The weather determines the number of cases of tick paralysis in dogs and cats in eastern Australia, caused by Ixodes holocyclus, the eastern paralysis tick

We studied over 222,000 cases of emergency veterinary consultations in four regions along the eastern coast of Australia. We found that cases of tick paralysis (TP) caused by the eastern paralysis tick, Ixodes holocyclus, accounted for 7.5% of these cases: >16,000 cases. The season of TP and the number (prevalence) of TP cases varied among regions and over the years. Our study of the association between weather and (i) the start of the season of TP, and (ii) the number of TP cases revealed much about the intricate relationship between the weather and I. holocyclus. We studied the effect of the hypothetical availability of isoxazoline-containing tick-preventative medicines and found that an increase in the availability of these medicines had significantly contributed to the decrease in TP cases. We found that the weather in winter accounted for the time of the year the season of TP starts whereas the weather in summer accounted for the number of TP cases in the TP season. Last, through a study of the effects of shifts in the climate under four hypothetical scenarios (warmer/cooler and drier/wetter than average), we propose that the start of the season of TP depends on how soon the weather in winter becomes suitable for the activity (e.g. host-seeking) and the development of I. holocyclus nymphs, and that the number of TP cases during the TP season depends on how many engorged female ticks and their eggs survive during summer.

Impact of war on veteran life span: natural experiment involving combat versus non-combat exposed military personnel

INTRODUCTION

There is still uncertainty around the impact of combat exposure on the life span of war veterans. Therefore we made use of a natural experiment to study the impact on veteran life span of combat versus non-combat exposure in World War II (WW2).

METHODS

The combat-exposed military personnel were derived from a random (10%) sample of the military roll of the 28th (Māori) Battalion from New Zealand. One non-combat cohort was the 15th Reinforcements of this same Battalion, since the war ended before they reached the front line. The other non-combat cohort were Māori personnel who were only involved in Jayforce, which occupied Japan at the end of the WW2. Data on life span were mainly derived from an official repository of birth and death records, but supplemented with other sources, including military files.

RESULTS

When comparing life spans of service veterans, there was no statistically significant reduction for the average life span of the 234 combat-exposed veterans in our sample from the 28th (Māori) Battalion (66.7 years), relative to the Māori veterans from two non-combat cohorts: the 132 personnel in the 15th Reinforcements (67.2 years) and the 147 personnel in Jayforce (66.9 years).

CONCLUSIONS

Despite a very high level of wounding in the combat-exposed group (48%), there were no statistically significant reductions in life span between this group and comparable non-combat exposed veterans. This finding contrasts to life span reductions found in a similar study of New Zealand veterans of WW1.

Differential lifespan impacts on veterans by war exposure in the First World War

INTRODUCTION

There remains uncertainty around the impact of war on the lifespan of First World War (WW1) veterans. In particular, study comparison groups do not typically consider the 'healthy soldier effect'.

METHODS

We obtained lifespan data on a random sample of 857 war-exposed New Zealand WW1 veterans and compared this with lifespans of a non-war military cohort (n=1039). This comparison was possible as the non-war-cohort arrived in Europe too late to participate in the war, allowing a 'natural experiment' that avoided the 'healthy solider effect'.

RESULTS

The lifespan comparisons indicated lower mean lifespan in the war-exposed veteran cohort compared with the non-war veteran cohort (69.7 vs 71.1 years; p=0.0405). This gap persisted (range: 0.8-1.1 years) but was no longer statistically significant when only considering the non-Māori ethnic grouping (nearly all European/Pākehā personnel), when excluding additional deaths in the immediate postwar period up to 31 December 1923, and when excluding participation in any other wars. This was the case in both analysis of variance and Cox proportional hazards regression adjusting for year of birth and occupational status. Within the war-exposed cohort, there were suggestive patterns of increasing lifespan with increasing occupational status and military rank (eg, 69.5, 70.0 and 70.7 mean years as group-level occupational status progressively increased). There were also stark differences in lifespan of 8.3 years between Māori (Indigenous) and non-Māori veterans (p=0.0083).

CONCLUSIONS

The pattern of reduced lifespan in war-exposed versus non-war-exposed veterans was compatible with a smaller previous New Zealand study with comparable methodology. Veterans who were Māori had significantly lower lifespans than non-Māori veterans. There are a number of feasible avenues to further improve this type of work with existing data sources.

