Nurses' use of 'wellness' supplements during the COVID-19 pandemic in the United States

AIM

Quantify disparities and identify correlates and predictors of 'wellness' supplement use among nurses during the first year of the pandemic.

DESIGN

Longitudinal secondary analysis of Nurses' Health Studies 2 and 3 and Growing Up Today Study data.

METHODS

Sample included 36,518 total participants, 12,044 of which were nurses, who completed surveys during the first year of the COVID-19 pandemic (April 2020 to April 2021). Analyses were conducted in March 2023. Modified Poisson models were used to estimate disparities in 'wellness' supplement use between nurses and non-healthcare workers and, among nurses only, to quantify associations with workplace-related predictors (occupational discrimination, PPE access, workplace setting) and psychosocial predictors (depression/anxiety, county-level COVID-19 mortality). Models included race/ethnicity, gender identity, age and cohort as covariates.

RESULTS

Nurses were significantly more likely to use all types of supplements than non-healthcare workers. Lacking personal protective equipment and experiencing occupational discrimination were significantly associated with new immune supplement use. Depression increased the risk of using weight loss, energy and immune supplements.

CONCLUSION

Nurses' disproportionate use of 'wellness' supplements during the COVID-19 pandemic may be related to workplace and psychosocial stressors. Given well-documented risks of harm from the use of 'wellness' supplements, the use of these products by nurses is of concern.

IMPACT

'Wellness' supplements promoting weight loss, increased energy, boosted immunity and cleansing of organs are omnipresent in today's health-focused culture, though their use has been associated with harm. This is of added concern among nurses given their risk of COVID-19 infection at work. Our study highlighted the risk factors associated with use of these products (lacking PPE and experiencing occupational discrimination). Findings support prior research suggesting a need for greater public health policy and education around the use of 'wellness' supplements.

REPORTING METHOD

STROBE guidelines were followed throughout manuscript.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution was involved.

Pediatric healthcare professionals' attitudes and beliefs about weight stigma: A descriptive study

PURPOSE

Children face weight-based stigma from their healthcare providers at a disconcerting rate, and efforts to mitigate this have been scant. This study aimed to quantify pediatric healthcare professionals' attitudes and beliefs about weight stigma and to determine stigma reduction interventions that are most supported by pediatric healthcare providers.

DESIGN AND METHODS

Participants completed two validated instruments which measured implicit and explicit weight bias, respectively. They then completed a researcher-designed questionnaire to assess their attitudes and beliefs about weight stigma, and demographic questions. ANOVA models were used to examine associations between bias measures and participant characteristics, chi-square analyses were used to examine associations between questionnaire responses and participant characteristics, and Spearman's rank was used to determine correlations between weight bias and questionnaire responses.

RESULTS

Participants exhibited moderate-to-high levels of implicit and explicit weight bias (mean Implicit Association Test score = 0.59, mean Crandall Anti-Fat Attitudes Score = 38.95). Associations were noted between implicit bias and years in practice (p < 0.05), and implicit bias and occupation (p < 0.05). There was a significant correlation between explicit bias and multiple questionnaire items, suggesting that healthcare providers with greater weight bias are aware of those biases and are ready to take action to address them.

CONCLUSION

Though pediatric healthcare exhibit weight-based biases, they are invested in taking steps to mitigate these biases and their impact on patients.

PRACTICE IMPLICATIONS

The results of this study can inform the design of future interventions that aim to reduce healthcare-based weight bias, thus improving the quality of pediatric healthcare.

Population-level policy recommendations for the prevention of disordered weight control behaviors: A scoping review

OBJECTIVE

The aim of this scoping review was to identify recommendations and gaps in knowledge surrounding the prevention of disordered weight control behaviors (DWCBs) through policy.

METHOD

A search was conducted in several databases to identify English language articles that described an active policy, recommendation, guideline, or educational curriculum that could be implemented by governments or regulatory bodies to prevent DWCBs or related constructs (e.g., weight stigma, body dissatisfaction). Two researchers independently screened articles with oversight from a third researcher. Data were extracted from the final sample (n = 65) and analyzed qualitatively across all articles and within the domains of education, public policy, public health, industry regulation, and media.

RESULTS

Only a single empirical evaluation of an implemented policy to reduce DWCBs was identified. Over one-third of articles proposed recommendations relating to industry regulation and media (n = 24, 36.9%), followed by education (n = 21, 32.3%), public policy (n = 19, 29.2%), and public health (n = 10, 15.4%). Recommendations included school-based changes to curricula, staff training, and anti-bullying policies; legislation to ban weight discrimination; policies informed by strategic science; collaboration with researchers from other fields; de-emphasizing weight in health communications; diversifying body sizes and limiting modified images in media; and restricting the sale of weight-loss supplements.

DISCUSSION

The findings of this review highlight gaps in empirically evaluated policies to reduce DWCBs but also promising policy recommendations across several domains. Although some policy recommendations were supported by empirical evidence, others were primarily based on experts' knowledge, highlighting the need for greater research on population-level DWCBs prevention through policy.

PUBLIC SIGNIFICANCE

Our scoping review of the evidence on policies for the prevention of disordered weight control behaviors identified several recommendations across the domains of education, public policy, public health, and industry regulation and media. Although few empirical investigations of implemented policies have been conducted, expert recommendations for policies to prevent disordered weight control behaviors among populations are plentiful and warrant future consideration by researchers and policymakers alike.

Understanding and responding to COVID-19 in Wales: protocol for a privacy-protecting data platform for enhanced epidemiology and evaluation of interventions

INTRODUCTION

The emergence of the novel respiratory SARS-CoV-2 and subsequent COVID-19 pandemic have required rapid assimilation of population-level data to understand and control the spread of infection in the general and vulnerable populations. Rapid analyses are needed to inform policy development and target interventions to at-risk groups to prevent serious health outcomes. We aim to provide an accessible research platform to determine demographic, socioeconomic and clinical risk factors for infection, morbidity and mortality of COVID-19, to measure the impact of COVID-19 on healthcare utilisation and long-term health, and to enable the evaluation of natural experiments of policy interventions.

METHODS AND ANALYSIS

Two privacy-protecting population-level cohorts have been created and derived from multisourced demographic and healthcare data. The C20 cohort consists of 3.2 million people in Wales on the 1 January 2020 with follow-up until 31 May 2020. The complete cohort dataset will be updated monthly with some individual datasets available daily. The C16 cohort consists of 3 million people in Wales on the 1 January 2016 with follow-up to 31 December 2019. C16 is designed as a counterfactual cohort to provide contextual comparative population data on disease, health service utilisation and mortality. Study outcomes will: (a) characterise the epidemiology of COVID-19, (b) assess socioeconomic and demographic influences on infection and outcomes, (c) measure the impact of COVID-19 on short -term and longer-term population outcomes and (d) undertake studies on the transmission and spatial spread of infection.

