Involvement of AMPA/kainate-excitotoxicity in MK801-induced neuronal death in the retrosplenial cortex

MK801 is a prototypical non-competitive NMDA receptor-antagonist that induces behavioural changes and reversible toxicity at low doses, while at higher doses triggers neuronal death that mainly affects the retrosplenial cortex (RSC) and to a lesser extent other structures such as the posterolateral cortical amygdaloid nucleus (PLCo). The mechanism of MK801-induced neurodegeneration remains poorly understood. In this study we analysed the participation of GABA-ergic and glutamatergic neurotransmission in MK801-induced neuronal death. We used a single i.p. injection of MK801 (2.5 mg/kg) that induced moderate neuronal death in the RSC and PLCo of female rats, and combined this treatment with the i.p., i.c.v., or intra-RSC infusion of drugs that are selective agonists or antagonists of the GABA-ergic or glutamatergic neurotransmission. We found that neuronal death in the RSC, but not the PLCo, was significantly reduced by the i.p. injection of thiopental, and the i.c.v. application of muscimol, both GABA-A agonists. MK801-toxicity in RSC was abrogated by intra-RSC infusion of muscimol, but the GABA antagonist picrotoxin had no effect. HPLC-analysis showed that levels of glutamate, but not GABA, in the RSC decreased after i.p. treatment with MK801. Intra-RSC infusion of MK801 did not enhance toxicity triggered by the i.p. injection of MK801, indicating that toxicity is not due to direct blockade of NMDA receptors in RSC neurons. MK801-toxicity in the RSC was abrogated by i.c.v. and intra-RSC infusions of the AMPA/kainate antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX). Interestingly, i.c.v. application of neither muscimol or DNQX inhibited MK801-toxicity in the PLCo, suggesting that the mechanism of neuronal death in the RSC and the PLCo might be different. 1-naphthylacetyl spermine trihydrochloride (NASPM), which blocks Ca2+ permeable AMPA/kainate receptors, also reduced MK801-induced toxicity in the RSC. Intra-RSC infusion of AMPA or kainic acid alone promoted death of RSC neurons and was reminiscent of the degeneration induced by the i.p. treatment with MK801. Collectively, these experiments provide evidence for an AMPA/kainate-dependent mechanism of excitotoxicity in the death of RSC neurons after i.p. treatment with MK801.     

Synthesis, characterization, and osteocompatibility evaluation of novel alanine-based polyphosphazenes

This study deals with the synthesis and in vitro osteocompatibility evaluation of two novel alanine-containing biodegradable ester polyphosphazenes as candidates to form self-setting composites with hydroxyapatite (HAp) precursors. The two novel biodegradable polyphosphazenes synthesized were poly[(ethyl alanato)1.0(ethyl oxybenzoate)1.0 phosphazene] (PN-EA/EOB) and poly[(ethyl alanato)1.0(propyl oxybenzoate)1.0 phosphazene] (PN-EA/POB). The polymers were characterized by multinuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). Biodegradability and percentage water absorption of the polymers were evaluated by following the mass change in phosphate buffer (pH 7.4) at 37 degrees C. PN-EA/POB underwent faster degradation and showed higher water absorption compared to PN-EA/EOB. Both polymers became insoluble in common organic solvents following hydrolysis presumably due to crosslinking reactions accompanying the degradation process. Osteoblast cell adhesion and proliferation on PN-EA/EOB and PN-EA/POB was followed by scanning electron microscopy (SEM) and by using a biochemical assay. Both PN-EA/EOB and PN-EA/POB supported the adhesion and proliferation of primary rat osteoblast cells in vitro. Furthermore, the enzymatic activity of the osteoblast cells cultured on the polymers was confirmed by the alkaline phosphatase activity. Thus, these biodegradable amino-acid-based polyphosphazenes are promising new materials for forming self-setting bone cements.     

Competitive ELISA employing monoclonal antibodies specific for coronafacoyl amino acid conjugates

Coronatine (COR) is composed of two structural components, coronafacic acid (CFA) and the amino acid coronamic acid (CMA), linked by an amide bond. Monoclonal antibodies (MAbs) were prepared against COR and incorporated into competitive ELISAs. MAbs were secreted by hybridoma cells which had been prepared from mice immunized with COR and conjugated, through the free carboxyl group on CMA, to ovalbumin, the available amino groups of which had been increased by derivatization with propyl diamine via free carboxyl groups. COR and coronafacoyl valine could be quantified at 6.800 ng ml^‐1(0.34–40 ng/assay) using peroxidase‐labelled MAb 8H3G2 in an indirect competitive ELISA. The corresponding limit of detection was 1 ng ml～’. Reduction and subsequent acetylation of the ketone oxygen of the CFA moiety of COR reduced the affinity of MAb 8H3G2 some 250 times, whereas methylation of the free carboxyl group on COR slightly enhanced the affinity four‐fold. These and other results suggest that CFA and the amide bond are important structural features of the epitope recognized by MAb 8H3G2.     

