Endogenous CO2 ice mixture on the surface of Europa and no detection of plume activity

Jupiter's moon Europa has a subsurface ocean beneath an icy crust. Conditions within the ocean are unknown, and it is unclear whether it is connected to the surface. We observed Europa with the James Webb Space Telescope (JWST) to search for active release of material by probing its surface and atmosphere. A search for plumes yielded no detection of water, carbon monoxide, methanol, ethane, or methane fluorescence emissions. Four spectral features of carbon dioxide (CO2) ice were detected; their spectral shapes and distribution across Europa's surface indicate that the CO2 is mixed with other compounds and concentrated in Tara Regio. The 13CO2 absorption is consistent with an isotopic ratio of 12C/13C = 83 ± 19. We interpret these observations as indicating that carbon is sourced from within Europa.

Psychological and psychosocial aspects of major trauma care: A survey of current practice across UK and Ireland

Introduction

Psychological and psychosocial impacts of major trauma, defined as any injury that has the potential to be life-threatening and/or life changing, are common, far-reaching and often enduring. There is evidence that these aspects of major trauma care are often underserved. The aim of this research was to gain insight into the current provision and operationalisation of psychological and psychosocial aspects of major trauma care across the UK and Ireland.

Methods

A cross-sectional online survey, open to health professionals working in major trauma network hospitals was undertaken. The survey had 69 questions across six sections: Participant Demographics, Psychological First Aid, Psychosocial Assessment and Care, Assessing and Responding to Distress, Clinical Psychology Services, and Major Trauma Keyworker (Coordinator) Role.

Results

There were 102 respondents from across the regions and from a range of professional groups. Survey findings indicate a lack of formalised systems to assess, respond and evaluate psychological and psychosocial aspects of major trauma care, most notably for patients with lower-level distress and psychosocial support needs, and for trauma populations that don't reach threshold for serious injury or complex health need. The findings highlight the role of major trauma keyworkers (coordinators) in psychosocial aspects of care and that although major trauma clinical psychology services are increasingly embedded, many lack the capacity to meet demand.

Conclusion

Neglecting psychological and psychosocial aspects of major trauma care may extend peritraumatic distress, result in preventable Years Lived with Disability and widen post-trauma health inequalities. A stepped psychological and psychosocial care pathway for major trauma patients and their families from the point of injury and continuing as they move through services towards recovery is needed. Research to fulfil knowledge gaps to develop and implement such a model for major trauma populations should be prioritised along with the development of corresponding service specifications for providers.

Correction: Standen et al. Aboriginal Population and Climate Change in Australia: Implications for Health and Adaptation Planning. Int. J. Environ. Res. Public Health 2022, 19, 7502

In the original publication [...].

Aboriginal Population and Climate Change in Australia: Implications for Health and Adaptation Planning

The health impacts of climate are widely recognised, and extensive modelling is available on predicted changes to climate globally. The impact of these changes may affect populations differently depending on a range of factors, including geography, socioeconomics and culture. This study reviewed current evidence on the health risks of climate change for Australian Aboriginal populations and linked Aboriginal demographic data to historical and projected climate data to describe the distribution of climate-related exposures in Aboriginal compared to non-Aboriginal populations in New South Wales (NSW), Australia. The study showed Aboriginal populations were disproportionately exposed to a range of climate extremes in heat, rainfall and drought, and this disproportionate exposure was predicted to increase with climate change over the coming decades. Aboriginal people currently experience higher rates of climate-sensitive health conditions and socioeconomic disadvantages, which will impact their capacity to adapt to climate change. Climate change may also adversely affect cultural practices. These factors will likely impact the health and well-being of Aboriginal people in NSW and inhibit measures to close the gap in health between Aboriginal and non-Aboriginal populations. Climate change, health and equity need to be key considerations in all policies at all levels of government. Effective Aboriginal community engagement is urgently needed to develop and implement climate adaptation responses to improve health and social service preparedness and secure environmental health infrastructure such as drinking water supplies and suitably managed social housing. Further Aboriginal-led research is required to identify the cultural impacts of climate change on health, including adaptive responses based on Aboriginal knowledges.

