Relationship of personal, situational, and environmental factors to injury experience in commercial fishing

INTRODUCTION

Commercial fishing work involves a variety of activities and is hazardous. While much is understood to mitigate fatalities in this industry, research must further explore nonfatal injury characteristics, factors related to injury, and potential injury prevention strategies. This paper determines if fishing experience is associated with injury risk and explores common work activities associated with injury.

METHOD

Key informant interviews and a survey of fishermen were conducted to refine work activity codes and collect injury experiences. Independent sample t-tests compared the means of the years fishing by injury incident for all crab fishermen then stratified by position. Descriptive statistics explored the nature of injury in relation to work activity.

RESULTS

The level of experience was significantly lower for injured fishermen compared to fishermen who reported no injuries, but when stratified by position at the time of the injury, the association of injury to experience was only significant for owners. This stratified result demonstrates that the work activity, rather than experience, drives the apparent relationship of experience to injury. Being tired (24%) and weather (26%) were indicated as contributing factors at the time of injury.

CONCLUSION

Modifying the work environment to better control hazards would benefit all fishermen, regardless of their experience, age, or position. Further work into effective interventions that fishermen would adopt is needed to reduce injury risk. Any formal or informal training of new fishermen should focus on the most hazardous activities, but more experienced fishermen would also benefit. Additionally, effective training or interventions for fatigue management, and decision support tools for weather- and navigation-related decisions would further reduce risk of at sea injuries.

PRACTICAL APPLICATIONS

Injury prevention training, for all fishermen, regardless of their position and years of experience, should cover the most hazardous tasks, fatigue risk management strategies, and weather decisions.

Commercial Fishing Fatalities and Injuries Described by Linked Vessel Incidents

OBJECTIVES

The Risk Information System for Commercial Fishing (RISC Fishing) merged information on fishermen and vessel incident types from various databases. This descriptive study examined linked fisherman injury records (fatal and nonfatal) and vessel incident records in Oregon and Washington from 2000 to 2018 in the RISC Fishing database. The circumstances of incidents and any association with fishermen outcomes were explored to identify injury prevention opportunities.

METHODS

The statistical analyses included a descriptive study of incidents related to the injury characteristics and frequency of outcomes by incident type. Further analyses included contingency tables and Pearson Chi-Square tests for selected variables to determine if there were associations between vessel incident outcomes (fatality, nonfatal injury, no injury).

RESULTS

A total of 375 reported incidents with 93 cases of fatalities, 239 nonfatal injuries, and over 6,575 fishermen with no injury were described. Of fatalities, 90% were due to drowning, with only 2% of victims reported donning survival equipment. Deckhands experienced fatal and nonfatal injuries most frequently. The most common factors associated with nonfatal injuries included contact with objects (event), walking on vessel and hauling gear (work activities), and fractures and open wounds (nature). The most common final event leading to a vessel disaster with no injury being reported was sinking (76%). Distributions between the incident outcomes (fatality, nonfatal injury, and no injury) differed by vessel activity/type, fishery/gear, and event leading to the incident.

CONCLUSION

Linked information of fishermen injury outcomes and vessel incident information showed that events and settings that involve fatalities are qualitatively different from incidents resulting in only nonfatal injuries or uninjured survivors. Vessel-level approaches for mitigating fatalities, such as ensuring vessel stability, improving navigation/operation decisions, and spotlighting survival equipment policies/rescue priorities could have a significant impact. Work task-specific prevention strategies for nonfatal injuries related to the larger vessels (catcher/processors and processors) and smaller vessels (with pot/trap gears) are paramount. The use of linked information provided in reports can provide a fuller incident picture to advance efforts to improve the working conditions of commercial fishermen.

Characterization of Musculoskeletal Injury Risk in Dungeness Crab Fishing

OBJECTIVES

Commercial Dungeness crab fishermen's manual crab pot handling activities can be done in harsh outdoor working environments at sea and can pose well-known physical risk factors associated with musculoskeletal injury including forceful exertion, repetition and awkward posture. The nonfatal injury rate in this fishing fleet is 3.4 per 1,000 full-time equivalent workers. Two-thirds of self-reported injuries in the fleet were musculoskeletal sprains and strains. To date, no objective biomechanical assessment of musculoskeletal disorder (MSD) risk has been conducted due to the challenging work environment.

METHODS

The aim of this study was to determine the feasibility of collecting objective biomechanical assessments (i.e., posture and repetition) using inertial measurement unit (IMU) sensors placed on the arms and torso of professional deckhands (n = 7) while at sea, harvesting Dungeness crab. Based on the IMU-measured posture data, fishermen's anthropometry, and crab pot weights, biomechanical loading of the low back and both shoulders was estimated.

RESULTS

The IMU sensor data showed that commercial Dungeness crab fishing is highly repetitive and poses awkward postures in the shoulders and back. The estimated static low back compression, shear force, and flexion moment about the shoulders and low back (L5/S1) indicate potential injury risk associated with harvesting crab.

CONCLUSION

The results indicate that objective biomechanical assessment using the IMU sensors is feasible in the commercial fishing environment.

