Increase In Mean Blood Flow Research Articles

Comparison of Testicular Volume and Blood Flow in Children Before and After Surgery for Inguinoscrotal Diseases- A Prospective Cohort Study

Introduction: Testicular diseases in children include hernia, hydrocele, undescended testis, epididymal cyst or torsion testis. Some of these like hernia and undescended testis will have affect on the testicular volume and blood flow. These are predictors for the future function of the testis. Manipulations during surgery can also affect blood flow to the testis. Aim: To compare testicular volume and blood flow in children undergoing surgery for inguinoscrotal diseases in both normal and diseased sides, before and after surgery. Materials and Methods: A prospective cohort study was conducted from March 2019 to December 2019 in which 30 children were selected from Surgery Outpatient Department (OPD), Department of Paediatrics, Gian Sagar Medical College, Rajpura, Punjab, India. For patients having inguinoscrotal disease, ultrasonography (US) and colour doppler was done preoperatively on all cases by an experienced radiologist, using the same machine settings on the seventh day and three months postsurgery. Preoperative and postoperative testicular volume and blood flow was recorded in all the patients. The Statistical Package for Social Sciences (SPSS) software was used to statistically analyse the data arising, p<0.05 was accepted as statistically significant. Results: Total of 30 children (10 months to 10 years of age) formed the total sample of the study. Pathology was found in 18 patients on the right side and 12 patients on the left side. When the right and left side pathology were compared, it was found that right testicular volume was less as compared to left side. This difference was statistically significant with the p-value 0.006. There was a significant difference in blood flow between the right and left testis, both before (p-value 0.007) and after surgery (p-value=0.004). Testicular volume increased three months postsurgery in all the patients. This difference was more evident in left side pathology (p<0.05) as compared to right side (p>0.05). The increase in mean blood flow of diseased testis was significant after seven days of surgery (p-value <0.05). But change in mean testicular volume and blood flow after three months of follow-up was found to be non-significant. Conclusion: Inguinal surgery does not affect the testicular volume and blood flow. But long term follow-up for children of inguinal surgery for its effect on fertility should be evaluated.

Anterior Tibial Artery Blood Flow is Unaffected by Age during a Fatiguing Submaximal Dorsiflexor Contraction

Muscle blood flow is a critical factor in the ability to maintain exercise, particularly during isometric efforts. However, relatively few studies have directly monitored blood flow during isometric exercise. PURPOSE: To use Doppler ultrasound and near-infrared spectroscopy to assess the effect of healthy aging on dorsiflexor blood flow and tissue oxygenation during a sustained isometric contraction. METHODS: Fifteen young men (24 ± 2 years) and 15 old men (76 ± 4 years) performed a contraction at 60% of maximal strength until exhaustion. Mean blood velocity (MBV) was recorded from the anterior tibial artery and diameter measures were obtained off-line to calculate mean blood flow (MBF) through the artery. RESULTS: Old men were 17% weaker and had a longer time-to-exhaustion than young men (107.1 ± 30.9s and 81.9 ± 19.8s, respectively). Arterial diameter, total hemoglobin and oxygenation decreased in both groups but to a greater extent in young. MBV and MBF increased throughout exercise and were not different between groups. After exercise, diameter increased to a greater degree in young than old men. Both groups had a striking increase in MBV and MBF following exercise but the effect was two-fold greater in young than old. The post-contraction increases in total hemoglobin and oxygenation were not different between groups. CONCLUSIONS: These data suggest that despite similar MBF in the anterior tibial artery during exercise, muscle perfusion was impaired to a greater extent in the stronger young men than in the weaker old men, but at a site distal to the conduit artery.

Oral nelfinavir before and during radiation therapy for rectal cancer: Changes in tumor perfusion and correlation between tissue and radiological markers of response.

