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Dohadwala MM, Hamburg NM, Holbrook M, Kim BH, Duess MA, Levit A, Titas M, Chung WB, Vincent FB, Caiano TL, Frame AA, Keaney JF, Vita JA. Effects of Concord grape juice on ambulatory blood pressure in prehypertension and stage 1 hypertension. Am J Clin Nutr 2010; 92:1052-9. [PMID: 20844075 PMCID: PMC2954442 DOI: 10.3945/ajcn.2010.29905] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Consumption of flavonoid-containing foods may be useful for the management of hypertension. OBJECTIVE We investigated whether 100% Concord grape juice lowers blood pressure in patients with prehypertension and stage 1 hypertension. DESIGN We conducted a double-blind crossover study to compare the effects of grape juice (7 mL · kg⁻¹ · d⁻¹) and matched placebo beverage on 24-h ambulatory blood pressure, stress-induced changes in blood pressure, and biochemical profile. Participants consumed each beverage for 8 wk with a 4-wk rest period between beverages. They ceased consumption of grapes and other flavonoid-containing beverages throughout the study. RESULTS We enrolled 64 otherwise healthy patients taking no antihypertensive medications (31% women, 42% black, age 43 ± 12 y). Baseline mean (± SD) cuff blood pressure was 138 ± 7 (systolic)/82 ± 7 (diastolic) mm Hg. No effects on the primary endpoint of 24-h mean systolic blood pressure, diastolic blood pressure, or stress-induced changes in blood pressure were observed. A secondary endpoint was nocturnal dip in systolic pressure. At baseline, nocturnal pressure was 8.3 ± 7.1% lower at night than during daytime. The mean nocturnal dip increased 1.4 percentage points after grape juice and decreased 2.3 percentage points after placebo (P = 0.005). Fasting blood glucose was 91 ± 10 mg/dL at baseline for the entire cohort. Glucose decreased 2 mg/dL after consumption of grape juice and increased 1 mg/dL after consuming the placebo (P = 0.03). CONCLUSIONS We observed no effect of grape juice on ambulatory blood pressure in this cohort of relatively healthy individuals with modestly elevated blood pressure. Secondary analyses suggested favorable effects on nocturnal dip and glucose homeostasis that may merit further investigation. This trial was registered at clinicaltrials.gov as NCT00302809.
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Affiliation(s)
- Mustali M Dohadwala
- Evans Department of Medicine and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
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Lee JY, Azar SH. Wistar-Kyoto and spontaneously hypertensive rat blood pressure after embryo transfer into different wombs and cross-suckling. Exp Biol Med (Maywood) 2010; 235:1375-84. [PMID: 20864459 DOI: 10.1258/ebm.2010.010081] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Blood pressure (BP) varies based on genetic and environmental factors. To test genetic and environmental influences on body weight (BW) and BP, one-cell homozygous embryos were transferred into spontaneously hypertensive (SHR, pup:shr) or (Wistar-Kyoto normotensive [WKY], pup:wky) normotensive rats' oviducts (embryos: s,w; oviduct-uterine: S,W), cross-suckled at birth (nurses S,W) and weaned to normal diets at day-21. BP at day-120 was measured by radiotelemetry and analyzed by methods of linear least square rhythmometry and analysis of variance. Genetics dominantly affected shr BP, causing it to be significantly higher at birth (24.6 ± 1.8 in sS versus 21.8 ± 1.7 mmHg in wW, P < 0.005), and at day-120 (198 ± 0.5 in sSS versus 127 ± 0.2 mmHg in wWW, P < 0.001), with lower BW than those of wky (5.3 ± 0.2 versus 5.7 ± 0.2 g at birth, 332 ± 5 versus 404 ± 6 g at day-120, both P < 0.001). Surprisingly, uterine-suckling milieus lowered shr BP significantly at day-120 (198 ± 0.5 in sSS versus 178 ± 0.5, 147 ± 0.6, 179 ± 0.5 mmHg in sSW, sWS, sWW, respectively, all P < 0.01). BP was slightly elevated when wky-genetics were implanted into the S-uterine by 4 mmHg (wSW, P < 0.05), whereas implanting shr embryos into the W-uterine environment (sWS) lowered BP by 51 mmHg (P < 0.001). In summary, the hypertensive shr-strain showed significantly lower BP when provided with an WKY-uterine environment and/or by WKY-nursing mothers, indicating that environment can modify genetic influences; yet the shr MESORs (rhythm-adjusted 24-h mean: midline estimating statistic of rhythm) lowered by WKY environments remained above MESORs encountered in wky-donors.
