Simultaneous determination of cytosolic aminoacyl-tRNA synthetase activities by LC-MS/MS.

In recent years, pathogenic variants in ARS genes, encoding aminoacyl-tRNA synthetases (aaRSs), have been associated with human disease. Patients harbouring pathogenic variants in ARS genes have clinical signs partly unique to certain aaRSs defects, partly overlapping between the different aaRSs defects. Diagnosis relies mostly on genetics and remains challenging, often requiring functional validation of new ARS variants.

Self-Generated Lower Body Negative Pressure Exercise: A Low Power Countermeasure for Acute Space Missions.

Microgravity in spaceflight produces headward fluid shifts which probably contribute to Spaceflight-Associated Neuro-Ocular Syndrome (SANS). Developing new methods to mitigate these shifts is crucial for preventing SANS. One possible strategy is the use of self-generated lower body negative pressure (LBNP).

Timeline to dysphagia resolution after endoscopic intervention of an interarytenoid defect based on Video Fluoroscopic Swallow Study dysphagia severity.

Introduction: We previously reported that endoscopic repair of a Type 1 Laryngeal Cleft (LC1) or Deep Interarytenoid Groove (DIG) improves swallowing function postoperatively. However, caregivers often ask about the timeline to resolution of the need for thickening. This study re-examines this cohort to answer this important caregiver-centered question.

Pediatric formulas: Categories, composition, and considerations.

Formulas, liquid nutrition, may be consumed orally or via a feeding tube to provide partial or complete nutrition that a given individual could not obtain using natural food stuffs in their native form. A wide range of commercially available formulas exist, which may be used as sole-source nutrition or in conjunction with other foods. Physicians and dietitians must understand the nature of and indications for specific formulas to treat diseases, provide complete nutrition to patients, and avoid harm.

Optimal timing and technique for endoscopic management of dysphagia in pediatric aerodigestive patients.

Introduction: The best strategy to manage an interarytenoid defect [Type 1 laryngeal cleft (LC-1) or deep interarytenoid groove (DIG)] in pediatric aerodigestive patients with dysphagia remains uncertain. This study compared benefit of interarytenoid augmentation (IAA) to suture repair or clinical observation alone in pediatric patients.

Methods: A 3-year retrospective, single-center analysis of children with dysphagia undergoing endoscopic airway evaluation was performed.

Acute Liver Failure in a Healthy Young Female With COVID-19.

Several well-described manifestations of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported. Among them, a transient elevation of liver enzymes is the typical presentation of coronavirus disease 2019 (COVID-19) liver-related injury. The mechanism of liver involvement is likely a combination of viral injury and immune-mediated inflammation.

Treatment of ARS deficiencies with specific amino acids.

Purpose: Recessive cytosolic aminoacyl-tRNA synthetase (ARS) deficiencies are severe multiorgan diseases, with limited treatment options. By loading transfer RNAs (tRNAs) with their cognate amino acids, ARS are essential for protein translation. However, it remains unknown why ARS deficiencies lead to specific symptoms, especially early life and during infections.

Antibiotics promote the sampling of luminal antigens and bacteria via colonic goblet cell associated antigen passages.

Bacterial translocation is defined as the passage of live bacteria from the gut lumen to distant sites. Gut commensal bacteria translocation has been attributed to 'leakiness', or 'barrier breach' of the intestinal epithelium, allowing live bacteria to cross an inappropriately permeable barrier and disseminate to distant sites. Alternatively, studies suggest dendritic cells directly capture luminal commensal bacteria and transport them to distant sites in the steady-state by extending dendrites between epithelial cells into the lumen.

Scurvy revealed by difficulty walking: three cases in young children.

Scurvy is rare in developed countries but is known to cause lower-extremity pain and refusal to ambulate in children. Since the discovery of the link between scurvy and dietary deficiency of ascorbic acid, there has been a substantial decrease in its prevalence and recognition. Here we describe 3 cases of scurvy in young children presenting with difficulty walking.

HCV+ hepatocytes induce human regulatory CD4+ T cells through the production of TGF-beta.

Background: Hepatitis C Virus (HCV) is remarkably efficient at establishing persistent infection and is associated with the development of chronic liver disease. Impaired T cell responses facilitate and maintain persistent HCV infection. Importantly, CD4(+) regulatory T cells (Tregs) act by dampening antiviral T cell responses in HCV infection.

