Changes in limb volume during head-out water immersion in humans.

In order to investigate the contribution of fluid shift from the legs to immersion-induced diuresis, 7 normal and 2 legless (both legs disarticulated at the hip) individuals were tested to measure changes in leg volume (normal subjects) and urinary excretion of solutes and water during a 3-h head-out water immersion (HOI) in thermoneutral water (34.5 +/- 0.5 degrees C) with a 1-h control period before and after immersion. On a separate day, a 5-h time control (TC) experiment on the same subjects was carried out by having them sit in thermoneutral air (29 +/- 0.1 degrees C, relative humidity 60%). The leg volume decreased by 192 +/- 20 ml during the 3-h HOI, which accounted for 3.5% of the average leg volume of the preimmersion period. During TC, however, the leg volume increased by 110 ml in the same time course. An increase in urine volume and sodium excretion was observed during HOI in both normal (P less than 0.05) and legless subjects. Net urine volume induced by HOI (urine volume during HOI minus urine volume during corresponding TC) in normal subjects was 494 +/- 89 ml in 3 h, which was close to a calculated volume reduction of the lower extremities during HOI (508 +/- 53 ml). The average net urine volume during HOI in the legless subject was 183 +/- 48 ml/min. The above results may suggest that the increase in renal water output is largely accounted for by a fluid shift from the lower extremities during HOI, however, the fluid other than that from the extremities should be accounted for as the urine source.(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of the effectiveness of sympathectomy using the skin oximetry method]. / Otsenka éffektivnosti simpatéktomii metodom nakozhnoi oksigenometrii.

The use of the method of epicutaneous oxygenometry showed that it reflects objectively the condition of circulation in the extremity. Oxygen tension in the skin of patients with atherosclerosis obliterans of the lower extremities reduced with the gradual advancement of the disease. The operation of lumbar sympathectomy increases the level of skin oxygenation. The efficacy of the operation is highest in stage II but diminishes in stage III of the disease. Sympathectomy fails to improve regional circulation essentially in later stages of the disease.

Teicoplanin: Part 1. An evaluation of the concentrations seen in serum and the subcutaneous fat of the relatively ischaemic lower limb following a single intravenous bolus.

Teicoplanin is a new antibiotic currently undergoing clinical evaluation. Consecutive patients undergoing elective vascular surgery (n = 28) were randomised to receive a single intravenous bolus of 400 mg teicoplanin 1, 3, 6 or 12 h prior to surgery as prophylaxis against Gram-positive infection. Serum and fat antibiotic levels were measured and found to exceed the established MICs for common staphylococcal and streptococcal infections for at least 12 h following administration. This suggests that teicoplanin would be a useful choice of antibiotic in the prophylaxis and treatment of appropriate infections in elective surgery. By extrapolation, teicoplanin would also be of use in the prophylaxis and treatment of suitable infections seen in traumatised patients.

Measurement of L-[1-14C]leucine kinetics in splanchnic and leg tissues in humans. Effect of amino acid infusion.

Although whole-body leucine flux is widely measured to study body protein turnover in humans, the contribution of specific tissues to the total-body measurement remains unknown. By combining the organ-balance technique with the systemic infusion of L-[1-14C]leucine, we quantitated leucine production and disposal by splanchnic and leg tissues and by the whole body, simultaneously, in six normal men before and during amino acid infusion. At steady state, disposal of arterial leucine by splanchnic and leg tissues was calculated from the percent extraction (E) of L-[1-14C]leucine counts: uptake = E x [Leu]a x flow. Tissue release of cold leucine (from protein turnover) into vein was calculated as the difference between leucine uptake and the net tissue leucine balance. In the postabsorptive state, despite substantial (P less than .01) extraction of L-[1-14C]leucine by splanchnic (23 +/- 1%) and leg (18 +/- 2%) tissues, net leucine balance across both tissue beds was small, indicating active simultaneous disposal and production of leucine at nearly equivalent rates. Splanchnic tissues accounted for approximately 50% of the measured total-body leucine flux. During amino acid infusion, the net leucine balance across splanchnic and leg tissues became positive, reflecting not only an increase in leucine uptake but also a marked suppression (by approximately 50%, P less than .02) of cold leucine release. This reduction in splanchnic and leg leucine release was indicated by a sharp decline in whole-body endogenous leucine flux.(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction of the oxygenation of human organs at varying blood oxygen carrying properties.