491 Background: Nelfinavir, an inhibitor of AKT in the PI3-kinase pathway, is a radiosensitizer which increases tumor blood flow and reduces hypoxia in preclinical models. We conducted a pilot study of nelfinavir before and during hypofractionated pelvic radiotherapy (RT) in patients with rectal cancer to evaluate the safety of the combination, changes in tumor perfusion and a tissue biomarker of radiosensitization, tumor cell density (TCD). Methods: Eight patients with T3-4 N1-2 M1 rectal cancer received 7 days of oral nelfinavir (1250 mg bd) and a further 7 days of nelfinavir during pelvic RT (25 Gy/5 fractions/7 days). Safety was evaluated by CTCAE v 4.0. Dynamic contrast enhanced (DCE) CT and MRI scans were performed pre-treatment, after 7 days nelfinavir and prior to last fraction of RT. TCD was performed in biopsies taken pre-treatment and 7 days post-radiotherapy (West N et al. Br J Cancer. 2010, 102; 1519-23). Radiological response and tumor regression grade (TRG) was assessed on MRI 8 weeks from end of RT (Patel UB et al. J Clin Oncol. 2011, 29:3753-60). Results: This was the first clinical trial to combine nelfinavir with hypofractionated RT. There were 3 grade 3 adverse events (diarrhea, rash, lymphopenia). After 7 days of nelfinavir, there was a 40% increase in mean Ktrans on DCE-MRI (p = 0.029, paired t test). On DCE-CT, there was a 30% increase in mean blood flow from before RT to the last day of RT (p = 0.028). The median TCD in biopsies decreased from 41.2% (IQR = 23.5, 53.0%) at baseline to 9.2% (IQR = 2.8, 18.2%) after RT (p = 0.007, paired t test). By RECIST criteria, 3/8 patients treated had complete radiological responses and 4/8 had partial responses. TRG was associated with the magnitude of decrease in TCD measured in paired biopsies for individual patients (p = 0.029, Fisher’s Exact Test). Conclusions: These data suggest that the radiosensitizing drug, nelfinavir, can increase blood flow to rectal cancer when given prior to RT. Nelfinavir added to hypofractionated pelvic radiotherapy has acceptable toxicity and is associated with radiological and tissue biomarker responses. Funded by Oxford NIHR BRC, OCIC, Yorkshire Cancer Research, Oxford and Leeds ECMCs. Clinical trial information: 2010-020621-40.

Resistance Training Improves Vasoreactivity in End-Stage Heart Failure Patients on Inotropic Support

Peripheral vascular abnormalities contribute to compromised functional status in heart failure (HF) patients. The purpose of the present study was to test whether the intervention of moderate-intensity, resistance training could improve peripheral vascular responsiveness, that is, flow-mediated dilation (FMD) in HF. Baseline brachial artery FMD analysis (2 minutes of cuff occlusion and 5 minutes of reperfusion) was measured in HF patients on intravenous inotropic support (n = 9) awaiting cardiac transplantation. Unilateral, upper-body resistance exercises (moderate intensity, combination of isometric and isotonic exercises at 60%-80% of maximum) were performed 3 d/wk for 4 weeks. Follow-up FMD analysis was conducted after training. Central hemodynamics were defined via right-side-heart catheterization. At baseline prior to training, HF patients elicited a significant hyperemic response 10 seconds following cuff occlusion (mean increase in blood flow: 194 ± 44 mL/min, P < .05). Despite this significant hyperemic response, HF patients demonstrated a mild, but paradoxical vasoconstriction of nearly 3% at 1-minute after cuff release. Four weeks of resistance training corrected the paradoxical vasoconstriction observed at baseline and resulted in vasodilatation (a positive increase in brachial artery diameter of 0.04 ± 0.04 mm, at 1 minute after cuff release; P < .05). Conversely, in a subset of 3 HF patients, studies in the untrained contralateral arm revealed no change in the FMD response. Moderate-intensity upper-body resistance training improved brachial artery FMD in end-stage HF patients on inotropic support. The reversal of the paradoxical vasoconstrictive response to reactive hyperemia following 4 weeks of training may be secondary to local improvements in vascular endothelial function rather than a quantitative change in the reactive hyperemic stimulus.

Ultrahigh-Pressure Angioplasty versus the Peripheral Cutting Balloon™ for Treatment of Stenoses in Autogenous Fistulas: Comparison of Immediate Results

