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Biomedical subjects

C O'Brien

Publications and source records attributed to C O'Brien.

At least 253 records · Page 14Linked to original sources
PubMed1986

Indium-111-labeled autologous leukocyte scanning in gastrointestinal graft versus host disease (GVHD).

The technique of scanning with indium-111 autologous leukocytes has been used to assess gastrointestinal graft-versus-host disease (GVHD) following allogenic marrow transplantation. In patients with active disease, abdominal scans showed extensive abnormal localization in the bowel, while in those whose disease was quiescent after responding to treatment, scans showed localized ileocecal involvement. Rectal histology showed excellent agreement with scanning in the diagnosis of GVHD, but in three of six cases with active disease underestimated disease severity. Indium-111 leukocyte scanning is a useful noninvasive technique for the diagnosis and assessment of gut GVHD.

Acute Disease↗
PubMed1986

The spectrum of liver disease in the acquired immunodeficiency syndrome.

Abnormal liver chemistries, unexplained fevers, or hepatomegaly prompted 36 liver biopsies on 34 patients with the acquired immunodeficiency syndrome. The most common finding was the presence of hepatic granulomas, seen in 13 of the biopsy specimens. Eight of these granulomas were ill-defined, and 5 were more clearly associated with mycobacterial disease. Portal fibrosis and fatty infiltration were common, but a paucity of significant inflammatory activity was seen despite elevated aspartate aminotransferase levels, perhaps related to the underlying immunoincompetent status. Other noteworthy histopathologic findings included 1 patient each with peliosis hepatis and cryptococcal hepatitis. Electron-microscopic evidence of cytoplasmic tubular structures or viral particles were seen within the hepatocytes of 2 patients. It is concluded that a broad spectrum of hepatic histopathology may be seen in the acquired immunodeficiency syndrome, and that liver biopsy may be diagnostically valuable in the clinical investigation of such patients.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Rising incidence of lymphoid malignancies--true or false?

The report contrasts the ascertainment of cases by the regional cancer registry with a specially designed search for records and pathology material which was then submitted to critical review irrespective of the original diagnosis. Boundary changes over the intervening years were accounted for and the results contrasted between time periods and with the cancer registry records. A large proportion of cancer registry cases were never subjected to histopathological diagnosis and comparisons between the new data and records are not easy to undertake. The study describes a probable true rise in the incidence of follicular non-Hodgkin's lymphoma in certain parts of Yorkshire over the last 20 years; there is less evidence of a similar change in Hodgkin's disease incidence over the same period of time.

Adolescent↗
PubMed1985

Peripheral mucociliary clearance with high-frequency chest wall compression.

We investigated the effects of high-frequency chest wall compression (HFCWC) on peripheral and tracheal mucus clearance in anesthetized spontaneously breathing dogs. HFCWC was achieved by oscillating the pressure in a thoracic cuff with a piston pump. Regional lung retention of a technetium-99m sulfur colloid aerosol was monitored with a gamma camera. A peripheral mucus clearance index (PMCI) was defined for each region of interest. The tracheal mucus clearance rate (TMCR) was determined by bronchoscopic visualization of marker particle transport. Phase I: In seven dogs, 30 min of HFCWC at 13 Hz with peak cuff pressure (Pcuff) 100-120 cmH2O was found to significantly enhance PMCI in regions immediately under the cuff. (delta PMCI = 24.4 +/- 4.6 in the basal peripheral region.) Phase II: Because of subpleural hemorrhage in phase I, the effect of HFCWC on TMCR at various Pcuff levels was studied in five dogs. The enhancement of TMCR by HFCWC reached a plateau level at Pcuff = 50 cmH2O. Phase III: HFCWC at 13 Hz with Pcuff = 50-60 cmH2O was found to significantly enhance PMCI in five dogs without the consequence of hemorrhage. Correlations were found between the enhancement of PMCI and TMCR by HFCWC. These results demonstrate that HFCWC is effective in enhancing both peripheral and central mucus clearance in dogs and safe when moderate pressures are applied.

Animals↗
PubMed1985

The Neuman Systems Model in practice. Planning phase.

How do you choose and plan for the implementation of a conceptual model for professional nursing practice? This article discusses one institution's experience with the Neuman Systems Model. The process discussed in this article will serve as a guide for other nursing administrators considering this significant undertaking.

Curriculum↗
PubMed1983

The histopathology of adult T-cell lymphoma/leukaemia in blacks from the Caribbean.

