The effects of r-aminobutyric acid(GABA) agonsits and antagonists were explored by the intracellular recording method to discern the preferential suppression of the ON component by GABA on the ON-OFF transient cell in the catfish (Ictalurus punctatus) retina. Experiments were performed in the superfused eyecup preparation. The animals were decapitated and pited before the eye, and the surrounding tissue was removed from the skull. The retina was exposed by excising the cornea, iris, and vitreous. This preparation rested on a wad of Ringer`s soaked cotton in contact with an Ag/Agcl reference electrode. Solutions were delivered through a manifold system that was connected to a pipette located near the absorbent wick. Electro-physiological recordings were made using standard intracellular electrodes filled with 2 M potassium acetate. The electrical signal was recorded with an amplifierand a penwriter, viewed on an oscilloscope, and stored on a data recorder. The light sources were red light-emitting-diode (LED) and the stimuli were full field illumination covering the cntire retina. GABA preferentially reduced ON light responses in ON-OFF transient cell. and GABA hyperpolarized bipolar cells, but the effects on ON bipolar cells were more sensitive than OFF bipolar cells. CACA and TACA, GABAc receptor agonist, did not act on bipolar cells. CACA and TACA, GABAc receptor agonists, hyperpolarized bipolar cells but the sensitivity deferences between ON and OFF bipolar cell were not observed. These results suggest that the preferential suppression of the ON component of the ON-OFF transient cell by GABA was resulted from the presynaptic mechanism that reduced bipolar cell input.
Animals ; Catfishes* ; Cornea ; Electrodes ; gamma-Aminobutyric Acid ; Iris ; Lighting ; Potassium Acetate ; Retina* ; Skull

To investigate the mechanism of the excitatory signal transmission, the effects of N-methyl-D-aspartate(NMDA, ionotropic glutamate agonist) and kynurenic acid(glutamate antagonist) on catfish retinal neurons were explored using conventional intracellular recording techniques. Horizontal cells were depolarized by glutamate, kainate, quisqualate, and NMDA but gyperpolarized by kynurenate. Transient components of both ON-and OFF-bipolar cells were reduced either by glutamate or by NMDA. Kynurenate suppressed sustained components of the third-order neurons or OFF-bipolar cells. Furthermore, kynurenate blocked the depolarizing actions of NMDA on horizontal cells and ON-sustained cells with large ON-transient components. The results suggest that NMDA would exert a tonic depolarization in the horizontal cells and the 3rd-order neurons, and there might be a preferential suppression on the a NMDA receptors by kynurenic acid in the catfish retina.
Catfishes ; Glutamic Acid ; Kainic Acid ; Kynurenic Acid* ; N-Methylaspartate ; Neurons* ; Quisqualic Acid ; Receptors, N-Methyl-D-Aspartate ; Retina* ; Retinal Neurons

The catfish (Ictalurus punctatus) retinal neurons were investigated by using the intracellular recording techniques to analyze the function of the chloride ions in the light responses and the ionic mechanisms of the depolarizing actions by GABA. Experiments were performed in the superfused retina-eyecup preparation. The retina was exposed by exicising the cornea, iris, and vitreous. A piece of absorbent tissue with a hole large enough to expose the retina was centered over the eyecup to serve as a wick to draw off the superfusate. Diffuse light stimuli were generated by light-emitting diode positioned above the eyecup. The recordings were made with the use of borosilicate glass micropipettes fashioned from' omega dot' capillary tubing filled with 2 M potassium acetate. Voltage recordings were obtained using an amplifier and amplified signals were recorded on a storage oscillocope, penwriter, and a data recorder. In the catfish retina, the dark membrane potentials were depolarized and the light evoked responses were enhanced in the chloride"-free medium on the catfish horizontal cells. The amplitude of the light evoked potentials were increased by chloride free Ringer's solution on the ON- and OFF-bipolar cells. But the dark membrane potentials were hyperpolarized on the ON-bipolar cell and depolarized on the OFF-bipolar cells in the chloride free medium. The chloride free Ringer's solution changed the light response from ON-sustained to OFF-sustained without any change in amplitude on the ON-sustained cell. The depolarizing actions by GABA on the horizontal cells were maintained in chloride-free environment. But GABA did not abolished the light evoked potentials of the horizontal cell and the ON-sustained cell under the chloride free environment. The results suggest that chloride ion has important roles on the signal transmission of the dark periods in the catfish retina and the depolarizing actions by GABA on the neurons in the catfish retina might be chloride dependent.
Capillary Tubing ; Catfishes* ; Cornea ; Evoked Potentials ; gamma-Aminobutyric Acid ; Glass ; Ions* ; Iris ; Membrane Potentials ; Neurons ; Potassium Acetate ; Receptors, GABA ; Retina ; Retinal Neurons* ; Retinaldehyde*

