Chronic generalized fibrotic skin lesions from disseminated leishmaniasis caused by Leishmania martiniquensis in two patients from northern Thailand infected with HIV.

BACKGROUND: Leishmaniasis is a newly emerging infection in Thailand. Most of the previous human cases have presented with the clinical features of visceral leishmaniasis and were mainly found in southern Thailand. Here we report the first two patients from northern Thailand presenting with disseminated cutaneous leishmaniasis. OBJECTIVES: To determine the nature of the infection of leishmaniasis and to identify the species of parasite responsible. METHODS: Clinical investigations included the taking of biopsy samples and histology. Parasitological diagnosis was performed by establishment of Leishmania promastigote cultures, and identification was performed by DNA sequencing of four independent gene loci (ribosomal RNA internal transcribed spacer 1; large subunit of RNA polymerase II; heat shock protein 70; RPL23a intergenic sequence). RESULTS: Both patients were infected with HIV, and had multiple cutaneous lesions and accompanying visceral leishmaniasis. They had similar cutaneous manifestations characterized by chronic generalized fibrotic lesions, which were more prominent on traumatic areas. In both patients the parasite was identified as Leishmania martiniquensis. This is a recently described species that is distinct and only distantly related to the classical agents of cutaneous leishmaniasis in Asia (Leishmania major and Leishmania tropica) or of visceral leishmaniasis (Leishmania donovani and Leishmania infantum). Each patient responded well to therapy with intravenous amphotericin B followed by oral itraconazole. CONCLUSIONS: Leishmania martiniquensis is a cause of cutaneous leishmaniasis in Thailand.

Exsheathment and midgut invasion of nocturnally subperiodic Brugia malayi microfilariae in a refractory vector, Aedes aegypti (Thailand strain).

Exsheathment and midgut invasion of nocturnally subperiodic Brugia malayi microfilariae were analyzed using light and scanning electron microscopy in a refractory vector, Aedes aegypti (Thailand strain). Results showed that exsheathed microfilariae represented only approximately 1% of the total microfilaria midguts dissected at 5-min post-infected blood meal (PIBM). The percentage of exsheathed microfilariae found in midguts progressively increased to about 20, 60, 80, 90, and 100% at 1-, 2-5-, 6-12-, 18-36-, and 48-h PIBM, respectively. Importantly, all the microfilariae penetrating the mosquito midguts were exsheathed. Midgut invasion by the exsheathed microfilariae was observed between 2- and 48-h PIBM. SEM analysis revealed sheathed microfilariae surrounded by small particles and maceration of the microfilarial sheath in the midguts, suggesting that the midguts of the refractory mosquitoes might have protein(s) and/or enzyme(s) and/or factor(s) that induce and/or accelerate exsheathment. The microfilariae penetrated the internal face of the peritrophic matrix (PM) by their anterior part and then the midgut epithelium, before entering the hemocoel suggesting that PM was not a barrier against the microfilariae migrating towards the midgut. Melanized microfilariae were discovered in the hemocoel examined at 96-h PIBM suggesting that the refractory mosquitoes used melanization reactions against this parasite. This study provided evidence that A. aegypti (Thailand strain) has refractory mechanisms against B. malayi in both midgut and hemocoel.

The characterization of the Phlebotomus papatasi transcriptome.

