Expression in plants and immunogenicity of plant virus-based experimental rabies vaccine

A new approach to the production and delivery of vaccine antigens is the use of engineered amino virus-based vectors. A chimeric peptide containing antigenic determinants from rabies virus glycoprotein (G protein) (amino acids 253-275) and nucleoprotein (N protein) (amino acids 404-418) was PCR-amplified and cloned as a translational fusion product with the alfalfa mosaic virus (AlMV) coat protein (CP). This recombinant CP was expressed in two plant virus-based expression systems. The first one utilized transgenic Nicotiana tabacum cv. Samsun NN plants providing replicative functions in trans for full-length infectious RNA3 of AlMV (NF1-g24). The second one utilized Nicotiana benthamiana and spinach (Spinacia oleracea) plants using autonomously replicating tobacco mosaic virus (TMV) lacking native CP (Av/A4-g24). Recombinant virus containing the chimeric rabies virus epitope was isolated from infected transgenic N. tabacum cv. Samsun NN plants and used for parenteral immunization of mice. Mice immunized with recombinant virus were protected against challenge infection. Based on the previously demonstrated efficacy of this plant virus-based experimental rabies vaccine when orally administered to mice in virus-infected unprocessed raw spinach leaves, we assessed its efficacy in human volunteers. Three of five volunteers who had previously been immunized against rabies virus with a conventional vaccine specifically responded against the peptide antigen after ingesting spinach leaves infected with the recombinant virus. When rabies virus non-immune individuals were fed the same material, 5/9 demonstrated significant antibody responses to either rabies virus or AlMV. Following a single dose of conventional rabies virus vaccine, three of these individuals showed detectable levels of rabies virus-neutralizing antibodies, whereas none of five controls revealed these antibodies. These findings provide clear indication of the potential of the plant virus-based expression systems as supplementary oral booster for rabies vaccinations.     

Diary cards and the assessment of cough symptoms in community pharmacies

The aim of this study is to compare cough symptom assessment and medication efficacy as recorded in a diary card with that obtained through direct questioning by a pharmacist. Clients visiting six pharmacies, purchasing a cough medication and meeting the inclusion criteria were recruited. They were asked to fill out diary cards to obtain a daily retrospective assessment of symptoms and medication efficacy. After three days the subjects returned to the pharmacy and were asked to recall their symptoms through a structured questionnaire administered by the pharmacist.48 clients were recruited to the study and of these 44 (92% completed the study. A good correlation was obtained between ratings of medication efficacy as recorded by diary cards and recall. Symptom assessment also showed a statistically significant correlation for days two and three only.For studies assessing symptoms over a 48 hour period, detailed poststudy assessments may not be required. The study provides further evidence for the viability of clinical trials conducted through community pharmacies.     

Alcohol consumption and the body's biological clock

This review summarizes new findings on the bidirectional interactions between alcohol and the clock genes, underlying the generation of circadian rhythmicity. At the behavioral level, both adult and perinatal ethanol treatments after the free-running period and light response of the circadian clock in rodents; genetic ethanol preference in alcohol-preferring rat lines is also associated with alterations in circadian pacemaker function. At the neuronal level, it has been shown that ethanol consumption alters the circadian expression patterns of period (per) genes in various brain regions, including the suprachiasmatic nucleus. Notably, circadian functions of beta-endorphin-containing neurons that participate in the control of alcohol reinforcement become disturbed after chronic alcohol intake. In turn, per2 gene activity regulates alcohol intake through its effects on the glutamatergic system through glutamate reuptake mechanisms and thereby may affect a variety of physiological processes that are governed by our internal clock. In summary, a new pathologic chain has been identified that contributes to the negative health consequences of chronic alcohol intake. Thus, chronic alcohol intake alters the expression of per genes, and as a consequence, a variety of neurochemical and neuroendocrine functions become disturbed. Further steps in this pathologic chain are alterations in physiological and immune functions that are under circadian control, and, as a final consequence, addictive behavior might be triggered or sustained by this cascade.     

Duration of the increase in amniotic fluid index (AFI) after acute maternal hydration

The long-term effect of acute maternal hydration on amniotic fluid index (AFI) has not been previously studied. We evaluated the AFI of 25 pregnant women (ten women with normal AFI and 15 with decreased AFI) at 3, 24 and 48 h after maternal oral hydration with 2 l of water over 1 h. Post-hydration AFI at 3 h was significantly greater than pre-hydration AFI. However, AFI at 24 and 48 h were not significantly different from pre-hydration AFI. Maternal hydration increases AFI in women with normal and decreased amniotic fluid, but the increase in AFI lasts for less than 24 h.     

Surgical access to parapharyngeal space tumours--the Manipal experience

A few series of parapharyngeal space tumours have been reported earlier but recently not many series have been published in English literature. It is rare for any medical center, let alone an individual surgeon, to develop sufficient experience in evaluating these tumours. We present our experience in the treatment of 41 cases of parapharyngeal tumours from January 1992 to December 2001. FNAC, ultrasound and CT scan of the presenting mass was done in most of the patients as the main pre-operative work-up. The strategic location and extension of the tumour may occasionally alter the surgical approach for tumour excision.     

Mechanisms of oncogenic KIT signal transduction in primary gastrointestinal stromal tumors (GISTs)

Most gastrointestinal stromal tumors (GISTs) express constitutively activated forms of the KIT receptor tyrosine kinase protein, resulting from oncogenic mutations in the extracellular, juxtamembrane, or kinase domains. KIT oncoproteins are detected early in GIST tumorigenesis, and most GIST patients respond well to treatment with the KIT kinase inhibitor imatinib mesylate (STI571, Gleevec). However, GISTs can develop resistance to imatinib, and additional therapeutic strategies are needed. Little is known about oncogenic KIT signal transduction in GISTs, and whether the type of KIT mutation accounts for selective activation of downstream signaling intermediates. We therefore evaluated KIT downstream signaling profiles in 15 primary GISTs with mutations in KIT exons 9, 11, 13, and 17, and in two human GIST cell lines. All GISTs showed constitutive phosphorylation at KIT tyrosine residues Y703 and Y721. Additionally, most GISTs showed activation of MAPK p42/44, AKT, S6K, STAT1, and STAT3. STAT5 and JNK were not demonstrably activated in any GIST. Using GIST in vitro models, we showed that activation of MAPK p42/44, AKT, and S6K was KIT dependent, whereas STAT1 and STAT3 phosphorylation was only partially dependent on KIT activation. Correlation of activated signaling pathways with the type of KIT mutation revealed low levels of AKT phosphorylation in exon 9 mutant GISTs in contrast to a subset of GISTs with exon 11 mutations. However, additional factors are likely to modify the engagement of signaling pathways in GISTs as suggested by the fact that four GISTs with identical KIT exon 9 mutations had differential activation of MAPK p42/44 and STAT proteins. In summary, in this first report on KIT signal transduction in primary GISTs and GIST cell lines, we identified pathways that are constitutively activated in a KIT-dependent manner and therefore warrant further study as molecular targets in GISTs.