There and back again; historical perspective and future directions for Vaccinium breeding and research studies

The genus Vaccinium L. (Ericaceae) contains a wide diversity of culturally and economically important berry crop species. Consumer demand and scientific research in blueberry (Vaccinium spp.) and cranberry (Vaccinium macrocarpon) have increased worldwide over the crops' relatively short domestication history (~100 years). Other species, including bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), and ohelo berry (Vaccinium reticulatum) are largely still harvested from the wild but with crop improvement efforts underway. Here, we present a review article on these Vaccinium berry crops on topics that span taxonomy to genetics and genomics to breeding. We highlight the accomplishments made thus far for each of these crops, along their journey from the wild, and propose research areas and questions that will require investments by the community over the coming decades to guide future crop improvement efforts. New tools and resources are needed to underpin the development of superior cultivars that are not only more resilient to various environmental stresses and higher yielding, but also produce fruit that continue to meet a variety of consumer preferences, including fruit quality and health related traits.

Sediment and nutrient sources and sinks in a wet-dry tropical catchment draining to the Great Barrier Reef

Many tropical river systems have altered water quality due to human land use, impacting the biodiversity of freshwater and coastal ecosystems. Long-term, catchment-scale monitoring is needed to understand pollutant sources, controls, and trends. This 12-year study monitored baseflow and flood event nutrient and sediment concentrations, and estimated sediment loads across the Normanby Basin in northern Australia. Suspended sediment concentrations and yields were highest in upper catchment areas where cattle grazing occurred on erosion-prone sodic soils. Mid- and lower catchment rivers and floodplains were a sink for sediments and nutrients, trapping around 75% of suspended sediments during events. Clays (<4 μm) were preferentially transported to the estuary, with an estimated 46% sediment delivery ratio. In the estuary, suspended sediment concentrations were influenced by tidal resuspension processes and there were significant sources of DIN. These findings can help prioritise land management investments for the protection of Great Barrier Reef and freshwater ecosystems.

Evaluation of a Dog Population Management Intervention: Measuring Indicators of Impact

Dogs are important companions to people but can also present challenges to health and safety of communities if their populations are not effectively managed. Dog population management (DPM) is often undertaken by individual dog owners; however, some communities require additional DPM interventions, especially when veterinary services are unavailable or underutilised. This study evaluated the effectiveness of a DPM intervention conducted in 13 communities between September 2016 and November 2019 and assessed the utility of routinely collected data-program metrics and secondary data collected by local governments-to measure indicators of impacts. The intervention resulted in significant increases in the proportion of dogs presenting that were microchipped and surgically sterilised in participating communities. The intervention also resulted in significant reductions in dog attack incidents and euthanasia of dogs in council pounds in communities that participated for three or more years. Ongoing monitoring and evaluation of DPM interventions is critical to determine if impacts are being achieved. This study demonstrates the potential benefits of a DPM intervention for community safety and dog welfare and highlights the utility of routinely collected data. We also suggest benchmarks for indicators of community engagement to guide planning and monitoring of similar interventions.

In silico study directed towards identification of the key structural features of GyrB inhibitors targeting MTB DNA gyrase: HQSAR, CoMSIA and molecular dynamics simulations

Mycobacterium tuberculosis DNA gyrase subunit B (GyrB) has been identified as a promising target for rational drug design against fluoroquinolone drug-resistant tuberculosis. In this study, we attempted to identify the key structural feature for highly potent GyrB inhibitors through 2D-QSAR using HQSAR, 3D-QSAR using CoMSIA and molecular dynamics (MD) simulations approaches on a series of thiazole urea core derivatives. The best HQSAR and CoMSIA models based on IC₅₀ and MIC displayed the structural basis required for good activity against both GyrB enzyme and mycobacterial cell. MD simulations and binding free energy analysis using MM-GBSA and waterswap calculations revealed that the urea core of inhibitors has the strongest interaction with Asp79 via hydrogen bond interactions. In addition, cation-pi interaction and hydrophobic interactions of the R₂ substituent with Arg82 and Arg141 help to enhance the binding affinity in the GyrB ATPase binding site. Thus, the present study provides crucial structural features and a structural concept for rational design of novel DNA gyrase inhibitors with improved biological activities against both enzyme and mycobacterial cell, and with good pharmacokinetic properties and drug safety profiles.