ETHICS AND DISSEMINATION

The Secure Anonymised Information Linkage-independent Information Governance Review Panel has approved this study. The study findings will be presented to policy groups, public meetings, national and international conferences, and published in peer-reviewed journals.

Development of an Injury Indicator Tool to Support Policy and Practice across Wales

Background with rationaleInjury is a leading cause of premature mortality, morbidity and disability worldwide. In Wales, injuries result in approximately 3 deaths, 107 hospital admissions and 868 emergency department (ED) attendances every day. Health indicators are quantifiable measures designed to summarise a population’s health, and ultimately inform policy and practice. In 2017, several experts identified a need for injury indicators in Wales, to support injury surveillance and prevention efforts. Main AimTo develop a suite of injury indicators, accessible to the public via an online tool, to inform policy and practice across Wales. Methods/ApproachInjury specialists in the All Wales Injury Surveillance System (AWISS) proposed a list of measurable injury indicators, based on: data availability, major areas of interest from a Welsh Government strategy perspective, injuries contributing the greatest burden, and injuries for which effective interventions existed. A consultation process with experts and stakeholders resulted in 25 agreed indicators covering all-cause injuries, falls in older adults, hip fractures, road traffic injuries, injuries in the home and at leisure, burns and scalds, poisonings and intentional injuries. Anonymised, routinely collected ED data, inpatient and mortality data in the Secure Anonymised Information Linkage (SAIL) databank at Swansea University were used to generate indicator estimates. Estimates will be updated annually and are accessible via an online interactive tool. ResultsThe development of a free, online injury indicator tool provides practitioners and policy makers across Wales, with the information required to make informed decisions. However, data quality issues hamper the extent to which conclusions can be made. ConclusionsInjury indicators have the potential to inform policy and practice across Wales. The adoption of a simplified, standardised data collection system in EDs across Wales is recommended to improve data validity and reliability.

Codifying unstructured data: A Natural Language Processing approach to extract rich data from clinical letters

ABSTRACT ObjectivesElectronic healthcare records (EHR) are the main data sources that facilitate epidemiology research. Routinely collected data such as primary and secondary care are now easily linked to produce novel and high impact research. There are, however, rich data locked in the free text of clinical letters that are not otherwise translated into EHRs. It is highly desirable to be able to extract this information to strengthen the body of information in existing EHRs. The Swansea Collaborative in Analysis of NLP Research (SCANR) group at Swansea University has been established to evaluate the usage of Natural Language Processing platforms for obtaining new clinical data. To use Clix Enrich to extract SNOMED concepts from a variety of clinical free texts and produce EHRs from the extraction process. Approach SNOMED concepts contain common items of interest such as diagnosis, medication and symptoms, as well as contextual concepts such as historical reference and negation. Clix Enrich uses the SNOMED dictionary to encode clinical free text (pre-co-ordinated) and find contextually correct SNOMED concepts (post co-ordinated). We used Clix Enrich to extract meaningful clinical terms from MS and Epilepsy consultant letters, as well as presenting complaint fields from a Welsh Emergency Department (ED). ResultsWe tailored Clix Enrich to extract a wide variety of clinical terms from each source (fourty texts per source) and validated the extraction accuracy with clinical experts in each domain. Clix Enrich was able to accurately extract the correct diagnosis for MS, Epilepsy and ED attendance (100%, 95% and 80%), dosage and frequency of anti-epileptic medication and MS modifying therapy (90%, 100%) and EDDS score (94%). We note a probable source of discrepancy in extraction accuracy between letter sources in the frequency of abbreviated terms, particularly within the presenting complaint field of the ED sample. ConclusionClix Enrich can be used to accurately extract SNOMED concepts from clinical letters. The resulting datasets are readily available to link to existing EHRs, and can be linked to EHRs that adopt the SNOMED coding structure, or backward compatible hierarchies. Clix Enrich comes with out-of-the-box extraction methods but the optimum way to extract the correct information would be to build in custom queries, thus requiring clinical expertise to validate extraction.

Long Term Patient Reported Urinary Function Following External Beam Radiotherapy for Prostate Cancer

INTRODUCTION

This study reports long-term patient reported urinary function and urinary-related quality of life (uQoL) after external beam radiotherapy (EBRT) for localized prostate cancer.

METHODS

574 men underwent definitive prostate EBRT to 70-78 Gy±androgen deprivation therapy between 2000 and 2009. The median follow-up from EBRT was 44 months. Patients were evaluated at baseline (pre-EBRT) and at intervals post-treatment using the International Prostate Symptom Score (IPSS) instrument.

RESULTS

Patients with mild IPSS at baseline (total 0-7) reported median total scores of 3, 4 and 3 at baseline, 6 and 48 months respectively post-EBRT. For patients with moderate IPSS at baseline (total 8-19), median total IPSS was 12 at baseline and 9 at both 6 and 48 months. For the severe IPSS group at baseline (total 20-35), the median total IPSS was 24, 12 and 14 at baseline, 6 and 48 months post-EBRT. The cumulative risk of persistent IPSS increase (greater than 5 points above baseline) at 48 months was 16%, 10% and 6% for patients with mild, moderate and severe baseline IPSS respectively. 94%, 54% and 11% of patients with mild, moderate and severe baseline IPSS reported good uQoL at baseline respectively, with these proportions increasing to 95%, 83% and 69% at 48 months.

CONCLUSION

Urinary symptoms and uQoL as measured by the IPSS instrument remained stable or improved for the majority of men after definitive EBRT with or without ADT for prostate cancer. This was especially notable for the group of men with worse baseline symptoms or uQoL, with risk of persistent worsening of urinary symptoms decreasing with higher baseline IPSS category. Understanding the expected pattern of urinary symptoms and related uQoL in the months and years following EBRT taking into account baseline urinary function is highly valuable for counselling men as part of the therapeutic decision-making process.

Risk factors associated with unintentional house fire incidents, injuries and deaths in high-income countries: a systematic review

OBJECTIVE

To identify the distinguishing risk factors associated with unintentional house fire incidents, injuries and deaths.

STUDY DESIGN

Systematic review.

METHODS

A range of bibliographical databases and grey literature were searched from their earliest records to January 2016. To ensure the magnitude of risk could be quantified, only those study types which contained a control group, and undertook appropriate statistical analyses were included. A best evidence synthesis was conducted instead of a meta-analysis due to study heterogeneity.

RESULTS

Eleven studies investigating a variety of risk factors and outcomes were identified. Studies ranged from medium to low quality with no high quality studies identified. Characteristics commonly associated with increased risk of house fire incidents, injuries and fatalities included: higher numbers of residents, male, children under the age of 5 years, non-working households, smoking, low income, non-privately owned properties, apartments and buildings in poor condition. Several risk factors were only associated with one outcome (eg, living alone was only associated with increased risk of injurious fires), and households with older residents were at increased risk of injurious fires, but significantly less likely to experience a house fire in the first place.