Utilizing Haddon matrix to assess nonfatal commercial fishing injury factors in Oregon and Washington

BACKGROUND

Commercial fishing is a precarious industry with high fatal and nonfatal injury rates. The Risk Information System of Commercial [RISC] Fishing project at Oregon State University has been tracking both fatal and nonfatal injuries among Oregon and Washington commercial fishermen. We examined the utility of the RISC dataset variables in highlighting injury factors and prevention opportunities.

METHOD

We identified 245 nonfatal commercial fishing injuries in Oregon and Washington (2000-2018) and assessed the top three injury events (contact with objects or equipment, transportation incidents, and slips/trips/falls) using a cross-sectional design. We generated a Haddon matrix for each event type and populated the matrices with injury-associated factors following our a-priori matrix.

RESULTS

We observed 108 nonfatal injuries due to contact with objects. Contact injuries occurred during fishing (40%) with fishing gears (40%), often while hauling the fishing gear (22%). Common injury mechanisms included getting caught in running equipment or machinery (19%) or compressed by shifting objects or equipment (18%). Of the 58 transportation injuries most occurred in catchers (93%) and smaller vessels (1 to 3 crew) (55%). Vessel casualties were common as several vessels struck rocks/bottom (29%) or experienced fire and explosion (19%). The crew was abandoned to water (38%), often due to no raft or raft malfunctions (19%). Slip/trip/fall injuries (n = 43) typically happened during onboard traffic (49%). Such events were largely experienced by the catcher-processors (44%) including large vessels with > 100 crew (28%).

CONCLUSION

The Haddon matrix demonstrated the injury-event timeline and helped to identify potential injury-associated factors. Our injury-specific risk matrices will let commercial fishing stakeholders determine priorities and work with the experts on prevention efforts.

Health-Related Exposures and Conditions among US Fishermen

Commercial fishing is a high-risk occupation, yet there is a lack of surveillance documenting health conditions, health behaviors, and health care coverage among US fishermen. We used publicly available data sources to identify exposures and health outcomes common among fishermen. We utilized the National Institute for Occupational Safety and Health-Worker Health Charts to estimate the prevalence of general exposures, psychosocial exposures, health behaviors, and health conditions from the national surveys National Health Interview Survey - Occupational Health Supplement (NHIS-OHS, 2015) and Behavioral Risk Factor Surveillance System (BRFSS) (2013-2015). We compared fishing workers with both agricultural workers and all-workers. Fishermen commonly reported general exposures, psychosocial exposures, non-standard work arrangements, frequent night shifts, and shift work. The prevalence of musculoskeletal conditions such as carpal tunnel syndrome (33%) and severe low-back pain (27%) was also high. Smoking (45%) and second-hand smoke exposure (25%) were widespread, and 21% reported no health care coverage. National household surveys such as NHIS-OHS, and BRFSS can be utilized to describe the health status of fishermen. This workforce would benefit from increased access to health care and health promotion programs. More comprehensive evaluations of existing data can help to identify occupation-specific health challenges.

Efficacy of text messaging apprentices to reinforce ergonomics and safety voice training

INTRODUCTION

Injuries and work-related musculoskeletal disorders (MSDs) are common among masons. SAfety Voice for Ergonomics (SAVE) integrates training in ergonomic and safety problem-solving skills into masonry apprenticeship training. The purpose of this study was to assess the efficacy of text messaging to reinforce SAVE program content.

METHOD

SAVE effectiveness was evaluated at masonry apprenticeship training centers across the United States by comparing three experimental groups: (1) Ergonomics training, (2) Ergonomics and Safety Voice training, and a (3) Control. Apprentices received SAVE training with their standard instruction. To reinforce classroom training, refresher training was implemented by sending weekly text messages for six months. Half of the text messages required a response, which tested knowledge or assessed behavior, while the remaining reiterated knowledge. Apprentices (n = 119) received SAVE text messages. Response rates and percentage of correct responses were compared with chi-square tests and independent group t-tests. Multivariable logistic regression analysis predicted apprentice response with selected demographic and work experience variables. Finally, feedback on of the use of text messaging was obtained.

RESULT

Of 119 participants, 61% (n = 72) responded to at least one text message. Logistic regression revealed that being a high school graduate and a brick and block mason significantly affected the odds of responding. Sixty-nine percent of apprentices agreed that text messages reinforced SAVE content.

CONCLUSION

Even though there was no training center requirement to respond, the high response rate suggests that text messaging can effectively be used to reinforce ergonomics and safety voice training for both knowledge and behavior. Practical Application: The prevalent use of text messaging creates opportunities to reinforce health and safety training and engage workers, especially for populations that may be at various locations over time such as construction sites. Instructors and practitioners should consider the utility of text messaging for supporting their training and safety programs.

