Achievement rate of target blood pressure in patients with hypertension treated by hypertension specialists and non-specialists in a real-world setting

Hypertension remains a major global healthcare issue. Considering that most Japanese patients with hypertension are managed by general practitioners, hypertension specialists should be involved in actual clinical practice. We investigated the blood pressure (BP), guidelines recommended for achievement rate of the target BP, and clinical variables of patients with hypertension treated by hypertension specialists and those treated by non-specialists in a real-world setting. Factors associated with the target BP achievement in this population were also investigated. Outpatients with hypertension from 12 medical facilities in Okinawa Prefecture were enrolled (n = 1469 [specialist group, 794; non-specialist group, 675]; mean age, 64.2 years; females, 45.8%). For all patients, BP and rate of the target BP achievement were 129.0 ± 15.5/74.6 ± 10.6 mmHg, and 51.8%, respectively. BP and the rate of target of BP achievement were 128.0 ± 15.1/73.4 ± 10.4 mmHg and 56.7% in the specialist group, and they were 130.1 ± 15.9/76.0 ± 10.8 mmHg and 46.1% in the non-specialist group. The urinary salt excretion and obesity rates were comparable between the specialist and non-specialist groups. Multivariable logistic analyses indicated that hypertension specialists and good medication adherence were positive factors, whereas obesity, chronic kidney disease, diabetes mellitus, and urinary salt excretion were inverse factors associated with target BP achievement in this population. Initiatives for salt reduction, medication adherence, and proper obesity management are crucial to improving BP management in patients with hypertension. Hypertension specialists are expected to play an essential role in them. For all patients, the target blood pressure (BP) achievement rate were 51.8%. Hypertension specialists and good medication adherence were positive factors in achieving target BP; conversely, obesity, diabetes mellitus, chronic kidney disease, and high urinary salt excretion were inverse factors in achieving target BP among patients with hypertension.

Urate-lowering drugs for chronic kidney disease with asymptomatic hyperuricemia and hypertension: a randomized trial

INTRODUCTION

Xanthine oxidase (XO) inhibitors may slow down chronic kidney disease (CKD) progression. The comparative effectiveness of the different urate-lowering drugs is unknown. The aim of this study was to determine whether urate-lowering therapy with an XO inhibitor (febuxostat) and that with a uricosuric drug (benzbromarone) are comparable in slowing renal function decline in patients with CKD complicated with hypertension and hyperuricemia.

METHODS

This study was an open-label randomized parallel-group clinical trial of 95 patients with stage G3 CKD in Japan. The patients had hypertension and hyperuricemia without a history of gout. They were randomized to receive febuxostat ( n  = 47; febuxostat group) or benzbromarone ( n  = 48; benzbromarone group) and titrated to reduce their serum urate level to <6.0 mg/dl. The primary end-point was change in estimated glomerular filtration rate (eGFR) from baseline to 52 weeks. The secondary end-points included changes in uric acid level, blood pressure, urinary albumin-to-creatinine ratio, and XO activity.

RESULTS

Of the 95 patients, 88 (92.6%) completed the trial. There were no significant differences in change in eGFR (in ml/min/1.73 m 2 ) between the febuxostat [-0.23, 95% confidence interval (CI), -2.00 to 1.55] and benzbromarone (-2.18, 95% CI, -3.84 to -0.52) groups (difference, 1.95; 95% CI, -0.48 to 4.38; P  = 0.115) nor in the secondary end-points, except for XO activity. Febuxostat significantly reduced XO activity ( P  = 0.010). There were no significant differences in primary and secondary outcomes between the groups. A decrease in eGFR was significantly less in the febuxostat group than that of the benzbromarone group in the CKDG3a, but not in CKDG3b, in the subgroup analysis. There were no adverse effects specific to either drug.

CONCLUSIONS

No significant differences were found in the effects of febuxostat and benzbromarone in renal function decline in stage G3 CKD complicated with hyperuricemia and hypertension.

