Local muscle blood flow and sustained contractions of human arm and back muscles.

The endurance during sustained contraction of elbow, flexors, elbow extensors, and back extensors was tested in 3 human subjects. The force level used was varied between ca. 15 and ca. 75% of maximal isometric strength (IS). The clearance of 133Xe from contracting muscles was registered during and after the endurance test. In this way it was possible to determine whether muscle blood flow (MBF) was increased or had stopped during the contraction. Experiments with artificial ischaemia of the upper arm together with MBF measurements showed that MBF was of no importance for continuing sustained contractions above a certain force level, which was 50,25, and 40% of IS for elbow flexors, elbow extensors and back extensors, respectively. However, the level, where longer lasting ( greater than 15 min) sustained contraction is possible is directly related to MBF. These levels were 22, 15, and 20% IS for elbow flexors, elbow extensors, and back extensors, respectively.


A simple force platform.

The force platform consists of a sandwhich of steel, Rockwool and concrete plates about 900 X 700 mm in surface. Four steel rings were bolted to the under side of the steel plate in each corner. Each steel ring was furnished with only one strain gauge, two of which were placed on the outer- respectively on the inner side of each ring. The four strain gauges were connected to a measuring bridge. Before mounting the rings on the steel plate, the sensitivity to pressure of each ring was adjusted in such a way that they were all similar. Because of this the platform responded with a signal which was independent of where a pressure was applied within the surface of the platform. The platform showed a rectilinear response for static forces up to 500 kp with a stable zero value. In response to dynamic forces the platform showed a resononance frequency of about 50 Hz, with a damping factor of 0.15. Calibration of dynamic forces was carried out by calculation of the forces during a vertical jump compared with what would be expected from the time of flight also registered by the platform-measuring-bridge-ink-writer-set-up. The time of flight was significantly higher (11%) than exected from the time-force relations beforetake-off. This was esplained partly by the relatively low damping factor in the system, partly by the subjects not extending their knees at landing on the platform.


The assessment of the static component in rhythmic exercise.

A new approach has been devised to assess the "static component" of dynamic exercise. This technique involves the measurement of the isometric endurance of muscles which have just taken part in rhythmic exercise and depends on the repeatability of trained subjects in isometric effort. The premise is that isometric endurance will be inversely related to the static component of the preceeding dynamic exercise. The subjects worked on a bicycle ergometer at known fractions of their maximal aerobic capacity (max Vo2). The rate of pedalling was varied from 30 to 90 rpm, so that for a given % max Vo2, the belt tension varied inversely with the speed of cycling. At any one speed of cycling, isometric endurance decreased as the belt tension increased. Following exercise at 30 rpm, the isometric endurance was 25 to 50% lower than that found at the most advantageous speed of cycling for our subuects; at these faster rates of cycling two subjects showed least static component following exercise at 90 rpm while the remaining subject performed best after cycling at 50 rpm.


Evaluation of Hill slopes and Hill coefficients when the saturation binding or velocity is not known.

1. The Hill coefficient (nH), an often-used measure of deviations from hyperbolic behaviour (nonhyperbolicity) in kinetic and binding systems, is usually estimated from the maximum or minimum slope of the Hill plot. The method depends strongly on the assumed magnitude of the asymptotic velocity (V) or binding (P) whose evaluation may be difficult in nonlinear/co-operative systems. Therefore, alternative procedures were devised for the estimation nH which do not require the prior knowledge of V or P. 2. When pairs of velocity/binding readings (v and w) are obtained at concentrations of c and alpha c, respectively (where alpha is a fixed constant), then the relation between w and v is described by a hyperbola, provided that Hill's equation is valid. In this case, linearizing plots, v/w versus v, w versus, w/v, and 1/w versus 1/v, can be used for estimation of the degree of the equation. However, if the Hill expression is applicable, these methods are not efficient and traditional procedures, particularly nonlinear regression, should be used. 3. The 'linearizing' plots of the Hill equation can be applied advantageously for the evaluation of the Hill slope and of nH also in the general case, when the Hill expression is actually not valid, provided that deviations from hyperbolic behaviour are positive. Appropriately extrapolated intercepts of the first two plots estimate alphanH. Furthermore, the slope of the third plot yields, similarly to the method of Kurganov et al., a continuous measure of the Hill slope (including its maximum) at all concentrations. The agreement is, at positive nonhyperbolicities, excellent theoretical values of Hill slopes and coefficients and those estimated by the proposed methods. 4. A coefficient of nonhyperbolicity (theta) is defined for 2nd-degree rate equations which provides a quantitative measure of positive or negative deviation from first-degree, hyperbolic characteristics. It is closely related to the Hill coefficient.


Free diiodotyrosine effects on protein iodination and thyroid hormone synthesis catalyzed by thyroid peroxidase.

Free diiosotyrosine exerts two opposite effects on the reactions catalyzed by thyroid peroxidase, thyroglobulin iodination and thyroid hormone formation. 1. Inhibition of thyroglobulin iodination catalyzed by thyroid peroxidase was observed when free diiodotyrosine concentration was higher than 5 muM. This inhibition was competitive, suggesting that free diiodotyrosine interacts with the substrate site(s) of thyroid peroxidase. Free diiodotyrosine also competively inhibited iodide peroxidation to I2. 2. Free diiodotyrosine, when incubated with thyroid peroxidase in the absence of iodide was recovered unmodified; in the presence of iodide an exchange reaction was observed between the iodine atoms present in the diiodotyrosine molecule and iodide present in the medium. Using 14C-labelled diiodotyrosine, 14C-labelled non-iodinated products were also observed, showing that deiodination occurred as a minor degradation pathway. However, no monoiodo[14C]tyrosine or E114C]tyrosine were observed. Exchange reaction between free diiototyrosine and iodide is therefore direct and does not imply deiodination-iodination intermediary steps. Thyroglobulin inhibits diiodotyrosine-iodide exchange and vice versa, again suggesting competition for both reactions. These results support, by a different experimental approach, the two-site model for peroxidase previously described by us in this journal. 3. Free diiodotyrosine when present at a very low concentration, 0.05 muM, exerts a stimulatory effect on throid hormones synthesis. The relationship between diiodotyrosine concentration and thyroid hormone synthesis give an S-shaped curve, suggesting that free diiodotyrosine acts as a regulatory ligand for thyroid peroxidase. Evidence is also presented that free diiodotyrosine is not incorporated into thyroid hormones. Therefore, thyroid peroxidase catalyzes only intra-molecular coupling between iodotyrosine hormonogenic residues. 4. Finally, although no direct proof exists that these free diiodotyrosine effects upon thyroglobulin iodination and thyroid hormone synthesis are physiologically significant, such a possibility deserves further investigation.


Nucleotide pyrophosphatase of rat liver. A comparative study on the enzymes solubilized and purified from plasma membrane and endoplasmic reticulum.

Studies on the subcellular distribution of rat liver nucleotide pyrophosphatase activity revealed its presence in the plasma membrane and the endoplasmic reticulum only. The enzymes from either source were solubilized specifically with trypsin without an apparent change of their catalytic properties. A 200-fold and 1600-fold purification, respectively, was achieved by a procedure including DEAE-cellulose and affinity-chromatography with AMP as ligand, gel filtration on Sephadex G-200 and gel electrophoresis. Both nucleotide pyrophosphatases were isolated as electrophoretically homogeneous soluble proteins. They were shown to contain carbohydrate moieties. The electrophoretic mobility of both enzymes in polyacrylamide gels was identical at three pH values. Dodecylsulfate gel electrophoresis indicated a molecular weight of 137 000 for both glycoproteins. The enzymes hydrolyze a variety of purine and pyrimidine nucleotides yielding a 5'-nucleoside monophosphate. Adenosine 3':5'-monophosphate, nucleic acids and phosphate monoesters are not cleaved, but p-nitrophenyl-thymidine5'-monophosphate is readily hydrolyzed. In view of their substrate and inhibitor specificities the enzymes are considered nucleotide pyrophosphatases rather than phosphodiesterases.


Computer simulation study of hexokinase II from Ehrlich ascites cells.

A study of the mechanism of hexokinase II from ascites cells the effects of its binding to mitochondrial membranes has been carried out by computer simulation. This is based on experimental data of Kosow and Rose and of Gumaa and McLean, and the theoretical methods of cleveland. For the soluble enzyme the mechanism is random with ternary produce-inhibition complexes; when bound to mitochondria, the mechanism becomes ordered-on, random-off, as the binding of ATP to the free enzymes becomes negligibly slow. The requirements of experimental data for mechanistic studies are discussed.


On the interaction of a lipophilic drug with different sites of rat-liver microsomes. Equilibrium studies with a substituted pleuromutilin.

The binding of the diterpenoid drug 14-deoxy-14-[(2'-diethylamino-ethyl)-mercaptoacetoxy]-dihydromutilin hydrogen fumarate in the cell of rat liver is mainly to the microsomal fraction. Besides specific binding to cytochrome P-450, where the enzymic degradation of the drug occurs, we observed a very high number of identical sites (site A) with an affinity of approximately 4.2 x 10(3) M(-1) (25 degrees C, PH 7.4). Model investigations demonstrate that these interactions occur almost exclusively with the microsomal phospholipid moiety. Their capacity for the drug was determinated to be of the order of 0.2 mol/mol phospholipid. The specific interaction of the pleuromutilin derivative with cytochrome P-450 gives rise to different spectral changes of the protein. At low concentrations where weak cooperativity of the overall binding to microsomes (sites B) was found, the formation of a type I complex was observed. At increasing concentrations of the drug this interaction vanishes and a spectral change of a different type (modified type II) arises. The affinity for this complex is identical with that of the phospholipid binding sites. The interaction of the drug with the phospholipid moiety might give rise to dual effects. Firstly the very near neighbourhood of a multitude of relatively weak binding sites will facilitate a transport of the drug along the microsomal membranes. Secondly, the loading of the membranes with the drug at high concentrations might influence the binding to cytochrome P-450 so that a qualitatively different interaction takes place.


Pyrimidine-rich oligonucleotides from rat-liver ribosome surface.

The distribution of oligonucleotides which are released from rat liver ribosomes by treatment with pancreatic ribonuclease has been studied. Rat liver monoribosomes lost from 15 to 17% of their nucleotides by treatment with pancreatic ribonuclease. This quantity was highly reproducible and did not depend significantly on the temperature (0-20 degrees C) and time (10-120 min) of incubation or on the concentration of enzyme (1:5000-1:50). Whereas the amounts of oligonucleotides liberated was 16%, it was shown by column chromatography that they consisted of 71% mononucleotides, 16% dinucleotides, 6% trinucleotides, 4% tetranucleotides and 2% pentanucleotides and that these oligonucleotides were enriched in uridine, containing approximately half of the uridine residues present in the high-molecular-weitht ribosomal RNA. The high molecular weight of the RNA from ribonuclease-treated ribosomes was preserved until it was heated; after heating, RNA fragments having sedimentation coefficients of 5 S and less were present. It is inferred that the olignucleotides are derived from pyrimidine-rich clusters located in single-stranded "hairpin" loops on the outside surface of the ribosome.


