Surgery versus intrapleural fibrinolysis for management of complicated pleural infections: a systematic review and meta-analysis.

BACKGROUND: Complicated pleural infection comprises of complex effusions and empyema. When tube thoracostomy is ineffective, treatment options include surgical drainage, deloculation and decortication or intrapleural fibrinolysis. We performed a systematic review and meta-analysis to examine which technique is superior in treating complicated pleural infections. METHODS: PubMed, MEDLINE and EMBASE databases were searched for studies published between January 2000 to July 2023 comparing surgery and intrapleural fibrinolysis for treatment of complicated pleural infection. The primary outcome was treatment success. Secondary outcomes included hospital length of stay, chest drain duration and in-hospital mortality. RESULTS: Surgical management of complicated pleural infections was more likely to be successful than intrapleural fibrinolysis (RR 1.18; 95% CI 1.02, 1.38). Surgical intervention group benefited from statistically significant shorter hospital length of stay (MD: 3.85; 95% CI 1.09, 6.62) and chest drain duration (MD: 3.42; 95% CI 1.36, 5.48). There was no observed difference between in-hospital mortality (RR: 1.00; 95% CI 0.99, 1.02). CONCLUSION: Surgical management of complicated pleural infections results in increased likelihood of treatment success, shorter chest drain duration and hospital length of stay in the adult population compared with intrapleural fibrinolysis. In-hospital mortality did not differ. Large cohort and randomized research need to be conducted to confirm these findings.

Impaired calcium influx underlies skewed T helper cell differentiation in children with IgE-mediated food allergies.

BACKGROUND: Reasons for Th2 skewing in IgE-mediated food allergies remains unclear. Clinical observations suggest impaired T cell activation may drive Th2 responses evidenced by increased atopic manifestations in liver transplant patients on tacrolimus (a calcineurin inhibitor). We aimed to assess differentiation potential, T cell activation and calcium influx of naïve CD4+ T cells in children with IgE-mediated food allergies. METHODS: Peripheral blood mononuclear cells from infants in the Starting Time for Egg Protein (STEP) Trial were analyzed by flow cytometry to assess Th1/Th2/Treg development. Naïve CD4+ T cells from children with and without food allergies were stimulated for 7 days to assess Th1/Th2/Treg transcriptional factors and cytokines. Store operated calcium entry (SOCE) was measured in children with and without food allergies. The effect of tacrolimus on CD4+ T cell differentiation was assessed by treating stimulated naïve CD4+ T cells from healthy volunteers with tacrolimus for 7 days. RESULTS: Egg allergic infants had impaired development of IFNγ+ Th1 cells and FoxP3+ transitional CD4+ T cells compared with non-allergic infants. This parallels reduced T-bet, IFNγ and FoxP3 expression in naïve CD4+ T cells from food allergic children after in vitro culture. SOCE of naïve CD4+ T cells was impaired in food allergic children. Naïve CD4+ T cells treated with tacrolimus had reduced IFNγ, T-bet, and FoxP3, but preserved IL-4 expression. CONCLUSIONS: In children with IgE-mediated food allergies, dysregulation of T helper cell development is associated with impaired SOCE, which underlies an intrinsic impairment in Th1 and Treg differentiation. Along with tacrolimus-induced Th2 skewing, this highlights an important role of SOCE/calcineurin pathway in T helper cell differentiation.

Preoperative Nonselective Chest Computed Tomography Prior to Primary Cardiac Surgery Results in Meaningful Change to Surgical Management: Systematic Review and Pooled Prevalence Meta-Analysis.

BACKGROUND: Routine screening chest computed tomography (CT) prior to primary cardiac surgery is advocated by some surgeons due to the purported benefits of identifying significant aortic calcification that impacts ongoing management, such as performing anaortic off-pump surgery or adjusting cannulation strategy. Additionally, axial imaging can identify incidental findings that may require concomitant or staged procedures such as ascending aortic dilatation or pulmonary lesions. The objective of this study was to quantify the impact that nonselective chest CT prior to primary cardiac surgery had on subsequent management. METHOD: A systematic review and pooled prevalence meta-analyses were performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Included studies performed non-selective chest CT prior to primary cardiac surgery. RESULTS: A total of eight studies, including 2,250 patients were included. The rate of mortality and stroke was low (1% and 2%, respectively). Calcification of the ascending aorta was identified in 15% of patients (95% confidence interval [CI] 5.0-26.0). A significant change to the surgical plan such as cannulation strategy, off-pump surgery, cancellation, or an additional procedure was required in 7% (95% CI 2.0-12.0). Clinically relevant incidental findings requiring in-patient management or follow-up were identified in 10% (95% CI 6.0-14.0). CONCLUSIONS: Nonselective CT chest prior to primary cardiac surgery identifies clinically relevant findings that result in a modification of the surgical plan in a significant population of patients to address the risk of stroke associated with aortic calcification as well as the identification of important incidental findings such as pulmonary lesions.