Salt and potassium intake evaluated with spot urine and brief questionnaires in combination with blood pressure control status in hypertensive outpatients in a real-world setting

Reducing salt and increasing potassium intake are recommended lifestyle modifications for patients with hypertension. The estimated 24-h urinary salt excretion value from spot urine using Tanaka's formula and the salt check-sheet scores, questionnaire-based scores of salt intake, are practical indices of daily salt intake. However, few studies have evaluated salt intake with these methods in hypertensive outpatients. We examined salt and potassium intake with the spot urine method and the salt check-sheet scores of hypertensive outpatients in a multi-facility, real-world setting and examined whether the salt or potassium intake evaluated with these methods related to inadequate blood pressure control. Hypertensive outpatients from 12 medical facilities in the Okinawa prefecture were enrolled from November 2011 to April 2014 (n = 1559, mean age 63.9 years, 46% women). The mean blood pressure, urinary salt excretion value, urinary potassium excretion value, and total score on the salt check-sheet were 129/75 mmHg, 8.7 g/day, 1.6 g/day, and 10.4 points, respectively. The urinary salt excretion value and total score on the salt check-sheet but not urinary potassium excretion value were associated with inadequate blood pressure control (≥140/90 mmHg). Higher body mass index, estimated glomerular filtration rate, urinary potassium excretion value, total score on the salt check-sheet, and presence of inadequate blood pressure control were associated with high urinary salt excretion (≥10.2 g/day). In conclusion, hypertensive outpatients with high urinary salt excretion values estimated using Tanaka's formula or with high scores on the salt check sheet may be candidates for more intensive salt reduction guidance.

A questionnaire survey to assess lower urinary tract symptoms in patients with chronic stroke

OBJECTIVES

In this study, we evaluated the prevalence of lower urinary tract symptoms and the associated clinical features in patients with chronic stroke.

METHODS

Patients with stroke who had been regularly followed up at general medical hospitals in Okinawa, Japan were enrolled in the study. The patients were asked to complete a self-reported questionnaire regarding their physical activity, medical history, and the core lower urinary tract symptom score (CLSS) questionnaire, with anonymity. The association between each urinary disturbance category and the clinical characteristics of the patients such as age, gender, physical activity, and underlying disease was evaluated.

RESULTS

In total, 51 patients (33 men and 18 women; mean age, 71.7 years) were eligible for analysis. The average time after the first stroke onset was 8.5 years. Nocturia and urgency incontinence had the greatest impact on the quality of life. Overactive bladder symptoms such as nocturia, urgency, urgency incontinence, and stress urinary incontinence were associated with age, female sex, and having a co-existing medical condition (such as ischemic heart disease, hypertension, and depression). Voiding symptoms such as slow stream and straining were associated with age and physical activity after stroke.

CONCLUSIONS

Storage symptom is associated with not only neurological deficits but also sex and the presence of general diseases, whereas voiding symptom is influenced by physical activity in patients with chronic stroke. Therefore, lower urinary tract symptoms should be carefully monitored and physical rehabilitation should also be considered in patients with stroke.

Network analysis of wildlife translocations in New Zealand

AIMS

To identify network measures with relevance to disease spread in a network of movements derived from the Department of Conservation (DOC) translocation records from 1970 to mid-2014, and to identify conservation sites that should be prioritised for surveillance activities and improvements to data collection to make the best use of network analysis techniques in the future.

METHODS

Data included the source and destination of translocated specimens, the species and the dates the translocations were expected to occur. The data were used to construct a directed, non-weighted network in which a translocation event represented a tie in the network. Network density, in-degree (movements entering a node of interest) and out-degree (movements leaving a node of interest) and reciprocity were calculated.

RESULTS

The data analysed consisted of 692 unique translocations between 307 sites, with the majority (518; 73%) being for birds. The constructed network for bird, reptile and frog translocations comprised 260 nodes, with 34/260 (13%) having two-way movements and 47/260 (18%) non-reciprocal movements. The median degree score (sum of in- and out-degree) was two (min 0, max 36) with a mean of 3.5 in a right skewed distribution. Most sites acted as receivers or senders of consignments with only a few having both high in- and high out-degree, and thus had characteristics that made them sites of interest for surveillance activities. These included the National Wildlife Centre at Mount Bruce, Tiritiri Matangi Island and Te Kakahu (Chalky Island).

CONCLUSIONS

The presence of linking sites that join larger clusters within the network creates the potential for rapid disease spread if a pathogen were to be introduced. The important sites that supply or receive specimens for translocations are already well recognised by those performing translocations in New Zealand, and this paper provides further information by quantifying their role within the network.