The oxygenation of some human organs (brain, heart, kidneys, and legs) is correlated to the oxygen carrying characteristics of blood by predicting the PVO2 vs Q relationship at a given metabolic level of the organ. The effect of moderate shifts of the oxygen equilibrium curve [approximately equal to 2 Torr (0.27 kPa), comparable to the shifts caused by non-massive transfusions of blood with altered 2,3-diphosphoglycerate (DPG) concentration] is evaluated in terms of the efficiency of organ oxygenation. The results indicate the following. (1) An increase of the P50 from 27.9 to 30.0 Torr (3.71 to 3.99 kPa), that is the consequence of an increase of the [DPG]/[Hb] ratio from 0.8 to 1.04 M/M, is advantageous for all organs, because the normal metabolic level can be maintained with a considerable reduction of Q (approximately 10%). (2) This reduction is similar to that caused by an increase of [Hb] from 160 to 182 g/L, but without increasing the blood viscosity and the vascular resistance. (3) This advantage is different for the various organs, as a function of their blood supply and metabolic level characteristics. These features were also observed at any PaO2 in the range 60-300 Torr (7.98-39.9 kPa), and when simulating acidemia or alkalemia, as well as a pH gradient across the organ.

Energy costs of walking and standing with functional neuromuscular stimulation and long leg braces.

Two complete paraplegic subjects (T4 and T8), implanted with intramuscular electrodes, walked via functional neuromuscular stimulation (FNS) using a rolling walker and a reciprocal gait. The subjects also ambulated with long leg braces (LLB), using a rolling walker, and a drag/swing-to gait; and they stood using LLB and FNS separately. Oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory exchange ratio (VCO2/VO2), kcal/kg/meter, kcal/kg/minute, heart rate, blood pressure, and O2 debt with recovery time were recorded. During FNS walking, energy costs (kcal/kg/min) were 59% to 75% of maximal aerobic power (MAP), as determined during the combined activities of maximal arm ergometry and FNS leg stimulation. As the speed of FNS walking increased, there was no increase in energy costs; energy efficiency (kcal/kg/meter) equaled that of LLB ambulation. One subject showed decreased O2 debt with increased speed of FNS walking. At speeds approaching .4m/sec, FNS walking energy costs were similar to those of LLB ambulation. FNS energy costs relative to working muscle mass were less than those of LLB. When maximal stimulus parameters were used for FNS standing (20mA amplitude, 25 pps frequency, and 150 microseconds pulse width), energy costs were 100% more than those of normal or LLB standing. However, when the minimal stimulus necessary to maintain a standing position was used, FNS energy costs decreased by 35% to 47%. At speeds between .4 and .6m/sec, FNS walking is a viable alternative to LLB ambulation. Major energy cost reduction should be possible in the future.

Quantitation of phosphate metabolites in human leg in vivo.

Slice-selective 31P MR spectra were recorded from human legs with a pulse program which has only a 1.5-ms delay between excitation and acquisition. The volume of the slice was calculated from its thickness and cross-sectional area measured with the aid of a computer program. A phosphate reference standard spectrum was recorded from the same interplanar location as that of the human leg slice. Since signal integral is proportional to the phosphate concentration and to the volume of the slice, metabolite concentrations in the selected slice could be quantitated.

Reliability of transcutaneous oxygen tension (TcPO2) measurements in elderly normal subjects.

This study was conducted to evaluate the reliability of TcPO2 measurements in a well characterized group of 10 elderly normal subjects with an age distribution typical for the population with peripheral vascular disease (PVD) and amputation. The TcPO2 values were obtained on three separate occasions at 2-week intervals at seven anatomic sites commonly measured in patients with PVD. The TcPO2 values were comparable to those previously reported for similar sites in normal elderly subjects. Measurement to measurement variation averaged 1.1 kPa (8 mmHg) for a coefficient of variation (CV) of 14.4%. Confidence intervals ranging from 2.1 kPa (16 mmHg) above a single TcPO2 value to 2.1 kPa (16 mmHg) below were necessary to contain the true value 95% of the time. While TcPO2 measurement is assuming an important role in the evaluation of disease states in both paediatric and adult medicine, our observations emphasize the importance of using such measurements as an adjunct in clinical decision making and not basing such decisions on a single TcPO2 value alone. The size of the confidence intervals can be reduced substantially for a given site by taking the mean of two or more TcPO2 measurements taken at separate times.