Two Loci, RiAF3 and RiAF4, Contribute to the Annual-Fruiting Trait in Rubus

Most Rubus species have a biennial cycle of flowering and fruiting with an intervening period of winter dormancy, in common with many perennial fruit crops. Annual-fruiting (AF) varieties of raspberry (Rubus idaeus and Rubus occidentalis L.) and blackberry (Rubus subgenus Rubus) are able to flower and fruit in one growing season, without the intervening dormant period normally required in biennial-fruiting (BF) varieties. We used a red raspberry (R. idaeus) population segregating for AF obtained from a cross between NC493 and 'Chilliwack' to identify genetic factors controlling AF. Genotyping by sequencing (GBS) was used to generate saturated linkage maps in both parents. Trait mapping in this population indicated that AF is controlled by two newly identified loci (RiAF3 and RiAF4) located on Rubus linkage groups (LGs) 3 and 4. The location of these loci was analyzed using single-nucleotide polymorphism (SNP) markers on independent red raspberry and blackberry populations segregating for the AF trait. This confirmed that AF in Rubus is regulated by loci on LG 3 and 4, in addition to a previously reported locus on LG 7. Comparative RNAseq analysis at the time of floral bud differentiation in an AF and a BF variety revealed candidate genes potentially regulating the trait.

Close Cassini flybys of Saturn’s ring moons Pan, Daphnis, Atlas, Pandora, and Epimetheus

Saturn’s main ring system is associated with a set of small moons that either are embedded within it or interact with the rings to alter their shape and composition. Five close flybys of the moons Pan, Daphnis, Atlas, Pandora, and Epimetheus were performed between December 2016 and April 2017 during the ring-grazing orbits of the Cassini mission. Data on the moons’ morphology, structure, particle environment, and composition were returned, along with images in the ultraviolet and thermal infrared. We find that the optical properties of the moons’ surfaces are determined by two competing processes: contamination by a red material formed in Saturn’s main ring system and accretion of bright icy particles or water vapor from volcanic plumes originating on the moon Enceladus.

In Situ Observations of Preferential Pickup Ion Heating at an Interplanetary Shock

Nonthermal pickup ions (PUIs) are created in the solar wind (SW) by charge-exchange between SW ions (SWIs) and slow interstellar neutral atoms. It has long been theorized, but not directly observed that PUIs should be preferentially heated at quasiperpendicular shocks compared to thermal SWIs. We present in situ observations of interstellar hydrogen (H^{+}) PUIs at an interplanetary shock by the New Horizons' Solar Wind Around Pluto (SWAP) instrument at ∼34  au from the Sun. At this shock, H^{+} PUIs are only a few percent of the total proton density but contain most of the internal particle pressure. A gradual reduction in SW flow speed and simultaneous heating of H^{+} SWIs is observed ahead of the shock, suggesting an upstream energetic particle pressure gradient. H^{+} SWIs lose ∼85% of their energy flux across the shock and H^{+} PUIs are preferentially heated. Moreover, a PUI tail is observed downstream of the shock, such that the energy flux of all H^{+} PUIs is approximately six times that of H^{+} SWIs. We find that H^{+} PUIs, including their suprathermal tail, contain almost half of the total downstream energy flux in the shock frame.

Identifying Critical Habitat for Australian Freshwater Turtles in a Large Regulated Floodplain: Implications for Environmental Water Management

Freshwater turtles face many threats, including habitat loss and river regulation reducing occupancy and contributing to population decline. Limited knowledge of hydrological conditions required to maintain viable turtle populations in large floodplain wetlands hinders effective adaptive management of environmental water in regulated rivers. We surveyed three turtle species over 4 years across the Lower Murrumbidgee River floodplain, a large wetland complex with a long history of water resource development. Using site and floodplain metrics and generalized linear models, within a Bayesian Model Averaging framework, we quantified the main drivers affecting turtle abundance. We also used a hierarchical modeling approach, requiring large sample sizes, quantifying possible environmental effects while accounting for detection probabilities of the eastern long-necked turtle (Chelodina longicollis). The three species varied in their responses to hydrological conditions and connectivity to the main river channel. Broad-shelled turtles (Chelodina expansa) and Macquarie River turtles (Emydura macquarii macquarii) had restricted distributions, centered on frequently inundated wetlands close to the river, whereas the eastern long-necked turtles were more widely distributed, indicating an ability to exploit variable habitats. We conclude that turtle communities would benefit from long-term management strategies that maintain a spatiotemporal mosaic of hydrological conditions. More specifically, we identified characteristics of refuge habitats and stress the importance of maintaining their integrity during dry periods. Neighboring habitats can be targeted during increased water availability years to enhance feeding and dispersal opportunities for freshwater turtles.

