bluuebunny/crossref_metadata_2025 huggingface dataset:
Limited Supersaturation versus Phase Equilibration in Predicting the Occurrence of Decompression Sickness
Authors: Hills B. A.
Published: August 2015

1. Three experiments have been designed to test the following assumptions underlying the conventional methods for calculating decompression schedules: (a) that there is a critical limit to the supersaturation of a tissue by a gas, and (b) that no gas is formed in the tissues of a subject who does not develop symptoms of decompression sickness.

2. When decompression time was titrated by cutting back upon the time spent at various last stops, it was found that a last stop at a depth of 30 ft was more effective than one at 20 ft which was, in turn, more effective than one at the conventional last stop of 10 ft for each of five schedules. These trials involved fourteen goats and 486 exposures.

3. In a second method, an exposure was selected for each animal from which the ‘titrated’ stop was now the only one required; but the results were inconclusive since the interval of uncertain diagnosis was now of comparable order of magnitude to the total decompression time.

4. In a third method, symptoms could not be induced in three goats, which had just completed marginally safe decompressions, by exposure to high-intensity ultrasound whose energy would be expected to cause the tissue to exceed any hypothetical metastable limit to supersaturation.

5. It was concluded that it is far more likely that the quantity of gas separating from solution determines the imminence of decompression sickness rather than its mere presence as determined by a critical limit to supersaturation.

6. This is discussed in relation to modifying the diving tables, and the serious implication that conventional schedules are really treating a gas phase in the tissues which does not give rise to symptoms due to the remaining compression afforded by the stopping pressures, rather than preventing the separation of gas from solution in tissue.
Divalent Ion Excretion in Chronic Kidney Disease: Relation to Degree of Renal Insufficiency
Authors: Popovtzer M. M. , Schainuck L. I. , Massry S. G. , Kleeman C. R.
Published: August 2015

1. The excretory patterns of sodium, calcium, magnesium and phosphorus were evaluated in seventy-eight patients with varying degrees of renal insufficiency, and in twelve normal subjects.

2. In mild renal failure the fractional excretion of filtered sodium, magnesium and phosphorus are significantly higher while that of calcium is significantly lower than values seen in normals. In advanced renal failure the fractional excretions of the filtered loads of all these ions increase steeply. These patterns are not influenced by the type of renal disease.

3. The fractional excretions of filtered sodium and calcium, calcium and magnesium, and sodium and magnesium were plotted against each other. The analysis of the plots showed that the fractional excretions of their filtered loads correlate poorly in patients with mild and moderate renal insufficiency, but closely in patients with severe renal failure.

4. These results indicate that the relation between the renal handling of divalent ions is not uniform at all levels of renal insufficiency. The dissociation between the excretory patterns observed in patients with early renal failure is consistent with the concept that different mechanisms may influence each individual ion separately. This is in contrast to the close association which exists between the excretory patterns of these ions in patients with advanced renal disease, and in which a single common mechanism may underlie the renal handling of these ions.
The Hypoxic Drive to Breathing in Chronic Bronchitis and Emphysema
Authors: Flenley D. C. , Franklin D. H. , Millar J. S.
Published: August 2015

1. We measured the ventilatory response to CO2 at two levels of arterial Po2 in twelve patients who suffered from chronic obstructive bronchitis. We also determined the lumbar cerebrospinal fluid bicarbonate in ten of these patients.

2. The CO2 response was depressed in nine patients who suffered from hypoxia and CO2 retention when breathing air. The hypoxic drive to breathing was normal in six cases, increased in one and absent in two cases who had severe chronic hypoxia and secondary polycythaemia.

3. The slope of the acute on chronic whole body CO2 titration line expressed in terms of arterial H+ and arterial Pco2 was the same in the hypercapnic patients as in normal men. This relationship allows predictions of the duration of hypercapnia in clinical practice.

4. Increased buffering in cerebrospinal fluid does not account for the depressed ventilatory response to CO2 in these patients.

5. By calculating the probable rise in jugular venous Pco2 which will follow correction of chronic hypoxia in these patients, we conclude that the administration of oxygen will remove a peripheral chemoreceptor stimulus to breathing but increase the central stimulus by a rise in cerebrospinal fluid acidity.
Urinary Excretion of Calcium and Creatinine in Relation to Age and Body Weight in Normal Subjects and Patients with Renal Calculus
Authors: Bulusu L. , Hodgkinson A. , Nordin B. E. C. , Peacock M.
Published: August 2015

1. Variations with age in body weight, urine volume and calcium and creatinine excretion were determined in 246 normal subjects and 305 patients with calcium-containing renal stones.

2. Body weight, urine volume and creatinine excretion increased with age to a maximum in the third decade in both male and female controls and stone-formers. Thereafter body weight and urine volume did not change appreciably but creatinine excretion decreased.

3. In normal subjects the daily excretion of calcium and calcium concentration increased in the first two decades and remained relatively constant thereafter until the eighth decade when they decreased. The calcium/creatinine ratio was high in the first decade and fell during the second and third decades. Thereafter it remained relatively constant in men until the eighth decade when it fell. In women, however, there was a second rise in the fifth and sixth decades. The calcium/body weight ratio remained relatively constant with age until the eighth decade, when it fell.

