Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Laser-Doppler Flowmetry”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources
PubMed1993

[Colored biomicrospheres for studies of cochlear microcirculation].

For many years in our laboratory, toads red blood cells have been used as biomicrospheres for study of cochlear microcirculation. In the present experiments the cochlear blood flows (CBF) was twice determined in the same animal by using colored biomicrospheres. The red blood cells were stained separately with eosin and azure blue. The biomicrospheres of two different colors were injected intracardially in the same guinea pig at two different times with an interval of 4 min. The CBF were detected by using a laser Doppler system simultaneously. The finding showed that color of red and blue biomicrospheres were contrast sharply, they were all distinguished easily from the surrounding tissue. The adequate number of microspheres injected each time was 9 x 10(6)/ml. The results of CBF were not different between the first and second injection.

Animals↗
PubMed1993

[The effect of superior cervical sympathetic ganglionectomy on cochlear blood flow in guinea pigs].

The effect of superior cervical sympathetic ganglionectomy on cochlear blood flow (CoBF) was observed in 21 guinea pigs. The CoBF was measured with Laser Doppler Flowmeter. The systemic blood pressure (BP) was simultaneously recorded. The elevation of BP as well as the increase in CoBF following ganglionectomy were not statistically significant; the change in CoBF was somewhat consistent with the variation of BP. The results imply that there is no significant effect of superior cervical sympathetic ganglionectomy on CoBF of guinea pigs.

Animals↗
PubMed1993

The relationship between subjective vasospastic complaints and finger blood flow measurements in Raynaud's phenomenon.

BACKGROUND: Objective circulatory tests in patients with Raynaud's phenomenon have only rarely been related to subjective complaints. METHODS: In 55 Raynaud patients the correlation between daily self-recorded frequency, duration and severity of vasospastic attacks and the measurement of finger skin blood flow during local cooling was investigated. RESULTS: No significant correlations were found between complaints as registered in the diaries and finger skin temperature and laser Doppler flux before, during and after a standardized local cooling procedure. CONCLUSION: Finger skin blood flow measurements do not necessarily reflect digital vasospasm in daily life. Besides studies on the diagnostic value and reproducibility of skin blood flow measurements in Raynaud's phenomenon, the relationship of test results to subjective complaints should be established.

Activities of Daily Living↗
PubMed1993

Effect of preoperative irradiation on wound healing after bronchial anastomosis in mongrel dogs.

To determine the endurable radiation dose before bronchial anastomosis, the bronchial circulation of mongrel dogs was assessed after bronchoplastic surgery conducted after various single doses of radiation. Plastic surgery of the right main bronchus was carried out 1 week after cobalt 60 irradiation to the right hilar region. Bronchial blood flow was measured with laser Doppler velocimetry 7, 14, and 30 days after operation. Animals were killed 30 days after operation and the region of the bronchial anastomosis was examined histologically. The animals were divided into five groups: group A (control group without irradiation), group B (8 Gy irradiation), group C (16 Gy), group D (19 Gy), and group E (24 Gy). Wound healing of the anastomosed bronchus was excellent in groups A and B. In group A, bronchial blood flow did not drop below 80% of the preoperative level throughout the postoperative observation period. In group B, bronchial blood flow on day 7 after operation was only 65% of the preoperative level, but blood flow had returned to the preoperative level by day 30. In groups C, D, and E, bronchial blood flow was less than 60% of the preoperative level on day 30. There was a high prevalence of radiation-induced morbidity in the region of anastomosis in groups C, D, and E. Postoperative recovery of bronchial blood flow and wound healing of the anastomosed bronchus were thus delayed in dogs that had received high doses of radiation before operation. We conclude that the safe dose of preoperative radiation in clinically used fractionation is 36 Gy or less (corresponding to a single dose of 16 Gy or less in dogs).

Anastomosis, Surgical↗
PubMed1993

[Warm ischemia and reperfusion injury in the regenerating rat liver].

