Biomedical subjects

Matthew C Cheung

Publications and source records attributed to Matthew C Cheung.

5 recordsLinked to original sources

PubMed2006

Yttrium 90 ibritumomab tiuxetan in lymphoma.

Radioimmunoconjugates are radioisotope-bound monoclonal antibodies that target radiation specifically to sites of lymphoma involvement. Initial studies of 90Y-ibritumomab tiuxetan in non-Hodgkin's lymphoma (NHL) have suggested benefit in patients with relapsed or refractory indolent disease. However, the routine adoption of this agent is tempered by concerns of associated toxicities and unclear long-term benefit. A comprehensive search for studies on 90Y-ibritumomab tiuxetan use in lymphoma was completed. The aims of this systematic review were to summarize and evaluate the evidence on: (1) the benefits and risks of this novel therapy; (2) predictors for response and toxicity; and (3) the role of dosimetry and imaging studies prior to treatment. A total of twenty trials investigating the use of 90Y-ibritumomab tiuxetan for the treatment of adult patients with NHL were identified. In trials of patients with relapsed or refractory indolent NHL, overall response rates ranged from 67 - 83%. In patients with follicular NHL refractory to the monoclonal antibody, rituximab, response rates remained high (74%). However, in rituximab-naïve patients with relapsed or refractory indolent or transformed NHL, the higher response rate seen with 90Y-ibritumomab tiuxetan therapy compared to rituximab monotherapy has not translated into clear improvements in time-to-progression or survival. 90Y-ibritumomab tiuxetan is an active agent in relapsed and refractory non-Hodgkin's lymphoma that should be considered in select patients.

Antibodies, Monoclonal↗

PubMed2004

Thrombocytosis.

Explore the source record for details and available documents.

Humans↗

PubMed2003

A cryptic cause of cryptococcal meningitis.

Cryptococcus neoformans commonly causes opportunistic infection in immunocompromised patients, especially in patients with AIDS. The CD4+ T-lymphocyte count is measured in patients with HIV infection, because it signals an increased risk of opportunistic infection and a decline in immunological function. We report a case of cryptococcal meningitis in a patient with persistently low CD4+ cell counts without evidence of HIV infection. The patient's underlying immunocompromised state was attributed to idiopathic CD4+ T-lymphocytopenia (ICL), a recently described syndrome characterized by depletions in the CD4+ T-cell subsets without evidence of HIV infection. Immunodeficiency can exist in the absence of laboratory evidence of HIV infection, highlighting the importance of evaluating T-cell subsets in patients who present with unusual infections.

Adult↗

PubMed2003

Evaluating paramedic comfort with field pronouncement: development and validation of an outcome measure.

OBJECTIVES: Interventions designed to improve cardiac resuscitation and the quality of field pronouncement need to consider outcomes on paramedic providers. The authors developed and evaluated the reliability and validity of a survey instrument measuring paramedic comfort with field pronouncement. METHODS: A mail survey of 120 paramedics (EMT-Ps) was performed using the Modified Dillman survey methodology. Questions were sorted for analysis into subgroups assessing psychological comfort and technical skills. Sixty-five respondents were retested within two weeks. RESULTS: The overall response rate was 96% (115). Respondents had an average age of 36 years (SD +/- 5), with 5.2 years (SD +/- 3.8) of out-of-hospital experience as an EMT-P, and were involved in a median of ten field pronouncements annually (range = 2-60). The face and content validity of the survey instrument was consistent with a content matrix derived by a focus group. The Cronbach's alpha for the survey instrument was 0.91. The retest response rate was 76% (46). The test-retest reliability coefficient was 0.84. CONCLUSIONS: This survey is a valid and reliable instrument for measuring the paramedic psychological comfort with field pronouncement. The high response rate and intrareliability support its generalizability. This outcome measure may be helpful in evaluating the psychological impact of changes to emergency medical services (EMS) policy with respect to termination of resuscitation promoted by the National Association of EMS Physicians.

Adult↗

PubMedDate not supplied

AIDS-related malignancies: emerging challenges in the era of highly active antiretroviral therapy.

Human immunodeficiency virus (HIV)-infected patients are at increased risk of developing cancer, particularly in the later stages of acquired immune deficiency syndrome (AIDS). Despite the advent of highly active anti-retroviral therapy (HAART), malignancy in this population is a leading cause of morbidity and mortality. Kaposi's sarcoma (KS) and AIDS-related non-Hodgkin's lymphoma (ARL) are the most common AIDS-defining malignancies. AIDS-related KS varies from minimal to fulminant disease. Treatment decisions for AIDS-related KS are guided largely by the presence and extent of symptomatic disease. In addition to HAART, excellent treatments exist for both localized disease (topical gel, radiotherapy, and intralesional therapy) and advanced disease (liposomal anthracyclines, paclitaxel). Novel therapies that have become available to treat AIDS-related KS include angiogenesis inhibitors and antiviral agents. ARL comprises a heterogeneous group of malignancies. With the immune restoration afforded by HAART, standard-dose chemotherapies now can be safely administered to treat ARL with curative intent. The role of analogous treatments used in HIV-negative patients, including monoclonal antibodies and autologous stem cell transplantation, requires further clarification in HIV-positive patients. HIV-infected patients also appear to be at increased risk for developing certain non-AIDS-defining cancers, such as Hodgkin's lymphoma and multiple myeloma. Although the optimal treatment of these neoplasms is at present uncertain, recent advances in chemotherapy, antiretroviral drugs, and supportive care protocols are allowing for more aggressive management of many of the AIDS-related cancers. This article provides an up-to-date review of the epidemiology, pathogenesis, clinical features, and treatment of various AIDS-related malignancies that are likely to be encountered by an oncologist practicing in the current HAART era.

Acquired Immunodeficiency Syndrome↗