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Biomedical subjects

S Pittman

Publications and source records attributed to S Pittman.

At least 19 recordsLinked to original sources
PubMed2000

A minimalist approach to gene mapping: locating the gene for acheiropodia, by homozygosity analysis.

Acheiropodia is an autosomal recessive disease that results in hemimelia (lack of formation of the distal extremities). We performed a complete genome screen of seven members of an extended pedigree that included three siblings with acheiropodia. Homozygosity mapping was used to identify regions most likely to harbor the gene for acheiropodia in this pedigree. In these two key regions (14p and 7q), further genotyping of one additional affected member of this pedigree plus seven additional unaffected siblings provided evidence, through linkage analysis, that the 7q36 region contains the acheiropodia gene. In this region, a maximum two-point LOD score of 3.81 (4.2 with multipoint analysis) was achieved, and a homozygous haplotype spanning a region of 11.7 cM was seen in all affected in this pedigree. Finally, genotypic analysis of two additional cases of acheiropodia with no known relation to the other samples revealed homozygous sharing of a portion of the same haplotype on 7q36, which reduces the chromosomal location of the acheiropodia gene to an 8.6-cM region. Localization of this gene, at the screening level, by use of data from only three affected subjects, provides an example of how certain genes may be mapped by use of a minimal number of affected cases.

Brazil↗
PubMed1997

Multiple centrosomal microtubule organising centres and increased microtubule stability are early features of VP-16-induced apoptosis in CCRF-CEM cells.

Microtubular reorganisation contributing to apoptotic morphology occurs in normal and neoplastic cells undergoing apoptosis induced by cytotoxic drugs [1-3]. The aim of this study was to correlate the changes in the microtubules (MTs) with behavior of the centrosome in apoptotic cells, and to see whether post-translational changes in tubulin occurred with the emergence of apoptotic MT bands. Apoptosis was induced in the human T-cell leukaemia line (CCRF-CEM) by treatment with 17 microM etoposide over a 4 h period. The time course of changes was assessed using flow cytometry (FCM) and immunocytochemistry in cells labelled for a centrosomal antigen (CSP-alpha) or alpha-tubulins. One hour following treatment we observed multiple centrosomal microtubule organising centres (MTOCs) associated with the nucleus and the transient appearance of a subset of stable MTs detected with an antibody specific for acetylated alpha-tubulin, as the bands of MTs which lobulate the nucleus are formed. The altered properties of the MTs thus reflect changes in function as apoptosis progresses.

Antigens↗
PubMed1989

Cytogenetic abnormalities in benign lymphoid hyperplasia: a dual-parameter study using chromosome analysis and flow cytometry.

This is a prospective study of lymphoid tissue showing benign reactive hyperplasia (18 lymph nodes and 2 tonsils), using cytogenetic analysis of cells stimulated with T- or B-cell mitogens. The reason for this study was the detection of an abnormal chromosomal population in cells from an enlarged lymph node excised from a 7-year-old female who on further investigation was found to be clinically well and after one year's close follow-up had not developed any further signs or symptoms of malignancy. In addition, DNA content was measured by flow cytometry (FCM) on fresh cell suspensions in 17 cases and fixed cell suspensions in 3 cases. Structural and numerical clonal chromosome abnormalities were found in 9 of the 20 samples, but no common specific defect was identified. FCM showed an abnormal DNA content in 10 of the 20 samples studied; 3 of these showed clonal chromosome abnormalities. Surface membrane immunoglobulin studies were carried out on 15 of the 20 samples using cell suspensions and frozen tissue sections. In 5 of the 15 cases, monoclonal surface immunoglobulin was detected. There was no direct correlation between the surface membrane immunoglobulin studies and the chromosome and FCM analyses. We conclude that aneuploidy is a common feature in reactive lymphoid tissue, but both cytogenetics and FCM are needed to identify it.

