Functional analysis of the role of the A + T-rich region and upstream flanking sequences in simian virus 40 DNA replication.

One boundary of the minimal origin of replication of simian virus 40 DNA lies within the A + T-rich region. Deletion of only a few bases into the adenine-thymine (AT) stretch results in a DNA template which is defective for replication both in vivo and in vitro (B. Stillman, R.

[Intravenous sotalol in the acute treatment of supraventricular tachycardias].

The effects of intravenous sotalol (0.5 mg/kg in 6 minutes) were studied in 23 patients with supraventricular tachycardia (ventricular rate greater than 120 bpm) after failure of placebo (isotonic dextrose). Thirteen patients had atrial flutter or fibrillation and 10 a junctional tachycardia of recent onset.

[Total or partial electrical interruption of the atrioventricular pathway. Evaluation of clinical results and indications].

After checking on the efficacy and innocuity of catheter ablation of the His bundle in an experimental study in the sheep, 22 patients with supraventricular tachycardia resistant to an average of 5.5 +/- 1.7 antiarrhythmic drugs per patient underwent this procedure.

[Delayed filling of the anterior interventricular artery. Apropos of 9 cases].

Selective coronary angiography has shown that typical angina pectoris may occur in the absence of atheromatous coronary stenosis. Other causes of these attacks of pain have been found: coronary spasm, small vessel disease, abnormal dissociation of haemoglobin or metabolic disturbances of the myocardial cell. Of all the patients undergoing coronary angiography in 1984 at the Centre Cantini, 9 had no classical coronary lesions but delayed filling of the left anterior descending artery.

[Sinus dysfunction associated with catecholaminergic ventricular tachycardia. Therapeutic implications].

The presence of resting sinus bradycardia (less than or equal to 45 bpm) with junctional escapes in an 8 year old child with catecholamine induced ventricular tachycardia, raised the problem of an underlying sinus node dysfunction. This was an important consideration bearing in mind the potential risk of the high dose betablocker therapy aggravating the sinus bradycardia. Electrophysiological studies showed pathological sinus node recovery times.

A new method for evaluating the effect of antiarrhythmic drugs on atrioventricular nodal conduction.

Electrophysiological variables were studied in 19 patients before and after one of three commonly used antiarrhythmic agents. The pacing rate at which alternating Wenckebach periods appeared in eight patients was significantly reduced by intravenous digoxin (0.01 mg/kg body weight).

New host cell system for regulated simian virus 40 DNA replication.

Transformed monkey cell lines (CMT and BMT) that inducible express simian virus 40 (SV40) T antigen from the metallothionein promoter have been isolated and characterized. Immunoprecipitation of pulse-labeled T antigen demonstrates a 5- to 12-fold increase in the rate of synthesis on addition of heavy-metal inducers to the culture medium. Radioimmunoassay of cell extracts indicates the accumulation of three- to fourfold more total T antigen after 2 days of induction by comparison with uninduced controls.

T antigen and template requirements for SV40 DNA replication in vitro.

A cell-free system for replication of SV40 DNA was used to assess the effect of mutations altering either the SV40 origin of DNA replication or the virus-encoded large tumor (T) antigen. Plasmid DNAs containing various portions of the SV40 genome that surround the origin of DNA replication support efficient DNA synthesis in vitro and in vivo. Deletion of DNA sequences adjacent to the binding sites for T antigen either reduce or prevent DNA synthesis.

[Oral and intravenous bepridil in the treatment of recurrent sustained ventricular tachycardias. Electropharmacological study].

The antiarrhythmic properties of bepridil on ventricular tachycardia (VT) termination and prevention were studied in 16 patients using programmed electrical stimulation techniques. All patients were admitted for documented sustained VT resistant to 3.5 +/- 2.

[Treatment of recurrent ventricular tachycardias using oral propafenone].

The effect of oral propafenone on prevention of pacing-induced ventricular tachycardia (VT) was studied in 11 patients. All patients experienced documented sustained VT refractory to 4.1 +/- 2 antiarrhythmic agents per patient including amiodarone in 8.

[Supraventricular tachycardia induced by effort and by catecholamines].

The role played by catecholamines in the initiation of certain forms of ventricular tachycardia is now recognised. On the other hand, a similar predominant or exclusive mechanism has not been demonstrated in supraventricular tachycardia. We observed a rate case of reproducible attacks of junctional tachycardia on effort in a 45 year old man.

