Turnover of polyadenylated messenger RNA in fission yeast. Evidence for the control of protein synthesis at the translational level.

Polyadenylated RNA was isolated from fission yeast (Schizosaccharomyces pombe) total RNA using oligo(dT)-cellulose, and was studied as a model for messenger RNA. The half-life of poly adenylated RNA was measured by two independent methods. (a) The rate of labelling of polyadenylated RNA during incubation of cells with [5-3H]uridine was measured. A half-life of 40-45 min was found by comparing the experimental data with theoretical curves calculated for labelling of RNAs with various half-lives. The influence of precursor-pool specific activity on RNA labelling kinetics is considered. (b) Cells were labelled with [5-3H]uridine then further RNA synthesis was inhibited by addition of 8-hydroxyquinoline. The rate of loos of radioactivity from polyadenylated RNA indicated a half-life of 50 min. The half-life found by these two methods is about one-third of the cell doubling time, and is much longer than previous estimates by indirect methods of yeast messenger RNA half-life. Both experimental methods provided evidence for the existence of tas a half-life of 40-50 min; a much smaller population is probably turning over more rapidly. After inhibition of RNA synthesis by 8-hydroxyquinoline, the rate of total protein synthesis declined much more rapidly than the polyadenylated RNA content of the cells. However, 60 min after inhibition of RNA synthesis there was a small rise in the rate of portein synthesis. These data are interpreted as evidence for mechanisms controlling protein synthesis which operate at the level of messenger RNA translation.


DNA polymerases of rat liver. Partial characterization and effect of various inhibitors.

Three distinct DNA-dependent DNA polymerase activities have been partially purified from normal rat liver. Soluble activities are separable into two distinct fractions (P1 and P2) by phosphocellulose chromatography. A low-molecular-weight DNA polymerase was isolated from purified nuclei. The enzymes were characterized according to chromatographic and sedimentation behavior, enzymological properties, and response to various inhibitors. The results indicate that fraction P1 corresponds to the high-molecular-weight enzyme and suggest that polymerase P2 may be derived from partial dissociation of the high-molecular-weight enzyme. The molecular weight of polymerase P1 was estimated to be about 250 000 by Sephadex column chromatography. Both fraction P2 and nuclear DNA polymerase appeared to be low-molecular-weight enzymes. However, the molecular size of these activities was apparently different. The estimated molecular weights of nuclear and P2 enzyme are about 40 000 and 25 000, respectively. As with the nuclear enzyme, polymerase P2 (but not P1) appeared to be free of detectable exonuclease activity. All of these polymerases showed a marked preference for initiated polydeoxyribonucleotide templates. The rat liver polymerases differed in their ability to use poly[d(A-T)-A1 primer-template, as is shown by the ratios of their activity with this synthetic polymer to that with activated DNA: 0.5, 2.75, and 1.34 for P1, P2, and nuclear polymerase, respectively. Denatured DNA was a poor template for both enzymes P1 and P2, but it was inert as template for the nuclear enzyme. Although each of these polymerases required all four deoxynucleoside triphosphates for maximal activity, they catalyzed a high rate of synthesis in the absence of one or more deoxynucleoside triphosphates. Such a 'limited' synthesis was much more extensive for polymerase P2 and nuclear enzyme than for P1 was the most sensitive of the three to sulphydryl reagents, ehtidium bromide, heparin, and single-stranded DNA. The responses of P2 and nuclear enzymes to various inhibitors were very similar. However, these two enzymes respond differently to heat and high ionic strength.


Heterogeneity of human milk beta(1-4)-D-galactosyltransferase.

beta(1-4)-Galactosyltransferase from human milk (the A protein of lactose synthase) has been found to be heterogeneous when fractionated by affinity chromatography against insolubilized alpha-lactalbumin, using a linear gradient of decreasing N-acetylglucosamine concentration. Three forms were isolated. Molecular weights of the different species, as determined by sodium dodecylsulphate gel electrophoresis, were found to be 38 000, 43 000 and 50 000. The 38 000 and 50 000 species were studied for their catalytic ability to synthesize either lactose in the presence of alpha-lactalbumin, or N-acetyllactosamine in the presence and absence of the 'specifier' protein. Appreciable difference was observed between the two enzyme forms with respect to their catalysis of lactose synthesis with alpha-lactalbumins from various sources. Differences in the rate of production of N-acetyllactosamine in the presence of alpha-lactalbumin were also observed. For the lowest-molecular-weight species it was found that the inhibitory effect of alpha-lactalbumin upon N-acetyllactosamine synthesis becomes an activating effect at higher alpha-lactalbumin concentrations, while no such inversion was observed for the other species. The results suggest that the conformation at the site of association of the enzyme with the acceptor saccharide or alpha-lactalbumin has been changed, presumably by a pratial enzymic hydrolysis.


Some actions of purified toxins from Bungarus fasciatus venom on isolated pig-heart mitochondria.

I. In the presence of succinate as an oxidation substrate, neurotoxins alpha, beta and gamma induce the following. Firstly, an increasing stimulation of oxygen uptake, which in potentiated by 25 muM Ca2+, Mg2+ 1.3 mM completely inhibits the effect of toxin alpha but not of toxins beta and gamma. Secondly, a depletion of the Mg2+, Ca2+ and K+ content of the water-soluble and membrane-bound mitochondrial compartments, following complex kinetics, which suggest a multistep interaction mechanism of the toxins with the mitochondria. 25 muM Ca2+ also potentiates the effect of the toxins on these ionic flows. Thirdly, no decrease of turbidity with toxin alpha, and a limited decrease with toxins beta and gamma. 2. In the absence of respiration, the neurotoxins induce a cationic depletion, the kinetics of which are different than with succinate, suggesting an instantaneous maximal effect on the inner membrane. Toxins beta and gamma (but not alpha) induce, under these conditions, a turbidity decrease of large amplitude, which is proportional to the amount of toxin added and tends to reach a maximum. With gamma toxin this turbidity decrease is faster than the rate of water uptake (which never exceeds 18%) indicating that it is due rather to structural modifications than to swelling. The same is observed with beta toxin, provided the mitochondrial protein concentration to be lower than 0.7 mg/ml. For higher concentrations, a continuous decrease of turbidity with a considerable uptake of water probably reflects the onset of phospholipasic activities. 3. It is postulated that structural modifications of the mitochondrial membranes are initiated which lead to the loss of their selective impermeability. The simultaneous loss of respiratory control with succinate may be due to the direct (though Ca2+-potentiated) displacement of the fraction of the membrane-bound Mg2+ ions which controls its energy-transducing properties. 4. In addition, correlations between the effects of the toxins on mitochondria and their neurotoxicity in vivo are discussed.


Luminescence studies of saccharide binding to wheat germ agglutinin (lectin).

The fluorescence and phosphorescence emission of wheat germ agglutinin are reported. Fluorescent tryptophan residues of wheat germ agglutinin are found highly exposed to solvent: fluorescence quenching induced by temperature fits with a single Arrhenius critical energy close to that of tryptophan in solution; the whole fluorescence emission is susceptible to iodide ion quenching and data reveal the homogeneity of fluorescence arising from only one type of tryptophan exposition. Energy transfers are analyzed at singlet and triplet state level. Tyrosine fluorescence at 25 degrees C is very weak. Results obtained from the relative excitation fluorescence quantum yield and from intrinsic fluorescence polarization show that a large amount of energy absorbed by tyrosine at 280 nm is transferred to tryptophan residues. However, tyrosine fluorescence is highly increased at 70 degrees C although disulfide bridges are not reduced. The phosphorescence spectrum at 77 K in 50% ethylene glycol is finely structured with several resolved vibrational bands at 405, 432 and 455 nm. Phosphorescence decay can be fitted with a single exponential. Lifetime is independent of excitation wave-length. Its value is very close to that of free tryptophan. Influence of tri-N-acetyl-chitotriose binding on luminescence properties are investigated. Results are analyzed in terms of steric tryptophan-ligand relationships. It is shown that all the fluorescent chromophores are concerned by the ligand binding but all fluorescence emission is still susceptible to iodide ion quenching. There is no change induced in energy transfer at the singlet state level and no modification in triplet state population.


A contribution of nonhistone proteins to the conformation of chromatin.

1. Changes in circular dichroism (CD) spectra and thermal melting profiles of guinea pigliver DNA reassociated with histones and/or nonhistone proteins from the cerebral of liver chromatin are described. 2. In the DNA-histone complex, positive ellipiticity in the CD spectrum at 260-300 nm is progressively lod by a red-shift of the crossover point at around 260 nm. DNA in this complex is thermally stabilised to a considerable extent, but not to such a full extent as is shown with DNA in native chromatin. 3. DNA-nonhistone complex in 0.14 M NaCl is, in contrast to DNA-histone complex, not precipitable by centrifugation at 20 000 X g. DNA in this complex shows only a slight reduction in ellipticity at 260-300 nm, and a very weak thermal stabilisation. 4. Characteristics in the CD spectrum of the native chromatin are most satisfactorily reproduced in the DNA-histone-nonhistone complex. These include a large decrease in ellipticity at 260-300 nm, a red-shift of the crossover point at around 260 nm, and a slight negative band at around 305 nm. Also, DNA in this complex is thermally stabilised to the extent comparable with DNA in the native chromatin. 5. Addition of nonhistone proteins to the preformed DNA-histone complex in 3 M urea renders a half of the complex, named DNA-histone(-nonhistone), unprecipitable upon centrifugation at 20 000 X g in 0.14 M NaCl. CD spectrum and thermal melting profile of the precipitable DNA-histone(-nonhistone) complex are similar to those of the DNA-histone-nonhistone complex, while in the unprecipitable DNA-histone(-nonhistone) comples, the ellipticity at 260-300 nm is significantly elevated and the highest melting transition (at 80 degrees C) is lacking. 6. The CD spectrum of native cerebral chromatin closely resembles that of unprecipitable DNA-histone(-nonhistone) complex, while in liver chromatin, the spec.trum is an intermediate between those of the unprecipitable and pn of chromatin by nonhistone proteins. Cerebral nonhistone proteins bind to DNA and to the DNA-histone complex more extensively than liver nonhistone proteins. 7. It is concluded that, although the basic conformation of DNA in native chromatin is determined largely by histones, nonhistone proteins also play an individual role. There is also an indication that nonhistone proteins exert an organ-specific modification of chromatin superstructure.


