Viral metagenomics reveals the presence of novel Zika virus variants in Aedes mosquitoes from Barbados

Background

The Zika virus (ZIKV) epidemic of 2015/2016 spread throughout numerous countries. It emerged in mainland Latin America and spread to neighboring islands, including the Caribbean island of Barbados. Recent studies have indicated that the virus must have already been circulating in local mosquito populations in Brazil for almost 2 years before it was identified by the World Health Organization in 2015. Metagenomic detection assays have the potential to detect emerging pathogens without prior knowledge of their genomic nucleic acid sequence. Yet their applicability as vector surveillance tools has been widely limited by the complexity of DNA populations from field-collected mosquito preparations. The aim of this study was to investigate local vector biology and characterize metagenomic arbovirus diversity in Aedes mosquitoes during the ongoing 2015/2016 ZIKV epidemic.

Methods

We performed a short-term vector screening study on the island of Barbados during the ongoing 2015/2016 ZIKV epidemic, where we sampled local Aedes mosquitoes. We reanalyzed mosquito viral microbiome data derived from standard Illumina MiSeq sequencing to detect arbovirus sequences. Additionally, we employed deep sequencing techniques (Illumina HiSeq) and designed a novel bait capture enrichment assay to increase sequencing efficiency for arbovirus sequences from complex DNA samples.

Results

We found that Aedes aegypti seemed to be the most likely vector of ZIKV, although it prevailed at a low density during the observed time period. The number of detected viruses increased with sequencing depth. Arbovirus sequence enrichment of metagenomic DNA preparations allowed the detection of arbovirus sequences of two different ZIKV genotypes, including a novel one. To our knowledge, this is the first report of the S3116W mutation in the NS5 gene region of ZIKV polyprotein.

Conclusions

The metagenomic arbovirus detection approach presented here may serve as a useful tool for the identification of epidemic-causing arboviruses with the additional benefit of enabling the collection of phylogenetic information on the source. Apart from detecting more than 88 viruses using this approach, we also found evidence of novel ZIKV variants circulating in the local mosquito population during the observed time period.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04840-0.

Have we forgotten about heller’s? a case report of childhood disintegrative disorder

Introduction

We report on the case of a 15 year old young person with a known diagnosis of autism presenting with a rapid and acute regression in functional abilities, decline in expressive speech and bizarre posturing. The symptoms first started during lockdown (April 2020) with anxiety related to school work followed by urinary incontinence, insomnia, muttering to self and incongruent smiling. Initial medical investigations including MRI, lumbar puncture and 24hour EEG were inconclusive, so she was referred to Paediatric Liaison for assessment.

Objectives

We demonstrate the value of a child psychiatry liaison service being involved with young people in an acute medical hospital

Methods

This young person had a thorough psychiatric assessment.

Results

Through daily psychiatric assessment and reviews with the young person, her parent, social care, wider community team, school and Paediatric Inpatient ward in order to expand on the understanding of the young person and develop a case formulation. She was started on oral Olanzapine 2.5mg which was gradually increased to 10mg OD with minimal improvement.

Conclusions

Childhood Disintegrative Disorder (CDD or Heller’s Syndrome) is a rare pervasive disorder presenting as a loss of previously acquired skills after at least two years of normal development. Despite no longer being included in DSM-V, it is important for Psychiatrists to have a working knowledge of CDD and consider other differentials when assessing young people.

Disclosure

No significant relationships.

Complications of augmentation procedures for dental implants in private practice, Victoria, Australia

PURPOSE

This study audited complications associated with augmentation for dental implants, retrospectively over a 5-year period in a variety of private dental practices in Victoria (Australia).

METHODS

Complications were categorized as surgical or biological and compared to a group not requiring augmentation. Implant factors underwent univariate and multivariate analysis.

RESULTS

The study assessed 8486 implants with 26.9% undergoing augmentation. Augmentation had no effect on implant survival, however, a significant increase in complications for those implants requiring augmentation was found (P = <0.001). The hard tissue augmented group had significantly more cases of insufficient bone/dehiscences at implant placement (P < 0.001), and post-placement bone loss (P = 0.0014). These implants were grafted simultaneously (P < 0.05) with particulate autogenous bone and/or Bio-Oss (P < 0.05) with resorbable xenograft membrane (P < 0.001). There was significantly more bone loss in open sinus lifted cases than implants placed in native bone (1.90% v 0.30%; P = 0.009).