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Affiliation(s)
- Jong Y Lee
- Department of Medicine, University of Minnesota School of Medicine, P.O. Box 14945, Minneapolis, MN 55414, USA.
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Abstract
PURPOSE OF REVIEW Circadian variation is commonly seen in healthy people; aberration in these biological rhythms is an early sign of disease. Impaired circadian variation of blood pressure (BP) has been shown to be associated with greater target organ damage and with an elevated risk of cardiovascular events independent of the BP load. The purpose of this review is to examine the physiology of circadian BP variation and propose a tripartite model that explains the regulation of circadian BP. RECENT FINDINGS The time-keeper in mammals resides centrally in the suprachiasmatic nucleus. Apart from this central clock, molecular clocks exist in most peripheral tissues including vascular tissue and the kidney. These molecular clocks regulate sodium balance, sympathetic function and vascular tone. A physiological model is proposed that integrates our understanding of molecular clocks in mice with the circadian BP variation among humans. The master regulator in this proposed model is the sleep-activity cycle. The equivalents of peripheral clocks are endothelial and adrenergic functions. Thus, in the proposed model, the variation in circadian BP is dependent upon three major factors: physical activity, autonomic function, and sodium sensitivity. SUMMARY The integrated consideration of physical activity, autonomic function, and sodium sensitivity appears to explain the physiology of circadian BP variation and the pathophysiology of disrupted BP rhythms in various conditions and disease states. Our understanding of molecular clocks in mice may help to explain the provenance of blunted circadian BP variation even among astronauts.
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Sayk F, Teckentrup C, Becker C, Heutling D, Wellhöner P, Lehnert H, Dodt C. Effects of selective slow-wave sleep deprivation on nocturnal blood pressure dipping and daytime blood pressure regulation. Am J Physiol Regul Integr Comp Physiol 2009; 298:R191-7. [PMID: 19907004 DOI: 10.1152/ajpregu.00368.2009] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Nocturnal blood pressure (BP) decline or "dipping" is an active, central, nervously governed process, which is important for BP regulation during daytime. It is, however, not known whether the sleep process itself or, more specifically, slow-wave sleep (SWS) is important for normal dipping. Therefore, in the present study, healthy subjects (6 females, 5 males) were selectively deprived of SWS by EEG-guided acoustic arousals. BP and heart rate (HR) were monitored during experimental nights and the following day. Additionally, nocturnal catecholamine excretion was determined, and morning baroreflex function was assessed by microneurographic measurements of muscle sympathetic nerve activity (MSNA) and heart rate variability (HRV). Data were compared with a crossover condition of undisturbed sleep. SWS was successfully deprived leading to significantly attenuated mean arterial BP dipping during the first half (P < 0.05), but not during the rapid-eye-movement-dominated second half of total sleep; however, dipping still evolved even in the absence of SWS. No differences were found for nighttime catecholamine excretion. Moreover, daytime resting and ambulatory BP and HR were not altered, and morning MSNA and HRV did not differ significantly, indicating that baroreflex-mediated sympathoneural BP regulation was not affected by the preceding SWS deprivation. We conclude that in healthy humans the magnitude of nocturnal BP dipping is significantly affected by sleep depth. Deprivation of SWS during one night does not modulate the morning threshold and sensitivity of the vascular and cardiac baroreflex and does not alter ambulatory BP during daytime.
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Affiliation(s)
- Friedhelm Sayk
- First Dept. of Medicine, Univ. of Luebeck, Ratzeburger Allee 160, D-23538 Luebeck, Germany.
