Spin trapping agent, phenyl N-tert-butyl nitrone, inhibits induction of nitric oxide synthase in endotoxin-induced shock in mice

Spin trapping agent, phenyl N-tert-butyl nitrone (PBN) significantly reduces mortality due to lipopolysaccharide (LPS)-induced shock in Balb/c mice as had previously been shown in rats. We hypothesized that PBN decreases mortality by directly or indirectly inhibiting nitric oxide (NO) generation. Therefore, we determined the effect of PBN administration on LPS-induced NO generation in mice. NO generation was monitored in the mouse liver after administration of LPS by an in vivo NO-spin trapping, followed by ex vivo EPR measurement. When the mice was treated with PBN 0.5hr before LPS administration, NO generation in the liver was reduced by 80%. However, when PBN was given 3hrs after LPS, NO generation did not change. Both pre- or post-administration of NO synthase (NOS) inhibitor, NG-monomethyl-L-arginine inhibited the NO generation. Western blotting of inducible NOS (iNOS) in mouse liver cytosol obtained from PBN-pretreated animals demonstrated a decreased expression of iNOS, indicating the reduction in NO generation was caused by the decrease in the amount of enzyme present but not by the inhibition of iNOS enzyme activity per se.

Effects of alcohol moderation on blood pressure and intracellular cations in mild essential hypertension

It is known that moderation of alcohol intake reduces blood pressure, although the exact mechanism has not yet been established. To clarify the hypotensive mechanism of alcohol reduction, we evaluated the change in cellular magnesium and sodium metabolism during alcohol reduction in mild hypertensive patients. We measured intraerythrocyte sodium and magnesium, intraplatelet free magnesium concentrations, and erythrocyte ouabain-sensitive 22Na efflux rate constant (Kos) in 17 mild essential hypertensive patients regularly consuming more than 40 g/day of alcohol, before and after 4 weeks of alcohol reduction, and 12 age-matched nondrinking hypertensives. Intraerythrocyte magnesium (P < .01) and intraplatelet free magnesium (P < .05) concentrations were significantly lower in drinkers than in nondrinkers. In drinkers, advice to reduce alcohol intake for 4 weeks resulted in a reduction in self-reported alcohol consumption from 461.7 to 71.6 g/week, a significant fall in both supine systolic blood pressure (136.3 +/- 10.8 to 130.8 +/- 11.3 mm Hg, P < .001) and supine diastolic blood pressure (85.1 +/- 8.6 to 82.6 +/- 8.7 mm Hg, P < .05). The fall in mean blood pressure correlated positively with the reduction in weekly alcohol consumption. Intraerythrocyte magnesium and Kos were increased (P < .05, P < .01, respectively), while intraerythrocyte sodium was decreased (P < .01). The increase in intraerythrocyte magnesium correlated negatively with the fall in mean blood pressure and positively with the increase in Kos, which correlated negatively with the decrease in intraerythrocyte sodium.(ABSTRACT TRUNCATED AT 250 WORDS)

Alternation of QRS morphology and effect of radiofrequency ablation in idiopathic ventricular tachycardia

We performed electrophysiological studies in 13 patients with idiopathic VT and attempted radiofrequency (RF) catheter ablation in 4 of them.

RESULTS

VT was induced by programmed stimulation in all patients and the mean cycle length was 363 +/- 58 msec. In 8 of 13 patients (62%), alternation of either the cycle length and/or morphology of VT was observed. Transient entrainment was achieved in all patients by rapid pacing from the right ventricular outflow tract so reentry was considered the underlying mechanism of VT. The site of earliest activation (EAS) during VT was located at the apicoposterior portion of the left ventricular septum and used as the target site for RF catheter ablation. Spikelike presystolic activity was detected 20-40 msec prior to the large deflection of the local electrogram in four patients. VT was terminated by a few seconds of RF current in all four patients, but subsequently new VTs with a slightly different morphology were induced in three of them and re-mapping showed a shift of the EAS. After additional RF ablation at the new EAS, VT was no longer induced. No complication was noted and VT did not recur during a follow-up period for a mean of 9.3 +/- 5.2 months.

CONCLUSION

RF catheter ablation seems useful and safe for idiopathic VT. The alternation of QRS morphology and the findings at the time of catheter ablation suggest that an alternative pathway or multiple exists may be present in some patients with idiopathic VT, because the change in VT morphology was associated with a shift of the EAS.

