Synthesis of [[(benzenesulfonamido)alkyl]phenyl]alkanoic acid derivatives containing pyridyl or imidazolyl groups and their thromboxane A2 receptor antagonistic and thromboxane A2 synthase inhibitory activities

As part of our search for a dual inhibitor possessing both thromboxane A2 (TXA2) receptor antagonistic and TXA2 synthase inhibitory activities, some [[(benzenesulfonamido)alkyl]phenyl]alkanoic acid derivatives possessing a pyridyl or imidazolyl group were synthesized. Their TXA2 receptor antagonistic and TXA2 synthase inhibitory activities were evaluated in terms of the inhibitory effects on U-46619-induced guinea-pig platelet aggregation and on thromboxane B2 (TXB2) production in human platelets, respectively. It was found that 3-[4-[2-(1-imidazolyl)-1-(4-chlorobenzenesulfonamido)ethyl]phenyl] propionic acid (22a), containing an imidazolyl group, is a well-balanced dual inhibitor having both TXA2 receptor antagonistic activity (IC50 = 0.31 microM) and TXA2 synthase inhibitory activity (IC50 = 0.39 microM).

An Economic Analysis of Water and Sanitation Infrastructure Improvements in the Colonias of El Paso County, Texas

The authors conducted a cost-benefit analysis of a project to improve water supply and sanitation infrastructure in a rural community (colonia) along the United States-Mexico border. The present value of total costs in the scenario without improvements was $42,937,507, compared with net costs with improvements of $34,600,800. It is estimated that improved access to safe drinking water and solid waste sanitation prevented 155 cases of hepatitis A and 5,165 cases of gastrointestinal illness over 26 years and saved $846,541 in associated health care costs, approximately 10% of the total estimated savings. The majority of benefits was in the form of time savings and increased land values. The authors did not consider the value of improving environmental conditions for future generations and preventing communicable disease epidemics associated with poor sanitation. Accurate value estimates for these benefits might strengthen the argument for undertaking similar infrastructure-improvement projects in the colonias and in other underdeveloped rural areas of the United States. cost-benefit analysis; water supply and sanitation; health care costs; disease-prevention effectiveness Hanley & Belfus, Inc. Int J Occup Environ Health 1077-3525 2 3 1996 July/September Decreases in Subpopulations of T Lymphocytes and Natural Killer Cells in the Blood of Retired Chromate Workers 222 225 EN Takeshi Tanigawa Shunichi Araki Department of Public Health, Faculty of Medicine, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan. Akinori Nakata Takaharu Araki Susumu Sakurai To examine the effects of past exposure to chromates on lymphocyte subpopulations in man, the authors measured subpopulations of T lymphocytes and natural killer (NK) cells by flow cytometry together with B lymphocytes in blood samples from 27 male workers and 22 healthy controls. All subjects were nonsmokers. The numbers of CD4+CD45RA+ (suppressor-inducer), CD8+ (suppressor/cytotoxic) and total T lymphocytes, CD16+CD57+ NK cells, and total lymphocytes in the blood of chromate workers were significantly smaller than those in the blood of healthy controls (analysis of covariance with age as a covariate). It is suggested that suppressor-inducer and suppressor/cytotoxic T lymphocytes and NK cells with intermediate NK cell activity are most susceptible to the effects of past exposure to chromates as compared with other lymphocyte subpopulations such as B and CD4+CD29+ T lymphocytes.

[Differentiation of hypertrophic cardiomyopathy and hypertensive cardiac hypertrophy using the patterns of interventricular septum hypertrophy]

The patterns of interventricular septal hypertrophy were analyzed on two-dimensional echocardiograms to differentiate hypertrophic cardiomyopathy (HCM) from hypertensive cardiac hypertrophy. The control group comprised 110 patients without cardiovascular disease who were matched for age and gender with the hypertension group. The hypertension group comprised 110 patients with uncomplicated essential hypertension, and the HCM group comprised 32 patients in whom the wall thickness of the interventricular septum was 12 mm or more at the mid-portion and no underlying heart disease responsible for cardiac hypertrophy was detected. The interventricular septal thickness was measured both at the thickest portion within 15 mm distal to the aortoseptal junction (basal portion: B) and at the mid-portion (M) in the end-diastolic image on the left parasternal long-axis tomograms, and the B/M ratio was calculated in each patient. The B/M ratio was 1.07 +/- 0.16 in the control group, 1.19 +/- 0.18 in the hypertension group, and 0.83 +/- 0.12 in the HCM group. Compared with the control group, the B/M ratio was significantly high in the hypertension group (p < 0.05) and significantly low in the HCM group (p < 0.01). These results indicate that hypertrophy of the interventricular septum is dominant at the basal portion in hypertensive patients but at the mid-portion in patients with HCM.