The effect of warm ischemia and reperfusion injury in the regenerating rat liver after portal vein branch ligation (PBL) was examined by monitoring hepatic high energy phosphorous metabolism using in vivo Phosphorus-31 Magnetic Resonance Spectroscopy (31P-MRS). On 14 days after 70% occlusion of the portal vein, energy metabolism of non-occluded lobe of the liver was evaluated by measuring the ratio of beta-ATP to Pi obtained using 31P-MRS. During 30min-ischemia, beta-ATP/Pi dropped down similarly below the limit of observation in both of control and regenerating liver. However, after reperfusion, in the regenerating liver, the earlier and better recovery of beta-ATP/Pi was observed compared with the control. In the any examination of m-GOT, GPT, increase in enzyme level was apparently restrained in the PBL group. On the pathological examination, centrilobular necrosis and hepatocyte degeneration were remarkable in the normal liver, while in the regenerating liver, these changes were slight. In conclusion, these results suggest that reperfusion injury observed in the regenerating liver seems to be reduced compared with that in the normal liver. Functional and structural changes in the regenerating liver could be claimed as a course of this observation. However, to understand the mechanism, further study will be needed both in morphological and biochemical aspect.

Animals↗
PubMed1993

Tooth discoloration and resolution following a luxation injury: significance of blood pigment in dentin to laser Doppler flowmetry readings.

Discoloration of teeth is common sequel of dental trauma and is often taken as a sign of irreversible pulpal degeneration, particularly if the crown becomes gray or blue-gray in appearance. If a viable blood supply remains or revascularization occurs following trauma to teeth, removal of blood pigments by normal biologic processes can occur. The assessment of blood flow with laser Doppler flowmetry is an additional diagnostic aid following dental injuries. This technology has been used to monitor the clinical progress of two central incisors that had been palatally luxated in a sporting accident. Color changes were observed and were correlated with symptomatic and radiographic evaluation, sensibility tests, and laser Doppler readings. The results of these examinations indicated that the blood pigment within a discolored tooth crown interfered with laser light transmission. The limitation of this new technology in the assessment of teeth discolored following trauma is significant. Visual radiographic and symptomatic assessment remain as the principal diagnostic criteria at the present time.

Adolescent↗
PubMed1993

Doppler velocimetry study of maternal hemodynamics and fetal vascular pattern in a case of chronic hypertension with superimposed severe preeclampsia and impending fetal death.

A case is presented of chronic hypertension with superimposed severe preeclampsia; absence of end-diastolic velocity in the umbilical artery had been noted at gestational age of 20 weeks. Because the fetus was previable, the mother was treated with pharmacotherapy according to the maternal hemodynamics; uteroplacental circulation and fetal vascular blood flow were monitored by Doppler velocimetry. Deterioration of the fetal condition occurred during crossover of maternal hemodynamics from a low-resistance to a high-resistance state. Serial Doppler velocimetry studies done within 40 minutes of fetal death are described. There were two types of absent end-diastolic velocity in the umbilical artery, and the pathophysiology and clinical management may be quite a different in these two situations.

Adult↗
PubMed1993

Effects of skin blood flow and temperature on bioelectric impedance after exercise.

To examine the effects of increased skin blood flow (BFsk) and skin temperature (Tsk) on bioelectric impedance (BIA), 30 young males participated as subjects. All subjects underwent the following measurements: 1) BFsk and Tsk for the chest, biceps, thigh, and calf; 2) body composition using the BIA prediction equations and underwater weighting (UW); and 3) triceps skinfold (SFtri) thickness. After the baseline studies (M1) the subjects exercised for 30 min at approximately 83% of maximal heart rate. The above measurements were repeated immediately after exercise (M2), and at 1-h recovery from exercise (M3). Repeated measures ANOVA showed that mean Tsk and BFsk, and for the four measured sites were significantly increased from M1 to M2 (P < 0.05) and decreased from M2 to M3 (P < 0.05). These changes did not affect BIA measurement for resistance (R) and reactance between M1 and M2 (P > 0.05), and between M2 and M3 (P > 0.05). With regression analysis the following independent variables were identified as strong contributing factors for predicting fat-free mass (FFM): 1) SFtri and total body water for M1 and M3; and 2) WT, SFtri, and Tsk of the chest for M2. Two FFM equations have little multicolinearity (M1 and M2), e.g., they have low root mean square errors (< or = 2.6 kg), very high values for R2 (> or = 0.94), and relatively low values for coefficient of variations (< or = 5.65%). Differences (P < 0.05) were observed between the UW method and the Lukasi equation for estimating FFM for M1 and M3, but not for M2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Biological zero of laser Doppler fluxmetry: microcirculatory correlates in the hamster cheek pouch during flow and no flow conditions.

