The vigilance-promoting drug modafinil counteracts the reduction of tyrosine hydroxylase immunoreactivity and of dopamine stores in nigrostriatal dopamine neurons in the male rat after a partial transection of the dopamine pathway

We studied the ability of the vigilance-promoting drug modafinil to modulate the anterograde and retrograde changes in tyrosine hydroxylase (TH) immunoreactivity and in dopamine (DA) stores in the nigro-neostriatal DA neurons, following a partial hemitransection of this ascending DA system, using a combined morphometrical, biochemical and behavioural analysis. Modafinil was given daily i.p. in doses of 10–100 mg/kg, starting 15 min after the lesion, and the partially hemitransected rats were killed 2 weeks later. Changes in TH-immunoreactive nerve cell bodies and nerve terminals induced by the partial hemitransection were studied in the substantia nigra and neostriatum in combination with image analysis. The substantia nigra and neostriatum were also subjected to biochemical analysis of DA, 3,4-dihydroxyphenylacetic acid and homovanillic acid levels. Modafinil treatment dose-dependently (10–100 mg/kg) counteracted the hemitransection-induced disappearance of nigral TH-immunoreactive nerve cell body profiles and neostriatal TH-immunoreactive nerve terminal profiles. A 2-week treatment with 100 mg/kg of modafinil also counteracted the hemitransection-induced depletion of DA stores in the neostriatum and the ventral midbrain. Moreover, the repeated daily treatment with modafinil (100 mg/kg) protected against the hemitransection-induced disappearance of striatal 5-hydroxytryptamine, 5-hydroxyindoleacetic acid and noradrenaline levels. Striatal DA function was analysed by studying apomorphine-induced (1 mg/kg, s.c.) ipsilateral rotational behaviour 4 and 11 days after the operation. A marked dose-dependent reduction of ipsilateral rotational behaviour was demonstrated after the daily modafinil treatment in the partially hemitransected rats. In another model involving unilateral nigral microinjections of 6-hydroxydopamine, acute (one single dose) modafinil (100 mg/kg) did not affect the contralateral rotational behaviour induced by apomorphine (0.05 mg/kg s.c.), when given 30 min before the apomorphine. Taken together, morphological, neurochemical and behavioural evidence has been obtained that anterograde and retrograde changes induced in the DA stores and TH immunoreactivity of the nigro-neostriatal DA neurons by a partial hemitransection are counteracted by modafinil in a dose dependent way with 100 mg/kg producing a significant protective action against impairment of DA transmission. The results of this study open up the possibility that modafinil may protect against the anterograde and retrograde degeneration of nigrostriatal DA neurons seen after mechanically induced injury.     

Evaluation of the E test for susceptibility testing of anaerobic bacteria.

The susceptibilities of 105 clinical isolates of anaerobic bacteria were determined by a new method, the E test (AB Biodisk, Solna, Sweden), and were compared with the MICs for these organisms obtained by the reference agar dilution method by using supplemented brucella and Wilkins-Chalgren agars. The E test is a plastic strip with a predefined antibiotic gradient immobilized on one side and a MIC interpretive scale printed on the other side. Strips with cefoxitin, cefotaxime, imipenem, penicillin, metronidazole, and clindamycin were used in this study. A suspension of the test strain equal to the visual turbidity of a no. 0.5 McFarland standard was prepared and swabbed onto a 150-mm-diameter plate. The strips were applied in a radial fashion, and the plates were incubated under anaerobic conditions. After growth had occurred, an ellipse of inhibition was seen around each strip. At the point of intersection of the ellipse with the strip, the MIC was read from the interpretive scale. For most antibiotic-organism combinations, the ellipse was clear and the endpoint was sharp. The E-test MICs were interpreted after overnight and 48-h incubation for 58 of the strains. After overnight incubation, 87% of the E-test MICs were within 1 dilution of the agar dilution MICs, and 98% were within 2 dilutions. After 48 h of incubation, agreement was 86 and 97% respectively. E-test MICs obtained for the Bacteroides fragilis group after overnight incubation were more comparable than those obtained after 48 h of incubation to agar dilution MICs determined at 48 h for all drugs except clindamycin. On brucella agar, there was a 2% categorical discrepancy rate between the E-test MICs and agar dilution MICs, which occurred mostly with cefoxitin. The E test is easy to perform and read, is suitable for all anaerobes, can be used to test single patient isolates as needed, and offers the laboratory a reliable method for susceptibility testing of anaerobic bacteria.     