Ligand binding of organic sulfides to microsomal cytochrome P-450.

Octyl methyl-, butyl methyl- and pentamethylene sulfide react with about 50% of oxidized cytochrome P-450 in liver microsomes from phenobarbital-pretreated rats by formation of optical difference spectra with maxima at 435 and 552 nm and concomitant shifts in the electron paramagnetic resonance spectrum. Reduction by NADPH or sodium dithionite yielded a Soret absorption band at 449 nm and alpha and beta bands at 573 and 545 nm, respectively. The ligand metyrapone and the substrate n-octane competitively inhibited the formation of these difference spectra and pentamethylene sulfide was a strong competitive inhibitor of the 0-deakylation of 7-ethoxycoumarin. These results indicate a direct ligand binding of the sulfides to cytochrome P-450 with concomitant blocking of the hydrophobic substrate binding site. Some sulfides did not interact as ligands but as substrates, in variation, however, with the source of microsomes.


A comparison of two methods for the computer analysis of arterial blood pressure waveforms.

Two different methods, one analogue and one digital, for the analysis of the arterial blood pressure waveform are described and compared. Little difference was found in the systolic and diastrlic pressures determined by the two methods.


Regional lung function following prosthetic hip replacement surgery.

With a Xenon133 radiospirometric technique the regional lung function was evaluated before and after prosthetic hip arthroplasty performed in the lateral decubitus position with either respirator-controlled neuroleptic anesthesia or epidural anesthesia with spontaneous breathing. Regional lung function measured in a supine position 1, 20 and 72-96 hours postoperatively revealed a reduction of the perfusion, ventilation and volume of ventilated alveoli on the dependant lung. The reduction was most pronounced immediately postoperatively, especially following respirator-controlled anesthesia. There was also an increase of pulmonary blood volume and a decrease of total lung volume in this group. The changes of lung function are probably caused by congestive atelectasis, secondary to impaired ventilation of the dependent lung. Peroperatively induced microembolism might have potentiated the effect.


Haemodynamic response to slow plasma volume expansion in uncomplicated myocardial infarction.

Left ventricular performance in 16 patients with uncomplicated acute myocardial infarction (AMI) has been estimated, by measuring the haemodynamic response to a moderate increase in left ventricular filling pressure (LVFP), obtained by an espansion in blood volume with a slow infusion of 250 ml of plasma. In 9 cases the infusion was repeated. This represents a total of 25 tests. In 17 tests (group A) cardiac index (CI) and left ventricular stroke work index (LVSWI) did not increase significantly and sometimes decreased. In 8 tests (group B) The same plasma volume expansion (PVE) induced a moderate but significant increase in CI(p less than 0.001) and LVSWI (p less than 0.001). A higher incidence of inferior wall infarction was present in group B. Control CI and LVFP did not differ between the two groups and there was no correlation between the initial LVFP and the type of response to PVE. For the same volume load, the increase in pulmonary capillary wedge pressure (CWP) showed large individual variations (+1 to +8 mm Hg). As a general rule when CI improved, the increment in CWP was minimal (+1 mm Hg). It is concluded that there is no unique optimal LVFP and that PVE must be carefully monitored, in all cases.


Haemodynamic performance and weaning from mechanical ventilation following open-heart surgery.

In 38 patients ventilated after open-heart surgery the effect of a 20 minutes spontaneous breathing period on right atrial pressure (RAP), left atrial pressure (LAP), pulmonary artery pressure (PAP), aortic pressure (AoP), ECG and cardiac index (CI) was monitored. Arterial bloodgas analysis before and during spontaneous breathing ruled out any respiratory failure. The test period of spontaneous breathing provoked an increase in systemic and pulmonary vascular resistance. By this and by a direct aggravation of cardiac failure the work of both ventricles dropped inspite of an increase in enddiastolic ventricular pressure. If these hemodynamic effects of a spontaneous breathing test period are taken as a guide for deciding, if a patient after open-heart surgery is ready for being extubated, the need for reintubation will be extremely rare. The study encourages us to sue mechanical ventilation as an additional instrument for treating heart failure even if no respiratory failure is present.


Factors influencing the indomethacin-induced intestinal lesions in the rat.

The influence of various experimental conditions such as partial hepatectomy, administration of hepatotoxic drugs such as carbontetrachloride or ethionine, and starvation on the ulcerogenic activity of indomethacin at intestinal level has been studied in the rat. While lesions produced by oral administration of high doses of indomethacin are reduced by starvation, the incidence of ulcers was significantly increased by partial hepatectomy and by hepatotoxic drugs reaching the maximum of severity (intestinal perforation) in partially hepatectomized animals. These findings suggest that ulcerogenic activity of indomethacin is strictly correlated to the drug metabolising capacity of the liver.


[Transformation of nitrates in the digestive tract of the rat].

The in vitro transformation of nitrates in nitrites in the various parts of the gastro-intestinal tract has been analysed in the Rat. Results show that nitrites can be found at the different levels of the alimentary tract, especially in the stomach and small intestine. This nitrite production is discussed with regard to the possible formation of nitrosamines in mammals.


[Activities of molecules similar to carboxyhydroxamic acid chromone-2 (sodium salt) in experimental mercury chloride poisoning; importance of the chromone cycle].

The carbo-hydroxamic-2 chromone acid (sodium salt) shows a higher protective action in vivo than in vitro against mercury chloride induced intoxications. The higher effect observed in vivo might be due to the activity itself of the chromone cycle which added up to that of the carbo-hydroxamic acid function. This latter alone appears in vitro. The antihyaluronidasic properties of this protective agent allow it to prevent the toxic substances to be diffused.


[Effects of different toxic compounds (Pb, Cu, formol, NH4) on the carp: histologic changes in excretory and hematopoietic organs].

Here is a comparative study of the impairments observed on the histological structure of the excretory and hematopoietic organs of carps after acute intoxication (by formol and ammonia) and chronic intoxication (by copper sulfate and lead nitrate). Although all these toxic substances induce the same type of impairments, their degree of seriousness vary. The most affected organs are the gills which present with congestive reactions and partial destruction of respiratory lamellae, and the spleen whose red pulp is usually destroyed. On the other hand, the proliferation of a parasitic fungus was observed on all intoxicated carps. This was understood as a weakening of their body's natural defenses.


[Toxicologic analysis of chloralose. Application to 3 cases of acute intoxication].

The authors describe the study of three human intoxication case by chloralose. The detection and dosage of the toxic in the urine of patients have been carried out by the mean of a technic perfected by the same authors. In two case, it has been possible to trace the elimination of the toxic in the urine, the data relative to the third case were not sufficiently precised but they enable to show the existence of criminal etiology of chloralose.


Development of intertectal neuronal connections in xenopus: the effects of contralateral transposition of the eye and of eye removal.

The development of intertectal neruonal connections has been investigated in Xenopus laevis. Contralateral eye grafts and enucleations were performed in embryos and the resultant visual projections to the optic tecta were mapped electrophysiologically after metamorphosis. In enucleated animals the ipsilateral projections were found to be normally organised retinotopically but consisted of visual units with abnormally large multi-unit receptive fields. In 10 animals with contralaterally grafted eyes a normal ipsilateral projection had developed from the abnormal eye and an abnormal projection from the normal eye, to produce congruent maps via the two eyes to one tectum. All the maps in these animals were retinotopically organised. In another 11 animals the ipsilateral projection from the operated eye was fragmentary or absent, while that from the unoperated eye resembled the pattern found after enucleation. Retinotopically abnormal contralateral projections had developed in 5 animals of this group. These results suggest that prefunctional specification determines the initial development of diffuse intertectal visual connections but these may be modified by a process of binocular interaction in the presence of a normal primary contralateral input.


An ultrastructural study of normal and injured hypoglossal nuclei after injection of horseradish peroxidase.

The left hypoglossal nuclei of normal rats, and rats which had received left hypoglossal nerve axotomies 7-21 days previously, were studied by electron microscopy after injection of horseradish peroxidase as a marker of extracellular space and pinocytosis. Quantitative analysis showed that the number of pinocytotically-derived structures in presynaptic boutons was significantly increased in rats at 7, 14, and 21 days after axotomy when compared with normal rats. It was suggested that presynaptic boutons which became detached from injured neurones retracted by a membrane cycling mechanism involving pinocytotic uptake of bouton plasmalemma, without compensatory membrane production elsewhere. It was confirmed that the channels in the microglial cells communicated with the extracellular space.


Factors determining decussation at the optic chiasma by developing retinotectal fibres in Xenopus.

In Amphibia all primary retinotectal nerve fibres cross at the chiasma. To investigate why this decussation takes place, a series of embryological operations were performed in which one host eye was replaced by an eye from the opposite side of a donor in Xenopus laevis. The visual projections to the optic tecta were mapped electrophysiologically in these animals when adult to reveal to which side of the brain the nerve fibres had become connected. In the majority of cases the contralaterally grafted eyes had developed primary projections to both tecta, in others all the fibres had innervated the contralateral tectum and in 2 animals optic axons were detected only from the ipsilateral side. In 2 other animals optic nerve fibres from both the normal and operated eyes had innervated both tecta. Control experiments showed that section of the optic nerve and stalk without any misalignment of the eye and stalk did not disturb the normal decussation of the fibres. Neither did enucleation in the embryo affect the decussation of the fibres from the remaining eye. It is concluded that no "side specificity" has been shown to exist to determine the side of the brain into which retinotectal fibres develop; rather it seems that complete decussation depends on the developing optic nerve fibres being able to enter a normally aligned optic stalk as they leave the eye.