Patterns of allelic loss on chromosome 17 in sporadic breast carcinomas detected by fluorescent-labeled microsatellite analysis

Loss of heterozygosity (LOH) on chromosome 17 is a frequent genetic alteration in breast cancer. To assess whether the location of potential tumor suppressor genes is compatible with the LOH pattern in individual tumors, we analyzed allele loss on chromosome 17 in 121 invasive ductal breast carcinomas and 16 benign breast tumors with 14 polymorphic microsatellite markers (4 on 17p and 10 on 17q). Fluorescent polymerase chain reaction (PCR) for typing microsatellites coupled with DNA fragment analysis in an automated DNA sequencer was applied. Frequencies of LOH varied from 29.4% (D17S1322) to 57.4% (TP53-Alu). No LOH could be detected in benign breast tumors. In 54 tumors the deletion patterns were consistent with the complete loss of 17p (n = 28), 17q (n = 9), or the whole chromosome 17 (n = 17). Five smallest regions of overlap (SROs) were identified in tumors with interstitial deletion patterns. On 17p, two foci were detected affecting the TP53 locus and the hypermethylated in cancer I (HICI) region (17p13.3). On 17q, SROI was localized between markers THRAI and D17S855, centromeric to the breast/ovarian cancer gene BRCAI; SRO2 was flanked by markers AFM234 and NMEI, and SRO3 was centered between markers MPO and GH. Associations between LOH and histopathological characteristics were determined. Significant correlations were found between higher grade and loss of the TP53 gene (marker TP53, P = 0.019), loss of the BRCAI region (P < 0.009), LOH of marker AFM155 (P = 0.003) and marker NMEI (P = 0.026). For positive estrogen receptor status, only LOH of the THRAI marker correlated significantly, whereas highly significant correlations were determined between positive progesterone receptor and markers centromeric to the BRCAI region D17S250 (P = 0.00002), THRAI (P = 0.0006), and the intragenic BRCAI markers [D17S1322 (P = 0.021), D17S855 (P = 0.029)]. Results presented in this study identify five independent regions of chromosome 17 which are likely to contain potential tumor suppressor genes involved in the carcinogenesis of sporadic breast cancer. Genes Chromosom. Cancer 18:181–192, 1997. © 1997 Wiley-Liss, Inc.     

Genetic testing for inherited eye conditions in over 6,000 individuals through the eyeGENE network

Genetic testing in a multisite clinical trial network for inherited eye conditions is described in this retrospective review of data collected through eyeGENE®, the National Ophthalmic Disease Genotyping and Phenotyping Network. Participants in eyeGENE were enrolled through a network of clinical providers throughout the United States and Canada. Blood samples and clinical data were collected to establish a phenotype:genotype database, biorepository, and patient registry. Data and samples are available for research use, and participants are provided results of clinical genetic testing. eyeGENE utilized a unique, distributed clinical trial design to enroll 6,403 participants from 5,385 families diagnosed with over 30 different inherited eye conditions. The most common diagnoses given for participants were retinitis pigmentosa (RP), Stargardt disease, and choroideremia. Pathogenic variants were most frequently reported in ABCA4 (37%), USH2A (7%), RPGR (6%), CHM (5%), and PRPH2 (3%). Among the 5,552 participants with genetic testing, at least one pathogenic or likely pathogenic variant was observed in 3,448 participants (62.1%), and variants of uncertain significance in 1,712 participants (30.8%). Ten genes represent 68% of all pathogenic and likely pathogenic variants in eyeGENE. Cross‐referencing current gene therapy clinical trials, over a thousand participants may be eligible, based on pathogenic variants in genes targeted by those therapies. This article is the first summary of genetic testing from thousands of participants tested through eyeGENE, including reports from 5,552 individuals. eyeGENE provides a launching point for inherited eye research, connects researchers with potential future study participants, and provides a valuable resource to the vision community.     

Suicidal desire and the capability for suicide: tests of the interpersonal-psychological theory of suicidal behavior among adults

The interpersonal-psychological theory of suicidal behavior (T. E. Joiner, 2005) proposes that an individual will not die by suicide unless he or she has both the desire to die by suicide and the ability to do so. Three studies test the theory's hypotheses. In Study 1, the interaction of thwarted belongingness and perceived burdensomeness predicted current suicidal ideation. In Study 2, greater levels of acquired capability were found among individuals with greater numbers of past attempts. Results also indicated that painful and provocative experiences significantly predicted acquired capability scores. In Study 3, the interaction of acquired capability and perceived burdensomeness predicted clinician-rated risk for suicidal behavior. Implications for the etiology, assessment, and treatment of suicidal behavior are discussed.     