CONCLUSIONS

This best evidence synthesis indicates that several resident and property characteristics are associated with risk of experiencing house fire incidents, injuries or death. These findings should be considered by the Fire and Rescue Services and others with a role in fire prevention. Future research should adopt robust, standardised study designs to permit meta-analyses and enable stronger conclusions to be drawn.

Dynamic ultrasonic contact detection using acoustic emissions

For a non-contact ultrasonic material removal process, the control of the standoff position can be crucial to process performance; particularly where the requirement is for a standoff of the order of <20 μm. The standoff distance relative to the surface to be machined can be set by first contacting the ultrasonic tool tip with the surface and then withdrawing the tool to the required position. Determination of this contact point in a dynamic system at ultrasonic frequencies (>20 kHz) is achieved by force measurement or by detection of acoustic emissions (AE). However, where detection of distance from a surface must be determined without contact taking place, an alternative method must be sought. In this paper, the effect of distance from contact of an ultrasonic tool is measured by detection of AE through the workpiece. At the point of contact, the amplitude of the signal at the fundamental frequency increases significantly, but the strength of the 2nd and 3rd harmonic signals increases more markedly. Closer examination of these harmonics shows that an increase in their intensities can be observed in the 10 μm prior to contact, providing a mechanism to detect near contact (<10 μm) without the need to first contact the surface in order to set a standoff.

ADAMs and ADAMTSs in cancer

ADAMs and ADAMTSs are multi-domain proteins characterised by the presence of both metalloproteinase and disintegrin-like domains. ADAM proteins are usually type 1 transmembrane proteins, and ADAMTSs are secreted from cells. The dysregulated expression of ADAMs and ADAMTSs has been reported in a wide range of human cancers, where, in many cases, they are implicated as positive regulators of cancer progression. Proteolytically active ADAMs act as ectodomain sheddases, which release extracellular regions of membrane-bound proteins (e.g., adhesion molecules, growth factors, cytokines, chemokines and receptors). Certain ADAMTSs break down extracellular matrix (ECM) proteoglycans (e.g., aggrecan, brevican and versican). Through these actions they are able to sculpt the tumour microenvironment and modulate key processes involved in cancer progression, including cell proliferation, migration and angiogenesis. Members of both groups of protein can also act to inhibit or slow cancer progression: ADAMs can interact with specific integrins to elicit inhibitory effects on cancer dissemination, and certain ADAMTSs possess antiangiogenic activity, which prevents an increase in tumour size. This review covers recent developments in the involvement of ADAM and ADAMTS proteins in human cancer.

Phylogenetic analysis of rabbit haemorrhagic disease virus strains from the Arabian Peninsula: did RHDV emerge simultaneously in Europe and Asia?

Rabbit haemorrhagic disease virus (RHDV) emerged in 1984 in China and subsequently a single strain apparently dispersed worldwide killing millions of rabbits. Two isolates that caused outbreaks in Saudi Arabia and Bahrain have been sequenced and analysed phylogenetically. The Saudi Arabian lineage is directly descended from the Chinese strain, but the Bahrain isolate occupies a distinct and more divergent lineage than the Chinese virus implying that epidemic RHDV strains have emerged at least twice during the past 20 years and are co-circulating in both domestic and wild rabbits.

Glucosamine-induced insulin resistance in L6 muscle cells

BACKGROUND

Glucosamine increases flux through the hexosamine pathway, causing insulin resistance and disturbances similar to diabetic glucose toxicity.

AIM

This study examines the effect of glucosamine on glucose uptake by cultured L6 muscle cells as a model of insulin resistance.

METHODS

Glucose uptake by L6 myotubes was measured using the non-metabolized glucose analogue 2-deoxy-d-glucose after incubation with glucosamine for 4 and 24 h, with and without insulin and several other agents (metformin, peroxovanadium and d-pinitol) that improve glucose uptake in diabetic states.

RESULTS

After 4 h, high concentrations of glucosamine (5 x 10(-3) and 10(-2) M) reduced basal and insulin-stimulated glucose uptake by up to 50%. After 24 h, the effect of insulin was completely abolished by 10(-2) M glucosamine and reduced over 50% by 5 x 10(-3) M glucosamine. Lower concentrations of glucosamine did not significantly alter glucose uptake. The effect of glucosamine could not be attributed to cytotoxicity assessed by the Trypan Blue test. Metformin, peroxovanadium and d-pinitol, each of which increased glucose uptake by L6 cells, did not prevent the decrease in glucose uptake with glucosamine.

CONCLUSION

Glucosamine decreased insulin-stimulated glucose uptake by L6 muscle cells, providing a potential model of insulin resistance with similarities to glucose toxicity. Insulin resistance induced by glucosamine was not reversed by three agents (metformin, peroxovanadium and d-pinitol) known to enhance or partially mimic the effects of insulin.

Evolution and dispersal of encephalitic flaviviruses

There are two major groups of encephalitic flaviviruses, those that infect and are transmitted by ticks, particularly Ixodes spp. and those that infect and are transmitted by mosquitoes, particularly Culex spp. The tick-borne encephalitic flaviviruses exhibit evolutionary characteristics that are largely determined by the protracted life cycle of the tick, its habitat and the prevailing climatic conditions. These viruses appear to have evolved gradually from non-encephalitic viruses that radiated eastwards and north eastwards out of Africa into Asia and the southern islands, then northwards to far east Asia and finally westwards across Eurasia to western Europe, during the past two to four thousand years. Only one of these recognized species has found its way to North America viz. Powassan virus. In contrast, the evolution of the recognized mosquito-borne encephalitic flaviviruses reflects the wide range of mosquito species that they infect. They emerged out of Africa relatively recently and at roughly the same time, i.e., probably during the past few centuries. Although many of these mosquito-borne viruses are geographically widely dispersed, with the exception of West Nile virus, they are found either in the Old World or the New World, never in both, and we are now beginning to understand the reasons. Phylogenetic trees will be used here to describe the evolution, epidemiology and dispersal characteristics of these viruses, taking into account the importance of virus persistence and recombination.

