20 research outputs found
Cervical emphysema: an unusual presentation of laryngeal cancer
Abstract Background: Acute respiratory decompensation can occur on a background of slowly progressive airway compromise, for example in laryngeal squamous cell cancer. Surgeons in ENT, together with anaesthetists, are often asked to evaluate airway risk and as yet there is no widely adopted standardised approach. Case report: This paper reports the case of an 82-year-old male, who presented with acute airway compromise due to both endolaryngeal obstruction from a squamous cell cancer and extralaryngeal compression from massive subcutaneous emphysema. Results: Primary total laryngectomy was performed, but the patient declined adjuvant radiotherapy. He died a year later from a heart attack without evidence of recurrence. Conclusion: To the best of our knowledge, this is the first case report of acute airway compromise from extralaryngeal subcutaneous emphysema secondary to laryngeal cancer. Options for acute airway management are discusse
Computational Model of the Insect Pheromone Transduction Cascade
A biophysical model of receptor potential generation in the male moth olfactory receptor neuron is presented. It takes into account all pre-effector processes—the translocation of pheromone molecules from air to sensillum lymph, their deactivation and interaction with the receptors, and the G-protein and effector enzyme activation—and focuses on the main post-effector processes. These processes involve the production and degradation of second messengers (IP3 and DAG), the opening and closing of a series of ionic channels (IP3-gated Ca2+ channel, DAG-gated cationic channel, Ca2+-gated Cl− channel, and Ca2+- and voltage-gated K+ channel), and Ca2+ extrusion mechanisms. The whole network is regulated by modulators (protein kinase C and Ca2+-calmodulin) that exert feedback inhibition on the effector and channels. The evolution in time of these linked chemical species and currents and the resulting membrane potentials in response to single pulse stimulation of various intensities were simulated. The unknown parameter values were fitted by comparison to the amplitude and temporal characteristics (rising and falling times) of the experimentally measured receptor potential at various pheromone doses. The model obtained captures the main features of the dose–response curves: the wide dynamic range of six decades with the same amplitudes as the experimental data, the short rising time, and the long falling time. It also reproduces the second messenger kinetics. It suggests that the two main types of depolarizing ionic channels play different roles at low and high pheromone concentrations; the DAG-gated cationic channel plays the major role for depolarization at low concentrations, and the Ca2+-gated Cl− channel plays the major role for depolarization at middle and high concentrations. Several testable predictions are proposed, and future developments are discussed
Cervical emphysema: an unusual presentation of laryngeal cancer
Background: Acute respiratory decompensation can occur on a background of slowly progressive airway compromise, for example in laryngeal squamous cell cancer. Surgeons in ENT, together with anaesthetists, are often asked to evaluate airway risk and as yet there is no widely adopted standardised approach. Case report: This paper reports the case of an 82-year-old male, who presented with acute airway compromise due to both endolaryngeal obstruction from a squamous cell cancer and extralaryngeal compression from massive subcutaneous emphysema. Results: Primary total laryngectomy was performed, but the patient declined adjuvant radiotherapy. He died a year later from a heart attack without evidence of recurrence. Conclusion: To the best of our knowledge, this is the first case report of acute airway compromise from extralaryngeal subcutaneous emphysema secondary to laryngeal cancer. Options for acute airway management are discusse
Pneumo-thorax/mediastinum/(retro)peritoneum/ - a full house of complications following JET ventilation
We present a patient who presented to our clinic with airway obstruction secondary to oropharygeal cancer. He underwent emergent tracheostomy with JET ventilation, the latter resulting in a "full house" of barotraumatic complications including pneumothorax, pneumomediastinum, pneumoperitoneum, pneumoretroperitoneum and pneumo-scrotum. Free air, while sometimes dramatic as in our case, need not always be a cause for alarm and can often be managed expectantly. Our patient was treated with only a chest drain and otherwise made an uneventful recovery
Pneumo-thorax/mediastinum/(retro)peritoneum/scrotum - a full house of complications following JET ventilation
We present a patient who presented to our clinic with airway obstruction secondary to oropharygeal cancer. He underwent emergent tracheostomy with JET ventilation, the latter resulting in a "full house" of barotraumatic complications including pneumothorax, pneumomediastinum, pneumoperitoneum, pneumoretroperitoneum and pneumo-scrotum. Free air, while sometimes dramatic as in our case, need not always be a cause for alarm and can often be managed expectantly. Our patient was treated with only a chest drain and otherwise made an uneventful recovery
Merkel cell carcinoma of the head and neck: a single institutional experience
Merkel cell carcinoma (MCC) is a rare cutaneous malignancy occurring mostly in older immunocompromized Caucasian males. A growing incidence of MCC has been reported in epidemiological studies. Treatment of MCC usually consists of surgical excision, pathological lymph node evaluation, and adjuvant radiotherapy. This paper reports the experience of a single tertiary center institution with 17 head and neck Merkel cell carcinoma patients. Median followup for the cohort was 37.5 months. After five years, recurrence-free survival, disease specific survival, and overall survival were 85%, 90%, and 83%, respectively. Our limited data support the use of adjuvant radiotherapy. We also report two cases of MCC located at the vestibule of the nose and two cases of spontaneous regression after diagnostic biopsy. About 40% of our patients were referred to our center for surgical revision and pathological lymph node evaluation. Increased awareness of MCC and an interdisciplinary approach are essential in the management of MCC