CONCLUSIONS

The study demonstrated no increase in graft complications that could be related to any specific augmentation technique, suggesting that routine grafting procedures used in private practice were safe and appropriate. Previously augmented sites were found to be more likely to require further augmentation at implant placement.

Glanzmann thrombasthenia in pregnancy: Optimising maternal and fetal outcomes

Glanzmann thrombasthenia is a rare autosomal recessive haemorrhagic disorder. The risks of miscarriage, antepartum and postpartum haemorrhage, and neonatal complications are all increased in individuals presenting with the disease in pregnancy. Some individuals may develop antibodies to platelet glycoproteins; the presence of these antibodies is a rare cause of neonatal alloimmune thrombocytopenia and potential intracranial haemorrhage. Multidisciplinary care is paramount for ensuring optimal fetal and maternal outcomes in such cases. We report a case of neonatal alloimmune thrombocytopenia secondary to maternal Glanzmann thrombasthenia in pregnancy.

Analysis of commonly reported medical conditions amongst patients receiving dental implant therapy in private practice

BACKGROUND

The population seeking implants in private practice is a demographically and medically unique group. Understanding their medical needs can improve treatment planning and service delivery specifically for this population.

METHODS

Privately practising dental clinicians from Victoria, Australia, participated in a five-year retrospective study. Data were collected from the medical histories of 4116 patients who met the inclusion criterion of at least one implant placed within the study period of 1 January 2005 to 31 December 2009. Descriptive statistics were used to describe patient demographics and commonly reported medical conditions.

RESULTS

The most common age group to receive implant therapy was between 51 and 60 years (30.4% of patients). The patient population reported a broad range of co-morbidities including psychiatric disorders (83 patients), cardiovascular disorders (253 patients), gastrointestinal disorders (224 patients) and respiratory disorders (502 patients). Smoking was less prevalent amongst the study population compared to the general population.

CONCLUSIONS

The population assessed in this study was a medically diverse group. Clinicians must be familiar with their target demographic and understand how the common co-morbidities amongst this patient group can influence clinical decision making and outcomes.

Successful combined liver/kidney transplantation from a donor with Pompe disease

Pompe disease results from inherited deficiency of the enzyme acid alpha-glucosidase resulting in lysosomal accumulation of glycogen primarily in skeletal muscle. Reported is the first case in which a donor with late onset Pompe disease (LOPD) was successfully used for deceased donor liver and kidney transplantation. This case demonstrates co-operative transplant surgery and genetic medicine evaluation and risk estimation for donors with inherited metabolic disorders some of which may be suitable for donation of selected organs for transplantation.

Third Åland islands conference on von Willebrand disease, 26-28 September 2012: meeting report

The first meeting of international specialists in the field of von Willebrand disease (VWD) was held in the Åland islands in 1998 where Erik von Willebrand had first observed a bleeding disorder in some members of a family from Föglö and a summary of the meeting was published in 1999. The second meeting was held in 2010 and a report of the meeting was published in 2012. Topics covered included progress in understanding of VWD over the last 50 years; multimers; classification of VWD; pharmacokinetics and laboratory assays; genetics; treating the paediatric patient; prophylaxis; geriatrics; gene therapy and treatment guidelines. This third meeting held over 3 days covered the structure and function of von Willebrand factor (VWF); type 1 VWD, the most common form of the disease; a lifespan of pharmacokinetics in VWD; detecting inhibitors in VWD patients; and special challenges in understanding and treating the female VWD patient.

Longitudinal study of Pelvicol pubovaginal slings using magnetic resonance imaging

The mechanism of urinary continence is complicated and is poorly understood. One current opinion is that there is an absence or weakness of the endopelvic fascial supports of the urethra. Pubovaginal slings are rapidly becoming the surgical procedure of choice in the management of urodynamic stress incontinence but their method of action is unclear. This study using magnetic resonance imaging shows how a pubovaginal sling can restore the normal anatomy and continence and adds to the global understanding of this condition.

