NP7 protects from cell death induced by oxidative stress in neuronal and glial midbrain cultures from parkin null mice

Parkin mutations produce Parkinson’s disease (PD) in humans and nigrostriatal dopamine lesions related to increased free radicals in mice. We examined the effects of NP7, a synthetic, marine derived, free radical scavenger which enters the brain, on H₂O₂ toxicity in cultured neurons and glia from wild-type (WT) and parkin null mice (PK-KO).NP7, 5-10 μM, prevented the H₂O₂ induced apoptosis and necrosis of midbrain neuronal and glial cultures from WT and PK-KO mice. NP7 suppressed microglial activation and the H₂O₂ induced drop-out of dopamine neurons_. Furthermore, NP7 prevented the increased phosphorylation of ERK and AKT induced by H₂O₂. NP7 may be a promising neuroprotector against oxidative stress in PD.     

Intraventricular somatostatin-14, arginine vasopressin, and oxytocin: analgesic effect in a patient with intractable cancer pain

The analgesic effect of intraventricular somatostatin-14 (SOM-14), arginine vasopressin (AVP), and oxytocin (OT) were tested in one terminally ill cancer patient with a diffuse mesothelioma suffering intractable continuous and incapacitating thoracic pain. SOM-14 reduced pain by 90% for 48 min; AVP reduced pain by 95% for 75 min, and OT reduced pain by 88% for 77 min. The only notable side effects were seen after the administration of AVP, which induced anesthesia and flaccid paralysis of the lower limbs, from which the patient fully recovered after 20 h.     

Monoamine oxidase inhibitory properties of milacemide in rats

Milacemide is a glycine prodrug with reported antiepileptic antimyoclonic properties. In this study, milacemide increased "wet dog shakes" in rats pretreated with 5-Hydroxytryptophan (5-HTP) and carbidopa. Moreover, it worsened the serotonin behavior syndrome precipitated by 5-HTP and the monoamine oxidase inhibitor tranylcypromine. The serotonin syndrome was also elicited by the combination of milacemide and 5-HTP without tranylcypromine. In vitro, milacemide inhibited both monoamine oxidase A and B from the frontal cortex of rats, to a greater extent for MAO B. This drug is currently under investigation in humans as an antiepileptic agent and precautions for the consequences of monoamine oxidase inhibition should be considered when the drug is used in high doses.     

Modification of galactose and N-acetylgalactosamine residues by oxidation of C-6 hydroxyls to the aldehydes followed by reductive amination: model systems and antifreeze glycoproteins

Amino acids and peptides have been attached to the C-6 hydroxyls of the galactose and the N-acetylgalactosamine by first oxidizing the C-6 hydroxyls to the aldehydes by galactose oxidase in the presence of small amounts of catalase, followed by reductive amination (-amino group) in the presence of cyanoborohydride. The activity of oxidized antifreeze glycoprotein was >70% of the original, and considerable activity has been retained with some substitutions on reductive amination using cyanoborohydride. The following were some activities retained (as compared with the oxidized antifreeze glycoprotein): Gly, 64; (Gly)₂, 88; (Gly)₃, 82; (Gly)₄, 70; Gly-Gly-NH₂, 44, Gly-Glu, 13; Gly-Leu, 40; Gly-Tyr, 57; Gly-Gly-Leu, 50; Gly-Gly-Phe, 30; and Gly-Gly-Val, 35. On amino acid analysis of acid hydrolysates, some release of the amino acid attached by amination occurred; e.g., Gly-Tyr gave 0.26 Gly and 0.49 Tyr per disaccharide.     

Amplification dynamics of human-specific (HS) Alu family members.

We have investigated the distribution of several recently inserted Alu family members within representatives of diverse human groups. Human population studies using 65 unrelated human DNA samples, as well as a familial study to test inheritance, showed that individual Alu family members could be divided into three groups. The first group consisted of relatively older Alu family members which were monomorphic (homozygous) throughout the population tested (HS C3N1 and C4N6). The second group (HS C4N2, C4N5 and C4N8), apparently inserted into other repetitive regions of the genome, resulting in inconclusive results in the PCR test used. However, it is clear that these particular Alu insertions were present in a majority if not all of the loci tested. The third group was comprised of three dimorphic Alu family members (HS C2N4, C4N4 and TPA 25). Only a single Alu family member (TPA 25) displayed a high degree of dimorphism within the human population. This latter example also showed different allele frequencies in different human groups. The isolation and characterization of additional highly dimorphic Alu family members should provide a useful tool for human population genetics.     