BACKGROUND: The purpose of this study is to evaluate what kind of crystalloid solution could function as the best buffer and correct the metabolic acidosis most effectively in rabbits with hemorrhagic shock. METHODS: Twenty eight rabbits were bled until mean arterial pressure(MAP) became 70% of control. Thirty minutes after hemorrhagic shock fluid resuscitation was started with either plasmalyte or Hartmann's solution or 0.9% normal saline until MAP returned to 90% of the control. Hemodynamic and blood gas study, plasma lactate and electrolyte concentration were measured before, during, and 30 minutes after recovery from shock. RESULTS: The amount of shed blood to reduce MAP to 70% of control ranged 76~87 ml. And the volume for fluid resuscitation was 274~324 ml. There was no statistically significant difference among the three groups. The pH decreased during shock in all group and still decreased after resuscitation in Hartmann's solution and normal saline. But it increased significantly after resuscitation in plasmalyte. Lactate was increased in all group during shock and decreased by 22 and 23 mg/dl after resuscitation in plasmalyte and normal saline. But it still increased by 40 mg/dl in Hartmann's solution. Serum potassium level decreased significantly after resuscitation with normal saline. Serum calcium level decreased significantly after resuscitation with plasmalyte and normal saline. CONCLUSION: With the above results the plasmalyte which has pH closer to that of normal blood might be able to avoid the metabolic acidosis and maintain acid-base equilibrium effectively after fluid resuscitation in acute hemorrhagic shock.
Acid-Base Equilibrium ; Acidosis ; Calcium ; Hemodynamics ; Hydrogen-Ion Concentration ; Lactic Acid ; Plasma ; Potassium ; Rabbits* ; Resuscitation* ; Shock ; Shock, Hemorrhagic*

The pathologic spectrums of the tennis elbow are varies as lateral epicondylitis, degenerative partial tear of extensor tendon origin, annular ligament lesion, synovial fringe between radio-capitellar joint, bursitis and posterior interosseous nerve pathology. So it is difficult to perform separate treatments for each different pathologic conditions. Conservative treatments for the tennis elbow are consisted of rest, immobilization, non-steroidal anti-inflammatory drugs (NSAID), and local injection of the steroid. Usual success rates of the conservative treatment have been reported approximately more than 90%. Several methods of surgical treatm nt of the resistant tennis elbow have been reported. Authors performed surgical treatment for twelve cases of the resistant tennis elbow from Jan. 1989 to Jan. 1994. Authors modified the Nirschl's technique; flap retraction of the extensor carpi radilais brevis (ECRB) and common extensor tendon to expose the radio-capitellar joint and no reattachment of detached tendons to the lateral epicondyle and side-to-side suture with maximal stretching of the ECRB tendon. Identified pathologic conditions were the degenerative partial tear and friable granulation tissues at the ECRB origin, sclerosis of the lateral epicondyle (ten cases), synovial fringe bewteen the radio-capitellar joint (two cases). In one case, authors couldn't find any abnormal pathologic conditions. Microscopic examinations (two cases) showed angioblastic proliferation, fibrosis, degeneration of the collagen fiber. Among these patients, eleven patients were industrial worker (eight painter, two welder and one carpenter). They have something in common with using hammer mainly. The hammering might be a possible cause of the tennis elbow. After the surgery, the functional recoveries were satisfactory. The final results were four excellent (33.3%) and good (66.6%) by Nirsh & ettrone grading system. The time required to return to the original job were varied from one month to eight months (average 4.3 months).
Bursitis ; Collagen ; Elbow ; Fibrosis ; Granulation Tissue ; Humans ; Immobilization ; Joints ; Ligaments ; Pathology ; Sclerosis ; Sutures ; Tendons ; Tennis Elbow* ; Tennis*

