BACKGROUND: A mixture of local anesthetics such as lidocaine and bupivacaine has frequently been used in clinical practice. The rationale behind this is to take advantage of lidocaine's rapid onset and bupivacaine's perpetuation in anesthesia. The purpose of this study was to examine the changes in the onset and recovery of nerve blocking action exerted by the different combinations of these two in the mixture. METHODS: Isolated sciatic nerve preparations obtained from adult male Sprague-Dawley rats were used in this study. Recordings of A-fiber compound action potentials (A-CAPs) were made at the end of the isolated nerve while single pulse stimuli (0.5 msec, supramaximal intensity, 2 Hz) were applied to the opposite end of the nerve. Seven different composition of lidocaine-bupivacaine mixtures were prepared (0 : 6, 1 : 5, 2 : 4, 3 : 3, 4 : 2, 5 : 1, 6 : 0 vol./vol.), where basal concentrations of lidocaine and bupivacaine were 0.2% and 0.05%, respectively. Amplitudes of A-CAPs were measured before, during and after perfusion of mixture solution. The time needed for A-CAPs amplitude to decrease to 10% of the basal value after starting perfusion (onset time) and that needed to reach to 50% of the basal value after ceasing the perfusion (recovery time) were measured. RESULTS: With increasing concentration ratios of lidocaine to bupivacaine in the mixture as mentioned above, the following onset and recovery times were obtained (6.0 +/- 0.3, 5.6 +/- 0.3, 6.0 +/- 0.5, 8.3 +/- 0.5, 7.3 +/- 0.6, 7.8 +/- 0.3, and 10.8 +/- 0.8, minutes; 38 +/- 4, 63 +/- 12, 87 +/- 19, 100 +/- 13, 104 +/- 18, 137 +/- 27, and 157 +/- 18 minutes, respectively). CONCLUSION: Onset times were, in general, exponentially decreased with the increase in the lidocaine concentration. However, recovery times were lineary increased with the increase in the bupivacaine concentration. So, it should be kept in mind that rapid onset can only be obtained with the expense of substantial reduction in the duration of local anesthetic effect of the mixture, and vice versa.
Action Potentials ; Adult ; Anesthesia ; Anesthetics ; Anesthetics, Local ; Bupivacaine ; Humans ; Lidocaine ; Male ; Nerve Block ; Neural Conduction* ; Perfusion ; Rats, Sprague-Dawley ; Sciatic Nerve

BACKGROUND AND OBJECTIVES: The Deiters' cell is one of the supporting cells in the organ of Corti and is known to possibly regulate the signal transduction pathway in the organ of Corti. The signal transduction process can be modulated by ATP and acetylcholine, the so-called neurotransmitters, in Deiters' cells. Intracellular Ca2+ concentration can be also increased by these neurotransmitters and the control mechanism on the organ of Corti is highly suggested in Deiters' cells. Potassium ion (K+) is known to be important both in hair cells and supporting cells. Through K+ channel, the membrane potential may be controlled and the signal transduction pathway can be regulated. Furthermore, the motility of outer hair cell and the signal transduction from the apical stereocilia are considered to be regulated by this channel. The aim of this study is to record the K+ current in the isolated Deiters' cells from guinea pig cochlea. MATERIALS AND METHODS: Deiters' cells were isolated from the organ of Corti of guinea pig by using collagenase and a pipet. A whole cell patch clamp was performed under the inverted microscope and the current was measured with List-7 amplifier and pClamp 8.0.2 software. RESULTS: The resting membrane potential was -15.02+/-2.66 mV (n=6). When the cell membrane was hyperpolarized into -110 mV from the -40 mV holding potential, the peak current was -227+/-39.9 pA (n=15). After having depolarized to the maximum, (50 mV), the peak current was 7123+/-737 pA, and the reversal potentials of different external K+ concentration changed in the K+-dependent manner. About 80% of this current was inhibited by TEA. When K+ was substituted by Cs+, the peak current was 1788+/-231 pA at 50 mV step pulse. Activation curve of this outward current showed two different Vh (half activation voltage) and K (slope factor). CONCLUSION: Outward rectifying K+ channels exist in Deiters' cells and they can be inhibited by TEA and permeable to Cs+. More than two types of K+ current can exist and they may play a role in the recovery of membrane potential after depolarization,
Acetylcholine ; Adenosine Triphosphate ; Animals ; Cell Membrane ; Cochlea* ; Collagenases ; Guinea Pigs* ; Guinea* ; Hair ; Labyrinth Supporting Cells ; Membrane Potentials ; Neurotransmitter Agents ; Organ of Corti ; Patch-Clamp Techniques ; Potassium ; Potassium Channels ; Signal Transduction ; Stereocilia ; Tea

