Biomedical subjects

A Porwit

Publications and source records attributed to A Porwit.

At least 37 records · Page 2Linked to original sources

PubMed1993

DNA image analysis in childhood acute lymphoblastic leukemia.

DNA index (DI) and percentages of cells in S and G2/M phase were determined in Feulgen stained nuclei of blasts from 31 cases of childhood ALL at diagnosis. In 6 cases the results of DNA analysis and cytogenetics were concordant showing hyperdiploidy. Two other cases with normal karyotype were revealed as DNA aneuploid with image analysis. Cases with cytogenetic abnormalities like translocation, deletion or presence of single or double supernumerary chromosomes had DI within normal ranges. Nine ALL cases (29%) were found to be DNA aneuploid--8 hyperdiploid and 1 hypodiploid. The percentages of cells in S and G2/M phase for blasts from bone marrow (mean 17.6%) were significantly higher than those estimated in the peripheral blood (mean 1.57%). We conclude that analysis by image cytometry can detect aneuploid DNA content even in cases, which showed a normal karyotype and provides new information concerning the biological aspects of leukemic blasts.

Adolescent↗

PubMed1993

Methodological aspects of DNA image cytometry in normal bone marrow smears.

The possibility of using DNA image cytometry in hematological material was evaluated in 27 Feulgen stained normal bone marrow smears. The 95% normal limits of DNA index (DI) determined separately for each cell population in bone marrow were 0.89-1.15, 0.93-1.09 and 0.92-1.12 for blasts, granulocytes and lymphocytes, respectively. The mean DI for blasts, granulocytes and lymphocytes was 1.02, 1.01 and 1.02, respectively. In the blasts population the mean percentage of cells in S+G2/M phase was 38.1% (S.D. 12.9%, range 14.3-65.6%), whereas the corresponding values for granulocytes and lymphocytes were below 1%. Calculation of DI and G0/G1 C.V. obtained in bone marrow smears subjected to Feulgen hydrolysis (5 N HCl, 22 degrees C) for different periods of time revealed the presence of a plateau of results between 60 and 120 min for all of the cell types. The intraobserver and interobserver reproducibility was confirmed by duplicate measurements of each subpopulation (P > 0.05). A comparison of DI and G0/G1 C.V. using smears from the same donors stained with the Feulgen method either straight away or after destaining from May-Grunwald-Giemsa confirmed that destained smears can be used, provided applying appropriately prepared reference cells. We conclude that image cytometry can be used reliably to analyze DNA content in hematological material.

Adolescent↗

PubMed1992

Bone marrow cells in the DNA-synthesis-phase in the myelodysplastic syndrome and lymphome.

The bromodeoxyuridine (BRDU) labelling of bone marrow cells was studied in 46 subjects. The labelling in 14 patients, mostly untreated, with the myelodysplastic syndrome (MDS) and four lymphoma patients was significantly (p = 0.043) higher (11.38 +/- SE 2.3% S-phase cells) than that of marrow cells (7.18 +/- SE 1.04%) from 14 apparently healthy normal controls and from nine patients with non hematologic disease. Six iron deficiency had numerically but not significantly increased values. Bone marrow samples from MDS-patients showing the highest numbers of cells in the DNA-synthesis phase had the lowest numbers of colonies and clusters in the CFU-C assay (p < 0.03). The data suggest that the DNA-synthesis period is longer in MDS than in controls.

Adult↗

PubMed1992

A supportive role of neural cell adhesion molecule (NCAM) in adhesion between leukaemic blasts and cytotoxic lymphocytes.

