Glucose concentration gradient through the cerebral cortex in normoglycaemic anaesthetized rabbits.

In this pilot study, the relationships between glucose and lactate concentrations of plasma, cerebrospinal fluid (CSF), cerebral cortex and subjacent white matter were investigated in one hyperglycaemic and three normoglycaemic anaesthetized rabbits. After a 90 min stabilization period, CSF was sampled and the brain frozen in situ. Triplet samples (n = 3 X 21) were obtained from the outer and inner halves of cortex and from the white substance and analysed for their water content as well as for glucose and lactate by enzymatic fluorescence methods. Preservation of the ATP content was demonstrated in brain slices by a bioluminescence method. The glucose and lactate levels of CSF seemed to reflect those of the outer half of the cortex. In the normoglycaemic animals, the tissue glucose and tissue lactate levels correlated inversely (r = 0.477: p less than 0.01). While the glucose concentrations were nearly identical in the inner cortex and white substance, there was a concentration difference of 0.54 mmol/kg tissue water between the outer half of the cortex and the white matter (p much less than 0.02). This might correspond to a steep intra-cortical glucose gradient starting from the CSF-facing surface and approximating the general cerebral glucose level in a depth of about 4-500 microns. The possible significance of this gradient in regulating CSF glucose is discussed.

Lactate and pyruvate content of the human cisternal cerebrospinal fluid. Normal values, age and sex dependency, correlations with glucose concentrations.

Cisternal CSF specimens were obtained from 144 fasted individuals free from organic brain disease (42 males and 102 females; mean age 41 +/- 10.3 years, range 16-69 years). In 30 cases a simultaneous lumbar puncture was also performed. The concentration of CSF glucose (G1) was measured by the o-toluidine method, and that of lactate (La) and pyruvate (Py) by enzymatic tests. No significant difference was found between the mean G1 and Py values of the lumbar and cisternal CSF but the lumbar La was somewhat higher than the cisternal one (P less than 0.10). In the cisternal CSF the frequency distribution of G1, La and Py samples was a Gaussian one (P less than 0.05). The normal ranges, as mean +/- 2SD, were for La 0.680-2.100 mM/1, and for Py lower limits of the range (between mean +/- 2 SD and mean +/- 1 SD) are considered to be potentially pathological. No significant difference was found between the mean G1, La and Py values in males and females. Consistent age-related changes could not be detected either in the G1 or Py levels, however, a tendency for La increase was observed in the oldest-age-group (over 54 years). A negative correlation was found between the G1 and La concentrations of the cisternal CSF (r = 0.375; P less than 0.001).

Comparative study of the effect of ethyl apovincaminate and xantinol nicotinate in cerebrovascular diseases. Immediate drug effects on the concentrations of carbohydrate metabolites and electrolytes in blood and CSF.

Randomly selected 34 cerebrovascular patients were treated with ethyl apovincaminate (RGH-4405, Cavinton) and 109 with xanitinol nicotinate. The effects of drugs given in slow i.v. infusions on the concentration of carbohydrate metabolites and electrolytes in serum and CSF were observed. Cavinton improved the paresis in 60.6% of patients while xantinol nicotinate did so only in 47.1%. On the basis of the biochemical changes it can be concluded that Cavinton enhances both the glycolytic and the oxidative glucose breakdown in CNS.

[Thrombotic complications due to oral contraceptives]. / Thrombotische Komplikationen der per os verabreichten Antikonzipientia

Cases reported here as well as the literary date tell attention to the vascular complications following contraceptive therapy. Shift of clotting-fibrinolysis system towards hypercoagulobolity is remarkable because of its role as a risk factor. If contraceptive therapy is accompanied by a condition or a disease altering clotting factors, vessel walls or circulation so that it presents an enhanced thrombosis capacity the risk may increase. In such cases indication of oral contraceptive therapy should be considered cautiously and the patients should be controlled with more intention.

PIP: Thromboembolic complications of oral contraception (Infecundin and Bisecurin) in 5 women aged 18-41 years are reported. In 1 case, the patient had had surgery while under oral contraceptive treatment; vascular disorders were present in the histories of 3 other patients. No risk factor was present in the 5th case. The possible mechanisms of the vascular complications are discussed, and the importance of respecting vascular contraindications to oral contraception is emphasized.