Genome Mining for New Enzyme Chemistry

A revolution in the field of biocatalysis has enabled scalable access to compounds of high societal values using enzymes. The construction of biocatalytic routes relies on the reservoir of available enzymatic transformations. A review of uncharacterized proteins predicted from genomic sequencing projects shows that a treasure trove of enzyme chemistry awaits to be uncovered. This Review highlights enzymatic transformations discovered through various genome mining methods and showcases their potential future applications in biocatalysis.

Experience of French patients with olfactory disorders

OBJECTIVES

To assess the experience of subjects with olfactory disorders in their daily life and medical management, and their expectations and proposals for improvement.

MATERIAL AND METHODS

A cross-sectional observational study was conducted over the period January 2020 to December 2021, with 300 subjects with olfactory disorders: 222 female, 78 male; mean age 46±15 years. In total, 126 were patients consulting in ENT, and 174 were members of the Anosmie.org patients' association. Participants filled out a questionnaire; free texts were analyzed thematically and coded for various qualitative variables.

RESULTS

Olfactory disorders considerably impacted health, safety and quality of life. Non-COVID-19 acute etiologies (non-COVID-19 viral infection, cranial trauma) showed particularly high risk of psychological, social, safety-related and nutritional consequences. Almost all patients (94%) were dissatisfied with their medical management: 28% had received little explanation, and 23% felt their dysosmia was completely neglected, with no exploration and no etiology suggested. Patients wished above all to have follow-up and accompaniment.

CONCLUSION

Despite significant impact on health and quality of life, olfactory disorders are neglected by the medical community. Patients should be given an ENT assessment with olfactometry, to establish diagnosis and prognosis. Global multidisciplinary management is necessary, including therapeutic education, and psychological, social and nutritional follow-up.

Biosynthesis of macrocyclic peptides with C-terminal β-amino-α-keto acid groups by three different metalloenzymes

Advances in genome sequencing and bioinformatics methods have identified a myriad of biosynthetic gene clusters (BGCs) encoding uncharacterized molecules. By mining genomes for BGCs containing a prevalent peptide-binding domain used for the biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs), we uncovered a new class involving modifications installed by a cytochrome P450, a multi-nuclear iron-dependent non-heme oxidative enzyme (MNIO, formerly DUF692), a cobalamin- and radical S-adenosyl-L-methionine-dependent enzyme (B12-rSAM), and a methyltransferase. All enzymes encoded by the BGC were functionally expressed in Burkholderia sp. FERM BP-3421. Structural characterization with 2D-NMR and Marfey's method on the resulting RiPP demonstrated that the P450 enzyme catalyzed the formation of a biaryl C-C crosslink between two Tyr residues with the B12-rSAM generating β-methyltyrosine. The MNIO transformed a C-terminal Asp residue into aminopyruvic acid while the methyltransferase acted on the β-carbon of the α-keto acid. Exciton-coupled circular dichroism spectroscopy and microcrystal electron diffraction (MicroED) were used to elucidate the stereochemical configurations of the atropisomer that formed upon biaryl crosslinking. The conserved Cys residue in the precursor peptide was not modified as in all other characterized MNIO-containing BGCs; However, mutational analyses demonstrated that it was essential for the MNIO activity on the C-terminal Asp. To the best of our knowledge, the MNIO featured in this pathway is the first to modify a residue other than Cys. This study underscores the utility of genome mining to discover new macrocyclic RiPPs and that RiPPs remain a significant source of previously undiscovered enzyme chemistry.

Bioinformatics-guided discovery of biaryl-linked lasso peptides

Lasso peptides are a class of ribosomally synthesized and post-translationally modified peptides (RiPPs) that feature an isopeptide bond and a distinct lariat fold. A growing number of secondary modifications have been described that further decorate lasso peptide scaffolds. Using genome mining, we have discovered a pair of lasso peptide biosynthetic gene clusters (BGCs) that include cytochrome P450 genes. Using mass spectrometry, stable isotope incorporation, and extensive 2D-NMR spectrometry, we report the structural characterization of two unique examples of (C-N) biaryl-linked lasso peptides. Nocapeptin A, from Nocardia terpenica, is tailored with a Trp-Tyr crosslink, while longipepetin A, from Longimycelium tulufanense, features a Trp-Trp linkage. Besides the unusual bicyclic frame, a Met of longipepetin A undergoes S-methylation to yield a trivalent sulfonium, a heretofore unprecedented RiPP modification. A bioinformatic survey revealed additional lasso peptide BGCs containing P450 enzymes which await future characterization. Lastly, nocapeptin A bioactivity was assessed against a panel of human and bacterial cell lines with modest growth-suppression activity detected towards Micrococcus luteus.

Critical review of diagnosis in rhinology and its therapeutical implications

Diagnosis in rhinology is currently based on the concept of inflammation (chronic rhinosinusitis [CRS]) or the clinical concept of chronic nasal dysfunction (CND). The complementarity between these two approaches can be discussed by a critical review of the literature structured by the analysis of the fundamental and diagnostic bases and the therapeutic implications linked to each. The concept of CRS is based on the anatomical continuity of the nasal and sinus respiratory mucosa and molecular biology data, seeking to analyze the mechanisms of chronic inflammation and to identify proteins and biomarkers involved in the different supposed endotypes of chronic inflammation of this mucosa. The concept of CND seeks to analyze medical, instrumental or surgical diagnostic and therapeutic strategies, taking account of both inflammatory and non-inflammatory causes impacting the anatomy or physiology of each of the three noses (olfactory, respiratory and sinus) that make up the mid-face sinonasal organ of evolution-development (Evo-Devo) theory. Thus, the concept of CRS offers an endotypic approach, based on biological characterization of mucosal inflammation, while the concept of CND offers a compartmentalized phenotypic and pathophysiological approach to sinonasal diseases. The joint contribution of these two concepts in characterizing nasal functional pathology could in future improve the medical service provided to patients.

Maxillary ostium preservation in ethmoidectomy

The paranasal sinuses play a role in producing and storing nitric oxide (NO). NO is a powerful antiviral and antibacterial gas which may be involved in the non-specific immune defenses of the respiratory tract. Conducted by the inspiratory current at the alveolar-capillary membrane, it increases pulmonary venous blood oxygenation. NO is actively released in the form of independent boluses in the respiratory tract, thanks to a sphincter function that can be identified during ethmoidectomy under general anesthesia. Safeguarding paranasal sinus physiology necessarily involves conserving this ostial sphincter function, which is essential to the respiratory role of the paranasal sinuses. Although it has not yet been demonstrated that the destruction of this ostial function has measurable consequences for respiratory function, it makes sense to avoid systematic antrostomy and to preserve this ostial function whenever possible, depending on the clinical conditions. This technical note describes step-by-step how to conserve the maxillary ostium, in the example of radical ethmoidectomy with mucosal ablation for nasal polyposis (nasalization). It is illustrated by two videos. The discussion focuses on the respective indications for ostial preservation and middle meatotomy (antrostomy).

