Population genomics of the invasive Northern Giant Hornet Vespa mandarinia in North America and across its native range

The northern giant hornet Vespa mandarinia (NGH) is a voracious predator of other insect species, including honey bees. NGH's native range spans subtropical and temperate regions across much of east and southeast Asia and, in 2019, exotic populations of the species were discovered in North America. Despite this broad range and invasive potential, investigation of the population genomic structure of NGH across its native and introduced ranges has thus far been limited to a small number of mitochondrial samples. Here, we present analyses of genomic data from NGH individuals collected across the species' native range and from exotic individuals collected in North America. We provide the first survey of whole-genome population variation for any hornet species, covering this species' native and invasive ranges, and in doing so confirm likely origins in Japan and South Korea for the two introductions. We additionally show that, while this introduced population exhibited strongly elevated levels of inbreeding, these signatures of inbreeding are also present in some long-standing native populations, which may indicate that inbreeding depression alone is insufficient to prevent the persistence of NGH populations. As well as highlighting the importance of ongoing monitoring and eradication efforts to limit the spread of this species outside of its natural range, our data will serve as a foundational database for future genomic studies into introduced hornet populations.

Molecular signatures of alternative reproductive strategies in a facultatively social hover wasp

Social insect reproductives and non-reproductives represent ideal models with which to understand the expression and regulation of alternative phenotypes. Most research in this area has focused on the developmental regulation of reproductive phenotypes in obligately social taxa such as honey bees, while relatively few studies have addressed the molecular correlates of reproductive differentiation in species in which the division of reproductive labour is established only in plastic dominance hierarchies. To address this knowledge gap, we generate the first genome for any stenogastrine wasp and analyse brain transcriptomic data for non-reproductives and reproductives of the facultatively social species Liostenogaster flavolineata, a representative of one of the simplest forms of social living. By experimentally manipulating the reproductive 'queues' exhibited by social colonies of this species, we show that reproductive division of labour in this species is associated with transcriptomic signatures that are more subtle and variable than those observed in social taxa in which colony living has become obligate; that variation in gene expression among non-reproductives reflects their investment into foraging effort more than their social rank; and that genes associated with reproductive division of labour overlap to some extent with those underlying division of labour in the separate polistine origin of wasp sociality but only explain a small portion of overall variation in this trait. These results indicate that broad patterns of within-colony transcriptomic differentiation in this species are similar to those in Polistinae but offer little support for the existence of a strongly conserved 'toolkit' for sociality.

Corrigendum: Invasion potential of hornets (Hymenoptera: Vespidae: Vespa spp.)

[This corrects the article DOI: 10.3389/finsc.2023.1145158.].

Invasion potential of hornets (Hymenoptera: Vespidae: Vespa spp.)

Hornets are large, predatory wasps that have the potential to alter biotic communities and harm honey bee colonies once established in non-native locations. Mated, diapausing females (gynes) can easily be transported to new habitats, where their behavioral flexibility allows them to found colonies using local food and nest materials. Of the 22 species in the genus Vespa, five species are now naturalized far from their endemic populations and another four have been detected either in nature or during inspections at borders of other countries. By far the most likely pathway of long-distance dispersal is the transport of gynes in transoceanic shipments of goods. Thereafter, natural dispersal of gynes in spring and accidental local transport by humans cause shorter-range expansions and contribute to the invasion process. Propagule pressure of hornets is unquantified, although it is likely low but unrelenting. The success of introduced populations is limited by low propagule size and the consequences of genetic founder effects, including the extinction vortex linked to single-locus, complementary sex determination of most hymenopterans. Invasion success is enhanced by climatic similarity between source locality and introduction site, as well as genetic diversity conferred by polyandry in some species. These and other factors that may have influenced the successful establishment of invasive populations of V. velutina, V. tropica, V. bicolor, V. orientalis, and V. crabro are discussed. The highly publicized detections of V. mandarinia in North America and research into its status provide a real-time example of an unfolding hornet invasion.

Rapid evolution, rearrangements and whole mitogenome duplication in the Australian stingless bees Tetragonula (Hymenoptera: Apidae): A steppingstone towards understanding mitochondrial function and evolution

The extreme conservation of mitochondrial genomes in metazoans poses a significant challenge to understanding mitogenome evolution. However, the presence of variation in gene order or genome structure, found in a small number of taxa, can provide unique insights into this evolution. Previous work on two stingless bees in the genus Tetragonula (T. carbonaria and T. hockingsi) revealed highly divergent CO1 regions between them and when compared to the bees from the same tribe (Meliponini), indicating rapid evolution. Using mtDNA isolation and Illumina sequencing, we elucidated the mitogenomes of both species. In both species, there has been a duplication of the whole mitogenome to give a total genome size of 30,666 bp in T. carbonaria; and 30,662 bp in T. hockingsi. These duplicated genomes present a circular structure with two identical and mirrored copies of all 13 protein coding genes and 22 tRNAs, with the exception of a few tRNAs that are present as single copies. In addition, the mitogenomes are characterized by rearrangements of two block of genes. We believe that rapid evolution is present in the whole Indo-Malay/Australasian group of Meliponini but is extraordinarily elevated in T. carbonaria and T. hockingsi, probably due to founder effect, low effective population size and the mitogenome duplication. All these features - rapid evolution, rearrangements, and duplication - deviate significantly from the vast majority of the mitogenomes described so far, making the mitogenomes of Tetragonula unique opportunities to address fundamental questions of mitogenome function and evolution.

