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Biomedical subjects

P Dunn

Publications and source records attributed to P Dunn.

At least 73 records · Page 4Linked to original sources
PubMed1997

Determination of factors associated with condom use among women infected with human immunodeficiency virus.

To better understand potential barriers to condom use and the sexual behaviour of women infected with human immunodeficiency virus (HIV), an anonymous self-administered survey was performed on a convenience sample of 83 predominantly single HIV+ women. Most women had only one sexual partner who usually knew of the subject's serostatus. Only a minority of partners (26%) were known to also be HIV infected. Subjects were surprisingly more likely to use condoms with their main partner as opposed to other partners. Factors found to be associated with condom non-use included younger age, low education level, partner HIV+, history of a sexually transmitted disease (STD), and use of drugs or alcohol during sex. Although most subjects indicated the decision was mutual when deciding not to use a condom, 20% stated it a was a partner decision. Future intervention efforts should target these identified high-risk individuals and optimally involve the partners of HIV-infected women.

Adolescent↗
PubMed1996

Active minimisation of radiation scatter during breast radiotherapy: management implications for young patients with good-prognosis primary neoplasms.

BACKGROUND AND PURPOSE: Radiotherapy is used to reverse or prevent local tumour growth but is also a carcinogen in its own right. A recent audit of post-radiotherapy second malignancies in this institution revealed a striking preponderance of tumours originating near the outside edge of the treatment field. Since this finding suggests the existence of a critical subtherapeutic dose range predisposing to tumourigenesis, we attempted to define and reduce this radiation scatter dose. MATERIALS AND METHODS: We undertook a dosimetric review of 6 MV scatter from a linear accelerator in sites matching the putative tumourigenic region, and then extended this analysis to patients and tissue phantoms. RESULTS: A wide range of radiation scatter doses was confirmed-for example, doses 3 cm from the field edge varied from 1.7 to 22% of the therapeutic dose depending upon the field parameters. Scatter doses were then assessed in a sample of eight patients undergoing standard breast radiotherapy. Contralateral breast sites 4-12 cm from the midline received 4-10% of the therapeutic dose, or 200-500 cGy for a 50 Gy treatment, approximating historical estimates of the tumourigenic range. The deep component of this scatter dose from medial field breast irradiation was reduced 19% simply by replacing the 15 degrees medial tangential field wedge with a 30 degrees lateral wedge. Other manoeuvres which reduced contralateral breast dose by up to 46% included making the posterior field edges co-planar and shielding the breast during medial field irradiation. CONCLUSIONS: These results suggest that the risk of radiogenic second malignancies could be significantly decreased by careful attention to the treatment details. Greater awareness of these measures may prove particularly relevant to the conservative management of young patients with good-prognosis breast neoplasms such as ductal carcinoma in situ.

Breast↗
PubMed1996

Adolescents' perceptions of relative weight and self-reported weight-loss activities: analysis of 1990 YRBS (Youth Risk behavior Survey) national data.

PURPOSE: The purpose of the study was to examine, among public high school students across the United States, perceptions of relative weight-loss and its relationship to physical activity levels, time spent viewing television, and efforts to lose weight. METHODS: Self-reported data from the 1990 Youth Risk Behavior Survey (YRBS) were used to analyze these relationships. The YRBS was developed and administered by the Division of Adolescent and School Health (DASH), Centers for Disease Control and Prevention (CDC), to assess important health behaviors which contribute significantly to adverse health outcomes among American youth. A total of 10,870 black, Hispanic, and white respondents were included in this analysis. RESULTS: From this sample, 24.8% perceived themselves as being "too fat." Of that group, 76.4% were trying to lose weight. Females comprised 74.4% of those reporting that they were "too fat" and trying to lose weight. Gender differences in weight perceptions were significant (p < .001), with females (34.6%) being more likely than males (14.4%) to report being "too fat." Whites (26.0%) reported being "too fat" more often than did Hispanics (23.9%) and blacks (17.2%) (p < .001). Skipping meals and exercise were the most commonly reported weight loss strategies. Hispanics were most likely to skip meals, followed by whites and blacks. Whites were more likely than the other groups to use exercise as a means of losing weight. Adolescents who perceived themselves as "too fat" reported fewer days of strenuous activity (p < .001), fewer hours of strenuous exercise in physical education class (p < .001), and more hours spent viewing television on school days (p < .001) than others. CONCLUSIONS: One quarter of U.S. high school students perceive themselves as overweight; three-quarters of these students are trying to lose weight. Adolescents who perceive themselves as overweight are less physically active and spend more time viewing television than those who do not perceive themselves as overweight.

Adolescent↗
PubMed1995

Localised plasmacytomas in Taiwan: comparison between extramedullary plasmacytoma and solitary plasmacytoma of bone.