Prevalence of work-related musculoskeletal pain in masonry apprentices

The construction industry, specifically masonry, reports more work-related musculoskeletal disorders (WMSD) rates than the general industry. Masonry apprentices are assumed to be healthy, yet may have WMSDs. The purpose of this study was to evaluate the prevalence of musculoskeletal symptoms (MSS), time loss, and healthcare use among apprentices. 183 brick and block masonry apprentices completed surveys on demographics, work history, MSS, and functional well-being. The prevalence of MSS was calculated by body region, time loss, and healthcare use. The relationship between MSS, and perceived global physical and mental health was assessed. Approximately 78% of apprentices reported MSS, most in several body regions. Low back and wrists/hands were most prevalent, although few missed work or sought healthcare. Lower functional health and well-being was reported. Apprentices reported MSS comparable to previous studies of journey-level masons. Apprenticeship programmes could integrate ergonomics education to help apprentices develop safety culture early in their careers. Practitioner Summary: New masonry workers (apprentices) are assumed to be healthy yet work-related musculoskeletal symptoms (MSS) may be common early in their career. The prevalence of MSS was assessed among apprentices. Approximately 78% of apprentices reported MSS, most in several body regions, comparable to journey-level masons. Abbreviations: WMSD: work-related musculoskeletal disorders; MSS: musculoskeletal symptoms; SAVE: SAfety voice for ergonomics; MNQ: modified nordic questionnaire; FTE: full-time equivalent; SF-12: short from-12v2.

Safety Voice for Ergonomics (SAVE): Evaluation of a masonry apprenticeship training program

BACKGROUND

Masons have a high rate of musculoskeletal disorders among construction workers and greater than all other industries. Viable solutions to musculoskeletal hazards have been identified by industry stakeholders, yet masons receive minimal ergonomics training. Apprentices, as the next generation of masons, need training and strategies to identify and speak up about ergonomic and safety issues on job sites. To fill this gap, our team developed the Safety Voice for Ergonomics (SAVE) training program.

METHODS

The interactive, 7-unit SAVE program was developed specifically for masonry brick and block apprentices. This innovative training contains detailed ergonomics lessons focusing on risk factors and solutions specific to this masonry craft. It also contains lessons that provide communication and problem solving strategies. Evaluation of SAVE employed a randomized control trial designed to assess the effectiveness of SAVE for apprentices over a six-month period.

RESULTS

Our findings demonstrated that compared to controls, SAVE trained apprentices used their safety voice more (P = .049) and had greater safety participation (P = .028). They adopted more ergonomic practices such as adjusting scaffolding (P = .016) and using better body postures (P = 042). Apprentices liked SAVE and indicated that it prompted them to change workplace safety behaviors.

CONCLUSIONS

SAVE is an effective program, providing needed ergonomic and safety communication training for workers as they begin their trade. The broad adoption of SAVE training by the masonry industry has the potential to empower apprentices, elevate the trade's safety culture, and ultimately reduce musculoskeletal disorders.

Assessment of Instrumental Activities of Daily Living in Older Adults with Subjective Cognitive Decline Using the Virtual Reality Functional Capacity Assessment Tool (VRFCAT)

BACKGROUND

Continuing advances in the understanding of Alzheimer's disease progression have inspired development of disease-modifying therapeutics intended for use in preclinical populations. However, identification of clinically meaningful cognitive and functional outcomes for individuals who are, by definition, asymptomatic remains a significant challenge. Clinical trials for prevention and early intervention require measures with increased sensitivity to subtle deficits in instrumental activities of daily living (IADL) that comprise the first functional declines in prodromal disease. Validation of potential endpoints is required to ensure measure sensitivity and reliability in the populations of interest.

OBJECTIVES

The present research validates use of the Virtual Reality Functional Capacity Assessment Tool (VRFCAT) for performance-based assessment of IADL functioning in older adults (age 55+) with subjective cognitive decline.

DESIGN

Cross-sectional validation study.

SETTING

All participants were evaluated on-site at NeuroCog Trials, Durham, NC, USA.

PARTICIPANTS

Participants included 245 healthy younger adults ages 20-54 (131 female), 247 healthy older adults ages 55-91 (151 female) and 61 older adults with subjective cognitive decline (SCD) ages 56-97 (45 female).

MEASURES

Virtual Reality Functional Capacity Assessment Tool; Brief Assessment of Cognition App; Alzheimer's Disease Cooperative Study Prevention Instrument Project - Mail-In Cognitive Function Screening Instrument; Alzheimer's Disease Cooperative Study Instrumental Activities of Daily Living - Prevention Instrument, University of California, San Diego Performance-Based Skills Assessment - Validation of Intermediate Measures; Montreal Cognitive Assessment; Trail Making Test- Part B.

RESULTS

Participants with SCD performed significantly worse than age-matched normative controls on all VRFCAT endpoints, including total completion time, errors and forced progressions (p≤0001 for all, after Bonferonni correction). Consistent with prior findings, both groups performed significantly worse than healthy younger adults (age 20-54). Participants with SCD also performed significantly worse than controls on objective cognitive measures. VRFCAT performance was strongly correlated with cognitive performance. In the SCD group, VRFCAT performance was strongly correlated with cognitive performance across nearly all tests with significant correlation coefficients ranging from 0.3 to 0.7; VRFCAT summary measures all had correlations greater than r=0.5 with MoCA performance and BAC App Verbal Memory (p<0.01 for all).