Contamination from historic metal mines and the need for non-invasive remediation techniques: a case study from Southwest England

The UK is legally required by the EU Water Framework Directive (WFD) to improve the environmental quality of inland and coastal waters in the coming years. Historic metal mine sites are recognised as an important source of some of the elements on the WFD priority chemicals list. Despite their contamination potential, such sites are valued for their heritage and for other cultural and scientific reasons. Remediating historic mining areas to control the contamination of stream waters, whilst also preserving the integrity of the mine site, is a challenge but might be achieved by novel forms of remediation. In this study, we have carried out environmental monitoring at a historic, and culturally-sensitive, lead-silver mine site in southwest England and have undertaken a pilot experiment to investigate the potential for a novel, non-invasive remediation method at the site. Concentrations of Pb and Zn in mine spoil were clearly elevated with geometric mean concentrations of 6,888 and 710 microg g(-1), respectively. Mean concentrations of Pb in stream waters were between 21 and 54 microg l(-1), in exceedance of the WFD environmental quality standard (EQS) of 7.2 microg l(-1) (annual average). Mean Zn concentrations in water were between 30 and 97 microg l(-1), compared to the UK EQS of 66.5 microg l(-1) (average). Stream sediments within, and downstream from, the mining site were similarly elevated, indicating transport of mine waste particles into and within the stream. We undertook a simple trial to investigate the potential of hydroxyapatite, in the form of bonemeal, to passively remove the Pb and Zn, from the stream waters. After percolating through bonemeal in a leaching column, 96-99% of the dissolved Pb and Zn in stream water samples was removed.

Effect of AC II, an herbal formulation in cyclophosphamide-induced immunosuppression in BALB/c mice--Implication in HIV treatment

Effect of AC II, herbal drug formulation in reducing immunosuppression caused by administration of cyclophosphamide was studied. Mice were injected cyclophosphamide (CTX) 50 mg/kg b.wt. for 14 days with or without the drug and total WBC, bone marrow cellularity and alpha-esterase positive cells were determined. On day 15, total WBC count in cyclophosphamide treated mice was 1500 +/- 420 cells/mm3, while in AC II-treated mice it was 7658 +/- 376 cells/mm3. On day 16, administration of cyclophosphamide reduced bone marrow cellularity to 3.42 +/- 0.38 x 10(6) cells/femur from the normal value of 13.83 +/- 0.96 x 10(6) cells/femur. In AC II treated group bone marrow cellularity was increased to 8.05 +/- 0.7 x 10(6) cells/femur. The number of alpha-esterase positive cells was found to be reduced to 177 +/- 25 cells per 4000 cells in CTX treated groups. But in AC II-treated group the number of alpha-esterase positive cells were raised to 843 +/- 86 cells per 4000 cells, which was closer to that of normal (710 +/- 49 cells per 4000 cells). Results indicate the usefulness of AC II to combat immunosuppression induced by chemical and biological agents.

An audit of corneal abrasion management following the introduction of local guidelines in an accident and emergency department

BACKGROUND AND OBJECTIVES

Corneal abrasions are a common presentation to accident and emergency (A&E) departments. Patients can be treated and discharged by A&E staff without the need for an ophthalmologist's attention; complicated cases, however, should be recognised and referred. Inexperience and limited training in ophthalmology may lead to suboptimal patient care and inappropriate use of ophthalmology outpatient clinics. Issues of poor documentation may also arise. The purpose of this audit was to assess the effect of guidelines on the management of corneal abrasion by A&E staff.

METHODS

A retrospective case note audit was performed to assess current management of corneal abrasions. Guidelines for management of corneal abrasions were formulated following a literature search and collaboration between A&E and ophthalmology staff. A prospective case note audit was undertaken to assess management after introduction of the guidelines.

RESULTS

A total of 51 cases were audited before the introduction of the guidelines and 57 cases after. Following the introduction of the guidelines documentation of visual acuity increased to 93% and specific enquiry into contact lens wear rose from 35.3% to 71.9%. A&E staff stopped giving out local anaesthetic eye drops. The follow up profile also improved; appropriate patient discharges increased by 40% whereas inappropriate referrals to eye clinic dropped by 75%. More patients were given abrasion advice (a 101% increase).

CONCLUSIONS

A&E staff members are capable of managing corneal abrasions if they are given guidance and some training. This audit identified shortcomings in current management and showed that guidelines can significantly improve clinical practice.

Staffing: know your liability

Read this case of poor staffing judgment regarding outside agency employees and answer the questions, then check your answers at http://www.nursingmanagement.com.