The clinical features and response to therapy of 32 Chinese patients with localised plasmacytoma are presented, and a comparison between extramedullary plasmacytoma (EMP) and solitary plasmacytoma of bone (SPB) is made. Twenty-two patients had SPB and ten had EMP, accounting for 9% of all of our plasma cell neoplasms. Both groups had a male predominance with a median age of 54 years for SPB and 63 years for EMP. The common sites of SPB included vertebral bodies (15) and the skull (4). Most EMPs occurred in the oronasopharynx (6) and paranasal sinuses (2). An M-protein was detected in eight patients with SPB and in six with EMP. Seventeen patients with SPB and seven with EMP received radiation therapy, and all achieved initial local control. The pattern of failure in 22 patients with SPB manifested as local recurrence in two, multiple bone metastases without bone marrow plasmacytosis in two, multiple EMP progression in two, and development of multiple myeloma (MM) in one. There were two local recurrences, one further solitary bone involvement and one MM conversion in the EMP group. Local recurrence or dissemination was associated with the appearance of M-protein or an increase in the M-protein level in both groups. There was no significant difference in M-protein status or incidence and patterns of failure between the two groups. Patients with EMP had a more favourable overall survival than those with SPB (P = 0.03). The 5 year disease-free survival rate was 79% for EMP and 58% for SPB (P = 0.53). Patients aged less than 60 years had a better overall survival in the SPB group, but location of tumour, presence of M-protein, radiation dose and chemotherapy did not influence prognosis in either group. Our results indicate that adequate local therapy can result in long-term survival with a low frequency of MM progression for patients with localised plasmacytomas, and both EMP and SPB appear to be similar in terms of frequency and patterns of failure.

Adult↗
PubMed1995

Hairy cell leukemia variant.

A 59-year-old man presented with lymphocytosis with huge splenomegaly. The abnormal lymphocytes had a high nucleoplasm:cytoplasm ratio, a prominent nucleolus and hairy cytoplasmic projections. Immunophenotyping revealed B-cell leukemia with negative reactions to CD5 and CD25. Cytogenetic study showed 46,XY,der(5)t(5;6)(q35;p21), del(7)(p13)/46,idem,add(22)(q13). The patient did not respond to chlorambucil and a combination of cyclophosphamide, vincristine and prednisolone. Splenic irradiation induced partial remission. He developed progressive anemia and thrombocytopenia and died of Escherichia coli septicemia 33 months after the diagnosis of hairy cell leukemia variant.

Fatal Outcome↗
PubMed1995

Plasmacytoid lymphocytic lymphoma presenting with IgG hyperviscosity syndrome and peritoneal lymphomatosis.

We reported a 74-year-old woman with plasmacytoid lymphocytic lymphoma who initially presented with exertional dyspnea, conscious disturbance, ascites, and lytic skull lesions. Protein electrophoresis and immunoelectrophoresis showed monoclonal IgG-lambda gammopathy with IgG level of 13300 mg/dl and marked suppression of the residual normal immunoglobulins. Abdominal computed tomography (CT) revealed a pattern mimicked cancerous peritonitis. She responded to plasmapheresis with much clinical improvement of the hyperviscosity syndrome but died of H. influenza sepsis 3 weeks after diagnosis. The unusual and interesting features of this case included: (1) IgG hyperviscosity syndrome and diffuse peritoneal involvement as the initial manifestations in plasmacytoid lymphocytic lymphoma, and (2) presence of lytic bone lesions in conjunction with high level of M--component and marked suppression of normal residual immunoglobulins in a patient with lymphoma rather than multiple myeloma.

Aged↗
PubMed1995

Acute hepatitis A with coexistent hepatitis C virus infection presenting as a virus-associated hemophagocytic syndrome: a case report.

A 23-yr-old male with acute hepatitis A and coexistent hepatitis C became critically ill 3 wk after the onset of fever and jaundice with progressive anemia, thrombocytopenia, and hepatosplenomegaly. Bone marrow biopsy revealed hemophagocytosis. Despite aggressive supportive treatment with parenteral steroids, the patient died of disseminated intravascular coagulopathy with gastrointestinal bleeding. Necropsy of the liver showed histiocyte aggregation in the portal area with hemophagocytosis.

Acute Disease↗
PubMed1995

Richter's syndrome: report of a case.

A 42-year-old male presented with generalized massive lymphadenopathy, fever, weight loss and numerous cutaneous nodules. Peripheral blood examination showed lymphocytosis with small lymphocytes, and immunophenotyping revealed B-cell chronic lymphocytic leukemia (CLL). Cytogenetic analysis of bone marrow aspirate revealed a clonal abnormality of chromosome 11. Lymph node biopsies showed a B-immunoblastic lymphoma. A diagnosis of Richter's syndrome (RS) was made. The patient did not respond to doxorubicin, cyclophosphamide, vincristine and prednisolone (CHOP) and died of progressive disease with pneumonia and respiratory failure 9 months later. CLL is not common among Chinese people and RS is extremely rare.

Adult↗
PubMed1994

Primary small-intestinal lymphomas in Taiwan: immunoproliferative small-intestinal disease and nonimmunoproliferative small-intestinal disease.

