Prior Dengue Virus Exposure Shapes T Cell Immunity to Zika Virus in Humans.

While progress has been made in characterizing humoral immunity to Zika virus (ZIKV) in humans, little is known regarding the corresponding T cell responses to ZIKV. Here, we investigate the kinetics and viral epitopes targeted by T cells responding to ZIKV and address the critical question of whether preexisting dengue virus (DENV) T cell immunity modulates these responses. We find that memory T cell responses elicited by prior infection with DENV or vaccination with tetravalent dengue attenuated vaccines (TDLAV) recognize ZIKV-derived peptides. This cross-reactivity is explained by the sequence similarity of the two viruses, as the ZIKV peptides recognized by DENV-elicited memory T cells are identical or highly conserved in DENV and ZIKV. DENV exposure prior to ZIKV infection also influences the timing and magnitude of the T cell response. ZIKV-reactive T cells in the acute phase of infection are detected earlier and in greater magnitude in DENV-immune patients. Conversely, the frequency of ZIKV-reactive T cells continues to rise in the convalescent phase in DENV-naive donors but declines in DENV-preexposed donors, compatible with more efficient control of ZIKV replication and/or clearance of ZIKV antigen. The quality of responses is also influenced by previous DENV exposure, and ZIKV-specific CD8 T cells from DENV-preexposed donors selectively upregulated granzyme B and PD1, unlike DENV-naive donors. Finally, we discovered that ZIKV structural proteins (E, prM, and C) are major targets of both the CD4 and CD8 T cell responses, whereas DENV T cell epitopes are found primarily in nonstructural proteins.IMPORTANCE The issue of potential ZIKV and DENV cross-reactivity and how preexisting DENV T cell immunity modulates Zika T cell responses is of great relevance, as the two viruses often cocirculate and Zika virus has been spreading in geographical regions where DENV is endemic or hyperendemic. Our data show that memory T cell responses elicited by prior infection with DENV recognize ZIKV-derived peptides and that DENV exposure prior to ZIKV infection influences the timing, magnitude, and quality of the T cell response. Additionally, we show that ZIKV-specific responses target different proteins than DENV-specific responses, pointing toward important implications for vaccine design against this global threat.

Newly developed and validated eosinophilic esophagitis histology scoring system and evidence that it outperforms peak eosinophil count for disease diagnosis and monitoring.

Eosinophilic esophagitis (EoE) is diagnosed by symptoms, and at least 15 intraepithelial eosinophils per high power field in an esophageal biopsy. Other pathologic features have not been emphasized. We developed a histology scoring system for esophageal biopsies that evaluates eight features: eosinophil density, basal zone hyperplasia, eosinophil abscesses, eosinophil surface layering, dilated intercellular spaces (DIS), surface epithelial alteration, dyskeratotic epithelial cells, and lamina propria fibrosis. Severity (grade) and extent (stage) of abnormalities were scored using a 4-point scale (0 normal; 3 maximum change). Reliability was demonstrated by strong to moderate agreement among three pathologists who scored biopsies independently (P ≤ 0.008). Several features were often abnormal in 201 biopsies (101 distal, 100 proximal) from 104 subjects (34 untreated, 167 treated). Median grade and stage scores were significantly higher in untreated compared with treated subjects (P ≤ 0.0062). Grade scores for features independent of eosinophil counts were significantly higher in biopsies from untreated compared with treated subjects (basal zone hyperplasia P ≤ 0.024 and DIS P ≤ 0.005), and were strongly correlated (R-square >0.67). Principal components analysis identified three principal components that explained 78.2% of the variation in the features. In logistic regression models, two principal components more closely associated with treatment status than log distal peak eosinophil count (PEC) (R-square 17, area under the curve (AUC) 77.8 vs. R-square 9, AUC 69.8). In summary, the EoE histology scoring system provides a method to objectively assess histologic changes in the esophagus beyond eosinophil number. Importantly, it discriminates treated from untreated patients, uses features commonly found in such biopsies, and is utilizable by pathologists after minimal training. These data provide rationales and a method to evaluate esophageal biopsies for features in addition to PEC.

Post-acute phase and sequelae management of epidermal necrolysis: an international, multidisciplinary DELPHI-based consensus.