The suppressive potential of a gene drive in populations of invasive social wasps is currently limited

Social insects are very successful invasive species, and the continued increase of global trade and transportation has exacerbated this problem. The yellow-legged hornet, Vespa velutina nigrithorax (henceforth Asian hornet), is drastically expanding its range in Western Europe. As an apex insect predator, this hornet poses a serious threat to the honey bee industry and endemic pollinators. Current suppression methods have proven too inefficient and expensive to limit its spread. Gene drives might be an effective tool to control this species, but their use has not yet been thoroughly investigated in social insects. Here, we built a model that matches the hornet's life history and modelled the effect of different gene drive scenarios on an established invasive population. To test the broader applicability and sensitivity of the model, we also incorporated the invasive European paper wasp Polistes dominula. We find that, due to the haplodiploidy of social hymenopterans, only a gene drive targeting female fertility is promising for population control. Our results show that although a gene drive can suppress a social wasp population, it can only do so under fairly stringent gene drive-specific conditions. This is due to a combination of two factors: first, the large number of surviving offspring that social wasp colonies produce make it possible that, even with very limited formation of resistance alleles, such alleles can quickly spread and rescue the population. Second, due to social wasp life history, infertile individuals do not compete with fertile ones, allowing fertile individuals to maintain a large population size even when drive alleles are widespread. Nevertheless, continued improvements in gene drive technology may make it a promising method for the control of invasive social insects in the future.

The molecular basis of socially mediated phenotypic plasticity in a eusocial paper wasp

Phenotypic plasticity, the ability to produce multiple phenotypes from a single genotype, represents an excellent model with which to examine the relationship between gene expression and phenotypes. Analyses of the molecular foundations of phenotypic plasticity are challenging, however, especially in the case of complex social phenotypes. Here we apply a machine learning approach to tackle this challenge by analyzing individual-level gene expression profiles of Polistes dominula paper wasps following the loss of a queen. We find that caste-associated gene expression profiles respond strongly to queen loss, and that this change is partly explained by attributes such as age but occurs even in individuals that appear phenotypically unaffected. These results demonstrate that large changes in gene expression may occur in the absence of outwardly detectable phenotypic changes, resulting here in a socially mediated de-differentiation of individuals at the transcriptomic level but not at the levels of ovarian development or behavior.

Queen succession conflict in the paper wasp Polistes dominula is mitigated by age-based convention

Reproduction in cooperative animal groups is often dominated by one or a few individuals, with the remaining group members relegated to nonreproductive helping roles. This reproductive skew can evolve if helpers receive fitness benefits such as potential future inheritance of the breeding position, but the mechanisms by which inheritance is determined are not well resolved. Polistes paper wasps form highly reproductively skewed groups and inheritance of the breeding position is likely to play a key role in the maintenance of this social structure, making them excellent models for the processes by which simple societies are maintained. Reproductive succession is thought to be determined via an age-based convention in some Polistes species, but there is also evidence for contest-based succession systems in which the replacement queen uses physical aggression to overpower and thereby subordinate her nestmates. Here, we provide evidence that queen succession in colonies of the European paper wasp Polistes dominula is determined via convention rather than contest, with little disruption to the colony’s social functioning. We use queen removal experiments and fine-scale behavioral analyses to confirm that age is a strong predictor of succession, and that behavioral responses to queen removal are restricted to the oldest individuals rather than being experienced equally across the group. We provide the most comprehensive and detailed experimental analysis on the dynamics of breeder succession in a cooperatively breeding invertebrate to date, thereby shedding light on the mechanisms by which animal societies are able to maintain cohesion in the face of within-group conflict.

Patterns of reproductive differentiation and reproductive plasticity in the major evolutionary transition to superorganismality

Major evolutionary transitions in individuality are characterised by the formation of new levels of biological complexity from the cooperation of previously independent lower-level units. The evolution of superorganismality in insects is one such major transition, and is characterised by an extreme division of reproductive labour between ancestrally autonomous units, in the form of queen and worker castes. Here, we discuss the nature of plasticity in the emergence of castes across the major transition to superorganismality in insects. We identify key changes in plasticity which act at different levels of selection: a loss of reproductivity plasticity at the individual level is matched by a gain in plasticity at the colony level. Taking multi-level selection into consideration has important implications for formulating testable hypotheses regarding the nature of plasticity in a major transition from a lower to a higher level of biological complexity.

Weight bias among exercise and nutrition professionals: a systematic review

Obesity affects approximately one-third of American adults. Recent evidence suggests that weight bias may be pervasive among both exercise and nutrition professionals working with adults who have obesity. However, the published literature on this topic is limited. This review aimed to (i) systematically review existing literature examining weight bias among exercise and nutrition professionals; (ii) discuss the implications of this evidence for exercise and nutrition professionals and their clients; (iii) address gaps and limitations of this literature; and (iv) identify future research directions. Of the 31 studies that met the criteria for this review, 20 examined weight bias among exercise professionals, of which 17 (85%) found evidence of weight bias among professionals practicing physical therapy (n = 4), physical education (n = 8) and personal/group fitness training (n = 5). Of 11 studies examining weight bias among nutrition professionals, eight (73%) found evidence of weight bias. These findings demonstrate fairly consistent evidence of weight bias among exercise and nutrition professionals. However, the majority of studies were cross-sectional (90%). Given that weight bias may compromise quality of care and potentially reinforce weight gain and associated negative health consequences in patients with obesity, it is imperative for future work to examine the causes and consequences of weight bias within exercise and nutrition professions using more rigorous study designs.