The microcirculation of the hamster cheek pouch was visualized by the intravenous injection of FITC-dextran 150,000 during normal flow conditions and when flow was interrupted by clamping proximal to the pouch. Laser Doppler fluxmetry (LDF) was used to evaluate flow during control, 30 min of occlusion and after reperfusion. Intravital video recordings of the microcirculation during occlusion show that blood moves between the different arteriolar segments after occlusion and during the whole period of no flow. This motion was oscillatory in nature, had maximum velocity of order of 30 microns sec-1, and was related to progressive decrease of arteriolar diameter. The LDF output was in the range of 60-100 AU during control. This value fell in the range of 5-25 +/- 15% AU during occlusion and was assumed to constitute the biological zero for this system. The variability of the LDF signals was characterized by the autoregressive modeling power spectrum technique. The power spectra during control, occlusion, and reperfusion were similar, suggesting that motion of blood not related to perfusion or blood flow is present in all conditions. These findings suggest that the biological zero arises from signals that are not flow related and that it should be subtracted from the flow signal.

Animals↗
PubMed1993

[Doppler microprobe allows evaluation of local coronary circulation].

The local coronary flow in 42 patients (mean age: 59 +/- 9 years) with ischemic heart disease was assessed by means of an 0.018" intracoronary Doppler guidewire. Study population was divided into two groups: group I--"normal vessels" (diameter stenosis < 30%) and group II--"stenosis vessels" (diameter stenosis > 60%). Measurements of: averaged peak velocity (APV), diastolic-systolic velocity ratio (DSVR) were performed in proximal segments of normal vessels and proximally to stenosis in group II. APV and DSVR were recorded at rest (bas) and during papaverine induced hyperemia. Coronary flow reserve (CFR) was calculated as ratio hyperemic and resting values of APV. Mean value of APV at rest was highest for left main stem, lowest for venous by-passes (SVBG) but did not differ among three coronary arteries (LAD, LCX, RCA). CFR value was significantly higher for group I then for group II (2.75-3.3 vs 1.8-2.0) but did not differ significantly among particular arteries in both groups. Mean value of DSVRbas in both examined groups was lowest for right coronary artery and for SVBG (ca. 1.0) and did not change significantly during hyperemia. This value was significantly higher (ca. 2.0) for left coronary arteries (LAD, LCX) then for RCA and SVBG and significantly decreased after administration of papaverine.

Aged↗
PubMed1993

[Doppler microprobe for evaluation of coronary circulation after successful coronary angioplasty].

The influence of angiographically successful coronary angioplasty (PTCA) in 27 patients (mean age 64 +/- 8 years) was assessed by means of 0.018" intracoronary Doppler guidewire. Averaged peak flow velocity (APV) and diastolic-systolic velocity ratio (DSVR) were recorded in resting conditions (bas) and during papaverine induced hyperemia before and after PTCA. Coronary flow reserve (CFR) was calculated as ratio of hyperemic and resting APV. The parameters mentioned above were estimated proximally and distally to coronary stenosis to be dilated. Mean value of APVbas for distal part of the vessels was significantly lower (about 46-57%) then for the two proximal segments. PTCA caused significant increase of APVbas as for proximal (about 21-69%) as for distal segments (about 62-77%). That procedure caused significant increase of CFR only for right coronary artery (RCA). Mean values of DSVRbas in proximal position for left descendens (LAD) and left circumflex (LCx) arteries before PTCA were significantly higher than DSVbas for distal position but did not differ for RCA. PTCA caused significant increase of DSVRbas in distal position only for LAD and LCx. Our results showed that angiographically successful PTCA causes significant increase of APVbas for right and left coronary arteries and normalization of DSVRbas in distal segments of LAD and LCx.

Adult↗
PubMed1993

[Oxygenation of the dermis and subcutis in dermatoliposclerosis].