As important vectors of human disease, phlebotomine sand flies are of global significance to human health, transmitting several emerging and re-emerging infectious diseases. The most devastating of the sand fly transmitted infections are the leishmaniases, causing significant mortality and morbidity in both the Old and New World. Here we present the first global transcriptome analysis of the Old World vector of cutaneous leishmaniasis, Phlebotomus papatasi (Scopoli) and compare this transcriptome to that of the New World vector of visceral leishmaniasis, Lutzomyia longipalpis. A normalized cDNA library was constructed using pooled mRNA from Phlebotomus papatasi larvae, pupae, adult males and females fed sugar, blood, or blood infected with Leishmania major. A total of 47 615 generated sequences was cleaned and assembled into 17 120 unique transcripts. Of the assembled sequences, 50% (8837 sequences) were classified using Gene Ontology (GO) terms. This collection of transcripts is comprehensive, as demonstrated by the high number of different GO categories. An in-depth analysis revealed 245 sequences with putative homology to proteins involved in blood and sugar digestion, immune response and peritrophic matrix formation. Twelve of the novel genes, including one trypsin, two peptidoglycan recognition proteins (PGRP) and nine chymotrypsins, have a higher expression level during larval stages. Two novel chymotrypsins and one novel PGRP are abundantly expressed upon blood feeding. This study will greatly improve the available genomic resources for P. papatasi and will provide essential information for annotation of the full genome.

High-average-power, carrier-envelope phase-stable, few-cycle pulses at 2.1 µm from a collinear BiB3O6 optical parametric amplifier.

We generate self-carrier-to-envelope phase-stable, 630 µJ pulses, centered at 2.1 µm, with 42 fs (6 cycle) duration based on collinear optical parametric amplification in BiB(3)O(6) at 3 kHz. These pulses are generated through a traveling wave amplifier scheme, and the bandwidth supports 28 fs (4 cycle) pulse duration. Carrier-to-envelope phase stability was measured to be 410 mrad over 10 min or 260 mrad over 35 s.

Wavelength dependence of the suppressed ionization of molecules in strong laser fields.

We study ionization of molecules by an intense laser field over a broad wavelength regime, ranging from 0.8 to 1.5 µm experimentally and from 0.6 to 10 µm theoretically. A reaction microscope is combined with an optical parametric amplifier to achieve ionization yields in the near-infrared wavelength regime. Calculations are done using the strong-field S-matrix theory and agreement is found between experiment and theory, showing that ionization of many molecules is suppressed compared to the ionization of atoms with identical ionization potentials at near-infrared wavelengths at around 0.8 µm, but not at longest wavelengths (10 µm). This is due to interference effects in the electron emission that are effective at low photoelectron energies but tend to average out at higher energies. We observe the transition between suppression and nonsuppression of molecular ionization in the near-infrared wavelength regime (1-5 µm).

The impact of COVID-19 on major trauma (ISS>15) in London, across its four Level 1 centres.

INTRODUCTION: The COVID-19 pandemic has led to reconfiguration of healthcare resources to manage increased demand for acute hospital beds and intensive care places. Concerns were raised regarding continuing provision of critical care for non-COVID patients during the pandemic. The aim of this study was to assess the impact of the COVID-19 pandemic on patients admitted with major trauma (Injury Severity Score >15) across the four Level 1 trauma centres in London. METHODS: Data were collected from all four major trauma centres (MTCs) in London using the Trauma Audit and Research Network database and from local databases at each centre. A 2-month period from 5 March to 5 May 2020 was selected and the same period during 2019 was used to compare changes due to the pandemic. RESULTS: There was a 31% decrease in overall number of patients presenting to the four MTCs during the COVID-19 period compared with 2019. There was no difference in patient demographics or mechanism of injury between the two periods. Sports-related injuries and proportion of self-presentation to hospital were reduced slightly during the pandemic, although the differences were not statistically significant. The mortality rate and association between mortality and injury severity were similar. Proportion of patients requiring intensive care unit facilities also did not change. CONCLUSION: Despite diversion of critical care resources to deal with COVID-related admissions, we did not observe a change in mortality rate or proportion of severely injured patients requiring critical care. Our results suggest London MTCs were able to provide their usual standard of care for critically injured major trauma (Injury Severity Score >15) patients during the pandemic.

Sub-250-mrad, passively carrier-envelope-phase-stable mid-infrared OPCPA source at high repetition rate.