Full-mouth Tooth Extraction Lowers Systemic Inflammatory and Thrombotic Markers of Cardiovascular Risk

Prior studies of a link between periodontal and cardiovascular disease have been limited by being predominantly observational. We used a treatment intervention model to study the relationship between periodontitis and systemic inflammatory and thrombotic cardiovascular indicators of risk. We studied 67 adults with advanced periodontitis requiring full-mouth tooth extraction. Blood samples were obtained: (1) at initial presentation, immediately prior to treatment of presenting symptoms; (2) one to two weeks later, before all teeth were removed; and (3) 12 weeks after full-mouth tooth extraction. After full-mouth tooth extraction, there was a significant decrease in C-reactive protein, plasminogen activator inhibitor-1 and fibrinogen, and white cell and platelet counts. This study shows that elimination of advanced periodontitis by full-mouth tooth extraction reduces systemic inflammatory and thrombotic markers of cardiovascular risk. Analysis of the data supports the hypothesis that treatment of periodontal disease may lower cardiovascular risk, and provides a rationale for further randomized studies.

Decisional conflict in patients considering diagnostic thyroidectomy with indeterminate fine needle aspirate cytopathology

BACKGROUND

Fine needle aspiration (FNA) cytopathology is the gold standard work-up for thyroid nodules. However, indeterminate lesions are encountered commonly and can lead to difficult treatment decisions. We sought to determine whether patients experienced decisional conflict surrounding management with diagnostic thyroidectomy in the setting of indeterminate FNA results.

METHODS

Patients with indeterminate results of thyroid nodule FNA were prospectively enrolled. All consultations were carried out by three otolaryngologists in a consistent manner. After consultation, participants completed a demographics form and the Decisional Conflict Scale (DCS) questionnaire.

RESULTS

Thirty-five patients (28 female) between the ages of 30 and 88 years (mean age 54.89) participated. The median total DCS score was 10.94 (interquartile range, 4.69-25.0). Twelve patients (34%) scored at or above 25 on the DCS, indicating clinically significant level of decisional conflict. Patients reported feeling significantly more confident about their decision after the surgical consultation compared to before the consultation (p = 0.00). The total DCS score was significantly negatively correlated with self-reported confidence after the consultation (r = -0.421, p = 0.012).

CONCLUSION

Many patients experienced clinically significant decisional conflict when considering thyroidectomy for management of a thyroid nodule with indeterminate cytopathology. Future research should be directed at developing decision support tools for this patient group, and exploring the impact of decisional conflict on health outcomes.

Balloon dilation of the Eustachian tube: a tympanometric outcomes analysis

BACKGROUND

Eustachian tube dysfunction (ETD) is a common medical issue, occurring in at least 1% of the adult population. Patients suffering from ET dysfunction typically present with complaints of hearing loss or sensation of pressure or plugged ear, which can lead to impaired quality of life. Over time ETD can result in conductive hearing loss or choleastatoma formation. Effective theraputic options for ET dysfunction are few. Eustachian tube balloon dilation is a novel surgical technique being used to treat ETD. The aim of our study is to objectively measure the success of Eustachian tube balloon dilation by comparing pre and post-operative middle ear pressures using tympanometric testing.

METHODS

RA retrospective chart review was preformed on all patients who underwent balloon dilation of the Eustachian tube by authors NC or MB from 2010 to 2014. Pre and post-operative tympanograms were analyzed and categorized based on type (Type A, Type B, Type C). Success was defined by an improvement in tympanogram type: Type B or C to Type A, or Type B to type C. Pre and post-operative tympanograms were further analyzed using middle ear pressure values. Follow-up ranged from 3 to 15 months.

RESULTS

Twenty-five ears (18 patients) were included in the study. Overall 36% of ears had improvement in tympanogram type, and 32% had normalization of tympanogram post-operatively. The Jerger tympanogram type improved significantly following the procedure (p = 0.04). Patients also had statistically significant improvement in measured middle ear pressure post-operatively (P = 0.003).

CONCLUSION

The natural history of Eustachian tube dysfunction is poorly understood, and evidence for current treatments are limited. Eustachian tube balloon dilation is a safe procedure, and produces significant improvement in tympanogram values up to 15 months post-operatively. Further refinement of patient selection and standardization of technique is required to optimize the effect of this therapy. Longterm follow-up data will clarify the persistence of the effect.

Evaluation of SWI in children with sickle cell disease

BACKGROUND AND PURPOSE

SWI is a powerful tool for imaging of the cerebral venous system. The SWI venous contrast is affected by blood flow, which may be altered in sickle cell disease. In this study, we characterized SWI venous contrast in patients with sickle cell disease and healthy control participants and examined the relationships among SWI venous contrast, and hematologic variables in the group with sickle cell disease.

MATERIALS AND METHODS

A retrospective review of MR imaging and hematologic variables from 21 patients with sickle cell disease and age- and sex-matched healthy control participants was performed. A Frangi vesselness filter was used to quantify the attenuation of visible veins from the SWI. The normalized visible venous volume was calculated for quantitative analysis of venous vessel conspicuity.

RESULTS

The normalized visible venous volume was significantly lower in the group with sickle cell disease vs the control group (P < .001). Normalized visible venous volume was not associated with hemoglobin, percent hemoglobin F, percent hemoglobin S, absolute reticulocyte count, or white blood cell count. A hypointense arterial signal on SWI was observed in 18 of the 21 patients with sickle cell disease and none of the 21 healthy control participants.

CONCLUSIONS

This study demonstrates the variable and significantly lower normalized visible venous volume in patients with sickle cell disease compared with healthy control participants. Decreased venous contrast in sickle cell disease may reflect abnormal cerebral blood flow, volume, velocity, or oxygenation. Quantitative analysis of SWI contrast may be useful for investigation of cerebrovascular pathology in patients with sickle cell disease, and as a tool to monitor therapies. However, future studies are needed to elucidate physiologic mechanisms of decreased venous conspicuity in sickle cell disease.

Location of theSas-1 locus on mouse chromosome 1

Using three sets of recombinant inbred strains (BXD, BXH, and BXJ), we found the locus controlling an antigenic substance (Sas}-1) in murine serum to be closely linked to the Chromosome-1 marker,Dip-1. This linkage was confirmed by an analysis of backcross linkage. The BXD and backcross data suggest that the gene order isId-1-Dip-1-Sas-1-Mls. Data from the three sets of RI strains and the 32 backcross mice lead to the estimate that the recombination frequency betweenDip-1 andSas-1 is 0.030 ±0.015.

