Changes in transport functions of isolated rabbit choroid plexus under the influence of oestrogen and progesterone

Isolated choroid plexuses from rabbits were used to determine uptake and accumulation of 10^-5 M radiolabelled choline (expressed as tissue/medium ratio) and the activities of various types of ATPases (based on ouabain inhibition and bicarbonate stimulation) following pre-treatment of the animals with 0.5 mg kg^-1 17-β-oestradiol, alone or in combination with 2 mg kg^-1 progesterone. The combined treatment reduced the choline uptake by 35% and also lowered the activity of Na⁺, K⁺-ATPase by 31%, without influencing tissue wet weight. The reduction in HCO₃-ATPase was smaller and not statistically significant. There was a tendency also for oestrogen alone to lower these activities, but only by less than 20%. The Ca²⁺, Mg²⁺-ATPase activity was not significantly affected by any of the hormones.     

HEMIMEGALENCEPHALY: A CLINICOPATHOLOGICAL STUDY OF FOUR CASES

Pathological findings in four cases of hemimegalencephaly are presented. These cases demonstrated diffuse enlargement of the cortex with disappearance of horizontal layering of the neurons restricted to one hemisphere. In all cases there was marked enlargement of a high percentage of neurons. The nosological situation is discussed and is considered to be heterogeneous; cases 1-3 had cerebral lesions without lesions of the skin or viscera. In these three cases, significant glial abnormalities were found in only one. These cases and others quoted in the literature were considered to be a separate entity completely different from Bourneville's tuberous sclerosis. The aetiology of this developmental malformation remains unknown; genetic factors were not found. Case 4 was associated with a cardiac lesion and with a linear sebaceous naevus characteristic of Solomon's syndrome. Periventricular tumours resembling candlewax drippings were noted. This case, close to Bourneville's disease, could be incorporated into the framework of neuroectodermoses together with tuberous sclerosis.     

A comparative study on the uptake and subsequent decarboxylation of monoamine precursors in cerebral microvessels

The endothelial cells and pericytes of brain microvessels (capillaries and small veins) are equipped with an enzymatic barrier, impeding the passage of circulating amino acids, such as amine precursors, into the brain. The properties of this mechanism was studied in brain slices and isolated microvessels from various species including man and also fetal material, following incubation in dihydroxyphenylalanine (DOPA), 5-hydroxytryptophan (5-HTP) and dihydroxyphenylserine (DOPS). A stereospecific, energy-dependent uptake leading to accumulation in the brain microvessel walls was found in all species studied; this process was found to exist already prenatally. The capacity of decarboxylation, the second step in the trapping mechanism at the blood-brain interphase, showed considerable species variation. The enzyme was present also in fetal brain microvessels. Inhibition experiments provided support for the presence of monoamine oxidase, but absence of catechol-O-methyl transferase, in the microvessel walls.     

Endothelial-related coagulation in cardiac surgery

The endothelium appears to play an important degrees in theregulation of intravascular coagulation. Thrombomodulin is oneof the anticoagulant substances that is expressed by endothelialcells. The influence of age and illness on the thrombomodulin-proteinC system was studied prospectively in 80 cardiac surgery patients.Patients > 70 yr old (n = 20) were compared with patients< 50 yr (n = 20) (group I), and patients undergoing a simplecardiac procedure (n = 20) were compared with patients scheduledfor complex surgery (n = 20) (group II). Thrombomodulin (normal<40 ng ml^–1 protein C and (free) protein S plasma concentrationswere measured by enzyme-linked immunosorbent assays (ELISA)after induction of anaesthesia (baseline values), during andafter cardiopulmonary bypass (CPB), at the end of surgery, 5h after CPB and on the first day after operation. Blood lossand use of homologous blood and blood products were significantlygreater in patients > 70 yr and in those undergoing complexsurgery. At baseline, thrombomodulin concentration was increasedin patients undergoing complex surgery (mean 52 (SD 9) ng ml^–1After bypass and after operation, thrombomodulin increased mostin patients > 70 yr (from 40 (8) to 78 (10) ng ml^–1and in those patients who underwent complex cardiac operations(from 52 (8) to 79 (10) ng ml^–1 (P < 0.05). Changesin protein C and protein S concentrations were similar in allgroups. On the first day after operation only, protein C concentrationswere reduced in patients > 70 yr and in patients who underwentcomplex cardiac surgery. Older patients and those who underwentcomplex cardiac surgery had greater changes in the thrombomodulin-proteinC system which may contribute to increased postoperative bloodloss.     

Effect of Epidural Morphine on Post-operative Pulmonary Dysfunction

The effect of post-operative epidural morphine analgesia on pulmonary function was assessed after abdominal surgery and compared to conventional analgesia. In a control group, ten patients received a parenteral analgesic, non-narcotic drug. In a second group of 11 patients, epidural morphine was injected after the operation and continuous analgesia was prolonged until the 3rd post-operative day by means of repeated injections through an epidural catheter. Analgesia was tested on a visual pain scale. Pulmonary function was evaluated by measurements of blood gases, pulmonary volumes (vital capacity, by spirometry, and functional residual capacity by helium dilution technique) and forced expiratory volume in one second. Measurements were performed on the day before the operation and on the first, third and sixth post-operative days. Pain scoring documented a better analgesia in the epidural group during the post-operative period. By contrast, epidural morphine was unable significantly to improve VC, FEV1 and FRC during the post-operative course. The results suggest that pain is not an important factor of decreased post-operative pulmonary function.     

Reproducibility of skin tests

Fifty patients allergic to mite were tested for D. pteronyssinus using two prick-test techniques; the classical method by Pepys and the Morrow-Brown needle. Each patient received six tests with each method on the two forearms. The evaluation of the weal areas was conducted in two ways: by weighing the shapes of the tests transferred on to paper, and by measuring the two greatest diameter lengths. No significant difference was observed between the two methods. No significant difference was observed between the measurements of the same tests carried out at 2-monthly intervals by the same examiner. With the Pepys method the weal area sizes are significantly larger than with the Morrow-Brown needle, and the variance is much greater with the Pepys technique. However, the coefficients of variation are similar and in both cases the techniques are equally reproducible. No significant difference was found in the weal sizes with regard to the injection sites on the forearm with either of the two methods. The correlation between the weal area sizes and the log of the IgE levels is closer with the Morrow-Brown needle.