Myoelectric effects of vasoactive intestinal peptide on rabbit small intestine

1983 ◽  
Vol 244 (1) ◽  
pp. G46-G51
Author(s):  
C. A. Sninsky ◽  
M. M. Wolfe ◽  
J. L. Martin ◽  
B. A. Howe ◽  
T. M. O'Dorisio ◽  
...  
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Venous Blood ◽  
Intestinal Secretion ◽  
Similar Rate ◽  
Myoelectric Activity ◽  
Rabbit Ileum ◽  
Blood Samples ◽  
Rabbit Small Intestine ◽  
The Mean ◽  
Potential Complex

Myoelectric recording techniques were used to study the motility of rabbit ileum during infusions of vasoactive intestinal peptide (VIP). VIP was infused intravenously at a rate of 300 pmol X kg-1 X h-1, and peripheral venous blood samples were obtained hourly for VIP assay. VIP was also infused intraluminally at a similar rate, and hourly portal vein blood samples were obtained for VIP assay. Alterations in motility were observed after both intravenous and intraluminal infusions of VIP. These alterations in motility consisted of the migrating action potential complex and repetitive bursts of action potentials. The VIP infusion rate used and the mean peripheral plasma VIP level of 267 +/- 29 pg/ml attained during intravenous VIP infusion were similar to those that induced intestinal secretion in other animal species. Portal venous VIP levels (93 +/- 21 pg/ml) were unchanged during the intraluminal infusion of VIP. These studies show that intravenous infusion of VIP causes alterations in motility of rabbit ileum. These alterations in motility with concomitant secretion of water and electrolytes may contribute to the diarrhea induced by VIP infusion. In addition, intraluminal infusion of VIP also induced alterations in myoelectric activity, which suggested that this peptide has a luminal effect as well as a hormonal effect.

Alterations in motor function of the small intestine from intravenous and intraluminal cholecystokinin

1984 ◽  
Vol 247 (6) ◽  
pp. G724-G728
Author(s):  
C. A. Sninsky ◽  
M. M. Wolfe ◽  
J. E. McGuigan ◽  
J. R. Mathias
Keyword(s):  
Small Intestine ◽  
Action Potentials ◽  
Intestinal Motility ◽  
Venous Blood ◽  
Regulatory Peptides ◽  
Similar Rate ◽  
Myoelectric Activity ◽  
Blood Samples ◽  
Portal Venous Blood ◽  
The Individual

Cholecystokinin has been found within the lumen of the gastrointestinal tract; however, its effect on intestinal motility has not been studied. We examined the effect of intraluminal and intravenous infusion of the octapeptide of cholecystokinin (CCK-OP) on myoelectric activity in the intestine of rabbits. CCK-OP was infused intraluminally at 1,000 ng X kg-1 X h-1, and portal venous blood samples were obtained hourly for plasma immunoreactive CCK. CCK-OP was also infused intravenously at a similar rate, and hourly peripheral venous blood samples were obtained for plasma immunoreactive CCK. Myoelectric activity was monitored in a 12-cm ligated ileal segment and the proximal adjacent small intestine after the infusion of intraluminal or intravenous CCK-OP. Intraluminal infusion of CCK-OP caused a significant increase (P less than 0.01) in both migrating action potential complexes (MAPC) and repetitive bursts of action potentials (RBAP) (3.1 +/- 0.8 MAPC/h and 4.6 +/- 1.3 RBAP/h). In contrast, intravenous CCK-OP induced only repetitive bursts of action potentials (8.3 +/- 1.7 RBAP/h, P less than 0.01). In summary, alterations in intestinal motility may vary according to the route of administration of the individual peptide. Furthermore, results from these studies suggest that intraluminal release of regulatory peptides may be important in the modulation of intestinal motility.

