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Biomedical subjects

K Metze

Publications and source records attributed to K Metze.

At least 19 recordsLinked to original sources

Phenotypic quantitative features of patients with acute myeloid leukemia.

The recent WHO classification for acute myeloid leukemias (AML) separates entities by recurrent cytogenetic abnormalities and immunophenotypic features presenting prognostic impact. We have examined the expression of several lineage and maturation linked antigens used in routine immunophenotyping of patients with de novo AML, using a 3-color two-step panel. Cases were diagnosed by peripheral blood counts, bone marrow cytology, cytochemistry, cytogenetics and immunophenotyping (CD2, CD3, CD7, CD19, CD13, CD33, myeloperoxydase -- MPO, CD14, CD15, HLA-DR, CD34, CD56 and CD45). Antigen expression was measured by mean fluorescence intensity (MFI) by flow cytometry (Paint-a-gate software). Thirty five patients were analyzed. Median age: 51 years (15-79). Predominant FAB types were M2 and M4. In 6 cases more than one phenotypically distinct blast subpopulation could be detected. Although our set was small, we tried to analyze the impact of MFI of the examined antigens on the overall survival of the patients. In Cox univariate analysis, age, peripheral leukocytes (WBC) at diagnosis, MFI of CD45, and MPO were significant for worse a survival. In the multivariate analysis only MFI of CD45 and WBC remained in the model (p=0.018 and p=0.014 respectively). After bootstrap resampling, MFI of CD45 entered the model in 69%, WBCin 60%, age in 42% and MFI of MPO in 35% of the sets. Analysis of antigen expression by MFI permitted to detect cases presenting phenotypically distinct blast subpopulations. This may represent a pitfall in studies of minimal residual disease by flow cytometry, as chemotherapy may select one of these subsets.

Acute Disease↗

Optimization of CD34+ collection for autologous transplantation using the evolution of peripheral blood cell counts after mobilization with chemotherapy and G-CSF.

BACKGROUND: Peripheral blood progenitor cells (PBPC) collection after high dose chemotherapy can be influenced by several factors. We searched for parameters that may predict the best day to start harvesting of PBPC in order to collect most CD34+ cells with the least number of aphereses. METHODS: We studied patients who underwent mobilization chemotherapy for autologous transplantation. The influence of age, sex, diagnosis, number of previous chemotherapy cycles, peripheral blood (PB) counts at day of mobilization (D0), day of neutrophils <1.0 x 10(9) l(-1) and day of nadir and interval between both (delta) on harvesting was investigated. Multivariate linear correlation models were built to predict the best harvesting with principles of parsimony. In patients where sequential CD34+ cell count was performed, the theoretical day of peak was calculated by interpolation in polynomial regression. RESULTS: One hundred and thirty four patients entered the analysis: 36 Hodgkin's lymphoma (HL), 65 B-large cell lymphoma (NHL) and 33 multiple myeloma (MM). Day of harvesting correlated with nr CHT, hemoglobin on D0, day of granulocytes <1.0 x 10(9) l(-1), delta and dosis of mobilization therapy. The day of CD34+ peak could be calculated by the formula = (-0.41) x Hemoglobin D0 + (day peripheral CD34+ cells = 10 x 10(6) microl(-1)) x 0.99 + 7.8. This model could explain 81% of the variance of the peak day and was stable by bootstrap resampling. Day of peripheral CD34+ cells = 10 x 10(6) microl(-1) preceded the calculated peak by 3-9 days. CONCLUSIONS: Although the day of best collection can be predicted using only sequential PB counts after mobilization chemotherapy, a model of prediction using peripheral CD34+ cell count is important especially for optimizing collection in poor mobilizing patients.

Adolescent↗

Usefulness of HBME-1, cytokeratin 19 and galectin-3 immunostaining in the diagnosis of thyroid malignancy.

