The response of isolated rabbit atria to aconitine

The arrhythmias observed in isolated rabbit atria appear to be due to two actions of aconitine. One is an apparent direct stimulant effect on the sino-atrial node and the other is a depressant effect on the processes involved in intra-atrial propagation of impulses. Acetylcholine has either an inhibitory or stimulatory effect on atria pretreated with aconitine because it antagonizes the actions of aconitine both on the sinus node and on conduction. When conduction block is not apparent, acetylcholine depresses the atrial rate. On the other hand, when conduction is markedly depressed, acetylcholine increases the atrial rate.     

The effect of reinstatement stimulus conditions on the maintenance of long-term memory

Weanling rats trained on an appetitive S^DS^Δ discrimination were subsequently exposed to different components of the training stimulus for 15 min each week for 10 successive weeks. On the week following the final stimulus exposure retention was measured by a 2-hr relearning test. Those subjects exposed to all acquisition cues (S^DS^Δ with reinforcement), as well as those exposed to S^Δ conditions alone, demonstrated enhanced retention relative to a control group receiving no reinstatement experience. All other exposure conditions including presentation of S^D with reinforcement were either ineffective or impaired retention.     

Cytogenetic studies in primary amenorrhea]

Cytogenetic analysis in 125 women with primary amenorrhea consisting of determinations of sex chromatin and karyotype, and in some cases of autoradiography were performed. On the basis of clinical, endocrinologic and cytogenetic criteria, the women were divided into ten clinical groups. In Turner's syndrome 45,X monosomie was observed only in 9 patients and in the remaining 12 cases varies types of mosaicism or of structural aberrations of the X chromosome. In pure gonadal dysgenesis, the patients exhibited 46,XY karyotype have the tendency to malign tumors of the gonads. In all cases with male pseudohermaphroditism the karyotypes 46,XY were observed. The remaining patients with primary amenorrhea exhibited 46,XX karyotype and belonged to the cases with Mayer-Rokitansky-Kustner syndrome, with adrenogenital syndrome, with hypoplasia of the ovaries, with primary amenorrhea of uterine or pituitary origin or at last with pubertas tarda.     

Nafcillin Entry into Human Cerebrospinal Fluid

The entry of nafcillin into the cerebrospinal fluid (CSF) of humans was studied in the absence of meningeal inflammation. Twenty studies were performed in 18 patients receiving 40 mg of sodium nafcillin per kg intravenously over 30 min. The CSF specimens were obtained at 1, 2, 3, and 4 h postinfusion, and sera were obtained at 5 min and 1, 2, 3, and 4 h. Nafcillin was uniformly detected in the lumbar CSF at 1 h, peaked at 2 h postinfusion, and was still detectable in the CSF of three of four patients studied at 4 h.     

SPECT analysis of recent cerebral infarction

We measured regional cerebral blood flow and [123I]iodoamphetamine (IMP) uptake in 16 patients with unilateral brain infarcts during the subacute period (Day 3 to Day 50) and again after 3 months. Our results show that the central and peripheral areas described earlier in the chronic period were already differentiated in the subacute period. The central area presented a short phase of luxury perfusion and a longer phase of IMP hyperfixation. The peripheral area showed both a slight regional cerebral blood flow decrease and an early IMP uptake decrease similar to those previously found in the chronic period. Contralateral regional cerebral blood flow during the subacute period, considered normal, was significantly lower than that during the chronic period.