BACKGROUND: Long-term sequelae are frequent and often disabling after epidermal necrolysis (Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)). However, consensus on the modalities of management of these sequelae is lacking. OBJECTIVES: We conducted an international multicentric DELPHI exercise to establish a multidisciplinary expert consensus to standardize recommendations regarding management of SJS/TEN sequelae. METHODS: Participants were sent a survey via the online tool "Survey Monkey" consisting of 54 statements organized into 8 topics: general recommendations, professionals involved, skin, oral mucosa and teeth, eyes, genital area, mental health, and allergy workup. Participants evaluated the level of appropriateness of each statement on a scale of 1 (extremely inappropriate) to 9 (extremely appropriate). Results were analyzed according to the RAND/UCLA Appropriateness Method. RESULTS: Fifty-two healthcare professionals participated. After the first round, a consensus was obtained for 100% of 54 initially proposed statements (disagreement index < 1). Among them, 50 statements were agreed upon as 'appropriate'; four statements were considered 'uncertain', and ultimately finally discarded. CONCLUSIONS: Our DELPHI-based expert consensus should help guide physicians in conducting a prolonged multidisciplinary follow-up of sequelae in SJS-TEN.

Surgical management and epidemiological trends of pediatric electrical burns.

Electrical burns are an uncommon yet devastating class of burn injuries. Shriners Hospitals for Children - Boston a pediatric burn center in New England and cares for both domestic and international patients. We utilized our experience over the past 13 years to review surgical management and evaluate historical trends for this unique patient group. A retrospective chart review was conducted on 68 patients aged 0-18 years admitted to our pediatric center with an electrical burn from January 2005 to December 2018. We collected and analyzed data pertaining to patient demographics, burn characteristics, clinical course, and surgical interventions. Our cohort included 31 patients from the US (46%) and 37 transferred from a variety of international countries (54%). The majority of US patients were admitted with low voltage burns (81%), whereas the majority of international patients were admitted with high voltage burns (95%). Acute and reconstructive surgical interventions were performed mainly for high voltage burns (94% and 89%). Based on our experience, epidemiology and surgical intervention varied based on voltage of the burn injury and residence of the patient. We have seen a reduction in US pediatric high voltage injuries over the past two decades, likely due to enhancement of electrical safety. It may be possible to use a similar strategy to reduce the frequency of severe high voltage electrical burn injuries in developing countries.

A 5' leader sequence regulates expression of methanosarcinal CO dehydrogenase/acetyl coenzyme A synthase.

In vivo expression of CO dehydrogenase/acetyl coenzyme A synthase in Methanosarcina spp. is coordinately regulated in response to substrate by at least two mechanisms: differential transcription initiation and early elongation termination near the 3' end of a 371-bp leader sequence. This is the first report of regulation of transcription elongation in the Archaea.

The archetype gamma-class carbonic anhydrase (Cam) contains iron when synthesized in vivo.

A recombinant protein overproduction system was developed in Methanosarcina acetivorans to facilitate biochemical characterization of oxygen-sensitive metalloenzymes from strictly anaerobic species in the Archaea domain. The system was used to overproduce the archetype of the independently evolved gamma-class carbonic anhydrase. The overproduced enzyme was oxygen sensitive and had full incorporation of iron instead of zinc observed when overproduced in Escherichia coli. This, the first report of in vivo iron incorporation for any carbonic anhydrase, supports the need to reevaluate the role of iron in all classes of carbonic anhydrases derived from anaerobic environments.

Chemoreceptors in lepidoptera: stereochemical differentiation of dual receptors for an achiral pheromone.

The racemate and optically pure enantiomers of 9-(2-cyclopenten-1yl)nonyl acetate have been synthesized and shown to mimic certain biological properties of (Z)-11-tetradecenyl acetate. European corn borers and red-banded leaf rollers respond differently to the racemate and to the enantiomers in precopulatory behavior bioassay. The responses demonstrate the presence of two stereospecific chemoreceptors, show the chiral character of these receptors, and define the conformation of carbon atoms 10 to 14 of (Z)-11-tetradecenyl acetate in these receptors.

Polony analysis of gene expression in ES cells and blastocysts.

Expression profiling of stem cells is challenging due to their small numbers and heterogeneity. The PCR colony (polony) approach has theoretical advantages as an assay for stem cells but has not been applied to small numbers of cells. An assay has been developed that is sensitive enough to detect mRNAs from small numbers of ES cells and from fractions of a single mouse blastocyst. Genes assayed include Oct3, Rex1, Nanog, Cdx2 and GLUT-1. The assay is highly sensitive so that multiple mRNAs from a single blastocyst were easily detected in the same assay. In its present version, the assay is an attractive alternative to conventional RT-PCR for profiling small populations of stem cells. The assay is also amenable to improvements that will increase its sensitivity and ability to analyze many cDNAs simultaneously.

