Myocardial necrosis depth prediction during extracellular photosensitization reaction of talaporfin sodium by defined index using fluorescence measurement.

An application of photodynamic therapy for myocardial ablation, which would induce myocardial electrical conduction block, is proposed. For the proposed application, an extracellular photosensitization reaction (PR) is performed while photosensitizer is distributed in myocardial interstitial space by employing a short drug-light interval. Because the myocardial necrosis depth must be accurately controlled to prevent surrounding tissue injury during the myocardial ablation procedure, the necrosis depth during PR needs to be predicted. The purpose of this study is to investigate the availability of predicting PR-induced myocardial necrosis depth (d(nec)) using a defined fluorescence-fall amount (FA), which is the calculated result of fluorescence intensity decrease from the start of the PR multiplied by irradiation duration and corresponds to photosensitizer consumption amount under an assumption that the photosensitizer consumption rate is faster than the photosensitizer supply rate. The correlation between FA and d nec was experimentally investigated in vivo using an open-chested canine heart model with 2.5 and 5.0 mg/kg of talaporfin sodium at an irradiance of 5-20 W/cm(2) for 5-20 s. The fluorescence measurement was performed at a wavelength of 710 nm during the PR to derive FA. One week after the PR, a uniform necrosis depth was measured histopathologically as d(mnec). A logarithmic correlation between d(mnec) and FA was confirmed with R(2) = 0.69-0.80 and a d(mnec) range of 0.2-7.1 mm. The defined FA might be useful for predicting d nec for the extracellular PR in myocardium when using talaporfin sodium.

Circulating fibrocytes are increased in children and young adults with pulmonary hypertension.

Chronic inflammation is an important component of the fibroproliferative changes that characterise pulmonary hypertensive vasculopathy. Fibrocytes contribute to tissue remodelling in settings of chronic inflammation, including animal models of pulmonary hypertension (PH). We sought to determine whether circulating fibrocytes were increased in children and young adults with PH. 26 individuals with PH and 10 with normal cardiac anatomy were studied. Fresh blood was analysed by flow cytometry for fibrocytes expressing CD45 and procollagen. Fibrocyte numbers were correlated to clinical and haemodynamic parameters, and circulating CC chemokine ligand (CCL)2 and CXC chemokine ligand (CXCL)12 levels. We found an enrichment of circulating fibrocytes among those with PH. No differences in fibrocytes were observed among those with idiopathic versus secondary PH. Higher fibrocytes correlated to increasing mean pulmonary artery pressure and age, but not to length or type of treatment. Immunofluorescence analysis confirmed flow sorting specificity. Differences in plasma levels of CCL2 or CXCL12, which could mobilise fibrocytes from the bone marrow, were not found. We conclude that circulating fibrocytes are significantly increased in individuals with PH compared with controls. We speculate that these cells might play important roles in vascular remodelling in children and young adults with pulmonary hypertension.

Cor triatriatum sinister: an incidental finding in a patient with paroxysmal atrial fibrillation.

A 58-year-old male was referred for catheter ablation for atrial fibrillation. He was incidentally diagnosed with cor triatriatum sinister by preoperative transesophageal echocardiography and cardiovascular computed tomography. The patient has since been free from atrial fibrillation for over 24 months following successful electrical pulmonary vein isolation. The rapidly soaring number of cases undergoing catheter ablation for atrial fibrillation and imaging investigation prior to the procedure may increase the incidental detection of asymptomatic congenital heart diseases.

Determination of refractory periods and conduction velocity during atrial fibrillation using atrial capture in dogs: direct assessment of the wavelength and its modulation by a sodium channel blocker, pilsicainide.

