Biomedical subjects

P D Line

Publications and source records attributed to P D Line.

15 recordsLinked to original sources

PubMed2004

Assessment of mucosal inflammation and blood flow in response to four weeks' intervention with probiotics in patients operated with a J-configurated ileal-pouch-anal-anastomosis (IPAA).

BACKGROUND: Pouchitis is a common and troublesome condition in patients operated on with ileal-pouch-anal-anastomosis (IPAA). A disturbed mucosal perfusion in the pouch has been suggested as a possible cause. Laser Doppler flowmetry (LDF) has been used successfully to measure gastric and colonic mucosal perfusion in humans. In a previous study, we demonstrated a reduced mucosal perfusion in the distal part of the pouch, during probiotic intervention, examined by LDF measurement. The aim of the present study was to confirm our previous results in a much larger material, and to compare the results of LDF measurements and inflammatory activity in ulcerative colitis (UC) patients with those in familial adenomatous polyposis (FAP) patients. METHODS: Five hundred millilitres of a fermented milk product (Cultura), containing live lactobacilli (La-5) and bifidobacteria (Bb-12), was given daily for 4 weeks to 41 UC and 10 patients with FAP, operated on with IPAA. Mucosal perfusion was measured with LDF and the degree of inflammation was examined at predefined levels of the distal bowel by histology and faecal calprotectin measurements both before and after intervention. We also evaluated the applicability of a Pouchitis Disease Activity Index (PDAI). RESULTS: The LDF measurements were reproducible in the pelvic pouch at each of the predefined levels, but did not change during intervention. Mucosal perfusion was significantly reduced in the distal compared to the proximal part of the pouch in the UC group (P < 0.05). The perfusion levels were higher in the FAP patients compared to the UC patientsat all predefined levels (P < 0.05). Calprotectin levels and histological score did not change significantlyafter intervention in any of the groups. The calprotectin level was significantly lower in the FAP compared to the UC group both before and after intervention. The PDAI decreased in both groups from alevel considered diagnostic for pouchitis to a level considered as not active pouchitis. The decreasewas significant for the UC patients. CONCLUSIONS: The results did not demonstrate an effect of probiotics on histology, although a significant effect on the PDAI was achieved, which concurs with the previously reported effect on symptoms and endoscopic score. The significantly reduced blood flow in the UC group compared to the FAP group, operated on with the same procedure, and the significantly increased calprotectin levels in the UC group, are original findings. Both findings may be related to an increased risk for pouchitis among UC patients. The lack of effect of intervention on mucosal perfusion does not exclude a role for reduced circulation as a cause of pouchitis based on the reduced LDF measurements in the distal part of the pouch.

Adult↗

PubMed2003

Assessment of mucosal inflammation and circulation in response to probiotics in patients operated with ileal pouch anal anastomosis for ulcerative colitis.

BACKGROUND: Pouchitis is a common and troublesome condition, and a disturbed microbiological flora and mucosal blood flow in the pouch have been suggested as possible causes. Laser Doppler flowmetry (LDF) has been used successfully to measure gastric and colonic mucosal perfusion in humans. The aim of this study was to evaluate the effect of intervention with probiotics on ileal pouch inflammation and perfusion in the pouch, assessed by endoscopy, histology, fecal calprotectin and LDF. METHODS: A fermented milk product (Cultura; 500 ml) containing live lactobacilli (La-5) and bifidobacteria (Bb-12) was given daily for 4 weeks to 10 patients operated with ileal-pouch-anal anastomosis (IPAA) for ulcerative colitis (UC). Mucosal perfusion was measured with LDF and the degree of inflammation was examined at predefined levels of the distal bowel by endoscopy and histology. Stool samples were cultured for lactobacilli and bifidobacteria and calprotectin were measured before and after intervention. RESULTS: The LDF measurements were reproducible in the pelvic pouch at each of the predefined levels, but did not change after intervention. The mucosal perfusion was reduced in the distal compared to the proximal part of the pouch. Calprotectin levels did not change significantly after intervention. The median endoscopic score for inflammation was significantly reduced by 50% after intervention, whereas the histological score did not change significantly. CONCLUSION: The results suggest that probiotics primarily act superficially, with change of gross appearance of the mucosa at endoscopy, but without significant effect on histological picture, mucosal perfusion or faecal calprotectin, during a relatively short period of 4 weeks.

Adolescent↗

PubMed1996

[Local thrombolytic treatment of peripheral arterial thrombosis and embolism].