Investigation of 'stone fruit' aroma in Chardonnay, Viognier and botrytis Semillon wines.

Despite numerous studies, the identity of the compounds that are responsible for 'stone fruit' aroma in wine has not been conclusively established. This study focussed on wine varieties that often display peach and apricot characters, such as Chardonnay, Viognier and botrytis-affected sweet Semillon wines. Wines with high and low 'stone fruit' aroma were evaluated by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) using extracts representative of the aroma of the wine in a glass. No aroma-active zone was described as 'stone fruit' aroma across all three wine varietals. However, for the individual varieties, terpenes, such as linalool and geraniol, in the Viognier wines, several esters in the Chardonnay wines, and γ-nonalactone in the botrytis Semillon were associated with 'stone fruit' aroma. Notably, this is the first study assessing the aroma profile of Viognier wine by GC-O. In addition, an extension study of Viognier grape monoterpene profiles clarified its classification as an aromatic variety.

Analysis, potency and occurrence of (Z)-6-dodeceno-γ-lactone in white wine.

(Z)-6-Dodeceno-γ-lactone is a potent aroma compound that has been little studied and its prevalence in wines is unknown. An efficient stable isotope dilution assay was developed using a simple, direct immersion solid-phase microextraction and gas chromatography-tandem mass spectrometry method suitable for routine use with a low ng/L limit of quantitation. Using this method, 99 out of 104 young white wines analysed were found to contain detectable (Z)-6-dodeceno-γ-lactone. The highest concentrations were found in Riesling and Viognier wines. (Z)-6-Dodeceno-γ-lactone was found to have an aroma detection threshold of 700 ng/L in a neutral white wine. This study established that (Z)-6-dodeceno-γ-lactone is widely present in Australia's most popular white wine varieties, but generally at concentrations below its aroma detection threshold.

Hepatic Hilar Lymph Node Reactivity at Kasai Portoenterostomy for Biliary Atresia: Correlations With Age, Outcome, and Histology of Proximal Biliary Remnant.

We hypothesized that if infection is the proximate cause of congenital biliary atresia, an appropriate response to antigen would occur in lymph nodes contiguous with the biliary remnant. We compared the number of follicular germinal centers (GC) in 79 surgically excised hilar lymph nodes (LN) and 27 incidentally discovered cystic duct LNs in 84 subjects at the time of hepatic portoenterostomy (HPE) for biliary atresia (BA) to autopsy controls from the pancreaticobiliary region of non-septic infants >3 months old at death. All 27 control LN lacked GC, a sign in infants of a primary response to antigenic stimulation. GC were found in 53% of 106 LN in 56 of 84 subjects. Visible surgically excised LN contiguous with the most proximal biliary remnants had 1 or more well-formed reactive GC in only 26/51 subjects. Presence of GC and number of GC/LN was unrelated to age at onset of jaundice or to active fibroplasia in the biliary remnant but was related to older age at HPE. Absent GC in visible and incidentally removed cystic duct LNs predicted survival with the native liver at 2 and 3 years after HPE, P = .03, but significance was lost at longer intervals. The uncommon inflammatory lesions occasionally found in remnants could be secondary either to bile-induced injury or secondary infection established as obstruction evolves. The absence of consistent evidence of antigenic stimulation in LN contiguous with the biliary remnant supports existence of at least 1 major alternative to infection in the etiology of biliary atresia.

Volatile Compounds Related to 'Stone Fruit' Aroma Attributes in Viognier and Chardonnay Wines.

A 'stone fruit' aroma is important in many white wine varieties and styles, but little is known about the chemical basis of this wine aroma attribute. A set of Viognier and Chardonnay wines that featured 'stone fruit' aroma attributes were selected by a panel of wine experts. The selected wines were characterized by sensory descriptive analysis and detailed volatile chemical composition analyses. This comprehensive data also allowed Viognier wine to be profiled for the first time. By partial least-squares regression, several esters and fatty acids and benzaldehyde were indicated as contributing to the 'peach' attribute; however, a reconstitution sensory study was unsuccessful in mimicking this attribute. A mixture of γ-lactones, monoterpenes, and aldehydes were positively correlated to the 'apricot' aroma, which were generally higher in the Viognier wines. Reconstitution studies confirmed that the monoterpenes linalool, geraniol, and nerol were the most important compounds for the mixture being perceived as having an 'apricot' aroma.

