Aneurysmal Rupture of the Anterior Leaflet of the Mitral Valve Secondary to Bicuspid Aortic Valve Endocarditis

Aneurysm formation and rupture of the anterior mitral leaflet is a rare complication of infectious aortic valve endocarditis. Prompt diagnosis and early surgical treatment can prevent complications such as embolization and cardiogenic shock. It is also related to the acute and severe mitral regurgitation. We describe a case of aneurysm of the anterior mitral leaflet secondary to bicuspid aortic valve endocarditis.

Screening of genes differentially expressed in cultured human periodontal ligament cells and human gingival fibroblasts / 대한치주과학회지

Periodontal ligament(PDL) cells and human gingival fibroblasts(HGFs) play important roles in development, regeneration, normal function, and pathologic alteration. PDL cells and HGFs have the similarity related with general characteristics of fibroblast such as spindle shaped morphology, the presence of vimentin intermediate filament and the synthesis of interstitial collagens and fibronectin. There were many studies about the differences between PDL cells and HGFs, but they were not about whole gene level. In this study, we tried to explain the differences of gene expression profiles between PDL cells and HGFs, and the differences among three individuals by screening gene expression patterns of PDL cells and HGFs, using cDNA microarray. Although there were some variants among three experiments, a set of genes were consistentely and differentially expressed in one cell type. Among 3,063 genes, 49 genes were more highly expressed in PDL cells and 12 genes were more highly expressed in HGFs. The genes related with cell structure and motility were expressed more highly in PDL cells. These are cofilin 1, proteoglycan 1 secretory granule, collagen type I(alpha1), adducin gamma subunit, collagen type III(alpha1), fibronectin, lumican(keratan sulfate proteoglycan), and alpha-smooth muscle actin. Tissue inhibitor of metalloproteinase known as the enzyme controlling extracellular matrix with matrix metalloproteinase is more highly expressed in PDL cells, osteoprotegerin known as osteoclastogenesis inhibitory factor is more highly expressed in HGFs. We performed northern blot to verify cDNA microarray results on selected genes such as tissue inhibitor of metalloproteinase, fibronectin, osteoprogeterin. The result of northern blot analysis showed that each cell expressed the genes in similar pattern with cDNA microarray result. This result indicates that cDNA microarray is a reliable method in screening of gene expression profiles.

Effects of Ethosuximide on the Pilocarpine Induced Seizure in Rat Model of Neuronal Migration Disorder

Cortical malformation-associated epileptic seizures are resistant to conventional anticonvulsant drugs. Relatively little research has been conducted on the effects of antiepileptic drugs (AEDs) on seizure activity in a rat model of dysplasia. We have used rats exposed to methylazoxymethanol acetate (MAM) in utero, an animal model featuring nodular heterotopia, to investigate the effects of ethosuximide (ETX) in the dysplastic brain. Pilocarpine was used to induce acute seizure in MAM-exposed and age-matched vehicle-injected control animals. Field potential recordings were used to monitor the amplitude and number of population spikes, and paired pulse inhibition in response to stimulation of the commissural pathway. Pharmaco-resistance was tested by measuring seizure latencies after pilocarpine administration (320 mg/kg, i.p.) with and without pre-treatment with ETX. Pre-treatment with 300 mg of ETX significantly prolonged the latency to the status epilepticus (SE) in both control and MAM-treated groups. Pre-treatment with ETX 100mg and ETX 200 mg had little effect in MAM-exposed rats. However, ETX 200 mg prolonged the latency to the SE in control groups. Spontaneous field potential and secondary after-discharges were higher for MAM-treated rat in comparison with control rats injects with ETX. The main findings of this study are that acute seizures initiated in MAM-exposed rats are relatively resistant to standard ETX assessed in vivo. These data suggest that ETX do not prolong seizure latencies in MAM-rats exposed to pilocarpine.

Changes of CA1 Excitability in Rats after Prenatal Methylazoxymethanol Treatment

Experimentally induced cortical disorganization exhibits many anatomical features which are characteristic of cortical malformations in children with early-onset epilepsy. We used an immunocytochemical technique and extracellular field potential recordings from the dorsal hippocampus to determine whether the excitability of the CA1 pyramidal cells was enhanced in rats with experimentally induced hippocampal dysplasia. Compared with control rats, the MAM-treated rats displayed a decrease of paired pulse inhibition. When GABAA receptor antagonists were blocked with 10microM bicuculline, the amplitude of the second population spike of the MAM-treated of rats was similar to that of the first population spike, as was in the control rats. The MAM-treated rats had fewer somatostatin and parvalbumin-immunoreactive neurons than the control rats. These results suggest that the enhanced neuronal responsiveness of the in vivo recording of the CA1 in this animal model may involve a reduction of CA1 inhibition.