4. Patients with renal calculus showed similar variations in calcium excretion with age. The mean values, however they were expressed, were higher than those in normal subjects of the same age and sex.

5. The daily excretion of calcium was higher in men than women, whether normal subjects or stone-formers. This difference was abolished when calcium excretion was related to body weight and reversed when excretion was related to creatinine.

6. Comparison of the present data with previous data from the same population indicated that the mean daily excretion of calcium by both normal subjects and patients with renal calculi has increased during the last decade.

7. The significance of these observations in relation to calcium homeostasis and renal calculus formation is discussed.
Distribution of Blood Flow in the Renal Cortex during Saline Loading
Authors: Munck O. , de Bono E. , Mills I. H.
Published: August 2015

1. The effect of infusion of isotonic saline on the circulation in the renal cortex in the dog was investigated by an external counting technique involving measurement of the transit times for 85Krypton and 131I-labelled albumin after rapid injection into the renal artery.

2. During saline infusion superficial renal cortical blood flow and overall cortical blood flow rose by 23 and 15%, respectively. There was a 6% rise in the ratio superficial cortical blood flow to overall cortical flow, which however, was not significant.

3. Resistance to flow through cortex decreased.

4. Mean transit time for plasma through cortex decreased from an average of 2·9 sec in the control period to 2·6 and 2·1 sec during saline infusion.

5. Renal cortical blood volume, as estimated from the cortical blood flow and the mean transit time for plasma, was virtually unchanged.

6. These studies indicate that the decrease in resistance to flow during acute isotonic saline infusion is probably caused by a dilatation of the resistance vessels only. No significant redistribution of blood flow in cortex takes place; this, however, does not exclude regional changes in glomerular filtration rate.
Resistance and Collapse in Bronchial Airways
Authors: Howard P. , Webster I. W.
Published: August 2015

1. The Forced Expiratory Volume (FEV) was measured in normal persons and patients with obstructive airways disease at mouth pressures from 0 mmHg to levels high enough to prevent air flow altogether by using a Starling resistor at the mouth.

2. Evidence was obtained in support of the idea that, during forced expiratory flow, airways might function with the properties of a Starling resistor. This is considered to divide the airway into upstream and downstream segments at the site of airway collapse. The technique was simple, capable of being performed on outpatients and provided a means of studying the collapsibility of airways, airways resistance and alveolar pressure.

3. The FEV in normal persons and patients with disease was determined by the properties of the upstream segment. Since this segment contains only a proportion of the total airways resistance it was not surprising to find imprecise correlations between the FEV and airways resistance measured by the body plethysmograph.

4. Preliminary observations of patients during acute exacerbations of chest disease suggest that functional changes can occur throughout the length of the airway (i.e. in both upstream and downstream segments).

5. In the longer term during the natural history of obstructive airways disease, airways resistance and the more ready collapse of airways may develop independently.

6. Impaired alveolar pressure may contribute towards the reduction in air flow during acute exacerbations of chest disease.
The Excretion of Calcium in the Urine and its Relation to Calcium Intake, Sex and Age
Authors: Davis R. H. , Morgan D. B. , Rivlin Rosa S.
Published: August 2015

1. Until recently estimates of the urinary excretion of calcium have largely been based upon studies of patients in hospital and, consequently, with changes in the person's diet and physical activity.

2. We have measured the urinary excretion of calcium in seventy-five men and ninety-eight women aged 20–69 years, who were all apparently healthy and who were taking their chosen free diet.

3. For 7 consecutive days each person recorded the weight of all food that was eaten and collected 24 h specimens of urine. We have examined in these persons the relation between the urinary calcium, the dietary intake of calcium, age and sex.

4. 95% of the men excreted less than 400 mg of calcium in the urine per day and 95% of the women excreted less than 340 mg/day.

5. Within the limits of the calcium intake (mean values: men 1148 mg/day, women 1042 mg/day) found in this study, there was no relationship between the dietary calcium and the urinary excretion of calcium except in men over the age of 50 years. Even then the regression accounted for only a minor part of the variation in urine calcium.

6. The urinary excretion of calcium diminished in men over the age of 60 and in women over the age of 50 years.

7. These results are discussed in relation to previous studies of the urinary excretion of calcium. It is concluded that the urinary excretion of calcium is determined more by the absorption of calcium from the intestine than by the intake of calcium, and that the efficiency of absorption decreases in men and women as they grow older.
Renal Responses to Vena Caval and Portal Venous Infusions of Sodium Chloride in Unanaesthetized Dogs
Authors: Potkay S. , Gilmore J. P.
Published: August 2015

1. Recent investigation has shown that sodium excretion is greater following portal venous infusion of 5% sodium chloride (w/v) than after systemic infusion in anaesthetized dogs. It was suggested that a factor of hepatic origin which is capable of depressing renal tubular reabsorption may be involved in this response. The present experiments were undertaken to determine the renal responses of conscious, unanaesthetized dogs to infusions of 5% NaCl administered systemically and by the portal venous routes.

2. No differences were observed in urine flow or sodium excretion rates in normal dogs when responses to the two routes of NaCl infusion were compared; potassium excretion was elevated following systemic as compared to portal NaCl infusion (P < 0·05). Urine flow was significantly greater (P < 0·05) in vasopressin and mineralocorticoid treated dogs following portal infusion of 5% NaCl, but no differences in electrolyte excretion were observed between routes of administration.

