In Vivo Imaging of Flavoprotein Fluorescence During Hypoxia Reveals the Importance of Direct Arterial Oxygen Supply to Cerebral Cortex Tissue.

Live imaging of mitochondrial function is crucial to understand the important role played by these organelles in a wide range of diseases. The mitochondrial redox potential is a particularly informative measure of mitochondrial function, and can be monitored using the endogenous green fluorescence of oxidized mitochondrial flavoproteins. Here, we have observed flavoprotein fluorescence in the exposed murine cerebral cortex in vivo using confocal imaging; the mitochondrial origin of the signal was confirmed using agents known to manipulate mitochondrial redox potential. The effects of cerebral oxygenation on flavoprotein fluorescence were determined by manipulating the inspired oxygen concentration. We report that flavoprotein fluorescence is sensitive to reductions in cortical oxygenation, such that reductions in inspired oxygen resulted in loss of flavoprotein fluorescence with the exception of a preserved 'halo' of signal in periarterial regions. The findings are consistent with reports that arteries play an important role in supplying oxygen directly to tissue in the cerebral cortex, maintaining mitochondrial function.

Use of multicriteria decision analysis to address conservation conflicts.

Conservation conflicts are increasing on a global scale and instruments for reconciling competing interests are urgently needed. Multicriteria decision analysis (MCDA) is a structured, decision-support process that can facilitate dialogue between groups with differing interests and incorporate human and environmental dimensions of conflict. MCDA is a structured and transparent method of breaking down complex problems and incorporating multiple objectives. The value of this process for addressing major challenges in conservation conflict management is that MCDA helps in setting realistic goals; entails a transparent decision-making process; and addresses mistrust, differing world views, cross-scale issues, patchy or contested information, and inflexible legislative tools. Overall we believe MCDA provides a valuable decision-support tool, particularly for increasing awareness of the effects of particular values and choices for working toward negotiated compromise, although an awareness of the effect of methodological choices and the limitations of the method is vital before applying it in conflict situations.

Carbon monoxide-releasing molecule tricarbonyldichlororuthenium (II) dimer induces concentration-dependent alterations in the electrophysiological properties of axons in mammalian spinal cord.

Traumatic spinal cord injury (SCI) typically involves intraparenchymal hemorrhage and a cascade of inflammatory and cytotoxic processes leading to tissue necrosis and apoptosis. A consequence of the hemorrhage is the accumulation of deoxygenated heme proximal and distal to the epicenter of the lesion. The heme oxygenase (HO) system is an endogenous heme degradation system and is upregulated following neurotrauma. The breakdown of heme via HO activity yields the byproducts carbon monoxide (CO), biliverdin, and iron. CO has documented neuromodulatory properties; however, the effects of elevated concentrations of CO on axonal conduction in the spinal cord have not previously been studied. The present study tested the hypothesis that CO causes alterations in the electrophysiological properties of axons within the isolated guinea-pig spinal cord. Ex vivo spinal cord preparations were exposed to 100, 500, and 1000 microM concentrations of the carbon monoxide-releasing molecule (CORM) 2 for 30 min in a double sucrose gap electrophysiological recording system and the compound action potential (CAP) and membrane potential (CMP) were recorded continuously during pretreatment, CORM-2 treatment, and washout (30 min) with Krebs' solution. CAP amplitude and area were significantly (P<0.05) reduced following treatment with 500 and 1000 microM CORM-2 and did not recover during washout. No effect on CMP was observed, however, stimulus-peak latency did increase significantly (P<0.05) following CORM-2 treatment at these concentrations, and a decrease in the amplitude of the second CAP elicited by paired-pulse stimulation was also evident at interpulse intervals of 2 and 4 ms. These results are consistent with a CO-induced alteration in axonal conduction, possibly attributable to modified Na+ channel conductance. They also identify a new mechanism by which post-traumatic hemorrhage contributes to the neurological deficits observed following SCI.

The current role of video-assisted thoracic surgery (VATS) in the overall practice of thoracic surgery. A review of 207 cases.