The human intestinal B-cell response

The intestinal immune system is chronically challenged by a huge plethora of antigens derived from the lumen. B-cell responses in organized gut-associated lymphoid tissues and regional lymph nodes that are driven chronically by gut antigens generate the largest population of antibody-producing cells in the body: the gut lamina propria plasma cells. Although animal studies have provided insights into mechanisms that underpin this dynamic process, some very fundamental differences in this system appear to exist between species. Importantly, this prevents extrapolation from mice to humans to inform translational research questions. Therefore, in this review we will describe the structures and mechanisms involved in the propagation, dissemination, and regulation of this immense plasma cell population in man. Uniquely, we will seek our evidence exclusively from studies of human cells and tissues.

Diversity of gut microflora is required for the generation of B cell with regulatory properties in a skin graft model

B cells have been reported to promote graft rejection through alloantibody production. However, there is growing evidence that B cells can contribute to the maintenance of tolerance. Here, we used a mouse model of MHC-class I mismatched skin transplantation to investigate the contribution of B cells to graft survival. We demonstrate that adoptive transfer of B cells prolongs skin graft survival but only when the B cells were isolated from mice housed in low sterility "conventional" (CV) facilities and not from mice housed in pathogen free facilities (SPF). However, prolongation of skin graft survival was lost when B cells were isolated from IL-10 deficient mice housed in CV facilities. The suppressive function of B cells isolated from mice housed in CV facilities correlated with an anti-inflammatory environment and with the presence of a different gut microflora compared to mice maintained in SPF facilities. Treatment of mice in the CV facility with antibiotics abrogated the regulatory capacity of B cells. Finally, we identified transitional B cells isolated from CV facilities as possessing the regulatory function. These findings demonstrate that B cells, and in particular transitional B cells, can promote prolongation of graft survival, a function dependent on licensing by gut microflora.

The role of palliative chemotherapy in hospitalized patients

BACKGROUND

Hospitalized patients with advanced cancer often have a poor performance status, which is considered a relative contraindication to cytotoxic chemotherapy. We investigated outcomes in hospitalized solid tumour oncology patients who received palliative chemotherapy (pct).

METHODS

With ethics approval, we performed a single-institution chart review of all patients hospitalized on our oncology unit who received pct between April 2008 and January 2010. Patient demographics, reasons for admission, cancer type, prior therapy, and administered chemotherapy were recorded. The primary endpoint was median survival from date of inpatient chemotherapy until death or last known follow up. We also investigated place of discharge and whether patients received additional therapy.

RESULTS

During the study period, 199 inpatients received pct. Median age was 61 years; 59% of the patients were women. Most had been admitted with dyspnea (31%) or pain (29%) as the dominant symptom. Common cancers represented were breast (23%), small-cell lung cancer (sclc, 22%), non-small-cell lung cancer (nsclc, 16%), and colorectal cancer (9%). Most patients (67%) were receiving first-line chemotherapy. Median overall survival duration was 4.5 months, and the 6-month survival rate was 41%. The longest and shortest survivals were seen in the sclc and nsclc groups (7.3 and 2.5 months respectively). Factors significantly associated with shorter survival were baseline hypoalbuminemia and therapy beyond the first line. In this cohort, 77% of patients were discharged home, and 72% received further chemotherapy.

CONCLUSIONS

Despite a short median survival, many patients are well enough to be discharged home and to receive further chemotherapy. The development of risk models to predict a higher chance of efficacy will have practical clinical utility.

Defective CD8+CD28+ regulatory T cell suppressor function in rheumatoid arthritis is restored by tumour necrosis factor inhibitor therapy

Balanced immunoregulatory networks are essential for maintenance of systemic tolerance. Disturbances in the homeostatic equilibrium between inflammatory mediators, immune regulators and immune effector cells are implicated directly in the pathogenesis of autoimmune diseases, including rheumatoid arthritis (RA). In this study we characterize the peripheral blood CD8(+) CD28(-) regulatory T cells (Treg) contribution to the immunoregulatory network in health and in RA. In health, CD8(+) CD28(-) Treg are suppressive but, unlike CD4(+) Treg , they function predominantly through the action of soluble mediators such as interleukin (IL)-10 and transforming growth factor (TGF)-β. Neutralization of TGF-β consistently reduced CD8(+) CD28(-) Treg suppressor function in vitro. RA, CD8(+) CD28(-) Treg are increased numerically, but have reduced expression of inducible co-stimulator (ICOS) and programmed death 1 (PD-1) compared to healthy or disease controls. They produce more IL-10 but autologous T cells express less IL-10R. This expression was found to be restored following in-vitro addition of a tumour necrosis factor inhibitor (TNFi). Deficiencies in both the CD8(+) CD28(-) Treg population and reduced sensitivity of the T responder cells impact upon their regulatory function in RA. TNFi therapy partially restores CD8(+) CD28(-) Treg ability in vivo and in vitro, despite the defects in expression of functionally relevant molecules by RA CD8(+) CD28(-) Treg compared to healthy controls. This study places CD8(+) CD28(-) Treg cells in the scheme of immune regulation alongside CD4(+) Treg cells, and highlights the importance of understanding impaired responsiveness to regulation that is common to these suppressor subsets and their restored function in response to TNFi therapy.