Aneuploidy↗
PubMed1988

A pathologic study of allergic bronchopulmonary aspergillosis.

A lung biopsy specimen was obtained from a 10-year-old boy with cystic fibrosis and allergic bronchopulmonary aspergillosis. Light microscopy revealed a marked inflammatory process that was largely bronchocentric. Infiltrating cells included lymphocytes, plasma cells, monocytes, and numerous eosinophils. Elastin layers were intact in blood vessels and markedly disrupted in bronchioles. By immunofluorescent, major basic protein was demonstrated in eosinophils, was freely deposited outside of eosinophils, especially in the interlobular septum, and was taken up by macrophages. A number of lymphocytes stained positively for IgE. Through an immunoperoxidase stain, septate hyphae of Aspergillus were clearly observed in the lung parenchyma. A significant increase in interleukin-2 positive-staining T cells was observed with an approximate 2:1 ratio of helper to suppressor cells. The use of newer immunohistologic techniques has enabled us to gain additional insights into the pathogenesis of allergic bronchopulmonary aspergillosis.

Aspergillosis, Allergic Bronchopulmonary↗
PubMed1987

A simple and rapid immunological technique for visualising chromosome-mediated gene transfer (CMGT).

A method is described for visualising chromosome-mediated gene transfer (CMGT) by detecting chromosomes labelled with bromodeoxyuridine (BrdU) using a monoclonal antibody to BrdU. In this experiment, the CCRF-CEM T cell line was grown in the presence of BrdU and the labelled chromosomes were isolated and transfected into human embryonic fibroblasts. Uptake and retention of chromosomes were compared for transfection with either PEG or DMSO treatments. Following transfection the labelled chromosomes could be visualised in recipient cells using a monoclonal antibody to BrdU, followed by immunoperoxidase staining. Chromosome uptake into cells was similar for both DMSO and PEG treatments and was a relatively frequent event; about 1 in 5 recipient cells had labelled material present. This technique can be used to assess the technical aspects of the earliest stages of chromosome-mediated gene transfer.

Antibodies, Monoclonal↗
PubMed1987

Flow cytometric and karyotypic analysis of a primary small cell carcinoma of the prostate: a xenografted cell line.

A human small cell undifferentiated carcinoma of the prostate, xenografted in nude mice, was analyzed both cytogenetically and by DNA flow cytometry. The DNA content of the line indicated its stability on serial passage, and was consistent with the cytogenetic findings. The banded karyotype was hypodiploid with nonrandom losses of chromosomes #6, #7, #10, and #13. Structural rearrangements involved chromosomes #1 and #2, and there were three unidentified markers. The findings were compared with those described in other types of prostatic carcinoma.

Animals↗
PubMed1987

Cytogenetic studies on prolymphocytic leukemia. 1. B-cell prolymphocytic leukemia.

We describe clonal chromosome abnormalities in 13 new cases of B-cell type prolymphocytic leukemia (B-PLL) investigated using pokeweed, lipopolysaccharide B, TPA (phorbol ester), and Epstein-Barr virus (EBV) as mitogens. B-PLL showed a much better response to all four mitogens when compared with B-cell chronic lymphocytic leukemia (B-CLL). A 14q+ was the most frequent abnormality and was observed in 7 of the 13 cases. A t(11;14)(q13;q32) was observed in 2 patients in this series and in 2 cases from a previous series of 9 patients studied in this laboratory, giving an incidence in B-PLL of 18% for this abnormality. The more frequent rearrangement of both IgH genes in B-PLL when compared to B-CLL may predispose to a higher incidence of 14q+ in B-PLL. Trisomy 12 which is a feature of B-CLL was observed in one case in the present series. Other abnormalities of chromosome 12 included 12p-(p12-13) in 2 cases and t(12;14)(q22;q32) in 1 case. The t(6;12) previously described as a specific abnormality in B-PLL was not observed in the 22 cases (13 present series, 9 previous series) studied in our laboratory.

