Sex Hormone and Gender Difference?Role of Testosterone on Male Predominance in Brugada Syndrome

INTRODUCTION

The clinical phenotype is 8 to 10 times more prevalent in males than in females in patients with Brugada syndrome. Brugada syndrome has been reported to be thinner than asymptomatic normal controls. We tested the hypothesis that higher testosterone level associated with lower visceral fat may relate to Brugada phenotype and male predominance.

METHODS AND RESULTS

We measured body-mass index (BMI), body fat percentage (BF%), and several hormonal levels, including testosterone, in 48 Brugada males and compared with those in 96 age-matched control males. Brugada males had significantly higher testosterone (631 +/- 176 vs 537 +/- 158 ng/dL; P = 0.002), serum sodium, potassium, and chloride levels than those in control males by univariate analysis, and even after adjusting for age, exercise, stress, smoking, and medication of hypertension, diabetes, and hyperlipidemia, whereas there were no significant differences in other sex and thyroid hormonal levels. Brugada males had significantly lower BMI (22.1 +/- 2.9 vs 24.6 +/- 2.6 kg/m(2); P < 0.001) and BF% (19.6 +/- 4.9 vs 23.1 +/- 4.7%; P < 0.001) than control males. Testosterone level was inversely correlated with BMI and BF% in both groups, even after adjusting for the confounding variables. Conditional logistic regression models analysis showed significant positive and inverse association between Brugada syndrome and hypertestosteronemia (OR:3.11, 95% CI:1.22-7.93, P = 0.017) and BMI (OR:0.72, 95% CI:0.61-0.85, P < 0.001), respectively.

CONCLUSIONS

Higher testosterone level associated with lower visceral fat may have a significant role in the Brugada phenotype and male predominance in Brugada syndrome.

Association of genetic polymorphisms of ACADSB and COMT with human hypertension

OBJECTIVES

Genetically hypertensive rats provide an excellent model to investigate the genetic mechanisms of hypertension. We previously identified three differentially expressed genes, Acadsb (short/branched chain acyl-CoA dehydrogenase), Comt (catecholamine-O-methyltransferase), and Pnpo (pyridoxine 5'-phosphate oxidase), in hypertensive and normotensive rat kidneys as potential susceptibility genes for rat hypertension. We examined the association of human homologues of these genes with human hypertension.

METHODS

We sequenced three genes using samples from 48 or 96 hypertensive patients, identified single nucleotide polymorphisms, and genotyped them in a population-based sample of 1818 Japanese individuals (771 hypertensive individuals and 1047 controls).

RESULTS

After adjustments for age, body mass index, present illness (hyperlipidaemia, diabetes mellitus), and lifestyle (smoking, alcohol consumption), multivariate logistic regression analysis revealed that -512A>G in ACADSB was associated with hypertension in women (AA vs AG + GG: odds ratio = 0.70, 95% confidence interval = 0.53-0.94). This single nucleotide polymorphism was in tight linkage disequilibrium with -254G>A. Furthermore, -1187G>C in COMT was associated with hypertension in men (GG vs CG + CC: odds ratio = 0.69, 95% confidence interval = 0.52-0.93) and was in tight linkage disequilibrium with 186C>T. After adjustments described above, -512 A>G and -254G>A in ACADSB were associated with variations in systolic blood pressure. ACADSB was in tight linkage disequilibrium with MGC35392 across a distance of 18.3 kb. COMT was not in linkage disequilibrium with any adjacent genes. Analysis indicated that two haplotypes of COMT were significantly associated with hypertension in men.

CONCLUSION

Our study suggests the possible involvement of genetic polymorphisms in ACADSB and COMT in essential hypertension in the Japanese population.

Association of Sixty-One Non-Synonymous Polymorphisms in Forty-One Hypertension Candidate Genes with Blood Pressure Variation and Hypertension

We previously selected a group of hypertension candidate genes by a key word search using the OMIM database of NCBI and validated 525 coding single nucleotide polymorphisms (SNPs) in 179 hypertension candidate genes by DNA sequencing in a Japanese population. In the present study, we examined the association between 61 non-synonymous SNPs and blood pressure variations and hypertension. We used DNA samples taken from 1,880 subjects in the Suita study, a population-based study using randomly selected subjects. Analyses of covariance adjusting for age, body mass index, hyperlipidemia, diabetes, smoking, drinking, and antihypertensive medication revealed that 17 polymorphisms in 16 genes (APOB, CAST, CLCNKB, CTNS, GHR, GYS1, HF1, IKBKAP, KCNJ11, LIPC, LPL, P2RY2, PON2, SLC4A1, TRH, VWF) were significantly associated with blood pressure variations. Multivariate logistic regression analysis with adjustment for the same factors revealed that 11 polymorphisms in 11 genes (CAST, CTLA4, F5, GC, GHR, LIPC, PLA2G7, SLC4A1, SLCI8A1, TRH, VWF) showed significant associations with hypertension. Five polymorphisms in five genes, CAST(calpastatin), LIPC (hepatic lipase), SLC4A1 (band 3 anion transporter), TRH (thyrotropin-releasing hormone), and VWF (von Willebrand factor), were significantly associated with both blood pressure variation and hypertension. Thus, our study suggests that these five genes were susceptibility genes for essential hypertension in this Japanese population.