Urban-rural disparities in acceptance of human papillomavirus vaccination among women in Can Tho, Vietnam

Background

In Vietnam, cervical cancer is a significant public health concern for women. Unfortunately, despite the availability of the HPV vaccine, low vaccination rates persist.

Objectives

This study investigates the discrepancy between urban and rural areas in the willingness to receive HPV vaccination with or without fees.

Methods

A cross-sectional study was conducted on a sample of 648 women aged between 15 and 49, living in two urban and two rural Vietnamese districts of Can Tho, between May and December 2021.

Results

The overall vaccination rate was 4%, with urban women having a higher rate of 4.9% compared to rural women at 3.1%. Among unvaccinated women, those from rural areas expressed a significantly higher desire to receive the free vaccine (91.4%) than urban women (84.4%). However, the intention to vaccinate declined when rural women and urban women were advised to pay the cost (63.4% and 57.1%, respectively). A strong correlation was found between a positive attitude and intention for vaccination, irrespective of its price or free availability. Education and access to information about the HPV vaccine were also identified as the most significant factors influencing the intention to vaccination among urban and rural women.

Conclusion

The low HPV vaccination rates among women aged 15-49 living in both urban and rural regions of Vietnam are a notable public health concern. These outcomes emphasize the critical need for effective programs of vaccine laterization, as an introduction to the offer of affordable and accessible HPV vaccines for women in Can Tho, Vietnam.

Bioinformatics-Guided Discovery of Biaryl-Tailored Lasso Peptides

Lasso peptides are a class of ribosomally synthesized and post-translationally modified peptides (RiPPs) that feature an isopeptide bond and a distinct lariat fold. A growing number of secondary modifications have been described that further decorate lasso peptide scaffolds. Using genome mining, we have discovered a pair of lasso peptide biosynthetic gene clusters (BGCs) that include cytochrome P450 genes. Here, we report the structural characterization of two unique examples of (C-N) biaryl-containing lasso peptides. Nocapeptin A, from Nocardia terpenica, is tailored with Trp-Tyr crosslink while longipepetin A, from Longimycelium tulufanense, features Trp-Trp linkage. Besides the unusual bicyclic frame, longipepetin A receives an S-methylation by a new Met methyltransferase resulting in unprecedented sulfonium-bearing RiPP. Our bioinformatic survey revealed P450(s) and further maturating enzyme(s)-containing lasso BGCs awaiting future characterization.

Catheter ablation for atrial fibrillation in adult congenital heart disease: an international registry study

Background

Life expectancies for patients with congenital heart disease (CHD) have dramatically increased in recent years, accompanied by a rise in atrial fibrillation (AF) prevalence. Data on AF ablation strategy and outcomes are limited in CHD.

Purpose

We aimed to investigate the characteristics of CHD patients presenting for AF ablation and their outcomes.

Methods

A multicenter, retrospective analysis was performed of CHD patients undergoing AF ablation between 2004 and 2020 at 13 participating centers. The severity of CHD was classified using the 2014 PACES/HRS guidelines. Clinical data were collected including ablation strategy and follow up. One-year procedural success was defined as freedom from AF in the absence of antiarrhythmic drugs (AADs, complete) or including previously failed AADs (partial).

Results

Of 240 patients, 127 (53.4%) had persistent AF, 62.5% were male, and mean age was 55.2±0.9 years. CHD complexity categories included 147 (61.3%) simple, 69 (28.8%) intermediate and 25 (10.4%) severe. The most common CHD type was atrial septal defect (n=78). More complex CHD conditions included transposition of the great arteries (n=14), anomalous pulmonary veins (n=13), tetralogy of Fallot (n=8), cor triatriatum (n=7), single ventricle physiology (n=2), among others. The majority (71.3%) of patients had AF despite at least one AAD. 46 patients (22.1%) had a reduced systemic ventricular ejection fraction <50%, and the mean left atrial diameter was 44.1±0.7 mm. PV isolation (PVI) was performed in 227 patients (94.6%); additional ablation strategies included left atrial linear ablations (25.4%), CFAE (19.2%), and cavotricuspid isthmus ablation (40.8). One-year complete and partial success rates were 45.0% and 20.5%, respectively, with no significant difference in the rate of complete success between complexity groups. Overall, 38 patients (15.8%) required more than one ablation procedure. There were 3 (1.3%) major and 13 (5.4%) minor procedural complications.

Conclusion

AF ablation in this complex population was safe and resulted in AF control in the majority of patients. Future work should address the most appropriate ablation targets in the challenging population.

Funding Acknowledgement

Type of funding sources: None.

Accessing Diverse Pyridine-Based Macrocyclic Peptides by a Two-Site Recognition Pathway

Macrocyclic peptides are sought-after molecular scaffolds for drug discovery, and new methods to access diverse libraries are of increasing interest. Here, we report the enzymatic synthesis of pyridine-based macrocyclic peptides (pyritides) from linear precursor peptides. Pyritides are a recently described class of ribosomally synthesized and post-translationally modified peptides (RiPPs) and are related to the long-known thiopeptide natural products. RiPP precursors typically contain an N-terminal leader region that is physically engaged by the biosynthetic proteins that catalyze modification of the C-terminal core region of the precursor peptide. We demonstrate that pyritide-forming enzymes recognize both the leader region and a C-terminal tripeptide motif, with each contributing to site-selective substrate modification. Substitutions in the core region were well-tolerated and facilitated the generation of a wide range of pyritide analogues, with variations in macrocycle sequence and size. A combination of the pyritide biosynthetic pathway with azole-forming enzymes was utilized to generate a thiazole-containing pyritide (historically known as a thiopeptide) with no similarity in sequence and macrocycle size to the naturally encoded pyritides. The broad substrate scope of the pyritide biosynthetic enzymes serves as a future platform for macrocyclic peptide lead discovery and optimization.

Description of a new species of the Charaeacoomani group (Coleoptera: Chrysomelidae: Galerucinae) from Vietnam with a key to species

Background

The genus Charaea Baly is distributed in the eastern Palaearctic, Himalayas, China and adjacent countries of the Oriental Region. Currently, 59 species of the genus Charaea have been recorded. The species of Charaea is characterised with a robust tubular aedeagus that terminates with a more or less distinct apical process with the Charaeacoomani group having an internal sac with long sharp lateral sclerites. Up to now, 13 species of this group have been described in the Oriental Region, four of which are found in Vietnam.

New information

Charaeadinhcuongi sp. nov. is described as a new species, based on specimens collected from Phu Quoc Island in southern Vietnam. Colour photographs of habitus and body details and DNA barcode sequences are presented. An identification key is provided for all Vietnamese species from the Charaeacoomani group.