Temporal frequency characteristics of spatial interaction in human vision.

In psychophyscial experiments the bright-dark contrast effects observed in a steady test-field were measured as a function of the temporal frequency of an inducing-field modulated symmetrically about the test-field luminance. The frequency-contrast functions obtained from these measurements were interpreted as reflecting the temporal frequency characteristics of the lateral pathways within the B and D systems (the on-center and off-center neurons) in human vision. Psychophysical evidence is further presented that the lateral neural pathways have lower temporal cut-off frequencies than the "straight-through" pathways. The results are discussed in terms of the frequency characteristics of the center and surround of the receptive fields of on-center and off-center neurons. It is doubtful, however, whether the psychophysical results can be fully explained by the properties of the single-unit receptive field mechanisms.


The Aubert-Fleischl phenomenon: a temporal frequency effect on perceived velocity in afferent motion perception.

Apparent velocities of moving visual stimuli are known to be different depending on whether the subject pursues the stimulus (efferently controlled motion perception) or whether the eye is stationary and the image moves across the retina (afferent motion perception). Afferent motion perception of a periodic pattern or a moving single object causes overestimation of velocity (magnitude estimations) as compared to smooth pursuit. This socalled Aubert-Fleischl phenomenon is shown to depend on local temporal frequency stimulation on the retina caused by the repetitive passage of contrast borders of the moving periodic pattern. This is evidenced by the fact that for a given stimulus speed the amount of overestimation is a function of the spatial frequency of the pattern (or the angular subtend of a single moving object) and that the Aubert-Fleischl phenomenon is not observed if a single edge moves. Background characteristics seem not to influence the apparent velocity during smooth pursuit.


The association connexions of the suprasylvian fringe (SF) and other areas of the cat auditory cortex.

The association connexions of the peri-auditory (SF, Ea and INS) and auditory (AI, AII and Ep) areas of the cat cortex were studied in silver impregnated material of 32 experiments with cortical lesions. The cortex of the lateral bank of the rostral part of the middle suprasylvian sulcus (SF) sends many fibres to AI and to the insular cortex (INS), and has scanty projections upon AII and Ep. In addition, it sends fibres to the visual area 17 as well as to the ventral bank of the medial part of the cruciate sulcus. It receives fibres from the three auditory areas AI, AII and Ep, as well as from Ea and INS. The dorsal part of the anterior ectosylvian gyrus (Ea) projects upon SF, AI, and AII. Ea sends few fibres to Ep, and receives relatively dense projections from AI and AII. The anterior sylvian gyrus (INS) projects heavily upon AII as well as upon the superficial part of SF. It sends a few fibres also to Ep. INS receives heavy projections from AII and relatively lighter connections from SF, AI and Ep. The three auditory areas AI, AII and Ep are strongly mutually interconnected. AI and Ep have scanty projections upon the visual area 19, and AI also to the lateral suprasylvian visual area, as well as upon the ventral bank of the medial cruciate sulcus. Correlations of the association connexions with the functions of each area are discussed.


Columnar distribution of U-fibres from the postcruciate cerebral projection area of the cat's group I muscle afferents.

Needle stitch lesions were made in the maximal point of the cerebral projection area of the low threshold muscle afferents near the postcruciate dimple of the cat's posterior sigmoid gyrus. The lesions did not exceed 500 mum in diameter and were restricted to the cortical grey matter. Degenerating nerve fibres and terminals were investigated with Fink-Heimer technique in four cats (survival times: 26, 48 and 96 hours). The cytoarchitectonic areas of the sensori-motor cortex were determined in cresyl violet and van Gieson sections. All lesions were made in area 3a. Degenerating U-fibres originating from the lesion travelled in the white matter to the cortex of area 4 gamma, 3b and 2. They reentered the cortex and branched in layer III. Terminal degeneration was found in layer I. The degeneration was distributed to distinct columns with a diameter of about 1mm. Such columns were observed laterally and medially in area 4 gamma, in area 3b near the caudal end of the coronal sulcus, in area 2 near the lateral ansate sulcus and in the forelimb region of SII. The distribution of the cortico-cortical connections from the cerebral projection area of the forelimb group I muscle afferents was discussed in relation to the known cerebral projections of group I muscle afferents, low threshold joint afferents, pacinian afferents and low threshold skin afferents.


Functional organization of vestibulofastigial projection in the horizontal semicircular canal system in the cat.

Spike potentials of fastigial nucleus neurons were recorded extracellularly in decerebrate, unanesthetized cats. The neurons responding to head rotation in the horizontal plane with a type I fashion were located mainly in the middle and caudal regions of the fastigial nucleus. Three fourth of these fastigial type I neurons were antidromically activated by stimulation of the contralateral vestibular nuclei. These neurons were excited transsynaptically from the ipsilateral vestibular nerve or nuclei. Intra cellular recordings were made from those neurons which were located in the caudal half of the fastigial nucleus and were activated antidromically from the contralateral vestibular nuclei. Stimulation of the ipsilateral vestibular nerve produced EPSPs in these neurons with latencies of 1.0-6.6 msec. The shortest conduction time along primary vestibular aggerents from the labyrinth to the ipsilateral fastigial nucleus was 0,7 msec. The EPSPs with the shortest latency of 1.0 msec were therefore postulated to be due to monosynaptic connections of primary vestibular afferents with fastigial neurons. Stimulation of ipsilateral vestibular nuclei also produced monosynaptic EPSPs in fastigial neurons. These EPSPs were facilitated by conditioning stimulation of the ipsilateral vestibular nerve, indicating the existence of polysynaptic activation of fastigial neurons from the ipsilateral vestibular nerve through the vestibular nuclei.


Distribution of phenylalanine transaminase and phenylalanine ammonia-lyase activities in etiolated and light irradiated radish seedlings (Raphanus sativus L.).

In dark-grown Raphanus sativus seedlings the level of phenylalanine transaminase is higher in cotyledons than in root and hypocotyl. The maximum activity of phenylalanine ammonia-lyase (PAL) is found in the root. Only PAL is significantly increased by light.


In vitro lipid synthesis by lathyrogen-treated L-929 fibroblasts.

Aside from cholesterol, cholesterol esters and lyso-lecithin, the de novo lipid synthesic mechanisms which operate in cells grown in the presence of beta-amino-propionitrile are largely depressed and suggest that there may be in operation specific metabolic control mechanisms for regulation of cellular lipid composition.


Kininase and anti-inflammatory activities of acid carboxypeptidase from Penicillium janthinellum.

The acid carboxypeptidase from Penicillium janthinellum catalyzed the rapid release of arginine, and the slow release of phenylalanine, proline, serine and glycine from the carboxy-terminal of bradykinin at pH 4.15 to 4.8. Anti-inflammatory activity of the acid carboxypeptidase seems to suggest that the enzyme hydrolyzed bradykinin in vivo.


Ligand-leakage in affinity chromatography: a second note on the mathematical approach.

A leakage function describing the hydrolytic release of ligand molecules covalently attached to insoluble supports by the CNBr method has been derived. Statistical factors were taken into account. The results of this random order model are compared with those of a consecutive order model proposed by Gribnau and Tesser.


On the role of divalent cations in the reaction mechanism of malic enzyme.

The kinetic order of addition of Mg2+ and L-malate to malic enzyme has been determined. Mg2+ is the first to bind, and probably acts as a link between the substrate and the active site.


Renal glucose utilization in genetically diabetic microangiopathy.

Glucose uptake into kidney tissue is not influenced by the development of glomerulosclerosis in KK mice. Glucosyltransferase activity remains at a normal level even at an age having a highest incidence of serious development of glomerulosclerosis. The observation suggests that biosynthesis of basement membrane reflected by its glucosyltransferase activity does not accelerate in genetically transmitted microangiopathy.


Effect of sex hormones on uric acid metabolism in rats.

The effects of sex hormones on purine metabolism were investigated in rats. No influence on purine synthesis was shown by the injection of estrogen and androgen. The plasma urate levels were significantly lowered from 2.43 +/- 1.04 mg/100 ml to 1.53 +/- 0.57 mg/100 ml by the injection of progesterone. Urinary excretion of uric acid plus allantoin was slightly reduced. These results suggested that progesterone may influence age and sex differences in human plasma urate levels.


Evidence for purine biosynthesis in human leukocytes.

Human leukocytes and lymphocytes have shown to be equipped with 5-phosphoribosyl-1-pyrophosphate amidotransrease, the enzyme which catalyzes the synthesis of the first intermediate of the purine pathway, thus providing evidence that these cells have the capacity for de novo purine biosynthesis.


Karyological heterogeneity in the Falconiformes (Aves).

Chromosome studies in 4 families of Falconiformes, Cathartidae, Falconidae, Sagittariidae and Accipitridae showed that the karyological variety in this order is much wider than in any other avian order, which underlines the heterogeneous character of the group. Of the 4 families only the Cathartidae show karyological similarities with other avian groups (Gruiformes, Ciconiiformes), while the karyotypes of the Accipitridae are most uncommon among birds, because of the presence of only 8 microchromosomes.


Male-linked translocations and the control of insect pest populations.

Published data on an experimental release of Culex pipiens carrying a male-linked translocation are re-examined and it is shown that the steady decline in translocation frequency after termination of releases agrees with theoretical expectations, because of the selective disadvantage of translocation heterozygote males. Systems based on negative heterosis or meiotic drive are considered whereby it might be possible to prolong the population control which would be achieved by a short term release.


Karyotype of Geomys pinetis (Mammalia: Geomyidae), with a discussion of the chromosomal relationships within the genus.

4 of the 5 subspecies of Geomys pinetis were karyotyped. All specimens examined had a diploid number of 42 and a fundamental number of 80. This karyotype was compared with the described karyotypes of other species of Geomys and was considered to be derived from an ancestoral form having a karyotype of about 70 acrocentric elements.


Morphology of colloidal gold, ferritin and anti-ferritin antibody complexes.

The morphology of model complexes between colloidal gold, ferritin and anti-ferritin antibodies has been studied in order to evaluate the potential of colloidal gold as a cytochemical marker.


Hybridization of mitochondrial and cytoplasmic ribosomal RNA with mitochondrial and nuclear DNA.

Hybridization assays of rat liver mitochondrial and cytoplasmic rRNAs with in vitro labelled mitochondrial and nuclear DNA were performed in liquid medium. Sensitivity towards S1 enzyme and Tms of the RNA-DNA hybrids were studied. Our results are in favour of a distinct genetic origin of the two types of cellular rRNAs.


Norepinephrine in fetal and neonatal rabbit brain.

In the first hour after parturition, the newborn rabbit brain norepinephrine content is about 37% less than that of the fetus of 30th or 31st day. Later on, within 2 to 4 h, the norepinephrine level returns to the prenatal value and remains unchanged between 8 to 12 h. This transitory fall of the brain norepinephrine seems to be linked to the stress conditions which occur during parturition.


Interaction between sugars and amino acids in intestinal absorption by rat, in vivo.

The inhibitory action of L-leucine on the intestinal absorption of D-glucose and D-galactose, as well as the inhibitory action of D-galactose on the absorption of L-leucine at various concentrations by rat small intestine has been studied. The further effect was more clearly evidenced when the medium was perfunded through the intestine in a closed circuit system using a peristaltic pump.


Study on sex-specific transferrin polymorphism and on the identification of transferrins by radioactive labelling.

Sex-specific differences with regard to the intensity of transferrin bands were observed in a noninbred adult mouse population after separation of the serum proteins by polyacrylamide gel electrophoresis. Amongst the female animals, an additional protein fraction was found just above the position of the transferrin bands. By means of a tracer method, using 59Fe-labelling, it could be shown that the additional fraction is not a part of the transferrin bands.


Autonomic control of renal portal blood flow in the domestic fowl.

Electrical stimulation of the intrinsic nerves of the renal portal valve of the domestic fowl demonstrated the presence of noradrenergic inhibitory, and cholinergic excitatory fibres. They may be involved in the control of venous return.


[Investigations on the Influence of Thrombocytes and Temperature on the Whole Blood- and Plasma-Viscosity as Comparative Measurements Between a Capillary- and a Plate-Cone-Viscosimeter (author's transl)].

The capillary viscosimeter (Viscotimer) tested with different Ubbelohde-viscosimeters is suitable for measurements of plasmaviscosity; the limitting factor of the measuring method is the exact adjustment of the temperature. When testing the plate-cone-viscosimeter (Wells-Brookfield Microviscosimeter), we achieved scientifically adequate results only when using shear rates 230, 115 and 46 sec-1. An influence of different thrombocyte-concentrations on the viscosity of whole blood and plasma could not be detected. The flow capacity of whole blood and plasma is distinctly dependent on the temperature.


Collagen in aging muscles.

The salt, acid and insoluble collagen fractions were estimated in red, white and cardiac muscles of 10-, 15- and 20-month-old albino rats. The total collagen level with reference to total proteins is more in red than in white and cardiac muscle. Accumulation of more of insoluble collagen and decrease in salt extractable collagen is seen in all three muscles with aging.


[Lysosome-rich synaptosomal preparations from rat mesencephalus (author's transl)].

Subcellular fraction, enriched with synaptosomes, obtained from rat brain has been found contaminated by lysosomes, as evidenced by the high content of acid phosphatase, their biochemical marker.


Reduction of hypoxia-induced disturbances by previous treatment with benserazide and L-dopa in rats.

Pretreatment by benserazide (50 mg/kg i.p.) and L-Dopa (100 mg/kg i.p.) in rats induces a reduction of the diminution of motility after hypoxia and a stabilization of cerebral blood flow during and after hypoxia. An overload of cerebral dopamine and norepinephrine seems to be the original process of this phenomenon.


Prostaglandin-induced choleresis in the rat.

It could be demonstrated that intraportal infusion of prostaglandin A1 (1 mug/min/100 g body wt.) in Wistar rats significantly increases bile flow. An analysis of the relationship between bile salt excretion and bile flow revealed that this choleresis is due to an increase in the bile salt independent fraction of bile.


High permeability of insect blood-brain barrier to alcohols demonstrated by an electrophysiological technique.

Using the anaesthetic effects of the alcohols to measure their concentration within the cockroach central nervous system, it is shown that the lower homologues have access half-times of only a few seconds. Slower access of the higher homologues is interpreted in terms of a reservoir effect resulting from their higher liposolubility.


Modification of the contractile responses of rabbit mammary strips to oxytocin by prostaglandin E1.

PGE1 administration to isolated strips from pregnant and lactating rabbit mammary gland resulted in different effects on oxytocin-induced contractions. In strips from pregnant animals, oxytocin action was enhanced; in those from lactating animals, it was reduced and threshold doses for oxytocin were markedly higher.


Antagonistic effects of pemoline to colchicine and caffeine.

Pemoline, the constituent of Tradon, is able to slow down the decrease of the mitotic index caused by 0.1% caffeine in roots of Vicia faba, and mitotic aberrations are reduced. With 0.005% colchicine and 3 x 10(-4) g/ml pemoline, no metaphase-accumulation can be observed, and anaphase-disorder is delayed.


Ultrastructural changes in the neural lobe of the rat pituitary induced by reserpine treatment.

The doses of reserpine, which are generally used to deplete amines from the nervous tissue caused marked ultrastructural changes in the neural lobes of reserpine treated rats. The findings suggested depletion of neurosecretory granules, increased lysosomal activity and changes in the pituicytes.


Mastocytosis in suckling mice.

In suckling mice injected intraperitoneally with mitomycin C on the 1st to 5th day after birth and sacrificed in the course of 24 or 48 h after injection, mastocytosis occurred in the oral mucosa membrane, skin of the trunk or extremities and bone marrow of extremities.


Pentobarbital sodium and chromosome abnormalities in rabbit blastocysts.

Female rabbits were injected with pentobarbital sodium at 1/4 h or 6 h post coitum. A slight delay in oocyte maturation was evident in animals killed at 17 h pc, however, zygote development appeared normal by 24 h pc. At 6 days pc, a greater frequency of chromosomally abnormal blastocysts was found in animals injected with pentobarbital than in control rabbits.


Effects of gamma-rays on the developing embryos of Calotes versicolor.

The gamma-ray irradiation causes mortality, retardation in development and growth rate, haemorrhage, axial defects and unilateral microphthalmia. Histological examination of microphthalmic embryos revealed a partial division of the left optic cup and a 'double lens'.


Establishment of normal diploid and malignant heteroploid cell lines from non-treated and benzo(a)pyrene treated hamster embryo cell cultures.

Two normal diploid control cell lines and a heteroploid malignant transformed cell line from B(a)P treated hamster embryo cell cultures were established. The 14-month-old B(a)P transformed cell line grew 8-times faster than the 20-month-old control cell line. The control cell line showed normal diploid chromosome complement in 93% cells and heteroploidy in 7% cells while B(a)P treated line showed 83% heteroploid cells and only 17% diploid cells. This is the first report on the establishment of diploid hamster cell cultures grown for extended period.


Potency of thyroid hormone analogues in suppressing prolactin-mediated mammary growth in thyroidectomized rats.

An antagonism between prolactin and thyroxine, similar to that found in amphibian tissues at metamorphosis, has been recently shown to occur at the level of the rat mammary epithelium. This phenomenon may be implicated in the pathogenesis of human breast cancer. This experiment demonstrates that two analogues of thyroid hormone, triiodothyropropionic acid and triiodothyroacetic acid, which are relatively very weak in their calorigenic action, are as potent as thyroxine and triiodothyronine in inhibiting the prolactin-mediated mammary growth in thyroidectomized rats. The possible implication of this finding in the treatment of mammary cancer is discussed.


Preliminary purification and dosages of the erythropoietic factor from ox-spleen.

The administration of ox-spleen homogenate, whether in rats made polycythemic by blood transfusion or in mice polycythemic by hypoxia, elicited a significant stimulatory effect on the rate of erythropoiesis. This activity remained unchanged even if the spleen, before being homogenized, was exhaustively washed with isotonic buffer pH 7.4 up to the total blood elimination.


ADP-induced platelet aggregation in vivo after exclusion of different circulatory districts.

The effect of the ADP infusion on the basal platelet count was studied in controls and in rats submitted to the exclusion of the following circulatory districts: splenic, renal, cerebral and of a hind-limb. After these exclusions the ADP-induced thrombocytopenia was less marked than the controls.


Change in levels of cholesterol and free fatty acids of lymphoid cells during tumor growth.

Growth of Ehrlich's ascitic carcinoma in mice resulted in increase of free cholesterol and free fatty acids in lymphoid cells from thymus, spleen and cervical lymph node, but decrease of these lipids in the cells from mesenteric lymph node.


Production of antibodies to amanitins as the basis for their radioimmunoassay.

The production of antibodies against amanitins is described. By means of these antibodies, a radioimmunoassay was developed which allows detection of as little as 0.5 ng of amanitins in 1 ml of serum. By this method, the clearance of alpha-amanitin from the blood of poisoned mice was measured.


Possible effect of caerulein on calcitonin secretion in man.

Caerulein, infused in normal subjects, significantly reduces serum Calcium levels; in addition, when infused 60 or 90 min after radioactive calcium, it increases the specific plasma radioactivity, in a manner similar to calcitonin. These results suggest that in man caerulein stimulates calcitonin release.


Suppression of pupal esterase activity in Aedes aegypti (Diptera: Culicidae) by an insect growth regulator.