Prevalence and Risk Factors for Nocturia in an Outpatient Clinic

OBJECTIVES

We evaluated the prevalence of and risk factors in patients with nocturia at a general medical clinic in Naha, Japan.

METHODS

We enrolled patients who had been regularly followed-up at a general medical clinic in Naha. Patients were asked to complete a self-reported questionnaire regarding medical history and the frequency of nocturnal voids in the last month with anonymity. Univariate and multivariate logistic regression tests were used to evaluate the risk factors for clinically significant nocturia.

RESULTS

In total, 357 patients (men, 192; women, 165; mean age, 60 years) were eligible for analysis. The prevalence rate of clinically significant nocturia in patients was 33.8%. Univariate, as well as multivariate, analysis revealed that age, gender, and hypertension were significant risk factors for nocturia.

CONCLUSION

Clinically significant nocturia is common among patients seen at a general medical clinic. Age and gender are the most definitive risk factors for nocturia. Hypertension may also be related to nocturia. Thus, it is important to evaluate not only urological problems but other medical problems in patients with nocturia.

Switching therapy from variable-dose multiple pill to fixed-dose single-pill combinations of angiotensin II receptor blockers and thiazides for hypertension

The efficacy and tolerability of switching therapy from free combinations of angiotensin II receptor blocker (ARB) and thiazide (A/T) to a fixed-dose of losartan and hydrochlorothiazide (L/H) has not been evaluated in Japan. We examined effects of switching therapy from variable-dose multiple-pill A/T to a fixed-dose L/H on blood pressure (BP) along with medication adherence and the degree of satisfaction in 91 hypertensive outpatients (mean age, 65.2 ± 9.6 years). After 6 months, a significant BP reduction (132 ± 9/76 ± 10 vs. 126 ± 12/72 ± 11 mm Hg), along with an improvement of attaining target BP (44.0 vs. 61.5%) and that of adherence, were observed. The magnitude of BP reduction in the participants increased their degree of satisfaction more significantly than in the participants who worsened their degree of satisfaction. The estimated glomerular filtration rate and the serum uric acid (UA) level decreased slightly but significantly. The hemoglobin A1c of participants with diabetes mellitus increased slightly but significantly. In conclusion, a switch in therapy from variable-dose, multiple-pill A/T combinations to a fixed-dose, single-pill L/H was effective in decreasing BP and serum UA in Japanese clinical practice. Metabolic side effects of L/H in patients with diabetes mellitus remain to be investigated.

Penicillin G-induced hemorrhagic cystitis with hydronephrosis

Irritable urological symptoms with gross hematuria and bilateral lumbar pain developed when the patient received penicillin G for endocarditis. These symptoms were followed by renal insufficiency. A contrast-enhanced abdominal computed tomography (CT) scan revealed a thickened bladder wall, bilateral hydroureter and hydronephrosis, suggesting hemorrhagic cystitis complicated with urinary tract obstruction. Urine culture was negative. After discontinuation of penicillin G, all symptoms subsided and renal function recovered; hence, penicillin G seems to have been associated with hemorrhagic cystitis and acute kidney injury. Positive findings in the drug lymphocyte stimulation test (DLST) for penicillin G were consistent with this diagnosis.

Two unusual cases of Anderson-Fabry disease in a Japanese family

A 16-year-old Japanese girl was admitted to our hospital on February 27, 2001, for acute renal failure. She had not shown proteinuria or hematuria in any school examination through 2000. The first renal biopsy specimen showed focal segmental glomerulosclerosis and tubulointerstitial change. Electron microscopy showed numerous myeloid bodies in the glomerular epithelium suggesting the diagnosis of Anderson-Fabry disease. After electron microscopy, we measured WBC alpha-galactosidase A, which was slightly decreased to 36.1 nmol/mg P/h (normal: 49.8 - 116.4). WBC alpha-galactosidase A levels for other family members were 74.3 for the mother, 4.8 for the father, 45.6 for the elder sister, and 16.3 for the younger sister. During the follow-up, she had two episodes of nephrotic syndrome, which responded well to steroid therapy. Both second and third renal biopsy showed numerous myeloid bodies by electron microscopy. A 52-year-old man, the father of the case one patient, was admitted for renal biopsy because of proteinuria and low levels of WBC alpha-galactosidase. Biopsy specimen showed typical changes under light microscopy and typical myeloid bodies by electron microscopy. Our cases underscore the importance of electron microscopy when examining the biopsy specimen and suggest that undiagnosed Anderson-Fabry disease may be present, in particular on chronic dialysis.

