摘要:

Abstract.A method has been developed whereby the splanchnic secretion rate of plasma triglycerides (TG) and the splanchnic uptake and mobilization of plasma free fatty acids (FFA) can be measured in man. The method includes constant intravenous infusion of albumin‐bound3H‐labelled palmitate, and simultaneous sampling of blood from the hepatic vein and an artery.The methodological problems associated with the quantitative determination of the small hepatio venous‐arterial differences of labelled and unlabelled plasma TG and FFA have been studied. By performing ten estimates on each hepatic vein and arterial sample, analytical precision was increased sufficiently to detect significant hepatic venous‐arterial differences in TG concentration and radioactivity.The splanchnic secretion rates of labelled plasma TG were found to be constant 3 hours after beginning the continous infusion of the precursor3H‐palmitate. The plasma TG turnover was calculated according to three different methods: the chemical, the isotope and the plasma TG clearance methods. The mean values and standard deviations of the three methods were 59 ± 105, 29 ± 12 and 37 ± 22 μmoles/min.The splanchnic uptake of plasma FFA was estimated to be between 225 and 269 μmoles/min and the splanchnic mobilization of plasma FFA was between 76 and

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1972.tb00580.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract.Investigations on the metabolism of3H‐25‐HCC have been performed in normal rats as well as in uremic, rachitic and rachitic‐uremic animals. The metabolic pattern of the uremic rats differs from that obtained in the control group in so far as uremic rats retain more of the injected radioactivity as peak IV (25‐HCC), whereas the normals have converted more into the peak V fraction. The results obtained in the rachitic group are completely different, as these animals have formed a rather high amount of peak I, a metabolic fraction which is considered to be an ester or other conjugate of 25‐HCC. Rachitic‐uremic rats show a metabolic pattern similar to the normal and uremic rats. These results suggest that a condition of uremia “normalizes” is some way the enzymatic disturbances provoked by a state of

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1972.tb00581.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract.1. Activities of phosphoglucomutase, hexokinase, glucose‐6‐phosphate dehydrogenase, triosephosphate dehydrogenase, mitochondrial glycerophosphate dehydrogenase, hexosediphosphatase and phosphoenolpyruvate‐carboxykinase, of enzymes involved in the citric acid cycle and connected pathways, of hydroxyacyl‐CoA dehydrogenase and carnitine acetyltransferase were determined in biopsy specimens of liver and of tibialis anterior muscle from thyrotoxic and hypothyroid patients and from controls. The results are compared with data obtained from liver and red and white muscle of thyrotoxic rats and guinea pigs. 2. Concomitant with diminished glucose tolerance, the glucokinase activity is decreased in thyrotoxic human liver. The decrease of rat liver glucokinase activity as a response to administered thyroid hormones is found to be dose‐dependent. A relationship between the diminished glucose tolerance in thyrotoxicosis and the decrease of glucokinase activity is discussed. The increase of hexokinase activity (isozyme II) is the most interesting finding in thyrotoxic human muscle because of its possible significance with respect to the elevated metabolic rate. The activity of triosephosphate dehydrogenase, (NADP) malate dehydrogenase, phosphoenolpyruvate carboxykinase and carnitine acetyltransferase is markedly enhanced in human thyrotoxic liver, whereas that of phosphoglucomutase is diminished. 3. Mitochondrial glycerophosphate dehydrogenase, which is known to be markedly increased in the liver and red muscle of thyrotoxic rats, is not increased in the liver and tibialis anterior muscle of thyrotoxic patients, nor in the liver and white muscle of thyrotoxic guinea pigs. The enzyme responses to thyrotoxicosis in human liver and muscle are more similar to those of the guinea pig than o

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1972.tb00582.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract.Plasma levels of TSH, FSH and LH were found to be low in cases of anorexia nervosa. Intravenous infusion of synthetic thyrotrophin‐releasing hormone provided a significant rise in TSH without having any effect on FSH or LH. The basal GH levels were normal or raised and no consistent effect of thyrotrophin‐releasing hormone was observed. The results suggest an impaired hypothalamic function as an essential mechanism in anorexia nerv

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1972.tb00583.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract.A lipid‐protein complex, which has a lethal effect on recipient animals, was isolated from mouse skin exposed to controlled thermal energy. A new isolation procedure was developed, which takes advantage of the toxic activity present in thermally modified skin, to trace the fate of the active compound. A bioassay was designed for this purpose by injecting Thorotrast into the recipient animals. The toxic lipid‐protein complex and the corresponding derivative from native skin were shown to have the same lipid (40%) and protein (60%) content. The lipid moieties of both derivatives were made up of six different lipid classes. The toxic compound differed from the non‐toxic material only by its larger size and higher density. Equivalent results were obtained on samples isolated, after the removal of surface lipids and soluble cell constituents, from the donor skins prior to the application of thermal energy i.e. processing “skin residues”. The biological activity was shown to reside in the apoprotein while the lipid moiety contributes to the toxic activity to a certain extent. The results suggest that the toxic compound is a polymeric form produced by thermal energy from a naturally occurring precursor. The toxin has a specific antigenic property protecting mice after active and passive immunotherapy against a lethal bum injuryin vivo.This suggests strongly that the toxic compound is an etiological factor responsible for the high mortality after severe burns. It is significant that, if scalding was applied to the same extent as the dry heat burns invivo, the injured animals survived. This was interpreted to support the hypothesis of a specific mechanism being responsible for toxin formation. The experimental results suggest that a specific therapy for the “late mortality” after severe human burns migh