Changes in non-specific esterases of Aedes aegypti were noted during pupal development. One esterase band was found to increase markedly within 3 h of pupation and this increase in activity was suppressed by prior treatment of larvae with an insect growth regulator, ZR 515. It is suggested that the esterase activity may help to reduce endogenous levels of juvenile hormone during metamorphosis and that the growth regulator may prevent this normal regulation.


Radioisotopic studies of human chorionic gonadotrophin in the mouse ovary.

The tissue localization of 125I-HCG was studied in intact mice. 125I-HCG concentrated in the thecal and interstitial tissues of the ovary. Differential uptake occurred in the corpora lutea which was dependent on the age and vascularization of the luteal body.


Changes in major liver constituents following hypophysectomy in goldfish (Carassius auratus).

The increase in the size of goldfish (Carassius auratus) liver following hypophysectomy is due to a net accumulation of glycogen and the addition of water to maintain a constant proportion with no change in the absolute amount of either protein or lipid.


Synthesis of histidine2-angiotensin II analogues.

The synthesis of histidine2-angiotensin II analogues, namely H-Asp-alpha-(im-Bzl)His-Val-Tyr-Ile-(im-Bzl)His-Pro-Phe-OH and H-Asp-beta-(im-Bzl)His-Val-Tyr-Ile-(im-Bzl)His-Pro-Phe-OH, are described. Also a new route leading to the synthesis of alpha-benzyl-L-aspartate, using N-trityl-L-aspartate di-benzyl ester as the starting material, is reported.


Regional distribution of lactate dehydrogenase isoenzymes in adult rat brain.

The highest lactate dehydrogenase (LDH) activity was found in thalamus, statistically significantly less in cerebral and cerebellar cortex and the lowest in pons. LDH1 and LDH4+5 represented 58% and 23% of the total activity in cerebral cortex, 54% and 20% in thalamus, 42% and 4% in cerebellar cortex and 55% and 7% in pons, respectively.


Effect of piperazine on the level of phospholipids and on the activities of certain enzymes of phospholipid metabolism in human Ascaris lumbricoides.

The phospholipid level in the human parasitic nematode Ascaris lumbricoides is decreased by piperazine, by partially stimulating catabolic enzymes such as phospholipase C and partially inhibiting anabolic enzymes such as choline kinase.


Studies on the effect of allicin (diallyl disulphide-oxide) on alloxan diabetes.

On oral administration to alloxan diabetic rabbits, allicin produces an increase in its hypoglycemic action with relation to dose. A short-term treatment  with allicin, as well as with tolbutamide, significantly reduced the blood sugar levels and glucose nitrogen ratio of the above animals.


Effects of tryptophan and other amino acids on glucose uptake and carbon dioxide output by the insulin-stimulated adipose tissue.

Tryptophan (4-10 mM) reduces the stimulating effect of insulin on glucose uptake, CO2 output and lactate production by adipose tissue. Similar but lesser effects were also obtained with high concentrations of other amino acids.


Conversion of p-hydroxyphenylpyruvic acid into homogentisic acid: possible participation of p-quinol intermediates.

A proposed intermediate in the metabolic transformation of p-hydroxyphenylpyruvic acid into homogentisic acid has been synthetized. In an experiment with radioactive material in pig liver homogenate it could be shown that this compound does not occur as a free intermediate.


Cannabidiol and its pharmacokinetic interaction with delta1-tetrahydrocannabinol.

Co-administration of cannabidiol with delta1-tetrahydrocannabinol was found to have no effect on the rate of disappearance of delta1-tetrahydrocannabinol from the blood of rats. The implications of this finding are discussed.


Giemsa banding and heterochromatin distribution in Ornithogalum.

In Ornithogalum virens, following Giemsa staining, the mitotic chromosomes revealed distinct C-banding pattern. Interphase nucleus also showed 12 chromocentres corresponding to the number of C-bands. Based on the measurements of C-bands, about 13.5% of the genome is heterochromatic.


Unchanged r-RNA-gene dose in mice liver cells of different developmental stages.

The content of ribosomal DNA in mice liver at the beginning as well as near the end of the hematopoietic period was measured by RNA/DAN-hybridization in solution. At both stages the amount of ribosomal DNA was the same and comparable to that of postnatal liver.


Oocyte maturation in vitro: contribution of the oviduct to total maturation in Xenopus laevis.

Contact of progesterone matured oocytes of Xenopus laevis with the oviduct reduces the time necessary to attain cleavage capacity from 24 h to 3 h. Full maturity has been demonstrated by normal development of the matured eggs after fertilization.


Relationship between size of muscle fibres and body dimensions in a number of teleosts.

In a survey of 17 species of teleosts, a direct relationship was found between the diameter of muscle fibres and estimated volume of the fish. The results also suggested an inverse relationship between muscle fibre diameter and 'streamlinedness' of the fish (as measured by length:height ratio).


Sporeless mutants of Bacillus thuringiensis. II. mutants derived from var. thuringiensis and var. sotto.

Three sporeless mutants of Bacillus thuringiensis, 2 derived from var. thuringiensis and 1 from var. sotto were selected after mutagenic treatment. They were completely lacking in ability to form spores, yet maintained intact insecticidal activity.


Action of Bacillus thuringiensis preparation against larch bud moth, Zeiraphera diniana (Gn.), enhanced by beta-exotoxin and DDT.

Addition of either DDT or the supernatant of a centrifuged liquid culture of Bacillus thuringiensis, serotype H1, containing beta-exotoxin, enhanced the action of the bacterial preparation Thuricide 90 T against larvae of the larch pest Zeiraphera diniana, increasing mortality from 53% to more than 80%. Since DDT alone produced 57% mortality, its combined action corresponds to independent action. The preparation of beta-exotoxin, on the other hand, had only little effect alone but synergized the action of the bacterial preparation considerably.


Development of the electric discharge in mormyrid and gymnotid fish (Marcusenius sp. and Eigenmannia virescens).

Larvae of both species start discharging at 8 days. Eigenmannia immediately produces pulses similar to those of the adult. Marcusenius however, possesses a characteristic larval discharge 20 times longer and of opposite polarity to the adult discharge which appears on Day 40.


Post-tetanic changes of bilateral dorsal root potentials evoked by stimulation of the cutaneous afferents.

In spinal cats following tetanic stimulation of the cutaneous nerve bilateral dorsal root potentials in the lumbar spinal cord are depressed. Because of differences between ipsi- and contralateral potentials, this depression can usually be evoked only on one side of the cord.


Development of longitudinal retraction of carotid arteries in neonatal dogs.

Longitudinal retraction of carotid arteries, was examined in 105 neonatal puppies as a measure of longitudinal traction. Percent vessel retraction increased linearly with age. This was attributed to stretching of the vessels by growth and to changes in connective tissue composition. The mechanical significance of artery retraction was discussed.


Seasonal changes in the circadian variation of oral temperature during wakefulness.

The circadian change of oral temperature in 26 subjects was compiled for December, March and June. Average peak time delays up to 70 min, and a reduced daytime temperature rise were found in June compared with December.


Acute effect of hypophysectomy on the natriuresis following saline infusion in dogs.

The natriuresis following an i.v. isotonic saline loading corresponding to 10% of body wt. was markedly decreased after acute hypophysectomy, due to lowered urinary sodium concentration, in anaesthetized dogs. A role of the pituitary in such a homeostatic natriuresis is suggested.


Hemodynamic and ventilatory effects of skin-cooling in cattle.

Cooling the skin of cattle at an ambient temperature of 25 degrees C decreased cardiac output and increased systemic and pulmonary vascular resistances. Minute ventilation was reduced by about 50%. There was no change in alveolar ventilation as measured by arterial blood gases. These results indicate that thermoregulatory ventilation has significant cardiopulmonary effects in cattle at normal laboratory temperatures.


Seasonal variations of cardiac output in rats.

Cardiac output of rats shows seasonal variations with low values in spring and summer and high ones in autumn and winter. The stroke volume was much more implicated in these changes than the heart rate. The seasonal changes of cardiac output are probably due to changes of thyroid function.


Effect of furosemide on the permeability to Cl of the isolated skin of Leptodactylus ocellatus.

Furosemide added to the Ringer solution bathing the external side of the isolated skin of Leptodactylus ocellatus increased the PD and SCC and inhibited both active chloride influx and passive chloride efflux. The action on chloride permeability is thought to contribute to the diuretic effect of the drug.


Increased sensitivity to pentobarbital in rats fed a diet lacking flavonoids.

Pentobarbital-sensitivity is highly increased in rats fed a diet lacking flavonoids; sleeping time was found to be increased by 42 and 30% as compared with rats fed a normal diet. These studies confirm our previous statement according to which for the rat, benzopyrones are vitamins.


Embryonic death in mouse due to lead exposure.

Female mice which displayed a vaginal plug after mating were given a diet containing 0, 0.125, 0.250, 0.500% of lead as lead acetate and were dissected 16 to 18 days later. Lead treatment was found to reduce significantly the incidence of pregnancies and to increase the postimplantation loss in the pregnant females.


Effect of ethanol intake on phenytoin metabolism in volunteers.

Ingestion of ethanol, 1 g/kg, did not influence the phenytoin half-life in 5 volunteers after single i.v. administration of 3 mg/kg phenytoin. The control phenytoin half-life was 12.4 h (SD +/- 4.4); with ethanol ingestion it was 12.3 h (SD +/- 5.2).


Pathological changes in the liver of mice given 2,3,7,8-tetrachlorodibenzo-p-dioxin.

In C57BL/6 mice a single oral dose of 2,3,7,8-tetrachlorodibenzodioxin (LD50 126 mug/kg) results in loss of body weight and death with an enlarged fatty liver after ca. 21 days. A progressive necrotic centrilobular liver lesion is also seen.


Role of bile in intestinal absorption of 203Pb in rats.