From December 1991 to June 1995, video-assisted thoracic surgery (VATS) was performed on 207 patients at the Medical Center of Delaware with minimal complications and no mortality. A definitive diagnosis was made in all patients. Results with VATS procedures appear to be comparable to those with the standard open technique. Operating time was comparable to that with the open technique. Length of stay and pain and suffering were dramatically reduced compared with the open technique. We now consider VATS to be the preferred procedure in the following conditions: 1. Undiagnosed pulmonary infiltrate in the non-ventilator-dependent patient. 2. Indeterminate pulmonary nodule. 3. Undiagnosed disease of the pleural space. 4. Recurrent or persistent pneumothorax. 5. Mediastinal or pericardial cystic tumors. 6. Thoracic sympathectomy. 7. Selected patients requiring esophagocardiomyotomy. The utilization of VATS for resection of a pulmonary mass in patients with compromised pulmonary status (i.e., FEV < 1) is being studied.

Risk factors for Neisseria meningitidis carriage in a school during a community outbreak of meningococcal infection.

As part of the management of an outbreak of meningococcal infection, 119 school contacts of an index case were swabbed for nasopharyngeal carriage. In a cohort study, risk factors for Neisseria meningitidis carriage were ascertained by means of a questionnaire, completed by 114 (96%) of those swabbed. Twenty five (21%) cultures were identified as "neisseria positive'; of which there were 18 (15%) Neisseria meningitidis isolates, 2 (2%) Neisseria lactamica isolates and 5 (4%) showed contaminants only. Two (2%) carriers were identified as harbouring the implicated outbreak strain. Single variable analysis identified six statistically significant risk factors for meningococcal carriage; increasing age, female sex, manual social class, personal smoking, regular attendance at a discotheque and rhinorrhoea. Multivariate analysis, using logistic regression modelling, found that of these six variables only age, sex and social class remained statistically significant when the other factors were controlled for. Nevertheless the role of smoking, social events and respiratory/viral infections in nasopharyngeal carriage, and other plausible mechanisms whereby age, sex and social class might exert their effect, could usefully be investigated further.

Video-assisted thoracic surgery: experience with 126 cases.

VATS was performed in 126 patients at the Medical Center of Delaware from December 1991 to August 1993, with no major complications and no mortality. A definitive diagnosis was made in all cases. Results with VATS therapeutic procedures appear to equal those of the standard open technique. Operating time was comparable to that with the open technique. Length of stay and pain and suffering were dramatically reduced when compared with those associated with the open technique. We now consider VATS to be the preferred procedure in cases of: 1. Undiagnosed pulmonary infiltrate in the nonventilator-dependent patient 2. Indeterminate pulmonary nodule 3. Undiagnosed disease of the pleural space 4. Recurrent or persistent pneumothorax 5. Mediastinal or pericardial cystic tumors 6. Thoracic sympathectomy 7. Selected patients requiring esophagocardiomyotomy. The utilization of VATS for resection of a pulmonary mass in patients with cardiopulmonary compromise (i.e., FEV < 1) is being studied. Further development of this technique and expansion to formal pulmonary resection and cardiovascular procedures must follow the philosophy presented in our conclusion. The place of VATS in the management of penetrating thoracic trauma has been studied at several centers, with excellent results when precise guidelines have been followed. Obviously, one-lung anesthesia is not well tolerated when a patient is in profound shock, but if the patient can be stabilized before thoracotomy, the introduction of a camera to diagnose a carotid or internal mammary artery laceration or to staple an easily accessible pulmonary tear could obviate the need for a thoracotomy and its consequences for the patient. Again, as in all surgical operations, common sense and good judgment must prevail.

Video-assisted thoracic surgery: our first 20 cases.

Video-assisted thoracic surgery has been performed in 20 patients at the Medical Center of Delaware. Operations included seven pulmonary wedge resections, one mediastinal procedure, and 12 pleural procedures. In all cases, a definitive diagnosis was made or the lesion was removed. One postoperative atypical pneumonia occurred. One patient whose wedge resection proved to be squamous cell carcinoma on frozen section underwent a formal thoracotomy and lobectomy. Estimated savings in the eight patients who formerly would have undergone a thoracotomy incision is estimated at $30,000 for room cost alone. We foresee a markedly expanded role for this technique in major pulmonary resections, esophageal procedures, and cardiac surgery in the near future.

The gothic arch tracing and the upper canine teeth as guides in the positioning of upper posterior teeth.

The relationship between the position of the buccal cusps of the natural upper posterior teeth and the distance between the lateral arms of the Gothic arch tracing or the distance between the upper canine teeth has been found to be constant to within +/- 2 mm. This may be of value when setting up artificial teeth for denture patients, enabling them to be positioned close to the natural predecessors.