To compare the immediate results of ultrahigh-pressure (UHP) balloons vs. peripheral cutting balloons (PCB) for the treatment of stenoses associated with autogenous fistulas using intra-access blood flow measurements. This prospective randomized study consisted of 22 hemodialysis (HD) patients with autogenous fistulas who had decreased intra-access blood flow (<500 mL/min). All patients underwent a fistulogram and intraprocedural blood flow measurements. Patients were randomized once into two groups; one group undergoing UHP angioplasty and the second group undergoing PCB angioplasty. Randomization occurred once after the diagnostic fistulogram and each patient in each arm only underwent percutaneous transluminal angioplasty with either UHP or PCB. The study cohort consisted of 12 patients in the UHP group and 10 patients in the PCB group. Data collected included fistula anatomy, degree of stenosis, length of stenosis, balloon specifications and residual stenosis. The 22 study patients underwent 35 angioplasty procedures; 23 in the UHP group (12 patients) and 12 in the PCB group (10 patients). The technical success rate was 91%. The pre-intervention mean blood flow was 288 mL/min in the UHP group and 391 mL/min in the PCB group. The post-intervention mean blood flow was 613 mL/min in the UHP group and 606 mL/min in the PCB group. The mean increase in blood flow was 325.8 mL/min in the UHP group and 213 mL/min in the PCB group. This represents a relative mean increase in blood flow of 253% in the UHP group and 85% in the PCB group. An unpaired t-test showed there was no significant difference between the groups with respect to pre-flow, post-flow, and mean and relative mean increase in flow. There were two failures; one in the UHP group and one in the PCB group. There was one minor complication (2.8%) but no major complications. In this small group of HD patients with autogenous fistulas our comparison of UHP to the PCB demonstrated that the immediate results, as determined by measurement of intra-access blood flow, were equivalent. Further long-term follow-up will be required to determine the longevity of these results.

Blood flow in denture-supporting maxillary mucosa in response to simulated mastication by loading

The purpose of this study was to determine the effect of number of chewing strokes on change in blood flow in denture-supporting maxillary mucosa. Subjects consisted of 11 healthy dentate men. Mastication was simulated by intermittent loading (10 N, 1/0.75 Hz) on a lateral area of the hard palate using a 2-cm(2) test plate. Loading duration was set at 1, 4, 8 or 12 min (80, 320, 640 or 960 chewing strokes). A non-contact laser Doppler blood flow meter was used to determine change in blood flow and time taken for recovery to 110% of the pre-loading value. Mean blood flow at pre-loading and at each duration of intermittent loading were compared using a repeated measures ANOVA (α=0.05) and the Dunnett test. Recovery times for each loading duration were compared using a one-way ANOVA (α=0.05) and the Bonferroni-test. Three subjects showed no increase in mean blood flow with loading. Eight subjects consistently showed an increase in mean blood flow during intermittent loading relative to at pre-loading. Duration of loading yielded no significant difference in mean blood flow. Significant differences were observed in recovery time between at after 8 min loading and at after the other 3 loading (1, 4, and 12 min loading) durations. Number of simulated chewing strokes showed no influence on mean blood flow during intermittent loading in denture-supporting mucosa. It did, however, affect recovery time taken for blood flow to return to its pre-loading level.

Characteristics of arterial wall shear stress which cause endothelium-dependent vasodilatation in the anaesthetized dog.

1. The effects of changes in the mean and amplitude of arterial wall shear stress on endothelium-dependent arterial dilatation of the iliac artery of the anaesthetized dog were examined. 2. Changes in the mean and amplitude of blood flow and wall shear stress were brought about by varying local peripheral resistance and stroke volume using a distal infusion of acetylcholine and the stimulation of the left ansa subclavia. Changes in the diameter of a segment of the iliac artery with the endothelium intact, relative to a segment with no endothelium, were used as an index of the release of nitric oxide. 3. The increase in mean blood flow was from 84 +/- 12 to 527 +/- 53 ml min-1 and in amplitude was from 365 +/- 18 to 695 +/- 38 ml min-1 (means +/- S.E.M.). The increase in mean wall shear stress was from 1.78 +/- 0.30 to 7.66 +/- 1.01 N m-2 and in amplitude was from 7.37 +/- 0.46 to 13.9 +/- 2.00 N m-2 (means +/- S.E.M.). 4. Increases in mean shear stress caused an increase in the diameter only of the section of artery with endothelium; the slope of the relationship was 0.064 +/- 0.006 mm N-1 m2 (mean +/- S.E.M., P < 0.001); changes in the amplitude of shear stress did not cause an increase in diameter. Changes in both the mean and amplitude of shear stress had no significant effect on the diameter of the section of artery with no endothelium. 5. These findings coupled with the known anti-atheroma effects of nitric oxide and the effect of shear stress on cell adhesion and platelet aggregation offer a possible explanation for the disposition of atheroma in those parts of the arterial system which have low mean and high amplitude of wall shear stress.