The author studied absorption of 203Pb after administering intraduodenally 203Pb eliminated with bile. The results obtained were compared with absorption of 203Pb administered into the duodenum as 203PbCl2 in rats forming 2 groups, one with bile ducts cannulated, the other intact. It was found that bile played an important role in absorption of Pb from the gastrointestinal tract. Absorption of Pb203 is significantly reduced if the bile is drained off by means of a canula.


Effects of temperature on the responses to noradrenaline, isoprenaline and histamine on isolated rabbit mesenteric artery.

On the rabbit mesenteric artery, the elevation of temperature from 25 degrees up to 42 degrees diminished the affinity of histamine, whereas that of noradrenaline to the alpha-adrenoceptors remained unchanged. The presence of beta-adrenoceptors could not be demonstrated.


The influence of pigmentation of rats and guinea-pigs on the ototoxicity of kanamycin and neomycin.

Following the finding that melanin pigment played a role in the accumulation of ototoxic drugs in the inner ear, an investigation was made of the possible influence of the pigmentation of animals on their susceptibility to the ototoxic effects of drugs. Hearing acuity was assessed by measurement of acoustic startle reaction. Preliminary experiments suggested that pigmented animals might be more likely to suffer hearing impairment following ototoxic drug administration. However, in a controlled study using rats treated with kanamycin, it was not possible to confirm this and albino animals appeared no less vulnerable than pigmented animals to kanamycin-induced deafness.


Conformations and biological properties of apomorphine and its phenanthro(10,1-b,c)azepine homologue.

11,12-Dihydroxy-7-methyl-4,5,6,7,7a,8-hexahydrophenanthro[10,1-b,c]-azepine (2), a homologue of apomorphine (1), has been found to be devoid of dopaminergic effects. The biological differences between apomorphine and this homologue are explained in terms of differences in conformation of the two molecules.


The process of survival of denervated and freely autotransplantated skeletal muscle.

The study shows that two distinct processes occur in free autografts of denervated intact muscle during the early critical phase of the transplantation: survival of transplanted fibres at the periphery of the graft, and regeneration of new muscle fibres following breakdown of the originally transplanted fibres in the central areas.


Respiratory control in liver mitochondria of rats hosting the walker 256 carcinoma tumor.

The decrease in the respiratory control ratio of mitochondria is a first order process when these organelles are incubated in isotonic sucrose. Furthermore, the initial respiratory control ratios and the rates of loss in respiratory control in liver mitochondria from rats hosting the Walker 256 carcinoma are not significantly different form the same properties of mitochondria from untreated animals.


Ferritin synthesis by splenic tumor tissue of Hodgkin's disease.

Increased ferritin synthesis by Hodgkin's disease splenic tumor tissue was demonstrated by incorporation of 14C-leucine and radioautography. This suggests that elevated tumor and serum ferritin concentrations found in patients with Hodgkin's disease is derived from tumor tissue per se.


Tubuloreticular structures in hepatic endothelial cells in a case of malignant melanoma liver metastasis.

The presence of tubuloreticular structures within hepatic endothelial cells in a case of malignant melanoma liver metastasis is described. This finding may reflect a host cell response to the neoplastic proliferation in the liver tissue, possible a host-tumor immunological reaction.


Quantitative morphological investigations on smooth muscle cells in vascular surgical specimens and their clinical importance.

A distinct distribution of activated SMC could be demonstrated in atherosclerotic plaques and the neighbouring media of human beings. An increased proliferation was found in the younger age group and generally in the marginal regions of the plaques. The occurrence of activated SMC is thought to be a sequel of metabolic hypoxic damages. A high frequency of activated SMC is a bad prognostic sign in surgical specimens indicating a tendency for proliferation and occlusion.


Further evidence of a positive correlation between exposure to nitrate fertilizers (NaNO3 and KNO3) and gastric cancer death rates: nitrites and nitrosamines.

Mean age-adjusted death rates for gastric cancer in Chile for 1960, 1962 and 1964 were associated with exposure to sodium nitrate and nitrates (NaNO3 and KNO3) used as fertilizers, by province. The general population exposure to NaNO3 and nitrates exhibited correlation coefficients of 0.745 and 0.718 with the death rates, respectively.


Ring chromosomes and leukaemia.

The observation of 2 leukaemic patients with ring chromosomes, and their comparison with a few previously reported cases, suggests a close association between this rare chromosomal abnormality and erythroleukaemia and indicate a poor prognostic significance of this finding.


The effect of luteineizing hormone on chicken testis and pineal gland uptake of 32P.

The glandular uptake of radioactive phosphorus (32P), administered carrier-free, was used as an endpoint for the study of the effects of luteinizing hormone (LH) on the testis and pineal gland of 3-, 10- and 13-day-old White Leghorn cockerels. Pineal uptake of 32P of the 13-day-old birds decreased and testis uptake of 32P increased following LH treatment. Maximum effects were observed when 20 mug LH was administered 4.0 h before autopsy. Although testis uptake of 32P increased following LH treatment in 3- and 10-day-old cockerels, pineal uptake of 32P remained unchanged.


Corticosteroid-like effect of cyproterone and cyproterone acetate in mice.

Cyproterone and cyproterone acetate exert the corticoid-like effect on the adrenal and spleen weight in the mice. When compared with prednisone, cyproterone acetate has approximately 1/5 of the corticoid potency of prednisone, expressed by the decrease of the spleen weight.


Effect of cortexolone on the feedback action of dexamethasone.

Cortexolone in a dose of 1 mg/100 g body wt., administered to rats prior to dexamethasone, prevented dexamethasone from suppressing stress-induced ACTH-release without interfering with the effect of dexamethasone on the resting plasma corticosterone level.


Effect of progesterone on human corticosteroid 21-hydroxylation.

Progesterone inhibits the 21-hydroxylation of 17alpha-hydroxyprogesterone by human adrenal cortex microsomes. The possible light this finding may shed on the genetic condition, the 'adrenogenital syndrome' is discussed. Km and Vmax data for the above hydroxylation reaction are given.


Effect of cyproheptadine hydrochloride on spermatogenesis.

Administration of cyproheptadine hydrochloride (5 mg/kg/day) to old rats for 48 days stimulated spermatogenesis. It also initiated spermatogenesis in the abdominal testis of unilaterally cryptorchid rats after a 15-day treatment.


Changes of electro-shock seizure threshold in alloxan diabetic rats.

During a 4-week period, the electroshock seizure threshold (EST) of R Amsterdam rats was determined. When alloxan induced diabetes, the EST values significantly decreased, while in the alloxan-treated non-diabetic group they remained unchanged. The results suggest that diabetes induces increased excitability in the central nervous system.


A method for distinction between RNA and DNA in aldehyde and osmiumtetroxide-fixed electron microscopic autoradiographs.

A simple method for distinction between RNA- and DNA-containing structures in aldehyde- and osmiumtextroxide-fixed electron microscopic autoradiographs (or ordinary thin sections) is described: the developer and the acetic acid used for processing autoradiographs extract selectively uranium acetate from DNA containing-structures which, after staining with lead citrate, leads to a characteristically 'bleached' appearance of the DNA.


Evaluation of a conductometric method to determine the volume fraction of the suspensions of biomembrane-bounded particles.

Supported by the fact of correspondence between the results of several independent techniques compared, we recommend here a conductometric method as a simple, nondestructive and reliable tool for determining the volume fraction of the suspensions of membrane-limited particles of biological relevance. It requires only conductivity measurements on a suspension and its medium.


[Chemical and pharmacological research on derivatives of 1H-naphtho/2,1-b/pyran. V. Behavior of some 1-oxo-3-dialkylamino-1H-naphtho/2,1-b/pyrans substituted in the Mannich reaction].

1-Oxo-3-dialkylamino-1H-naphtho [2,1-b] pyrans substituted in positions 5, 8 or 9 with halogen, alkyl, alkoxycarbonyl, hydroxyl, methoxyl, by the Mannich reaction will yield the corresponding 2-dialkylamino-methyl derivatives when a correct amount of acetic acid is present in the reaction mixture. Excess acid will give rise to the formation of substituted 1-oxo-2-[(1'-oxy-3'-oxo-3'H-naphtho [2',1'-b']pyran-2'-yl)methyl]-3-dialkylamino-1H-naphtho [2,1-b] pyrans when the group in the 3 position is dimethylamino or N-pyrrolidyl. In a few cases Mannich bases were accompanied by an appreciable quantity of substituted 2,2'-methylenebis (1-oxo-3-dialkylamino-1H-naphtho-E12,1-B] PYRANS). Therefore, these compounds were synthesized with excellent yields by treating Mannich bases with acetic anhydride. The behavior of some compounds in the acidic hydrolysis was also considered. Some Mannich bases of 1-oxo-3-dialkylamino-9 methoxy-1H-naphtho-[2,1-b] pyrans showed a more specific anticonvulsant activity than the parent compounds.


[Reaction of 1,8-naphthyridine azides with ethyl acrylate].

The reaction of 1,8-naphthyridine azides with ethyl acrylate leads to the formation of 2-pyrazolines instead of 1,2,3-triazolines. Some of the compounds obtained have undergone pharmacological and microbiological (antibacterial) testing.


Tetracycline derivatives. Note III - 7- and 9-methyltetracyclines: synthesis and biological activity.

The synthesis of some 7- and 9-methyltetracyclines is reported together with the biological activity of the new compounds.


[Thiourea derivatives of 1,3,4-thiadiazole and their cyclization products].

The synthesis and chemical behaviour of 1-methoxycarbonyl-3-(1,3,4-thiadiazol-2-yl)thyoureas and 7-alkyl-2-methyltio-1,3,4-thiadiazolo [3,2-a]-s-triazine-4-ones is described. All compounds were tested in vitro for their antibacterial activity.


The anti-mycoplasmal activity of aminosidine.