Oral disease and subsequent cardiovascular disease in people with type 2 diabetes: a prospective cohort study based on the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified-Release Controlled Evaluation (ADVANCE) trial

AIMS/HYPOTHESIS

While there are plausible biological mechanisms linking oral health with cardiovascular disease (CVD) and mortality rates, no study, to our knowledge, has examined this association in a representative population of people with type 2 diabetes.

METHODS

We used the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified-Release Controlled Evaluation (ADVANCE) study, a large, detailed, randomised controlled trial among a general population of individuals with type 2 diabetes. For the purposes of the present analyses, data from the trial are used within a prospective cohort study design. A total of 10,958 men and women, aged 55 to 88 years and with type 2 diabetes, participated in a baseline medical examination, during which they counted their number of natural teeth and reported the number of days that their gums had bled over the preceding year. Study members were followed up for mortality and morbidity over 5 years.

RESULTS

After controlling for a range of potential confounding factors, the group with no teeth had a markedly increased risk of death due to all causes (HR 1.48, 95% CI 1.24-1.78), CVD (1.35, 1.05-1.74) and non-CVD (1.64, 1.26-2.13), relative to the group with the most teeth (≥22 teeth). Frequency of bleeding gums was not associated with any of the outcomes of interest. There was no suggestion that treatment group or sex modified these relationships.

CONCLUSIONS/INTERPRETATION

In people with type 2 diabetes, oral disease, as indexed by fewer teeth, was related to an increased risk of death from all causes and of death due to CVD and non-CVD.

Management of obstetric anal sphincter injuries--a role for the colorectal surgeon

AIM

To determine if surgical repair of third and fourth degree obstetric perineal tears by an experienced colorectal surgeon produces satisfactory functional results in the short and long term.

METHOD

Consecutive deliveries were studied prospectively over a 32-month period. All patients with suspected third or fourth degree tears were referred to the colorectal team. Following confirmation of the injury, patients underwent surgical repair using a standard overlapped technique according to an established protocol. The patients were reviewed 2 months later. Long-term continence was determined, by postal and telephone follow up, after a minimum of 3 years.

RESULTS

Fifty-nine sphincter injuries were identified and repaired by the colorectal team. Two months following repair 51 (86%) of patients had normal continence, four (7%) had urgency, and five (8%) had occasional incontinence of flatus. All patients with any degree of incontinence underwent endoanal ultrasound at which no sphincter defects were noted, and all improved symptomatically following pelvic floor physiotherapy. Long-term follow up data was obtained in 45 women. Thirty-nine (87%) had normal continence scores, 11 (24%) described urgency, but only three (7%) were often incontinent of liquid stool. Seven (15%) were occasionally incontinent of flatus.

CONCLUSION

Excellent short and long-term functional results were obtained in the repair of third and fourth degree tears when performed by experienced colorectal surgeons. Since the protocol was established, obstetricians in North Cheshire have adopted the double overlapped technique, and now manage the majority of these injuries themselves.

SAA and PLTP activity in plasma of periodontal patients before and after full-mouth tooth extraction

OBJECTIVE

To assess whether treatment of advanced periodontal disease affects plasma levels of serum amyloid A (SAA) and phospholipid transfer protein (PLTP) activity.

DESIGN

We measured the levels of SAA and PLTP activity in plasma of 66 patients with advanced periodontal disease before and after treatment by full-mouth tooth extraction (FME).

RESULTS

At baseline, median SAA levels in our study population were within the normal range (2.7 microg ml(-1)) but SAA was elevated (>5 microg ml(-1)) in 18% of periodontitis patients. Three months after FME, SAA levels were significantly reduced (P = 0.04). SAA did not correlate with any of the periodontal disease parameters. PLTP activity was elevated in patients with periodontitis, compared to the PLTP activity reference group (age-matched systemically healthy adults, n = 29; 18 micromol ml(-1) h(-1)vs 13 micromol ml(-1) h(-1), respectively, P = 0.002). PLTP activity inversely correlated with average periodontal pocket depth (PPD) per tooth (r(s) = -0.372; P = 0.002). Three months after FME, median PLTP activity did not change significantly.

CONCLUSIONS

Full-mouth tooth extraction significantly reduces SAA, a marker of inflammation, while it does not affect plasma PLTP activity. However, the inverse correlation between PLTP activity and average PPD suggests that increased PLTP activity may limit periodontal tissue damage.

Inter-relationships between platelet count, platelet IgG, serum IgG, immune complexes and severity of liver disease

Thrombocytopenia is a common finding in subjects with chronic liver diseases. A variety of mechanisms may underlie this. Immunological disturbances are commonly a feature in chronic liver disease, including hyperglobulinaemia and the presence of autoantibodies and circulating immune complexes and immune mechanisms could therefore contribute to thrombocytopenia. We have investigated the relationships between blood platelet count, serum IgG and IgG immune complexes and IgG associated with platelets in 92 subjects with chronic liver disease (27 with chronic active hepatitis, 38 with primary biliary cirrhosis and 27 with alcoholic liver disease). Severity of liver impairment was a major determinant of degree of thrombocytopenia. Also, an inverse relationship was demonstrated between platelet count and platelet-associated IgG. In subjects with chronic active hepatitis the relationships between platelet count, serum IgG immune complexes and platelet-associated IgG were consistent with a role for immune mechanisms in general and immune complexes in particular as mediators of the thrombocytopenia.

