PC-based system for collection and analysis of physiological data

A personal computer based system for data acquisition and analysis appropriate to physiological experiments is described in detail. The system is independent of the details of the analog signal generation. The software, written in C, is modular and easily portable to other PC systems. The system is capable of: (a) sampling many analog signals at an appropriate rate (100 Hz), (b) storing large quantities of digitized data, (c) analysing digitized waveforms to obtain signal parameters, and (d) storing signal parameters in a format suitable for statistical analysis. Computer processed cardiopulmonary data are compared with data derived from standard ICU equipment.     

Medication adherence in patients with HIV infection: a comparison of two measurement methods

Two measurements of adherence, patient self-report and electronic measurement by the Medication Event Monitoring System (MEMS), were compared in a 3-month adherence study of 44 HIV-infected patients who had been placed on regimens that included protease inhibitors (PIs). The dose percentage and degree of clinically significant dosing time fluctuation were calculated monthly. The mean dose percentage by self-report versus MEMS was 97.5% versus 90.3% during month 1 of adherence monitoring, 96.5 versus 90.1% during month 2, and 98.4% versus 92.8% during month 3. Thirty-two percent of patients taking PIs and 21% of patients taking nucleoside analogues demonstrated clinically significant dosing time fluctuation. Our data confirm that self-reports of adherence overestimate true adherence behavior, and patients' self-reports of dosing times may not accurately reflect their deviation from those times.     

The role of the graft in the induction of tolerance by antilymphocyte serum and cellular antigen

Intravenous donor antigen in the form of spleen cells can significantly potentiate the effects of ALS in prolonging the survival of skin allografts exchanged across both weak and strong histocompatibility barriers. This effect depends on the proper timing of antigen administration and can result in immunologic unresponsiveness of sufficient strength to permit acceptance of second set grafts. The skin allograft itself apparently plays a role in the establishment of this unresponsive state since ALS and antigen alone followed by delayed allografts at 21 days resulted in normal graft rejection times.     

Diabetic ketoacidosis: low-dose insulin therapy by various routes.

Since in normal persons the hypoglycemic effect of low-dose intramuscular exceeds that of subcutaneous insulin we studied the effect of routes of insulin therapy in diabetic ketoacidosis. Forty-five patients with diabetic ketoacidosis entered a randomized prospective protocol with insulin administered either intravenously, subcutaneously or intramuscularly. Initial priming dose of insulin had to be repeated in two of 15, three of 15 and six of 15 of the intravenous, subcutaneous and intramuscular groups respectively. The intravenous group had a more rapid fall in plasma glucose (P less than 0.01) and ketone bodies (P less than 0.05) during the first two hours. Thereafter, there were no significant differences in the rate of decline of plasma glucose or ketones nor in the time required for glucose to reach 250 mg per deciliter or for complete recovery from diabetic ketoacidosis. The data confirm the efficacy of low-dose insulin therapy for diabetic ketoacidosis and indicate that the optimal route of insulin administration is by initial intravenous combined with subcutaneous or intramuscular.     

Taxonomic and diagnostic markers for identification of Coccidioides immitis and Coccidioides posadasii.

The ribosomal Internal Transcribed Spacer (ITS) regions of the two recognized species of Coccidioides were studied using a reference set of strains that had been previously identified with species defining microsatellite polymorphisms. Unambiguous identification of the two species proved to be possible by amplifying and sequencing the ITS region. PCR-reactions are sensitive to amplification conditions requiring their careful optimization. Stable amplification and sequencing was achieved with primers ITS3 and 4, enabling species diagnosis. Alternatively, Restriction Fragment Length Polymorphism (RFLP) of the entire ITS region using an annealing temperature of 52 degrees C with the restriction enzymes BsrI and XcmI can also distinguish the species. Three strains typifying the species, Glenospora meteuropaea, G. metamericana and Geotrichum louisianoideum, were analyzed and found to be conspecific with C. posadasii. Although these species have nomenclatural priority over C. posadasii, the latter will be proposed for conservation as it has been included in the US select agent list. In addition, Coccidioides immitis is neotypified in this report. Results of antifungal susceptibility testing did not reveal differences between the two species.     

Degree of light damage to the retina varies with time of day of bright light exposure

After adaptation to cyclic illumination (14:10 light-dark cycle; intensity = 1.4 log ftc) male albino rats were exposed to brighter light (2.15 log ftc) seven hours daily for 25 days. The extent of retinal damage was determined histologically. Daily exposure to bright light in the morning produced greater photoreceptor loss than daily afternoon exposure. Severe retinal damage was partially prevented by brief light adaptation (20 minutes duration, at 1.4 log ftc intensity) before the onset of morning exposure. However, light adaptation did not remove the differential effect of time of day. The authors conclude that increased light exposure during the period of rod outer segment phagocytosis enhances photoreceptor damage.