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G W Dewald

Publications and source records attributed to G W Dewald.

At least 73 records · Page 4Linked to original sources

Dual color fluorescence in situ hybridization to investigate aneuploidy in sperm from 33 normal males and a man with a t(2;4;8)(q23;q27;p21)

OBJECTIVE: To establish the relative frequency of aneuploidy in sperm from normal and abnormal subjects using dual color fluorescence in situ hybridization and probes for six different chromosomes. DESIGN: Semen from 33 normal males and a patient with a translocation was studied using dual color fluorescence in situ hybridization with probes for chromosomes 4, 7, 8, 12, 18, X and Y. The frequency of aneuploidy for each chromosome is compared with one another and with the patient who had a t(2;4;8)(q23;q27;p21). SETTING: Specimens were obtained from patients at the Mayo Clinic, Rochester, Minnesota. RESULTS: The percentage of sperm with disomy or nullisomy in normal subjects ranged from 0.2% to 0.6% for each of the chromosomes studied. No statistically significant differences were observed between these chromosomes. The frequency of aneuploidy in sperm from a patient with a t(2;4;8) was 3.3% and 4.8% for chromosomes 4 and 8, respectively. CONCLUSION: Fluorescence in situ hybridization was useful to establish the normal range of nullisomic and disomic sperm for six different chromosomes and to study a patient with a clinically significant chromosome abnormality. In normal males, no difference in the frequency of meiotic nondisjunction was observed among the chromosomes studied.

Adult↗

Efficacy of fluorescence in situ hybridization for detecting PML/RARA gene fusion in treated and untreated acute promyelocytic leukemia.

OBJECTIVE: To test the efficacy of fluorescence in situ hybridization (FISH) for detection of fusion of the promyelocytic leukemia (PML) and retinoic acid receptor alpha (RARA) genes in patients with treated or untreated acute promyelocytic leukemia (APL). DESIGN: We conducted a retrospective blind study on a series of stored bone marrow specimens from normal subjects and patients with APL. MATERIAL AND METHODS: Conventional cytogenetic and FISH analyses were done on interphase and metaphase cells in specimens from 31 normal subjects and 19 patients with untreated or treated APL. RESULTS: From 25 of the normal specimens, we calculated a normal cutoff of 10% for interphase cells and 0% for metaphase cells. With use of these criteria, the other six specimens from normal subjects showed normal findings, and each of the seven specimens from patients with untreated APL was abnormal by FISH analysis. The specimens from four patients in clinical relapse or with residual APL were abnormal. Of the eight specimens from patients in clinical remission, three were abnormal; two of these patients had a relapse within 8 months, and the other patient had received 1 month of chemotherapy and was entering remission. Of the other five patients in remission, four had normal FISH results and have now been in remission for 2.5 to 10 years. The other patient in remission with normal FISH results had a relapse within 6 months. PML/RARA fusion was detectable in three patients with hypogranular APL and in three with a cytogenetic variant of the t(15;17). CONCLUSION: The results of this study suggest that FISH with PML and RARA probes can be used to diagnose APL and may be useful for monitoring treated patients.

Antineoplastic Agents↗

Frequency and photographs of HGM11 chromosome anomalies in bone marrow samples from 3,996 patients with malignant hematologic neoplasms.

This study establishes the prevalence of Human Gene Mapping 11 (HGM11) chromosome abnormalities in bone marrow (BM) samples from 3,996 patients with malignant hematologic disorders. Examination of the karyotype of the stemline in these patients showed that 71.6% had one abnormality and 26.4% had two or more; the remaining 2.1% had two different abnormal clones. We observed 9,431 chromosome abnormalities, of which 56% were structural and 44% numeric, but these figures varied slightly with karyotype complexity. Because the HGM11 committee studied published cases with a single chromosome abnormality to identify potential "primary anomalies," we examined the karyotype from our 2,860 patients with a single abnormality in their stemline. We observed all but 12 of the 34 HGM11 numeric abnormalities. Except for 21 patients with a +Y, we did not observe two or more patients with any non-HGM11 numeric abnormality. We observed 91 of the 124 HGM11 structural abnormalities and noted 6 that were not listed by HGM11, and each of these occurred in two or more patients. Among patients with two abnormal clones, 34% had a t(9;22)(q34;q11), del(20)(q11q13), or +8. In 50% of the males with two abnormal clones, one of the clones was -Y. We attempted to create a reference table that lists HGM11 abnormalities in hematologic disorders and their frequency in our series, the reported associated disorders, and photographs of representative chromosome abnormalities.