Local intra-arterial low-dose thrombolysis has become a therapeutic alternative for acute and subacute occlusion of vascular grafts and native vessels in the lower limbs. The series comprises 31 patients treated with Streptokinase as thrombolytic agent. Complete primary thrombolysis was achieved in 20 patients, whereas in 11 patients the outcome was only partially successful or a failure. Vascular stenoses were considered to precipitate thrombosis in 18 cases, and prompted percutaneous transluminal angioplasty after thrombolysis. Two-year patency was 48% (30-66%) in the total series and 74% (56-92%) among the patients with successful primary thrombolysis. There were no major complications. Five patients sustained local inguinal haemorrhage, of whom three required surgical revision. Local intra-arterial thrombolysis is an elaborate procedure associated with potential hazardous complications. It should be carried out in institutions with radiological and vascular surgical expertise.

Adult↗

PubMed1996

[The recurrence frequency in inguinal hernia. A 10-year survival material].

Over a period of ten years, from 1980 to 1989, 701 hernioplasties were performed in 592 patients. 582 of these patients were available for follow-up examination (83%). The average follow-up was 10.3 years, median 10.2 years. The recurrence rate was 12%, 8% of the recurrences occurred after hernioplasties performed by specialists, and 13% after operations performed by surgeons in training. The results are discussed. The authors briefly review recent developments in hernia surgery.

Adolescent↗

PubMed1996

Postocclusive hyperaemia in skin measured in pigs by laser Doppler: influence of site of arterial stenosis in the limb.

OBJECTIVE: To investigate how site and severity of arterial stenosis, and distance between tourniquet and measuring probe influences the postocclusive hyperaemic response in limb skin recorded by laser Doppler. DESIGN: Open study. MATERIAL: Nine Norwegian Landrace pigs. INTERVENTION: Experimental stenoses in the abdominal aorta, the external iliac and femoral arteries. The hyperaemic responses were recorded with the probe at two different distances from the tourniquet. MAIN OUTCOME MEASURES: Curve pattern, relative reduction in flux between the two peaks in double humped curves, and time to peak hyperaemic flux. RESULTS: Double humped curves were produced at all sites, but the blood pressure gradient required at the stenosis was greater the more proximal the stenosis. In distal stenoses there was a greater relative reduction in flux between the two peaks (p < 0.05). The time to peak hyperaemic flux was related to the gradient of the stenosis (mmHg) (r = 0.62, p < 0.0001), but was independent of its site. Increased distance between the tourniquet and the probe gave lower laser Doppler amplitudes and prolonged the time to peak hyperaemia in experiments with femoral artery stenosis (p < 0.05). CONCLUSION: The hyperaemic response is governed by both the severity and the site of arterial stenosis. Stenoses distal to the tourniquet seem to impair the initial reperfusion more than comparable lesions proximal to the tourniquet. Time to reach peak hyperaemia is the single variable most closely related to the severity of the stenosis.

Animals↗

PubMed1994

[Ulcer surgery and anti-ulcer agents. Changes in surgical activities and sale of anti-ulcer agents in Nord-Trøndelag 1975-89].

During recent decades the number of operations for peptic ulcer has decreased significantly. The incidence of operations for peptic ulcer or related complications during the period 1975-89 in persons older than 15 years was investigated in the Nord-Trøndelag region of Norway, with a population of approximately 100,000. The number of elective surgical procedures decreased by 72% from 1975 to 1989. The greatest reduction was found for duodenal ulcers. The incidence of acute operations decreased by 35%. The main reason was fewer surgical interventions in patients with haemorrhage, since the number of operations for perforation remained almost constant during the period of 15 years. The reduction in surgical treatment can be explained mainly by the introduction of new H2-antagonists in the seventies, leading to more successful pharmacological treatment of peptic ulcer.

Adult↗

PubMed1994

Infusion methods for determination of peripheral resistance: influence of infused medium and back pressure.

It has been suggested that peripheral vascular resistance (PR), measured intraoperatively, can predict the outcome of infrainguinal reconstructions. There is, however, a great deal of variability in design and predictive value with this method, and it is prone to technical difficulties and possible errors. The present study evaluated the influence of the choice of infusion medium and the back pressure on PR as measured by the infusion technique. In a porcine model of experimentally induced stenosis, standard PR (calculated by the pressure difference across the stenosis and the Doppler volume flow) was compared with PR based on infusions of blood or saline solution. With blood as the infusion medium there was a significant correlation between the PR and the standard values (r = 0.795, p = 0.0005), whereas there was no correlation when saline solution was infused (r = 0.067, p = 0.345). Subtracting the back pressure resulted in a slight improvement in the correlations between standard PR and PR measured after infusion of blood but not saline solution. In summary, blood should be used as an infusion medium in methods of PR determination, but the influence of back pressure remains uncertain.

Animals↗

PubMed1994

Correlation between peripheral vascular resistance and time to peak flow during reactive hyperaemia.