Transcription of isolated nuclei and nucleoli by exogenous RNA polymerase A and B.

Both forms A and B RNA polymerases solubilised from rat liver nuclei transcribed templates within these organelles when added exogenously to freshly prepared nuclei. The enzymes initiated more efficiently in the presence of KCL than ammonium sulphate and required manganese rather than magnesium as the divalent cation. Form A enzyme initiated most successfully at 375 mM KC6, activity was proportional to the amount of template added and continued linearly for at least 30 min. Form B enzyme initiated with two ionic strength optima, 125 mM and 500 mM KCl. Activity in the latter case was critically dependent on the enzyme: nuclei ratio. In both instances incorporation of nucleotide precurors was linear for less than 20 min. Form A enzyme synthesised products with a size distribution mainly larger than 18 S; form B enzyme synthesised products of mainly less than 5 S at 125 mM KCl and about 10 S at 500 mM KCl. Subfractionation of nuclei indicated that exogenous RNA polymerase A activity and form B at 125 mM KCl were occurring in nucleoli; form B activity at 500 mM KCl was nucleoplasmic. Measurements of U : G ratios in the RNA products suggested that exogenous form A was synthesising species with similar base ratios to the ribosomal RNA precurosrs. Both enzymes formed rifamycin AF/0-13 resistant complexes with nucleolar templates. Size analyses of products showed that whereas form B enzyme synthesised very small RNA species, RNA polymerase A produced a range of species of similar sizes to the ribosomal RNA precurosors.


Regulation of the synthesis of nucleoside diphosphate sugars in reticulo-endothelial tissues.

The kinetic and regulatory properties of enzymes involved in the biosynthesis of UDP-D-galactose, UDP-N-acetylglucosamine. GDP-alpha-D-mannose and GDP-beta-L-fucose from D-glucose 6-phosphate in various reticulo-endothelial tissues was studied. The tissues examined include bovine liver, thyroid, spleen, salivary gland, lung, intestine and mesenteric; pulmonary, portal and sub-maxillary lymphnodes. The maximum rates of specific enzymes in these pathways which were slow enough to be rate-limiting in the formation of glycoproteins in these tissues was determined. UDP-D-galactose 4-epimerase was consistently the rate-limiting reaction in the conversion of -d-glucose 6-phosphate to UDP-D-galactose in all of the tissues examined. The series of reactions leading to the formation of GDP-alpha-D-mannose and GDP-beta-L-fucose were limited by the activity of GDP-alpha-D-mannose pyrophosphorylase and GDP-alpha-D-mannose oxidoreductase, respectively. The formation of UDP-N-acetylglucosamine was limited by the rate of the amination reaction which converts -d-fructose 6-hosphate to D-glucosamine 6-phosphate in the presence of glutamine. Several of these rate-limiting enzymes were partially purified from mesenteric lymph node extracts, and their regulatory properties were examined. GDP-alpha-D-mannose was found to be a competitive inhibitor of GDP-alpha-D-mannose pyrophosphorylase. The apparent Km for GTP was 0.06 mM and the Ki for GDP-alpha-D-mannose was 0.03 mM. The concentrations of GTP and GDP-alpha-D-mannose in lymph node extracts were determined to be 0.095 and 0.012 mumol per g, respectively. UDP-N-acetylglucosamine and UDP-D-glucose inhibited D-fructose 6-phosphate amidotransferase in a manner competitive with D-fructose 6-phosphate. The Km for fructose 6-phosphate was 0.3 mM, while the Ki for UDP-D-glucose and UDP-N-acetyglucosamine were determined to be 0.4 mM and 0.045 mM, respectively. The concentrations of these metabolites in lymph node tissue were: UDP-D-glucose, 0.42; UDP-N-acetylglucosamine 0.095; and D-fructose 6-phosphate, 0.073 mumol per g wet weight of tissue. The results obtained in these studies show that specific rate-limiting enzymes in the pathways for the biosynthesis of nucleoside diphosphate sugars in reticulo-endothelial tissues may be subject to cumulative feedback inhibition by the nucleoside diphosphate sugars which are the final products of these systems and the initial precursors of the oligosaccharide units of glycoproteins in these tissues.


Improved techniques for the fractionation of non-histone proteins of chromatin on hydroxyapatite.

The effect of the dissociation medium on the fractionation of chromatin on hydroxyapatite has been studied. Optimal separations of the histones and non-histone protein are only achieved when columns are run in buffers containing high concentrations of sodium ions. We have modified our previously published method such that the chromosomal proteins can be recovered in virtually quantitative yields. Each of the hydroxyapatite fractions has been analysed with respect to nucleic acid content and the proteins have been analysed by two-dimensional gel electrophoresis.


Kinetics of histone methylation in vivo and its relation to the cell cycle in Ehrlich ascites tumor cells.

The appearance of methylated lysines in newly synthesized histones from Ehrlich ascites tumor cells was measured during one generation time. Newly synthesized histones were pulse-labeled in vivo by L-[3H]lysine, and the time course of the uptake of label into monomethyl, dimethyl and trimethyllysine from gel-electrophoretically isolated histones F2a1 (H4) and F3 (H3) was followed. Methylation starts immediately after histone biosynthesis. It proceeds, however, more slowly than histone synthesis. Both the rate of methylation and the mechanism of methylation in F3 and F2a1 histones differ. F3 methylation can be described by a first-order reaction, i.e. the reaction rate depends only on the concentration of free methylation sites available. Rate constants of approximately 0.21 h-1 were found for all three methylation steps. Methylation in the F2a1 histone proceeds more slowly than in F3. The dimethylation step in this fraction can be described by a zero-order reaction with a rate constant which is the reciprocal of the duration of the DNA synthesis phase. Alternatively this step could be correlated with the transition of the cells from the S phase into the G2 phase. By the end of one generation time all methylation sites in all F2a1 and F3 molecules are occupied by methyl groups at a ratio of about 1:3:1 for monomethyl, dimethyl and trimethyllysine in the F3 histone. In the F2a1 molecule the methyllysines consist mainly of dimethyllysine.


Sequence of a specifically encapsidated RNA fragment originating from the tobacco-mosaic-virus coat-protein cistron.

When 25-S tobacco mosaic virus (TMV) protein aggregate and TMV RNA, which has been partially digested by T1 RNase, are mixed under conditions suitable for reconstitution, only a few RNA fragments are encapsidated. These fragments were isolated and purified by polyacrylamide gel electrophoresis. The sequence of the three main fragments, the longest of which (fragment 1) was estimated to contain 103 nucleotides, has been determined. The two smaller fragments are portions of the longer chain produced by an additional specific scission. Because of the great affinity of 25-S TMV protein for this nucleotide sequence, it will be referred to as the "specifically encapsidated RNA fragment". The occurrence of a "hidden break" in the sequence has been demonstrated: fragment 1, purified by electrophoresis on a polyacrylamide gel without 8 M urea, gives rise upon further electroporesis in the presence of urea to two new bands corresponding to the two halves of the molecule. A stable hair-pin secondary structure has been derived from the base sequence which can account for the specificity of action of the enzyme. Because of its properties, we have suggested elsewhere that the sequence of fragment 1 might correspond to the disk recognition site for reconstitution, which is known to be located at the 5' end of the intact RNA. But experiments with TMV RNA whose 5'-OH end has been radioactively phosphorylated with polynucleotide kinase show that this is not the case. Analysis of the amino acid coding capacity of the fragment has instead revealed that fragment 1 is a portion of the TMV coat protein cistron.


Observations concerning the sequence of two additional specifically encapsidated RNA fragments originating from the tobacco-mosaic-virus coat-protein cistron.

The incubation of 25-S tobacco mosaic virus (TMV) protein with a mixture of RNA fragments produced by partial T1 RNase digestion of TMV RNA results in the encapsidation of only a few species of RNA. In addition to the most predominant species, fragment 1, whose sequence has been described in the prededing paper, two other species, fragment 41 and fragment 21 are coated by the protein. These two RNA fragments were purified by polyacrylamide gel electrophoresis and subjected to total digestion with pancreatic and T1 RNase. The oligonucleotides were separated by paper electrophoresis and characterized insofar as possible by digestion with the complementary ribonuclease. From the amino acid coding capacity of the oligonucleotides liberated from fragments 41 and 21 by T1 RNase digestion, it appears that these two fragments, like fragment 1, are derived from the coat protein cistron. They are situated immediately prior to fragment 1 and, together with this fragment, consitute a continuous stretch of 232 nucleotides of the cistron which codes for animo acids 53 to 130 of the coat protein. The order of the fragments in the sequence is 21-41-1. A possible model for the secondary structure of this portion of the sequence is proposed.


Two enzymically active forms of glycyl-tRNA synthetase from Bacillus brevis. Purification and properties.

Using sucrose density centrifugation and gel filtration of a 105000 X g supernatant of Bacillus brevis two enzymic activities of glycyl-tRNA synthetase were separated. Enzyme catalyzing the aminoacylation of tRNA (E1) elutes in a high-molecular-weight region. Enzyme active in glycylhydroxamate formation (E2) elutes from a Sephadex gel column and sediments in sucrose density gradient in a region of relatively low molecular weight. The presence of two enzymic activities does not depend on the method of cell disruption; their proportion does not change when protease inhibitor (diisopropylphosphorofluoridate) is added to the extraction buffer. Both E1 and E2 were purified to a nearly homogeneous state. Sedimentation coefficients (sw,20) were found to be 8.6 S and 3.6 S and molecular weights 226000 and 66000 for E1 and E2, respectively. During storage, E1 dissociates into two components, one of which has electrophoretic mobility identical to E2. The molecular weight of the other component is about 1600000. Electrophoresis of E1 in the presence of sodium dodecylsulfate reveals two bands corresponding to molecular weights of 81000 and 30000. Under these conditions, E2 dissociates into a polypeptide with a molecular weight of 30000. Valine was found to be the N-terminal amino acid for E2 and both valine and glutamic acid were N-terminal amino acids for E1. It is concluded that E1 is a tetrameric protein consisting of two large and two small subunits (alpha2beta2). E2 is a component of E1 with a structural formula alpha2.


The losozyme from Asterias rubens.

