Biomedical subjects

C R Hung

Publications and source records attributed to C R Hung.

At least 37 records · Page 2Linked to original sources

PubMed1997

Concentrations of serum interleukin-8 after successful cardiopulmonary resuscitation in patients with cardiopulmonary arrest.

To assess differences in serum interleukin-8 concentrations in resuscitated and nonresuscitated patients after cardiopulmonary resuscitation (CPR), and to compare changes of interleukin-8 levels with hemodynamic variables after restoration of spontaneous circulation, 39 patients with out-of-hospital cardiopulmonary arrest who had undergone CPR were studied. Venous blood samples were taken after CPR and 1 and 2 hours after restoration of spontaneous circulation to measure serum interleukin-8 levels by the enzyme-linked immunosorbent assay method. The median serum interleukin-8 levels after CPR were significantly higher in resuscitated than in nonresuscitated patients (64.9 pg/ml; range 30.2 to 1497 vs 0 pg/ml; range 0 to 31.6 pg/ml; p < 0.001). One and 2 hours after restoration of spontaneous circulation, the median serum interleukin-8 levels were 96.2 pg/ml and 155.4 pg/ml, respectively. Mean values of systolic blood pressure immediately after and 1 and 2 hours after restoration of spontaneous circulation were 117 +/- 9 mm Hg, 130 +/- 11 mm Hg, and 136 +/- 13 mm Hg, respectively. No significant correlations were found between hemodynamic values and serum interleukin-8 levels. In conclusion, successful initial resuscitation was associated with increased serum interleukin-8 concentrations. The interleukin-8 levels remained at high values 2 hours after restoration of spontaneous circulation.

Adult↗

PubMed1997

Simulatory effect of porcine insulin on noradrenaline secretion in guinea-pig ileum myenteric nerve terminals.

1. The effect of insulin on the release of noradrenaline (NA) from nerve terminals was investigated in isolated ileal synaptosomes of guinea-pig. Release was determined as the amount of NA, quantified by h.p.l.c.-electrochemical detection, from samples incubated with insulin minus that in parallel blanks treated with some volume of vehicle. 2. Porcine insulin stimulated the secretion of NA in a concentration-dependent manner from 0.01 i.u. ml-1, while the value of lactate dehydrogenase in the incubated medium was not influenced by insulin. 3. The presence of insulin receptors in this preparation was illustrated by immunoblotting with insulin receptor monoclonal antibodies. 4. The release of NA by insulin was reduced by guanethidine and bretylium and it was markedly lowered in the samples obtained from guinea-pigs that had received an intraperitoneal injection of DSP-4, the noradrenergic neurotoxin. 5. Tetrodotoxin attenuated the action of insulin at concentrations sufficient to block sodium channels. The depolarizing effect of insulin on the membrane potential was also illustrated by a concentration-dependent increase in the fluorescence of bisoxonol, a potential-sensitive dye. 6. The action of insulin was attenuated by removal of calcium chloride from the bathing medium. The induction of calcium ion influx by insulin into the synaptosomes is supported by the inhibitory effects of the calcium channel blockers omega-conotoxin GVIA (for the N-type channels) and nifedipine (for the L-type channels). 7. These findings suggest that insulin can stimulate NA release from noradrenergic terminals via activation of calcium influx.

Adrenergic Agents↗

PubMed1997

Acid-induced gastric damage in rats is aggravated by starvation and prevented by several nutrients.