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Abstract
OBJECTIVE To investigate whether black and white adults benefit similarly from perceived social support in relation to blood pressure (BP) dipping during sleep. METHODS The Interpersonal Support Evaluation List (ISEL, 12-item version), which measures the perceived availability of several types of functional social support, was examined for interactive effects with race on dipping of mean arterial pressure (MAP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) derived from 24-hour ambulatory blood pressure monitoring (ABPM). The sample consisted of 156 young to middle-aged adults (61 blacks, 95 whites; mean age = 35.7 years). RESULTS Mean ISEL scores did not differ between racial groups. Controlling for age, body mass index (BMI), resting BP, and socioeconomic status (SES), the interaction of social support by race yielded associations with nighttime dipping in MAP and DBP (p < .001) as well as SBP (p < .01). As ISEL scores increased among white participants, the extent of dipping increased in MAP, SBP, and DBP (p < .01), explaining 10%, 10%, and 8% of the variance, respectively. Conversely, black participants exhibited associations between increasing ISEL scores and decreasing levels of dipping in MAP, SBP, and DBP (p < .05), accounting for 9%, 8%, and 8% of the variance, respectively. CONCLUSION As perceived social support increased, white adults received cardiovascular benefits as suggested by enhanced nocturnal dipping of BP, but black adults accrued risks as evidenced by blunted declines in BP during sleep.
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A blunted decrease in nocturnal blood pressure is independently associated with increased aortic stiffness in patients with resistant hypertension. Hypertens Res 2009; 32:591-6. [DOI: 10.1038/hr.2009.71] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Grassi G, Seravalle G, Quarti-Trevano F, Dell'Oro R, Bombelli M, Cuspidi C, Facchetti R, Bolla G, Mancia G. Adrenergic, Metabolic, and Reflex Abnormalities in Reverse and Extreme Dipper Hypertensives. Hypertension 2008; 52:925-31. [DOI: 10.1161/hypertensionaha.108.116368] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Guido Grassi
- From the Clinica Medica (G.G., F.Q.-T., R.D., M.B., C.C., R.F., G.B., G.M.), Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan) and Istituto Auxologico Italiano Milan (G.S.), Italy
| | - Gino Seravalle
- From the Clinica Medica (G.G., F.Q.-T., R.D., M.B., C.C., R.F., G.B., G.M.), Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan) and Istituto Auxologico Italiano Milan (G.S.), Italy
| | - Fosca Quarti-Trevano
- From the Clinica Medica (G.G., F.Q.-T., R.D., M.B., C.C., R.F., G.B., G.M.), Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan) and Istituto Auxologico Italiano Milan (G.S.), Italy
| | - Raffaella Dell'Oro
- From the Clinica Medica (G.G., F.Q.-T., R.D., M.B., C.C., R.F., G.B., G.M.), Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan) and Istituto Auxologico Italiano Milan (G.S.), Italy
| | - Michele Bombelli
- From the Clinica Medica (G.G., F.Q.-T., R.D., M.B., C.C., R.F., G.B., G.M.), Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan) and Istituto Auxologico Italiano Milan (G.S.), Italy
| | - Cesare Cuspidi
- From the Clinica Medica (G.G., F.Q.-T., R.D., M.B., C.C., R.F., G.B., G.M.), Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan) and Istituto Auxologico Italiano Milan (G.S.), Italy
| | - Rita Facchetti
- From the Clinica Medica (G.G., F.Q.-T., R.D., M.B., C.C., R.F., G.B., G.M.), Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan) and Istituto Auxologico Italiano Milan (G.S.), Italy
| | - Gianbattista Bolla
- From the Clinica Medica (G.G., F.Q.-T., R.D., M.B., C.C., R.F., G.B., G.M.), Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan) and Istituto Auxologico Italiano Milan (G.S.), Italy
| | - Giuseppe Mancia
- From the Clinica Medica (G.G., F.Q.-T., R.D., M.B., C.C., R.F., G.B., G.M.), Dipartimento di Medicina Clinica, Prevenzione e Biotecnologie Sanitarie, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan) and Istituto Auxologico Italiano Milan (G.S.), Italy