Chromosome Aberrations↗

Absence of chromosome fragility at 19q13.3 in patients with myotonic dystrophy.

Myotonic dystrophy (DM) is an autosomal dominant disorder characterized by a trinucleotide (AGC) amplification at 19q13.3. The degree of trinucleotide amplification may increase in successive generations and generally correlates with severity of the disorder. Because amplification of a trinucleotide repeat is also associated with the observation of a fra(X)(q27.3) in the fragile X syndrome, we investigated whether chromosome fragility at 19q13.3 might be inducible in patients with DM. Using 3 different culture stress systems (medium 199, RPMI 1640 with excess TdR, and RPMI 1640 with FudR) and high resolution chromosome analyses, we studied 6 individuals with DM and 5 unaffected relatives representing two unrelated families. Molecular studies were done on two of the most affected patients and showed AGC repeat sequences of 970 and 1,260 at 19q13.3. The normal range of AGC repeat is 5 to 30. We found no indication of fragility at 19q13.3 in any of these individuals.

Adolescent↗

Method for sequential staining of GTL-banded metaphases with fluorescent-labeled chromosome-specific paint probes.

We describe a method for use of fluorescent-labeled whole chromosome-specific paint probes on GTL-banded metaphases to utilize the combined potential of these techniques for defining chromosome abnormalities. The efficacy of this method was tested on 6 cases involving different chromosome abnormalities and various tissues, including blood, amniotic fluid, skin fibroblasts, and bone marrow.

Abnormalities, Multiple↗

The 5q- syndrome: a single-institution study of 43 consecutive patients.

A favorable prognosis and a low rate of leukemic transformation has been attributed to the 5q- syndrome, a myelodysplastic syndrome (MDS) characterized by macrocytic anemia, hypolobulated micromegakaryocytic hyperplasia, and an interstitial deletion of chromosome 5. We examined the characteristics and outcome of 43 consecutive patients in our institution strictly defined by morphologic criteria and a solitary 5q- cytogenetic defect. The median age at diagnosis was 68 years, with a clear female predominance (7:3). Eighty percent of the patients were red blood cell transfusion-dependent at diagnosis and all untransfused patients had macrocytic indexes. In contrast, significant neutropenia or thrombocytopenia was rare. The French-American-British (FAB) class distributions were RA (72%), RARS (7%), RAEB (16%), and RAEB-IT (5%). At a median follow-up of 31 months, 56% of the patients survive, with a projected median survival of 63 months. The incidence of acute leukemia was 16% and was uniformly fatal. Clinical hemosiderosis occurred in 28% of the patients, resulting in two deaths. Neither survival nor the risk of leukemic transformation was predictable from initial clinical parameters, including FAB classification, Bournemouth score, and degree of aneuploidy. The lack of significant neutropenia and thrombocytopenia seemed to account for a very low incidence of infection and bleeding resulting in a prognosis equal or superior to historical patients with MDS. Therapeutic endeavors, including the use of corticosteroids, androgens, cis-retinoic acid, pyridoxine, and danazol, were largely unsuccessful.

Acute Disease↗

The application of fluorescent in situ hybridization to detect Mbcr/abl fusion in variant Ph chromosomes in CML and ALL.

We investigated the usefulness of fluorescent in situ hybridization with different-colored major breakpoint cluster region (Mbcr) and Abelson oncogene (abl) probes in clinical practice. In standard Ph chromosomes with a Mbcr breakpoint, these probes produced a fusion of Mbcr and abl signals that was visible in interphase and metaphase cells. The normal range for apparent Mbcr/abl fusion signals in interphase nuclei was established in bone marrow from 25 normal controls. We tested the probes on 35 bone marrow specimens from five normal subjects and 29 patients with various kinds of Ph chromosomes and chronic myelogenous leukemia or acute lymphocytic leukemia. This method produced Mbcr/abl fusion signals in patients with a standard Ph chromosome, simple or complex variants of Ph chromosomes, and "Ph-negative chronic myelogenous leukemia." In metaphase cells of patients with acute lymphocytic leukemia, this method established Ph chromosomes with minor bcr (mbcr) breakpoints. Fluorescent in situ hybridization is a relatively inexpensive and rapid method. When this method is used in conjunction with conventional chromosome analysis, the cytogeneticist can combine the power of complete karyotype studies and the resolution of molecular techniques for patients suspected of having a Ph chromosome.

Bone Marrow Cells↗

Karyotypic analysis in primary myelodysplastic syndromes.