Long-term survival of New Zealand rabbit haemorrhagic disease virus RNA in wild rabbits, revealed by RT-PCR and phylogenetic analysis

Because Rabbit haemorrhagic disease virus (RHDV) is highly pathogenic for rabbits, farmers illegally introduced it as a bio-control agent onto New Zealand farms in 1997. The virus was dispersed rapidly, initially causing high fatality rates in rabbits. Nevertheless, many survived and these surviving rabbits have been investigated for evidence of infection by RHDV. Livers from healthy rabbits contained RHDV-specific RNA, as shown by nested RT-PCR sequencing. The sequences of the viral capsids were related closely to the released Czech strain of RHDV, although the sequence from one rabbit was related most closely to a Spanish strain of RHDV. Phylogenetic analysis of the capsid sequences of 38 samples implied that there have been at least two introductions of the Czech virus into New Zealand, probably corresponding firstly to the original illegal introduction by farmers and secondly to the introduction of the same virus under governmental control. Genomic length sequence of two samples was obtained, suggesting that they may have retained the potential to be infectious, although this has not yet been demonstrated. The detection of genomic-length RNA in the liver of healthy rabbits suggests that even though a highly virulent virus was introduced into New Zealand, it rapidly established persistent or latent infections in a proportion of rabbits. This might account for their ability to survive in the face of virulent released virus. Moreover, the co-circulation of other strains of RHDV in the same rabbit population, such as the Spanish strain, might also impact on their susceptibility to the bio-control agent.

Pharmacokinetics of S-1, an oral formulation of ftorafur, oxonic acid and 5-chloro-2,4-dihydroxypyridine (molar ratio 1:0.4:1) in patients with solid tumors

S-1 is an oral formulation of ftorafur (FT), oxonic acid and 5-chloro-2,4-dihydroxypyridine (CDHP) at a molar ratio of 1:0.4:1. FT is a 5-fluorouracil (5-FU) prodrug, CDHP is a dihydropyrimidine dehydrogenase (DPD) inhibitor and oxonic acid is an inhibitor of 5-FU phosphoribosylation in the gastrointestinal mucosa and was included to prevent gastrointestinal toxicity. We determined the pharmacokinetics of S-1 in 28 patients at doses of 25, 35, 40 and 45 mg/m(2). The plasma C(max) values of FT, 5-FU, oxonic acid and CDHP increased dose-dependently and after 1-2 h were in the ranges 5.8-13 microM, 0.4-2.4 microM, 0.026-1.337 microM, and 1.1-3.6 microM, respectively. Uracil levels, indicative of DPD inhibition, also increased dose-dependently from basal levels of 0.03-0.25 microM to 3.6-9.4 microM after 2-4 h, and 0.09-0.9 microM was still present after 24 h. The pharmacokinetics of CDHP and uracil were linear over the dose range. The areas under the plasma concentration curves (AUC) for CDHP and uracil were in the ranges 418-1735 and 2281-8627 micromol x min/l, respectively. The t(1/2) values were in the ranges 213-692 and 216-354 min, respectively. Cumulative urinary excretion of FT was predominantly as 5-FU and was 2.2-11.9%; the urinary excretion of both fluoro-beta-alanine and uracil was generally maximal between 6 and 18 h. During 28-day courses with twice-daily S-1 administration, 5-FU and uracil generally increased. Before each intake of S-1, 5-FU varied between 0.5 and 1 microM and uracil was in the micromolar range (up to 7 microM), indicating that effective DPD inhibition was maintained during the course. In a biopsy of an esophageal adenocarcinoma metastasis that had regressed, thymidylate synthase, the target of 5-FU, was inhibited 50%, but increased four- to tenfold after relapse in subsequent biopsies. In conclusion, oral S-1 administration resulted in prolonged exposure to micromolar 5-FU concentrations due to DPD inhibition, and the decrease in uracil levels after 6 h followed the pattern of CDHP and indicates reversible DPD inhibition.

Serum from patients anesthetized with opiates less effective in the support of chondrocyte growth in vitro

Risk of viral and/or prion disease transmission associated with the use of fetal bovine serum in clinical cell culture has led to the increasing use of autologous human serum in tissue engineering. A relatively large volume of blood is needed and so, to decrease patient discomfort, we have investigated the feasibility of taking blood when the patient is anesthetized. Two serum samples were prepared from each of 22 patients: (1). from the awake patient (PRE) and (2). from the patient 5 min after induction of general anesthesia (PER). The sera were compared for their ability to support the in vitro proliferation of primary human chondrocytes, determined by cell counting. The effects of anesthetic agents on the PER/PRE cell number ratio were established by analysis of variance and stepwise multilinear regression analysis. The PER sample supported higher growth in 2 of 22 patients, equivalent growth in another 11, and significantly lower growth in the remaining 8. Only the opiate analgesics (fentanyl [Sublimaze], alfentanyl [Rapifen], and diamorphine) had a significant and inhibitory effect on chondrocyte proliferation. It is suggested that opiate analgesics be avoided when blood is taken to support the in vitro growth of human cells.

Characterization of a siberian virus isolated from a patient with progressive chronic tick-borne encephalitis

A strain of Tick-borne encephalitis virus designated Zausaev (Za) was isolated in Siberia from a patient who died of a progressive (2-year) form of tick-borne encephalitis 10 years after being bitten by a tick. The complete genomic sequence of this virus was determined, and an attempt was made to correlate the sequence with the biological characteristics of the virus. Phylogenetic analysis demonstrated that this virus belongs to the Siberian subtype of Tick-borne encephalitis virus. Comparison of Za virus with two related viruses, a Far Eastern isolate, Sofjin, and a Siberian isolate, Vasilchenko, revealed differences among the three viruses in pathogenicity for Syrian hamsters, cytopathogenicity for PS cells, plaque morphology, and the electrophoretic profiles of virus-specific nonstructural proteins. Comparative amino acid alignments revealed 10 individual amino acid substitutions in the Za virus polyprotein sequence that were different from those of other tick-borne flaviviruses. Notably, the dimeric form of the Za virus NS1 protein migrated in polyacrylamide gels as a heterogeneous group of molecules with a significantly higher electrophoretic mobility than those of the Sofjin and Vasilchenko viruses. Two amino acid substitutions, T(277)-->V and E(279)-->G, within the NS1 dimerization domain are probably responsible for the altered oligomerization of Za virus NS1. These studies suggest that the patient from whom Za virus was isolated died due to increased pathogenicity of the latent virus following spontaneous mutagenesis.

Molecular diversity of arbuscular mycorrhizal fungi and patterns of host association over time and space in a tropical forest

We have used molecular techniques to investigate the diversity and distribution of the arbuscular mycorrhizal (AM) fungi colonizing tree seedling roots in the tropical forest on Barro Colorado Island (BCI), Republic of Panama. In the first year, we sampled newly emergent seedlings of the understory treelet Faramea occidentalis and the canopy emergent Tetragastris panamensis, from mixed seedling carpets at each of two sites. The following year we sampled surviving seedlings from these cohorts. The roots of 48 plants were analysed using AM fungal-specific primers to amplify and clone partial small subunit (SSU) ribosomal RNA gene sequences. Over 1300 clones were screened for random fragment length polymorphism (RFLP) variation and 7% of these were sequenced. Compared with AM fungal communities sampled from temperate habitats using the same method, the overall diversity was high, with a total of 30 AM fungal types identified. Seventeen of these types have not been recorded previously, with the remainder being similar to types reported from temperate habitats. The tropical mycorrhizal population showed significant spatial heterogeneity and nonrandom associations with the different hosts. Moreover there was a strong shift in the mycorrhizal communities over time. AM fungal types that were dominant in the newly germinated seedlings were almost entirely replaced by previously rare types in the surviving seedlings the following year. The high diversity and huge variation detected across time points, sites and hosts, implies that the AM fungal types are ecologically distinct and thus may have the potential to influence recruitment and host composition in tropical forests.