The aggravation of acid-induced gastric damage and its prevention by glucose, ascorbate or glutathione precursors was studied in fed and food-deprived rats. The stomachs of fed rats and those starved for 1, 3 or 5 d were vagotomized just before irrigating for 3 h with solutions containing 0-150 mmol HCI/L. Mucosal glutathione, mucus, lipid peroxides and acid back-diffusion were measured. Stomach ulcers were evaluated by morphological and histological examination. The preventive effects of glucose, ascorbate and a mixture of L-glutamine, L-glycine and L-cysteine were evaluated in the stomachs of rats that were starved for 5 d, vagotomized, then perfused for 3 h with 100 mmol HCI/L. Greater acid back-diffusion and ulcer formation, and lower glutathione and mucus levels in starved rats were dependent on the duration of starvation and luminal acidity. Increased acid back-diffusion and decreased glutathione and mucus production were negatively correlated (r < -0.80, P < 0.05) with ulcer formation. A significant enhancement in mucosal lipid peroxide concentration and serious damage of forestomach and corpus mucosal cells were observed in starved rats exposed to 100 mmol HCI/L. These ulcerogenic factors were effectively inhibited in acid-perfused stomachs of food-deprived rats by daily intraperitoneal injection of the amino acid mixture (150 mg/kg) or by an average daily consumption via drinking water of glucose (10 g) or ascorbate (1.2 g). Starvation aggravated acid-induced gastric damage and was associated with greater acid back-diffusion and oxygen radical generation, and lower mucosal glutathione and mucus production.

Amino Acids↗

PubMed1997

Radiofrequency catheter modification of sinus node for inappropriate sinus tachycardia: a case report.

We present here, the case of a 22-year-old male suffering from persistent tachycardia for the past 3 years. His resting pulse rate was rarely below 100 beats/min, and it frequently increased to as high as 150 beats/min even after a minimal of activity. Associated symptoms included palpitation, chest tightness, dyspnea and presyncope, either during rest or with exercise. Propranolol and verapamil could not control the tachycardia. The application of radiofrequency energy to an area in the superior right atrium that demonstrated a discrete electrogram with earliest endocardial activation during tachycardia resulted in a decrease in sinus rate from 120 beats/min to 70 beats/min. Follow-up on Holter monitor, performed one month later, demonstrated an average heart rate of 84 beats/min (range 60-125). In exercise tolerance test, the patient exercised for 9 minutes, achieving a maximum heart rate of 140 beats/min. This patient remained asymptomatic without any antiarrhythmic drug during the 3-month follow-up period. Medical management in case of patients showing disabling inappropriate sinus tachycardia refractory, sinus node modification could be considered as an suitable alternative to complete atrioventricular junctional ablation.

Adult↗

PubMed1996

Malalignment-type ventricular septal defect in double-chambered right ventricle.

Double-chambered right ventricle (DCRV) is commonly associated with ventricular septal defect (VSD). In this study, an assessment was made of the relevance of a malalignment-type VSD to hemodynamic and morphologic features in DCRV. During an 8.5-year period, 53 patients with DCRV were enrolled after study with echocardiography, catheterization, and angiography. Patients were divided into 2 groups: group I included 40 patients, aged 3.7 +/- 3.2 years, with a malalignment-type VSD; group II consisted of 13 patients, aged 8.6 +/- 2.7 years, without a malalignment-type VSD. History of congestive heart failure in infancy was present in 21 group I and 2 group II patients (53% vs 15%, respectively, p <0.05). The mean pulmonary-to-systemic flow ratio was significantly higher in group I than in group II (1.89 +/- 0.74 vs 1.14 +/- 0.21, respectively, p <0.05). The mean pressure gradient across the right ventricular outflow tract was lower in group I than in group II (41 +/- 16 vs, 73 +/- 33 mm Hg, respectively, p <0.05). Among 42 patients who had a series of echocardiograms recorded, progression of pressure gradient was evident in 35: 28 in group I and 7 in group II. A subaortic ridge was present exclusively in 29 group I patients (73%). Prolapse of the aortic valve was present in 26 (49%): 20 group I (50%) and 6 group II (46%) patients. Aneurysm formation of the septal defect was found in 17 (43%) and 7 (54%) group I and II patients, respectively. It can be concluded that a history of congestive heart failure was more common in DCRV patients with a malalignment-type VSD. Malalignment-type VSD is significantly associated with a larger pulmonary-to-systemic flow ratio and subaortic ridge.

Adolescent↗

PubMed1996

Anomalous pulmonary venous pathway traversing pulmonary parenchyma. Diagnosis and implication.

