scholarly journals Independent jejunal mechanisms for glycine and glycylglycine transfer in man in vivo

1973 ◽  
Vol 30 (1) ◽  
pp. 13-19 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Absorption Rate ◽  
Clinical Evidence ◽  
Double Lumen Tube ◽  
Transport Mechanisms ◽  
Perfusion System ◽  
Double Lumen ◽  
Lumen Tube ◽  
Jejunal Segment ◽  
Rate Of Absorption

1. Rates of absorption of glycine and glycylglycine from a 300 mm jejunal segment were compared in vivo when those compounds were given alone or together to six Zambian African subjects who had no clinical evidence of malnutrition or of gastro-intestinal disease. Solutions containing (A) glycine (100 mmol/1), (B) glycine (100 mmol/l)+glycylglycine (50 mmol/l), and (C) glycylglycine (50 mmol/l) were infused into the upper jejunum by means of a double-lumen tube perfusion system.2. Rate of absorption of glycine was significantly higher from the glycylglycine solution (C) than from the glycine solution (A). Glycine absorption rate from solution B (glycine+glycylglycine) was very similar to the sum of absorption rates of glycine from solutions A and C in each subject. Luminal disappearance rate of glycylglycine from solutions C and B were very similar; however, the rate was significantly greater than the total glycine absorption rate from solution C and indicates back-diffusion of glycine into the lumen after glycylglycine hydrolysis.3. The results are interpreted as indicating that the transport mechanisms for glycine and glycylglycine in man are partly, and possibly wholly, separate.

scholarly journals Lactose aborption kinetics in Zambian African subjects

1973 ◽  
Vol 30 (3) ◽  
pp. 519-527 ◽  
Author(s):  
G. C. Cook ◽  
N.-G. Asp ◽  
A. Dahlqvist
Keyword(s):  
Brush Border ◽  
Narrow Range ◽  
Double Lumen Tube ◽  
Jejunal Mucosa ◽  
Lactase Activity ◽  
Perfusion System ◽  
Double Lumen ◽  
Lumen Tube ◽  
Jejunal Segment ◽  
Abdominal Colic

1. Using a double-lumen tube perfusion system, solutions of lactose (50, 125 and 250 mmol/l) were introduced into the upper jejunum of six Zambian African subjects. By reference to a non-absorbable marker, polyethylene glycol, mol. wt 4000, the rates of absorption of lactose from each solution were calculated for a 300 mm jejunal segment.2. In three subjects total lactase activity of the jejunal mucosa and brush-border lactase and other disaccharidase activities were estimated. The jejunal total and brush-border lactase activities were low. Jejunal morphology was normal for African subjects.3. All subjects suffered abdominal colic and diarrhoea during and after the lactose perfusions. The kinetic curves for lactose were very shallow, and with all perfused solutions, there was a net movement of water into the jejunal lumen. The limited number of subjects, and the low and narrow range of enzyme activity, did not permit correlation between lactose absorption rate and lactase activity.4. In Zambian African subjects with adult hypolactasia, the jejunal mucosa absorbs a very small proportion of the perfused lactose.

scholarly journals Jejunal absorption rates of glucose, glycine and glycylglycine in Zambian African adults with malnutrition

1974 ◽  
Vol 32 (3) ◽  
pp. 503-513 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Bacterial Infections ◽  
Absorption Rate ◽  
Clinical Evidence ◽  
Gastrointestinal Disease ◽  
Systemic Infection ◽  
Abdominal Tuberculosis ◽  
Double Lumen Tube ◽  
Albumin Concentration ◽  
Control Subjects

1. Absorption rates of glucose (from a 200 mM solution), glycine (from a 100 mM solution), and glycylglycine (from a 50 mM solution) have been estimated in six Zambian African adults with clinical evidence of malnutrition. A double-lumen tube technique was used to determine absorption rates from a 300 mm section of jejunum in vivo.2. Two of the subjects had ileal tuberculosis and Kaposi's sarcoma respectively. A third probably had abdominal tuberculosis. Three of them had pellagra. Mean serum albumin concentration was 24 (14–43) g/l. Absorption rates have been compared with those in Zambian Africans (control subjects), previously studied, who had no clinical evidence of malnutrition, systemic infection or of gastrointestinal disease.3. Mean glucose, glycine and glycylglycine absorption rates in the malnourished subjects were not significantly different from those in the control subjects. Mean net water absorption rate from the glucose solution was similar in the malnourished subjects and controls; during the glycine and glycylglycine perfusions the mean net absorption rate was, however, significantly lower in the malnourished subjects (P < 0.01 and P < 0.05 respectively); mean net water transfer during the glycine perfusions was towards the jejunal lumen in the malnourished subjects. One subject with pellagra had an abnormal excretion of D-xylose after a 25 g oral load; all other tests were normal.4. It seems probable that malnutrition must be very severe, with jejunal mucosal abnormalities, before absorption rates of glucose, glycine and glycylglycine are significantly altered. The present study does not support the view that subclinical malnutrition is important in producing malabsorption of dietary components in Zambian African subjects. Systemic bacterial infections, and raised serum γ-globulin and immunoglobulin IgG concentrations have previously been associated with an impairment of glucose absorption rate in Zambian African subjects; those factors seem much more likely than subclinical malnutrition to be relevant, in the context of absorption, in the pathogenesis of overt malnutrition.

