Buckling mechanics: A Nosetta Stone to understand rhinoglyphics.

The wet noses of dogs and other mammals are attributed to polygonal arrays of fluid-retaining grooves thought to aid in thermoregulation, chemosensation, and even hunting. A new study reveals the mechanical basis of their morphogenesis.

Elongation of the nascent avian foregut requires coordination of intrinsic and extrinsic cell behaviors.

The foregut tube gives rise to the lungs and upper gastrointestinal tract, enabling vital functions of respiration and digestion. How the foregut tube forms during embryonic development has historically received considerable attention, but over the past few decades this question has primarily been addressed indirectly through studies on morphogenesis of the primitive heart tube, a closely related process. As a result, many aspects of foregut development remain unresolved.

MATERIAL PROPERTIES OF THE EMBRYONIC SMALL INTESTINE DURING BUCKLING MORPHOGENESIS.

During embryonic development, tissues undergo dramatic deformations as functional morphologies are stereotypically sculpted from simple rudiments. Formation of healthy, functional organs therefore requires tight control over the material properties of embryonic tissues during development, yet the biological basis of embryonic tissue mechanics is poorly understood. The present study investigates the mechanics of the embryonic small intestine, a tissue that is compactly organized in the body cavity by a mechanical instability during development, wherein differential elongation rates between the intestinal tube and its attached mesentery create compressive forces that buckle the tube into loops with wavelength and curvature that are tightly conserved for a given species.

Hox gene activity directs physical forces to differentially shape chick small and large intestinal epithelia.

Hox transcription factors play crucial roles in organizing developmental patterning across metazoa, but how these factors trigger regional morphogenesis has largely remained a mystery. In the developing gut, Hox genes help demarcate identities of intestinal subregions early in embryogenesis, which ultimately leads to their specialization in both form and function. Although the midgut forms villi, the hindgut develops sulci that resolve into heterogeneous outgrowths.

The developmental mechanics of divergent buckling patterns in the chick gut.

Tissue buckling is an increasingly appreciated mode of morphogenesis in the embryo, but it is often unclear how geometric and material parameters are molecularly determined in native developmental contexts to generate diverse functional patterns. Here, we study the link between differential mechanical properties and the morphogenesis of distinct anteroposterior compartments in the intestinal tract-the esophagus, small intestine, and large intestine. These regions originate from a simple, common tube but adopt unique forms.

A Retrospective Study of Glottic Cyst Histopathology and Its Clinical Presentation.

To understand the frequency and clinical presentation of the four types of vocal-fold cyst described by the Koren classification. Glottic cysts operated in a 1-year period were grouped retrospectively into Koren A, B, C and D (KA, KB, KC, KD). The age and sex of the patient, cyst location, laterality, associated lesions, profession, daily water consumption, duration of symptoms prior to surgery and postoperative healing time were noted.

Hemorrhagic Pseudocyst (Polyst) and True Hemorrhagic Cyst of the Vocal Fold.

Objectives: Though hemorrhagic vocal fold polyps are a common entity, hemorrhagic vocal fold cysts have not been previously described. In our study, we have evaluated patients who were diagnosed on stroboscopy with "hemorrhagic" cysts.

Methods: This 18-month retrospective study has received institutional ethics clearance.

Autonomous circadian rhythms in the human hepatocyte regulate hepatic drug metabolism and inflammatory responses.

Critical aspects of physiology and cell function exhibit self-sustained ~24-hour variations termed circadian rhythms. In the liver, circadian rhythms play fundamental roles in maintaining organ homeostasis. Here, we established and characterized an in vitro liver experimental system in which primary human hepatocytes display self-sustained oscillations.

Elastic fibers define embryonic tissue stiffness to enable buckling morphogenesis of the small intestine.

During embryonic development, tissues must possess precise material properties to ensure that cell-generated forces give rise to the stereotyped morphologies of developing organs. However, the question of how material properties are established and regulated during development remains understudied. Here, we aim to address these broader questions through the study of intestinal looping, a process by which the initially straight intestinal tube buckles into loops, permitting ordered packing within the body cavity.

Vocal Outcomes Following Pitch Alteration Surgeries.

Our study aims to ascertain the results of speech therapy and surgery in patients who desire pitch alteration. Typically, patients desirous of an increase in their vocal pitch are male-to-female transpersons, and patients desirous of a drop in their pitch are puberphonia patients. This is a 3-year retrospective study of patients who have been operated for pitch alteration.

A chemo-mechanical model of endoderm movements driving elongation of the amniote hindgut.

Although mechanical and biochemical descriptions of development are each essential, integration of upstream morphogenic cues with downstream tissue mechanics remains understudied during vertebrate morphogenesis. Here, we developed a two-dimensional chemo-mechanical model to investigate how mechanical properties of the endoderm and transport properties of fibroblast growth factor (FGF) regulate avian hindgut morphogenesis in a coordinated manner. Posterior endoderm cells convert a gradient of FGF ligands into a contractile force gradient, leading to a force imbalance that drives collective cell movements that elongate the forming hindgut tube.

Vocal Outcomes Following Laser-Assisted Sulcus Release for Superficial and Deep Vocal Fold Sulcus.

Background: The objective is to study vocal outcomes following laser-assisted sulcus release (LASR), having documented the length and depth of the sulcus intraoperatively. LASR performed for superficial and deep sulci were included.