A mouse TRAPP-related protein is involved in pigmentation

We identified a new spontaneous recessive mutation in the mouse, mhyp (mosaic hypopigmentation), in a screen for novel proviral integration sites in a multiple ecotropic provirus mapping stock. Integration of an 8.4-kb retrovirus results in mosaic loss of coat pigment in mhyp homozygotes. Patchy loss of pigmentation in the retinal pigmented epithelial layer of the eye with abnormal melanosomes is also evident. We mapped mhyp to mouse chromosome 7 and cloned the underlying gene. mhyp is a defect in the Trappc6a gene. Expression of Trappc6a is markedly diminished in mhyp homozygotes. The normal protein, TRAPPC6A, is a subunit of the TRAPP (transport protein particle) I and II complexes. While TRAPP complexes are essential for ER-to-Golgi and intra-Golgi vesicle trafficking in yeast, TRAPP subunits participate in additional, including post-Golgi, transport events in mammals. The data implicate mammalian TRAPPC6A in vesicle trafficking during melanosome biogenesis.

Prevalence and clinical significance of superficial abdominal reflex abnormalities in idiopathic scoliosis

To determine prevalence and significance of abnormal superficial abdominal reflexes (SARs) in idiopathic scoliosis. Study of 73 patients with presumed idiopathic scoliosis referred for magnetic resonance imaging (MRI), either as a routine pre-operative assessment (n=42) or because of abnormal symptoms or neurological signs (n=31). All patients were examined prior to magnetic resonance imaging (MRI), and the presence of abnormal SARs was noted. All patients then underwent MRI of the whole spine from the foramen magnum to the sacrum. The presence of Chiari 1 malformation and syrinx was recorded. The study group consisted of 11 males and 62 females with a mean age at time of MRI of 18 years (range 5-51 years) and a mean Cobb angle of 48 degrees (range 10-104 degrees). Abnormality of the SARs was recorded in eight cases (prevalence 11%). An abnormal MRI study was recorded in nine cases (12.3%), all patients having a syrinx and four having in addition, a Chiari 1 malformation. Of the patients with abnormal SARs, only 2 (25%) had an abnormal MRI study; 1 had unilateral absence of the reflexes whereas the other had complete absence of SARs. Of patients referred for MRI as a routine pre-operative assessment, 5 (11.6%) had an abnormal MRI study. In patients with idiopathic scoliosis, abnormality of the SARs was recorded in 11% of cases. Unilateral absence was present in one case only and was associated with the presence of syrinx. Other patterns of abnormality were not a useful indicator of underlying cord abnormality.

Comparison of plain radiographs with CT scan to evaluate interbody fusion following the use of titanium interbody cages and transpedicular instrumentation

The availability of lumbar interbody cages has fuelled renewed interest in interbody fusion. Despite this, there is no consensus regarding the best non-invasive method for evaluation of interbody fusion, especially where cages have been used. The purpose of this study was to determine whether high-quality thin-slice (1- to 3-mm) computed tomography (CT) scans allow proper evaluation of interbody fusion through titanium cages. Patients undergoing lumbar interbody fusion were prospectively evaluated with CT scan and plain radiographs 6 months following surgery. These images were blindly and independently evaluated by a consultant radiologist and a spine research fellow, for bridging bony trabeculation both through and surrounding the cages as well as for changes at the cage endplate interface. Fifty-three patients (156 cages) undergoing posterior lumbar interbody fusion using titanium interbody cages were evaluated. Posterior elements were used to pack the cages and no graft was packed outside the cages. The outcome data were analysed using the Kappa co-efficient and chi-squared analysis. On CT scan, both observers noted bridging trabeculation in 95% of the cages (Kappa 0.85), while on radiographs this was present in only 4% (Kappa 0.74). Both observers also identified bridging trabeculation surrounding the cages on CT scan in 90% of cages (Kappa 0.82), while on the radiographs this was 8% (Kappa 0.86). Radiographs also failed to demonstrate all the loose cages. The results of the study show that high-quality CT scans show images suggesting bridging bony trabeculae following the use of titanium interbody cages. They also appear to show consistent bone outside the cages in spite of no bone graft having been used, and they appear to be better than plain radiographs in the early detection of cage loosening.

Radiologic evaluation of adjacent superior segment facet joint violation following transpedicular instrumentation of the lumbar spine

STUDY DESIGN

The location of pedicle screws in relation to adjacent superior segment facet joints in 106 patients after lumbar spinal fusion was assessed using computed tomography and plain radiographs.

OBJECTIVES

To document the incidence of adjacent superior segment facet joint violation following transpedicular instrumentation in the lumbar spine.

SUMMARY OF BACKGROUND DATA

Review of the literature failed to show any documented study examining this incidence.

METHODS

A total of 106 patients (212 top-level facet screws) undergoing lumbar spinal fusion surgery using transpedicular instrumentation between 1996 and 1999 were prospectively evaluated with a computed tomography scan and plain radiographs at 6 months following surgery. These were blindly and independently evaluated by a consultant radiologist and a spinal research fellow to document the incidence of superior segment facet joint violation. Calculation of the kappa coefficient and chi2 analysis were carried out.

RESULTS

The spinal research fellow noted the incidence of facet joint violation on the computed tomography scan to be present in 20% of the screws and 32% of the patients, whereas the consultant radiologist noted this to be the case in 23% and 35%, respectively. The kappa coefficient for computed tomography scan was 0.88, whereas for the plain radiographs it was 0.39. The incidence of facet joint violation was noted to be independent of the sex, level, and diagnosis. There was also an almost uniform incidence in each of the years from 1996 to 1999.

CONCLUSION

Facet joint violation occurred in just >30% of the patients and 20% of the screws in this study. This, therefore, raises the theoretical possibility of long-term deterioration in the clinical results following the use of transpedicular instrumentation.

