Identification of roadkill hotspots and the factors affecting wombat vehicle collisions using the citizen science tool, WomSAT

Roads directly impact wildlife through vehicle collisions. In Australia only a few studies have examined the impact of environmental characteristics on wombat roadkill. We analysed wombat roadkills reported into WomSAT, a website and application where citizen scientists can upload sightings of wombats, to map wombat roadkill across their distribution. We used Maxent software to identify the main factors influencing wombat roadkill hotspots. A total of 2391 wombat deaths on roads were reported by 567 citizen scientists from 2015 to 2019. More wombat roadkill deaths occurred in winter, with most unaffected by sarcoptic mange. The average daily solar exposure, distance to populated areas, precipitation of warmest quarter (bio 18), temperature seasonality (bio 4), and precipitation seasonality (bio 15) were identified as the main factors influencing wombat roadkill. The most roadkills reported per kilometre (3.7/km) occurred on Old Bega Road and Steeple Flat Road, in the New South Wales southern tablelands. Reduced reporting corresponded with a reduced number of citizen scientists continuing to report sightings over time, reflecting the limitations of the data collected by citizen scientists. However, data should continue to be collected by citizen scientists as it is an easy and low-cost method of collecting data over large areas, and can provide information to managers to support conservation efforts directed at reducing roadkill. Our study emphasises the need to continue to engage and reward citizen scientists for their efforts.

Exploring a role for Human Herpesvirus 6B-mediated mitochondrial dysfunction in dysregulating antiviral innate immunity

Human herpesviruses are ubiquitous in the world population, in part due to the ability of this family of viruses to establish life-long, persistent infections. Human herpesvirus 6B (HHV-6B) is generally acquired early in life, and is the causative agent of the benign childhood febrile illness, Roseola Infantum, and severe encephalitis in rare instances. Mitochondria play diverse roles in cell homeostasis, including metabolism, energy production, and regulation of antiviral innate immunity. As a family, herpesviruses are known modulators of mitochondria and we have observed that HHV-6B significantly alters mitochondrial function of infected T-cells. Specifically, we have discovered that HHV-6B alters mitochondrial DNA replication and transcription, while also dramatically decreasing mitochondrial membrane potential during infection. We hypothesize that HHV-6 disrupts mitochondrial function by altering mitochondrial gene expression and oxidative phosphorylation, leading to metabolic and signaling imbalances that influence cellular homeostasis and anti-HHV-6 immunity.

Oxidative stress enhances mitochondrial DNA-dependent type I interferon responses

It is increasingly well-appreciated that mitochondrial DNA (mtDNA) can engage the cGAS-STING cytosolic DNA sensing machinery to trigger type I interferon (IFN-I) responses. However, the exact immunostimulatory features of mtDNA and whether other nucleic acid sensors participate in triggering IFN-I remain poorly defined. We have discovered that mitochondrial reactive oxygen species potentiate mtDNA-driven IFN-I responses by enhancing the immunostimulatory properties of this DNA toward the cGAS-STING pathway. Moreover, we report that elevated oxidative stress results in the accumulation of mtDNA species with unique secondary structures that enhance IFN-I production. Finally, we report that Zbp1/DAI cooperates with cGAS to sustain IFN-I responses triggered by mtDNA. These results provide new insight into the molecular mechanisms of mtDNA recognition by the cytosolic DNA sensing machinery, with broad implications for understanding human diseases with mtDNA as a pathogenic inflammatory driver.

Defining how mitochondrial DNA stress regulates innate immune responses

Polymerase gamma (pol γ) is nuclear-encoded protein responsible for mtDNA replication. POLG mutations are recognized as a significant cause of primary mitochondrial diseases and are implicated in a range of disorders. Several mouse models of POLG-related disease have been reported, the most well studied is the POLG-mutator mouse. Animals homozygous for the mutant alleles exhibit elevated mtDNA instability, and POLG-mutator mice exhibit pathology that mirrors various aspects of human POLG-related diseases. The literature has few descriptions about the immune system of POLG-mutator mice or patients with POLG-related disorders, despite the fact that aberrant immune responses have been implicated in the pathology of diseases with similar phenotypes. We have found that mitochondrial dysfunction, resulting from POLG mutation, alters innate immune responses at baseline and after challenge, which we hypothesize may exacerbate pathology in POLG-related mitochondrial disorders. To explore this hypothesis, we have stimulated macrophages from WT and POLG-mutator mice with various innate immune stimuli, and have uncovered that POLG-mutator macrophages display alterations in type I interferon responses, but strikingly, exhibit profound decreases in inflammasome-dependent interleukin-1 beta (IL-1b) secretion. Ongoing work will determine how mitochondrial dysfunction impairs inflammasome activation and IL-1b secretion in order to appreciate how aberrant innate immune responses influence POLG-related disease progression.

