Evidence-based health policy-making, hospital funding and health insurance.

An important goal of health services research is to improve the efficiency and effectiveness of health services through a quantitative and evidence-based approach. There are many limitations to the use of evidence in health policy-making, such as differences in what counts as evidence between the various disciplines involved, and a heavy reliance on theory in social science disciplines. Community and interest group values, ideological positions and political assessments inevitably intrude into government health policy-making. The importance of these factors is accentuated by the current absence of evidence on the impact of policy options for improving the health status of the community, and ensuring that efficiency and equity objectives for health services are also met. Analysis of recent hospital funding and private health insurance initiatives shows the limited role of evidence in the making of these decisions. Decision-making about health policy might be improved in the future by initiatives such as greater exposure of health professionals to educational inputs with a policy focus; increased contribution of doctors to health services research via special postgraduate programs; and establishing a national, multidisciplinary centre for health policy research and evaluation.

Diagnosis-related group refinement with diagnosis- and procedure-specific comorbidities and complications.

Diagnosis-related groups have been revised through more refined uses of secondary diagnoses. Under the refined diagnosis-related groups, patients are distinguished with respect to classes of secondary diagnoses that are disease- and procedure-specific. Each class represents a different level of utilization for a given principal diagnosis or surgical procedure. The refined system was evaluated with national data from the Medicare program. Estimates of hospital costs and utilization based on refined diagnosis-related groups were more precise than those based on unrefined diagnosis-related groups. This approach to diagnosis-related group refinement does not represent a radical departure from the current diagnosis-related group framework and does not require new data collection efforts. Moreover, a payment system based on the refined model is less affected by the ordering of the diagnoses than under the existing diagnosis-related group system. How the refined diagnosis-related group framework can accommodate future refinements at all levels of the classification scheme is also discussed.

Mechanism of Nitrogenase Inhibition in Soybean Nodules : Pulse-Modulated Spectroscopy Indicates that Nitrogenase Activity Is Limited by O(2).

A novel, pulse-modulated spectroscopic system for measuring fractional leghemoglobin oxygenation and infected cell O(2) concentration (O(i)) in intact attached nodules of soybean (Glycine max) is described. The system is noninvasive and uses a pulsed (1000 Hertz) light-emitting diode coupled to an optical fiber to illuminate the nodule with light at 660 nanometer. A second optical fiber receives a portion of the light reflected from the nodule and directs this to a photodiode. A lock-in amplifier measures only the signal from the photodiode which is in phase with the pulsed light from the light-emitting diode, and the voltage output from the amplifier, proportional to reflectance, is used to calculate fractional leghemoglobin oxygenation and the nanomolar concentration of free O(2) in the infected cells of the nodule (O(i)). The system was used to show that inhibition of nitrogenase activity in soybean nodules by NO(3) (-) treatment, stem-girdling, continuous darkness, or nodule disturbance is caused by a reduction in O(i) and limitation of respiration in support of nitrogenase activity. A plot of nitrogenase activity (measured as peak H(2) evolution in Ar:O(2)) versus O(i) for the various treatments was consistent with the concept that O(i) limits in vivo nitrogenase activity in legume nodules under adverse conditions. The potential for using O(i) to estimate nitrogenase activity in laboratory and field-grown legumes is discussed.

Motility of bovine spermatozoa studied by laser light scattering.

Laser light scattering has been employed to determine the swimming speed distribution and the fraction of motile cells in samples of bovine spermatozoa. As predicted from theory, average trajectory velocities determined by laser light scattering were approximately four times the average translational speed estimated using light microscopy. The proportion of motile spermatozoa decreased with time at the same rate when samples were prepared in either HEPES or phosphate buffers. However, whereas the mean swimming velocity declined slowly in HEPES buffer, it dropped rapidly when phosphate buffer was used. Dilution (in the range 40 - 0.4 X 10(6) spermatozoa X ml-1) in either of these two buffers reduced the fraction of motile spermatozoa in the sample, but the mean swimming velocity of the remaining active spermatozoa was unchanged. Lowering the temperature from 37 degrees C to 15 degrees C reduced the mean swimming speed by a factor of 2-3 and the fraction of motile cells by a factor of 4-5.

Laser-light scattering diffusion measurements on brain microtubule protein from dogfish (Squalus acanthus) and beef.

Laser photon correlation spectroscopy and analytical ultracentrifugation were used to compare the equilibrium properties of disassembled, assembly-competent, brain microtubule protein from dogfish (Squalus acanthus) and beef. Analytical ultracentrifugation confirmed that assembly-competent bovine material at 4 degrees C, purified in the presence of glycerol through 2 cycles of assembly and disassembly, consisted of 6 S (dimer) and 35 S (ring) components, whereas assembly-competent dogfish material prepared in the same way was composed primarily of 6 S protein. By means of photon correlation spectroscopy, z-average diffusion coefficients (D'20, w) of 0.55 (+/- 0.04) x 10(-11) m2 s-1 (beef) and 1.27 (+/- 0.11) x 10(-11) m2 s-1 (dogfish) were measured at 4 degrees C for the twice-cycled assembly competent microtubule protein. Although D'20, w values for dogfish material are significantly higher than those for beef, they depart from the calculated value of 5.0 x 10(-11) m2 s-1 for a pure 6 S (dimer) solution. Microtubule accessory proteins were detectable on sodium dodecyl sulphate/polyacrylamide gels of dogfish microtubule protein. By fitting photocount autocorrelation functions to a 2-particle (dimer-ring) model it was estimated that the presence in a solution of assembly-competent dogfish microtubule protein of less than 1 ring per 250 dimers could account for the measured z-average diffusion coefficient. The temperature sensitivity of D'20, w showed that dogfish brain microtubule protein polymerized at lower temperatures than samples prepared by the same methods from beef brain.

Paper point transfer of minimal numbers of microorganisms from a prepared canal in vitro.

A strain of Str. faecalis resistant to 2 mg./c.c. streptomycin was developed, and serial dilutions of known quantities of the organism were introduced into prepared root canals of extracted teeth. The canals were cultured with sterile dry paper points, incubated in tubes of thioglycollate media containing 2 mg./c.c. streptomycin at 37 degrees C. These tubes were checked for growth at 24-hour intervals for 7 days. Some tubes yielded growth on the first day, while those with greater dilutions of sample took 7 days. All samples with bacteria did yield growth by the seventh day. At the time of transfer of the organism into the prepared root canals, an identical sample of suspended organisms were spread on pour plates of brain-heart infusion broth containing 2 mg./c.c. streptomycin. After incubation at 37 degrees C. for 24 hours, the numbers of colonies were counted in order to determine the exact number of organisms in each serial dilution. Taking a culture after introduction of sterile distilled water into a canal and evaluation of the culture at the time of the scheduled filling appointment are recommended clinical procedures.

Light microscopic demonstration of myoid material in nuclei.

During the development of configurational staining methods for proteins of the myosin-fibrin group, nuclei showed staining properties similar to those of myofibrils. This dye binding could be attributed to nuclear alpha-helical proteins. More recent chemical and electron microscopic studies demonstrated actomyosins in nuclei of various species. Possible roles of nuclear actomyosin in chromosome movements and condensation and in cell proliferation have been suggested. It seems therefore permissible to assume that the tannic acid-phosphomolybdic acid (TP)-Levanol Fast Cyanine 5RN method and similar technics visualize myosin in nuclei. Comparative studies of actomyosins from various sites indicated significant chemical an histochemical differences. It is therefore suggested that, in analogy to the different classes of collagens, there may be several subgroups of myosin which differ in their physico-chemical properties and sensitivity to fixation procedures and pathological conditions.