An all-optical and passively carrier-to-envelope-phase-stabilized (CEP-stabilized) optical parametric chirped pulse amplification (OPCPA) system is demonstrated with sub-250-mrad CEP stability over 11 min and better than 100 mrad over 11 s. This is achieved without any electronic CEP stabilization loop for 160 kHz pulse repetition rate in the few cycle regime.

Few-cycle pulse characterization with an acousto-optic pulse shaper.

An acousto-optic pulse shaper has been used to characterize few-cycle pulses generated in a hollow-core fiber. A grism pair precompensates for the dispersion of the acousto-optic crystal, allowing the full pulse-shaping window to be used for replica generation rather than self-compensation. A 9.4 fs pulse was measured, the shortest ever measured with an acousto-optic pulse shaper, to our knowledge.

Ultrashort pulse characterization in the mid-infrared.

We describe a second-harmonic-generation frequency-resolved optical gating measurement device optimized for the characterization of few-cycle pulses in the mid-IR spectral range. The system has a temporal range of 100 ps with resolution of 0.12 fs, and it is capable of measuring pulses as short as 1.5 cycles (15 fs) at 3 microm. Through interchangeable beam splitters and detectors it covers a wavelength range from 800 nm to 5 microm with up to 0.5 cm(-1) resolution. We demonstrate measurement of a richly featured 3.2 microm pulse with 9.6 cycle duration, recovering the main pulse of 96 fs, as well as low-intensity post-pulses with picosecond offset. We also characterize a 100 fs pulse after dispersion through a 1 cm sapphire plate, comparing the measured phase difference with the calculated one.

Six-cycle mid-infrared source with 3.8 µJ at 100 kHz.

We report on the shortest pulses to date from a mid-IR optical parametric chirped pulse amplification: 67 fs duration with 3.8 µJ energy operating at 3.2 µm. The system is all solid state and diode pumped and operates at 100 kHz with unprecedented power stability of 0.75%rms over 30 min.

The sticking point: How integrins bind to their ligands.

The integrin adhesion receptors are alpha beta heterodimers that exist in different ligand-binding states. Because of their large size and conformational lability, it has been difficult to determine how they interact with their ligands. Ligand-binding sites have been identified in the beta subunit, and now more recently in the 'I' domain and EF-hand-like domains V and VI of the alpha subunit. We speculate here about how these various sites might operate together to bind ligand in a stable manner.

Efficient incorporation of human CD4 protein into avian leukosis virus particles.

Virus envelope (Env) proteins are thought to contain specific signals for selective uptake by virus particles. In the course of attempting to define these signals by testing virus incorporation of CD4-Env chimeric proteins, normal human CD4 was found to be efficiently and selectively assembled into avian leukosis virus particles in quail cells. Viruses bearing CD4 at their surface may be useful reagents in the design of retrovirus-mediated gene therapy for the acquired immune deficiency syndrome.

Geometric and potential driving formation and evolution of biomolecular surfaces.

This paper presents new geometrical flow equations for the theoretical modeling of biomolecular surfaces in the context of multiscale implicit solvent models. To account for the local variations near the biomolecular surfaces due to interactions between solvent molecules, and between solvent and solute molecules, we propose potential driven geometric flows, which balance the intrinsic geometric forces that would occur for a surface separating two homogeneous materials with the potential forces induced by the atomic interactions. Stochastic geometric flows are introduced to account for the random fluctuation and dissipation in density and pressure near the solvent-solute interface. Physical properties, such as free energy minimization (area decreasing) and incompressibility (volume preserving), are realized by some of our geometric flow equations. The proposed approach for geometric and potential forces driving the formation and evolution of biological surfaces is illustrated by extensive numerical experiments and compared with established minimal molecular surfaces and molecular surfaces. Local modification of biomolecular surfaces is demonstrated with potential driven geometric flows. High order geometric flows are also considered and tested in the present work for surface generation. Biomolecular surfaces generated by these approaches are typically free of geometric singularities. As the speed of surface generation is crucial to implicit solvent model based molecular dynamics, four numerical algorithms, a semi-implicit scheme, a Crank-Nicolson scheme, and two alternating direction implicit (ADI) schemes, are constructed and tested. Being either stable or conditionally stable but admitting a large critical time step size, these schemes overcome the stability constraint of the earlier forward Euler scheme. Aided with the Thomas algorithm, one of the ADI schemes is found to be very efficient as it balances the speed and accuracy.

