A cerebral decarboxylase for 5-hydroxytryptophane in humans

1961 ◽  
Vol 16 (6) ◽  
pp. 1050-1054 ◽  
Author(s):  
William Sacks

Little or no cerebral decarboxylation of 5-hydroxytryptophane could be found using the in vivo technique developed in this laboratory for determination of human cerebral metabolism. Following intravenous injection of dl-5-hydroxytryptophanecarboxyl-C14 little or no significant venous-arterial C14O2 differences resulted in four normal control subjects and four chronic mental patients. No significant differences were found between the two groups. Levels of arterial blood C14O2 activities showed that 5-hydroxytryptophane was decarboxylated readily by other body tissues. Of four subjects pretreated with 1-benzyl-2-methyl-5-methoxytryptamine (BAS), slightly lowered results occurred with the mental patient pretreated with a double dose of BAS. Submitted on June 19, 1961

1964 ◽  
Vol 46 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Claus Rerup

ABSTRACT Corticotrophin release in mice was determined from plasma free corticosteroid levels. The blocking effect of dexamethasone against non-specific stress was compared with that of pentobarbital-morphine. In marked contrast to the findings in the rat, pentobarbital-morphine pretreatment in mice did not prevent the activation of the pituitary-adrenal hormonal system, following the non-specific stress of histamine injection. Pentobarbital-morphine thus does not render the mouse a specific in vivo preparation for the determination of corticotrophin releasing activity (CRA). Dexamethasone, on the other hand, appears to be effective in blocking corticotrophin release due to non-specific stress and allowed of activation of the pituitary-adrenal system after intravenous injection of vasopressin and hypothalamic extract only. The steroid had no direct effect on the adenohypophysis.


1961 ◽  
Vol 7 (5) ◽  
pp. 536-541 ◽  
Author(s):  
May K Purcell ◽  
Gertrude M Still ◽  
Theodore Rodman ◽  
Henry P Close

Abstract A technic is described for the determination of the in vivo pH of red blood cell hemolysates. The mean arterial red cell pH of 20 normal subjects was 7.19 with a range of 7.15 to 7.22. The fiducial probability at the 0.95 level is 7.13 to 7.25. The mean difference in pH between plasma and cells was 0.21, with a range of 0.15 to 0.23. It is suggested that changes in pH of erythrocytes may reflect changes in other less accessible cells of the body and that the determination may be a useful research and clinical procedure in the study of metabolic and respiratory derangements.


1980 ◽  
Vol 188 (3) ◽  
pp. 705-713 ◽  
Author(s):  
G Livesey ◽  
P Lund

1. A procedure is described for the purification of leucine dehydrogenase (EC 1.4.1.9) from Bacillus subtilis. 2. The preparation is suitable for the quantitative assay of branched-chain amino acids and their 2-oxoacid analogues. 3. The content of total branched-chain 2-oxoacids in freeze-clamped liver, kidney, heart or mammary gland of fed rats is less than 5 nmol/g fresh wt. Higher amounts are present in skeletal muscle and arterial blood (25 +/- 4 nmol per g fresh wt., and 33 +/- 6 nmol per ml respectively; means +/- S.D. of 3 and 11 animals respectively). The values are not significantly affected by starvation for 24 h. 4. Arteriovenous difference measurements show that considerable amounts of branched-chain 2-oxoacids are released by skeletal muscle into the circulation and similar amounts are removed by the liver (about 1 mmol/24 h in a 400 g rat).


Author(s):  
Colin P. McDonald ◽  
Sukhinder K. Bilkhu ◽  
Victor Chang ◽  
Casey Bachison ◽  
Stephen W. Bartol ◽  
...  

Degenerative disc disease (DDD) of the cervical spine is a common condition that causes significant pain and disability. Treatment for DDD in 2000 exceeded 110,000 patients in the United States alone [1]. A common treatment option for patients involves removal of the degenerated disc and fusion of the adjacent vertebral bodies. However, previous research has shown that as many as 25–92% of patients treated with fusion have disc degeneration at the adjacent levels within 10 years after surgery [2,3]. It has been hypothesized that this is the result of a change in adjacent vertebral segment motion [4]. However, it is unknown if spinal fusion alters motion at these segments. Thus, the objective of this study was to compare the dynamic, three-dimensional (3D) motion of the cervical spine in normal control subjects and spinal fusion patients.


Perception ◽  
1986 ◽  
Vol 15 (2) ◽  
pp. 95-109 ◽  
Author(s):  
Alice Cronin-Golomb

The right and left hemispheres of four complete commissurotomy subjects were tested for the ability to recognize and integrate figure and background elements of composite visual stimuli. In the first experiment the subjects were required to identify from a four-choice array in free vision the stimulus card that matched the briefly lateralized sample stimulus. For all subjects the left hemisphere was proficient at identifying the figure, but performed at near-chance level in recognizing the textured background. In contrast, the right hemisphere was equally adept at identifying figures and backgrounds. Both hemispheres could easily identify the isolated figure or background from a choice array, demonstrating that the observed hemisphere effects were due to figure–background interactions rather than the result of any difficulty in processing specific elements of the composite stimulus. The second experiment involved the determination of the size and position of a dot that appeared against various plain and textured backgrounds. The right hemisphere of two subjects, but not the left, performed with greater accuracy when the background consisted of a ‘natural’ texture gradient rather than a plain white backing. Similar though less consistent results were obtained when an inverted gradient or an evenly spaced grid was used as the background. For each condition, right-hemisphere performance resembled that of normal control subjects. In contrast, the left hemisphere provided a pattern of results dissimilar to that of control subjects for the various figure–background tasks described. It appeared to be generally insensitive to background effects, except when the information provided by the background was highly unusual, as from an inverted texture gradient. The results suggest a preeminent role for the right hemisphere in (i) the recognition of background components of a whole-field stimulus, (ii) sensitivity to the influence of the background on the perception of an object, and (iii) the ability to use natural perspective cues to assist in the accurate perception of an object.


