Design, Multigram Synthesis, and in Vitro and in Vivo Evaluation of Propylamycin: A Semisynthetic 4,5-Deoxystreptamine Class Aminoglycoside for the Treatment of Drug-Resistant Enterobacteriaceae and Other Gram-Negative Pathogens.

Infectious diseases due to multidrug-resistant pathogens, particularly carbapenem-resistant Enterobacteriaceae (CREs), present a major and growing threat to human health and society, providing an urgent need for the development of improved potent antibiotics for their treatment. We describe the design and development of a new class of aminoglycoside antibiotics culminating in the discovery of propylamycin. Propylamycin is a 4'-deoxy-4'-alkyl paromomycin whose alkyl substituent conveys excellent activity against a broad spectrum of ESKAPE pathogens and other Gram-negative infections, including CREs, in the presence of numerous common resistance determinants, be they aminoglycoside modifying enzymes or rRNA methyl transferases. Importantly, propylamycin is demonstrated not to be susceptible to the action of the ArmA resistance determinant whose presence severely compromises the action of plazomicin and all other 4,6-disubstituted 2-deoxystreptamine aminoglycosides. The lack of susceptibility to ArmA, which is frequently encoded on the same plasmid as carbapenemase genes, ensures that propylamycin will not suffer from problems of cross-resistance when used in combination with carbapenems. Cell-free translation assays, quantitative ribosome footprinting, and X-ray crystallography support a model in which propylamycin functions by interference with bacterial protein synthesis. Cell-free translation assays with humanized bacterial ribosomes were used to optimize the selectivity of propylamycin, resulting in reduced ototoxicity in guinea pigs. In mouse thigh and septicemia models of Escherichia coli, propylamycin shows excellent efficacy, which is better than paromomycin. Overall, a simple novel deoxy alkyl modification of a readily available aminoglycoside antibiotic increases the inherent antibacterial activity, effectively combats multiple mechanisms of aminoglycoside resistance, and minimizes one of the major side effects of aminoglycoside therapy.

Structural basis for selective targeting of leishmanial ribosomes: aminoglycoside derivatives as promising therapeutics.

Leishmaniasis comprises an array of diseases caused by pathogenic species of Leishmania, resulting in a spectrum of mild to life-threatening pathologies. Currently available therapies for leishmaniasis include a limited selection of drugs. This coupled with the rather fast emergence of parasite resistance, presents a dire public health concern. Paromomycin (PAR), a broad-spectrum aminoglycoside antibiotic, has been shown in recent years to be highly efficient in treating visceral leishmaniasis (VL)-the life-threatening form of the disease. While much focus has been given to exploration of PAR activities in bacteria, its mechanism of action in Leishmania has received relatively little scrutiny and has yet to be fully deciphered. In the present study we present an X-ray structure of PAR bound to rRNA model mimicking its leishmanial binding target, the ribosomal A-site. We also evaluate PAR inhibitory actions on leishmanial growth and ribosome function, as well as effects on auditory sensory cells, by comparing several structurally related natural and synthetic aminoglycoside derivatives. The results provide insights into the structural elements important for aminoglycoside inhibitory activities and selectivity for leishmanial cytosolic ribosomes, highlighting a novel synthetic derivative, compound 3: , as a prospective therapeutic candidate for the treatment of VL.

The Florida Scoring System for stratifying children with suspected Sjögren's disease: a cross-sectional machine learning study.