A case-control study of nutritional factors associated with chronic suppurative otitis media in Yemeni children

BACKGROUND/OBJECTIVES

Undernutrition and chronic suppurative otitis media (CSOM) in children are common in low resource settings, but there are few studies of their interactions. The aim is to evaluate nutritional factors associated with CSOM in Yemeni children.

SUBJECTS/METHODS

A case-control study of 75 children with CSOM and 74 healthy controls. Assessment included dietary history, anthropometry, haemoglobin (Hb) and serum analytes zinc (Zn), copper (Cu), selenium (Se), iron, calcium, phosphate (PO(4)) and total 25-hydroxy vitamin D (25(OH)D).

RESULTS

Cases had lower mean Z-scores for weight-for-age, weight-for-height, body mass index and mid-upper arm circumference (MUAC) (all P<0.05), and lower mean concentrations of serum Zn (P=0.032), Se (P<0.001) and calcium adjusted for albumin (P=0.026). Age-adjusted Hb and iron biomarkers did not differ between cases and controls. There was high prevalence of low serum Zn concentration (≥ 90%) and vitamin D deficiency in both cases (80%) and controls (96%). Duration of ear discharge was negatively correlated with total 25(OH)D (P=0.028), calcium adjusted for albumin (P<0.001), PO(4) (P=0.002), transferrin receptor/log ferritin ratio (P<0.001) and Cu (P<0.001), and positively correlated with child age and MUAC (both P<0.001).

CONCLUSIONS

Children with CSOM were more undernourished than controls with lower mean serum Zn, Se and calcium concentrations. Vitamin D-deficient and iron-replete children had longer duration of infection, although this association was lost with age adjustment. Trials evaluating specific micronutrients are required in order to investigate specific nutrient-infection interactions in CSOM.

Micronutrient concentrations in respiratory syncytial virus and human metapneumovirus in Yemeni children

BACKGROUND

Acute respiratory infections (ARI) cause significant childhood mortality. Nutritional homeostasis, particularly micronutrient levels, is important in modulating response to infection. More information is required regarding micronutrient levels in ARI viral infections, especially newly identified viruses such as human metapneumovirus (HMPV).

AIM

To describe zinc, copper, selenium and vitamins A and E concentrations in children with respiratory syncytial virus (RSV) and/or HMPV in relation to levels of C-reactive protein (CRP).

METHODS

The presence of RSV/HMPV in nasopharyngeal aspirates (NPA) was identified in 246 children using RTPCR. Zinc, copper, selenium and vitamins A and E concentrations were measured using inductive coupled plasma mass spectrometry and high performance liquid chromatography.

RESULTS

183 children had RSV, 39 had HMPV and 24 were co-infected. Zinc concentrations were lower in children with HMPV than in children with RSV or RSV/HMPV co-infection. Copper concentrations were lower in children with RSV than in children with RSV/HMPV or HMPV and zinc/copper ratios were lower in children with HMPV/RSV or RSV than in children with HMPV alone. Retinol and a alpha-tocopherol were lower in children with RSV than in children with HMPV. Most children had low selenium concentrations. Children with RSV and raised CRP (>5 mg/L) had higher copper and lower zinc/copper ratios than those with low CRP (< or =5 mg/L). Children with HMPV and raised CRP had higher copper and lower zinc concentrations than children with low CRP. Children with RSV/HMPV and raised CRP had higher copper concentrations. Children with RSV/HMPV and raised CRP had higher a alpha-tocopherol concentrations.

CONCLUSION

The profiles of micronutrients differ in children with RSV and HMPV and are confounded by CRP. These results may guide strategies for micronutrient supplementation in ARI.

Microsatellite flanking region similarities among different loci within insect species

Although microsatellites are ubiquitous in eukaryota, the number of available markers varies strongly among taxa. This meta-analysis was conducted on 32 insect species. Sequences were obtained from two assembled whole genomes, whole genome shotgun (WGS) sequences from 10 species and screening partial genomic libraries for microsatellites from 23 species. We have demonstrated: (1) strong differences in the abundance of microsatellites among species; (2) that microsatellites within species are often grouped into families based on similarities in their flanking sequences; (3) that the proportion of microsatellites grouped into families varies strongly among taxa; and (4) that microsatellite families were significantly more often associated with transposable elements - or their remnants - than unique microsatellite sequences.

