiesis with impaired maturation; cytogenetically, there was a 100% persistence of Philadelphia chromosome-positive metaphases. By allogeneic bone marrow transplantation, a complete reconstitution of hematopoiesis was achieved.

Adult↗
PubMed1999

[Problems in biopsy differential diagnosis in lymphomas of the small and large intestines].

Besides the problems inherent in endoscopically obtained tissue and the low incidence of intestinal lymphomas, the major difficulties reside in the distinction to reactive processes and in the differential diagnosis among several lymphoma entities. Knowledge of the microanatomical and biological properties of the intestinal MALT, supplemented by sufficient clinical information, are important prerequisites for the diagnostic work-up which has to include immunohistochemical studies. Whereas the diagnosis of aggressive B-cell lymphomas (diffuse large B-cell lymphoma, Burkitt's lymphoma) is usually straightforward, lymphomatous polyposis (LP, the intestinal equivalent of mantle cell lymphoma) and low-grade B-cell lymphoma of MALT-type may be difficult to diagnose and to separate from reactive lymphoproliferations. The characteristic immunohistochemical profile of LP (cyclin D1 + CD5 + CD43 + CD23 - CD10 - IgM kappa or lambda, is very helpful in this regard and similarly useful to exclude intestinal involvement by B-CLL or follicular center lymphoma. In addition, the endoscopic appearance characterized by seeds of small polyps along the colorectum favors LP although MALT-type lymphoma may occasionally produce polypoid lesions. Focal lymphoid hyperplasia occurs in the terminal ileum and may present with a mass in the right iliac fossa. The diagnosis of intestinal T-cell lymphoma (ITL) represents the most challenging task for both clinicians and pathologists. This disease is often associated with and may closely mimick celiac disease of adult onset type, or can be misdiagnosed as inflammatory bowel disease. The presence of an abnormal activated T-cell phenotype, i.e. different from that of normal intraepithelial lymphocytes, strongly suggests ITL and is of particular importance in cases that lack overt cytological atypia.

Adult↗