HMGB1 acts as an agent of host defense at the gut mucosal barrier

Mucosal barriers provide the first line of defense between internal body surfaces and microbial threats from the outside world. ¹ In the colon, the barrier consists of two layers of mucus and a single layer of tightly interconnected epithelial cells supported by connective tissue and immune cells. ² Microbes colonize the loose, outer layer of colonic mucus, but are essentially excluded from the tight, epithelial-associated layer by host defenses. ³ The amount and composition of the mucus is calibrated based on microbial signals and loss of even a single component of this mixture can destabilize microbial biogeography and increase the risk of disease. ^4-7 However, the specific components of mucus, their molecular microbial targets, and how they work to contain the gut microbiota are still largely unknown. Here we show that high mobility group box 1 (HMGB1), the prototypical damage-associated molecular pattern molecule (DAMP), acts as an agent of host mucosal defense in the colon. HMGB1 in colonic mucus targets an evolutionarily conserved amino acid sequence found in bacterial adhesins, including the well-characterized Enterobacteriaceae adhesin FimH. HMGB1 aggregates bacteria and blocks adhesin-carbohydrate interactions, inhibiting invasion through colonic mucus and adhesion to host cells. Exposure to HMGB1 also suppresses bacterial expression of FimH. In ulcerative colitis, HMGB1 mucosal defense is compromised, leading to tissue-adherent bacteria expressing FimH. Our results demonstrate a new, physiologic role for extracellular HMGB1 that refines its functions as a DAMP to include direct, virulence limiting effects on bacteria. The amino acid sequence targeted by HMGB1 appears to be broadly utilized by bacterial adhesins, critical for virulence, and differentially expressed by bacteria in commensal versus pathogenic states. These characteristics suggest that this amino acid sequence is a novel microbial virulence determinant and could be used to develop new approaches to diagnosis and treatment of bacterial disease that precisely identify and target virulent microbes.

Acoustic and vibration isolation for a gravity gradiometer

Vibration in the audio frequency band affects the performance of rotating gravity gradiometers used for airborne mineral exploration. This is probably due to translation to rotation coupling inside the gradiometer platform. It was found that the DC gravity gradient signal was proportional to the square of the third time derivative of position, or jerk squared. The demanding airborne environment for such instrumentation demands a light weight broadband acoustic shield and vibration isolator. This paper presents the design principles for such an isolator, based on vibration isolated spherical shell structures. Performance data are presented as well as flight test data that demonstrated a 14% gravity gradient noise reduction compared with an unshielded instrument.

Breeding systems of floral colour forms in the Drosera cistiflora species complex

Variation in plant breeding systems has implications for pollinator-mediated selection on floral traits and the ecology of populations. Here we evaluate pollinator contribution to seed production, self-compatibility and pollen limitation in different floral colour forms of Drosera cistiflora sensu lato (Droseraceae). These insectivorous perennial plants are endemic to fynbos and renosterveld vegetation in the Cape Floristic Region of South Africa, and the species complex includes five floral colour forms (pink, purple, red, white and yellow), some of which are known to be pollinated by beetles. Controlled hand-pollination experiments were conducted in 15 populations of D. cistiflora s.l. (two to four populations per floral colour form) to test whether the colour forms vary in their degree of self-compatibility and their ability to produce seeds through autonomous self-fertilization. Yellow-flowered forms were highly self-incompatible, while other floral colour forms exhibited partial self-compatibility. Seed set resulting from autonomous selfing was very low, and pollinator dependence indices were high in all populations. Since hand cross-pollination resulted in greater seed set than open pollination in 13 of the 15 populations, we inferred that seed production is generally pollen-limited. Drosera cistiflora s.l. typically exhibits high levels of pollinator dependence and pollen limitation. This is unusual among Drosera species worldwide and suggests that pollinators are likely to mediate strong selection on attractive traits such as floral colour and size in D. cistiflora s.l. These results also suggest that the floral colour forms of D. cistiflora s.l. which are rare and threatened are likely to be vulnerable to local extinction if mutualisms were to collapse indefinitely.