Placental malaria and immunity to infant measles

The efficiency of transplacental transfer of measles specific antibody was assessed in relation to placental malaria. Infection at delivery was associated with a 30% decrease in expected cord measles antibody titres. Uninfected women who received anti-malarial drugs during pregnancy transmitted 30% more antibody than those who received no antimalarial drugs.

Characterisation of pararetrovirus-like sequences in the genome of potato (Solanum tuberosum)

Three families of pararetrovirus-like sequences were isolated from the genome of potato using PCR of a characteristic fragment extending from the end of the transactivator domain. The potato pararetrovirus-like sequences are abundant in the nuclear genome of potato as demonstrated by their hybridisation to high-molecular weight DNA in Southern transfers and by fluorescence in situ hybridisation. Sequencing of cloned PCR products demonstrated that the potato pararetrovirus-like sequences were similar to other pararetroviral sequences and also to some expressed sequences from tobacco and tomato, notably from callus and Agrobacterium-infected tissue. It is possible that the potato pararetroviral sequences defend against viral genes via silencing mechanisms, although, as in Petunia or banana, their transcription and recombination may cause infection under stress conditions.

The diversity of Banana streak virus isolates in Uganda

In a study of the variation among isolates of Banana streak virus (BSV) in Uganda, 140 sequences were obtained from 49 samples by PCR across the conserved reverse transcriptase/RNaseH region of the genome. Pairwise comparison of these sequences suggested that they represented 15 different species and phylogenetic analyses showed that all species fell into three major clades based on 28% sequence difference. In addition to the Ugandan sequences, clade I also contained BSV species that are known as both integrated sequences and episomal viruses; clade II also contained integrated BSV sequences but which have not previously been identified as episomal viruses. Clade III comprised of Sugarcane bacilliform virus isolates and Ugandan BSV sequences and for which there is no evidence of integration. The possible reasons for the extraordinary levels of virus sequence variation and the potential origins and epidemiology of these viruses causing banana streak disease are discussed.

The polarisation of hair cells from the ear of the European bass (Dicentrarchus labrax)

The polarisation of ciliary bundles on the macula of the saccule in the European bass (Dicentrarchus labrax L) has been studied using a scanning electron microscope (SEM). These data show that D. labrax possesses ciliary bundles arranged in four dichotomous quadrants with a standard orientation, comparable to hearing generalists from the order Perciformes. The spacing between ciliary bundles was investigated in three size classes of fish, with the results indicating that the addition of receptor cells in the ear of D. labrax continues for at least the first 2 years of development. The lengths of the kinocilia from ciliary bundles in each quadrant of the macula were also studied, and found to be of uniform length. In addition, we look at the internal structure of the afferent using transmission electron microscopy (TEM), revealing the nucleated cell body and peripheral nerve fibres of the saccule consistent with other TEM examinations of saccular ultrastructure. This information is required to gain an insight into the inner ear of D. labrax, as part of a larger study of the morphology and physiology of the hearing systems of both vertebrate and invertebrate marine animals.

The Reduced Graph Descriptor in Virtual Screening and Data-Driven Clustering of High-Throughput Screening Data

Virtual screening and high-throughput screening are two major components of lead discovery within the pharmaceutical industry. In this paper we describe improvements to previously published methods for similarity searching with reduced graphs, with a particular focus on ligand-based virtual screening, and describe a novel use of reduced graphs in the clustering of high-throughput screening data. Literature methods for reduced graph similarity searching encode the reduced graphs as binary fingerprints, which has a number of issues. In this paper we extend the definition of the reduced graph to include positively and negatively ionizable groups and introduce a new method for measuring the similarity of reduced graphs based on a weighted edit distance. Moving beyond simple similarity searching, we show how more flexible queries can be built using reduced graphs and describe a database system that allows iterative querying with multiple representations. Reduced graphs capture many important features of ligand-receptor interactions and, in conjunction with other whole molecule descriptors, provide an informative way to review HTS data. We describe a novel use of reduced graphs in this context, introducing a method we have termed data-driven clustering, that identifies clusters of molecules represented by a particular whole molecule descriptor and enriched in active compounds.

