Microtubule-organizing centers such as the γ-tubulin ring complex (γ-TuRC) act as a template for polarized growth and regulation of microtubules that are essential for diverse cellular structures and processes in eukaryotes. New structural models of the budding yeast γ-tubulin small complex (γ-TuSC) of the γ-TuRC combined with functional studies done in multiple eukaryotes are revealing the first mechanistic clues into control of microtubule nucleation and organization. Cross-species studies of human and budding yeast γ-TuSC proteins in fission yeast revealed conserved and divergent structural and functional features of the γ-TuSC.
View Article and Find Full Text PDFBackground: A decreased latency of onset of neural blockade has been noted when muscular exercise of the hand was performed after supraclavicular brachial plexus block using lidocaine. In this observational study, we examined the effect of repetitive muscle contraction of the hand on the speed of onset of interscalene brachial plexus block (ISB) using bupivacaine.
Methods: Forty patients were enrolled, all of whom received an ISB as one component of their anesthetic management for elective arthroscopic shoulder surgery.
J Pharmacol Toxicol Methods
October 2002
Introduction: The purpose of the present study was to develop a simple method for the simultaneous determination of mepivacaine, tetracaine, and p-butylaminobenzoic acid (BABA) in human plasma using high-performance liquid chromatography (HPLC) with a multiwavelength detector.
Methods: Human blood samples containing heparin, as an anticoagulant, and physostigmine (100 microg/ml), as an anticholinesterase, or human plasma containing physostigmine were spiked with various concentrations of mepivacaine, tetracaine and, in some cases, BABA. Blood samples were centrifuged and plasma was deproteinized with trifluoroacetic acid (TFA; 7%).
Background And Objectives: Buprenorphine added to local anesthetic solutions for supraclavicular block was found to triple postoperative analgesia duration in a previous study when compared with local anesthetic block alone. That study, however, did not control for potentially confounding factors, such as the possibility that buprenorphine was affecting analgesia through intramuscular absorption or via a spinal mechanism. To specifically delineate the role of buprenorphine in peripherally mediated opioid analgesia, the present study controlled for these 2 factors.
View Article and Find Full Text PDFBackground And Objectives: Over the past 10 years, several studies have suggested that the addition of certain opiates to the local anesthetic used for brachial block may provide effective, long-lasting postoperative analgesia. One of these studies indicated that the agonist-antagonist, buprenorphine, added to bupivacaine provided a longer period of postoperative analgesia than the traditional opiates, but in this study, it is impossible to determine the relative contributions of the local anesthetic and the opiate to the postoperative analgesia because of the extremely long duration of the anesthesia provided by the local anesthetic, bupivacaine. By repeating the study using a local anesthetic of a shorter duration, the present study delineates more clearly the contribution of the buprenorphine to postoperative analgesia when added to a shorter-acting local anesthetic.
View Article and Find Full Text PDFUnlabelled: We compared the clinical efficacy of 1.5% lidocaine in dextrose 7.5% in water, which is currently available as a commercial preparation but approved for use only in obstetrical patients, with the traditional 5% lidocaine in dextrose 7.
View Article and Find Full Text PDFIn addition to its possible role as a replacement source in CNS degenerative diseases, neural transplantation may be used to augment the normal production of neuroactive substances. Our laboratory at the University of Illinois at Chicago has shown, in both acute and chronic pain models, that transplantation of adrenal medullary tissue or isolated chromaffin cells into CNS pain modulatory regions can reduce pain sensitivity in rodents. Chromaffin cells were chosen as the donor source since they produce high levels of both opioid peptides and catecholamines, substances which reduce pain sensitivity when injected locally into the spinal subarachnoid space.
View Article and Find Full Text PDFBackground And Objectives: In an effort to elucidate further the effect of alkalinization of bupivacaine on its anesthetic effect, a study was undertaken using alkalinized and non-alkalinized bupivacaine for lumbar plexus block and comparing the results with those obtained previously with brachial plexus block.
Methods: Thirty consenting adult patients about to undergo lower extremity surgery under regional anesthesia were selected for the study. All of the patients received an inguinal paravascular lumbar plexus block ("3-in-1 block"), along with a sciatic block to allow the anticipated surgery to be carried out.
Background: The prolonged use of opioids to treat intractable pain with currently available therapeutic modalities is often unsatisfactory, usually because of tolerance or complications. Extensive studies carried out in the authors' laboratories have indicated that the transplantation of adrenal medullary tissue into the spinal subarachnoid space can significantly reduce pain in animal pain models, most likely via release of opioid peptides and catecholamines. The current study was undertaken to assess the feasibility and efficacy of subarachnoid adrenal medullary transplantation in alleviating terminal cancer pain in humans.
View Article and Find Full Text PDFBackground And Objectives: Since Rosenak's original report more than 50 years ago as to the efficacy of sympathetic blocks in terminating acute herpes zoster, many investigators have reported that a more important benefit of this form of therapy is the prevention of post-herpetic neuralgia. However, most of these reports have indicated that sympathetic blocks are effective in preventing post-herpetic neuralgia only if applied soon after the onset of the acute phase of the disease; in fact, if applied too late, this form of therapy failed to prevent the development of post-herpetic neuralgia. The present study was carried out to determine more precisely the relationship between the time of treatment of acute herpes zoster and the prevention of post-herpetic neuralgia and to attempt to correlate this time with the authors' previously published theory on the mechanism by which sympathetic blocks provide the therapeutic benefit.
View Article and Find Full Text PDFThe treatment of intractable pain with currently available therapeutic regimens is often unsatisfactory due to tolerance and untoward complications. Studies in our laboratory have suggested that the transplantation of adrenal medullary tissue into the spinal subarachnoid space can significantly reduce pain in animal models, most likely via release of opioid peptides and catecholamines. The current study was an initial attempt to assess the potential for adrenal medullary transplants in the spinal subarachnoid space to alleviate pain in humans.
View Article and Find Full Text PDFThe present study compares the effectiveness of 0.25% ropivacaine and 0.25% bupivacaine in 44 patients receiving a subclavian perivascular brachial plexus block for upper extremity surgery.
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