Pharmacokinetics of levobupivacaine 0.25% following caudal administration in children under 2 years of age † †Declaration of interest. This work was funded by Chiroscience Limited, Cambridge, UK

BACKGROUND

Levobupivacaine, the S(-)enantiomer of racemic bupivacaine is less cardiotoxic than racemic bupivacaine and the R(+)enantiomer dexbupivacaine, while retaining similar local anaesthetic properties and potency to racemic bupivacaine. The pharmacokinetic profiles of the two bupivacaine enantiomers differs and that of racemic bupivacaine may be age dependent. We examined the pharmacokinetics of levobupivacaine after its single shot caudal epidural administration in children.

METHODS

An open-label phase 2 study was undertaken to examine the pharmacokinetics of levobupivacaine 0.25% 2 mg kg(-1) in 49 children aged less than 2 yr, after single shot caudal epidural administration. Plasma concentrations were determined at intervals up to 60 min after caudal injection.

RESULTS

Time to peak plasma concentration (T(max)) ranged between 5 and 60 min (median 30 min) and was reached later in children aged less than 3 months (P<0.005). Peak plasma concentration (C(max)) ranged between 0.41 and 2.12 micro g ml(-1) (median 0.80, mean (SD) 0.91 (0.40) micro g ml(-1)).

CONCLUSION

After the caudal epidural administration of levobupivacaine 2 mg kg(-1) in children less than 2 yr of age, C(max) was within the accepted safe range for racemic bupivacaine. T(max) varied and occurred later in some children, particularly those aged less than 3 months. Sampling in future pharmacokinetic studies in this age group should extend beyond 60 min.

Efficacy and safety of caudal injection of levobupivacaine, 0.25%, in children under 2 years of age undergoing inguinal hernia repair, circumcision or orchidopexy

BACKGROUND

Levobupivacaine is the S(-)-enantiomer of racemic bupivacaine. Evidence suggests that it is less cardiotoxic than racemic bupivacaine and the R(+)-enantiomer, dexbupivacaine, while retaining similar local anaesthetic properties and potency to racemic bupivacaine.

METHODS

This was an open study designed to assess the efficacy and safety of 0.25% levobupivacaine administered as a caudal injection at a dose of 2 mg.kg(-1) to 49 paediatric patients aged less than 2 years old undergoing circumcision (group 1), or hernia repair or orchidopexy (group 2).

RESULTS

Adequate analgesia (an increase of <20% in pulse or respiratory rate compared with baseline and an absence of gross movement on application of surgical stimulus) was achieved in 43/48 patients evaluable for efficacy (89.6%). All 22 patients in the circumcision group had adequate analgesia, and two of these patients did not require additional analgesia. The mean time to the use of additional analgesia was 7.3 h. Only one event (a mild rash) was considered possibly related to study medication.

CONCLUSIONS

Levobupivacaine is a promising new local anaesthetic agent for pain management in paediatric patients and appears to offer similar anaesthetic efficacy to racemic bupivacaine with a potentially improved tolerability profile.

COX-2 inhibitors and the cardiovascular system

Cyclooxygenase-2 selective inhibitors (coxibs) represent a new class of non steroidal anti-inflammatory drugs that exhibit preference for inhibition of cyclooxygenase-2 (COX-2), the COX isoform thought to account largely for prostanoid formation in inflammation. We review the divergent incidence of cardiovascular events derived from the two large clinical trials of coxibs, the Vioxx Gastrointestinal Outcomes Research Trial (VIGOR) and the Celecoxib Long-term Arthritis Safety Study (CLASS), in the context of current understanding of relevant clinical and basic pharmacology. The incidence of cardiovascular events was higher in patients receiving rofecoxib than in those receiving naproxen in VIGOR and did not differ between the groups in CLASS. By contrast, while the primary gastrointestinal (GI) endpoint comparison favored rofecoxib in VIGOR, no significant difference in the incidence of the primary GI endpoint was evident between celecoxib and two NSAID comparators not attained in CLASS. The cardiovascular results in VIGOR may have resulted from chance, a cardioprotective effect of naproxen, or suppression of prostacyclin but not thromboxane on rofecoxib. Differences in cardiovascular outcome between the two trials may also have resulted either from chance, or from aspects of the trial design (such as the use of aspirin by roughly one-fifth of the participants in CLASS), or from differences in the COX-2 selectivity or other pharmacology of the coxibs. Individuals who warrant low-dose aspirin for cardioprotection may have less likelihood of a GI event if they combine aspirin with rofecoxib, rather than a traditional NSAID. However, evidence addressing directly this hypothesis is currently unavailable. On the other hand, coxib consumption alone does not currently warrant initiation of a cardioprotective regimen, such as low-dose aspirin.