3. These findings are not compatible with the concept that a natriuretic factor is released from the liver consequent to elevation of portal venous sodium concentration in the conscious dog.
The Role of Parathyroid Hormone in the Gastro-Intestinal Absorption of Calcium
Authors: Wills M. R. , Wortsman J. , Pak C. Y. C. , Bartter F. C.
Published: August 2015

1. Gastrointestinal calcium absorption was studied in six normal subjects and in one patient with idiopathic hypoparathyroidism during a control period and during treatment with parathyroid extract.

2. In all subjects there was a small increase in the gastro-intestinal absorption of calcium during the administration of parathyroid extract.
Cardiorespiratory Disturbances Associated with Infective Fever in Man: Studies of Ethiopian Louse-Borne Relapsing Fever
Authors: Warrell D. A. , Pope Helen M. , Parry E. H. O. , Perine P. L. , Bryceson A.D.M.
Published: August 2015

1. Nineteen patients with louse-borne relapsing fever were studied in Addis Abeba (altitude 2285 m).

2. Following treatment with tetracycline a febrile Jarisch—Herxheimer-like reaction developed which showed the phases described in artificially-induced endotoxin fever.

3. During the chill phase body temperature, metabolic rate and pulmonary ventilation increased. Despite alveolar hyperventilation pulmonary venous admixture was high. Cardiac output, heart rate and systemic arterial pressure increased but pulmonary arterial pressure decreased.

4. During the flush phase systemic arterial pressure fell and remained low for many hours due to reduced vascular resistance, but pulmonary arterial pressure and inflow resistance increased. Small increases in glucose, lactate, and pyruvate concentrations were prevented by inhaling oxygen.

5. Stimulation of metabolic rate, ventilation and cardiac output during the reaction was not due simply to increased body temperature, hypoxia, or acidosis but was probably attributable to spirochaetal endotoxin.

6. Limitation of pulmonary oxygen diffusion may have been responsible for the impaired pulmonary oxygen uptake in these patients.

7. During the prolonged flush phase a greatly increased cardiac output is necessary to maintain systemic arterial pressure because of the very low vascular resistance. Prevention of extracellular fluid volume depletion, early detection and prompt treatment of cardiac failure and oxygen therapy may reduce fatalities during this critical period but hydrocortisone in large doses failed to reduce the severity of the reaction.
Physiological Effects of Repeated Exercise
Authors: Davies C. T. M. , Tuxworth W. , Young J. M.
Published: August 2015

1. The physiological responses to repeated continuous (progressive) exercise together with the relationship between continuous and discontinuous work tests on an upright bicycle ergometer have been studied in healthy male subjects.

2. The results show a marked decline in mean cardiac frequency (fH) from 145 beats/min to 124 beats/min during the first four experiments at a given submaximal oxygen intake of 1·5 1/min and thereafter a smaller decline to reach 118 beats/min on the final (sixteenth) day of the investigation. This latter decrease was associated with a small but significant rise in maximum oxygen intake (V̇O2 max) which occurred from Day 8 onwards. Pulmonary minute ventilation at an oxygen intake of 1·5 1/min (V̇E 1·5) decreased by about 5 1/min immediately following the first occasion of submaximal work but thereafter remained unchanged. There was however no decrease in O2 cost of exercise, as V̇O2 at a fixed rate of external work remained unchanged throughout the investigation.

3. At maximal effort there was no significant decrease in either V̇E max or fHmax, but the fH at which the V̇O2 max was reached declined significantly from Day 8. Thus the asymptotic nature of the fH/V̇O2 curve which was very pronounced on Day 1 virtually disappeared following the third visit to the laboratory. The accuracy of predicting V̇O2 max from fH and V̇O2 increased noticeably from − 15·4 ± 8·9% on Day 1 to −6·5 ± 10·5% on Day 7 and −0·9 ± 3·4% on Day 15. The possible physiological basis and implications of the results are discussed.

4. No significant differences were found between continuous and discontinuous work. Thus in large scale population studies of work capacity or in the evaluation of training programmes in rehabilitation studies, a continuous test may be used but attention must be paid to familiarization procedures. At least three preliminary test periods are necessary before the results become reproducible and reliable.
Blood Pyruvate and Lactate Levels during Oral and Intravenous Glucose Tolerance Tests in Diabetes Mellitus
Authors: Doar J. W. H. , Cramp D. G. , Maw D. S. J. , Seed M. , Wynn V.
Published: August 2015

1. Blood pyruvate and lactate levels during oral and intravenous glucose tolerance tests are described in obese and non-obese non-diabetic, maturity-onset diabetic and insulin-requiring diabetic groups of women.

2. Mean fasting blood pyruvate levels were similar in non-diabetic, maturity-onset diabetic and insulin-requiring diabetic subjects of similar degree of obesity. Mean levels were higher in the obese groups of non-diabetic and maturity-onset diabetic subjects compared to those of non-obese subjects of similar degree of glucose tolerance.

3. After oral glucose administration similar mean increases of blood pyruvate levels above the fasting base-line were found in non-diabetic and maturity-onset diabetic subjects matched for degree of obesity.