Effects of Zinc on Spontaneous Miniature GABA Release in Rat Hippocampal CA3 Pyramidal Neurons

The effects of Zn2+ on spontaneous glutamate and GABA release were tested in mechanically dissociated rat CA3 pyramidal neurons which retained functional presynaptic nerve terminals. The spontaneous miniature excitatory and inhibitory postsynaptic currents (mEPSCs and mIPSCs, respectively) were pharmacologically isolated and recorded using whole-cell patch clamp technique under voltage-clamp conditions. Zn2+ at a lower concentration (30 micrometer) increased GABAergic mIPSC frequency without affecting mIPSC amplitude, but it decreased both mIPSC frequency and amplitude at higher concentrations (> or =300 micrometer). In contrast, Zn2+ (3 to 100 micrometer) did not affect glutamatergic mEPSCs, although it slightly decreased both mIPSC frequency and amplitude at 300 micrometer concentration. Facilitatory effect of Zn2+ on GABAergic mIPSC frequency was occluded either in Ca2+ -free external solution or in the presence of 100 micrometer 4-aminopyridine, a non-selective K+ channel blocker. The results suggest that Zn2+ at lower concentrations depolarizes GABAergic nerve terminals by blocking K+ channels and increases the probability of spontaneous GABA release. This Zn2+ -mediated modulation of spontaneous GABAergic transmission is likely to play an important role in the regulation of neuronal excitability within the hippocampal CA3 area.

Effects of nicotine on the attachment and proliferation of periodontal ligament cells, and reversibility of nicotine-induced cytotoxicity / 대한치주과학회지

No abstract available.

Differential Effects of Typical and Atypical Antipsychotics on MK- 801-induced EEG Changes in Rats

We examined whether the abnormal EEG state by NMDA receptor blocker MK-801 can be reversed by typical and atypical antipsychotics differentially by comparing their spectral profiles after drug treatment in rats. The spectral profiles produced by typical antipsychotics chlorpromazine (5 mg/kg, i.p.) and haloperidol (0.5 mg/kg, i.p.) were differ from that by atypical antipsychotic clozapine (5 mg/kg, i.p.) in the rats treated with or without MK-801 treatment (0.2 mg/kg, i.p.) which produce behavioral abnormalities like hyperlocomotion and stereotypy. The dissimilarity between the states produced by antipsychotics and the control state was examined with the distance of the location of the canonical variables calculated by stepwise discriminant analysis with the relative band powers as input variables. Although clozapine produced more different state from normal state than typical antipsychotics, clozapine could reverse the abnormal schizophrenic state induced by MK-801 to the state closer to the normal state than the typical antipsychotics. The results suggest that atypical anesthetic can reverse the abnormal schizophrenic state with negative symptom to the normal state better than typical antipsychotic. The results indicate that the multivariate discriminant analysis using the spectral parameters can help differentiate the antipsychotics with different actions.

Intra-articular Injection of IL-1beta Facilitated Formalin-induced Temporomandibular Joint Pain in Freely Moving Rats

The present study was performed to investigate the effects of intra-articular injection of interleukin-1beta (IL-1beta) on the formalin-induced temporomandibular joint (TMJ) pain. Under anesthesia, a 30-gauge needle was introduced into the right TMJ region for injection of formalin. Microinjection of 50 microliter of 5% formalin significantly produced noxious scratching behavioral response, and the scratching behavior lasted for 40 min. Although the responses produced by formalin injection were divided into two phases, the response of 1st phase did not significantly differ from the scratching behavior response in the saline-treated group. We examined the effects of intra-articular injection of IL-1beta on the number of noxious behavioral responses produced by 50microliter of 5% formalin injection. Intra-articular injection of 100 pg and 1 ng of IL-1beta significantly increased the number of behavioral responses of the 2nd phase, while 10 pg of IL-1beta did not change the formalin-induced behavioral responses. To investigate whether IL-1 receptor was involved in the intra-articular administration of IL-1beta-induced hyperalgesic response, IL-1 receptor antagonist (IL- ra, 50 ng) was administrated together with IL-1beta injection. IL-1beta receptor antagonist blocked IL-1beta- induced hyperalgesic response in the TMJ formalin test. These results suggest that intra-articular injection of IL-1beta facilitated the transmission of nociceptive information in the TMJ area.

