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Biomedical subjects

A Glassman

Publications and source records attributed to A Glassman.

At least 19 recordsLinked to original sources
PubMed2002

Comparison of competitive-nested PCR and real-time PCR in detecting BCR-ABL fusion transcripts in chronic myeloid leukemia patients.

Real-time RT-PCR has great advantages for estimating transcript levels in a variety of situations. These include relative rapid assay times (hours), reliability and ease of performing replicate analyses. In contrast, competitive PCR is a very labor-intensive procedure requiring a few days to generate useful data. We compared the same samples from CML patients by both methods. Importantly, we used the Bcr-Abl junction plasmid DNA, which is used as a competitor in the manual competitive PCR assay, to generate a standard curve for the real-time assay. This permitted reporting the real-time data as the number of BCR-ABL transcripts per microg of total RNA, which is the same format used for the competitive PCR assay. In this study, a total of 435 peripheral blood and marrow samples from 285 CML patients were analyzed by RT-PCR; these patients were undergoing therapy by STI-571, interferon, and bone marrow transplantation treatment. Most samples also had assay values for the Philadelphia chromosome (Ph), FISH and Western blotting for the Bcr-Abl oncoprotein. Our findings indicated that the real-time assay was less sensitive than the manual competitive RT-PCR assay (t = 5.118; P < 0.001). Of interest, the transcript levels in cell line mixtures with various ratios of K562/KG-1 (BCR-ABL positive/negative) cells were also significantly higher with the competitive RT-PCR assays than real-time RT-PCR, except for levels of BCR-ABL below 200 transcripts per microg of RNA. In both patient and cell line experiments, dividing the BCR-ABL transcripts by the total ABL transcripts virtually eliminated the difference between real-time BCR-ABL transcript values and quantitative competitive BCR-ABL transcript values, indicating that both BCR-ABL and ABL transcripts were underestimated by the real-time assay. In addition, the increased sensitivity of the nested, competitive RT-PCR was readily apparent in patients with minimal residual disease, which by the real-time were negative in the majority of patients but were positive by nested, competitive RT-PCR in 44.6% (n = 29) of samples analyzed (n = 65). These findings indicate that real-time RT-PCR, when normalized for the total ABL transcripts, can be used to monitor CML patients during therapy, but we suggest that nested, competitive RT-PCR be used to determine BCR-ABL/ABL transcript ratios at low transcript values or especially when real-time analyses are negative.

Fusion Proteins, bcr-abl↗
PubMed2002

Quantitative measurement of BCR/abl transcripts using real-time polymerase chain reaction.

BACKGROUND: Quantitative real-time polymerase chain reaction (Q-Rt-PCR) is a new tool in the detection and quantification of the BCR/abl fusion transcripts in chronic myelogenous leukemia (CML). This study investigates its specificity, sensitivity and potential clinical usefulness. PATIENTS AND METHODS: Parallel analysis of Q-Rt-PCR and the conventional reverse transcription-mediated PCR (RT-PCR) were performed on 567 samples from 481 patients. Treatment response was monitored by Q-Rt-PCR at 6 and 12 months of 61 patients on STI-571 and 103 patients on interferon. RESULTS: The concordance rate between Q-Rt-PCR and RT-PCR was 96.3% (546/567), with 341 positives and 205 negatives. The positive equivalents ranged from 2 x 10(-6) to 1.2 microg of K562 cell RNA. Karyotyping in 372 samples revealed excellent correlation with Q-Rt-PCR measurements (P < 0.001). Setting residual BCR/abl < 0.01 as an early goal of molecular response, we observed that STI-571 induced a better response than interferon: 49% (20 of 41 patients) versus 35% (15 of 62 patients) at 6 months (P = 0.025) and 52% (32 of 61 patients) versus 34% (35 of 103 patients) at 12 months (P = 0.01), respectively. CONCLUSIONS: Q-Rt-PCR provides reliable measurements of BCR/abl fusion transcripts. It is potentially useful in assessing molecular residual disease after therapy.

Base Sequence↗
PubMed2001

Spectral karyotyping study of chromosome abnormalities in human leukemia.

