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Biomedical subjects

P Dunn

Publications and source records attributed to P Dunn.

At least 19 recordsLinked to original sources
PubMed1992

HTLV-I-positive and HTLV-I-negative peripheral T-cell lymphomas in Taiwan Chinese.

The clinico-pathologic features of 107 adult Chinese patients with peripheral T-cell lymphoma (excluding primary cutaneous lymphoma) are described and a comparison between HTLVI+ and HTLV-I- patients is made. There were 27 HTLV-I+ and 80 HTLV-I- patients. The virus-positive and -negative groups both had a male predominance and an identical median age of 48. Most patients in both groups presented with stage-IV disease, B symptoms, lymphadenopathy and hepatosplenomegaly. The HTLV-I+ group had a significantly higher incidence of skin and pulmonary lesions, bone marrow and peripheral blood involvement, hypercalcemia, and elevated LDH level compared to the HTLV-I- group. Sinonasal lesions (10), mediastinal mass (5), and GI tract involvement (6) were only seen in the HTLV-I- group. Leukocytosis with the presence of circulating pleomorphic lymphoid cells was characteristic of HTLV-I+ cases, while cytopenia was more frequently present in HTLV-I- cases. All of the 24 HTLV-I+ patients tested were CD4+CD8-; of the 67 HTLV-I- patients tested, 46 were CD4+CD8-, 9 were CD4-CD8 , 5 were CD4-CD8- and 7 were CD4+CD8+. Phenotypic studies revealed significant differences in the expression of CD7 and CD25 between virus-positive and -negative groups. Both groups responded poorly to therapy. The median survival of HTLVI+ and HTLV-I- patients was 4 months and 13.5 months, respectively. Apart from the presence of more than 3 extranodal lesions, none of the other clinical features or histologic subtypes had prognostic significance in the entire group or either of the subgroups. This series of peripheral T-cell lymphomas in Taiwan indicate that HTLV-I+ and HTLV-I- patients had many features in common, but presented several distinct differences.

Adolescent↗
PubMed1992

Acyclovir bioavailability in human skin.

Clinical experience demonstrates that oral acyclovir (ACV) is superior to topical ACV in treating recurrent cutaneous herpes simplex virus type 1 (HSV-1) infections. Cutaneous HSV-1 infections are complex in their pathology, affecting the basal epidermis in skin as well as establishing a latency phase in sensory ganglia. In vitro and in vivo human skin model systems were used in the present study to quantitate ACV disposition and absorption in skin and blood following two routes of administration and to investigate whether bioavailability differences were the result of insufficient drug delivery. Physiochemical and physiologic parameters determined from these experiments were used to develop a mathematical model to predict ACV disposition and absorption in human subjects. Model predictions and in vivo data agree; topical administration of commercial 5% ACV ointment and cream result in a 48 times greater total epidermal ACV concentration than after oral administration. Mathematical modeling of the ACV concentration gradient through the epidermis revealed, however, that the drug concentration in the target site of HSV-1 infections, the basal epidermis, is 2-3 times less after topical administration than after oral administration. Thus, the observed lack of clinical efficacy with topical ACV therapy in the recurring HSV-1 infection likely reflects the insufficient delivery of the drug to the target site of the HSV-1 infection, the basal epidermis.

Absorption↗
PubMed1992

Adolescents' perceptions of relative weight and self-reported weight loss activities.

Data from the 1990 North Carolina Youth Risk Behavior Survey (YRBS) were used to examine adolescents' perceptions of relative weight and the relationship of these perceptions to physical activity levels, efforts to lose weight, and time spent viewing television. A total of 3,437 ninth and 12th grade respondents to the May 1990 survey were included in the analysis. Of this sample, 25% perceived themselves as "too fat." Of that group, 68% were trying to lose weight. Females made up 75% of those reporting they were "too fat" and were trying to lose weight. White females were more likely to think of themselves as overweight and were more likely to be trying to lose weight than black females. Adolescents who perceived themselves as "too fat" reported fewer days of strenuous activity, fewer hours of strenuous exercise in physical education classes, and more hours spent viewing television on school days.

Adolescent↗
PubMed1992

Characterization of cDNAs encoding two isoforms of granule-bound starch synthase which show differential expression in developing storage organs of pea and potato.

