The beneficial effect of a beta-D-xyloside, Iliparcil, in the prevention of postthrombolytic rethrombosis in the rat.

The effect of Iliparcil, a new orally active beta-D-xyloside venous antithrombotic, was studied on the rethrombosis following thrombolytic therapy in rats, using a modified Umetsu model. The drug was administered by oral route prior to thrombolytic therapy, which consisted of administering a combination of heparin and urokinase (H/U) at 37.5 and 70,000 IU/kg, respectively. Time to reocclusion increased from 3.9 min with saline to 10.5 min following H/U injection. When Iliparcil (30 mg/kg, oral route) was administered 4 h before H/U injection, the time to reocclusion was increased by 250% compared with H/U alone (p < 0.001). Similarly, dermatan sulfate (DS), administered intravenously (3 mg/kg) 5 min before thrombus induction, also increased the time to reocclusion (300% compared with H/U alone; p < 0.001). It was also shown that times to reocclusion following Iliparcil or DS treatments were still increased even when heparin dosage was decreased. These results suggest that an antithrombotic product derived from the beta-D-xyloside family could be advantageously used in combination with thrombolytic treatment instead of heparin, which causes complications and side effects.     

Lack of correlation between in vivo peroxidatic activity patterns and tumoricidal activity in vitro of peritoneal macrophages after intraperitoneal immunization with tumor cells

Immunization of C57BL mice with one inoculum of 10(7) DBA/2-derived SL2 lymphosarcoma cells resulted in a +/- 20-fold increase in the total number of peritoneal cells. The number of macrophages showed a 10-fold increase from 3 x 10(6) (control mice) to 3.4 x 10(7) cells at day 8 after immunization. Within this macrophage population, four different cell types, based on the ultrastructural peroxidatic activity patterns, could be distinguished: exudate macrophages, resident macrophages, resident-exudate macrophages and peroxidatic-activity-negative macrophages. The number of exudate macrophages significantly increased in the peritoneal cavity after immunization: at day 8 after immunization, a peak value of 10(7) cells was observed. At the same time, there were 2.2 x 10(7) peroxidase-activity-negative macrophages present (representing the control value x 50). Significant in vitro tumoricidal activity of the isolated macrophages could not be measured until 8 days after immunization. At that time, a cytotoxicity index of 68 was reached. After immunization of the C57BL mice with 3 injections with allogeneic SL2 cells, there were no dramatic changes in the number of peritoneal cells after the last immunization. Only immediately after the last immunization was a minor increase in peroxidatic-activity-negative macrophages seen. But already at 5 days after the last immunization, the composition of the peritoneal suspension was similar to that of non-immunized mice with predominantly resident macrophages. The cytotoxicity of the peritoneal macrophages from hyperimmunized mice was constantly high during 1-15 days after the last immunization (cytotoxicity index ranged from 66-72). In order to study which type(s) of macrophage(s) (resident, exudate, resident-exudate or peroxidatic-activity-negative) is/are responsible for the cytotoxicity measured in vitro, peritoneal cell suspensions (obtained after immunization) were fractionated according to their affinity to wheat germ agglutinin (WGA) coupled to Sepharose columns. Comparison of the values of cytotoxicity measured before and after separation into "subtypes" of the macrophages revealed that the expression of cytotoxicity is not correlated with any of the "sub-types", especially when the peroxidatic activity pattern is is taken as a criterion.     

A prenotification letter increased initial response,whereas sender did not affect response rates

ObjectiveTo find ways to improve response rates of medical and health surveys. We investigated whether a prenotification letter instead of a second reminder and varying senders of the questionnaires would affect response rates.Study Design and SettingWe present the results of two studies. In the first study, four groups were compared that either received a prenotification letter (group 1 and 2) or a second reminder letter (group 3 and 4); received the questionnaire from either a research institute (group 1 and 3) or a health insurance company (HIC; group 2 and 4). In the second study, we compared two groups that received the questionnaire sent by either a HIC or a hospital. Response rates, response speed, respondent characteristics, item nonresponse, and mean scores on quality aspects and global ratings were compared.ResultsResponse rates did not differ significantly between groups. Prenotification groups returned their questionnaires faster. No other significant differences were found for response speed, respondent characteristics, item nonresponse, or mean scores.ConclusionA prenotification letter does only increase initial response speed and does not increase total response rates. A prenotification letter should be considered when quick response is desirable. Varying senders had no effect on response rates.     