OBJECTIVES: The purposes of this study were to measure the atrial refractory period and the conduction velocity (CV) during atrial fibrillation (AF) and to explore the antiarrhythmic mechanism of a sodium channel blocker, pilsicainide, during AF. BACKGROUND: Sodium channel blockers not only decrease the CV, but also prolong the atrial refractory period, particularly during rapid excitation. Because these effects on the wavelength are counteractive and rate dependent, it is critical to measure these parameters during AF. METHODS: In eight dogs, after AF was induced under vagal stimulation, a single extra-stimulus was repeatedly introduced from the left atrium and its capture was statistically determined for each coupling interval. The local CV was also measured during constant capture of the fibrillating atrium by rapid pacing. The same procedure was repeated after pilsicainide administration. RESULTS: Pilsicainide significantly increased the mode of AF intervals from 81 +/- 10 to 107 +/- 16 ms (p < 0.01). While the CV was decreased from 0.9 +/- 0.1 to 0.7 +/- 0.1 m/s (p < 0.02), the effective refractory period during AF was increased from 69 +/- 11 ms to 99 +/- 17 ms (p < 0.01). As a result, the wavelength was significantly increased by pilsicainide from 6.6 +/- 0.9 to 7.6 +/- 1.2 cm (p < 0.05). CONCLUSIONS: During AF, whereas the sodium channel blocker pilsicainide decreases CV, it lengthens the wavelength by increasing the refractory period, an action that is likely to contribute to the drug's ability to terminate the arrhythmia. The direct measurement of refractoriness and CV during AF may provide new insights into the determinations of the arrhythmia and antiarrhythmic drug action.

Diagnostic value of a bedside test for cardiac troponin T in the patient with chest pain presenting to the emergency room.

Identification of patients with acute chest pain due to acute coronary syndrome is a common and difficult challenge for emergency physicians. A prospective study was conducted to assess the diagnostic value of a bedside test of cardiac troponin T in the emergency room setting. Forty-nine consecutive patients, who visited the emergency room within 6 hours of the onset of acute chest pain, were enrolled. Of the 26 patients who were ultimately diagnosed as having acute coronary syndrome, seven patients (27%) had positive cardiac troponin T assay results, whereas none of the patients without acute coronary syndrome had positive results (0%). For patients with acute coronary syndrome who presented later than 3 hours after the onset (n = 4), the test was positive in all cases (positive predictive value: 100%, negative predictive value: 100%, p < 0.01). However, the positive rate was only 14% for those who presented earlier than 3 hours after the onset (n = 22) (positive predictive value: 100%, negative predictive value: 47%, p = 0.84). In conclusion, bedside troponin T test results should be evaluated considering the time interval from the onset of chest symptoms.

A case of traumatic shock complicated by methamphetamine intoxication.

A case of a 38-year-old male with traumatic shock complicated by methamphetamine intoxication is presented. The patient was involved in an assault which resulted in cardiac tamponade and right ventricular outflow laceration. Pericardiocentesis was immediately performed. However, profound metabolic acidosis greatly in excess of that expected from the short duration of the shock was revealed by arterial blood gas analysis. Another cause of the metabolic acidosis was suspected. The patient subsequently admitted to intravenous use of methamphetamine. Following hemodynamic and metabolic stabilization by continuous pericardial drainage and intravenous administration of sodium bicarbonate, the patient underwent cardiac surgery. His postoperative course was uneventful. There is a substantial association between methamphetamine users and traumatic accidents. In such cases, early identification of drug use is important. Marked metabolic acidosis, which conflicts with the diagnosed cause of shock, may be a clinical clue to methamphetamine intoxication.

Recovery of electrophysiological parameters after conversion of atrial fibrillation.