STUDY OBJECTIVES: To describe four patients having total anomalous pulmonary venous connection with an intrapulmonary vertical vein, rendering difficulty in diagnosis and surgery. SETTING: a tertiary referral center. PATIENTS AND METHODS: By reviewing medical records, 4 of 25 patients with right atrial isomerism and total anomalous pulmonary venous connection were identified to have an intrapulmonary vertical vein. All four patients underwent echocardiography, catheterization, and angiography. One underwent MRI. Two underwent open-heart surgery and one received a modified Blalock-Taussig shunt. RESULTS: Right atrial isomerism was present in all four patients. On chest x-ray films, an abnormal shadow resembling scimitar syndrome was seen in two patients. Imaging the vertical vein was unsuccessful with an echocardiogram in all four patients. The intrapulmonary course of the vertical vein was depicted with a pulmonary venogram in two patients and with magnetic resonance in one patient. The intrapulmonary segment remained undetected until autopsy in one patient. All four patients died. At autopsy, the pulmonary venous confluence was hypoplastic in all four hearts. The vertical vein was buried in pulmonary parenchyma and drained to superior vena cava with significant obstruction. CONCLUSION: In the presence of right atrial isomerism and total anomalous pulmonary venous connection, there may be an intrapulmonary pulmonary venous connection that may be obstructed. Anastomosing the pulmonary venous confluence to the atrium may be difficult because of hypoplasia of the pulmonary venous confluence.

Anastomosis, Surgical↗

PubMed1995

Surgical treatment of complete atrioventricular septal defect associated with tetralogy of Fallot.

The combination of complete atrioventricular septal defect (AVSD) and tetralogy of Fallot (TF) was reported to occur in less than 2% of patients undergoing repair of TF. From September 1981 to November 1989, five consecutive patients with such combination underwent total correction at National Taiwan University Hospital. Their age ranged from 3.8 years to 6.3 years. Two cases were associated with Down's syndrome. All interventricular communications were repaired by combined transatrial and transventricular approach and a separate pericardial patch was used to repair the interatrial communication. The transannular patch (TAP) was not used in one case; of the four cases with TAP, a pericardial monocusp was mounted in one of them. There was one hospital mortality, and one late death. Both were related to intractable right heart failure. We conclude that total repair of this anomaly could be accomplished after 3 years of age provided there is thorough awareness of anatomical features and avoidance of right heart failure.

Child↗

PubMed1995

The involvement of metabotropic glutamate receptors in long-term depression of N-methyl-D-aspartate receptor-mediated synaptic potential in the rat hippocampus.

The frequency-dependent long-term modifications of pharmacologically isolated N-methyl-D-aspartate (NMDA) receptor-mediated excitatory postsynaptic potential (EPSPNMDA) was studied. Intracellular recordings were obtained from CA1 cells of rat hippocampal slices and in the presence of 6-cyano-7-nitroquinoxaline-2,3-dione (10 microM) and bicuculline (20 microM) which block non-NMDA and GABAA receptors, respectively. Low-frequency stimulation at 5 Hz resulted in a long-term depression (LTD) of EPSPNMDA in 12 of 17 cells. However, when the stimulus frequency was increased to 30 Hz, a long-term potentiation (LTP) of EPSPNMDA was observed in 7 out of 9 cells. The LTD was not affected by pretreating the slices with okadaic acid (0.5-1 microM) suggesting that activation of endogenous protein phosphatase is not responsible for this process. In the presence of L-2-amino-3-phosphonopropionic acid (50 microM) or (RS)-alpha-methyl-4-carboxyphenylglycine (200 microM), 5 Hz tetanization resulted in LTP instead of LTD. These results suggest that activation of metabotropic glutamate receptor (mGluR) is necessary for the induction of EPSPNMDA LTD and blockade of mGluR unmasks a LTP.

Animals↗

PubMed1995

Evolution of coronary artery pattern according to short-axis aortopulmonary rotation: a new categorization for complete transposition of the great arteries.