Some in vivo experiments of therapeutic activity in severe experimental infection (intracranial) in the mouse due to different strains of Mycoplasma proved the high efficacy of the antibiotic aminosidine when administered subcutaneously at the dose of 30 mg/kg and have also demonstrated that oral treatment is moderately effective against Mycoplasma hominis 2. Sensitivity test carried out in vitro on the same Mycoplasma strains confirmed the bactericidal activity of aminosidine. These experiments have therefore shown that the therapeutic spectrum of aminosidine, which includes Gram-positive, Gram-negative, acid-fast bacteria and some protozoa, may be enlarged to include the genus Mycoplasma. For this reason the antibiotic can find a useful application in the treatment of primary atypical neumonia. In addition, from a clinical research point of view, aminosidine may constitute a promising tool for the treatment of different illnesses in which Mycoplasma have been described as important co-factors of pathogenicity in man.


[Experimental research on the hyperprothrombinemic activity of an isocoumarin derivative: antagonism against anticoagulant dicoumarol (Warfarin)].

In previous research and tests it was found that some isocoumarin derivatives showed marked hyperprothrombinemic activity in rats. This action has now been demonstrated also in rabbits by using one of the most active compounds (allylamide of 4-phenyl-3-isocoumarinic acid). In both species it was found that the drug under test strong by antagonises the anticoagulant action of a dicoumarol compound (Warfarin). This result leads to the supposition that the isocoumarin derivatives tested act in a similar way to Vitamin K.


[Ultrastructural study of the activity of phospholipids in experimental liver damage induced by isoniazide].

The authors studied the activity of egg-derived phospholipids on the hepatotoxic effect induced in rats by isoniazid (INH) given orally for 20 consecutive days in doses of 25, 50 and 100 mg/kg/day. In the animals treated with the highest dose of INH, a great number of liver cells showed structural and ultrastructural changes. Their hyaloplasm was more electron-dense, the cytoplasmic structure was condensed and collapsed, without apparent endoplasmic reticulum and ribosomes. A very different structural and ultrastructural picture was observed in the animals treated with INH + phospholipids. The structure was quite normal without degenerating cells. There was a greater richness of endoplasmic reticulum, ribosomes and glycogen particles.


Anticestode quinolinehydrazones.

One hundred and seven 4-quinolinehydrazones were synthesized and tested in vivo against the tapeworm Hymenolepis nana. Twenty-five derivatives showed significant cestocidal activity; structure-activity correlations were performed using Free-Wilson methodology. Two compounds, 2,6-dimethyl-4-[(3-pyridinylmethylene)hydrazino]quinoline and 2,6-dimethyl-4-[2p][(6-methyl)pyridinylmethylene]hydrazino)quinoline, predicted to be maximally active, effected 100% reduction of H. nana in mice at 200 mg/kg, p.o.


[Research on substances with antiviral activities. IV. Position of the lateral chain and activity of hydrazonic derivatives of benzindanones and naphthofuranones].

Hydrazonic derivatives of some nephtofuranones and benzindanones have been synthetized with a view to finding out what connection there might be between the antiviral activity and the side chain position on the pentatomic ring.


Cardiovascular pharmacology of bombesin, a new polypeptide from amphibian skin.

Bombesin is a tetradecapeptide extracted from the side of discoglossid frogs Bombina bombina and Bombina variegata variegata. In anaesthetized dogs bombesin causes mainly systemic hypertension, bradycardia and constriction of the renal, mesenteric and coeliac arterial vessels. The other vascular beds studied (carotid, femoral and coronaric) passively follow the blood pressure. Tachyphylaxis may occur. Dibenzyline and hexamethonium do not antagonize the hypertensive property of bombesin, while the occlusion either of the renal vessels or of the mesenteric, coeliac arteries and portal vein reduces the intensity and the duration of the hypertensive response. The simultaneous occlusion of all the above mentioned vessels further reduces the duration of the hypertensive response evoked by bombesin and reverses its effect on the heart from mainly bradycardic to pure tachycardic. In these condition bombesin causes carotid and peripheral vasoconstriction. The increase of heart rate and of blood pressure, while occurs after ligation of aplanchnic vessels, is completely or partly antagonized by propranolol. In normal conscious dogs bombesin is at least 10 times more potent and less tachyphylactic than in anesthetized dogs.


[New isoxazol /5,4-b/ pyridine-3-acetic acids].

We prepared two isoxazol [5,4-b] piridin-3-acetic acids by two different synthetic methods. 4,6-Dimethylisoxazole [5,4-b] pyridin-3-acetic acid was obtained by reaction with hydroxylamine of 4-hydroxy-5,7-dimethyl-2H-pyrano [2,3-b]pyridin-2-one, which was in turn prepared starting from 2-hydroxy-3-acetyl-4,6-dimethylpyridine. Isoxazolo [5,4-b] pyridine-3-acetic acid was obtained starting from 3-methyl-5-aminoisoxazole and has shown interesting auxin activity.


[Participation of the cardiac sympathetic innervation in the occurrence of vagotomic and atropine tachycardia in anesthetized dogs].

The sympathetic nervous system's role in the post-vagotomy and atropin-induced tachycardia was studied in anesthetized dogs. Bilateral vagotomy was followed by 166% tachycardia while on exclusion of the heart sympathetic innervation (inderal or novocain injections into the right stellate ganglion) the bilateral vagotomy was accompanied by a considerably lesser tachycardia (33%). The i.v. atropine administration increased the heart rate by 177% whereas in the presence of inderal it increased the heart rate by 77% only. Thereupon, the post-vagotomy or atropin-induced tachycardia in anesthetized dogs was to a considerable extent associated with activation of the sympatho-adrenal system.


[Electrical and contractile activity of the myocardium during a change in temperature].

In rhythmically stimulated (0.05/sec) isolated strips of the ventricle myocardium of the fresh water fish, drop of the temperature (from 20 degrees C to 10 degrees C) increased the AP duration but decreased the extent of contractions; raise of the temperature (from 10 degrees C to 20 degrees C) increased the extent of contractions but decreased the AP duration. The discrepancy between the electric and the contractile activities points out the importance of processes of the transmembrane and intracellular redistribution of ions occurring at rest, for refilling of intracellular Ca deposit released during excitation.


[Activation mechanisms for contractions of the smooth musculature of the cerebral vessels].

Pial arteries and veins were found to differ by their contractile features. Pial arteries are highly sensitive to noradrenaline, adrenaline, histamine, serotonin, rapid stretching, and potassium ions. The effects of the mediators, potassium ions, and rapid stretching could be blocked by manganese ions. Pial veins are insensitive to the mediators effects, potassium ions, or rapid stretching, although they are highly sensitive to transmural electric stimulation. Manganese ions have no effect on the veins' responses to electric stimulation. A spontaneous activity of the smooth muscle cells of the a. carotis' intracranial portion was revealed in man. The activation mechanisms for the cerebral arteries smooth muscle contractions are suggested to depend on the calcium extracellular ions. The activation mechanism for the veins' smooth muscle contractions depends on the intracellular store of calcium ions.


[Amine receptors in brain vessels].

Isolated middle cerebral arteries from cats and pial arteries from humans (obtained during lobe resection) were studied in a sensitive in vitro system allowing a detailed pharmacological characterization of various amine receptors and related dissociation constants. It was found that the adrenergic receptors comprise contractile (alpha) and dilatory (beta) receptors. Acetylcholine induced dilation (at low doses) as well as constriction (at high doses) both responses being inhibited in a comparative way by atropine. Experiments with selective inhibitors showed the presence of specific histamine H2 (dilatory) receptors; at high doses histamine contracted the vessels in a non-specific way. 5-Hydroxytryptamine was the most efficient vasoconstrictor agent, and the response could be blocked by the serotonin-antagonist, methysergide.


[Functioning of the microvascular mechanisms in the pial artery system].

In rabbits, the functional behavior of the pial arterial offshoots (PAO), the pial arterial anastomoses (PAA), and the precortical arteries (PCA), was studied. In functional and postischemic hyperemia, as well as on changes of cerebral blood flow (caused by changes of the systemic arterial pressure), dilatatory and constrictory responses of the active portions of the microvessels suggest that the PAO and PAA participate mainly in the regulation of blood supply to the cerebral cortex adequate to its metabolic demands, while the PCA get involved during superfluous inflow of blood to the cerebral cortex.


[Assessment of the regulatory resources of the pial and intracerebral arteries by using mathematical modeling].

A mathematical model for estimation of regulatory abilities of pial and intracerebral arteries was used for studying the pressure - radius relationships for arteries of various calibres in passive and active states. In passive state the arteries were found to be characterized by high elasticity and low tensile force. The radius of the artery depends mainly on the smooth muscle contractile force. The data obtained suggest that the wall structure of small pial and intracerebral arteries well correspond to their function: the control of the adequate and rapid cerebral blood flow.


[Effect of the hypothalamus and reticular formation on the cerebral cortex in hypoxic brain states].

In anesthetized cats and unanesthetized rabbits, the reticular formation and the posterior hypothalamus were shown to be able to reduce the resistance of cortical vessels thus increasing the blood supply of the brain cortex. This effect decreased after stimulation of the cortex and in conditions of hypoxia, hypercapnia, section of the vagus, chronic circulatory deficit in the myocardium and the brain.


[Changes in the resistance and capacity of the cerebral vascular bed under the influence of vasoactive substances].

Effects of intracarotid injections of vasoactive agents on cerebrovascular resistance (CVR) and cerebral blood volume (CBV) were studied in hemodynamically isolated brain of cats. Perfusion pressure shifts at a constant blood volume perfusion reflected CVR changes, and changes of venous outflow - CBV alterations. Administration of adrenaline, serotonin, and angiotensine was followed mainly by an increase of CVR  and a decrease of CBV. The CBR could be reduced by isopropilnoradrenaline, acetylcholine, histamine, and caffeine. CBV was decreased after isopropilnoradrenaline, acetycholine, histamine injections and increased by caffeine. The possible role of the active changes of cerebral capacitance vessels in the transcapillary fluid exchange is discussed. Capacitance vessels active responses are supposed to entail wrong results when using certain techniques for measurement of cerebral blood flow and metabolism.