Assessing learner engagement with virtual educational events: Development of the Virtual In-Class Engagement Measure (VIEM)

BACKGROUND

The COVID-19 pandemic has necessitated virtual education, but effects on learner engagement are unknown. We developed a virtual in-class engagement measure (VIEM) to assess learner engagement in online surgical education events.

METHODS

Using the STROBE, an observer collected tool to document student engagement, as a template an ASE committee workgroup developed the VIEM. The VIEM had two parts: observer assessment and learner self-assessment of engagement. Trained observers collected engagement data from two institutions using the VIEM. Surgical attendings, fellows and residents were observed during virtual learning events. Educator attitudes towards online teaching were also assessed via survey.

RESULTS

22 events with 839 learners were observed. VIEM distinguished between sessions with low and high engagement. 20% of learners pretended to participate. Half of instructors were comfortable with virtual teaching, but only 1/3 believed was as effective as in-person. 2/3 of teachers believed video learners were more engaged than audio learners.

CONCLUSIONS

Virtual platforms do not automatically translate into increased engagement. Standard tools such as VIEM may help with assessment of engagement during virtual education.

Therapeutics potentiating microglial p21-Nrf2 axis can rescue neurodegeneration caused by neuroinflammation

Neurodegenerative disorders are caused by progressive neuronal loss, and there is no complete treatment available yet. Neuroinflammation is a common feature across neurodegenerative disorders and implicated in the progression of neurodegeneration. Dysregulated activation of microglia causes neuroinflammation and has been highlighted as a treatment target in therapeutic strategies. Here, we identified novel therapeutic candidate ALGERNON2 (altered generation of neurons 2) and demonstrate that ALGERNON2 suppressed the production of proinflammatory cytokines and rescued neurodegeneration in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease model. ALGERNON2 stabilized cyclinD1/p21 complex, leading to up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2), which contributes to antioxidative and anti-inflammatory responses. Notably, ALGERNON2 enhanced neuronal survival in other neuroinflammatory conditions such as the transplantation of induced pluripotent stem cell-derived dopaminergic neurons into murine brains. In conclusion, we present that the microglial potentiation of the p21-Nrf2 pathway can contribute to neuronal survival and provide novel therapeutic potential for neuroinflammation-triggered neurodegeneration.

Spontaneous arytenoid dislocation and crico-arytenoid instability

INTRODUCTION

Arytenoid dislocation is a rare occurrence, for which the pathophysiology is still unclear.

METHODS

We report here an unusual case of spontaneous arytenoid dislocation, which casts doubts on the prevailing classical theory of hemarthrosis.

RESULTS AND CONCLUSIONS

This case and a review of the literature suggest that arytenoid dislocation could be linked to congenital or acquired arytenoid instability, thus facilitating arytenoid dislocation after even minor trauma. Once the diagnosis is established, we recommend to first attempt reduction, followed by speech therapy, though underlying diseases should be researched.

[Covering of Finger-Tissue Loss by Local Flaps in Hanoi, Vietnam]

The accidental loss of fingertip soft tissues, which may expose tendons and bones, is a common injury in emergency departments. If these lesions are poorly treated, they can impair fine motor skills and tactile sensitivity of the fingertips. The study was conducted on 30 patients (24 males and 6 females) with 32 soft tissue defects of the fingertip treated in emergency plastic surgery with local pedicled flap at the Plastic Surgery Department of Saint Paul Hospital Hanoi from 01/2016 to 06/2017. The most common cause of injury (21/30) was occupational accidents. At the time of the accident, 12 patients did not have personal protective equipment (PPE). Among 18 patients who had one, eight had incomplete equipment. Of 32 implanted skin flaps, 31 survived completely without necrosis or infection, only one being affected by epidermolysis. Postoperative evaluation showed excellent motor skills for 31/32 fingers and a sensitivity restoration at S4 level for 27/32. Workplace accident is the main cause of fingers soft tissue defects. Covering the fingers soft tissue defects with local pedicled flap in emergency preserves the fine motor function and the delicated tactile sensation of the fingers.

Suitability of Estimated Glomerular Filtration Rate for Live Kidney Donor Selection

INTRODUCTION

The assessment of the glomerular filtration rate (GFR) in kidney donor candidates is required for determining donor candidate acceptability. This assessment can be done using an estimated GFR (eGFR) or a measured GFR (mGFR). The primary objective of the present study was to compare, in healthy adult kidney donor candidates, GFR measured by the clearance of iothalamate to GFR estimated using the Chronic Kidney Disease Epidemiology Collaboration equation and to determine if eGFR was a suitable stand-alone assessment. A secondary objective was to explore demographic factors that affect the relationship of the eGFR and the mGFR.

METHODS

A retrospective review of kidney donor candidates' records at the J. C. Walter, Jr., Transplant Center, Houston Methodist Hospital, from January 2013 to March 2016 was undertaken. GFR was measured by the plasma clearance of radioisotopic iothalamate and estimated using the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

The median mGFR was 108 mL/min/1.73 m². The eGFR underestimated the mGFR by 11.5%. The underestimation was greatest in subjects with an mGFR of ≥90 mL/min/1.73 m². The eGFR overestimated the mGFR in donor candidates of black race.

CONCLUSIONS

The Chronic Kidney Disease Epidemiology Collaboration eGFR can be used for screening potential kidney donors restricting the use of iothalamate (mGFR) to those donors with an eGFR below the transplant centers' acceptable GFR threshold for donation, thereby effecting cost savings and greater donor convenience. The eGFR in black donor candidates should be used with caution.

Intestinal and non-intestinal nasal cavity adenocarcinoma: Impact of wood dust exposure

The aim of the present study was to investigate the role of wood dust exposure in intestinal (ITAC) and non-intestinal type (non-ITAC) nasal adenocarcinoma, so as to improve understanding of the oncogenic mechanisms in the light of the recent literature and of evo-devo concepts.

MATERIALS AND METHODS

All consecutive patients operated in our institution for nasal adenocarcinoma diagnosed on anatomopathology between May 2004 and February 2014 were included. Surgical specimens were examined twice by independent pathologists, blind to wood dust exposure status. Clinical and demographic data, including wood dust exposure, were collected for the two groups (ITAC and non-IATC).

RESULTS

90 patients (84 ITAC, 6 non-ITAC) were included. No non-ITAC patients had history of wood dust exposure, versus 83/84 cases (99%) in ITAC (mean exposure duration: 30±16 years; range 2-65 years). Only 12 ITAC patients (18%) were still exposed at diagnosis. ITAC may develop long after the end of wood dust exposure (up to 60 years). Eight patients (12%) had exposure durations of less than 5 years. Latency between onset of exposure and onset of disease did not decrease with exposure duration.

