Screening for the Prevention of Stroke: Use of a Doppler Flowmeter

1973 ◽  
Vol 53 (6) ◽  
pp. 1761-1761
Keyword(s):  
Doppler Flowmeter

Direct measurement of renal medullary blood flow in the dog

1994 ◽  
Vol 267 (1) ◽  
pp. R253-R259 ◽  
Author(s):  
D. M. Strick ◽  
M. J. Fiksen-Olsen ◽  
J. C. Lockhart ◽  
R. J. Roman ◽  
J. C. Romero
Keyword(s):  
Blood Flow ◽  
Pressure Range ◽  
Perfusion Pressure ◽  
Renal Perfusion ◽  
Flow Probe ◽  
Renal Autoregulation ◽  
Renal Perfusion Pressure ◽  
Medullary Blood Flow ◽  
Renal Medullary Blood Flow ◽  
Doppler Flowmeter

We studied the responses of total renal blood flow (RBF) and renal medullary blood flow (RMBF) to changes in renal perfusion pressure (RPP) within and below the range of renal autoregulation in the anesthetized dog (n = 7). To measure RMBF, we developed a technique in which the medulla is exposed by excising a section of infarcted cortex and a multiple optical fiber flow probe, connected to a laser-Doppler flowmeter, is placed on the medulla. At the baseline RPP of 120 +/- 1 mmHg, RBF was 2.58 +/- 0.33 ml.min-1.g perfused kidney wt-1, and RMBF was 222 +/- 45 perfusion units. RPP was then decreased in consecutive 20-mmHg steps to 39 +/- 1 mmHg. At 80 +/- 1 mmHg, RBF remained at 89 +/- 4% of the baseline value; however, RMBF had decreased significantly (P < 0.05) to 73 +/- 4% of its baseline value. The efficiency of autoregulation of RBF and of RMBF within the RPP range of 120 to 80 mmHg was determined by calculating an autoregulatory index (AI) for each parameter using the formula AI = (%delta blood flow)/(%delta RPP). An AI of 0 indicates perfect autoregulation, and an index of 1 indicates a system with a fixed resistance. The AI for RBF averaged 0.33 +/- 0.12 over this pressure range and showed a significantly greater (P < 0.05) autoregulatory ability than did the RMBF (0.82 +/- 0.13). Decreasing perfusion pressure < 80 mmHg produced significant decreases in both RBF and RMBF.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Pancreatic capillary blood flow during caerulein-induced pancreatitis evaluated by a laser-doppler flowmeter in rats

2003 ◽  
Vol 18 (suppl 5) ◽  
pp. 18-22 ◽  
Author(s):  
Roberto Ferreira Meirelles Jr. ◽  
Reginaldo Ceneviva ◽  
José Liberato Ferreira Caboclo ◽  
Michael M. Eisenberg
Keyword(s):  
Blood Flow ◽  
Serum Amylase ◽  
Tissue Injury ◽  
Capillary Blood ◽  
Laser Doppler ◽  
Capillary Blood Flow ◽  
Control Group ◽  
Laser Doppler Flowmeter ◽  
Significant Difference ◽  
Doppler Flowmeter

PURPOSE: The pancreatic capillary blood flow (PCBF) was studied to determine its alterations during caerulein-induced pancreatitis in rats. METHODS: Twenty rats were divided in groups: control and caerulein. A laser-Doppler flowmeter to measure PCBF continuously was used. Blood pressure (BP) and heart rate (HR) were monitored. Serum biochemistry analyses were determined. Histopathological study was performed. RESULTS: The PCBF measured a mean of 109.08 ± 14.54% and 68.24 ± 10.47% in control group and caerulein group, respectively. Caerulein group had a mean decrease of 31.75 ± 16.79%. The serum amylase was 1323.70 ± 239.10U.I-1 and 2184.60 ± 700.46U.I-1 in control and caerulein groups, respectively. There was a significant difference in the PCBF (p<0.05) and serum amylase (p<0.05) when compared to control and caerulein groups. Although micro and microvacuolization were seen in 30% in caerulein group, no significant difference was seen between the groups. CONCLUSION: A decrease in the PCBF may be one of the leading events and it is present before histopathological tissue injury had been established in this model of acute pancreatitis.

