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Biomedical subjects

Y Badrinath

Publications and source records attributed to Y Badrinath.

13 recordsLinked to original sources

Betulinic acid induces apoptosis in human chronic myelogenous leukemia (CML) cell line K-562 without altering the levels of Bcr-Abl.

Betulinic acid (BA), a plant derived triterpenoid, isolated from various sources shows cytotoxicity in cell lines of melanoma, neuroectodermal and malignant brain tumors. Chronic myelogenous leukemia (CML) is characterized by Philadelphia chromosome (Bcr-Abl), a molecular abnormality leading to the intrinsic tyrosine kinase activity that provides growth and survival advantage to the cells. Present study describes the cytotoxicity of BA on human CML cell line K-562, positive for Bcr-Abl. The decrease in the viability of K-562 cells treated with BA at different concentrations and time intervals was assessed using MTT assay. Cell death induced by BA was determined to be apoptotic as measured by FACS analysis of PI stained nuclei, PS externalization by Annexin-V fluorescence and characteristic DNA fragmentation. DiOC6(3) fluorescent probe determined alterations in the mitochondrial membrane potential (MMP). RT-PCR confirmed the expression levels of Bcr-Abl in controls and K-562 cells treated with BA. The rapid loss of MMP of K-562 cells upon treatment with BA shows the direct activation of apoptosis at the level of mitochondria, overcoming the resistance of the high levels of expression of Bcr-Abl.

Annexin A5↗

Protection of Ewing's sarcoma family tumor (ESFT) cell line SK-N-MC from betulinic acid induced apoptosis by alpha-DL-tocopherol.

Betulinic acid (BA) is known to induce apoptosis in melanoma neuroectodermal and malignant brain cancer cell lines. Present report describes the role of antioxidants on the BA-induced toxicity to human cell line SK-N-MC. Hydrophilic antioxidants viz., L-ascorbic acid (VitC) and N-acetyl-L-cysteine (l-NAC) had no protective effect on BA-induced apoptosis at the maximal concentrations tested. The lipophilic antioxidant, alpha-DL-tocopherol (VitE) showed a concentration and a time dependent effect on the protection of SK-N-MC cells from BA-induced apoptosis. The apoptotic parameters were analyzed using FACS analysis of propidium iodide (PI) stained nuclei, PS externalization using Annexin-V assay and changes in mitochondrial membrane potential. Generation of superoxide radical was monitored by the fluorescent dye hydroethidium (HE). Cells showed Annexin-V positivity and an increase in the propidium iodide (PI) uptake in the early hours of treatment with BA, which was concomitant with the loss of mitochondrial membrane potential. Addition of alpha-DL-tocopherol to the cell cultures 1-h prior to the treatment with BA abolished all the effects of BA-induced apoptosis. These observations suggest that BA initiates events at membrane level leading to induction of apoptosis. The observed ineffectiveness of hydrophilic antioxidants and substantial protection by lipophilic antioxidants indicate involvement of membrane-associated damages that form the basis of BA-induced cytotoxicity.

Acetylcysteine↗

Leukemia in infants.

OBJECTIVE: Acute Leukemia is rare in infants. It is characterized by non-specific symptomatology requiring a high index of suspicion on the part of a pediatrician for referral and diagnosis. It has peculiar biological features, unresponsiveness to treatment and poor prognosis. METHODS: Eighteen infants with acute leukemia were seen during 1994 to 2001 and were analyzed on the basis of clinical and laboratory data. There were 13 cases of Acute Lymphoblastic Leukemia (ALL), 4 cases of Acute Myeloid Leukemia (AML) and one case remained unclassifiable, as the surface markers could not be done. Morphologically 9/13 cases of ALL were of FAB L1 type and remaining of L2 subtype, and 2/4 cases of AML were of FAB M1 type and remaining of M2 subtype. RESULT: Clinical data was available completely only in 11 cases. Hyperleucocytosis was present in 4 cases, organomegaly in 8 cases and lympadenopathy in 5 cases. One patient presented with a chloroma in the retrorbital region although there was no parenchymal involvement of the brain. Immunophenotyping could be done in 13 cases, where 7 cases were diagnosed as CALLA positive-ALL (HLADR+, CD19+, CD10+), 2 cases as Early Pre-B ALL (HLADR+, CD19+, CD10 negative), one as T ALL (cCD3+, CD2+, CD7+) and 3 cases as AML (CD13+, CD33+, HLADR+). None of our patients received treatment.

Female↗

Production & evaluation of a monoclonal antibody against human myeloperoxidase.