Nitric oxide induction by pertussis toxin in mouse spleen cells via gamma interferon

We examined the major pathogenic substances of Bordetella pertussis for the ability to induce nitric oxide, and important biological function of macrophages, via gamma interferon in spleen cells. B. pertussis, which produces a variety of pathogenic substances, including pertussis toxin and filamentous hemagglutinin, causes a severe respiratory disease. Nitric oxide was detected in the culture fluid of spleen cells stimulated with pertussis toxin or its B oligomer but not in the culture fluid of spleen cells stimulated with the A protomer of pertussis toxin or with filamentous hemagglutinin. Incubation of the peritoneal exudate macrophages with pertussis toxin, B oligomer, A protomer, or filamentous hemagglutinin induced little nitric oxide, whereas incubation with gamma interferon induced a significant amount of nitric oxide. The induction of nitric oxide in spleen cells stimulated with pertussis toxin was completely inhibited by anti-gamma interferon antibody. The treatment of spleen cells with anti-Thy-1.2 antibody plus complement followed by stimulation with pertussis toxin decreased the secretion of gamma interferon and nitric oxide. These results suggest that gamma interferon from T lymphocytes stimulated with pertussis toxin induces nitric oxide.

Synthesis and thromboxane A2 antagonistic activity of [[1-aryl(or benzyl)-1-(benzenesulfonamido)methyl]phenyl]alkanoic acid derivatives

In order to find new antiasthmatic and antithrombotic agents, various [[1-aryl(or benzyl)-1-(benzenesulfonamido)methyl]phenyl]alkanoic acid derivatives were synthesized. Evaluation of these compounds for thromboxane A2 (TXA2) antagonistic activities indicated that 4-[4-[(4-chlorobenzenesulfonamido)phenylmethyl]phenyl]butyric acid (6h) ,4-[4-[1-(4-chlorobenzenesulfonamido)-2-phenylethyl]phenyl]butyric acid (6y) and many other compounds have potent inhibitory effects on U-46619-induced guinea-pig platelet aggregation. No significant difference in the inhibitory effect between (+)-6h and its antipode could be detected, although (+)-6h and its antipode could be detected, although (+)-6y was about 10 times more potent than (-)6y. The pKb values of 6h and 6y were estimated to be 8.9 and 10, respectively on U-46619-induced contraction of guinea-pig trachea as a pharmacological measure of TXA2 antagonistic activity. These compounds also showed potent inhibitory effects on U-46619-induced bronchoconstriction in guinea-pig after oral administration in vivo. They were also evaluated for other related pharmacological effects involving the arachidonic acid cascade. It was found that these compounds possess TXA2 synthase inhibitory activity together with TXA2 antagonistic activity, and 6h also possesses weak leukotriene D4 (LTD4) antagonistic activity. Structure-activity relationships for TXA2 antagonistic activity of these derivatives are discussed.

Hypertrophic neuritis due to chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): a postmortem pathological study

A postmortem pathological study of a 65-year-old woman with hypertrophic neuritis associated with hand tremor and limb ataxia is described. There were many onion bulbs and loss of myelinated nerve fibers in the peripheral nerves, including the facial and subserosal visceral nerves. The hypertrophic neuritis was caused by chronic inflammatory demyelinating neuropathy (CIDP), in which interstitial amorphous substances in the endoneurium and onion bulb formation might contribute to nerve swelling. We speculate that visceral autonomic nerves as well as somatic peripheral nerves are involved in patients with a long clinical CIDP course and that peripheral nerve pathology in this disorder shows more heterogeneous changes than previously recognized.