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Bouhanick B, Bongard V, Amar J, Bousquel S, Chamontin B. Prognostic value of nocturnal blood pressure and reverse-dipping status on the occurrence of cardiovascular events in hypertensive diabetic patients. DIABETES & METABOLISM 2008; 34:560-7. [PMID: 18926758 DOI: 10.1016/j.diabet.2008.05.005] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Revised: 04/30/2008] [Accepted: 05/11/2008] [Indexed: 02/06/2023]
Abstract
AIM To assess whether reverse-dipping status is associated with cardiovascular (CV) events such as CV death, myocardial infarction (MI) or stroke in diabetic patients with hypertension. METHODS A total of 97 diabetic patients underwent their first ambulatory blood pressure monitoring (ABPM 1). "Reverse dippers" were defined as patients with a nighttime systolic and/or diastolic blood pressure (BP) greater than daytime systolic and/or diastolic BP. Other patients were called "others". A second ABPM (ABPM 2) was done after a median delay of 2.6 years. Patients were then followed for a further 2.9-year median period (total median follow-up: 5.5 years). RESULTS After ABPM 1, CV events occurred in 53% of the reverse dippers (n=15) and in 29% of the others (n=82). Kaplan-Meier curves showed significant differences between the two groups (P=0.003). Mean nighttime systolic BP on ABPM 1 was 148+/-23 mmHg and 142+/-19 mmHg in patients who did and did not experience a CV event, respectively. With Cox analysis adjusted for confounders, a 10 mmHg increase in nighttime systolic BP was associated with a 35% increase in the risk of a CV event (hazard ratio [HR]: 1.35, P=0.003). The HR for a CV event in reverse- versus nonreverse-dipping status was 2.79 (P=0.023). After ABPM 2, the relationship between the reverse-dipping status and occurrence of CV events was no longer evident (P=0.678). Nighttime systolic BP remained predictive of CV events (P=0.001). CONCLUSION These findings suggest that nighttime systolic BP per se appeared to be a stronger predictor of an excess risk of CV events compared with reverse-dipping status.
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Affiliation(s)
- B Bouhanick
- Service de médecine interne et HTA, CHU de Rangueil, TSA 50032, 31059 Toulouse cedex 09, France.
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Sayk F, Vietheer A, Schaaf B, Wellhoener P, Weitz G, Lehnert H, Dodt C. Endotoxemia causes central downregulation of sympathetic vasomotor tone in healthy humans. Am J Physiol Regul Integr Comp Physiol 2008; 295:R891-8. [DOI: 10.1152/ajpregu.90444.2008] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Experimental endotoxemia as a model of the initial septic response affects the autonomic nervous system with profound cardiovascular sequelae. Whether the postsynaptic sympathoneural activity to the muscle vascular bed is altered in the early septic phase remains to be determined. The present study aimed to elucidate the early effects of LPS on muscle sympathetic nerve activity (MSNA) and cardiovascular regulation in healthy humans. Young, healthy volunteers randomly received either an LPS bolus (4 ng/kg body wt, n = 11) or placebo (saline; n = 7). Experimental baroreflex assessment (baseline measurements followed by infusion of vasoactive drugs nitroprusside/phenylephrine) was done prior to and 90 min following LPS or placebo challenge. MSNA, heart rate, blood pressure, and blood levels of catecholamines, TNF-α and IL-6 were measured sequentially. Endotoxin but not placebo-induced flu-like symptoms and elevated cytokine levels. In contrast to placebo, LPS significantly suppressed MSNA burst frequency 90 min after injection [mean ± SE: 12.1 ± 2.9 vs. 27.5 ± 3.3 burst/min (post- vs. pre-LPS); P < 0.005] but increased heart rate [78.4 ± 3.1 vs. 60.6 ± 2.0 beats/min (post- vs. pre-LPS); P < 0.001]. Baseline blood pressure was not altered, but baroreflex testing demonstrated a blunted MSNA response and uncoupling of heart rate modulation to blood pressure changes in the endotoxin group. We conclude that endotoxin challenge in healthy humans has rapid suppressive effects on postsynaptic sympathetic nerve activity to the muscle vascular bed and alters baroreflex function which may contribute to the untoward cardiovascular effects of sepsis.