We describe the production of a mouse monoclonal antibody (H2E1) against human myeloperoxidase antigen. After production and characterisation, this antibody was compared with commercially available monoclonal antibodies, cytochemical myeloperoxidase and previously produced polyclonal antibody. Reaction with various cell lines proved that this monoclonal antibody was specific for myeloid lineage. This monoclonal showed positivity in 81.8 per cent of acute myeloid leukaemias whereas the polyclonal antibody was 100 per cent positive. We found that the polyclonal antibody was more sensitive as compared to the monoclonal. This is probably due to the lack of recognition of individual epitopes on the antigen. We recommend the use of antibodies which have different epitope recognition as most specific for myeloperoxidase.

Animals↗

Hairy cell leukemia--an unusual presentation.

Hairy cell leukemia is a chronic lymphoproliferative disorder affecting middle-aged adults, with the median age of 50-55 years. The majority of the patients present with cytopenia. A high count is usually a feature of the hairy cell leukemia variant. We report a case of a 23-year-old male who presented with fever and cough of 15 days duration. His peripheral blood count was 63 x 10(9)/l. His peripheral blood and bone marrow smear showed hairy cells which were positive for tartarate-resistant acid phosphatase stain. Surface markers and electron microscopic study on peripheral blood ruled out hairy cell leukemia variant as a differential diagnosis.

Adult↗

Calla positive acute lymphoblastic leukemia after etoposide-based therapy for Ewing's sarcoma.

This is an unusual and interesting case report concerning a 10 year old boy with an initial diagnosis of Ewing's sarcoma of the right tibia. He was successfully treated with a chemotherapy regimen consisting of vincristine, cyclophosphamide (cumulative dose 7200 mg/m2), doxorubicin, etoposide (cumulative dose 2700 mg/m2) and cisplatin and local radiotherapy to the tibia. After an interval of 37 months he developed CALLA positive acute lymphoblastic leukemia with 11q23 chromosomal abnormality. The possible roles of etoposide and cyclophosphamide are discussed.

Antineoplastic Combined Chemotherapy Protocols↗

Evaluating efficiency of bone marrow harvest and its manipulation--role of CD 34 positivity.

We evaluated harvested marrow cells for total nucleated cells (27.49 x 10(9)), absolute 'lymphocyte' count (6.29 x 10(9)) and CD 34 positive cells (3.57 x 10(9)). The same parameters were studied after in vitro manipulation to remove RBCs and plasma. Reinfused WBCs contained 12.87 x 10(9) nucleated cells, 4.25 x 10(9) absolute 'lymphocyutes' and 3.34 x 10(9) CD 34 positive cells. The corresponding figures for loss during in vitro manipulation (tubing, RBCs and plasma) are 14.62 (53.18%), 2.04 (32.43%) and 0.23 x 10(9) (6.44%) cells respectively. Therefore CD 34 positivity may be a better indicator of total yield, loss during manipulation and reinfusion of hemopoietic progenitor cells in bone marrow transplantation.

Antigens, CD34↗

Acute non-lymphocytic leukemia with expression of surface antigen CD7--morphological, cytochemical, immunological and ultrastructural features in eight patients.

Of late, there has been an increase in the number of acute leukemias coexpressing markers believed to be restricted to a single lineage. Eight patients with ANLL whose blast coexpressed the T cell associated CD7 antibody were identified among 462 consecutive ANLL cases. Seven had FAB defined AML according to morphocytochemical criteria, whereas one patient was classified as MO on the basis of ultrastructural studies. The incidence of CD7 positivity was particularly significant in the less differentiated sub-types MO and M1 compared to other FAB sub-groups. Detailed long term studies will be required to realize their biological and clinical significance.

Adolescent↗

Minimally differentiated acute myeloid leukemia: a morphologic, cytochemical and ultrastructural study.

Seven of 368 cases of acute myeloid leukemia (AML) could not be subclassified by routine morphologic, cytochemical and immunologic analyses during the period January 1989 to December 1990. Further investigations including ultrastructural examination, anti-myeloperoxidase and myeloid specific antigen analysis were carried out in all these patients and they were classified as AML-MO, as per the FAB criteria. Morphologically these blasts resembled ALL-L2/AML-M1. Cytochemically they were negative for Sudan black, myeloperoxidase, periodic acid-Schiff, and non-specific esterase. On initial immunophenotypic analysis, they could not be classified into B, T or myeloid lineages. Further investigations revealed CD13 and CD33 positivity in 4 of 6 patients. Anti-myeloperoxidase was positive in 6 of 6 patients and ultrastructural examination revealed myeloperoxidase-positive blasts in 6 of 7 cases. Cytogenetic analysis done in one patient revealed 60% abnormal metaphases. Six of 7 cases were treated with aggressive chemotherapy. One patient achieved complete remission but relapsed after 6 months, whereas others were resistant to treatment. Hence we conclude that an aggressive investigative and therapeutic approach is required to identify and treat AML-MO.

Acute Disease↗

Characterisation of blast cells during blastic phase of chronic myeloid leukaemia by immunophenotyping--experience in 60 patients.