A safe standard of care for medication administration

Review caregivers' degree of responsibility and accountability when administering medication.

Cell toxicity caused by products of the p(L) operon of bacteriophage lambda

Induction of a lambda prophage causes the death of the host cell even in the absence of phage replication and lytic functions due to expression of functions from the lambda p(L) operon. We genetically modified the lambda prophage to determine which lambda p(L) operon functions were involved in cell killing. Viability assays and flow cytometry were used to monitor cell death and filamentation. The kil gene was shown to cause cell death and filamentation as described previously. Another killing activity was mapped within the p(L) operon to the gam gene. Inspection of the DNA sequence showed that there are two possible translation start points for both kil and gam. In both cases, the shorter of the two possible products could cause cell killing. The shorter products were also sufficient for the known filamentation and recombination activities of the respective Kil and Gam functions. The expression level of the p(L) operon is down-regulated by Cro repressor. In the absence of Cro, higher p(L) expression levels allow either Kil or Gam to be lethal or growth inhibitory, whereas at lowered expression in Cro-repressed conditions, only Kil is lethal. The filamentation function of Kil and recombination activity of Gam are unaffected at Cro-repressed levels of expression.

Proper equipment use makes or breaks care

Review the following case that addresses proper staff education regarding equipment usage and standards. Test your knowledge with the following questions, then check your answers at http://www.nursingmanagement.com.

An analysis of the factory model for chromosome replication and segregation in bacteria

Recent advances in microscopy have given us important clues as to the nature of chromosome segregation in bacteria. Most current observations favour the view that the process is co-replicational: DNA replication forks are anchored at the cell centre, and the newly replicated DNA is moved towards the cell poles. This scheme can account for orderly segregation even at high growth rates where multiple replication cycles overlap. We argue that there are five distinct activities directly involved in co-replicational segregation dynamics. These we refer to as Push, Direct, Condense, Hold and Clear. We attempt to assign one of these roles to each protein implicated in chromosome segregation. The proposed process is very different from mitosis in eukaryotic cells and perhaps more closely resembles the formation of separate sister chromatids during DNA replication.

Policies and procedures: friend or foe? Part 3

Review a case where policy and procedure violation resulted in patient death and hospital liability. Test your knowledge with the following questions, then check your answers at http://www.nursingmanagement.com.

Activation of the murine EP3 receptor for PGE2 inhibits cAMP production and promotes platelet aggregation

The importance of arachidonic acid metabolites (termed eicosanoids), particularly those derived from the COX-1 and COX-2 pathways (termed prostanoids), in platelet homeostasis has long been recognized. Thromboxane is a potent agonist, whereas prostacyclin is an inhibitor of platelet aggregation. In contrast, the effect of prostaglandin E2 (PGE2) on platelet aggregation varies significantly depending on its concentration. Low concentrations of PGE2 enhance platelet aggregation, whereas high PGE2 levels inhibit aggregation. The mechanism for this dual action of PGE2 is not clear. This study shows that among the four PGE2 receptors (EP1-EP4), activation of EP3 is sufficient to mediate the proaggregatory actions of low PGE2 concentration. In contrast, the prostacyclin receptor (IP) mediates the inhibitory effect of higher PGE2 concentrations. Furthermore, the relative activation of these two receptors, EP3 and IP, regulates the intracellular level of cAMP and in this way conditions the response of the platelet to aggregating agents. Consistent with these findings, loss of the EP3 receptor in a model of venous inflammation protects against formation of intravascular clots. Our results suggest that local production of PGE2 during an inflammatory process can modulate ensuing platelet responses.