Lysozyme (mucopeptide N-acetylmuramylhydrolase) from Asterias rubens was obtained in a chromatographically and electrophoretically pure state by gel filtration and affinity chromatography. The quantitative amino acid composition, the molecular weight and the N-terminal sequence determined by a sequencer are reported. This new invertebrate enzyme presents important differences when compared to previously studied lysozymes.


Effects of vincamin on cerebral metabolism.

In this study the effects of vincamin (Pervincamine) on cerebral metabolism were investigated. 60 subjects were tested. Vincamin was administrated to 36, aminophillin to 12. No drug was given to the remaining 12 subjects who were used as controls. A definite increase in cerebral metabolism was observed in patients receiving vincamin either by intravenous or intramuscular injection. Practically no change in cerebral metabolism was detected in subjects treated with aminophyllin.


Occult disorders of the cerebrospinal fluid dynamics. Early diagnosis criteria.

Workable criteria are proposed that allow early recognition of mild forms of occult hydrocephalus and correlated disorders. Two groups of patients are analyzed, i.e., a group of twelve mild but classical forms of low-pressure hydrocephalus and another group of 20 patients with atypical clinical forms of disorders of the CSF dynamics. Two control groups are presented for neuropsychological comparison purposes: a normal control group of 50 subjects and a small group of three commissurotomized subjects. Patients with an overt demential syndrome due to a normotensive hydrocephalus syndrome were excluded from the study. The authors found the grasp reflex of the foot and the tonic foot response to be present in all cases with the Hakim and Adams triad. In such cases the grasp reflex is usually accompanied by the forward groping of the foot and the grasp reflex of the hand. The most helpful and useful clinical findings for an early diagnosis are the presence of the grasp reflex of the foot and of the tonic foot response of the sole in such organic brain-damaged patients with (1) a normal routine neurological examination and (2) an apparently normal mental status and even with a rather normal IQ. These reflexes are usually the single objective clinical findings in all forms of mild and occult disorders of the CSF dynamics, i.e., low-pressure hydrocephalus syndromes, cerebral atrophies and mixed forms cases. The next step for the diagnosis consists in a conventional IQ evaluation and a battery of tests exploring more specifically the sensorimotor integration, i.e. bimanual vs. unimanual activity, the Kohs block design test and part of the Halstead-Reitan neuropsychological test battery.


Central neuroblastic tumour associated with smooth muscle fibers. A study in the optic and electron microscopes.

The present paper is a study of a microcystic intraspinal tumour that developed in a 4-year-old child. The histologic examination showed the presence of neuroblastic elements developing next to smooth muscle fibers. The tumour had diffusely invaded the meninges, presenting a marked collagen reaction. Ultrastructurally, the neuroblastic elements exhibited an arrangement proper to the neural tube and the presence of a series of osmiophil neurosecretory dense-core vesicles. The fine structural morphology of the smooth muscle fibers was clearly revealed, the cells containing microfibrils and being delimited by a basement membrane. The muscular fibers were visibly in contact with the blood vessels. These aspects demonstrate that the medullomyoblastoma is a malignant bidermal teratoid tumour of the central nervous system. Dysgenesis of the ectomesenchyma may be considered to stand at the basis of the development of this type of tumour.


A case of late onset lipid storage myopathy. Electromyographic, histochemical and ultrastructural findings.

A 65-year-old woman showed the clinical picture of a myogenic myopathy, confirmed electromyographically. Detailed histopathological, histochemical and ultrastructural studies were performed on deltoid and quadriceps femoris biopsy specimens. Many muscle fibres were found to contain vacuolar spaces with lipid droplets: perivascular inflammatory changes were also observed. The affected fibres were consistently type I. Under the electron microscope the fibres contained large numbers of lipid droplets, usually next to normal mitochondria. A slight improvement occurred after prednisone therapy.


Cerebrospinal fluid spectrophotometry and computerized transverse axial tomography (EMI scanning) in cerebrovascular diseases. Comparative study between two actual diagnostic methods in cerebrovascular disorders.

51 patients with cerebrovascular diseases were examined by CSF spectrophotometry (CSF-SPE) and computerized transverse axial tomography (CTAT: EMI scanning), most cases being followed by several examinations. Specific diagnoses were detected in 98 (CSF-SPE) and 75% (CTAT) of the cases, generally by only one examination. In cases examined angiographically or by isotope encephalography, the corresponding figures were 50 and 0%. The combination of CSF-SPE and CTAT examination obviously means a breakthrough in diagnosis of cerebrovascular diseases which is naturally a prerequisite for the more rational therapy of these common and frequently disabling disorders.


Motor lesions in herpes zoster. Incidence and special features.

In the review of 117 patients hospitalized for herpes zoster (HZ) during the 10-year-period of 1960-1969, six patients with motor paralysis of the limbs were found. The incidence of motor paralysis in HZ which ranges in the literature between 0.5 and 31%, was 18% in our series. Reasons for these differences are discussed. An uncommon feature, local recurrence of HZ with motor deficit pertaining to the same segments is reported, and joint subluxation, a rare complication of motor HZ, is also described. The importance of looking for diaphragmatic paralysis and motor deficit in the thoracoabdominal segments, not readily revealed in routine examination, is stressed.


Treatment of parkinsonism with l-dopa and a decarboxylase inhibitor. An electrophysiological and clinical study.

Twelve parkinsonian patients with an unsatisfactory therapeutic result on L-Dopa alone due to nausea, vomiting and involuntary movements were treated WITH L-Dopa and decarboxylase inhibitor. The daily dose reached 800mg L-Dopa and 200 mg decarboxylase inhibitor. Single doses of each of the components were also given. Electrophysiological examination of hypokinesia, tremor and rigidity, and clinical observation revealed clear evidence of rapid improvement on small doses of L-Dopa combined with decarboxylase inhibitor. Most of the improvement occurred during the 1st week before the maximal dose was reached. A single oral dose of decarboxylase inhibitor resulted in an improvement, suggesting the presence in the organism of a small AMOUNT OF L-Dopa. This work also shows the absence of liver toxicity of the drug used. Elimination of the extracerebral side effects nausea and vomiting in our opinion is a principle advantage of the compound compared to L-Dopa alone, wheras abnormal involuntary movements, which were found in all patients, remain the limiting adverse side effect.


Myogenic scapuloperoneal syndrome - muscular dystrophy in the K. kindred. Reexamination of the K. family described for the first time by Oransky in 1927.

Additional study of six generations belonging to the K. kindred, which were previously investigated by Oransky in 1927 was carried out. 18 members of this kindred were studied. At the early stages of the disease a sharp dissimilarity of the phenotypes in the K. kindred resulting from the different rate of the development and intensity in the course of the disease was observed, varying from evident scapuloperoneal amyotrophy to the cases resembling Landouzy-Déjerine muscular dystrophy. At the late stages of the disease a considerable clinical simularity of those affected was noted. The clinical and genetic data allowed at the present time to consider the muscular dystrophy in the K. kindred as one of the varieties (namely, as a descending type with a "jump") of the facio-scapulo-limb (or facioscapulohumeral) muscular dystrophy. The scapuloperoneal syndrome could be a long stage in the development of the disorder in some members of the K. kindred.


Electrophysiological abnormalities in cases of dystrophia myotonica.

EMG, nerve conductions, repetitive nerve stimulation and SSEPs were studied in 14 patients with dystrophia myotonica. Fibrillation potentials were seen in two of these patients. Motor nerve conduction velocities of the medial popliteal nerve were decreased in 4 of the 13 patients studied. Three of these patients also showed decrease in the antidromic sensory conduction velocities. Motor conduction velocities of the lateral popliteal nerve were similarly reduced in four patients. Taking both  the nerves into consideration, 6 of the 14 patients showed a decrease in the motor nerve conduction velocities of either, or both, of these nerves. Repetitive nerve stimulation showed abnormal responses in 13 of these 14 cases. SSEPs from stimulation of the lateral popliteal nerve showed increased latencies in three of the ten cases studied. Sensory conduction velocities as measured from SSEPs were decreased in three of the four cases. SSEPs for the medial popliteal nerve showed similar values. The significance of these abnormalities has been discussed.


Unusual motor conduction velocity values in Charcot-Marie-Tooth disease associated with essential tremor: report of a kinship.

In the cases of Charcot-Marie-Tooth disease associated with essential tremor so far reported, motor conduction velocity studies strongly suggested that demyelination was a prominent feature of the neuropathy. For the first time two sibs are reported in whom the electrophysiological changes favour axonal degeneration as the main trait of their peripheral neuropathy.


Influence of long-term anesthesia on regional blood flow distribution and hemodynamics in the dog.

The effects of 8 h sodium pentobarbital anesthesia on the cardiovascular function and blood flow distribution have been studied on dogs under controlled ventilation. A myocardial depressant action was registered in heart rate, cardiac output and left ventricular work, compensated by an increased peripheral resistance. Blood flow distribution judged by 15 mum carbonized microspheres revealed reduction of the fraction of the blood distributed to the brain. Simultaneously infused microspheres of 15 and 50 mum showed arteriovenous shunting of the smaller spheres compared to the larger through the heart, kidneys, stomach, small and large intestine and the brain. Correspondingly increased fractions of the smaller microspheres were found in the lungs and the liver. The preportal arteriovenous shunting to the liver was larger after 8 h of pentobarbital anesthesia than after 20 min or in conscious dogs.


Hemorrhagic shock in dogs without major pulmonary changes.

Dogs were submitted to one of three hemorrhagic shock procedures: normovolemic shock, oligemic hypotension or posthemorrhagic hypotension. 13 animals fulfilled well-filled criteria of irreversible hemorrhagic shock, based on mortality, take-up volume and metabolic changes. Lung function was measured at regular intervals. Lungs were fixed by infusion fixation. The macroscopial aspect of the lungs was not different from that of six control dogs which were anesthetized for the same period. Minor microscopical changes were found, but the only histological parameter which was significantly different from the controls was accumulation of granulocytes. Gas exchange remained normal, ventilation was increased with an enlarged dead space and veno-arterial shunting was reduced. Pulmonary vascular resistance was not different from the control group.


Effect of acute ischemia on the motility of the small bowel in the awake dog.

The effect of acute ischemia obtained by clamping the feeding arteries was studied on a 30-cm loop of upper jejunum in mongrel dogs. In order to eliminate the side-effects of anesthetics on the small bowel, the studies were performed on the awake dog, where access to the upper jejunum was permitted by the construction of a jejunostomy with a Roux-en-Y anastomosis for reestablishment of intestinal continuity. The motility was estimated after stimulation of the mucosa with a standard bolus of isotonic 0.1 N HCl. This technique presented the advantage of a much higher reproducibility than the usual recordings of the spontaneous motility alone. Acute ischemia caused an immediate hyperexcitability of the segment of jejunum under study despite complete destruction of the mucosa followed by an irregular hyperexcitable pattern during the first 48 h after injury. The controls on the other hand presented a strongly diminished response to stimulation with a slow recovery.


