Health-care decision making, Part II. Choices for incapacitated patients.

The traditional, informal approach to making medical decisions for incapacitated patients is often inappropriate today. Guidelines are needed in two major areas: assessing incapacity and seeking surrogate decision makers. Judicially declared incompetency does not necessarily imply incapacity to make medical choices. Proposed standards for determining incapacity require a multistep evaluation of the patient's abilities to understand, reason, and communicate. When decisions must be made for an incapacitated patient, priority is given to the patient's previously stated preferences. An advance directive--living will or durable power of attorney--simplifies the process. If no advance directive was prepared, a surrogate decision maker may be designated according to applicable state statutes. Standards are still evolving for protecting the autonomy and best interests of vulnerable, incapacitated patients.     

Platelet utilization in a university hospital

Two hundred forty-three patients received 22,717 U of platelets in our hospital during a three-month period. Those with hematologic diseases accounted for 43% of the patients but used 86% of the platelets. Sixty-eight percent of the transfusions were given to prevent bleeding and 32% were given to treat active bleeding. Ninety-two percent of therapeutic transfusions but only 22% of prophylactic transfusions met guidelines established by the Transfusion Therapeutics Committee of the University of Minnesota Hospital and Clinics, Minneapolis. However, 78% of prophylactic platelet transfusions that did not meet the guidelines involved patients with at least one clinical factor that their physicians believed placed them at an increased risk of bleeding. Following this analysis, the guidelines were modified and applied prospectively to requests for platelets. This resulted in a 14% decrease in the number of platelet units used during the following year. We conclude that published recommendations for platelet transfusions do not reflect the complex nature of many patients' conditions and that the use of guidelines developed by the medical staff can alter the use of platelet transfusions.     

Evaluation of three substitutes for Percoll in sperm isolation by density gradient centrifugation

Silane-coated silica particle solutions (ISolate(TM) and PureSperm)TM)) and iodixanol (OptiPrep(TM)) were compared to polyvinylpyrrolidone (PVP)-coated silica particles (Percoll(TM)) in their efficacy to recover spermatozoa by gradient centrifugation for use in assisted reproductive procedures. Efficacy was assessed in terms of percentages of sperm recovery, sperm vitality and motility, normal sperm morphology and normal sperm chromatin condensation. No significant difference was found in the recovery of spermatozoa for men with both normal sperm counts and oligozoospermia, between PVP-coated and silane-coated particle solutions. Iodixanol had significantly lower sperm recovery compared to the other products. Sperm vitality, progressive motility, normal morphology and normal chromatin condensation did not differ significantly between any of the sperm isolation products.      

The magnitude and encephalogenic potential of autoimmune response to MOG is enhanced in MOG deficient mice

Myelin oligodendrocyte glycoprotein (MOG) is a minor component of central nervous system myelin presumably implicated in the pathogenesis of Multiple Sclerosis (MS). Immunization with MOG leads to the development of Experimental Autoimmune Encephalomyelitis (EAE), the experimental model of MS. It has been suggested that its encephalitogenic potential may be due to the lack of MOG self-immune tolerance. To clarify this, we have generated a MOG deficient mouse (MOG(-/-)) strain. Surprisingly, MOG(35-55)specific proliferation and Th1-type cytokine production were markedly enhanced in MOG(-/-)mice compared to wild type control. Furthermore, adoptive transfer of MOG(35-55)specific T cells, isolated from MOG deficient mice, into wild-type recipients resulted in the development of a more severe disease, indicating a high capacity of MOG(-/-)T cells to initiate effector responses. Interestingly, T cell reactivity to overlapping MOG peptides in MOG(-/-)mice did not reveal new potential immunodominant epitopes in H-2(b)mice. Taken together, our data suggests that MOG self-tolerance modulates the encephalitogenic potential of autoreactive MOG T cells in the periphery.