4. Peak oral glucose tolerance test blood pyruvate levels were generally delayed in the maturity-onset diabetic subjects and mean blood pyruvate levels were elevated above those of the non-diabetic subjects during the later stages of the test. Qualitatively similar changes occurred during intravenous glucose tolerance tests.

5. Mean blood lactate/pyruvate ratios were similar in non-obese and obese non-diabetic and maturity-onset diabetic groups of subjects and changed little after oral glucose administration.
The Effects of Obesity and Maturity-Onset Diabetes Mellitus on L(+) Lactic Acid Metabolism
Authors: Doar J. W. H. , Cramp D. G.
Published: August 2015

1. A sodium L(+) lactate infusion technique is described.

2. The results were fitted satisfactorily to a single compartment model, from which the endogenous production rate, fractional rate removal constant and volume of distribution of lactate were derived. The fractional rate removal constant of lactate was assumed to be independent of the blood lactate level.

3. Obesity was associated with an elevated endogenous production rate of lactate but the rate of lactate removal was normal; the rate of lactate removal was impaired in subjects with maturity-onset diabetes mellitus.

4. The volume of distribution of lactate, as a percentage of body weight, was similar in control, obese and maturity-onset diabetic subjects, and was of the order of magnitude of the extracellular fluid volume.

5. The relation of these findings to blood pyruvate and lactate levels after oral glucose administration to subjects with obesity and maturity-onset diabetes is discussed.
Magnesium Metabolism in Primary Hyperparathyroidism
Authors: King R. G. , Stanbury S. W.
Published: August 2015

1. Magnesium metabolism has been studied in forty-eight patients with primary hyperparathyroidism. Metabolic balance studies were undertaken in forty-three untreated patients and in fifteen patients after parathyroidectomy. The data obtained are compared with the pattern of magnesium metabolism in healthy adults, as established by analysis of collected nutritional studies. The renal handling of magnesium was assessed from measurements of 24-h renal clearances.

2. The mean serum magnesium in primary hyperparathyroidism was normal but low levels were present in nine of the forty-eight patients. There was a significant inverse correlation between serum levels of calcium and magnesium.

3. The magnesium balance was negative by amounts >5% of the dietary intake in eleven patients, and positive to a similar degree in twenty-one. Patients in negative balance ingested and consequently absorbed less magnesium than those in positive balance; the negative balance was apparently due to inadequate renal conservation of magnesium in the face of this lower intake and, in some cases, despite a low serum magnesium. When related to the level of dietary intake, intestinal net absorption of magnesium tended to be greater than normal.

4. In eleven of twelve patients studied, the urinary output of magnesium was lower after parathyroidectomy irrespective of changes in the serum level of magnesium. This fall in output appeared to depend mainly on reduction in the serum calcium. In untreated patients without advanced secondary renal disease there was a positive correlation between the serum calcium and the clearance ratio CMg/Ccreatinine. Additional mechanisms may contribute to renal loss of magnesium when renal failure is advanced.

5. The tendency to develop a negative magnesium balance and hypomagnesaemia in untreated patients of this series thus appeared related to the height of the serum calcium, the presence of advanced secondary renal disease and inadequate dietary intake.

6. Significant and sustained hypomagnesaemia after parathyroidectomy occurred only in patients with generalized bone disease. Its development appeared to depend on the inadequacy of the ordinary diet to meet the combined requirements for magnesium of new soft tissue formation and deposition in mineralizing bone.
Renal Function Studies in Renal Carcinoma
Authors: Ofstad J. , Kolsaker L.
Published: August 2015

1. In ten patients with renal cell carcinoma (Grawitz tumour) a selective kidney function study was performed with the intention of measuring the effect of the tumour upon the function of the parenchyma surrounding the tumour.

2. The excretion fraction of sodium and chloride and the osmolal clearance per unit of glomerular filtrate were significantly less and the urinary concentration of inulin and para-amino-hippuric acid were significantly greater in the affected than in the non-affected kidneys. In three patients with poorly vascularized tumours the difference between the affected and the non-affected kidney was insignificant or small.

3. The findings indicate hypoperfusion of the parenchyma surrounding the tumour. The hypoperfusion may be caused by diversion of circulating blood from the parenchyma to the tumour.

4. There was no correlation between the occurrence and degree of hypoperfusion and the blood pressure.
Chest Movements in Patients with Traumatic Injuries of the Cervical Cord
Authors: Moulton A. , Silver J. R.
Published: August 2015

1. The chest movements of three normal subjects and three patients with traumatic tetraplegia were studied with a specially designed caliper and correlated with the volume of air breathed while seated.

2. The chest movements of the tetraplegic patients were reduced; and there was paradoxical sucking in of the lateral wall of the rib cage.

3. The movements were estimated in a further normal subject and the three tetraplegic patients during tilting procedures (30° head up, horizontally and 30° head down); postural effects were observed in the apical and sternochondral regions of the tetraplegics.