Surgical aspects of spleen grafting in rats.

Grafting of the spleen as an organ of full immunological competence in inbred rats was found to be a useful tool for studies of immunological parameters, which would be difficult to evaluate in outbred and larger animals. Early results indicate that the spleen is under certain circumstances less susceptible to rejection than other organs in the rat and knowledge about principles, underlying this phenomenon, might have application for grafting of organs in other species. Experimences gained in grafting more than 400 rat spleens heterotopically were described together with the technique employed.


Effect of portacaval transposition on hepatic function in dogs with obstruction to  the hepatic venous outflow.

Complete hepatic venous outflow obstruction (COB) in dogs resulted in impairment of hepatic function and cellular injury. Thus both the serum albumin concentration and the plasma clearance of indocyanine green (ICG) were reduced, whilst serum glycoproteins, aminotransferases and alkaline phosphatase levels were increased. Partial outflow block (POB)resulted in less severe functional changes although a significant decrease in serum albumin was also observed. The changes in liver function in dogs with portacaval transposition (PCT) and COB were generally similar to those in dogs with COB alone. However, the increases in serum enzyme activities and the decrease in plasma clearance of ICG were greater in the group with PCT. A late improvement in the clearance of ICG in dogs with COB and PCT was probably related to retrograde portal flow. When the hepatic lesion was only moderate (POB) PCT had little effect on either the liver function tests or plasma clearance of ICG, although no improvement in function was observed. It is concluded that PCT has no beneficial effect on dogs with either severe or moderate hepatic lesion and may cause further functional deterioration.


Microcirculation of the cat stomach.

Radioactive microspheres 15 mum in diameter were injected into the left ventricle of the heart of cats. Simultaneously a blood sample was drawn from the aorta. Standardized samples of the stomach wall were separated into mucosa and muscularis samples. For each sample the blood flow was calculated in terms of ml/minute/100 g tissue weight. The distribution of microspheres to different layers of the samples was determined microscopically. In the mucosa samples the majority of spheres were found in the propria and glandular layer, only a few persent in the submucosa. In the mscularis samples most of the microspheres were present in the muscle tissue, only 1--9% in the submucosa fraction. The present method is considered to give a good expression of the capillary blood flow in the glandular layer of the mucosa and the muscularis.


The serum cholesterol value at birth and at the age of 5 weeks.

The cholesterol value of cord blood has been determined in 303 newborns and their mothers at parturition. The mean value was 72 mg/100 ml for the newborns and 253 mg/100 ml in the mothers. By multiple regression analysis it has been shown that a significant independent correlation exists between cord blood cholesterol and the cholesterol of the mothers, birth weight, sex and the blood group of the ABO system of both the newborn and the mother. This demonstrates that several factors known to influence cholesterol in adult life are already operating at birth. Within 1 month the mean serum cholesterol value rises from 77 mg/100 ml at birth to 131 mg/100 ml in 45 infants in whom it was measured.


Angiographic determination of left ventricular muscle mass in the dog.

Left ventricular (LV) cineangiography in the right anterior oblique projection was carried out in 7 dogs. Calculation of LV muscle mass (LMM) was based on the determination of end-diastolic volume (EDV) and posterior wall thickness (h). Three different procedures of calculation were used. (A) EDV was determined according to the technique of Greene [8]; h was assumed to be equal around the LV cavity. (B) Systematic overestimation of EDV by Greene's method was corrected according to the regression equation proposed by Bentivoglio [9]; h was the same as in A. (C) EDV was corrected as in B; h at the ends of the long axis was assumed to be only half of that at the minor axis (i.e. h/2). The calculated values of LMM (4 to 11) in the individual dogs were averaged and compared with the true LMM determined at autopsy. True LMM in 7 dogs was 96 +/- 6 g (SE). Method A yielded 122 +/- 9 g (P less than 0.01) and method C 91 +/- 6 G (P greater than 0.05). Linear regression analysis between calculated and weighed LMM yielded a correlation coefficient of 0.936 in A, 0.938 in B and 0.931 in C. The SEE was 8.8 g, 7.5 g and 6.6 g, respectively. It is concluded that LMM can be determined with reasonable accuracy from linear regression equations whereby method C appears to be the preferable mode of calculation (smallest SEE).


Early hemodynamic adaptations to physical training in patients with healed myocardial infarction.

Seven patients with coronary heart disease (CHD) but no angina pectoris had hemodynamic studies at rest and during submaximal and maximal exercise levels 2 mth after an acute uncomplicated myocardial infarction. The hemodynamic study was repeated after 3 mth of regular physical training. Maximal oxygen intake (VO2max) increased by 16.1% after physical training while maximal heart rate unsignificantly decreased (minus 3.3%). Higher VO2max after training resulted from an increase in maximal cardiac output (+7%) and stroke volume (+9.2%) and from a widening of the maximal arterio-venous oxygen (A-VO2) difference (+7.3%). The fall in stroke volume observed from submaximal to maximal exercise level was not affected by training. During submaximal exercise, the lower heart rate after training was attended by both a greater stroke volume and a wider A-VO2 difference; the cardiac output slightly decreased. We conclude that the increase in VO2max observed with early physical training in CHD results on one hand from an increased stroke volume whose specificity is not established, and on the other hand from a wider maximal A-VO2 difference; the latter is entirely due to a greater extraction of oxygen from the blood by the working muscles during maximal exercise.


Electrophysiologic effects of new ester of ajmaline 17-monochloroacetyl ajmaline hydrochloride (MCAA).

A new ajmaline ester, 17-monochloroacetyl ajmaline hydrochloride (MCAA) which has shown important clinical antiarrhythmic effects was studied in 20 isolated perfused rabbit hearts. Transmembrane potentials were recorded in atrial ventricular and A-V junctional fibers before and after perfusion of 3 mg/l of MCAA. There was a significant decrease in the action potential amplitude (81.1 plus or minus 6.0 to 75.2 plus or minus 5.8mV) overshoot (23.1 plus or minus 5.9 to 16.1 plus or minus 2.9mV) and maximum rate of depolarization (63.4 plus or minus 30.8 to 40.7 plus or minus 19.7 V/sec) and an increase in the action potential duration (119.8 plus or minus 12.6 to 135.6 plus or minus 25.1 msec). The strength interval curve was shifted to the right by MCAA. Conduction was increased in the atria and AV junction but not in the His-Purkinje system. MCAA appears to be a quinidine-like agent except for His-Purkinje conduction. This agent could offer important antiarrhythmic effects in atrial and ventricular arrhythmias.


Acute idiopathic pericarditis in the aged.

Eleven elderly patients with idiopathic pericarditis are reported. All but one were older than 60 yr. Evidence of ischemic cardiovascular disease was present in 8 patients. The initial diagnosis was heart failure with pulmonary complications in 4 cases and myocardial infarction in 3. Respiratory infection preceded the onset of pericarditis in 5 cases. Presenting symptoms were typical precordial pain, fever and dyspnea. Pericardial friction was found in 7 cases and transient rhythm disturbances in 5. Four patients had ST elevation and 3 had ST depression in their electrocardiograms. Other findings included  an increased sedimentation rate, leukocytosis, elevated venous pressure and normal SGOT levels. Antibiotics were of no avail but prednisone had a dramatic effect. Two patients had a relapsing course lasting 2 yr or more. One patient, who died at the age of 75 from bleeding ulcer, had patent coronary arteries and mild perimyocardial fibrosis. The diagnosis of idiopathic pericarditis in the aged is difficult because the disease simulates ischemic heart disease in patients who frequently have evidence of arteriosclerotic cardiovascular involvment.


Syndrome of short P-R, narrow QRS and repetitive supraventricular tachyarrhythmias: the possible occurrence of the R-on-T phenomenon and the limits of this syndrome.

The R-on-T phenomenon was observed in two patients with narrow QRS complexes and repetitive supraventricular tachyarrhythmias. Case 1 had a typical Lown-Ganong-Levine syndrome in which the shortening of the P-R interval was due to a reduction of the A-H interval. In Case 2 the P-R interval (140 msec) was not short but the A-H interval was at the lower limits of normal (50 msec) and the P-A interval at the upper limits of normal (40 msec). Both patients showed the R-on-T phenomenon during periods of 1:1 A-V conduction occurring during atrial stimulation at a rate of 200/min (Case 1) and atrial flutter with a rate of 300/min (Case 2). Although total A-V conduction time was prolonged, the magnitude of this prolongation appeared to have been less than that occurring in normal subjects. This was attributed to the presence of an accessory pathway bypassing the area where the most significant delay occurred at the A-V node. The findings in Case 2 suggest, but do not prove, that a similar bypass might be operative in patients with atrial flutter with periods of 1:1 conduction, regardless as to whether the R-on-T phenomenon is, or is not, present.


Mitral insufficiency complicating acute myocardial infarction.

The pathological processes underlying the symptom of mitral insufficiency appearing during the course of acute myocardial infarction are reviewed. The mitral valve apparatus can be considered as being composed of fibrous elements (the annulus fibrosus, the valve leaflet and the chordae tendineae), the left atrial endocarduim and the muscular elements (the papillary muscles together with their supporting myocardium). Since the fibrous elements are avascular, it is concluded that they are unlikely to be directly affected by ischemia. For this and other reasons dilatation of the mitral annulus is not considered a cause of incompetence. It is suggested that muscular involvement is the most likely cause of mitral incompetence during acute myocardial infarction. The syndrome of 'papillary muscle dysfunction' is therefore reviewed under the headings of (1) conditions producing abnormal spatial orientation of the muscles, (2) conditions producing abnormal or absent contraction of the muscles and (3) conditions producing improper timing of muscular contraction. Cases are illustrated which demonstrated generalized dilatation of the left ventricle, localized dilatation and both complete and imcomplete papillary muscle rupture. Mitral insufficiency under these circumstances may ensue from either improper orientation or improper functioning of the muscular elements of the mitral valve apparatus, or from both. It is also emphasized that direct involvement of the papillary muscles by the ischemic process is not necessary for incompetence to occur, and that most cases of mitral incompetence complicating the acute stage of myocardial infarction are of transient nature, resolving during the recovery phase.


Hepatic balances of glucose and insulin in response to physiological increments of endogenous insulin during glucose infusions in dogs.