Bi-National Outcomes of Redo Surgical Aortic Valve Replacement in the Era of Valve-in-Valve Transcatheter Aortic Valve.

BACKGROUND: Implantation of bioprosthetic valves is more common as the population ages and there is a shift towards implanting bioprosthetic aortic valves in an increasingly younger surgical population. Bioprosthetic heart valve insertion, however, carries the long-term risk of valve failure through structural valve degeneration. Re-operative surgical aortic valve replacement has historically been the only definitive management option for patients with prosthetic valve dysfunction, however, data on the short- and long-term outcomes following re-operative surgery in Australia and New Zealand is limited. METHOD: Data on all patients who underwent redo aortic valve surgery, over a 20-year period (up to 2021) was obtained from the Australian and New Zealand Society of Cardiothoracic Surgery Registry. RESULTS: A total of 1,199 patients (770 males; 64.2% and 429 females; 35.8%) were included in the overall analysis. The 30-day mortality was 6.4% with operative urgency status the most important risk factor for peri-operative mortality. The long-term survival rate of 1,145 patients was 90.5% (95% confidence interval [CI] 88.8%-92.3%), 77% (95% CI 73.9%-80.2%) and 57.2% (95% CI 55.2%-62.8%) at 1-, 5- and 10-years post-procedure, respectively, with a median survival of 12.7 years. Pre-existing chronic kidney disease was strongly associated with poorer long-term survival. For patients under 70 years of age the 1-, 5- and 10-year survival rates were 92.9% (95% CI 90.9%-95.1%), 83.6% (95% CI 80.1%-87.3%) and 73.1% (95% CI 67.4%-79.3%), respectively. CONCLUSIONS: The results from this registry study indicate that in Australia and New Zealand, a repeat surgical aortic valve replacement can result in a relatively low mortality rate, serving as a reference point for medical procedures in these regions.

Detection of molecular oxygen using nanosecond-laser-induced plasma.

Molecular oxygen (O2) concentration is measured by employing nanosecond laser-induced plasmas (ns-LIP) over a broad temperature spectrum ranging from 300 K to 1000 K, in the presence of an additional oxygen-containing molecule, CO2. Typically, emission spectra emanating from ns-LIP are devoid of molecular information, as the ns-LIP causes the dissociation of molecular species within the plasma. However, atomic oxygen absorption lines that momentarily appear at 777 nm in the broadband emission from the early-stage plasma are determined to be highly sensitive to the O2 mole fraction but negligibly affected by the CO2 mole fraction. The atomic O absorbing the plasma emission originates from the O2 adjacent to the plasma: robust UV radiation from the early-stage plasma selectively dissociates adjacent O2, exhibiting a relatively low photodissociation threshold, thus generating the specific meta-stable oxygen capable of absorbing photons at 777 nm. A theoretical model is introduced, explicating the formation of the meta-stable O atom from adjacent O2. To sustain the UV radiation from the plasma under high-temperature and low-density ambient conditions, a preceding breakdown is triggered by a split laser pulse (532 nm). This breakdown acts as a precursor, seeding electrons to intensify the inverse-Bremsstrahlung photon absorption of the subsequent laser pulse (1064 nm). Techniques such as proper orthogonal decomposition (POD) and support vector regression (SVR) are employed to precisely evaluate the O2 mole fraction (<1% uncertainty), by analyzing the short-lived (<10 ns) O2-indicator depicted in the early-stage plasma.

A vanguard randomised feasibility trial comparing three regimens of peri-operative oxygen therapy on recovery after major surgery.