Radiofrequency current catheter ablation for ventricular tachycardia

Radiofrequency current catheter ablation was attempted for 17 morphologies of ventricular tachycardia (VT) in 14 patients. Five patients had underlying heart disease. The site of VT origin was determined as the earliest site of ventricular activation, or by pacing within the area of slow conduction. In 15 VTs, ablation was performed during VT, and 12 VTs (80%) were terminated within an average of 5.4 +/- 4.2 seconds. After ablation, 14 VTs (14/17 = 82%) of 11 patients (11/14 = 79%) could not be induced by electrical stimulation. Radiofrequency ablation appeared to be more effective in VTs without underlying heart disease (91%), and in VTs originating from the right ventricle (100%). Successful ablation sites usually showed a normal local electrograms during VT. Ablation in the slow conduction area was attempted in 3 VTs, and 2 VTs became noninducible. The mean number of applications of radiofrequency current for each VT origin was 7.7 +/- 6.4 at 20-50 Watts. In 4 patients, application of radiofrequency current was required 10 or more times because of a possible large arrhythmogenic area, or because of reinduction of VT, even though VT was terminated by radiofrequency current. No major complication was observed except for complete right bundle branch block in 1 patient.

IN CONCLUSION

(1) Radiofrequency catheter ablation was considered to be effective and safe, especially for VT without underlying heart disease or VT originating from the right ventricle. (2) Ablation during VT was considered to be useful for identifying the proper ablation site and to avoid creating an unnecessary lesion.

[Lennox-Gastaut syndrome with series of spasms intermixed with tonic seizures]

A patient with Lennox-Gastaut syndrome developed an unusual feature of periodic spasms (PS), intermixed with tonic seizures. At age 14, she began to have unilateral seizures on awaking, followed by series of spasms Each spasm consisted of rotation of the head to the left and global muscle contraction of the whole body lasting for 0.5-1 second. Ictal EEGs revealed diffuse high voltage slow waves (HVSW), sometimes superimposed upon by diffuse low voltage fast activity, which was related to the increase of muscle activity following the spasms. When the duration of the fast activity on EEG became longer than 2 seconds, the peculiar seizures consisting of combination of asymmetrical spasms and tonic seizures occurred. It is speculated that the fast activity superimposed on HVSW seen in PS represents a transition from PS to tonic seizures.

Hepatitis C viral markers in patients who received blood that was positive for hepatitis C virus core antibody, with genetic evidence of hepatitis C virus transmission

BACKGROUND

Despite the use of the anti-c100-3 assay for blood donor screening, posttransfusion non-A,non-B hepatitis still occurred. A more sensitive assay should be developed to prevent this.

STUDY DESIGN AND METHODS

Stored serum specimens from 2020 healthy blood donors who were negative for c100-3 antibody to hepatitis C virus (HCV) were retrospectively screened for the presence of antibodies against a core protein of HCV using an enzyme-linked immunosorbent assay and Western blot analysis as part of a study on posttransfusion non-A,non-B hepatitis.

RESULTS

Eight (0.4%) of the 2020 donors were positive for HCV core antibody. Posttransfusion non-A,non-B hepatitis occurred in 5 of five patients known to have received blood that was positive for HCV core antibody and 1 of 141 patients transfused with blood that was negative for HCV core antibody. The total incidence of posttransfusion non-A,non-B hepatitis was 4.1 percent (6/146). The nucleotide sequence of the nonstructural 5 region of the HCV genome obtained from two donors and corresponding recipients was also analyzed. The HCV genome sequences were identical for one donor-recipient pair, and there was 99.4-percent homology for a second pair.

CONCLUSION

Anti-core-positive blood proved to be highly infectious for HCV, and this validated the use of the second-generation anti-HCV assay for blood donor screening.

A case of early infantile epileptic encephalopathy (EIEE) with anatomical cerebral asymmetry and myoclonus

The authors report a case of early encephalopathy with myoclonus, tonic spasms and a suppression-burst pattern on electroencephalography (EEG) associated with unilateral cerebral hypertrophy following hemiatrophy. This patient showed frequent myoclonus in relation to a suppression-burst pattern resembling that in early myoclonic encephalopathy (EME). Moreover, the case also showed tonic spasms, from the age of 13 days, in series, as seen in Ohtahara syndrome. On the other hand, there was a previously undescribed peculiar CT scan finding, which showed hypertrophy of the right cerebral hemisphere at birth, following hemiatrophy. Neuropathological examination revealed cerebral atrophy associated with heterotopia and an ependymal hyperplasia in the right hemisphere, suggesting hemimegalencephaly. This case should be classified as Ohtahara syndrome accompanied by myoclonus, because of the spasms in series interrupting the suppression-burst pattern, and the etiological factor of brain malformation. The nosological aspects of this epileptic encephalopathy are discussed.