In horizontal cells (HCs) that were freshly dissociated from goldfish retina, two types of voltage- dependent calcium currents (ICa) were recorded using a patch-clamping configuration: a transient type current and a sustained type current. The cell was held at -40 mV, and the prepulse step of -90 mV was applied before command pulse between -65 and +55 mV. The transient Ca2+ current was activated by depolarization to around -50 mV from a prepulse voltage of -90 mV lasting at least 400 ms and reached a maximal value near -25 mV. On the other hand, the sustained Ca2+ current was induced by pre-inactivation for less than 10 ms duration. Its activation started near -10 mV and peaked at +20 mV. Co2+ (2 mM) suppressed both of these two components, but nifedipine (20microM), L-type Ca2+ channel antagonist, blocked only the sustained current. Based on the activation voltage and the pharmacological specificity, the sustained current appears to be similar to L-type ICa and the transient type to T-type ICa. This study is the first to confirm that transient type ICa together with the sustained one is present in HCs dissociated from goldfish retina.
Calcium* ; Goldfish* ; Hand ; Nifedipine ; Retina ; Sensitivity and Specificity

BACKGROUND: The purpose of this study is to examine the effect of intravenous ketorolac administration before surgical stimulation for postoperative pain control. METHODS: Forty four patients scheduled for total hip replacement were randomly assigned to one of three groups of prospectively designed study. Group 1 (n=14) received intravenous saline (placebo) and Group 2 (n=15) received intravenous ketorolac (30 mg) at one hour after skin incision and Group 3 (n=15) received intravenous ketorolac (30 mg) before induction. Postoperative pain relief was provided with intravenous morphine from PCA system. Postoperative visual analogue pain score (VAS), analgesic requirement and side effects were evaluated and compared between groups for postoperative two days. RESULTS: VAS at rest were significantly less in Group 2,3 than in Group 1 at 3 hours after surgery (p<0.05) and significantly less in group 3 than in group 1 at 6 and 9 hours after surgery (p<0.05). VAS on movement were significantly less in group 3 than group 1 at 1 hour and significantly less in group 2,3 than group 1 at 3 and 6 hours after surgery (p<0.05). Patient controlled morphine consumption in group 1 was significantly higher than in group 2,3 for 12 hours after surgery. After administration of intravenous ketorolac any side effect did not occur. CONCLUSIONS: Administration of intravenous ketorolac before skin incision as a pre-emptive analgesia has better analgesia than those of 1 hour after skin incision and no administration of ketorolac.
Analgesia ; Arthroplasty, Replacement, Hip* ; Humans ; Ketorolac* ; Morphine ; Pain, Postoperative ; Passive Cutaneous Anaphylaxis ; Prospective Studies ; Skin