Cytogenetics has provided new insights into the biology and pathogenesis of myelodysplastic syndromes. In patients with refractory anemia, it has provided proof of clonality and has helped differentiate chronic myelomonocytic leukemia from chronic myeloid leukemia. As a prognostic tool, cytogenetics has been predictive of duration of survival and leukemic transformation. However, its role as an independent prognostic factor compared with recent prognostic scoring systems remains to be determined. New techniques such as fluorescent in situ hybridization using chromosome-specific DNA probes may expand the usefulness of cytogenetics. The prognostic impact of cytogenetics may not be fully realized until more effective treatments become available.

Adult↗

Fluorescence in situ hybridization with X and Y chromosome probes for cytogenetic studies on bone marrow cells after opposite sex transplantation.

We investigated the efficacy of fluorescence-labelled chromosome probes (CEP-X/Y) for the X and Y chromosomes to study patients who have had opposite sex BMT. These probes hybridize to the centromere region of the X chromosome and nearly the entire long arm of the Y chromosome. These probes are direct-labelled and produce X and Y signals that can be simultaneously viewed and readily distinguished from each other by color and size after only five brief washes. We investigated BM specimens from 20 normal donors and 16 patients who had undergone an opposite sex BMT. We found no significant interinvestigator differences with respect to scoring XX or XY interphase cells. The 'normal range' for XX cells in males was up to 0.628% and for XY cells in females it was up to 0.299%. Each of the specimens from the patients who underwent BMT had a significant number of donor cells compared with normal range. We suggest that an economical, rapid and accurate cytogenetic test can be achieved by using these probes as an adjunct to conventional cytogenetics.

Bone Marrow↗

Cytogenetic guidelines for fragile X studies tested in routine practice.

Several organizations have proposed guidelines for fra(X) studies on peripheral blood lymphocytes. To evaluate these guidelines, we reviewed 1,033 consecutive specimens referred for fra(X) analysis. Each specimen was cultured with medium 199 and RPMI 1640 with 5-fluorodeoxyuridine or excess thymidine. The karyotype and expression of fra(X) were established from 20 GTL- or QFQ-banded cells and by screening of up to 130 more banded cells. We found anomalies other than fra(X) in 37 (3.6%) of the patients. We found 4% or more fra(X) cells in 38 (3.7%) cases from 36 unrelated families, including 33 (3.9%) of 850 males and 5 (2.7%) of 183 females. Another 4 females had 1 to 3% fra(X) cells. Six specimens were fra(X)-positive in only one stress system, and 32 were positive in 2 systems. To find the first 2 fra(X) cells in males, we needed to study up to 36 cells in 31 cases, 50 in one case, and 57 in another. To find the first 2 fra(X) cells in females, we needed to study up to 17 cells in 4 cases and 57 in another. A strong family history of fra(X) occurred in 5 patients, and each one was fra(X)-positive. Some manifestations of the fragile X syndrome occurred in 507 cases, 17 (3%) of which were fra(X)-positive. Abnormalities considered unlikely to be the fragile X syndrome occurred in 103 cases, 3 (3%) of which were fra(X)-positive. Use of chromosome breakage and fra(3)(p14) as quality control indicators of the fra(X) stress systems was found to be unreliable.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Xp22.3 microdeletion syndrome with microphthalmia, sclerocornea, linear skin defects, and congenital heart defects.

We report on an infant girl with congenital erythematous, linear skin lesions on face and neck, bilateral microphthalmia, sclerocornea, cataracts, and a complex cardiac anomaly including atrial septal and ventricular septal defects. This patient had an Xp22.3 microdeletion and a chromosome satellite on the abnormal X p-arm. The abnormal X chromosome was late replicating in peripheral blood lymphocytes and cultured skin fibroblasts. Four other patients with similar congenital anomalies and Xp deficiency have been reported previously and are compared with this patient. One patient had an interstitial or terminal deletion, but in others the material translocated to Xp22.3 was variable (Yq material in two patients, and Yp material and an unidentifiable satellite in one patient each). Several mechanisms are suggested by which this chromosome abnormality might produce this phenotype in these patients. Our patient is the first with this syndrome to have a congenital heart defect.

Abnormalities, Multiple↗

Cytogenetic analysis of six renal oncocytomas and a chromophobe cell renal carcinoma. Evidence that -Y, -1 may be a characteristic anomaly in renal oncocytomas.