Continuous Monitoring of Respiratory Variables During Sleep by Microcomputer

A microcomputer system has been developed to acquire, process and store respiratory and heart rate data for all-night sleep studies. Signals monitored continuously are: expired carbon dioxide (an index of airflow); respiratory inductance plethysmography (an index of the volume of air exchanged); oxygen saturation; and heart rate. The respiratory inductance Plethysmograph signal is reduced to a set of values which summarize each complete respiratory cycle (inspiratory time, expiratory time, and tidal volume index). Values of oxygen saturation and heart rate are saved at two points: the onset of inspiration and expiration. These signals, and derived values, are continuously updated on the system video display terminal. An audible alarm signals the presence of apneic events, and defects in the computer-polygraph interface. The software identifies three forms of apnea (central, obstructive, and mixed) in accordance with conventional definitions. A continuous polygraphic recording is time-synchronized, by a software generated time-coded signal, to enable the subsequent incorporation of the manually reduced sleep stage data. The sleep stage distribution data is placed, under program control, on the same storage medium as the computer-acquired data. Statistical relationships between sleep stage and respiration are investigated.

Maternal colonization with Staphylococcus aureus and Group B streptococcus is associated with colonization in newborns

OBJECTIVES

Although Staphylococcus aureus and Group B streptococcus (GBS) are major causes of neonatal sepsis in sub-Saharan Africa, it is unclear how these bacteria are transmitted to the neonate.

METHODS

In a cohort of 377 Gambian women and their newborns, nasopharyngeal swabs were collected at delivery (day 0), and 3, 6, 14 and 28 days later. Breast milk samples and vaginal swabs were collected from the mother. Staphylococcus aureus and GBS were isolated using conventional microbiological methods.

RESULTS

Most women were carriers of S. aureus (264 out of 361 with all samples collected, 73.1%) at some point during follow up and many were carriers of GBS (114 out of 361, 31.6%). Carriage of S. aureus was common in all three maternal sites and GBS was common in the vaginal tract and breast milk. Among newborns, carriage of S. aureus peaked at day 6 (238 out of 377, 63.1%) and GBS at day 3 (39 out of 377, 10.3%). Neonatal carriage of S. aureus at day 6 was associated with maternal carriage in the breast milk adjusted OR 2.54; 95% CI 1.45-4.45, vaginal tract (aOR 2.55; 95% CI 1.32-4.92) and nasopharynx (aOR 2.49; 95% CI 1.56-3.97). Neonatal carriage of GBS at day 6 was associated with maternal carriage in the breast milk (aOR 3.75; 95% CI 1.32-10.65) and vaginal tract (aOR 3.42; 95% CI 1.27-9.22).

CONCLUSIONS

Maternal colonization with S. aureus or GBS is a risk factor for bacterial colonization in newborns.

Cell death patterns in Arabidopsis cells subjected to four physiological stressors indicate multiple signalling pathways and cell cycle phase specificity

Corpse morphology, nuclear DNA fragmentation, expression of senescence-associated genes (SAG) and cysteine protease profiles were investigated to understand cell death patterns in a cell cycle-synchronised Arabidopsis thaliana cell suspension culture treated with four physiological stressors in the late G2 phase. Within 4 h of treatment, polyethylene glycol (PEG, 20 %), mannose (100 mM) and hydrogen peroxide (2 mM) caused DNA fragmentation coinciding with cell permeability to Evans Blue (EB) and produced corpse morphology corresponding to apoptosis-like programmed cell death (AL-PCD) with cytoplasmic retraction from the cell wall. Ethylene (8 mL per 250-mL flask) caused permeability of cells to EB without concomitant nuclear DNA fragmentation and cytoplasmic retraction, suggesting necrotic cell death. Mannose inducing glycolysis block and PEG causing dehydration resulted in relatively similar patterns of upregulation of SAG suggesting similar cell death signalling pathways for these two stress factors, whereas hydrogen peroxide caused unique patterns indicating an alternate pathway for cell death induced by oxidative stress. Ethylene did not cause appreciable changes in SAG expression, confirming necrotic cell death. Expression of AtDAD, BoMT1 and AtSAG2 genes, previously shown to be associated with plant senescence, also changed rapidly during AL-PCD in cultured cells. The profiles of nine distinct cysteine protease-active bands ranging in size from ca. 21.5 to 38.5 kDa found in the control cultures were also altered after treatment with the four stressors, with mannose and PEG again producing similar patterns. Results also suggest that cysteine proteases may have a role in necrotic cell death.