4. These paradoxical movements appeared to be due to both the loss of the action of the paralysed intercostal muscles and the impairment of the action of the diaphragm secondary to the paralysis of intercostal and abdominal muscles.
The Relative Importance of Urinary pH and Urinary Content of Citrate, Magnesium and Calcium in the Production of Nephro Calcinosis by Diet and Acetazolamide in the Rat
Authors: Györy A. Z. , Edwards K. D. G. , Robinson J. , Palmer A. A.
Published: August 2015

1. The association of varying levels of urinary pH, urinary citrate and urinary calcium and magnesium excretion rates with kidney citrate, calcium and magnesium concentrations in experimental nephrocalcinosis was examined in twenty-four rats in a 3 × 2 multifactorial experiment with four replicates. All rats received the same synthetic diet for 6 weeks before being killed in the seventh week. In addition the rats received calcium supplements as calcium chloride (diet A), calcium carbonate (diet B), or as an equal mixture of calcium chloride and carbonate (diet N), the content of calcium being kept constant at 6·3 mg per g of diet for all rats. Half of the rats also received 2·5 mg of acetazolamide per g of diet.

2. Diet A produced a systemic acidosis and the most acid urinary pH. Diet B plus acetazolamide produced a more severe systemic acidosis and the most alkaline urinary pH. Urinary magnesium, citrate and calcium excretion rates were generally reduced below normal. Urinary excretion of magnesium and calcium were significantly higher in those rats on diet A than in those on diet B, while urinary citrate excretion was highest in the latter. Acetazolamide caused a further increase in urinary calcium excretion but a decrease in urinary magnesium and citrate excretions.

3. Acetazolamide significantly reduced plasma calcium but elevated plasma magnesium. The changes produced in plasma and urinary calcium and magnesium in the present study were consistent with an action through systemic acidosis for calcium and through urinary pH for magnesium, both being effected at a tubular site.

4. Variation in diet alone as well as acetazolamide administration were significantly associated with variation in the degree of nephrocalcinosis (P < 0·05 and P < 0·005 respectively). Acetazolamide increased nephrocalcinosis by a factor of at least 10. Analysis of covariance showed that acetazolamide was no longer associated with significant nephrocalcinosis when its effects on urinary pH and magnesium were removed from its effect on nephrocalcinosis. Removal of the effect of acetazolamide on urinary citrate excretion did not alter the effect of acetazolamide in producing nephrocalcinosis. Although urinary citrate was reduced to below 10% of normal whenever nephrocalcinosis was severe, it was also reduced to below 10% in rats on diet A which had normal kidney tissue calcium content, the most acid urinary pH and the highest urinary magnesium.

5. Elevation of urinary pH and reduction in urinary magnesium excretion were therefore considered to be of major importance in the causation of experimental nephrocalcinosis; reduction in urinary citrate excretion appeared to be only of secondary importance.
Effect of Vasopressin on the Renal Excretion of Phosphate in Man
Authors: Eisinger A. J. , Jones N. F. , Barraclough M. A. , McSwiney R. R.
Published: August 2015

1. The effect of vasopressin on the tubular reabsorption of phosphate was studied in both water-restricted and water-loaded man at different baseline rates of phosphate excretion. The latter was varied by altering phosphate intake or by administering aluminium hydroxide to reduce phosphate absorption from the gut.

2. It was found that when phosphate excretion was high, vasopressin had no consistent effect on the phosphate/creatinine clearance ratio. However at low rates of phosphate excretion, vasopressin significantly increased the phosphate/creatinine clearance ratio, suggesting a decrease in net tubular reabsorption of phosphate.

3. This effect of vasopressin was also demonstrated in a patient with hypoparathyroidism, indicating that it is not mediated by release of parathormone.

4. It thus appears that vasopressin has a small parathormone-like effect on the renal tubules, which may result from the common action of both hormones on the adenyl cyclase system.
Extravascular Albumin in Human Tissues
Authors: Katz J. , Bonorris G. , Sellers A. L.
Published: August 2015

1. Extravascular albumin in human tissue was determined by direct immunochemical analysis. Samples of muscle, skin and intestinal tract obtained at surgery were extracted with a solution of 0· 9% sodium chloride plus 0· 1% desoxycholate and total albumin of the extracts was determined by radial diffusion in agarose plates containing antibody to human albumin. Occluded blood in tissues was estimated from the haemoglobin content of the extracts and the albumin due to blood calculated. This was used to obtain by difference the extravascular albumin content of the tissues. The extravascular albumin content of muscle and skin from seven patients was (mean and range) 3·6 (2·7–6·4) and 8·4 (6·5–12) mg/g, respectively. The albumin content of intestinal tissue (five patients) ranged from 4·3 to 9·0 mg/g (mean 6·3), and of stomach wall (three patients), from 3·5 to 5·4 mg/g (mean 4·4). Total extravascular albumin in humans is estimated to be at least 4 g/kg.

2. The extravascular (EV) albumin of human tissue is similar to that of rats. It is concluded that calculation of the extravascular albumin from the intercepts and slopes of the decay curve of injected radioactive iodine-labelled albumin leads to underestimation of the extravascular mass by 20–40%. The validity of the conventional multicompartmental model of albumin metabolism in the human is questioned.
Abnormal Excretion of the Isomers of Urinary Coproporphyrin by Patients with Dubin—Johnson Syndrome in Israel
Authors: Ben-Ezzer Judith , Rimington C. , Shani M. , Seligsohn U. , Sheba Ch. , Szeinberg A.
Published: August 2015

1. The urinary excretion of isomers I and III of coproporphyrin by fifty-nine patients with Dubin—Johnson syndrome has been examined, and compared with the results obtained for normal control subjects and patients with various types of jaundice.