(Research Papers) Design of a Compound Screening Collection for use in High Throughput Screening

In this paper we introduce a quantitative model that relates chemical structural similarity to biological activity, and in particular to the activity of lead series of compounds in high-throughput assays. From this model we derive the optimal screening collection make up for a given fixed size of screening collection, and identify the conditions under which a diverse collection of compounds or a collection focusing on particular regions of chemical space are appropriate strategies. We derive from the model a diversity function that may be used to assess compounds for acquisition or libraries for combinatorial synthesis by their ability to complement an existing screening collection. The diversity function is linked directly through the model to the goal of more frequent discovery of lead series from high-throughput screening. We show how the model may also be used to derive relationships between collection size and probabilities of lead discovery in high-throughput screening, and to guide the judicious application of structural filters.

Prioritisation of health technology assessment. The PATHS model: methods and case studies

OBJECTIVES

To develop a method of economic evaluation and triage for research prioritisation, before the funding decision.

DATA SOURCES

Existing models were researched focusing on MEDLINE, HealthSTAR, IBSS and HEED.

REVIEW METHODS

Papers of primary relevance that included a proposed model were reviewed in detail, and their models appraised using criteria adapted from the EUR-ASSESS project and the authors' previous experience. From this the PATHS model was developed. It assumes three or more possible alternative outcomes or scenarios in terms of research results: 'favourable' to the technology being assessed, 'unfavourable' or 'inconclusive'. An associated flow of benefits or disbenefits, costs or savings is identified for each potential research outcome depending on the likely implementation of the results as judged by experts. These benefits and costs are weighted and discounted in the model to give an expected incremental cost-effectiveness ratio (EICER). EICERS could be estimated for any number of research areas or proposals to inform funding prioritisation. The model was tested and evaluated on three case studies identified in liaison with the NHS R&D HTA programme and the UK Medical Research Council. These case studies were funded research projects, where full evaluation was underway and where results would be reported during the PATHS project. The studies were selected to include surgery or other invasive procedures, and non-invasive health services projects (a fourth case study did not complete during the course of the study). The three case studies included randomised controlled trials of early surgery or observation for small abdominal aortic aneurysms, infusion protocols for adult pre-hospital care, and postnatal midwifery support.

RESULTS

Each of the three assessments indicated net clinical benefit or no clinical loss of benefit, in addition to health service cost savings in excess of the cost of the trial. For two case studies, the value of the proposed trial, as evaluated by the model in the prediction, was consistent with the ex post evaluation, thus providing positive tests of the value of the model. In the third case meaningful ex post analysis was not possible as very poor compliance with the trial protocol (indicated in the ex ante evaluation) seriously undermined its conclusions. During the study, at the request of the UK HTA programme, the model was also applied to a funding request for a large randomised trial of beta-interferon for multiple sclerosis treatment.

CONCLUSION

The PATHS model has a useful part to play in the research prioritisation process. Its strengths lie in its emphasis on the impact of research results on policy and practice (the keystone for NHS research) and net effects on health benefits and costs. It assesses the cost-effectiveness of the research and may identify ways to enhance the research design, endpoints relevant to implementation, analytical methods and dissemination. Further research is recommended to investigate the scope for synthesising the strengths of the PATHS model with other approaches including value of information; to compare ex ante and immediate ex post assessments of implementation with long term follow-up of actual implementation; and to assess the robustness of such approaches to the choice and number of experts used.

Functional outcome following excision of tumours of the distal radius and reconstruction by autologous non-vascularized osteoarticular fibula grafting

The distal radius and its articulations clearly have a vital role in the functional abilities of the hand and wrist. The treatment of tumours of the radius, therefore, needs to achieve satisfactory clearance of the lesions while also preserving as much wrist function as possible. We have employed osteoarticular autologous fibula grafts to reconstitute the distal radius after tumour excision. Since 1992, 13 patients have been treated by this technique for tumours of the distal radius. The group comprised patients with primary and recurrent giant cell tumours of bone, osteosarcoma, chondrosarcoma and Ewing's tumour. This technique achieves a satisfactory functional result without compromise of the prognosis for the tumour.

Cultural influences on diagnosis

Contemporary child psychiatry has both embraced the relevance of culture to diagnosis (in endorsing cultural competence) and taken a largely culture-blind approach to classification (in adopting the Diagnostic and Statistical Manual of Mental Disorders-IV). Different kinds of diagnoses serve different purposes in child psychiatry: classification, understanding the child, and guiding intervention. All discourse about diagnosis is shaped by culture, especially aspects of culture that may be difficult to acknowledge. Integration of the role of culture into clinical practice is facilitated by balancing the use of categorical diagnoses with consensus-based assessment, including acknowledgment of the relative positions of clinician and child.