Earlier studies have proposed that the time to reach peak hyperaemic flux recorded with laser Doppler (tp) is a simple and accurate method of evaluating ischaemic limbs and possibly a method of estimating the peripheral vascular resistance (PR). The aim of this study was to investigate the relationship between the tp and changes in limb vascular resistance caused by arterial stenosis. Forty postocclusive hyperaemia tests with arterial stenoses of different pressure gradients were performed in four pigs. A laser Doppler fluxmeter was used to record postocclusive hyperaemia in the skin of one hind limb. A specially designed tourniquet was used for the arterial occlusion. Proximal and distal to the occlusion level a snare was used to form different grades of stenosis. The PR (mmHg.ml-1.min-1) was either estimated by infusion of a known blood volume into the tested limb over a given time period with simultaneous measurement of pressure or calculated on the basis of measurements of limb blood flow and blood pressure gradients. The tp was closely related to total limb vascular resistance assessed by the blood infusion method (r = 0.83, p < 0.0003) and to the resistance calculated from volume blood flow and intraarterial pressures (r = 0.86, p < 0.0001). This study suggests that the tp accurately reflects limb vascular resistance in an experimental model. Thus tp may be used as a quantitative indicator of overall blood flow impairment, and should be evaluated in patients with lower-limb atherosclerosis.

Animals↗

PubMed1993

The significance of probe design in evaluation of colonic perfusion with laser Doppler flowmetry.

The significance of probe design for laser Doppler flowmetry measurement depth and variation was investigated by determining flux versus pressure relations and spatial variability with various probes placed on the serosal surface of porcine sigmoid colon. For two large probes (three optical fibers with diameter and center separation > or = 500 microns) the flux versus pressure relations showed autoregulation, indicating that the mucosal perfusion contributed to the flux signal. The curves were reproducible between individuals. With two smaller probes linear flux versus pressure relations were obtained, indicating a shallow measurement not influenced by the autoregulated mucosal perfusion. The spatial variation expressed as coefficients of variation of repeated recordings at each pressure level was significantly greater with the smaller probes (p < 0.001). For clinical use the larger probes should be preferred. These include all wall layers, and only 3 repeated recordings are needed to obtain a reproducible mean flux value within +/- 10%, as opposed to 10 with the smaller probes.

Animals↗

PubMed1993

Laser Doppler flux and tissue oxygen tension as indicators of colonic perfusion in pigs.

OBJECTIVE: To evaluate laser Doppler flowmetry (LDF) and tissue oximetry (TpO2) for intraoperative assessment of colonic perfusion in pigs. MATERIAL: Eight pigs weighing from 19-22 kg. INTERVENTIONS: Relationships of laser Doppler flux and TpO2 to mean arterial pressure (MAP) were measured in porcine sigmoid colon. The influence of different fractional inspired oxygen concentrations (FiO2) and the variability of the laser Doppler flux were evaluated. RESULTS: Highly significant reproducible non-linear perfusion compared with pressure relations were found with both methods (r > or = 0.9, p < 0.0001). There was a rapid decrease when MAP fell below 90 mmHg. The dependency of TpO2 on FiO2 was omitted by using the ratio TpO2:PaO2. The coefficient of variation of repeated LDF recordings of 30 second duration with the hand held probe was 0.11 (0.07-0.16) (median and 95% confidence interval). Three recordings gave a reproducible mean flux with an estimated precision of 10% either way. Simultaneous recordings with sutured and hand-held probes correlated well (r > or = 0.9, p < or = 0.01). CONCLUSION: Both methods yielded quantitative and reproducible intraoperative assessments of colonic perfusion, and are applicable for clinical use.

Animals↗

PubMed1993

Human bronchial perfusion evaluated with endoscopic laser Doppler flowmetry.

Endoscopic laser Doppler flowmetry (LDF) was used to study human bronchial microvascular perfusion in 25 healthy subjects. In total 617 recordings with good signal to noise ratio were obtained and, in the hands of an experienced bronchoscopist, the procedure did not cause major technical problems. Curve fluctuations synchronous to heart rate and respiration were identified. The spatial variation of measurements in one region was considerable, but when the mean of four measurements was used, acceptable precision levels were obtained. Regional differences were observed between 40.3 arbitrary perfusion units (PU) (34.0-46.6) in the right upper lobe bronchus and 77.3 PU (63.6-91.0) at the main carina. Measurements were obtained from the main carina, the right upper lobe bronchus, the apical segment of the right and left lower lobe bronchus. In all bronchi, recordings were performed at two locations distal to the bifurcation; 1-5 mm (central) and 6-10 mm (peripheral). The peripheral flux levels were significantly higher than the central (p < 0.001). Analysis of the short and long term temporal variation showed no significant differences, when the data was analyzed on a group basis. We conclude that LDF seems to be a promising method for future clinical investigations.

Adult↗

PubMed1992

Aerobic endurance, anatomical factors and time properties of laser Doppler recorded skin postocclusive hyperaemia.