Chromosomal analysis plays an important role in the diagnosis, treatment and prognosis of human leukemia. Currently, the GTG-banding technique (G-banding) is the most commonly used diagnostic method in clinical cytogenetics. G-banding analysis of subtle chromosomal rearrangements or complex karyotypes with multiple markers can be inadequate because of poor chromosome morphology and/or an insufficient yield of analyzable metaphases. Fluorescence in situ hybridization (FISH) is a highly sensitive and specific method to detect chromosomal alterations. Conventional FISH is used optimally in instances where only one or a few abnormalities are investigated. Spectral karyotyping (SKY), a novel cytogenetic technique, has been developed to unambiguously display and identify all chromosomes at one time using a spectrum of 24 different colors. This report presents the use of SKY for examination of the entire karyotype in specimens with complex chromosomal abnormalities from three leukemia patients. Conventional cytogenetic analysis (G-banding) showed complex hyperdiploid clones with multiple markers in each case. SKY was able to clarify and identify additional cryptic chromosomal translocations [e.g., t(2;10), t(3;10), t(5;7), t(7;18), t(9;17), t(10;12), t(13;16)] insertions [e.g., ins(17;9), ins(20;Y)], duplications [e.g., i(8)(q10), dup(4)(q31q35)] and marker chromosomes in each case. This study demonstrates that the combination of SKY and G-band techniques results in a more complete characterization of the complex chromosomal aberrations seen in leukemia.

Bone Marrow Cells↗
PubMed2001

Cytogenetic findings in lymphoplasmacytic lymphoma/Waldenström macroglobulinemia. Chromosomal abnormalities are associated with the polymorphous subtype and an aggressive clinical course.

We correlated bone marrow cytogenetic findings with morphologic and immunophenotypic data in 37 patients with lymphoplasmacytic lymphoma (LPL)/Waldenström macroglobulinemia (WM). Each LPL/WM case was classified as lymphoplasmacytoid (n = 18), lymphoplasmacytic (n = 10), or polymorphous (n = 9) using the Kiel criteria. Of 12 cases with chromosomal abnormalities, a single numeric abnormality was present in 4 and a complex karyotype in 8. The most common numeric abnormalities were and -8 in 3 cases each; the most common structural abnormality was del(6q) in 6 cases. Cytogenetic abnormalities were significantly less common in the lymphoplasmacytic and lymphoplasmacytoid groups (5/28 [18%]) compared with the polymorphous group (7/9 [78%]). Clinical follow-up was available for 28 patients for a median of 36 months. Six (67%) of 9 patients with aneuploid tumors, including 4 with polymorphous subtype, subsequently had clinical progression or developed high-grade lymphoma. In contrast, 4 (21%) of 19 patients with diploid tumors, including 1 of polymorphous type, developed clinical progression or high-grade lymphoma. We conclude that abnormal cytogenetic findings in LPL/WM correlate with the polymorphous subtype and poor prognosis.

Adult↗
PubMed2001

Mature B-cell leukemias with more than 55% prolymphocytes. A heterogeneous group that includes an unusual variant of mantle cell lymphoma.

We studied 20 cases of mature B-cell leukemia with more than 55% prolymphocytes in peripheral blood or bone marrow, fulfilling the French-American-British criteria for B-cell prolymphocytic leukemia (PLL). Cases segregated into 3 groups: de novo PLL, 6; PLL occurring in patients with a previous well-established diagnosis of chronic lymphocytic leukemia (PLL-HxCLL), 10; and t(11;14)(q13;q32)-positive neoplasms, 4. All cases expressed monotypic immunoglobulin light chain, and most were positive for CD5. All t(11;14)-positive neoplasms were CD23- and uniquely positive for cyclin D1. Cytogenetic abnormalities were present in 19; in all 19, the karyotype was complex, indicating clonal evolution and genomic instability. The most frequent cytogenetic abnormality in de novo PLL involved chromosome 7 in 4 cases. Trisomy 12 or add(12p) was present in 4 cases of PLL-HxCLL. We conclude that mature B-cell leukemias with more than 55% prolymphocytes are a heterogeneous group that includes t(11;14)-positive neoplasms, which we suggest are best classified as mantle cell lymphoma. We also suggest that prolymphocytic morphologic features are a common end-stage of transformation for several B-cell neoplasms.