Hepatic glucose uptake was measured in dogs in relation to physiological increments of plasma insulin levels under steady state conditions. Endogenous insulin secretion was stimulated by the infusion of small glucose loads, achieving normoglycaemia or mild hyperglycaemia. The measurement of hepatic arterial and portal venous blood flows allowed calculation of the relationships between net hepatic balances of insulin and glucose, the magnitude of insulin extraction by the liver and the hepatic sensitivity to physiological levels of insulin. During normoglycaemia, small glucose loads (2 and 4.5 mg/min. kg) reduced hepatic glucose output without a concomitant increase of the estimated total glucose utilization. No changes in arterial or hepatic venous plasma insulin levels occurred. Portal venous plasma insulin alone rose under the influence of the glucose stimulus. In the presence of hyperglycaemia, the liver further reduced its glucose output. Infusions of 11.3 mg/min. kg glucose resulted in reversal of hepatic glucose output to a net uptake of glucose. However, due to the large amounts of insulin emerging from the liver, peripheral tissue glucose utilization was significantly increased. A strong inverse correlation existed between arterial glucose concentration and hepatic glucose output as well as between portal venous plasma insulin level and hepatic glucose output. The net hepatic balance of insulin was promptly raised in response to the glucose perfusions, even when normoglycaemia was maintained. A highly significant, inverse correlation was demonstrated between net hepatic balance of insulin (i.e. net uptake of insulin by the liver) and hepatic glucose output. Hepatic insulin extraction ratio and hepatic plasma insulin clearance increased during glucose administration but no evident relationship to portal venous plasma insulin levels was found. These data suggest that insulin rather than glucose is the primary agent responsible for the reversal of the hepatic gradient of glucose in vivo.


Double isotope measurement of peritoneal clearance of iodide and albumin loss during peritoneal dialysis in man (labelled albumin loss in peritoneal dialysis).

131I-labelled Human Serum Albumin and 125I-sodium iodide were used to measure protein loss from the peritoneum and peritoneal clearance of iodide in a group of 8 uraemic patients, each one being studied after a different number of dialyses. Both albumin loss and iodide clearance reached a maximum at about the 10th dialytic treatment and then tended towards the initial levels. Protein loss as determined isotopically was markedly lower than indicated by direct radioimmunoassay measurements performed in three cases. Fitting experimental points by a model which assumes direct passage of protein from plasma to peritoneal cavity suggests the presence of a "delay" pool between plasma and the peritoneal cavity itself (extravascular sites adjacent to peritoneum?). The shorter retention time of the dialysis solution in the abdomen (4-8 minutes) seemed to us to cause lower protein losses than reported by authors using longer retention times.


Effects of oral contraceptive therapy on the circadian patterns of cortisol and thyrotropin (TSH).

The daily variation of serum cortisol and thyrotropin (TSH) has been simultaneously recorded every 30-min. in 4 women taking the same oral contraceptive containing oestrogens and progestogens and in 4 control women. The circadian rhythm of cortisol persisted under contraceptive therapy with about a 2.5 fold elevation of the mean level and amplitude of the basal rhythm. Theoretical equilibrium calculations of the circadian variations of the free, transcortin-bound and albumin-bound cortisol fractions showed that these elevations are explained qualitatively and quantitatively by an oestrogen-induced increase of the same order of the transcortin cortisol-binding sites. As a consequence of the already high saturation of transcortin in normal conditions, the magnitude of the variation of free cortisol level resulting from a burst in cortisol secretion varies with the time of day. The role of albumin as a buffer is thereby emphasized. The early morning maximum, characterizing the normal TSH daily pattern, appeared to be considerably enhanced in women under contraceptive therapy. If the circadian variations of TSH are driven by thyrotropin releasing hormone (TRH), these higher morning peaks probably reflect a higher burst of TRH secretion rather than an increased responsiveness of the pituitary to TRH secretion induced by contraceptive therapy. Finally these results do not support the hypothesis of a regulation of TSH circadian variations by an inhibiotry action of cortisol. Contraceptive therapy does not appear to play a role at the level of the central clock or on the resetting mechanism.


Glucuronidation in cultures of human skin epithelial cells.

Glucuronidation of p-aminophenol, p-nitrophenol and bilirubin has been investigated in cultures of human skin epithelial cells (HE cells) and human skin fibroblasts (FB) and in homogenates from the same cells. HE cells in culture glucoronidated p-aminophenol and p-nitrophenol at rates of about 5 and 10 nmol/mg cell protein per h respectively. Bilirubin was not conjugated by HE cells. In homogenates from HE cells supplemented with UDP glucuronic acid (UDPGA) both p-aminophenol and p-nitrophenol were glucuronidated at about the same rate as by living cells in culture. Assuming that the transferase activity is the same in the whole cells compared to the homogenates, transferase activity and not UDPGA production may be the limiting factor in glucuronidation of p-aminophenol and p-nitrophenol in these cells. The glucuronidation rate of HE cells was not increased by benzpyrene or benzanthrazene. FB did not glucuronidate p-aminophenol, p-nitrophenol or bilirubin.


Hepatic cholesterol synthesis in man: effect of diazepam and other drugs.

The hepatic synthesis of cholesterol-measured as incorporation of 14C-acetate into digitonin-precipitable sterols-has been evaluated in needle biopsy material of normal untreated patients and patients under short-term treatment with Diazepam, Phenobarbital, Chlorpromazine or Diphenylhydantoin. A significant increase of cholesterol synthesis was observed in the first two groups with much higher levels of incorporation in the Diazepam-treated patients. Moreover in this group the levels were still elevated from 4 to 7 days after drug withdrawl. Ultrastructural and morphometric studies performed on the same biopsy material showed a significant increase of smooth endoplasmic reticulum in hepatocytes of Diazepam-treated patients; in addition, there seemed to be a positive correlation between the increased cholesterol synthesis and the formation of areas of non vesicular, type 2, smooth endoplasmic reticulum. These findings suggest an early stimulation of the liver cell microsomal system by Diazepam in man; they also point to side effects of some drugs, which are not predictable from studies in Wistar rats.


Lack of effect of cholestyramine on the pharmacokinetics of clofibrate in man.

The study was undertaken to determine whether cholestyramine (16 g daily) interfered with clofibrate absorption when the two drugs were given together. Fifteen patients taking 1 g of clofibrate twice daily (for 2 to 416 weeks) participated in the study. Clofibrate (as the acid, p-chlorophenoxyisobutyric acid, CPIB) was quantified by thin-layer and gas-liquid chromatography. In patients taking clofibrate only, mean plasma CPIB concentration before the morning dose of clofibrate was 123 mug/ml. Peak levels were reached 3.5 hours after drug intake, the mean peak plasma CPIB concentration being 193 mug/ml. Absorption of CPIB exceeded 99%. Ninety-eight percent of the daily CPIB-intake was excreted in the urine, 61% being conjugated. In vivo degradation of CPIB did not occur. Free and conjugated CPIB was present in bile (mean fasting level being 55 mug/ml. The decay of radioactive CPIB in plasma was not log-linear: the mean t 1/2 of the first exponential was 0.45 hours, and of the second 15.1 hours. The pool size in 3 patients 3 hours after the morning dose of clofibrate was 1054 mg. CPIB was not detectable in adipose tissue, and kinetic data gave no hint of drug accumulation in patients on long-term therapy. In 6 patients given cholestyramine together with clofibrate, there was no significant alteration in fasting plasma CPIB levels, 24-hour urinary and faecal excretion of CPIB or in the half-life and pool size of the drug. A short delay in reaching peak plasma CPIB levels was the only consistent finding.


Deoxyribonucleoside triphosphates in human cells: changes in disease and following exposure to drugs.

Deoxyribonucleic acid synthesis requires adequate cellular concentrations of the four deoxyribonucleoside triphosphates. Using a sensitive enzymic assay, we have measured the concentrations (pools) of these compounds in human bone marrow cells and in lymphocytes. The mean concentrations (pmol/10(6) cells) in normal human bone marrow cells were: deoxyadenosine triphosphate (dATP) 1.5; deoxyguanosine triphosphate (dGTP) 0.4; thymidine triphosphate (dTTP) 1.4 and deoxycytidine triphosphate (dCTP) 0.6; and in normal phytohaemagglutinin (PHA)-stimulated lymphocytes (72 h cultures); dATP 3.7; dGTP 1.9; dTTP 9.4 and dCTP 2.9. The deoxyribonucleoside triphosphate concentrations were increased approximately threefold in the nucleated marrow cells from patients with leukaemia and myeloproliferative diseases. PHA-stimulation of lymphocytes caused a marked increase of the deoxyribonucleoside triphosphate concentrations, particularly of dTTP, between 24 and 48 h of culture. In PHA-stimulated lymphocytes, the antifolate drugs methotrexate, pyrimethamine and trimethoprim, all produced a fall in dTTP and a rise in dATP concentrations within 1 h. These effects could be reversed by folinic acid. 5-Fluorouracil caused a fall in dTTP and in dCTP but no consistent changes in dATP; hydroxyurea caused a fall in dATP with a rise in dTTP. BCNU caused a significant fall in dATP and dCTP. Dibutyryl cyclic 3', 5' adenosine monophosphate and theophylline had no consistent effect on the deoxyribonucleoside triphosphate concentrations. 6-Mercaptopurine caused a fall in dATP and dGTP, the fall in dATP being marked after 4 h incubation. It is concluded that measurement of the deoxyribonucleoside triphosphates in human cells provides a new method of studying DNA synthesis in human disease states and of analysing the action of antimetabolite drugs on normal and diseased cells.


Defective thyroglobulin endocytosis and hydrolysis in thyroid cold nodules.

The catabolic phase of thyroid secretion has been studied by incubating thyroid slices with 0.1 % 125-I thyroglobulin (Tg) in the following cases: 11 follicular adenomas (FA), 8 hyerplastic nodules in multinodular glands (NM), 3 carcinomas (follicular or papillary, FC, PC) and normal (N) or micronodular tissue (M). Tg pinocytosis is severely impaired in all cold nodules (25 to 60 % reduction). In the follicular tumours (FA, FC), Tg hydrolysis is more affected than would be expected based only on reduced Tg endocytosis: the hydrolysis products remain in the phagolysosomes instead of being secreted. As far as the acid hydrolases are concerned these enzymatic activities are increased in nearly all nodules, in particular in follicular adenomas and carcinomas.


Turnover of a prostaglandin precursor, arachidonic acid, in rheumatoid arthritis.

The plasma concentration and the turnover of free arachidonic and oleic acids were determined in patients with rheumatoid arthritis and in control subjects. The plasma level of free arachidonic acid, but not of oleic acid, was significantly decreased in male rheumatoid patients. Female patients did not differ from healthy subjects in this respect. Following treatment with indomethacin, a significant increase in the plasma concentration of free arachidonic acid was observed in rheumatoid patients of both sexes. It is suggested that the findings in the rheumatoid patients reflect a partial exhaustion of the pool of arachidonic acid serving as precursor in the synthesis of prostaglandin.