Aerobic endurance capacity is partly dependent on blood supply to and metabolic capacity of the active muscles. Recordings of lower limb skin postocclusive hyperaemia with laser Doppler flowmetry can differentiate between patients with lower limb atherosclerosis and healthy controls. In this study, we investigated the relationship between aerobic endurance, calf volume, common femoral artery diameter and time properties of the postocclusive laser Doppler curve. A group of 16 healthy male subjects with values for aerobic endurance which varied from those of untrained men to elite endurance trained athletes were examined. Duration of laser Doppler recorded skin postocclusive hyperaemia was significantly correlated to both aerobic power and anaerobic threshold (P less than 0.01). Hyperaemia in subjects with large common femoral artery diameter was of shorter duration (P less than 0.05). The peak and mean body mass related blood flow during hyperaemia was correlated to anaerobic threshold (P less than 0.05). These results were in agreement with previous studies indicating an effect of endurance training on the blood supply to the muscles concerned.

Adolescent↗

PubMed1992

Repeated measurement variation and precision of laser Doppler flowmetry measurements.

The repeated measurement variation of laser Doppler flowmetry (LDF) recordings is essential for the precision level of the method in the assessment of tissue perfusion. The objective of this paper was to discuss the practical consequences of this problem by presenting a statistical method which can be used to estimate the number of replicates needed to reach a certain precision standard. By a repeated measures analysis of variance with a single-factor design, the mean variation of repeated measurements and its standard deviation were estimated. This estimate was used for simulation of a 95% confidence interval with length defined as a percentage of the mean of repeated measurements. The analyses were made in LDF samples performed in skin, gastric mucosa, and pig kidney in order to exemplify the use of the method. Paired values gave an unacceptable precision estimate in all tissues, but by increasing the number of replicates, the estimated precision was greatly enhanced. A preliminary recommendation for the practical use of LDF in the assessment of tissue perfusion is to perform at least four to six repeated measurements. Further studies are needed in order to establish methodological standards. The presented statistical considerations could also be relevant for other procedures used in microvascular research.

Adult↗

PubMed1992

Intraoperative prediction of ischaemic injury of the bowel: a comparison of laser Doppler flowmetry and tissue oximetry to histological analysis.

Intraoperative diagnosis of inadequate colonic perfusion would contribute to prevention of ischaemic colitis after abdominal aortic reconstructions. The aim of this study was to evaluate laser Doppler flowmetry (LDF) and tissue oximetry (TpO2) as predictors of the development of bowel necrosis. Devascularised loops of colon and ileum in anaesthetised pigs were divided into 10-20 mm segments and measurements of laser Doppler flux and TpO2 were performed in each segment. After 7 h of ischaemia the segments were resected for histological and biochemical analysis. In 65 colonic and 58 ileal segments a significantly lower flux was found in segments with necrosis of greater than or equal to 30% of the mucosal thickness compared to segments with necrosis of less than or equal to 10% (p less than 0.01). The discriminant flux value was 50 perfusion units, confirming a previous clinical study. The specificity was 0.96 and the sensitivity 0.94. Flux was inversely correlated to tissue lactate concentration. Significantly lower TpO2 was found in 19 colonic segments with necrosis of greater than or equal to 30% of mucosa compared to 19 colonic segments with necrosis of less than or equal to 10% (p less than 0.01). Using a discriminant value of 5kPa, a specificity of 0.79, and a sensitivity of 0.95 were calculated. In 27 ileum segments no significant difference in TpO2 between different histological groups was found (p greater than 0.30). The results show that LDF and TpO2 can predict ischaemic injury of the colon, and LDF also of the small bowel.

Animals↗

PubMed1992

Assessment of the physiological importance of iliac artery stenosis by laser Doppler flowmetry in pigs.

OBJECTIVE: To test the hypothesis that a curve with two peak values (double hump) recorded by laser Doppler flowmetry over the skin of the lower limb during postocclusive hyperaemia reflects pathological vascular resistance in the aortoiliac segment. DESIGN: Open study. MATERIAL: Six Norwegian Landrace pigs. INTERVENTION: Arterial stenoses were induced in the external iliac arteries. MAIN OUTCOME MEASURES: Presence of double humped laser Doppler curves, relative decrease in laser Doppler flux between the two peaks, and time taken to reach peak hyperaemic flux. RESULTS: Double humped curves were seen only when arterial stenoses were present. The relative decrease in laser Doppler flux between the two peaks, and the time to reach peak hyperaemic flux were related to the blood pressure gradient (mmHg) at the stenosis (r = 0.88 and 0.83, p less than 0.0001). The laser Doppler curve pattern can be explained by similar dynamic changes in arterial blood pressure distal to the tourniquet during hyperaemia. CONCLUSION: These results confirm the hypothesis, and suggest that laser Doppler flowmetry recordings of postocclusive hyperaemia may be a non-invasive way of assessing the condition of the iliac artery.

Animals↗