No abstract available.
Temporomandibular Joint*

There are several variations in normal mastication. In them, unilateral mastication is chewing, predominantly on a preferred side of the dentition and hardly on the non-preferred side. Continual unilateral mastication may alter the coordination of masticatory muscles. Although they studied about these EMG of masticatory muscles, there were no information about characteristics of masticatory muscle activity in unilateral mastication. Therefore, In this study, we investigated the activity of the masseter and anterior temporal muscles during rest, clenching in maximum intercuspation and gum chewing in habitually unilateral mastication group com-pared with normal group and tried to know effects of continual unilateral mastication on activity of masticatory muscles. The results of this study were as follows 1. In electromyographic activity during rest, in bilateral mastication group pattern of muscle activity of right and left side was symmetrical. But, in unilateral mastication group, records of anterior part of temporal muscle was higher than that of bilateral mastication group (p<.01) and patterns of muscle activity of right and left side in both muscle were asymmetrical.(p<.05). 2. In electromyographic activity during clenching in maximum intercuspation, records of superficial part of masseter muscle were higher than anterior part of temporal muscle in both group. Muscle activity of temporal muscle in unilateral mastication group was a little higher than bilateral mastication group and asymmetry of activity pattern in temporal and masseter muscle was shown but these differences were not statistically significant. (p< .05). 3. In electromyographic activity during gum chewing, temporal muscle was activated earlier than masseter muscle and .aximum bite force is derived from masseter muscle in both group. In unilateral mastication group, electromyographic activity of masseter and temporal muscle of preferred chewing side, regardless of right or left side chewing, was higher than that of bilateral mastication group and especially, difference in masseter muscle was statistically significant. (p< .01) Based on the above results, our study suggested that recording of masticatory muscle activity will be helpful in the effective diagnosis and treatment of some types of the parafunctional habits.
Bite Force ; Dentition ; Diagnosis ; Gingiva ; Masseter Muscle ; Mastication ; Masticatory Muscles* ; Temporal Muscle

STATEMENT OF PROBLEM: Proper proximal contact is important for maintaining and stabilizing the dental arch. However, the proximal contact strength (PCS) is not a constant value and can be affected by a variety of factors. PURPOSE: This study examined the influences of postural changes on the posterior PCS. MATERIAL AND METHODS: Twelve adults with a normal occlusion and had not undergone prosthetic treatment or proximal restoration were participated in this study. A metal strip was inserted into the proximal surface and removed at a constant velocity. The contact strength was measured in every contact point between canine to second molar in both arches. The PCSs were obtained initially in the upright position, secondly in the supine position and finally in the upright position again. All measurements were repeated after a 2 hour period. Statistical analysis was carried out using the Friedman test (P < .05). RESULTS: Generally, a decrease in PCS occurred when the posture was changed from the initial upright to supine position, while it increased when the posture was changed from the supine to upright position. A significant change was observed in all areas except for between the canine-first premolar in the maxilla and between the first molarsecond molar in the mandible areas. CONCLUSION: The posterior PCS, which dentists generally believe to be a static feature of occlusion, is affected significantly by posture.
Adult ; Bicuspid ; Dental Arch ; Dentists ; Humans ; Mandible ; Maxilla ; Molar ; Posture ; Supine Position

No abstract available.
Echocardiography* ; Humans ; Infant, Newborn*

AIMTo investigate the role of oxygen free radicals (OFR) in hepatic ischemia and reperfusion injury (HI/RI) and effect of propofol on them.

METHODSThe rabbits were randomly divided into three groups (n=10), sham operated group (Control), HIR group(I/R) and HIR + propofol group (PRO). Changes of several parameters which included malondialdehyde (MDA), superoxide dismutase (SOD), xanthine oxidase (XO) and alanine aminotransferase(ALT) were measured before ischemia, 45 minutes after ischemia and 45 minutes after reperfusion in plasma. Meanwhile MDA concentration, SOD, XO activities and ALT value in liver tissue were measured, and the ultrastructure changes in liver tissue were observed under electron microscope at 45 minutes after reperfusion.

