A Randomized Comparison of the Straight Linear Approach with Electrogram Mapping Focal Approach in Selective Slow Pathway Ablation

HAYASHI, M., et al. : A Randomized Comparison of the Straight Linear Approach with Electrogram Mapping Focal Approach in Selective Slow Pathway Ablation. The aim of this study was to evaluate the efficacy and safety of the anatomic linear approach in selective AVN slow pathway ablation, in comparison to the widely used electrogram mapping focal approach. It remains undetermined whether or not anatomic linear ablation has a greater potential for eliminating slow pathway conduction than does focal ablation. Fifty consecutive patients (21 men, 29 women, age  56 ± 14  years) with common type AVNRT were randomly assigned to the linear approach (25 patients) or local electrogram mapping approach (25 patients). A linear lesion was created between the tricuspid annulus, at the midlevel of the coronary sinus (CS) ostium, and the anterior aspect of the CS infundibulum. In 22 (88%) patients in the linear group, the AVNRT was successfully eliminated by  1.5 ± 0.8  linear RF applications without any complications. All 25 patients in the focal group satisfied the endpoint criteria after  3.8 ± 2.4  focal RF deliveries. The success rate did not significantly differ between the two groups. Out of the 22 patients with a successful outcome in the linear group, 17 (77%) attained complete abolition of the slow pathway conduction, whereas this was observed in only eight (32%) patients in the focal group (  P < 0.005  ). The session time was significantly shorter in the linear group. Recurrence of the tachycardia was not documented in any patient during a mean follow-up of  18 ± 8  months except one with residual slow pathway conduction in the focal ablation group. In conclusion, the anatomic linear approach can be performed safely and possesses a greater potential for slow pathway interruption compared to the electrogram mapping focal approach.     

Morphological Investigation of Cavity Formation in Articular Cartilage Induced by Oiloxacin in Rats

Morphological Investigation of Cavity Formation in ArticularCartilage Induced by Ofloxacin in Rats. Kato, M., andOnodera,T.( 1988).Fundam. Appl Toxwol. 11, 110–119. Ofloxacin,a quinolone antibacterial agent, induced blisters and/or erosionsin the articular cartilage of the humeral trochlea, femoralcondyle, and femoral head of immature rats. Histologically,cavity formation was seen in the middle zone of the articularcartilage. Changes were detected as early as 5 hr after a singleoral administration of 1000 or 3000 mg/kg. These changes werecharacterized by condensation, atrophy, and deformation of thenuclei of chondrocytes distributed in the middle zone. In suchnuclei, aggregation of heterochromatin was observed. Degeneratedcells with vacuolated and partially disintegrated cytoplasmswere also seen in this zone. These lesions were followed byedema of the matrix accompanied with markedly decreased stainabilitywith safranin-O, and a cavity was formed later by liquefactionof the cartilage. The changes were reversible, with reboundingoccurring even with continued treatment with ofloxacin. Theproliferation of chondrocytes around the lesion chiefly contributedto the repair. Ofloxacin had no adverse effects on the articularcartilage in rats when treatment was initiated at 8 weeks ofage or later.     

HYPERMINERALOCORTICISM WITHOUT ELEVATION OF PLASMA ALDOSTERONE: DEOXYCORTICOSTERONE-PRODUCING ADRENAL ADENOMA AND HYPERPLASIA

Two female patients were admitted for evaluation of hypertension and hypokalaemia. Plasma renin activity was suppressed and plasma aldosterone levels were within the normal value in a 52-year-old woman and below the normal value in the other patient, a 62-year-old woman. Plasma 11-deoxycorticosterone (DOC) levels were as high as 1.13 and 1.47 nmol/l, respectively. Adrenal scintigram and abdominal CT scan clearly showed a right adrenal tumour in the 52-year-old woman. After adrenalectomy plasma DOC level decreased to the normal level of 0.12 nmol/l, and her blood pressure and serum potassium became normal. Abdominal CT scan revealed no finding of adrenal tumour in the older woman. These results indicate that these two patients had hypermineralocorticism with elevation of plasma DOC. One patient had a DOC-producing adrenal adenoma, and the other probably had bilateral adrenal hyperplasia.     