The blast cell population of 60 patients with chronic myeloid leukaemia in blast crisis (CML-BC) were analyzed with a panel of monoclonal antibodies to determine the cell surface antigen phenotypes. In addition, cytochemical stains periodic acid Schiff (PAS), myeloperoxidase (MP), Sudan black B (SBB) and terminal deoxynucleotidyl transferase (TdT) were also utilized for subtyping. Nineteen cases (31.6%) expressed lymphoid phenotypes characteristic of common ALL cells and one case with extramedullary lymph node crisis expressed T-cell surface phenotypes. Thirty cases (50%) expressed solely myelomonocytic surface antigens with significant TdT activity in three. Cytochemical stains contributed to recognize only 57% of these myeloid blasts. Seven cases (11.7%) were with a mixture of heterogenous group of cells expressing phenotypic characteristics for various haemopoietic cells of different lineage--five of them from the cells of non-lymphoid series (myelomono-erythromegakaryocytic series) and the other two with cells from both lymphoid and myeloid series. Additionally, in two cases (3.3%), the precursor cells reacted only with the erythroid monoclonals. Finally, in one case, the blast cells remained unclassified due to nonreactivity with any of the monoclonals used but expressed significant TdT positivity. The response to uniform vincristine and prednisolone (V + P) therapy has shown that lymphoid blast crisis cases were highly responsive in contrast to the cases with non-lymphoid blast crisis (complete remission rate 86 vs 21.4%). The results confirm the evidence of multilineage blast crisis involving either single or mixed haemopoietic differentiation pathway and the utility of having phenotypic characterisation for designing protocols for chemotherapy in the CML patients at the time of blast crisis.

Adolescent↗

Terminal deoxynucleotidyl transferase in acute leukemias by direct immunofluorescence.

TdT (terminal deoxynucleotidyl transferase) can be detected by radio enzymatic assay, biochemical assay in cell extracts, serum or plasma, and intracellularly in the smear by indirect immunofluorescent methods. The IgG fraction of anti-TdT serum is conjugated with fluoresceinisothiocyanate and used directly on the cytospin smears of methanol fixed bone marrow/blood smears. The mice thymocytes and peripheral mononuclear cells of healthy donors were used as positive and negative controls, respectively, for TdT. 64% of our cases of ALL were found to be TdT+. The lymphoblasts of L1 morphology (FAB classification) were more frequently positive for TdT as compared to blasts with L2 morphology. 71% of our cALLa positive blasts in acute lymphoblastic leukemias were TdT+ve as compared to 58% of T-ALL blasts. 75% of PAS positive ALL cases were positive for TdT as well. Only 57% of the cases when acid phosphatase showed unipolar positivity (T type) were positive for TdT. 12% of cases with acute myeloid leukemia (6/47) were TdT+ve and 33% of CML in blastic crisis had TdT+ve blasts. Biochemical assay and IF assay for TdT were in good correlation in our study.

Bone Marrow↗

Haematologic and immunophenotypic profile of acute myeloid leukemia: an experience of Tata Memorial Hospital.

OBJECTIVES: To study the hematologic and immunophenotypic profile of 260 cases of acute myeloid leukemia at diagnosis. MATERIAL AND METHODS: This is a retrospective analysis of 260 cases of AML diagnosed at our institution between 1998 and 2000. Diagnosis was based on peripheral blood and bone marrow examination for morphology cytochemistry and immunophenotypic studies. SPSS software package, version 10, was used for statistical analysis. RESULTS: Seventy-six percent of our cases were adults. The age of the patients ranged from one year to 78 years with a median age of 27.2 years. There were 187 males and 73 females. The commonest FAB subtype, in both children and adults, was AML-M2. The highest WBC counts were seen in AML-M1 and the lowest in AML-M3 (10-97 x 10(9)/L, mean 53.8 x 10(9)/L). The mean values and range for hemoglobin was 6.8 gm/l (1.8 gm/l to 9.2 gm/l), platelet count 63.3 x 10(9)/L (32-83 x 10(9)/L), peripheral blood blasts 41.4% (5 to 77%) and bone marrow blasts 57.6% (34-96%). Myeloperoxidase positivity was highest in the M1, M2 and M3 subtypes. CD13 and CD33 were the most useful markers in the diagnosis of AML. CD14 and CD36 were most often seen in monocytic (38%) and myelomonocytic (44%) leukemias. Lymphoid antigen expression was seen in 15% of cases. CD7 expression was the commonest (11%). CONCLUSION: AML accounted for 39.8% of all acute leukemias at this institution. The most common subtype was AML-M2. Myeloperoxidase stain was a useful tool in the diagnosis of myeloid leukemias. CD13 and CD33 were the most diagnostic myeloid markers.

Adolescent↗