Molecular epidemiology of Rabbit haemorrhagic disease virus

Millions of domestic and wild European rabbits (Oryctolagus cuniculus) have died in Europe, Asia, Australia and New Zealand during the past 17 years following infection by Rabbit haemorrhagic disease virus (RHDV). This highly contagious and deadly disease was first identified in China in 1984. Epidemics of RHDV then radiated across Europe until the virus apparently appeared in Britain in 1992. However, this concept of radiation of a new and virulent virus from China is not entirely consistent with serological and molecular evidence. This study shows, using RT-PCR and nucleotide sequencing of RNA obtained from the serum of healthy rabbits stored at 4 degrees C for nearly 50 years, that, contrary to previous opinions, RHDV circulated as an apparently avirulent virus throughout Britain more than 50 years ago and more than 30 years before the disease itself was identified. Based on molecular phylogenetic analysis of British and European RHDV sequences, it is concluded that RHDV has almost certainly circulated harmlessly in Britain and Europe for centuries rather than decades. Moreover, analysis of partial capsid sequences did not reveal significant differences between RHDV isolates that came from either healthy rabbits or animals that had died with typical haemorrhagic disease. The high stability of RHDV RNA is also demonstrated by showing that it can be amplified and sequenced from rabbit bone marrow samples collected at least 7 weeks after the animal has died.

Phylogenies of atpD and recA support the small subunit rRNA-based classification of rhizobia

The current classification of the rhizobia (root-nodule symbionts) assigns them to six genera. It is strongly influenced by the small subunit (16S, SSU) rRNA molecular phylogeny, but such single-gene phylogenies may not reflect the evolution of the genome as a whole. To test this, parts of the atpD and recA genes have been sequenced for 25 type strains within the alpha-Proteobacteria, representing species in Rhizobium, Sinorhizobium, Mesorhizobium, Bradyrhizobium, Azorhizobium, Agrobacterium, Phyllobacterium, Mycoplana and Brevundimonas. The current genera Sinorhizobium and Mesorhizobium are well supported by these genes, each forming a distinct phylogenetic clade with unequivocal bootstrap support. There is good support for a Rhizobium clade that includes Agrobacterium tumefaciens, and the very close relationship between Agrobacterium rhizogenes and Rhizobium tropici is confirmed. There is evidence for recombination within the genera Mesorhizobium and Sinorhizobium, but the congruence of the phylogenies at higher levels indicates that the genera are genetically isolated. rRNA provides a reliable distinction between genera, but genetic relationships within a genus may be disturbed by recombination.

Sibutramine metabolites increase glucose transport by cultured rat muscle cells

BACKGROUND

The anti-obesity agent sibutramine, a serotonin and noradrenaline reuptake inhibitor (SNRI), has been shown to reduce insulin resistance and improve glycaemic control in obese-diabetic ob/ob mice and overweight type 2 diabetic patients.

OBJECTIVE

To investigate whether sibutramine or its metabolites act directly on muscle cells to improve glucose uptake and insulin action.

DESIGN

Uptake of the non-metabolized glucose analogue 2-deoxyglucose was measured in cultured L6 rat muscle cells after incubation with sibutramine, its two pharmacologically active metabolites and related agents.

RESULTS

Sibutramine itself (10(-8)-10(-6) M) did not significantly affect 2-deoxyglucose uptake during incubations up to 72 h. The primary amine metabolite M2 (10(-7) and 10(-6) M) increased basal and insulin-stimulated 2-deoxyglucose uptake (by 12% and 34%) after 24 h incubation. These effects of M2 were lost by 72 h incubation. However, the secondary amine metabolite M1 (10(-6) M) increased basal and insulin-stimulated 2-deoxyglucose uptake (by 50%) after 72 h incubation, although M1 was ineffective after 24 h. M2 stimulated 2-deoxyglucose uptake in the presence of LY-294,002 (an inhibitor of phosphatidylinositol 3-kinase) but the effect of M2 was inhibited by cytochalasin B, which acutely blocks glucose transporters. Incubations with serotoninergic, noradrenergic and dopaminergic agents, or agents known to stimulate release or inhibit reuptake of these substances in nervous tissues indicated that the sibutramine metabolites were not affecting 2-deoxyglucose uptake via mechanisms associated with their SNRI properties.

CONCLUSIONS

Sibutramine metabolites can improve insulin-sensitive 2-deoxyglucose uptake by cultured muscle cells independently of SNRI effects.

Less pain does equal better quality of life following strontium-89 therapy for metastatic prostate cancer

93 patients with hormone refractory metastatic prostate cancer were entered on a prospective study to measure reduction in pain and changes in quality of life (QoL) after the administration of 150 MegaBequerel (MBq) Strontium-89 (Sr-89). QoL was assessed using a validated instrument, the Functional Living Index - Cancer (FLIC) questionnaire. Pain response was measured using the Radiation Therapy Oncology Group scoring system. Overall there was limited QoL improvement over 3 months following Sr-89. However, in the 53 patients (63%) achieving pain responses, QoL did significantly improve within 6 weeks of receiving Sr-89 compared to patients with stable or worsening bone pain, and this was independent of other parameters that might influence QoL outcomes, such as performance status, baseline PSA and extent of skeletal disease (P = 0.004). PSA 'response' occurred in 30 patients (37%) over 4 months after Sr-89. This did not appear to correlate with clinical improvement. This study supports the presumption that improvement in pain following Sr-89 is accompanied by better QoL. The lack of correlation of PSA response and clinical parameters indicates that in the palliative setting, PSA may not provide a useful surrogate for treatment outcome.

Sequence diversity of the plasmid replication gene repC in the Rhizobiaceae

The repABC operon is essential for stable maintenance of some Rhizobiaceae plasmids and of pTAV320 from Paracoccus versutus. These plasmids are the largest described family of homologous, yet compatible replicons. The repC gene is essential for plasmid replication, and previous work identified four distinct sequence groups (repC1, repC2, repC3, and repC4) that appear to define different compatibility classes. Probes for these different groups were used to characterize plasmids in Rhizobium leguminosarum population studies and three new repC sequence groups, repC5, repC6, and repC7 were identified. The general repC primers were modified to amplify a wider range of repC sequences and repC sequences were identified in Sinorhizobium and Mesorhizobium type strains. We also showed that the repC3 group-specific primers described previously do not amplify all repC3 sequences and developed a new repC3 amplification strategy.