Hypertension susceptibility genes on chromosome 2p24-p25 in a general Japanese population

BACKGROUND

Genome-wide scans from Italy and China suggest a hypertension-susceptible locus between D2S2278 (nucleotides 11,245,080 - 11,245,358) and D2S168 (nucleotides 11,467,214 - 11,467,422) on chromosome 2.

METHODS

We performed a large association study of polymorphisms in this region with blood pressure modulation in a Japanese general population. Forty-seven polymorphisms in 14 genes between nucleotide 8,845,292 and nucleotide 11,946,689, which contains D2S2278 and D2S168, were genotyped in 1880 individuals, 796 of whom were hypertensive and 1084 normotensive.

RESULTS

Multivariate logistic regression analysis with adjustment for age, body mass index, presence of hyperlipidemia, diabetes mellitus, and current smoking and drinking revealed that one single nucleotide polymorphism (SNP), IMS-JST126186, in HPCAL1 (hippocalcin-like 1) in women and two SNPs, IMS-JST149391 and IMS-JST149390, in GREB1 (gene regulated by estrogen in breast cancer 1) in men were significantly associated with both prevalence of hypertension and blood pressure levels. To examine the role of GREB1 in more detail, we identified 38 additional genetic variations in GREB1 by direct sequencing, and eight polymorphisms were genotyped. One SNP, 45718A>G, was significantly associated with hypertension and blood pressure level in men, and this SNP was in linkage disequilibrium with a SNP present at the 3' splice site of intron 11.

CONCLUSION

Our study suggests that GREB1 and HPCAL1 are candidate hypertension-susceptibility genes in the Japanese general population and supports previous studies that also identified hypertension-related loci in this narrow region.

Genetic analysis of 22 candidate genes for hypertension in the Japanese population

OBJECTIVE

We performed association studies between 118 single-nucleotide polymorphisms (SNPs) of 22 candidate genes (or gene family) and hypertension in a Japanese population.

DESIGN AND PARTICIPANTS

The study population consisted of 1880 subjects representing the general population in Japan, recruited from the Suita study. The candidate genes were selected based on their functions, including insulin resistance (APM1, CD36, HSD11B1), oxidative stress (CYBA, GPX1, GSTMs), steroid hormone (ESR1, ESR2, HSD11B2), renal functions (PTGS2, KLK1, NPHS1, NPHS2, SGK, SLC12A1, PTGES), and others related to cardiovascular physiology (GJA4, NOS1, NTRK3, P2RX4, SPP1, ALDH2).

RESULTS

Multiple logistic analyses, with age and body mass index as covariates, indicated that 13 SNPs (eight genes), six SNPs (four genes) and 11 SNPs (four genes) were associated with hypertension (P < 0.05) in the total, male, and female populations, respectively. PTGS2 seems to be a promising candidate gene for hypertension in men. GSTM3 and SLC12A1 seem to be promising candidate genes for hypertension in women. Especially, a polymorphism in SLC12A1 was significantly associated with hypertension in women even after correction by the Bonferroni method (corrected P = 0.0236). Multiple logistic analyses, with age and body mass index as covariates, indicated that the prevalence of hypertension in females was significantly higher in subjects with the CC genotype than in those with the TT + TC genotypes (P < 0.0001, odds ratio = 1.967, 95% confidence interval = 1.430-2.712).

CONCLUSION

Although the present results should be replicated in other study populations for confirmation, the present results suggest that SLC12A1 may contribute to hypertension in Japanese women.

Association Analysis Between Hypertension and CYBA, CLCNKB, and KCNMB1 Functional Polymorphisms in the Japanese Population-The Suita Study-

BACKGROUND

Reproducibility of results is important for the validity of genetic association studies. Recently, 3 functional polymorphisms, G(-930)A in CYBA, T481S in CLCNKB, and E65K in KCNMB1, were reported to be associated with blood pressure (BP) status and the aim of this study was to confirm those findings using a large cohort representing the general Japanese population.

METHODS AND RESULTS

The study population consisted of 3,652 subjects recruited from the Suita study as representative of the general population in Japan. The genotypes of the 3 polymorphisms were determined by the TaqMan method. Logistic analysis indicated that the CYBA/G(-930)A polymorphism was associated with hypertension in male subjects. In the male population, the odds ratio of the GG genotype over GA + AA was 1.27 (95% confidence interval 1.01-1.57, p=0.034). Moreover, residuals of systolic and diastolic BP values were significantly higher in subjects with the GG genotype than in those with the GA or AA genotype (p=0.0007). However, such significant effects of the genotype on BP status were not observed in the female population. The significance of the CLCNKB/T481S and KCNMB1/E65K polymorphisms were not replicated in the present study.

CONCLUSION

The significance of the G(-930)A polymorphism of CYBA was confirmed in the present study with adequate statistical power, which strengthens the hypothesis that this polymorphism is important in the pathogenesis of hypertension and confers susceptibility.