Aged↗
PubMed1986

The 14q+ marker in hairy cell leukaemia. A cytogenetic study of 15 cases.

Leukaemic cells from 19 patients with hairy cell leukaemia (HCL), characterised by morphological, immunological and ultrastructural criteria, were investigated for chromosome abnormalities after stimulation with B-cell mitogens (Pokeweed mitogen (PWM), lipopolysaccharide B and EBV). The cells from all cases had a B-cell phenotype and in each case only a single light chain type was expressed on the membrane of the cells. Only 15 patients with adequate metaphases are included in this study. Clonal chromosome abnormalities were observed in 12 patients of which five had a 14q + involving q32. Of the remaining 3 cases 1 had nonclonal abnormalities and 2 had normal karyotypes. The donor chromosomes were identified in 3 cases and were found to be 9, 18 and 22. An interstitial rearrangement of chromosome 14 involving band q22 was seen in 2 cases and a deletion of chromosome 14 at q24 in 1 case. Amongst other chromosome abnormalities 12p was involved in 4 cases, 12q in 2 cases and chromosomes 7 and 22 in 3 cases each. The significance of the abnormalities has been discussed in relation to sites of cellular oncogenes. Our study demonstrates that chromosome abnormalities common to other B-cell disorders are present in HCL.

B-Lymphocytes↗
PubMed1984

Prognostic significance of chromosome abnormalities in chronic lymphocytic leukaemia.

Lymphocytes from 33 out of 63 patients with B-cell chronic lymphocytic leukaemia (B-CLL) were successfully stimulated for cytogenetic analysis by means of two B-cell mitogens: pokeweed mitogen and lipopolysaccharide-B, used after pretreatment of the cells with neuraminidase and galactose oxidase. All patients had abnormal clones in 30-100% of the cells analysed. Chromosomes more frequently involved were Nos. 1, 3, 6, 11, 12, 13 and 14. The most common abnormality was a marker 14q+ (breakpoint 14q32) seen in 17 cases; trisomy 12 was observed in seven cases. A clinical scoring system was used to investigate the correlation of chromosome abnormalities with prognosis. The group with 14q+ was often associated with features of progressive disease, namely; prolymphocytoid or Richter transformation, refractoriness to therapy, high WBC and advanced staging. A significant difference in survival was observed between patients with 14q+ and the rest: median survival from diagnosis being 45 months and over 64 months, respectively (P less than 0.05); when survival was calculated from the time of chromosome analysis the values were 8 months and more than 41 months, respectively (P less than 0.01). It is suggested that 14q+ is acquired during the evolution of CLL and that this development may be a key event in the clinical progression of B-CLL. Other abnormalities, including trisomy 12, were not found to be associated with a worse prognosis.

B-Lymphocytes↗
PubMed1983

Chromosome abnormalities in B-cell prolymphocytic leukemia: a study of nine cases.

Chromosome abnormalities were demonstrated in 50-100% of Giemsa-banded metaphases from nine cases of B-cell prolymphocytic leukemia (B-PLL). Mitoses were obtained with pokeweed mitogen following pretreatment of peripheral blood (PB) prolymphocytes with neuraminidase-galactose oxidase. Chromosome 14 was abnormal in eight of the nine cases: a marker 14q+, with breakpoint at band q32 in seven and trisomy 14 in one. In four cases the abnormal No. 14 was one of several primary abnormalities and in four others it was seen in secondary clones. The origin of the translocated material was unknown in three cases, in two it resulted from t(11;14), later becoming t(11;14;21) in one of them, t(1;14) in another, progressing later to t(1;14;17); in yet another patient, the 14q+ was the result of a complex rearrangement t(6;14;17). Abnormalities of chromosome 6 were seen in six cases: 6q- as the primary abnormality in three; trisomy 6 was part of secondary changes in one case. Structural abnormalities of chromosome 1 were seen in six cases: 1q- in four (in one as the only abnormality), 1q+ in one case, and 1p- in another, both in the main clone. Trisomy 12 was demonstrated in three cases but not as the primary change. Spleen cells in two patients showed a higher frequency of abnormalities than in the PB, supporting the concept of the spleen being the organ primarily involved in B-PLL. Evidence of karyotypic evolution was demonstrated in six patients, in some clearly associated with clinical progression of the disease. The type and frequency of the abnormalities observed in B-PLL resemble those seen in non-Hodgkin's lymphomas and suggest major differences from B-CLL, although a relationship with the latter can not be completely ruled out at present.

