Growth characteristics of the chimeric Japanese encephalitis virus vaccine candidate, ChimeriVax-JE (YF/JE SA14--14--2), in Culex tritaeniorhynchus, Aedes albopictus, and Aedes aegypti mosquitoes

The Japanese encephalitis (JE) virus vaccine candidate, ChimeriVax-JE, which consists of a yellow fever (YF) 17D virus backbone containing the prM and E genes from the JE vaccine strain JE SA14--14--2, exhibits restricted replication in non-human primates, producing only a low-level viremia following peripheral inoculation. Although this reduces the likelihood that hematophagous insects could become infected by feeding on a vaccinated host, it is prudent to investigate the replication kinetics of the vaccine virus in mosquito species that are known to vector the viruses from which the chimera is derived. In this study ChimeriVax-JE virus was compared to its parent viruses, as well as to wild-type JE virus, for its ability to replicate in Culex tritaeniorhynchus, Aedes albopictus, and Aedes aegypti mosquitoes. Individual mosquitoes were exposed to the viruses by oral ingestion of a virus-laden blood meal or by intrathoracic (IT) virus inoculation. ChimeriVax-JE virus did not replicate following ingestion by any of the three mosquito species. Additionally, replication was not detected after IT inoculation of ChimeriVax-JE in the primary JE virus vector, Cx. tritaeniorhynchus. ChimeriVax-JE exhibited moderate growth following IT inoculation into Ae. aegypti and Ae. albopictus, reaching titers of 3.6-5.0 log(10) PFU/mosquito. There was no change in the virus genotype associated with replication in mosquitoes. Similar results were observed in mosquitoes of all three species that were IT inoculated or had orally ingested the YF 17D vaccine virus. In contrast, all mosquitoes either IT inoculated with or orally fed wild-type and vaccine JE viruses became infected, reaching maximum titers of 5.4-7.3 log(10) PFU/mosquito. These results indicate that ChimeriVax-JE virus is restricted in its ability to infect and replicate in these mosquito vectors. The low viremia caused by ChimeriVax-JE in primates and poor infectivity for mosquitoes are safeguards against secondary spread of the vaccine virus.     

Use of a Surrogate Chimeric Virus To Detect West Nile Virus-Neutralizing Antibodies in Avian and Equine Sera

A chimeric yellow fever virus/West Nile virus (WNV) was compared to WNV alone as a biosafety level 2 reagent in the plaque reduction neutralization test for determining WNV infection histories. Concordance was 96.3% among 188 avian and equine serum samples. Neutralizing antibody titers were frequently more than twofold lower with the chimera.     

Uterine artery embolization for symptomatic fibroids with imaging follow up

The aim of this study was to determine the effectiveness of uterine artery embolization (UAE) as a primary treatment method in treatment of symptomatic fibroids, whether there are any preembolization MRI characteristics of fibroid predictive of reduction in volume and assess reduction in uterine and dominant fibroid volumes using ultrasound (US) and MRI. Study was carried out in total of 32 patients aged 25–49 years (mean 40.9 years). Uterine and dominant fibroid volume were determined using US and MRI before UAE, MRI and US at 3 months and US alone at 6 and 12 months post‐UAE, supplemented by clinical evaluation at interval of 3, 6 and 12 months. Procedure was carried out through unilateral femoral puncture using poly vinyl alcohol (PVA) particles 355–500 μm in size. All 32 patients had successful procedures. Overall, 25 patients responded, giving a clinical success rate of 78.12%. Mean reduction in volume of uterus and fibroid was 33 and 59.7% and 48.9 and 75.5% on US at 3 and 12 months respectively, and 33.3 and 58.6% on MRI at 3 months. Volume reduction on US and MRI at 3 months was highly correlative. There was no statistical difference in size reduction in volume of fibroids, which were hypointense or hyperintense on T2‐weighted image (T2WI) on pre‐UAE MRI. Uterine artery embolization leads to good technical success and fibroid volume reduction. Ultrasound alone may be used for follow up of patients post‐UAE. Preprocedure signal characteristics on T2WI are not predictors of volume reduction after UAE.     