Prediction of biological activity for high-throughput screening using binary kernel discrimination

High-throughput screening has made a significant impact on drug discovery, but there is an acknowledged need for quantitative methods to analyze screening results and predict the activity of further compounds. In this paper we introduce one such method, binary kernel discrimination, and investigate its performance on two datasets; the first is a set of 1650 monoamine oxidase inhibitors, and the second a set of 101 437 compounds from an in-house enzyme assay. We compare the performance of binary kernel discrimination with a simple procedure which we call "merged similarity search", and also with a feedforward neural network. Binary kernel discrimination is shown to perform robustly with varying quantities of training data and also in the presence of noisy data. We conclude by highlighting the importance of the judicious use of general pattern recognition techniques for compound selection.

Molecular complexity and its impact on the probability of finding leads for drug discovery

Using a simple model of ligand-receptor interactions, the interactions between ligands and receptors of varying complexities are studied and the probabilities of binding calculated. It is observed that as the systems become more complex the chance of observing a useful interaction for a randomly chosen ligand falls dramatically. The implications of this for the design of combinatorial libraries is explored. A large set of drug leads and optimized compounds is profiled using several different properties relevant to molecular recognition. The changes observed for these properties during the drug optimization phase support the hypothesis that less complex molecules are more common starting points for the discovery of drugs. An extreme example of the use of simple molecules for directed screening against thrombin is provided.

Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

Persistent cough in an adolescent

Jessica, a 14-year-old girl with a history of asthma, went to her pediatrician's office because of a persistent cough. She had been coughing for at least 3 months with occasional cough-free periods of less than a few days. The cough was nonproductive and was not accompanied by fever, rhinorrhea, or facial or chest pain. Jessica and her mother observed that the cough increased with exercise and typically was not present during sleep. She has used two metered-dose inhalers--albuterol and cromolyn--without any change in the cough pattern. For the past 5 years, Jessica has had mild asthma responsive to albuterol. She enjoys running on the cross-country team, soccer, and dancing. She is an average student and denies any change in academic performance. She has never been hospitalized or had an emergency department visit for asthma or pneumonia. There has been no recent travel or exposure to a person with a chronic productive cough, tobacco smoke, or a live-in pet. Jessica lives with her mother and younger sister in a 10-year-old, carpeted apartment without any evidence of mold or recent renovation. In the process of taking the history, the pediatrician noticed that Jessica coughed intermittently, with two or three coughs during each episode. At times, the cough was harsh; at other times, it was a quiet cough, as if she were clearing her throat. She was cooperative, without overt anxiety or respiratory distress. After a complete physical examination with normal findings, the pediatrician interviewed Jessica and her mother alone. Jessica's parents had been divorced for the past 6 years. She lived with her mother but visited her father, and his new family with two young children, every weekend. She spoke about this arrangement comfortably and said that she loved her father and mother but didn't like the tension she experienced at her father's home. "I don't like adults arguing when kids are around." When asked why she thought the cough persisted so long, she commented in a neutral tone, "I don't know. It's never been like this before." Jessica's pediatrician prescribed an inhaled steroid with the albuterol. When the cough did not respond after 1 week, he ordered a chest radiograph (normal) and a tuberculin skin test (purified protein derivative-negative), and he added montelukast (a leukotriene inhibitor) and monitored airway resistance with a peak flow meter. The cough persisted, and the peak flow recording showed normal airway resistance. At this time, Jessica's pediatrician suspected a conversion reaction and contemplated the next best therapeutic strategy.

Simulated blood levels of CF3I in personnel exposed during its release from an F-15 jet engine nacelle and during intentional inhalation

Of the agents under consideration for protecting unoccupied areas from fire, CF3I (trifluoroiodomethane) has physicochemical properties that give it potential as a "drop-in" replacement for halon 1301. One of the issues concerning the use of CF3I is the potential hazard to ground crews should an inadvertent discharge occur while workers are in or near an engine nacelle. A discharge test of CF3I was conducted on an F-15A jet to record CF3I concentration time histories at locations near the aircraft. The conditions of the discharges simulated an inadvertent ground discharge with the engine nacelle doors open and also with the doors closed. The use of three types of gas analysis instrumentation allowed gas sampling from several locations during the discharge tests. Concentrations measured at selected sensor locations were used as the input to a physiologically based pharmacokinetic model to simulate blood levels that would be attained by individuals inhaling CF3I at sensor locations. Blood levels reached during these exposures were compared with the blood level associated with the lowest observable adverse effect level (LOAEL) for cardiac sensitization to evaluate the possibility of safe egress. The highest blood concentrations simulated were twice the target blood concentration associated with cardiac sensitization. However, simulated blood concentrations of subjects who actually inhaled CF3I reached levels that were 100 times the target level without reported adverse effect. Thus, actual human data may supersede the use of the cardiac sensitization LOAEL obtained from animal studies.