Protein biosensing with fluorescent microcapillaries

Capillaries with a high-index fluorescent coating represent a new type of whispering-gallery-mode (WGM) microcavity sensor. By coating silicon quantum dots (Si-QDs) onto the channel wall of a microcapillary, a cylindrical microcavity forms in which the optical confinement arises from the index contrast at the interface between the QD layer and the glass capillary wall. However, the ability to functionalize the QD layer for biosensing applications is an open question, since the layer consists of a mixture of Si-QDs embedded in a glassy SiOx matrix. Here, we employ a polyelectrolyte (PE) multilayer approach to functionalize the microcapillary inner surface and demonstrate the potential of this refractive index sensing platform for label-free biosensing applications, using biotin-neutravidin as a specific interaction model.

Todorokite-type manganese oxide nanowires as an intercalation cathode for Li-ion and Na-ion batteries

Extended hydrothermal treatment at an elevated temperature of 220 °C allowed high yield synthesis of manganese oxide nanowires with a todorokite crystal structure suitable for reversible intercalation of Li⁺ and Na⁺ ions.

Groundwater Iron Assessment and Consumption by Women in Rural Northwestern Bangladesh

In Bangladesh, approximately 97 % of the rural population uses groundwater as a drinking source. In many areas of the country this water is known to have elevated levels of iron. The contribution to iron intake that this exposure provides, and the impact on health, are unknown. In the pre- and post-monsoon seasons of 2008, we measured iron content of household tube well water, explored local water collection methods, and estimated iron intake through consumption of groundwater for 276 women of reproductive age in a rural setting in northwestern Bangladesh. Groundwater samples were analyzed for total iron (mg/L), arsenic (category of µg/L), pH, temperature (oC), and oxidation-reduction potential (Eh). Participants drank [mean (SD); 2.7 (0.8) L] of water per day, all of which was collected from domestic tube wells. Total iron concentration in groundwater was high, [median (IQR) 16.3 (6.9, 28.2) mg/L], and variable throughout the area. Using this value, estimated daily iron intake [median (IQR)] was 41.1 (16.0, 71.0) mg from drinking water alone. The amount of water consumed was unrelated to its iron concentration (r = - 0.06; p = 0.33) despite potentially unpleasant organoleptic qualities of high iron content in water. Groundwater contributes substantially to daily iron intake of rural Bangladeshi women and currently represents an under-assessed potential source of dietary iron.

Hospital discharge correspondence — how effective is it?

Continuity of patient care after discharge from hospital relies on effective discharge communication between the hospital doctors and the patient's general practitioner. The aim of this study was to investigate the effectiveness of discharge communication, in terms of its content and timing. The study involved analysing all discharge correspondence received by two city-based group practice medical centres over a period of one month. Three hundred and one pieces of discharge correspondence were scrutinised. These comprised 164 initial discharge summaries and 137 follow-up discharge letters. In general, information was more thoroughly and more accurately recorded in the follow-up letters than in the discharge summaries; however, there were significant delays in the receipt of the letters by the GPs. Results showed that there are many aspects of the correspondence between secondary and primary care which need improving. These include: improvement in the design of discharge correspondence forms; improvement in completing the forms; and improvement to the administrative systems for dispatching discharge correspondence. Although not specifically looked at in this study, we also believe that it would be useful for a mechanism to be set up for hospital pharmacists to establish links with their community colleagues in advance of a patient's discharge in order that the patient's pharmaceutical needs may be readily met in the community.