Hemodynamic and metabolic responses of the exercising lower limb of humans.

This study was performed to determine the hemodynamic and metabolic responses of the human lower limb during exercise. Blood flow to the lower extremity was measured and sampled for lactate, catecholamines, and oxygen content in 12 normal men at rest, at all stages of bicycle ergometry, and during the postexercise recovery period. Whole body oxygen consumption and cardiac output were recorded throughout the experiment. Limb blood flow increased in a near-linear manner with both whole body and limb oxygen consumption. Although cardiac output rose with increasing whole body oxygen consumption, the increment in cardiac output diminished between submaximal and maximal levels of exercise resulting in a curvilinear relationship between blood flow to the exercising limb and cardiac output; this indicates that a major redistribution of cardiac output to the exercising lower extremity occurs, particularly at maximal levels of exercise. Covariance analysis suggested that limb oxygen consumption was the primary determinant of limb blood flow and limb vascular resistance during exercise. Arterial and venous lactate and catecholamine concentrations, obtained from the exercising lower extremity, could not be implicated as factors having a major influence on blood flow to that limb. The rate of lactate efflux from the limb during and after exercise, however, was directly related to limb blood flow.

Organ extraction of atrial natriuretic peptide (ANP) in man. Significance of sampling site.

Arterial plasma immunoreactivity of endogenous human alpha-atrial natriuretic peptide (ANP) underwent mean 54%, 28% and 40% extraction during one passage through the circulation in the kidney (n = 12), liver-intestine (n = 14) and lower limb (n = 8), respectively, in supine fasting subjects with no detectable disease or subjects with cardiovascular or hepatic disorders of minor degree undergoing a haemodynamic investigation. No extraction was identified across the lungs as evaluated by the same concentration of ANP in pulmonary and femoral arteries (n = 7). The concentration of ANP in a superficial arm vein relative to the femoral artery varied considerably and extractions from 0% up to 58% were identified (mean 18%). The results suggest a high degree of, but only to some extent selective, extraction of ANP, which may account for its proposed short plasma half-life. Due to the different concentrations of ANP in various vascular beds, sampling site should be thoroughly specified.

The exchange of blood-borne amino acids in the leg during abdominal surgical trauma: effects of glucose infusion.

The exchange of plasma amino acids and glucose, lactate, glycerol and 3-hydroxybutyrate in the leg was studied in otherwise healthy patients undergoing elective cholecystectomy. Seven patients were given a constant intravenous infusion of glucose at a rate of 1.1 mmol/min throughout the study. Seven other patients who received normal saline only served as a control group. Measurement of leg blood flow and arterio-femoral venous differences of amino acids and other energy metabolites were made on four occasions: (I) before surgery, (II) 10 min after skin incision, (III) at the end of surgery, and (IV) 30 min after the end of anaesthesia. The release of amino acids from the leg was comparable in the two groups before and during the early part of surgery. At the end of surgery the release of several individual amino acids, as well as the total release of amino acids, from the leg was higher in the patients given glucose infusion compared with the control patients. The infusion of glucose prevented the intraoperative rise in arterial levels and uptake of 3-hydroxybutyrate in the leg. A high release of amino acids at the end of surgery was thus associated with low arterial levels of 3-hydroxybutyrate while the reverse pattern was seen in the control patients. These effects of glucose infusion were qualitatively different from those seen in uninjured postabsorptive man.

Splanchnic and leg exchange of free fatty acids in patients with liver cirrhosis.

