Atypical atrial flutter involving the isthmus between the right pulmonary veins and fossa ovalis

Typical atrial flutter, counterclockwise or clockwise movement around the tricuspid annulus, has been well studied. However, the reentrant circuits in atypical atrial flutter are not well defined. A patient without a prior history of cardiac surgery who presented with incessant atypical atrial flutter is described. Activation mapping demonstrated a circular movement around the fossa ovalis in the interatrial septum. Entrainment mapping demonstrated a protected isthmus between the right pulmonary veins and the fossa ovalis. Radiofrequency ablation of this isthmus terminated atrial flutter without recurrence during the follow-up period.

Acute open perilunate dislocation--a case report

A rare case of acute open dorsal perilunate dislocation of the left hand was encountered in a 30-year-old man with exposure of the lunate and distal radius. No other combined injury was identified except open dislocation and chip avulsion fracture of triquetrum. Open reduction was performed through a dorsal approach after debridement. Such a severe injury, to our knowledge, has not been reported previously.

Differentiating the ligament of Marshall from the pulmonary vein musculature potentials in patients with paroxysmal atrial fibrillation: electrophysiological characteristics and results of radiofrequency ablation

It was reported that paroxysmal atrial fibrillation (PAF) can be initiated by ectopic atrial beats originating from the pulmonary vein (PV) or left atrial tract (LAT) within the ligament of Marshall (LOM). The aim of this study was to differentiate the LAT from the PV potentials, and to investigate the results of radiofrequency ablation guided by these potentials. Ten patients (age 60 +/- 12 years) with PAF who had a recording of double potentials (DPs) in or around the left PV were included. Group I had five patients with the second deflection of DPs (D2) due to activation of the LAT, and Group II had five patients with D2 due to activation of the PV musculature. There were no significant difference in the isoelectric interval between DPs, the activation time, and amplitude of D2 between Groups I and II. During distal coronary sinus (CS) pacing, the CS ostium (CSO) to D2 interval was shorter compared with that during sinus rhythm in Group I (39 +/- 19 vs 71 +/- 25 ms, P = 0.04), but was longer in Group II (96 +/- 16 vs 44 +/- 19 ms, P = 0.04). During ectopic activation, three patients in Group I, but no Group II patients, had transformation of recorded DPs into triple potentials. Radiofrequency ablation guided by the earliest activation of the LAT potential was performed with transient suppression of PAF, but ablation guided by the earliest activation of the PV potentials had a high success rate in eliminating PAF. In conclusion, differentiating the LAT from the PV potentials for initiation of PAF is feasible by an electrophysiological approach, and may be important for radiofrequency ablation of PAF.

Effect of phenylephrine on focal atrial fibrillation originating in the pulmonary veins and superior vena cava

OBJECTIVES

This study was aimed at evaluating the effects of phenylephrine infusion on the occurrence of focal atrial fibrillation (AF).

BACKGROUND

Paroxysmal AF can be initiated by ectopic atrial beats originating in the pulmonary vein (PV) or superior vena cava (SVC). The effect of change in autonomic tone on this focal AF is unknown.

METHODS

This study included 12 patients with frequent bursts of AF documented by 24-h Holter monitoring. The number and coupling interval of spontaneous ectopic activity and bursts of AF were evaluated for 1 min before and after phenylephrine (2 to 3 microg/kg) injection.

RESULTS

After detailed mapping, four patients had a focus located in the left superior PV, six in the right superior PV and two in the SVC. In 10 patients with AF foci originating in the PVs, the frequency of ectopic activity (19.5 +/- 27.4 vs. 11.4 +/- 22.9 beats/min, p = 0.059) was reduced as well as AF bursts (14 +/- 3 vs. 1.8 +/- 2.7 bursts/min, p = 0.005) before versus after phenylephrine injection; the minimal coupling interval of ectopic activity and AF bursts became longer compared with baseline. The maximal percent increase in sinus cycle length after phenylephrine injection was significantly greater in patients with complete suppression of AF compared with those with partial suppression (43 +/- 19 vs. 14 +/- 5%, p = 0.01). However, no significant effect of phenylephrine on AF originating in the SVC was found.

CONCLUSIONS

Change in autonomic tone induced by phenylephrine injection was effective in suppressing focal AF originating in the PVs but not in the SVC.

Pulmonary vein electrogram characteristics in patients with focal sources of paroxysmal atrial fibrillation

INTRODUCTION

The major source of ectopic beats initiating paroxysmal atrial fibrillation (AF) is from pulmonary veins (PVs). However, the electrogram characteristics of PVs are not well defined.

