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Biomedical subjects

C M Rubin

Publications and source records attributed to C M Rubin.

At least 55 records · Page 3Linked to original sources

Morphology in Ki-1(CD30)-positive non-Hodgkin's lymphoma is correlated with clinical features and the presence of a unique chromosomal abnormality, t(2;5)(p23;q35).

Ten patients with strongly Ki-1(CD30)-positive non-Hodgkin's lymphoma (NHL) were identified at our institution during the past 5 years. Based on morphology, the lymphomas of five of these patients were classified as anaplastic large-cell lymphoma (ALCL); the lymphomas of four patients lacked the morphologic features of ALCL (non-ALCL); and the lymphoma of one patient was unclassifiable. Significant clinical and cytogenetic differences were observed between patients with ALCL and those with non-ALCL. The patients with ALCL tended to be young at the time of diagnosis. They presented with peripheral lymphadenopathy, and two of the five patients had skin involvement. An identical reciprocal translocation involving chromosomes 2 and 5 [t(2;5)(p23;q35)] was observed in lymph nodes from each of the two ALCL patients whose chromosomes were studied. Four of the five patients with ALCL are alive and in complete remission 10-27 months after receiving systemic chemotherapy. In contrast, the patients with non-ALCL were heterogeneous with respect to clinical findings. All of the non-ALCLs were histologically aggressive; however, their morphology varied. The t(2;5) was absent in the lymphoma specimens from each of three non-ALCL patients studied. Three of the four patients died within 17 months after receiving systemic chemotherapy. Thus, differences in morphology are correlated with differences in the clinical findings, karyotype, and outcome in Ki-1-positive NHL.

Antigens, CD↗

Splenic and renal abscesses following Salmonella virchow septicaemia--conservative management with ciprofloxacin.

Splenic abscess formation is a serious condition which usually requires prompt surgical intervention. We report on a patient with Salmonella virchow septicaemia, complicated by peritonitis and multiple splenic and renal abscesses. This is an uncommon manifestation of non-typhoid salmonella infection, which was managed conservatively with oral ciprofloxacin, leading to satisfactory resolution and cure.

Abscess↗

Detection of the Philadelphia chromosome in acute lymphoblastic leukemia by pulsed-field gel electrophoresis.

The Philadelphia (Ph1) chromosome is an acquired abnormality in the malignant cells of 10% to 25% of patients with acute lymphoblastic leukemia (ALL). Unlike chronic myelogenous leukemia (CML), where the molecular detection of the Ph1 chromosome is relatively straightforward using conventional Southern hybridization analysis, the detection of the Ph1 chromosome in ALL is complicated by the existence of several molecular subtypes, and the fact that translocation breakpoints are dispersed over a large genomic area. To circumvent these difficulties, we investigated pulsed-field gel electrophoresis (PFGE) to determine if this method could be used directly on clinical samples to detect the Ph1 chromosome in ALL. We report that, in a study of seven patients with Ph1-positive ALL, we could easily detect the Ph1 using only a single PFGE analysis, regardless of the Ph1 subtype, and we could confirm that the translocations occur either within or very near the BCR gene in all seven. We conclude that PFGE is a useful technique for the detection of the Ph1 in ALL, which ultimately may find wide applicability in the detection of other chromosomal abnormalities in other malignancies.

Adolescent↗

Clinical, radiological and cytological diagnosis of breast cancer in young women.

In women over the age of 35 years, an accurate diagnosis of breast cancer can be made in over 95 per cent of patients using a 'triple assessment' system collating information from clinical examination, mammography, sonomammography, and fine-needle aspiration cytology. These methods have not been specifically evaluated in women aged 35 years or less, hence a study was undertaken on 30 such patients. Clinical examination was unreliable in predicting malignancy with a sensitivity of only 37 per cent. Thirty per cent of patients presented with a lump which had the clinical features of a fibroadenoma. Radiological methods were less sensitive in detecting malignancy in this age group than in older patients. The sensitivity of aspiration cytology was 78 per cent which was higher than that for breast cancer at all ages. Histology showed that there were fewer low grade tumours and fewer scirrhous tumours in this age group than in a control group of women aged over 35 years. This study indicates that cytological confirmation of apparently benign focal breast lesions in young women is essential, especially when these are managed conservatively.