CONCLUSION

Exposure to wood dust, even for short periods of time, incurs a risk of developing ITAC, usually after a long latency period. Any exposure requires lifetime follow-up, to ensure prompt treatment. Factors leading to the development of nasal ITAC and non-ITAC are probably different. The analogy with Barret's esophagus and esophageal adenocarcinoma may shed light on the oncogenesis of nasal ITAC.

Olfactory cleft dilatation

The surgical technique of olfactory cleft dilatation consists in transmucosal lateral fracture-dislocation of the lateral wall of each olfactory cleft (i.e., of the turbinate wall of the ethmoid, composed, from anterior to posterior, of the middle, superior and supreme turbinates), in order to get access to the recess hosting the human olfactory mucosa and to the roof of the olfactory cleft (i.e., cribriform plate), with minimal trauma to the mucosa. Olfactory cleft dilatation is indicated for dysosmia secondary to constitutional stenosis of the olfactory clefts due to abnormal development of the ethmoid. Constitutional stenosis of the olfactory clefts should be differentiated from inflammatory obstruction and other diseases of the olfactory clefts, and especially from respiratory epithelial adenomatoid hamartoma, which enlarges the olfactory clefts and must be treated by resection. The technique of olfactory cleft dilatation is illustrated by three surgical cases. There was clear improvement in dysosmia in all three cases, without any complications. The place of constitutional olfactory cleft stenosis needs still to be defined in both diagnosis and treatment of dysosmia.

Chronic respiratory rhinitis

The clinical distinction of chronic respiratory rhinitis appears to confirm the evo-devo theory of the three noses. The authors report two cases of advanced allergic rhinitis, in which chronic inflammation had induced a violaceous colour of the mucosa of the respiratory nose and a whitish polypoid appearance of the free edge of the middle turbinate. Nose and paranasal sinus CT scan revealed, beyond the virtual nasal cavities observed on nasal endoscopy and CT imaging, normal radiolucency or only minor opacities of the ethmoid (i.e. olfactory nose) and paranasal sinuses that could not explain the severity of the chronic nasal dysfunction. The hypothesis of non-allergic chronic respiratory rhinitis is developed according to these two observations. The differential diagnosis between chronic respiratory rhinitis and dysfunction of the cavernous plexuses of the respiratory nose is discussed. A precise diagnosis appears to be a prerequisite for appropriate and effective management. Surgery of the respiratory nose can associate septoplasty to inferior turbinoplasty, but must be preceded and combined with medical treatment adapted to the underlying inflammatory process.

Nasal polyposis (or chronic olfactory rhinitis)

The concept of chronic rhinosinusitis with or without polyps is founded on the structural and functional unicity of the pituitary mucosa and its united response to environmental aggression by allergens, viruses, bacteria, pollution, etc. The present review sets this concept against the evo-devo three-nose theory, in which nasal polyposis is distinguished as specific to the olfactory nose and in particular to the non-olfactory mucosa of the ethmoid, which is considered to be not a sinus but rather the skull-base bone harboring the olfactory mucosa. The evo-devo approach enables simple and precise positive diagnosis of nasal polyposis and its various clinical forms, improves differential diagnosis by distinguishing chronic diseases of the respiratory nose and those of the paranasal sinuses, hypothesizes an autoimmune origin specifically aimed at olfactory system auto-antigens, and supports the surgical concept of nasalization against that of functional sinus and ostiomeatal-complex surgery. The ventilation function of the sinuses seems minor compared to their production, storage and active release of nitric oxide (NO) serving to oxygenate arterial blood in the pulmonary alveoli. This respiratory function of the paranasal sinuses may indeed be their most important. NO trapped in the ethmoidal spaces also accounts for certain radiographic aspects associated with nasal polyposis.

Appearance of reassortant European avian-origin H1 influenza A viruses of swine in Vietnam

Three subtypes-H1N1, H1N2 and H3N2-of influenza A viruses of swine (IAVs-S) are currently endemic in swine worldwide, but there is considerable genotypic diversity among each subtype and limited geographical distribution. Through IAVs-S monitoring in Vietnam, two H1N2 influenza A viruses were isolated from healthy pigs in Ba Ria-Vung Tau Province, Southern Vietnam, on 2 December 2016. BLAST and phylogenetic analyses revealed that their HA and NA genes were derived from those of European avian-like H1N2 IAVs-S that contained avian-origin H1 and human-like N2 genes, and were particularly closely related to those of IAVs-S circulating in the Netherlands, Germany or Denmark. In addition, the internal genes of these Vietnamese isolates were derived from human A(H1N1)pdm09 viruses, suggesting that the Vietnamese H1N2 IAVs-S are reassortants between European H1N2 IAVs-S and human A(H1N1)pdm09v. The appearance of European avian-like H1N2 IAVs-S in Vietnam marks their first transmission outside Europe. Our results and statistical analyses of the number of live pigs imported into Vietnam suggest that the European avian-like H1N2 IAVs-S may have been introduced into Vietnam with their hosts through international trade. These findings highlight the importance of quarantining imported pigs to impede the introduction of new IAVs-S.

Factors Influencing Acute Stroke Thrombolytic Treatments in Hispanics In the San Diego Region

BACKGROUND

Since the introduction of recombinant tissue plasminogen activator (rt-PA) for acute ischemic stroke, rt-PA rate and number of stroke centers have increased. Despite this, studies have shown racial and ethnic disparities in stroke care especially in Black and Hispanic populations. What factors are related to the administration of rt-PA within the Hispanic population has to date been unclear.

METHODS

We performed a retrospective review of IRB approved, prospectively collected data from the UC San Diego Stroke Registry from 7/2004-7/2016. Patients were included based on the primary diagnosis of Transient Ischemic Attack or Ischemic Stroke. Hispanic vs non-Hispanic patients were compared to assess for overall rt-PA treatment rates and process of care intervals. For the Hispanic cohort itself, demographics and NIHSS scores were assessed to determine why some Hispanics received rt-PA while others were not.

RESULTS

Overall, 1489 patients (300 Hispanic vs. 1189 non-Hispanic) were included. Comparing Hispanics to non-Hispanics, there was no difference in rt-PA rate (35.3% vs. 33.1%; p=0.49). In rt-PA treated patients, "onset to arrival" interval was higher in Hispanics (1.03 vs. 0.88 hours; p=0.04), while the "arrival to treatment" interval was not different (1.13 vs. 1.02 hours; p=0.07). When looking at Hispanic patients only, there was no difference in baseline characteristics except for initial NIHSS in treated vs. non-treated patients (13.27 vs. 7.24; p<.001).

CONCLUSION

Our analyses sought to determine the factors important to administration of rt-PA to Hispanic patients. These findings highlight the need for strategies to improve recognition and presentation pathways for Hispanics.