Expression of human nerve growth factor receptor on cells derived from all three germ layers

Nerve growth factor (NGF) is a protein which promotes the survival and differentiation of neuronal cells in vitro and plays an important role in neuronal development. In this study, we have examined the expression of the receptor for NGF (NGFR) in human neuronal and nonneuronal cells, both in tissue culture and in vivo. In addition to cell lines derived from neuroblastoma, astrocytoma, and melanoma, all of which share a common neuroectodermal origin, NGFR was detected in a number of cultured cells of mesenchymal, epithelial, and hematopoietic derivation. Immunohistochemical analysis showed that NGFR is expressed in several nonneural human tissues, and the cell types in which NGFR was found include derivatives from all three germ layers. Thus, our findings demonstrate that NGFR is much more widely expressed in human cells and tissues than was previously thought.     

Inhibition of non-genomic responses to oestrogen in the rat uterus by testosterone propionate

Testosterone propionate (50 mg/kg), administered together with oestradiol, inhibited the oestrogen-induced uterine eosinophilia, deep endometrial oedema and the increase in uterine wet weight, 6 h after treatment. The same dose of the androgen decreased the number of eosinophils in the blood and increased their degranulation, explaining the effect of testosterone in the uterus. The high doses of the androgen used were in the range of the doses reported by others to block selectively the oestrogen-induced increase in uterine peroxidase content but not other responses to oestrogen or the cytosolic oestrogen receptor translocation to the nucleus. The dissociation by high doses of testosterone of the oestrogen-induced uterine eosinophilia, wet weight increase and oedema from other responses to oestrogen in the absence of any measurable effect of testosterone upon cytosolic-nuclear oestrogen receptors supports the idea that uterine eosinophilia and oedema are oestrogenic responses regulated by mechanisms different from those of the genomic responses, and is in agreement with the hypothesis of the mediation of uterine oedema by eosinophils.     

Ionic regulation of glutamate binding sites

Cl- and Ca2+ increase glutamate binding to rat synaptic plasma membranes (SPMs) by revealing a distinct class of L-glutamate (L-Glu) binding sites. The present study was conducted to examine both the anion specificity of this response and the nature of the interaction between Cl- and Ca2+. Of the anions tested, Br- was the most effective in increasing the levels of L-Glu binding. Other effective anions were Cl-, NO3- and formate while F-, HCO3-CIO4-, propionate, SO42- and PO43- were ineffective. The anion specificity was similar to that observed for the Cl- membrane channel, suggesting that this binding site and the ion channel may be related. In the absence of Cl-, Ca2+ has little effect on L-Glu binding. Increasing the Cl- concentration increased the apparent affinity (decreased KCa2+) of the Ca2+-stimulated, L-Glu binding component and also increased the maximal amount of the enhancement. Conversely, increasing Ca2+ levels increased the maximal enhancement of L-Glu binding brought about by Cl- without affecting the KCl- of the effect. Prior incubation of membranes with Ca2+ did not raise the level of L-Glu binding. Furthermore, EGTA was able to reverse the stimulation of L-Glu binding due to Ca2+. The results indicate that Ca2+ acts ionically to enhance L-Glu binding to rat SPMs.     

Abnormal electrophoretic mobility of spectrin tetramers in hereditary elliptocytosis

Summary Hereditary elliptocytosis (HE) is a genetically determined disorder of the red cell membrane. The main protein which composes the proteinaceous skeleton of the membrane is an elongated molecule named spectrin which is a heterodimer composed of two chains, and . In the membrane spectrin dimers are associated head-to-head to form tetrameric structures. We and other authors have reported that spectrin studied from many HE patients exhibited a dimer self-association defect (type I HE). A mutation in the head of the spectrin chain was mostly found in type I HE. We have previously described one of the three known spectrin pathological variants shown on mild tryptic digest pattern. This variant was characterized by the appearance of an abnormal 65,000-dalton peptide (Sp ^I/65). Using nondenaturating gel electrophoresis, we describe in this paper a triplicated pattern of the spectrin tetramer bands which is found in heterozygous HE cases displaying the 65,000-dalton variant. Study of a homozygous case allowed us to characterize the electrophoretic mobility of the abnormal symmetrical spectrin tetramer (₂ ^I/65-₂) and to study the correlation between the fraction of this abnormal symmetrical tetramer found in heterozygous patients and the amount of the 65,000-dalton peptide observed in spectrin tryptic digests.