Long-lasting memory of jasmonic acid-dependent immunity requires DNA demethylation and ARGONAUTE1.

Stress can have long-lasting impacts on plants. Here we report the long-term effects of the stress hormone jasmonic acid (JA) on the defence phenotype, transcriptome and DNA methylome of Arabidopsis. Three weeks after transient JA signalling, 5-week-old plants retained induced resistance (IR) against herbivory but showed increased susceptibility to pathogens. Transcriptome analysis revealed long-term priming and/or upregulation of JA-dependent defence genes but repression of ethylene- and salicylic acid-dependent genes. Long-term JA-IR was associated with shifts in glucosinolate composition and required MYC2/3/4 transcription factors, RNA-directed DNA methylation, the DNA demethylase ROS1 and the small RNA (sRNA)-binding protein AGO1. Although methylome analysis did not reveal consistent changes in DNA methylation near MYC2/3/4-controlled genes, JA-treated plants were specifically enriched with hypomethylated ATREP2 transposable elements (TEs). Epigenomic characterization of mutants and transgenic lines revealed that ATREP2 TEs are regulated by RdDM and ROS1 and produce 21 nt sRNAs that bind to nuclear AGO1. Since ATREP2 TEs are enriched with sequences from IR-related defence genes, our results suggest that AGO1-associated sRNAs from hypomethylated ATREP2 TEs trans-regulate long-lasting memory of JA-dependent immunity.

Pathogenicity of Nipah henipavirus Bangladesh in a swine host.

In 1998 an outbreak of fatal encephalitis among pig farm workers in Malaysia and Singapore led to the discovery of Nipah henipavirus (NiV), a novel paramyxovirus closely related to Hendra henipavirus with case fatality rates of nearly 40%. Following its initial emergence nearly annual outbreaks of NiV have occurred in Bangladesh with a different, NiV Bangladesh, genotype, where the role of pigs in its transmission remains unknown. The present study provides the first report on susceptibility of domestic pigs to NiV Bangladesh following experimental infection, characterizing acute and long-term phases of disease and pathogenesis. All pigs were successfully infected with NiV Bangladesh following oronasal inoculation, with viral shedding confirmed by a novel genotype-specific qRT-PCR in oral, nasal and rectal excretions and dissemination from the upper respiratory tract to the brain, lungs, and associated lymphatic tissues. Unlike previous NiV Malaysia findings in pigs, clinical signs were absent, viremia was undetectable throughout the study, and only low level neutralizing antibody titers were measured by 28/29 days post-NiV-B infection. Results obtained highlight the need for continued and enhanced NiV surveillance in pigs in endemic and at-risk regions, and raise questions regarding applicability of current serological assays to detect animals with previous NiV-B exposure.

Unintentional subdural block during labor epidural in a parturient with prior Harrington rod insertion for scoliosis. Case report.

BACKGROUND AND OBJECTIVES: The authors report a case of unintentional subdural block in a parturient with prior Harrington rod insertion. METHODS: The epidural technique was performed successfully at the L5-S1 interspace using the loss-of-resistance technique after two failed attempts at the L3-4 interspace. RESULTS: Twenty to 30 minutes after total initial dose of 9 mL 0.25% bupivacaine with 1/200,000 epinephrine, the patient developed hypotension and a high sensory block involving the trigeminal nerve. The patient also complained of difficulties in swallowing and breathing. Signs and symptoms strongly suggested an unintentional subdural block. After careful monitoring and reassurance, the patient's sensory level receded and she could breathe and swallow comfortably. Intubation was not required. The epidural catheter was maintained in the same space. The amount of 0.25% bupivacaine was reduced to 2 mL for subsequent top-ups. Adequate analgesia was provided throughout the course of her labor and delivery without other complications. CONCLUSIONS: Lumbar epidural anesthesia is not always an easily performed technique and is known to be associated with a higher incidence of complications in patients with prior Harrington rod insertion. Prompt recognition and proper management of subdurally placed needle and catheter avoided more serious complications.

Solitary eosinophilic granuloma of the temporal lobe: a case report and long-term follow-up of previously reported cases.

A case of solitary eosinophilic granuloma of the temporal lobe is reported and compared with seven previously documented cases. Long-term clinical follow-up information was obtained on two cases that were originally reported in 1977 and 1981. Solitary eosinophilic granuloma of the cerebral hemisphere, a rare manifestation of Langerhans cell histiocytosis, had excellent long-term clinical outcomes in this small number of patients.

A Gla domain mutation (Arg 15-->Trp) in the protein C (PROC) gene causing type 2 protein C deficiency and recurrent venous thrombosis.

A heterozygous CGG-->TGG (Arg 15-->Trp) substitution was detected in a family with inherited type II protein C deficiency and recurrent venous thrombosis. The mutation, which co-segregates with the deficiency state, occurs in a conserved pentapeptide within the gamma-carboxyglutamic acid (Gla) domain of the protein.

Recurrent deletion in the human antithrombin III gene.