Differences among hyperlipoproteinaemic subjects in the response of lipoprotein lipids to resin therapy.

Ih has been reported that cholesterol turnover is raised when hypercholesterolaemia occurs in association with elevated levels of very low density lipoprotein, but normal when hypercholesterolaemia reflects an increase in the concentration of low density lipoprotein alone. The relationship of plasma lipoprotein levels to cholesterol metabolism has been further investigated in the present experiments, in which the acute effects on lipoprotein lipids of stimulating cholesterol turnover with a bile acid-sequestering resin, colestipol, have been compared in normal subjects and in patientw with four types of hyperlipoproteinaemia.  Very low density lipoprotein (VLDL) lipids increased in every subject. The increase was greatest in patients with type IV or type V hyperlipoproteinaemia, least in normal subjects and in those with type IIa hyperlipoproteinaemia, and intermediate in patients with type IIb hyperlipoproteinaemia. The induced increments in VLDL cholesterol and triglyceride mass were accordingly positively correlated with the pre-treatment concentrations. Low density lipoprotein (LDL) lipids decreased during resin therapy in all subjects, except those with type IV or type V hyperlipoproteinaemia in whom there was a transient rise. The reductions in LDL cholesterol were significantly greater in patients with type II hyperlipoproteinaemia than in the normal volunteers, and in both groups of subjects were proportionately greater than those in LDL triglyceride. These findings demonstrated clear differences among the hyperlipoproteinaemias in the response of lipoprotein lipids to resin therapy, and profide further evidence for the heterogeneity of cholesterol metabolism in these conditions. The colestipol-induced changes in type UV and type V patients could be partially reproduced in normal subjects during the consumption of high carbohydrate diets, which might be expected to increase VLDL synthesis. It is suggested, therefore, that the synthesis of VLDL cholesterol may be enhanced in such patients, and that any rise in LDL cholesterol observed during resin therapy reflected subsequent metabolism of VLDL to LDL rather than diminished LDL cholesterol clearance.


Human milk lipases. III. Physiological implications of the bile salt-stimulated lipase.

Human milk contains a bile salt-stimulated lipase in amounts that, at pH 6.5 and in the presence of bile salts, might account for a total hydrolysis of the milk triacylglycerols in less than 30 min. In the absence of bile salts the enzyme has no activity against milk fat or against emulsified trioleylglycerol. The primary bile salts sodium cholate and sodium chenodeoxycholate and their taurine and glycine conjugates, but not the secondary bile salt sodium deoxycholate or its taurine and glycine conjugates, caused a pronounced activation of the enzyme against emulsified trioleylglycerol. The lipase was stable at pH 3.5 and 37 degrees C for 1 hour. It was inactivated when incubated with trypsin or chymotrypsin at pH 6.5 but these inactivations were almost abolished in the presence of bile salts. High concentrations of pepsin slowly inactivated the enzyme at pH 4.0. The bile salt-stimulated lipase in human milk is thus stable enough to be active in the intestine, and it is present in high enough activity to contribute significantly to the hydrolysis of the milk triaclyglycerols in the intestine.


The glucose-induced gastrointestinal stimulation of insulin secretion in man: relation to age and to gastrin release.

An oral 50 g glucose tolerance test and a simple intravenous glucose infusion test were performed in 20 young (20 - 32 years), 20 middle-aged (42 -55 years), and 20 old (65 - 81 years) normal subjects. Blood glucose, serum insulin, and serum gastrin concentrations were measured during all tests. The intravenous glucose infusion duplicated the oral blood glucose curve in young, middle-aged, and half of the old subjects. In the remaining old subjects the intravenous blood glucose curve was below the oral blood glucose curve. Glucose and insulin concentrations were of similar magnitude in all groups, but maximum concentrations were reached later in the old subjects. Glucose per os induced a rapid rise in serum gastrin concentrations of the order of 10 pmol/1 and a subsequent decrease of about 20 pmol/1 in all groups. The  intravenous glucose infusion induced no significant changes in serum gastrin concentrations. The non-glycaemic (i.e. enteral) stimulation of insulin secretion was expressed as the difference between the integrated incremental areas of the oral and intravenous insulin curves in subjects with identical glucose curves during the two tests. This stimulation was of similar magnitude in all age groups, and it was not correlated to variations in gastrin concentrations. However, in the young subjects the enteral stimulation was greater during the first 30 minutes and smaller during the two last hours when compared to the old subjects. The results suggest that: 1. A simple intravenous glucose infusion test can be used to copy the oral blood glucose curve. 2. The size of the enteral stimulation of insulin secretion during the whole test is independetn of age. 3. The action of the glucose-induced enteral stimulation is delayed with age, and closely linked to the dynamics of the glycaemic stimulus. 4. The glucose-induced gastrin release is probably too small to affect insulin secretion significantly.


Is phlorizin or its aglycon the inhibitor of intestinal glucose transport? A study in normal and lactase deficient man.

Inhibition of glucose transport by phlorizin was examined in man by perfusion of an isolated small bowel segment. Inhibition was similar in normal and lactase deficient subjects. Since the small bowel of lactase deficient subjects contains only very small amounts of phlorizin hydrolase, phlorizin and not a product of enzymatic cleavage is the inhibitor of the small intestinal glucose carrier.


The growth hormone response to insulin induced hypoglycaemia in anorexia nervosa and control underweight or normal subjects.

Hypoglycaemic stimulation of growth hormone (GH) secretion has been measured in 12 anorexia nervosa patients, 11 adolescents approximately matched for weight and age, 14 underweight adults with no history of anorexia nervosa and 27 normal patients. The results showed a high proportion of blunted growth hormone responses among the anorexia nervosa patients as compared to normal subjects, underweight adolescents or adults. In the group of underweight adults, diminshed growth hormone responses were most frequently seen in patients with depressive illness. The complex pathogenesis of the diminshed growth hormone response in anorexia nervosa involves many factors; undernutrition itself, possible hypothalamic insufficiency related to the psychopathological background and other endocrine abnormalities like hypogonadism, relative hypercorticism and hypothyroidism. The interference of the nutritional, psychological and endocrine factors could not be dissociated in our investigation or from the review of the literature on this subject. It is suggested that hypothalamic insufficiency plays a prominent role in the growth hormone hyporesponsiveness in anorexia nervosa. Although diminished, the stimulated growth hormone response remains higher in anorexia nervosa than in true hypopituitarism. This phenomenon coupled to a preserved or even increased suprarenal function enables one to differentiate cachexia resulting from anorexia nervosa and hypopituitarism leading eventually to cachexia.


Immune complex deposits in systemic lupus erythematosus kidney without histological or functional alterations.

This study demonstrates that in systemic lupus erythematosus (SLE), the presence of immune complexes on the glomerular basement membrane (GEM) does not invariabley result in histological and/or functional lesions of the kidney. Among a group of 29 lupus patients, six subjects were selected for thorough investigation, because their renal function was normal or only slightly altered though they had suffered from SLE for 20 months to 18 years. All patients had antinuclear factor, anti-native-DNA antibody and a low level of complement; 3 had anti-denatured-DNA antibody, 2 had denatured DNA-anti-denatured-DNA circulating complexes and 3 had anti-RNA-protein antibody. Kidney biopsies disclosed either no histological lesion or minimal changes in five of them and diffuse proliferative glomerulonephritis in one. By contrast, using the immunofluorescent technique, granular deposits containing the third component of complement (C3) were found on the GBM of all patients; IgG was present in 5 cases, IgM in 3, fibrinogen in two cases and around the tubules of one. Electron microscopy confirmed the presence of subendothelial and mesangial deposits. Our results also showed a good correlation between the importance of deposits and the presence of denatured DNA-anti-denatured-DNA circulating complexes. From the data obtained in these 6 cases as well as in the 23 other patients of the group, 3 categories of lupus patients could be distinguished with regard to kidney involvement: 1) patients with insignificant histological lesions, no immune deposits and essentially normal function; 2) patients with definite histological lesions, immune deposits and renal insufficiency and 3) patients with few if any histological lesions and little functional impairment contrasting with important immune deposits. The resistance of some patients to the mephrotoxic effects of immune deposits shows that lupus nephritis depends on intricate pathogenic mechanisms and suggests that these are possible antagonized by "protective" factors.


Liver blood flow and blood volume following chronic phenobarbitone administration.

Mlae rats were ra&ndomly divided into 2 groups one of which received 30 mg/kh phenobarbitone for 4 days i.p. and the other sodium chloride. Liver blood flow was measured 24 hr following the last injection of phenobarbitone or sodium chloride using the radioactive colloidal gold clearance technique. In addition, blood volume, liver weight and extraction of radioactive gold were estimated. Following 4 daily infections of phenobarbitone the body weight and the blood volume of both groups were not significantly different. The liver weight in the phenobarbitone treated groups was 27% higher than that found in the control group. Liver blood flow increased from 22.7 ml/min (92,8 ml/min/kg body weight) to 30.1 ml/min (123.7 ml/min/kg body weight). This increase of 33% was highly significant (p less than 0.005). In contrast, the extraction of radioactive gold was 11% lower in the phenobarbitone treated groups than in the controls. The earlier, semiquanititative finding of increased blood flow using a chronic implanted thermocouple could thus be quantified by the present study.


Biphasic action of ethanol on contraction of skeletal muscle.

Ethanol (160-640 mM) produces a biphasic action on the indirectly stimulated rat phrenic nerve--diaphragm preparation. This consists of a potentiation followed by a blockade of muscle contraction. Concomitant with the increase in the force of contraction was the appearance of multiple neural action potentials recorded antidromically in response to a single nerve stimulation. In stimulated curarized muscle only blockade was observed. There was no difference in the degree of blockade between directly and indirectly stimulated preparations. We conclude that the potentiation of muscle contraction strength is produced by a facilitatory action of the drug on the motor nerve terminal and the blockade of contraction is produced by an action of the drug directly on the muscle fibers.


Central inhibitory effect of alpha-methyldopa on blood pressure, heart rate and body temperature of renal hypertensive rats.

The central inhibitory effect of alpha-methyldopa on blood pressure, heart rate and body temperature was studied in conscious renal hypertensive rats. Systemic administration of alpha-methyldopa decreased mean arterial blood pressure and body temperature and caused a short lasting increase in heart rate followed by a long lasting decrease. Inhibition of central decarboxylase activity prevented the decrease in blood pressure, heart rate and body temperature but not the initial increase in heart rate. Inhibition of peripheral decarboxylase activity blocked the increase in heart rate and partially reduced the decrease in heart rate and body temperature but did not affect the decrease in blood pressure. Alpha-Methyldopa also decreased blood pressure at an ambient temperature of 30 degrees C, but the decrease of body temperature was absent and the heart rate remained elevated for 7 hr. Similar results were obtained in normotensive rats. The decrease in heart rate was correlated with the decrease in body temperature in normotensive and renal hypertensive rats. These findings suggest that in the renal hypertensive rat the decrease in blood pressure and in body temperature depends on a central action of alpha-methyldopa metabolites.