Hemophagocytic lymphohistiocytosis (HLH) is a rare but fatal complication after solid organ transplantation. Acquired forms of HLH are described in association with severe sepsis, autoimmune disorders, malignancy, immune-compromised states, infections, and solid organ transplantation. We experienced a case of hemophagocytic lymphohistiocytosis after bilateral lung transplantation. Leukopenia, thrombocytopenia, and hyperbilirubinemia were noted and became aggravated 50 days after transplantation. Diagnosis of HLH was based on clinical and laboratory findings of splenomegaly, cytopenia, elevated ferritin, elevated interleukin-2 receptor, and hemophagocytosis in bone marrow. Other features such as elevated bilirubin, lactate dehydrogenase, and D-dimer which can be present in HLH were also noted. The patient was immediately treated with etoposide and dexamethasone. Despite aggressive therapy, the patient deteriorated and died. Awareness of the diagnostic criteria of HLH after lung transplantation is important for clinicians.
Bilirubin ; Bone Marrow ; Dexamethasone ; Diagnosis ; Etoposide ; Ferritins ; Humans ; Hyperbilirubinemia ; Interleukin-2 ; L-Lactate Dehydrogenase ; Leukopenia ; Lung Transplantation* ; Lymphohistiocytosis, Hemophagocytic* ; Organ Transplantation ; Sepsis ; Splenomegaly ; Thrombocytopenia ; Transplants

BACKGROUND: The diagnosis of coronary artery disease (CAD) is often delayed in patients with type 2 diabetes. Serum total bilirubin levels are inversely associated with CAD. However, no studies have examined whether this can be used as a biochemical marker for identifying asymptomatic diabetic patients at higher risk for having obstructive CAD. METHODS: We performed a cross-sectional study of 460 consecutive asymptomatic patients with type 2 diabetes. All patients underwent coronary computed tomographic angiography, and their serum total bilirubin levels were measured. Obstructive CAD was defined as > or =50% diameter stenosis in at least one coronary artery. RESULTS: Serum total bilirubin tertiles showed an inverse association with the prevalence of obstructive CAD. In multivariate logistic regression analysis, the odds ratio for the highest versus the lowest tertile of total bilirubin was 0.227 (95% confidence interval [CI], 0.130 to 0.398), and an increment of 1 micromol/L in serum total bilirubin level was associated with a 14.6% decrease in obstructive CAD after adjustment for confounding variables. Receiver operating characteristic curve analysis showed that the area under the curve for the Framingham Risk Score (FRS) plus serum total bilirubin level was 0.712 (95% CI, 0.668 to 0.753), which is significantly greater than that of the FRS alone (P=0.0028). CONCLUSION: Serum total bilirubin level is inversely associated with obstructive CAD and provides additive risk information over the FRS. Serum total bilirubin may be helpful for identifying asymptomatic patients with type 2 diabetes who are at higher risk for obstructive CAD.
Angiography ; Bilirubin* ; Biomarkers ; Confounding Factors (Epidemiology) ; Constriction, Pathologic ; Coronary Artery Disease ; Coronary Stenosis* ; Coronary Vessels* ; Cross-Sectional Studies ; Diabetes Mellitus ; Diagnosis ; Humans ; Logistic Models ; Multidetector Computed Tomography ; Odds Ratio ; Prevalence ; ROC Curve

Hemophagocytic lymphohistiocytosis (HLH) is a rare but fatal complication after solid organ transplantation. Acquired forms of HLH are described in association with severe sepsis, autoimmune disorders, malignancy, immune-compromised states, infections, and solid organ transplantation. We experienced a case of hemophagocytic lymphohistiocytosis after bilateral lung transplantation. Leukopenia, thrombocytopenia, and hyperbilirubinemia were noted and became aggravated 50 days after transplantation. Diagnosis of HLH was based on clinical and laboratory findings of splenomegaly, cytopenia, elevated ferritin, elevated interleukin-2 receptor, and hemophagocytosis in bone marrow. Other features such as elevated bilirubin, lactate dehydrogenase, and D-dimer which can be present in HLH were also noted. The patient was immediately treated with etoposide and dexamethasone. Despite aggressive therapy, the patient deteriorated and died. Awareness of the diagnostic criteria of HLH after lung transplantation is important for clinicians.
Bilirubin ; Bone Marrow ; Dexamethasone ; Diagnosis ; Etoposide ; Ferritins ; Humans ; Hyperbilirubinemia ; Interleukin-2 ; L-Lactate Dehydrogenase ; Leukopenia ; Lung Transplantation ; Lymphohistiocytosis, Hemophagocytic ; Organ Transplantation ; Sepsis ; Splenomegaly ; Thrombocytopenia ; Transplants