Detection of episomal banana streak badnavirus by IC-PCR

A polymerase chain reaction (PCR) based strategy to detect episomal banana streak badnavirus (BSV) in banana and plantain plants that carry integrated BSV sequences was developed. Antisera used in immuno-capture polymerase chain reaction (IC-PCR) are capable of binding a large number of BSV serotypes. The primers used for PCR are capable of annealing to and amplifying across the aspartic protease-reverse transcriptase domain boundaries of both episomal and integrated BSV sequences and result in similar or identical sequence size fragments from either template. However, we show that under the conditions selected for IC-PCR, nuclear, mitochondrial or chloroplast genomic sequences are not amplified and thus only captured episomal BSV is amplified. IC-PCR is suitable for the large-scale screening of Musa for episomal BSV which is necessary for germplasm movement.

Evidence that badnavirus infection in Musa can originate from integrated pararetroviral sequences

When some virus- and disease-free Musa spp. (banana and plantain) are propagated by tissue culture, the resulting plants develop infections with banana streak badnavirus (BSV), a pararetrovirus. In sharp contrast to the virion DNA recovered from natural infections, the virion DNA from tissue culture-associated infections of different Musa spp. was highly similar if not identical. Although BSV does not employ integration during the infection cycle, BSV DNA was found to be integrated into the Musa genome. While one integration consisted of a partial BSV genome, a second contained more than one complete genome that was almost identical to BSV recovered from tissue culture-derived plants. The arrangement of this integrated BSV DNA suggests that it can yield an infectious episomal genome via homologous recombination. This report documents the first instance of integrated DNA of a nonintegrating virus giving rise to an episomal viral infection and identifies tissue culture as a possible trigger for the infection, raising the question of whether similar activatable viral sequences exist in the genomes of other plants and animals.

Integration of banana streak badnavirus into the Musa genome: molecular and cytogenetic evidence

Breeding and tissue culture of certain cultivars of bananas (Musa) have led to high levels of banana streak badnavirus (BSV) infection in progeny from symptomless parents. BSV DNA hybridized to genomic DNA of one such parent, Obino l'Ewai, suggesting integration of viral sequences. Sequencing of clones of Obino l'Ewai genomic DNA revealed an interface between BSV and Musa sequences and a complex BSV integrant. In situ hybridization revealed two different BSV sequence locations in Obino l'Ewai chromosomes and a complex arrangement of BSV and Musa sequences was shown by probing stretched DNA fibers. This is the first report of integrated sequences that possibly lead to a plant pararetrovirus episomal infection by a mechanism differing markedly from animal retroviral systems.

Cloning and sequence analysis of banana streak virus DNA

Banana streak virus (BSV), a member of the Badnavirus group of plant viruses, causes severe problems in banana cultivation, reducing fruit yield and restricting plant breeding and the movement of germplasm. Current detection methods are relatively insensitive. In order to develop a PCR-based diagnostic method that is both reliable and sensitive, the genome of a Nigerian isolate of BSV has been sequenced and shown to comprise 7389 bp and to be organized in a manner characteristic of badnaviruses. Comparison of this sequence with those of other badnaviruses showed that BSV is a distinct virus. PCR with primers based on sequence data indicated that BSV sequences are present in the banana genome.

The preliminary economic evaluation of health technologies for the prioritization of health technology assessments. A discussion

This paper critically evaluates methods for the preliminary economic evaluation of health technologies and the prioritization of health technology assessment projects. It reports on the literature, and considers methods currently employed and the purposes of preliminary appraisal. It concludes that a preliminary economic appraisal needs to be applied to the two main stages of the prioritization process; to have transparent criteria; to allow for an appropriate range of potential outcomes; to be practicable, flexible, and efficient; and to be relevant to the assessment of different research projects.

