The effect of gastric juice on electrolyte transport by the colon - abstract

Replacement of the oesophagus by the colon is a widely accepted method of treatment for neoplasms or benign strictures of the oesophagus. The colon normally plays an important role in the re-absorption of water and electrolytes in the body. In addition, peptic ulceration sometimes occurs in the colonic transplant. It is therefore important to study the effect of gastric juice on the colon. Trained dogs with chronic Pavlov pouches and isolated segments of colon were the experimental model. Gastric juice was collected from the Pavlov pouches. 25ml of gastric juice was instilled into the colon and samples aspirated at intervals over the next 6 hours. The samples were then analysed for sodium, patassium, chloride, bicarbonate, pH and osmolality. This response was compared with that obtained following the instillation of isotonic solutions of HCI, NaCi, mannitol and (NH4)2SO4. The results obtained show that gastric juice was rapidly and effectively buffered by the colon and there was no increase in the production of mucous. Hydrogen ions were absorbed in exchange for sodium and there was no effect on potassium or chloride transport. There was a decrease in the bicarbonate content of colonic samples. There was no evidence of active water transport (AU)

Active transport of the chloride ion by the colon - abstract

The present data represent some results of our continuing studies on the mechanisms of electrolyte transport in the colon. Trained dogs with chronic isolated segments of colon were used, and the transport of chloride ion was studied by instilling the following electrolyte solutions into the colon: sodium chloride (154 mEq/L, 100 mEq/L), Mannitol (5 percent) choline choride (100 mEq/L), lithium chloride (100 mEq/L), lithium chloride (60 mEq/L) plus potassium chloride (40 mEq/L), lithium chloride (75 mEq/L) plus sodium bicarbonate (75 m Eq/L). All solutions were made isotonic whenever necessary by the addition of mannitol and all contained the non-absorbable maker polyethylene glycol (PEG). Samples of colonic fluid were taken at intervals over a six-hour period following the instillation of solution into the isolated colonic segment. The samples were analysed for Na, K, Cl, HCO3 - pH, osmolality and PEG. The electrical potential difference across the colon was measured in several experiments. Chloride ion transport was also studied following the administration of Diamax or Aldosterone, mucosa. There was no evidence of active water transport. The mucosa is normally electrically negative with respect to serosa; however, in the presence of choline chloride the mucosa becomes electrically positive with respect to serosa. Our data also show that the chloride ion is actively transported against both an electrical and a chemical gradient. In addition chloride can be transported in the absence of sodium, but in the presence of sodium can be transported more rapidly than that ion. Chloride transport is to some extent linked to sodium transport and also to bicarbonate transport (AU)

Factors contributing to increased airway resistance with over humidification of inspired air - abstract

Inhalation of air containing increased water content has been shown to cause increased specific airway resistance (sRaw). It has been postulated that these changes might be related to reflex broncho-constriction and/or mucosal swelling. We attempted to elucidate the exact mechanism of action by a series of studies in rats, designed to demonstrate whether changes in specific airway resistance (as measured by whole body plethysmography), due to inhalation of air saturated with distilled water or tap water were preventable or reversible by either sympathomimetic (adrenaline), parasympatholytic (atropine) or mucolytic (N-acetyl cysteine) drugs. The results obtained showed that inhalation of air containing either tap or distilled water above the "safe level" (15.02gm/m(to the 3rd power) of humidification caused a significant increase in specific airway resistance above the control (p<0.01), with a slightly greater increase with tap water. Administration of adrenaline in aerosol to inspired air containing distilled or tap water vapour for six minutes caused no significant change in sRaw. A significant decrease in sRaw was obtained by injecting intramuscularly atropine (p0.01): and administration of N-acetylcysteine with inspired air containing distilled or tap water vapour caused an increase in sRaw above inhalation containing only tap or distilled water vapour, (p<0.05) which decreased with suction (p<0.05). Likewise N-acetyl cystine with distilled water or tap water vapour caused a significant increase in sRaw above that of inspired air with tap or distilled water alone (p<0.05) which significantly decreased with administration of atropine. These results suggest that mucosal swelling, reversible by parasympatholytic therapy, is a major factor in the increased specific airway resistance with over humidification of inspired air. There is no convincing evidence that broncho-constriction is of major importance. Mucolytic agents may aid in decomposing mucus but their effect on sRaw appears to be negative unless the decomposed products are moved by coughing or suction, and may be dangerous in patients who have no cough reflex (AU)