Association between hypertension and the alpha-adducin, beta1-adrenoreceptor, and G-protein beta3 subunit genes in the Japanese population; the Suita study

This study focused on 3 genetic polymorphisms that have previously been implicated in hypertension: the alpha-adducin (ADD1/Gly460Trp), beta1-adrenoreceptor (ADRB1/Arg389Gly), and G-protein beta3 subunit (GNB3/C825T) gene polymorphisms. We determined genetic variants using the TaqMan system in a large cohort representing the general population in Japan (867 males, 1,013 females). Logistic analysis indicated that the ADD1/ G460W polymorphism was associated with hypertension in female subjects. The odds ratio of the WW genotype for hypertension was 1.53 (95%Cl, 1.12-2.08) over the WG+GG genotype (p=0.0070, p corrected (p(c)) =0.0420 corrected by the Bonferroni method). The ADRB1/R389G polymorphism tended to be associated with hypertensive status in male subjects (p=0.0117, p(c)=0.0702). The odds ratio of the GG genotype for hypertension was 0.38 (95%CI, 0.167-0.780) over the RR+RG genotype. The GNB3/C825T polymorphism was not associated with hypertensive status in either male or female subjects. The present results do not agree with those in previous reports. Almost all common variants may have only a modest effect on common diseases, and a single study even employing 1,880 subjects may lack the statistical power to detect a real association. Accordingly, it will be necessary to verify the association between these three genes and hypertension using a larger number of subjects from the Suita cohort or another population.

Identification of 108 SNPs in TSC, WNK1, and WNK4 and their association with hypertension in a Japanese general population

The deletion of thiazide-sensitive Na-Cl cotransporter ( TSC, SLC12A3) causes Gitelman's syndrome characterized by low blood pressure, while deletions of the WNK1 ( PRKWNK1) and WNK4 ( PRKWNK4) genes cause familial hypertension known as pseudohypoaldosteronism type II. Recent studies have revealed that cell surface expression of TSC is regulated by WNK1 and WNK4. We hypothesized that molecular variations in TSC, WNK1, and WNK4 could lead to an increased morbidity of hypertension. We identified 52, 35, and 21 polymorphisms in Japanese hypertensives by sequencing the entire coding regions of TSC, WNK1 and WNK4, respectively. Twenty-one representative polymorphisms were genotyped in 1,818 Japanese individuals (771 subjects with hypertension and 1,047 controls) randomly sampled in Suita city. The results indicated that the systolic blood pressure in men with the CT+TT genotype in WNK4 C14717T was 3.1 mmHg higher than those with the CC genotype ( p=0.042) after adjustment with confounding factors such as age, BMI, hyperlipidemia, diabetes mellitus, antihypertensive drug use, smoking, and drinking. Multivariate logistic regression analysis (with adjustment for the same parameters) in men revealed that the odds ratio for the presence of hypertension of the CT+TT genotype in C14717T to the CC genotype was 1.62 ( p=0.010, 95% confidence interval, 1.12-2.33). Association of TSC and WNK1 with hypertension was not observed. In conclusion, our study suggests the possible involvement of WNK4 in essential hypertension in a Japanese general population.

A high prevalence of Gitelman's syndrome mutations in Japanese

Although Gitelman's syndrome (GS) is considered a rare disorder, it is an autosomal recessive phenotype and the frequency of heterozygote subjects might be higher than suspected. The purpose of this study was to assess the prevalence of GS in Japanese and the effects of heterozygous GS mutations on blood pressure levels. We used the TaqMan system to detect 9 Gitelman's syndrome mutations in SLC12A3 that have been reported in Japanese. We then conducted association studies between these mutations and blood pressure in 1,852 subjects recruited from the Suita study, representing the general population in Japan. Among these 1,852 subjects, we detected the T180K, A569V, L623P, R642C, and L849H heterozygote genotypes in 56, 14, 1, 1, and 47 subjects, respectively. The overall frequency of GS mutations was (56+14+1+1+47) / (1,852 x 2) = 0.0321, which was much higher than suspected. This means we should expect to find one subject with a heterozygous GS mutation among 15.6 Japanese or that we should find 10.3 GS subjects among 10,000 Japanese. Although the blood pressure levels of subjects heterozygous for the T180K, A569V, or L849H genotype were not significantly different from those of wild-type subjects, urine pH in subjects with GS mutations was significantly higher than that in subjects without mutations. In conclusion, GS could be one of the major causes of low blood pressure in Japanese.

Identification of 21 single nucleotide polymorphisms in human hepatocyte growth factor gene and association with blood pressure and carotid atherosclerosis in the Japanese population

It has been suggested that circulating concentrations of hepatocyte growth factor (HGF) are increased in individuals with vascular endothelial damage, such as in hypertensive patients and subjects with atherosclerosis. Because the influence of genetic variation of HGF has not been examined, we identified single nucleotide polymorphisms (SNPs) in the HGF gene, and investigated the association between these SNPs and blood pressure or carotid atherosclerosis in the Japanese general population. We identified 21 SNPs in the HGF gene by direct sequencing in a test population of 32 Japanese subjects. Among them, considering allele frequency and linkage disequilibrium, three SNPs, C-1652T in the promoter, T43839A in intron 8, and T44222C in intron 9, were genotyped in 2412 members of the Japanese general population randomly selected from the residents in Suita city. None of the three SNPs were significantly associated with blood pressure. After adjusting for age, smoking habits, consumption of alcohol, and the presence of diabetes mellitus and dyslipidemia, female subjects with the T allele of T43839A had more severe carotid atherosclerosis compared to individuals with the A allele. This study provides the first evidence that HGF may be a candidate susceptibility loci that affects the progression of atherosclerosis in Japanese subjects.