Alternation in the fusion complex during constant pacing of sustained ventricular tachycardia

In a patient with sustained ventricular tachycardia (VT), we observed two different conduction times through the reentry circuit at the critical paced cycle length. The cycle length of the VT was 420 msec and overdrive pacing initially performed at a paced cycle length of 400 msec and repeated at decrements of 10 msec until the VT was interrupted at a paced cycle length of 320 msec. During rapid pacing, constant fusion and progressive fusion were confirmed. The first post-pacing return cycle was identical to each paced cycle length. The conduction time between the stimulus artifact and the orthodromically captured electrogram at the left ventricle was constant at 350 msec in each paced cycle length. However, only at a pacing cycle length of 360 msec two conduction times were alternatively observed, one of 350 msec and the other of 365 msec. When the conduction time changed from 350 msec to 365 msec, morphological alternation both in the surface QRS complex and in the orthodromically captured electrogram was evident. Dual slow pathways or a single slow pathway with plural exits from the reentry circuit is a likely mechanism of the alternation.

[Prognosis of epilepsy in psychoneurologically normal children]

Prognosis of 175 psychoneurologically normal children with the onset of epilepsy after 18 months of age were studied. The remission rate of partial epilepsy (81 of 107 cases, 76%) was higher than that of generalized epilepsy (34 of 56 cases, 61%). Prognoses for patients with sleep epilepsy (52 of 62 cases, 84%) were better than those for patients with waking epilepsy (63 of 101 cases, 62%). Most (95%) of the children with sleep epilepsy had partial epilepsy, including benign childhood epilepsy with centrotemporal spike (BECT, 36 cases) and partial epilepsy other than BECT (23 cases). Benign courses were not limited to BECT patients. Generalized waking epilepsy other than absence had the lowest remission rate. Eleven children exhibited mild mental retardation on last examination. Most of them had atypical absence and/or myoclonic seizures with the onset of seizure before 3 years of age. It appeared important to classify the epileptic children with regard to time of seizure occurrence as well as seizure type to determine their prognoses.

Clinical symptoms of open lock position of the condyle. Relation to anterior dislocation of the temporomandibular joint

Nine cases of open lock position of the condyle of the temporomandibular joint (TMJ) are reported. In two patients recurrent dislocation of the TMJ was diagnosed clinically, and four had previous episodes of anterior dislocation. An arthrotomographic examination revealed that the condyles of the affected TMJs were located anterior to the anterior bands of the disks at an open-mouth position. An arthrographic fluoroscopic examination showed that the anterior bands mechanically obstructed the anteriorly displaced condyles from posterior movement into the articular fossae to various degrees at open-mouth position. One cause of anterior dislocation of the TMJ is thought to be fixation of the condyle in the open lock position resulting from a disturbance of a neuromuscular mechanism. In the two patients with dislocation, occlusal treatment eliminated muscular symptoms and the dislocations completely disappeared.

Expression of Fos-like immunoreactivity by yohimbine and clonidine in the rat brain

To elucidate the role of alpha 2-adrenoceptors in transcriptional control in the rat brain, we localized the Fos-like immunoreactivity (Fos-LI) induced by alpha 2-adrenoceptor agonists and by an antagonist. Injections of yohimbine (5 mg/kg, i.p.) into rats led to the induction of Fos-LI in areas with a dense alpha 2-adrenoceptor binding such as the locus coeruleus, the bed nucleus of stria terminalis, the central nucleus of amygdaloid complex, the paraventricular nucleus, the nucleus tractus solitarius, and ventrolateral medulla oblongata. Clonidine (500 micrograms/kg, i.p.) suppressed the Fos expression by yohimbine in these nuclei, and clonidine (100 micrograms/kg, i.p.) or guanabenz (4 mg/kg, i.p.) induced Fos-LI in oxytocin neurons in the paraventricular and supraoptic nuclei in the hypothalamus. Thus, the alpha 2-adrenoceptor is involved in transcriptional control via Fos expression in neurons related to autonomic and other functions.