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1972.tb00584.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract.The present work has demonstrated that portal blood of pig will stimulate growth of granular hepatocyte‐like cells from human embryonic liver explantsin vitro.Under otherwise identical cultural conditions, this cell type do not grow when using peripheral sera from human, pig, chicken, or fetal calf.The hepatocyte‐like cells were maintained in culture for up to 110 days before signs of degeneration appeared.The results support the theory that a portal blood factor may be necessary for liver regenerationin vivo, and emphasises the importance of the local environment of specialized ce

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1972.tb00585.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract.The effects of cholecystokinin and metoclopramide upon jejunal transit time of luminal fluid, net movements of water and electrolytes and unidirectional fluxes of sodium were studied in 11 normal subjects, each one being his own control. An intestinal perfusion technique with a four‐lumen tube was used. This allowed a simultaneous determination of mean transit time and absorption rate of water and electrolytes through a 35 cm segment of jejunum, (a) Cholecystokinin induced a significant decrease in mean transit time of fluid along the test segment. This effect was primarily due to a striking reduction (40% or more) in the mean diameter of the intestinal lumen, (b) Simultaneously there was a significant increase in net water, sodium and chloride secretion into the lumen, whereas net transport of potassium and bicarbonate was not affected. The lumen‐to‐blood unidirectional flux of sodium was obviously reduced but the opposite flux did not significantly change, (c) Similar changes in water and electrolyte movements were observed in subjects in whom transit time was primarily decreased by metoclopramide. (d) A close correlation was found between changes in transit time and net water and sodium transport into the lumen, in both cholecystokinin and metoclopramide studies.These results suggest that intestinal hypermotility may result,per se, in an increased secretion rate of water and electrolytes across the proximal small bowel. The implication of these findings in clinical conditions associating watery diarrhoea with intestinal hypermotility is disc

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1972.tb00586.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract.Using a gradient layer direct calorimeter, total heat losses were measured in 69 full term new‐borns at 5 different ambient temperatures (TA): 28, 30, 32, 34 and 36° C. The relative humidity of the air was kept constant at 50%. Oesophageal temperature (Teg) and mean skin temperature (T̄s) were continuously recorded. All experiments lasted at least one hour.The mean total heat loss was at 28° C: 3.55 W/kg; at 30° C: 2.97 W/kg; at 32° C: 2.35 W/kg; at 34° C: 1.92 W/kg and at 36° C: 2.05 W/kg. Dry heat loss was proportional to the external temperature gradient. Evaporative heat loss was constant when new‐borns were not subjected to heat or cold stress, with a mean of 0.39 W/kg. This value is a measurement of insensible perspiration.Sweating was elicited at aTAof 36° C when the internal temperature gradient reached a mean value of 0.68° C. Heat storage (S). was calculated and was found to be negative at aTAof 28 and 30° C, and positive at 34 and 36° C. A regression analysis between heat storage and total heat loss showed a mean heat loss of 2.61 W/kg when the new‐borns were in thermal equilibrium (S= 0). This occured in most babies at aTAslightly below 32° C.A minimal metabolic rate of about 6.0 ml kg‐1min‐1, determined by direct calorimetry and calculation ofS, was found at aTAof 34 and 36° C.The cutaneous thermal conductance, which is an index of cutaneous blood flow was minimal at aTAof 30° C. It increased sharply whenT̄sreached 36.3° C.These data indicate that the range of thermal comfort on the first day of life in normal full‐term new‐borns is very narrow and that there is a perfect thermal balance at aTAslightly below 32° C. However, at thisTA, the metabolic

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1972.tb00587.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract.The effects of physiological increments of plasma immunoreactive insulin upon tissue glucose uptake, tissue insulin uptake and lymph insulin levels were studied in the hind‐limb (65% muscle, 27% skin and subcutaneous fat) of 38 anaesthetized dogs.During intravenous glucose tolerance tests, the tissue glucose uptake remained within baseline values, whereas the net rates of glucose utilization and the concentrations of arterial plasma insulin increased as the load of glucose injected was raised. Significant amounts of endogenous insulin were cleared from plasma but were not recovered in lymph.No glucose response was observed in the hind‐limb tissues during intra‐arterial infusions of exogenous insulin in conditions of strict normoglycaemia and constant blood flow. The infusions of insulin were designed to simulate the levels of endogenous hormone achieved in plasma during the glucose tolerance tests. Again, a high percentage of the injected insulin was fixed to the hind‐limb tissues with no detectable rise of leg‐lymph levels. At higher plasma insulin concentrations, both tissue glucose uptake and lymph insulin levels were increased.The results show that the effect of plasma insulin on glucose uptake by muscle and fatin vivois a threshold phenomenon. From the present knowledge of the physiology of lymph formation, the threshold phenomenon could largely be accounted for by insulin adsorption to the blood capill

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1972.tb00588.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY