Role of calcium channels responsible for phenylephrine-induced contraction in rat aorta 3 days after acute myocardial infarction / 대한마취과학회지

BACKGROUND: Phenylephrine (PE) produces tonic contraction through involvement of various calcium channels such as store-operated calcium channels (SOCCs) and voltage-operated calcium channels (VOCCs). However, the relative contribution of each calcium channel to PE-induced contraction has not been investigated in isolated rat aorta of early acute myocardial infarction (AMI). METHODS: Endothelium-denuded rat aortic rings from rats 3 days after AMI or sham-operated (SHAM) rats were prepared in an organ chamber with Krebs-Ringer bicarbonate solution for isometric tension recording. We assessed the PE dose-response relationships in 2.5 mM calcium medium for both groups. The same procedure was repeated using rings pretreated with the SOCC inhibitor 2-aminoethoxydiphenyl borate, sarco/endoplasmic-reticulum calcium ATPase inhibitor thapsigargin (TG), diacyl glycerol lipase inhibitor RHC80267, and sodium-calcium exchanger inhibitor 3,4-dichlorobenzamil hydrochloride for 30 minutes before addition of calcium. When ongoing tonic contraction was sustained, dose-response curves to the VOCC inhibitor nifedipine were obtained to assess the relative contribution of each calcium channel under various conditions. RESULTS: The effect of SOCC induction with TG pretreatment on PE-induced contraction was significantly lower in the AMI group compared to the SHAM group. In addition, there were significant decreases in the sensitivity and efficacy of the VOCC inhibitor nifedipine on PE-induced contraction in the AMI group. CONCLUSIONS: Results suggest that the change of vascular reactivity of PE in rat aorta 3 days after AMI is characterized by a decreased contribution of L-type VOCCs. The enhanced VOCC-independent calcium entry mechanisms after AMI can be mediated by enhanced capacitative calcium entry through the activation of SOCCs.

Biomechanical Comparison of the Modified ML (Mattress Locking) Suture and the Modified MA (Mason-Allen) Suture in Rotator Cuff Repairs / 대한정형외과학회잡지

PURPOSE: In arthroscopic rotator cuff repairs, there is generally a weak link in the tendon suture interface, and arthroscopic rotator cuff repairs can have higher retear rates than open repairs. The purpose of this study was to compare the strength of modified ML (Mattress Locking) suture vs. the modified MA (Mason-Allen) suture when the suture is anchored into bone. MATERIALS AND METHODS: Paired human supraspinatus tendons were harvested and split in half, producing four tendons per one cadaver, for a total of 24 specimens. Two suture configurations (ML, MA) were randomized and checked for each set of tendons. Specimens were cyclically loaded under force control between 5 and 30 N at 0.25 Hz for fifty cycles. Each specimen was loaded to failure under displacement control at 1 mm/sec. Cyclic elongation, peak to peak displacement, stiffness, ultimate tensile load, and mode of failure were checked. RESULTS: No significant difference was found between the two suture configuration with respect to peak to peak displacement, cyclic elongation, and stiffness. With regard to ultimate failure load, there were no statistically significant differences between the modified ML suture and the modified MA suture (223.18N, 220.82N). The most common mode of failure between both sutures was suture pullout. CONCLUSION: The modified ML suture and the modified MA suture have similar biomechanical properties. The modified ML suture may be a simple and clever method and similar biomechanical alternative to the modified Mason-Allen suture in arthroscopic rotator cuff repair.

Film Dosimetry for Intensity Modulated Radiation Therapy: Dosimetric Evaluation / 대한방사선종양학회지