[All-trans retinoic acid induced a complete remission in a case of refractory relapsed acute promyelocytic leukemia]

Forty five year old male suffering from relapsed acute promyelocytic leukemia (APL) was treated with all-trans retinoic acid (ATRA) and attained second complete remission (CR) without bone marrow hypoplasia. He was diagnosed as having APL in September 1989. The DCMP-85 regimen first induced CR in October, however the disease relapsed in September 1990. The DCMP-85 and and the MEC (MIT, ETOP, Ara-C) regimens were applied for re-induction without success. Then, 45 mg/m2/day ATRA was given orally from December 28, 1990. Laboratory data before ATRA treatment were as follows; 35.4% leukemic cells in the bone marrow, Hb 11.0 g/dl, Plt 130,000/microliters, WBC 5,100/microliters without leukemic cells, and no DIC was detected. During the treatment, his bone marrow was examined frequently. The bone marrow series showed no hypoplasia at any time and gradual reduction of leukemic cells with proliferation of mature granulocytes. CR was attained on January 21, 1991. DIC did not develop. Cytogenetic anomalies including t(14;17;15) (q24;q11.2;q22) reduced from 29/30 cells at relapse to 4/30 cells at the time of CR. Dryness of mouth and lips, irritation around eyes and the elevations of GOT, GPT and triglyceride level were seen as the side effects of ATRA, however they were tolerable.

Incidence and mechanism of interruption of reentrant ventricular tachycardia with rapid ventricular pacing

BACKGROUND

Information concerning the electrophysiological characteristics of the reentrant circuit is still limited. To understand the incidence and mechanism of pacing-induced interruption of ventricular tachycardia (VT), rapid pacing was performed to entrain VT, and the local electrogram at the VT origin and the surface electrocardiogram were analyzed.

METHODS AND RESULTS

Among 25 patients, evidence of transient entrainment was confirmed in 20 patients, but the critical paced cycle length at which VT was interrupted was obtained in 13 patients when the paced cycle length was decreased in steps of 10 msec. During pacing at the critical cycle length (defined as block cycle length), changes in the local electrogram at VT origin were confirmed in all of the 13 patients; that is, 1) a change in morphology and 2) a change in the timing of activation: a sudden shortening in the stimulus to local electrogram time (third entrainment criterion by Waldo). The two changes mean that the exit is activated from a different direction (retrograde capture) because of an orthodromic block in the slow conduction zone. The QRS complex in the surface electrocardiogram showed a change in configuration from the fusion complex to the fully paced one at the same time when the exit was captured antidromically.

CONCLUSIONS

Based on our observations in these patients, ventricular tachycardia interruption is very often associated with orthodromic block in the reentrant circuit at a critical cycle length of rapid pacing.

Entrainment of ventricular tachycardia in arrhythmogenic right ventricular tachycardia

In two patients with arrhythmogenic right ventricular dysplasia (ARVD), sustained ventricular tachycardia (VT) was induced by programmed stimulations during serial drug testings. One patient had five and the other had two VT morphologies, and the sites of origin were determined by endocardial catheter mappings. When overdrive pacing was performed, constant fusion in the QRS complex was observed in the two patients. Constant fusion of a different degree was also observed at different paced cycle lengths. Both patients had dilated right ventricles and wall-motion abnormality, and the diagnosis of ARVD was further confirmed by the specimen resected at the site of origin of VT. Therefore, VT in ARVD can be entrained and reentry is the most likely mechanism of such VT.

Prevalence of antibody against non-A, non-B hepatitis virus in Japanese patients with hepatocellular carcinoma

Antibodies against a possible causative agent of non-A, non-B hepatitis, hepatitis C virus (HCV), in Japanese patients with hepatocellular carcinoma were analyzed using the enzyme-linked immunosorbent assay (ELISA) system from Ortho Diagnostic Systems, Japan. Fifty of 58 cases of hepatitis B virus surface antigen (HBsAg)-negative hepatocellular carcinoma were positive for the antibody (86%) and 8 of 42 cases of HBsAg-positive hepatocellular carcinoma were positive (19%). Among patients with HBsAg-negative hepatocellular carcinoma, the prevalence of the antibody was greater among those who had received a blood transfusion (97%) than among those with no history of transfusion (70%). Only 3 of 54 patients with cancers other than hepatocellular carcinoma were found to be antibody-positive (5.6%) and all three patients had a history of blood transfusion. These results show a close relationship between the presence of anti-HCV antibody and HBsAg-negative hepatocellular carcinoma in Japan.