摘要:

Summary.Intra‐axonal recording in Flechsig's fasciculus was used for a further investigation of the functional organization of the dorsal spino‐cerebellar tract.After ipsilateral section of lumbar and sacral dorsal roots, many neurons identified as belonging to the dorsal spino‐cerebellar tract (neurons activated by group I muscle afferents) were found to have a resting discharge. In silent neurons a discharge could be made to appear after repetitive stimulation of dorsal roots. It is concluded that these neurons receive excitatory action from interneurons.Convergence of excitation and inhibition onto DSCT neurons from various muscles was studied with the use of electrical stimulation of muscle nerves as well as with adequate activation of stretch receptors.As evidenced by monosynaptic excitation on single shock stimulation of muscle nerves, convergence of excitatory action mediated by group I afferents was found to be rather limited. A number of neurons can only be fired from one muscle nerve but some from as many as three out of seven nerves (including non‐synergists).Convergence of inhibitory action mediated by group I afferents is extensive also from other muscles than the antagonist of the nerve supplying the main excitatory

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01374.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

SUMMARY1Histamine was given subcutaneously to unanaesthetized guinea pigs and its effects on the respiration were studied by counting the respiratory frequency and observing the external respiratory movements.2The respiratory symptoms caused by histamine were potentiated by some histaminase in hibitors in doses, which did not increase the responses to β‐2‐pyridylethylamine, acetylcholine or carbaminoylcholine.3The specificity of the potentiation and the parallelism found between potentiating effects and histaminase inhibiting properties of the different histaminase inhibitors suggest that the increase in histamine sensitivity was due to diminished histaminase activity.4The maximum increase in sensitivity obtained by these inhibitors was about two‐fold. The skilful technical assistance given by miss M.‐B. Johanssonwas highly app

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01375.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.The rates of excretion of 24‐14C labeled cholic, chenodeoxy‐cholic, lithocholic and cholanic acid have been followed after intraperitoneal injection. The half‐life of these bile acids has been found to be 2–3 days. The quantitative aspects of the cholesterol‐bile acid relationship are

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01376.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.Cholic acid‐24‐14C has been administered to rats treated with intestinal chemotherapeutics and the rate of elimination has been followed. In rats given phtalylsulfathiazolum and terramycin a much slower rate of excretion was observed than in normal rats. The half‐lifetime of the bile acid molecule was estimated to be 10–

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01377.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.A technique. is described for the use of thc perfused paw of the cat as a test object for assaying the activity of histamine liberating agents.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01378.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.The experiments were performed on cats under Nembutal anesthesia. The mass discharge in the ventral spino‐cerebellar tract (VSCT) was recorded from the cerebella surface, the superior cerebella peduncle (SCP) and from different levels of the spinal cord on stimulation of various hind leg nerves. The characteristics of the VSCT mass discharge was determined by recording from the surface of the SCP, where the tract is found in isolation from other ascending spinal tracts.1A mass discharge in the VSCT appears on stimulation of contra lateral muscle nerves but not on stimulation of skin nerves or unilateral muscle nerves. The mass discharge recorded at the SCP on stimulation of thigh muscle nerves has duration of about 2 msec and appears after a latency of about 5 msec.1The discharge remains after contralateral hemisection of the spinal cord and after c section of Flechsig's fasciculus but disappears after a superficial lesion of the ipsilateral ventral quadrant.1As judged from the ingoing volley recorded at the dorsal root entryzone, the discharge is due to activation of the second component of the group I volley thus suggesting excitatory action from Golgi tendon organ afferents.2The transmission from the group I muscle afferents to the VSCT neurons is monosynaptic as judged from the duration of the synaptic delay.3The conduction velocity of the fastest fibres in the VSCT is higher than that in the DSCT and amounts to about 120 m/sec.4The VSCT is completely or almost completely crossed whereas the DSCT is completely or almost completely uncrossed.5Both spino‐cerebellar tracts cause potentials at the surface of the anterior vermis after a latency of about 5 msec on stimulation of thigh muscle nerves. The potentials due to VSCT activity are largest on the side contralateral to the tract indicating crossing of most VSCT fibres in the cerebellar commis