Association of restriction fragment-length polymorphisms in the alcohol dehydrogenase 2 gene with alcoholic brain atrophy

Alcohol abuse can induce brain atrophy, but it only occurs in some alcoholics. To investigate whether genetic polymorphism of alcohol-metabolizing enzymes [including alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH)] was related to alcoholic brain atrophy, we determined restriction fragment-length polymorphisms of the ADH2 and ALDH2 genes in 77 male alcoholics. Computed tomography was used to determine the severity of brain atrophy. Digestion with MaeIII and MboII after polymerase chain reaction amplification showed that the ADH2(1) gene frequency was significantly higher in patients with brain atrophy than in those without brain atrophy (chi 2 = 9.274, p < 0.01), whereas no significant association was observed between brain atrophy and the ALDH2 gene Multivariate analysis (including age, total alcohol intake, liver cirrhosis, and ADH2 genotype) showed that the ADH2(1)/ADH2(1) genotype was associated with alcoholic brain atrophy. These findings suggest that the ADH2(1) allele may be associated with alcoholic brain atrophy.

[Experimental production of tricuspid valve and papillary muscle lesions by premature ventricular contractions due to ventricular stimulation in rabbits]

Ventricular bigeminy or trigeminy can spontaneously occur in anesthetized rabbits forced into the supine position. Premature ventricular contractions (PVCs) of this type are characterized by a long coupling time and superimposition of the following P waves. Rabbits with PVCs of this type frequently develop peculiar mitral complex lesions which are detected by deposition of colloidal carbon. This study examined the effects on the tricuspid complex of artificial PVCs induced by left ventricular pacing in rabbits. Anesthetized rabbits were forced into the supine position under electrocardiographic monitoring. The animals were divided into those with spontaneous PVCs, those with artificial PVCs, and those without PVCs as controls. Colloidal carbon (1 ml) was intravenously injected into the animals the next day. All animals were sacrificed after 1 week. Tricuspid complex lesions were found in 2.0% of animals with spontaneous PVCs, in 17.6% of those with artificial PVCs, and in none of the controls. These results indicate that artificial PVCs induced by left ventricular pacing can cause peculiar tricuspid complex lesions.

Rat 5S rDNA spacer sequences and chromosomal assignment of the genes to the extreme terminal region of chromosome 19

Fragments of the spacer region of genes for rat 5S ribosomal RNA (rDNA), which are tandemly repeated, were amplified by PCR with primers specific to the two ends of the coding region for 5S rRNA. Two amplified fragments of approximately 1.6 kb were subcloned and sequenced. The spacer sequences showed a high degree of sequence identity to each other (99.2%) but substantial divergence from those of analogous mouse clones. The homologous regions in the mouse clones were interrupted by the duplication or deletion of small segments of DNA. A 12-mer, 5'-GGCTCTTGGGGC-3', thought to be responsible for efficient transcription, was located from position -33 to position -22 in the rat -5S clones. The genes were mapped by fluorescence in situ hybridization with cloned fragments of rat 5S rDNA as probe. The genes were localized exclusively in a single telomeric region of chromosome 19.

Increase in CD57 + CD16-lymphocytes in workers exposed to benzidine and beta-naphthylamine: assessment of natural killer cell subpopulations

Previously, we found a decrease in CD4 + CD45RA + T lymphocytes in workers exposed to the aromatic amines (AAs) [benzidine (BZ) and beta naphthylamine (BNA)]. For further investigation of the effects of AAs on lymphocyte subpopulations, we measured natural killer (NK) cell subpopulations using two-color staining with anti-Leu7 (CD57) and anti-Leu11 (CD16) monoclonal antibodies in peripheral blood in 78 male dyestuff workers. The workers had been exposed to AAs before 1972 at a chemical plant, either in the production of AAs (40 workers, high-exposure group) or in other work that involved handling dyestuffs (38 workers, low-exposure group). The controls were 30 "healthy" male volunteers without a history of occupational exposure to AAs or hazardous chemicals. The number of CD57 + CD16- cells in the high-exposure group was significantly higher than that in the controls (P < 0.01, analysis of covariance with age as a covariate). No significant differences were found in CD57 + CD16-, CD57 + CD16+ and CD57- CD16 + NK cells between the low-exposure group and the controls. It is suggested that a decrease in the number of CD4+ T lymphocytes following exposure to AAs might be compensated by the increase in CD57 + CD16- cells, i.e. circulating peripheral lymphocytes with poor NK cell activity.

Variations in ribosomal DNA and mitochondrial DNA among chromosomal species of subterranean mole rats

Restriction site variations in nuclear ribosomal DNA (rDNA) spacers and mitochondrial DNA (mtDNA) were examined in several populations of mole rats with variable numbers of chromosomes, which represented the two superspecies Spalax leucodon (2n = 38, 54, or 62) and Spalax ehrenbergi (2n = 52, 54, 58, or 60). Sequence divergence of rDNA spacers between the members of the superspecies was approximately 8%, while the variation within each superspecies was 4% on average. The intrasuperspecies differentiation of rDNA spacers was generally associated with changes in the diploid number of chromosomes. However, substantial divergence (approximately 1.5%) was also detected among populations with the same diploid number of chromosomes. The sequence divergence of mtDNA among haplotypes of S. ehrenbergi was 10% or higher and among haplotypes of S. leucodon it was approximately 12%. By contrast, the range of sequence divergence between superspecies was 7.4%-12%. The large divergence of mtDNAs within each superspecies of mole rats may be explained by the preservation of ancient mtDNA polymorphisms.

Association of a restriction fragment length polymorphism in the alcohol dehydrogenase 2 gene with Japanese alcoholic liver cirrhosis

BACKGROUND/AIMS

The association of ADH2 polymorphisms with alcoholic liver cirrhosis has not been clearly demonstrated.

METHODS

We investigated the association of two alleles in the ADH2 gene marked by restriction fragment length polymorphisms in patients with alcoholic liver cirrhosis. The ADH2 restriction fragment polymorphisms with Mae III were determined using the polymerase chain reaction on lymphocytes from 76 male Japanese alcoholics (non-cirrhotic patients; 34 cases, cirrhotic patients; 42 cases) and 60 healthy male subjects.

RESULTS

The frequency of the ADH2(1)/ADH2(1) genotype was significantly higher in the alcoholics than in the healthy subjects p < 0.001). In the alcoholics, the genotype ADH2(2)/ADH2(2) was significantly more prevalent in the cirrhotic group than in the non-cirrhotic group (p < 0.05).

CONCLUSIONS

These results suggest that the Mae III polymorphisms of the ADH2 gene may be associated not only with susceptibility to alcoholic liver cirrhosis, but also with the development of alcoholism in Japanese patients.

[Immunohistochemical analysis of adhesion molecules in directional coronary atherectomy specimens]

Chronic inflammatory cells are key components in the progression of atherosclerotic plaques and restenosis after coronary angioplasty. Adhesion molecules are fundamental in inflammatory processes. Therefore, the distributions of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM) were investigated in directional coronary atherectomy specimens obtained from 14 patients, in 6 with acute coronary syndromes (myocardial infarction and unstable angina within 1 month), 6 with old myocardial infarction and 2 with stable effort angina. There were eight primary lesions and six restenotic lesions. Atherectomy tissue fragments were snap frozen and cut into 4 microns thick cryostat sections for immunohistochemical staining by avidin-biotin complex immunoperoxidase techniques using adhesion molecule specific monoclonal antibodies BBIG-I1 (ICAM-1) and BBIG-V1 (VCAM). The cells of lesions were characterized in sequential sections by macrophage marker KP1 (CD68), endothelial marker JC/70A (CD31), and smooth muscle cell marker 1A4 (alpha-smooth muscle actin). Four restenotic lesions that had undergone a prior balloon angioplasty within a few months consisted of intimal proliferation and the other lesions were atherosclerotic plaque. Macrophage-rich areas were seen in the lesions from acute coronary syndromes and/or early restenotic lesions. Expression of ICAM-1 or VCAM was strongly associated with macrophage-rich areas, but VCAM staining was weaker than ICAM-1 except in one restenotic lesion. Macrophages that express ICAM-1 and/or VCAM may be important in the unstable plaques and restenotic lesions related to disease activity of ischemic heart disease.

Gastric adenoma-carcinoma sequence with special reference to p53 and Ki-ras gene alterations

With the aim of detecting the timing of p53 and Ki-ras gene alterations in the gastric adenoma-carcinoma sequence, 19 early gastric adenocarcinomas arising from adenomas were studied. Immunohistochemically, 5 adenocarcinomas were positive for p53; 3 focally and 2 diffusely. The p53 point mutations were detected in a focal area with p53 immunoreactivity in 2 of the 5 p53-positive adenocarcinomas. This indicated that p53 point mutations may play a less crucial part in malignant conversion of adenoma to adenocarcinoma in the stomach than in the colon. No Ki-ras gene mutations at codons 12 and 13 were detected in any lesion. These results suggest that the adenoma-carcinoma sequence in the stomach has a different mechanism from that in the colon.