A promoter variant of the ATP-binding cassette transporter A1 gene alters the HDL cholesterol level in the general Japanese population

To investigate the effects of polymorphisms in the ATP-binding cassette transporter A1 ( ABCA1) gene on the high-density lipoprotein cholesterol (HDL-C) level and the incidence of myocardial infarction (MI), we performed association studies. Sequence analysis identified 14 polymorphisms in the promoter region of ABCA1. After considering linkage disequilibrium, three polymorphisms in the promoter region and 11 polymorphisms from the JSNP database were determined in 1,880 subjects recruited from the Suita Study, representing the general population in Japan. We evaluated the association between the ABCA1 genotype and HDL-C level adjusted not only for standard factors, but also for genetic factors including ApoA1 and ApoE genotypes. Of the 14 polymorphisms tested, the G(-273)C ( P=0.0074), C(-297)T ( P=0.0195), and IMS-JST071749 ( P=0.0093) polymorphisms were significantly associated with the HDL-C level in the Suita population. We could reconfirm that the G(-273)C genotype was influential in another set of subjects ( P=0.0310, n=743). However, the distribution of the ABCA1 G(-273)C genotype in subjects with MI ( n=598) was not different from that in the control population ( n=801). These results indicate that ABCA1 G(-273)C has a significant effect on the HDL-C level in the general Japanese population, but not on the incidence of MI.

Genetic variants in PCSK9 affect the cholesterol level in Japanese

Mutations in the proprotein convertase subtilisin/kexin 9 ( PCSK9) gene have been reported in affected members of two families with autosomal dominant hypercholesterolemia. To investigate the effects of common variants in PCSK9 on the cholesterol level, we conducted an association study using a large cohort representing the general population in Japan (n=1,793). Direct sequencing in all of the exonic regions identified 21 polymorphisms. After consideration of linkage disequilibrium among these polymorphisms, we selected and genotyped nine polymorphisms by the TaqMan method. The intron 1/C(-161)T and exon 9/I474 V polymorphisms were associated with levels of total cholesterol (TC) [C(-161)T, P=0.0285; I474 V, P=0.0069] and low-density lipoprotein cholesterol (LDL-C) [C(-161)T, P=0.0257; I474 V, P=0.0007]. The distributions of these polymorphisms in subjects with miocardial infarction (MI) (n=649) were not different from those in the control population. These results provide the first evidence that common variants intron 1/C(-161)T and exon 9/I474 V in PCSK9 significantly affect TC and LDL-C levels in the general population in Japan.

Heterozygous disruption of CMA1 does not affect blood pressure

OBJECTIVE

It has been suspected that the mast cell chymase gene (CMA1) is important for the generation of angiotensin II and therefore might be associated with the pathogenesis of hypertension.

METHODS

We sequenced the promoter region, exons, and exon-intron junctions of CMA1 and found 13 single-nucleotide polymorphisms, two of which were loss-of-function mutations. The loss-of-function mutations resulted in: (1) a premature stop codon; and (2) atypical splicing which creates a frame-shift and a stop codon. To elucidate the role of CMA1 in blood pressure regulation, we conducted an association study using these polymorphisms, including the loss-of-function mutations. The study population consisted of 1859 subjects, selected consecutively from the Suita study, an epidemiological cohort representing the general population in Japan.

RESULTS

There was no difference in the genotype distribution of the polymorphisms we studied between hypertensive and normotensive subjects, among either men or women. Moreover, neither of the heterozygous loss-of function mutations had a significant effect on blood pressure values.

CONCLUSION

Our data suggest that CMA1 is unlikely to influence blood pressure levels in the Japanese population.

Association of Genetic Polymorphisms of Sodium-Calcium Exchanger 1 Gene, NCX1, with Hypertension in a Japanese General Population

The Na+/Ca2+ exchanger (NCX) is a membrane protein involved in calcium homeostasis, catalyzing the exchange of one Ca2+ ion for three Na+ ions across the cell membrane. The Na+/Ca2+ exchange has been suggested to play a role in the pathogenesis of hypertension. Therefore, we examined whether genetic variations in NCX1 were associated with hypertension. Among 15 polymorphisms identified in 96 hypertensive subjects by sequencing the entire exon and promoter regions of NCX1, 7 representative polymorphisms with a minor allele frequency of greater than 4% were genotyped in 1,865 individuals, of whom 787 were hypertensive and 1,072 were normotensive. These subjects were residents of Suita City and were randomly selected as a population for the Suita cohort study. Multivariate logistic regression analysis performed after adjusting for age, body mass index, hyperlipidemia, diabetes mellitus, smoking, and drinking revealed that the -23200T>C and -23181T>C polymorphisms in the 5' upstream region of exon 1c were significantly associated with hypertension in men (-23200T>C: CC vs. TC+TT: odds ratio=0.61; 95% confidence intervals: 0.39 to 0.97; p =0.04) and in women (-23181T>C: CC vs. TC+TT: odds ratio=1.45; 95% confidence intervals: 1.04 to 2.02; p =0.03), respectively. Thus, our study suggests that NCX1 is one of the genes related to susceptibility to essential hypertension in the Japanese general population.

