Evidence of temporal cortical dysfunction in rhesus monkeys following chronic cocaine self-administration.

Cocaine abusers show impaired performance on cognitive tasks that engage prefrontal cortex. These deficits may contribute to impaired control and relapse in abusers. Understanding the neuronal substrates that lead to these deficits requires animal models that are relevant to the human condition. However, to date, models have mostly focused on behaviors mediated by subcortical systems. Here we evaluated the impact of long-term self-administration of cocaine in the rhesus monkey on cognitive performance. Tests included stimulus discrimination (SD)/reversal and delayed alternation tasks. The chronic cocaine animals showed marked deficits in ability to organize their behavior for maximal reward. This was demonstrated by an increased time needed to acquire SDs. Deficits were also indicated by an increased time to initially learn the delayed alternation task, and to adapt strategies for bypassing a reliance on working memory to respond accurately. Working memory per se (delay dependent performance) was not affected by chronic self-administration. This pattern of cognitive deficits suggests dysfunction that extends beyond localized prefrontal cortical areas. In particular, it appears that temporal cortical function is also compromised. This agrees with other recent clinical and preclinical findings, and suggests further study into addiction related dysfunction across more widespread cortical networks is warranted.

[Surgical treatment of spondylolisthesis with mild displacement by pedicular fixation and posterolateral fusion in adults]. / Traitement chirurgical des spondylolisthésis de l'adulte à déplacement modéré par fixation pédiculaire et fusion postéro-latérale.

Thirty-two consecutive adults with low-grade spondylolisthesis treated by stabilisation with the AO Internal Fixator and posterolateral fusion have been retrospectively reviewed with a mean follow-up time of 4 years (range, 24 to 71 months). There were 17 grade I and 15 grade II spondylolisthesis. Eight patients had degenerative and 24 patients had isthmic spondylolisthesis. An unisegmental fusion was performed in 4 cases, a bisegmental fusion in 25 cases and 3 patients had a multisegmental fusion. There was one deep infection and one nerve root compromise (3 per 100). Satisfactory results were achieved in 84 per 100 of the patients. There was non-union. This study suggests that transpedicular fixation and posterolateral fusion significantly enhances the rate of solid union to an extent which outweighs the risk of neurological complications due to the screw insertion. Fusion in situ in patients with low-grade spondylolisthesis is recommended as well as nerve root revision for all adults with concomitant radioculopathy. However, this review does not specifically support the use of the AO-internal fixator, but rather that of transpedicular fixation in general.

Effect of elastic compression stockings on venous hemodynamics in hemiplegic patients.

Unilateral lower extremity edema and an increased risk of thromboembolism have been associated with hemiplegia following stroke. This study was undertaken to determine the effect of knee-high, graded elastic stockings on venous hemodynamics in hemiplegic patients. Thirty-six patients with recent cerebral infarcts were studied. The presence of underlying venous or arterial occlusive disease was excluded in all patients. Duplex scanning techniques were used to measure femoral and popliteal venous circumference, cross-sectional area, and peak flow velocity in the normal and paralyzed extremities both with and without stockings. All patients were examined and assessed for the degree of motor weakness and Brunnstrom stage of recovery. Associated medical illnesses were also reviewed. These patients were found to have a decreased flow in the femoral (p = 0.0002) and popliteal (p = 0.006) veins and an increase in the femoral vein size. The application of compression stockings resulted in a significant increase in venous size and flow velocity in both areas. The femoral and popliteal velocity correlated inversely with the degree of motor impairment and Brunnstrom stage, suggesting that factors other than the muscle pump may be responsible for the augmentation of femoral flow velocity in the paralyzed leg. There was no correlation demonstrated with other variables such as age, gender, cardiovascular disease, or diabetes. These results would indicate a potential benefit of graded knee-high elastic compression stockings in reducing venous flow stasis in hemi-paretic patients.

[Perioperative prevention of thrombosis in cesarean section: results of a randomized prospective comparative study with 6% hydroxyethyl starch and 0.62 low dose heparin]. / Die perioperative Thromboseprophylaxe beim Kaiserschnitt: Ergebnisse einer randomisierten prospektiven Vergleichsuntersuchung mit 6% Hydroxyäthylstärke 0.62 und Low-dose-Heparin.

In 207 consecutive randomized women undergoing cesarean section, of whom 104 received 3 X 5000 IE unfractionated heparin and 103 3 X 500 ml hydroxyethylstarch 6% 0.62, the frequency of deep vein thrombosis was evaluated with a non-invasive diagnostic technique-impedance plethysmography. 5.9% of the patients in the hydroxyethylstarch group and 7.8% in the heparin-group developed deep vein thrombosis. Activation of blood coagulation at cesarean section results in an increasing of factor VIIIR:Ag, Fibrinogen and Reptilase clotting time. Hydroxyethylstarch 6% 0.62 produces minor abnormalities of coagulation test results. After 1500 ml infusions HES the following effects were noted: 1. Factor VIIIR:Ag fell by about 20%, a greater decrease than could be explained simply by hemodilution. 2. Reptilase clotting times shortened without a different increase in fibrin activation products (resulting in an increased lysability of the thrombus). 3. Plasma fibrinogen decreased by approximately 7% due to hemodilution caused by plasma volume expansion. For patients with a low risk of deep vein thrombosis (Cesarean section) HES has an excellent safety record in doses not exceeding 1500 ml/24 h.

[Ophthalmology and standardization]. / Ophtalmologie et normalisation.

The standards are the references for quality and safety of materials, instruments and devices in ophtalmological use. The French standardisation association, "Association Française de Normalisation" (AFNOR), drafts his standards in connection with the concerned professionals. The ophthalmologists are concerned by standards of diagnostic and therapeutic instruments, intraocular and orbital implants, contact lenses, spectacle frames and glasses, and ocular protectors.