International recommendations encourage liberal administration of oxygen to patients having surgery under general anaesthesia, ostensibly to reduce surgical site infection. However, the optimal oxygen regimen to minimise postoperative complications and enhance recovery from surgery remains uncertain. The hospital operating theatre randomised oxygen (HOT-ROX) trial is a multicentre, patient- and assessor-blinded, parallel-group, randomised clinical trial designed to assess the effect of a restricted, standard care, or liberal peri-operative oxygen therapy regimen on days alive and at home after surgery in adults undergoing prolonged non-cardiac surgery under general anaesthesia. Here, we report the findings of the internal vanguard feasibility phase of the trial undertaken in four large metropolitan hospitals in Australia and New Zealand that included the first 210 patients of a planned overall 2640 trial sample, with eight pre-specified endpoints evaluating protocol implementation and safety. We screened a total of 956 participants between 1 September 2019 and 26 January 2021, with data from 210 participants included in the analysis. Median (IQR [range]) time-weighted average intra-operative Fi O2 was 0.30 (0.26-0.35 [0.20-0.59]) and 0.47 (0.44-0.51 [0.37-0.68]) for restricted and standard care, respectively (mean difference (95%CI) 0.17 (0.14-0.20), p < 0.001). Median time-weighted average intra-operative Fi O2 was 0.83 (0.80-0.85 [0.70-0.91]) for liberal oxygen therapy (mean difference (95%CI) compared with standard care 0.36 (0.33-0.39), p < 0.001). All feasibility endpoints were met. There were no significant patient adverse events. These data support the feasibility of proceeding with the HOT-ROX trial without major protocol modifications.

Nanosecond laser pulse modulation using seed electrons from cascade ionization induced by inverse-Bremsstrahlung photon absorption.

Nanosecond (ns) laser pulses are modulated by seeding electrons on the laser beam path. The seed-electrons are from auxiliary ns-laser-induced breakdown (ALIB), and the ALIB is induced by a focused 1064-nm pulse, which is split after the frequency-doubling that generates the 532-nm pulse; therefore, the 532-nm and 1064-nm pulses are synchronized. The slowly converging (focal length = 500 mm) 532-nm pulse is re-directed to transmit through the region in where the ALIB-generated electrons reside. The seed-electrons from the ALIB then absorb the 532-nm photons via the inverse-Bremsstrahlung photon absorption (IBPA) process. The number density of the seed-electrons on the 532-nm beam path (ne,ALIB) is controlled by varying 1) the 532-nm pulse arrival time at the ALIB region (ΔPAT) after the 1064-nm pulse triggers the ALIB and 2) the location of the 532-nm beam relative to the core of the ALIB; the electron number density in ALIB is highly non-uniform and evolves in time. Electron-seeded laser-induced breakdown (ESLIB) occurs when ne,ALIB is sufficiently high. The 532-nm beam convergence (controlled by the focusing lens) is adjusted so that the breakdown does not occur without the electron seeding. The ESLIB immediately stops the transmission of the trailing edge of the laser pulse acting as a fast shutter, and ne,ALIB above a threshold can cut the pulse leading edge to modulate the 532-nm laser pulse.

Evidence for a Square-Square Vortex Lattice Transition in a High-T_{c} Cuprate Superconductor.

Using sound velocity and attenuation measurements in high magnetic fields, we identify a new transition in the vortex lattice state of La_{2-x}Sr_{x}CuO_{4}. The transition, observed in magnetic fields exceeding 35 T and temperatures far below zero field T_{c}, is detected in the compression modulus of the vortex lattice, at a doping level of x=p=0.17. Our theoretical analysis based on Eilenberger's theory of the vortex lattice shows that the transition corresponds to the long-sought 45° rotation of the square vortex lattice, predicted to occur in d-wave superconductors near a van Hove singularity.

Staff and patient experience of the implementation and delivery of a virtual health care home monitoring service for COVID-19 in Melbourne, Australia.