Excision of an osteoid osteoma from the body of the axis through an anterior approach

Osteoid osteoma is seen less commonly in the vertebral body than in the posterior elements of the spine. To the authors' knowledge, this is only the second reported case of an osteoid osteoma affecting the body of the axis. The patient described in this report presented with the classic symptomatology of pain and torticollis. Radiological imaging confirmed the diagnosis. A superior extension of the anterior Smith-Robinson approach, through the "window of access" described by Fasel, was used to excise this lesion. Following surgical excision, there was complete resolution of the presenting symptomatology and functionally the range of motion of the cervical spine returned to normal. We avoided instrumentation and C1-C2 fusion so that rotation of the cervical spine could be maintained. There were no signs of recurrence of the tumour within the 4-year follow-up period. It presented in a classic way but, despite this, it took 2 years from the onset of these symptoms to reach a definitive diagnosis. This osteoid osteoma was successfully excised through a superior extension of the anterior Smith-Robinson approach.

Change in family income-to-needs matters more for children with less

Hierarchical linear modeling was used to model the dynamics of family income-to-needs for participants of the National Institute of Child Health and Human Development Study of Early Child Care (N = 1,364) from the time that children were 1 through 36 months of age. Associations between change in income-to-needs and 36-month child outcomes (i.e., school readiness, receptive language, expressive language, positive social behavior, and behavior problems) were examined. Although change in income-to-needs proved to be of little importance for children from nonpoor families, it proved to be of great importance for children from poor families. For children in poverty, decreases in income-to-needs were associated with worse outcomes and increases were associated with better outcomes. In fact, when children from poor families experienced increases in income-to-needs that were at least 1 SD above the mean change for poor families, they displayed outcomes similar to their nonpoor peers. The practical importance and policy implications of these findings are discussed.

Combined histologic and molecular features reveal previously unappreciated subsets of lymphoma in AKXD recombinant inbred mice

Hematopoietic neoplasms developing in AKXD recombinant inbred, NFS.V(+) and ICSBP knockout mice were assessed using morphologic, cytologic and molecular criteria that relate these disorders to human lymphoma and leukemia. Lymphoma types included precursor T-cell and B-cell lymphoblastic, small lymphocytic, splenic marginal zone, follicular, and diffuse large cell (DLCL). In addition to previously defined subtypes of DLCL composed of centroblasts or immunoblasts, two additional subtypes are defined here: lymphoblastic lymphoma like (LL) and lymphoma characterized by a histiocytic reaction (HS). DLCL(HS) were distinguished from true histiocytic lymphomas by the presence of clonal Ig gene rearrangements.

Close linkage of Mdm-1, a gene amplified and overexpressed in a transformed 3T3 cell line, with gamma interferon (Ifg) on chromosome 10 of the mouse

The Mdm-1 gene was mapped to the distal end of Chromosome (Chr) 10. An extensive series of restriction fragment variants was identified among conventional and exotic inbred strains of mice. Mapping was carried out with recombinant inbred strains and an intersubspecific testcross. No recombinants were observed between Mdm-1 and the gamma interferon locus (Ifg). These two loci appear to be in linkage disequilibrium among inbred strains. Data from the testcross place Mdm-1 approximately 11 centimorgans distal to the steel (Sl) locus. Because of its extensive polymorphism, Mdm-1 is a useful genetic marker for distal Chr 10.

Multiple obesity QTLs identified in an intercross between the NZO (New Zealand obese) and the SM (small) mouse strains

The inheritance of adiposity levels has been investigated in an intercross of the obese, diabetes-prone NZO and the small, lean SM mouse strains. Adiposity index (AI) was defined as the sum of four fat pad weights divided by body weight. DNA pools from fat and lean mice were analyzed with microsatellite variants to screen the genome for quantitative trait loci (QTLs) affecting AI. Ten significant QTLs affecting AI were identified on Chromosome (Chr) 1 (three loci), Chr 2, Chr 5 (two loci), Chr 6 (two loci), Chr 7, and Chr 17. Most of the QTLs appear to be novel. Several QTLs differentially affect specific fat depots. Thus, Chr 2 and Chr 7 QTLs affect gonadal more than inguinal fat, while the converse is true for the Chr 17 QTL. Gender influences the expression of several of the QTLs. For example, effects of the proximal Chr 1 QTL (Obq7) on AI appears to be primarily in males. The proximal AI QTL on Chr 6 (Obq13) maps near the neuropeptide Y (Npy) locus. Sequence analysis of the Npy gene revealed a 1-nucleotide deletion within a highly conserved portion of the 3' untranslated region in strain NZO. However, the deletion is polymorphic among mouse strains. Furthermore, lack of association between this same variant and AI in previously analyzed crosses raises doubt that it is the basis of Obq13. The present cross is the fourth in a series of intercrosses among 10 inbred strains arranged such that each strain is crossed with each adjacent strain within a circle. This design affords multiple opportunities to analyze each segregating QTL.

Teaching children with autism to engage in conversational exchanges: script fading with embedded textual stimuli

A multiple baseline across three sets of stimuli was used to assess the effects of a script-fading procedure using embedded text to teach 2 children with autism to engage in conversation statements about the stimuli. Both students stated all the scripted statements, and unscripted statements also increased. Generalization was assessed with novel peers and with untrained stimuli.

The risk of foraminal violation and nerve root impingement after anterior placement of lumbar interbody fusion cages

STUDY DESIGN

Three groups of six embalmed cadaver spines underwent placement of lumbar interbody fusion cages centered either at midline, 10% lateral of midline, or 20% lateral of midline. The spines were evaluated for evidence of neuroforamen violation or nerve root impingement.

OBJECTIVES

To determine the potential for foraminal violation or nerve root impingement after correct placement and lateral misplacement of lumbar interbody fusion cages.