Electromagnetic modelling of current flow in the heart from TASER devices and the risk of cardiac dysrhythmias.

Increasing use by law enforcement agencies of the M26 and X26 TASER electrical incapacitation devices has raised concerns about the arrhythmogenic potential of these weapons. Using a numerical phantom constructed from medical images of the human body in which the material properties of the tissues are represented, computational electromagnetic modelling has been used to predict the currents arising at the heart following injection of M26 and X26 waveforms at the anterior surface of the chest (with one TASER 'barb' directly overlying the ventricles). The modelling indicated that the peak absolute current densities at the ventricles were 0.66 and 0.11 mA mm(-2) for the M26 and X26 waveforms, respectively. When applied during the vulnerable period to the ventricular epicardial surface of guinea-pig isolated hearts, the M26 and X26 waveforms induced ectopic beats, but only at current densities greater than 60-fold those predicted by the modelling. When applied to the ventricles in trains designed to mimic the discharge patterns of the TASER devices, neither waveform induced ventricular fibrillation at peak currents >70-fold (for the M26 waveform) and >240-fold (for the X26) higher than the modelled current densities. This study provides evidence for a lack of arrhythmogenic action of the M26 and X26 TASER devices.

Auditory stream segregation in an insect.

Auditory stream segregation is the perceptual grouping of the acoustic mixture reaching the ear into coherent representations of sound sources. It has been described in a variety of vertebrates and underlies auditory scene analysis or auditory image formation. Here we describe a phenomenon in an invertebrate that bears an intriguing resemblance to auditory stream segregation observed in vertebrates: in Neoconocephalus retusus (Orthoptera, Tettigoniidae) an auditory interneuron segregates information about bat echolocation calls from background male advertisement songs. This process utilizes differences between the temporal and spectral characteristics of the two stimuli, a mechanism which is similar to those of auditory stream segregation in vertebrates. This similarity suggests that auditory stream segregation is a fundamental feature of auditory perception, widespread from invertebrates to humans.

Rates and equilibria at the acetylcholine receptor of Electrophorus electroplaques: a study of neurally evoked postsynaptic currents and of voltage-jump relaxations.

Kinetic measurements are employed to reconstruct the steady-state activation of acetylcholine [Ach] receptor channels in electrophorus electroplaques. Neurally evoked postsynaptic currents (PSCs) decay exponentially; at 15 degrees C the rate constant, alpha, equals 1.2 ms(-1) at 0 mV and decreases e-fold for every 86 mV as the membrane voltage is made more negative. Voltage-jump relaxations have been measured with bath-applied ACh, decamethonium, carbachol, or suberylcholine. We interpret the reciprocal relaxation time 1/tau as the sum of the rate constant alpha for channel closing and a first-order rate constant for channel opening. Where measureable, the opening rate increases linearly with [agonist] and does not vary with voltage. The voltage sensitivity of small steady-state conductances (e- fold for 86 mV) equals that of the closing rate alpha, confirming that the opening rate has little or no additional voltage sensitivity. Exposure to alpha-bungarotoxin irreversibly decreases the agonist-induced conductance but does not affect the relaxation kinetics. Tubocurarine reversibly reduces both the conductance and the opening rate. In the simultaneous presence of two agonist species, voltage-jump relaxations have at least two exponential components. The data are fit by a model in which (a) the channel opens as the receptor binds the second in a sequence of two agonist molecules, with a forward rate constant to 10(7) to 2x10(8) M(-1)s(-1); and (b) the channel then closes as either agonist molecule dissociates, with a voltage-dependent rate constant of 10(2) to 3x10(3)s(-1).

Functional stoichiometry at the nicotinic receptor. The photon cross section for phase 1 corresponds to two bis-Q molecules per channel.