BACKGROUND: Provision of virtual health care (VHC) home monitoring for patients who are experiencing mild to moderate COVID-19 illness is emerging as a central strategy for reducing pressure on acute health systems. Understanding the enablers and challenges in implementation and delivery of these programs is important for future implementation and re-design. The aim of this study was to explore the perspectives of staff involved with the implementation and delivery, and the experience of patients managed by, a VHC monitoring service in Melbourne, Australia during the COVID-19 pandemic. METHODS: A descriptive qualitative approach informed by naturalist inquiry was used. Staff interviews were analysed using the Consolidated Framework for Implementation Research (CFIR). Patient experience was captured using a survey and descriptive statistics were used to describe categorical responses while content analysis was used to analyse free text responses as they related to the CFIR. Finally, data from the interviews and patient experience were triangulated to see if patient experience validated data from staff interviews. RESULTS: All 15 staff were interviewed, and 271 patients were surveyed (42%). A total of four final overarching themes emerged: service implementation enablers, service delivery benefits for patients, fragmentation of care, and workforce strengths. 19 subthemes aligned with 18 CFIR constructs from staff and patient data. CONCLUSION: Rapid implementation was enabled through shared resources, dividing implementation tasks between senior personnel, engaging furloughed healthcare staff in design and delivery, and having a flexible approach that allowed for ongoing improvements. Benefits for patients included early identification of COVID-19 deterioration, as well as provision of accurate and trustworthy information to isolate safely at home. The main challenges were the multiple agencies involved in patient monitoring, which may be addressed in the future by attributing responsibility for monitoring to a single agency.

Descriptive Analysis of a Telephone Based Community Monitoring Service for COVID-19.

The coronavirus disease (COVID-19) pandemic has required health services to rapidly respond to the needs of people diagnosed with the virus. Over 80% of people diagnosed with COVID-19 experience a mild illness and there is a need for community management to support these people in their home. In this paper we present, a telephone based COVID-19 community monitoring service developed in an Australian public health network, and we describe the rapid implementation of the service and the demographic and clinical characteristics of those enrolled. A retrospective mixed methods evaluation of the COVID-19 community monitoring service using the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework. Eight hundred and fifty COVID-19 positive patients were enrolled, 54% female, 45% male, mean age 34 years SD 17. Four hundred and nine (48%) patients were born outside Australia. Among the 850 patients, 305 (36%) were classified as having a high risk of serious illness from COVID-19. The most prevalent risk factors were cardiovascular disease (37%), lung disease (30%) and age over 60 years (26%). The most common reported ongoing symptoms were fatigue (55%), breathing issues (26%) and mental health issues such as low mood (19%). There were no deaths in patients that participated in the service. The process of risk stratification undertaken with telephone triage was effective in determining risk of prolonged illness from COVID-19. Telephone monitoring by trained health professionals has a strong potential in the effective management of patients with a mild COVID-19 illness.

100 kHz krypton planar laser-induced fluorescence imaging.

Krypton planar laser-induced fluorescence (Kr PLIF) was demonstrated at a repetition rate of 100 kHz. To achieve this increased rate, a custom injection-seeded optical parametric oscillator was built to efficiently convert the 355 nm output of a high-energy, high-repetition-rate nanosecond burst-mode laser to 212.56 nm to excite Kr from the ground to the 5p[1/2]0 electronic state. Successful tracking of flow structures and mixture fraction was demonstrated using detection speeds 100 times greater than previously attained with a femtosecond laser source. The increase in repetition rate makes time-resolved Kr PLIF relevant for high-speed flows in particular.

Predicting outcomes after acute reperfusion therapy for basilar artery occlusion.

BACKGROUND AND PURPOSE: Basilar artery occlusion (BAO) leads to high rates of morbidity and mortality, despite successful recanalization. The discordance between flow restoration and long-term functional status clouds clinical decision-making regarding further aggressive care. We sought to develop and validate a practical, prognostic tool for the prediction of 3-month favorable outcome after acute reperfusion therapy for BAO. METHODS: This retrospective, multicenter, observational study was conducted at four high-volume stroke centers in the USA and Europe. Multivariate regression analysis was performed to identify predictors of favorable outcome (90-day modified Rankin scale scores 0-2) and derive a clinically applicable prognostic model (the Pittsburgh Outcomes after Stroke Thrombectomy-Vertebrobasilar (POST-VB) score). The POST-VB score was evaluated and internally validated with regard to calibration and discriminatory ability. External validity was assessed in patient cohorts at three separate centers. RESULTS: In the derivation cohort of 59 patients, independent predictors of favorable outcome included smaller brainstem infarct volume on post-procedure magnetic resonance imaging (P < 0.01) and younger age (P = 0.01). POST-VB score was calculated as: age + (10 × brainstem infarct volume). POST-VB score demonstrated excellent discriminatory ability [area under the receiver-operating characteristic curve (AUC) = 0.91] and adequate calibration (P = 0.88) in the derivation cohort (Center A). It performed equally well across the three external validation cohorts (Center B, AUC = 0.89; Center C, AUC = 0.78; Center D, AUC = 0.80). Overall, a POST-VB score < 49 was associated with an 88% likelihood of favorable outcome, as compared to 4% with a score ≥ 125. CONCLUSIONS: The POST-VB score effectively predicts 3-month functional outcome following acute reperfusion therapy for BAO and may aid in guiding post-procedural care.