METHODS AND RESULTS

Group I consisted of 129 patients with paroxysmal AF. Group II consisted of 10 patients with a concealed left-sided free-wall accessory pathway. All group I patients had spontaneous AF initiated by ectopic beats, including 169 ectopic foci originating from the PVs. We analyzed PV electrograms from the 169 ectopic foci during sinus beats and ectopic beats. During AF initiation, most (70%) ectopic beats showed PV spike potential followed by atrial potential; 16% of ectopic beats showed PV fragmented potential followed by atrial potential; and 14% showed fusion potentials. The coupling interval between the sinus beat and the ectopic beat was significantly shorter in the inferior PVs than in the superior PVs (171 +/- 48 msec vs 222 +/- 63 msec, P = 0.001) and was significantly shorter in the distal foci than in the ostial foci of PVs (206 +/- 52 msec vs 230 +/- 56 msec, P = 0.01). The incidence of conduction block in the PVs during AF initiation was significantly higher in the inferior PVs than in the superior PVs (12/24 vs 37/145, P = 0.03) and was significantly higher in the distal foci than in the ostial foci of PVs (43/121 vs 6/48, P = 0.04). The maximal amplitude of PV potential was significantly larger in the left PVs than in the right PVs, and the maximal duration of PV potential was significantly longer in the superior PVs than in the inferior PVs during sinus beats in both group I and II patients.

CONCLUSION

PV electrogram characteristics were different among the four PVs. Detailed mapping and careful interpretation are the most important steps in ablation of paroxysmal AF originating from PVs.

Predicting the arrhythmogenic foci of atrial fibrillation before atrial transseptal procedure: implication for catheter ablation

INTRODUCTION

Use of endocardial atrial activation sequences from recording catheters in the right atrium, His bundle, and coronary sinus to predict the location of initiating foci of atrial fibrillation (AF) before an atrial transseptal procedure has not been reported. The purpose of the present study was to develop an algorithm using endocardial atrial activation sequences to predict the location of initiating foci of AF before transseptal procedure.

METHODS AND RESULTS

Seventy-five patients (60 men and 15 women, age 68 +/- 12 years) with frequent episodes of paroxysmal AF were referred for radiofrequency ablation. By retrospective analysis, characteristics of the endocardial atrial activation sequences of right atrial, His-bundle, and coronary sinus catheters from the initial 37 patients were correlated with the location of initiating foci of AF, which were confirmed by successful ablation. The endocardial atrial activation sequences of the other 38 patients were evaluated prospectively to predict the location of initiating foci of AF before transseptal procedure using the algorithm derived from the retrospective analysis. Accuracy of the value <0 msec (obtained by subtracting the time interval between high right atrium and His-bundle atrial activation during atrial premature beats from that obtained during sinus rhythm) for discriminating the superior vena cava or upper portion of the crista terminalis from the pulmonary vein (PV) foci was 100%. When the interval between atrial activation of ostial and distal pairs of the coronary sinus catheter of the atrial premature beats was <0 msec, the accuracy for discriminating left PV foci from right PV foci was 92% in the 24 foci from the left PVs and 100% in the 19 foci from the right PVs.

CONCLUSION

Endocardial atrial activation sequences from right atrial, His-bundle, and coronary sinus catheters can accurately predict the location of initiating foci of AF before transseptal procedure. This may facilitate mapping and radiofrequency ablation of paroxysmal AF.

Radiofrequency catheter ablation of atrial fibrillation initiated by spontaneous ectopic beats

Several reports have demonstrated that most paroxysmal atrial fibrillation is initiated by ectopic beats from a focal area, and radiofrequency catheter ablation can effectively cure atrial fibrillation. Although most of the ectopic beats originate from the orifices of the pulmonary veins or from the myocardial sleeves in the pulmonary veins, ectopic beats can also originate from superior vena cava, crista terminalis, coronary sinus, ligament of Marshall, or left atrial posterior free wall. Owing to the potential risk and complexity of catheter ablation, the ideal candidates should have frequent episodes and drug refractory paroxysmal atrial fibrillation.

Pulmonary vein morphology in patients with paroxysmal atrial fibrillation initiated by ectopic beats originating from the pulmonary veins: implications for catheter ablation

BACKGROUND

Successful ablation of ectopic beats originating from the pulmonary veins (PV) could eliminate paroxysmal atrial fibrillation (PAF). However, information about the structure of the PV in patients with PAF that is initiated by PV ectopic beats has not been reported.