An interdimensional correlation framework for real-time estimation of six degree of freedom target motion using a single x-ray imager during radiotherapy

Increasing evidence suggests that intrafraction tumour motion monitoring needs to include both 3D translations and 3D rotations. Presently, methods to estimate the rotation motion require the 3D translation of the target to be known first. However, ideally, translation and rotation should be estimated concurrently. We present the first method to directly estimate six-degree-of-freedom (6DoF) motion from the target's projection on a single rotating x-ray imager in real-time. This novel method is based on the linear correlations between the superior-inferior translations and the motion in the other five degrees-of-freedom. The accuracy of the method was evaluated in silico with 81 liver tumour motion traces from 19 patients with three implanted markers. The ground-truth motion was estimated using the current gold standard method where each marker's 3D position was first estimated using a Gaussian probability method, and the 6DoF motion was then estimated from the 3D positions using an iterative method. The 3D position of each marker was projected onto a gantry-mounted imager with an imaging rate of 11 Hz. After an initial 110° gantry rotation (200 images), a correlation model between the superior-inferior translations and the five other DoFs was built using a least square method. The correlation model was then updated after each subsequent frame to estimate 6DoF motion in real-time. The proposed algorithm had an accuracy (±precision) of  -0.03  ±  0.32 mm, -0.01  ±  0.13 mm and 0.03  ±  0.52 mm for translations in the left-right (LR), superior-inferior (SI) and anterior-posterior (AP) directions respectively; and, 0.07  ±  1.18°, 0.07  ±  1.00° and 0.06  ±  1.32° for rotations around the LR, SI and AP axes respectively on the dataset. The first method to directly estimate real-time 6DoF target motion from segmented marker positions on a 2D imager was devised. The algorithm was evaluated using 81 motion traces from 19 liver patients and was found to have sub-mm and sub-degree accuracy.

Chronic nasal dysfunction

Chronic nasal dysfunction is a clinical concept in the diagnostic and therapeutic management of sinonasal diseases, based on the evo-devo theory of formation of the nose according to which the nose is not a single organ but rather an association of three organs: olfactory nose, respiratory nose and paranasal sinuses. In chronic nasal dysfunction theory, etiological diagnosis takes account of the possible pathophysiological independence of nasal symptoms, in accordance with the different origins and physiology of the three organs constituting the nose. The diagnostic approach of the chronic nasal dysfunction concept breaks down the pathology so as to propose treatment(s) adapted to the diseased organ(s) and to the capacity for physiological resolution of dysfunction induced in one organ by pathology in a neighboring nasal organ. The ethmoid is not a sinus according to evo-devo, and therefore functional endoscopic endonasal surgery (FEES) cannot be restricted to functional endoscopic sinus surgery (FESS). Evo-devo theory and the chronic nasal dysfunction concept offer an alternative to the concept of chronic rhinosinusitis with or without polyps for the management of sinonasal diseases.

Endoscopic surgery of the olfactory cleft

The olfactory cleft is the specific site of development of many tumours (respiratory epithelial adenomatoid hamartoma, intestinal-type adenocarcinoma, neuroblastoma, inverted papilloma, glomangiopericytoma, etc.) and is also the site of CSF rhinorrhoea via the cribriform plate (cribri-rhinorrhoea). Olfactory cleft surgery must therefore be considered to be a specific type of surgery, complementary to ethmoidal labyrinth surgery and anterior skull base surgery. Olfactory cleft tumours can be resected according to five different surgical procedures: olfactory cleft mucosal resection, partial resection of the olfactory cleft, total resection of the olfactory cleft, unilateral endoscopic anterior skull base resection, and bilateral endoscopic anterior skull base resection. The diagnosis and closure of cribri-rhinorrhoea (i.e. documented CSF rhinorrhoea, demonstrated to arise from the cribriform plate during endoscopic examination of the olfactory cleft under general anaesthesia in a patient with no localizing signs on imaging) completes this range of treatment options.

Sinonasal symptom-related sleep disorders before and after surgery for nasal polyposis

BACKGROUND

Patients with nasal polyposis (NP) complain of several sinonasal symptoms that impact their sleep and quality of life. However, data on sleep disorders related to NP symptoms, before and after surgery, is poor. The aim of the present study was to analyze sleep complaints related to each NP symptom, before and after surgery, using the Dynachron questionnaire.

METHODOLOGY

63 patients operated for NP were included in this prospective study. They filled the DyNaChron questionnaire one day before surgery (V0), 6 weeks (V1) and 7 months (V2) after surgery. The self-ratings (0-10 point visual analog scale) of nasal obstruction, anterior rhinorrhea, postnasal discharge, cough and 5 items related to sleep disturbances, due to each symptom of chronic nasal dysfunction, were extracted from the questionnaire and analyzed.

RESULTS

There was significant improvement of symptoms and symptom-related sleep disturbance scores at V1 and V2 compared to baseline scores. Before surgery, moderate/severe sleep disorders that patients attributed to nasal obstruction (the patient thinks it is due to nasal obstruction rather than a clinical test to show nasal obstruction) or anterior rhinorrhea were reported in two thirds of patients, postnasal discharge in one half, and chronic cough in one third. After surgery, less than 10% of patients reported moderate/severe sleep disorders at V1. There was a mild increase of patients who rated moderate/severe sleep disorders at V2 in comparison to V1. The correlation between scores of nasal obstruction and its impacts on sleep quality was weak before surgery and strong afterwards.

CONCLUSION

Nasalization improved sleep quality significantly at 6 weeks and at 7 months after surgery. However, there was a mild increase of complaints related to postnasal discharge and cough at 7 months after surgery.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

Optomechanical properties of GaAs/AlAs micropillar resonators operating in the 18 GHz range

Recent experiments demonstrated that GaAs/AlAs based micropillar cavities are promising systems for quantum optomechanics, allowing the simultaneous three-dimensional confinement of near-infrared photons and acoustic phonons in the 18-100 GHz range. Here, we investigate through numerical simulations the optomechanical properties of this new platform. We evidence how the Poisson's ratio and semiconductor/vacuum boundary conditions lead to very distinct features in the mechanical and optical three-dimensional confinement. We find a strong dependence of the mechanical quality factor and strain distribution on the micropillar radius, in great contrast to what is predicted and observed in the optical domain. The derived optomechanical coupling constants g₀ reach ultra-large values in the 10⁶ rad/s range.