Evidence for elevated pulse pressure in patients on chronic hemodialysis: a case-control study

BACKGROUND

Few analyses have compared pulse pressure (PP) values in hemodialysis patients with healthy individuals, and they have provided only limited data. We retrospectively examined PP in a large cohort of hemodialysis patients and healthy control subjects.

METHODS

The relationships of systolic blood pressure (SBP), diastolic blood pressure (DBP), and PP to mean arterial pressure (MAP) levels were investigated in 234 chronic hemodialysis patients and in 682 control subjects matched for age, sex, diabetes mellitus, and body mass index.

RESULTS

In both control and patients, PP was positively correlated with MAP, and the two regression lines were parallel (beta of control subjects = 0.52; beta of hemodialysis patients = 0.57, P = 0.48). According to the regression line, at any MAP level, the PP in hemodialysis patients was significantly higher than that in control subjects: the mean PP difference between control and patients was 19.2 mm Hg (95% CI, 17.2 to 21.1 mm Hg, P < 0.0001). When the relationships between MAP and SBP and that between MAP and DBP were analyzed, the regression lines were also parallel. However, at any MAP level, SBP was higher and DBP was lower in hemodialysis patients than control subjects; the mean SBP difference was 12.8 mm Hg (95% CI, 11.5 to 14.1 mm Hg, P < 0.0001) and mean DBP difference was 6.4 mm Hg (95% CI, 5.7 to 7.0 mm Hg, P < 0.0001).

CONCLUSIONS

At any MAP level, hemodialysis patients had a higher SBP, lower DBP, and higher PP values than those control subjects with a normal renal function who were matched for age, sex, diabetes mellitus, and body mass index. Further study is needed to determine whether preventing or reducing an elevated PP improves the prognosis for hemodialysis patients.

Angiotensin-converting enzyme (ACE) insertion/deletion polymorphism and survival in a cohort of chronic hemodialysis patients

BACKGROUND

There are conflicting reports regarding the relationship between the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and the initiation and progression of cardiovascular disease. Moreover, there is no report regarding the relationship between the ACE I/D polymorphism and the prognosis of chronic dialysis patients.

METHODS

We examined the frequency of the ACE I/D polymorphism in 727 chronic hemodialysis patients in Okinawa, Japan, and observed the prognosis over 2 years in 407 men and 320 women with mean age (SD) of 55.5 (13.9) years with a mean duration of dialysis of 84.3 (66.6) months.

RESULTS

Genotype frequencies were 42.1% for II, 43.2% for ID, and 14.7% for DD. The relative risks of death were examined by Cox-proportional hazards analysis after adjusting for age, sex, age at the start of dialysis, presence of diabetes mellitus and hypertension and total cholesterol and serum albumin levels. The adjusted hazard ratio (95% confidence interval) was 1.03 (0.38 - 2.85) for DD genotype and 1.50 (0.83 - 2.70) for DD+ID genotype when compared to II genotype.

CONCLUSION

ACE I/D polymorphism appears to have no relation to the short-term prognosis in chronic hemodialysis patients.

Analysis of drug prescription in chronic haemodialysis patients

BACKGROUND

Information concerning medication use in Asian haemodialysis patients is sparse. We surveyed prescribed medications and examined the relation between the number of medications and mortality and clinical characteristics in chronic haemodialysis patients, in Okinawa, Japan.

METHODS

We conducted a cross-sectional multicentre survey in August 1999 and patients were observed during 13 months of follow up.

RESULTS

The clinical demographics of 850 chronic haemodialysis patients in seven dialysis units were obtained. Compared with the mean number of medications prescribed in ambulatory patients treated in general practice reported from Ministry of Health and Welfare of Japan (2.7 (n=20 716)), the mean number medications in haemodialysis patients was larger (7.2 (n=850)). The three most prescribed drug types in haemodialysis patients were those related to calcium and phosphate metabolism (88%), antihypertensive agents (71%), and erythropoietin (60%). Among the 850 patients, 38 died during the 13-month follow-up period. The number of medications was positively associated with mortality after adjusting for age, sex, and other clinical factors: the hazard ratio was 1.14 (95% confidence interval 1.03-1.26, P=0.007). A multiple linear regression analysis using the number of medications as a dependent factor and sex and other clinical characteristics as independent factors revealed that male sex (P=0.04), diabetes mellitus (P<0.0001), and duplication of drugs (P<0.0001) were positively correlated with the number of medications.