Splanchnic and leg exchange of free fatty acids (FFA), glycerol and ketone bodies, as well as FFA turnover, were determined in the post-absorptive state in 8 patients with liver cirrhosis and in 6 healthy control subjects. The catheter technique was used together with tracer ([14C]oleate) infusion. The arterial concentrations of FFA, glycerol and ketone bodies were 2-6-fold higher in the patients than in the controls. The FFA turnover was 230% greater in the patients, while the fractional turnover was similar in the two groups. In the splanchnic region as well as in the leg, both FFA uptake and release were increased 2-4-fold in the patients. The fractional uptake of FFA was reduced in both areas, indicating that the augmented uptake was due to the high circulating FFA levels alone. The splanchnic production of ketone bodies was four times higher in the patients than in the controls (295 +/- 30 vs 87 +/- 11 mumol/min). The fraction of FFA converted to ketone bodies was greater (42 +/- 6 vs 20 +/- 5%, P less than 0.05), indicating that the accelerated ketone body production was a combined effect of raised FFA uptake and altered intrahepatic metabolism of FFA. The splanchnic production of glucose was reduced by approximately 50% in the patients, while the uptake of glycerol was augmented. The leg uptake of 3-hydroxybutyrate was increased 300% and the release of glycerol was 200% greater in the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Neurobehavioral sequelae of subcutaneous injection with metallic mercury.

A 19 year old, white male, with nine years of education, attempted suicide by injection of metallic mercury (Hg) into the left forearm. CT scan findings suggesting mercury infiltration of the brain and results from urinalysis indicated clinically high levels of Hg excretion. Premorbid cognitive history was essentially normal, yet comprehensive neuropsychological assessment revealed significant impairment of higher cortical functioning beyond those expected of a moderately to severely disturbed psychiatric patient. Neuropsychological test results appear to offer a more sensitive, quantitative assessment of heavy metal toxicity.

Ammonia metabolism during exercise in man.

Physical exercise is accompanied by increased plasma levels of ammonia but it is not known whether this rise primarily reflects accelerated formation in muscle or decreased removal by the liver. Consequently, leg and splanchnic exchange of ammonia was examined, using the catheter technique, in 11 healthy subjects at rest, during three consecutive 15 min periods of bicycle exercise at gradually increasing work loads (35%, 55% and 80% of maximum oxygen uptake) and for 60 min during post-exercise recovery. The basal arterial ammonia level was 22 +/- 2 mumol/l, the concentration rose curvilinearly in response to increasing work loads (peak value 84 +/- 12 mumol/l), and fell rapidly after exercise, reaching basal levels after 30-60 min. A linear regression was found for ammonia levels in relation to lactate concentrations at rest and during exercise (r = 0.85, P less than 0.001). A significant relationship was also observed between arterial ammonia and alanine levels (r = 0.75, P less than 0.001). Leg tissues showed a net uptake of ammonia in the basal state (2.4 +/- 0.5 mumol/min). During exercise this changed to a net production, which increased curvilinearly with rising work intensity (peak value 46 +/- 15 mumol/min) but reverted to a net ammonia uptake at 30-60 min after exercise. Splanchnic ammonia uptake (basal 12 +/- 2 mumol/min) did not change in response to exercise but increased transiently during the early post-exercise period. From the above observations we conclude that the hyperammonaemia of exercise comes primarily from muscle release, while the splanchnic removal of ammonia is essentially unaltered. Part of the ammonia formed in contracting muscle is most likely used in the synthesis of amino acids, mainly glutamine and probably alanine.

Leg metabolism of amino acids and ammonia in patients with chronic renal failure.

Leg metabolism of amino acids and ammonia in the postabsorptive state was evaluated in 10 patients with chronic renal failure (CRF) and in 10 patients with normal renal function (controls) by measuring the arterial-femoral venous (A-FV) differences for free amino acids and ammonia. Total amino acid release from the leg and alanine and glutamine release, which accounts for the greatest amount of the total amino acid release, are similar in patients and controls. Total amino acid uptake from the arterial blood and glutamate uptake, which is the amino acid extracted at the highest rate, are comparable in both groups. Taken together these data, in addition to the similarity of A-FV differences for proteolytic markers, namely tyrosine, phenylalanine and histidine, suggest that protein breakdown in peripheral tissues is not increased in patients with CRF. In CRF selective metabolic abnormalities for some amino acids are evident. Whilst only the A-FV differences for valine, leucine and isoleucine are decreased, additional alterations are observed by relating the A-FV difference for each amino acid to that of proteolytic markers. Such a procedure demonstrates that in CRF histidine release relative to that of proteolytic markers is reduced, whereas proline and arginine release is increased. In CRF the reduced release of some amino acids, mainly branched-chain amino acids, by the leg probably affects the pattern of circulating amino acids. Finally, both in patients and in controls a significant uptake of ammonia is observed; the ammonia uptake is related to arterial levels of this metabolite, confirming the role of peripheral tissues in removing ammonia from circulation.