Adult↗

The t(2;5)(p23;q35): a recurring chromosomal abnormality in Ki-1-positive anaplastic large cell lymphoma.

In lymphoid neoplasms, nonrandom cytogenetic abnormalities correlate with clinical, morphologic and immunophenotypic features. A subtype of non-Hodgkin's lymphoma, which expresses the Ki-1 antigen (CD30) and has distinct morphologic and clinical features, has recently been described. We now report the association of a reciprocal translocation involving the short arm of chromosome 2 (band p23) and the long arm of chromosome 5 (band q35), t(2;5)(p23;q35), with Ki-1 positive anaplastic large cell lymphoma. Rearrangement of the genes that are located at the breakpoints on chromosomes 2 and 5 may be a critical step in the pathogenesis of this lymphoma.

Adolescent↗

Heterogeneity of genomic fusion of BCR and ABL in Philadelphia chromosome-positive acute lymphoblastic leukemia.

Philadelphia chromosome-positive acute lymphoblastic leukemia occurs in two molecular forms, those with and those without rearrangement of the breakpoint cluster region on chromosome 22. The molecular abnormality in the former group is similar to that found in chronic myelogenous leukemia. To characterize the abnormality in the breakpoint cluster region-unrearranged form, we have mapped a 9;22 translocation from the Philadelphia chromosome-positive acute lymphoblastic leukemia cell line SUP-B13 by using pulsed-field gel electrophoresis and have cloned the DNA at the translocation junctions. We demonstrate a BCR-ABL fusion gene on the Philadelphia chromosome. The breakpoint on chromosome 9 is within ABL between exons Ia and II, and the breakpoint on chromosome 22 is approximately equal to 50 kilobases upstream of a breakpoint cluster region in an intron of the BCR gene. This upstream BCR breakpoint leads to inclusion of fewer BCR sequences in the fusion gene, compared with the BCR-ABL fusion gene of chronic myelogenous leukemia. Consequently, the associated mRNA and protein are smaller. The exons from ABL are the same. Analysis of leukemic cells from four other patients with breakpoint cluster region-unrearranged Philadelphia chromosome-positive acute lymphoblastic leukemia revealed a rearrangement on chromosome 22 close to the breakpoint in SUP-B13 in only one patient. These data indicate that breakpoints do not cluster tightly in this region but are scattered, possibly in a large intron. Given the large size of BCR and the heterogeneity in breakpoint location, detection of BCR rearrangement by standard Southern blot analysis is difficult. Pulsed-field gel electrophoresis should allow detection at the DNA level in every patient and thus will permit clinical correlation of the breakpoint location with prognosis.

Chromosome Mapping↗

Long-range mapping of the Philadelphia chromosome by pulsed-field gel electrophoresis.

The Philadelphia chromosome (Ph1) of chronic myelogenous leukemia (CML) contains sequences from chromosome 9, including the ABL protooncogene, that have been translocated to the breakpoint cluster region (bcr) of chromosome 22, giving rise to a bcr-ABL fusion gene, whose product has been implicated in the genesis of CML. Although chromosome 22 translocation breakpoints in CML virtually always occur within the 5.8-kilobase (kb) bcr, chromosome 9 breakpoints have been identified within the known limits of ABL in only a few instances. For a better understanding of the variability of the breakpoints on chromosome 9, we studied the CML cell line BV173. Using pulsed-field gel electrophoresis (PFGE), large-scale maps of the t(9;22) junctions were constructed. The chromosome 9 breakpoint was shown to have occurred within an ABL intron, 160 kb upstream of the v-abl homologous sequences, but still 35 kb downstream of the 5'-most ABL exon. bcr-ABL and ABL-bcr fusion genes were demonstrated on the Ph1 and the 9q+ chromosomes, respectively; both of these genes are expressed. These results suggest that the 9;22 translocation breakpoints in CML consistently occur within the limits of the large ABL gene. RNA splicing, sometimes of very large regions, appears to compensate for the variability in breakpoint location. These studies show that PFGE is a powerful new tool for the analysis of chromosomal translocations in human malignancies.

