Physicochemical characterization and functional activity of fibroid prolactin produced in cell culture

Evidence from our laboratory with the use of cultured (primary and passaged) cells has extended our initial observation that human uterine fibroid is an extrapituitary source of prolactin. Fibroid prolactin antigen in conditioned medium reacted specifically in radioimmunoassay for human pituitary prolactin. Control experiments demonstrated that the radioimmunoassay results were not spurious due to degradation of tracer 125I-labeled prolactin. Immunoparallel dilution curves indicated antigenic relatedness of pituitary and fibroid prolactin. In a calibrated Sephadex G-100 column, fibroid prolactin eluted in the same region (20.3 to 20.9 kd) as purified pituitary prolactin. Glycosylated prolactin, detected by concanavalin A affinity column chromatography, appeared to constitute only a small percentage of fibroid prolactin made in culture. The ratio of fibroid prolactin bioactivity (lactogen Nb2 lymphoma bioassay) to antigen (radioimmunoassay) was 0.77. These data indicate that human uterine fibroid tissue produces a molecule similar to or, perhaps, identical with pituitary prolactin.     

Modulation of glycine receptor function: a novel approach for therapeutic intervention at inhibitory synapses?

Transmitter-gated ion channels mediate rapid synaptic transmission in the CNS and constitute important targets for many neuroactive drugs. Inhibitory glycine receptors (GlyRs) are members of the nicotinic acetylcholine receptor superfamily and inhibit neuronal firing by opening Cl(-) channels following agonist binding. In this article, we discuss recent developments in GlyR pharmacology, delineate the receptor domains that are involved in binding of agonists and allosteric modulators, and present a molecular model of the extracellular architecture of the receptor. The recent discovery of compounds that act preferentially on specific GlyR isoforms and the differential expression of these isoforms in distinct regions of the developing and adult CNS show considerable promise towards the development of drugs that act in defined glycine-mediated pathways. In particular, compounds that can potentiate GlyR function should provide leads for novel muscle relaxants in addition to sedative and analgesic agents.     

The Satz-Mogel short form of the Wechsler Adult Intelligence Scale--revised: effects of global mental status and age on test-retest reliability

Abbreviated versions of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) have been developed as time saving devices that provide accurate estimates of overall level of general intellectual functioning while decreasing test administration time. The Satz-Mogel short form of the WAIS-R has received substantial attention in the literature as an accurate measure of intellectual functions when compared with the Full WAIS-R. However, most studies comparing the Satz-Mogel version to the Full WAIS-R have only provided correlational analyses. Our study was an attempt to apply a more rigorous statistical methodology in determining if the Full WAIS-R and abbreviated versions are equivalent. We explored the impact of level of global mental status and age on the Satz-Mogel version. Although the two forms of the test correlated highly, repeated measures design indicated significant differences between Satz-Mogel and Full WAIS-R when participants were divided into groups based on level of global impairment and age. Our results suggest that the Satz-Mogel version of the test may not be equivalent to the full WAIS-R and is likely to misrepresent a patient's level of intellectual functioning, particularly for patients with progressive degenerative conditions. The implications of applying Satz-Mogel scoring to the Wechsler Adult Intelligence Scale-III (WAIS-III) are discussed.     

Identification of the key amino acids of gliai cell line-derived neurotrophic factor family receptor alpha 1 involved in its biological function

Glial cell line-derived neurotrophic factor （GDNF） plays a critical role in neurodevelopment and survival of midbrain dopaminergic and spinal motor neurons in vitro and in vivo. The biological actions of GDNF are mediated by a two-receptor complex consisting of a glycosylphosphatidylinositol-linked cell surface molecule, the GDNF family receptor alpha 1 （GFR alpha 1）, and receptor protein tyrosine kinase Ret. Although structural analysis of GDNF has been extensively examined, less is known about the structural basis of GFR alpha 1 function. In this study, based on evolutionary trace method and relative solvent accessibility prediction of residues, a set of trace residues that are solvent-accessible was selected for site-directed mutagenesis. A series of GFR alpha 1 mutations was made, and PC12 cell lines stably expressing different GFR alpha 1 mutants were generated. According to the survival and differentiation responses of these stable PC12 cells upon GDNF stimulation and the GDNF- GFR alpha 1-Ret interaction assay, residues 152NN153, Arg259, and 316SNS318 in the GFR alpha 1 central region were found to be critical for GFR alpha 1 binding to GDNF and eliciting downstream signal transduction. The single mutation R259A in the GFR alpha 1 molecule simultaneously lost its binding ability to GDNF and Ret. However N152A/N153A or S316A/N317A/ S318A mutation in the GFR alpha 1 molecule still retained the ability to bind with Ret. These findings suggest that distinct structural elements in GFR alpha 1 may be involved in binding to GDNF and Ret.     