Aged↗
PubMed2000

Enhanced detection of chromosomal abnormalities with the use of RxFISH multicolor banding technique.

Hematological disorders often have complex karyotypes with multiple markers. Proper assignment of chromosome number or aberration or both can be difficult. Specific identification of chromosomal abnormalities aids in the diagnosis and selection of treatment of patients. Fluorescence in situ hybridization (FISH) has been applied to the identification of translocations, markers, and other chromosomal abnormalities in clinical cytogenetics. However, the standard FISH technique is unable to detect the entire genome in a single experiment. This report presents the use of a cross-species comparative genomic hybridization color-banding technique (RxFISH) that permits examination of an entire karyotype at one time. Specimens from two patients, one with acute lymphocytic leukemia (ALL) and the other with multiple myeloma (MM), were studied. Metaphases were prepared by standard culture techniques. Conventional cytogenetic analysis (GTG banding) showed multiple clones in each of the cases. These clones were hyperdiploid metaphases with complex chromosomal abnormalities and multiple markers. The slides were then hybridized with FITC-, Cy-3-, and Cy-5-labeled RxFISH probes; the results were analyzed by a digital imaging system. The RxFISH color banding confirmed the hyperdiploid metaphases and identified multiple chromosomal abnormalities. In the specimen from the patient with ALL, several chromosomes, which had been classified as markers by G-banding, were found to be specific chromosomes. This study suggests that RxFISH can provide more accurate and specific identification of complex chromosomal abnormalities. RxFISH is a useful complement to the clinical cytogenetic laboratory armamentarium.

Bone Marrow↗
PubMed2000

11q23 abnormalities in patients with acute myelogenous leukemia and myelodysplastic syndrome as detected by molecular and cytogenetic analyses.

11q23 chromosomal abnormalities and rearrangement of the mixed lineage leukemia (MLL) gene are important prognostic factors in acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS). However, the presence of 11q23 abnormalities does not always correlate with that of MLL gene rearrangement. We retrospectively compared the occurrence of 11q23 abnormalities (measured by karyotyping) and MLL gene rearrangement (measured by Southern blotting) in bone marrow from 311 consecutive adult patients with AML or MDS. 11q23 abnormalities were found in 18 patients (5.8%), of whom 7 (39%) did not have the MLL gene rearrangement. MLL gene rearrangement was detected in 35 patients (11.2%). Of these 35 patients, only 11 (31%) had cytogenetic evidence of 11q23 abnormalities. None of the 21 patients with chronic myelomonocytic leukemia had 11q23 abnormalities or MLL gene rearrangement. 11q23 abnormalities were associated with shorter survival than was a diploid karyotype. Both cytogenetic and molecular studies should be performed to detect 11q23 abnormalities in patients with AML or MDS.

Adolescent↗
PubMed1999

Deletions and losses in chromosomes 5 or 7 in adult acute lymphocytic leukemia: incidence, associations and implications.

Deletions or losses in chromosomes 5 or 7 are recurrent non-random abnormalities in acute myeloid leukemia (AML), and are associated with prior exposure to carcinogens or leukemogenic agents, and with poor prognosis. Their occurrence and significance in adult acute lymphocytic leukemia (ALL) is not well described. The aim of the study was to evaluate the incidence, associations and implications of chromosome 5 or 7 abnormalities in adult ALL. Patients with newly diagnosed ALL referred to MD Anderson Cancer Center between 1980 and 1996 were analyzed. Characteristics and outcome of patients with or without chromosome 5 or 7 abnormalities were compared by standard statistical methods. Thirty-one of 468 patients (6.6%) had chromosome 5 or 7 abnormalities. Loss of chromosome 5 occurred in six cases, three of them had both chromosome 5 and 7 abnormalities. Deletion or loss of chromosome 7 occurred as a single abnormality in three patients; in 28 patients it was associated with other abnormalities. The most significant cytogenetic association was with the Philadelphia chromosome (Ph) abnormality occurring in nine patients (29%). Compared with patients without the abnormalities, patients with chromosome 5 or 7 abnormalities tended to express CD34 more frequently (74% vs 54% P = 0.07), to be older (age >60 years 29% vs 18% P = 0.14), and to be associated with Ph (29% vs 11% P = 0.004). With therapy, the complete response (CR) rate with chromosome 5 or 7 abnormalities was lower (64% vs 79% P = 0.038) but the survival rate was similar (3-year survival rate 32% vs 36% P = 0.14). When the 22 patients without Ph were considered separately, the CR and survival rates were similar among patients with or without chromosome 5 or 7 abnormalities. Abnormalities in chromosome 5 or 7 are not specific for AML, and may occur in ALL. Unlike in AML, chromosome 5 or 7 abnormalities in ALL were not predictive of worse prognosis, which is accounted for mostly by the association with Ph.