Effect of "anti-thrombosis" stockings on the venous hemodynamics of the lower extremities. Study using mercury gauge plethysmography

Study by plethysmography with mercury gauge. The authors have analyzed the effects of "anti-thrombosis" stockings on venous hemodynamics of 18 lower extremities, by plethysmography with mercury gauge (Periflow J.S.I.). With this method, they delineate the limits of efficacy of the use of only elastic stockings as prophylactic treatment of the thrombo-embolic disease in immobilized patients.     

Advanced Parkinson's disease: use of partial dopamine agonist, ciladopa

Ciladopa is a partial dopamine agonist that is effective in patients with advanced Parkinson's disease who are no longer satisfactorily responding to levodopa. Thirty-one patients participated in a double-blind randomized study of ciladopa (added to levodopa) versus placebo. Among 21 patients randomized to treatment with ciladopa and levodopa, there was a 32% decrease in symptoms on the Modified Columbia University Disability Scale. This change was significant, p less than or equal to 0.05. Eight of the 21 patients (38%) improved by at least 50%. The mean number of hours "on" increased by 20%. This change was significant, p less than or equal to 0.05. Five of the 21 patients (24%) were on for at least 4 hours more than at baseline. Dyskinesias were not increased. The mean dose of ciladopa was 19.5 mg/d. The mean dose of levodopa in Sinemet was decreased by 10%. Studies with ciladopa in humans had to be discontinued because of the occurrence of microscopic testicular tumors in some rodents. Although improvement in patients taking ciladopa was modest, there were few adverse effects. These results are encouraging, because two other partial agonists are now available, and they may be as effective as ciladopa.     

Levels and causes of stress among residents

Medical and dental residents at the University of Rochester Medical Center were surveyed to measure stress and its causes. Their stress, as measured by the brief symptom inventory, showed levels slightly above those of an adult comparison group. The average levels of stress decreased with the residents' advancing levels of training. Comparison of the top quartile with the lowest quartile of scores of everyday stress showed significantly elevated stress for rotations in the emergency room, greater frequency of being on call, and lesser amount of sleep. The residents' reports showed that the bleakest three days of residency tended to occur in the first year and during intensive care rotations. Stress during these bleakest times was significantly higher than everyday levels. The residents described the major causes of distress during bleakest times as lack of sleep, inadequate support from senior professionals, large patient load, and competition from peers. "High quality" teaching rounds, a night-float system, and sick leave were felt by the residents to lessen stress. To cope with the stress, the residents reported they talked to others, tried to see humor in the situation, or slept.     

The automatic call distributor: one answer to appointment-making problems

This case study addresses one problem brought on by a significant increase in patient volume: the inability of appointment desk clerks to answer the telephone within a reasonable amount of time. In response to mounting complaints from both patients and clinic staff, conversion to a computerized appointment system was undertaken. However, when the conversion led to no immediate relief of the problems at hand, an automatic call distributor was installed. Though this experience in instituting two new systems simultaneously was not without its problems, it did prove successful in effectively smoothing clinic operations.     

Combined use of benserazide and carbidopa in Parkinson's disease

The pharmacokinetics of levodopa differs when it is combined with benserazide or carbidopa. Peak dopa levels are higher, occur sooner, but decline more rapidly with benserazide. Although many patients respond better to one drug than the other, we sought to exploit the differences in pharmacokinetics by giving both drugs to the same patient. Benserazide was combined with carbidopa in 38 patients who were experiencing a diminished response to carbidopa, including 22 patients with diurnal oscillations in performance, "wearing off" or on-off phenomena. Previous attempts to change the dose, sequence, or ratio of levodopa to carbidopa in these patients had been unrewarding. Ten of the patients improved on the combination of benserazide and carbidopa, with a 30% decline in disability. The mean dose of levodopa:carbidopa before benserazide was 910:100 (9 to 1 ratio); the mean dose of levodopa:benserazide was 355:90 (4 to 1 ratio). The mean dose of levodopa:carbidopa + benserazide was 925:155 (6 to 1 ratio). The combination of carbidopa with benserazide is useful in some parkinsonian patients.     

Prism adaptation and brain damage

Brain damaged (BD), psychiatric (P), and normal (N) groups were compared on adaptability to prism-displaced vision. Although no difference among the groups was found on compensatory pre-post shifts of felt limb position (“proprioceptive shift”), the BD group manifested significantly less shift in target-pointing accuracy (“negative aftereffect”) than either of the other two groups. The latter result suggests that brain damaged individuals are, in general, unable to acquire the “cognitive” component of adaptation which results from consistently accurate target-pointing performance during the prism-exposure period. Frontal and non-frontal BD Ss adapted equally on proprioceptive shift, while the non-frontals evidenced significantly less negative aftereffect. It was suggested that this result and the fact that frontals adapted equally (on all measures) with the N group had implications for Teuber's “corollary discharge” hypothesis.