Reappraisal of the coupling interval of ventricular extrasystoles as an index of ectopic mechanisms

OBJECTIVE

A mathematical model of modulated ventricular parasystole based on the relation between the coupling interval and the preceding RR interval was developed in an attempt to distinguish between parasystolic automaticity and other mechanisms. MATHEMATICAL MODEL: The relation between the coupling interval and the preceding RR interval was examined by plotting the coupling interval of each extrasystole against the preceding RR interval (coupling interval/RR diagram). The coupling interval/RR diagrams obtained from simulations with various modulation modes suggested that the parasystolic mechanism was likely when the dots representing extrasystoles appeared as discrete clusters. In contrast, a linear horizontal accumulation of dots indicated a non-parasystolic mechanism.

CLINICAL OBSERVATION

To verify the validity of the simulations, 24 hour electrocardiographic recordings from 60 patients with frequent ventricular extrasystoles (> 1000/day) were analysed to determine whether the extrasystoles showed intrinsic periodicity. Intrinsic periodicity indicative of a parasystolic mechanism was seen in 14 (93%) of 15 patients in whom the coupling interval/RR diagram was characteristic of a parasystolic mechanism. When the coupling interval did not change (variability < 200 ms) over a wide range of RR intervals (> 700 ms) intrinsic periodicity was never identified (0/17). Parasystolic automaticity was the likely mechanism in 11 of the remaining 28 patients (39.3%) in whom coupling interval/RR diagrams were not definitive.

CONCLUSION

These data indicate that definite patterns of coupling interval/RR diagrams can be used to distinguish between parasystolic and non-parasystolic mechanisms.

[A case of tranilast-induced cystitis with transient ECG changes]

A case of tranilast (Rizaben)-induced cystitis accompanied with possibly hypereosinophilic heart syndrome was described. A 75-year-old male, who had been taking tranilast for allergic dermatitis for two months, was admitted for severe bladder stimulating symptoms which was unresponsive to antibiotic therapies. Clinical examination revealed tenderness of the prostate, aseptic pyuria, eosinophilia, liver dysfunction and electrocardiographic disorders including atrial fibrillation, T-wave inversions and lowered ST segment without any cardiac symptoms. Cystitis symptoms, pyuria, eosinophilia and liver dysfunction improved within several days after discontinuance of tranilast, and ST-T changes on ECG gradually normalized within a few months. Tranilast-induced cystitis has been demonstrated as a type of eosinophilic cystitis. Since pathologic findings of eosinophilic cystitis and hypereosinophilic heart syndrome are markedly similar and all symptoms and signs disappeared after deprivation of tranilast, it appears likely that eosinophilic inflammation was induced to the heart, liver, bladder and prostate of the current patient by tranilast.

[The clinical significance of tissue, blood and urine polyamine in renal cell carcinoma]

With the use of a newly developed and convenient enzymatic method, tissue, urine and blood polyamine (diamine, spermidine and spermine) levels were evaluated as a tumor marker of renal cell carcinoma (RCC) in 50 cases with the disease. Furthermore, blood and urine polyamines were periodically determined and evaluated as a follow-up marker. The pretreatment three polyamine levels in tissue, blood and urine of the patients were all significantly higher than those of the controls. However, because of their low sensitivities, they were not always decisive for biochemical diagnosis of RCC. Tissue spermidine levels were increased with the advance of the stages. Tissue diamine level also showed a good correlation with the pathological grade. Tissue diamine was found to predict distant metastasis. Blood spermidine and urine diamine were useful as follow-up markers. In conclusion, combined determination of tissue, blood and urine polyamine levels was thought to be useful as tumor markers of RCC.

The amplified long genomic sequence (ALGS) located in the centromeric regions of mouse chromosomes

We reported previously that the haploid genome of standard strains of laboratory mice contains approximately 70 copies of an amplified long genomic sequence, designated ALGS, that includes a retroposon of the gene for elongation factor 2 (MER). The length of each repeating unit is more than 60 kb, and the sequence of the unit is highly conserved among the repeats. In the present study, Southern blot analysis of the genomes of wild rodents demonstrated that the ALGS is present in all subspecies of Mus musculus and is abundant in M. spicilegus, whereas it is absent in M. spretus as well as in Rattus and other closely related genera. This result indicates that the amplification occurred after the species differentiation with the genus Mus and at least prior to the differentiation of subspecies of M. musculus. To locate chromosomal positions of the ALGS, in situ hybridization was carried out with laboratory strains and wild mice. It appears that the ALGS is located in the centromeric regions of most chromosomes in laboratory mice, M. musculus and M. spicilegus, whereas no positive signals were observed with M. spretus, in accordance with the results from the Southern blotting analysis.