Is rural radiation oncology practice quality as good as the big smoke? Results of the Australian radiotherapy single machine unit trial

Radiotherapy utilization rates in rural Australia are suboptimal, with one solution being the building of single machine units (SMUs). One concern raised with such an approach is the quality of care delivered in SMUs. The Australian and Victorian governments have established two SMUs in the state of Victoria, with each SMU operated as a satellite service of a major ‘hub’ site. We report on the planned evaluation of practice quality. Radiation oncologist (RO) clinical practice was externally audited using the Royal Australian and New Zealand College of Radiologists Peer Review Audit instrument. This tool splits RO clinical practice into documentation/quality assurance (QA) criteria and decision‐making criteria. Over the four sites, 130 patients were randomly selected for audit. At hub sites, 79.6% of all criteria audited were adequate, compared with 84.4% of criteria audited at SMUs (P = 0.0002). This difference was largely because of better adherence to documentation/QA criteria at the SMU sites. RO decision‐making and protocol adherence were routinely very high and consistent with other clinical practice audits. There were no significant differences between hubs and SMUs for adherence to decision‐making criteria; however, the few potential deficiencies in patient care identified occurred only at the hub sites. In at least one of these cases, potential suboptimal management was as a direct result of inadequate documentation. This audit found that SMUs provide as high a standard of radiotherapeutic care as larger hub departments. The findings also emphasize the need for all departments to target clinical documentation.     

Local Anaesthesia for Fiberoptic Intubation : A Comparison of Three Techniques

Background

The successful conduct of fiberoptic aided intubation is dependent upon effective local anaesthesia. The aim of the study was to compare three different methods of anaesthetizing the airway.

Methods

60 adult patients (American Society of Anaesthesiologists status I-III and Mallampati class III & IV), scheduled for elective surgery, received sedation followed by spraying of the nares and posterior pharyngeal wall with 4% lignocaine. Thereafter the patients received 4 ml of 4% lignocaine either by transtracheal injection (n=20, group A), via intubating fiberscope (Pentax F1-10P2) using ‘spray as you go’ technique (n=20, group B) or by nebulizer (Devilbiss 5610W) 20 min before intubation, (n=20, group C). Patients were asked to score the procedure using visual analog scale (VAS) and severity scores. Episodes of coughing, choking, stridor, extra / total local anaesthetic used and intubation times were recorded. Patients were monitored continuously for vital parameters.

Results

Group B patients showed better VAS scores with shorter intubation times and had a lower incidence of coughing and choking. The endoscopists’ VAS scores also showed a preference for group B.

Conclusion

In conclusion the ‘spray as you go’ technique was safe, provided effective local anaesthesia and was preferred by both patients and endoscopists.Key Words: Awake intubation, Difficult airway, Fiberoptic intubation     

Arbovirus studies in Nupeko forest, a possible natural focus of yellow fever virus in Nigeria. I. Description of the area and serological survey of humans and other vertebrate hosts

Studies were conducted in a restricted area of gallery forest along the middle upper Niger River, Nigeria. Yellow fever neutralizing antibodies were found in 25% of the human population and in 57% of the monkeys tested. Both the abundance of monkeys and the ecological conditions in such forest appear to be favourable for year-round maintenance of yellow fever virus.     

Pain relief following Arthroscopy - a comparative study of Intra-articular Bupivacaine,Morphine and Neostigmine