AFM capabilities in characterization of particles and surfaces: from angstroms to microns

Scanning probe microscopy (SPM), invented 25 years ago, is now routinely employed as a surface characterization technique. Atomic force microscopy (AFM) is the most widely used form of SPM, since AFM can be used in ambient conditions with minimal sample preparation. Examples of applications relevant to cosmetics include, but are not limited to, hair and skin roughness measurements and powder particle and nano-emulsion characterization. AFM is well suited for individual particle characterization, especially for measurements of volume, height, size, shape, aspect ratio, and particle surface morphology. Statistical distributions for a large set of particles can be generated through single-particle analysis techniques (i.e., ensemble-like information). AFM is better capable of resolving complex particle-size distributions than dynamic light-scattering (DLS). Single-particle analysis techniques with AFM can be more cost- and time-effective than analyses using scanning electron microscopy (SEM). However, AFM offers resolution that is comparable to or greater than SEM or transmission electron microscopy (TEM) and routinely allows direct measurements of the particle height and volume and produces images easily displayed in a quantified 3D format.

Use of high-dose ganciclovir for a resistant cytomegalovirus infection due to UL97 mutation

Cytomegalovirus (CMV) infection is a major complication following solid organ transplantation resulting in significant morbidity and mortality. The guidelines published in 2004 have recommendations for therapy; however, the frequency of resistant CMV infection is increasing and therapy is not clearly defined. There are a few alternatives to ganciclovir such as foscarnet, cidofovir, and leflunomide; however, their use is limited by adverse effects. This report summarizes the successful use of high-dose ganciclovir for the treatment of a resistant CMV caused by UL97 mutation.

Controlled atmosphere treatment of broccoli after harvest delays senescence and induces the expression of novel BoCAR genes

The current study examines the transcription of four genes (BoCAR1A, BoCAR5, BoCAR6-4 and BoCAR25) found to be up-regulated in response to high CO(2)/low O(2) treatment in broccoli (Brassica oleracea). Messenger RNA levels for the four genes declined after tissues were removed from CA. Physiological and biochemical changes and gene expression patterns were examined in broccoli tissues held in one of four different atmospheres, namely air (<1% CO(2), 21% O(2)), high carbon dioxide and low oxygen (CA 10% CO(2), 5% O(2)), low oxygen (0% CO(2), 5% O(2)), and high carbon dioxide (10% CO(2), 20% O(2)). In a second trial gene expression was examined in tissues held for short periods in CA (6h, 12h or 24h) followed by air. Broccoli tissues were also exposed to CA after 48 h in air to determine whether CA treatment was effective in up-regulating the CA-responsive genes and/or delaying senescence after early senescence-associated gene changes had been initiated. Northern analysis showed that a combined high CO(2) and low O(2) atmosphere was more effective than high CO(2) or low O(2) alone for inducing maximum gene expression and delaying postharvest broccoli senescence. In addition, broccoli tissues responded to CA treatment after a 48-h period in air with increased CA-responsive gene expression. Certain transcripts were down-regulated in tissues exposed to salt and water stresses that promoted senescence, and down-regulated in tissues treated with cytokinin, a treatment that delays postharvest senescence in broccoli. The up-regulation of these four BoCAR genes appears to be specific to CA treatment in harvested broccoli tissues.

Characterization of extended-spectrum β-lactamase (ESBL)-producing Kuwait and UK strains identified by the Vitek system, and subsequent comparison of the Vitek system with other commercial ESBL-testing systems using these strains

Two hundred and fifty-one unique patient isolates of Klebsiella pneumoniae (123), Escherichia coli (114), Klebsiella oxytoca (7), Enterobacter cloacae (5) and Citrobacter freundii (2), flagged as extended-spectrum β-lactamase (ESBL) positive by the Vitek system (GNS-526 card), were collected. These strains were isolated from a variety of clinical specimens submitted to the clinical bacteriology laboratories of the Royal Infirmary of Edinburgh (RIE), Edinburgh, UK (and associated GP practices), Hairmyers Hospital, Glasgow, UK, and the Amiri and Farwania Hospitals, Kuwait. Of the 101 RIE strains tested, 15 E. coli strains were found to be ESBL negative by Etest ESBL strips. On retesting the 15 E. coli strains with the Vitek GNS-532 card, 14 were found to be ESBL negative, despite being originally flagged as ESBL positive. The remaining 236 ESBL-producing strains were also subjected to the double disc-diffusion (DDD) technique for the detection of ESBLs. Of these, two were false negatives by Etest ESBL test strips (using both cefotaxime and ceftazidime strips), and 38 were false negatives by the DDD method. The Etest false-negative ESBL-producing strains of K. pneumoniae were positive by DDD. Technically, the Vitek method was the least demanding method to perform, as it was an integral part of the routine susceptibility test card. Etest strips were reliable, but were the most expensive of all the techniques used. The DDD test, while relatively inexpensive, was technically subjective, and in our hands, seven of the ESBL-positive strains that were confirmed by the other two techniques were not detected. Despite the false-positive ESBL-producing E. coli strains, the Vitek susceptibility card with its integral ESBL test offers the clinical laboratory a valuable and quick option to screen for ESBL-producing Klebsiella spp. and E. coli as part of the routine laboratory methodology.

