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Objective. The correlation of cardiac output and cerebral perfusion is unclear. We tested this potential association by correlating cardiac output data obtained by echocardiography and cerebral blood flow data as determined by color M-mode measurements of carotid artery blood flow. Methods. We studied 43 patients with a broad spectrum of cardiac performance by means of transthoracic echocardiography. In these patients, different cardiac indices such as stroke volume, ejection fraction, and heart minute volume were determined. The data were correlated with volumetric flow measurements (color M-mode duplex system) of the common carotid arteries bilaterally. Results. Heart minute volume ranged from 1.632 to 9.836 mL/min (mean ± SD, 4.652 ± 1.621 mL/min); ejection fraction ranged from 18% to 76% (mean, 48% ± 16%). The relative fraction of carotid volume flow compared with heart minute volume was 15% ± 6%. There was no correlation between ejection fraction, stroke volume, or heart minute volume and absolute volume flow in the carotid arteries when being adjusted for age. There was a highly significant inverse correlation (r = -0.8; P < .0001) of the relative fraction of the carotid volume flow (carotid volume flow/heart minute volume [percent]) and the heart minute volume. Conclusion. Our data support the concept that cerebral blood flow is independent of cardiac output. Key words: cardiac output; cerebrovascular circulation; ultrasonography.Received January 18, 2001, from the Departments of Neurology (B.M.E., J.v.S., H.C.H.) and Cardiology (S.M.-K., A.S., R.S.v.B.) Abbreviations ASV, absolute stroke volume; BS, body surface; CBF, cerebral blood flow; CCA, common carotid artery; CI, cardiac index; EDV, end-diastolic volume; EF, ejection fraction; ESV, end-systolic volume; HMV, heart minute volume; HR, heart rate; LV, left ventricular; RSV, relative stroke volume; SPECT, single-photon emission computed tomography; Vol, volume erebral autoregulation maintains constant brain perfusion over a wide blood pressure range between 60 and 150 mm Hg. 1 Within these limits, cerebral blood flow (CBF) is not directly correlated with cerebral perfusion pressure. 2 A review of the literature suggests that the impact of cardiac output on CBF is uncertain, with conflicting data in animals, healthy volunteers, and neurosurgical or cardiologic patients. [3][4][5][6][7][8] In addition, methodological differences to define CBF enhance difficulties with interpreting these studies. Cerebral blood flow was assessed by means of singlephoton emission computed tomography (SPECT) 3,6,7 or blood flow velocity of the middle cerebral artery. 9 These methods are difficult, because they either require radioactive tracers (SPECT) or reflect only flow velocity (transcranial Doppler ultrasonography) rather than flow volume data. Clinical trials comparing xenon Xe 133 SPECT and transcranial Doppler data revealed conflict-

Black and purple carrots have attracted interest as colored extracts for coloring food due to their high content of anthocyanins. This study aimed to investigate the polyphenol composition of black carrots. Particularly, the identification and quantification of phenolic compounds of the variety Deep Purple carrot (DPC), which presents a very dark color, was performed by HPLC-PDA and HPLC-ESI-MS(n) analyses. The separation of polyphenols from a DPC XAD-7 extract into an anthocyanin fraction (AF) and co-pigment fraction (CF; primarily phenolic acids) was carried out by membrane chromatography. Furthermore, possible anti-diabetic effects of the DPC XAD-7 extract and its AF and CF were determined. DPC samples (XAD-7, CF, and AF) inhibited α-amylase and α-glucosidase in a dose-dependent manner. Moreover, DPC XAD-7 and chlorogenic acid, but not DPC CF and DPC AF, caused a moderate inhibition of intestinal glucose uptake in Caco-2 cells. However, DPC samples did not affect glucagon-like peptide-1 (GLP-1) secretion and dipeptidyl peptidase IV (DPP-4) activity. Overall, DPC exhibits an inhibitory effect on α-amylase and α-glucosidase activity and on cellular glucose uptake indicating potential anti-diabetic properties.

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