Interlaboratory Study of a Thermospray-Liquid Chromatographic/Mass Spectrometric Method for Selected N-Methyl Carbamates, N-Methyl Carbamoyloximes, and Substituted Urea Pesticides

A thermospray-liquid chromatographic/mass spectrometric (TS-LC/MS) method was evaluated in an interlaboratory study for determining 3 N-methyl carbamates (bendiocarb, carbaryl, and carbofuran), 3 N-methyl carbamoyloximes (aldicarb, methomyl, and oxamyl), 2 substituted urea pesticides (diuron and linuron), and 1 ester of a substituted carbamic acid (carbendazim). The purpose of this study was to establish whether these 9 compounds can be reliably detected and quantitated with this method, and to establish the interlaboratory precision and accuracy of the method with currently available instrumentation. The study design was based on AOAC INTERNATIONAL’S blind replicate design with balanced replicates. The samples consisted of solutions of the 9 test compounds in methanol at 3 concentrations that were unknown to the participating laboratories and that covered the linear range of the method. Nine volunteer laboratories participated in the study. Linear regression equations are presented that calculate the accuracy of the method, i.e., the percent recovery of each of the 9 compounds at any concentration within the range of concentrations tested (5–90 (μg/mL for each compound, except carbendazim, for which the range was 1.25–22.5 μg/mL). The intra laboratory precisions of the TS-LC/MS method ranged from 6.5 to 33.1 % relative standard deviation, depending on the compound. The interlaboratory method precisions ranged from 29.8 to 98.2% relative standard deviation over the concentration range tested. Analysis of variance indicates that for all compounds tested, the variation from laboratory to laboratory is greater than that attributed to analytical error displayed within laboratories. There are many operational parameters that could contribute to interlaboratory variability; one of them, the thermospray tip temperature, can play a major role in adduct formation and ion fragmentation in the case of thermally labile carbamate pesticides and, therefore, needs to be monitored and controlled carefully. The correlation of mass spectral data with the thermospray tip temperature was attempted using principal component analysis.

Idiopathic myointimal hyperplasia is a distinct cause of chronic colon ischaemia

AIM

Colon ischaemia (CI) is most commonly an acute and reversible manifestation of a transient, non-occlusive decrease of blood flow in the colonic microvasculature. Irreversible complications are uncommon and the progression to chronic CI remains controversial. Our objective was to identify cases of chronic CI and assess for distinct clinicopathological features.

METHOD

A retrospective review was performed of CI patients having symptom chronicity of ≥ 1 month and ischaemic histology at our institution from 1994 to 2015. Demographic, clinical, endoscopic, radiological, pathological and outcome variables were abstracted. Histological evaluation was performed by two gastrointestinal pathologists.

RESULTS

Fifteen patients (n = 9; 67% men) with a median age of 65 years (range 22-88) were identified. The most common presenting symptoms were diarrhoea and abdominal pain (n = 6, 86%; n = 5, 71%, respectively). The typical endoscopic appearance was segmental ulceration of the sigmoid colon (n = 6, 75%). Vascular imaging showed patent mesenteric vessels in all patients. Histopathological evaluation revealed venous intimal hyperplasia consistent with idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) in eight patients; the remainder showed non-specific ulceration and fibrosis. Surgical resection was performed in seven IMHMV patients, resulting in symptom resolution. On re-review of pre-resection biopsies, all IMHMV patients had characteristic changes of hyperplastic, thick-walled, hyalinized vessels in the lamina propria.

CONCLUSIONS

IMHMV is a unique histopathological entity causing chronic CI. The small vessel histological changes in IMHMV are distinctive in colonic resections and undetectable by routine vascular imaging. Preoperative diagnosis of IMHMV is possible with endoscopic biopsy and segmental colon resection is curative.

Breast cancer survivor's perspectives on the role different providers play in follow-up care

IMPORTANCE

Significant variation in the number and types of oncologists that provide breast cancer follow-up exists. However, there is limited understanding regarding breast cancer survivors' preferences for who provides their follow-up. Our objective was to explore breast cancer survivors' perspectives on the goals of breast cancer follow-up, the preferred role for primary care providers, and the perceived roles of different types of oncologists during follow-up.

METHODS

A convenience sample of stage 0-III breast cancer survivors was identified and in-depth one-on-one interviews conducted. Data were analyzed using inductive content analysis.