1961 ◽  
Vol 38 (1) ◽  
pp. 13-21 ◽  
Author(s):  
A. Pekkarinen ◽  
A. Kasanen

ABSTRACT The concentrations of free and conjugated 17-OHCS in the plasma, the excretion of 17-OHCS into the urine, and the 17-OHCS clearance were determined in control subjects and renal patients after an intravenous injection of cortisol. The average content of conjugated 17-OHCS in the plasma before the injection was three times higher in the renal group than in the control group. The conjugated 17-OHCS clearance after cortisol injection in the renal patients was three times lower than in the control group. As the clearance investigation does not offer any advantages compared with the determination of conjugated 17-OHCS in the plasma, the authors consider that, because of its simplicity the last-mentioned determination is as the best clinical test for measuring the steroid status in renal patients.


1979 ◽  
Vol 236 (3) ◽  
pp. F240-F245 ◽  
Author(s):  
R. Park ◽  
W. J. Leach ◽  
A. I. Arieff

An in vivo method is presented for the determination of liver intracellular pH (pHi) using [14C]dimethadione (DMO) in dogs. This method differs from those previously published in that hepatic venous and portal venous blood pH were selected as the extracellular reference pH, and liver blood space corrections are applied to whole liver tissue [14C]DMO activity. Using these corrections, a normal liver pHi of 6.99 +/- 0.03 (SE) was obtained. During acute metabolic acidosis and alkalosis, as well as during acute respiratory acidosis and alkalosis, the liver pHi remained normal; metabolic acidosis was 7.04 +/- 0.04; metabolic alkalosis was 6.92 +/- 0.08; respiratory acidosis was 6.98 +/- 0.04; and respiratory alkalosis was 7.00 +/- 0.10. None of these values was significantly different from normal (P greater than 0.05). Changes in intracellular bicarbonate and lactate appeared to account in part for the observed stability of the liver pHi despite acute manipulations resulting in a range of pH values between 7.09 and 7.63 in arterial blood.


2013 ◽  
Vol 305 (6) ◽  
pp. R630-R638 ◽  
Author(s):  
Candice M. Klingerman ◽  
Neil Trushin ◽  
Bogdan Prokopczyk ◽  
Philippe Haouzi

Our aim was to establish in spontaneously breathing urethane-anesthetized rats, the relationship between the concentrations of H2S transported in the blood and the corresponding clinical manifestations, i.e., breathing stimulation and inhibition, during and following infusion of NaHS at increasing rates. The gaseous concentration of H2S (CgH2S, one-third of the total soluble form) was computed from the continuous determination of H2S partial pressure in the alveolar gas, while H2S, both dissolved and combined to hemoglobin, was measured at specific time points by sulfide complexation with monobromobimane (CMBBH2S). We found that using a potent reducing agent in vitro, H2S added to the whole blood had little interaction with the plasma proteins, as sulfide appeared to be primarily combined and then oxidized by hemoglobin. In vivo, H2S was undetectable in the blood in its soluble form in baseline conditions, while CMBBH2S averaged 0.7 ± 0.5 μM. During NaHS infusion, H2S was primarily present in nonsoluble form in the arterial blood: CMBBH2S was about 50 times higher than CgH2S at the lowest levels of exposure and 5 or 6 times at the levels wherein fatal apnea occurred. CgH2S averaged only 1.1 ± 0.7 μM when breathing increased, corresponding to a CMBBH2S of 11.1 ± 5.4 μM. Apnea occurred at CgH2S above 5.1 μM and CMBBH2S above 25.4 μM. At the cessation of exposure, CMBBH2S remained elevated, at about 3 times above baseline for at least 15 min. These data provide a frame of reference for studying the putative effects of endogenous H2S and for testing antidotes against its deadly effects.


1985 ◽  
Vol 228 (1) ◽  
pp. 103-110 ◽  
Author(s):  
P Ferré ◽  
A Leturque ◽  
A F Burnol ◽  
L Penicaud ◽  
J Girard

A quantitative method allowing determination of glucose metabolism in vivo in muscles and white adipose tissue of the anaesthetized rat is presented. A tracer dose of 2-deoxy[3H]glucose was injected intravenously in an anaesthetized rat and the concentration of 2-deoxy[3H]glucose was monitored in arterial blood. After 30-80 min, three muscles, the soleus, the extensor digitorum longus and the epitrochlearis, periovarian white adipose tissue and brain were sampled and analysed for their content of 2-deoxy[3H]glucose 6-phosphate. This content could be related to glucose utilization during the same time period, since (1) the integral of the decrease of 2-deoxy[3H]glucose in arterial blood was known and (2) correction factors for the analogue effect of 2-deoxyglucose compared with glucose in the transport and phosphorylation steps were determined from experiments in vitro. Glucose utilization was then measured by this technique in the tissues of post-absorptive rats in the basal state (0.1 munit of insulin/ml of plasma) or during euglycaemic-hyperinsulinaemic glucose clamp (8 munits of insulin/ml of plasma) and of 48 h-starved rats. Results corresponded qualitatively and quantitatively to the known physiological characteristics of the tissues studied.


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