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Biomedical subjects

R Bernstein

Publications and source records attributed to R Bernstein.

At least 73 records · Page 4Linked to original sources

Fanconi's anemia--chromosome breakage studies in homozygotes and heterozygotes.

The in vitro enhancement of chromosome breakage by diepoxybutane (DEB) and mitomycin C (MMC) was studied in 24 Fanconi's anemia (FA) homozygotes and 28 heterozygotes. Both drugs were shown to enhance chromosome breakage significantly in the homozygotes. In the great majority of cases, DEB and MMC stressing are reliable techniques for the definitive cytogenetic diagnosis of FA homozygosity. However, the present study provides no evidence that individual FA heterozygotes can be differentiated from normal individuals on the basis of spontaneous, DEB- or MMC-induced chromosome breakage.

Anemia, Aplastic↗

Cytogenetic analysis of 688 couples experiencing multiple spontaneous abortions.

We report on cytogenetic analysis of 688 couples experiencing two or more first- and/or second-trimester abortions (less than 20 weeks). The overall abnormality rate was 6.83% (47 couples). However, exclusion of those anomalies not generally accepted as being causal in spontaneous abortion leaves an abnormality rate of only 2.33% (16 couples). We discuss the significance of balanced translocations, inversions, sex chromosome aneuploidies, and mosaicisms thereof in the causation of multiple abortions.

Abortion, Habitual↗

HLA and immunoglobulin allotypes in mixed connective tissue disease.

A group of patients with mixed connective tissue disease (MCTD) were HLA and immunoglobulin allotyped. We found that the incidence of DR4 in the patient group was increased compared with that in the normal controls, but the increase was restricted to the subgroup of patients with arthritis. The age at onset of MCTD was lower in patients with DR4 and higher in patients with DR2 compared with patients who did not have these antigens. A1, B8, and DR3 were more frequent, but not significantly so, in the MCTD patient group. We also found that there was a significant perturbation of the Gm allotype frequencies in patients with MCTD.

Adolescent↗

Translocation t(1;7) revisited. Report of three further cases and review.

Three white patients, two with myelofibrosis and one with refractory anemia, presented with a t(1;7). The clinical and cytogenetic findings are discussed in the context of 45 cases already published. Rather than the specific association of t(1;7) with a particular hematologic disorder, a review of the literature strongly suggests correlation with therapeutic or environmental exposure to toxic substances. The proposed mechanisms to explain the origin of t(1;7) are briefly reviewed.

Adolescent↗

Trisomy 18 syndrome with cleft foot.

Ectrodactyly of the feet has been reported only twice in association with trisomy 18 syndrome. A severe form of this anomaly, the first with published illustrative x rays, is described in a male infant with trisomy 18 syndrome. It is suggested that this may represent an extreme expression of the foot anomalies more commonly associated with this syndrome.

Chromosomes, Human, Pair 18↗

A retrospective analysis of the efficacy of epidural steroid injections.

Forty patients were studied retrospectively to evaluate the effect of epidural steroid injections on low back pain and sciatica characteristic of spinal stenosis or a herniated lumbar disc. All but one of these patients had radicular symptoms. The average age was 55 years, and the average follow-up time was eight months. All patients were injected by the same anesthesiologist with 2 cc of Depomedrol-40. Thirty-six patients received either one, two, or three injections. Four patients received either four or five injections. The overall results were poor, with about 60% of patients reporting varying degrees of relief from leg and back pain immediately after injection. However, at follow-up examination, only 24% were asymptomatic; 40% reported no change in preinjection numbness, weakness, or pain; and approximately 35% had varying degrees of relief with no consistent pattern. Of those who had complete relief, there was no correlation between relief of pain, age, or number of injections. From this study, it appears that approximately 50% of patients with radicular symptoms may receive temporary relief with steroid injection. However, long-term relief occurs in less than 25% of patients.

Adult↗

XX true hermaphroditism in southern African blacks: an enigma of primary sexual differentiation.

A high incidence of 46,XX true hermaphroditism exists among southern African blacks. The gonadal distribution and clinical presentation of 38 patients are described. The aim of our study on 11 families with histologically proven XX true hermaphroditism was to determine whether a common genetic or environmental etiology could be identified. Pedigree analysis excluded the presence of a simple inheritance pattern, and no constant environmental factors could be implicated. Hybridization studies with Y chromosome--specific probes (pDP132, pDP61, pDP105, pDP31, pDP97, and pY431-HinfA) excluded the presence of a large portion of Yp in these patients. It is possible that smaller portions of the Y chromosome or one or more X-linked or autosomal mutations, either interacting and/or with incomplete penetrance, are present.

Black People↗

Cytogenetics of chronic myelogenous leukemia.