For the investigation of the receptive field of the retinal neurons, the spatial and temporal properties of horizontal cells and the center-surround antagonisms of bipolar cells and the third-order neurons were studied using conventional intracellular recording techniques. Horizontal cells were hyperpolarized by the large annulus light stimuli (id: 3.5mm) and required at least 0.2 seconds of dark periods to respond enough. The amplitudes of the response of the ON-bipolar cell were decreased as the diameter of the spot stimuli was increased to 2.6mm and the responses were inverted at 2.6mm of inner diameter of the spreading annulus stimuli with fixed width. ON-sustained cell with spikes generated ON-sustained light responses by small annulus (1400-2100micrometer), but elicited OFF-sustained responses by large annulus (2100-2800micrometer). ON-sustained cell without spikes also showed surround antagonism. The spikes were generated at the spot of 490micrometer diameter and they were disappeared at the spot of 5600micrometer diameter. And, OFF-transient component of the ON-OFF transient cell was enhanced as annulus stimuli spread. The results suggest that the horizontal cells have large and monotonic receptive fields while the bipolar cells and the ON-sustained cells have large biphasic receptive fields in the catfish retina.
Catfishes* ; Neurons* ; Retina ; Retinal Neurons

BACKGROUND AND OBJECTIVES: Imidapril, one of the ACE inhibitor, has been used to treate hypertension, congestive heart failure, diabetes mellitus and renal disease. ACE inhibitor, however often causes dry cough and this adverse effect affects the compliance rate negatively. This report aimed to examine the incidence rate of coughing caused by Imidapril treat-ment. And we compared the results with the incidence and tendency of dry cough caused by the other ACE inhibitors. MATERIALS AND METHOD: This study enrolled 38 patients who followed up at internal medicine and took Imidapril from the period of May 9, 1997 to December 17, 1997. We tested its effectiveness, safety and tolerance. The initial dosage of it was 5mg/day and the maximum dosage according to blood pressure was 10mg/day for 8 weeks. The tendency and the incidence of dry cough have been analyzed and compared with recently published Korean reports. RESULTS: The 5 mg dosage of Imidapril showed 68.1% in lowering blood pressure rate and it went up to 81.8% during the 8 weeks treatment perriod. The blood pressure regularity rate was 36.3% after the 8 weeks treatment. The overall rate of adverse effect occurrence was 26.1% (6/23) and 8.7% of them were likely to cough. One of the patients who showed nausea stopped medication. The recent articles reported that the incidence of dry cough had been reduced: Enalapril (33.8%), Fosinopril (16%), Ramipril (15%), Imidapril (7.8 - 8.7%), Losartan (4.3%). CONCLUSION: Imidapril is as safe and effective as other ACE inhibitors. Various ACE inhibitors that were newly developed show their effectiveness in lessening incidence rate of dry cough, and Imidapril is thought to be an excellent drug for this matter. Even though Losartan shows the lowest incidence rate of dry cough, it needs to more regular usages since it is still on the stage of its medical adaptation.
Angiotensin-Converting Enzyme Inhibitors ; Angiotensins* ; Blood Pressure ; Compliance ; Cough* ; Diabetes Mellitus ; Enalapril ; Fosinopril ; Heart Failure ; Humans ; Hypertension ; Incidence* ; Internal Medicine ; Losartan ; Nausea ; Peptidyl-Dipeptidase A* ; Ramipril

Endotracheal tube obstruction during anesthesia can have many causes. Hyperinflation of the remaining lung after a pneumonectomy can severely displace the trachea, and attachment of an endotracheal tube tip to the wall of a deviated trachea may also cause severe airway obstruction. The right lung of the patient was removed 3 years ago due to lung cancer. Compensatory hyperinflation of the left lung and severe right-sided tracheal deviation was seen on a chest X-ray. An armored endotracheal tube without Murphy's eye was used. Two hours after beginning the operation, peak airway pressure and PETCO2 began to increase gradually. A wheezing-like sound was heard. Bronchospasm was suspected, but signs of a spasm were not relieved by medications. The signs completely disappeared after pulling the tube 2 cm proximal. The position of the tube should be confirmed by fiberoptic bronchoscopy or chest X-ray after intubation when the trachea is deviated.
Airway Obstruction ; Anesthesia ; Bronchial Spasm ; Bronchoscopy ; Endarterectomy, Carotid* ; Humans ; Intubation ; Lung ; Lung Neoplasms ; Pneumonectomy ; Spasm ; Thorax ; Trachea