PURPOSE: X-ray film over responds to low-energy photons in relative photon beam dosimetry because its sensor is based on silver bromide crystals, which are high-Z molecules. This over-response becomes a significant problem in clinical photon beam dosimetry particularly in regions outside the penumbra. In intensity modulated radiation therapy (IMRT), the radiation field is characterized by multiple small fields and their outside-penumbra regions. Therefore, in order to use film dosimetry for IMRT, the nature the source of the over-response in its radiation field need to be known. This study is aimed to verify and possibly improve film dosimetry for IMRT. MATERIALS AND METHODS: Modulated beams were constructed by a combination of five or seven different static radiation fields using 6 MeV X-rays. In order to verify film dosimetry, we used X-ray film and an ion chamber were used to measure the dose profiles at various depths in a phantom. In addition, in order to reduce the over-response, 0.01 inch thick lead filters were placed on both sides of the film. RESULTS: The measured dose profiles showed a film over-response at the outside-penumbra and low dose regions. The error increased with depths and approached 15% at a maximum for the field size of 15X15 cm(2) at 10 cm depth. The use of filters reduced the error to 3%, but caused an under-response of the dose in a perpendicular set-up. CONCLUSIONS: This study demonstrated that film dosimetry for IMRT involves sources of error due to its over-response to low-energy photons. The use of filers can enhance the accuracy in film dosimetry for IMRT. In this regard, the use of optimal filter conditions is recommended.

Renin-responsive Adrenal Adenoma with a Suspicious Abberant Adrenal Vein / 대한내분비학회지

A renin- or angiotensin-II responsive aldosterone producing tumor is a rare cause of primary hyperaldosteronism. This tumor can be identified by tests that show that the aldosterone producing adrenal tumor is not fully autonomous. In other words partially it is responsible for the stimulation of aldosterone secretion that results aldosterone levels in an increase in serum in response to the upright posture and spironolactone treatment. Furthermore, the urinary 18-hydroxycortisol level is within the normal range. Because of different responses to surgical removal, the differential diagnosis of the causes of primary aldosteronism can't be overemphasized even for rare causes of primary aldosteronism such as unilateral nodular hyperplasia or a renin-responsible aldosterone producing tumor. We should consider renin or angiotensin-II responsive adrenal adenoma in the differential diagnosis of primary aldosteronism when biochemical data shows atypical results. Here we present the first case in Korea of a renin-responsive aldosterone producing adrenal adenoma which was fully accessible and was successfully treated by surgical removal. Also, sampling for aldosterone secretion just above the insertion site in the left renal vein before surgery showed a suspiciously abberant left adrenal vein drainage into the IVC, This was very helpful information during adrenal vein ligation in laparoscopic adrenalectomy.

A Endotracheal Intubation in a Child with Mocopolysaccharidoses Using the Fiberoptic Laryngoscopy / 대한마취과학회지

Mucopolysaccharidoses are a group of inherited disorders of metabolism resulting in the deposition of mucopolysaccharide in various tissues. This leads to organ dysfunction and anatomical abnormalities which can be important to the anesthetist. These abnormalities result in airway difficulty and difficult intubation. We successfully performed endotracheal intubation in a case of mucopolysaccharidoses in a 9-year-old female patient using fiberoptic laryngoscopy.

The Hemodynamic Effect of Nerve Block by Cranial Pinning in Brain Surgery Patients / 대한마취과학회지

BACKGROUND: It is already known that the cranial pinning causes a sudden increment of blood pressure and heart rate which is harmful especially in brain surgery patient. These changes may be reduced by local infiltration at the sites of cranial pinning. This study was designed to investigate the hemodynamic effects of nerve block by cranial pinning and compare them with the effects of local infiltration at the pinning site. METHODS: Forty patients of brain surgery with cranial pinning were involved. After general anesthesia with isoflurane and 50% N2O, they were divided into 2 groups randomly: the control group (n = 20), had local infiltration at each pinning site with 1% lidocaine 2 ml, and the study group (n = 20), had nerve block of the supraorbital, and supratrochlear, and postauricular branches of the great auricular nerve with lidocaine 2 ml, the auriculotemporal nerve with lidocaine 2.5 ml, and the greater and lesser occipital nerves with lidocaine 2.5 ml. The hemodynamic variables(systolic, diastolic, mean blood pressure, and heart rate) were measured at the 3 different points just before cranial pinning, and 1 min and 5 min after cranial pinning. RESULTS: The values of hemodynamic variables at 1 min after cranial pinning increased in both groups when compared with just before cranial pinning, but there was no difference between the two groups. The increased values at 1 min were not high clinically, and returned to the levels recorded before cranial pinning by the 5 min recording time in both groups. CONCLUSION: From these results, we concluded that nerve block could also reduced the harmful hemodynamic effect of cranial pinning.