RESULTS

Survivors cited a strong preference for oncology-based follow-up within the first 5 years after diagnosis, driven by their need for reassurance that cancer had not recurred. Survivors also thought that their primary care provider needed to be involved. Survivors assumed that oncology follow-up was directed by a standard protocol that included streamlining the follow-up team. Survivors recognized that patients with more complex cancers or challenging treatment courses may require more intensive follow-up and deviate from the standard protocol. Most survivors were comfortable deferring decisions regarding who participated in follow-up to the oncology team.

CONCLUSIONS

Most patients think a streamlined approach to oncology-based breast cancer follow-up already occurs, driven by a standard protocol. The use of a standard protocol to provide guidance for which types of oncology providers should participate in breast cancer follow-up will streamline care and represents a significant opportunity to reduce unnecessary variation. This approach is especially critical given patients' strong preferences for oncology-based follow-up.

Capillary Refill Time in Adults Has Poor Inter-Observer Agreement

Objectives

Capillary refill time (CRT) has been taught as a rapid indicator of circulatory status but to be a useful clinical test, CRT needs to be reproducible when performed by another health care worker. No inter-rater agreement studies have been reported for adult patients. The aim of this study was to determine the inter-observer reliability of CRT in a sample of adult emergency department (ED) patients. Methods This prospective observational study included clinically stable ED patients with a variety of conditions from two community EDs. A doctor and a nurse each measured CRT by estimation to the nearest half-second using a standard method on each patient. They were blinded to each other's measurements. The primary outcome of interest was inter-rater agreement. Secondary outcome was agreement in classification as normal or abnormal according to accepted definitions. Data was analysed using bias plot analysis, correlation, absolute percent agreement and kappa analysis. Results Totally, 209 patients were enrolled; 51% were female and 86% were Caucasian. Median CRT was 2 seconds (95% CI 2–2.35 seconds). The mean difference between measurements by the different observers was 0 second, however the 95% limits of agreement were very wide (–1.7 to +1.9 seconds). Agreement was 70% for classification of ‘normal’ or ‘abnormal’ using the 2-second definition of normal, with a kappa of 0.38. Conclusion Interobserver agreement in measurement of CRT was poor in adult subjects with wide limits of agreement. This is a serious threat to the appropriateness of this test for use in clinical practice.

Detection of latent tuberculosis infection among migrant farmworkers along the US-Mexico border

Background

Migrant farmworkers are among the highest-risk populations for latent TB infection (LTBI) in the United States with numerous barriers to healthcare access and increased vulnerability to infectious diseases. LTBI is usually diagnosed on the border using the tuberculin skin test (TST). QuantiFERON-TB Gold In-Tube (QFT-GIT) also measures immune response against specific Mycobacterium tuberculosis antigens. The objective of this study is to assess the comparability of TST and QFT-GIT to detect LTBI among migrant farmworkers on the border, as well as to examine the effects of various demographic and clinical factors on test positivity.

Methods

Participants were recruited using mobile clinics on the San Luis US-Mexico border and tested with QFT-GIT and TST. Demographic profiles and clinical histories were collected. Kappa coefficients assessed agreement between TST and QFT-GIT using various assay cutoffs. Logistic regression examined factors associated with positive TST or QFT-GIT results.

Results

Of 109 participants, 59 of 108 (55 %) were either TST (24/71, 34 %) or QFT-GIT (52/106, 50 %) positive. Concordance between TST and QFT-GIT was fair (71 % agreement, ĸ = 0.38, 95 % CI: 0.15, 0.61). Factors associated with LTBI positivity included smoking (OR = 1.26, 95 % CI–1.01–1.58) and diabetes/high blood sugar (OR = 0.70, 95 % CI = 0.51–0.98).

Discussion

Test concordance between the two tests was fair, with numerous discordant results observed. Greater proportion of positives detected using QFT-GIT may help avoid LTBI under-diagnosis. Assessment of LTBI status on the border provides evidence whether QFT-GIT should replace the TST in routine practice, as well as identifies risk factors for LTBI among migrant populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1959-3) contains supplementary material, which is available to authorized users.