A pilot randomised controlled trial of the management of systolic blood pressure during endovascular thrombectomy for acute ischaemic stroke.

It is unknown whether systolic blood pressure augmentation during endovascular thrombectomy improves clinical outcomes. This pilot randomised controlled trial aimed to assess the feasibility of differential systolic blood pressure targeting during endovascular thrombectomy procedures for anterior circulation ischaemic stroke. Fifty-one eligible patients fulfilling the national criteria for endovascular thrombectomy were randomly assigned to receive either standard or augmented systolic blood pressure management from the start of anaesthesia to recanalisation of the target vessel. Systolic blood pressure targets for the standard and augmented groups were 130-150 mmHg and 160-180 mmHg, respectively. The study achieved all feasibility targets, including a recruitment rate of 3.5 participants per week and median (IQR [range]) of mean systolic blood pressure separation between groups of 139 (135-143 [115-154]) vs. 167 (150-175 [113-188]) mmHg, p < 0.001. Data completeness was 99%. Independent functional recovery at 90 days (modified Rankin Scale 0, 1 or 2) was achieved in 30 (59%) patients, which is consistent with previously published data. There were no safety concerns with trial procedures. In conclusion, a large randomised controlled efficacy trial of standard vs. augmented systolic blood pressure management during endovascular thrombectomy is feasible.

Viability and development of Ascaridia galli eggs recovered in artificial media followed by storage under different conditions.

Eggs oviposited by Ascaridia galli females in artificial media are commonly used as a source of infective material. We investigated the rate of egg production by cultured mature females (n = 223), and changes in egg viability under different storage and incubation conditions. Eggs recovered after 1, 2 or 3 days of culture were subjected to either (1) storage in water at 4°C (1, 4 or 8 weeks) followed by incubation in 0.1 N H2SO4 at 26°C (2, 4 or 6 weeks); or (2) prolonged storage at 4°C (up to 14 weeks). Egg development and viability was assessed by morphology coupled with a viability dye exclusion test of hatched larvae. Of the 6,044 eggs recovered per mature female 49.2, 38.5 and 12.3% were recovered on days 1, 2 and 3 of worm incubation respectively with similar initial viability (≥99%) between days. Eggs recovered on different days had only minor differences in viability after storage. The prolonged storage period at 4°C significantly affected both viability and embryonation ability resulting in decline in viability of 5.7-6.2% per week. A smaller but significant decline in egg (2.0%) and hatched larval (1.4%) viability per week of incubation at 26°C was also observed. We conclude that storage and incubation conditions, not the day of egg recovery, are the main factors affecting A. galli egg viability. Our findings indicate that under aerobic conditions storage at 26°C may be preferable to 4°C whereas other studies indicate that under anaerobic conditions storage at 4°C is preferable.

National risk prediction model for perioperative mortality in non-cardiac surgery.

BACKGROUND: Many multivariable models to calculate mortality risk after surgery are limited by insufficient sample size at development or by application to cohorts distinct from derivation populations. The aims of this study were to validate the Surgical Outcome Risk Tool (SORT) for a New Zealand population and to develop an extended NZRISK model to calculate 1-month, 1-year and 2-year mortality after non-cardiac surgery. METHODS: Data from the New Zealand National Minimum Data Set for patients having surgery between January 2013 and December 2014 were used to validate SORT. A random 75 per cent split of the data was used to develop the NZRISK model, which was validated in the other 25 per cent of the data set. RESULTS: External validation of SORT in the 360 140 patients who underwent surgery in the study period showed good discrimination (area under the receiver operating characteristic curve (AUROC) value of 0·906) but poor calibration (McFadden's pseudo-R2 0·137, calibration slope 5·32), indicating it was invalid in this national surgical population. Internal validation of the NZRISK model, which incorporates sex and ethnicity in addition to the variables used in SORT for 1-month, 1-year and 2-year outcomes, demonstrated excellent discrimination with AUROC values of 0·921, 0·904 and 0·895 respectively, and excellent calibration (McFadden's pseudo-R2 0·275, 0·308 and 0·312 respectively). Calibration slopes were 1·12, 1·02 and 1·02 respectively. CONCLUSION: The SORT performed poorly in this national population. However, inclusion of sex and ethnicity in the NZRISK model improved performance. Calculation of mortality risk beyond 30 days after surgery adds to the utility of this tool for shared decision-making.