Effects of stretching on the frictional stress of rubber

In this paper, we report on new experimental results on the effects of in-plane surface stretching on the friction of poly(dimethylsiloxane) (PDMS) rubber with smooth rigid probes. Friction-induced displacement fields are measured at the surface of the PDMS substrate under steady-state sliding. Then, the corresponding contact pressure and frictional stress distributions are determined from an inversion procedure. Using this approach, we show that the local frictional stress τ is proportional to the local stretch ratio λ at the rubber surface. Additional data using a triangular flat punch indicate that τ(λ) relationship is independent on the contact geometry. From friction experiments using pre-stretched PDMS substrate, it is also found that the stretch-dependence of the frictional stress is isotropic, i.e. it does not depend on the angle between stretching and sliding directions. Potential physical explanations for this phenomenon are provided within the framework of Schallamach's friction model. Although the present experiments are dealing with smooth contact interfaces, the reported τ(λ) dependence is also relevant to the friction of statistically rough contact interfaces, while not accounted for in related contact mechanics models.

Non-enhanced CT Maximum Intensity Projections for the Detection of Large Vessel Occlusions

BACKGROUND

Identification of large vessel occlusions (LVO) is important with recent guidelines supporting endovascular therapy in selected acute ischemic stroke patients. Many stroke centers perform CT angiography (CTA) in patients with suspected LVO, however this requires additional time and contrast administration. Non-enhanced CT maximum intensity projection (NECT-MIPs) may offer a rapid alternative to CTA.

METHODS

We retrospectively reviewed acute stroke patients with LVO in the UCSD Stroke Registry, presenting between 6/2014-7/2016. NECT-MIPs were evaluated for presence of LVO. Gold standard comparison was to CTA. Results were stratified by level of training (Faculty, Fellow and Acute Care Practitioners [ACPs]). Inter-rater agreement was assessed using Fleiss' Kappa Coefficient.

RESULTS

We reviewed 24 patients using NECT-MIPs for the detection of LVO. Faculty had a sensitivity and specificity of 95% & 92% for ICA/M1, 42% & 100% for M2, and 67% & 96% for basilar occlusions. Fellows and ACPs had a sensitivity and specificity of 61% & 94% for ICA/M1, 19% & 83% for M2, and 75% & 95% for basilar occlusions. Inter-rater agreement among Faculty readers was k=0.75 for ICA/M1, k=0.79 for M2 and k=0.14 for basilar occlusions. Among Fellows and ACPs, k=0.57 for ICA/M1, k=0.40 for M2, and k=0.27 for basilar occlusions.

CONCLUSIONS

NECT-MIPs have high sensitivity and specificity for the detection of LVO when compared to CTA. Inter-rater agreement is fair and higher amongst more experienced reviewers. These results suggest that NECT-MIPs may be helpful to streamline the identification of LVO and reduce door to needle and door to intervention times.

"Watchful observation" follow-up scheme after endoscopic CO2 laser treatment for small glottic carcinomas: A retrospective study of 93 cases

OBJECTIVES

Evaluate the clinical outcome of patients treated with CO₂ laser surgery for early-stage glottic carcinomas followed up with 3-month laryngoscopy regardless of tumor grade and margins.

DESIGN

Case series.

SETTING

Retrospective review of the clinical records of patients treated at the ENT department of a tertiary university hospital.

PARTICIPANTS AND METHOD

Clinical records from patients with early-stage glottic carcinomas (Tis/T2) treated with curative intent by CO₂ laser surgery in a ten-year period were evaluated. Regardless of tumor margin status, patients underwent fiber endoscopy 6 weeks after surgery and a systematic second look by direct laryngoscopy under general anesthesia at 3 months.

MAIN OUTCOME MEASURES

Local control, laryngeal preservation rate.

RESULTS

Ninety-three patients were included. Disease control was obtained in 90/93 cases. Laryngeal preservation rate was 96.8%. Twenty patients had a local residual disease or recurrence after the first laser surgery, but 17 were salvaged (85%). Local residual disease and recurrence were more frequent in patients with advanced disease (T1b/T2), invasion of anterior commissure and "non-safe" margins.

CONCLUSION

The proposed follow-up scheme might be a valuable option, but with caution for positive or unevaluable margins as the latter is an independent risk factor for local recurrence. An early laser excision procedure (eg, within the first two months after surgery) or an alternative strategy may be discussed in this situation. "Watchful observation" should be reserved for compliant patients only so that the risk of missing potential recurrences is minimised.

Awareness of obstructive sleep apnea-hypopnea syndrome among the general population of the Lorraine Region of France

OBJECTIVE

Obstructive sleep apnea-hypopnea syndrome (OSAHS) seems to be underdiagnosed. The aim of this study was to assess awareness of OSAHS among the general population of the Lorraine Region of France.

METHODS

A descriptive epidemiological study was carried out from July to November 2015 in the Lorraine Region, using an anonymous questionnaire that assessed knowledge of OSAHS-related symptoms and complications. The survey was also circulated on the Internet via social media. Exclusion criteria comprised age under 18 years, refusal to fill out the questionnaire and linguistic barrier.

RESULTS

1307 subjects filled out the survey: 1020 on paper format and 287 via the Internet. About two-thirds of the population recognized a majority of symptoms. However, there was a significant lack of knowledge of complications, especially cardiological and neurological. Suffering from OSAHS, having had higher education, and being under 40 years of age, were factors linked to better awareness of the syndrome. Internet respondents also showed better awareness.

CONCLUSION

Despite encouraging results regarding OSAHS symptoms, the general population showed limited awareness of its complications. Innovative educational campaigns must be organized to inform practitioners and the general public about the disease and raise awareness of its complications.

Assessment of facial pain and headache before and after nasal polyposis surgery with the DyNaChron questionnaire

OBJECTIVES

Facial pain/headache is reported in 16-67% of nasal polyposis (NP) patients. This wide range may be due to differences in assessment methods. The present prospective study assessed facial pain/headache and quality-of-life (QoL) impact before and after NP surgery.

METHODS

Pain was assessed on the DyNaChron self-administered questionnaire in patients undergoing NP surgery, the day before the procedure (V0) and 6 weeks (V1) and 7 months (V2) after. All patients underwent the same nasalization procedure, sparing the middle turbinates when possible. The questionnaire extract comprised 1 item assessing pain, 13 assessing physical impact and 4 assessing psychosocial impact, with responses on visual analog scales (VAS) graded 0 (no discomfort) to 10 (unbearable discomfort).

RESULTS

Sixty-three patients (mean age: 50.6±12.8 years; 32 male [50.8%], 31 female [49.2%]) were included. Thirty-seven patients (58.7%) had history of NP surgery. Fifty-two percent reported moderate to severe pain before surgery, 17.5% at 6 weeks, and 22.2% at 7 months. One-third reported no pain preoperatively, versus a half at 6 weeks and 7 months. Scores for the physical and psychosocial impact of pain were improved after surgery.

CONCLUSION

Headache/facial pain is frequent in patients for whom NP surgery is indicated. Endoscopic surgery relieves the symptom and its physical and psychosocial impacts. However, one-fifth of patients reported residual postoperative pain.