We have isolated cDNA clones to two isoforms of granule-bound starch synthase (GBSS) from pea embryos and potato tubers. The sequences of both isoforms are related to that of glycogen synthase from E. coli and one, GBSSI, is very similar to the waxy protein of maize and other species. In pea, GBSSII carries a novel 203-amino-acid domain at its N-terminus. Genes encoding both proteins are expressed during pea embryo development, but GBSSII is most highly expressed earlier in development than GBSSI. Similarly, GBSSI and GBSSII are differentially expressed in developing potato tubers. Expression of both isoforms is much lower in other organs of pea than in embryos. GBSSII is expressed in every organ tested while GBSSI is not expressed in roots, stipules or flowers. The possible consequences of this differential use of GBSS isoforms are discussed.

Amino Acid Sequence↗
PubMed1991

Genome mapping with anchored clones: theoretical aspects.

As part of our effort to construct a physical map of the genome of Arabidopsis thaliana we have made a mathematical analysis of our experimental approach of anchoring yeast artificial chromosome clones with genetically mapped RFLPs and RAPDs. The details of this analysis are presented and their implications for mapping the Arabidopsis genome are discussed.

Chromosome Mapping↗
PubMed1991

Clinical nursing research priorities: a Delphi study.

Using the delphi technique, a group of clinical nurse specialists was surveyed regarding delineation of clinical nursing research priorities. Upon completion of the four-round survey, the results suggested that the top priorities for nursing research are: (1) factors which influence longevity in clinical nursing practice, (2) patient care delivery systems as related to nurse satisfaction, and (3) indicators of quality nursing care.

Attitude of Health Personnel↗
PubMed1991

Human T-cell lymphotropic virus type I associated adult T-cell leukaemia/lymphoma in Taiwan Chinese.

Twenty-five Chinese patients with human T-cell lymphotropic virus type I (HTLV-I) associated adult T-cell leukaemia/lymphoma (ATLL) were identified in Taiwan. No patients had been outside Taiwan and none were descendants of Japanese heritage. Their ages ranged from 28 to 71 years. There were 17 men and eight women. Main clinical and laboratory features at presentation were lymphadenopathy (16), skin lesions (11), hepatosplenomegaly (11), pulmonary lesions (11), hypercalcaemia (10) and bone marrow infiltration (14). Peripheral blood was characterized by leucocytosis with presence of pleomorphic abnormal lymphocytes but rare anaemia or thrombocytopenia. The clinical subtypes were acute in 15, chronic in three, smouldering in one, and lymphoma type in six. The immunophenotypes of the ATLL cells were characterized by the expression of CD2+, CD4+, CD7-, CD8- and CD25+. The overall prognosis was poor with a median survival of 5 months. The acute form had a significantly shorter survival (2 months) than lymphoma type (13 months). Susceptibility to various infections was common. Pulmonary complications accounted for 73% of the causes of death. The clinicopathologic features of ATLL in Taiwan are indistinguishable from those in HTLV-I endemic areas. The present series adds to the knowledge of the worldwide pattern of the disease.

Adult↗
PubMed1991

Treating the vaginal vault in carcinoma of the endometrium using the Buchler afterloading system.

The advent of high-dose-rate afterloading intracavitary radiotherapy has implications for both staff safety and the possibility of convenient, outpatient-based treatment for the patient. We have carried out a retrospective analysis of its use with high-activity iridium 192 and the Buchler machine to treat the vaginal valut in patients with adenocarcinoma of the endometrium, most of whom also received external-beam radiotherapy to the pelvis. We have compared the survival, complication and local control rates with a comparable group of historical controls treated with low-dose-rate intracavitary caesium ovoids. Complication rates, which included vaginal stenosis not volunteered by the patient, were 16% (95% confidence intervals 6-26%) in the study group and 28% (95% confidence intervals 17-41%) in the control group, with no serious complications requiring surgery. The actuarial survival was 92% at 5 years in the study group, and 94% at 5 years in the control group. Local control was 94% at 5 years in the control group and 98% at 5 years in the study group. The authors suggest that the use of high-dose-rate intracavitary radiotherapy, with the Buchler afterloading system, for vaginal vault irradiation in carcinoma of the endometrium is a convenient, safe and quick method, which does not necessitate admission or sedation of the patient. In addition it provides complete radiation protection for staff.

Adenocarcinoma↗
PubMed1991

Paroxysmal nocturnal hemoglobinuria: analysis of 40 cases.