CONCLUSIONS

Multiple drug use was observed in haemodialysis patients. The number of prescribed drugs was a significant predictor of short-term mortality. Male sex, diabetes mellitus, and duplication of drugs were correlated with increases in the number of medications.

[A case of hemodynamic brain infarction with postprandial hypotension]

A 76-year-old man with left internal carotid artery occlusion developed a progressing right hemiparesis. Brain MRI presented reinfarctions in the left anterior border zone and terminal zone in the left deep white matter. Ambulatory blood pressure monitoring showed a decrease in systolic blood pressure by more than 20 mmHg one hour after starting meals, which is considered as postprandial hypotension. The recurrent stroke occurred probably by a hemodynamic mechanism with the presence of internal carotid artery occlusion and postprandial hypotension. Administration of voglibose, an alpha-glucosidase inhibitor, improved postprandial hypotension. In patients with severe carotid or intracranial artery disease, the postprandial hypotension should be carefully monitored for prevention of hemodynamic brain ischemia.

Severe abdominal pain associated with allergic reaction to nafamostat mesilate in a chronic hemodialysis patient

A 33-year-old woman was referred from an outside dialysis clinic to our hospital because of severe abdominal pain during hemodialysis. She had been on chronic hemodialysis for the past 11 years due to chronic glomerulonephritis. Nafamostat mesilate was used as an anticoagulant for hemodialysis, because it was during her menstrual period with hypermenorrhea. On admission, she had no abdominal pain or gynecological abnormalities. On the second day, she had similar abdominal pain during hemodialysis with nafamostat mesilate in our dialysis unit. The abdominal pain disappeared within 60 minutes after discontinuing the hemodialysis. We re-started dialysis using heparin instead of nafamostat mesilate and she had no symptoms. The titer of total immunoglobulin E was high. The drug lymphocyte stimulation test was positive for nafamostat mesilate and antigen specific immunoglobulin E to nafamostat mesilate was highly positive in her blood. Although an allergic reaction to nafamostat mesilate is a rare complication, it should be one of the differential diagnoses of abdominal pain occurring during hemodialysis.

End-stage renal disease associated with familial Mediterranean fever

A 39-year-old man had been suffering from periodic fever since childhood. He was started on hemodialysis due to secondary amyloidosis on December 2000. The patient was believed to have Familial Mediterranean fever (FMF) because of recurrent fever with peritonitis, arthritis and inflammatory changes and secondary amyloidosis in his kidneys, heart and colon. No other family member had recurrent fever. IL-6, TNF, and dopamine beta-hydroxylase were not increased in the febril phase. The patient was homozygous for the M6941 mutation. We report the first Japanese case of FMF associated with amyloidosis and confirmed by a gene mutation.

A patient with adult-onset type II citrullinemia on long-term hemodialysis: reversal of clinical symptoms and brain MRI findings

A 40-year-old woman was referred for several episodes of coma lasting from 2 hours to 2 days. She had been on maintenance hemodialysis for polycystic kidney disease for 9 months. Laboratory findings showed high serum levels of ammonia and citrulline, and a diagnosis of adult-onset type II citrullinemia was made. Multiple areas of focal brain edema were shown by magnetic resonance imaging. The clinical manifestations of coma and abnormal behavior were resolved with intensified dialysis (ie, four 5-hour sessions per week with glycerol and continuous ambulatory peritoneal dialysis). No abnormal shadow was present on follow-up magnetic resonance imaging. Such intensified dialysis therapy may be effective for adult-onset type II citrullinemia and may be applicable even in patients who do not have end-stage renal disease if liver transplant is not an option.