Structure of the lateral mass of the ethmoid by curved stacking of endoturbinal elements

CONTEXT

According to evo-devo theory, the embryonic development of the nasal organ mimics its phylontogenic formation: the lateral masses of the human ethmoid bone develop by curved "onion" stacking of the endoturbinals (the horizontal bone septa of the mammalian olfactory chamber) under the impact of facial and skull-base remodeling, rather than by pneumatization of cavities communicating via ostia.

OBJECTIVES

To assess the frequency of the onion structure on coronal CT.

MATERIAL AND METHODS

Three independent examiners performed a retrospective descriptive study of coronal CT scans taken ahead of septorhinoplasty between June 2010 and December 2012 in adult patients without history of sinonasal surgery.

RESULTS

Fifty patients were included. In the anterior right and left and posterior right ethmoid, an onion arrangement of the endoturbinals was systematically found on at least 1 view, and on 60% of views taking all ethmoid compartments together. Two endoturbinals were generally involved, but a rolling-up of 3 endoturbinals was also observed, significantly more frequently in the posterior compartments (P=0.004 on the right side, P=0.012 on the left).

CONCLUSION

The onion structure of the lateral masses of the ethmoid can be observed on coronal CT scans. This structure confirms evo-devo theory. The ethmoid thus appears fundamentally different from the paranasal sinuses, suggesting that the pathogenesis of nasal polyposis and ethmoidectomy techniques need to be reconsidered.

Nasal or canthal-alar parentheses: A study of the facial base of the nose

OBJECTIVES

The facial implantation of the osseous nasal pyramid corresponds to the piriform aperture, the shape of which is projected on the facial skin in the form of bracket-shaped parentheses. The objective of this study was to compare inter-parenthesis width with subjective visibility on frontal photographs.

MATERIAL AND METHODS

The "patient" group came from a retrospective cohort of photographs taken ahead of septorhinoplasty. The "model" group photographs were collected from the Web or magazines. Nasal parentheses were first judged subjectively as frank or faint. Then, independently, parenthesis width was measured by computer in pixels and converted into millimeters by iris-dependent calibration. Inter-parenthesis width was compared statistically with the frank/faint assessment, according to gender and group.

RESULTS

A total of 113 photographs were included: 46 patients (19 women, 27 men) and 67 models (43 women, 24 men). Sixty-seven of the 113 nasal parentheses appeared frank (59.3%), more frequently in men than women (70.6% vs 50.0%, P=0.02) and in patients than models (69.6% vs 52.2%, P=0.06). Inter-parenthesis width was significantly greater in frank than faint presentations (34.9±3.5mm vs 30.7±3.4mm, P<0.0001), in men than women (35.2±4.1mm vs 31.5±3.1mm, P<0.0001), and in patients than models (34.9±4.0mm vs 32.0±3.6mm, P<0.0001).

CONCLUSION

Frank nasal parentheses correspond to wider facial implantation of the nose.

Sinusology

This paper presents a brief history of the successive anatomical, physiological and pathophysiological concepts about the paranasal sinuses. Sinusology, the science of the paranasal sinuses, is founded on scientific work on the production of nitric oxide (NO) by the sinuses and on the evo-devo theory of their formation. The paranasal sinuses seem to develop after regression of the erythropoietic marrow in the maxillary, frontal and sphenoid bones and its replacement by cavities filled with gas, which escapes into the nasal fossae through the ostium. The sinus epithelium synthesizes NO continuously. The paranasal sinus cavities form a compartmentalized reservoir of NO, which is released discontinuously in boli after an opening of the ostium. Ostium opening can be induced by sound vibration, either internal (humming) or external (an acoustic vibration added to the in-breath). NO plays the role of an "aerocrine" messenger between the upper and lower respiratory tracts, reducing pulmonary vascular resistance and facilitating alveolar oxygen transfer into the bloodstream. Its physiological role in arterial blood oxygenation could be involved in speech and singing or be activated by physiological snoring during sleep. Rhinology, the science of the nose, in which the evo-devo concept distinguishes the respiratory and the olfactory nose, is now backed up by sinusology.

High-frequency nano-optomechanical disk resonators in liquids

Nano- and micromechanical resonators are the subject of research that aims to develop ultrasensitive mass sensors for spectrometry, chemical analysis and biomedical diagnosis. Unfortunately, their merits generally diminish in liquids because of an increased dissipation. The development of faster and lighter miniaturized devices would enable improved performances, provided the dissipation was controlled and novel techniques were available to drive and readout their minute displacement. Here we report a nano-optomechanical approach to this problem using miniature semiconductor disks. These devices combine a mechanical motion at high frequencies (gigahertz and above) with an ultralow mass (picograms) and a moderate dissipation in liquids. We show that high-sensitivity optical measurements allow their Brownian vibrations to be resolved directly, even in the most-dissipative liquids. We investigate their interaction with liquids of arbitrary properties, and analyse measurements in light of new models. Nano-optomechanical disks emerge as probes of rheological information of unprecedented sensitivity and speed, which opens up applications in sensing and fundamental science.

Investigating the utility of in vivo bio-impedance spectroscopy for the assessment of post-ischemic myocardial tissue

Increased myocardial structural heterogeneity in response to ischemic injury following myocardial infarction (MI) is purported as the mechanism of ventricular arrhythmogenesis. Current modalities for in vivo assessment of structural heterogeneity for identification of arrhythmogenic substrate are limited due to the complex nature of the structural microenvironment post-MI. We investigated the utility of in vivo bio-impedance spectroscopy (BIS) in a large post-infarct animal model for differentiation between normal and infarcted tissue. We also investigated the quantitative effects of adipose and collagen on BIS assessment of myocardium. The results indicate that the degree of myocardial injury following chronic post-infarction remodeling could be reliably quantified (performed in triplicates) using BIS. Furthermore, the presence of intramyocardial adipose tissue that develops in conjunction with collagen within the infarct zone had a greater and significant influence on BIS then collagen tissue alone. These preliminary results indicate a potential role of BIS for quantitative assessment and characterization of complex arrhythmogenic substrates in ischemic cardiomyopathy.