The fundamental pathogenetic significance of the Ph chromosome abnormality in CML has been clarified by molecular studies. However, this balanced reciprocal t(9;22) is probably not the primary event in the pathogenesis of this disease, at least at a cytogenetic level. The cause of Ph variants in +/- 5% of patients is still unknown. Improvements in cytogenetic techniques and molecular studies in a limited number of cases indicate that simple variants do not exist: Region 9q34 appears to be involved in all types of Ph variants. There is tentative evidence that these variants may in fact represent a clonal evolution from a standard t(9;22). The types of additional secondary abnormalities found in Ph variants are the same as those commonly found in standard cases. Ph negative CML represents a heterogeneous group of myeloproliferative/myelodysplastic disorders. The various mechanisms that could lead to Ph negativity are discussed. Some karyotypically normal cases and those showing a chromosome abnormality other than the Ph during the chronic phase have shown the same molecular changes as found in Ph positive CML. The types of clonal changes accompanying transformation to an acute phase are similar to those seen in myeloid disorders as a whole. The prognostic karyotypic factors in predicting imminent metamorphosis to the acute stage and during the acute phase are discussed. The extent of clonal evolution, the type of secondary abnormalities, and their relationship to the hematopoietic lineage of blast cells should be assessed. The nonrandom clonal changes found in 80% of cases are +Ph, +8, i(17q), +19, and loss of the Y. The significance of +Ph is possibly related to amplification of the bcr/abl fusion gene product, but the reason for the other persistent nonrandom changes is still speculative. Recent cytogenetic data indicate that the specific changes observed in various types of ANLL may be seen in corresponding types of MT, such as t(15;17) in promyelocytic transformations and abnormalities of 3q21-3q26 in megakaryoblastic transformations. Patients with LT usually have an early precursor B phenotype associated with a better prognosis. They tend to have either normal or hypodiploid karyotypes. An i(17q) is never seen and +8 and +19 are absent in most series. Duplication of the Ph and loss of the Y are common to both MT and LT. Data relating 14q+ abnormalities to LT are presently ambiguous.(ABSTRACT TRUNCATED AT 400 WORDS)

Chromosome Aberrations↗

Acute mixed-lineage leukaemia involving myeloid and T-cell phenotypes. A case report.

Among the rare acute mixed-lineage leukaemias, a myeloid T-cell phenotype has recently been recognised. An additional case characterised by myeloid cytochemistry, development of Auer rods in culture and Tdt, WT1 and T11 phenotypes on cell-marker analysis is reported. The patient died from disseminated non-reactive tuberculosis after chemotherapy.

Adolescent↗

B-cell chronic lymphatic leukemia in Hodgkin's disease. A report of two patients with unusual chromosome features.

The development of B-cell chronic lymphatic leukemia in two patients who had previously been treated for Hodgkin's disease is described. In both cases aneuploidy and multiple chromosome aberrations of hemopoietic cells were evident. In one patient these changes included a clonal 14q + abnormality in association with other complex rearrangements, interpreted as translocation abnormalities involving t(6;14), 5(1;15), and t(17;19). Although the chromosome abnormalities in the other patient were nonclonal, a 14q abnormality also was detected, namely t(14q+;18q-). Other chromosome abnormalities (all nonclonal) in the two patients included translocations involving chromosome 5 and deletion of 7q in one patient and trisomy of chromosome 8 in the other. Although these abnormalities have been associated with the presence or development of non-Hodgkin's lymphoma, acute nonlymphoblastic anemia, or myelodysplastic disorders, the findings in these patients suggest that the detection of clones and potential clones with these abnormalities may be only one stage in the development of secondary malignancy.

Adult↗

Fanconi anemia: another disease of unusually high prevalence in the Afrikaans population of South Africa.

We have investigated the prevalence of homozygous and heterozygous Fanconi anemia (FA) in the Afrikaans community of the southern Transvaal Province. The minimum birth incidence of FA in white, Afrikaans-speaking South Africans was estimated to be 1 in 22,000, with the calculated heterozygote prevalence being approximately 1 in 77. Alternatively, based on a point prevalence of 1 in 26,000, the carrier rate may be estimated as 1 in 83. It is postulated that this unusually high frequency of the gene for FA is attributable to founder effect.

Abnormalities, Multiple↗

Localization of the human c-mos gene by in situ hybridization in two cases of acute nonlymphocytic leukemia type M2.

The t(8;21)(q22.1;q22.3) is specific for the FAB-M2 subtype of acute nonlymphocytic leukemia (ANLL). The human c-mos protooncogene is located near the site of rearrangement on chromosome #8, at a position corresponding to band 8q22. The present in situ hybridization studies were performed in order to establish if c-mos is transposed from chromosome #8 to chromosome #21, in two cases of M2-ANLL showing the typical t(8;21). A statistical analysis of the results revealed that the c-mos oncogene was definitely not translocated from chromosome #8 to #21 in one of these patients, and was inconclusive in the other patient. The findings in the former patient suggest that either c-mos is not involved in the etiology of M2-ANLL or, alternatively, if c-mos is important in the pathogenesis of this disease, it must be activated by some mechanism other than transposition of this oncogene to an aberrant position.