CONCLUSIONS

Findings suggest the VRFCAT provides a sensitive tool for evaluation of IADL functioning in individuals with subjective cognitive decline. Strong correlations with cognition across groups suggest the VRFCAT may be uniquely suited for clinical trials in preclinical AD, as well as longitudinal investigations of the relationship between cognition and function.

Tuning the endothelial response: differential release of exocytic cargos from Weibel-Palade bodies

Essentials Endothelial activation initiates multiple processes, including hemostasis and inflammation. The molecules that contribute to these processes are co-stored in secretory granules. How can the cells control release of granule content to allow differentiated responses? Selected agonists recruit an exocytosis-linked actin ring to boost release of a subset of cargo.

SUMMARY

Background Endothelial cells harbor specialized storage organelles, Weibel-Palade bodies (WPBs). Exocytosis of WPB content into the vascular lumen initiates primary hemostasis, mediated by von Willebrand factor (VWF), and inflammation, mediated by several proteins including P-selectin. During full fusion, secretion of this large hemostatic protein and smaller pro-inflammatory proteins are thought to be inextricably linked. Objective To determine if secretagogue-dependent differential release of WPB cargo occurs, and whether this is mediated by the formation of an actomyosin ring during exocytosis. Methods We used VWF string analysis, leukocyte rolling assays, ELISA, spinning disk confocal microscopy, high-throughput confocal microscopy and inhibitor and siRNA treatments to demonstrate the existence of cellular machinery that allows differential release of WPB cargo proteins. Results Inhibition of the actomyosin ring differentially effects two processes regulated by WPB exocytosis; it perturbs VWF string formation but has no effect on leukocyte rolling. The efficiency of ring recruitment correlates with VWF release; the ratio of release of VWF to small cargoes decreases when ring recruitment is inhibited. The recruitment of the actin ring is time dependent (fusion events occurring directly after stimulation are less likely to initiate hemostasis than later events) and is activated by protein kinase C (PKC) isoforms. Conclusions Secretagogues differentially recruit the actomyosin ring, thus demonstrating one mechanism by which the prothrombotic effect of endothelial activation can be modulated. This potentially limits thrombosis whilst permitting a normal inflammatory response. These results have implications for the assessment of WPB fusion, cargo-content release and the treatment of patients with von Willebrand disease.

Unmeasured costs of haemophilia: the economic burden on families with children with haemophilia

INTRODUCTION AND OBJECTIVES

Although economic evaluations of haemophilia-related care have highlighted both the health care payer and societal perspectives, the costs to families with children with haemophilia have not been examined. This study determined the costs incurred by families of children with haemophilia, attending a haemophilia treatment centre (HTC), servicing a large geographical area in Eastern Canada.

METHODS

Families recorded all direct and indirect costs associated with haemophilia-related care for a year. Costs incurred to receive care at the HTC and local health care centres were compared. The relationship between distance to the HTC and costs was modelled using linear regression.

RESULTS

Participants included 31/45 children (68%) from 27 families attending the HTC. Median age was 12 years (range: 0.5-17 years); 24/31 (77%) had severe haemophilia. The median distance to the HTC and local health care facility was 230 km (range: 7-600 km) and 33.5 km (range: 2-400 km) respectively. Due to this difference in distance, 23/31 (74%) children do not attend the HTC for management of acute haemorrhage. The median annual total cost per family to attend the HTC is $775.93 (range: $200.00-$5741.00). The total cost to attend the HTC increases by $2.16 (95% CI 1.24-3.9) per kilometer from the HTC. The median total annual cost of haemophilia-related care per family is $1222.50 (range: $396.00-$8037.00).

CONCLUSION

Families incur high costs related to haemophilia care. The distance to the HTC is a barrier to care. Improving access to HTCs is paramount in improving haemophilia-related outcomes.

Preliminary evidence for biologic activity of toceranib phosphate (Palladia(®)) in solid tumours

The purpose of this study was to provide an initial assessment of the potential biologic activity of toceranib phosphate (Palladia®, Pfizer Animal Health, Madison, NJ, USA) in select solid tumours in dogs. Cases in which toceranib was used to treat dogs with apocrine gland anal sac adenocarcinoma (AGASACA), metastatic osteosarcoma (OSA), thyroid carcinoma, head and neck carcinoma and nasal carcinoma were included. Clinical benefit (CB) was observed in 63/85 (74%) dogs including 28/32 AGASACA [8 partial response (PR), 20 stable disease (SD)], 11/23 OSAs (1 PR and 10 SD), 12/15 thyroid carcinomas (4 PR and 8 SD), 7/8 head and neck carcinomas [1 complete response (CR), 5 PR and 1 SD] and 5/7 (1 CR and 4 SD) nasal carcinomas. For dogs experiencing CB, the median dose of toceranib was 2.8 mg kg(-1) , 36/63 (58.7%) were dosed on a Monday/Wednesday/Friday basis and 47/63 (74.6%) were treated 4 months or longer. Although these data provide preliminary evidence that toceranib exhibits CB in dogs with certain solid tumours, future prospective studies are necessary to define its true activity.