Regulation of CDK7-carboxyl-terminal domain kinase activity by the tumor suppressor p16(INK4A) contributes to cell cycle regulation

The eukaryotic cell cycle is regulated by cyclin-dependent kinases (CDKs). CDK4 and CDK6, which are activated by D-type cyclins during the G(1) phase of the cell cycle, are thought to be responsible for phosphorylation of the retinoblastoma gene product (pRb). The tumor suppressor p16(INK4A) inhibits phosphorylation of pRb by CDK4 and CDK6 and can thereby block cell cycle progression at the G(1)/S boundary. Phosphorylation of the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II by general transcription factor TFIIH is believed to be an important regulatory event in transcription. TFIIH contains a CDK7 kinase subunit and phosphorylates the CTD. We have previously shown that p16(INK4A) inhibits phosphorylation of the CTD by TFIIH. Here we report that the ability of p16(INK4A) to inhibit CDK7-CTD kinase contributes to the capacity to induce cell cycle arrest. These results suggest that p16(INK4A) may regulate cell cycle progression by inhibiting not only CDK4-pRb kinase activity but also by modulating CDK7-CTD kinase activity. Regulation of CDK7-CTD kinase activity by p16(INK4A) thus may represent an alternative pathway for controlling cell cycle progression.

Eligibility audits for the randomized neuropathic bone pain trial (TROG 96.05)

In February 1996 the Trans-Tasman Radiation Oncology Group (TROG) initiated a two-arm, multicentre, prospective randomized trial on radiotherapy for neuropathic pain due to bone metastases (TROG 96.05). This trial compares the response to a single 8-Gy fraction with 20 Gy in five fractions. The accrual target is 270 patients. In order to evaluate compliance with eligibility criteria after approximately 1 year of accrual, an independent audit of the first 42 randomized patients was commissioned. This found that only one of these patients did not have genuine neuropathic pain, but that this patient and seven others (19%) had infringements of other eligibility/exclusion criteria for the trial. Accordingly it was decided to continue the full audit up to 90 patients. This detected no further patients without genuine neuropathic pain, and found only one other eligibility infringement (1/48; 2%). It is concluded that this quality assurance (QA) measure undertaken early in the trial led to significantly improved clinician awareness of, and compliance with, eligibility/exclusion criteria. It also enabled an accurate comparison of outcome data for all randomized versus all eligible patients at the time of the preplanned first interim analysis at 90 patients. In view of the excellent compliance demonstrated in the second audit, a one-in-five sampling is proposed for future audits from centres that have already accrued at least five consecutive eligible patients. This is consistent with TROG QA guidelines now operational.

The common nodulation genes of Astragalus sinicus rhizobia are conserved despite chromosomal diversity

The nodulation genes of Mesorhizobium sp. (Astragalus sinicus) strain 7653R were cloned by functional complementation of Sinorhizobium meliloti nod mutants. The common nod genes, nodD, nodA, and nodBC, were identified by heterologous hybridization and sequence analysis. The nodA gene was found to be separated from nodBC by approximately 22 kb and was divergently transcribed. The 2. 0-kb nodDBC region was amplified by PCR from 24 rhizobial strains nodulating A. sinicus, which represented different chromosomal genotypes and geographic origins. No polymorphism was found in the size of PCR products, suggesting that the separation of nodA from nodBC is a common feature of A. sinicus rhizobia. Sequence analysis of the PCR-amplified nodA gene indicated that seven strains representing different 16S and 23S ribosomal DNA genotypes had identical nodA sequences. These data indicate that, whereas microsymbionts of A. sinicus exhibit chromosomal diversity, their nodulation genes are conserved, supporting the hypothesis of horizontal transfer of nod genes among diverse recipient bacteria.

Phase I clinical and pharmacokinetic study of oral S-1 in patients with advanced solid tumors

PURPOSE

To investigate the side effects, determine the maximum-tolerated dose (MTD), and study the pharmacokinetics of S-1, an oral fluoropyrimidine-based antineoplastic agent consisting of the fluorouracil (5-FU) prodrug tegafur combined with two modulators, 5-chloro-2,4-dihydroxypyridine and potassium oxonate.

PATIENTS AND METHODS

Patients with advanced solid tumors received S-1 bid for 28 days, followed by 1 week of rest. 5-FU pharmacokinetics were investigated after a single initial dose of S-1 during the first 24 hours and weekly thereafter.

RESULTS

Twenty-eight patients received S-1 at the four consecutive dose levels of 25, 45, 35, and 40 mg/m(2). The MTD was initially found at 45 mg/m(2), with diarrhea as the dose-limiting toxicity (DLT). Diarrhea was also the DLT at the dose of 40 mg/m(2), which was the MTD for patients exposed to extensive prior chemotherapy. Other toxicities were generally mild. Two patients had a reduction of more than 50% in tumor dimension. Plasma pharmacokinetics of 5-FU were linear; at the highest S-1 dose level, 5-FU plasma peak concentrations reached 1 to 2 micromol/L, and the half-life of 5-FU was 3 to 4 hours. A statistically significant relationship was observed between the severity of diarrhea and pharmacokinetic parameters of 5-FU.

CONCLUSION

The recommended dose of S-1 in chemotherapy-naive or minimally chemotherapy-exposed patients is 40 mg/m(2) bid on 28 consecutive days, every 5 weeks. In heavily pretreated patients, the recommended dose is 35 mg/m(2) bid. Phase II trials are warranted in tumors known to be responsive to 5-FU treatment.

A role for radiotherapy in neuropathic bone pain: preliminary response rates from a prospective trial (Trans-tasman radiation oncology group, TROG 96.05)

PURPOSE

Radiotherapy (RT) has a proven role in palliation of pain from bone metastases with numerous randomized trials obtaining response rates (RRs) of typically 70-80% regardless of the fractionation employed. However RT for neuropathic bone pain (NBP), i.e., pain with a radiating cutaneous component due to compression/irritation of nerves by tumor has not previously been studied, and its role is thus uncertain.

METHODS AND MATERIALS

In February 1996, the Trans-Tasman Radiation Oncology Group (TROG) initiated a multicenter randomized trial comparing a single 8 Gy fraction with 20 Gy in 5 fractions for NBP with an accrual target of 270. Formal interim analyses were planned at 90 and 180 patients. The 90th patient was accrued in June 1998, and data from the first interim analysis with both arms combined form the basis of this report.