Protein-protein interactions in the complex between the enhancer binding protein NIFA and the sensor NIFL from Azotobacter vinelandii

The enhancer binding protein NIFA and the sensor protein NIFL from Azotobacter vinelandii comprise an atypical two-component regulatory system in which signal transduction occurs via complex formation between the two proteins rather than by the phosphotransfer mechanism, which is characteristic of orthodox systems. The inhibitory activity of NIFL towards NIFA is stimulated by ADP binding to the C-terminal domain of NIFL, which bears significant homology to the histidine protein kinase transmitter domains. Adenosine nucleotides, particularly MgADP, also stimulate complex formation between NIFL and NIFA in vitro, allowing isolation of the complex by cochromatography. Using limited proteolysis of the purified proteins, we show here that changes in protease sensitivity of the Q linker regions of both NIFA and NIFL occurred when the complex was formed in the presence of MgADP. The N-terminal domain of NIFA adjacent to the Q linker was also protected by NIFL. Experiments with truncated versions of NIFA demonstrate that the central domain of NIFA is sufficient to cause protection of the Q linker of NIFL, although in this case, stable protein complexes are not detectable by cochromatography.

Policies and procedures: Friend or foe? Part 2

Review a case where policy and procedure breaches resulted in disaster. Test your knowledge with the following questions, then check your answers at http://www.nursingmanagement.com.

Policies and procedures: friend or foe? Part 1

Policy and procedure wording can make or break caregiving accountability. Test your knowledge with the following questions, then check your answers at http://www.nursingmanagement.com.

Cyclo-oxygenase products and atherothrombosis

The advent of selective inhibitors of the cyclo-oxygenase (COX)-2 enzyme has afforded the opportunity to reduce the incidence of gastrointestinal complications of traditional nonsteroidal anti-inflammatory drugs (NSAIDs). The widespread use of these drugs has increased interest in their role in the cardiovascular system. Although deletion of the prostacyclin receptor (the IP) accelerates atherogenesis in the mouse, retention of one copy of the IP is atheroprotective. This is consistent with the failure of biochemically defined, selective doses of a COX-2 inhibitor to accelerate atherogenesis in the mouse, despite suppressing prostacyclin biosynthesis by roughly 60%. Inhibition of both COX isozymes, by contrast, markedly retards atherogenesis. Consistent with these observations, antagonism of the thromboxane receptor (the TP) retards atherogenesis and diminishes the proliferative response to vascular injury in the mouse. Even partial suppression of prostacyclin (without coincident inhibition of platelet COX-1-dependent thromboxane formation) by COX-2 inhibitors may be undesirable in acute vascular occlusive syndromes. However, these drugs are unlikely to accelerate progression of the underlying vascular disease. By contrast, the effects of TP antagonists, aspirin, and even traditional NSAIDs on atherosclerotic plaque progression merit further evaluation in humans.

A case for sliding SeqA tracts at anchored replication forks during Escherichia coli chromosome replication and segregation

SeqA is an Escherichia coli DNA-binding protein that acts at replication origins and controls DNA replication. However, binding is not exclusive to origins. Many fragments containing two or more hemi-methylated GATC sequences bind efficiently. Binding was optimal when two such sequences were closely apposed or up to 31 bases apart on the same face of the DNA helix. Binding studies suggest that neighboring bound proteins contact each other to form a complex with the intervening DNA looped out. There are many potential binding sites distributed around the E.coli chromosome. As replication produces a transient wave of hemi-methylation, tracts of SeqA binding are likely to associate with each fork as replication progresses. The number and positions of green fluorescent protein-SeqA foci seen in living cells suggest that they correspond to these tracts, and that the forks are tethered to planes of cell division. SeqA may help to tether the forks or to organize newly replicated DNA into a structure that aids DNA to segregate away from the replication machinery.

Sinonasal disease and olfactory impairment in HIV disease: endoscopic sinus surgery and outcome measures

OBJECTIVES

To investigate the effects of ESS (ESS) on olfactory impairment, disease-specific symptoms, and general quality of well-being In HIV+ patients with sinonasal disease.

STUDY DESIGN

Study 1: Nasal cytology, rhinomanometry, nasal examination including endoscopy, disease-specific sinonasal symptoms, olfactory threshold sensitivity, and odor identification testing were performed before and after ESS in HIV+ patients with sinonasal complaints. Study 2: Quality of well-being was assessed before and after ESS in HIV+ patients with sinonasal complaints and controls.