Lack of association of the interleukin-1 receptor antagonist gene with palmoplantar pustulosis in Japanese

We analysed a polymorphism of the interleukin (IL)-1 receptor antagonist (IL1RN) gene in 93 Japanese patients with palmoplantar pustulosis (PPP). None of the IL1RN alleles was significantly increased in the patients compared with controls. Because PPP has been reported to be associated with the tumour necrosis factor (TNF) region, we examined the association between the TNF and IL1RN genes. There was a difference in IL1RN*2 positivity between patients with and without the AA genotype of the TNF gene. In contrast, such a difference was not found in controls. These data indicate a possible epistatic effect between TNF and IL1RN linked genes for susceptibility to the pathogenesis of PPP.

Association of methylenetetrahydrofolate reductase gene polymorphism with carotid atherosclerosis depending on smoking status in a Japanese general population

BACKGROUND AND PURPOSE

The association of the methylenetetrahydrofolate reductase gene (MTHFR) with carotid atherosclerosis remains inconsistent. This may be due to small sample size and inappropriate analysis. We investigated the association of C677T/MTHFR with blood pressure and carotid atherosclerosis in a Japanese general population.

METHODS

Subjects (30 to 89 years of age; 1693 women, 1554 men) who gave informed consent were randomly selected from a general population in Suita, Japan. MTHFR genotypes were determined by TaqMan polymerase chain reaction. Carotid atherosclerosis was evaluated by high-resolution ultrasonography with atherosclerotic indexes of intimal-medial thickness (IMT), maximum IMT in the common carotid artery (CCA), plaque score, and stenosis (>50%).

RESULTS

Age-adjusted diastolic blood pressure was significantly higher in women with the TT genotype than in those with the CC genotype. In a recessive model (CC+CT versus TT), all adjusted odds ratios for hypertension and >50% stenosis in women were 1.42 and 3.42 (95% confidence intervals, 1.01 to 1.99 and 1.23 to 9.53), respectively. In women, maximum IMT in CCA for smokers with the TT genotype was significantly higher than for smokers with the CC genotype and nonsmokers with the TT genotype (P<0.05).

CONCLUSIONS

Our study suggests that the MTHFR TT genotype is a risk factor for hypertension and carotid stenosis in women. Significant interactions between C677T/MTHFR and smoking on maximum IMT in CCA were observed in women but not in men. Smoking cessation for subjects with the TT genotype is important in the prevention of cerebrovascular disease.

Epsilon 4 allele of apolipoprotein E gene associates with lower blood pressure in young Japanese subjects: the Suita Study

OBJECTIVES

The apolipoprotein epsilon 4 allele (APOE/epsilon 4) increases plasma cholesterol level and the risk for the late onset type of Alzheimer's disease. However, the correlation between hypertension and APOE/epsilon 4 has not yet been clarified. To examine the APOE/epsilon 4 effect in the general population of Japan, we performed a large genetic epidemiological survey (the Suita Study).

DESIGN AND METHODS

The Suita Study was a cohort study based on a random sample of 14,200 Japanese residents of Suita city. Subjects who gave informed consent for genetic analysis were recruited in the current study ( = 3997). APOE polymorphism was clearly determined by the TaqMan polymerase chain reaction method.

RESULTS

Subjects with APOE/epsilon 4 were significantly ( P < 0.03) more frequent (19.7%) in normotensives than in hypertensives (16.9%), the estimated odds ratio for hypertension (with APOE/epsilon 4 versus without APOE/epsilon 4) being 0.83 [95% confidence interval (CI), 0.70-0.98]. The significance of the association (OR = 0.64; 95% CI, 0.48-0.86) was increased in young subjects ( < or = 60 years old) but disappeared in old subjects. APOE/epsilon 4 also significantly contributed to a 2.9% increase of total cholesterol, 11.8% increase of triglyceride and 3.2% of decrease of high-density lipoprotein-cholesterol.

CONCLUSIONS

We concluded that APOE/epsilon 4 was associated with an increase of plasma lipid levels and with a decrease of systolic blood pressure. The final conclusion on whether APOE/epsilon 4 contributes to the risk for cardiovascular disease will be clarified by analysis of the cumulative incidence, which will be obtained in the future Suita Study.

Low potentiality of angiotensin-converting enzyme gene insertion/deletion polymorphism as a useful predictive marker for carotid atherogenesis in a large general population of a Japanese city: the Suita study

BACKGROUND AND PURPOSE

Some previous studies, almost all western, have investigated whether there is a relationship between the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) and carotid atherosclerosis. The results, however, have not been consistently positive. Further, there have been few investigations based on a large, general population. Therefore, the present study aimed to clarify whether ACE gene deletion polymorphism was associated with carotid atherosclerosis in a large Japanese general population with a more homogeneous genetic background than Caucasian populations.

METHODS

Subjects aged 30 to 86 years were randomly selected from Suita City, located in Osaka, the second largest urban area of Japan, and included 1894 men and 2137 women. With the aid of high-resolution ultrasonography, carotid atherosclerosis was evaluated using our atherosclerotic indexes of intimal-medial thickness (IMT), plaque number (PN), plaque score (PS), and percentage of stenosis of the carotid artery assessed using high-resolution B-mode ultrasonography. ACE gene I/D polymorphism was detected by polymerase chain reaction.