All-atom empirical potential for molecular modeling and dynamics studies of proteins

New protein parameters are reported for the all-atom empirical energy function in the CHARMM program. The parameter evaluation was based on a self-consistent approach designed to achieve a balance between the internal (bonding) and interaction (nonbonding) terms of the force field and among the solvent-solvent, solvent-solute, and solute-solute interactions. Optimization of the internal parameters used experimental gas-phase geometries, vibrational spectra, and torsional energy surfaces supplemented with ab initio results. The peptide backbone bonding parameters were optimized with respect to data for N-methylacetamide and the alanine dipeptide. The interaction parameters, particularly the atomic charges, were determined by fitting ab initio interaction energies and geometries of complexes between water and model compounds that represented the backbone and the various side chains. In addition, dipole moments, experimental heats and free energies of vaporization, solvation and sublimation, molecular volumes, and crystal pressures and structures were used in the optimization. The resulting protein parameters were tested by applying them to noncyclic tripeptide crystals, cyclic peptide crystals, and the proteins crambin, bovine pancreatic trypsin inhibitor, and carbonmonoxy myoglobin in vacuo and in crystals. A detailed analysis of the relationship between the alanine dipeptide potential energy surface and calculated protein φ, χ angles was made and used in optimizing the peptide group torsional parameters. The results demonstrate that use of ab initio structural and energetic data by themselves are not sufficient to obtain an adequate backbone representation for peptides and proteins in solution and in crystals. Extensive comparisons between molecular dynamics simulations and experimental data for polypeptides and proteins were performed for both structural and dynamic properties. Energy minimization and dynamics simulations for crystals demonstrate that the latter are needed to obtain meaningful comparisons with experimental crystal structures. The presented parameters, in combination with the previously published CHARMM all-atom parameters for nucleic acids and lipids, provide a consistent set for condensed-phase simulations of a wide variety of molecules of biological interest.

Comprehensive and high-resolution typing of swine leukocyte antigen DQA from genomic DNA and determination of 25 new SLA class II haplotypes

We previously reported the development of genomic-DNA-based high-resolution genotyping methods for SLA-DQB1 and DRB1. Here, we report the successful typing of SLA-DQA using similar methodological principles. We designed a method for comprehensive genotyping of SLA-DQA using intronic sequence information of SLA-DQA exon 2 that we had obtained from 12 animals with different SLA-DQB1 genotypes. We expanded our typing to 76 selected animals with diverse DQB1 and DRB1 genotypes, 140 random animals from 7 pig breeds, and 3 wild boars. This resulted in the identification of 17 DQA alleles with 49 genotypes. Two new alleles were identified from wild boars. Combine with SLA-DQB1, and DRB1 typing results, we identified 34 SLA class II haplotypes including 25 that were previously unreported.

Descriptive results of a prospective cohort study of avian influenza in the Mekong River Delta of Viet Nam

A prospective cohort study of avian influenza infection in poultry flocks was carried out in the Mekong River Delta of Viet Nam between December 2008 and April 2010. Our objectives were to (i) estimate the prevalence and incidence of avian influenza virus infection and (ii) assess the efficacy of H5N1 vaccination programmes as indicated by the presence of H5 antibody in vaccinated and unvaccinated poultry. Real-time PCR and H5 multiplex assays were used to detect the antigen of avian influenza viruses from swab samples. The haemagglutination inhibition test was used to detect H5 antibody. A total of 17 968 swab and 14 878 blood samples were collected from 5476 birds over the study period. The overall incidence rate of influenza type A virus infection was 5 (95% CI 4-7) positive birds per 100 bird-months at risk. The overall incidence rate of H5 virus infection was 0.2 (95% CI 0.1-0.5) positive birds per 100 bird-months at risk. Fifty (95% CI 48-52) birds per 100 tested birds were H5 HI positive in the unvaccinated group compared with 71 (95% CI 69-73) birds per 100 in the vaccinated group. Influenza type A and H5 viruses were circulating in village poultry throughout the study period with no recorded signs of clinical disease. This implies that interventions need to be carried out continuously throughout the year rather than only focusing on the established high-risk periods. Broiler ducks had an incidence rate of influenza H5 virus infection approximately four times greater than that of layer ducks and in-contact species. We conclude that broiler ducks are likely to be the main entry route for H5 virus into poultry flocks in the MRD. Control efforts would benefit from understanding why there is a difference between villages in H5 incidence and developing strategies to provide greater protection to broiler ducks.

Balancing mechanical strength with bioactivity in chitosan-calcium phosphate 3D microsphere scaffolds for bone tissue engineering: air- vs. freeze-drying processes

The objective of this study was to evaluate the potential benefit of 3D composite scaffolds composed of chitosan and calcium phosphate for bone tissue engineering. Additionally, incorporation of mechanically weak lyophilized microspheres within those air-dried (AD) was considered for enhanced bioactivity. AD microsphere, alone, and air- and freeze-dried microsphere (FDAD) 3D scaffolds were evaluated in vitro using a 28-day osteogenic culture model with the Saos-2 cell line. Mechanical testing, quantitative microscopy, and lysozyme-driven enzymatic degradation of the scaffolds were also studied. FDAD scaffold showed a higher concentration (p < 0.01) in cells per scaffold mass vs. AD constructs. Collagen was ∼31% greater (p < 0.01) on FDAD compared to AD scaffolds not evident in microscopy of microsphere surfaces. Alternatively, AD scaffolds demonstrated a superior threefold increase in compressive strength over FDAD (12 vs. 4 MPa) with minimal degradation. Inclusion of FD spheres within the FDAD scaffolds allowed increased cellular activity through improved seeding, proliferation, and extracellular matrix production (as collagen), although mechanical strength was sacrificed through introduction of the less stiff, porous FD spheres.

The sternalis muscle-incidental finding of a rare chest wall muscle variant during keloid excision-chest wall reconstruction

INTRODUCTION

The sternalis is a rare (strap-like) parasternal muscle that is well known to anatomists, but relatively unknown to clinicians, including surgeons. Familiarity with the muscle is important in avoiding potential confusion when incidentally encountered. When available, the muscle can be harvested for reconstruction of the chest wall or of nearby region.

PRESENTATION OF CASE

The patient is a 55-year-old man with significant sternal keloids secondary to a previous history of severe acne. The patient desires removal of the keloids. Hence, a decision was made to excise the keloids, followed by immediate reconstruction with a propeller flap. Intraoperative excision of the keloids and undermining of adjacent subcutaneous tissue revealed chest muscle fibers fitting the description of the sternalis muscle. The patient tolerated the procedure without any complications.

DISCUSSION

The sternalis muscle can be confused for a mass on mammography, but confusion is resolved by computed tomography/magnetic resonance imaging. It has unclear embryonic origin-perhaps a remnant of the panniculus carnosus and/or derivative of a primitive ventral-longitudinal muscle sheet that give rise to the sternocleidomastoid and the rectus abdominis muscles. It is uni- or bilateral and has 1 or 2 bellies. It originates in the intraclavicular region and inserts onto the rectus sheath, costal cartilages, lower ribs, or external oblique aponeurosis.

CONCLUSION

Not enough is known about the sternalis muscle to draw any conclusion about its utility in reconstructive surgery. It is hoped that cases will be presented in the foreseeable future describing its usage in reconstruction of the neck, chest, abdomen, and perhaps even other places.