Infection control and anesthesia: Lessons learned from the Toronto SARS outbreak

PURPOSE: To describe the outbreak of severe acute respiratory syndrome (SARS) in Toronto, its impact on anesthesia practice and the infection control guidelines adopted to manage patients in the operating room (OR) and to provide emergency intubation outside the OR. Clinical features: The SARS outbreak in Toronto was the result of a single index patient. The causative virus, SARS-CoV, is moderately contagious, and is spread by droplets and contact. The virus gains access to host through the mucosa of the respiratory tract and the eyes. It can affect both healthy and compromised patients. The use of several precautionary measures such as goggles, gloves, gowns and facemasks and the application of various infection control strategies designed to minimize the spread of the virus are discussed. CONCLUSION: In containing the spread of SARS, vigilance and strict infection control are important. This results in the rediscovery of standards of infection control measures in daily anesthesia practice.     

The lateral chest X-ray: Is it necessary for emergency department patients?

To determine the utility of the lateral view of the chest in emergency department patients, records of all patients who had had 2-view chest x-rays ordered in the emergency department were reviewed retrospectively. A study radiologist recorded a reading of the posteroanterior (PA) radiograph alone. The lateral radiograph was then provided, along with the PA view, and a second reading was recorded. A comparison was then made between the first and second readings.A total of 417 sets of x-rays were included. The PA view alone successfully diagnosed or suspected 92% of pulmonary nodules, 95% of effusions, 97% of cases of emphysema, 98% of pneumonias, and 100% of cases of cardiomegaly, pulmonary edema, interstitial pulmonary disease, and atelectasis.In the emergency department patient population, lateral views of the chest have minimal diagnostic yield and therefore may be used selectively to safely decrease the amount of breast radiation exposure to young women.     

Radionuclide targeting and dosimetry at the microscopic level: the role of microautoradiography

The understanding of localisation mechanisms and microdosimetry of diagnostic and therapeutic radiopharmaceuticals depends on knowledge of their biodistribution at the microscopic level (cellular and subcellular) in the target tissues. Various methods have been advanced for obtaining information about this microdistribution: subcellular fractionation, secondary ion mass spectrometry imaging, microprobe elemental analysis in the electron microscope, and microautoradiography. This review compares these approaches, and discusses in detail the methodology of microautoradiography (the most generally useful approach) with imaging and therapy radionuclides. Literature examples of applications of microautoradiography in nuclear medicine are reviewed, and the future potential contribution of the techniques is assessed.     

Genetic ablation of the t-SNARE SNAP-25 distinguishes mechanisms of neuroexocytosis.

Axon outgrowth during development and neurotransmitter release depends on exocytotic mechanisms, although what protein machinery is common to or differentiates these processes remains unclear. Here we show that the neural t-SNARE (target-membrane-associated-soluble N-ethylmaleimide fusion protein attachment protein (SNAP) receptor) SNAP-25 is not required for nerve growth or stimulus-independent neurotransmitter release, but is essential for evoked synaptic transmission at neuromuscular junctions and central synapses. These results demonstrate that the development of neurotransmission requires the recruitment of a specialized SNARE core complex to meet the demands of regulated exocytosis.     

Regional anaesthesia in ambulatory surgery

Regional anaesthesia provides many advantages and can be practised safely in ambulatory surgery. It provides better postoperative pain control, avoids many complications associated with general anaesthesia and shortens recovery time. However, extra time required, associated complications and acceptance of patients are the factors of concern in practising regional anaesthesia in an ambulatory setting. This review will discuss various regional anaesthesia techniques suitable for outpatients.     

Lesions of T-Cell-Mediated Kidney Allograft Rejection in Mice Do Not Require Perforin or Granzymes A and B

Organ allograft rejection is strongly associated with the presence of alloreactive cytotoxic T cells but the role of cytotoxicity in the pathologic lesions is unclear. Previous studies showed that the principal lesions of kidney rejection - interstitial infiltration, tubulitis, and endothelial arteritis - are T-cell-dependent and antibody-independent. We studied the role of cytotoxic granule components perforin and granzymes A and B in the evolution of the T-cell-mediated lesions of mouse kidney transplant rejection. By real-time RT-PCR, allografts rejecting in wild-type hosts at days 5, 7, 21, and 42 showed massively elevated and persistent expression of perforin and granzymes A and B, but evolution of tubulitis and arteritis did not correlate with increasing granzyme or perforin expression. Allografts transplanted into hosts with disrupted genes for perforin or granzymes A and B showed no change in tubulitis, arteritis, or MHC induction. Thus the development of the histologic lesions diagnostic of T-cell-mediated kidney transplant rejection are associated with but not mediated by perforin or granzyme A or B. Together with previous graft survival studies, these results indicate that the granule-associated cytotoxic mechanisms of T cells are not the effectors of T-cell-mediated allograft rejection.