Chromosome Mapping↗

Molecular analysis of TCRB and ABL in a t(7;9)-containing cell line (SUP-T3) from a human T-cell leukemia.

A translocation between chromosomes 7 and 9, t(7;9), has been described in cell lines derived from the malignant cells of children with acute T-cell lymphoblastic leukemia or lymphoma. Our cytogenetic analysis of one such cell line, SUP-T3, demonstrates that the breakpoints on chromosomes 7 and 9 lie within bands q36 and q34, respectively, corresponding to the location of the gene encoding the beta chain of the T-cell receptor, TCRB, and the gene homologous to the transforming gene of the Abelson murine leukemia virus, ABL. We investigated the role of these genes in the t(7;9). In situ chromosomal hybridization of TCRB and ABL probes to metaphase cells from SUP-T3 demonstrated that ABL is translocated from chromosome 9 to 7 and that all or part of TCRB is translocated from chromosome 7 to 9. Southern blot analysis revealed that both TCRB alleles were rearranged; however, it could not be determined whether the translocation breakpoint lies within this gene. Pulsed-field gel electrophoresis and Southern blot analysis were used to examine more than 500 kilobases of the ABL locus; we concluded that there are no rearrangements within 250 kb in either direction of the sequences homologous to v-abl. Additionally, no abnormal ABL protein was detected in an in vitro phosphorylation assay. These results indicate that, in SUP-T3, the breakpoint on chromosome 9 lies proximal to ABL and that the break results in no apparent alteration of the ABL protein. We therefore hypothesize that another gene on chromosome 9, at band q34, plays a role in this translocation. This study also demonstrates that pulsed-field gel electrophoresis is a powerful new tool for the analysis of human chromosomal translocations.

Abelson murine leukemia virus↗

The first intron in the human c-abl gene is at least 200 kilobases long and is a target for translocations in chronic myelogenous leukemia.

The c-abl protooncogene is unusual in two respects; it has multiple, widely space N-terminal coding exons transcribed by different promoters, and it is the target of the translocations that form the Philadelphia chromosome found in cells of chronic myelogenous leukemia patients. To understand the organization of the gene in normal and chronic myelogenous leukemia patient DNA we have mapped c-abl by pulsed field gradient gel electrophoresis. We find that one of the alternative 5' exons of the gene lies at least 200 kilobases upstream of the remaining c-abl exons, posing formidable transcription and splicing problems. The 5'-most c-abl exon includes an unusually long 1,276-base-pair segment that contains 15 ATG codons and multiple short open reading frames, upstream of the abl initiator codon. Its peculiar structure suggests that c-abl may be decapitated in most chronic myelogenous leukemia patients, and we demonstrate that this is the case in the chronic myelogenous leukemia cell line K562.

Amino Acid Sequence↗

Comparison of low-osmolar contrast media in paediatric cardiac angiography.

Sixty-two children investigated by cardiac angiography for a wide spectrum of congenital heart disease were randomly assigned to one of two groups, one for iohexol, 350 mg I/ml (Omnipaque, Nycomed UK Ltd) and one for iopamidol, 370 mg I/ml (Niopam, E. Merck Ltd). Changes in systolic pressure, end-diastolic pressure when the injection was made into a ventricle, heart rate and rhythm and plasma osmolality were assessed at 1 min and 3 min after the injection of contrast medium. The angiograms were subjectively assessed for angiographic quality. No significant differences were detected between the two groups.