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01379.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.Unanaesthetized rats provided with a thoracic duct fistula were fed [14C]‐labeled chimyl alcohol (α‐[1‐14C]‐hexadecylglyceryl ether) dissolved in olive oil.The labelled chimyl alcohol was absorbed to 95 per cent. The remainder was recovered in the unsaponifiable fraction of fecal lipids. About 50 per cent of the absorbed activity was recovered in the lymph lipids.In the lymph lipids about half of the radioactivity was associated with palmitic acid, indicating a splitting of the ether bond of the chimyl alcohol and subsequently oxidation of the cetyl alcohol moiety to palmitic acid in the mucosa cells. The palmitic acid was incorporated into the lymph triglycerides and phospholipids in the usual way.The other half of the activity in the lymph was present as chimyl alcohol about half of which was present as free chimyl alcohol. The remainder of the chimyl alcohol had been esterified during the absorption process and behaved chromatographically as a triglyceride that yielded chimyl alcohol after alkaline saponification.Chimyl alcohol is thus well absorbed but extensively metabolized already during the absorption

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01380.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.A suspension of living heart muscle cells has been obtained by trypsin treatment of embryonic chick hearts, and subsequently kept in tissue culture.Both discrete single cells and cell elusters were observed in the tissue culture. Histologic preparations and electrophysiologic evidence indicated that the cell clusters have a syncytial structure.The electrophysiologic properties of clusters of heart muscle cells in tissue culture have been investigated with the intracellular microelectrode technique.The values for the resting and action potentials in cell clusters are found to be of the same magnitude as those reported by other investigators in the intact embryonic chick heart.In cell clusters obtained from embryos younger than 8 days, a “prepotential” always preceded the action potential.When occasionally the spontaneous contractions of heart cell clusters temporarily stopped it was observed that oscillatory fluctuations of the membrane potential initiated the appearance of contractions.The effects of acetylcholine on the spontaneous frequency of contraction of cell clusters have been investigated. The spontaneous contractions of cell clusters deriving from the ventricular part of embryonic chick hearts were rarely (4 out of 110 clusters) inhibited by acetylcholine in a concentration of 104g/ml. The contractions of cell clusters obtained from the atrial part of the hearts were stopped to a considerable extent (115 out of 169 clusters) by this concentration of acetylchol

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01381.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.Seventeen hours after labelling the circulating iron‐βrglobulin, with59Fe, 14–34 p. c. of the labeled iron is found in the 21 days old foetus of the rabbit.Exposure of the rabbit to 500 r of X‐rays increases the amount of59Fe passing the placenta to almost twice the value in non‐exposed animals.Seventy‐three–eighty‐three p. c. of the59Fe content of the embryo is found in the liver.The specific activity of the hemoglobin iron present in the nuclear fraction of the liver amounts to one fourth of that of the circulating hemoglobin in the maternal, to about twice in the embryonic organism.Exposure to radiation one day prior to labeling the plasma depresses the fraction of embryonal59Fe incorporated into the hemoglobin of the nuclear liver fraction to about half of the value observed in non‐irradiated rabbits.The valuable assistance of Miss JuttaSchliackand the generous support of this investigation by the Riksföreningen fijr kräft‐sjukdomarnas bekämpande, Cancernämnden and the Knut och Alice Wallenbergs Stiftelse is g

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01382.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.1Prom theoretical reasoning the maximal energy output of humans rimy he expected to be a linear function of (weight adipose tissue)2/3.2In a material of 65 human male and female subjects the value for the exponent was empirically found to he 0.71 ± 0.056.3The correlation coefficimt between (weight — adiposetissuc)2/3and maximal oxygen intake, though slightly higher. Was not significantly different from the correlation coefficient between total hemoglobin and maximal oxygen intake.4The total amount of hemoglobin was correlated with (weight — adipose tissue)2/3witha correlation coefficient of 0.85. The partial correlation coefficient between total hemoglobin and maximal oxygen intakes after elimination of the influence of body size was

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01383.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY