The cognitive, subjective, and physical effects of a ginkgo biloba/panax ginseng combination in healthy volunteers with neurasthenic complaints

We evaluated the effects of a Ginkgo biloba/ginseng combination on cognitive function in this 90-day, double-blind, placebo-controlled, parallel-group study. Sixty-four healthy volunteers (aged 40 to 65 years), selected on the basis of fulfilling the ICD-10 F48.0 criteria for neurasthenia, were assigned randomly to four equal dosing groups, receiving 80, 160, or 320 mg of the combination b.i.d. or placebo. Assessments were performed on the day before dosing, and again at Days 1, 30, and 90 at 1 hour after the morning dose and 1 hour after the afternoon dose. The assessments included the Cognitive Drug Research (CDR) computerized assessment system, the Vienna Determination Unit, cycle ergometry, and various questionnaires. The treatments were well tolerated by all volunteers. On Day 90 at 1 hour post morning dosing, dose-related improvements were seen on the CDR tests, the 320 mg dose being significantly superior to placebo. These effects, however, were reversed 1 hour after the afternoon dose, possibly suggesting that a longer inter-dosing interval would be preferable. The 80-mg dose produced a significant benefit on the ergometry assessment of heart rate at maximum load. There were also several supporting changes from other assessments, including an advantage of 320 mg over placebo on the global score from the Symptom Checklist-90-revised (SCL-90-R) at Day 90.     

Diffusing capacity of the lung for carbon monoxide

A phage-display technology was used to produce a single-chain Fv antibody fragment (scFv) from the 30AA5 hybridoma secreting anti-glycoprotein monoclonal antibody (MAb) that neutralizes rabies virus. ScFv was constructed and then cloned for expression as a protein fusion with the g3p minor coat protein of filamentous phage. The display of antibody fragment on the phage surface allows its selection by affinity using an enzyme-linked immunosorbent assay (ELISA); the selected scFv fragment was produced in a soluble form secreted by E. coli. The DNA fragment was sequenced to define the germline gene family and the amino-acid subgroups of the heavy (VH) and light (VL) chain variable regions. The specificity characteristics and neutralization capacity of phage-displayed and soluble scFv fragments were found to be identical to those of the parental 30AA5 MAb directed against antigenic site II of rabies glycoprotein. Phage-display technology allows the production of new antibody molecule forms able to neutralize the rabies virus specifically. The next step could be to engineer and produce multivalent and multispecific neutralizing antibody fragments. A cocktail of multispecific neutralizing antibodies could contain monovalent, bivalent or tetravalent scFv fragments, for passive immunoglobulin therapy.     

Pathogenesis of non-traumatic atlanto-axial subluxation (Grisel''s syndrome)

Ten years ago' endothelium derived relaxing factor' was identified as nitric oxide (NO.). This highly significant discovery revealed the importance of NO. in normal physiology and pathophysiology. Research over the past decade into the potential therapeutic use of inhaled NO. in the management of ARDS is reviewed. In critical care, inhaled NO. seems to produce selective pulmonary vasodilation and this is already beginning to have an impact on the management of lung injuries including ARDS. The effect of NO. in multi-system failure is not yet established. Formal evaluation in the form of clinical trials has yet to be undertaken, and further study of all the potential side effects and toxicity are required for conclusive evidence of the value of inhaled NO. in the treatment of ARDS.     

Postmortem serum and tissue redistribution of fluoxetine and norfluoxetine in dogs following oral administration of fluoxetine hydrochloride (Prozac)

Antemortem serum and postmortem serum and tissues were evaluated to determine if postmortem redistribution of the antidepressant, fluoxetine (Prozac) and its major active metabolite, norfluoxetine, occurred in dogs following oral administration of fluoxetine hydrochloride. Beagle dogs (four males) received daily oral doses of 10 mg fluoxetine/kg for five days. Antemortem serum concentrations of fluoxetine and norfluoxetine were determined 3 and 24 h following administration of the first four daily doses of fluoxetine and 3 h after the fifth dose in order to monitor for steady-state serum concentrations of parent and metabolite prior to postmortem serum concentration determinations. Antemortem serum concentrations of fluoxetine and norfluoxetine 3 h postdose on Day 5 ranged from 530 to 1210 ng/mL and 1460 to 1980 ng/ mL, respectively. Immediately following the 3 h blood sample on Day 5, each dog was euthanized. Serum concentrations of fluoxetine and norfluoxetine were determined from blood samples collected from the vena cava, heart, and clotted blood within the heart at 2 h after death in two dogs and 12 h after death in the remaining two dogs. Similarly, tissue concentrations of fluoxetine and norfluoxetine in heart, liver, and lung were determined 2 and 12 h postmortem. Serum concentrations of fluoxetine and norfluoxetine from the vena cava and heart 2 h postmortem were 2.2- to 6.0-fold and 2.3- to 3.6-fold higher, respectively, than antemortem serum concentrations. Similarly, serum concentrations of fluoxetine and norfluoxetine from vena cava and heart 12 h postmortem were 1.3- to 3.5-fold and 1.7- to 3.3-fold higher, respectively, than antemortem serum concentrations. However, 2-h and 12-h postmortem serum concentrations of fluoxetine and norfluoxetine from clotted blood within the heart were equal to or less than levels determined in antemortem serum. Results from 2-h and 12-h postmortem average tissue concentrations of fluoxetine and norfluoxetine in heart, liver, and lung demonstrated that fluoxetine and norfluoxetine concentrations in myocardium were similar 2 h and 12 h postmortem. However, in liver, fluoxetine concentrations decreased 39% and norfluoxetine concentrations decreased 23% from 2 h to 12 h postmortem. Even greater postmortem decreases in fluoxetine and norfluoxetine concentrations were observed in lung. Fluoxetine and norfluoxetine concentrations in lung decreased 49% and 39%, respectively, from 2 h to 12 h postmortem. In conclusion, this study demonstrated that fluoxetine and norfluoxetine undergo postmortem redistribution in the dog. Furthermore, postmortem serum concentrations appear to be dependent on the sample site and the degree of coagulation of the blood. Finally, postmortem decreases in concentrations of fluoxetine and norfluoxetine in liver and lung may, in part, explain the observed increase in serum concentrations at 2 and 12 h postmortem.     

High-frequency AC-DC differences of NML single-junction thermalvoltage converters

Frequency-dependent AC-DC transfer differences of a new set of single-junction thermal converters that serve at NML as primary standards for AC-DC transfer have been determined. The new determination has led to a reduction of the standard measurement uncertainty from 30 μV/V to less than 10 μV/V at frequencies up to 1 MHz