BACKGROUND: Childhood Sjögren's disease is a rare, underdiagnosed, and poorly-understood condition. By integrating machine learning models on a paediatric cohort in the USA, we aimed to develop a novel system (the Florida Scoring System) for stratifying symptomatic paediatric patients with suspected Sjögren's disease. METHODS: This cross-sectional study was done in symptomatic patients who visited the Department of Pediatric Rheumatology at the University of Florida, FL, USA. Eligible patients were younger than 18 years or had symptom onset before 18 years of age. Patients with confirmed diagnosis of another autoimmune condition or infection with a clear aetiological microorganism were excluded. Eligible patients underwent comprehensive examinations to rule out or diagnose childhood Sjögren's disease. We used latent class analysis with clinical and laboratory variables to detect heterogeneous patient classes. Machine learning models, including random forest, gradient-boosted decision tree, partial least square discriminatory analysis, least absolute shrinkage and selection operator-penalised ordinal regression, artificial neural network, and super learner were used to predict patient classes and rank the importance of variables. Causal graph learning selected key features to build the final Florida Scoring System. The predictors for all models were the clinical and laboratory variables and the outcome was the definition of patient classes. FINDINGS: Between Jan 16, 2018, and April 28, 2022, we screened 448 patients for inclusion. After excluding 205 patients due to symptom onset later than 18 years of age, we recruited 243 patients into our cohort. 26 patients were excluded because of confirmed diagnosis of a disorder other than Sjögren's disease, and 217 patients were included in the final analysis. Median age at diagnosis was 15 years (IQR 11-17). 155 (72%) of 216 patients were female and 61 (28%) were male, 167 (79%) of 212 were White, and 20 (9%) of 213 were Hispanic, Latino, or Spanish. The latent class analysis identified three distinct patient classes: class I (dryness dominant with positive tests, n=27), class II (high symptoms with negative tests, n=98), and class III (low symptoms with negative tests, n=92). Machine learning models accurately predicted patient class and ranked variable importance consistently. The causal graphical model discovered key features for constructing the Florida Scoring System. INTERPRETATION: The Florida Scoring System is a paediatrician-friendly tool that can be used to assist classification and long-term monitoring of suspected childhood Sjögren's disease. The resulting stratification has important implications for clinical management, trial design, and pathobiological research. We found a highly symptomatic patient group with negative serology and diagnostic profiles, which warrants clinical attention. We further revealed that salivary gland ultrasonography can be a non-invasive alternative to minor salivary gland biopsy in children. The Florida Scoring System requires validation in larger prospective paediatric cohorts. FUNDING: National Institute of Dental and Craniofacial Research, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Heart, Lung, and Blood Institute, and Sjögren's Foundation.

Developing a production workflow for 3D-printed temporal bone surgical simulators.

INTRODUCTION: 3D-printed temporal bone models enable the training and rehearsal of complex otological procedures. To date, there has been no consolidation of the literature regarding the developmental process of 3D-printed temporal bone models. A brief review of the current literature shows that many of the key surgical landmarks of the temporal bone are poorly represented in models. This study aims to propose a novel design and production workflow to produce high-fidelity 3D-printed temporal bone models for surgical simulation. METHODS: Developmental phases for data extraction, 3D segmentation and Computer Aided Design (CAD), and fabrication are outlined. The design and fabrication considerations for key anatomical regions, such as the mastoid air cells and course of the facial nerve, are expounded on with the associated strategy and design methods employed. To validate the model, radiological measurements were compared and a senior otolaryngologist performed various surgical procedures on the model. RESULTS: Measurements between the original scans and scans of the model demonstrate sub-millimetre accuracy of the model. Assessment by the senior otologist found that the model was satisfactory in simulating multiple surgical procedures. CONCLUSION: This study offers a systematic method for creating accurate 3D-printed temporal bone models for surgical training. Results show high accuracy and effectiveness in simulating surgical procedures, promising improved training and patient outcomes.

Long-term efficacy of sialendoscopy in treating childhood Sjögren's disease with chronological monitoring by salivary gland ultrasonography: A novel approach.

BACKGROUND: Childhood Sjögren's Disease (cSjD) is an underdiagnosed phenomenon with clinical and pathophysiological nuances in contrast to Sjögren's Disease (SjD) in the adult population. While adults typically experience sicca symptoms, children with cSjD often present with recurrent parotitis, diverse autoantibody profiles, and renal and neurological manifestations. Diagnosis and classification in pediatric rheumatology remain controversial due to the reliance on adult-focused diagnostic criteria and the lack of standardized treatment and understanding of outcomes. The purpose of the paper is to propose a multimodal treatment plan and demonstrate the effectiveness of sialendoscopy in the management of cSjD. CASE PRESENTATION: We present the case of a twelve-year-old female diagnosed with cSjD using the 2016 American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) diagnostic criteria for SjD. In addition to medical management, she underwent sialendoscopy with triamcinolone irrigation under sedation and was monitored for progress via salivary gland ultrasonography (SGUS). Over the course of one year, she demonstrated significant improvement in symptoms, with serial SGUS scores gradually decreasing by five points. CONCLUSIONS: This paper proposes a multimodal treatment plan involving sialendoscopy and medical management as a non-invasive and potentially more effective approach for cSjD. Standardized monitoring through SGUS scoring allows objective and quantifiable measurement of treatment progress, enabling better assessment of glandular tissue status. Recurrence is possible, and each cSjD patient may present differently. Nevertheless, our year-long observation of a patient with cSjD demonstrates that sialendoscopy, as seen in adults, can promote remission of recurrent parotitis in children as well.