Endovascular coil embolization of a recurrent giant internal carotid artery aneurysm via the posterior communicating artery after cervical carotid ligation: case report

The case of a 29-year-old man with a giant fusiform aneurysm of the left internal carotid artery (ICA) is presented. The aneurysm, treated by cervical ICA ligation and extracranial-intracranial bypass, recurred 4 years later owing to recruitment of the posterior communicating artery (PCoA). Because of the previous bypass surgery a direct surgical approach was excluded. After an initial failure with balloon embolization, the aneurysm was embolized successfully with occlusive platinum microcoils through the microcatheter navigated into the aneurysm via the enlarged PCoA. Endovascular coil embolization may be useful in the treatment of cerebral aneurysms not amenable to direct surgery or balloon embolization.

Involvement of the cholinergic system in the effects of nefiracetam (DM-9384) on carbon monoxide (CO)-induced acute and delayed amnesia

The effects of N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)-acetamide (DM-9384, nefiracetam), a cyclic derivative of GABA, were investigated in the carbon monoxide (CO)-induced amnesia model in mice using the passive avoidance task. Memory deficiency occurred when mice were exposed to CO before memory was completely consolidated after training (acute amnesia), at 7 days before training and 7 days after training (delayed amnesia). DM-9384 prolonged the step-down latency in mice with CO-induced amnesia. Scopolamine blocked the anti-amnesic effect of DM-9384 on delayed amnesia that had been induced by pre- or post-training exposure to CO. Bicuculline had a tendency to antagonize the anti-amnesic effect of DM-9384, but this tendency was not significant. Under these conditions, no significant change in the activity of choline acetyltransferase and glutamic acid decarboxylase was observed in the frontal cortex, striatum and hippocampus. These results suggest that DM-9384 potentiates cholinergic neuronal function and that it may modify acquisition and/or consolidation of memory.

BY-1949 elicits vasodilation via preferential elevation of cyclic GMP levels within the cerebral artery: possible involvement of endothelium-mediated mechanisms

The pharmacological mechanisms by which BY-1949, a novel dibenzoxazepine derivative, increases in regional cerebral blood flow, were investigated using the canine basilar artery in vitro. BY-1949 inhibited contractions elicited by serotonin (5-HT), prostaglandin (PG) F2 alpha, endothelin and phorbol-12,13-diacetate (PDA), respectively, to the same extent. In addition, pretreatment of the artery with methylene blue significantly suppressed the vasodilating effect of BY-1949. BY-1949 also dose dependently suppressed contractions of the basilar artery induced by CaCl2 (Ca2+) in a non-competitive manner. Biochemical studies disclosed that BY-1949 significantly increased cyclic GMP without causing any apparent change in cyclic AMP. These increases in cyclic GMP were virtually abolished after the endothelial cells were removed. These results strongly suggest that the increased regional cerebral blood flow induced by BY-1949 is explicable, at least partly, in terms of a preferential elevation of cyclic GMP within the cerebral vasculature, where the endothelium plays a pivotal role.

Neurochemical correlates of selective neuronal loss following cerebral ischemia: role of decreased Na+,K(+)-ATPase activity

In order to investigate the role of Na+,K(+)-ATPase in the development of neuronal necrosis following cerebral ischemia, ischemia was induced in gerbils by occluding the common carotid artery unilaterally for 10 min. A time-course analysis revealed that significant reductions of the Na+,K(+)-ATPase activity in the cerebral cortex and hippocampus were manifested at 15 min, 30 min, and 1 h, and returned to the control level one day following recirculation. No apparent alterations of the Mg(2+)-ATPase activity, on the other hand, were obtained throughout the experimental period. Furthermore, Scatchard analyses of [3H]ouabain binding to the cerebral cortex membranes disclosed that the Bmax values invariably decreased without any change of Kd values following ischemia. It has also been shown that treatment of the animals with an agent known to mitigate ischemic neuronal necrosis, i.e. BY-1949, significantly reversed such derangements. These results suggest that the recovery of decreased Na+,K(+)-ATPase activity shortly after ischemia exerts a protective effect against ischemic brain damage.

