Use of hypertonic (3%) saline/acetate infusion in the treatment of cerebral edema: Effect on intracranial pressure and lateral displacement of the brain

OBJECTIVE: To determine the effect of continuous hypertonic (3%) saline/acetate infusion on intracranial pressure (ICP) and lateral displacement of the brain in patients with cerebral edema. DESIGN: Retrospective chart review. SETTINGS: Neurocritical care unit of a university hospital. PATIENTS: Twenty-seven consecutive patients with cerebral edema (30 episodes), including patients with head trauma (n = 8), postoperative edema (n = 5), nontraumatic intracranial hemorrhage (n = 8), and cerebral infarction (n = 6). INTERVENTION: Intravenous infusion of 3% saline/acetate to increase serum sodium concentrations to 145 to 155 mmol/L. MEASUREMENTS AND MAIN RESULTS: A reduction in mean ICP within the first 12 hrs correlating with an increase in the serum sodium concentration was observed in patients with head trauma (r2 = .91, p = .03), and postoperative edema (r2 = .82, p = .06), but not in patients with nontraumatic intracranial hemorrhage or cerebral infarction. In patients with head trauma, the beneficial effect of hypertonic saline on ICP was short-lasting, and after 72 hrs of infusion, four patients required intravenous pentobarbital due to poor ICP control. Among the 21 patients who had a repeat computed tomographic scan within 72 hrs of initiating hypertonic saline, lateral displacement of the brain was reduced in patients with head trauma (2.8 +/- 1.4 to 1.1 +/- 0.9 [SEM]) and in patients with postoperative edema (3.1 +/- 1.6 to 1.1 +/- 0.7). This effect was not observed in patients with nontraumatic intracranial bleeding or cerebral infarction. The treatment was terminated in three patients due to the development of pulmonary edema, and was terminated in another three patients due to development of diabetes insipidus. CONCLUSIONS: Hypertonic saline administration as a 3% infusion appears to be a promising therapy for cerebral edema in patients with head trauma or postoperative edema. Further studies are required to determine the optimal duration of benefit and the specific patient population that is most likely to benefit from this treatment.     

Structure-based design of cathepsin K inhibitors containing a benzyloxy-substituted benzoyl peptidomimetic

Peptidomimetic cathepsin K inhibitors have been designed using binding models which were based on the X-ray crystal structure of an amino acid-based, active site-spanning inhibitor complexed with cathepsin K. These inhibitors, which contain a benzyloxybenzoyl group in place of a Cbz-leucine moiety, maintained good inhibitory potency relative to the amino acid-based inhibitor, and the binding models were found to be very predictive of relative inhibitor potency. The binding mode of one of the inhibitors was confirmed by X-ray crystallography, and the crystallographically determined structure is in close qualitative agreement with the initial binding model. These results strengthen the validity of a strategy involving iterative cycles of structure-based design, inhibitor synthesis and evaluation, and crystallographic structure determination for the discovery of peptidomimetic inhibitors.     

Functional complementation by electroporation of human BACs into mammalian fibroblast cells

Bacterial Artificial Chromosomes (BACs) have been used to complement a metabolic defect and to transfer a drug resistance marker into mammalian cells by electroporation. The selectable markers are stable and the recipient cells have BAC DNA integrated into the chromosomes as shown by fluorescent in situ hybridization, PCR and Southern hybridization.     

Problems in the design of power transformers

The power loss of transformer cores can still be considerably reduced by improved joint design based on new knowledge of the localized flux distribution, both in the corners and in the limbs. Rotational flux has been measured in the T-joints of experimental cores, and it has been found to cause localized high loss regions dependent on the joint design. Circulating harmonic fluxes have been found in individual laminations in the limbs of three-phase cores. The path of the harmonics is independent of joint design although their magnitudes are dependent. Circulating 3rd harmonics as large as 0.3 T have been found in a core magnetized sinusoidally at 1.6 T. These cause additional losses calculated to be 20% of the nominal core loss, and great savings would be possible if the circulating harmonics could be reduced or eliminated.     

Effects of different doses of apomorphine on the glutamate decarboxylase activity of the substantia nigra and the medial basal hypothalamus

The activity of gamma-aminobutyric acid (GABA) synthesizing enzyme glutamic acid decarboxylase (GAD, EC 4.1.1.15) was assayed in the rat substantia nigra (SN) and medial basal hypothalamus (MBH) following systemic injection of different doses of the dopamine receptor agonist apomorphine. In SN, the highest dose of apomorphine (1000 micrograms/kg) causes an increase of the GAD activity whilst an opposite effect is observed with the lowest dose (35 micrograms/kg). Results obtained in SN are in accordance with previous neurochemical and behavioural data suggesting an opposite action of high (500 micrograms/kg) and low doses (100 micrograms/kg) of apomorphine in nigro-striatal system, probably due to the existence of two classes of dopamine receptors, i.e. classical postsynaptic dopamine receptors and presynaptic inhibitory dopamine autoreceptors. In MBH, the evidence for similar effects of low and high doses of apomorphine (the decrease of GAD activity) may suggest that, as already reported, at this level only one class of dopamine receptors is present.     

Letter: Electrical method of detecting optimum time to inseminate

Recently translated studies of the electrical resistance of cervical mucus as a test for the optimum time of insemination of agricultural animals are reviewed. The technique involves the measurement of the electrical conductivity of the surface of the mucosa in the vaginal vestibule. Experiments with cows and sows have shown that pregnancy or fertilization rates are considerably higher when mucosal electrical resistance is low at the time of insemination than when resistance is high. It has also been demonstrated in sows that mucosal resistance is higher in pregnant than in nonpregnant animals. Further research into these results is recommended.     

Cross-validation of an abbreviated form of the Halstead Category Test.

Cross-validated the use of a short form of the Halstead Category Test as suggested by D. A. Calsyn et al (see record 1981-02450-001). For 60 Ss (mean age 36.72 yrs), it was found that the total score estimated from their formula (based on the 1st 4 subtests of the Category Test) correlated .88 with the overall score. The formula was cross-validated in 3 samples with all correlations above .83. It was found that the formula could reliably predict who would exceed the cutoff of the entire test, with an overall accuracy across the 4 samples of 184 out of 205. (3 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex and the single hemisphere: specialization of the right hemisphere for spatial processing

Specialization of the right hemisphere for spatial processing was studied in 200 normal boys and girls between 6 and 13 years of age. Boys performed in a manner consistent with right hemisphere specialization as early as the age of 6. Girls showed evidence of bilateral representation until the age of 13. The results suggest a sexual dimorphism in the neural organization underlying cognition during a major period of childhood. The results, which have implications for reading instruction, are discussed in terms of a possible sex difference in neural plasticity during development and the clinical consequences of such a difference.