Indirect impacts of invasive cane toads (Bufo marinus) on nest predation in pig-nosed turtles (Carettochelys insculpta)

The cane toad (Bufo marinus) was introduced into Australia in 1935. Because this toxic frog is novel to the Australian fauna, its introduction has impacted native fauna in a variety of ways. We anticipated a severe decline in the yellow-spotted monitor lizard (Varanus panoptes) associated with the arrival of cane toads along the Daly River, Northern Territory, and predicted a simultaneous impact on nest predation in the pig-nosed turtle (Carettochelys insculpta) because the lizard is the chief predator of C. insculpta eggs at the site. We surveyed for monitors and cane toads for five years at two sites before and after the arrival of cane toads, and surveyed for turtle nest predation for three years before, and one year after, the arrival of the toads. Collectively, our data and observations, combined with unpublished reports, indicate that: (1) cane toads arrived at our study sites during the wet seasons of 2003–04 and 2004–05; (2) the lizard V. panoptes readily succumbs to cane toad toxins; (3) . panoptes has experienced a marked decline in relative population numbers coincident with the arrival of the toads at the site; and (4) V. panoptes has been reduced to such low numbers that it is currently no longer a significant predator of pig-nosed turtle eggs.

Assessment of quality of life in the supportive care setting of the big lung trial in non-small-cell lung cancer

PURPOSE

The Big Lung Trial (BLT) was a large, pragmatic trial to evaluate the addition of chemotherapy to primary treatment (ie, surgery, radical radiotherapy, or supportive care) in non-small-cell lung cancer (NSCLC). In the supportive care group, there was a small but significant survival benefit in patients treated with chemotherapy compared with supportive care alone (no chemotherapy). A substudy was undertaken to evaluate the quality of life (QoL) implications of the treatment options. QoL was assessed using European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaires C30 (QLQ-C30) and LC17, and daily diary cards.

PATIENTS AND METHODS

EORTC QLQ-C30 and LC17 were collected at 0, 6 to 8, 12, 18, and 24 weeks. Diary cards were completed during the first 12 weeks of the study. The primary end point was global QoL at 12 weeks.

RESULTS

A total of 273 patients were randomly assigned: 138 to no chemotherapy and 135 to chemotherapy. There was no evidence of a large detrimental effect on QoL of chemotherapy. No statistically significant differences in global QoL or physical/emotional functioning, fatigue and dyspnea, and pain were detected at 12 weeks. Higher rates of palliative radiotherapy in the no chemotherapy arm may have lessened differences in QoL. Global QoL, role functioning, fatigue, appetite loss, and constipation were prognostic indicators of survival at 12 weeks.

CONCLUSION

There were no important adverse effects of chemotherapy on QoL.

Estimation of the additional costs of chemotherapy for patients with advanced non-small cell lung cancer

BACKGROUND

A large multicentre randomised trial, the Big Lung Trial, which in part compared supportive care with or without cisplatin-based chemotherapy in patients with advanced non-small cell lung cancer, provided an opportunity to evaluate the impact on the UK National Health Service of the costs incurred with the use of chemotherapy.

METHODS

This costing study was based on the retrospective collection of resource use data from hospital records. Case notes from 194 patients (98 chemotherapy + supportive care (C), 96 supportive care alone (NoC)) were inspected in eight centres recruiting the largest numbers of patients into the Big Lung Trial. Quantities were multiplied by fixed unit costs to calculate a total cost for each patient. The main outcome measure was the total cost incurred by the use of secondary care resources (including investigations, chemotherapy, radiotherapy, surgical procedures, inpatient days, outpatient attendances, and hospice inpatient care) in the two groups.