OBJECTIVES: We studied the correlation between coronary artery pattern and aortopulmonary rotation in complete transposition of the great arteries. BACKGROUND: Classifications of the coronary arteries in complete transposition are puzzling and incomplete. METHODS: Coronary artery anatomy and relation of the great arteries were identified at angiography, echocardiography, surgical intervention or autopsy in 76 patients with complete transposition from 1988 to 1993. Five main types (type 0 and Shaher types 1,2,4 and 9) and their similar variants of epicardial configuration were categorized into five patterns (O, I, II, IV and IX). In addition, data from 568 cases from published reports were collected for analysis. RESULTS: As the aorta rotated from a left anterior to a directly anterior location relative to the pulmonary trunk, the left anterior descending coronary artery arose from the left-hand sinus together with the right coronary artery (type 0, one case decreased to no cases); then it gradually shifted to the left to have the same origin as the left circumflex coronary artery from the right-hand sinus (type 1, 10 cases increased to 146, p < 0.0003). When the aorta rotated farther clockwise from directly anterior to right anterior (type 1, 146 cases increased to 235; type 2, 9 cases increased to 50, p < 0.0006) or from right anterior to right lateral (type 1, 235 cases decreased to 6 cases; type 2, 50 cases decreased to 20, p < 0.00000), the left circumflex coronary artery tended to move retropulmonically and originated from the left-hand sinus with the right coronary artery (type 2). When the aorta moved from right anterior to right lateral (type 2, 50 cases decreased to 20; type 4, 13 cases increased to 14, p < 0.031) or from right lateral to right posterior (type 2, 20 cases decreased to 1; type 4, 14 cases increased to 16, p < 0.0003), the right coronary artery shifted to the right-hand sinus anteaortically to join the left anterior descending coronary artery (type 4). Finally, the left anterior descending coronary artery combined with the left circumflex coronary artery (type 9, 12 cases increased to 21, p = 0.407) to become the usual pattern for normally related great arteries. Eta-square analysis showed that the evolution from pattern O to IX was dependent on clockwise aortopulmonary rotation. CONCLUSIONS: The coronary arteries in complete transposition of the great arteries can be classified into five patterns and their evolution deduced on the basis of aortopulmonary rotation. Dependence of coronary artery type on aortopulmonary rotation made it possible to anticipate the coronary pattern from the relation of the great arteries in transposition.

Adolescent↗

PubMed1995

Role of acid back-diffusion in the formation of mucosal ulceration and its treatment with drugs in diabetic rats.

We have studied the role of acid back-diffusion in the formation of gastric mucosal ulceration and its treatment with several drugs in streptozotocin-induced diabetic rats. After vagotomy, the stomach of 1-8 week-old diabetic rats and age-matched control rats were irrigated with acid solutions of graded concentrations (50-150 mm HCl) for 1 or 3 h. A marked increase in acid back-diffusion and in haemorrhagic ulceration was found in diabetic rats. The extent of acid back-diffusion and the severity of mucosal ulceration were dependent on the concentration and the time of contact of acid solutions with the gastric mucosa. A high correlation (r = 0.9227) between acid back-diffusion and mucosal ulceration was found in 3-h acid-irrigated diabetic rats. In the 2-week diabetic rat, intragastric cimetidine (300 mg kg-1) or NaHCO3 (52 mg kg-1) significantly (P < 0.05) reduced both acid back-diffusion and haemorrhagic ulcer formation, while atropine (1.0 mg kg-1) or bupivacaine (0.5%, 0.4 mL/rat) was ineffective. High blood glucose levels in diabetic rats were not influenced by these agents. Acid back-diffusion and ulceration in the diabetic rat were markedly reduced by daily administration but not single injection of insulin (50 units kg-1, s.c.). Taken together, in the early stage of diabetes development, chronic insulin deficiency rather than nerve degeneration or hyperglycaemia may be responsible for the disruption of mucosal barriers. It is concluded that acid back-diffusion played an important role in the formation of acute haemorrhagic ulceration that can be inhibited by intragastric cimetidine, NaHCO3 or daily injection of insulin.