Validation of Oxygen Saturation Monitoring in Neonates

2007 ◽  
Vol 16 (2) ◽  
pp. 168-178 ◽  
Author(s):  
Shyang-Yun Pamela K. Shiao ◽  
Ching-Nan Ou
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Venous Blood ◽  
Arterial Oxygen ◽  
Dissociation Curve ◽  
Oxyhemoglobin Dissociation Curve ◽  
Blood Samples ◽  
Arterial Blood ◽  
The Mean ◽  
Oxyhemoglobin Dissociation

•Background Pulse oximetry is commonly used to monitor oxygenation in neonates, but cannot detect variations in hemoglobin. Venous and arterial oxygen saturations are rarely monitored. Few data are available to validate measurements of oxygen saturation in neonates (venous, arterial, or pulse oximetric). •Purpose To validate oxygen saturation displayed on clinical monitors against analyses (with correction for fetal hemoglobin) of blood samples from neonates and to present the oxyhemoglobin dissociation curve for neonates. •Method Seventy-eight neonates, 25 to 38 weeks’ gestational age, had 660 arterial and 111 venous blood samples collected for analysis. •Results The mean difference between oxygen saturation and oxyhemoglobin level was 3% (SD 1.0) in arterial blood and 3% (SD 1.1) in venous blood. The mean difference between arterial oxygen saturation displayed on the monitor and oxyhemoglobin in arterial blood samples was 2% (SD 2.0); between venous oxygen saturation displayed on the monitor and oxyhemoglobin in venous blood samples it was 3% (SD 2.1) and between oxygen saturation as determined by pulse oximetry and oxyhemoglobin in arterial blood samples it was 2.5% (SD 3.1). At a Pao2 of 50 to 75 mm Hg on the oxyhemoglobin dissociation curve, oxyhemoglobin in arterial blood samples was from 92% to 95%; oxygen saturation was from 95% to 98% in arterial blood samples, from 94% to 97% on the monitor, and from 95% to 97% according to pulse oximetry. •Conclusions The safety limits for pulse oximeters are higher and narrower in neonates (95%–97%) than in adults, and clinical guidelines for neonates may require modification.

scholarly journals Accuracy and Precision of a Point-of-Care HbA1c Test

2019 ◽  
Vol 14 (5) ◽  
pp. 883-889
Author(s):  
William D. Arnold ◽  
Kenneth Kupfer ◽  
Randie R. Little ◽  
Meera Amar ◽  
Barry Horowitz ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Venous Blood ◽  
Reference Laboratory ◽  
Test Results ◽  
Blood Samples ◽  
Accuracy And Precision ◽  
The Mean ◽  
Whole Blood Samples ◽  
Highly Correlated

Background: Point-of-care (POC) hemoglobin A1c (HbA1c) testing has advantages over laboratory testing, but some questions have remained regarding the accuracy and precision of these methods. The accuracy and the precision of the POC Afinion™ HbA1c Dx test were investigated. Methods: Samples spanning the assay range were collected from prospectively enrolled subjects at three clinical sites. The accuracy of the POC test using fingerstick and venous whole blood samples was estimated via correlation and bias with respect to values obtained by an NGSP secondary reference laboratory (SRL). The precision of the POC test using fingerstick samples was estimated from duplicate results by calculating the coefficient of variation (CV) and standard deviation (SD), and separated into its components using analysis of variance (ANOVA). The precision of the POC test using venous blood was evaluated from samples run in four replicates on each of three test cartridge lots, twice per day for 10 consecutive days. The SD and CV by study site and overall were calculated. Results: Across the assay range, POC test results from fingerstick and venous whole blood samples were highly correlated with results from the NGSP SRL ( r = .99). The mean bias was −0.021% HbA1c (−0.346% relative) using fingerstick samples and −0.005% HbA1c (−0.093% relative) using venous samples. Imprecision ranged from 0.62% to 1.93% CV for fingerstick samples and 1.11% to 1.69% CV for venous samples. Conclusions: The results indicate that the POC test evaluated here is accurate and precise using both fingerstick and venous whole blood.

Accuracy of Point of Care Testing in Patients on Dual Anticoagulation During Initiation of Anticoagulation or Bridging,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3360-3360
Author(s):  
Anja B Drebes ◽  
Paul Priest ◽  
Shaila Bates ◽  
Lida Moghaddam ◽  
Edward GD Tuddenham ◽  
...  
Keyword(s):  
Point Of Care ◽  
Venous Blood ◽  
Plasma Concentrations ◽  
Internal Quality ◽  
Point Of Care Testing ◽  
Blood Samples ◽  
The Mean ◽  
Group 2 ◽  
Therapeutic Doses ◽  
Group 1