Immunogenicity and serotype-specific efficacy of a 9-valent pneumococcal conjugate vaccine (PCV-9) determined during an efficacy trial in The Gambia

This study aimed to determine the immunogenicity of a 9-valent pneumococcal conjugate vaccine (PCV-9) in a subgroup of Gambian children enrolled in a large vaccine efficacy trial. To place the antibody results in context, in this paper we also report previously unpublished data on serotype-specific clinical vaccine efficacy from the main trial. In the sub-study, a single 2-4 ml venous blood specimen was collected from 212 Gambian children 4-6 weeks after the administration of a third dose of PCV-9 or placebo. IgG antibodies to pneumococcal serotype 1, 4, 5, 6B, 9V, 14, 18C, 19F and 23F polysaccharides were measured by ELISA. The proportions of infants with antibody concentrations above 0.2, 0.35 and 1.0 microg/ml, and the geometric mean concentrations (GMCs) of anti-pneumococcal polysaccharide antibodies were substantially higher for each serotype in children who received three doses of PCV-9 than those in the placebo group. Among PCV-9 recipients, GMCs ranged between 2.61 and 11.09 microg/ml with the highest being against serotype 14 and the lowest against 9V polysaccharide. The estimated overall protective antibody level for all nine serotypes, based on the vaccine efficacy against vaccine-type invasive pneumococcal disease (IPD) of 77% (95% CI: 51, 90) observed in the trial, was 2.3 microg/ml (95% CI: 1.0, 5.0). The PCV-9 studied was immunogenic in a Gambian population where it was also found to be efficacious.

Efficacy of nine-valent pneumococcal conjugate vaccine against pneumonia and invasive pneumococcal disease in The Gambia: randomised, double-blind, placebo-controlled trial

BACKGROUND

Pneumonia is estimated to cause 2 million deaths every year in children. Streptococcus pneumoniae is the most important cause of severe pneumonia. We aimed to assess the efficacy of a nine-valent pneumococcal conjugate vaccine in children.

METHODS

We undertook a randomised, placebo-controlled, double-blind trial in eastern Gambia. Children age 6-51 weeks were randomly allocated three doses of either pneumococcal conjugate vaccine (n=8718) or placebo (8719), with intervals of at least 25 days between doses. Our primary outcome was first episode of radiological pneumonia. Secondary endpoints were clinical or severe clinical pneumonia, invasive pneumococcal disease, and all-cause admissions. Analyses were per protocol and intention to treat.

FINDINGS

529 children assigned vaccine and 568 allocated placebo were not included in the per-protocol analysis. Results of per-protocol and intention-to-treat analyses were similar. By per-protocol analysis, 333 of 8189 children given vaccine had an episode of radiological pneumonia compared with 513 of 8151 who received placebo. Pneumococcal vaccine efficacy was 37% (95% CI 27-45) against first episode of radiological pneumonia. First episodes of clinical pneumonia were reduced overall by 7% (95% CI 1-12). Efficacy of the conjugate vaccine was 77% (51-90) against invasive pneumococcal disease caused by vaccine serotypes, 50% (21-69) against disease caused by all serotypes, and 15% (7-21) against all-cause admissions. We also found an efficacy of 16% (3-28) against mortality. 110 serious adverse events arose in children given the pneumococcal vaccine compared with 131 in those who received placebo.

INTERPRETATION

In this rural African setting, pneumococcal conjugate vaccine has high efficacy against radiological pneumonia and invasive pneumococcal disease, and can substantially reduce admissions and improve child survival. Pneumococcal conjugate vaccines should be made available to African infants.

Genetic mapping of genes conferring permethrin resistance in the malaria vector, Anopheles gambiae

Resistance to permethrin in an East African population of the major malaria vector, Anopheles gambiae is multifactorial. A mutated sodium channel allele and enhanced insecticide metabolism contribute to the resistance phenotype. We used microsatellite markers to scan the genome for quantitative trait loci (QTL) associated with permethrin resistance. Two major and one minor QTL were identified. The first QTL, rtp1, colocalizes with the sodium channel gene on chromosome 2L thus further supporting the importance of mutations in this gene in conferring permethrin resistance. The second two loci are located on the third chromosome and one of these, rtp2, flanks a large cluster of cytochrome P450 genes. Further detailed mapping of these regions will help elucidate the molecular mechanisms of metabolic resistance to insecticides.

Sharing laughter: the humour of pre-school children with Down syndrome

Humour and laughter have often been portrayed as fundamentally cultural and social phenomena. They can be used to tell us about children's ability to engage socially and to understand others, but have rarely been explored for this purpose. The present paper summarises the results of a study of simple forms of humour in children with Down syndrome and with autism, two groups which are reported to differ in their sociality and interpersonal understanding. Sixteen children with Down syndrome and 19 children with autism, matched on non-verbal mental age, participated in a cross-sectional study. Parental reports and video-tapes of naturalistic interaction between parents and children were analysed to show that although there were no overall differences in the presence or frequency of child or parent laughter between the two groups, there were differences in what sorts of events were more likely to prompt child laughter, the extent to which child laughter was shared, and how the children responded to others' laughter. The children with Down syndrome were more likely than the children with autism to laugh at funny faces and socially inappropriate acts and less likely to laugh in strange or inexplicable situations, and more likely to laugh at shared events. They also responded to others' laughter with attention or smiles more, and tried to re-elicit it through acts of clowning. Children with Down syndrome are thus active participants in humour and laughter, sharing it at both an emotional and a cultural level.