SUMMARY OF BACKGROUND DATA

Radicular symptoms after anterior cage placement have raised some concern about the potential for inadvertent device-related foraminal violation not adequately appreciated by intraoperative fluoroscopy.

METHODS

Preoperative computed tomography scanning and plain radiography was used to measure endplate dimensions at L4-L5 and to template the appropriately sized interbody fusion cages. The cadaveric specimens were randomly divided into three groups of six (Groups I-III) and instrumented at L4-L5 either at midline (I) or 10% (II) or 20% (III) lateral of midline. Postoperative computed tomography and plain radiography was evaluated for evidence of neuroforamen violation, followed by dissection of the specimens.

RESULTS

Foraminal violation occurred in one of six spines in group II (10% off midline) and in three of six spines in group III (20% off midline). Two of the three cadavers in group III with foraminal violation also were noted to have nerve root abutment on computed tomography scans and spinal dissection.

CONCLUSIONS

Excessive lateral placement of lumbar interbody fusion cages may result in foraminal violation and possible nerve encroachment. The "safe zone" for centering the cages extends approximately 5 mm on either side of midline.

Management of drug-induced gingival enlargement with orthodontic complications

Gingival enlargement (GE) may be induced by cyclosporin A, phenytoin or calcium channel blockers, used either singly or in combination. The lesion can cause significant disfigurement and functional difficulty as it interferes with eating and speech, impedes effective plaque control, and disturbs occlusal relationships. Orthodontic problems may originate independently of the soft tissue lesion or they may develop secondary to the GE. Management of drug-induced GE with orthodontic complications requires co-operative teamwork. This will be discussed in the management of cases with medical, orthodontic and periodontal interventions.

A case of recurrent trigger thumb

In this report we present a case of recurrent trigger thumb after surgical release. A 3-year-old girl underwent surgical release of the first annular pulley at another institution. The resected first annular pulley had been confirmed by pathologic analysis. After surgery the triggering and locking recurred, and she developed limited function due to persistent pain. The second operative release revealed a fibrous band in the region of the previous first annular pulley and a thickened flexor tendon sheath.

Imaging features of cervical spondylolysis--with emphasis on MR appearances

AIM

To describe the imaging features of cervical spondylolysis, with emphasis on magnetic resonance imaging (MRI) appearances.

MATERIALS AND METHODS

The clinical and imaging features (plain radiographic, CT and MRI) of three patients with cervical spondylolysis were reviewed.

RESULTS AND CONCLUSIONS

Three cases of C6 cervical spondylolysis have been described and the world literature reviewed. The plain radiographic features in two cases with bilateral defects showed spondylolisthesis and abnormalities of the pars and adjacent facet joints. CT demonstrated well corticated defects and associated spina bifida occulta in all cases. The defects were seen in only one case on MRI but in all cases, absence of the spinous process of C6 was noted on sagittal sequences due to the spina bifida occulta. Cervical spondylolysis is an uncommon condition that must be distinguished from an acute fracture and diagnosed radiologically to prevent mismanagement. Although the defect may be difficult to identify on MRI, absence of the spinous process on sagittal sequences should raise the suspicion of the abnormality.

Gender-influenced obesity QTLs identified in a cross involving the KK type II diabetes-prone mouse strain

The inheritance of adiposity and related traits has been investigated in the obese, diabetes-prone KK/HlLt (KK) and the lean, normoglycemic C57BL/6J (B6) mouse strains, their F(1) hybrids, and a large intercross generation. Adiposity index (AI) was defined as the sum of four fat depot weights divided by body weight. Both male and female KK mice were obese, but AI values averaged twofold higher in females than in males. In contrast, B6 females were slightly more lean than males. A genome-wide search revealed several qualitative trait loci (QTLs) affecting AI. The proximal region of Chromosome (Chr) 9 has a large effect on AI, with a much stronger effect in females (lod = 6.3) than in males (lod = 2.7). The data for females fit a model in which a dominant allele from KK increases AI by 30%, with the lod score peak falling between markers D9Mit66 and D9Mit328. This QTL has large effects on inguinal and mesenteric fat pad weights, with smaller effects on gonadal and retroperitoneal fat pads. The region of Chr 9 containing this QTL has extensive homology to human Chr 11q. An X-linked QTL affecting AI was evident in males (lod = 3.77), but not females (lod = 0.7). Exclusion of mesenteric fat from male AI resulted in an increased lod score (lod = 5.0) at 8 cM distal to DXMit166. A suggestive AI QTL (lod = 4.2), differentially affecting males, was localized to Chr 18 near the glucocorticoid receptor locus. A region of Chr 7 had a strong effect on body weight (lod = 6.9), a significant effect on inguinal fat% (lod = 4.4), and a suggestive effect on AI in females (lod = 4.1). Plasma leptin levels were associated with genotypes on Chr 9 (lod = 5.9) and Chr 7 (lod = 4.2). A region of Chr 1 had a suggestive effect on fasted blood glucose (lod = 3.6).