Chronic venous insufficiency (CVI) leads to morphological and functional changes in nutritive capillaries resulting in disturbances of the nutrition of the skin. Up to now, data obtained from transcutaneous measured pO2 were taken as an indication for a decreased oxygen supply to the skin. With the aim of obtaining direct information on the tissue oxygenation of dermis and subcutis we have measured the distribution of tissue pO2 values with needle probes (300 microns tip diameter, Eppendorf-Netheler-Hinz-GmbH, Hamburg). 12 patients with CVI III and 8 healthy volunteers were included in this study. The needle probes were inserted into the skin of the proximal third of the lower leg and, in patients, in the areas with mild and with severe sclerosis (ulcer edge). The pO2 data from the needle probes were compared with pO2 data obtained from transcutaneous surface probes (tcpO2) and with data from laser doppler flux measurements LDF). In clinically healthy skin the intracutaneously measured pO2 (icpO2) was 51 +/- 7 mmHg (mean +/- S.D.) and the subcutaneously measured pO2 (scpO2) was 47 +/- 8 mmHg. In lipodermatosclerosis invasively determined pO2-values were lower than in healthy skin, however, no hypoxic or anoxic values were found. Compared with tcpO2-values there was no considerable difference between icpO2-values measured in mild sclerosis and severe sclerosis (icpO2 28 mmHg as compared to 25 mmHg; scpO2 31 mmHg as compared to 27 mmHg). The icpO2 values obtained from the edge of the ulcer showed a large variation from patient to patient (6 mmHg to 42 mmHg). There was no correlation between the pO2 data and the LDF-values.

Aged↗
PubMed1993

Postocclusive reactive hyperemia and postural vasoconstriction in different kinds of leg ulcers--investigations with laser Doppler.

Laser-Doppler fluxmetry was performed in 42 patients with leg ulcers (18 venous, 8 arterial, 12 diabetic-arteriolar and 4 mixed arterio-venous) and in 9 healthy controls. Using a bipolar probe measurement was carried out at the ulcer border and on the dorsum of the foot in the supine and in the sitting position. Reactive hyperemia after three minute arterial occlusion was produced in both body-positions. In every ulcer-group resting and peak fluxes showed a statistically significant increase in the ulcer region as compared to normal skin of the lower leg in the control group, the quotient between peak and resting flux ("reactive hyperemia index" RHI) being significantly lower. The RHI values for four ulcer-patients with a dramatic deterioration worsening eight months later were close to one, while the unchanged and improved cases showed median values above 1,2. Sitting up was followed by a decrease of flux in all ulcer-groups as well as in the control group. On the dorsum of the foot there was an increase of the laser Doppler flux in patients with arterial occlusive disease, i.e. in the group with arterial and mixed ulcers. This study shows that the kind of microcirculatory flow damage is not different in various causes of ulcerations. The reduced reactive hyperemic response compared to the increased resting fluxes (amount of RHI-decrease) might be a useful predictor for healing or non-healing of the ulcer.

Adult↗
PubMed1992

[Microcirculatory changes in mitral prolapse as an expression of a systemic change in the connective tissue].

Many authors hypothesize that mitral valve prolapse (MVP) can be, in most cases, only a clinical sign of a primitive and systemic disorder of the connective tissue, like in Marfan Syndrome (MS). In our previous works we supported the presence of morphological and functional alterations of the microcirculation in patients affected by MS. In order to characterize a possible common denominator between these pathologies we have studied the cutaneous microcirculation in a group of patients affected by MVP, divided into 2 groups: anatomic MVP (MVP) and MVP syndrome (MVPS). The morphologic parameters have been investigated by nailfold capillaroscopy while digital laser-Doppler was used to study skin flowmetry. The results have been compared with a control group. Capillaroscopic remarkers showed an architecturally disorganized microvasculature with aspects related to a reduced compactness of the microvasculature unit with a significatively higher score compared with controls (7.3 +/- 2.9 vs 3.6 +/- 1 p less than 0.0005). Laser-Doppler flowmetry showed a significatively reduced rest flow; ischemic test showed: spike time 48.9 +/- 36.9 vs 15.3 +/- 7.7 s (p less than 0.0005), hyperemic acme 6.6 +/- 2.7 vs 12.5 +/- 8.4 UP (p less than 0.002); % increase 32.1 +/- 20.2 vs 51.5 +/- 15.4 (p less than 0.002). Thermic test showed a significatively higher thermic acme 8.7 +/- 4.2 vs 12.6 +/- 9.11 UP (p less than 0.05). These results appeared to be correlated with stage pathology as it was observed a severe microvasculature disorders in MVPS. Therefore we suppose that a phenotypic continuum may exist between MS and MVP.

