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Biomedical subjects

David Porter

Publications and source records attributed to David Porter.

7 recordsLinked to original sources
PubMed2003

Combinatorial auction design.

Combinatorial auctions allow for more expressive bidding in which participants can submit package bids with logical constraints that limit allowable outcomes. This type of auction can be useful when participants' values are complementary or when participants have production and financial constraints. However, combinatorial auctions are currently rare in practice. The main problems confronted in implementing these auctions are that they have computational uncertainty (i.e., there is no guarantee that the winning bids for such an auction can be found in a "reasonable" amount of time when the number of bidders and items becomes larger) and that the auction is cognitively complex and can lead participants to pursue perverse bidding strategies. This article describes a type of combinatorial auction that, during laboratory testing, eliminated these problems and produced extremely efficient outcomes.

Journal Article↗
PubMed2003

Combination anti-inflammatory and antiviral therapy of influenza in a cotton rat model.

The cotton rat was evaluated as a model for anti-inflammatory and antiviral influenza therapy. Beginning 3 days after intranasal infection with 10(7) tissue culture infectious doses-50% (TCID)(50) of an H3N2 human influenza, animals were treated topically via intranasal lavage with a range of doses of triamcinolone acetonide (1, 4, or 16 mg/kg), alone or in combination with a neuraminidase inhibitor or anti-influenza convalescent serum. Pulmonary histopathologic changes were dramatically decreased in animals treated with 4 or 16 mg/kg of triamcinolone, with little additional benefit from addition of a neuraminidase inhibitor or topical serum, agents which were much less effective when used alone. A high degree of suppression of IFN-gamma levels was observed in all combinations where 4 or 16 mg/kg of triamcinolone were used. Viral replication was not prolonged by corticosteroid therapy. Tissue damage during influenza infection may be greatly reduced by combination antiviral and anti-inflammatory therapy.

Acetamides↗
PubMed2002

High rate of invasive fungal infections following nonmyeloablative allogeneic transplantation.

Nonmyeloablative allogeneic transplantation is an emerging therapy for hematologic and solid malignancies and potentially offers patients reduced transplant-related toxicity. Data regarding infectious complications of these protocols are limited, but early studies have demonstrated little infectious morbidity, particularly low rates of invasive fungal infections (IFIs). In the present study, 31 consecutive cases of nonmyeloablative transplantation were reviewed over a 2.5-year period, with a specific focus on infectious complications. Twenty-six patients (84%) had at least 1 significant infection during the year after transplantation, and infection-related mortality was 37%. Cytomegalovirus end-organ disease was diagnosed in 3 patients (10%). Ten patients (32%) were given the diagnosis of IFI; 7 (23%) met criteria for proven IFI. Fungal-related mortality was 80% within the group of patients with IFI and accounted for a significant portion of the overall mortality in the study. Severe graft-versus-host disease, high-dose corticosteroid use, recurrent neutropenia, and relapsed or refractory disease were factors associated with development of IFI.

Adult↗
PubMed2002

Acute myelogenous leukemia: advances and limitations of treatment.

Acute myelogenous leukemia (AML) describes a group of related hematologic malignancies that are being approached therapeutically from several perspectives. Conventional chemotherapeutic agents, such as anthracyclines and cytosine arabinoside (Ara-C), are useful in treating AML but now appear to have reached their maximum potential. Newer therapeutic approaches to AML have recently focused on immune-based therapy through monoclonal antibodies that target and destroy malignant cells via specific cell receptors. One such agent is gemtuzumab (CMA-676), an agent that targets the CD33 antigen on malignant myeloid cells. Initial studies have shown significant anticancer activity. We will discuss traditional and newer therapeutic approaches to AML and review the role of monoclonal antibody based therapies for patients with AML. A case of a 30-year-old man with refractory AML who was treated with gemtuzumab will be mentioned, highlighting potential applications and possible limitations to this novel therapy. Despite the effective reduction in the number of malignant cells in bone marrow, gemtuzumab ineffectively treated extramedullary leukemic gingival infiltrate. Regardless of limitations, monoclonal-based therapy offers an exciting and potentially safer adjunctive therapy for patients with AML.

Adult↗
PubMed2002

The effects of duration and frequency of Achilles tendon stretching on dorsiflexion and outcome in painful heel syndrome: a randomized, blinded, control study.

The American Orthopedic Foot and Ankle Society recommends at least six months of nonsurgical treatment before considering surgical intervention for painful heel syndrome. Achilles tendon stretching exercises are consistently reported to be one of the more effective nonsurgical modalities for treatment of painful heel syndrome. However, the optimal duration and frequency of the exercises has not been reported. The purpose of this study was to evaluate and compare the effectiveness of sustained and intermittent Achilles tendon stretching for the relief of pain associated with painful heel syndrome. This prospective, randomized, blinded study was performed from May 1997 to July 2000. A total of 94 people (122 affected feet) fit the inclusion criterion and agreed initially to participate in a treatment study group. To achieve our purpose, study participants were randomized into two stretching groups. One group performed sustained Achilles tendon stretches (three minutes, three times daily), the other performed intermittent stretches (five sets, 20 seconds each, two times daily). Participants were evaluated once a month for a period of four months subsequent to diagnosis. At each monthly visit, participants completed subjective questionnaires about their pain. Also, a physical therapist measured each participant's Achilles tendon flexibility. The study determined that both sustained and intermittent Achilles tendon stretching exercises increase Achilles tendon flexibility. This increase in flexibility correlated with a decrease in pain. There was no significant difference in outcome between the sustained and intermittent stretching groups. The data suggest that both sustained and intermittent Achilles tendon stretching exercises were effective nonsurgical treatments for painful heel syndrome.

Achilles Tendon↗
PubMedDate not supplied

Development of the antimicrobial effectiveness test as USP chapter <51>.

The antimicrobial effectiveness test first appeared as a USP General Chapter in the 18th revision, official September 1, 1970. This chapter, at the beginning, was designed to evaluate the performance of antimicrobials added to inhibit the growth of microorganisms that might be introduced during or subsequent to the manufacturing process. As Good Manufacturing Practices (GMPs) became a governing principal in pharmaceutical manufacturing, the purpose of the test was refined to focus on activity of the preservative system as a protection against inadvertent contamination during storage and usage of the product. This article will review the history of the antimicrobial test; its function, technique, and the background discussions that resulted in the changes from the test that appeared in USP XVIII to that of the current USP 25.

Bacteria↗