Abstract Abstract 3360 Background: Point-of-care testing (POCT) is widely used for monitoring of the international normalized ratio (INR) in patients on oral anticoagulation with a vitamin-K antagonist (VKA) and numerous clinical studies have assessed the accuracy of this method in comparison with INR results from venous blood samples analysed in the laboratory. There is however a paucity of clinical data to support the use of POCT in patients on dual anticoagulation with low molecular weight heparin (LMWH) and a VKA during initiation of anticoagulation or bridging after a surgical procedure. Aim: To test the hypothesis whether therapeutic doses of LMWH interfere with INR measurements when using a POCT system during times of dual anticoagulation with LMWH and a VKA. To further investigate whether the effect is most pronounced once LMWH has reached peak plasma levels and less evident 10 hours and more after administration of LMWH. Methods: We prospectively collected 160 consecutive venous blood samples from patients on therapeutic doses of LMWH - Tinzaparin (175 IU/kg once daily) and a VKA commonly warfarin for INR testing in our laboratory. At the same time all patients had their INR determined on capillary blood collected by finger prick using a CoaguChek XS Pro and INR test strips with the same lot number (Roche Diagnostics Ltd, UK). 60 blood samples were collected within 3–6 hours after administration of LMWH (group 1) and 100 samples were collected 10 hours or more after the last injection of LMWH (group 2). For each sample the dose and time of the last injection of LMWH was recorded along with the time of the venepuncture and the result of the capillary INR. To ensure that we had a wide variation in the plasma concentrations of LMWH we carried out anti-Xa testing on a cross-section of venous samples The dosing advice for Warfarin was based on the INR result of the venous blood sample processed in the laboratory. Results: The correlation coefficient between the POCT INR and the laboratory INR was 0.98 in group 1 and 0.97 in group 2. In the Bland Altman analysis for group 1 the mean 95% confidence interval (CI) was 0.03 (range+/− 1.96 SD: −0.26 to +0.32) and for group 2 the mean 95% CI was 0.00 (range −0.28 to +0.29). These results are comparable to results of our internal quality control between POCT INR and laboratory INR in patients on VKA alone with a mean 95% CI of −0.02 (range −0.26 to +0.29). The mean INR was 1.8 by both methods in group 1 and 1.7 by both methods in group 2 and anti-Xa levels ranged from 0 to1.19 U/mL. A variation in the result of the POCT INR and laboratory INR of 0.5 or greater is thought to affect dosing decisions for Warfarin. Such a variation was observed in 3% (2/60) in group 1 and 2% (2/100) in group 2. Conclusion: There was good accuracy of the INR obtained with the POCT system used and this was not affected by the timing of the administration of LMWH in relation to testing. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Ovarian function in ewes after treatment with mifepristone early during the oestrous cycle

Reproduction ◽  
2003 ◽  
pp. 205-210 ◽  
Author(s):  
EM Paslay ◽  
U Salli ◽  
F Stormshak ◽  
Keyword(s):  
Ovarian Function ◽  
Venous Blood ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Blood Samples ◽  
Treatment Groups ◽  
Significant Difference ◽  
Preovulatory Follicles ◽  
Prostaglandin F ◽  
The Mean

The aim of this study was to determine whether endogenous progesterone regulates synthesis and secretion of luteal oxytocin. In Expt 1, mature ewes (n = 5 per group) were assigned randomly to control or mifepristone (RU486) treatment groups. Ewes were injected s.c. twice a day with vehicle or 10 mg RU486 on days 5-7 of the oestrous cycle (oestrus = day 0). On day 8, after an i.v. injection with prostaglandin F(2alpha) (250 microg cloprostenol), venous blood samples were collected at frequent intervals to determine plasma oxytocin concentrations. Plasma oxytocin concentrations of RU486-treated ewes were not significantly different from those of control ewes. In Expt 2, ewes were injected s.c. each day with vehicle or 175 mg RU486 on days 2-5 of the oestrous cycle followed by administration of prostaglandin F(2alpha) on day 6. Four of five RU486-treated ewes showed 'split-oestrus' (oestrous behaviour for 36 h and then again at 84-108 h after the onset of initial oestrus). There was no significant difference in mean plasma oxytocin or progesterone concentrations between treatment groups. The mean masses of mature corpora lutea from control and RU486-treated ewes on day 6 of the oestrous cycle did not differ significantly (394.8 +/- 28.8 versus 319.5 +/- 48.3 mg). RU486-treated ewes contained mature corpora lutea, new corpora lutea (two of four ewes) and preovulatory follicles (>or= 10 mm, two of four ewes). The average interoestrous interval for RU486-treated ewes was 9 days more than that for control animals (26.2 +/- 2.9 versus 17 +/- 0.5 days; P < 0.025).