[Study of sodium metabolism in the bodies of patients with essential hypertension by the profile scanning technic using 22Na]. / Izuchenie obmena natriia v organizme bol'nykh gipertonicheskoi bolezn'iu metodom profil'nogo skennirovaniia s nuklidom 22Na.

Profile scanning with sodium-22 nuclide was performed in 37 patients with essential hypertension to determine the time-course of the isotope distribution in different parts of the body and the rate of its elimination. The rate of sodium-22 infiltration into the tissues of the pelvis and lower extremities was higher in women than in men, and that of elimination lower than in men with a stable course of arterial hypertension. This index showed no correlation with changes of the central hemodynamics and glomerular filtration. The labile and stable courses of arterial hypertension were characterized by different rates of sodium-22 uptake by the renal tissue.

Haemoglobin saturation during incremental arm and leg exercise.

There are few reports concerning the alterations in the percent of haemoglobin saturated with oxygen (%SO2) during non-steady state incremental exercise. Further, no data exist to describe the %SO2 changes during arm exercise. Therefore, the purpose of this study was made to assess the dynamic changes in %SO2 during incremental arm and leg work. Nine trained subjects (7 males and 2 females) performed incremental arm and leg exercise to exhaustion on an arm crank ergometer and a cycle ergometer, respectively. Ventilation and gas exchange measurements were obtained minute by minute via open circuit spirometry and changes in %SO2 were recorded via an ear oximeter. No significant difference (p greater than 0.05) existed between arm and leg work in end-tidal oxygen (PETO2), end-tidal carbon dioxide (PETCO2), or %SO2 when compared as a function of percent VO2 max. These results provide evidence that arterial O2 desaturation occurs in a similar fashion in both incremental arm and leg work with the greatest changes in %SO2 occurring at work rates greater than 70% VO2 max.

Carbohydrate and lipid metabolism in cirrhosis. Evidence that hepatic uptake of gluconeogenic precursors and of free fatty acids depends on effective hepatic flow.

Splanchnic arteriovenous differences for several intermediary metabolites of carbohydrate and lipid metabolism were determined simultaneously with hepatic blood flow in seven normal subjects, eight patients with cirrhosis, and six patients with cirrhosis after surgical portosystemic shunt ( SPSS ) after an overnight fast. Arteriovenous differences in the legs were also determined together with flux measurement. The individual turnover rates of acetoacetate (AcAc) and 3 hydroxybutyrate (beta OHB) were also determined by means of isotopic techniques. Splanchnic gluconeogenic precursors and FFA uptakes were lower in cirrhotic patients with SPSS than in normal subjects (P less than 0.05 and P less than 0.01, respectively). Splanchnic triglyceride output was also lower in cirrhotic patients with SPSS than in normal subjects (P less than 0.01), whereas no significant differences were found for AcAc, beta OHB, and glucose release. In the group of cirrhotic patients without SPSS , those patients with negligible signs of portal systemic shunt and normal splanchnic blood flow had uptake of gluconeogenic precursors and of FFA normal or higher than that of normal subjects, whereas those patients with signs of spontaneous portal systemic shunt behaved like cirrhotic patients with SPSS . Alanine release from the leg was lower in both cirrhotic patient groups. Tracer determined hepatic output of AcAc and beta OHB was higher in cirrhotic patients with SPSS (P less than 0.05). Plasma clearance rates of AcAc and beta OHB were significantly elevated in both cirrhotic patient groups. Close agreement was found between tracer and catheterization techniques in the evaluation of ketone body production in cirrhotic patients with SPSS , whereas in cirrhotic patients without SPSS tracer determined hepatic output was slightly lower, possibly because of extrahepatic splanchnic tissue ketone body uptake. In conclusion, our data in patients with cirrhosis indicate that: 1) splanchnic uptake of gluconeogenic precursors and of FFA was related to the degree of portal systemic shunt, e.g. to the degree of effective hepatic blood flow; 2) liver triglyceride but not ketone body output was decreased by the impaired FFA (and glycerol) liver uptake; 3) the higher circulating levels of gluconeogenic precursors (except alanine) and of FFA appeared at least partially due to lower hepatic removal of these metabolites; and 4) peripheral use of ketone bodies was increased and alanine release from the leg reduced in patients with cirrhosis.