RESULTS

Forty-four patients were randomized to a single 8 Gy, 46 to 20 Gy in 5 fractions. The commonest primary sites were prostate (34%), lung (28%) and breast (10%). Median age was 68 years (range 37-89). The index site was spine (86%), rib (13%), base of skull (1%). On an intention-to-treat basis, the overall RR was 53/90 = 59% (95% CI = 48-69%), with 27% achieving a complete response and 32% a partial response. The overall RR for eligible patients was 49/81 = 60% (95% CI = 49-71%) with 27% and 33% achieving complete and partial responses respectively. Estimated median time to treatment failure was 3.2 months (95% CI = 2.1-5.1 months), with estimated median survival of 5.1 months (95% CI = 4.2-7.2 months). To date, six spinal cord/cauda equina compressions and four new or progressive pathological fractures have been detected at the index site after randomization, although one cord compression occurred before radiotherapy was planned to commence. In February 1999, the Independent Data Monitoring Committee strongly recommended continuation of the trial.

CONCLUSION

Although these results are preliminary, it seems clear that there is indeed a role for RT in the treatment of NBP. Analysis of outcome by treatment arm awaits completion of the randomized trial.

The glutamine synthetases of rhizobia: phylogenetics and evolutionary implications

Glutamine synthetase exists in at least two related forms, GSI and GSII, the sequences of which have been used in evolutionary molecular clock studies. GSI has so far been found exclusively in bacteria, and GSII has been found predominantly in eukaryotes. To date, only a minority of bacteria, including rhizobia, have been shown to express both forms of GS. The sequences of equivalent internal fragments of the GSI and GSII genes for the type strains of 16 species of rhizobia have been determined and analyzed. The GSI and GSII data sets do not produce congruent phylogenies with either neighbor-joining or maximum-likelihood analyses. The GSI phylogeny is broadly congruent with the 16S rDNA phylogeny for the same bacteria; the GSII phylogeny is not. There are three striking rearrangements in the GSII phylograms, all of which might be explained by horizontal gene transfer to Bradyrhizobium (probably from Mesorhizobium), to Rhizobium galegae (from Rhizobium), and to Mesorhizobium huakuii (perhaps from Rhizobium). There is also evidence suggesting intrageneric DNA transfer within Mesorhizobium. Meta-analysis of both GS genes from the different genera of rhizobia and other reference organisms suggests that the divergence times of the different rhizobium genera predate the existence of legumes, their host plants.

The in vitro growth of human chondrocytes

Autologous chondrocyte implantation (ACI) for the treatment of articular cartilage defects has been described by other workers, however, relatively few details of the in vitro growth of the cells have been published. Here we describe the release of cells from adult human articular cartilage and their growth characteristics in vitro.Cultures were successfully established from 29 of 30 biopsies taken from patients aged 20-72 year. No significant relationship was found between donor age and initial cell yield following cartilage digest, however, the time to primary confluence increased in direct proportion to age. Thereafter the kinetics of cell proliferation was independent of donor age.The proportion of apoptotic or necrotic cells in the cartilage digest was low and increased with time in culture only in those cells which remained non-adherent. Conversely, entry into cell cycle was restricted to those cells which had become adherent.These results illustrate that previously reported techniques for isolating and culturing chondrocytes are reproducible, that adherent chondrocytes have considerable proliferative potential, and that concern about cell growth and viability need not, in itself, limit the clinical application of ACI to younger patients.

Sexual dysfunction after radical radiation therapy for prostate cancer: a prospective evaluation

OBJECTIVES

To determine the rate of loss of potency after radiation therapy (RT).

METHODS

Two hundred ninety men with localized prostate cancer were evaluated prospectively before and after RT to the prostate alone for change in erectile function. Data were collected before treatment by way of a questionnaire using a simple three-tier potency scale and after RT by the clinician at each follow-up visit.

RESULTS

At 12 months, 62% of men (90 of 146) who were potent before RT preserved their potency; at 24 months, this figure was 41%. Men who had "normal" potency before RT were statistically significantly more likely to remain potent after RT.

CONCLUSIONS

We believe that detailed knowledge of potency rates before and after RT is important for current decision-making and for evaluating new treatment techniques.

A meaningful health assessment course for baccalaureate nursing students

In response to the challenge of teaching health assessment to large groups of entry-level BSN students with minimal experience in the health professions and a faculty belief that theory and practice are best actualized with small groups, a new health assessment course was implemented. Based on a philosophy of student accountability and self-direction in learning, faculty willingness to try new teaching strategies, and using computer testing, a successful course was developed. Students rotated through specific small group clinical labs while preparing with textbooks, study questions, videotapes, and computer-assisted instruction. Evaluation methods based on case application and the use of computer testing technology were implemented for this course. The result was increased satisfaction for the faculty and the students with enhanced application experiences supportive of the clinical practice.

Prevention of dexamethasone-induced insulin resistance by metformin

This study investigates the effect of the antidiabetic drug metformin on dexamethasone-induced hyperglycaemia and insulin resistance in mice. Normal mice were treated with dexamethasone (2.5 mg/kg/day p.o.) plus metformin (250 mg/kg/day p.o.) and pair-fed to those receiving dexamethasone alone. Metformin reduced the extent of dexamethasone-induced hyperglycaemia and decreased insulin resistance as indicated by an improved insulin-hypoglycaemia test. Metformin-treated mice also showed increased basal glucose uptake into isolated diaphragm (by 38%), soleus (by 19%) and deep (red) quadriceps (by 31%). Measurements in the quadriceps showed that the increase in glucose uptake occurred without increasing either the mRNA levels or total cellular membrane abundance of the GLUT1 or GLUT4 glucose transporter isoforms. Thus metformin can ameliorate dexamethasone-induced hyperglycaemia and insulin resistance in part by increasing glucose disposal into skeletal muscle. Since this was achieved in quadriceps muscle without increasing mRNA or total membrane abundance of GLUT1 or GLUT4, it is possible that metformin might influence the intrinsic activity of glucose transporters, as well as altering their intracellular translocation.

The effectiveness of guided design on ethical decision making and moral reasoning among community nursing students

This study evaluated the effectiveness of guided design as an instructional method in ethical decision making and moral reasoning among 145 community health nursing students. Changes in the process of ethical decision making and moral reasoning were measured using Ketefian's judgment About Nursing Decisions (JAND) one week after the intervention. Results indicated a significant difference in ethical decision-making scores after instruction, but no difference in moral reasoning. The one specific component--Taking professional initiatives--increased on both subscales.

The influence of fashion magazines on the body image satisfaction of college women: an exploratory analysis

This study examined the impact of exposure to fashion magazines on women's body image satisfaction. Participants were 39 undergraduate women, randomly assigned to two experimental conditions: half viewed fashion magazines prior to completing a body image satisfaction survey, and the remaining half, news magazines. Mean height and weight did not differ for the two groups. As hypothesized, women who viewed fashion magazines preferred to weigh less, were less satisfied with their bodies, were more frustrated about their weight, were more preoccupied with the desire to be thin, and were more afraid of getting fat than were their peers who viewed news magazines.