Modulation of protein C inhibitor activity by histidine-rich glycoprotein and platelet factor 4: role of zinc and calcium ions in the heparin-neutralizing ability of histidine-rich glycoprotein

Effects of zinc and calcium ions on the heparin-neutralizing abilities of histidine-rich glycoprotein (HRG) and platelet factor 4 (PF4) were examined. Both HRG and PF4 effectively neutralized the ability of heparin to accelerate the activated protein C (APC) and the thrombin inhibitions by protein C inhibitor (PCI). the heparin-neutralizing ability of HRG in the APC inhibition by PCI, however, was decreased in a Ca(2+)-dependent manner and apparently lost at 1 mM Ca2+, while it was enhanced by Zn2+ regardless of the presence or absence of Ca2+. The heparin-neutralizing ability of HRG in the thrombin inhibition by PCI was not affected by Ca2+. In contrast to HRG, there was no significant difference in the heparin-neutralizing ability of PF4 in the presence or absence of 1 mM Ca2+. These results strongly suggest additional physiological functions of HRG and PF4 as modulators of PCI.

A strategy of cystine stone management

Simple mechanical disintegration of cystine calculi by extracorporeal shock wave lithotripsy and/or percutaneous nephrolithotomy is being performed widely around the world. However, it cannot be denied that the cystine calculus is one of the most difficult stones for mechanical disintegration. We previously reported the oral medical chemolysis of cystine calculi in 1982 and a third of the patients became stone-free. In another third of the patients the cystine component was replaced by apatite during the medical treatment and apatite stones formed in this manner are easily disintegrated. In view of the complications of mechanical disintegration, oral medical treatment for chemolysis should be recommended before simple destruction of cystine calculi.

Incidentally diagnosed renal cell carcinoma

We analyzed the incidence, sex and age distribution, diagnostic methods and survival rate of incidentally detected renal cell carcinomas (RCCs) and compared these factors with those of symptomatic RCCs. Of 141 patients with RCC treated between 1980 and 1989, 44 cases (31.4%) were incidentally detected. Thirty-one of these 44 cases were diagnosed by abdominal ultrasonography. The age of the incidental cases was significantly higher than that of the symptomatic ones (p = 0.045), particularly in male patients (p = 0.049). The tumor size in incidental cases was smaller and tumor stage earlier (p less than 0.0001). Moreover, the grade of malignancy was significantly lower, and clear cell type tumors were more frequently detected in the incidental cases. No difference was observed between the survival rates of incidental and symptomatic cases with stage 1 or 2 tumors. Of the incidental cases with stage 1 or 2, however, no patient with a tumor 3 cm or less in diameter has died. In conclusion, abdominal ultrasonography is a useful tool to detect RCC at an early stage, and patients with a relatively small tumor tend to have a good prognosis.

An Activation of Synaptosomal Na+, K+-ATPase by a Novel Dibenzoxazepine Derivative (BY-1949) in the Rat Brain: Its Functional Role in the Neurotransmitter Uptake Systems

In search of factors mitigating the final outcome of ischemic and epileptic brain damage, we tested a novel dibenzoxazepine derivative (BY-1949), as the compound has been shown to be effective under these two conditions. First, using rat brain, we assessed whether or not BY-1949 affects the Na+,K(+)-ATPase activity. Although in vitro applications of either BY-1949 or its three major metabolites did not cause any apparent effects, both acute and chronic oral administrations of the compound (10 mg/kg) invariably increased the Na+,K(+)-ATPase activity in the synaptosomal plasma membranes by increasing Vmax values. Second, it was shown by this study that the drug treatment caused marked increases in the uptake of both glutamic acid and gamma-aminobutyric acid into the synaptosomes. These results suggest that the activity against ischemic/epileptic brain damage by BY-1949 is explicable, at least partly, in terms of improvement of ionic derangements across the neural membranes via Na+,K(+)-ATPase activation.