AIMS: To investigate the usefulness of immunohistochemical expression and immunolocalization of a panel of thyroid malignancy markers including HBME-1, cytokeratin (CK) 19 and galectin-3. METHODS AND RESULTS: We evaluated 170 thyroid lesions including 148 neoplastic lesions [84 papillary carcinomas (PC), 38 follicular carcinomas (FC), 18 follicular adenomas, one hyalinizing trabecular tumour, five medullary carcinomas, two anaplastic carcinomas] and 22 non-neoplastic lesions (12 adenomatous nodules and 10 Hashimoto's thyroiditis). HBME-1, galectin-3 and CK 19 were expressed in 94%, 72.6%, 72.6% of PCs and in 63%, 21%, 21% of FCs. The three markers were mostly negative in all normal tissues. Although the most helpful marker in terms of sensitivity and specificity for the follicular variant of PC and for FC diagnosis was HBME-1, when we consider the differentiation between cases of follicular variant of papillary carcinoma (FVPC) and FC or adenoma, in terms of percentage of positive cells, galectin-3 and CK 19 were more relevant. CONCLUSIONS: HBME-1 is the most sensitive marker for thyroid malignancy but the three markers may be useful in specific cases. This panel of markers is useful to differentiate the follicular patterned lesions, with special reference to the FVPC.

Biomarkers, Tumor↗

Late effects of chronic graft-vs.-host disease in minor salivary glands.

BACKGROUND: The established pathologic criteria for minor salivary gland (MSG) involvement in chronic graft-vs.-host disease (cGVHD) could play a role in monitoring response to therapy. METHODS: We evaluated MSG sequential biopsies during cGVHD therapy in 14 allogeneic bone marrow transplantation (BMT) patients. Nine patients that did not develop GVHD after BMT entered the control group. Biopsies were examined using hematoxylin-eosin, Periodic acid-Schiff (PAS) and leukocyte common antigen staining. RESULTS: A significant loss of PAS+ acinar volume was observed at the diagnosis of cGVHD as much as at the end of treatment when compared with the control group. In the second evaluation, the inflammatory infiltrate was still greater than control group. CONCLUSIONS: The results suggest that persistent xerostomia after cGVHD treatment is because of maintenance of lymphocytic infiltrate and consequent absence of MSG secretory unit recovery. This data may be useful to provide improved insight into the histopathology of this organ involvement.

Adolescent↗

Immunoexpression of CD95 in chronic gastritis and gastric mucosa-associated lymphomas.

CD95 (Fas/APO-1)-mediated apoptosis plays an important role in immunological regulation and is related to the pathogenesis of autoimmune diseases. Immunoexpression of CD95 has been reported to frequently occur in low grade non-Hodgkin lymphomas, especially of post-germinal center histogenesis, among which those originating in mucosa-associated lymphoid tissue (MALT lymphomas). However, there is no report comparing in situ immunoexpression of this marker in lymphomas and the hyperplastic lymphoid reaction (chronic gastritis) related to Helicobacter pylori infection. The purpose of the present research was to compare the intensity of lymphoid CD95 immunoexpression in 15 cases of H. pylori-related chronic gastritis and 15 gastric MALT lymphomas. CD95 (anti-CD95) was detected by an immunoperoxidase technique in paraffin sections using the catalyzed amplification system. Graduation of reaction intensity (percentage of CD95-positive cells) was semiquantitative, from 1+ to 4+. Nine cases of chronic gastritis were 4+, five 2+ and one 1+. Three lymphomas were 4+, three 3+, four 2+, four 1+, and one was negative. Although 14 of 15 lymphomas were positive for CD95, the intensity of the reaction was significantly weaker compared to that obtained with gastric tissue for patients with gastritis (P = 0.03). The difference in CD95 immunoexpression does not seem to be useful as an isolated criterion in the differential diagnosis between chronic gastritis and MALT lymphomas since there was overlapping of immunostaining patterns. However, it suggests the possibility of a pathogenetic role of this apoptosis-regulating protein in MALT lymphomas.

Antigens, Neoplasm↗

Comparison of immunoexpression of 2 antibodies for estrogen receptors (1D5 and 6F11) in breast carcinomas using different antigen retrieval and detection methods.