Pollination, mating and reproductive fitness in a plant population with bimodal floral-tube length

Mating patterns and natural selection play important roles in determining whether genetic polymorphisms are maintained or lost. Here, we document an atypical population of Lapeirousia anceps (Iridaceae) with a bimodal distribution of floral-tube length and investigate the reproductive mechanisms associated with this pattern of variation. Flowers were visited exclusively by the long-proboscid fly Moegistorhynchus longirostris (Nemestrinidae), which exhibited a unimodal distribution of proboscis length and displayed a preference for long-tubed phenotypes. Despite being visited by a single pollinator species, allozyme markers revealed significant genetic differentiation between open-pollinated progeny of long- and short-tubed phenotypes suggesting mating barriers between them. We obtained direct evidence for mating barriers between the floral-tube phenotypes through observations of pollinator foraging, controlled hand pollinations and measurements of pollen competition and seed set. Intermediate tube-length phenotypes produced fewer seeds in the field than either long- or short-tubed phenotypes. Although floral-tube length bimodality may not be a stable state over long timescales, reproductive barriers to mating and low 'hybrid' fitness have the potential to contribute to the maintenance of this state in the short term.

Search for Spectral Irregularities due to Photon-Axionlike-Particle Oscillations with the Fermi Large Area Telescope

We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in the γ-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5×10^{-12}  GeV^{-1} for ALP masses 0.5≲m_{a}≲5  neV at 95% confidence. The limits are competitive with the sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain the possibility that ALPs can reduce the γ-ray opacity of the Universe.

Search for Pompe disease among patients with undetermined myopathies

OBJECTIVE

Pompe disease is a rare treatable glycogen storage disease with in adults - a limb-girdle muscle weakness. Muscle biopsy may fail to show the typical vacuolar myopathy. We asked if we had un-diagnosed patients with Pompe disease in western Sweden.

MATERIAL AND METHODS

We searched the muscle biopsy registry during the time period 1986 until 2006 including 3665 biopsies and included patients at our Neuromuscular Center with unspecified myopathy or limb-girdle muscular dystrophy. The dry blood spot test was used to identify patients with Pompe disease.

RESULTS

A total of 82 patients (46 from the biopsy register and 36 from our center) were seen and dry blood spot test was obtained. No patient with Pompe disease was found. The dry blood spot test was low in three cases (11, 16, and 18% of normal) but a second blood sample showed a normal result based on GAA enzyme activity in lymphocytes in all three patients. In one patient with low normal result of the analysis in lymphocytes a genetic test showed no pathogenic mutations. Further investigation gave a definite diagnose of another myopathy in 12 patients.

CONCLUSIONS

The prevalence of Pompe disease in western Sweden (3 in 1.27 million or 0.24 per 100.000 inhabitants) is lower than in the Netherlands and New York. Re-evaluation of patients with myopathies but without definite diagnosis is rewarding since 12 of 82 patients in our study had a definite molecular diagnosis after workup.

Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data

The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on γ-ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new Pass8 event-level analysis. None of the dSphs are significantly detected in γ rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs. These constraints are among the strongest and most robust to date and lie below the canonical thermal relic cross section for DM of mass ≲100  GeV annihilating via quark and τ-lepton channels.

Measurement of the Target-Normal Single-Spin Asymmetry in Quasielastic Scattering from the Reaction (3)He(↑)(e,e')

We report the first measurement of the target single-spin asymmetry, A(y), in quasielastic scattering from the inclusive reaction (3)He(↑)(e,e') on a (3)He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero A(y) can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the substructure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at Q(2)=0.13, 0.46, and 0.97  GeV(2). These measurements demonstrate, for the first time, that the (3)He asymmetry is clearly nonzero and negative at the 4σ-9σ level. Using measured proton-to-(3)He cross-section ratios and the effective polarization approximation, neutron asymmetries of -(1-3)% were obtained. The neutron asymmetry at high Q(2) is related to moments of the generalized parton distributions (GPDs). Our measured neutron asymmetry at Q(2)=0.97  GeV(2) agrees well with a prediction based on two-photon exchange using a GPD model and thus provides a new, independent constraint on these distributions.