Fibrinolytic effect of tissue plasminogen activator on cerebral embolism in stroke-prone spontaneously hypertensive rats

To study the thrombolytic effect of tissue plasminogen activator (t-PA) on cerebral emboli, we characterized cerebral embolization in stroke-prone spontaneously hypertensive rats (SHRSPs) and Wistar Kyoto rats (WKYs). [125I]Fibrin clot particles (20-100 microns diameter) were injected twice at an interval of 90 min into the left internal carotid artery of WKYs and SHRSPs. After each injection, spontaneous embolus dissolution was monitored with a gamma-ray detector placed on the head of the embolic rats. Embolus dissolution was spontaneously generated in 15 min after the injection of fibrin clots. In WKYs, 21% and 42% of the clots were dissolved 30 and 90 min after the second embolization, respectively. On the other hand, the spontaneous embolus dissolution in SHRSPs was significantly lower than that of WKYs, indicating that the endogenous fibrinolytic ability of SHRSPs is less potent than that of normotensive rats. The intravenous administration of t-PA at doses of 75, 250 and 750 micrograms/kg caused a dose-dependent embolus dissolution in SHRSPs. Furthermore, systematically applied t-PA produced embolus dissolution without causing systemic plasminogen activation, fibrinogen breakdown or bleeding. In conclusion, the intravenous administration of t-PA produces selective embolus dissolution without systemic fibrino(geno)lysis in a cerebral embolic SHRSP.

[Primary hyperparathyroidism: problems on surgical indication and procedure]

Between 1959 and Oct. 1990, 307 cases of primary hyperparathyroidism (PHPT) were operated on in our hospital. Among them, 23 cases (7.5%) were asymptomatic chemical type of PHPT, and the incidence of this type has been increasing these days. Various symptoms or signs including urolithiasis, bone disease, cardiovascular disease, gastrointestinal disease, diabetes mellitus and others were associated with PHPT. Especially, as a lethal factor, malignant tumors developed in 14 cases (4.6%); 9 cases of non-medullary thyroid cancer and tumors of other organs. In consideration of these associated disorders, the chemical type of PHPT should be operated prophylactically. In order to reduce operative complications, unilateral exploration is available for the cases of single normally localized adenoma; 85.7% of our 307 cases. Moreover, the positive rate of preoperative localized test by CT and ultrasonography for such adenomas is 78% in the recent 5 years. The predictive values of successful operation by unilateral exploration are 89% in the cases of normally localized single adenoma and 76% in all PHPT.

[A case of synchronous ipsilateral renal cell carcinoma and transitional cell carcinoma]

A case of synchronous ipsilateral renal cell carcinoma with renal pelvic and ureteral transitional cell carcinoma is reported. A 80-year-old man, who had had transurethral resection of bladder tumor three times, was admitted on August, 1989 for recurrence of bladder tumor. Excretory pyelography revealed a filling defect of left renal pelvis. Findings of retrograde pyelography and computed tomography were in accord with those of the excretory urograms. Under a diagnosis of the left renal pelvic and ureteral tumor associated with the bladder tumor, left nephroureterectomy with bladder cuff resection was performed. Pathological diagnosis was renal pelvic and ureteral transitional cell carcinoma with renal cell carcinoma, which existed incidentally in the same kidney. Double unrelated primary carcinoma in urinary tract, especially, double dissimilar primary carcinoma in the same kidney, is rare. To our knowledge, this case is the 20th double cancer in upper urinary tract reported in Japan.

[The effect of kanpou medicine on the growth and aggregation of calcium oxalate crystals in vitro]

The effects of the compositional drugs of kanpou medicine on the growth and aggregation of calcium oxalate crystals were investigated in vitro. In the seeded crystal system, the inhibitory activities were calculated from the change of the number (Ia), total volume (Ig) and fractional volume (I) of crystals determined by a Coulter Multisizer. Among the tested drugs (Takusha, Akyou, Chorei, Bukuryou, Kasseki, Kinsensou, Kagosou), only Takusha and Kagosou had strong inhibitory activities on the growth and aggregation at the concentration of 5 micrograms/ml and 10 micrograms/ml (Ia greater than 80%, Ig, I greater than 90%). No significant correlation was observed between inhibitory activities and alcian blue precipitable polyanions (ABPP) of each drug. Thus some naturally existing substances composing the kanpou medicine may help prevent the stone formation in clinical use.