Impact of intraoperative wound dressing on post-tracheostomy pressure injuries.

OBJECTIVE: Determine the efficacy of a team-based approach to reduce tracheostomy-related skin breakdown by creating a standardized intraoperative dressing and nursing wound care protocol. METHODS: Prospective data collection of pediatric tracheostomy outcomes before and after interventions consisting of intraoperative wound dressing and standardized nursing wound care bundles. RESULTS: Before intervention, the incidence of skin breakdown within the first-week post-tracheostomy was 52% (13/25). Among patients who received an intraoperative wound dressing and nursing wound care bundles, the incidence of skin breakdown was reduced to 6.1% (3/49). CONCLUSION: The adoption of intraoperative wound dressings and nursing wound care bundles has nearly eliminated the incidence of skin breakdown in the first week post-tracheostomy among patients 0-12 years of age.

Blood markers of alcohol use in epistaxis patients.

Epistaxis and alcohol overconsumption are frequently encountered in patients admitted to emergency wards. The aim of the study was to analyze indirect markers of alcohol overconsumption in epistaxis patients and evaluate its role as a risk factor. In a cohort of 510 epistaxis patients indirect markers of alcohol overuse were measured including the mean corpuscular volume (MCV), gamma glutamyltransferase (GGT), aspartate aminotransferase and alanine aminotransferase. The results were compared to the normal findings in literature. Pathologic mean levels of GGT were found in epistaxis patients. Almost 5% had macrocytosis and MCV correlated positively with liver enzyme levels. Platelet counts were negatively correlated with both corpuscular volumes and liver enzymes. Indirect markers of alcohol overconsumption were found to be elevated in epistaxis patients. These results suggest that a subgroup of epistaxis patients overconsumes alcoholic beverages supporting the idea of alcohol abuse being a risk factor in epistaxis. Questioning about drinking habits should be employed and help offered to affected patients.

Salmonella Retropharyngeal Abscess Linked to Backyard Poultry Exposure in a 12-Month-Old Girl.

We report a rare complication of nontyphoidal Salmonella infection in a 12-month-old girl with a retropharyngeal abscess. The patient presented with a four-day history of nasal congestion, cough, decreased oral intake, and increased irritability. She was admitted for a suspected deep neck infection. Computed tomography confirmed a retropharyngeal abscess with airway narrowing. Incision and drainage was performed, and intraoperative cultures grew nontyphoidal Salmonella. Epidemiologic investigation revealed exposure to a backyard flock of chickens. The patient had little direct contact with chickens but did go with family to collect eggs, riding on a vehicle that likely became contaminated. This case highlights the risks to infants and young children in contact with live poultry or contaminated environments.

Postoperative Pain Exacerbation After Adenotonsillectomy Due to Oral Candida Infection?

Post-tonsillectomy complications can include bleeding, dehydration, edema, airway obstruction, and infection. Oral candidiasis or thrush is a rare complication that can occur post-operatively. We describe a case of a 10-year-old female with oral candidiasis as a postoperative complication of bilateral adenotonsillectomy, presenting on postoperative day (POD) 7 for poor oral intake secondary to worsening odynophagia. A physical exam revealed an easily scrapable, white plaque located mainly over her surgical sites, tongue, and hard palate. Microscopic examination of tissue scrapings revealed pseudohyphae confirming the diagnosis of oral candidiasis. She was treated with seven days of topical nystatin therapy, including topical and systemic pain control with significant improvement of symptoms by POD 13 and complete resolution on POD 21.

A Rare Case of Ectopic Colonic Mucosa Presenting With Airway Compromise in a Neonate.