The expression and function of neural cell adhesion molecule (NCAM, CD56, Leu19) on leukaemic blasts was investigated. The expression of NCAM was frequent (64%) in 14 studied cases of acute myeloid leukaemia (AML) but not in chronic lymphocytic leukaemia (CLL: 1/3 cases positive) or immunocytoma (IC: no positivity). No correlation with the expression of other AM (intercellular adhesion molecule-1 (ICAM-1), leucocyte function antigen-1 (LFA-1). VLA beta chain) or with AML type, according to FAB classification, was observed. Blocking of NCAM with anti-Leu 19 MoAb on AML targets resulted in a significant decrease of their susceptibility to LAK killing and in inhibition of conjugate formation. In the case of B prolymphocytic leukaemia (B-PLL) which did not express ICAM-1 or LFA-1 but was NCAM+, a complete resistance to LAK activity and lack of conjugate formation was observed. Blocking of NCAM on LAK effectors did not decrease their cytotoxic activity. Our results suggest that NCAM, in the presence of other AM, may have a supportive role in adhesion of leukaemic targets to LAK effectors.

Adult↗

PubMed1991

B-cell lymphoma in transplanted liver. Clinical, histological and radiological manifestations.

An isolated, centroblastic lymphoma developed in a 25-year-old female liver transplant recipient in her liver graft a few months after transplantation. Her immunosuppressive therapy consisted of antithymocyte globulin, cyclosporin, corticosteroids and, periodically, azathioprine. Chromosome analysis showed the tumor to be of female origin, thus excluding the possibility of transfer from the male donor. The tumor cells expressed EBV nuclear antigen (EBNA). The tumor was located in the left lobe of the liver. It was successfully removed 11 months after transplantation by a hemihepatectomy following a very brief combined chemotherapy course, and was then found to be replaced by necrotic tissue. No further treatment for lymphoma was given, and the patient is now free from lymphoma 3 years after transplantation.

Adult↗

PubMed1991

Resistance of leukemic blasts to lymphokine activated killer (LAK)-mediated cytotoxicity is not related to their adhesion properties.

The expression of adhesion molecules on blasts from 14 patients with acute myeloid leukemia (AML) was investigated by immunofluorescence and flow cytofluorometry. All tested blast populations expressed CD18/CD11a complex [leukocyte function antigen-1 (LFA-1)] and CD29 (very-late antigen (VLA)) and the majority were positive for CD54 [intercellular adhesion molecule-1 (ICAM-1), 78.6%] and CD56 [neural cell adhesion molecule (NCAM), 64.3%]. The expression of two other alpha chains of CD18/CD11b and CD11c varied considerably (64.3% and 42.8% of positive cases, respectively). Only one case (AML-M4) showed a weak expression of the activated platelet antigen CD41b. None of the tested blasts expressed the vitronectin receptor (CD61/CD51). No significant correlation between the expression of adhesion molecules and the FAB type of leukemia could be found. All tested blast populations were completely resistant to NK-mediated cytotoxicity and relatively resistant to LAK-mediated cytotoxicity in the standard 51Cr release assay. While no statistically significant correlation of the results in cytotoxicity assays with the expression of adhesion molecules or the expression of HLA-DR antigen could be observed, 2 out of 3 completely resistant cases lacked ICAM-1. These results show that even leukemic blasts which express all of the tested adhesion molecules can still be resistant to LAK-mediated cytotoxicity.

Adult↗

PubMed1990

Studies on the distribution of abnormal cells in cytological smears. VII. Cervical brush versus plastic and wooden spatulas.

A model system of exfoliated normal human cervicovaginal squamous cells, exfoliated rodent tumor cells, and acellular, viscous, mucuslike material was used to investigate cell deposition on smear preparations made with three different instruments: plastic spatulas, wooden spatulas, and brush-tipped collectors. The total number of exfoliated cells and the total number of tumor cells present within the randomly distributed holes were then recorded for 41 smear preparations. For smears done with the brush, a total of 47,146 exfoliated cells were recorded; with wooden spatulas, 4517 cells; and with plastic spatulas, 7648 cells. When the brush was used, 6905 tumor cells were recorded. When wooden or plastic spatulas were applied, 563 and 1132 tumor cells were found, respectively. Thus, the brush yielded 12.2 and 6.1 times more tumor cells than plastic and wooden spatulas, respectively.

Cervix Uteri↗

PubMed1989

A monoclonal antibody, H2, defines a new surface antigen expressed on human lymphocytes.