Both emerin and lamin C depend on lamin A for localization at the nuclear envelope

Physical interactions between lamins and emerin were investigated by co-immunoprecipitation of in vitro translated proteins. Emerin interacted with in vitro translated lamins A, B1 and C in co-immunprecipitation reactions. Competition reactions revealed a clear preference for interactions between emerin and lamin C. Structural associations between lamins and emerin were investigated in four human cell lines displaying abnormal expression and/or localisation of lamins A and C. In each cell line absence of lamins A and C from the nuclear envelope (NE) was correlated with mis-localisation of endogenous and exogenous emerin to the ER. In two cell lines that did not express lamin A but did express lamin C, lamin C as well as emerin was mis-localised. When GFP-lamin A was expressed in SW13 cells (which normally express only very low levels of endogenous lamin A and mis-localise endogenous emerin and lamin C), all three proteins became associated with the NE. When GFP-lamin C was expressed in SW13 cells neither the endogenous nor the exogenous lamin C was localised to the NE and emerin remained in the ER. Finally, lamins A and C were selectively eliminated from the NE of HeLa cells using a dominant negative mutant of lamin B1. Elimination of these lamins from the lamina led to the accumulation of emerin as aggregates within the ER. Our data suggest that lamin A is essential for anchorage of emerin to the inner nuclear membrane and of lamin C to the lamina.

An analysis of bacteriocins produced by lactic acid bacteria isolated from malted barley

AIMS

The aim of this study was to perform a detailed characterization of bacteriocins produced by lactic acid bacteria (LAB) isolated from malted barley.

METHODS AND RESULTS

Bacteriocin activities produced by eight LAB, isolated from various types of malted barley, were purified to homogeneity by ammonium sulphate precipitation, cation exchange, hydrophobic interaction and reverse-phase liquid chromatography. Molecular mass analysis and N-terminal amino acid sequencing of the purified bacteriocins showed that four non-identical Lactobacillus sakei strains produced sakacin P, while four Leuconostoc mesenteroides strains were shown to produce bacteriocins highly similar or identical to leucocin A, leucocin C or mesenterocin Y105. Two of these bacteriocin-producing strains, Lb. sakei 5 and Leuc. mesenteroides 6, were shown to produce more than one bacteriocin. Lactobacillus sakei 5 produced sakacin P as well as two novel bacteriocins, which were termed sakacin 5X and sakacin 5T. The inhibitory spectrum of each purified bacteriocin was analysed and demonstrated that sakacin 5X was capable of inhibiting the widest range of beer spoilage organisms.

CONCLUSION

All bacteriocins purified in this study were class II bacteriocins. Two of the bacteriocins have not been described previously in the literature while the remaining purified bacteriocins have been isolated from environments other than malted barley.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study represents a thorough analysis of bacteriocin-producing LAB from malt and demonstrates, for the first time, the variety of previously identified and novel inhibitory peptides produced by isolates from this environment. It also highlights the potential of these LAB cultures to be used as biological controlling agents in the brewing industry.

A school and community outbreak of tuberculosis in Auckland

AIM

To describe a school and community outbreak of tuberculosis in South Auckland in 1997/8.

METHODS

Cases were diagnosed according to national guidelines at Middlemore, Green Lane and Starship Hospitals. Public health follow-up was conducted by Auckland Healthcare.

RESULTS

Twelve cases were diagnosed during the outbreak. Nine cases were from the same South Auckland secondary school; six reported no association outside school. Three cases were in younger children who had close household contact with two of the school cases. Nine cases (including eight from the school) had identical Mycobacterium tuberculosis isolates on restriction fragment length polymorphism testing. No microbiological culture was obtained from the three remaining cases. Contact investigation detected five of the cases. Chemoprophylaxis was prescribed for twenty-six school students, two adult staff, and nine household contacts.

CONCLUSION

This is the first published account of a tuberculosis outbreak in a New Zealand school setting for decades. Recognition of the outbreak was delayed. DNA fingerprinting played a valuable role in the investigation. The source case may have been a school student. The social impact of the outbreak and preventability with routine adolescent BCG vaccination are discussed.