ANTECEDENTES: Muchos modelos multivariados de estimación del riesgo de mortalidad después de la cirugía están limitados por haberse desarrollado a partir de tamaños muestrales insuficientes o por haberse aplicados a cohortes distintas de las poblaciones de derivación. Los objetivos de este estudio fueron validar el Surgical Outcome Risk Tool (SORT) para una población de Nueva Zelanda y desarrollar un modelo NZRISK extendido para calcular la mortalidad al mes y a los 1 y 2 años de una cirugía no cardíaca. MÉTODOS: Para validar el SORT se utilizó el Conjunto Mínimo Básico de Datos de Nueva Zelanda para los pacientes sometidos a cirugía entre enero de 2013 y diciembre de 2014. Se realizó una división aleatoria del 75% de los datos para desarrollar el modelo NZRISK que, posteriormente, se validó en el otro 25% del conjunto de datos. RESULTADOS: La validación externa de SORT en 360.140 pacientes intervenidos en el periodo analizado mostró una buena discriminación (área bajo las curvas de característica operativa del receptor (area under the receiver-operator characteristic curves (AUROC) 0,906)) pero con una mala calibración (pseudo-R2 de McFaddens 0,137 y pendiente de calibración 5,32), lo que indicaba que SORT no era válido para esta población quirúrgica nacional. La validación interna del modelo NZRISK, que incorpora el género y la etnia además de las variables utilizadas en el SORT, para los resultados al mes y a los 1 y 2 años demostró una excelente capacidad de discriminación con una AUROC de 0,921, 0,904, 0,895 respectivamente y una calibración excelente, con una pseudo-R2 de McFaddens de 0,275, 0,308 y 0,312 respectivamente. Las pendientes de calibración fueron de 1,12, 1,02 y 1,02, respectivamente. CONCLUSIÓN: El SORT no fue útil en esta población nacional. Sin embargo, la inclusión del género y la etnia en el modelo NZRISK mejoró sus resultados. El cálculo del riesgo de mortalidad más allá de 30 días después de la cirugía añade utilidad a esta herramienta para la toma de decisiones compartida.

Laser pulse width control using inverse-Bremsstrahlung photon absorption.

Nanosecond laser pulses (6 ns FWHM, produced by a Q-switched, frequency-doubled Nd:YAG laser) are chopped using the inverse-Bremsstrahlung (IB) photon absorption process in a cell with variable pressure. The IB process that quickly absorbs the majority of the laser pulse energy is triggered by focusing the pulse in the cell. Prior to the initiation of the IB process, the gaseous medium in the cell is transparent, while it suddenly becomes opaque with the IB process activated; therefore, the pressure cell can be used as a virtual optical shutter. The shutter "closing time" depends strongly on the pressure of the cell and the laser pulse energy and thus can be controlled. Dependence of the "closing time" on these two parameters is experimentally investigated.

Comparison of femtosecond and nanosecond two-photon-absorption laser-induced fluorescence of krypton.

Two-photon-absorption laser-induced fluorescence of Kr was explored using both nanosecond- and femtosecond-duration laser excitation sources. Fluorescence signals following two-photon excitation at two wavelengths (212.56 nm and 214.77 nm) were compared while varying laser pulse duration, energy, and excitation wavelength as well as pressure and Kr mole fraction in mixtures with nitrogen. Our findings show that stronger fluorescence was observed when the excitation wavelength was tuned to 212.56 nm, regardless of the excitation-pulse duration. Moreover, an approximate 100-fold signal enhancement from nanosecond excitation (∼3 mJ/pulse, 10 ns duration) was observed as compared to femtosecond excitation (∼6 µJ/pulse, 90 fs duration).