RESULTSAs compared with group control, XO, MDA and ALT increased and SOD decreased during HI/RI (P < 0.05 and P < 0.01) in plasma, and XO, MDA increased as well as SOD decreased at 45 minutes after reperfusion (P < 0.05 and P < 0.01) in liver tissue and there were abnormal changes of the hepatic ultrastructure at 45 minutes after reperfusion. Propofol reversed the results of mentioned indices as above markedly (P < 0.05 and P < 0.01).

CONCLUSIONOFR is an important factor during HI/RI, propofol may attenuate hepatic ischemia-reperfusion injury by dropping OFR level (raising SOD activity and dropping XO activity) and antagonizing lipid pe-reoxidation (reducing MDA content).

Alanine Transaminase ; metabolism ; Animals ; Free Radical Scavengers ; metabolism ; Liver ; blood supply ; ultrastructure ; Malondialdehyde ; metabolism ; Oxidation-Reduction ; drug effects ; Propofol ; pharmacology ; therapeutic use ; Rabbits ; Reactive Oxygen Species ; metabolism ; Reperfusion Injury ; drug therapy ; metabolism ; Superoxide Dismutase ; metabolism ; Xanthine Oxidase ; metabolism

AIMTo explore the role of ligustrazin on dynamic changes of lipid peroxidation in hepatic ischemia/reperfusion injury (HIRI) and its mechanism.

METHODSThe HIRI model was used. Twenty rabbits were randomly divided into control group (n = 10) and ligustrazin group (n = 10). The xanthine oxidase (XO) activity, superoxide dismutase (SOD) activity,malondialdehyde (MDA) content and glutamic pyruvic transaminase (GPT) activity in plasma were observed before ischemia and at ischemia 25 min, reperfusion 25 min, reperfusion 60 min and reperfusion 120 min.

RESULTSThe XO activity, SOD activity, MDA content and GPT activity of ligustrazin group, as compared with control group, showed significant differences (P < 0.05 or P < 0.01) at total time points of reperfusion.

CONCLUSIONLigustrazin has notable anti-lipid peroxidation effect on HIRI, which is due to its inhibiting the generation of oxygen free radicals and its strengthening scavenging of oxygen free radicals.

Alanine Transaminase ; metabolism ; Animals ; Female ; Lipid Peroxidation ; drug effects ; Liver ; drug effects ; metabolism ; Male ; Malondialdehyde ; blood ; Pyrazines ; pharmacology ; Rabbits ; Reperfusion Injury ; metabolism ; Superoxide Dismutase ; metabolism ; Xanthine Oxidase ; metabolism

AIM To prepare the soluble microneedles of Aconitum brachypodum Diels alkaloids.METHODS Centrifugal molding method was adopted in the preparation of soluble microneedles.With chondroitin sulfate consumption,PVP K120 consumption and 40%ethanol consumption as influencing factors,piercing rate as an evaluation index,the formulation was optimized by Box-Behnken response surface method,after which the morphology,piercing performance,drug content and in vitro transdermal performance were investigated.RESULTS The optimal formulation was determined to be 123 mg for chondroitin sulfate consumption,298 mg for PVP K120 consumption,and 2.4 mL for 40%ethanol consumption,the piercing rate was 98.3%.The soluble microneedles were yellow and square patch with conoid needle,which could pierce aluminum foil and rat skin,along with the drug content of(0.94±0.025)mg.The soluble microneedle group demonstrated the accumulative permeability rate of 91.4%within 24 h,which was higher than that in the gel ointment group,and the permeability accorded with Higuchi equation.CONCLUSION The soluble microneedles of A.brachypodum alkaloids exhibit good mechanical strength,which can achieve effective transdermal delivery of drugs.