The effect of the oral contraceptive pill on the passive stiffness of the human gastrocnemius muscle in vivo

The aim of this investigation was to determine the effect of sustained monophasic oral contraceptive pill (MOCP) use on the in vivo passive stiffness of the gastrocnemius medialis (GM) muscle-tendon unit. Twenty four females volunteered for this study (age range 20-25 yrs); twelve participants had been taking the combined MOCP for a minimum of 12 months, and twelve participants, who had never taken the MOCP, formed a control group. Distal displacement of the GM myotendinous junction (MTJ) was measured during passive dorsiflexion at 2 Nm increments to 20 Nm, and at end range of motion using ultrasonography. In addition, GM MTJ displacement was measured at passive torques equivalent to 5, 10 and 15% of plantarflexion maximal voluntary contraction (MVC) torque, and relative to GM length. MOCP users had significantly greater GM MTJ displacement at all passive torques (P<0.01), reaching 40% more at 20 Nm; these displacements remained significantly different when MVC and GM length were accounted for (P<0.01). Passive muscle stiffness from 0-20 Nm was 31% less in MOCP users compared to non-users (P<0.01). In conclusion, based on the in vivo assessment of GM MTJ displacement, passive muscle stiffness is less in MOCP using females, compared to non-pill users.

Control of type 1 diabetes mellitus and shift work

BACKGROUND

People with type 1 diabetes may find diabetic control more difficult when working shifts.

AIMS

To investigate the proportion of people with type 1 diabetes in employment undertaking shift work and diabetic control as assessed by glycosylated haemoglobin (HbA1c) among individuals undertaking shift work compared to those not doing so.

METHODS

A postal questionnaire sent to all those aged 16-65 attending two city hospitals for type 1 diabetes care. HbA1c results were used to assess diabetic control.

RESULTS

Twenty-two per cent (296 of 1370 eligible patients) responded. Sixty-seven (23%) respondents were involved in shift work. Shift workers had higher mean HbA1c values than non-shift workers (9.02 versus 8.35; P < 0.01).

CONCLUSIONS

Poorer control of diabetes was associated with working shifts in this study. Occupational health practitioners should be aware of this association and be able to advise on management strategies to improve diabetic control while working shifts.

Translational Mini-Review Series on B cell subsets in disease. Transitional B cells in systemic lupus erythematosus and Sjögren's syndrome: clinical implications and effects of B cell-targeted therapies

Systemic lupus erythematosus (SLE) and Sjögren's syndrome are autoimmune disorders which are characterized by a disturbed B cell homeostasis which leads ultimately to dysfunction of various organs. One of the B cell subsets that appear in abnormal numbers is the population of transitional B cells, which is increased in the blood of patients with SLE and Sjögren's syndrome. Transitional B cells are newly formed B cells. In mice, transitional B cells undergo selection checks for unwanted specificity in the bone marrow and the spleen in order to eliminate autoreactive B cells from the circulating naive B cell population. In humans, the exact anatomical compartments and mechanisms of the specificity check-points for transitional B cells remain unclear, but appear to be defective in SLE and Sjögren's syndrome. This review aims to highlight the current understanding of transitional B cells and their defects in the two disorders before and after B cell-targeted therapies.

Yeast identification: reassessment of assimilation tests as sole universal identifiers

AIMS

To assess whether assimilation tests in isolation remain a valid method of identification of yeasts, when applied to a wide range of environmental and spoilage isolates.

METHODS AND RESULTS

Seventy-one yeast strains were isolated from a soft drinks factory. These were identified using assimilation tests and by D1/D2 rDNA sequencing. When compared to sequencing, assimilation test identifications (MicroLog™) were 18·3% correct, a further 14·1% correct within the genus and 67·6% were incorrectly identified. The majority of the latter could be attributed to the rise in newly reported yeast species.