METHODS AND RESULTS

We studied the morphology of the PVs and measured their diameters in 3 groups of patients. Group I included 52 patients (aged 66+/-14 years; 44 men) with focal atrial fibrillation (AF) from the PVs. Group II included 8 patients (aged 50+/-10 years; 3 men) with focal AF from the superior vena cava or cristal terminalis. Group III included 23 control patients (aged 55+/-16 years; 17 men). Of the control patients, 11 had AV node and 12 had AV reentrant tachycardia. After an atrial transseptal procedure, selective PV angiography using a biplane system with a right anterior oblique view of 30 degrees, a left anterior oblique view of 60 degrees, and a cranial angle of 20 degrees was performed. The ostial and proximal portions of the right and left superior PVs (RSPV and LSPV) were significantly dilated in group I patients compared with those in groups II and III. Furthermore, the ostia of the RSPV and LSPV were significantly dilated in group II compared with group III patients. However, the mean diameters of the inferior PVs were similar between the 3 groups. Comparisons of the individual PV diameters among the 3 subgroups of group I (which was divided according to where the ectopic focus was located) showed nonselective dilatation of the PV.

CONCLUSIONS

Nonspecific dilatation of the ostia and proximal portion of superior PVs were found in patients with PAF initiated by ectopic beats from the superior PVs.

Direct magneto-optical observation of a structural phase transition in thin films of manganites

The spontaneous formation of twins in La(2/3)Ca(1/3)MnO3 films below T(S) approximately 105 K is observed by a magneto-optical technique. The twins are revealed as stripes along the {110} directions where magnetization tilts out of the film plane due to the stresses in twins. Their appearance is associated with a martensitic phase transition in the film triggered by the cubic-to-tetragonal transition in the SrTiO3 substrate. It is found that magnetization of the films proceeds by inhomogeneous rotation of magnetic moments. This is due to the presence of microscopic structural inhomogeneities. Their dominating role in the low-temperature transport can explain small effects of the transition at T(S) on the resistivity.

Early recurrence of atrial fibrillation after external cardioversion

Early recurrence of atrial fibrillation (AF) has been reported to occur in a significant number of patients after internal cardioversion. However, information about early recurrence of AF after external cardioversion has never been reported. The present study was conducted to investigate the clinical and electrophysiological characteristics of early recurrence of AF and its role in failure of cardioversion in patients with chronic AF.

METHODS AND RESULTS

The study included 50 consecutive patients, age 69+/-9, with a history of chronic AF for more than 3 months duration and electrical cardioversion. They were divided into two groups according to the presence (group 1) or absence (group 2) of early recurrence of AF. There were 13 (26%) patients in group 1 and 37 (74%) patients in group 2. The age, gender, duration of AF, left ventricular function, left atrial dimension, and underlying heart disease were similar between group 1 and 2. Forty-five patients were successfully converted to sinus rhythm with a mean energy of 158+/-57 . Among those who failed to be converted to sinus rhythm, 4 (80%) belonged to group 1 and 1 (20%) belonged to group 2. The early recurrences of AF were initiated with consecutive APDs; but the numbers of APD in the first 30 seconds after cardioversion were similar between group 1 and 2. However, the coupling interval of the second APD was shorter in group 1 than group 2 (188+/-22 vs 324+/-59 ms, P = 0.003). Nine of the 13 early recurrences were prevented by an increase of shock energy (n = 3) or intravenous amiodarone infusion (n = 6). There were no differences in duration of follow-up, recurrence rate, and time interval to recurrence between group 1 and group 2. Early recurrence of AF occurred in 26% of chronic AF patients who underwent external electrical cardioversion and was a major cause of failure in cardioversion. Early recurrence of AF was initiated by APDs with decreasing coupling intervals and could be prevented with an increase of shock energy or amiodarone.

Traumatic diaphragmatic hernia with delayed presentation

BACKGROUND

Traumatic diaphragmatic rupture may occur in patients with thoracoabdominal injuries, and still poses a diagnostic challenge to surgeons. Those patients who survive the events without being diagnosed in the acute phase develop chronic traumatic diaphragmatic hernia. In this study, we reviewed cases of chronic traumatic diaphragmatic hernia managed over the past 35 years.

METHODS

We retrospectively evaluated the clinical courses and radiologic images of 24 cases with chronic traumatic diaphragmatic hernia.