[Treatment of recurrent ventricular tachycardia with hydroquinidine. Evaluation of its efficacy with electrophysiological technics].

Electrophysiological investigations were used to test the efficacy of dihydroquinidine chlorhydrate (600 or 1 200 mg/day) in a prospective study of 18 patients with recurrent ventricular tachycardia documented by electrocardiography. These patients did not respond to an average of 3.1 +/- antiarrhythmic drugs, including amiodarone in 12 patients.

[Behçet's disease and cardiovascular pathology].

Behçet's syndrome appears in different localisations. Some of them were at the source of the initial description of the disease and are therefore well known. However, cardiovascular localisations were discovered later on and are worthy of detail.

Alternate ventriculo-atrial Wenckebach conduction during ventricular tachycardia.

Although pacing-induced ventriculo-atrial (VA) Wenckebach conduction has been previously described, the occurrence of this phenomenon during ventricular tachycardia has received little attention. The latter is defined as 2:1 VA block in which the conducted beats show progressive lengthening of VA conduction until the sequence is terminated by two or three blocked ventricular beats. This phenomenon was observed in a 16-year-old boy who underwent electrophysiologic study for ventricular tachycardia as a late complication of surgical correction of tetralogy of Fallot.

[Large right intracardiac thrombus cause of recurrent pulmonary embolism. Apropos of a case of favourable course].

Echocardiography may be used in patients presenting with pulmonary embolism to visualise the right heart. The authors report the case of a patient who had recurrent pulmonary embolism. Echocardiography demonstrated a large, mobile thrombus moving freely through the tricuspid valve.

[Coronary occlusion immediately following a successful coronary angioplasty. Treatment by repeat angioplasty].

The authors report the case of a 52 year old patient with a significant stenosis of the medial portion of the left anterior descending artery (LAD) with excellent left ventricular function. Transluminal coronary angioplasty (TCA) was indicated following a positive exercise stress test. This was initially performed successfully.

[Transcutaneous measurement of PO2 in healthy subjects and in arteriopathy patients during the exercise test].

The authors studied the variation in tcPO2 during a stress test conducted on a treadmill in normal subjects and in patients with stage I and II vascular disease according to Fontaine's classification. The tcPO2 was measured in the foot. In normal subjects, during exercise, there was an inital fluctuation in the tcPO2 which subsequently remained stable.

[Ventricular arrhythmia following repair of Fallot's tetralogy. Apropos of 59 cases].

Fifty-nine patients operated for Fallot's tetralogy were reviewed over 3 years after surgery. The average age at surgery was 7.4 years (range 6 months to 37 years).

Role of specific simian virus 40 sequences in the nuclease-sensitive structure in viral chromatin.

A nuclease-sensitive region forms in chromatin containing a 273-base-pair (bp) segment of simian virus 40 DNA encompassing the viral origin of replication and early and late promoters. We have saturated this region with short deletion mutations and compared the nuclease sensitivity of each mutated segment to that of an unaltered segment elsewhere in the partially duplicated mutant. Although no single DNA segment is required for the formation of a nuclease-sensitive region, a deletion mutation (dl45) which disrupted both exact copies of the 21-bp repeats substantially reduced nuclease sensitivity.

[Accentuation of myocardial ischemia during coronary recanalization in the acute phase of myocardial infarction].

Coronary recanalisation during the acute phase of myocardial infarction, especially by in situ infusion of thrombolytic agents, is accompanied in most cases by rapid regression of chest pain and a reduction in the degree of ST elevation. However, a multicentre retrospective study of 104 attempts at recanalisation, including 78 successful procedures, showed in 10 cases (12.8 p.

Bepridil for recurrent sustained ventricular tachycardias: assessment using electrophysiologic testing.

Bepridil was found to possess electrophysiologic properties common to class I and IV antiarrhythmic agents. Intravenous and oral bepridil were evaluated using serial electrophysiologic studies in a selected group of 9 patients with recurrent sustained ventricular tachycardia (VT) unresponsive to usual therapy, including amiodarone therapy in 15 patients. Intravenous bepridil treatment terminated sustained, well tolerated, pacing-induced VT in 3 of 6 patients and prevented the initiation of VT in 2 of these and in a patient in whom the drug failed to restore sinus rhythm.