We investigated the recovery of electrophysiological parameters from electrical remodeling after conversion of chronic lone atrial fibrillation in humans. Clinical studies have shown that the longer atrial fibrillation lasts, the more difficult it becomes to maintain the sinus rhythm after cardioversion. To explore the effects of the duration of atrial fibrillation on changes of electrophysiological parameters after conversion, we determined the atrial effective refractory period and P wave duration during right atrial pacing at 1 and 24 h after electrical cardioversion in 15 patients with chronic lone atrial fibrillation (median duration, 6 months). By 24 h after cardioversion, the effective refractory period at a pacing cycle length of 600 ms increased from 225+/-19 to 254+/-27 ms. However, the P wave duration did not decrease significantly 24 h after conversion. As the duration of atrial fibrillation became longer, the prolongation of effective refractory period was more delayed (P<0. 001, r=0.82), and the shortening of P wave duration was significantly smaller within 24 h after cardioversion (P<0. 001, r=0.67). After cardioversion of chronic lone atrial fibrillation, the recovery of shortened atrial refractoriness and prolonged intraatrial conduction time is dependent on the duration of preexisting atrial fibrillation.

Genetic Variations Revealed by Microsatellite Markers ina Small Population of the Sika Deer (Cervus nippon)on Kinkazan Island, Northern Japan.

Genetic variations within a population of the Japanese sika deer, Cervus nippon, on Kinkazan Island were studied by microsatellite analysis. Seventeen pairs of polymerase chain reaction primers designed for several species of ungulates successfully amplified polymorphic microsatellite DNA in sika deer. About 20% of the Kinkazan population was sampled and genotyped for nine diagnostic microsatellite loci. Alleles at those loci in the Kinkazan population were found to be under the Hardy-Weinberg equilibrium. To determine whether the Kinkazan deer have a reduced level of genetic variability, an average heterozygosity in the population was calculated and compared with the values determined for other populations from Hyogo, Yamaguchi, Shimane, Tsushima, and Nagasaki. Neither the observed nor the expected heterozygosity in the Kinkazan deer significantly differed from that in the other populations. Our result indicated that, despite its small population size, the Kinkazan deer preserve extensive microsatellite variations.

Histological difference between retrograde corpora lutea of pregnancy and those of estrus in sika deer, Cervus nippon.

Histological characteristics of retrograde corpora lutea (RCL) were examined for 105 pairs of ovaries of adult female sika deer, Cervus nippon. Animals were captured in various seasons at Mt. Goyo, Iwate Prefecture, the northern part of Japan. No histological differences were recognizable between RCL of pregnancy and retrograde accessory corpora lutea (RACL), so far as examined by means of hematoxylin-eosin and Weigert's resorcin-fuchsin staining. They were both irregularly shaped and had well developed arteries in their thick capsules and a number of small arteries in the parenchyma. These arteries showed the proliferation of elastic fibers showing elastosis in older RCL. The total number of these retrograded bodies per female increased with age, suggesting that both the retrograded bodies would retain in the ovaries over 7 years. RCL of estrus were small hyaline bodies scattered with some degenerated luteal cells in the hyaline matrix. They were distinguishable from those of pregnancy since the capsule and parenchyma in those of estrus were poorer in blood vessels. RCL of estrus appeared in October and November but were rarely seen in February and March, suggesting that they will disappear within three months after ovulation.

Validity of retrograde corpora lutea of pregnancy as an index of past gestation in Sika deer, Cervus nippon.

Corpora lutea of the sika deer (Cervus nippon, Cervidae) were histologically examined in order to elucidate their retrograding processes after parturition. They showed a remarkable regression within one month as luteal cells decreased in number and, by nine months after parturition, turned into masses of blood vessels containing many arterioles with a diameter of 30 microns or less. In retrograde corpora lutea (RCL), older than 1.5 years after parturition, arterioles of these dimensions decreased markedly, while those measuring 50 microns or more became dominant. These findings indicate that an examination of RCL can distinguish females less than nine months after parturition from those more than 1.5 years after parturition. Based on the findings of RCL from the ovaries of a 10.5-year-old female, it is suggested that RCL remain in the ovaries for at least 8.5 years after parturition. It was, however, difficult to distinguish RCL of pregnancy from retrograde accessory corpora lutea (RACL). In order to arrive at a complete count of RCL, the ovaries should be examined at thicknesses of 0.5 mm. To check the presence/absence of RCL of pregnancy within nine months or less after parturition, sectioning at thicknesses of 2 mm is sufficient.