Pain after arthroscopy is quite distressing. Intra-articular bupivacaine produces transient analgesia and reports of analgesia using intra-articular opioids have produced conflicting results. Recently, spinal administration of neostigmine was shown to produce dose-dependant analgesia. However, this was limited by adverse effects. The purpose of this study was to compare the effects on intra-articular neostigmine, bupivacaine and morphine. 75 patients were randomized to receive intra-articular saline, bupivacaine, morphine, neostigmine and bupivacaine-neostigmine after arthroscopic surgery under spinal anaesthesia. Visual analog pain scores (VAS), duration of analgesia as defined as time for first demand for parenteral opioids and the total subsequent consumption of morphine was evaluated. Intra-articular bupivacaine resulted in significant VAS reduction at one and four hours as compared to those receiving intra-articular saline and morphine. Analgesia lasted longer after 500ugm intra-articular neostigmine as compared with bupivacaine, morphine or saline. The need for supplementary analgesia was lowest in the neostigmine group as compared to the other groups. No significant difference was found if bupivacaine was added to neostigmine. Among all the groups, no significant side-effects were observed.Key Words: Arthroscopy, Bupivacaine, Morphine, Neostigmine     

Phenotypic and molecular analyses of yellow fever 17DD vaccine viruses associated with serious adverse events in Brazil

The yellow fever (YF) 17D virus is one of the most successful vaccines developed to data. Its use has been estimated to be over 400 million doses with an excellent record of safety. In the past 3 years, yellow fever vaccination was intensified in Brazil in response to higher risk of urban outbreaks of the disease. Two fatal adverse events temporally associated with YF vaccination were reported. Both cases had features similar to yellow fever disease, including hepatitis and multiorgan failure. Two different lots of YF 17DD virus vaccine were administered to the affected patients and also to hundreds of thousands of other individuals without any other reported serious adverse events. The lots were prepared from the secondary seed, which has been in continuous use since 1984. Nucleotide sequencing revealed minor variations at some nucleotide positions between the secondary seed lot virus and the virus isolates from patients; these differences were not consistent across the isolates, represented differences in the relative amount of each nucleotide in a heterogeneous position, and did not result in amino acid substitutions. Inoculation of rhesus monkeys with the viruses isolated from the two patients by the intracerebral (ic) or intrahepatic (ih) route caused minimal viremia and no clinical signs of infection or alterations in laboratory markers. Central nervous system histological scores of rhesus monkeys inoculated ic were within the expected range, and there were no histopathological lesions in animals inoculated ih. Altogether, these results demonstrated the genetic stability and attenuated phenotype of the viruses that caused fatal illness in the two patients. Therefore, the fatal adverse events experienced by the vaccinees are related to individual, genetically determined host factors that regulate cellular susceptibility to yellow fever virus. Such increased susceptibility, resulting in clinically overt disease expression, appears to be extremely rare.     

High rates of recurrence and of transient reinfections of Helicobacter pylori in a population with high prevalence of infection

OBJECTIVES: Little is known concerning the magnitude of reinfection versus recrudescence of Helicobacter pylori (H. pylori) infection after eradication treatment. The aims of this study were to determine the magnitude of H. pylori reinfection versus recrudescence, and to identify possible risk factors for reinfection. METHODS: Children and adults with upper GI symptoms treated at the Centro Médico Nacional Siglo XXI (Instituto Mexicano del Seguro Social, in Mexico City, Mexico) were studied. H. pylori infection was diagnosed with urea breath test (UBT), histology, and culture. Infected patients received triple therapy, and those who became UBT negative 4-6 wk after treatment were considered as eradicated and were included in the study. A cohort of 141 patients in whom the disease was eradicated was monitored for recurrence with UBT at 3, 6, 9, 12, 18, and 24 months. H. pylori was isolated from gastric biopsy samples before treatment and at recurrence and isolates compared by genotyping. RESULTS: During this period, 32 (22.7%) cases of recurrence were documented the majority occurring during yr 1. In nine of the 32 (28.1%) cases, recurrence was eradicated spontaneously, suggesting these were transient reinfections. Recurrence rates were significantly higher in the subjects 41-60 yr of age than in younger or older subjects. H. pylori isolates from 12 recurrence cases were genotyped; nine (75%) were classified as true reinfection and three as recrudescence. CONCLUSIONS: In our population, recurrence rate is high in adults and transient reinfection is common. In several cases, reinfection occurred by multiple strains, which suggests that soon after eradication, patients are exposed to multiple sources of reinfection.