Usefulness of the [13C]-urea breath test for detection of Helicobacter pylori infection in fasting patients

Most of the reported [¹³C]-urea breath test procedures use a test meal, which is believed to assist in the spread of the [¹³C]-urea solution into the entire stomach, as results without a test meal may mainly reflect urease activity in the antrum. Yet, procedures for the [¹³C]-urea breath test and interpretation of the obtained ¹³C excess value have not been well established. We carried out the present study to validate the usefulness of the [¹³C]-urea breath test in fasting subjects and to establish cut-off values. [¹³C]-Urea breath tests were performed on 258 Helicobacter pylori-positive and 151 -negative subjects (247 H. pylori positive and 26 negative prior to any H. pylori cure treatment and 125 H. pylori negative and 11 positive after undergoing H. pylori cure treatment). The breath test procedure was performed under the following conditions: an 8 h fast, mouth washing before and after dosing, administration of 100 mg [¹³C]-urea, collection of breath sample in a plastic bag, a baseline and a 20 min sampling point and subject in a sitting position. Delta-¹³C at the 20 min sampling point in H. pylori-positive and -negative subjects was 31.0 ± 1.25 and 1.6 ± 0.11%o, respectively. Although the mean Δ¹³C value was greatest in duodenal ulcer or ulcer scar patients, there were no significant differences among mean Δ¹³C values in the various diseases. From Receiver Operator Characteristic curves and calculation of accuracy of the test, a cut-off value of 5.0%o is considered to be appropriate for diagnosis of H. pylori infection, which provides 96.7% specificity and 96.5% sensitivity, suggesting that the [¹³C]-urea breath test in the fasting state is as effective in detecting the presence of H. pylori as other reported methods.     

Effects of genetic defects in the CYP2C19 gene on the N-demethylation of imipramine, and clinical outcome of imipramine therapy

Abstract  The relationship between the genetic polymorphism of S-mephenytoin 4'-hydroxylation catalyzed by CYP2C19 and the N-demethylation of imipramine was examined in 10 Japanese depressed patients. Five patients, who were poor metabolizers of S-mephenytoin, were determined to be either homozygous for a mutation in exon 5 or heterozygous for mutations in exon 4 and exon 5 of the CYP2C19 gene. In contrast, five patients, who were extensive metabolizers, had no mutations. The demethylation index (the desipramine/imipramine ratio) was significantly lower in patients with genetic defects. Plasma levels of imipramine and 2-hydroxyimipramine normalized by the daily dose (mg) per weight (kg) were significantly higher in patients with genetic defects. This suggests that the N-demethylation of imipramine is impaired in patients with genetic defects in the CYP2C19 gene, and that genotype determination may be useful in preventing side effects induced by unexpectedly elevated levels of imipramine.     

Color Doppler ultrasonography as a routine clinical examination in male infertility

AIM: We assessed the value of scrotal color Doppler ultrasonography as a routine examination in infertile men. METHODS: Color Doppler ultrasonography was performed in 545 infertile men with a mean age of 35.8 years to detect intrascrotal abnormalities. Findings were compared with those of physical examination. RESULTS: Intrascrotal abnormalities were detected by ultrasonography in 65.3% of patients. Of 374 abnormalities, 58.3% were undetected by physical examination. Left varicocele was found in 313 patients (57.4%); testicular microlithiasis in 30 (5.5%); epididymal cyst in 21 (3.9%); right varicocele in 4 (0.8%); and testicular cysts in 3 (0.6%). One occurrence each (0.2%) was found for testicular tumor, intrascrotal hemangioma, and hydrocele of the spermatic cord. Compared to ultrasonography, sensitivity in detecting left varicocele by physical examination was 58.4%; specificity, 79.3%; accuracy, 67.3%; and positive predictive value, 79.3%. Venous diameters in the pampiniform plexus were 3 mm or more in 61.5% of 130 subclinical left varicoceles. Of 30 patients with testicular microlithiasis, 14 had varicocele, 2 had epididymal cyst,s 3 had a history of mumps orchitis, 1 had retractile testis, and 1 had a history of orchiectomy for contralateral testicular tumor. CONCLUSIONS: The routine Color Doppler ultrasonography is valuable for diagnosing scrotal abnormalities in infertile men, frequently detecting non-palpable lesions.     

Electrophysiological Demonstration of Anterograde Concealed Conduction in Accessory Atrioventricular Pathways Capable Only of Retrograde Conduction

Anterograde concealed conduction into the concealed accessory atrioventricular (AV) pathway has been postulated to be one of the factors preventing the reciprocating process via the accessory pathway in patients with the concealed Wolff-Parkinson-White(WPW) syndrome but its presence has not been documented. To demonstrate the occurrence of anterograde concealment, 12 patients with the concealed WPW syndrome were selected for study. A pacing protocol was designed in which the retrograde conduction of the ventricular extrastimulus over the accessory pathway was assessed during ventricular pacing aione (conventional method) and during the AV simultaneous pacing (simultaneous method); the results were then compared. When the high right atrium was simultaneously paced, the effective refractory period of the concealed accessory pathway shortened as compared with the conventional method in five of 12 patients (from 341.7 ± 110.8 to 312.5 ± 108.2 msec, n = 12), whereas, it decreased in all patients studied when the coronary sinus near the accessory pathway was simultaneously paced (from 375.7 ± 135.0 to 287. ± 116.1 msec, n = 7). These results demonstrate that the AV simultaneous pacing frequently shortens the refractoriness of the concealed accessory AV pathway and such facilitation seems to he well explained by the probable anterograde concealment in it and peeling back of the refractory barrier.