RESULTS

Motor vehicle accident with blunt abdominal trauma was the most important mode of injury. Herniation was more common to the left plural cavity than to the right. The interval between injury and the onset of symptoms ranged from two weeks to 40 years (average, 7.3 years). Vague chest pain, shortness of breath, and bowel obstruction are the most common presentations. Chest radiographic findings suggested the diagnosis of diaphragmatic hernia in 20 patients. Barium study of the gastrointestinal tract was required to confirm the diagnosis. The most common herniated abdominal viscera were the stomach and colon. All patients received thoracotomy with reduction of hernia organs and closure of the diaphragmatic defect. The hospital course was uneventful with no operative mortality.

CONCLUSIONS

Careful interpretation of radiographic images and early surgical intervention are essential in the management of patients with chronic traumatic diaphragmatic hernia. Thoracotomy with reduction of herniated organs can be performed safely with satisfactory results.

E5 proteins of human papillomavirus types 11 and 16 transactivate the c-fos promoter through the NF1 binding element

Human papillomavirus type 11 (HPV-11) and HPV-16 contain an E5 gene that can induce c-fos gene expression in mouse fibroblasts. This study investigated the human c-fos promoter characteristics by mapping the c-fos promoter sequence with several deletion and point mutants that confer responsiveness to E5 of HPV-11 or HPV-16. The mutant studies show that NF1 binding sequences within the c-fos promoter were crucial for the induction of the c-fos gene by E5, and the gel shift assay study suggested that E5 of both HPV-11 and HPV-16 is associated, perhaps indirectly, with this NF1 element in the transactivation of the human c-fos promoter. Using an inducible system, we demonstrate that increased induction of the HPV-11 E5 gene in cells led to increased transactivation of the NF1 element. In addition, the transactivating activity of a series of HPV-11 E5 mutants on the NF1 element had a strong correlation with their respective transforming activities.

Differential induction and regulation of c-jun, junB, junD and c-fos by human papillomavirus type 11 E5a oncoprotein

The E5a gene of human papillomavirus type 11 (HPV-11) is a transforming oncogene. In this study, we investigated the mechanism of E5a induced transformation. Our results show that the expression of c-jun and junB, but not junD, was activated by HPV-11 E5a in NIH 3T3 cells and human epidermal keratinocytes. However, the expression of c-fos was activated by E5a in NIH 3T3 cells, but not in keratinocytes. We further investigated the mechanism of c-jun and junB induction by E5a. The amount of c-jun and junB RNAs correlated with the amount of E5a RNA in the heavy metal inducible system. E5a constitutively activated the expression of c-jun and junB at the initiation of transcription level. In addition, analyses of the effect of serum on c-jun expression in E5a transformed human epidermal keratinocytes show that EGF might have a stimulatory effect on c-jun gene expression in E5a expressing keratinocytes.

Protein kinase C-and ras-dependent activation of c-jun gene by human papillomavirus type 11 E5a oncoprotein

E5a of HPV-11 is a transforming oncogene. Previously, we have shown that E5a constitutively activates the expression of protooncogene c-jun by transcriptional regulation through the AP-1 binding site in the c-jun promoter. In the present study, we used two different types of cells: the E5a transfected NIH 3T3 cells and human epidermal keratinocytes, and selectively inhibited different signal transduction pathways to investigate effects of E5a on c-jun expression. We find that protein kinase C and ras-dependent pathways are important for the c-jun induction by E5a, but not the cAMP-dependent pathway.

Primary uncommon malignant tumors of the esophagus: an analysis of 30 cases

BACKGROUND

Uncommon malignant tumors of the esophagus are defined as any histological type of malignant esophageal tumors other than the typical squamous cell carcinoma. Their biological characteristics remain obscure because of their rarity. Thus, this is a retrospective review of patients here with uncommon esophageal cancers in an attempt to evaluate their prognostic factors and proper therapeutic modalities.

METHODS

Among 1,674 patients with esophageal cancers, only 30 (1.8%) with uncommon esophageal cancers were collected between 1977 and 1992. The clinical parameters for evaluation consisted of age, sex, histological type, location, staging and a variety of therapeutic management techniques and their results.