A community based study of vitamin A and vitamin E status of adolescent girls living in the Shire Valley, Southern Malawi

OBJECTIVE

To assess vitamin A and E status and anaemia in non-pregnant Malawian adolescent girls.

DESIGN

A cross-sectional study in rural village communities in the Shire Valley, Southern Malawi.

SUBJECTS

Adolescent girls, n = 118, aged between 10 and 19 y, 112 of whom were unmarried.

METHODS

Socio-demographic information was collected by questionnaire, heights and weights were measured. Vitamin A was assessed by the Modified Relative Dose Response (MRDR) test, in addition to serum retinol values. Blood samples were collected 4-5 h after administration of 3,4-didehydroretinyl acetate. Retinol and alpha-tocopherol levels were measured by HPLC. Serum retinol results for non-pregnant girls were compared with values for 43 adolescent pregnant girls which were available from a previous study.

RESULTS

26.6% of non-pregnant girls had serum retinol values < 0.70 micromol/L; 40.2% had an MRDR ratio > 0.060. In 59.3%, serum tocopherol levels were < 11.5 micromol/L and the tocopherol/cholesterol ratio was < 2.2 in 23.9%. 11.3% had a haemoglobin > or = 12 g/dl. Vitamin A levels were significantly related to age, and younger girls were more likely to be deficient. Significant correlations were found between serum retinol, MRDR values and serum tocopherol. Girls with a low body mass index for age had tocopherol cholesterol ratios < 2.2. Low serum retinol values occurred significantly more often in stunted girls (P=0.01). Serum retinol values of adolescent pregnant girls were significantly lower than those of non-pregnant adolescents (P=0.002).

CONCLUSIONS

Vitamin A and E deficiency and anaemia were common in adolescent non-pregnant girls, and thought to partly result from increased growth requirements. Girls who become pregnant at an early age are at risk of depletion of their nutritional reserves. Measures to reduce nutritional deficiencies before the first pregnancy are needed.

Comparison of sequences of RNAs 3 and 4 of rice stripe virus from China with those of Japanese isolates

The sequences were determined of RNAs 3 and 4 of a Chinese isolate (Y) of rice stripe tenuivirus (RStV) and were compared with those of two RStV isolates (M and T) from Japan. Both RNAs of the Y isolate were longer than those of the M and T isolates. There was almost complete conservation in the 5' and 3' non-coding regions for each RNA between the isolates. The analogous ambisense coding regions for each isolate were exactly the same size and the sequences were highly conserved. The major differences were in the intergenic regions, the sizes of which accounted for the differences in size of each RNA of the three isolates. There were no obvious patterns of differences in comparisons of the two RNA over the three isolates. The significance of the similarities and differences in sequences of isolates of RStV separated by more than 3500 km is discussed.

Tryptophan, Tryptophan-Leucine, and BSA Adsorption at an Oil-Water Interface

Adsorption of the amino acid tryptophan, the peptide tryptophan-leucine and the protein bovine serum albumin (BSA) at buffered water-oleyl alcohol interfaces has been studied by ellipsometry. Tryptophan-leucine solutions showed a systematic change in ellipticity with concentration indicating an adsorption of 0.5 mg/m2 for a solution concentration of 1 g/L and evidence of saturation at that concentration. BSA showed an adsorption of 0.45 mg/m2 for a concentration of 3.5 g/L with no sign of saturation. There appeared to be little adsorption of tryptophan at the interface.

A decade of change for patients

Although expressing concern that the quality of care in the ESRD program will be negatively impacted by the changes occurring in health care delivery and oversight today, Peter Lundin cogently describes the past, current, and future state of ESRD care when he says, "I believe that the life-expectancy for all ESRD patients ... is markedly improved, but remains, as always, primarily determined by the skills and motivations of those providing care." I hope that the renal community will benefit from these patient views and perceived needs as they ponder ESRD care in the next decade.

Neurobiochemical changes from Taxol/Neupogen chemotherapy for metastatic breast carcinoma corresponds with suicidal depression

A patient under Taxol and granulocyte colony stimulating factor (G-CSF, Neupogen) treatment for metastatic breast carcinoma of the liver experienced repeated suicidal depression on days 10 and 11 of therapy. MRI and MRS were performed during the fifth and sixth cycles of chemotherapy on days 1 and 10. The MRI was normal in all four examinations. The MRS showed normal levels of metabolites on days 1 of therapy, with remarkable reproducible declines in neurobiochemicals myo-inositol (23-27%), choline (20-24%), creatine (10-14%) and glutamate/glutamine (22-39%) on day 10 of therapy. The neurobiochemical declines coincided with the patient's experience of suicidal depression. Patients reporting depression during standard cancer therapy may be experiencing previously undocumented chemotherapeutic neurobiochemical imbalances or neurotoxicity.