Adolescent↗
PubMed1999

Political analysis of health reform in the Dominican Republic.

This article examines the major political challenges associated with the adoption of health reform proposals, through the experience of one country, the Dominican Republic. The article briefly presents the problems of the health sector in the Dominican Republic, and the health reform efforts that were initiated in 1995. The PolicyMaker method of applied political analysis is described, and the results of its application in the Dominican Republic are presented, including analysis of the policy content of the health reform, and assessment of five key groups of players (public sector, private sector, unions, political parties, and other non-governmental organizations). The PolicyMaker exercise was conducted in collaboration with the national Office of Technical Coordination (OCT) for health reform, and produced a set of 11 political strategies to promote the health reform effort in the Dominican Republic. These strategies were partially implemented by the OCT, but were insufficient to overcome political obstacles to the reform by late 1997. The conclusion presents six factors that affect the pace and political feasibility of health reform proposals, with examples from the case of the Dominican Republic.

Developing Countries↗
PubMed1998

A simple efficient method of sequential G-banding and fluorescence in situ hybridization.

Several methods of chromosome identification to be used in combination with G-banding by the trypsin technique with Giemsa staining (G-banding) and fluorescence in situ hybridization (FISH) have been developed in the past few years. Unfortunately, these methods are impractical to use in the clinical laboratory and can provide inconsistent results. We report a simple, efficient, and reliable method of G-banding and FISH for use in clinical cytogenetics. G-banded chromosomes are codenatured with a direct- or indirect-labeled DNA prove (by using either chromosome painting or a chromosome centromeric probe) followed by a hybridization and signal detection. The procedure requires no pretreatment or additional fixation and results in good preservation of chromosome morphology and good intensity of the FISH signal.

Azure Stains↗
PubMed1998

Prognostic value of cytogenetics in multiple myeloma.

Karyotypic studies of bone marrow were conducted in 79 previously untreated patients with multiple myeloma who received a standard programme of chemotherapy. An abnormal karyotype was observed in 46% of patients, virtually all showing multiple abnormalities consistent with a long period of preclinical clonal evolution. Patients with an abnormal pattern showed various aberrations with hyperdiploidy in 64%, pseudodiploidy in 5% and hypodiploidy in 31%. The number of chromosomes affected ranged from two to 19 (median 10), with at least one trisomy in 83%, one monosomy in 75%, and one translocation in 42% of patients. Lymphoma-like karyotypes were present in 17% of patients with an abnormality but were not associated with atypical clinical features, such as an extramedullary mass, leukaemia, or increased serum lactate dehydrogenase. Monosomy or deletion of chromosome 13 was present in 47% of patients with an abnormal pattern, who lived for a shorter duration (median 10 months) than patients with other abnormalities (median 34 months) or with diploidy (median 35 months). The cause of the short survival of patients with monosomy or deletion of chromosome 13 was not clear, but further studies on the relationship with specific oncogenes are indicated.

Bone Marrow Cells↗
PubMed1998

Philadelphia chromosome-positive myeloid cells in the peripheral blood of chronic myelogenous leukemia patients: comparison with the frequency detected in cycling cells of the bone marrow.