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Pulse pressure or dipping pattern: which one is a better cardiovascular risk marker in resistant hypertension? J Hypertens 2008; 26:878-84. [PMID: 18398329 DOI: 10.1097/hjh.0b013e3282f55021] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Nocturnal blood pressure (BP) reduction and ambulatory pulse pressure (PP) are well known prognostic markers obtained from ambulatory BP monitoring (ABPM). The aim of this study is to investigate which one of these ABPM parameters is related to high cardiovascular risk profile in resistant hypertension, based on their associations with target organ damage (TOD). METHODS Clinical-demographic, laboratory and ABPM variables were recorded in a cross-sectional study involving 907 resistant hypertensive patients. Nocturnal systolic BP reduction and 24-h PP were assessed both as continuous and dichotomized variables (PP at the upper tertile value: 63 mmHg). Statistical analyses included bivariate tests and multivariate logistic regression with each TOD as the dependent variable. RESULTS Patients with the nondipping pattern and high 24-h PP shared some characteristics: they were older, had higher prevalence of cerebrovascular disease and nephropathy, higher office and 24-h BP levels, increased serum creatinine and microalbuminuria, and higher left ventricular mass index than their counterparts. Additionally, patients with high PP had a greater prevalence of diabetes and other TOD. In multivariate logistic regression, high PP was independently associated with all TODs even after adjustment for sex, age, BMI, cardiovascular risk factors, 24-h mean arterial pressure and antihypertensive treatment, whereas nondipping pattern was only associated with hypertensive nephropathy. Furthermore, PP was more strongly associated with the number of TOD than the nocturnal systolic blood pressure (SBP) fall. CONCLUSIONS In a large group of resistant hypertensive patients, an increased 24-h PP shows a closer correlation with high cardiovascular risk profile than the nocturnal BP reduction.
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Silvani A. Physiological sleep-dependent changes in arterial blood pressure: central autonomic commands and baroreflex control. Clin Exp Pharmacol Physiol 2008; 35:987-94. [PMID: 18565197 DOI: 10.1111/j.1440-1681.2008.04985.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sleep is a heterogeneous behaviour. As a first approximation, it is subdivided objectively into two states: non-rapid eye movement sleep (NREMS) and rapid eye movement sleep (REMS). The mean value and variability of arterial blood pressure (ABP) decrease physiologically from wakefulness to NREMS. In REMS, there may be a further decrease or increase in mean ABP as well as phasic hypertensive events, which enhance the variability of ABP. The reduced mean ABP during NREMS results from a decrease in either heart rate or sympathetic vasoconstrictor tone. During REMS, sympathetic activity to the different cardiovascular effectors undergoes a substantial repatterning. Thus, the mean ABP in REMS reflects a balance between changes in cardiac output and constriction or dilatation of different vascular beds. In both sleep states, the phasic changes in ABP are driven by bursts of vasoconstriction, which may be accompanied by surges of heart rate. The available evidence supports the hypothesis that the sleep-dependent changes in ABP, either tonic or phasic, result from the integration between cardiovascular reflexes and central autonomic commands that are specific to each sleep state.
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Affiliation(s)
- Alessandro Silvani
- Department of Human and General Physiology, University of Bologna, Bologna, Italy.
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CARDOSO CR, LEITE NC, FREITAS L, DIAS SB, MUXFELD ES, SALLES GF. Pattern of 24-Hour Ambulatory Blood Pressure Monitoring in Type 2 Diabetic Patients with Cardiovascular Dysautonomy. Hypertens Res 2008; 31:865-72. [DOI: 10.1291/hypres.31.865] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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