CONCLUSIONS

Assimilation tests alone are unreliable as a universal means of yeast identification, because of numerous new species, variability of strains and increasing coincidence of assimilation profiles. Assimilation tests still have a useful role in the identification of common species, such as the majority of clinical isolates.

SIGNIFICANCE AND IMPACT OF THE STUDY

It is probable, based on these results, that many yeast identifications reported in older literature are incorrect. This emphasizes the crucial need for accurate identification in present and future publications.

Global oral health inequalities: task group--implementation and delivery of oral health strategies

This paper reviews the shortcomings of present approaches to reduce oral diseases and inequalities, details the importance of social determinants, and links that to research needs and policies on implementation of strategies to reduce oral health inequalities. Inequalities in health are not narrowing. Attention is therefore being directed at determinants of major health conditions and the extent to which those common determinants vary within, between, and among groups, because if inequalities in health vary across groups, then so must underlying causes. Tackling inequalities in health requires strategies tailored to determinants and needs of each group along the social gradient. Approaches focusing mainly on downstream lifestyle and behavioral factors have limited success in reducing health inequalities. They fail to address social determinants, for changing people's behaviors requires changing their environment. There is a dearth of oral health research on social determinants that cause health-compromising behaviors and on risk factors common to some chronic diseases. The gap between what is known and implemented by other health disciplines and the dental fraternity needs addressing. To re-orient oral health research, practice, and policy toward a 'social determinants' model, a closer collaboration between and integration of dental and general health research is needed. Here, we suggest a research agenda that should lead to reductions in global inequalities in oral health.

Mouse and human intestinal immunity: same ballpark, different players; different rules, same score

The study of animal immune physiology and animal models of human disease have accelerated many aspects of translational research by allowing direct, definitive investigations. In particular, the use of mice has allowed genetic manipulation, adoptive transfer, immunization, and focused cell and tissue sampling, which would obviously be unthinkable for studies in humans. However, the disease relevance of some animal models may be uncertain and difficulties in interpretation may occur as a consequence of immunological differences between the two species. In this review, we will consider general differences in the structure and development of human and mouse mucosal lymphoid microenvironments and then discuss species differences in mucosal B- and T-cell biology that relate to the current concepts of intestinal immune function.

Dentine hypersensitivity - Australian dentists' perspective

BACKGROUND

Dentine hypersensitivity is a frequent clinical presentation though inadequately comprehended by dentists. The objective of this study was to describe Australian dentists' perception on the occurrence, predisposing factors, triggers, diagnosis and management of dentine hypersensitivity.

METHODS

Eight hundred dentists were randomly selected using the Australian Dental Association membership list and invited to participate in a questionnaire-based survey.

RESULTS

Out of 295 responding dentists, 284 private practitioners were included in the final analysis. Most dentists perceived that the occurrence of dentine hypersensitivity was <20% and commonest among 30-49 year olds. According to them, abrasion and gingival recession were the main predisposing factors whilst cold stimuli were the commonest trigger. A differential diagnosis-based approach was adopted by a majority to diagnose dentine hypersensitivity although routine screening was resorted to by a few. Most dentists were aware of the current mechanisms underlying dentine hypersensitivity whereas the majority perceived that ongoing predisposing factors was the main reason for dentine tubules to remain exposed. The commonest management strategy employed by most dentists was to prescribe desensitizing agents for home use.

CONCLUSIONS

Australian dentists' perception of dentine hypersensitivity is generally consistent with the current scientific consensus on this subject.

Sequence analysis of immunoglobulin variable region genes that encode autoantibodies expressed by lymphomas of mucosa associated lymphoid tissue

Aim-To determine whether the immunoglobulin genes used by three gastric mucosa associated lymphoid tissue type lymphomas with known autoreactivity are mutated from germline as mutation from germline is an indicator of exposure to a mutational mechanism which characteristically acts on B cells as they undergo a follicle centre response.Methods-Cell lines established from two cases of MALT type lymphoma secrete autoantibodies recognising follicular dendritic cells (one case) and basement membrane (one case). The immunoglobulin heavy chain variable region genes (IgV(H)) and light chain variable region genes (IgV(L)) used by these cell lines, and the IgV(H) genes from a third case recognising human IgG were sequenced.Results-All three cases studied had mutated IgV(H) genes, while the IgV(L) genes were unmutated.Conclusion-The presence of mutations in IgV(H) genes is consistent with the origin of gastric MALT type lymphomas from B cells which have traversed the lymphoid follicle.