PURPOSE: The clinicopathologic findings in 45 adult Chinese patients with primary small-intestinal lymphoma (PSIL) are described and compared with those in Western countries and in underdeveloped nations. The efficacy of combination chemotherapy is also assessed. PATIENTS AND METHOD: Six patients had immunoproliferative small-intestinal disease (IPSID) indicated by the presence of alpha-heavy chain protein (alpha-CP) in body fluids or tumor tissues. Thirty-nine patients had non-IPSID, including one with postrenal transplant lymphoma. Thirty-three non-IPSID patients received a minimum of four cycles of combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP). RESULTS: All IPSID patients presented with the clinical and laboratory features of severe intestinal malabsorption, and all had diffuse lymphoplasmacytic infiltration in the mucosa of the small bowel. Lymphomas were localized mainly in the jejunum and mesenteric nodes. The histologic subtypes were diffuse large cell in two, immunoblastic in three, and diffuse mixed in one. All patients responded poorly to chemotherapy, with a median survival duration of 10.5 months. The common presenting symptoms of the 39 non-IPSID patients included abdominal pain (90%), weight loss (31%), abdominal mass (26%), obstruction (26%), and perforation (23%). Diffuse large-cell and immunoblastic lymphomas constituted 82% of cases. Four patients had stage IE, 19 stage II 1E, and 16 stage 112E disease according to the Musshoff's criteria; 22 had bulky tumors and 19 had multiple tumors. The tumors were completely resected in 14 patients. Of 33 patients treated with combination chemotherapy, 73% achieved a complete remission. With a median follow-up duration of 90 months, there have been four relapses, with only one at the primary tumor site. The overall 5-year survival and disease-free survival rates for non-IPSID patients who were treated with chemotherapy were 59% and 54%, respectively. CONCLUSION: Intensive chemotherapy produces long-term disease-free survival in locally advanced non-IPSID PSIL.

Adult↗
PubMed1994

Extramedullary plasmacytoma of the head and neck.

Extramedullary plasmacytoma (EMP) is an uncommon malignant plasma cell neoplasm which usually presents as soft tissue mass in the head and neck. We retrospectively reviewed 7 cases with EMP of the head and neck between 1978 and 1992. All patients were male. Their ages ranged from 27 to 66 years. M-protein was identified in 5 patients (IgG-kappa in 3, IgG-lambda in 1 and Lambda light chain in 1). All but one were treated with local irradiation. Three patients received chemotherapy. All patients have been alive for 37+ to 116+ months since the diagnosis of EMP. One patient had a cervical node recurrence 9 years after local irradiation and the other one who refused local irradiation but received chemotherapy developed multiple myeloma 5 years later. Based on our experience and the review of the literature, it is recommended that irradiation to the primary sites and the involved cervical nodes is the treatment of choice. Additional chemotherapy may be considered in patients with disease progression, recurrence, or dissemination. The M-protein is a useful parameter to assess tumor control or disease progression.

Adult↗
PubMed1994

Solitary plasmacytoma of bone.

From 1978 to 1992, 19 patients were diagnosed with solitary plasmacytoma of bone (SPB) accounting for 5.5% of plasma cell neoplasms in Chang Gung Memorial Hospital. Fourteen were male and five were female, with ages ranging from 21 to 71 years (median, 53 years). M-protein was detected at diagnosis in five patients, and during follow-up in three. The most common sites of SPB were the vertebral bodies, with seven involving the thoracic, four involving the lumbar and two involving the cervical spine. The remaining sites included the skull in four, and femur and pelvis in one each. Fifteen of the patients received local radiotherapy, local control was achieved in all; nine patients were alive with no evidence of disease for seven to 77 months, two patients remained in apparent remission at 14 and 92 months, two patients progressed to multiple myeloma at 12 and 84 months, one patient developed extramedullary plasmacytoma at three months, and one patient died of intercurrent disease at four months. The four patients who were not treated with radiation therapy ultimately developed local recurrence or dissemination within four years. In our series, local recurrence or dissemination was always associated with the appearance of, or an increase in, the M-component; thus, measurement of M-protein is helpful in assessing tumor control or progression. Based on our experience and a review of the literature, it is recommended that irradiation of the primary sites is the treatment of choice. Chemotherapy is indicated in those patients with disease progression, recurrence, or dissemination.

Adult↗
PubMed1993

Bone marrow necrosis in 38 adult cancer patients.

From 1977 to 1990, 40 cases of bone marrow necrosis (BMN) were diagnosed among 10,856 (0.37%) consecutive bone marrow aspirations performed alone or with biopsy. All but two patients had underlying malignancies. Leukemia, nasopharyngeal cancer and cancer of unknown origin were the most common underlying diseases. Severe bone pain and fever were the predominant presenting symptoms. Anemia, schistocytes and leukoerythroblastosis were noted in the peripheral blood smears in 97% (37/38), 72% (22/32), and 66% (23/35) of the patients with cancer and BMN. Malignant cells were found in bone marrow aspirates or biopsy specimens in all but one of the patients. Varied degrees of disseminated intravascular coagulation were demonstrated in all of the 10 patients examined who displayed coagulation status. Four of seven patients with leukemia achieved complete remission after chemotherapy, and the survival time for the complete responders ranged from 10 months to eight years. The outcome of cancer patients with BMN who did not respond to chemotherapy was poor, with a median survival time of six weeks.

Adolescent↗
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↗