This case report documents a rare and unique presentation of an oropharyngeal duplication cyst and subsequent neonatal airway management. A one-day-old premature female presented with postpartum respiratory distress requiring emergent intubation secondary to an oropharyngeal mass of the left tongue. After being stabilized and transferred to an academic center, imaging revealed a cystic lesion that was then marsupialized and drained by the otolaryngology team. Pathology demonstrated mature colonic tissue and was consistent with an enteric duplication cyst. This report highlights the importance of prenatal diagnosis and the potential of a lifesaving ex utero intrapartum treatment (EXIT) procedure.

A Post-Auricular Accessory Tragus.

Here, we document a rare and unique presentation of an accessory tragus (AT). A 3-year-old male presented with a 2-cm congenital post-auricular mass on his right side. Upon resection and histologic examination, the mass demonstrated histologic features consistent with an AT. To the best of our knowledge, this is the first reported case of an AT presenting posterior to the auricle.

Synaptopathy as a Mechanism for Age-Related Vestibular Dysfunction in Mice.

Age-related decline of inner ear function contributes to both hearing loss and balance disorders, which lead to impaired quality of life and falls that can result in injury and even death. The cellular mechanisms responsible for the ear's functional decline have been controversial, but hair cell loss has been considered the key cause for a long time. However, recent studies showed that in the cochlea, loss of inner hair cell (IHC) synapses precedes hair cell or neuronal loss, and this synaptopathy is an early step in the functional decline. Whether a similar process occurs in the vestibular organ, its timing and its relationship to organ dysfunction remained unknown. We compared the time course of age-related deterioration in vestibular and cochlear functions in mice as well as characterized the age-associated changes in their utricles at the histological level. We found that in the mouse, as in humans, age-related decline in vestibular evoked potentials (VsEPs) occurs later than hearing loss. As in the cochlea, deterioration of VsEPs correlates with the loss of utricular ribbon synapses but not hair cells or neuronal cell bodies. Furthermore, the age-related synaptic loss is restricted to calyceal innervations in the utricular extrastriolar region. Hence, our findings suggest that loss of extrastriolar calyceal synapses has a key role in age-related vestibular dysfunction (ARVD).

Aspiration and Dysphagia in the Neonatal Patient.

Dysphagia and aspiration are commonly encountered problems in the neonatal population. It is often multifactorial in nature and management should be tailored to the individual patient. Multiple causes should be considered, including anatomic abnormalities, neurologic/developmental delay, cardiopulmonary disease/infection, and gastroesophageal reflux disease, in addition to those cases where a definitive reason may not be identified. Management should be multidisciplinary in nature and surgical intervention may be indicated in certain populations of patients. Here, we discuss the presentation, workup, and management of the neonatal patient with dysphagia and aspiration.

Spontaneous retropharyngeal and mediastinal thoracic duct cyst in an infant with respiratory distress.

Thoracic duct cysts (TDC) within the retropharyngeal space and mediastinum are exceedingly rare lesions, with the majority related to trauma or neoplasm. We describe a case of an otherwise healthy 8-month-old boy who presented with severe respiratory distress, which was found to be caused by a large, spontaneous TDC occupying most the retropharyngeal and mediastinal space. To our knowledge, this is the youngest patient to date presenting with TDC. Ultimately, his TDC was completely resolved with sclerotherapy, however the patient's age and size presented unique challenges to his medical management, which we describe below.

From Otic Induction to Hair Cell Production: Pax2EGFP Cell Line Illuminates Key Stages of Development in Mouse Inner Ear Organoid Model.

Producing hair cells of the inner ear is the major goal of ongoing research that combines advances in developmental and stem cell biology. The recent advent of an inner ear organoid protocol-resulting in three-dimensional stem cell-derived tissues resembling vestibular sensory epithelia-has sparked interest in applications such as regeneration, drug discovery, and disease modeling. In this study, we adapted this protocol for a novel mouse embryonic stem cell line with a fluorescent reporter for Pax2 expression. We used Pax2EGFP/+ organoid formation to model otic induction, the pivotal developmental event when preplacodal tissue adopts otic fate. We found upregulation of Pax2 and activation of ERK downstream of fibroblast growth factor signaling in organoid formation as in embryonic inner ear development. Pax2 expression was evident from the EGFP reporter beginning at the vesicle formation stage and persisting through generation of the sensory epithelium. The native ventralizing signal sonic hedgehog was largely absent from the cell aggregates as otic vesicles began to form, confirming the dorsal vestibular organoid fate. Nonetheless, cochlear- or vestibular-like neurons appeared to delaminate from the derived otic vesicles and formed synaptic contacts with hair cells in the organoids. Cell lines with transcriptional reporters such as Pax2EGFP/+ facilitate direct evaluation of morphological changes during organoid production, a major asset when establishing and validating the culture protocol.