Bladder movement during radiation therapy for bladder cancer: implications for treatment planning

PURPOSE

To describe and quantify bladder movement during radical radiation therapy (RT). To attempt to identify factors that predict for excessive alterations in bladder position. To use the above information to assist in defining the "adequate" planning target volume margin.

METHODS AND MATERIALS

Thirty patients with bladder cancer suitable for radical courses of RT were followed prospectively. Patients had an initial planning computerized tomography (CT) scan of the pelvis and three subsequent scans performed weekly during the treatment period. The following measurements were made on each scan in the midbladder slice: maximum anteroposterior (AP) and lateral bladder dimensions, AP rectal diameter, and the distance (margin) between the bladder walls (anterior, posterior, right, and left lateral) and the 95% isodose line. Various patient and tumor data, including bladder and bowel symptoms, were recorded to attempt correlation with bladder movement.

RESULTS

Bladder size: the median bladder size (area) over all scans in all patients was 36.9 cm2 (range: 16.2 to 80.9 cm2). The change in bladder area across each sequence varied from 3.3 to 29.1 cm2 (7-55% change in area between scans). Patients with bladders of larger than the median size on the planning scan (despite emptying) were more likely to have alteration in size than those with small bladders, and this change was in the direction of contraction (p = 0.01). Bladder displacement: bladder wall movement of > 1.5 cm was defined as "significant." Eighteen of 30 patients (60%) demonstrated "significant" movement of at least one bladder wall relative to the original isodose plot. Movement resulting in margin reduction occurred in 10 patients (33%). Two patients required treatment replanning due to consistently altered bladder position. There was no pattern to displacement through RT, and all walls were at approximately equal risk of movement. Factors influencing bladder movement: posterior bladder wall movement appeared to relate to "marked" (>2 cm) rectal diameter change. There was a trend for patients with larger amounts of residual bladder tumor (greater than the median) to exhibit more bladder movement; 11 of 14 "moved" compared with 7 of 16 patients with less residual tumor. Other clinical factors including age, sex, body size, acute RT reaction, and tumor stage did not appear to relate to bladder movement.

CONCLUSION

Bladder movement during RT is clinically relevant and is random with respect to both time and direction. We recommend, at least with respect to tumor-bearing regions of the bladder, that no less than a 2.0 cm margin should be allowed.

The roles of herpes simplex virus in neuroscience

Herpes simplex virus (HSV) has been a focus of research in many laboratories during the last 30-35 years, with the majority centered on the virus' replication, molecular biology and pathogenesis. Recently, HSV has begun to receive considerable attention in the field of neuroscience, where scientists have begun to use the virus as a tool or model for several areas of investigation. These areas include the construction and development of HSV-based vectors for gene therapy and the use of HSV as a neuronal tracer, as a model for demyelinating disease and to study interactions between the nervous, immune and endocrine systems. The goal of this paper is to review these different roles for HSV in the broad field of neuroscience.

Antihyperglycaemic effect of saccharin in diabetic ob/ob mice

1. The effect of chronic saccharin (benzosulphimide) consumption on glucose homeostasis was examined in normal lean +/+ mice and genetically obese hyperglycaemic insulin-resistant ob/ob mice. 2. Consumption of a 5% (w/v) sodium saccharin solution for 7 weeks prevented the development of hyperglycaemia, improved glucose tolerance (area under curve decreased by 51%), reduced the extent of hyperinsulinaemia (by 21%), and reduced excessive weight gain (by 18%) in ob/ob mice. 3. Consumption of 5% (w/v) sodium saccharin temporarily decreased hyperphagia at the beginning of treatment, decreased hepatic glycogen content (by 47%), increased abdominal muscle glycogen content (by 82%), but did not significantly alter the hypoglycaemic response to exogenous insulin in ob/ob mice. 4. Consumption of a 1% (w/v) sodium saccharin solution did not prevent the development of hyperglycaemia in ob/ob mice. 5. Normal lean +/+ mice consuming 5% (w/v) sodium saccharin solution showed a marginal decrease (by 8%) in glycaemia, and glucose tolerance was improved (area under curve decreased by 30%) without a significant change in the insulin response to glucose or the hypoglycaemic effect of exogenous insulin. 6. These results suggest that chronic consumption of saccharin can defer the development of hyperglycaemia and improve glucose homeostasis in insulin-resistant ob/ob mice through a mechanism that is independent of insulin.

Radical external beam radiotherapy for 333 squamous carcinomas of the oral cavity--evaluation of late morbidity and a watch policy for the clinically negative neck

BACKGROUND AND PURPOSE

The aims of this study were to examine local control/morbidity for all cases and a 'watch policy' for the node-negative neck.

PATIENTS/METHODS

333 patients with squamous cell carcinoma of the oral cavity were treated with a short radical radiotherapy regime to the primary site and involved lymph node groups at the Christie Hospital, Manchester, between 1980 and 1987. Only 10 of 278 node-negative patients received elective neck node irradiation.

RESULTS

Actuarial cancer-free survival and local control rates at 5 years for the whole group were 55% and 61%, respectively. Control at the primary site was adversely related to increasing T-stage, node positivity and bone involvement at presentation. Osteonecrosis was seen in 14 (5.9%) of 237 cases without bone involvement at presentation. Taking all patients, late morbidity (non-healing soft tissue injury or bone necrosis) was seen in 45 patients (13.6%) at a median time of 21 months from treatment. The factors contributing to late morbidity were: (1) bone involvement at presentation, (2) synchronous MTX chemotherapy, (3) the contribution of scattered radiation from elective neck treatment, (4) increasing radiation dose, (5) increasing target volume for doses less than 55 Gy and (6) dental extractions. Eighty-four (31%) patients who were initially node-negative developed disease in the untreated neck during follow-up. Salvage neck dissections controlled neck disease in half of the node-only recurrences (21/42 cases).

CONCLUSION

These results have influenced our treatment policy, with lowering of the primary tumour dose in some cases and addition of elective neck irradiation for T2-T4 No patients.

Herpes simplex virus: a tool for neuroscientists

Herpes viruses have received a great deal of attention due to their widespread and ubiquitous prevalence in the human population and to the diverse range of diseases caused as a result of an infection. During the last 20-25 years, many research laboratories have investigated the pathogenesis and molecular biology of these viruses; particularly herpes simplex virus (HSV). As a result of this research, HSV has begun to get the attention of neuroscientists. In fact, in the last few years there has been an explosion of research involving the use of HSV and related viruses as tools or model systems for different areas of neuroscience research. This brief review will describe several of these areas including demyelinating diseases, neuronal tracings, and genetic therapy.