Animals↗

PubMed1995

Prophylactic effects of sucralfate and geraniin on ethanol-induced gastric mucosal damage in rats.

The aim is to study the protective effects of topical sucralfate and geraniin on acidified ethanol (EtOH dissolved in 100 mM HCI plus 54 mM NaCl)-induced gastric acid back-diffusion, mucus production and mucosal ulcerations in the rat. After irrigation the stomach with acidified EtOH (10-40% v/v) for 3 hrs, a concentration-dependent increase in acid back-diffusion and in mucosal lesions, and -dependent reduction in mucus production was found. These ulcerogenic effects of EtOH were dose-relatedly inhibited by pretreatment of intragastric sucralfate (10-200 mg/kg). A high correlation (r = -0.9572) between sucralfate-induced inhibition in acid back-diffusion and -induced reduction in mucosal ulceration provoked by 30% EtOH was observed. Geraniin (10-100 mg/kg), given 30 min prior to EtOH perfusion, produced potent inhibitory effects on those ulcerogenic parameters provoked by EtOH in a dose-dependent manner. The correlation (r = -0.8638) between geraniin-induced inhibitions in acid back-diffusion and in mucosal ulceration produced by EtOH was achieved. These cytoprotective effects of sucralfate and geraniin were further confirmed by morphological and histological studies. The results suggested that the protective effects of sucralfate and geraniin on gastric mucosa against acidified EtOH-induced damage are at least partly through the inhibition in acid back-diffusion and the elevation of gastric mucus production.

Animals↗

PubMed1994

Usefulness of magnetic resonance imaging in the assessment of venoatrial connections, atrial morphology, bronchial situs, and other anomalies in right atrial isomerism.

Multiple complex venous and intracardiac anomalies are frequently seen in patients with right atrial isomerism, and complete anatomic information may not always be obtained from combined echocardiography and angiography. Twenty patients with right atrial isomerism were prospectively studied with use of magnetic resonance imaging (MRI); satisfactory imaging was obtained in 18 patients, aged 6 days to 12 years (median 3 months). All patients had undergone echocardiography, cardiac catheterization, and angiocardiography. The purpose of this study was to assess the usefulness of MRI in the evaluation of venoatrial connections, atrial morphology, bronchial situs, and additional anomalies. Bilateral superior venae cavae were documented in 12 patients and anomalous hepatic venous drainage in 11. The pulmonary venous system was imaged in all 18 patients, of whom 12 had total anomalous pulmonary venous connection: 9 supracardiac, 2 infracardiac, and 1 mixed type. Some obstruction to pulmonary venous return was present in 9 of the 12 patients, and the site of obstruction was demonstrated by MRI in 6. Bilateral morphologic right atrial appendages were imaged in 7 patients. Bilateral morphologic right bronchi were identified in 17 patients, asplenia was confirmed in 17 of 18 patients by the absence of splenic tissue on imaging, and hiatal hernia was imaged in 4. Compared with angiography and echocardiography, MRI more clearly defined the pulmonary venous connections in 10 patients with pulmonary venous obstruction. Anomalous hepatic venous connections were better defined by MRI in 2. Therefore, MRI provided valuable supplementary information on the cardiovascular and visceral anomalies in these patients.

Abnormalities, Multiple↗

PubMed1994

Valproic acid suppresses the synaptic response mediated by the NMDA receptors in rat amygdalar slices.