2. The control subjects (with one exception) excreted less than 45% of the coproporphyrin as isomer I. Fifty-six patients with the Dubin—Johnson syndrome excreted more than 65% isomer I (mode, 87%). In three cases the relative content of isomer I was normal. These exceptional patients differed also in some other characteristics from typical cases of the Dubin—Johnson syndrome.

3. Patients with obstructive jaundice or infectious hepatitis showed an intermediate pattern of the isomer distribution. In Gilbert's disease the isomer pattern was normal (six cases). In Rotor syndrome the relative content of isomer I was increased (three cases).

4. The abnormal urinary excretion of coproporphyrins in the various types of jaundice is probably caused by different mechanisms. In obstructive jaundice and infectious hepatitis the absolute excretion of isomer I is raised and isomer III is normal or elevated. This pattern may be explained by a shift from the biliary to the urinary route of excretion affecting mainly isomer I. On the other hand, in Dubin—Johnson syndrome an increased excretion of isomer I was accompanied by a significant decrease of isomer III excretion in the urine. It is suggested that this abnormal pattern might be a result of a deficiency or inhibition of uroporphyrinogen isomerase (uroporphyrinogen III co-synthetase) in the liver of patients with the Dubin—Johnson syndrome.
Serum Protein Concentrations in Normal Children
Authors: Abrams Berenice
Published: August 2015

1. Serum proteins were studied in 106 children ranging from 3 to 14 years using a modification of Laurell's method of quantitative immunoelectrophoresis.

2. Quantitative values are given for eleven proteins, viz.: α1 lipoprotein, α1 antitrypsin, α1 easily precipitable glycoprotein, α1 group specific component, α2 macroglobulin, caeruloplasmin, haptoglobin, transferrin, haemopexin, β lipoprotein, and β1AC(C3).

3. There were no significant differences in protein levels between the sexes, and no correlation between age and protein level within the age range studied.

4. The values were also compared with those of infants aged 6–12 months, young adults of 16–25 years, and adults of 16–65 years.
Circulatory and Respiratory Changes during Unilateral and Bilateral Cranial Nerve IX and X Block in Two Asthmatics
Authors: Eisele John H. , Jain Sushil K.
Published: August 2015

1. The respiratory and circulatory effects of bilateral block of the IXth and Xth cranial nerves (IX and X) with local anaesthetic were studied in two subjects with obstructive airways disease (asthma).

2. In one subject bilateral block of IX and X decreased alveolar ventilation as evidenced by a rise in Pa,co2 and a fall in Pa,o2. There was no apparent ventilatory change in the other subject. The lung volumes (ERV and FRC) were unaffected by the block; however, the forced vital capacity and 1 s forced expired volume were slightly improved in both subjects.

3. During bilateral IX and X block neither subject showed a ventilatory response after 3 min of breathing 8·7% O2 in 91·3% N2. In one subject during a left-sided IX and X block, there was a normal hypoxic-ventilatory increase, whereas during a right-sided IX and X block the hypoxic-ventilatory response was slightly less than normal.

4. Unilateral IX and X block in both subjects produced tachycardia and hypertension which was approximately one half the increased heart rate and blood pressure that followed bilateral IX and X blockade.

5. Unlike the control responses, breathing 8·7% O2 in 91·3% N2 during bilateral IX and X block produced no change in heart rate and there was a continuous fall in the systemic blood pressure. The pulmonary arterial pressure, however, increased in response to hypoxia in the same manner as before the block.
The Effect of Moderate Exercise on Blood Metabolites in Patients with Hypopituitarism
Authors: Johnson R. H. , Rennie M. J. , Walton J. L. , Webster M. H. C.
Published: August 2015

1. Six patients with panhypopituitarism and eight controls were studied before, during and after 30 min of moderate, steady exercise on a bicycle ergometer. Venous blood samples were taken for estimation of growth hormone, pyruvate, lactate, glucose, FFA, glycerol and ketone bodies.

2. Exercise caused a rise in serum growth hormone levels in control subjects and these fell to pre-exercise levels within 90 min. There was no change in the levels in the patients. The patients showed changes in blood metabolites resembling those of the controls. FFA levels were considerably elevated and post-exercise ketosis developed, these changes being more marked in the patients.

3. The differences in FFA and ketone bodies between patients and controls may be due to the lower levels of fitness in the patients. A further explanation may be that growth hormone depresses FFA levels after initial mobilization during exercise in normal subjects, but no such action can occur in patients with hypopituitarism.

4. It is concluded that growth hormone does not necessarily have a major role in fat mobilization or in the production of post-exercise ketosis. Thus, the lower levels of ketosis observed in athletes are not due to their lower levels of growth hormone.
The Effect of Enzymatic Depolymerization of Arterial Mucopolysaccharides on Sodium Ion Content and Vessel Reactivity
Authors: Harris G. S. , Palmer W. A.
Published: August 2015

1. The presence of mucopolysaccharides within arterial walls may be associated with the high concentration of sodium ions within this tissue. These polyanions are sensitive to enzymatic depolymerization which results in a loss of the cation binding properties of the molecule.