[Determination of 2,4,6-tri-tert-butylphenol and related compounds in foods].

An analytical method has been developed for the determination of 2,4,6-tri-tert-butylphenol (TTBP) in foods. TTBP was determined by GC/MS (SIM) after extraction from food samples using a steam distillation technique. The developed method was able to determine simultaneously 2,4-di-tert-butylphenol (2,4-DTBP), 2,6-di-tert-butylphenol (2,6-DTBP), 3,5-di-tert-butylphenol (3,5-DTBP) and 2,4-di-tert-pentylphenol (2,4-DTPP). The method was applied to analyze the residues of the 5 phenolic compounds in 101 food samples purchased from markets. TTBP was found in some samples of meat, liver and fish (muscle) at the levels of trace (tr)-0.50 ng/g, tr and tr-1.83 ng/g, respectively. 2,4-DTBP was found in some samples of vegetables, meat, liver, fish (muscle) and fish (viscera) at the levels of 1.4-10.6 ng/g, 2.7-26.4 ng/g, tr-34.2 ng/g, tr-21.6 ng/g and tr, respectively. 2,6-DTBP was found in some samples of fish (muscle) and fish (viscera) at the levels of tr-3.9 ng/g and tr, respectively. 3,5-DTBP and 2,4-DTPP were not found in any of the analyzed samples.

[Studies on the stability of 89 pesticides in organic solvent].

The stability of 89 pesticides (17 organochlorine, 33 organophosphorus, 8 pyrethroid, 12 carbamate, and 19 other pesticides) in 6 kinds of organic solvents (methanol, ethanol, 2-propanol, ethyl acetate, n-hexane, and acetone) was investigated using gas chromatography/mass spectrometry (GC/MS). All of the investigated pesticides were stable in all of the tested organic solvents during storage for 6 hours at room temperature in the dark except captafol, captan, phosmet, chinomethionat, and dicofol. However, the decreases of captafol, captan, phosmet, and chinomethionat were observed in methanol. The decreases of captafol, captan, and phosmet were also observed in ethanol. Moreover, the decrease of dicofol was observed in acetone. The decrease of captafol dissolved in methanol at a concentration of 2 micrograms/ml was faster than those of captan, phosmet, and chinomethionat; the residual captafol was 75% after 30 min of storage. Dicofol dissolved in acetone also decreased during storage in a refrigerator. 4,4'-dichlorobenzophenone (DCBP) and chlorobutanol were detected in the acetone solution of dicofol after storage. Furthermore, it was found that dicofol was decomposed by acetone at an injection port, and DCBP and chlorobutanol were formed when it was injected into GC with acetone.

[Specific determination of deltamethrin and tralomethrin by preparative HPLC and GC-ECD].

Tralomethrin quickly changes to deltamethrin in gas chromatograph by debromination. Therefore deltamethrin and tralomethrin are not able to be distinguished by gas chromatographic determination. A method for specific determination of deltamethrin and tralomethrin was established. The method consists of fractionation by high performance liquid chromatography and determination by gas chromatography. Recoveries of deltamethrin and tralomethrin spiked to three agricultural products were from 42 to 78% and from 18 to 76%, respectively with relative standard deviations ranging from 0.3 to 15%. From the analysis of samples spiked with tralomethrin, it was found that a part of tralomethrin quickly changed to deltamethrin in homogenate of agricultural products. The addition of phosphoric acid to the homogenate did not prevent the change of tralomethrin.

Catheter ablation of a monofocal premature ventricular complex triggering idiopathic ventricular fibrillation.