Eight unrelated patients with recurrent thromboembolism, a family history of thrombosis, and plasma antithrombin III (ATIII) activity/antigen levels consistent with a diagnosis of heterozygous type I ATIII deficiency were studied by polymerase chain reaction/direct sequencing of ATIII gene exon-coding regions. Frameshift mutations of one base and two bases, respectively, were found to have occurred in two unrelated patients at the same GAG codon (Glu 245) within exon 4 of the ATIII gene. A literature search showed six further hitherto unrecognized deletion "hotspots" in four other human genes. These deletion-prone sites exhibited sufficient sequence homology with each other to derive a consensus sequence (T G A/G A/G G A/C), suggesting that deletion in human genes may not only be non-random but also sequence-directed.

Anti-idiotypes to factor VIII antibodies and their possible role in the pathogenesis and treatment of factor VIII inhibitors.

Studies on the production and characterization of anti-idiotype antibodies (AId) to monoclonal factor VIII antibodies (McFVIIIAb) are reported. Two AIds were produced and one of these exhibited cross-reactivity with two other McFVIIIAb but showed no reactivity with haemophilic and non-haemophilic FVIIIAb. This AId was also active against McFVIIIAb which bound immunologically active forms of factor VIII but it did not neutralize McFVIIIAb directed against procoagulant factor VIII. The in vitro effect of therapeutic pooled human IgG concentrates upon haemophilic and non-haemophilic FVIIIAb was also assessed. Approximately 25% of non-haemophilic FVIIIAb were inhibited following incubation with human IgG whereas the latter had no effect upon haemophilic FVIIIAb activity. Studies on haemophilic sibling pairs of FVIIIAb and non-FVIIIAb producing individuals indicated FVIIIAb neutralizing activity in the non-FVIIIAb producing sibling's IgG fraction which may be of anti-idiotypic origin. These findings lend further support to suggestions that anti-idiotypes have a regulatory role in FVIIIAb production and are of potential therapeutic value.

Effect of intravenous immunoglobulin on a spontaneous inhibitor to factor VIII.

A 71-year-old woman with a spontaneous anti-factor VIII inhibitor fractured her right wrist and 2 months later her left femur. She received treatment with porcine factor VIII for the first fracture and developed a secondary anti-porcine antibody response (from 10 to 200 Bethesda units). Following the second fracture she received intravenous immunoglobulin (i.v. IgG) (0.4 g/kg day for 5 days) in an attempt to reduce antibody activity. Despite further treatment with porcine factor VIII, the antibody level declined instead of rising as expected and the anti-human antibody activity also declined. We were not able to demonstrate neutralizing activity to her antibody but did demonstrate a reduced helper: suppressor ratio and reduced B-cell numbers and function after treatment with i.v. IgG. These changes were transient and as B-cell function improved over the following 4 months, her anti-human activity returned toward its previous level. Anti-porcine activity remained at its previous low level. We speculate that one of the mechanisms of action of i.v. IgG may be a direct cellular effect influencing both T-suppressor and B-lymphocyte function.

A study of cell mediated and humoral immunity in haemophilia and related disorders.

Helper (OKT4) and suppressor (OKT8) T lymphocyte populations and functional assays of cellular immunity were studied in 37 patients with haemophilia and related disorders in parallel with age matched control subjects. The study included 26 patients with factor VIII (FVIII:C) deficiency, eight patients with factor IX deficiency and three patients with severe von Willebrand's disease (vWd). In patients with factor VIII deficiency low helper T lymphocyte counts, low T helper: suppressor ratios and a diminished response to the lymphocyte mitogen phytohaemagglutinin with decreased natural killer cell activity were observed. Individuals with factor IX deficiency had low absolute T lymphocyte (OKT3) counts and T helper cell counts. Patients with severe factor VIII deficiency (FVIII:C less than 1 u/dl) had lower T helper suppressor ratios and lower killer cell and natural killer cell activity in comparison to mildly affected individuals and all of the severely affected factor IX deficient cases. Studies of humoral immunity revealed a generalized increase in immunoglobulin levels in patients with coagulation disorders of any type. The total haemolytic complement activity was reduced in a significant proportion of haemophilic subjects. Levels of alpha-1-interferon were elevated in the groups of haemophilic subjects studied. The abnormalities of cellular and humoral immunity observed did not correlate with the amount or type of coagulation factor administered to individual patients in the preceding 2 years. The most marked abnormalities of immune function occurred in the one patient diagnosed as suffering from AIDS on clinical grounds.

The effect of desamino-D-arginine vasopressin (DDAVP) and naloxone infusions on factor VIII and possible endothelial cell (EC) related activities.

Studies on the effect of DDAVP both in vitro and in vivo are reported. In order to define the extent of the DDAVP induced rise of circulating endothelial cell proteins in normal individuals and the endothelial cell defect in von Willebrand's disease (vWd) we have measured the effect of intravenous DDAVP on a range of possible endothelial cell markers in normal subjects and in patients with mild haemophilia and vWd. In a series of double blind cross over studies on normal volunteers we have tested the effect of naloxone, DDAVP or saline on circulating levels of factor VIII related activities (VIIIR) and plasminogen activator (PA). The results confirmed the effect of DDAVP on circulating levels of VIIIR and PA but showed that it did not induce release of these activities from cultured endothelial cells in vitro nor did it influence circulating levels of other endothelial cell markers including fibronectin, antithrombin III and platelet factor 4. Infusion of nalaxone did not significantly alter circulating levels of VIIIR or PA nor the response of these to DDAVP suggesting that normally these activities are not subjected to a vasopressin drive.