Inhibition of prostaglandin biosynthesis as the mechanism of analgesia of aspirin-like drugs in the dog knee joint.

A method has been developed to measure the analgesic action of aspirin-like drugs in knee joints of anaesthetized dogs. Bradykinin, injected into the joint cavity, induced a reflex rise in blood pressure which was dose-dependent; this was used as a measure of nociceptive activity. The joint cavity became more sensitive to bradykinin as the experiment proceeded, or when a low concentration of prostaglandin E1 or E2 was infused locally. The increase in sensitivity with time was prevented by local injection of aspirin or indomethacin, but that induced by exogenous prostaglandin infusion was not. Injections of carrageenin into dog knee joints increased the prostaglandin E2 content of synovial fluid by up to 160 ng per joint; indomethacin prevented this increase. These experiments support our previous conclusion that local biosynthesis of a prostaglandin (induced by mild trauma) sensitizes pain receptors to mechanical or chemical stimuli. Aspirin-like drugs are analgesic because they prevent prostaglandin biosynthesis, thereby preventing this sensitization.


Inhibition by halothane of release of norepinephrine, but not of dopamine-beta-hydroxylase, from guinea-pig vas deferens.

Halothane strikingly decreases spontaneous and electrically stimulated release of norepinephrine from the isolated guinea pig hypogastric nerve--vas deferens preparation. This depression of adrenergic discharge appears to be a direct action on the sympathetic nerve endings and may in part account for the cardiovascular depression seen during halothane administration. Although halothane depressed stimulation-induced release of norepinephrine, it did not proportionately diminish release of dopamine-beta-hydroxylase. Possible mechanisms of the dissociation between catecholamine and enzyme release are discussed.


Muscarinic receptors in rat intestinal muscle: comparison with the guinea pig.

The properties of muscarinic receptors in rat intestinal muscle have been investigated by examining the binding of 3H-propylbenzilylcholine mustard, 3H-PrBCM, a specific and virtually irreversible muscarinic antagonist. It is shown that the properties of these muscarinic receptore correspond in general closely to those observed in the guinea pig, in particular the binding curve inferred for carbachol shows the same apparent negative cooperativity, but there is a notable difference in the rate of binding 3H-PrBCM.


Effects of ruthenium red and KCL on responses of guinea pig umbilical veins.

5-Hydroxytryptamine (10(-5) M), norepinephrine (10(-5) M) and acetylcholine (10(-5) M) induced maximal contractions in isolated guinea pig umbilical vein strips. Pretreatment with ruthenium red (2.7--90 mug/ml) for ten minutes reduced 5-hydroxytryptamine and norepinephrine responses in a dose-related manner but did not affect acetylcholine-induced responses. Ruthenium red alone did not produce contractions. In the presence of KC1 (125 MM) the responses to norepinephrine and acetylcholine were enhanced significantly. The sensitivity of umbilical veins to ruthenium red may be useful in determining to what extent various vasoactive agents utilize extracellular calcium to induce contractions.


Methylphenidate effects on avoidance learning at two ages in the rat.

The major purpose of this investigation was to assess the effects of methylphenidate on avoidance learning at two ages. The subjects were 96 naive albino rats, equally divided between the sexes. One-half received daily drug administrations beginning at 47 days of age; one-half began at 87 days of age. Both groups were divided into three drug dosage levels (0.5, 1.5 and 4.5 mg/kg) and a distilled water control group. Methylphenidate was administered s.c. for a total of 18 days. Following 3 days of drug administrations only, 10 daily trials on avoidance conditioning were administered approximately 10 min after drugging to a total of 150 trials. The major findings indicated that: (1) no significant difference in avoidance response acquisition was obtained in the comparison between drug and control groups, (2) a dose effect was obtained in that the M4.5 group made siginificantly more correct responses than the M1.5 group, and (3) animals drugged beginning at 87 days made significantly more correct responses than those drugged beginning at 47 days.


Evidence that prostaglandin is responsible for the 'rebound contraction' following stimulation of non-adrenergic, non-cholinergic ('purinergic') inhibitory nerves.

The prostaglandin synthesis inhibitor, indomethacin, blocks the "rebound contractions" which characteristically follow the inhibitory responses of the guinea-pig taenia coli to non-adrenergic, non-cholinergic (purinergic) nerves and to exogenously applied ATP, without affecting the responses to periaterial adrenergic nerves. Since adenine nucleotides are known to induce prostaglandin synthesis, this result is consistent with the purinergic hypothesis and suggests that purinergic nerves may form a link with prostaglandin in the physiological regulation of a variety of organs.


Nature of neuronal uptake and noradrenaline--adrenaline effects in the isolated rat vas deferens.

Uptake mechanisms in the rat vas deferens have not yet been thoroughly investigated. In this study we show that uptake inhibition by cocaine, amantadine and desmethylimipramine induces increases in sensitivity that are greater for adrenaline than for noradrenaline. However, this does not occur when guanethidine is used. These results are clearly in disagreement with the neuronal uptake hypothesis. Uptake mechanisms in the rat vas deferens may be different from those of other tissues.


Supersensitivity of caudate neurones after repeated administration of haloperidol.

The microiontophoretic potencies of dopamine, apomorphine and alpha-aminobutyric acid were examined on caudate neurones, using the same electrodes, in control animals and animals that had received 2mg/kg/day of haloperidol for 9 days. In the haloperidol group, a greater percentage of cells were inhibited by dopamine and apomorphine, indicating the development of a post-synaptic supersensitivity.


Inhibition of antigen-induced tone in isolated trachea.

The relaxing effect of the beta-adrenoceptor stimulating agent terbutaline was studied on the spirally cut trachea from actively ovalbumin-sensitized guinea pigs. Terbutaline counteracted the antigen-induced muscular tone more effectively when added 5 min before the addition of the antigen than when added at the peak effect. The reason for the improved efficacy of pretreatment with terbutaline might be terbutaline's synergistic effect on the release of spasmogens from the preparation and on the direct relaxing effect of the muscle.


Bronchopulmonary responses to prostaglandin F2alpha, histamine and acetylcholine in the dog.

This investigation compared quantitatively the effects of prostaglandin F2alpha, histamine and acetylcholine on pulmonary airway resistance and dynamic lung compliance in the spontaneously breathing, anesthetized dog. Airway responses were evaluated by computer analysis before and after pharmacological blockade by either atropine or propranolol. In a dose range of 1.0-10.0 mug/kg i.v., prostaglandin F2alpha was the most potent bronchoconstrictor studied. At the highest dose, prostaglandin F2alpha increased airway resistance 153.3% and decreased lung compliance 55.4% from basal levels. Similar doses of either histamine or acetylcholine produced much less effect. Atropine significantly reduced the bronchopulmonary responses evoked by histamine, acetylcholine and prostaglandin F2alpha. Propranolol did not inhibit any of the respiratory effects of those bronchoconstrictors analyzed. The bronchopulmonary effects of prostaglandin F2alpha and histamine appear to be augmented by cholinergic stimuli.


Behavioral effects of 2,5-dimethoxy-4-methylamphetamine (DOM) in rats and mice.

The characteristics of the behavioral effects of 2,5-dimethoxy-4-methylamphetamine (DOM or STP) were compared with those of mescaline and methamphetamine in rats and mice. DOM significantly increased locomotor activity in an open-field situation at 0.5-1.0 mg/kg i.p., but at doses above 5 mg/kg i.p. caused biphasic changes, i.e. an initial decrease followed by an increase in motility and exploratory behavior. This hyperactivity was not accompanied by simultaneous increase in rearing. Besides, DOM induced head twitches in rats as well as in mice at doses above 0.1 mg/kg i.p., and marked backward locomotion only in rats at doses larger than 5 mg/kg i.p. The occurrence of backward locomotion might be attributable to the initial decrease in general activity. Behavioral effects of DOM were different from those of either mescaline or methamphetamine although they resembled those of mescaline in some respects.


The influence of propranolol on catecholamine-induced changes in carbohydrate metabolism in the rabbit.

In vitro evidence has indicated that isoproterenol (ISO) is more potent than epinephrine (EPI) in releasing glucose from rabbit liver slices and that propranolol (PROP) is a competitive antagonist of ISO. In contrast, dose-response data from fasted rabbits have shown that EPI is more potent than ISO in increasing plasma glucose levels and in lowering hepatic glycogen levels. Pretreatment with PROP abolished ISO-induced hyperglycemia and changes in liver and muscle glycogen levels whereas only the muscle glycogen depleting effect of EPI was altered significantly. These results suggest that factors other than stimulation of hepatic beta-receptors must be involved in EPI-stimulated depletion of liver glycogen and hyperglycemia in the intact rabbit.


Accumulation of basic drugs in 5-hydroxytryptamine storage organelles of rabbit blood platelets.

The subcellular distribution of basic substances such as mepacrine, chloroquine, chlorpromazine and imipramine was studied in rabbit blood platelets exposed to these compounds in vitro and to some in vivo. All the drugs showed a preferential concentration in the 5-hydroxytryptamine (5HT) storage organelles (5HT vesicles). Chloroquine and mepacrine accumulated more specifically in the organelles than did chlorpromazine and imipramine. After osmotic shock of the 5HT vesicles chlorpromazine sedimented mostly with the vesicular membranes, whereas the other compounds preferentially went into the supernatant. It is concluded that (a) fluorescent basic compounds such as mepacrine are rather specific markers for the 5HT storage organelles in live platelets and (b) drugs such as chlorpromazine and imipramine also have a considerable affinity for these organelles.


Development of radioimmunoassay for chlorpromazine.

Antiserum against chlorpromazine (CPZ) was produced in rabbits immunized with CPZ hapten conjugated to bovine serum albumin. The antiserum was used to develop a radioimmunoassay for CPZ. As little as 10 pg of CPZ can be detected with this radioimmunoassay. Major metabolites, CPZ sulfoxide, Nor1 -CPZ and Nor2 -CPZ are not bound significantly by the antibody unless the concentrations are very high. Although the antibody can bind 7-HO-CPZ, 8-HO-CPZ and promazine, the concentrations required to produce a 50% inhibition of 3H-CPZ-antibody binding are 5-10 times greater than CPZ. The plasma levels of CPZ and some minor metabolites in rats following administration of 10 mg/kg i.v. were determined by radioimmunoassay and showed a biphasic decay curve. Brain levels revealed that following i.v. administration CPZ traverses the blood-brain barrier rapidly and achieves peak concentration within 5 min. Plasma and brain levels can be detected for at least 24 hr.