Zinc promotes the repair of wounded monolayers of cultured vascular endothelial cells

The effect of zinc on the repair of wounded monolayers of bovine aortic endothelial cells in a culture system was investigated. It was morphologically found that zinc promotes the appearance of the cells in the wounded area; cell number in the area was significantly increased by zinc. However, other heavy metals including copper, manganese, nickel and cobalt failed to exhibit a similar effect. The repair induced by exogenous basic fibroblast growth factor (bFGF) was potentiated by zinc but that by exogenous acidic fibroblast growth factor was unaffected by the metal. Promotion of the repair of the wounded area by zinc was completely blocked by either cycloheximide or anti-bFGF antibody. In addition, zinc-induced repair was significantly inhibited by a lipoxygenase inhibitor, nordihydroguaiaretic acid but not by a cyclooxygenase inhibitor, indomethacin. From these results, it is suggested that zinc promotes the repair process of damaged vascular endothelium through the lipoxygenase pathway that mediates the response of vascular endothelial cells to endogenous bFGF.

[Squamous cell carcinoma of the ureter as a late complication of ureterocutaneostomy--a case report]

A case of squamous cell carcinoma of the ureter was reported. A 62-year-old woman, who underwent left nephrectomy and right ureterocutaneostomy at the age of thirty-one because of tuberculosis of the urinary tract, visits our hospital periodically for an ureteral catheter change. An urgent nephrostomy was performed because of ureteral stricture on March 8, 1994. Three months later tenderness and induration appeared at the former ureteral stoma. The resected specimen was histologically diagnosed as squamous cell carcinoma. Right palliative ureterectomy did not produce the desired effects due to the invasion of the tumor into the surrounding organs. In this rare case, it is suggested that chronic infection and irritation of the indwelling catheter might be causative of squamous cell carcinoma of the ureter.

Effects of systolic anterior motion of the mitral valve on haemodynamics. Evaluation by a direct method

We evaluated the effects of systolic anterior motion systolic anterior motion of the mitral valve on cardiac haemodynamics. Seven adult mongrel dogs in which systolic anterior motion-septal contact was observed after dobutamine administration were used. To exclude the effects of left ventricular function and morphology, a stone removal basket catheter was placed in the left ventricular outflow tract, and haemodynamics were compared with the basket closed and opened. The basket was opened five times in three dogs not showing systolic anterior motion-septal contact, but the basket itself did not effect the haemodynamics. In the seven dogs that showed systolic anterior motion-septal contact without left ventricular hypertrophy, the basket was opened a total of 33 times in the presence of various degrees of systolic anterior motion-septal contact. After opening the basket, systolic anterior motion was reduced echocardiographically, and significant (P<0.01) changes were observed in the left ventricle-aorta pressure gradient (from 68 +/- 22 to 25 +/- 15 mm Hg), the systolic ejection period (from 146 +/- 19 to 135 +/- 16 ms), and the stroke volume (SV; from 9.4 +/- 2.9 to 10.1 +/- 3.3 ml). After basket inflation, aortic pressure and aortic flow waveforms changed but the peak pressure and flow velocity did not. The temporal distribution of left ventricular ejection also definitely changed after the basket was opened. No changes were observed in the peak dp/dt, peak negative dp/dt, time constant, left ventricular end-diastolic pressure, or left atrial pressure. These observations in this animal model of systolic anterior motion without left ventricular hypertrophy suggest that: (1) there is no potential for generation of an intra-cavity gradient in the absence of systolic anterior motion of the mitral valve, so that (2) systolic anterior motion narrowed the left ventricular outflow tract and, consequently, produced the systolic ejection period, and affected the left ventricular ejection dynamics, and that (3) the basket catheter is useful because it allows these assessments in the same heart with a nearly fixed left ventricular contractility, at least in our animal model.