2. In this study testicular hyaluronidase perfused through isolated arterial segments resulted in a decrease in reactivity of the artery to 65% that of control arteries. Associated with this finding was a 33% decrease in the sodium ion content of the stimulated hyaluronidase-treated artery. When a variety of other sympathetically innervated tissues were treated with hyaluronidase there was no decrease in reactivity or sodium ion content.
Isotope Studies in Normal and Diseased Knee Joints: 99mTc Uptake Related to Clinical Assessment and to Synovial Perfusion Measured by the 133Xe Clearance Technique
Authors: Dick W. C. , Deodhar S. D. , Provan Carol J. , Nuki G. , Buchanan W. W.
Published: August 2015

1. Uptake of intravenously administered radioactive technetium (99mTc) was measured over the knee joints in normal human volunteers, in patients with osteoarthritis and in groups of synovectomized and unoperated patients with rheumatoid arthritis. The uptake was compared with clinical indices of inflammation (pain, tenderness swelling and stiffness), and the clearance rate of intra-articularly injected radioactive xenon (133Xe). The 99mTc uptakes were found to be unrelated to the isotope dose and the day-to-day reproducibility was acceptable.

2. The mean uptake of 99mTc was within normal limits in osteoarthritis. Both in synovectomized and in unoperated rheumatoid arthritis 99mTc uptake was significantly higher than in normal subjects.

3. Of the clinical indices studied significant correlation of 99mTc uptake was found with pain and swelling in all groups of patients studied.

4. Faster clearance of 133Xe in unoperated rheumatoid arthritis correlated well with the higher 99mTc uptakes.

5. The results confirm that 99mTc uptakes are raised in inflammatory arthritis but not in degenerative arthritis. The relation of 99mTc uptake to the clinical indices of inflammation and to the 133Xe clearance from the joint is discussed.
Lung Mechanics during Provocation of Asthma
Authors: Cade J. F. , Woolcock Ann J. , Rebuck A. S. , Pain M. C. F.
Published: August 2015

1. The mechanical properties of the lungs of five symptom-free asthmatic subjects and two normal subjects were measured before and during provocation with nebulized methacholine.

2. Before provocation abnormalities of some aspects of the mechanical function of the lungs were found in four of the asthmatic subjects.

3. Pulmonary resistance increased within one breath of the methacholine inhalation and was the measurement of lung function which changed most in response to methacholine in both asthmatic and normal subjects. However, asthmatic subjects had a much greater response than normal subjects.

4. The results of the study suggest that both the large and the small airways respond to provocation with methacholine. The larger airways appear to respond faster than the smaller airways and the response of the smaller airways appears to be more prolonged.
Simultaneous Determination of Plasma Converting Enzyme and Angiotensinase Activity by Radioimmunoassay
Authors: Poulsen K. , Poulsen L. L.
Published: August 2015

1. Homologous angiotensin-I was added to untreated plasma. Angiotensin-II which is formed by plasma converting enzyme and subsequently degradated by angiotensinases was determined as a function of time by using radioimmunoassay. Having determined the kinetics, the activities of converting enzyme and angiotensinases were calculated by a least-square fit of the theoretical curve to the experimentally measured values.

2. The method gives a simple measurement of converting-enzyme activity in untreated plasma; in plasma from salt-depleted and renal hypertensive rats this was found to be slightly increased but was normal in plasma from nephrectomized rats.

3. The half-lives for angiotensin-I in normal rat and human plasma were found to vary between 0·8 and 2·1 min, and the possibility that plasma converting enzyme participates in the regulation of the formation of angiotensin-II in vivo cannot be excluded.

4. The angiotensinase activity in rat plasma gave half-lives for angiotensin-II between 1·5 and 3·3 min; the half-life in normal human plasma was 10 min.
Intracellular pH Measured in Isolated Normal Human Leucocytes, by Using 5,5-Dimethyl-2,4-Oxazolidinedione under Conditions of Varying Extracellular Pco2 and Bicarbonate
Authors: Ahmed S. A. , Baron D. N.
Published: August 2015

1. Leucocytes were separated from human peripheral blood and incubated under conditions of constant extracellular pH (about 7·40) but variable extracellular Pco2 and bicarbonate concentration. Intracellular pH of leucocytes was measured by the 5,5-dimethyl-2[14C],4-oxazolidinedione procedure.

2. At Pco2 40 mmHg, the intracellular pH was 7·104 ± 0·115 (mean±SD). At Pco2 15 mmHg, intracellular pH was 7·567 ± 0·084, and at Pco2 72 mmHg it was 7·098 ± 0·063.
The Haemodynamic Consequences of Adaptive Structural Changes of the Resistance Vessels in Hypertension
Authors: Folkow Björn
Published: August 2015

It is generally accepted that a rise in systemic flow resistance constitutes the essential background of the increased arterial blood pressure in well-established hypertension, though the early ‘labile’ phases of essential hypertension in particular may exhibit a pattern simulating a moderately intense defence reaction, with enhanced cardiac output and muscle blood flow as the most characteristic features, apart from the rise in blood pressure. With respect to the increased flow resistance in the well-established phase, it is accepted that the vessels respond readily, and apparently normally, to vasodilator substances, from which the correct conclusion has been drawn that the resistance increase cannot be ascribed to any sclerotic narrowing of the resistance vessels (Pickering, 1968).

