PubMed Health⌕ Search

Biomedical subjects

N Clare

Publications and source records attributed to N Clare.

18 recordsLinked to original sources
PubMed2000

Establishment of a human polyclonal oral epithelial cell line.

OBJECTIVE: To develop a human oral epithelial cell line to constitute a continuous source of cells readily available for human oral epithelial cell research. STUDY DESIGN: Oral epithelial cells from a 30-week gestational, stillborn male fetus were grown in serum-free medium and transfected by lipid-mediation with the shuttle vector plasmid, pZ189, containing the T-antigen coding region and replication origin from the SV40 virus. RESULTS: Resulting cultures produced foci of rapidly multiplying cells that failed to senesce, in contrast to controls. The transformed culture, designated GMSM-K, was polyclonal. The original culture possessed a normal human male karyotype, and the transformed line was largely hypotetraploid. Multiple clones, isolated from soft agar studies and low density plating, showed decreased doubling times. Electron microscopy and immunohistochemistry confirmed an epithelial phenotype. Cells did not generate tumors in nude mice. CONCLUSION: Few human epithelial cell lines are available to investigators and most are tumor-derived. The nontumor-derived GMSM-K line has value as a resource for human oral epithelial cell research.

Animals↗
PubMed1998

The distal cytoplasmic domain of the erythropoietin receptor induces granulocytic differentiation in 32D cells.

The role of hematopoietic growth factors in lineage commitment and differentiation is unclear. We present evidence that heterologous expression of an erythroid specific receptor allows granulocytic differentiation of a myeloid cell line. We have previously characterized a truncation mutant of the erythropoietin receptor (EpoR), which is associated with familial erythrocytosis (Blood 89:4628, 1997). This truncated EpoR lacks the distal 70 amino acids of the cytoplasmic domain. To study the functional role of this distal receptor domain, 32D cells, a murine interleukin-3 (IL-3)-dependent myeloid line, were transfected with the wild-type EpoR (32D/EpoR WT) or the truncated EpoR (32D/EpoR FE). 32D cells expressing either the full-length or truncated EpoR display equivalent proliferative rates in saturating concentrations of Epo. There is a dramatic difference in maturational phenotype between the two cell lines, however. The 32D/EpoR FE cells and mock transfected 32D cells have an immature, monoblastic morphology and do not express the primary granule protein myeloperoxidase. The 32D/EpoR WT cells, on the other hand, demonstrate granulocytic differentiation with profuse granulation, mature, clumped chromatin, and myeloperoxidase expression. There is no evidence of erythroid differentiation in 32D cells transfected with either the full-length or truncated EpoR. Treatment of the cells with the specific Jak2 inhibitor tyrphostin AG 490 inhibits myeloid differentiation driven by the distal EpoR. We conclude that: (1) the distal cytoplasmic domain of the EpoR is able to induce a specific myeloid differentiation signal distinct from mitogenic signaling, and (2) these data extend to myelopoiesis the growing body of evidence that the cellular milieu, not the specific cytokine receptor, determines the specificity of differentiation after cytokine receptor activation.

Animals↗
PubMed1994

Cytogenetics in the diagnosis of hematologic malignancies.

Practical uses of cytogenetic analysis in hematopoietic disorders include the following: confirm/establish a diagnosis of chronic myelocytic leukemia (CML) confirm/predict blast crisis of CML help in diagnosis/prognosis of acute leukemia confirm/establish remission or relapse in acute leukemia help in diagnosis/prognosis of myelodysplastic states evaluate post-bone marrow transplant recipients help in diagnosis of some lymphoproliferative disorders aid researchers in discovery of critical gene loci that may eventually result in more effective treatment. Cytogenetic laboratories and molecular genetic laboratories should be in close communication to recommend the most appropriate studies in any given case and to avoid expensive duplication of work.

Cytogenetics↗
PubMed1991

Hodgkin's disease in association with human immunodeficiency virus infection. Pathologic and immunologic features.