Measurement of portal blood flow by an ultrasonic “duplex” system composed of a pulsed Doppler flowmeter and a linear-type real time B mode electroscanner

1988 ◽  
Vol 23 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Shigehiro Shiraki ◽  
Katsuhiko Tsukada ◽  
Norishige Ozeki ◽  
Toshihiko Takeuchi ◽  
Kazuo Gotoh ◽  
...  
Keyword(s):  
Blood Flow ◽  
Real Time ◽  
Portal Blood Flow ◽  
Portal Blood ◽  
Pulsed Doppler ◽  
Duplex System ◽  
Linear Type ◽  
Doppler Flowmeter

scholarly journals Evaluation of the intraoperative hemodynamics in abdominal visceral organs of portal system with the use of Laser Doppler flowmeter.

1990 ◽  
Vol 23 (1) ◽  
pp. 65-69 ◽  
Author(s):  
Yoshio Arai ◽  
Kenji Koyama ◽  
Yoshihiro Asanuma ◽  
Susumu Omokawa ◽  
Shugo Kashima ◽  
...  
Keyword(s):  
Laser Doppler ◽  
Portal System ◽  
Laser Doppler Flowmeter ◽  
Visceral Organs ◽  
Doppler Flowmeter

MEASUREMENT OF LOCALIZED FLOW VELOCITIES IN GASES WITH A LASER DOPPLER FLOWMETER

1965 ◽  
Vol 7 (4) ◽  
pp. 77-78 ◽  
Author(s):  
J. W. Foreman ◽  
E. W. George ◽  
R. D. Lewis
Keyword(s):  
Laser Doppler ◽  
Laser Doppler Flowmeter ◽  
Doppler Flowmeter ◽  
Flow Velocities

Observations of cochlear blood flow dynamics using the laser Doppler flowmeter

1989 ◽  
Vol 246 (3) ◽  
pp. 147-150 ◽  
Author(s):  
M. Kawakami ◽  
K. Makimoto ◽  
T. Nakajima ◽  
H. Takahashi
Keyword(s):  
Blood Flow ◽  
Flow Dynamics ◽  
Laser Doppler ◽  
Laser Doppler Flowmeter ◽  
Cochlear Blood Flow ◽  
Blood Flow Dynamics ◽  
Doppler Flowmeter

Nitric oxide-dependent and -independent components of cerebrovasodilation elicited by hypercapnia

1994 ◽  
Vol 266 (2) ◽  
pp. R546-R552 ◽  
Author(s):  
C. Iadecola ◽  
F. Zhang
Keyword(s):  
Nitric Oxide ◽  
Methyl Ester ◽  
Time Course ◽  
Slow Time ◽  
Independent Components ◽  
Arterial Partial Pressure ◽  
Partial Pressure Of Co2 ◽  
Nos Inhibitor ◽  
Oxide Synthase ◽  
Doppler Flowmeter

We studied the effect of nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase (NOS) inhibitor, on the increases in cerebral blood flow (CBF) elicited by stepwise elevations in arterial partial pressure of CO2 (PaCO2) from normocapnia up to 204 mmHg. Rats were anesthetized with halothane and ventilated. CBF was monitored over the parietal cortex using a laser-Doppler flowmeter. Increasing levels of hypercapnia elicited graded elevations in CBF that reached a plateau at PaCO2 = 82 +/- 1 mmHg (CBF +215 +/- 25%; n = 8; P < 0.05, analysis of variance). L-NAME (40 mg/kg i.v.; n = 8), but not nitro-D-arginine methyl ester (n = 8), reduced resting CBF (-42 +/- 4%) and attenuated the increase in CBF elicited by hypercapnia. The attenuation occurred only at PaCO2 40-80 mmHg and was maximal (-75 +/- 8%; P < 0.05) at 54 +/- 2 mmHg. At PaCO2 > or = 100 mmHg, L-NAME (40-80 mg/kg) did not attenuate the response (P > 0.05). Reduction of resting CBF (-50 +/- 4%; n = 6) by administration of chloralose (20-40 mg/kg i.v.) did not attenuate the CBF response to hypercapnia (P > 0.05). We also found that the attenuation by L-NAME of resting CBF (n = 5) and of the cerebrovasodilation elicited by hypercapnia (n = 6) has a relatively slow time course, the effects reaching a maximum 45-60 min after intravenous administration of the drug. We conclude that L-NAME does not attenuate the CBF response to CO2 uniformly at all levels of hypercapnia.(ABSTRACT TRUNCATED AT 250 WORDS)

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