These experiments examine changes in the agonist-induced conductance that occur when the agonist-receptor complex is perturbed. Voltage-clamped Electrophorus electroplaques are exposed to the photoisomerizable agonist trans-Bis-Q. A 1-microsecond laser flash photoisomerizes some trans-Bis-Q molecules bound to receptors; because the cis configuration is not an agonist, receptor channels close within a few hundred microseconds. This effect is called phase 1. We compare (a) the fraction of channels that close during phase 1 with (b) the fraction of trans-Bis-Q molecules that undergo trans leads to cis photoisomerization. Parameter a is measured as the fractional diminution in voltage-clamp currents during phase 1. Parameter b is measured by changes in the optical spectra of Bis-Q solutions caused by flashes. At low flash intensities, a is twice b, which shows that the channel can be closed by photoisomerizing either of two bound agonist molecules. Conventional dose-response studies with trans-Bis-Q also give a Hill coefficient of two. As a partial control for changes in the photochemistry caused by binding of Bis-Q to receptors, spectral measurements are performed on the photoisomerizable agonist QBr, covalently bound to solubilized acetylcholine receptors from Torpedo. The bound and free agonist molecules have the same photoisomerization properties. These results verify the concept that the open state of the acetylcholine receptor channel is much more likely to be associated with the presence of two bound agonist molecules than with a single such molecule.

Conductance increases produced by bath application of cholinergic agonists to Electrophorus electroplaques.

When solutions containing agonists are applied to the innervated face of an Electrophorus electroplaque, the membrane's conductance increases. The agonist-induced conductance is increased at more negative membrane potentials. The "instantaneous" current-voltage curve for agonist-induced currents is linear and shows a reversal potential near zero mV; chord conductances, calculated on the basis of this reversal potential, change epsilon-fold for every 62-mV change in potential when the conductance is small. Conductance depends non-linearly on small agonist concentrations; at all potentials, the dose-response curve has a Hill coefficient of 1.45 for decamethonium (Deca) and 1.90 for carbamylcholine (Carb). With agonist concentrations greater than 10(-4) M Carb or 10(-%) M Deca, the conductance rises to a peak 0.5-1.5 min after introduction of agonist, then declines with time; this effect resembles the "desensitization" reported for myoneural junctions. Elapid alpha-toxin, tubocurarine, and desensitization reduce the conductance without changing the effects of potential; the apparent dissociation constant for tubocurarine is 2 X 10(-7) M. By contrast, procaine effects a greater fractional inhibition of the conductance at high negative potentials.

Chemotaxis-defective mutants of the nematode Caenorhabditis elegans.

The technique of countercurrent separation has been used to isolate 17 independent chemotaxis-defective mutants of the nematode Caenorhabditis elegans. The mutants, selected to be relatively insensitive to the normally attractive salt NaCl, show varying degrees of residual sensitivity; some are actually weakly repelled by NaCl. The mutants are due to single gene defects, are autosomal and recessive, and identify at least five complementation groups.

NSAID use and BP in treated hypertensives: a retrospective controlled observational study.

The objective of this study was to investigate the association between NSAID use and blood pressure (BP) among a sample of treated hypertensive patients. A controlled observational study was designed in UK primary care setting. Patients with diagnosed hypertension and currently being prescribed antihypertensive medication registered with four general practices, comparing patients also prescribed NSAIDs (exposed) to those not prescribed NSAIDs (unexposed). Majority of the patients were elderly. Systolic and diastolic pressure were the outcome measures. Data were collected for 184 NSAID users and 762 nonusers with a mean age of 68 years. There was no difference in either systolic (adjusted difference 1.9 mmHg, 95% CI -0.7 to 4.5, P=0.15) or diastolic (adjusted difference 1.0 mmHg, 95% CI -0.3 to 2.3, P=0.15) blood pressure. There was no evidence of any interactions according to categories of age, sex, or number of antihypertensive drugs prescribed. Among NSAID users, there was no evidence of any differences in blood pressure according to NSAID type or dose. In conclusion we found no evidence for an association between NSAID usage and BP control in known hypertensive patients receiving antihypertensive medication in primary care. The reported association between NSAID use and BP control appears much less substantial than has been previously suggested.

Autonomous secretion of follicle-stimulating hormone by long term organ cultures of rat pituitaries.

Pituitaries removed from ovariectomized adult rats were maintained for 18 weeks in organ culture using three different culture media. Gonadotropin secretion was assessed by RIA and was correlated with the histological features of the cultures. In medium favoring prolonged survival of the cultures, LH content of the medium fell to a low level within a few days. In the same cultures, FSH production initially decreased before increasing and leveling at a plateau which persisted until the end of the culture period. Cultures in medium unsuitable for long term survival of pituitary tissue displayed a similar decrease in LH production along with a gradual fall of FSH. It was concluded that contrary to LH, FSH may be secreted autonomously by pituitaries removed from hypothalamic control, provided that culture conditions are adequate for survival of gonadotropes.