The mechanism of action of the anticonvulsant drug valproic acid (VPA) was studied in rat amygdaloid slices using intracellular recording techniques. In the presence of bicuculline (20 microM), stimulation of the endopyriform nucleus evoked an excitatory postsynaptic potential (EPSP) followed by a paroxysmal depolarizing shift (PDS). Superfusion of VPA (2 mM) reversibly suppressed the PDS. Synaptic response mediated by the N-methyl-D-aspartate (NMDA) receptors (EPSPNMDA) was isolated pharmacologically by application of a solution containing nonNMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and gamma-aminobutyric acid receptor antagonist bicuculline (20 microM). VPA (0.2-10 mM) reversibly reduced the amplitude of the EPSPNMDA in a dose-dependent manner. Higher concentration of VPA (10 mM), in addition, suppressed the normal synaptic transmission. These results suggest that VPA's anticonvulsant effect is due, at least in part, to its blocking action on the EPSPNMDA.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1994

Protective effects of arginine-vasopressin on aspirin-induced gastric mucosal damage in anaesthetized dogs.

The protective effects of graded doses of arginine-vasopressin (AVP) on acidified acetylsalicylic acid (ASA) solution-induced changes in gastric prostaglandin E2 (PGE2) secretion, mucus production, acid back-diffusion and mucosal damage were studied in the bilateral truncal vagotomized stomach of anaesthetized dogs. After 1-4 h intragastric irrigation of the stomach with AVP (1-100 ng kg-1) plus 20 mM acidified ASA solution, a significant (P < 0.05) inhibition in gastric mucosal lesions and acid back-diffusion produced by acidified ASA solution was observed. The reduction in the gastric PGE2 secretion and in mucus production provoked by the same dose of acidified ASA solution was also diminished. Furthermore, a correlation (r = 0.883; P < 0.01) between AVP-induced inhibition in ASA-provoked reduction in gastric PGE2 secretion and in mucus production was found. During the experiment, the heart rate, the peripheral arterial blood pressure and the gastric arterial blood pressure were not altered by AVP (1-100 ng kg-1). Thus, intragastric AVP protects gastric mucosa against ASA-induced damage without producing cardiovascular side effects. The inhibitory effects of AVP (100 ng kg-1) on acidified ASA-induced reduction in PGE2 and mucus secretion, as well as on ASA-induced enhancement in acid back-diffusion and erosion production were dose-dependently reversed by a specific V1 antagonist, 1-(beta-mercapto-beta,beta-cyclopenta-methylene-propionic acid), 2-(o-methyl)tyrosine-Arg8-vasopressin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Betel quid chewing damaged gastric mucosa: protective effects of cimetidine and sodium bicarbonate.

The effects of cimetidine and NaHCO3 on gastric acid back-diffusion (either the H+ loss or the Na+, K+ and CA++ gain in the gastric lumen) and mucosal ulceration were studied in rats with chronic feeding of betel quid chewing (BQC)- or its individual component-containing food. After 30 and 90 days of feeding, the animal was fasted for 24 hrs and vagotomized. An acid solution (100 mM HCl plus 54 mM NaCl) with or without drugs was irrigated in the rat stomach for 3 hrs. The results indicated that BQC and its individual component produced a variety of change in enhancement in acid solution-induced acid back-diffusion and mucosal hemorrhagic ulceration but in decrease of gastric mucus secretion. These parameters were dose-dependently reversed by intragastric cimetidine (50-300 mg/kg) in BQC-treated rats. Similar but lesser effect than cimetidine (300 mg/kg) was obtained by intragastric administration of NaHCO3 (52 mg/kg). It is concluded that in BQC- or its component-feeding rats, the enhancement in acid back-diffusion and the reduction in mucus secretion are at least in part responsible for the formation of hemorrhagic ulceration which can be inhibited by intragastric cimetidine or NaHCO3.

Animals↗

PubMed1993

Diagnostic accuracy of transesophageal echocardiography for detecting left atrial thrombi in patients with rheumatic heart disease having undergone mitral valve operations.