RESULTS

There were no significant differences among the ACE genotypes for age and conventional cardiovascular risk factors, except for systolic blood pressure (SBP) and the percentage of hypertension in men. The values of IMT, PN, and PS as carotid atherosclerotic indexes were not significantly different among genotypes for either sex. After adjusting for age, body mass index, smoking habit, high-density lipoprotein cholesterol, triglycerides, presence of hypertension, presence of diabetes mellitus, and presence of hyperlipidemia, the estimated ORs for the presence of IMT >/=1.10 mm (defined as thickened IMT), according to ACE genotype (DD versus II, DD+ID versus II, and DD versus ID+II), for men were 0.80 (95% CI 0.60 to 1.23), 0.89 (0.62 to 1.29), and 0.89 (0.70 to 1.28), respectively. On the other hand, the ORs for women after the same adjustment were 0.92 (95% CI 0.58 to 1.35), 0.93 (0.59 to 1.45), and 0.91 (0.59 to 1.27), respectively.

CONCLUSIONS

Our present data suggest that ACE I/D polymorphism is not potentially a useful predictive marker for carotid atherogenesis when investigated in a large and homogeneous general Japanese population of 4031 subjects, a finding similar to that in a Caucasian population study, the Perth Carotid Ultrasound Disease Assessment Study, an Australian study based on a general population using 1111 subjects.

Lack of correlation between Mbo I restriction fragment length polymorphism of renin gene and essential hypertension in Japanese

Predisposition to essential hypertension is associated with gene polymorphisms of the renin angiotensin system (RAS). Gene polymorphisms of the angiotensinogen and angiotensin converting enzyme genes are known to be risk factors for hypertension, while few studies concerning the renin gene polymorphism have been published. In the present investigation, we carried out a case control study using a Japanese population to examine the genetic influence of the renin gene on the predisposition to hypertension. Patients (n=235) recruited from outpatients at Osaka University Hospital and diagnosed with essential hypertension or receiving long-term antihypertensive medication participated in the study. Normotensive control subjects (n=510) without a history of hypertension and without diabetes mellitus were recruited from the same population, and were sex-matched with experimental subjects. A polymorphism in intron 9 of the human renin gene was determined as the Mbo I restriction fragment length polymorphism (Mbo I-RFLP). There was no significant association between Mbo I-RFLP of the renin gene and predisposition to essential hypertension in Japanese (p>0.05, chi2=2.1). These results suggest that the Mbo I (+) allele of the renin gene does not increase the risk for hypertension in Japanese.

Arteriovenous haemangioma in chronic liver disease: clinical and histopathological features of four cases

Chronic liver diseases are known to cause several skin manifestations, including cutaneous vascular changes such as spider naevus and palmar erythema. Arteriovenous haemangioma (AVH), a benign acquired cutaneous vascular lesion, has also been reported to be associated with chronic liver disease. We report here four cases of AVH in patients with chronic liver disease: (i) a 59-year-old man who had suffered from chronic active hepatitis associated with hepatitis C virus for 15 years; (ii) a 48-year-old man who had suffered from alcoholic hepatitis for 3 years and was diagnosed with liver cirrhosis 1 year ago; (iii) a 69-year-old female who had had chronic active hepatitis associated with hepatitis C virus infection for 20 years and was diagnosed with liver cirrhosis 7 years ago; and (iv) a 48-year-old man who had had chronic active hepatitis associated with hepatitis B virus infection for about 20 years. All patients showed an asymptomatic solitary dome-shaped reddish papule, 5-10 mm in diameter, on the face (first, second and third patients) or chest (fourth patient). Histopathological examination of the tumours revealed features of AVH, namely a well-circumscribed lesion composed of vascular structures of various sizes reminiscent of arteries and veins. In all four cases, elastic-van Gieson stain showed the absence of an internal elastic lamina in the thick-walled vessels as well as the thin-walled vessels. Examination of multiple sections demonstrated glomus cells and an ascending artery feeding the tumour vessels in only one case. Slight inflammatory cell infiltration was seen in the stroma of three patients while Toluidine blue staining revealed an increased number of mast cells in the stroma in all lesions. The present cases suggest that the occurrence of AVH associated with chronic liver disease is not related to any specific liver disease, but may be related to chronic liver dysfunction itself.

Additive effects of nicorandil on coronary blood flow during continuous administration of nitroglycerin

OBJECTIVES

We examined whether patients with ischemic heart disease (IHD) should be treated with nicorandil, an adenosine triphosphate-sensitive potassium channel opener, in addition to the regular use of nitrates.

BACKGROUND

It has been reported that nicorandil possibly has additive effects on nitroglycerin (NTG) treatment for angina, but the mechanism is not clear.

METHODS

We directly measured anterograde coronary blood flow (CBF) with a Doppler guide wire to examine the effects of intravenous administration of NTG (0.3 mg) and nicorandil (6 mg) during continuous administration of NTG at a sufficient dose (25 microg/min) in subjects with normal and stenotic coronary arteries.

RESULTS

Additional systemic administration of NTG decreased anterograde CBF (normal -19.7%; stenotic -21.2%). In contrast, nicorandil increased anterograde CBF in both normal (54.6%) and stenotic (89.6%) coronary arteries, without the coronary steal phenomenon. There was a tendency toward nicorandil-dilated diameters in the patients with stenotic arteries (p = 0.06). There were no effects of additional administration on pulmonary artery wedge pressure. There was no difference in changes in heart rate and mean aortic blood pressure between NTG and nicorandil therapy.