Drugs modifying dopaminergic activity and behaviour, the EEG and epilepsy in Papio papio.

Acute changes in spontaneous motor activity, the EEG and photically induced epileptic responses have been observed in baboons (Papio papio) following the i.v. injection of drugs acting on dopaminergic transmission. Apomorphine hydrochloride, 0.5-1.0 mg/kg, produced a phase of acute excitement with accentuated vigilance and abnormal buccal motor activity lasting 30-40 min; during this phase myoclonic responses to intermittent photic stimulation were absent. After piribedil (ET 495, 1,2'' -pyrimidyl-4-piperonylpiperazine), 2-10 mg/kg, acute excitement was not seen. Intermittent delta activity was prominent in the EEG for 1-3 hr, and was associated with a slight reduction in photically induced epileptic responses. Haloperidol 0.6-1.2 mg/kg, produced a long-lasting reduction in spontaneous motor activity with an increased incidence of spontaneous EEG spikes and waves and a great enhancement of paroxysmal EEG activity during photic stimulation. Pimozide, 0.5-2.5 mg/kg, normally produced mild sedation and some EEG slowing. 2 animals responded idiosyncratically to both haloperidol and pimozide, displaying intermittent dystonic episodes with bucco-facial dyskinesia. These findings suggest that activation of dopaminergic receptors can lead to a reduction in myoclonic responses to photic stimulation.


The effect of autonomic and psychotropic drugs on adrenaline reversal in the rat uterus.

Desipramine and other psychotropic and autonomic drugs were tested for their ability to prevent the motor response of the rat uterus to adrenaline in vitro. Those agents which have been shown to prevent catecholamine uptake into stores most readily reversed the motor response; those which had little or no effect on catecholamine storage were usually without effect on the motor response to adrenaline. The motor response of the rat uterus to adrenaline is due to prostaglandin E2. Agents blocking the motor response prevented the release of prostaglandin and did not block the action of prostaglandin on the uterus. Since all the effective agents also interfered with uptake with catecholamine stores it seems likely that passage of catecholamine in and out of storage depots is involved with the synthesis of prostaglandins.


Permanent bile duct cannulation in the monkey. A model for studying intestinal absorption.

Our aim has been to obtain an experimental model where the test animal is subjected to the least amount of stress and restraint, and can serve for the repeated sampling of biliary excretion over a prolonged period of time. By using a special end-piece at the outer terminals of the two cannulas the monkeys could be given full freedom after experimentation. During the course of the study it was found that insertion of the cannula into the common bile duct led to the development of collateral pathways for passage of bile around the point of insertion. This adaption reaction for the restoration of a normal bile channel would seem to be characteristic of Rhesus monkeys, for we did not encounter it in similar experiments on dogs and minipigs. The experimental model described is intended to serve for the determination of intestinal absorption of compounds that are mainly excreted via the bile. Results with radioactive ergotamine are presented.


Lack of a role for cardiac sympathetic nerves in the uptake and metabolism of 3H-5-hydroxytryptamine by isolated rabbit hearts.

Perfused rabbit hearts removed 3H-5-hydroxytryptamine (3H-5-HT) from a perfusion solution containing 2.6 ng/ml and a tissue-to-medium ratio of about 10 was achieved after a 55 min perfusion period. 12.4 +/- 1.0% of the cardiac total radioactivity consisted of metabolites and metabolites appeared in the venous effluent during the course of the perfusion. Pretreatment of animals with 6-hydroxydopamine reduced cardiac noradrenaline concentrations by 92%, abolished the histochemical fluorescence characteristic of noradrenaline in sympathetic nerves and abolished the mechanical response to sympathetic nerve stimulation. In these hearts, the removal of 3H-5-HT from the perfusion fluid and the accumulation of total radioactivity was normal. There was, however, a significant increase in the proportion of the total cardiac radioactivity which was present as metabolites. The results suggest that the cardiac sympathetic nerves are not the site of 3H-5-HT uptake when the concentration in the perfusion medium is low. By analogy with work in the lung, it may be the endothelial cells of the coronary microcirculation which are responsible.


Dantrolene effects on neuromuscular function in cat soleus muscle.

Dantrolene sodium (DS) was investigated for its effects on cat soleus muscle contractile properties and motor nerve terminal activity in particular. DS, 0.1-1.5 mg/kg i.v., caused a dose-dependent depression of indirectly elicited contractile strength which was more pronounced at lower frequencies of stimulation. Maximum tetanic strength at frequencies of 10-400 Hz was depressed to a lesser degree than contractile responses evoked by lower frequencies of stimulation; the twitch/tetanus contraction ratios were reduced with increasing dose, primarily because of diminished twitch. DS was without effect on motor nerve terminals as evidenced by normal post-tetanic repetition in the nerves following DS administration. Post-tetanic potentiation became relatively larger in amplitude as contractile strength was diminished. These data suggest that DS depresses neuromuscular function at a site other than the neural apparatus at the neuromuscular junction.


Effects of AY-22,241 (Actodigin) on electrical and mechanical activity of cardiac tissues.

AY-22,241 (Actodigin) is a new rapid-acting semisynthetic cardiotonic steroid. In experiments on contractility of cat papillary muscle, Actodigin (2 times 10(-7) to 4 times 10(-6) M) produced a dose-dependent positive inotropic effect, a marked increase in the maximum rate of force development, and no change in resting tension. Electrophysiologic studies performed with microelectrode techniques on isolated Purkinje fibers superfused with Tyrode solution, revealed dose-dependent decreases in resting membrane potential, action potential amplitude and duration, and the maximum rate of rise of phase 0 (Vmax). Purkinje fibers superfused with extracorporeally circulated blood from a donor dog receiving 0.075 mg/kg/min Actodigin showed small decreases in resting membrane potential preceding the onset of donor premature ventricular contractions. Progressive decreases in resting membrane potential, action potential amplitude and duration, and Vmax accompanied donor ventricular tachycardia. All effects were rapidly reversible, and compared to ouabain, equi-inotropic concentrations of Actodigin caused significantly less electrophysiologic toxicity.


The effect of atropine on the turnover of acetylcholine in the mouse brain.

The effect of atropine on the acetylcholine (ACh) turnover in the mouse brain has been studied and related to the central effect (motor activity) of the drug. At the threshold dose for maximal increase in motor activity, atropine had no measurable effect in the brain on the initial rate of formation of labelled ACh from labelled choline (Ch) i.v. injected. However, if atropine was injected 3 min after the injection of labelled Ch, when the labelled ACh had reached its peak value in the brain, there was a more rapid exponential decline of labelled ACh. This was assumed to be an indication that atropine increases the turnover of ACh in the brain. The specific radioactivity of ACh was not changed 2-17 min after the atropine injection, which indicates that atropine does not preferentially increase the release of newly synthetized ACh.


Comparison of the action of different barbiturates on squid axon membranes.

Experiments utilizing squid giant axons have been carried out to determine if the duration of anesthesia obtained from phenobarbital, pentobarbital and hexobarbital can be explained by events related to their action at the nerve membrane level. For comparison, the barbiturates were perfused both outside and inside the squid axon at concentrations which produced an approximately equivalent depression of the maximum rate of rise of the action potential. The time to 50% maximum block and the time to 50% maximum recovery following washing, were compared for all three drugs. All three barbiturates were more potent from inside the squid axon than from the outside. This finding coupled with the fact that the time course of the drug effects was much shorter when applied inside as compared to outside suggests an internal site of action. There was no statistically significant difference between a short acting barbiturate and a long acting barbiturate with respect to their time course of action or recovery when they were both applied to either the inside or outside of the membrane.


The positive inotropic effect of glucagon in the chronically failed right ventricle as demonstrated in the isolated cat heart.

Previous in vitro studies had provided evidence to show that papillary muscles obtained from cats with chronic right ventricular failure had lost their ability to develop a positive inotropic response to glucagon. Since it is difficult to extrapolate from the isolated papillary muscle to the intact heart, studies were done to assess the effects of glucagon in the perfused isovolumically beating heart obtained from cats four months after surgical banding of the pulmonary artery for the experimental production of chronic right ventricular failure (CRVF). At the peak of the dose-response curve, glucagon increased right ventricular isovolumic pressure 25% (39.00 +/- 4.37 to 49.67 +/- 5.15 mm Hg; p less than 0.001) and right ventricular dP/dt 63% (522.2 +/- 93.9 to 852.6 +/- 159.9 mm Hg/sec; p less than 0.001) in 6 normal hearts. Similar dose related increases in right ventricular isovolumic pressure and dP/dt were obtained in 6 hearts taken from cats with chronic right ventricular failure. The respective increases in right ventricular isovolumic pressure and dP/dt were 43% (30.33 +/- 4.01 to 43.67 +/- 6.25 mm Hg; p less than 0.025) and 73% (317.50 +/- 30.29 to 550.83 +/- 89.04 mm Hg/sec; p less than 0.025). These results provide evidence that glucagon possesses the capacity to augment myocardial contractility in the heart with experimentally induced chronic right ventricular failure.


Comparative studies of a new 5HT-uptake inhibitor and some tricyclic thymoleptics.

The new 5HT-uptake inhibitor, FG 4963, and some tricyclic thymoleptics antagonized p-chloroamphetamine (PCA)-induced hypermotility in rats. FG 4963 was active in about the same s.c. and p.o. doses as chlorimipramine. FG 4963, imipramine and chlorimipramine potentiated hypermotility induced in mice by the 5HT precursor 5HTP, FG 4963 being slighly more active than chlorimipramine. In contrast to the tricyclic thymoleptics FG 4963 did not potentiate the heart rate increasing effect of NA in pithed rats. The peripheral anticholinergic effect of FG 4963 and of desipramine was almost identical while the other imipramine derivatives were more active. All tricyclic thymoleptics were strong peripheral antihistaminics, but FG 4963 was almost devoid of this action. Acute tests for ECG changes in guinea pigs and toxicity in mice and rats showed that FG 4963 and chlorimipramine were less toxic than imipramine and amitriptyline. FG 4963 is presumably a selective 5HT-uptake inhibitor producing much less potentiation of peripheral sympathetic mechanisms than do the tricyclic antidepressants.


Evidence of central influences on blood glucose level: malathion hyperglycemia.

To suppress the hyperglycemic effect of malathion in rats, a smaller amount of atropine was required when the drug was injected by intraventricular (i. vent.) than s.c. Pentobarbital, but not diazepam, blocked the hyperglycemic response. The results suggest that central accumulation of acetylcholine was the mediator of the response. Since hyperglycemia was not abolished by adrenalectomy and/or hypophysectomy, a hypothesis is presented to explain how central accumulation of acetylcholine might cause hyperglycemia.