Interhemispheric Modulation on Afferent Sensory Transmission to the Ventral Posterior Medial Thalamus by Contralateral Primary Somatosensory Cortex

Single unit responses of the ventral posterior medial (VPM) thalamic neurons to stimulation were monitored in anesthetized rats during activation of contralateral primary somatosensory (SI) cortex by GABA antagonist. The temporal changes of afferent sensory transmission were quantitatively analyzed by poststimulus time histogram (PSTH). Mainly, afferent sensory transmission to VPM thalamus was facilitated (15 neurons of total 23) by GABA antagonist (bicuculline) applied to contralateral cortex, while 7 neurons were suppressed. However, when ipsilateral cortex was inactivated by GABA agonist, musimol, there was significant suppression of afferent sensory transmission of VPM thalamus. This suppressed responsiveness by ipsilateral musimol was not affected by bicuculline applied to contralateral cortex. These results suggest that afferent transmission to VPM thalamus may be subjected to the interhemispheric modulation via ipsilateral cortex during inactivation of GABAergic neurons in contralateral SI cortex.

Synaptic connection and GABA-immunoreactivity of periodontal afferent terminals and their presynaptic endings in the trigeminal motor nucleus of the rat / 대한해부학회지

Periodontal-masseteric reflex is implicated in the control of jaw movement and masticatory force during chewing foods. This study is aimed to investigate the synaptic arrangement of mesencephalic periodontal afferents in the trigeminal motor nucleus and to identify the neurotransmitter involved in the presynaptic control of them through the intra-axonal staining of horseradish peroxidase combined with postembedding immunogold methods. Most of the labeled terminals showed synaptic contacts with the small sized dendritic shafts or distal dendrites, while synaptic contacts with the somata or proximal dendrites were not observed. More than one third of the analyzed labeled boutons received presynaptic input from pleomorphic vesicles containing ending (p-ending). About 11% of labeled boutons showed synaptic triads. All the analyzed boutons made synaptic contacts with one to four neuronal profiles and those showing synaptic contact with five or more were not observed. Labeled terminals were larger than presynaptic p-endings. A large number of the analyzed p-endings showed GABA like immunoreactivity. These observations provide evidence that periodontal afferent terminals show very simple and characteristic synaptic arrangements in the trigeminal motor nucleus and that p-endings presynaptic to them may use GABA as a neurotransmitter for presynaptic inhibition.

Characteristic intracellular response to lidocaine and MK-801 of hippocampal neurons: An in vivo intracellular neuron recording study

This study used in vivo intracellular recording in rat hippocampus to evaluate the effect of lidocaine and MK-801 on the membrane properties and the synaptic responses of individual neurons to electrical stimulation of the commissural pathway. Cells in control group typically fired in a tonic discharge mode with an average firing frequency of 2.4+/-0.9 Hz. Neuron in MK-801 treated group (0.2 mg/kg, i.p.) had an average input resistance of 32.8 +/- 5.7 Mg and a membrane time constant of 7.4 +/- 1. 8 ms. These neurons exhibited 2.4 +/- 0.2 ms spike durations, which were similar to the average spike duration recorded in the neurons of the control group. Slightly less than half of these neurons were firing spontaneously with an average discharge rate of 2.4 +/- 1.1 Hz. The average peak amplitude of the ABP following the spikes in these groups was 7.4+/-0.6 mV with respect to the resting membrane potentiaL Cells in MK-801 and lidocaine treated group (5 mg/kg, i.c.v.) had an average input resistance of 34.5+/-6.0 Mg and an average time constant of 8.0+/-1.4 ms. The cells were firing spontaneously at an average discharge rate of 0.6+/-0.4 Hz. Upon depolarization of the membrane by 0.8 nA for 400 ms, all of the tested cells exhibited accommodation of spike discharge. The most common synaptic response contained an EPSP followed by early-IPSP and late-IPSP. Analysis of the voltage dependence revealed that the early-IPSP and late-IPSP were putative Cl-and K+-dependent, respectively. Systemic injection of the NMDA receptor blocker, MK-801, did not block synaptic responses to the stimulation of the commissural pathway. No significant modifications of EPSP, early-IPSP, or late-IPSP components were detected in the MK-801 and/or lidocaine treated group. These results suggest that MK-801 and lidocaine manifest their CNS effects through firing pattern of hippocampal pyramidal cells and neural network pattern by changing the synaptic efficacy and cellular membrane properties.