CONCLUSIONS

These results suggest that in patients treated with nitrates, additional administration of nicorandil is more useful, in terms of increasing CBF, than additional administration of nitrates. Adjunctive use of nicorandil with nitrates may provide the further benefit of myocardial protection and may improve the prognosis of patients with IHD.

Frontal mucocele presenting as a subcutaneous tumour on the forehead

A 57-year-old Japanese woman had a 3-month history of an asymptomatic subcutaneous tumour on the forehead. The patient presented a slightly elevated, elastic soft subcutaneous mass, 3 cm in diameter, on the mid to left-side forehead. Slight swelling of the left upper eyelid was observed. CT scanning and magnetic resonance images revealed a sharply demarcated cystic mass from the subcutaneous area on the forehead expanding into the frontal sinus and intracranial space. The tumour was diagnosed as a frontal mucocele and combined external and endoscopic approaches were performed. It is rare that a patient with a frontal mucocele is initially referred as a case of a subcutaneous tumour because most of the patients complain primarily of the ophthalmic symptoms. However, the present case reminds us that frontal mucocele is one of the differential diagnoses for a subcutaneous mass on the forehead.

[Bilateral homonymous hemianopsia with atrial fibrillation]

We encountered an 80-year-old man with sudden bilateral visual disturbance. When he was admitted to the hospital, his blood pressure was 138/70 mmHg, and an ECG revealed atrial fibrillation. Neurological examination showed only bilateral homonymous hemianopsia with no nystagmus or impairment of eye movement. He did not have paralysis cerebellar ataxia, or speech disturbance. Therefore, there was no evidence of obstruction of the thalamogeniculate or thalamoperforating artery. Magnetic resonance imaging of the brain showed cerebral infarctions in both occipital lobes. Perimetry showed bilateral homonymous hemianopsia; the left side of the macula was spared. The lack of neurological deficit other than bilateral homonymous hemianopsia indicates that only the right and left cortical branches of the posterior cerebral artery were occluded.

Malignant histiocytosis presenting as multiple erythematous plaques and cutaneous depigmentation

We report on a patient with malignant histiocytosis (MH) presenting as multiple erythematous plaques and cutaneous depigmentation on her neck and chest. In a biopsy of an erythematous plaque, atypical large, foamy histiocytes infiltrated the dermis and positively stained with antibodies to lysozyme, leukocyte common antigen, and KP-1 (CD68). A few similar atypical cells were present in the superficial dermis focally in the depigmented areas. With use of immunohistochemical studies, most cases previously diagnosed as MH have been reclassified as T-cell lymphoma, B-cell lymphoma, or Ki-1-positive anaplastic large cell lymphoma. However, a few cases of "true" MH characterized by authentic histiocytes have been reported, presenting usually as red nodules. To our knowledge, our patient is the first with MH to present with erythematous plaques and vitiligo-like depigmentation.

Malignant melanoma and squamous cell carcinoma forming one tumour on a burn scar

Malignant melanoma occurring in burn scars is rare and cases of malignant melanoma and squamous cell carcinoma arising in a burn scar are extremely rare. We report a case of malignant melanoma and squamous cell carcinoma arising in one tumour on a stable thermal burn scar on the right leg of a 55-year-old man after a long latent period of about 50 years. The case was unique in that the malignant melanoma and squamous cell carcinoma occurred synchronously next to each other and produced one tumour. Immunohistochemical stainings with keratin, S-100 protein and HMB 45 clearly distinguished the two kinds of atypical tumour cells. Following the total resection of the original tumour, metastasis of malignant melanoma in the inguinal lymph node was found. This case underlines the possibility that another tumour may co-exist even if pathological observation reveals one kind of tumour.

HLA-DQA1, -DQB1 and -DRB1 genotyping in Japanese pemphigus vulgaris patients by the PCR-RFLP method

We performed HLA-DQA1, -DQB1 and -DRB1 genotyping using the PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) method for 32 Japanese pemphigus vulgaris (PV) patients. There was a significant association of either DQB1*0503 or DRB1*1405 with PV, and a negative association of either DQA1*0103 or DQB1*0601 with PV was found. Since the DQB1*0503+ patients had various DR14-related alleles, we concluded that the association with DQB1 is primary and that the association with DRB1 is simply due to linkage disequilibrium between the DQ and DR genes. These results may indicate that specific HLA class II antigens confer the susceptibility to PV among Japanese.

A case of pemphigus foliaceus after interferon alpha-2a therapy

We present here a 63-year-old man with chronic hepatitis C who developed bullous lesions and anti-intercellular antibodies when he received interferon (IFN) alpha-2a, 9 MU subcutaneously, 3 times a week for 3 months. The direct immunofluorescence was consistent with pemphigus features. The indirect immunofluorescence showed negative before IFN treatment, but it became positive after 3 months. The immunoblot study showed no specific bands. This is the third report of the bullous lesions with anti-intercellular antibodies following IFN therapy.

Is tubular apocrine adenoma a distinct clinical entity?