Relation of specific airway resistance to water content in inspired air in rats - abstract

Recent evidence has shown that increased humidification of inspired air increases airway resistance in healthy subjects and in patients with repiratory disease, and may produce gross pathological changes in the lungs. Ambient air (22§C, 50 percent relative humidity, 9.71 gm./m (to the 3rd power) water content) is assumed to be saturated and at body temperature by the time it reaches the tracheal bifurcation, so that any saturation deficit must exist only in small segments between the nasal or if ice and the main bronchi. Increasing the water content of inspired air should not theoretically affect airway resistance unless the air is incompletely saturated at the bifurcation, as assumed, and hence evaporative loss of water and heat from the mucosa is reduced with increased humidification of inspired air. This study, therefore, attempted to find out the lowest water content that would cause significant changes in specific airway resistance(sRaw) in rats by selectively increasing the water content of inspired air from 9.71 to 26.52gm./m (to 3rd power). sRaw was measured by whole body plethysmography. At water contents varying from 9.71 to 12.81gm./m (to 3rd power), however, sRaw showed a positive correlation with increased water content (p<0.01). Since increased water content can only be achieved by increasing the temperature, the effect of temperature on sRaw at a constant water content was investigated. At a constant water content of 12.7gm/m(to3rd power) mean sRAw did not change significantly from the control over a temperature range from 22 to 33§C. With water contents of 15.42, 17.48 and 19.53 gm./m(to 3rd power over the same temperature range, however, the mean sRaw increased significantly (p<0.01). Three factor analysis of variance showed that sRaw was significantly dependent on water content (p<0.01), the length of the exposure (p<0.01) and the type of water (p<0.01), since a significantly greater response was obtained with tap water. It is concluded that the transition point for significant changes in sRaw in rats is 15.02gm./m(to 3rd power) (22§C, 75 percent relative humidity). Increases above this level may be related to mucosal swelling and bronch-constriction. It seems that the repiratory system is adjusted to constantly eliminate some water, and interference with this function by overhumidifying the inspired air compromises pulmonary function. These findings may have implications in inhalation therapy of patients (AU)

Peritoneal dialysis in severe leptospiral renal failure

Three cases of severe leptospiral renal failure have been described. They had all intrinsic renal damage and were treated satisfactory by peritoneal dialysis. Renal biopsies were done in 2 patients in the recovery phase of their illness and showed signs of severe tubular damage (AU)

Congenital duodenal stenosis in an adult presenting with severe electrolyte imbalance

This case report studies congenital duodenal stenosis, which is rare, particularly when it presents in adults. This report is of such a patient, who on investigation had some features suggestive of the Zollinger-Ellison syndrome. The diagnosis of Zollinger-Ellison syndrome was entertained on the basis of the gastric acid studies and the radiological features of coarse mucosal folds in the stomach and the disordered small-bowel mucosal pattern, although the clinical features were atypical

Variation in forced expiratory volume curves of asthmatic patients with increased water content

An experiment was designed to provide information on the "safe" level of humidifiction of inspired air in asthmatic patients. It was found that air at 25 degrees celcius and 70 percent relative humidity (RH) (16.11 gm/cu m WC) and 35 degrees celcius, 40 percent RH (17.80 gm/cu m) had no significant effect on forced expiratiory volume parameters. At 25 degrees celcius, 95 percent RH (21.88 gm/cu m WC) and above changes in VC/PVC, FEV 1 and FEV 3, MMF and MBC were significantly affected (P < 0.01). Approximately 21.88 gm/cu m Water content is considered the point at which humidification of inspired air ceases to be therapeutically useful.(AU)