Study Design: Retrospective, observational.

ELASTIC FIBERS DEFINE EMBRYONIC TISSUE STIFFNESS TO ENABLE BUCKLING MORPHOGENESIS OF THE SMALL INTESTINE.

During embryonic development, tissues must possess precise material properties to ensure that cell-generated forces give rise to the stereotyped morphologies of developing organs. However, the question of how material properties are established and regulated during development remains understudied. Here, we aim to address these broader questions through the study of intestinal looping, a process by which the initially straight intestinal tube buckles into loops, permitting ordered packing within the body cavity.

Correlation of narrow-band imaging findings using the Ni and European Laryngeal Society classification systems during in-office flexible laryngoscopy with histopathology.

Objective: This study used the European Laryngeal Society (2016) and Ni (2011 and 2019) classifications for narrow-band imaging and correlated the findings with histopathology.

Methods: Retrospective analysis was conducted by retrieving data of patients who underwent micro-laryngoscopy for suspicious glottic lesions. The narrow-band imaging findings were classified using both classification systems.

A chemo-mechanical model of endoderm movements driving elongation of the amniote hindgut.

While mechanical and biochemical descriptions of development are each essential, integration of upstream morphogenic cues with downstream tissue mechanics remains understudied in many contexts during vertebrate morphogenesis. A posterior gradient of Fibroblast Growth Factor (FGF) ligands generates a contractile force gradient in the definitive endoderm, driving collective cell movements to form the hindgut. Here, we developed a two-dimensional chemo-mechanical model to investigate how mechanical properties of the endoderm and transport properties of FGF coordinately regulate this process.

Glottic Neurofibroma: An Unusual Case Report.

Solitary neurofibromas of the larynx occur sporadically and usually tend to involve the aryepiglottic folds. Non-plexiform variants of neurofibromas involving the glottis are extremely rare and may have defined margins versus plexiform subtype which are often unencapsulated and associated with Von Recklinghausen's disease. We report an unusual case of isolated glottic neurofibroma in an elderly male with gradually progressive hoarseness of voice with stroboscopy findings of a right unilateral, bulky subepithelial lesion mimicking a vocal fold cyst.

Evo-Devo Mechanobiology: The Missing Link.

While the modern framework of evolutionary development (evo-devo) has been decidedly genetic, historic analyses have also considered the importance of mechanics in the evolution of form. With the aid of recent technological advancements in both quantifying and perturbing changes in the molecular and mechanical effectors of organismal shape, how molecular and genetic cues regulate the biophysical aspects of morphogenesis is becoming increasingly well studied. As a result, this is an opportune time to consider how the tissue-scale mechanics that underlie morphogenesis are acted upon through evolution to establish morphological diversity.

A 6-Year Retrospective Study of the Demographics of Glottic Keratosis in a Tertiary Care Voice Centre.

Since Keratosis may be accompanied with severe dysplasia or malignancy; early management of this condition is of essence. However, since this condition has a high rate of recurrence the surgical dilemma remains as to how frequently the surgeries should be performed and what should be the factors to guide this decision. The objectives of our study are to attempt to understand the demographics of laryngeal keratosis and its behaviour pattern including the potential to recur, disease upstaging and malignant transformation.

A Four Year Retrospective Study of the Pattern of Fungal Laryngitis in a Tertiary Voice Care Centre.

Isolated Fungal Laryngitis (FL) has recently shown an increased incidence globally and is now being reported even in immunocompetent individuals. In our Voice Clinic we have documented an increasing number of cases of FL, specifically laryngeal candidiasis, with the lesion over the striking zone (anterior 1/3rd posterior-2/3rd) of vocal folds. Our objective was to study the sites of involvement of FL within the glottis along with a review of literature.

Rare Causes of Unilateral Vocal Fold Paralysis: Report of 3 Cases with Review of Literature.

Unilateral vocal fold paralysis is a common finding with a variety of underlying causes. The six main etiologic groups include neoplastic, traumatic (iatrogenic, accidental) neurological, inflammatory, congenital, and idiopathic. Various unusual causes have been described including foreign body ingestion, mediastinal lymph nodes, large pleural blebs, tracheal diverticulum, etc.

A Retrospective Study to Assess the Accuracy of Frozen Sections in Laser Laryngeal Surgery.

Objective: The basis of good vocal outcomes following Transoral Laser Microlaryngeal Cordectomy (TLMC) is the narrow margin that is oncologically accepted for the glottis. Our objective is to evaluate the reliability of frozen section (FS) compared to paraffin section (PS) during TLMC and during laser laryngeal surgery when an incisonal or excisional biopsy is being performed.

Methods: Retrospectively, records of 159 sequential patients who underwent CO laser laryngeal surgery with intraoperative FS were reviewed along with the final PS.

A Prospective Study to Correlate Difficult Intubation with Difficult Laryngeal Exposure for Microlaryngeal Surgery using Various Grading Scales of Difficult Intubation.

Adequate visualization of the vocal folds is essential for optimal phonosurgery. Pre-operative knowledge of a difficult laryngeal exposure (DLE) can alert the surgeon regarding the need for alternative measures. Our study is based on the hypothesis that a patient who has difficult intubation (DI) is likely to have DLE, thus scales anticipating DI should also anticipate DLE.