Aged↗
PubMed1982

Chronic T-cell leukemias. II. Cytogenetic studies.

Chromosome abnormalities were documented in the PHA-stimulated lymphoid cells from 10 patients with chronic T-cell leukemias (6 T-PLL, 3 T-CLL and 1 T-LCL). One or more marker chromosomes were present in most metaphases in every case of T-PLL but they were different in each case. Structural abnormalities were also observed in T-CLL and T-LCL but less consistently. Chromosomes involved in marker formation in two or more cases were: Nos. 2, 7, 8, 9, 11 and 16. The karyotype was hypodiploid in five cases and hyperdiploid in two. Chromosomes Nos. 2 and 8 were the most frequently involved in structural and numerical abnormalities: Nos. 8 in 2 T-CLL and the 6 T-PLL and No. 2 in 1 T-CLL, 1 T-LCL and 5 T-PLL. Abnormalities of chromosome No. 2 are rare in human neoplastic disease but may be common in T-lymphoproliferative disorders. The differences between T-PLL and T-CLL reported here may have some bearing on the clinical features. T-PLL, characterised in all cases by clonal abnormalities, has an aggressive clinical course. In contrast, T-CLL with less consistent karyotypic changes has a protracted and benign clinical evolution.

Adult↗
PubMed1982

[Monitoring of patients with primary chronic open-angle glaucoma].

Compliance to examinations performed in a specialised department was studied in patients with chronic open-angle glaucoma. A total of 429 case reports from patients treated from 1974 to 1977 were analyzed, follow up being for a period of up to 7 years. Examinations were performed two or three times a year and any patient who didn't return for two consecutive years was considered as lost. The number of lost patients was very few, about 10 percent a year, and this did not increase during the whole follow-up period. Overall, compliance was not related to sex. However, a higher proportion of women were lost between the second and third year of follow up. The distance between patient's homes and the medical center, near or far away, was not significant. As expected, a higher proportion of patients over sixty were lost after one year of follow up.

Adult↗
PubMed1981

Stimulation of chronic lymphatic leukaemia cells by pokeweed mitogen after treatment with neuraminidase-galactose oxidase.

CLL lymphocytes gave a low response upon stimulation with PHA or PWM in 3-day cultures. However, after treatment with neuraminidase-galactose oxidase (NGO), in the presence of PWM, CLL lymphocytes transformed into blasts and incorporated 3H-thymidine in 3-day cultures. This response of CLL lymphocytes was similar to that given by normal lymphocytes to PWM in 3-day cultures. The best stimulation of CLL lymphocytes was achieved when conditioned medium (CM) from normal T lymphocytes was present in PWM cultures. Purified B lymphocytes from CLL (T lymphocytes and monocytes removed) did not respond to PHA or PWM. However, after NGO treatment these cells were stimulated by PWM, but only in the presence of CM. PHA failed to stimulate NGO-treated CLL lymphocytes or purified B lymphocytes. This study shows that CLL lymphocytes, which usually fail to respond to mitogens, can be stimulated by PWM to proliferate after treatment with neuraminidase-galactose oxidase (NGO). This technique of B cell stimulation has been found useful in cytogenetic studies of B cell proliferative disorders.

B-Lymphocytes↗