The effect of diet on the utilization of glucose by rat liver slices - abstract

The effect of previous diets on the utilization of radioactive glucose by rat liver was tested by (a) feeding rats for two days on one of four purified diets each of which contained adequate amounts of vitamins, minerals, and choline, (b) incubating liver slices obtained from the rats with radioactive glucose; isolating carbon dioxide, fatty acid and glycogen, and measuring these products. It was found that a diet of bread or a purified diet which provided a comparitively low protein intake and a high proportion of carbohydrate to fat, produced the following changes in the utilization of glucose by liver slices: four-fold greater conversion of the radio-active glucose to fatty acid, greater conversion of the glucose to carbon dioxide, and decreased conversion of the glucose to glycogen (AU)

The role of anaerobic metabolism in the urine concentration mechanism

Rats maintained in a state of chronic water diuresis were given as osmotic loads intraperitoneally, 10 percent of their body weight of either 0.45 percent saline or 10 percent mannitol in water. Faeces-free urines were collected under the following experimental protocols: osmotic diuresis, osmotic diuresis plus ADH and osmotic diuresis plus ADH plus metabolic inhibitors. A number of inhibitors of aerobic and anaerobic metabolism were used. Samples of kidney cortex medulla and papilla were also collected and analysed. The results obtained show that rats maintained in chronic water diuresis excreted a dilute urine and had largely dissipated their cortico-medullary gradients of sodium and urea. Under ADH stimulation, the rats excreted a concentrated urine with marked restoration of the cortico-medullary gradients. These effects were markedly inhibited by iodo-acetate and fluoride, but not by 2-4 dinitrophenol, hydroxylamine HCl or cyanide. The results suggest that a large proportion of the energy required for the creation of a hypertonic medulla, and hence the formation of a concentrated urine, is derived from anaerobic glycolysis (AU)

Critical anatomical site in healthy subjects from observation of forced expiratory volume curves with external resistances

The internal diameter of the air passages narrows from the trachea to the periphery of the lungs. Because of this it should be possible to predict the site at which the greatest change in resistance would occur for a given flow rate using the orifice flow equation (P = p/Cý(1/A2ý 1/A1ý) Vý where p = density of air, C = discharge constant which depends on the roughness of the tube and on Reynolds number, V is the volume rate of flow and A1 and A2 are the cross sectional areas) and compare it with forced expiratory volume curves (FEV) in healthy subjects. Theoretical calculations showed that the 3rd-6th generation of the bronchial tree contributed about 40 percent to the total airway resistance. Direct measurements by previous workers showed that approximately 55 percent of the total pulmonary resistance was contributed by the 3rd-6th generation i.e. 3-6 mm internal diameter bronchi. Results of FEV curves in normal subjects against external resistance of known internal diameters will be presented. These results show that the critical orifice (i.e. the point at which greatest inflection begins in the FEV curve) is in the range of 6-9 mm internal diameter (around the 3rd generation of the tracheobronchial tree). An analog of the tracheobronchial tree is being prepared to simulate the resistance to breathing, and thereby provide a simple method of measuring airway resistance (AU)

Airway constriction in asthmatics determined from forced expiratory volume curves with external resistances

This study was undertaken to determine what role the level of bronchial constriction played in the dyspnoea of the asthmatic attack. Forced expiratory volume curves (FEV) of asthmatic patients were studied with and without external resistances (discs) of known internal diameters, during an attack, after bronchodilator therapy and during remission. The results show that the site of narrowing of the tracheobronchial tree was important. This "critical site" accounts for approximately 20-40 percentof the calculated equivalent resistance in an attack. From the matched FEV curves with external resistances it was observed that discs with internal diameters of 1.5-5.0 mm most frequently matched the asthmatic curve. On recovery disc of 5.0-9 mm matched the patient's curve. The data supports previously reported studies based on theoretical calculations and direct measurements which showed that the critical resistance to respiration occurs around the level of the 3rd-6th generation of the tracheobronchial tree with internal diameters of 3-8mm; it is of interest to note in this repect that endotracheal tubes have internal diameters in this same range (AU)