Comparison of the effects of fluticasone propionate aqueous nasal spray and loratadine on daytime alertness and performance in children with seasonal allergic rhinitis.

BACKGROUND: Concern has been directed at the relative sedating properties of lipophilic and lipophobic antihistamines, but few studies have sought to determine the comparative benefit of seasonal allergic rhinitis (SAR) treatments in controlling symptoms and consequently improving alertness. OBJECTIVE: To compare the relative contributions of fluticasone propionate aqueous nasal spray and loratadine in enhancing daytime performance in 8- to 17-year-old children. METHODS: All participants had a documented history of SAR, positive response to a skin prick (wheal 3-mm greater than negative control or equal to the positive control) for seasonal aeroallergens, and clinically identifiable symptoms at the time of randomization. Following confirmation during baseline of current SAR symptoms, participants were randomized to 1 of the 2 treatments and returned 2 weeks later for evaluation of symptom control, quality of life, attention, reaction time, and memory. RESULTS: Children in the fluticasone propionate aqueous nasal spray group but not the loratadine group demonstrated improvement in nasal symptoms, nasal quality of life score, and composite verbal memory. No differences were identified on any scores from the Conners Continuous Performance Test. CONCLUSIONS: Treatments that most effectively control SAR symptoms are also likely to provide the greatest benefit to children whose daytime functioning, including their capacity to learn at school, is compromised by their illness.     

Family influences on pediatric asthma

OBJECTIVE: To describe pathways by which families may influence the onset and course of a child's asthma. METHODS: We critically reviewed published articles and book chapters to identify research findings and integrated conceptualizations that demonstrate how families affect pediatric asthma. RESULTS: Family emotional characteristics, asthma management behaviors, and physiological factors account for key influences on pediatric asthma onset and outcomes. CONCLUSIONS: Multiple family characteristics are associated with pediatric asthma onset and outcomes. Behavioral and physiological mechanisms may act independently or may interact to affect asthma manifestations. Families with specific emotional characteristics may be at an elevated risk for poorer asthma outcomes.     

Hormonal control of brood care and social status in a cichlid fish with brood care helpers

We studied the role of steroid hormones for parental and alloparental brood care and social status in a cooperatively breeding fish. We measured excretion levels of testosterone and 11-ketotestosterone in males, estradiol-17β in females and cortisol in both sexes at different stages of the breeding cycle, and compared these values to data measured in non-reproductive fish.Brood care behaviour does not seem to relate to steroid hormone excretion levels in this species. Steroid hormones varied with social status, however. Non-territorial male aggregation members, for example, showed high testosterone and low 11-ketotestosterone excretion levels, suggesting that they might pursue a “stand-by strategy” for breeding to react quickly if an occasion for breeding arises. Cortisol excretion levels are high in juvenile helpers compared to same-size aggregation members, suggesting higher stress levels in subordinate members of reproductive groups. This is the first study assessing if steroid hormone control mechanisms are involved in brood care and social roles in a cooperatively breeding fish.     

A phase II trial of intraperitoneal EGEN-001, an IL-12 plasmid formulated with PEG–PEI–cholesterol lipopolymer in the treatment of persistent or recurrent epithelial ovarian,fallopian tube or primary peritoneal cancer: A Gynecologic Oncology Group study

Objective

The purpose of this phase II trial was to evaluate the toxicity and antitumor activity of EGEN-001 in platinum resistant recurrent ovarian cancer.

Methods

Eligible patients had weekly IP infusion of EGEN-001 at a dose of 24 mg/m². Toxicity and antitumor activity were evaluated using CTCAE and RESIST criteria, respectively. Co-primary endpoints were tumor response and survival without progression (PFS) for at least 6 months. Survival without progression before going onto a subsequent therapy (EFS) for at least six months was also considered.

Results

A total of 58 EGEN-001 cycles were administered to 20/22 enrolled patients (median 2 cycles, range 1–9). The most frequently associated adverse events related specifically to EGEN-001 treatment were grade 1/2 fatigue, fever, chills, abdominal pain, nausea, vomiting, anemia, thrombocytopenia, and leukopenia. Three of 20 EGEN-001 treated patients evaluable for toxicity elected to withdraw from the study motivated in part by grade 1 treatment related toxicities. There were no patients with partial or complete response (0%; 90% CI 0–10.9%). Seven (35%) of 16 patients evaluable for response had stable disease, and 9 (45%) had progressive disease. Six (30%) patients had a PFS of greater than six months, although three had gone off study and onto other therapies before six months. The estimated six-month EFS was 15%. The median PFS and OS were 2.89 and 9.17 months, respectively.

Conclusion

EGEN-001 at the dose and schedule evaluated was associated with some but limited activity and was seemingly less tolerated in platinum resistant recurrent ovarian cancer patients.