Transesophageal echocardiography (TEE) has emerged as an efficient method for detecting left atrial (LA) thrombi in recent years, but its accuracy has not been fully evaluated. A prospective clinicopathologic study in 213 consecutive patients with chronic rheumatic mitral valve disease over a period of 39 months was undertaken. All patients underwent open heart surgery within 3 days after the TEE study. The presence or absence of LA thrombi was confirmed at surgery by direct inspection of the left atrium and proven by histopathologic examination. Of the 213 patients, 147 had predominant mitral stenosis, and the remaining 66 patients had significant mitral regurgitation. Twenty-eight patients had LA thrombi by TEE criteria. These findings were all confirmed at surgicopathologic studies (specificity 100%). However, in 2 patients, LA thrombi were present but could not be detected by TEE (sensitivity 93.3%). Therefore, the positive predictive value was 100%, the negative predictive value was 98.9% and the diagnostic accuracy was 99.1%. No thrombi were found in patients with significant mitral regurgitation. The frequency of LA thrombi in patients with predominant mitral stenosis was 20% (30 of 147), and most of these patients had chronic atrial fibrillation (28 of 30, 93%). Only 16 patients (16 of 30, 53%) were found to have LA thrombi by transthoracic echocardiography. Furthermore, our data showed poor correlation between the echogenicity of LA thrombi and the degree of thrombus organization. Thus, TEE is excellent for detecting LA thrombi in patients with rheumatic heart disease severe enough to warrant mitral valve operations.

Adolescent↗

PubMed1993

Double-inlet ventricle in Chinese patients.

This study was performed to elucidate the anatomic features of double-inlet ventricle in the Chinese population. The echocardiograms of 60 Chinese patients diagnosed as having double-inlet ventricle were reviewed and analyzed. Both atria were connected to a dominant right ventricle in 36 patients (60%), to a dominant left ventricle in 17 (28%) and to an indeterminate ventricle in 7 (12%). Right atrial isomerism was present in 30 patients (83%) with double-inlet right ventricle, in 5 (29%) with double-inlet left ventricle, and in 6 (86%) with double-inlet indeterminate ventricle. Right atrial isomerism was more frequently associated with double-inlet right and indeterminate ventricles (p < 0.01; chi-square). Common atrioventricular valve was frequently present in both double-inlet right and indeterminate ventricles. Double-outlet main chamber was the predominant type of ventriculoarterial connection in double-inlet right and indeterminate ventricles. Total anomalous pulmonary venous connection was found exclusively in 9 patients with right atrial isomerism (5 with double inlet right and 4 with double-inlet indeterminate ventricles). In contrast to other reports, this series found double-inlet right ventricle to be the predominant type of double-inlet ventricle. This discrepancy may be due to a greater prevalence of right atrial isomerism that is usually associated with double-inlet right ventricle in Chinese patients.

Child↗

PubMed1993

Use-dependent modification of a slow NMDA receptor-mediated synaptic potential in rat amygdalar slices.

A single stimulus applied to the endopyriform nucleus evoked in 35 of the 101 basolateral amygdaloid (BLA) neurons a slow excitatory postsynaptic potential (s-EPSP) of varying latencies. The s-EPSP could be graded by changing the stimulus intensity and, on reaching the threshold, triggered action potentials. At stimulus intensity just subthreshold for evoking a spike, the s-EPSP has an average amplitude of 16.3 +/- 1.4 mV, a time to peak of 25.7 +/- 3.8 ms, and a duration of 124 +/- 14 ms. The s-EPSP was reversibly blocked by DL-2-amino-5-phosphonovaleate (DL-APV) or ketamine, indicating its mediation through N-methyl-D-aspartate (NMDA) receptor activation. However, the s-EPSP was not able to follow stimulus frequency of 1 Hz, suggesting that APV-sensitive s-EPSP is probably generated by a polysynaptic pathway. The s-EPSP was greatly enhanced by synaptic stimulation in the presence of bicuculline or in Mg(++)-free solution leading to the genesis of paroxysmal depolarizing shift (PDS). The s-EPSP can undergo robust long-term potentiation (LTP) following tetanic stimulation. These results suggest that the NMDA receptor-mediated s-EPSP may play an important role in epileptogenesis and synaptic plasticity in the amygdala.

2-Amino-5-phosphonovalerate↗