Reversible findings of restricted diffusion in 5‐flourouracil neurotoxicity

A 35‐year‐old woman presented with neurotoxicity correlated to an i.v. regimen of 5‐fluorouracil as episodes of acute confusional state and abnormalities of symmetrically restricted diffusion in the periventricular white matter and corpus callosum. On discontinuing the medication, the areas of severely restricted diffusion had entirely resolved, with minimal residual T2 signal abnormality. In this case, immediate discontinuation of the chemotherapeutic agent apparently reversed the patient's symptoms and findings on MRI. The scant information available in the published literature regarding this phenomenon is reviewed with regard to 5‐fluorouracil.     

Development of "heparin-like" polymers using swift heavy ion and gamma radiation. I. Preparation and characterization of the materials

The development of ideal antithrombogenic polymers, a major problem in biomaterials sciences, is a primary objective in the fields of cardiovascular prostheses, artificial hearts, and other devices. To decrease their thrombogenicity, which remains the major obstacle, we have developed polymeric materials endowed with a specific affinity for antithrombin III (ATIII) and thus able, like heparin, to catalyze the inhibition of thrombin by ATIII. Sulfonate and sulfonamide groups are introduced onto phenyl rings belonging to styrene residues, which are radiation grafted (using swift heavy ion and gamma radiation) onto poly(vinylidene difluoride) (PVDF) and also onto poly(vinylidene fluoride/hexafluoropropylene) [P(VDF-HFP)]. In contrast to gamma radiation, which leads to a homogeneous modification, the advantage of swift heavy ion grafting is that only small regions are modified; thus, the surface may present hydrophilic (corresponding to the modified areas) and hydrophobic microdomains (corresponding to the unmodified areas) of different sizes, depending on the absorbed dose and grafting yield. Surface topography and composition are characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Sulfur, sodium, fluorine, and carbon are determined by scanning electron microscopy combined with energy-dispersive X-ray analysis (SEM-EDXA). The amount of fluorine decreases as polystyrene (PS) is grafted, whatever the kind of radiation and polymer. When the polymers are functionalized, the amount of fluorine also decreases while sodium and sulfur appear. Functionalization seems to increase the roughness of the surface, and its area.     

Blood-brain barrier sodium transport limits development of brain edema during partial ischemia in gerbils

Sodium derived from the blood is known to accumulate in brain tissue during the early stages of incomplete ischemia. Our present studies were undertaken to determine the relation between blood-brain barrier sodium transport and the development of ischemic brain edema. Incomplete cerebral ischemia was produced in gerbils by ligation of the left common carotid artery under ether anesthesia. Following recovery from the anesthetic, the gerbis were evaluated for the presence of neurologic symptoms and were divided into symptomatic (n = 77) and asymptomatic (n = 94) groups. Tissue water, sodium, and potassium contents, tissue plasma volume, and brain uptake of 22Na were measured in both groups 1.5, 3, 6, 12, and 24 hours after carotid ligation. There was a progressive accumulation of sodium and water in the ipsilateral cerebral cortex of the symptomatic group compared with either the corresponding contralateral cortex of the same gerbils or with the asymptomatic group. Net changes in brain sodium and potassium concentrations appeared to be the main determinants of fluid accumulation. Brain edema was not due to opening of the blood-brain barrier because the unidirectional transport of 22Na remained low and was even reduced by 35-55% in the ischemic cortex. Nevertheless, this sodium transport activity appeared to be rate-limiting in the development of brain edema during the first 3 hours of ischemia because the rate of sodium accumulation in the tissue was the same as the rate of 22Na transport from the blood to the brain. We conclude that blood-brain barrier sodium transport is an important factor in the formation of ischemic brain edema.