Cadherin-catenin expression in primary colorectal cancer: a survival analysis

Both cell adhesion and cell signalling events are mediated by components of the cadherin-catenin complex. Loss of expression of the components of this complex have been shown to correlate with invasive behaviour in many tumour types although their exact role in colorectal cancer remains unclear. Immunohistochemical analysis of the expression of components of the cadherin-catenin complex in colorectal cancers from 60 patients was undertaken. Loss of memberanous expression of E-cadherin, alpha-catenin and beta-catenin was demonstrated in 52%, 85% and 40% of tumours respectively. Focal nuclear expression of beta-catenin (< 75% of cells per section), usually associated with cytoplasmic expression, was clearly demonstrated in 19 (32%) tumours while widespread nuclear expression (> 75% of tumour cells per section) was seen in 11 (18%) tumours. Loss of membranous alpha-catenin expression significantly correlated with tumour de-differentiation (P = 0.009). There was a trend towards an association between advanced tumour stage and loss of membranous expression of alpha-catenin or beta-catenin, although these associations were not statistically significant. Univariate analysis revealed that advanced Dukes' stage, tumour de-differentiation, loss of membranous beta-catenin expression, cytoplasmic beta-catenin expression and widespread nuclear expression of beta-catenin all correlated with short survival following apparently curative resection of the primary tumour. However, only Dukes' stage (P = 0.002), tumour grade (P = 0.02) and widespread nuclear expression of beta-catenin (P = 0.002) were independent predictors of short survival. Disturbed growth signalling events in colorectal tumours are thought to result in nuclear accumulation of beta-catenin. Consequently, tumours with widespread nuclear expression of beta-catenin are likely to have severely abnormal growth characteristics, and which therefore might be predictive of short survival in these patients.

Genotyping new BXD recombinant inbred mouse strains and comparison of BXD and consensus maps

Nine additional BXD recombinant inbred (RI) strains have been developed from the F2 cross of C57BL/6J and DBA/2J mouse strains. A tenth line stopped breeding in the F12 generation. F20 generation breeding pairs from the nine surviving strains and an F12 pair from the extinct line were genotyped at 319 genetic markers (primarily microsatellites) spanning most of the genome. Where typing data were lacking, the established set of 26 BXD strains also were genotyped at these same loci. The availability of these additional nine strains enhances the value of the BXD RI set for analysis of complex phenotypic traits. The proportion of loci still segregating at the F20 generation was found to closely approximate expectation, suggesting that selection favoring the retention of heterozygosity is not a strong factor. However, the number of crossovers between adjacent markers was frequently less than predicted from consensus map distances. A significant deficiency of recombinants was observed on Chrs 3, 4, 14, and X. On Chr 14, the estimated cumulative BXD map distance between the most proximal and distal markers was only 30.2 cM, compared with a distance of 60.0 cM in the consensus map. On the X Chr, the estimated and predicted cumulative distances were 38.8 and 69.5 cM, respectively. Over all chromosomes, the BXD RI map is 14.5% shorter than predicted from the consensus map. It is suggested that distances in some of the consensus maps are inflated. Alternatively, recombinant genotypes could be selected against during inbreeding owing to allelic interactions affecting fitness. The latter interpretation implies that relatively strong intrachromosomal epistasis is common.

Extradural inflammation associated with annular tears: demonstration with gadolinium-enhanced lumbar spine MRI

Annular tears are manifest on MRI as the high-intensity zone (HIZ) or as annular enhancement. Patients with annular tears may experience low back pain with radiation into the lower limb in the absence of nerve root compression. Inflammation of nerve roots from leak of degenerative nuclear material through full-thickness annular tears is a proposed mechanism for such leg pain. The aim of this study is to illustrate the appearance of extradural enhancement adjacent to annular tears in patients being investigated for low back pain with radiation into the lower limb(s). Sagittal T1- and T2-weighted spin echo and axial T1-weighted spin echo sequences were obtained in eight patients being investigated for low back and leg pain. In all patients, the T1-weighted sequences were repeated following intravenous gadopentetate dimeglumine (Gd-DTPA). Annular tears were identified at 12 sites in eight patients. Extradural inflammation appeared as a region of intermediate signal intensity replacing the fat between the posterior disc margin and the theca, which enhanced following Gd-DTPA. The inflammatory change was always associated with an annular tear, and in four cases directly involved the nerve root. Enhancement of the nerve root was seen in two cases. The findings may be relevant in the diagnosis of chemical radiculopathy secondary to inflammation at the site of an annular leak from a degenerating disc.

Hyperleptinemia and leptin receptor variant Asp600Asn in the obese, hyperinsulinemic KK mouse strain

KK obese mice exhibit a multigenic syndrome of moderate obesity, hyperinsulinemia and hyperglycemia. Here we show that the syndrome is accompanied by a marked elevation of leptin protein in adipose tissue, as well as leptin levels in serum, which corresponds with the degree of obesity. The cDNA sequence of leptin is normal in KK mice, whereas three nucleotide polymorphisms were found in the cDNA of the leptin receptor, one of them resulting in exchange of an aspartate residue for asparagine (Asp600Asn) in a highly conserved part of the second extracellular cytokine-receptor homology module. In female (but not male) F2 mice of a C57BL/6JxKK intercross, the weight of gonadal, retroperitoneal and mesenteric adipose tissue was positively correlated with the number of alleles inherited from the KK parental strain at a microsatellite marker (D4Mit175) which maps close (0.7 centimorgan proximal) to the leptin receptor gene. It is suggested that the Asp600Asn leptin receptor variant contributes to the obesity syndrome in KK female mice, but that its contribution is only a part of the multigenic syndrome.

Spinal canal capacity in simulated displacements of the atlantoaxial segment: a skeletal study

In normal, physiological circumstances there is ample room in the spinal canal to accommodate the spinal cord. Our study aimed to identify the degree of compromise of the spinal canal which could be anticipated in various atlantoaxial pathological states. We examined paired atlas and axis vertebrae using high-definition radiography and simultaneous photography in both normal and simulated pathological orientations in order to measure the resultant dimension of the spinal canal and its percentage occlusion. At the extreme of physiological axial rotation (47 degrees) the spinal canal is reduced to 61% of its cross-sectional area in neutral rotation. The spinal cord is thus safe from compromise. Atlantoaxial subluxation of up to 9 mm reduces the area of the spinal canal, in neutral rotation, to 60% with no cord compromise. Any rotation is, however, likely to cause cord compression. The mechanism of fixation in atlantoaxial rotatory subluxation could be explained by bony interlocking of the facet joint, reproducible in dry bones.