We have previously described a monoclonal antibody (MoAb), H2, which recognized a tumour-unique antigen on a human T-cell chronic lymphatic leukaemia (T-CLL, CD3,4+). However, further characterization of H2 has revealed a reactivity with the majority of T lymphocytes and a minority of B lymphocytes, some malignant T cells and a few cell lines of leukaemia or of hematopoietic tumour origin. The molecular weight of the antigen (80,000) precipitated by the MoAb H2 from the cell lines NALM-6 and Reh corresponded to that previously found. When PBL were stimulated with PHA, IL-2, or Con A a reduced reactivity of H2 could be seen. The MoAb H2 was submitted to the Fourth International Conference on Human Leucocyte Differentiation Antigens, Vienna, 1989. H2 did not cluster in any of the 78 clusters of differentiation (CD 1-78) discussed at the conference, indicating its unique reactivity. This suggests that we have defined a new antigen on lymphocytes with a possible role along the resting-proliferating axis.

Animals↗

PubMed1989

Cell association of HIV in AIDS-related encephalopathy and dementia.

The presence of HIV gag and env proteins (HIV Ag) and virus replicating cells was studied by immunohistochemistry and in situ hybridization, respectively, in brain specimens from five HIV infected patients. HIV antigens were detected in 3 of 5 brains in micronodular areas characterized by increased cellularity and the presence of multinuclear giant cells. By double immunostaining, HIV Ag positive cells were shown to express markers common to macrophages and microglia i.e. Leu M5+, My4+, HLA-Dr+, RCA-1+, and to a lesser extent CD4+ (Leu3+). Another macrophage specific marker, KiM6, was found only on HIV+ cells in HIV infected specimens and not in uninfected, control brains. Medium-sized, virus replicating cells were found exclusively in micronodular areas, but in much smaller quantities than HIV Ag+ cells. Our observations provide further evidence to support the hypothesis that macrophages play an important role in CNS infection by HIV and additionally support the concept that reactive microglial originate from activated macrophages infiltrating the brain. Both direct effects of viral components and cell mediated reactions can be implicated from our findings as mechanisms involved in the pathogenesis of the CNS lesions.

Acquired Immunodeficiency Syndrome↗

PubMed1989

Follicular involution in HIV lymphadenopathy. A morphometric study.

Lymph node biopsies from 75 HIV infected patients (71 homo- and bisexual men, 3 hemophiliacs and 1 woman) were studied using immunohistochemical methods with monoclonal antibodies (Mabs) against B lymphocytes, subsets of T lymphocytes, follicular dendritic cells (FDC) and HIV gag proteins p24 and p18. Histopathological changes were classified as follicular hyperplasia (FH), fragmentation (FF), atrophy (FA) and depletion (FD). Immunohistochemical stainings were quantified with the help of an Image Quantifier (IQ) and the reactivity for respective Mab-defined antigen was related quantitatively to other antigens and histopathological changes. Such measurements showed an increase in FDC in biopsies with FH and FF histology and a decrease in FA and FD cases in comparison with cases with non-HIV related lymphadenopathy. In addition it was found that the decrease in FDC was correlated with an increase in CD8+ within the follicles. Double immunostainings for p24 and various cellular markers showed that p24 was predominantly associated with follicular dendritic cells. Essentially the same findings were observed in the lymph nodes irrespective of risk group. Possible mechanisms involved in follicular involution in HIV-related lymphadenopathy are discussed.

AIDS-Related Complex↗

PubMed1988

Decreased blood natural killer cell activity and immunoglobulin synthesis in vitro in aplastic anemia.