Sheep lactate entry-rate measurements: error due to sampling jugular blood.

1977 ◽  
Vol 233 (3) ◽  
pp. E138
Author(s):  
P E Reilly ◽  
L G Chandrasena
Keyword(s):  
Venous Blood ◽  
Lactate Concentration ◽  
Specific Radioactivity ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Entry Rate ◽  
Blood Samples ◽  
The Mean ◽  
Carotid Arterial ◽  
Arteriovenous Difference

Carotid arterial and jugular venous blood samples were taken simultaneously during primed continuous infusions of L-[U-14C]lactate in four sheep. The mean rate (n = 4) of total net formation of lactate (0.394 +/- 0.047 mg C/min per kg) calculated from the results obtained by analyzing the jugular blood samples for lactate concentration and specific radioactivity was significantly higher (0.01 greater than P greater than 0.005) than the mean rate (n = 4) calculated from the results of analysis of the arterial samples (0.302 +/- 0.036 mg C/min per kg). The error in the estimation of the rate of total net formation of lactate due to jugular sampling resulted from the negative arteriovenous difference found for lactate across the tissues of the head. These results illustrate the general need for examination of the suitability of venous sampling in experiments that make use of the continuous infusion isotope-dilution method.

Effect of toxigenic Escherichia coli on myoelectric activity of small intestine.

1978 ◽  
Vol 235 (3) ◽  
pp. E311 ◽  
Author(s):  
T W Burns ◽  
J R Mathias ◽  
G M Carlson ◽  
J L Martin ◽  
R P Shields
Keyword(s):  
Escherichia Coli ◽  
Small Intestine ◽  
Culture Filtrate ◽  
Intestinal Motility ◽  
Myoelectric Activity ◽  
E Coli ◽  
Small Intestinal Motility ◽  
Rabbit Small Intestine ◽  
Small Intestinal ◽  
Potential Complex

When exposed to cholera toxin (CT), distal ileal loops of the rabbit small intestine showed an alteration in myoelectric activity. This alteration was defined as the migrating action potential complex (MAPC). The purpose of this study was to determine, using myoelectric recording techniques, the effects of live toxigenic Escherichia coli (TEC) on motility. Live TEC, live nontoxigenic E. coli (NTEC), and culture filtrates of these organisms were studied. Live TEC and its filtrate induced MAPC activity similar to that of CT. Live TEC induced a mean of 3.8 MAPCs/h, significantly greater than induced by live NTEC. TEC filtrate induced a mean of 14.2 MAPCs/h, significantly greater than NTEC filtrate. Heating the TEC filtrate to 100 degrees C before use resulted in a significant decrease of MAPC activity. This experiment demonstrated that live TEC and its culture filtrate altered ileal myoelectric activity. The effect may have been mediated by a heat-labile enterotoxin. This study suggests that alterations in small intestinal motility may be important in the pathogenesis of TEC diarrhea.

Neutrophil isolation from feline blood using discontinuous Percoll dilutions

2018 ◽  
Vol 46 (06) ◽  
pp. 399-402 ◽  
Author(s):  
Ayse Cakmak ◽  
Kader Yildiz ◽  
Neslihan Sursal
Keyword(s):  
Intact Cell ◽  
Venous Blood ◽  
Neutrophil Activation ◽  
Limiting Factor ◽  
Blood Samples ◽  
Percoll Gradients ◽  
Life Threatening ◽  
The Mean ◽  
Adult Cats

Summary Objective: Some studies have performed in vitro neutrophil isolation from feline blood. The major limiting factor for these studies is the small volume of blood that can be collected without development of potentially life-threatening complications. In the present study we attempted neutrophil isolation from feline venous blood samples using discontinuous Percoll gradients. Material and methods: Blood was collected from the cephalic vein of clinically healthy adult cats. The blood samples were layered on Percoll dilutions (72 %, 63 %, 54 % and 45 %). After centrifugation, the feline polymorphonuclear leukocytes (PMN) accumulated as a band between 72–63 % Percoll dilutions. The total cell count was calculated using light microscopy counts. The percentage of the neutrophils was determined microscopically after staining with Diff-Quik stain. Neutrophil viability was evaluated with a 0.01 % Trypan blue assay. The activation was determined based on intact cell morphology in the isolated neutrophils. Results: The mean PMN number was 22 x 105 per ml (minimum – maximum: 20–26 x 105/ml). Neutrophil homogeneity was > 95 % in the cell suspensions. The viability of isolated neutrophils was > 98 %. The technique did not result in neutrophil activation. Conclusion and clinical relevance: Discontinuous Percoll gradients (72 %, 63 %, 54 % and 45 %) can be used to isolate neutrophils from blood samples of cats. The technique was simple to perform and neutrophil activation was minimal.

scholarly journals Does varying the ingestion period of sodium citrate influence blood alkalosis and gastrointestinal symptoms?