Acute Disease↗

A unique 8;16 translocation in two infants with poorly differentiated monoblastic leukemia.

Acute monoblastic leukemia is nonrandomly associated with abnormalities involving 11q. Two infants, one a neonate and the other 19 months of age, had the same hitherto undescribed karyotypic abnormality, t(8;16)(p11;p13), associated with acute nonlymphocytic leukemia M5a. The older child had an additional translocation, t(10;11)(q11;p15), but the chromosome arms affected were the opposite to those described in acute nonlymphocytic leukemia M5a of childhood. Therefore, it is postulated that genes involved in monocytic differentiation may be situated on 8p11 or 16p13, as well as on 11q.

Bone Marrow↗

Cytogenetic and molecular studies on a recombinant human X chromosome: implications for the spreading of X chromosome inactivation.

A pericentric inversion of a human X chromosome and a recombinant X chromosome [rec(X)] derived from crossing-over within the inversion was identified in a family. The rec(X) had a duplication of the segment Xq26.3----Xqter and a deletion of Xp22.3----Xpter and was interpreted to be Xqter----Xq26.3::Xp22.3----Xqter. To characterize the rec(X) chromosome, dosage blots were done on genomic DNA from carriers of this rearranged X chromosome using a number of X chromosome probes. Results showed that anonymous sequences from the distal end of the long arm to which probes 4D8, Hx120A, DX13, and St14 bind as well as the locus for glucose-6-phosphate dehydrogenase (G6PD) were duplicated on the rec(X). Mouse-human cell hybrids were constructed that retained the rec(X) in the active or inactive state. Analyses of these hybrid clones for markers from the distal short arm of the X chromosome showed that the rec(X) retained the loci for steroid sulfatase (STS) and the cell surface antigen 12E7 (MIC2); but not the pseudoautosomal sequence 113D. These molecular studies confirm that the rec(X) is a duplication-deficiency chromosome as expected. In the inactive state in cell hybrids, STS and MIC2 (which usually escape X chromosome inactivation) were expressed from the rec(X), whereas G6PD was not. Therefore, in the rec(X) X chromosome inactivation has spread through STS and MIC2 leaving these loci unaffected and has inactivated G6PD in the absence of an inactivation center in the q26.3----qter region of the human X chromosome. The mechanism of spreading of inactivation appears to operate in a sequence-specific fashion. Alternatively, STS and MIC2 may have undergone inactivation initially but could not be maintained in an inactive state.

Abnormalities, Multiple↗

Combined surface display and reformatting for the three-dimensional analysis of tomographic data.

Radiologic examinations increasingly are based on sequences of cross-sectional images. In current clinical applications, the three-dimensional (3D) relationships contained in these examinations must be inferred by the observer through analysis of multiple two-dimensional (2D) images. In this article, methods for the direct display of 3D gray-level data are investigated. In the chosen approach, the 3D presentation of bone and skin surface serves to orient the viewer, while planar reformation and/or transparent projections can be applied for the assessment of soft-tissue structures in regions of interest. The resulting images represent the original image data in a way that is more suitable for observation of 3D relationships than the conventional cross-sectional viewing mode. This may facilitate the diagnostic process and enhance the interpretability of the images. Routine clinical application of this technique requires special computer hardware. Research applications, however, can be performed within tolerable times (10-30 sec/view) with computers found in radiologic research environments.

Humans↗

Abnormalities of chromosome 12p13 and malignant proliferation of eosinophils: a nonrandom association.

Four patients representing a spectrum of haematological malignancies are reported. Two patients had Philadelphia chromosome negative myeloproliferative disorders, one had acute lymphoblastic leukaemia and one had eosinophilic leukaemia. In each case eosinophilia was present and demonstrated to be part of the malignancy by the association of clonally abnormal metaphases with eosinophil granules. Abnormalities involving the short arm of chromosome 12 (12p13) were a constant feature in all four cases and therefore a nonrandom association between this chromosome region and malignant eosinophil proliferation is proposed.

Acute Disease↗

A unique dicentric X;Y translocation with Xq and Yp breakpoints: cytogenetic and molecular studies.

A 32-year-old woman presented with secondary amenorrhea and infertility. She was of normal height and her breasts were well developed, but she had streak gonads; there were no signs of virilization, and she showed no somatic stigmata of Turner syndrome. Chromosome analysis revealed a dicentric X;Y translocation with Xq and Yp breakpoints. Centromeric banding demonstrated a Y centromere and a "suppressed" X centromere. The karyotype of the patient was interpreted as 46,X,t(X;Y)(q22;p11). The Yp breakpoint was confirmed by DNA-hybridization studies with six probes detecting Y-specific sequences. These DNA-hybridization studies were consistent with the presence of the long arm, centromere, and much of the proximal short arm of the Y. The Y-DNA studies of this female also revealed the absence of the distal short arm of the Y chromosome, to which the testis-determining factor has previously been localized.

Adult↗