Aldehyde oxidase is coamplified with the World's most common Culex mosquito insecticide resistance-associated esterases

The evolution and spread of insecticide resistance is an important factor in human disease prevention and crop protection. The mosquito Culex quinquefasciatus is the main vector of the disease filariasis and a member of a species complex which is a common biting nuisance worldwide. The common insecticide resistance mechanism in this species involves germline amplification of the esterases estalpha21 and estbeta21. This amplification has arisen once and rapidly spread worldwide. Less common and more variable resistance phenotypes involve coamplification of estalpha3 and estbeta1, or individual amplification of a single estbeta1, different alleles of the same estalpha and estbeta gene loci. Estalpha21 and estbeta21 are on the same large fragment of amplified DNA (amplicon) 2.7 kb apart. We have now shown that this amplicon contains another full-length gene immediately 5' of estalpha21 which codes for a molybdenum-containing hydroxylase, with highest homology to aldehyde oxidase (AO) from other organisms. The full-length putative AO gene is not present on the estalpha3/estbeta1 or estbeta1 amplicons, but multiple truncated 5' ends of this gene are present around the presumed estalpha3/estbeta1 amplicon breakpoint. Polymerase chain reaction (PCR) analysis of insecticide-susceptible genomic DNA demonstrated that a different allele of the putative AO gene in its non-amplified form is immediately 5' of estalpha. The 'AO' gene on the estalpha21/estbeta21 amplicon is expressed and resistant insects have greater AO activity. This AO activity is sensitive to inhibition by an aldehyde-containing herbicide and pesticide. This enzyme may confer a selective advantage to these insects in the presence of insecticide, as AO in mammals is believed to be important in the detoxification process of several environmental pollutants.

Amplification of a serine esterase gene is involved in insecticide resistance in Sri Lankan Culex tritaeniorhynchus

Culex tritaeniorhynchus, the major vector of Japanese encephalitis in Sri Lanka, is resistant to organophosphorus insecticides, with a 10-fold resistance ratio at the LC50 for chlorpyrifos, and a high heterogenelty factor in the insect field population. The major mechanism of resistance in this species, as in the mosquito C. quinquefasciatus, is elevation of esterase activity. Basic biochemical, immunological and molecular analysis suggests that the C. tritaeniorhynchus CtrEstbeta1 gene is orthologous to the C. quinquefasciatus amplified Estbetas. The Estbeta2(1) antiserum cross-reacts strongly with CtrEstbeta1(1). Its corresponding cDNA, over the 545 base pairs sequenced, has approximately 84% identity with the various C. quinquefasciatus Estbetas. The gene is amplified in C. tritaeniorhynchus. Amplification of the same esterase in two independent species, along with multiple amplification events involving this esterase gene in C. quinquefasciatus suggests that the location of this gene within the genome predisposes it to amplification.

Why are there so few resistance-associated mutations in insecticide target genes?

The genes encoding the three major targets of conventional insecticides are: Rdl, which encodes a gamma-aminobutyric acid receptor subunit (RDL); para, which encodes a voltage-gated sodium channel (PARA); and Ace, which encodes insect acetylcholinesterase (AChE). Interestingly, despite the complexity of the encoded receptors or enzymes, very few amino acid residues are replaced in different resistant insects: one within RDL, two within PARA and three or more within AChE. Here we examine the possible reasons underlying this extreme conservation by looking at the aspects of receptor and/or enzyme function that may constrain replacements to such a limited number of residues.

Investigation of the relationship between farrowing environment, sex steroid concentrations and maternal aggression in gilts

Maternal oestrogen and progesterone have been shown to be important in the initiation of maternal behaviour. Thirty-three Large White x Landrace gilts, housed in groups during pregnancy, were observed and aggressive interactions recorded. Individuals had jugular catheters implanted 14.5 (s.e. 0.34) days before their expected parturition date (EPD). Five days before EPD gilts were randomly allocated and moved to either a conventional farrowing crate (C; without straw, 16 gilts) or a pen (P; 2.1 x 3.1 m2; with straw bedding, 17 gilts). Blood samples were taken at frequencies determined by the proximity to farrowing onset. Piglets were removed at birth and returned 2 h after placental expulsion. The reaction of each gilt to her piglets was monitored. Gilts savaging piglets were sedated with azaperone (n = 8). There was no overall effect of farrowing environment on oestradiol and progesterone concentrations. The pre-farrowing ratio of progesterone to oestradiol was higher for (P) gilts (0.45 vs. 0.25, (P) vs. (C); S.E.D. 0.085, P < 0.05) as was their overall maximum oestradiol level (3.39 vs. 2.29 ng/ml, (P) vs. (C); S.E.D. 0.39, P < 0.01). In contrast to progesterone, oestradiol patterns varied considerably between individuals. Dominance rank value during pregnancy, but not levels of aggression, correlated positively to pre-farrowing oestradiol concentrations. Treatment with azaperone was not related to farrowing environment, piglet weight or litter size. Azaperone treated gilts showed a higher pre-farrowing oestradiol to progesterone ratio (0.55 vs. 0.29, +/- azaperone; S.E.D. 0.10, P < 0.05), significantly higher levels of oestradiol post-partum (0.7 vs. 0.19 ng/ml, +/- azaperone; S.E.D. 0.20, P < 0.001) and significantly lower levels of aggression during pregnancy (1.68 vs. 2.23 aggressive interactions/h, +/- azaperone; S.E.D. 0.15, P < 0.001). The results indicate that there are no major effects of farrowing environment on sex steroid concentrations. Maternal aggression under these conditions appears to be negatively related to aggression during pregnancy, but this is not reflected in plasma concentrations of sex steroids around parturition.