Hemodynamic Effects of Combination of General and Caudal Anesthesia in Children / 대한마취과학회지

BACKGROUND: Caudal anesthesia has gained wide acceptance in pediatric anesthesia as a technique for providing postoperative pain relief and reducing general anesthetic requirement for surgical procedures below umbilicus. Although blood pressure has been shown to be well maintained with caudal anesthesia in pediatrics, little is known about the change in hemodynamics with combined general and caudal anesthesia. This study was designed to investigate the hemodynamic changes of combined general and caudal anesthesia for lower abdominal surgery in children. METHODS: Sixty children scheduled for lower abdominal surgery were involved. They were randomly divided into 2 groups: group G (n = 30); anesthesia with enflurane and N2O, and the group GC (n = 30); anesthesia with combined caudal block using 1% lidocaine 1 ml/kg and enflurane. Systolic (SBP), diastolic (DBP), mean blood pressure (MBP), and heart rate (HR) were measured at the 6 different time periods; at before induction (T1), just before skin incision (T2), just after skin incision (T3), 5 min (T4), 10 min (T5), and 30 min (T6) after skin incision. RESULTS: There were no significant differences in variables of hemodynamics between both group. Compared with the values at T1, those of SBP, DBP, and MBP at T2, T3, T4, T5, and T6 were decreased in both groups. However, there were no difference in those values at the same time periods between the two groups. The values of SBP, DBP, and MAP at T3, T4, T5, T6 in group G were higher compared with those at T2. CONCLUSIONS: From these results, we concluded that there were no significant changes in hemodynamics by combined general and caudal anesthesia in pediatric patients.

2 Cases of Peripheral Nerve Tumors of Anterior Neck Simulating Thyroid Nodule / 대한내분비학회지

Peripheral nerve tumors are mostly benign and can arise on any nerve trunk or twig. Although peripheral nerve tumors can occur anywhere in the body, including the spinal roots and cauda equina, many cases are subcutaneous in location and present as a soft swelling, sometimes with a purplish discoloration of skin. There are two major catagories, schwannoma(neurilemmoma), and neurofibroma. Schwannomas are usually solitary and grow in the nerve sheath, rendering them relatively easy to dissect free. In contrast, neurofibromas tend to be multiple, grow in the endoneural substance, which renders them difficult to dissect, may undergo malignant changes, and are the hallmark of von Recklinghausens neurofibromatosis. Masses in the anterior part of neck may be initially thought to be thyroid nodule and then other cervical masses should be considered. The diagnosis rests on clinical suspicion and diagnostic support may be obtained by CT scan, magnetic resonance imaging(MRI) and substraction angiography in the literature. After imaging, fine needle aspiration for cytology may be helpful. If they are resected unrecognized and/or without regard to their nerve origin, major and permanent nerve defects can unnecessarily occur. We experienced 2 cases of peripheral nerve tumors of anterior neck simulating a thyroid nodule.

Psychological Personality Test in Premature Ejaculation Patients / 대한비뇨기과학회지

On psychological aspect, premature ejaculation in psychosexual dysfunction is generally associated with anxiety. Psychiatrists consider that the treatment of choice for premature ejaculation is directive sextherapy with psychotherapy. We screened psychopathology according to the Symptom Checklist-90-Revision (SCL-90-R) in premature ejaculation group (n=120) and control group (n=92). The rate of abnormal RESULTS of both groups were similar as 5 (4.1%) in patient group and 4 (4.3%) in control group. And there was statistical significance in T scores on 5 symptom dimensions of Obsessive-Compulsive, Interpersonal Sensitivity, Depression, Anxiety and Psychoticism, but all of the T scores of those dimensions were with in the normal range. The psychological personality test does not reflect all of the psychosexual factors. But with the psychological screening, we could find that the psychological factors are not absolutely associated with premature ejaculation.