However, this observation has also generally led to the assumption that an increased smooth-muscle tone of the resistance vessels must be the explanation of the increased flow resistance and, despite the fact that there are numerous reports of medial hypertrophy in the precapillary resistance vessels for instance (Pickering, 1968), the possible haemodynamic consequences of such a type of structural vascular adaptation has hardly been considered at all. Instead the debate has mainly been concerned about whether the assumed increase of vascular tone is due to enhanced myogenic activity, to an increased neurogenic and/or hormonal exogenous stimulation of the vascular smooth muscles or whether these muscles might exhibit an enhanced sensitivity or ‘reactivity’ to such extrinsic stimuli.

In other words, if summarized in a diagram relating the extent of active smooth-muscle shortening to the degree of resistance increase in an idealized resistance vessel (Fig. 1), an increased smooth muscle activity, whatever its background, would mean a shift from the normal resting equilibrium at point O to a point B along the curve N.

However, one cannot safely deduce levels of vascular smooth-muscle activity between different individuals, or vascular beds, by simply assuming that they are proportional to the respective levels of current flow resistance. In each individual, or vascular bed, one must first relate the actual resistance level to that present when the vascular smooth muscles are completely inactive; i.e. when the resistance vessels are maximally dilated and exposed to the same amount of distending pressure. This latter resistance value provides the necessary ‘baseline’, or an equivalent of fully relaxed muscle length for a particular vascular bed, from which its current level of smooth muscle activity has to be judged in terms of the ratio between these two resistance values. This is simple and straightforward reasoning, but surprisingly enough studies along these lines were apparently not performed systematically until our group used this approach in analyses of the level of ‘basal tone’ in different vascular beds or individuals (Celander & Folkow, 1953; Löfving & Mellander, 1956; Folkow, 1956).
Hormones Released into the Circulation When the Urinary Bladder of the Anaesthetized Dog is Distended
Authors: Gilmore N. J. , Vane J. R.
Published: August 2015

1. In anaesthetized dogs urinary bladder distension caused variable changes of mean blood pressure; these were unaffected by vagotomy.

2. Catecholamines were detected in the circulation during bladder distension in fourteen of seventeen dogs. The catecholamine concentration during bladder distension was greater after cervical vagotomy.

3. Vasopressin could not be detected in the blood during urinary bladder distension before or after section of the cervical vagus nerves. Cervical vagotomy itself resulted in a. transient release of vasopressin.

4. A prostaglandin-like material was sometimes detected in the circulation during or immediately after urinary bladder distension. The origin of this material was not determined; it was detected in arterial and venous blood.

5. Urine flow consistently decreased during urinary bladder distension. This decrease was due neither to circulating catecholamines nor to vasopressin; it was probably caused by renal sympathetic activity. Cervical vagotomy did not abolish the antidiuresis.
The Effect of Methylguanidine on Tissue Respiration in Vitro
Authors: Felgate R. A. , Taylor W. H.
Published: August 2015

1. Slices of rat cerebral cortex, kidney and liver were incubated with Robinson's medium and the oxygen uptake measured for 4 h.

2. Methylguanidine was added to the incubation medium after 1 h to give final concentrations up to four times those found in chronic uraemia.

3. No significant inhibition of oxygen uptake was found at any of the concentrations tested.
A Quantitative Study of Skeletal-Muscle Purines and Pyrazolo[3,4-d]Pyrimidines in Gout Patients Treated with Allopurinol
Authors: Watts R. W. E. , Snedden W. , Parker R. A.
Published: August 2015

1. Hypoxanthine, xanthine, uric acid, allopurinol and oxipurinol have been determined in skeletal-muscle biopsies by quantitative high-resolution mass spectrometry.

2. The results obtained in six untreated gout patients and in seven gout patients who had been treated with the xanthine oxidase inhibitor allopurinol for periods of about 2 years, have been compared with those obtained on muscle tissue from non-gouty subjects and with the results of previous microscopical studies of the same biopsies.

3. Measurable amounts of xanthine were detected more frequently in the allopurinol-treated gout patients than in the untreated patients. The concentration of uric acid was generally lower in the allopurinol-treated than in the untreated gout patients' muscle; and all except one of the allopurinol-treated subjects' tissue contained a measurable amount of oxipurinol. Allopurinol was detected less frequently than oxipurinol.

4. The concentrations of hypoxanthine and xanthine in the allopurinol-treated patients' muscle tissue are very much less than those which have been reported in congenital xanthine oxidase deficiency.

5. It is concluded that allopurinol can still be recommended as a useful drug in the treatment of gout but that longer studies during the clinical use of the drug would be of value.
The Effect of Changes in Lactate Uptake on the Intracellular pH of the Perfused Rat Liver
Authors: Cohen R. D. , Iles R. A. , Barnett D. , Howell M. E. O. , Strunin J.
Published: August 2015

1. Mean intracellular pH (pHi) and lactate have been measured simultaneously in the isolated perfused rat liver on two successive occasions separated by an interval of 20 min. In some experiments extra lactate was added to the perfusion medium immediately after the first measurement of pHi.

2. There was a direct relationship between the change in pHi over this interval and the simultaneous change of lactate uptake.

3. This finding is consistent with the hypothesis that lactate enters the liver cell at least partly in the ionized form and that its metabolism is accompanied by the effective production of hydroxyl ions.

4. These observations are discussed in terms of a possible control mechanism for lactate uptake by the liver.