Alcohol-metabolizing enzyme polymorphisms and alcoholism in Japan

The liver enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), which are responsible for the oxidative metabolism of ethanol, are polymorphic in humans. Cytochrome P450IIE1, an ethanol-inducible isozyme of liver microsomal P450, is also important in ethanol metabolism. Genetic polymorphisms in the 5'-flanking region of the human cytochrome P450IIE1 gene have recently been reported. We hypothesized that the polymorphisms of ADH, ALDH, and P450IIE1 modify the susceptibility to development of alcoholism. We determined the genotypes of the ADH2, ALDH2, and P450IIE1 loci of 96 Japanese alcoholics and 60 healthy male subjects, using leukocyte DNA by the restriction fragment-length polymorphism by polymerase chain reaction. The alcoholics had significantly higher frequencies of the ADH2(1) and ALDH2(1) alleles than did the healthy subjects. No significant difference in the frequency of the P450IIE1 genotype was observed between the alcoholics and the healthy subjects. In conclusion, genetic polymorphisms of the ADH and ALDH genes, but not of the P450IIE1 gene, influence the risk of developing alcoholism in Japanese.

Unsuccessful effort to detect human papillomavirus DNA in urinary bladder cancers by the polymerase chain reaction and in situ hybridization

The association of human papillomavirus (HPV) with urinary bladder carcinogenesis is now a controversial issue. In order to certify the presence of HPV DNA in urinary bladder cancers, the polymerase chain reaction (PCR) using five primer sets for detecting various HPV types was used in this study as well as in situ hybridization (ISH) for HPV 16 and 18 detection. In the PCR study of 93 DNA samples extracted from formalin-fixed and paraffin-embedded urinary bladder cancers, no HPV DNA was detected in these tumor samples. The ISH study was also performed on the same tumor samples, but failed to demonstrate any HPV 16- or 18-positive signals in all except one of the tumor samples. However, the PCR failed to demonstrate HPV 16 DNA even in the bladder cancer positive for HPV 16 DNA by the ISH. This ISH technique was able to demonstrate HPV 16 and 18 DNA in eight of 13 paraffin-embedded cervical cancers, in which HPV 16 or 18 DNA had already been detected by the PCR. Our HPV study using PCR and ISH revealed that the HPV status of urinary bladder carcinomas was far different from that of cervical cancers.

Rapid identification by polymerase chain reaction of staphylococcal exfoliative toxin serotype A and B genes

A new system was designed to detect staphylococcal exfoliative toxin A (ETA) and B (ETB) genes by the polymerase chain reaction (PCR). The primer pairs for the ETA gene (eta) were 20 and 20-mer, and its PCR product was a 741-bp eta fragment, while the primer pairs for the ETB gene (etb) were also 20 and 20-mer, and its PCR product was a 629-bp etb fragment. When these primers were simultaneously used in the PCR, the two types of ET were clearly detected as two bands in an ETA and ETB double-producer using only one colony within 3 hr. We examined 66 strains of Staphylococcus aureus isolated from patients with staphylococcal scalded skin syndrome (SSSS) and compared the results obtained by ELISA and PCR. The same results were obtained for 56 of the strains, i.e., 30 strains were ETA producers, 20 strains were ETB producers, and 6 strains were double-producers. However, positive results were obtained for 5 of the 10 non-ET-producing strains. Two of these strains were judged by PCR as ETA producers and three as ETB producers. Thus, PCR is very sensitive and rapid in detecting ETA and ETB gene fragments in colonies isolated from patients with SSSS.

Prognosis of epilepsy withdrawn from antiepileptic drugs

Antiepileptic drugs (AED) were discontinued in 55 epileptics who had been free from seizures treated with AED, in accordance with the following criteria and procedures. (i) A reduction in AED commences when patients have been free from seizures for at least 2 years and epileptic discharges have also disappeared in repeated electroencephalogram (EEG) recordings during that period. (ii) AED are gradually reduced if no relapse is seen in clinical seizures and epileptic discharges in EEG. (iii) As a rule at least 2 years are required as the interval from the onset of a reduction to the withdrawal of AED. Forty-three patients were followed up by a questionnaire and/or by telephone and the follow-up period from the withdrawal of AED to the survey ranged from 0.9 to 8.8 years; in 38 patients (88.4%) the period was longer than 2 years. No relapse of seizures was found in any of the 43 patients. The severity of epilepsy judged by the total number of frequency of seizures, the presence of neuropsychiatric complications, the combination of different types of seizures, and the duration of epilepsy from the seizure onset to the last seizure appeared not to be risk factors for the recurrence of seizure. Normal EEG was, however, considered to be an important prerequisite for a good prognosis.