Monitoring the frequency of the Philadelphia (Ph) chromosome in chronic myelogenous leukemia (CML) is important in determining the effectiveness of treatment for patients during therapy. This can be done with high resolution by subjecting short-term bone marrow cultures (48 h) to 24 h of mitotic arrest before harvest and detecting Ph-positive (Ph+) metaphases by fluorescence in situ hybridization (FISH) in a procedure termed hypermetaphase FISH or HMF. Here, we compared procedures for detecting Ph+ interphase cells (interphase FISH or I-FISH) in peripheral blood polymorphonucleocytes (PMNs) with HMF results on the bone marrow of the same 26 CML patients in different stages of remission. The probes for I-FISH in these experiments were relatively large (200-300 kb) and sufficiently resolved in PMNs so that 97.5% of the cells were scorable. The correlation between the frequencies of Ph+ cells from the two different cell sources was excellent (r = 0.983, P < 0.0001); however, there was a consistently higher level of Ph+ cells observed in the cycling marrow cells than in the peripheral blood PMNs. This was discussed in terms of current theories of apoptosis in CML cells. The large number of PMNs analyzable by I-FISH (approximately 500/patient in this study) provided sufficiently narrow 99% confidence intervals to suggest the procedure as an effective and efficient method for monitoring the frequency of Ph+ cells in CML patients undergoing therapy. However, for detection and quantification of minimal residual disease, HMF is preferable to I-FISH because of the much lower frequency of false-positive readings with the former procedure.

Adult↗
PubMed1997

Diminished cardiac vagal tone in schizophrenia: associations to brain laterality and age of onset.

We measured high-frequency (rapid) heart rate variability (HRV) from 24-hour Holter electrocardiograms to index cardiovagal tone in 23 patients with DSM-III-R schizophrenia or schizoaffective disorder. High-frequency HRV, quantitated by measuring the percent of successive normal interbeat intervals greater than 50 msec (PNN50), demonstrated a bimodal distribution: 11 of 23 patients had a PNN50 of > and = 8.0 (mean value = 17.7 +/- 11.0), and 12 had a PNN50 of < and = 4.0 (mean value = 1.8 +/- 1.0); no subject had a PNN50 value between 4.0 and 8.0. All 12 low cardiovagal tone patients (versus only 6/11 of the other patients) had a schizophrenia (not schizoaffective) diagnosis (p = .013). PNN50 was not associated with present age, gender, smoking, IQ scores, or symptomatology, but patients with lower cardiovagal tone did have a significantly later age of onset (20.5 +/- 5.3 vs. 14.8 +/- 2.8 years: p = .005). PNN50 subgroups also differed on dichotic listening measures of brain laterality. The low group failed to show left ear (right hemisphere) advantage for complex tones seen in the other patients and normal adults. They also showed larger right ear (left hemisphere) advantage for dichotic words than the other patients. This evidence of relative right hemisphere disadvantage in patients with low cardiovagal tone is consistent with findings linking autonomic nervous system and right hemisphere function. These findings also support the existence of subgroups of schizophrenia patients differing in autonomic activity, brain laterality, and clinical features.

Adult↗
PubMed1997

Expression profile of MDM-2 proteins in chronic lymphocytic leukemia and their clinical relevance.

The MDM-2 oncoprotein exists in an autoregulatory feedback loop with the tumor suppressor protein p53. Therefore, intracellular levels of these two proteins may play important roles in cell proliferation and tumorigenesis. Several MDM-2 proteins (Mr 35-100 Kd) have been demonstrated in human cell lines. We report here the expression profile of MDM-2 and p53 proteins in 87 cases of chronic lymphocytic leukemia (CLL) as detected by immunoblot analysis. The MDM-2 proteins (p57, p59, p67, and p90) were found to be overexpressed in different combinations in 56/87 (64%) of cases of CLL when compared with normal volunteers. The MDM-2 protein p57 was predominantly overexpressed 46/87 (53%) in CLL. In 22/87 (25%) cases of CLL p57 was overexpressed alone, and in 24/87 (28%) cases it was co-overexpressed with other MDM-2 proteins p59/p67/p90. Six of the 87 cases of CLL showed overexpression of the tumor suppressor protein p53 by immunoblot analysis, and five of those cases also co-overexpress MDM-2 protein p57. No statistically significant correlation of MDM-2 protein overexpression to clinical disease stage and history of previous chemotherapy of CLL patients has been found. However, considering the oncogenic potential of overexpressed MDM-2 proteins, a possible role of MDM-2 proteins in the promotion of CLL disease remains to be evaluated.