Angiocardiography↗

Association of a chromosomal 3;21 translocation with the blast phase of chronic myelogenous leukemia.

An identical reciprocal translocation between the long arms of chromosomes 3 and 21 with breakpoints in bands 3q26 and 21q22, t(3;21)(q26;q22), was found in three male patients with the blast phase of chronic myelogenous leukemia (CML). The abnormality was clonal in all three patients and was always accompanied by either a standard or variant 9;22 translocation resulting in a Philadelphia chromosome (Ph1). In two cases, the t(3;21) was the only abnormality other than a t(9;22) in the primary clone. Serial studies of one patient demonstrated that the t(3;21) occurred as a result of clonal evolution near the time of development of the blast phase. We have not observed the t(3;21) in greater than 500 patients with CML in the chronic phase. Thus, the t(3;21) is a new recurring cytogenetic abnormality associated with the blast phase of CML.

Adult↗

Cytogenetic studies of long-term survivors of childhood acute lymphoblastic leukemia: a follow-up report.

Previous series including our earlier study of survivors of childhood acute lymphoblastic leukemia have documented the presence of nonclonal chromosome abnormalities in peripheral blood lymphocytes. To investigate whether or not these abnormalities persist, we restudied nine patients, all of whom had received radiotherapy and a minimum of 3 years of systemic chemotherapy. Therapy had been discontinued a median of 3.9 years prior to study in our first report and a median of 7.2 years prior to study in this follow-up report. Thirty metaphases from short-term cultures of phytohemagglutinin-stimulated peripheral blood from each of nine patients and nine matched controls were analyzed using G-banding. Nonclonal chromosome abnormalities were present in cells from six of the nine patients and 3.0% of patients' cells overall, as compared to seven of ten patients and 3.5% of patients' cells in the earlier study. All patients studied twice had abnormalities on one or both occasions. No evidence for the development of cytogenetically abnormal clones was found. Combined data from the two evaluations indicate that all of the patients have a small population of long-lived lymphocytes with nonclonal chromosome abnormalities, the frequency of these cells appears to remain remarkably constant over time, and the proportion of cells with chromosome abnormalities is approximately threefold greater in patients than in controls. It has become apparent that survivors of acute lymphoblastic leukemia are at increased risk for development of second malignant neoplasms. The relationship between therapy-induced chromosome damage and the development of second malignant neoplasms is currently unknown. We speculate that some cells, possibly in tissues other than peripheral blood, are preneoplastic by virtue of therapy-induced chromosome rearrangements involving critical genes and, following a long latent period, may undergo subsequent genetic or cellular changes that result in malignant transformation. Unfortunately, however, estimation of genetic damage through cytogenetic studies of peripheral blood T-lymphocytes does not appear to be a useful method for prediction of second malignant neoplasms following acute lymphoblastic leukemia, since most or all of the patients have a low level of abnormal cells.

Acute Disease↗

Molecular cloning, expression, and chromosomal localization of the gene encoding a human myeloid membrane antigen (gp150).

DNA from a tertiary mouse cell transformant containing amplified human sequences encoding a human myeloid membrane glycoprotein, gp150, was used to construct a bacteriophage lambda library. A single recombinant phage containing 12 kilobases (kb) of human DNA was isolated, and molecular subclones were then used to isolate the complete gp150 gene from a human placental genomic DNA library. The intact gp150 gene, assembled from three recombinant phages, proved to be biologically active when transfected into NIH 3T3 cells. Molecular probes from the gp150 locus annealed with a 4.0-kb polyadenylated RNA transcript derived from human myeloid cell lines and from tertiary mouse cell transformants. The gp150 gene was assigned to human chromosome 15, and was subchromosomally localized to bands q25-26 by in situ hybridization. The chromosomal location of the gp150 gene coincides cytogenetically with the region assigned to the c-fes proto-oncogene, another human gene specifically expressed by myeloid cells.

Antigens, Surface↗