BACKGROUND/AIMS: The aims of this study are to clarify the morphology of fundic gland polyp (FGP) and to compare the features of FGP between familial adenomatous polyposis-associated group and sporadic development group. METHODS: A total of 15 endo- scopic biopsy specimens of FGP from 13 patients were divided into three groups; Group A(3 cases; familial adenomatous polyposis family, multiple FGPs), Group B(3 cases; sporadic development, multiple FGPs) and Group C(7 cases; sporadic development, single FGP), and their endoseopic /microscopic features including mucin histochemistry and immunohistoc- hemistty(for PCNA) were compared. RESULTS: FGPs were confined to the gastric body and fundus in all 3 groups, and measured 2-8 mm. Their numbers varied even in Group A and Group B, The difference was observed in their median age: 26 years in Group A and 55 years in Group B, respectively, but there were no differences in endoscopic, histologic, mucin histochemical and immunohistochemical(for PCNA) features. Micro-scopically, all FGPs were composed of fundic glands and scattered microcysts with a spectrum of disordered glandular architecture which ranged from convoluted gland to Y-shaped gland, to stellateshaped gland, and to irregular tortuous glancl with dilated lumen. CONCLUSIONS: We assume that diversity af morphologic features of FGP may develop from progression of hyperplastic/hamartomatous fundic glandular proliferation which may end up with microcyst formation as an evolutional change. Familial adenomatous polyosis-associated FGPs were not endoscopically and histologically distingishable from sporadic deveoped FGPs.
Adenomatous Polyposis Coli* ; Biopsy ; Esophagus* ; Humans ; Intestines* ; Mucins ; Polyps* ; Stomach*

PURPOSE: Renal blood oxygen level-dependent (BOLD) MRI has been used in the evaluation of renal oxygenation. We tried to provide the normal R2* value of the human kidney with 3.0 T, and evaluated the differences in R2* values according to gender and location. MATERIALS AND METHODS: Twenty-four healthy volunteers underwent BOLD MRI at 3.0 T. Multi gradient echo-echo planar imaging sequence with seventeen echoes was used. After generation of the T2* map, the R2* was calculated. The statistical differences in R2* values between the cortex and medulla, males and females, and the right and left kidney were analyzed. The regional differences of R2* within the both kidneys were evaluated respectively. RESULTS: BOLD MRI was successful in all participants. No gross artifact interfered with R2* measurement. The mean R2* at 3.0 T was 17.1 +/- 2.60 s-1 in the cortex and 27.7 +/- 4.83 s-1 in the medulla (p < 0.001). The R2* value in the medulla was significantly higher in the male than female volunteers (p = 0.025). There were no statistical differences of R2* according to the side and location in the kidney (p = 0.197). CONCLUSION: Renal BOLD MRI can be efficiently performed with 3.0 T MRI. Renal medullary hypoxia is present in normal volunteers. Our results may be used as reference values in the evaluation of pathologic conditions using BOLD MRI.
Anoxia ; Artifacts ; Female ; Humans ; Kidney ; Male ; Oxygen ; Reference Values

PURPOSE: Many evidences about hyperuricemia as a risk factor to hypertension and renal progression in kidney diseases have been reported. We have analyzed the impact of uric acid on renal progression of IgA nephropathy while getting rid of possible confounding variables and revealed the possible pathophysiology of uric acid in terms of hypertension or renal vasculopathy provoked by uric acid. METHODS: We selected 172 patients with IgA nephropathy diagnosed by renal biopsy at Seoul National University Hospital. We adapted the criteria of renal progression as the final value of serum creatinine increased more then twice compared to the value at renal biopsy. RESULTS: Serum uric acid was correlated with the severity of interstitial fibrosis and tubular atrophy and the presence of artherosclerosis. The incidence of hypertension during follow-up period was not different between low uric acid group and high uric acid group. The high uric acid level was an independent risk factor to renal progression in IgA nephropathy with multivariate analysis regardless of the presence of hypertension or artherosclerosis of renal pathologic finding. The high uric acid level was also a risk factor to renal progression in patients with estimated GFR more than 60 mL/min/1.73m2. CONCLUSION: Serum uric acid was related to the presence of artherosclerosis and the renal progression of IgA nephropathy.
Atrophy ; Biopsy ; Confounding Factors (Epidemiology) ; Creatinine ; Fibrosis ; Follow-Up Studies ; Glomerulonephritis, IGA* ; Humans ; Hypertension ; Hyperuricemia ; Immunoglobulin A* ; Incidence ; Kidney Diseases ; Multivariate Analysis ; Risk Factors ; Seoul ; Uric Acid*