RESULTS

Histologically, there were 10 adenocarcinomas, 7 small cell carcinomas, 6 adenosquamous carcinomas, 3 carcinosarcomas, 1 mucoepidermoid carcinoma, 1 adenoid cystic carcinoma, 1 fibrosarcoma, and 1 basal cell carcinoma. The mean age was 65.8 years, ranging from 46 to 85 years. Upon admission to hospital, the most common clinical symptoms included dysphagia, body weight loss and substernal pain. The tumor staging, according to TNM classification was evaluated as follows: Stage I: 13.3%, Stage II: 46.7%, Stage III: 16.9%, Stage IV: 23.3%. The middle third thoracic esophagus was the most common location of tumor occurrence. Overall one-year, two-year, and five-year survival rates were 39.3%, 21.4%, and 10.7% respectively. These results were as poor as those of squamous cell carcinoma. However, the patients with Stage I and Stage II tumors (mean, 23.8 months) had significantly better survivals than those with Stage III and Stage IV (mean, 3.9 months). Furthermore, if the tumor was resectable, the patients undergoing esophagectomy had much better one-year and two-year survival rates than those without esophagectomy (p < 0.01). In addition, patients with small cell carcinoma seemed to have worse treatment outcome than those with other histological types of tumors.

CONCLUSIONS

These results suggested that key factors contributing to prognosis included tumor staging as well as respectability. Thus, it is recommended that, with early detection and diagnosis, esophagectomy might be the treatment-of-choice in managing these uncommon esophageal malignancies. Adjuvant therapy including irradiation and chemotherapy may be helpful, particular for small cell carcinoma.

[Fluorescent in situ hybridization of enriched SFA-DNA on pachytene chromosomes in mouse]

In the present study, the primary constrictions of mouse pachytene chromosomes stained with Hoechst 33258, and those stained by indirect immunofluorescence method with CREST antiserum were compared with those hybridized by the probe DNA isolated from the enriched mouse spindle fiber attachments. It was found that the DNA probe hybridized not only with the centromeric regions on synaptonema complexes but also with the DNA of pericentromeric heterochromatin of all autosomes. Moreover, the DNA probe hybridized also with the centromeric regions of both X and Y chromosomes. It was concluded that the DNA isolated from the enriched mouse spindle fiber attachments contains a complete set of the centromeric DNAs of all autosomes, X and Y chromosomes.

Thoracic epidural anesthesia for major abdominal surgery: a retrospective study

In 1986-1988, the authors had experiences with thoracic epidural anesthesia for a variety of major abdominal operations in 303 patients. It is proved to be reliable and effective. The puncture levels were between T8 to T12. 2% lidocaine, in plain form or with 1:200,000 epinephrine, was used as anesthetic agent. Perioperative complications were carefully managed with satisfactory results. Post-operative conditions were evaluated and seemed to be superior to those of general anesthesia in many aspects. No patient had neurologic deficit as a result of the epidural anesthesia. We concluded that thoracic epidural anesthesia is an excellent alternative technique in major abdominal surgeries.

[Studies on the chemical components of essential oil from the aerial parts of Ligusticum chuanxiong Hort]

Qualitative and quantitative analyses of the essential oil steamdistilled from the aerial parts of Ligusticum chuanxiong were made by means of GC-MS and GC. Forty-six components which make up 85.82% of the total oil were identified.

Bacterial N-succinyl-L-diaminopimelic acid desuccinylase. Purification, partial characterization, and substrate specificity

The enzyme N-succinyl-L-diaminopimelic acid desuccinylase from Escherichia coli has been purified 7,100-fold to apparent homogeneity. The enzyme is part of the diaminopimelic acid-lysine pathway in bacteria and catalyzes the hydrolysis of N-succinyl-L-diaminopimelic acid to produce L-diaminopimelic acid and succinate. The enzyme exists as a mixture of dimeric and tetrameric species of identical subunits of molecular weight approximately 40,000. Activity was completely abolished following dialysis of the enzyme against metal chelators. Cobalt(II) and zinc were effective in restoring the activity. The apparent affinities of the apoenzyme for cobalt and zinc were similar (Kd values near 1 microM) and the cobalt enzyme was 2.2-fold more active than the zinc enzyme. The Km and turnover number for the hydrolysis of the natural substrate, N-succinyl-L-diaminopimelic acid, were 0.4 mM and 16,000 min-1, respectively. The substrate specificity of the enzyme was defined by preparing a number of substrate analogues that systematically lack the various functional groups present in the molecule. These studies show that the enzyme is highly specific for the natural substrate. These properties of N-succinyl-L-diaminopimelic acid desuccinylase and the fact that the enzyme is essential for bacterial growth make it an ideal target for the development of inhibitors with potential antibacterial activity.