Electrolyte metabolism in the colon - abstract

Studies were designed to determine the role of the colon in electrolyte homeostasis, and to analyse some of the factors which affect electrolyte transport in the colon. These studies were carrried out in humans by the analysis of faecal fluid electrolytes, and in rats and dogs by in-vivo isolated loops of colon. The results obtained show that, particularly under conditions of electrolyte depletion, the colon plays an important role in electrolyte homeostasis. There is a suggestion that although there is a relationship between the transport of sodium and potassium, transport of potassium may occur independently of sodium transport. There may be a relationship between the transport of potassium and bicarbonate and there is a relationship between the transport of chloride and bicarbonate (AU)

The effect of metabolic inhibitors on urine concentration in rats

Progressive hypertonicity within the renal medulla is essential to the formation of a concentrated urine. The creation of this hypertonic medium requires energy. The aim of this study was to determine the effect of metabolic inhibitors on the production of a concentrated urine. Rats were maintained in a diuretic state by feeding them 5 percent glucose water ad lib. They were then given intraperitoneally 10 per cent of their body weight of 0.45 per cent Na Cl or 10 per cent mannitol in water. Studies were divided into three groups: 1) NaCl or mannitol diuresis, 2)NaCl or mannitol plus ADH, 3) NaCl or mannitol plus ADH plus metabolic inhibitor. Faeces-free urine was collected at 2-hourly intervals over a 12-hour period, and also after 24 hours. The metabolic inhibitors used were: a) 2-4 Dinitrophenol, sodium cyanide, hydroxylamine hydrochloride, b) iodoacetate, acetamide sodium fluoride. Urines were analysed for osmolaity, Na, K, urea, creatinine. Sections of kidney cortex, medulla and papilla were also analysed for Na, K, urea. Results are presented which show that: 1) The hypertonicity of the renal medulla is due to the active transport of sodium and urea. 2) Inhibition of anaerobic glycolysis inhibits the creation of a hypertonic medulla, and inhibits the formation of a concentrated urine. This inhibition was temporary, disappearing within 24 hours. The results obtained in this study suggest that the energy required for the production of a concentrated urine is derived from anaerobic glycolysis (AU)

The syndrome of inappropriate secretion of antidiuretic hormone, associated with cerebral aneurysm

The case is presented of a 69-year-old woman with a long standing lesion at the base of the brain who terminally developed the classical findings of the inappropriate secretion of antidiuretic hormone. It is postulated that the lesion, in close proximity to the pituitary stalk, could have acted as an irritative focus, resulting in over-production of antidiuretic hormone (AU)

An analysis of electrocardiographic changes occuring in infantile gastroenteritis and infantile malnutrition in Jamaica

In 84 percent of cases of abnormalities were found in electrocardiograms and those were related to electrolyte disturbances - particularly reflecting low serum levels of magnesium, potassium, sodium and calcium. It was suggested that magnesium should be included in replacement fluids (AU)

Renal function in infantile gastroenteritis in Jamaica

Dehydration may lead to acute tubular necrosis and thus complicate treatment and recovery. Evidence is presented that although renal function gradually return to normal, in some cases residual dysfunction is still apparent up to a fortnight after clinical recovery (AU)

Serum gamma globulins and infection in Jamaica

It is widely claimed that people living in the tropics, particularly negroes, have higher gamma globulin levels than Europeans. No such difference was found in a series of healthy Jamaicans and of healthy Europeans recently arrived in Jamaica. The zinc sulphate turbidity test does not measure gamma globulins alone (AU)

The quantitation of globulins by paper electrophoresis

A method is proposed for the quantitation of globulin sub-fractions by paper electrophoresis which overcomes certain difficulties, mainly albumin trailing and the differential dye uptake between albumin and globulins. By this method the globulin sub-fractions can be quantitated with good reproducibility and the results obtained compare favourably with those obtained by the use of Cellulose acetate strips. The error involved in the quantitation of the Alpha globulins is so great that one should be very cautious in interpreting quantitative results of the Alpha globulins. On the other hand the Beta and Gamma can be quantitated with reasonable accuracy (AU)