The importance of in situ immunodetection of hormone receptors for therapy planning and prognostic evaluation in patients with breast carcinoma is well established. Sensitive detection methods are of utmost importance, especially in poorly fixed tissues, which are not uncommon in routine pathologic practice. The purpose of the present study is to compare immunoexpression of estrogen receptors in 20 cases of invasive ductal carcinoma using two antibodies, 1D5 and 6F11, and to verify the effect of different antigen retrieval solutions and detection systems. Immunoperoxidase was performed on paraffin sections using 1D5 and 6F11 as primary antibodies. Heat-induced antigen retrieval was performed using citrate buffer (pH 6.0) or Tris-EDTA buffer (pH 8.9). Detection was achieved using the following systems: EnVision, EnVision Plus, and labeled streptavidin-biotin peroxidase complex. Reaction was semiquantified from 0 to 4. There were no differences between the two markers, 1D5 and 6F11, except when 6F11 was used with EnVision and citrate buffer, in which case weaker reactivity was observed. Only in this combination (6F11/EnVision) was EDTA buffer significantly better than citrate. Labeled streptavidin-biotin peroxidase complex presented the best results, followed by EnVision Plus.

Antibodies, Monoclonal↗

Insulin signalling pathways in aorta and muscle from two animal models of insulin resistance--the obese middle-aged and the spontaneously hypertensive rats.

AIMS/HYPOTHESIS: The aim of this study was to investigate insulin signalling pathways directly in vivo in skeletal muscle and thoracic aorta from obese middle-aged (12-month-old) rats, which have insulin resistance but not cardiovascular disease, and from spontaneously hypertensive rats (SHR), an experimental model of insulin resistance and cardiovascular disease. METHODS: We have used in vivo insulin infusion, followed by tissue extraction, immunoprecipitation and immunoblotting. RESULTS: Obese middle-aged rats and the SHR showed marked insulin resistance, which parallels the reduced effects of this hormone in the insulin signalling cascade in muscle. In aortae from obese middle-aged rats, the PI 3-kinase/Akt pathway is preserved, leading to a normal activation of endothelial nitric oxide synthase. In SHR this pathway is severely blunted, with reductions in eNOS protein concentration and activation. Both animals, however, showed higher concentrations and higher tyrosine phosphorylation of mitogen-activated protein (MAP) kinase isoforms in aortae. CONCLUSIONS/INTERPRETATION: Alterations in the IRS/PI 3-K/Akt pathway in muscle of 12-month-old rats and SHR could be involved in the insulin resistance of these animals. The preservation of this pathway in aorta of 12-month-old rats, apart from increases in MAP kinase protein concentration and activation, could be a factor that contributes to explaining the absence of cardiovascular disease in this animal model. However, in aortae of SHR, the reduced insulin signalling through IRS/PI 3-kinase/Akt/eNOS pathway could contribute to the endothelial dysfunction of this animal.

Age Factors↗

Acute leukemias in Piauí: comparison with features observed in other regions of Brazil.

Differences in age and sex distribution as well as FAB (French-American-British classification) types have been reported for acute leukemias in several countries. We studied the demographics and response to treatment of patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) between 1989 and 2000 in Teresina, Piau , and compared these results with reports from Brazil and other countries. Complete data concerning 345 patients (230 ALL, 115 AML) were reviewed. AML occurred predominantly in adults (77%), with a median age of 34 years, similar to that found in the southeast of Brazil but lower than the median age in the United States and Europe (52 years). FAB distribution was similar in children and adults and FAB-M2 was the most common type, as also found in Japan. The high frequency of FAB-M3 described in most Brazilian studies and for Hispanics in the United States was not observed. Overall survival for adults was 40%, similar to other studies in Brazil. A high mortality rate was observed during induction. No clinical or hematological parameter influenced survival in the Cox model. ALL presented the characteristic peak of incidence between 2-8 years. Most of the cases were CD10+ pre-B ALL. In 25%, abnormal expression of myeloid antigens was observed. Only 10% of the patients were older than 30 years. Overall survival was better for children. Age and leukocyte count were independent prognostic factors. These data demonstrate that, although there are regional peculiarities, the application of standardized treatments and good supportive care make it possible to achieve results observed in other countries for the same chemotherapy protocols.