Natural killer (NK) cell numbers and T lymphocyte subpopulations in peripheral blood were evaluated in six patients with aplastic anemia (AA). The immunophenotyping results were correlated to in vitro tests of NK cell cytotoxicity against K562 cells and of immunoglobulin (Ig) production after pokeweed mitogen (PWM) stimulation. A significant decrease was found both in the percentage of Leu 11 positive cells and in NK cell activity as compared to age- and sex-matched healthy controls. The decrease in NK cell activity could not be entirely compensated by an increase in effector/target cell ratios, thus suggesting not only a quantitative but also a functional defect in NK cells of the AA patients. Three of four AA patients tested showed no major increase of Ig production after PWM stimulation. All these three patients also had fewer "functional T helper" cells (Leu3+/Leu8-) and increased numbers of T suppressor/cytotoxic cells (Leu2+) when compared to controls. No significant differences in numbers of B lymphocytes (B1+) could be found. Our findings suggest a possible linkage between quantitative and qualitative abnormalities in lymphocyte subsets in aplastic anemia. However, no evidence was found to support the hypothesis of increased NK cell activation behind the hemopoietic depression in this disease.

Adolescent↗

PubMed1988

Resistance of some leukemic blasts to lysis by lymphokine activated killer (LAK) cells.

Peripheral blood mononuclear cells (PBMC) from healthy donors and AML patients in remission were stimulated with phytohemagglutinin (PHA) and recombinant interleukin-2 (IL-2). These stimulated cells (lymphokine activated killer (LAK) cells) showed increased DNA synthesis as measured by 3H-Thymidine uptake. A synergistic effect of PHA and IL-2 was found. LAK cells' ability to kill acute myeloid leukemia (AML) blasts was investigated by the 51Cr release assay. LAK cells showed a cytotoxicity (over 10% specific 51Cr release) against 9/12 leukemic blasts, even at effector/target (E/T) ratios as low as 5:1. However, on average only 22.2% (SD 11.8) and 36.5% (SD 12.5) 51Cr release were obtained in 4- and 18-hour cytotoxicity assays, respectively, at an E/T ratio of 20:1. Leukemic blasts in 3/12 AML cases and normal PBMC were entirely resistant to lysis, even at an E/T ratio of 80:1. Susceptibility to lysis was not correlated to peanut-agglutinin receptor expression. LAK cells were more cytotoxic towards the K-562 cell line (natural killer activity) than unstimulated PBMC.

Cell Line↗

PubMed1988

Method to quantitate intestinal metaplasia of stomach by image analysis.

With the aid of an image quantifier, the distribution of histochemically labelled (alcian blue, pH 2.5) mucin-producing goblet cells was recorded from a gastrectomy specimen with a peptic ulcer to determine the degree of metaplasia. Of 254 measurements made, 130 were in the antrum and 124 in the fundic area. The areas occupied by cells positive for alcian blue were 7.5 (SD 9.89)% in the antral region, and 1.8 (1.84)% and 0.92 (1.15)% in the two zones representing the fundic area. The difference between the positive mucosal areas in the antrum was significantly higher (p less than 0.001) than in the fundic area. The positively stained area found along the lesser curvature was 7.76 (12.0)% while along the greater curvature, it was 2.17 (3.02)% (p less than 0.001). This method will be useful for future studies of the extent and topographical distribution of intestinal metaplasia among populations with disparate incidences of gastric carcinoma because it permits comparison of different areas of intestinal metaplasia in mucous gastric zones.

Gastric Fundus↗

PubMed1988

The effect of a calf thymus acid lysate on bone marrow cell growth in vitro.

Granulocyte-macrophage colony forming units (CFU-GM) were studied in cultures of bone marrow from 16 apparently healthy normal controls, 9 patients with the myelodysplastic syndrome, 5 patients with myeloproliferative disease and 2 with myeloma. Supernatants from non-stimulated 72 hr cultures of nonadherent mononuclear blood cells ("lymphocytes") stimulated the forming of an average of 38.4 colonies per 100,000 cells from normal marrow. The addition of GIBCO's commercial conditioned medium or of a medium produced by lymphocytes stimulated with different concentrations (5, 10 and 20 mcg/ml) of an acid lysate of thymus (thymomoduline), increased growth to 65.2 - 55.4 colonies (p less than 0.001 to 0.05). Similarly, a significant increase (p less than 0.05) was found in the number of clusters and colonies formed in cultures of marrow from patients with the myelodysplastic syndrome. In contrast, no growth was found when the thymus acid lysate was added directly to the bone marrow cultures, suggesting that the lysate induces the production of colony stimulating activity by lymphocytes, but does not contain it. Similarly no significant increase was found as regards the initially high number of colonies from the five patients with myeloproliferative disease, or as regards the initially low number in the two myeloma patients.