The impact of Recovery Colleges on mental health staff, services and society.

AIMS: Recovery Colleges are opening internationally. The evaluation focus has been on outcomes for Recovery College students who use mental health services. However, benefits may also arise for: staff who attend or co-deliver courses; the mental health and social care service hosting the Recovery College; and wider society. A theory-based change model characterising how Recovery Colleges impact at these higher levels is needed for formal evaluation of their impact, and to inform future Recovery College development. The aim of this study was to develop a stratified theory identifying candidate mechanisms of action and outcomes (impact) for Recovery Colleges at staff, services and societal levels. METHODS: Inductive thematic analysis of 44 publications identified in a systematised review was supplemented by collaborative analysis involving a lived experience advisory panel to develop a preliminary theoretical framework. This was refined through semi-structured interviews with 33 Recovery College stakeholders (service user students, peer/non-peer trainers, managers, community partners, clinicians) in three sites in England. RESULTS: Candidate mechanisms of action and outcomes were identified at staff, services and societal levels. At the staff level, experiencing new relationships may change attitudes and associated professional practice. Identified outcomes for staff included: experiencing and valuing co-production; changed perceptions of service users; and increased passion and job motivation. At the services level, Recovery Colleges often develop somewhat separately from their host system, reducing the reach of the college into the host organisation but allowing development of an alternative culture giving experiential learning opportunities to staff around co-production and the role of a peer workforce. At the societal level, partnering with community-based agencies gave other members of the public opportunities for learning alongside people with mental health problems and enabled community agencies to work with people they might not have otherwise. Recovery Colleges also gave opportunities to beneficially impact on community attitudes. CONCLUSIONS: This study is the first to characterise the mechanisms of action and impact of Recovery Colleges on mental health staff, mental health and social care services, and wider society. The findings suggest that a certain distance is needed in the relationship between the Recovery College and its host organisation if a genuine cultural alternative is to be created. Different strategies are needed depending on what level of impact is intended, and this study can inform decision-making about mechanisms to prioritise. Future research into Recovery Colleges should include contextual evaluation of these higher level impacts, and investigate effectiveness and harms.

Minimal molecular surfaces and their applications.

This article presents a novel concept, the minimal molecular surface (MMS), for the theoretical modeling of biomolecules. The MMS can be viewed as a result of the surface free energy minimization when an apolar molecule, such as protein, DNA or RNA is immersed in a polar solvent. Based on the theory of differential geometry, the MMS is created via the mean curvature minimization of molecular hypersurface functions. A detailed numerical algorithm is presented for the practical generation of MMSs. Extensive numerical experiments, including those with internal and open cavities, are carried out to demonstrated the proposed concept and algorithms. The proposed MMS is typically free of geometric singularities. Application of the MMS to the electrostatic analysis is considered for a set of twenty six proteins.

Design and simulation of few-cycle optical parametric chirped pulse amplification at mid-IR wavelengths.

We present a design for a novel carrier to envelope phase stable optical parametric chirped pulse amplification source in the mid-infrared. We calculate the amplification of a 3.1 microm seed pulse, generated via DFG from a two-colour fibre laser, using a fully three dimensional OPCPA code. We combine this with a ray-tracing code to model pulse compression using a grating compressor and a deformable mirror for programmable phase compensation. The simulation models the complete system based on FROG measurements of the commercially available fibre laser, ensuring the simulation is realistic. The obtained results indicate energetic pulses of 56 fs duration, corresponding to 5.2 cycles, can be produced with calculated pulse energies of up to 9.6 microJ at a central wavelength of 3.3 microm.