RESULTS

Significant olfactory sensitivity loss persisted for patients with chronic sinusitis after ESS, suggesting that the impairment in these patients may be due to viral disease rather than inflammation. Significant improvement in other disease-specific symptom scores (nasal obstruction, nasal congestion, headache, sinus pain, etc.) and results of the general quality of well-being assessment showed ESS to be beneficial in the extended health management of HIV illness.

CONCLUSIONS

The current study indicated both olfactory dysfunction and subjective negative symptoms in HIV+ patients with chronic sinusitis. Although olfactory dysfunction remained, ESS was successful in providing marked alleviation of symptomatology in HIV+ patients with chronic sinusitis. The results support ESS as an appropriate treatment option for HIV+ patients with chronic sinusitis.

A plasmid partition system of the P1-P7par family from the pMT1 virulence plasmid of Yersinia pestis

The complete sequence of the virulence plasmid pMT1 of Yersinia pestis KIM5 revealed a region homologous to the plasmid partition (par) region of the P7 plasmid prophage of Escherichia coli. The essential genes parA and parB and the downstream partition site gene, parS, are highly conserved in sequence and organization. The pMT1parS site and the parA-parB operon were separately inserted into vectors that could be maintained in E. coli. A mini-P1 vector containing pMT1parS was stably maintained when the pMT1 ParA and ParB proteins were supplied in trans, showing that the pMT1par system is fully functional for plasmid partition in E. coli. The pMT1par system exerted a plasmid silencing activity similar to, but weaker than those of P7par and P1par. In spite of the high degree of similarity, especially to P7par, it showed unique specificities with respect to the interactions of key components. Neither the P7 nor P1 Par proteins could support partition via the pMT1parS site, and the pMT1 Par proteins failed to support partition with P1parS or P7parS. Typical of other partition sites, supernumerary copies of pMT1parS exerted incompatibility toward plasmids supported by pMT1par. However, no interspecies incompatibility effect was observed between pMT1par, P7par, and P1par.

The stability region of the large virulence plasmid of Shigella flexneri encodes an efficient postsegregational killing system

The large virulence plasmid pMYSH6000 of Shigella flexneri contains a determinant that is highly effective in stabilizing otherwise unstable plasmids in Escherichia coli. Expression of two small contiguous genes, mvpA and mvpT (formerly termed STBORF1 and STBORF2), was shown to be sufficient for stability. Mutations in mvpT abolished plasmid stability, and plasmids expressing only mvpT killed the cells unless mvpA was supplied from a separate plasmid or from the host chromosome. When replication of a plasmid carrying the minimal mvp region was blocked, growth of the culture stopped after a short lag and virtually all of the surviving cells retained the plasmid. Thus, the mvp system stabilizes by a highly efficient postsegregational killing (PSK) mechanism, with mvpT encoding a cell toxin and mvpA encoding an antidote. The regions that surround the mvp genes in their original context have an inhibitory effect that attenuates plasmid stabilization and PSK. The region encompassing the mvp genes also appears to contain an additional element that can aid propagation of a pSC101-based plasmid under conditions where replication initiation is marginal. However, this appears to be a relatively nonspecific effect of DNA insertion into the plasmid vector.

Suppression of chromosome segregation defects of Escherichia coli muk mutants by mutations in topoisomerase I

Escherichia coli muk mutants are temperature-sensitive and produce anucleate cells. A spontaneously occurring mutation was found in a DeltamukBkan mutant strain that suppressed the temperature-sensitive phenotype and mapped in or near topA, the gene that encodes topoisomerase I. Previously characterized topA mutations, topA10 and topA66, were found to be general suppressors of muk mutants: they suppressed temperature sensitivity and anucleate cell production of cells containing null or point mutations in mukB and null mutations in mukE or mukF. The suppression correlated with excess negative supercoiling by DNA gyrase, and the gyrase inhibitor, coumermycin, reversed it. Defects in topA allow 99% of cell division events in muk null mutants to proceed without chromosome loss or loss of cell viability. This observation imposes important limitations on models for Muk activity and is consistent with a role for MukBEF in chromosome folding and DNA condensation.

What's your liability in a survey?

You have liability exposure for regulatory issues when federal, state, and local officials, as well as other organization, such as JCAHO, survey your facility. Answer the questions about the following survey scenario below, then check your answers at www.nursingmanagement.com.