Adult↗

PubMed1988

Lymphadenopathy in HIV (HTLV-III/LAV) infected subjects: the role of virus and follicular dendritic cells.

Studies of human immunodeficiency virus (HIV) associated lymphadenopathy by histopathology and immunopathology showed conspicuous changes of follicular B-cell areas from a marked hyperplasia to complete involution. Immunohistochemistry showed a corresponding increase in follicular dendritic reticulum cells (FDRC) followed by progressive destruction of these cells during involution, concomitant with invasion of follicles by T-cells. HIV gag antigens were predominantly associated with FDRC in hyperplastic follicles and diminished during involution. Virus replication was by in situ hybridization seen predominantly in follicles, presumably reflecting productive infection of CD4+ cells and/or FDRC. It is concluded that local effects of the virus play an important role in HIV lymphadenopathy. The marked cytopathogenic effects on FDRC indicate that HIV infection with lymphadenopathy represents not only a disease of CD4+ cells but also of follicular antigen presenting cells (FDRC).

AIDS-Related Complex↗

PubMed1988

Effect of phytohemagglutinin and interleukin-2 on malignant and nonmalignant B and T lymphocytes.

Peripheral blood mononuclear cells (PBMC) from patients with acute myeloid leukemia (AML) or non-Hodgkin lymphoma (NHL) and healthy controls were stimulated with phytohemagglutinin (PHA) and interleukin-2 (IL-2). PHA (1 microgram/ml) induced higher 3H-thymidine incorporation than 800 U/ml IL-2 in PBMC from both controls and patients with AML in complete remission. A synergistic effect between PHA and IL-2 was found. Malignant B cells from 5/12 NHL expressed IL-2 receptors and showed proliferative response to IL-2, but not to PHA. PHA induced higher cytotoxicity toward AML blasts in lymphocytes from healthy controls than did IL-2. In addition, PHA induced higher cytotoxicity in lymphocytes from healthy controls than in those from patients with AML in remission. In contrast, no difference in cytotoxicity between controls' and patients' lymphocytes was found after stimulation with IL-2. No HLA restriction could be demonstrated. Normal peripheral blood mononuclear cells and leukemic blasts from 2/12 AML were completely resistant to cytotoxic cells even at effector:target ratios four times as high as those otherwise required.

B-Lymphocytes↗

PubMed1988

Quantitation of fibrosis in liver biopsies.

After 15 years of subjectively estimating the degree of fibrosis in liver biopsies stained with Sirius red F3BA, the amounts of Sirius red-stained fibrotic areas were quantitated with the help of a Cortex IQ 130 image quantifier. The percentage of Sirius red-stained areas was lowest in normal livers, increasing significantly in fatty livers, with stepwise higher values in chronic persistent hepatitis, toxic damage, chronic active hepatitis, fatty livers with obvious fibrosis, biliary cirrhosis and portal cirrhosis. Cases of portal cirrhosis had tenfold higher values than did normal livers. The results indicate that Sirius red is a reliable histochemical stain that can be used to quantitatively demonstrate the various degrees of fibrosis in liver biopsies.

Biopsy↗

PubMed1987

Cyclosporine A treatment in four cases of aplastic anemia.

Cyclosporine A (CyA) treatment of 4 patients with severe aplastic anemia, who were ineligible for bone marrow transplantation, was carried out for periods of between 12 weeks to 20 months. A normalization of Hb and bone marrow, together with a marked improvement in WBC and platelet counts, were observed in only one of these four patients. The remission was maintained for 20 months under continuous treatment. A relapse occurred only when the patient himself interrupted treatment. No serious side effects were observed with CyA doses of 4-10 mg/kg/daily and blood concentrations of 200-400 ng/ml. No significant changes in T helper/T suppressor ratios were noted during the course of CyA treatment.

Anemia, Aplastic↗