Adolescent↗

Spontaneous apoptosis in chronic lymphocytic leukemia and its relationship to clinical and cell kinetic parameters.

Chronic lymphocytic leukemia (CLL) presents considerable variability in clinical presentation as well as in its evolution. In contrast to the inhibition of apoptosis in vivo, spontaneous apoptosis after short-term culture occurs. We studied the degree of this apoptosis in vitro, and its interactions with several clinical and laboratory parameters. Apoptosis was measured by the annexin V technique. Proliferation rate was evaluated by the AgNOR (nucleolar organizer regions) technique. There were inverse correlations between the percentage of annexin V-positive cells and peripheral lymphocyte count (r = - 0.49), Rai stage (r = - 0.40), Binet stage (r = - 0.50), TTM (total tumor mass score; r = - 0.51), and percentage of cells with one AgNOR cluster (r = - 0.45). Direct correlations were found with hemoglobin values ( r = 0.34) and platelet counts (r = 0.52). The number of CD8-positive cells showed a correlation with peripheral lymphocyte count (r = 0.49). When this variable was held constant, a correlation was detected between CD8-positive cells and staging (r = -0.47), TTM (r = - 0.42), and platelet count (r = 0.67). CD4-positive lymphocytes presented a correlation only with CD8-positive lymphocytes. In a cluster analysis, it was possible to create three groups of patients with different apoptosis rates using the TTM and AgNOR values. We conclude that, with the progression of the disease, together with the increase of tumor mass and proliferation rate, there is a decrease in the susceptibility to apoptosis.

Aged↗

AgNOR pattern and PCNA analysis in fine needle biopsies of liver cell carcinoma.

The aim of this study was to evaluate the prognostic and diagnostic value of AgNOR and PCNA staining mainly in fine needle biopsies of 34 liver cell carcinomas using an image analyzing system. The AgNOR number per nucleus and the relative AgNOR area, but not the PCNA index, showed a significant correlation with the histological tumor grade according to the classical and the modified Edmondson-Steiner's classification. Regarding univariate survival, only the grade of the classical Edmondson-Steiner's classification was of prognostic significance. The parameters sex, age, maximum tumor diameter, mean AgNOR number, total nuclear area and relative AgNOR area, nuclear area, PCNA index or the grade of the modified Edmondson-Steiner's classification did not reach statistical significance regarding survival. By a factor analysis, two factors could be created, which could explain together 72% of the variance of all parameters included in the study. In a linear discriminant analysis, the AgNOR variables could separate between normal liver cells and cells from high grade or low grade carcinomas in 83.7% of the cases. Therefore, we think that the AgNOR technique can be usefully applied in needle biopsies of liver carcinomas for the differential diagnosis and tumor grading.

Adolescent↗

Nucleolus organizer regions (AgNORs) and total tumor mass are independent prognostic parameters for treatment-free period in chronic lymphocytic leukemia.

The aim of our study was to evaluate whether the nucleolus organizer regions (AgNOR) of circulating lymphocytes in chronic lymphocytic leukemia (CLL) could predict the duration of the stable phase (treatment-free period) of this disease. Age, sex, peripheral lymphoctes, hemoglobin, platelet count, Binet's stage, total tumor mass (TTM) and AgNOR pattern at diagnosis were assessed in 57 patients and compared with the time from diagnosis until patients fulfilled the criteria to start chemotherapy. In univariate Cox regression, Binet's stage, hemoglobin, number of peripheral lymphocytes, TTM and the percentage of lymphocytes containing one AgNOR cluster (circulating proliferative fraction) had predictive value. In the multivariate Cox model, only TTM and the percentage of cells with one AgNOR cluster were independent factors predicting the duration of the stable phase. Repetition of these analyses in 500 data sets created by bootstrap resampling confirmed the results. Summing up the percentage of lymphocytes with an AgNOR cluster and the TTM value, a simple prognostic index could be created to give information about the duration of the stable phase in CLL.

Cell Division↗