Site specific labeling of Rhodobacter sphaeroides reaction centers with dye probes for surface pH measurements.

Covalently bound pH sensitive dyes are an important tool for characterizing the proteolytic reactions of protein complexes that play key roles in biological energy transduction. Here we demonstrate the feasibility of this method for photosynthetic reaction centers (RCs) for the first time, by the highly selective attachment of two thiol reactive derivatives of fluorescein to the two H subunit cysteines of the photosynthetic RC from Rhodobacter sphaeroides R-26 The pK(a) shifts of the dyes upon binding to the protein and in response to high salt were measured, and interpreted based on the structure of the RC. 2-[(5-fluoresceinyl)aminocarbonyl]ethyl-methanethiosulfonate was attached to Cys H156 and fluorescein-5-maleimide to Cys H234. By following the absorption changes of bound fluorescein (500 nm), and those of the hydrophilic pH indicator 8-hydroxypyrene-1,3,6-tris-sulfonic acid (468 nm), the surface and bulk pH were monitored separately with less than 5% crosstalk. Flash-induced proton uptake and external calibrations by mixing with aliquots of acid were measured in different redox states of the RCs. The results indicate that the charge in the quinone acceptor complex after flash activation (primary quinone acceptor (Q(A))- or secondary quinone acceptor (Q(B))-) has no effect on the surface pH and potential in the vicinity of these two attachment sites, between pH 6.5 and 9. Application of the method to other surface locations is discussed.

Preferential binding of equine ferricytochrome c to the bacterial photosynthetic reaction center from Rhodobacter sphaeroides.

Redox titration of horse heart cytochrome c (cyt c), in the presence of varying concentrations of detergent-solubilized photosynthetic reaction center (RC) from Rhodobacter sphaeroides, revealed an RC concentration-dependent decrease in the measured cyt c midpoint potential that is indicative of a 3.6 +/- 0.2-fold stronger binding affinity of oxidized cytochrome to a single binding site. This effect was correlated with preferential binding in the functional complex by redox titration of the fraction of RCs exhibiting microsecond, first-order, special pair reduction by cytochrome. A binding affinity ratio of 3.1 +/- 0.4 was determined by this second technique, confirming the result. Redox titration of flash-induced intracomplex electron transfer also showed the association in the electron transfer-active complex to be strong, with a dissociation constant of 0.17 +/- 0.03 microM. The tight binding is associated with a slow off-rate which, in the case of the oxidized form, can influence the kinetics of P(+) reduction. The pitfalls of the common use of xenon flashlamps to photoexcite fast electron-transfer reactions are discussed with relation to the first electron transfer from primary to secondary RC quinone acceptors. The results shed some light on the diversity of kinetic behavior reported for the cytochrome to RC electron-transfer reaction.

Patient satisfaction with delivery of products and information by an ambulatory care pharmacy.

A survey for assessing ongoing patient satisfaction with ambulatory care pharmaceutical services was developed for and tested in a veterans population; acquiescence response to survey items and desire for potential future services were measured. A questionnaire based on key aspects of patient satisfaction described in the literature was distributed to 1451 patients visiting an ambulatory care pharmacy prescription-pickup window during five consecutive days in 1994. Patients were asked about current services and the desirability of potential future services. Patients indicated their responses to statements about current services. Acquiescence response (the tendency to agree with statements regardless of content) was measured by using matched pairs of contradictory statements. The response rate was 48.3%. Patients' mean +/- S.D. overall satisfaction with current services was 3.7 +/- 1.1. The responses of 72.0% of patients exhibited no contradictions. The potential new service wanted most by respondents was availability of a pharmacist to talk with patients by telephone; seeing a pharmacist in the clinic instead of a physician for drug-related problems was wanted least by respondents. Veterans responding to a survey of satisfaction with ambulatory care pharmaceutical services had a low tendency to agree with statements regardless of content. The survey can be used to assess veterans' ongoing satisfaction.

Physical therapy care for low back pain. Monitored program of first-contact nonphysician care.

We studied the process and outcomes of physical therapist management of 107 patients with low back pain at a walk-in clinic. Sixty-seven patients with low back pain concurrently were assigned randomly to internists at the clinic. Physicians and physical therapists recorded baseline clinical data and management plans on standard check lists. Physical therapists used a validated algorithm that directed diagnostic evaluations and physician consultations, but all other physical therapist treatment decisions were unconstrained. Patients in the physical therapist and physician groups did not differ significantly. Physical therapists referred more patients to the physical therapy department than did physicians but recommended muscle relaxants, prescription analgesics, and bed rest less frequently. The occurrence of new symptoms, duration of symptoms, and duration of activity limitations were similar between the physician and physical therapy patient groups at a one-month follow-up examination. Physical therapist-managed patients expressed greater satisfaction than physician-managed patients with several aspects of their care. The percentage of functional improvement for highly dysfunctional patients was significantly greater for the physical therapist-managed patients than for the physician-managed patients. The implications of a physical therapist first-contact care program for health service organizations, health care policy, physical therapist training, and credentialing are discussed.

Pericentric X chromosome ascertained during antenatal diagnosis.

A pericentric inversion of an X chromosome [46,X,inv(X)(p11q28] with no detectable deletions was ascertained by amniocentesis for prenatal diagnosis in a 42-year-old woman. No defintive counsel could be offered as such an inversion had not been previously reported. At 1 year, the infant appears normal. These data and the review of other recently published karyotypes suggest an absence of a somatic position effect in the human X chromosome and possible biases of ascertainment or possible alternative karyotypic interpretations of some previously reported inv(X) cases.

Voluntary ethanol drinking by the RAT: effects of 2-aminoethylisothiouronium Salt, a modifier of NAD:NADH and norelegnine, a beta-carboline derivative.

Voluntary intake of ethanol solution (ETOH) was decreased in rats administered 2-aminoethylisothiouronium bromide hydrobromide (AET), an agent reported to alter NAD:NADH ratios in rat liver. Repeated administration of same dose of AET to ETOH-naive rats produced a significant inhibition of liver aldehyde dehydrogenase. Ethanol intake was decreased in rats given noreleagnine (NLG), a beta-carbone derivative reported to inhibit monoamine oxidase. Repeated administration of NLG exerted a significant inhibitory effect on liver alcohol dehydrogenase activity. It is concluded that the observed reduction of ethanol under AET which inhibits liver aldehyde dehydrogenase may reflect an antabuse-like reaction and the reduction of ethanol intake under NLG may be due, in part, to a build-up of alcohol in the blood and brain through inhibition of ethanol metabolism. The results are discussed in reference to the possible mechanism of action underlying voluntary intake of ethanol in rats, implicating alteration of NAD:NADH ratios in the biochemical processes underlying alcohol intake of rats.

ABO-RH blood groups and psychiatric diagnosis: a critical review.

The authors studied 312 consecutive admissions to a psychiatric service for a relationship of the ABO - Rh blood groups with psychiatric diagnosis. Even though the results were significant, showing an increase of A blood group with M.D.D. and O group with Sch, the authors observe that the general patient population was skewed and significantly different from the general population of the area. This same observation was made for most of the previous studies that have reported significant correlations between various blood groups and different psychiatric diagnosis. Because of this, the conclusion of the present study is that at the present time positive associational findings of blood groups with psychiatric diagnosis are probably related to a skewed and stratified patient population sample.