Six patients with Hodgkin's disease (HD) and demonstrable serum antibodies to human immunodeficiency virus (HIV) and two additional patients with HD belonging to HIV-associated high-risk groups but with negative HIV serology were studied. All patients were men and ranged in age from 21 to 45 years. The HIV risk factors included homosexuality (6), intravenous drug abuse (2), and hemophilia A (1). All patients had high pathologically determined stage (one Stage III and seven Stage IV), and bone marrow involvement was observed in five patients with the initial diagnosis of HD based on marrow biopsy in two cases. Four cases were histologically subclassified as mixed cellularity (MC) and three as nodular sclerosis (NS); one patient underwent only bone marrow biopsy and was not subclassified. Histologically all cases were characterized by numerous Reed-Sternberg cells and variants, and with the exception of one case, all had a distinctive decrease in the proportion of reactive background lymphocytes compared with what is usually expected in MC or NS Hodgkin's disease (relative lymphocyte depletion). Flow-cytometric immunophenotypic studies done on cell suspensions from diagnostic lymph node biopsies in four cases showed decreased CD4:CD8 ratios (mean = 1.4) compared with expected values of 4 to 6. The relative lymphocyte depletion observed histologically is probably a reflection of the decreased tissue CD4:CD8 ratios, and this impairment of host immune response may be related to the observed high stage in all eight cases. Patients with high stage HD and the described histologic and immunologic features should be evaluated for the presence of HIV infection.

Adult↗
PubMed1991

The importance of the orientation of the electrode plates in recording the external anal sphincter EMG by non-invasive anal plug electrodes.

Two non-invasive anal plug electrodes of similar size have been compared, one with the electrode plates orientated circularly in the anal canal and the other with the plates in the long axis of the anal canal. There was a significant increase in the amplitude in the EMG signals recorded at rest and during squeeze from the external anal sphincter with a longitudinally placed electrode in 117 patients. Inappropriate contraction of the external anal sphincter when straining at stool was more readily detected using the longitudinal electrode in 52 patients investigated for intractable constipation. The longitudinal electrode detected the amplitude of the response to the elicitation of a pudeno-anal reflex more readily than the circular electrode. When in 12 of the 117 the pudeno-anal reflex EMG signal was either absent or not detected with the circumferential plug electrode, the longitudinal electrode detected the presence of a low amplitude response in 11 of these. When the non-invasive longitudinal electrode was compared to invasive fine wire stainless steel electrodes, a correlation was found for external anal sphincter resting EMG (r = 0.99, p less than 0.01), voluntary squeeze EMG (r = 0.99, p less than 0.001) and strain EMG (r = 0.91, p less than 0.01). The longitudinal anal plug electrode thus facilitates surface acquisition of EMG activity.

Adult↗
PubMed1991

Outlet obstruction constipation (anismus) managed by biofeedback.

Fifteen subjects presenting with intractable constipation due to obstructive defecation, mean (SEM) duration 8.8 (1.8) years, had the inappropriate contraction and electromyographic changes in the pelvic floor muscles and external and sphincter typical of this condition. An electromyographically derived index was used to grade its severity. A self applied biofeedback device was used to allow electromyographic recording of the abnormal external anal sphincter. The subjects were encouraged to reduce the abnormal electromyographic activity on straining after instruction and training. The procedure was intended as a relearning process in which the non-relaxing activity of the pelvic floor was gradually suppressed. Biofeedback training was maintained on a domiciliary basis for a mean time of 3.1 weeks and resulted in a significant reduction in the anismus index (mean (SEM) 69.9 (7.8)% before biofeedback, mean 14 (3.9)% after biofeedback, p less than 0.01). There was an associated reduction in the time spent straining at stool and in the difficulty of defecation and an increased frequency of defecation. Defecatory video proctograms in six subjects showed improvements in the anorectal angle during straining and evacuation. The clinical benefit to the patients persisted after a mean follow up of 6.2 months.

Adult↗
PubMed1988

The gingival biopsy in the diagnosis of thrombotic thrombocytopenic purpura.

Gingival biopsy specimens from five patients with a clinical diagnosis of thrombotic thrombocytopenic purpura (TTP) were reviewed. All biopsy specimens demonstrated the characteristic histologic lesion associated with TTP. Review of the literature showed an average diagnostic yield of 37% (30/81) for this procedure. The increase in diagnostic correlation in this study may be explained in part by the marked degree of disease expression in the patients who underwent gingival biopsy. Three of the five patients who underwent gingival biopsies ultimately died of their disease. In addition, a persistent search through multiple serial sections for the characteristic lesion, beyond the usual three levels, was performed. Despite the disparity in diagnostic yield, we consider the gingival biopsy to be a safe diagnostic correlate of TTP because of easy access, rich vascularity, and low surgical morbidity. Furthermore, we recommend biopsy, as Goodman and colleagues have, only in areas of the gingiva that appear clinically normal and free of inflammation in order to reduce misinterpretation as a consequence of false-positive intraluminal fibrin thrombi that may occur with inflammation.

Adult↗
PubMed1986

Acute promyelocytic leukemia: report of a variant translocation, t(1;17).