Resistance to insecticides in insect vectors of disease: est alpha 3, a novel amplified esterase associated with amplified est beta 1 from insecticide resistant strains of the mosquito Culex quinquesfasciatus

Vector control programmes in many countries face the dual problems of parasite drug resistance and insecticide resistance in the insect vectors of the disease. Here we report for the first time a new esterase-based insecticide resistance mechanism in the filariasis vector Culex quinquefasciatus. The field collected COL strain of C. quinquefasciatus from Columbia was heterogeneous for organophosphorus insecticide resistance. On native polyacrylamide gels it had an elevated beta-naphthyl acetate specific esterase with the same Rf as that for the Est beta 1s involved in insecticide resistance in other strains of this mosquito species. After five generations of temephos insecticide selection, both the esterase specific activity with p-nitrophenyl acetate and the temephos LC50 values were increased, suggesting that elevation of esterase activity was the underlying mechanism of resistance. Western blots with antisera raised to Est alpha 2(1) and Est beta 2(1) from C. quinquefasciatus indicated that the COL strain had an elevated Est alpha 3 enzyme which co-migrated on native gels with Est beta 1. Southern blots indicated that an est alpha 3 gene was amplified in the COL strain and a Cuban mosquito strain (MRes), although the restriction digest patterns of the est beta 1 genes in these two strains are different. In contrast, the Californian TEMR strain, with the amplified est beta 1(1) gene, had no associated elevated Est alpha. Restriction digest patterns for COL and TEMR DNA suggest that they contain an identical est beta 1(1) gene, but our data suggest that the est alpha 3 gene occurs on the same amplicon as an est beta 1 gene although the genes are probably > 10 kb apart. Hence, either the COL strain has two est beta 1 genes or the est beta 1(1) amplicon in TEMR has been disrupted at some stage during the long colonisation of this strain and the amplified est alpha has been lost.

Site-directed mutagenesis of an acetylcholinesterase gene from the yellow fever mosquito Aedes aegypti confers insecticide insensitivity

Insecticide resistance is a serious problem facing the effective control of insect vectors of disease. Insensitive acetylcholinesterase (AChE) confers resistance to organophosphorus (OP) and carbamate insecticides and is a widespread resistance mechanism in vector mosquitoes. Although the point mutations that underlie AChE insensitivity have been described from Drosophila, the Colorado potato beetle, and house flies, no resistance associated mutations have been documented from mosquitoes to date. We are therefore using a cloned acetylcholinesterase gene from the yellow fever mosquito Aedes aegypti as a model in which to perform site directed mutagenesis in order to understand the effects of potential resistance associated mutations. The same resistance associated amino-acid replacements as found in other insects also confer OP and carbamate resistance to the mosquito enzyme. Here we describe the levels of resistance conferred by different combinations of these mutations and the effects of these mutations on the kinetics of the AChE enzyme. Over-expression of these constructs in baculovirus will facilitate purification of each of the mutant enzymes and a more detailed analysis of their associated inhibition kinetics.

Co-amplification explains linkage disequilibrium of two mosquito esterase genes in insecticide-resistant Culex quinquefasciatus

The mosquito Culex quinquefasciatus (Say) is a vector of human disease and a world-wide biting nuisance. Organophosphorus insecticides (OPs) have been widely used to control C. quinquefasciatus populations and this has led to the emergence of OP-resistance. Predominantly, resistance is caused by increased production of two non-specific carboxylesterases, Estalpha2(1) and Estbeta2(1). Increased abundance of these esterases is associated with the amplification of their respective genes. The estalpha21 and estbeta21 genes were cloned and sequenced from OP-resistant Sri Lankan C. quinquefasciatus; the two adjacent genes are in a head to head configuration, within a single amplification unit (amplicon). The homology between the two genes suggests that they arose from an ancient duplication event. The two genes have different numbers of exons (estalpha21 has seven and estbeta21 has four); however, the intron/exon boundaries in estbeta21 are all conserved in estalpha21. The two genes are co-amplified in three other mosquito strains with the elevated Estalpha2(1)/Estbeta2(1) phenotype. Their complete linkage disequilibrium is explained by the location of the two genes involved in resistance within a single amplicon. In insecticide-susceptible C. quinquefasciatus, the non-amplified estalpha and estbeta gene loci are also found in a similar head to head configuration, but the size of the intergenic non-coding region is approx. 1 kb less than in the amplicon. The smaller intergenic spacer is also found in a strain with amplified estbeta11, which suggests that extensive laboratory selection for this amplified esterase has not eliminated the non-amplified genes. The intergenic spacer regions have been subcloned and sequenced. They contain numerous possible TATA boxes, promoters and a number of possible regulatory elements with high homology to the consensus sequence of the Barbie box. These latter putative regulatory elements are more numerous in the larger intergenic spacer, which differs from the non-amplified spacer by two large (>>420 bp) and one small (5 bp) insertions.