Identification and Characterization of Salmonella enterica Serotype Newport Isolates with Decreased Susceptibility to Ciprofloxacin in the United States.

Nontyphoidal Salmonella (NTS) causes an estimated 1.2 million illnesses, 23,000 hospitalizations, and 450 deaths each year in the United States. Decreased susceptibility to ciprofloxacin (DSC) has historically been associated with chromosomal mutations of the quinolone resistance determining region (QRDR), but plasmid-mediated quinolone resistance (PMQR) genes are increasing. To investigate DSC among Salmonella enterica serotype Newport strains, we examined 40 isolates from 1996 to 2016 with DSC. Thirty isolates (71%) contained the PMQR gene qnrB and eight isolates (19%) contained a QRDR.

Characterization of Ras k 1 a novel major allergen in Indian mackerel and identification of parvalbumin as the major fish allergen in 33 Asia-Pacific fish species.

BACKGROUND: Fish is a well-recognized cause of food allergy and anaphylaxis. The evolutionary and taxonomic diversity of the various consumed fish species pose a challenge in the identification and characterization of the major fish allergens critical for reliable diagnostics. Globally, fish is a rising cause of food allergy complicated by a large under-investigated variety of species as well as increasing global tourism and trade. This is the first comprehensive study on allergen profiles of heat-processed fish from Vietnam. OBJECTIVE: The aim of this study was to identify the major heat-stable allergens from frequently exported Asia-Pacific freshwater and marine fish and to characterize the major allergen parvalbumin (PV) from one of the most consumed and exported fish species from Asia, the Indian mackerel (Rastrelliger kanagurta). METHODS: Heated protein extracts from 33 fish species were separated by gel electrophoresis. PV isoforms were identified by immunoblotting utilizing 3 different PV-specific monoclonal and polyclonal antibodies and further characterized by mass spectrometry. IgE reactivity was investigated using sera from 21 patients with confirmed fish allergy. RESULTS: Heat-stable IgE-reactive PVs, with up to 5 isoforms per species, were identified in all 33 analysed fish species. In the Indian mackerel, 7 PV isoforms were identified by 2D-gel electrophoresis combined with mass spectrometric analyses. The amino acid sequence deduced from cDNA of the most expressed isoform showed a high identity (>90%) to PVs from 2 other mackerel species. CONCLUSIONS AND CLINICAL RELEVANCE: Different PVs were identified as the major heat-stable allergens in all 33 analysed freshwater and marine fish species from Vietnam, many of which are exported world-wide and 21 species that have never been investigated before. The Indian mackerel PV represents a novel fish allergen, now officially registered as Ras k 1. Improved diagnostics for fish allergy against Asia-Pacific species should be developed with focus on PV.

Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms.

Photoacclimation by strains of Haslea "blue" diatom species H. ostrearia and H. silbo sp. nov. ined. was investigated with rapid light curves and induction-recovery curves using fast repetition rate fluorescence. Cultures were grown to exponential phase under 50 µmol m-2 s-1 photosynthetic available radiation (PAR) and then exposed to non-sequential rapid light curves where, once electron transport rate (ETR) had reached saturation, light intensity was decreased and then further increased prior to returning to near growth light intensity. The non-sequential rapid light curve revealed that ETR was not proportional to the instantaneously applied light intensity, due to rapid photoacclimation. Changes in the effective absorption cross sections for open PSII reaction centres (σPSII') or reaction centre connectivity (ρ) did not account for the observed increases in ETR under extended high light. σPSII' in fact decreased as a function of a time-dependent induction of regulated excitation dissipation Y(NPQ), once cells were at or above a PAR coinciding with saturation of ETR. Instead, the observed increases in ETR under extended high light were explained by an increase in the rate of PSII reopening, i.e. QA- oxidation. This acceleration of electron transport was strictly light dependent and relaxed within seconds after a return to low light or darkness. The time-dependent nature of ETR upregulation and regulated NPQ induction was verified using induction-recovery curves. Our findings show a time-dependent induction of excitation dissipation, in parallel with very rapid photoacclimation of electron transport, which combine to make ETR independent of short-term changes in PAR. This supports a selective advantage for these diatoms when exposed to fluctuating light in their environment.