Amino Acid Sequence↗
PubMed1997

Electron microscopic localization of lacZ expression in the proximal convoluted tubular cells of the kidney in transgenic mice carrying chimeric erythropoietin/lacZ gene constructs.

Regulated expression of the erythropoietin (EPO) gene in the adult kidney plays a key role in the regulation of erythropoiesis. However, uncertainty exists regarding the type of kidney cells involved in EPO gene expression. We previously showed by light microscopy that the lacZ reporter gene is expressed and inducible by hypoxia/anemia in the proximal convoluted tubular (PCT) cells of the kidneys of transgenic mice carrying the 5'-lacZ construct, in which the lacZ gene was placed downstream of a 7.0-kb mouse EPO gene segment containing 6.5 kb of the 5'-flanking sequence. We, report here the light and transmission electron microscopic examination of lacZ expression in the kidneys of transgenic mice carrying the 5'-lacZ construct and two additional constructs carrying the 6.5-kb 5'-flanking sequence with the body of the gene alone, or along with the 1.2-kb 3'-flanking sequence. The electron microscopic analyses unequivocally demonstrated that lacZ under the regulatory control of the 6.5-kb 5'-flanking sequence with or without the body of the gene and the 1.2-kb 3'-flanking sequence was expressed predominantly in the proximal convoluted tubular cells of the kidney following hypoxia induction.

Anemia↗
PubMed1997

Usefulness of detection of minimal residual disease by 'hypermetaphase' fluorescent in situ hybridization after allogeneic BMT for chronic myelogenous leukemia.

Hypermetaphase FISH (HMF), a molecular cytogenetic procedure combining the long term mitotic arrest of bone marrow cultures with detection of a specific chromosomal rearrangement by fluorescence in situ hybridization (FISH), has recently been shown to be effective in determining the frequency of Philadelphia chromosome positive (Ph+) cells in the bone marrow of chronic myelogenous leukemia (CML) patients undergoing treatment. By combining the probe for the Ph chromosome with one for the detection of the X chromosome, we used HMF to monitor the presence of malignant cells within the emerging host cell population in the marrow of a CML patient that had undergone sex-mismatched allogeneic bone marrow transplantation. In successive studies, we detected 0.5% and 1.75% Ph+ cells, respectively, confirmed by Western blot analysis for p210 protein. These readings occurred concordantly with a repopulation of host-derived diploid female cells. Standard G-band cytogenetic analyses did not detect any Ph+ cells at these time points. Intervention with donor lymphocyte infusion reinduced complete remission. This experience indicates that HMF is useful to identify low levels of repopulation by Ph+ cells in the marrow post-BMT at a stage when intervention is most efficacious.

ABO Blood-Group System↗
PubMed1997

Assessing the efficiency of leukoreduction of cellular blood components. Use of a simplified formalin-fixation and batch-counting method.

To simplify the quality control procedure used to determine the efficiency and consistency of bedside leukoreduction, a counting protocol using prefiltration and postfiltration aliquots fixed in 10% formaldehyde was designed. To assess the reliability of the values obtained by counting the formalin-fixed samples, a parallel study was performed using our standard protocol of counting fresh propidium iodide-stained samples in a Nageotte chamber under a fluorescent microscope. A total of 30 single-donor platelet concentrates and 30 units of packed red blood cells were analyzed in parallel using the standard and formalin-fixation methods. Furthermore, the aliquots fixed in formaldehyde were split and counted at 1, 3, and 30 days. The results showed no significant quantitative difference between the two methods. Of note is that the counts in formaldehyde-fixed samples at 1, 3, and 30 days were consistent among themselves. The formaldehyde fixation of samples obtained for quality control of leukoreduction allows blood collection and storage at 4 degrees C and batch counting when and where convenient.

Blood Component Removal↗