Mutations in protein N-arginine methyltransferases are not the cause of FTLD-FUS

The nuclear protein fused in sarcoma (FUS) is found in cytoplasmic inclusions in a subset of patients with the neurodegenerative disorder frontotemporal lobar degeneration (FTLD-FUS). FUS contains a methylated arginine–glycine–glycine domain that is required for transport into the nucleus. Recent findings have shown that this domain is hypomethylated in patients with FTLD-FUS. To determine whether the cause of hypomethylation is the result of mutations in protein N-arginine methyltransferases (PRMTs), we selected 3 candidate genes (PRMT1, PRMT3, and PRMT8) and performed complete sequencing analysis and real-time polymerase chain reaction mRNA expression analysis in 20 FTLD-FUS cases. No mutations or statistically significant changes in expression were observed in our patient samples, suggesting that defects in PRMTs are not the cause of FTLD-FUS.     

Aggregation-prone c9FTD/ALS poly(GA) RAN-translated proteins cause neurotoxicity by inducing ER stress

The occurrence of repeat-associated non-ATG (RAN) translation, an atypical form of translation of expanded repeats that results in the synthesis of homopolymeric expansion proteins, is becoming more widely appreciated among microsatellite expansion disorders. Such disorders include amyotrophic lateral sclerosis and frontotemporal dementia caused by a hexanucleotide repeat expansion in the C9ORF72 gene (c9FTD/ALS). We and others have recently shown that this bidirectionally transcribed repeat is RAN translated, and the “c9RAN proteins” thusly produced form neuronal inclusions throughout the central nervous system of c9FTD/ALS patients. Nonetheless, the potential contribution of c9RAN proteins to disease pathogenesis remains poorly understood. In the present study, we demonstrate that poly(GA) c9RAN proteins are neurotoxic and may be implicated in the neurodegenerative processes of c9FTD/ALS. Specifically, we show that expression of poly(GA) proteins in cultured cells and primary neurons leads to the formation of soluble and insoluble high molecular weight species, as well as inclusions composed of filaments similar to those observed in c9FTD/ALS brain tissues. The expression of poly(GA) proteins is accompanied by caspase-3 activation, impaired neurite outgrowth, inhibition of proteasome activity, and evidence of endoplasmic reticulum (ER) stress. Of importance, ER stress inhibitors, salubrinal and TUDCA, provide protection against poly(GA)-induced toxicity. Taken together, our data provide compelling evidence towards establishing RAN translation as a pathogenic mechanism of c9FTD/ALS, and suggest that targeting the ER using small molecules may be a promising therapeutic approach for these devastating diseases.     

Progressive amnestic dementia, hippocampal sclerosis, and mutation in C9ORF72

The most common cause of familial frontotemporal lobar degeneration with TAR DNA-binding protein-43 pathology (FTLD-TDP) has been found to be an expansion of a hexanucleotide repeat (GGGGCC) in a noncoding region of the gene C9ORF72. Hippocampal sclerosis (HpScl) is a common finding in FTLD-TDP. Our objective was to screen for the presence of C9ORF72 hexanucleotide repeat expansions in a pathologically confirmed cohort of “pure” hippocampal sclerosis cases (n = 33), outside the setting of FTLD-TDP and Alzheimer’s disease (AD). Using a recently described repeat-associated non-ATG (RAN) translation (C9RANT) antibody that was found to be highly specific for c9FTD/ALS, we identified a single “pure” HpScl autopsy case with a repeat expansion in C9ORF72 (c9HpScl). Mutation screening was also performed with repeat-primed polymerase chain reaction and further confirmed with Southern blotting. The c9HpScl patient had a 14-year history of a slowly progressive amnestic syndrome and a clinical diagnosis of probable AD. Neuropsychological testing revealed memory impairment, but no deficits in other cognitive domains. Autopsy showed hippocampal sclerosis with TDP-43 immunoreactive neuronal inclusions relatively limited to limbic lobe structures. Neuritic pathology immunoreactive for p62 was more frequent than TDP-43 in amygdala and hippocampus. Frequent p62-positive neuronal inclusions were present in cerebellar granule neurons as is typical of C9ORF72 mutation carriers. There was no significant FTLD or motor neuron disease. C9RANT was found to be sensitive and specific in this autopsy-confirmed series of HpScl cases. The findings in this patient suggest that the clinical and pathologic spectrum of C9ORF72 repeat expansion is wider than frontotemporal dementia and motor neuron disease, including cases of progressive amnestic dementia with restricted TDP-43 pathology associated with HpScl.