Wide variation in surgical outcomes for acromegaly in the UK.

OBJECTIVE: Unsuccessful surgery for acromegaly has major consequences for the patient as well as financial consequences for the National Health Service (NHS). Surgical expertise affects the outcome. We have used the UK National Acromegaly Register to assess surgical outcomes in different centres to investigate whether these match the previously published case series. DESIGN: Retrospective and prospective observational study by analysis of anonymized national computer register records derived from individual clinical case records from 22 UK endocrine units and their associated pituitary surgical services. PATIENTS: Cases of acromegaly, presenting in 1970-2004, with levels of GH or IGF-1 (785 and 430 cases, respectively) recorded prior to transsphenoidal adenomectomy and in the 12 months postsurgery, before any subsequent pituitary surgery or radiotherapy. GH-lowering pharmacological therapy was permitted only if suspended for biochemical testing. MEASUREMENTS: Percentage of cases with 'safe' mean postoperative GH levels (< 5 mU/l) and/or IGF-1 in the age- and sex-adjusted normal range. RESULTS: 'Safe' GH, normal IGF-1, or both was achieved for 26%, 29% and 20% of extrasellar macroadenomas (> 1 cm), respectively, 39%, 39% and 29% of intrasellar macroadenomas, 56%, 51% and 37% of microadenomas (< 1 cm) and 39%, 39% and 28% of cases overall. In centres contributing more than 10 patients' data, rates of safe GH levels ranged from 20% to 68% and IGF-1 from 19% to 55%. Success rates in attaining safe postsurgical levels of GH improved only slightly in the UK between 1974 and 1999 but markedly thereafter. CONCLUSIONS: Surgical outcomes for acromegaly in UK centres vary widely and historically have not, except in a few centres, matched those of large published series, which mostly have a success rate around 60%. Results have, however, improved substantially since 2000 and in the most successful units match those of the best published series. Experience is an important determinant of surgical success in acromegaly and the very recent improvement in surgical results in the UK coincides with a trend to concentrate pituitary surgery in the hands of a smaller number of specialists. Therefore, patients should be offered surgery by a dedicated pituitary surgeon with a caseload sufficient to offer the prospect of safe postsurgical GH and IGF-1 levels for the majority of cases.

Second Blood Meal by Female Lutzomyia longipalpis: Enhancement by Oviposition and Its Effects on Digestion, Longevity, and Leishmania Infection.

Lutzomyia longipalpis is the main vector of visceral leishmaniasis (VL) in America. Physiological and molecular mechanisms of Leishmania infection in sand flies have been studied during the first gonotrophic cycle. There are few studies about these interactions during the second gonotrophic cycle mainly because of the difficulties maintaining sand flies through sequential feeds. Here we standardized conditions to perform the second blood feed efficiently, and our results show that oviposition is an essential factor for the success of multiple feeds. We evaluated the impact of the second blood meal on longevity, protein digestion, trypsin activity, and Leishmania mexicana development within L. longipalpis gut. Mortality of blood-fed females increases after second blood meal as compared to sugar-fed females. Trypsin activity was lower during the second gonotrophic cycle. However, no difference in protein intake was observed between blood meals. There was no difference in the population size of Leishmania in the gut after both blood meals. In this work, we presented an optimized protocol for obtaining sufficient numbers of sand fly females fed on a second blood meal, and we described some physiological and parasitological aspects of the second gonotrophic cycle which might influence the vectorial competence of sand flies.

Progress in protein structure prediction: assessment of CASP3.

The third comparative assessment of techniques of protein structure prediction (CASP3) was held during 1998. This is a blind trial in which structures are predicted prior to having knowledge of the coordinates, which are then revealed to enable the assessment. Three sections at the meeting evaluated different methodologies - comparative modelling, fold recognition and ab initio methods. For some, but not all of the target coordinates, high quality models were submitted in each of these sections. There have been improvements in prediction techniques since CASP2 in 1996, most notably for ab initio methods.