Comparative analysis of HLA restriction and cytokine production in hepatitis B surface antigen-specific T cells from low- and high-antibody responders in vaccinated humans

It is well known that individuals with low, or lack of, antibody production in response to hepatitis B surface antigen (HBsAg) exist in the human population. We have previously reported that HLA class I and class II genes are both involved in antibody production to HBsAg, and that specific alleles of HLA are associated with low and high antibody production. To elucidate further the mechanisms by which the diversity of antibody production to HBsAg is generated in humans, a total of 146 T-cell clones specific for HBsAg were produced from six healthy vaccinees (three low- and three high-antibody responders) and were examined for cytokine production and HLA restriction. It was found that the majority of the T-cell clones from the low-antibody responders were Th1- or Th0-like T cells (62% or 19%, respectively), whereas the majority of T-cell clones from the high-antibody responders were Th2-like T cells (77%), suggesting predominant expansion of Th1/Th0- and Th2-like T cells specific for HBsAg in the low- and high-antibody responders, respectively. This is the first evidence that the diversity of the response to HBsAg in humans is controlled by the activation of functionally distinct CD4+ T-cell subsets, i.e., Th0, Th1, or Th2 T cells.

Family history of hypertension and blood pressure in a screened cohort

We sought to determine whether a family history of hypertension is quantitatively associated with the prevalence of hypertension and blood pressure in a screened cohort. Clinical data and family (parents and siblings) histories regarding hypertension were collected from 9,914 individuals (probands) who were interviewed and examined during a one-day clinic by the Okinawa General Health Maintenance Association in 1997. We used logistic analysis to calculate odds ratios with adjustments for age, sex, body mass index, total cholesterol, presence of diabetes mellitus, alcohol use, cigarette smoking, and status of physical exercise. The age- and sex-adjusted hypertension prevalences in probands were 29.0% for those with 1 family member with a history of hypertension (n=2,112), 37.6% for those with 2 hypertensive family members (n=374), and 47.3% for those with 3 or more hypertensive family members (n=68). In contrast, only 16.4% of probands who reported no family history of hypertension (n=7,360) were hypertensive themselves. The trend of the prevalence according to the number of family members with a history of hypertension was significantly positive (p=0.003). The adjusted odds ratios (95% confidence interval) of hypertension were 2.74 (2.43-3.10) for 1 member, 4.62 (3.62-5.90) for 2 members, and 6.04 (3.51-10.4) for 3 or more members with a history of hypertension. In patients without antihypertensive medication (n=9,009), systolic/diastolic blood pressure (mean +/- SD) was 121 +/- 17/75 +/- 11 for 1 member, 124 +/- 18/77 +/- 12 for 2 members, and 127 +/- 17/78 +/- 11 for 3 or more members with a history of hypertension. In contrast, the mean systolic/diastolic blood pressure of probands who reported no family history of hypertension (n=7,360) was 119 +/- 15/74 +/- 10 mmHg, which was significantly (p<0.05) lower than that of any of the groups with hypertensive family members. In conclusion, an increase in the number of family members with hypertension was associated with an increasing prevalence of hypertension and blood pressure in the probands, independent of conventional risk factors for hypertension. Family members of hypertensive subjects may need to be treated in primary prevention efforts related to hypertension.

Multiple risk factor clustering of hypertension in a screened cohort

OBJECTIVE

A family history of hypertension, obesity, diabetes mellitus, hypercholesterolaemia and hypertriglyceridaemia have all been associated with the risk for hypertension. We evaluated whether the clustering of these risk factors increases the risk for hypertension or whether the accumulation of risk factors is associated with the blood pressure level in non-hypertensive subjects.

METHODS AND SUBJECTS

We assessed the clinical data and family history of hypertension (in parents and siblings) for 9914 individuals (6163 men and 3751 women, 18-89 years old) who were screened in Okinawa, Japan, in 1997.

RESULTS

In 9914 subjects (2465 hypertensive and 7449 non-hypertensive subjects), all the five factors were positively associated with hypertension. The odds ratios (95% confidence interval) for the number of risk factors were 1.88 (1.62-2.18) for one risk factor, 3.06 (2.62-3.57) for two, 5.25 (4.37-6.30) for three, 8.71 (6.48-11.72) for four and 24.48 (8.49-70.56) for five, after adjusting for age, sex, alcohol consumption, cigarette smoking and physical exercise habits. In non-hypertensive subjects, multivariate regression analyses showed that the number of risks was positively correlated with blood pressure; the regression coefficient was 1.96 (P < 0.0001) for systolic blood pressure, and 1.47 (P < 0.0001) for diastolic blood pressure after adjusting for age and sex.