RESULTS

Patients randomised to receive cisplatin-based chemotherapy had an average of 3.4 more inpatient bed days than the mean of 11.9 days for patients randomised to supportive care alone, and more outpatient attendances. NoC patients were more likely to have received palliative radiotherapy. The mean total cost for C patients was 5355 sterling pound compared with 3595 sterling pound for the NoC group, difference 760 sterling pound (95% CI 781 sterling pound to 2742 sterling pound ). When split, the cost in the C group associated with the administration of chemotherapy was 1233 sterling pound and non-chemotherapy costs were 4122 sterling pound .

CONCLUSION

The additional cost of chemotherapy was not offset by a reduction in subsequent costs (as the non-chemotherapy costs were similar), so the survival benefit of about 10 weeks observed in the C group was achieved with the cost of chemotherapy administration.

Dietary habits and children's family lives

PURPOSE

To investigate associations between 'less healthy eating' and 'unhealthy snacking' at age 11, and family life (family structure, meals and maternal employment status) together with potential socio-economic confounders and gender.

METHODS

Children participated in a school-based survey, questionnaires also being completed by parents. Analyses were based on those with complete data, weighted to account for bias in return of parental questionnaires (N = 2146). Data from a dietary inventory, questions on food choice and snacks were used to classify 'less healthy eating' and 'unhealthy snacking'.

RESULTS

Less healthy eating' (57%) and 'unhealthy snacking' (32%) were associated with greater deprivation, fewer maternal qualifications and being male. Compared with children of full-time homemakers, the likelihood of 'less healthy eating' was reduced among those whose mothers worked part-time (this effect remaining after socio-economic adjustment), full-time (effect removed after adjustment), or were unemployed, sick or disabled (effect emerging after adjustment). 'Unhealthy snacking' was not related to maternal employment, and neither measure was associated with family structure or daily meals.

CONCLUSIONS

There was no evidence that family structure or meals were associated with children's diets, although maternal employment had a positive association. Contrasting with the size of these effects, relationships between diet and socio-economic status were strong.

Chemotherapy versus supportive care in advanced non-small cell lung cancer: improved survival without detriment to quality of life

BACKGROUND

In 1995 a meta-analysis of randomised trials investigating the value of adding chemotherapy to primary treatment for non-small cell lung cancer (NSCLC) suggested a small survival benefit for cisplatin-based chemotherapy in each of the primary treatment settings. However, the meta-analysis included many small trials and trials with differing eligibility criteria and chemotherapy regimens.

METHODS

The aim of the Big Lung Trial was to confirm the survival benefits seen in the meta-analysis and to assess quality of life and cost in the supportive care setting. A total of 725 patients were randomised to receive supportive care alone (n = 361) or supportive care plus cisplatin-based chemotherapy (n = 364).

RESULTS

65% of patients allocated chemotherapy (C) received all three cycles of treatment and a further 27% received one or two cycles. 74% of patients allocated no chemotherapy (NoC) received thoracic radiotherapy compared with 47% of the C group. Patients allocated C had a significantly better survival than those allocated NoC: HR 0.77 (95% CI 0.66 to 0.89, p = 0.0006), median survival 8.0 months for the C group v 5.7 months for the NoC group, a difference of 9 weeks. There were 19 (5%) treatment related deaths in the C group. There was no evidence that any subgroup benefited more or less from chemotherapy. No significant differences were observed between the two groups in terms of the pre-defined primary and secondary quality of life end points, although large negative effects of chemotherapy were ruled out. The regimens used proved to be cost effective, the extra cost of chemotherapy being offset by longer survival.

CONCLUSIONS

The survival benefit seen in this trial was entirely consistent with the NSCLC meta-analysis and subsequent similarly designed large trials. The information on quality of life and cost should enable patients and their clinicians to make more informed treatment choices.