The Effect of IGF-1 on ALP Activity of MC3T3-E1 Cell / 대한치주과학회지

Polypeptide growth factors belong to a class of potent biologic mediators which regulate cell differentiation, proliferation, migration and metabolism. IGF-I is polypeptides secreted by skeletal cells and is considered as regulators of bone formation. The purpose of this study is to evaluate the effects of IGF-I on bone nodule formation and alkaline phosphatase activity of MC3T3-E1 cells. MC3T3-E1 cells were seeded at 1x10(4) cells/well, 1x10(5) cells/well in alpha-modified Eagle medium containing 10% fetal bovine serum, 10 mM beta-glycerophosphate and 50microgram/ml of ascorbic acid. Before 48 hours of indicated time, medium were changed with serum free medium. After 24 hours, 0.1, 1, 10 ng/ml IGF-I were added to the cells and cultured for 3, 7, 14, 21, 28 days. And histochemical analysis was done and ALP activity was measured and was expressed as nmol/min/mg of protein. The bone nodule formation in MC3T3-E1 cells of IGF-I was seen at 21, 28 days, but there were no difference between control group and experimental groups. The ALP activity decreased when it is compare to control 2 group except for 1 ng/ml, 10 ng/ml IGF-I of 21-day-groups and 1 ng/ml IGF-I of 28-day-groups. Dose response effects of IGF-I of ALP activity in MC3T3-E1 cells were seen the highest ALP activity at 1ng/ml until 21days and the highest ALP activity at 10 ng/ml of 28 daygroups. The peak times were seen at 7-day group, 14-day group on control group and experimental group respectively, and 1 ng/ml group was the highest ALP activity. From the above results, IGF-I was not seen notable effect on bone nodule formation and decreased ALP activity of MC3T3-E1 cells but the use of IGF-I to mediate biological stimulation of MC3T3-E1 cells shows promise for future therapeutic application.

The Effects of PDGF-BB on the ALP Activity of MC3T3-E1 Cells / 대한치주과학회지

The ultimate aim of periodontal treatment is periodontal regeneration, which necessiates the regeneration of bone tissues. This paper investigated the effect of growth factor on bone cells. Platelet-derived growth factor(PDGF) is the one of the polypeptide growth factor that has been reported as a biological mediator which regulates activities of the cell proliferation, migration and metabolism of undifferentiated mesenchymal cells. The purpose of this study is to evaluate the effects of PDGF on bone nodule formation and ALP activity of MC3T3-E1 cells. Cells were seeded at 1x10(5)cells/well in alpha-modified eagle medium containing 10% fetal bovine serum, 10ml beta-glycerophosphate and 50microgram/ml of ascorbic acid. PDGF 0, 0.1, 1, 10ng/ml were added to the cells at a confluent state and cultured for 3, 7, 14, 21, 28 days. We examined bone nodule formation and alkaline phosphatase activity. The results were as follows: There were bone nodule formation at day 21 both in control and all the experimental groups, and at day 28, all the experimental groups showed much more bone nodules than control groups. Compared to control-1 group, ALP activity was increased in PDGF 0.1ng/ml group and was decreased in 1,10ng/ml PDGF treated groups.(P< 0.05, P< 0.01) Compared to control-2, ALP activity was decreased in all the experimental groups except PDGF 0.1ng/ml in 21 day group. In the time-response effect, ALP activity was increased by the day 14 in all the experimental groups and thereafter ALP activity was decreased.(P<0.05, P< 0.01) In the dose-response effect, ALP activity was decreased as the dose of PDGF was increased, and after 21 day ALP activity was lowest in 1ng/ml group, ALP activity was highest in the day 7 in control group and 0.1ng/ml, 14 day experimental group. In conclusion, PDGF is considered more effective in the proliferation than differentiation of osteoblast-like cells, and it may be useful to study the combined effect of PDGF and other growth factors on osteoblast-like cells.

A Study on Status of Death in Rural Residents / 예방의학회지

A study on the status of death in rural area was conducted during the period from July '75 to August '75. 1,225 families and 8,067 population (4,124 male, 3,943 female) had been lived and 149 events of death since 5 years before study were occurred in survey area, Nammyon, Hwasoongun, chonnam, The summarized results were as follows : 1. Quinquennial death rate was 3.7 (5.2 for male, 2.1 for female). 2. In respect of age group, the highest group was over 70 years old group (age at death, 30.8% of total death). High age groups (over 50 years old) occupied 71.1% of total death and death rate in these groups were higher in male than female. Child death (0-4 years old) occupied 7.4% of total death and infant death rate was higher in female than male. 3. Duration of sickness before die was highest in 1 to 12 months (39.6%). 4. The most frequent cause of death was disease of digestive system (12.1%). Other important causes were disease of circulatory system (10.7%), disease of respiratory system (9.4%) and infectious and parasitic disease (4.7%). Diseases of digestive system was not the most frequent cause of death in male (14.0%) and disease of respiratory system was the most frequent cause in female (9.5%).