[Application of the nucleolar organizer regions to urinary cytology and its computer-assisted image analysis]

Quantification of argyrophilic nucleolar organizer regions (AgNORs) stained by the silver colloid method in urinary exfoliative cells from 36 benign urological diseases and 33 transitional cell carcinomas (TCC) of the urinary bladder was carried out. Also, AgNORs of these cells were measured by means of the computer-assisted image analysis system. There was a significant correlation between AgNORs numbers of cells from voided or wash-out smears and those from touch smears (p less than 0.01). The mean AgNOR numbers per nucleus showed a stepwise increase from non-infected benign urological diseases (mean +/- SD: 3.33 +/- 0.60) through infected urological diseases (3.88 +/- 0.58), grade 1 of TCC (5.23 +/- 1.39) and grade 2 of TCC (6.34 +/- 0.86), to grade 3 of TCC (8.09 +/- 1.19). The maximum number of AgNORs in each group indicated almost the same results. The estimation of the distribution of the maximum AgNOR number might be of great value for rapid and reliable detection of bladder cancers. Moreover, the computer-assisted image analysis of AgNORs could offer an objective index for the cytological assessment of urinary bladder diseases including TCC.

[Association of an epidermoid tumor with a cerebral aneurysm on the contralateral internal carotid artery]

A 71-year-old female was evaluated for a sudden loss of consciousness. Initial computed tomography and cerebral angiography revealed a severe subarachnoid hemorrhage, a large cystic lesion in the left occipital region, and an aneurysm at the bifurcation of the internal carotid and the posterior communicating artery on the right side. As the subarachnoid hemorrhage was thought to be due to rupture of the aneurysm, we attempted to clip the aneurysmal neck at first, and 2 weeks later the cystic tumor was removed for the purpose of internal decompression. The extirpated specimen proved to be an epidermoid tumor. Association of a brain tumor and an cerebral aneurysm is very rare, especially a combination of an epidermoid tumor and a cerebral aneurysm, and until now only 2 cases have been reported to the best of our knowledge. Moreover, the epidermoid tumor of our case was located intracerebrally. The phenomenon that the internal carotid aneurysm was on the left side and the tumor on the right side may suggest that these 2 lesions originated quite coincidentally. It is controversial to decide which lesion and when to treat first in a case of association of a tumor and an aneurysm, and we discussed as to the surgical therapy reviewing literature.

Thrombolytic effect of tissue plasminogen activator in a cerebral embolic model

An experimental cerebral embolic model was prepared by an injection of [125I]fibrin clot particles (20-100 microns) into the left internal carotid artery in rats, and the changes in radioactivity of the brain were continuously monitored by a gamma-ray detector. The autoradiograms of the caput transections showed the existence of emboli in small vessels of the left hemicerebrum. After the injection of [125I]fibrin clots, the radioactivity spontaneously decreased to a half of the initial radioactivity at 90 min. The decrease in radioactivity which represented the embolus dissolution was markedly suppressed by an antiplasmin agent, trans-4-aminomethyl cyclohexane carboxylic acid, indicating that the endogenous fibrinolysis through the activation of plasminogen is generated in the cerebral small vessels after the embolization. Consecutive injection of fibrin clots caused a summation of the radioactivity and decreased the rate of dissolution at every embolus preparation. The thrombolytic agents were infused via the left internal carotid artery for 30 min after the second successive injection of fibrin clots. Although the spontaneous dissolution of emboli was observed during the infusion of saline, tissue plasminogen activator (t-PA) as well as urokinase plasminogen activator (u-PA) produced a further dissolution. Approximately half of the emboli disappeared 60 min after the infusion of t-PA at a dose of 75 micrograms/kg and at a dose of 10000 IU/kg, respectively.

[Endourological re-establishment by transluminal puncture for a complete obliteration of traumatic urethral disruption]

We performed transluminal re-canalization by needle puncture under fluoro-endoscopic control on a total of ten patients (membranous urethra, 8; bulbous urethra, 2) with complete obliteration after traumatic urethral disruption. The re-canalized tract was created by balloon dilation, internal urethrotomy or endoscopic resection of the scar tissue. The patient age ranged from 10 to 57 years (mean age; 37.9 +/- 15.3 years). A transluminal puncture was attempted in three patients by transperineal-transurethral approach and in seven by transurethral approach. In one of them, who sustained a complete membranous disruption 5 weeks ago, transluminal puncture failed because of the movable proximal urethra. The remaining nine patients voided without difficulty for the mean follow-up period of 18.1 +/- 14.3 months (range: 2-46). Three patients had mild stress urinary incontinence. A transluminal puncture is less invasive, safe and reliable for re-establishment of the true proximal part of the disrupted urethra. It can be recommended as a useful technique for endo-urological re-establishment for a completely obliterated urethra. Although this endoscopic re-establishment requires urethral sounding or internal urethrotomy for 6 months postoperatively, it may be an alternative to conventional surgical repair.