Delta-conotoxin structure/function through a cladistic analysis

Delta-conotoxins are Conus peptides that inhibit inactivation of voltage-gated sodium channels. The suggestion that delta-conotoxins might be an essential component of the venoms of fish-hunting cone snails which rapidly immobilize their prey [Terlau, H., Shon, K., Grilley, M., Stocker, M., Stühmer, W., and Olivera, B. M. (1996) Nature 381, 148-151] has not been tested. On the basis of cDNA cloning, all of the fish-hunting Conus analyzed yielded at least one delta-conotoxin sequence. In addition, one delta-conotoxin isolated from the venom of Conus striatus had an amino acid sequence identical to that predicted from cDNA cloning. This new peptide exhibited properties of delta-conotoxins: it targeted sodium channels and potentiated action potentials by slowing channel inactivation. Homologous sequences of delta-conotoxins from two groups (clades) of related fish-hunting Conus species share consensus features but differ significantly from the two known delta-conotoxins from mollusc-hunting Conus venoms. Three large hydrophobic amino acids were conserved; analogues of the previously described delta-conotoxin PVIA with alanine substituted for the conserved amino acids F9 and I12 lost substantial biological activity. In contrast, both the T8A and K13A delta-conotoxin PVIA analogues, where substitutions were at nonconserved loci, proved to be biologically active. Taken together, our results indicate that a cladistic approach can identify amino acids critical for the activity of conotoxins and provide extensive information as to which amino acid substitutions can be made without significant functional consequences.

Poor but healthy? The youngest generation of Irish catholics in west Scotland

OBJECTIVE

Catholic adults in the West of Scotland, who are mainly of Irish origin, have been shown to suffer excess morbidity and mortality compared to the general population. A major contributing factor to this inequality is socio-economic disadvantage. This paper investigates the health and socio-economic position of Catholics in the youngest generation.

DESIGN

Secondary analysis of baseline data from the West of Scotland 11-16 STUDY: Teenage Health, which is a longitudinal school-based survey.

SETTING

One hundred and thirty five primary schools in Glasgow and surrounding districts.

SUBJECTS

Two thousand five hundred and eighty six final-year pupils (average age eleven years and three months), born in 1983/1984.

RESULTS

Comparing Catholics and non-Catholics on a range of indicators of general health, recent acute symptoms, chronic conditions, mental health and physical measures, we found no evidence of any systematic health inequality. A few indicators did show statistically significant differences at the five percent level, but these were not in any consistent direction. In terms of household socio-economic position, though, we found strong evidence of disadvantage for Catholics. Catholic children were more likely to have parents of manual social class, without any formal qualifications, who were less likely to own their home or a car, more likely to express difficulty 'making ends meet', and more likely to live in a deprived area.

CONCLUSIONS

We discuss the prospects for diminishing socio-economic inequality over time between Catholics and non-Catholics in this cohort, which will depend on Catholic social mobility. We consider the likelihood of enduring health equality for Catholics, which will depend on the effects of different influences on health over the life course.

Social class and smoking at age 15: the effect of different definitions of smoking

AIM

To explore whether the association between social class and smoking among teenagers varies according to the definition of smoking adopted. Design, setting and participants. A survey of 2196 15-year-olds in 43 secondary schools in the West of Scotland.

MEASURES

Current smoking status and number of cigarettes smoked, and social class based on the occupation of the head of the household.

FINDINGS

'Current smoker' was the only category not significantly differentiated by class; the ratio of smokers from unskilled compared with professional backgrounds rose with increasingly stringent definitions of smoking.

CONCLUSION

The extent to which teenage smoking is patterned by social class depends on the definition of smoking adopted.

FTIR microscopic imaging of collagen and proteoglycan in bovine cartilage

Articular cartilage, a connective tissue that provides resistance to compressive forces during joint movements, has not been examined in detail by conventional Fourier transform infrared (FTIR) spectroscopy, microspectroscopy (FTIRM), or imaging (FTIRI). The current study reports FTIRM and FTIRI analyses of normal bovine cartilage and identifies the specific molecular components of cartilage that contribute to its IR spectrum. FTIRM data acquired through the superficial, middle, and deep zones of thin sections of bovine articular cartilage showed a variation in intensities of the absorbance bands that arise from the primary nonaqueous components of cartilage, collagen, and proteoglycan (primarily aggrecan) and thus reflected the differences in quantity of these specific components. The spectra of mixtures of model compounds, which had varying proportions of type II collagen and aggrecan, were analyzed to identify spectral markers that could be used to quantitatively analyze these components in cartilage. Collagen and aggrecan were then imaged by FTIRI based on markers found in the model compounds. Polarization experiments were also performed to determine the spatial distribution of the collagen orientation in the different zones of cartilage. This study provides a framework in which complex pathological changes in this heterogeneous tissue can be assessed by IR microscopic imaging.