Knee-length versus thigh-length graduated compression stockings in the prevention of deep vein thrombosis

Graduated compression stockings can reduce the incidence of deep vein thrombosis by 60 per cent1, by providing a decreasing compression gradient from the ankle towards the thigh. There is both theoretical and clinical evidence that compression of the thigh as well as the calf does not give extra benefit2,3. Although regarded as safe, improperly used stockings are not without risk. Problems are usually due to areas of localized high pressure, especially under ‘rucked up’ constricting bands of stocking. This is particularly so in the presence of ischaemia; manufacturers state that ischaemia is a contraindication to stocking use. Cases of arterial thrombosis have been reported4, as well as more frequent skin necrosis, when stockings have been used in the presence of reduced arterial blood supply5.

African-American adolescents residing in high-risk urban environments do use condoms: correlates and predictors of condom use among adolescents in public housing developments

OBJECTIVE

African-American adolescents living in high-risk inner-city environments have been disproportionately affected by the epidemics of human immunodeficiency virus (HIV) and other sexually transmitted diseases. Understanding the factors that influence the use of condoms by adolescents is critical for developing effective behavioral interventions. The present study examined the demographic, psychosocial, and behavioral correlates of condom use among African-American adolescents residing in public housing developments in an HIV epicenter (San Francisco) and prospectively evaluated the stability of these significant cross-sectional variables to predict consistent condom use.

DESIGN

A prospective study.

SETTING

Two public housing developments in San Francisco.

PARTICIPANTS

African-American adolescents and young adults between 12 and 21 years of age were recruited though street outreach and completed a theoretically derived research interview assessing HIV-related knowledge, attitudes, and behaviors. After a 6-month period, adolescents completed a follow-up interview similar to the baseline measure. Among adolescents reporting sexual activity in the 6 months before completing the baseline interview (n = 116), logistic regression analysis evaluated the influence of demographic, psychosocial, and behavioral factors on consistent condom use.

RESULTS

Adolescents who had high assertive self-efficacy to demand condom use (adjusted odds ratio [OR], 11), perceived peer norms as supporting condom use (OR, 4.2), had greater impulse control (OR, 3.7), were male (OR, 4.7), and were younger (OR, 2.9) were more likely to report consistent condom use. Frequency of sexual intercourse was inversely related to condom use; adolescents with higher numbers of sexual episodes were less likely to use condoms consistently. Prospective analyses identified the baseline level of condom use as the best predictor of condom use at the 6-month follow-up. Adolescents who were consistent condom users at baseline were 7.4 times as likely to be consistent condom users during the follow-up period. Of those adolescents changing their frequency of condom use during the follow-up interval, significantly more engaged in risky behavior; 33.3% changed from consistent to inconsistent condom use, whereas 20.6% changed from inconsistent to consistent use (OR, 1.6).

CONCLUSIONS

The findings suggest that HIV prevention programs need to be implemented early, before high-risk behaviors are established and may be more difficult to modify.

Child and adolescent psychiatry: toward the twenty-first century

The history of child and adolescent psychiatry is reviewed, from its beginning in the Hull House movement in Chicago a century ago through subsequent social and scientific transformations. The field's relationships to academic medicine, to progress in the basic sciences, and to child advocacy are described. Current challenges to the field, including the gaps in and barriers to care, the emergence of for-profit enterprises, and the lack of consensus regarding health care regulation, are discussed in terms of the evolving social mission of the profession. Priorities for the next century are identified.

A new educational approach for supporting the professional development of third-year medical students

This paper describes a new course designed to support the professional development of third-year medical students. The course runs through the clinical clerkships, and has several additional features: it includes a multidisciplinary faculty; it is centrally based in the medical school; it addresses students' values and attitudes in addition to their knowledge and skills; and it makes use of small-group learning methods, and faculty, student, and group continuity during the year. The curriculum, which addresses ethical, social, and communicative issues in medicine, plus the evaluation of students and of the course, are described.