Effects of systemic and topical nicotine on pulpal blood flow in dogs

It has been suggested that nicotine exerts cardiovascular effects which are similar to stimulation of the sympathoadrenal system. If this observation is true, nicotine administration would decrease pulpal blood flow and possible alter the pulpal response to injury. The purpose of this study was to measure pulpal blood flow in dogs using the radiolabelled microsphere method following topical or systemic administration of nicotine for 28 days. Thirteen dogs were divided into three groups. Group one received topical nicotine (8 mg nicotine/kg/day) combined with orabase which was applied in two equal doses to the mandibular anterior gingiva. Group two received systemic nicotine (2.5 mg/kg/day) delivered by osmotic pumps implanted subcutaneously in the back of each animals' neck. Group three were controls, and these animals received either topical orabase twice daily applied to the mandibular anterior gingiva or saline via osmotic pumps. Results indicated pulpal blood flow increased from Day 0 to Day 28 in both nicotine treated groups. Group one (topical nicotine) exhibited a mean increase in blood flow of 21.8 ml/min/100 g, while group two exhibited a mean increase of 50.1 ml/min/100 g. Group three, the control animals, exhibited a mean decrease in pulpal blood flow of 22.1 ml/min/100 g over the 28-day interval. These changes were not statistically significant (p > 0.05).

Decreased distensibility of resistance vessels of the skin in type 1 (insulin-dependent) diabetic patients with microangiopathy.

The distensibility of the resistance vessels of the skin at the dorsum of the foot was determined in 11 long-term type 1 (insulin-dependent) diabetic patients with nephropathy and retinopathy, nine short-term type 1 diabetic patients without clinical microangiopathy and in nine healthy non-diabetic subjects. Blood flow was measured by the local 133Xe-xenon washout technique in a vascular bed locally paralysed by the injection of histamine. Blood flow was measured before, during and after a 40 mmHg increase of the vascular transmural pressure, induced by head-up tilt. The mean increase in blood flow during head-up tilt was only 24% in diabetic subjects with and 48% in diabetic patients without clinical microangiopathy, compared with 79% in normal non-diabetic subjects (P less than 0.0005 and P less than 0.05, respectively). An inverse correlation between microvascular distensibility and degree of hyalinosis of the terminal arterioles in biopsies from the skin was demonstrated (r = - 0.57, P less than 0.001). Our results suggest that terminal arteriolar hyalinosis reduces the microvascular distensibility and probably increases the minimal vascular resistance, thereby impeding hyperaemic responses.

The effects of myometrial activity on fetal thoracic dimensions and uterine blood flow during late gestation in the sheep.

We wished to investigate mechanisms by which non-labour contractions of the uterus influence fetal sleep states and respiratory activity during late pregnancy. The relationship between the dimensions of the fetal chest and uterine contractions was examined in 5 pregnant sheep. The dorso-ventral dimension at the level of the xiphisternum (3 fetuses) decreased, on average by 4.4-9.4% while increases of 16.6-18.7% were seen in the transverse dimension (4 fetuses). Blood flow in a middle uterine artery was monitored using a Doppler technique in 5 pregnant sheep. Non-labour uterine contractions were accompanied by mean reductions of 6.5-12.7% in blood flow. Postural adjustments by the ewe also influenced uterine blood flow. A mean increase in blood flow of 5.9-12.0% followed a change from standing to lying; standing caused a mean reduction of 5.9-11.8%. We conclude that the influence of uterine contractions on the fetus is likely to be complex, involving distortion of the body and alterations in utero-placental haemodynamics.

The variance of forearm blood flow as an indicator of emotional stress.

Forearm blood flow was measured four times per minute by venous occlusion plethysmography during rest and during a brief emotionally stressful mental task. During emotional stress not only was the mean forearm blood flow increased, but the single blood flow values fluctuated more than at rest. The greater fluctuation, expressed statistically as the variance, was an indicator of emotional stress, at least as sensitive as the mean increase in the blood flow. Both a tranquillizer (thioridazine) and a beta-blocker (toliprolol) reduced the greater variance during the emotionally stressful situation in doses insufficient to diminish the mean increase in forearm blood flow.