Renal oncocytomas are benign tumors whose morphologic features may sometimes be confused with those of certain low-grade malignant neoplasms of the kidney, e.g., chromophobe cell and granular cell variants of renal carcinoma. The presence of a specific genetic abnormality might help differentiate these tumors. Because very few cytogenetic studies of renal oncocytomas have been published, we investigated a consecutive series of six such tumors. We also performed chromosome analysis on a chromophobe cell carcinoma because cytogenetic analyses of this tumor have not been previously reported. Tumor cell metaphases were analyzed after mechanical and enzyme disaggregation, in situ culture, and robotic harvesting. Clonal abnormalities were present in five of the six oncocytomas, and loss of chromosome 1 with loss of the Y chromosome occurred in two. Review of the literature disclosed four other renal oncocytomas with the 44,X,-Y,-1 karyotype. In the chromophobe cell carcinoma, we noted an abnormal clone with a del(11)(p12p15.1); similar anomalies were not observed in the renal oncocytomas. We conclude that renal oncocytomas have clonal chromosome abnormalities and that a subgroup of these tumors may be specifically associated with loss of chromosomes 1 and Y. Because this is a small series, further investigation may help establish whether cytogenetic studies can provide diagnostic and pathogenic information about renal oncocytomas.

Adenoma↗

Prognostic value of cytogenetic analysis in human cerebral astrocytomas.

Cytogenetic analysis has become an important part of the diagnostic evaluation of most hematological neoplasms. However, there is limited information on the value of cytogenetic analysis in most solid tumors, including cerebral astrocytomas. This report summarizes a prospective cytogenetic study of 99 human cerebral astrocytomas, 16 mixed oligoastrocytomas, and 2 gliosarcomas. The cytogenetic procedure involved in situ culture and robotic harvesting techniques. Correlative clinical and survival data were available on all patients. We successfully cultured and obtained suitable metaphases in 107 of the 117 tumors. One or more chromosomally abnormal clones were observed in 72 tumors, and nonclonal or normal karyotypes were observed in 35 tumors. In a multivariate analysis, survival time was significantly better in patients whose tumors had normal or nonclonal karyotypes on cytogenetic analyses than in those whose tumors had clonal abnormalities (p = 0.0071). Our study demonstrates that cytogenetic analysis provides independent prognostic information in patients with cerebral astrocytomas.

Astrocytoma↗

Pseudomosaicism, true mosaicism, and maternal cell contamination in amniotic fluid processed with in situ culture and robotic harvesting.

This study was designed to test the usefulness of the common definitions for maternal cell contamination, true mosaicism, and pseudomosaicism for amniotic fluid specimens processed by in situ culture and robotic harvesting. We prospectively studied 4309 consecutive amniotic fluid specimens processed with these methods and found that 0.84 per cent had maternal cell contamination, 0.28 per cent had true mosaicism, and 5.4 per cent had pseudomosaicism. Although the frequencies of maternal cell contamination and true mosaicism were comparable to those in similar published studies, the frequency of pseudomosaicism was more than twice as high as that in previous reports. This finding is most likely not due to the method, but rather to a more accurate estimate of the actual frequency of pseudomosaicism in amniotic fluid cultures than reported heretofore. Follow-up clinical information was available on 72 per cent of the cases. In three cases of true mosaicism involving structural anomalies, the results of cytogenetic follow-up studies on the neonates were normal. None of the pseudomosaic cases involving trisomy 8, 13, 18, or 21; triple X; or monosomy X were associated with newborns who had birth defects.

Amniocentesis↗

Fluorescent in situ hybridization: use of whole chromosome paint probes to identify unbalanced chromosome translocations.

By identifying structural chromosome anomalies, the clinical cytogenetics laboratory can play a critical role in the diagnosis and treatment of patients with birth defects. Although many new staining techniques have been developed throughout the years to aid in the detection of anomalous chromosomes, some abnormalities still pose a special challenge to cytogeneticists. This difficulty is especially evident in patients with an abnormal chromosome that does not produce a recognizable banding pattern by conventional staining techniques. We describe a recently discovered method of identifying chromosomes by using whole chromosome-specific DNA probes and fluorescent in situ hybridization and provide examples of how this new procedure facilitated the identification of chromosome abnormalities in two patients with multiple birth defects.

Adult↗

A genetic review of complete and partial hydatidiform moles and nonmolar triploidy.

Complete and partial hydatidiform moles are genetically aberrant conceptuses. Usually, complete moles have 46 chromosomes (diploidy), all of paternal origin. Most partial moles have 69 chromosomes (triploidy), including 23 of maternal origin and 46 of paternal origin. Triploidy that involves 23 paternal chromosomes and 46 maternal chromosomes is not associated with molar placental changes and, rarely, can result in a live-born infant with multiple birth defects. Herein we review the mechanisms of fertilization that may produce these unbalanced sets of parental chromosomes and the role of genomic imprinting as a possible explanation for these clinical conditions.

Female↗