Forty cases of paroxysmal nocturnal hemoglobinuria (PNH) were studied from 1978 to 1988. Thirty patients were male and 10 were female. Their ages ranged from 15 to 58 years with a median of 32 years. Symptoms related to anemia (85%) and dark colored urine (45%) were the most frequent clinical manifestations. Seven patients (17.5%) had a previous history of aplastic anemia. The interval between the diagnosis of aplastic anemia and PNH ranged from 11 months to 26 years. All the patients had anemia with varying combinations of cytopenia. In 36 patients, bone marrow examinations were performed, and 32 were hypercellular, one normocellular and 3 hypocellular. Documented thrombosis was noted in 3 patients, involving the intra-abdominal, cerebral and renal veins, respectively. The patient with intra-abdominal venous thrombosis subsequently died of E. coli septicemia. The remaining two patients achieved complete recovery. All 40 patients were treated with corticosteroids and/or anabolic agents, 32 (80%) patients improved and 4 (10%) achieved normal hemoglobin levels. Our studies demonstrate that there is a male predominance in Chinese PNH patients and the incidence of thrombotic complications is much lower than that reported by Western countries.

Adolescent↗
PubMed1989

Non-Hodgkin's lymphoma of Waldeyer's ring: an appraisal of therapeutic effect.

From July 1978 to June 1987, non-Hodgkin's lymphoma was diagnosed in 667 patients at Chang Gung Memorial Hospital. Forty-eight (7%) patients presented primarily with involvement of Waldeyer's ring; their provisional clinical stage was I or II. The tonsils represented the most frequent site of involvement within Waldeyer's ring. A work-up showed 33.3% of patients with stage I, 50% with stage II, 8.3% with stage III and 8.3% with stage IV. All the patients had diffuse lymphomas. Diffuse large cell (46%) and immunoblastic lymphomas (23%) were the most common histologic subtypes. Eight patients received radiotherapy alone, 39 patients were treated with combination chemotherapy with or without local radiation and one patient was lost to follow-up. Eleven of 16 stage I (69%) and 18 of 23 stage II (78%) patients achieved a complete remission. The median survival for stage I patients was over 54 months and the median survival of stage II was 72 months. There was no significant difference between the stage I and II patients with lymphoma of Waldeyer's ring with respect to the complete remission rate and survival. Stage I patients had a relapse-free survival rate of 55% at 4 years, similar to that (49%) of stage II patients at 8 years. We recommend that chemotherapy be used as primary therapy for those patients with localized aggressive lymphoma of Waldeyer's ring.

Adolescent↗
PubMed1989

Association of ankylosing spondylitis with IgA-multiple myeloma: report of a case and pathogenetic considerations.

Multiple myeloma has rarely been reported in patients with ankylosing spondylitis. We observed a patient with a 20-year history of ankylosing spondylitis, who subsequently developed IgA myeloma. This association may not be simply coincidental. It has been proposed that the protracted stimulation of immunocytes by inflammatory lesions on the mucosal surfaces of the gastrointestinal, respiratory, and biliary tracts, where lymphocytes are already committed to IgA production, may be implicated in the pathogenesis of IgA myeloma in some patients. Ankylosing spondylitis is a chronic inflammatory disease, probably resulting from the interaction of a genetic predisposition involving HLA-B27 with an environmental event such as enteric bacterial infection. We propose that ankylosing spondylitis and IgA myeloma occurring concomitantly in our patient implies a possible pathogenetic relationship. In ankylosing spondylitis, persistent reticuloendothelial stimulation, due to chronic subclinical gastrointestinal infection, may lead to IgA-producing plasma cell activation and proliferation, and subsequent IgA myeloma development.

Humans↗
PubMed1988

In vitro culture studies of blood and marrow cells in chronic myeloid leukemia at different phases of the disease.

The in vitro culture growth of peripheral blood (PB) and bone marrow (BM) cells were studied simultaneously from 100 adult patients with chronic myeloid leukemia at different phases. Sixty-five patients were investigated at initial diagnosis, 30 patients in control phase, and 41 patients in blast phase. In untreated chronic phase, the relative concentrations of granulocyte-macrophage progenitor cells (CFU-GM) in BM were not significantly different from those of normal controls, but there was generally a marked increase in circulating CFU-GM. The 6 Ph1-negative patients did not show different growth characteristics. We were unable to correlate the CFU-GM number to any of the hematologic parameters as well as to the response to busulfan therapy. Pretreated patients with excessive cluster formation did not necessarily indicate impending blast crisis. In hematologic remission, the numbers of CFU-GM in both BM and PB were well within the ranges of normal controls. Culture results in blast phase revealed a spectrum of abnormal growth. In myeloid crisis, 14/29 BM and 12/29 PB samples showed increased colony and cluster formations which were composed predominantly of immature cells with variable degeneration. Marrow cells in lymphoid crisis produced low numbers of both colonies and clusters in 5 out of 8 patients, while blood cells from 8 out of 10 patients formed large amount of colonies of normal morphology. This study indicates that the in vitro CFU-GM assay may have diagnostic utility in differentiating lymphoid crisis from myeloid crisis.

Adult↗