Measurement of double-polarization asymmetries in the quasielastic (3)He[→](e[→],e(')d) process

We present a precise measurement of double-polarization asymmetries in the ^{3}He[over →](e[over →],e^{'}d) reaction. This particular process is a uniquely sensitive probe of hadron dynamics in ^{3}He and the structure of the underlying electromagnetic currents. The measurements have been performed in and around quasielastic kinematics at Q^{2}=0.25(GeV/c)^{2} for missing momenta up to 270  MeV/c. The asymmetries are in fair agreement with the state-of-the-art calculations in terms of their functional dependencies on p_{m} and ω, but are systematically offset. Beyond the region of the quasielastic peak, the discrepancies become even more pronounced. Thus, our measurements have been able to reveal deficiencies in the most sophisticated calculations of the three-body nuclear system, and indicate that further refinement in the treatment of their two-and/or three-body dynamics is required.

The prevalence of abnormal genital findings, vulvovaginitis, enuresis and encopresis in children who present with allegations of sexual abuse

OBJECTIVE

To assess the prevalence of vulvovaginitis, enuresis and encopresis in children who were referred for allegations of sexual abuse.

SUBJECTS

A retrospective chart review of 1280 children presenting for non-acute examination after allegations of sexual abuse during a 15-year time span. Interview documentation, physical examination documentation, urinalysis, urine and vaginal cultures were reviewed.

RESULTS

Of the 1280 children, 73.3% were female and 26.7% male. The ages of the children ranged from 6 months to 18 years (median age was 6 years). Interviews revealed that fondling contact was the most common allegation, followed by oral, vaginal, and anal penetration. Interviews also disclosed lower urinary tract symptoms, UTI, constipation, encopresis and enuresis. Physical examination revealed no abnormal genital findings in 44.7% of cases. Examinations of the vagina noted: erythema (18.1%); hymenal notching (posterior 16.8%, anterior 4.4%); vuvlovaginitis (14.0%); laceration or transection (0.6%); and bruising (0.4%). Examination of the anus noted: anal fissure/tear (14.9%); loss of anal tone (10.6%); reflex anal dilatation (9.2%); venous congestion (3.8%); and proctitis (0.9%). Vulvovaginitis was noted in 14% (131/936) and encopresis in 2.3% (21/936). Enuresis according to age was reported in 13% of 5-9 year olds, 14.7% of 10-16 year olds and 18.2% of 17-18 year olds suspected of being abused.

CONCLUSION

Prevalence of vulvovaginitis and enuresis were increased, and encopresis was decreased in children with allegations of sexual abuse when compared to the general pediatric population. Physicians should continue to be aware of the possibility of the presence of these conditions in children who have been sexually abused, and offer appropriate treatment.

Intraspecific divergence and convergence of floral tube length in specialized pollination interactions

Floral tubes are often thought to be a consequence of adaptive specialization towards pollinator morphology. We explore floral tube length evolution within Tritoniopsis revoluta (Iridaceae), a species with considerable geographical tube length variation. We ask whether tube lengths of T. revoluta populations are associated with pollinator proboscis lengths, whether floral divergence occurs in the presence of different pollinators and whether floral convergence occurs between distantly related populations pollinated by the same pollinator. Finally, we ask whether tube length evolution is directional. Shifts between morphologically different pollinators were always associated with shifts in floral morphology, even when populations were very closely related. Distantly related populations had similar tube lengths when they were pollinated by the same pollinator. Shifts in tube length tended to be from short to long, although reversals were not infrequent. After correcting for the population-level phylogeny, there was a strong positive, linear relationship between floral tube length and pollinator proboscis length, suggesting that plants are functionally specialized on different pollinators at different sites. However, because tube length evolution in this system can be a bidirectional process, specialization to the local pollinator fauna is unlikely to result in evolutionary or ecological dead-ends such as canalization or range limitation.

Fundamental mode operation of a ribbon fiber laser by way of volume Bragg gratings

Selection of the fundamental mode of an active large mode area "ribbon" fiber laser with core dimensions of 107.8 μm by 8.3 μm was produced by a transmitting Bragg grating (TBG) in a free-space resonator. The multimode performance of the original laser was characterized to have an M2 of 11.3 with an absorbed power slope efficiency of 76%. With the TBG aligned to provide maximum diffraction efficiency for the fundamental mode, the M2 improved to 1.45 at an absorbed power slope efficiency of 54% and enhanced the brightness by 5.1 times.