CONCLUSIONS

Clustering of risk factors was significantly associated with hypertension. The number of risk factors positively correlated with the blood pressure levels in nonhypertensive subjects. The accumulation of risk factors may play an important role in the pathogenesis of hypertension, and thus the aggregation of risk factors may need to be addressed in primary prevention efforts related to hypertension.

Magnitude of structural changes of the T-cell receptor binding regions determine the strength of T-cell antagonism: molecular dynamics simulations of HLA-DR4 (DRB1*0405) complexed with analogue peptide

In our model system, we generated T cell clones specific for the HLA-DR4 (DRB1*0405)-index peptide (YWALEAAAD) complex. Based on response patterns of the T cell clones, analogue peptides containing single amino acid substitutions of the index peptide were classified into three types, agonists, antagonists or null peptides (non-agonistic and non-antagonistic peptides). Subtle structural changes induced by the antagonists in the T-cell receptor (TCR) binding regions have already been explained using the root mean square (r.m.s.) deviations from the DR4-index peptide complex in the molecular dynamics (MD) trajectory. In this work, we performed additional MD simulations at 300 K with explicit solvent molecules to reveal the structural character of the HLA-DR4 complexed with the analogue peptides. We examined the r.m.s. deviations of the TCR-binding sites and the exposed areas of the bound peptides. Remarkable differences of the r.m.s. deviations among the DR4-antagonist complexes, together with our previous data, suggest that the magnitude of structural changes of TCR-binding regions would determine the strength of TCR antagonism. The simulations also indicate that TCR could discriminate null peptides from other ligands mainly through the changes of exposed side chains of the bound peptide, rather than the conformational changes of TCR-binding surfaces on HLA molecule.

Molecular dynamics simulations of HLA-DR4 (DRB1*0405) complexed with analogue peptide: conformational changes in the putative T-cell receptor binding regions

The specific recognition of foreign peptide bound to the major histocompatibility complex (MHC) molecule by T-cell receptor (TCR) leads to T-cell activation. We found that analogue peptides containing single amino acid substitutions at the third amino acid position (p3), p5, p7 and p8 of the index peptide (YWALEAAAD) induced different response patterns of T cell clones specific for the index peptide in the context of the human MHC class II molecule HLA-DR4. Analogue peptides were classified into three types, agonists, antagonists or null peptides (non-agonistic and non-antagonistic peptides). A molecular basis for how these slight changes lead to such different consequences for T cells has not been described. To explore the mechanistic basis of these observations, molecular dynamics simulations at 300 K of 300 ps duration were carried out for the DR4-index peptide, DR4-agonist, and DR4-antagonist complexes. The simulations showed that the DR4-antagonist complexes were distinguished from the DR4-index peptide and DR4-agonist complexes by relatively higher deviations of C(alpha) atoms in proposed TCR-binding regions, suggesting that subtle changes of the exposed framework of the peptide binding groove by the antagonist peptides could induce the TCR antagonistic activities.

An HLA-binding-motif-aided peptide epitope library: a novel library design for the screening of HLA-DR4-restricted antigenic peptides recognized by CD4+T cells

Susceptibility to a series of autoimmune diseases is strongly associated with particular HLA class II alleles. Identification of T cell clones and antigenic epitopes bound by HLA class II molecules involved in autoimmune diseases is critical to understanding the etiology of these HLA class II-associated diseases. However, establishment of T cell clones in autoimmune diseases is difficult because the antigenic peptides are unknown. Peptide library methods which include all possible peptide sequences offer a potentially powerful tool for the detection of cross-reactive antigenic peptides recognized by T cells. Here, we reduced the number of peptides per mixture by utilizing the known binding motifs of peptides for the HLA-DRB1*0405 molecule and evaluated the effectiveness of this library design. Each library mixture evoked a strong proliferative response in the unprimed peripheral blood lymphocytes (PBL) from HLA-DRB1*0405-positive donors but little or no response in the PBL from HLA-DRB1*0405-negative donors. The library also detected antigenic peptides that activated three antigen-specific T cell lines restricted by HLA-DRB1*0405, with different specificities. The motif-based approach thus presents a powerful method for monitoring T cells in large, heterogeneous T cell populations and is useful for the identification of the mimic peptide epitopes of T cell lines and clones.