Comparison of Absorption Rates of Glucose and Maltose in Man in Vivo

1973 ◽  
Vol 44 (4) ◽  
pp. 425-428 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Glucose Solution ◽  
Glucose Absorption ◽  
Double Lumen Tube ◽  
Proximal Jejunum ◽  
Perfusion Technique ◽  
Double Lumen ◽  
Lumen Tube ◽  
The Mean ◽  
The Difference

1. Using a double-lumen tube perfusion technique in vivo, the absorption rates of glucose from a glucose (200 mmol l−1) and from a maltose (100 mmol l−1) solution were measured in the proximal jejunum of six Zambian African adults. 2. In all of the subjects the rate of glucose absorption from the maltose solution was greater than that from the glucose solution. The difference between the mean rates was approximately 15% and is significant (P < 0.01).

scholarly journals Increased glycine absorption rate associated with acute bacterial infections in man

1973 ◽  
Vol 29 (3) ◽  
pp. 377-386 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Bacterial Infections ◽  
Absorption Rate ◽  
Reference Group ◽  
Normal Subjects ◽  
Double Lumen Tube ◽  
Present Observation ◽  
Chronic Infections ◽  
Jejunal Segment ◽  
Acute Bacterial Infections

1. Glycine absorption rate from a 300 mm jejunal segment was determined in vivo in four Zambian African subjects with acute, and four with chronic, respiratory infections. Glycine solutions (100, 150 and 250 mmol/l) were perfused, by means of a double-lumen tube technique. The results were compared with those for four relatively normal Zambian African subjects (‘reference’ group) previously studied. The group with acute-infections had a significantly higher mean absorption rate than the reference or chronic-infection group.2. Glycine absorption results from a 100 mmol/l glycine solution in an additional twenty-four Zambian African subjects have also been analysed. When results for the thirty-six subjects were combined, those with acute bacterial infections had a significantly higher mean absorption rate than the normal subjects or those with chronic infections. For the twenty-one normal subjects there was a significant positive correlation between the individual absorption rates and serum total globulin and γ-globulin concentrations.3. It seems likely that the rapid catabolism of protein associated with infection is counteracted by an increase in amino acid absorption rate. In subjects on a low-protein diet that mechanism would be limited. The deterioration in nutritional status during infections in developing countries could therefore be partly explained by the present observation.

Effect of Intraluminal Concentrations on the Impairment of Glycine Absorption by Glucose in the Human Jejunum

1972 ◽  
Vol 42 (5) ◽  
pp. 525-534 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Clinical Evidence ◽  
Random Order ◽  
Glucose Absorption ◽  
Double Lumen Tube ◽  
Three Solutions ◽  
Lumen Tube ◽  
Jejunal Absorption ◽  
Jejunal Segment ◽  
The Mean ◽  
African Patients

1. To investigate the effect of different intraluminal concentrations on the mutual inhibitive effect of glycine and glucose on their jejunal absorption rates, eighteen convalescent Zambian African patients who had no clinical evidence of intestinal disease or of malnutrition were given constant intrajejunal infusions with those solutes either together or alone. A double-lumen tube perfusion system was used, and three solutions containing (A) glycine, (B) glycine and glucose, and (C) glucose, all of which were rendered iso-osmotic with sodium chloride, were perfused in random order at 12·0 ml/min. The concentration of glycine in the perfusing fluid was either 10 or 20 mm, and that of glucose either 100, 200 or 280 mm. By reference to polyethylene glycol 4000, the absorption rates of the solutes and water were calculated for a 30 cm jejunal segment. 2. At a glucose concentration of 200 or 280 mm, but not 100 mm, the mean rate of glycine absorption was decreased by approx. 30%. Glucose absorption rates were not significantly altered by glycine. 3. These observations, taken in conjunction with those from a previous investigation, are consistent with the view that there are two mechanisms for the jejunal absorption of glycine in man, one of which is inhibited by glucose at high intraluminal concentration.

Comparison of Intestinal Absorption Rates of Glycine and Glycylglycine in Man and the Effect of Glucose in the Perfusing Fluid

1972 ◽  
Vol 43 (3) ◽  
pp. 443-453 ◽  
Author(s):  
G. C. Cook
Keyword(s):  
Absorption Rate ◽  
Kinetic Curve ◽  
Glucose Absorption ◽  
Double Lumen Tube ◽  
Jejunal Segment ◽  
The Mean ◽  
The Difference ◽  
Mean Glucose ◽  
Effect Of Glucose

1. Using a double-lumen tube perfusion system the rates of glycine, glycylglycine, and glycylglycine and glucose absorption from a 30-cm jejunal segment have been studied in vivo in a group of relatively normal Zambian African subjects. 2. To determine the kinetic curve for glycine absorption, four subjects were given consecutive perfusions of 50, 100 and 150 mm-glycine. 3. Six other subjects had consecutive perfusions of (1) a 100 mm-glycine and (2) a 50 mm-glycylglycine solution. Five of the six had a higher absorption rate of glycine from the glycylglycine solution. When data from a further six similar subjects in another study are included, the mean rate of glycine absorption is significantly greater from the glycylglycine compared with the glycine solution (P < 0·001). 4. A further six subjects were given consecutive perfusions of (1) 50 mm-glycylglycine, (2) 50 mm-glycylglycine and 200 mm-glucose, and (3) 200 mm-glucose. The absorption rate of glycine from glycylglycine was lower in all subjects when glucose was present in the perfusing fluid (P < 0·01). Although the mean glucose absorption rate was lower when glycylglycine was present in the perfusing fluid, the difference was not significant.

How clinical experience leads anesthetists in the choice of double-lumen tube size

2016 ◽  
Vol 32 ◽  
pp. 1-3 ◽  
Author(s):  
Gianluca Zani ◽  
Maitan Stefano ◽  
Bizzarri Federico Tommaso ◽  
Rispoli Marco ◽  
Buono Salvatore ◽  
...  
Keyword(s):  
Clinical Experience ◽  
Double Lumen Tube ◽  
Double Lumen ◽  
Tube Size ◽  
Lumen Tube
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