A 4-year-old female with acute promyelocytic leukemia (APL) was found to have a variant form of the 15;17 translocation, which is diagnostic of APL. The karyotype of the malignant cells was 47,XX,t(1;11)(q25;q21),t(1;17)(p36;q21), + 8. This case is additional evidence that the breakpoint of #17 at q21 is the characteristic chromosomal aberration of APL. The present case is also unusual because of the young age of the patient.

Child, Preschool↗
PubMed1986

Lymphocyte malignancy and chromosome 14: structural aberrations involving band q11.

Five patients with lymphocytic malignancies were found to have structural aberrations of chromosome 14, all involving band q11. The malignant cells of all five cases were analyzed by immunofluorescence to establish immunologic phenotypes. Three patients had T lymphoblastic lymphoma/leukemia with mediastinal masses (cases 1, 2, and 3); one patient had peripheral T cell lymphoma (case 4); and one patient had acute lymphocytic leukemia, common acute lymphoblastic leukemia antigen positive (case 5). Although aberrations of chromosome 14 frequently are associated with lymphocytic malignancies, these abnormalities most often result in extra material on the long arm, 14q+. However, none of the five patients reported here had a 14q+. Cases 1 and 2 had t(9;14)(q34;q11) and t(11;14)(p11 or 13;q11), respectively. Case 3 showed del(14)(q11), and cases 4 and 5 showed inv(14)(q11q32). Structural aberrations resulting in 14q- and inv(14) appear to occur infrequently. The five cases in this report, in conjunction with those found in the literature, indicate a strong association between breaks at 14q11 and T lymphocytic malignancies.

Adult↗
PubMed1984

Major karyotype aberrations, including t(3;12), in a patient with myelodysplastic syndrome.

Cytogenetic analysis of bone marrow cells was performed twice on a patient with myelodysplastic syndrome, specifically, refractory anemia with excess blasts. The patient had a progressive course, with transformation toward acute leukemia and death within 3 months. Chromosome analysis showed major karyotype abnormalities, including dir dup (1p), t(3;12), and a unique breakage of a #15 resulting in t(15;18) and dic(15;21). Involvement of #3 and #12 in a translocation has been recently reported, and a comparison with these cases is made with a discussion of the significance.

Bone Marrow↗
PubMed1983

A grading system for bone marrow cytogenetics and its use as a standard for quality control.

A grading system has been developed to assess the quality of the results of bone marrow cytogenetic procedures. The results of 3 1/2 years use of this grading system are reported. This grading system is a satisfactory internal standard for quality control and is adaptable for use as an external standard. The use of such an internal standard will improve the performance of the cytogenetics laboratory and will validate the quality of the results of cytogenetic examination. The use of an external standard will stimulate the standardization and improvement of cytogenetic laboratory techniques and may be used to develop performance standards for accreditation of both bone marrow and other cytogenetic laboratories. Internal and external quality controls have been used in general medical laboratories for many years, and their use should be instituted by cytogenetic laboratories as well.

Bone Marrow↗
PubMed1982

Cytogenetic studies of peripheral myeloblasts and bone marrow fibroblasts in acute myelofibrosis.

Chromosome analysis with giemsa-trypsin banding was performed on circulating myeloblasts and cultured bone marrow fibroblasts from a patient with acute myelofibrosis. Major karyotypic abnormalities were found in the myeloblasts involving chromosomes #1, 3, 5, 13, and 16; no chromosome abnormalities were detected in the fibroblasts. In addition, a pericentric inversion of number 7 was present in the circulating blasts but not the fibroblasts. Pericentric inversions have not previously been associated with acquired abnormalities of malignant cells. These findings support the concept that acute myelofibrosis is a primary malignancy of hematopoietic cells associated with secondary marrow fibrosis. The entity of acute myelofibrosis is discussed and the results of cytogenetic studies of previous reports are reviewed.

Acute Disease↗
PubMedDate not supplied

Solitary rectal ulcer: the place of biofeedback and surgery in the treatment of the syndrome.

Thirty-one patients with the solitary rectal ulcer syndrome were studied, the majority of whom presented with fresh blood per rectum and a rectal ulcer, mucorrhoea, or a varying degree of rectal prolapse. Fourteen patients were treated conservatively or with surgery and had a high rate of recurrence of the solitary rectal ulcer syndrome. Seventeen patients were treated with biofeedback for the associated obstructed defecation (anismus) either before or immediately after surgery with a lower recurrence rate. The final symptomatic cure rate was similar in both groups but 15 episodes of recurrence requiring further surgery were encountered in the non-biofeedback group compared to 4 recurrences in the biofeedback group.

Adolescent↗