The histopathological features of seven cases of adult T-cell lymphoma/leukaemia (ATLL), all occurring in black patients from the Caribbean, are described. Lymph node infiltrates are initially restricted to the paracortical zone, with preservation of the nodal shape and subcapsular sinus, and accompanied by a proliferation of post-capillary venules. Cytologically, a range of cell types is present, from smaller cells with irregularly shaped nuclei and clumped nuclear chromatin to larger cells with dispersed chromatin and more prominent nucleoli, apparently corresponding to the stages of peripheral T-lymphocyte transformation. The proportion of each cell type present varies from case to case, as do the numbers of admixed eosinophils, plasma cells and interdigitating reticulum cells. These histological appearances are very similar to those of the pleomorphic T-cell lymphoma described in Japan, which also shows many clinical similarities, including a high incidence of complicating hypercalcaemia. There is a strong association in both Japanese and Caribbean patients with a recently described human retrovirus, HTLV, which occurs endemically in those areas where the disease clusters. Morphological similarities exist between ATLL and other peripheral T-cell lymphomata and leukaemias. These are illustrated by one notable 'linking' case. However, while related to other disorders of mature T-lymphocytes, ATLL nevertheless represents an identifiably separate clinicopathological entity.

Adult↗
PubMed1981

Medullary carcinoma of the thyroid presenting as tumours of the pharynx and larynx.

Two cases of medullary carcinoma of the thyroid presenting as tumours of the pharynx and larynx are described. One patient had a tonsillar mass that resembled a carotid body tumour clinically, radiologically and microscopically. The other had an arytenoid tumour with multiple cervical lymph node metastases but without intrathyroidal carcinoma. The endocrine nature of the neoplasms was indicated by the presence of stromal amyloid, cellular argyrophilia and secretory granules whilst the demonstration of calcitonin and carcinoembryonic antigen provided evidence that they were medullary carcinomas.

Aged↗
PubMed1980

The cellular basis for viral-induced immunodeficiency: analysis by monoclonal antibodies.

Viral infections are often associated with immunodeficiency states. Although T lymphocytes have been thought to suppress the host's response, the precise etiology remains unclear. Therefore, we characterized T lymphocytes from six patients during both acute and convalescent phases of infectious mononucleosis (IM) with monoclonal antibodies (titer, 10(-5) to 10(-7) to antigens restricted to the TH2- helper (T4) and TH2 suppressor (T5) T cell subsets as well as to a common T cell antigen (T3) and HLA-D related Ia antigens. It was found that during acute infectious mononucleosis, there is both activation and increase of suppressor T cells (T5+, Ia+ phenotype). Fuctionally, the acute IM lymphocytes suppress autologous T cell proliferation to antigens as well as pokeweed mitogen driven B cell immunoglobulin production. In contrast, convalescence is associated with a return to normal of T cell subsets and immune function. These results demonstrate that viral infections can preferentially activate a specific T cell subset and suppress the overall human immune response.

Acute Disease↗
PubMed1980

Cell surface antigens: prognostic implications in childhood acute lymphoblastic leukemia.

Lymphoblasts from 93 children with acute lymphoblastic leukemia (ALL) were characterized by immunologic cell surface markers. These patients were treated on a single protocol, featuring adriamycin therapy during remission, and have been followed from 2 to 6.5 yr (median 4 yr). Three classes of patients were defined serologically: HTA+ Ia- CALLA-, Ia+ CALLA+ HTA-, and Ia+ CALLA- HTA-. Disease-free survival and sites of relapse were assessed within immunologic subsets. Similar to the findings of others, T-cell (HTA+ Ia-) patients fared poorly as compared to non-T-cell (Ia+ HTA-) patients (median disease-free survival was 12 and 47 mo. respectively; p = 0.0004). The majority of relapses in the HTA+ patients occurred at extramedullary sites. Late testicular relapse was rare among Ia+ patients. In addition, the "common ALL antigen" (CALLA) may identify a relatively favorable subset within the Ia+ population. The prognostic value of the immunologic markers was compared with traditional clinical factors. There was much overlap between HTA+, older age, and elevated WBC. However, neither age nor WBC alone were of prognostic significance among the Ia+ patients. We conclude that surface markers define both biologic and prognostic characteristics. The course of childhood ALL must be viewed in the context of homogeneous subsets and within particular therapeutic programs.

Antigens, Neoplasm↗
PubMed1979

Phenotypic and functional distinctions between the TH2+ and JRA+ T cell subsets in man.

Prior work has demonstrated the existence of distinct human peripheral blood T cell subsets by utilizing heterologous as well as autoimmune antisera. In the present study, the relationship between the TH2+ and JRA+ T cell subsets was examined. T cells were purified with Sephadex G-200 anti-F(ab)2' affinity chromatography and E-rosetting technique, and subsequently fractionated into TH2+ and TH2- subsets by utilizing indirect immunofluorescence on FACS. Approximately 40 to 45% of the TH2- subset was shown to be JRA+, whereas less than 5% of the TH2+ subset was JRA+. In reciprocal studies, T cells were fractionated into JRA+ and JRA- subsets and reacted with heterologous antisera with anti-TH2+ specificity and indirect immunofluorescence. FACS analysis demonstrated that the JRA+ population contained no TH2+ T cells. In contrast, the JRA- population contained TH2+ T cells and accounted for the entire TH2+ subset found in the unfractionated T cell population. Functional studies showed that the TH2+ subset, and not the JRA+ subset, contain the effector population for cell-mediated lympholysis. It is concluded that the TH2+ and JRA+ T cell subsets define distinct and different T cell populations in man.

Antilymphocyte Serum↗