Adult↗
PubMed1994

Effects of neural blockade and general anesthesia on the laser-Doppler skin blood flow waves recorded from the finger or toe.

Effects of neural blockade and general anesthesia on the basic wave (BW) and the reflex wave (RW) among the laser-Doppler (L-D) skin blood flow waves recorded on the finger or toe were studied in 2 volunteers and 42 patients. The BW was continuous, rhythmic and independent of respiratory movements. The RW, which was induced by a deep inspiration or a snapping sound, was a transient marked reduction in blood flow. The BW was almost flattened and the RW was no longer induced at the finger under complete wrist block (n = 2), or under cervical or upper thoracic epidural anesthesia extended caudally over T7 (n = 2). On the other hand, the BW was still detected with reducing frequency and the RW could be provoked with one exception at the finger on the side with a sympathetic ganglion block at the C6 vertebral level (n = 14). The BW and RW at the toe were retained under lumbar subdural anesthesia (n = 6) as well. However, under the combination of lumbar subdural anesthesia and lower thoracic epidural anesthesia extending rostrally over T4 (n = 6), both the BW and the RW disappeared at the toe. In the course of deepening nitrous oxide/enflurane anesthesia (n = 10), the BW gradually reduced in frequency until it was almost flattened, and it became difficult to provoke the RW. L-D flowmetry of the finger or toe could be a useful clinical measure for detecting the presence or absence of sympathetic function controlling cutaneous vasomotion.

Adult↗
PubMed1982

Current status of noninvasive tests in the diagnosis of peripheral arterial disease.

In this review of the current status of the vascular laboratory, the major emphasis has been upon those tests that have become well-established and documented, including resting pressure, pulse volume measurements, velocity studies, and three stress measurements--exercise ankle pressure, postocclusive reactive hyperemia, and the toe pulse reappearance time. Additional technology that may have application to peripheral arterial disease includes photoplethysmography, transcutaneous oxygen tension, laser-Doppler velocimetry, fluorescein angiography, infrared thermography, and transcutaneous electromagnetic flowmetry. These techniques, which are currently in development and experimental trial, were not discussed but are likely to provide significant additional information. The future role of the vascular diagnostic laboratory in the area of peripheral arterial occlusive disease appears clear. It has already become a standard resource of the community hospital and tertiary referral center. Its functions will become more and more generally accepted with time as newly graduating physicians who have been exposed to this technology enter the practice of medicine. It should permit obtaining an evaluation of all patients at the expert level, aid in the education of all physicians concerned with peripheral arterial disease, and play an important part in guaranteeing a higher level of patient care than has heretofore been available.

Arterial Occlusive Diseases↗
PubMed1988

Partitional measurement of capillary and arteriovenous anastomotic blood flow in the human finger by laser-Doppler-flowmeter.

This study was made to see whether changes in blood flow through the capillaries and arteriovenous anastomoses (AVA's) of the human finger can be measured by noninvasive flowmetry. Total finger blood flow (FBF) was measured by venous occlusion plethysmography; blood flow was measured by a laser-Doppler flowmeter (ADVANCE, ALF-2100, Tokyo, Japan) using probes with optic fiber separations of 0.3 mm (LDF-0.3) and 0.7 mm (LDF-0.7). The maximum sensitivities for LDF-0.3 and LDF-0.7 were at depths of 0.8 and 1.2 mm from the tissue surface respectively. Two series of experiments were performed on separate days. In the first series the test hand was immersed in a water bath whose temperature (Tw) was 25 degrees C at an ambient temperature (Ta) of 25 degrees C. Tw was raised to 35 degrees C (local hand warming), which was then followed by an increase in Ta to 35 degrees C (whole body warming). FBF, LDF-0.3, and LDF-0.7 increased during these thermal stimulations. However, the relationship of FBF to LDF-0.3 showed two different regression lines. In contrast, the relationship of FBF to LDF-0.7 showed a single regression line. In the second series, with Ta at 35 degrees C, the test hand was immersed in a water bath at Tw 35 degrees C. Tw was then raised every 10 min by 2 degrees C steps from 35 to 41 degrees C. At Tw 39-41 degrees C, FBF and LDF-0.7 in the test hand were significantly decreased compared with those at Tw 35 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