Age-related hearing impairment and the triad of acquired hearing loss.

Understanding underlying pathological mechanisms is prerequisite for a sensible design of protective therapies against hearing loss. The triad of age-related, noise-generated, and drug-induced hearing loss displays intriguing similarities in some cellular responses of cochlear sensory cells such as a potential involvement of reactive oxygen species (ROS) and apoptotic and necrotic cell death. On the other hand, detailed studies have revealed that molecular pathways are considerably complex and, importantly, it has become clear that pharmacological protection successful against one form of hearing loss will not necessarily protect against another. This review will summarize pathological and pathophysiological features of age-related hearing impairment (ARHI) in human and animal models and address selected aspects of the commonality (or lack thereof) of cellular responses in ARHI to drugs and noise.

Impact of posture and fixation technique on impedance spectroscopy used for continuous and noninvasive glucose monitoring.

Impedance spectroscopy allows for the assessment of changes in the permittivity and conductivity of erythrocyte cell membranes, induced by blood glucose variations. This study was performed to evaluate the potential influence of motion-induced microvascular blood flow variations from different forearm postures on the PENDRA (Pendragon Medical AG, Zürich, Switzerland) signal. Fifteen volunteers without diabetes were included (seven female, eight male, mean +/- SD age 33.3 +/- 9.9 years, body mass index 24.8 +/- 3.0 kg/m(2)). PENDRA devices were fixed at both upper extremities with different fixation techniques (bracelet and adhesive tape). Standardized position changes of the upper extremities were performed to induce variations in cutaneous microcirculation, which were assessed by laser-Doppler-fluxmetry with different probe temperatures on the forearm. Changes in microcirculation were seen in some of the different motion procedures: supine to hanging, 61.1 +/- 29.9 arbitrary units (AU) to 46.2 +/- 24.8 AU at 37 degrees C and 15.9 +/- 13.0 AU to 13.4 +/- 10.1 at skin temperature (P < 0.01 for both probes); supine to upright, 80.5 +/- 55.4 AU to 74.9 +/- 43.8 AU (not significant) at 37 degrees C and 18.7 +/- 16.8 AU to 20.9 +/- 16.1 AU at skin temperature (P < 0.01). An initially observed subtle influence of microcirculation variations on the impedance signal was minimized when the device was fixed by both bracelet and tape. Other influencing factors (such as temperature, local anatomy, etc.) are addressed in the complex calibration procedure. Well-educated patients might be the best candidates for first using the device for continuous glucose monitoring. They may especially benefit from the trend indication and the hypoglycemia/hyperglycemia threshold and alarm functions.

Clinical evaluation of the NiTiBOND stapes prosthesis, an optimized shape memory alloy design.

OBJECTIVE: To prospectively analyze short-term (3 mo) results in patients with otosclerosis who underwent stapedotomy with the newly designed NiTiBOND prosthesis and compare them with patients that underwent SMart piston stapedotomy. We aimed to assess "noninferiority" for the new prosthesis. STUDY DESIGN: Prospective controlled trial. SETTING: Tertiary referral center. PATIENTS: Thirty-eight patients were included in the NiTiBOND group (41 ears), and 74 patients were included in the SMart Piston group (75 ears). INTERVENTION(S): Stapedotomy. MAIN OUTCOME MEASURE(S): Pure-tone audiometry 3 months after surgery, intraoperative prosthesis handling as assessed using a questionnaire, and complications were analyzed. RESULTS: Pure-tone audiometry showed postoperative air-bone gap means (standard deviation) of 8.1 (8.3) and 9.9 (5.4) dB; air-bone gap closure within 10 dB was achieved in 71% and 72% and within 20 dB in 93% and 96% for the NiTiBOND and the SMart piston prosthesis, respectively. Noninferiority was shown at all frequencies and in the pure-tone average. The NiTiBOND prosthesis provides excellent intraoperative handling, and no adverse reactions were reported. CONCLUSION: Preliminary short-term results suggest safety and reliability for the new NiTiBOND stapes prosthesis.