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251808
Author(s):  
Charles S. Urwin ◽  
Rodney J. Snow ◽  
Liliana Orellana ◽  
Dominique Condo ◽  
Glenn D. Wadley ◽  
...  
Keyword(s):  
Experimental Design ◽  
Mixed Models ◽  
Sodium Citrate ◽  
Venous Blood ◽  
Gastrointestinal Symptoms ◽  
The Other ◽  
Strong Ion Difference ◽  
Blood Samples ◽  
Blood Ph ◽  
The Mean

Objectives To compare blood alkalosis, gastrointestinal symptoms and indicators of strong ion difference after ingestion of 500 mg.kg-1 BM sodium citrate over four different periods. Methods Sixteen healthy and active participants ingested 500 mg.kg-1 BM sodium citrate in gelatine capsules over a 15, 30, 45 or 60 min period using a randomized cross-over experimental design. Gastrointestinal symptoms questionnaires and venous blood samples were collected before ingestion, immediately post-ingestion, and every 30 min for 480 min post-ingestion. Blood samples were analysed for blood pH, [HCO3-], [Na+], [Cl-] and plasma [citrate]. Linear mixed models were used to estimate the effect of the ingestion protocols. Results For all treatments, blood [HCO3-] was significantly elevated above baseline for the entire 480 min post-ingestion period, and peak occurred 180 min post-ingestion. Blood [HCO3-] and pH were significantly elevated above baseline and not significantly below the peak between 150–270 min post-ingestion. Furthermore, blood pH and [HCO3-] were significantly lower for the 60 min ingestion period when compared to the other treatments. Gastrointestinal symptoms were minor for all treatments; the mean total session symptoms ratings (all times summed together) were between 9.8 and 11.6 from a maximum possible rating of 720. Conclusion Based on the findings of this investigation, sodium citrate should be ingested over a period of less than 60 min (15, 30 or 45 min), and completed 150–270 min before exercise.

Effect of an acute injection of melatonin on the basal secretion of hypophyseal hormones in prepubertal and pubertal healthy subjects

1986 ◽  
Vol 111 (3) ◽  
pp. 305-311 ◽  
Author(s):  
P. Lisoni ◽  
M. Resentini ◽  
R. Mauri ◽  
C. De Medici ◽  
F. Morabito ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Healthy Subjects ◽  
Pubertal Development ◽  
Venous Blood ◽  
Pituitary Hormones ◽  
Significant Rise ◽  
Saline Infusion ◽  
Blood Samples ◽  
The Mean ◽  
Acute Injection

Abstract. It is well known that the pineal gland can modulate the secretion of pituitary hormones. Melatonin, the main hormone produced by the pineal gland, acts at the hypothalamic site, whereas hypophyseal sensitivity to melatonin seems to change with age. To investigate the influence of pubertal development on the role of the pineal gland in the regulation of the secretion of pituitary hormones, FSH, LH, Prl, TSH and GH responses to melatonin were evaluated in a group of 9 prepubertal and 10 pubertal healthy subjects of both sexes. Melatonin was given im at a dose of 0.2 mg/kg body weight at 3 p.m. Venous blood samples were drawn −20, 0, 20, 40, 60, 90, 120, 180 and 240 min, after melatonin injection. According to the same experimental protocol, venous blood samples were collected during a saline infusion on a separate occasion. FSH, LH, Prl, TSH and GH plasma levels were measured with RIA. In pubertal subjects, a significant rise in the mean Prl levels was seen 90 min after melatonin as compared with those during saline infusion. The Prl melatonin response area was significantly lower in prepubertal treated subjects and significantly higher in pubertal ones compared with the respective controls. The mean GH values showed a significant decrease 120 min after melatonin only in prepubertal subjects; no significant variations were seen in 8 of 10 pubertal subjects, whereas in the last 2 a marked increase was observed. Finally, under these conditions, melatonin did not influence the basal FSH LH and TSH levels. These results seem to suggest that hypophyseal hormone reponses change with pubertal development.

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