MHC class I bound peptides of a colon carcinoma cell line, a Ki-ras gene-targeted progeny cell line and a B cell line

MHC class I associated peptides on cancer cells represent potential targets for CD8+ cytotoxic T cell activity against tumor cells. We eluted the naturally bound MHC class I peptides of a colon carcinoma cell line and compared them to peptides isolated from a B cell line and a slow-growing activated Ki-ras-disrupted colon cancer cell line. While we failed to detect any significant differences in class I associated peptides due to the presence or absence of activated Ki-ras in colon cancer cell lines, the colon cancer cell lines and B cell line presented vastly different peptide repertoires in the context of HLA-A*0201 molecules.

Identification of an epitope for T-cells correlated with antibody response to hepatitis B surface antigen in vaccinated humans

Two antigenic T-cell epitopes of HBsAg, designated HBs 16-31 and HBs 81-99, were identified using synthetic peptides and HBsAg-specific T-cell lines. HBs 16-31 was recognized by five HBsAg-specific T-cell lines from vaccinees with both high and low antibody titers, whereas HBs 81-99 was recognized by two T-cell lines derived from vaccinees with high antibody titers. The antibody titer against HBsAg was correlated significantly with the proliferation of vaccinee's PBLs in response to HBs 81-99 (r = 0.47) but not to HBs 16-31, suggesting that HBs 81-99 plays a critical role in anti-HBs antibody production in humans vaccinated with HBsAg.

Contribution of HLA class I and class II alleles to the regulation of antibody production to hepatitis B surface antigen in humans

The HLA multigene family consists of HLA class I (HLA-A, B and C) and class II (HLA-DR, DQ and DP) genes, and plays a central role in the regulation of immune response. To investigate how each HLA gene and each HLA allele contribute to the human immune response, we immunized 339 healthy Japanese medical students with recombinant hepatitis B surface antigen (rHBsAg) and determined the HLA types of all vaccinated subjects at the DNA level. The anti-HBs antibody titers showed a log-normal distribution, implying that the immune response to HBsAg in humans is a multifactorial and continuous trait. A stepwise multiple regression analysis demonstrated the alleles at the HLA-class I (HLA-A and B) and class II (HLA-DRB1, DQA1, DQB1, DPA1 and DPB1) loci significantly contributed to antibody production to HBsAg. The predicting equation of anti-HBs antibody levels for individuals with any HLA phenotype was proposed based on a multiple regression analysis. The multiple correlation coefficient of antibody production to HBsAg with the HLA-DRB1 locus was highest (0.34) among all of the HLA loci, whereas those with whole HLA class I or class II loci were 0.36 or 0.44 respectively. The incorporated correlation coefficient of the presence of all HLA gene families with antibody production became 0.50, suggesting that HLA class I and class II loci within the HLA multigene family are dynamically involved in regulation of the immune response to HBsAg.

[Two siblings with adult-onset sialidosis type I (cherry-red spot-myoclonus syndrome)]

Cases of two Japanese siblings with adult-onset sialidosis type I are reported. A 38-year-old man had gradually developed involuntary movement of the extremities from the age of 31. On admission, he had no skeletal abnormalities and hepatosplenomegaly, but showed myoclonus of the extremities and dyskinesia in the perioral region. We found cherry-red spots and a giant potential in a somatosensory evoked potential (SEP) study. Then, the diagnosis of sialidosis type I was confirmed by low activity of white blood cell sialidase. MRI (SE, TR 2,000/TE 100, 40) of the brain revealed a small high intensity are in the cerebral white matter adjacent to the posterior horn of the right cerebral ventricle. To our knowledge, no report on MRI findings of the brain in sialidosis type I has been reported. So far, it is uncertain whether or not such a lesion is caused by sialidosis. He was treated with clonazepam, sodium valproate, diphenylhydantoin, or haloperidol. The former two improved the symptoms, but SEP findings did not change. The subject's 43-year-old brother had also myoclonus and epilepsy since the age of 31, and low activity of sialidase. Their mother had no symptoms, but her sialidase activity level was as low as that of a carrier. These two are the eighth and ninth cases of sialidosis type I in Japan to be confirmed by enzyme activity.