Biomedical subjects

Samuel Louie

Publications and source records attributed to Samuel Louie.

3 recordsLinked to original sources

PubMed2003

Prediction of tyrosine sulfation sites in animal viruses.

Post-translational modification of proteins by tyrosine sulfation enhances the affinity of extracellular ligand-receptor interactions important in the immune response and other biological processes in animals. For example, sulfated tyrosines in polyomavirus and varicella-zoster virus may help modulate host cell recognition and facilitate viral attachment and entry. Using a Position-Specific-Scoring-Matrix with an accuracy of 96.43%, we analyzed the possibility of tyrosine sulfation in all 1517 animal viruses available in the Swiss-Prot database. From a total of 97,729 tyrosines, we predicted 5091 sulfated tyrosine sites from 1024 viruses. Our site predictions in hemagglutinin of influenza A, VP4 of rotavirus, and US28 of cytomegalovirus strongly suggest an important link between tyrosine sulfation and viral disease mechanisms. In each of these three viral proteins, we observed highly conserved amino acid sequences surrounding predicted sulfated tyrosine sites. Tyrosine sulfation appears to be much more common in animal viruses than is currently recognized.

Algorithms↗

PubMed2003

Severe chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) exacts a heavy toll on society, yet its prevention, diagnosis and treatment receives inadequate attention from both the medical community and from society at large. Guidelines released in 2001 from the Global Initiative for Chronic Obstructive Lung Disease (GOLD) are aimed at redressing this inequity. In this review, we integrate information from the GOLD guidelines with recent updates on the prevention, treatment and management as related specifically to the most severe form of this disease. In order to help distinguish COPD from other disorders that may mimic or confound its treatment, we place particular emphasis on the definition, underlying pathophysiology and diagnosis of COPD. In addition, we discuss future directions in pharmacotherapy.

Asthma↗

PubMed2003

Severe obstructive airway disorders and diseases: vocal fold dysfunction.

Vocal Fold Dysfunction is a syndrome characterized by abnormal adduction of the focal folds during inspiration and is the cause of a wide spectrum of clinical manifestations ranging from mild inspiratory stridor to an inability to move any air. Patients present with varying degrees of intermittent respiratory difficulty, the most severe caused by intense laryngospasm. Distinguishing Vocal Fold Dysfunction from Refractory Asthma is important to avoid unnecessary pharmacotherapy and intubation. The diagnosis of Vocal Fold Dysfunction can only be made with certainty by flexible fiberoptic laryngoscopy while the patient is symptomatic. Pulmonary function studies and a lack of response to bronchodilators may provide clues to the diagnosis. Most patients with the condition can be managed by speech therapy and the use of breathing strategies that eliminate the abnormal vocal fold movement. Chronic laryngeal irritation may be a trigger for Vocal Fold Dysfunction and conditions such as laryngopharyngeal reflux disease should be aggressively managed in this patient population.

Humans↗