Chronically inflamed livers up-regulate expression of inhibitory B7 family members.

Unlabelled: Hepatitis B virus, hepatitis C virus, autoimmune hepatitis, and nonalcoholic fatty liver disease can induce chronic liver disease. The Programmed Death-1 (PD-1) inhibitory pathway assists in T cell response regulation during acute and chronic inflammation and participates in the progression of inflammatory liver disease. To examine whether PD-1 and its ligands, B7-H1 and B7-DC, are modulated during chronic necroinflammatory liver disease, we investigated expression profiles in normal patients and patients with the aforementioned conditions.

gC1q receptor ligation selectively down-regulates human IL-12 production through activation of the phosphoinositide 3-kinase pathway.

gC1qR, a complement receptor for C1q, plays a pivotal role in the regulation of inflammatory and antiviral T cell responses. Several pathogens, including hepatitis C virus, exploit gC1qR-dependent regulatory pathways to manipulate host immunity. However, the molecular mechanism(s) of gC1qR signaling involved in regulating inflammatory responses remains unknown.

Differential effects of R5 and X4 human immunodeficiency virus type 1 infection on CD4+ cell proliferation and activation.

Human immunodeficiency virus type 1 (HIV-1) isolates can be distinguished by their chemokine coreceptor usage. Non-syncytium-inducing (NSI), macrophage-tropic viruses utilize CCR5 and are called R5 viruses; syncytium-inducing (SI) isolates use CXCR4 and are known as X4 viruses. R5 and X4 HIV isolates are both transmitted but, in most cases, R5 viruses predominate in the blood prior to the development of AIDS-related pathogenesis.

The incidence and management of chylous fistulae.

Two hundred neck dissections performed at Toronto General Hospital over a 3 year period are reviewed. There were six intra-operative lymph leaks and five postoperative chylous fistulae. The postoperative chylous fistulae are analysed in detail and the approach to conservative management of lymph leaks is discussed.

The use of topical tetracycline in the management of persistent chylous fistulae.

The management of chylous fistulae remains controversial. A detailed conservative protocol and guidelines regarding surgical intervention are lacking in the literature. This paper presents our experience in the management of two cases of persistent chylous fistulae by successfully employing topical tetracycline.

Alterations in nasal physiology after laryngectomy: the nasal cycle.

Several changes in nasal physiology have been reported following laryngectomy. This paper reviews these changes and investigates the cycle of alternating distribution of nasal airflow in 20 adults. Information about the cyclic activity was obtained from the areas of condensation formed by nasal expiration on the surface of a Gertner-Podoshin plate.

The nasal cycle after laryngectomy.

The cycle of alternating distribution of nasal airflow was investigated in 15 adults. Information about cyclic activity was obtained from the areas of condensation formed by nasal expiration on the surface of a Gertner-Podoshin plate. Consecutive measurements of these areas were made at 15 minute intervals during a 6-8 h period.

CT of the nasal cavity.

CT demonstrates nasal anatomy extremely well. The intimate relationship of the nasal cavity to the cerebral, orbital, paranasal sinus, nasopharyngeal, and oral tissues is noted. Examples of benign and malignant neoplasms, inflammatory processes, including intrinsic and extrinsic mass lesions are utilized to demonstrate the value of CT in assessing the nasal cavity in conjunction with its surrounding tissues.

Endotoxin-induced tumor necrosis factor.

The serum of BCG-infected mice treated with endotoxin contains a substance (tumor necrosis factor, TNF) which mimics the tumor-necrotizing action of endotoxin itself. TNF is not residual endotoxin, but a factor released from host cells, probably macrophages. TNF induced in the same way in rats and rabbits also causes necrosis of transplanted murine tumors.

Metrizamide gradient purification of mouse tumor cells.

A one-step isopycnic density gradient centrifugation procedure is described for purification of highly viable and homogeneous tumor cells from a variety of solid mouse tumors. Mechanically suspended cells are layered onto preformed continuous gradients of medium 199-buffered 7--33% metrizamide (density range 1.05--1.

Comparison of antitumor activities of pancreatic ribonuclease and its cross-linked dimer.

The cross-linked dimer of bovine pancreatic RNase (M.W. 28,000) is significantly more effective than the monomer in inhibiting tumor development in mice when administered i.