A 75-year-old Japanese man developed a tubular apocrine adenoma (TAA) (tubulopapillary hidradenoma with apocrine differentiation, a rare skin tumor), within a long-standing organoid nevus on the parietal area of his scalp. Histologically, the tumor consisted of dilated ductlike areas with some atypism and apocrine glandlike areas surrounded by myoepithelial cells. The superficial part of the tumor was connected to the epidermis and showed some of the characteristics of syringocystadenoma papilliferum (SCAP). The close relationship between TAA, SCAP, and papillary eccrine adenoma (PEA) is discussed. According to 19 reported cases of TAA, SCAP might occur together with TAA when they are preceded by an organoid nevus, and they might represent a spectrum of disease. Although TAA and PEA may represent another spectrum (designated as tubulopapillary hidradenoma), the relationship to SCAP should be considered in understanding and diagnosing an intermediate case.

Two cases of clear cell acanthoma: an immunohistochemical study

Two cases of clear cell acanthoma are reported. The expression of carcinoembryonic antigen (CEA), involucrin and keratin proteins in the tumors was investigated immunohistochemically. In 1981, Penneys et al. reported that this tumor was not of sweat gland origin because of the absence of CEA. This study confirmed this, further, the pattern of positive reaction of involucrin also indicated that this tumor is not of sweat duct origin.

Involucrin expression in skin appendage tumours

The expression of involucrin was examined in 23 skin tumours of hair follicle origin, 17 tumours of sweat gland origin and three tumours of unknown origin, using an immunoperoxidase technique. All tumours from the hair follicle showed a positive reaction for involucrin. In particular keratoacanthoma and the squamous eddies in various tumours stained strongly. Trichofolliculoma, trichilemmoma and pilomatrixoma exhibited characteristic staining patterns which resembled those in the normal hair follicle. On the other hand the majority of the tumours of sweat gland origin did not stain, with restricted positive reactions in areas showing lumen formation or squamous metaplasia. In contrast to the lack of staining in syringoma, a positive reaction was observed in desmoplastic trichoepithelioma, which is histologically similar to syringoma. Clear cell acanthoma, the origin of which is still controversial, showed a staining pattern which indicated that its origin may not be in the sweat gland. These results suggest that testing for involucrin in skin appendage tumours may be very useful for understanding the kinetics of maturation as well as in determining the origin of the tumours.

Microsurgical technique in resection of hemangioma in infants

A microsurgical dissection technique for residual strawberry marks applied to patients 6 years of age or older (a total of 7 cases) resulted in minimal bleeding during the operations. Therefore, the same technique was used for patients aged 4 months through 3 years and 4 months. The latter 8 patients had a minimal amount of intraoperative bleeding (no tourniquet was applied to the upper arm case), direct skin closure of the wound, and no postoperative complications. The procedure is tedious but makes dissection of the hemangioma easier because of the watery subcutaneous structure in the infant; it also is less traumatic than the usual surgical dissection technique. We found this procedure to be valuable for complete removal of the unwanted strawberry mark with subcutaneous hemangioma in infants.

Porokeratosis of Mibelli: benzylhydrochlorothiazide-induced new lesions accompanied by eosinophilic spongiosis

We observed the course of development of porokeratosis stimulated by benzylhydrochlorothiazide (BHCTh) in normal-appearing skin of a patient with long-standing stable porokeratosis of Mibelli. A 72-year-old Japanese man had had porokeratosis of Mibelli for more than 50 years. During administration of BHCTh for 1 year because of his hypertension, a lichenoid drug eruption developed over the lesions of porokeratosis on the flexor aspects of his legs. Readministration of BHCTh by another physician for 6 months resulted in the occurrence of a similar drug eruption that converted into typical skin lesions of porokeratosis 8 weeks later. Serial microscopic examination suggested that BHCTh administration resulted in eosinophilic spongiosis and cornoid lamella formation, which developed into epidermal changes characteristic of porokeratosis.

Dialyzing room disinfection with ultra-violet irradiation

Infections represent a major problem in dialysis treatment, thus the dialyzing room should be kept abacterial as possible. We have installed 15-watt ultra-violet (U-V.) lamps for every 13.5 m2 on the ceiling for the purpose of the room disinfection and used them for 16 hours nightly after working hours. Bacteria were killed with over 10 hours irradiation even at the areas of low U-V. intensity where the irradiation may not be direct. This unexpected effectiveness might be from the influence of reflected rays and 03 produced. When half the lamps were turned on, the bacteriocidal effect was not sufficient in some areas. Any living organism with nucleic acids must be inactivated by this treatment, for the baceteriocidal effect is due to the nucleic acids injury. Furthermore, safety, readiness after the treatment, easy application and the negligible costs would make this method more advantageous to the other methods in room disinfection.

Effect of HgCl2 on rat kidney cells in primary culture

Single cell suspensions, obtained from rat kidneys, were cultured with various concentrations of HgCl2 for different times to examine the effects on cellular synthetic activity. Unexpectedly, the RNA synthesis of kidney cells was stimulated with low doses of HgCl2, whereas it was inhibited with higher doses. Even at a higher dose, RNA synthesis was stimulated during early incubation but was inhibited during longer incubations. Thus, the effect of mercury showed a biphasic pattern both in dose-response and time-response relationships. Moreover, once the cells were exposed to HgCl2 for a certain period, RNA syntehsis was irreversibly inhibited. Since RNA synthesis was inhibited earlier than DNA or a protein synthesis, the RNA synthesizing system appeared most susceptible. Without HgCl2, by the time DNA synthesis reached its maximum, protein and RNA synthesis had already declined. In contrast, RNA synthesis of HgCl2-treated cells remained at its maximal level and showed no decline when DNA synthesis reached its peak.