A 62 year old man was admitted for evaluation of recurrent episodes of syncope. A surface ECG showed frequent repetitive premature ventricular complexes of right ventricular outflow tract origin. Ventricular fibrillation was inducible by programmed electrical stimulation but otherwise cardiac evaluation was unremarkable. A diagnosis of idiopathic ventricular fibrillation was made and an implantable cardioverter-defibrillator (ICD) was installed. However, spontaneous ventricular fibrillation recurred, requiring repeated ICD discharges. The ventricular fibrillation was reproducibly triggered by a single premature ventricular complex with a specific QRS morphology. Radiofrequency catheter ablation was carried out to eradicate this complex. No ventricular fibrillation has developed after this procedure, and the patient does not require drug treatment.

Accessory pathway associated with an anomalous coronary vein in a patient with Wolff-Parkinson-White syndrome.

We report a case of Wolff-Parkinson-White syndrome coexistent with atresia of the coronary sinus (CS) ostium and persistence of the left superior vena cava. The accessory pathway was located at the blind end of the CS, which was bumped with mechanical loss of preexcitation during mapping by a catheter from within the CS. The accessory pathway was successfully ablated with radiofrequency energy applied to this site from the right atrium. This unique combination of anatomically matched anomalies may be important in suggesting a potential embryologic link between the accessory pathway and the coronary vein.

[Determination of organochlorine and organophosphorus pesticide levels in imported beef].

A simple and efficient cleanup method was established for capillary gas chromatographic determination of 12 organochlorine and 11 organophosphorus pesticides in beef. Extracted fat was subjected to silica gel dry column chromatography and further cleaned up by Florisil minicolumn chromatography for organochlorine pesticide analysis, while partitioning between n-hexane and acetonitrile of the extract and silica gel minicolumn chromatography were employed for the analysis of organophosphorus pesticides. Several samples (imported Australian beef) were analyzed by the proposed method. DDT was detected in 14 (0.01-0.10 ppm). BHC was found in 11 (0.003-0.031 ppm) and dieldrin was demonstrated in 2 (0.004 and 0.008 ppm). Heptachlors and the 11 organophosphorus pesticides investigated were not detected in any of the meat samples.

Postrepolarization refractoriness as a potential anti-atrial fibrillation mechanism of pilsicainide, a pure sodium channel blocker with slow recovery kinetics.

The antifibrillatory effect of pilsicainide, a sodium channel blocker with slow recovery kinetics, was investigated in a canine model of atrial fibrillation. Prolonging the atrial effective refractory period is an important mechanism for pharmacological termination of atrial fibrillation. However, the effectiveness of potassium channel blockers has been questioned because of their reverse-use-dependent property. In eight open-chest dogs, the duration of the atrial endocardial monophasic action potential and the atrial effective refractory period were determined using a Franz catheter. Conduction velocity was obtained from a 96-channel mapping electrode at multiple cycle lengths. Inducibility of sustained atrial fibrillation (> 30 minutes) was confirmed by atrial burst pacing during bilateral vagal stimulation, and local fibrillation cycle lengths were measured. Five minutes after restarting fibrillation, pilsicainide (0.6 mg/kg + 0.04 mg/kg/min) was administered. After fibrillation was terminated, measurements were repeated. Pilsicainide successfully terminated atrial fibrillation in 7 of 8 dogs after the median time of 5.1 minutes. The conduction velocity decreased significantly. Although pilsicainide did not affect monophasic action potential duration, it caused use-dependent prolongation of the atrial effective refractory period (P < 0.05), creating postrepolarization refractoriness. Accordingly, pilsicainide prolonged the atrial fibrillation cycle length from 80.6 to 113.8 ms (P < 0.05) before termination of fibrillation. Sodium channel blockers with slow recovery kinetics can prolong the atrial effective refractory period without affecting monophasic action potential duration. Unlike potassium channel blockers, these sodium channel blockers maintain postrepolarization refractoriness, even at rapid stimulation rates, thus exerting a salutary antifibrillatory effect.