[Analysis of the phenomenon of lowered cerebral blood flow in cats under prolonged intracarotid microinfusion of vasodilator substances].

In 27 anesthetized cats, continual intracarotid microinfusion of 0.04% solution of noshpa first increased CBF by 12-76% and then CBF gradually decreased to the normal level and even 14% below it. There was no strict correlation between the degree of lowering CBF and the level of blood pressure, pH, pCO2, blood viscosity, or level of vasopressor substances. No signs of brain tissue oedema was found.


[Effect of generalized edema on blood flow distribution in the brain].

The correlation between increase in brain tissue pressure and cerebral blood flow distribution was studied in generalized brain edema induced by water intoxication in cats. Brain tissue pressure increased as the brain edema progressed. The intracranial vascular component was suggested to play a certain role in the volume buffering capacity at increased intracranial pressure. Transtentorial redirection of carotid blood flow observed in the early stages of water intoxication, is related to tissue pressure gradients. The meaning of tissue pressure gradients for blood flow distribution is discussed.


[Long- and short-term changes in engorgement in the cerebral vessels under rhythmic photic stimulation].

In 50 patients with cerebrovascular pathology, the EEG and REG were simultaneously recorded during an increase in the cerebral blood volume in response to rhythmic photostimulation. General, local, and short-term reactions of increased cerebral blood volume could be distinguished. The relationship between the EEG changes and cerebral blood volume was most obvious during the short-term reactions: EEG-desynchronization was always followed by increased blood volume. This suggests a possible neurogenic element in vascular reactions. Cerebrovascular pathology was concluded to affect both the neurogenic and the metabolic components of the regulatory mechanism of local circulation.


[Effect of potassium ions on the reactions of resistive and capacitive vessels in the skeletal muscles and intestines].

L. a. administration of 4.2% KCl was followed by contractile responses of the resistance intestinal vessels, whereas contractile-dilatatory responses were observed in the skeletal muscles. The intestinal capacitance vessels responded with insignificant increase of the venous outflow, while the contractile-dilatatory responses of the resistance vessel were not followed by any increase of the venous outflow in skeletal muscles. After papaverin administration, contractile responses of the resistance intestinal vessels were insignificant, while the contractile-dilatatory responses of the skeletal muscles resistance vessels became contractile only. After noradrenaline injections only contractile responses were observed in the resistance intestinal vessels.


[Background activity of the neurons and brain tissue oxygen tension in asphyxia].

The activity level of the cerebral cortex as estimated by the unit activity was found to correlate with the PO2 parameters. Two phasic changes of the unit activity dueing asphyxia were confirmed. The initial firing rate was unrelated to decrease of the PO2 but to the reticular formation influence rather. The following reduction of the unit activity was connected with the PO2 decrease in the brain tissue.


[Circadian periodicity of blood coagulation system indices and the hormonal activity of the adrenals in healthy persons (under conditions of rest and of stressed work)].

13 patients with the heart ischemic disease (HID) were examined in conditions of a relative rest (hospital) and 20 patients - during an intensive day work. Within the 24-hr rhythm of gemocoagulation parameters, 3 phases were distinguished (conventionally): I a tendency to hypercoagulation at 0-3-6 a.m.; II the most safe period at 9 a.m.; III an increased ability of coagulation at 12-3-6-9 p.m. During the intensive day work, hypercoagulative shifts become more obvious and the anticoagulating system becomes activated at the I and the III phases. Within the 24: hr rhythm of the plasma fibrinolytic activity, 2 phases were distinguished (conventionally): I low activity at 0-3-6-9-12 a.m.; II sufficient activity at 3-6-9 p.m. During the intensive day work fibrinolytic activity increases, and the character of 24-hr rhythm preserves. Within the 24-hr rhythm of the adrenal hormonal activity, 3 phases were distinguished (conventionally): I a reduced activity at 0-3-6 a.m.; II high activity at 9 a.m.; III high enough activity at 12-3-6-9 p.m. In conditions of intensive day work the 24-hr rhythm of the adrenal hormonal activity does not change.


[The role of Ca ions in desensitization induced by acetylcholine].

Abolition of cholinergic inhibition in the heart of fresh-water bivalves in absence of cholinesterase can be attained by inactivation of the acetylcholine receptor (R). The role of Ca in this process was studied. Determination of Ca in the perfusate at different stages of cholinergic inhibition showed that the concentration of Ca increased during the sistolic arrest, and the initiation of beats was accompanied by binding of Ca. This coincided with the onset of ATP release and went on till the complete desensitization. The increase of external Ca concentration up to 1.10-2M increased the half-time of desensitization while the binding of Ca with EDTA decreased it and eliminated the ATP anti-acetylcholine effect. Another bivalent ion, UO2, which binds phosphate groups, competes with Ca. The role of Ca and ATP in chemical inactivation of the acetylcholine receptor is discussed.


[Several pattern in the synthesis and uptake of H3-catecholamines by isolated rat vas deferens].

In the rat isolated vos deferens, increase of the thyrosine-H3, DOPA-H3, and Dopamine-H3 contents in the incubation medium increases respectively Km and Vmax of the noradrenaline-H3 biosynthesis. Increase of the Dopamine-H3 and noradrenaline-H3 in the medium also increases Km and Vmax of neuronal uptake and reservation of these catecholamines in the adrenergic granules. The simultaneous increase of Km and Vmax of the catecholamines synthesis and uptake leads to that the effectiveness of these processes undergoes much lesser alteration that the main parametres. The interrelationship between the substrate concentration in the medium and the velocity of catecholamines synthesis is, apparently, due to that the adrenergic granules differ from each other by the intensity of synthesis and reservation of noradrenaline. This is one of the factors regulating accumulation and release of the sympathetic mediators.


[The contractile and electrical activity of the smooth muscles of the major lymph vessels].

In rats, catecholamines were found to increase the rate of the muscles spontaneous rhythmic contractions while the alpha- and beta-blocking agents suppressed them. The spontaneous contractions were blocked in the uncalunm medium. Rhythmic electrical stimulation evoked contracture-like responses the uncalunm of which depended on the strength, frequency, and duration of the stimulation. In spontaneoulsy active preparations, single electrical stimuli evoked contractions according to the "all or nothing" rule. The membrane potential magnitude varied within the limits of 25-37 mV, and action potentials were related to the contractions. The data obtained suggest that the functional unit of conduction of spontaneous or evoked excitation waves is represented by a group of smooth muscle cells within a single lymphangion.


[The activity of the internal laryngeal muscles during respiration].

Electromyographic study of the laryngeal internal muscles in dogs showed that the character and intensity of the electrical activity are specific for each muscle not only in frequency and amplitude of potentials, but also in the relation to the phases of the breathing cycle. Phasic electrical activity of these muscles occurred either in inspiration or expiration, whereas in some muscles the activity was recorded both in inspiration and expiration. Besides the phasic electrical activity, a less pronounced constant activity in some muscles was observed. The functional value of this phenomenon may be connected  with the fixation of the larynx cartilages, whereas that of the phasic activity is connected with the realization of the larynx respiratory function. It was shown that the instrinsic laryngeal muscles activity coordination in the breathing act is not static and strictly determined but has a dynamic character: it can change under various conditions. The final result of the action of the intrinsic laryngeal muscles determining the degree of the glottis opening in the rspective phase of the breathing cycle is conditioned by the simultaneous but differently pronounced and differently derected activity of some of these muscles.


[The role of several limbic structures in neocortical activation following brain stem section at the level of the corpora quadrigemina].

In chronic experiments on 25 adult cats, after transection of the brain-stem at the level of oral margins of the anterior colliculus, the effect of high-frequency electrical stimulation of the posterior hypothalamus and basal-lateral portion of the amygdala was studied. While stimulation of the posterior hypothalamus resulted in diffuse activation, that of basal-lateral portion of the amygdala rather rarely evoked a relatively weak long-latency activation of the neocortex. Frequently, stimulation of the basal-lateral amygdala induced epileptiform activity in the neocortex. Bilateral lesion of the amygdaloid complex did not affect the activating influence of the posterior hypothalamus on neocortex. It is suggested that the posterior hypothalamus, independently of the mesencephalic reticular formation and amygdaloid complex, exerts an activating influence on the neocortex.


[The heterosensory interaction of neurons in the cat frontal association cortex].

The interaction of various sensory inputs in the cat frontal neurons was studied in the motor cortex (MI), the area of the hind-limb contralateral representation (SI), and the area of the fore-limb contralateral representation (S'I), with the aid of heteromodal stimulation. Mutual blocks between various inputs (visual, auditory, contralateral hind-limb and fore-limb projections) were observed in MI and SI within the 100-600 msec intervals. Teleceptive inputs in the contralateral fore-limb representation did not block the somatic ones, though the latter blocked the teleceptive inputs within long intervals (3000 msec and more). The somatic input interactions manifested themselves in asymmetric blocks. The cortical type of the heterosensory block seemed to prevail in the fore-limb cortical projection, while multisynaptic blocking throughout the entire neuronal chains prevailed in the MI zone and in the cortical hind-limb projection.


Immunogenic capacity of mouse alloantigens from ischaemic liver.

Immunogenic versus tolerogenic capacity of mouse alloantigens from ischaemic liver was tested in two different congenic strain combinations (H-2 compatible, non-H-2 incompatible). The recipients of test skin allografts were pretreated with tissue homogenate or particulate fraction and the survival pattern of the skin allografts was used as the criterion of the induced status. The results showed a difference in the immunogenicity of antigenic extracts from normal (healthy) and ischaemic liver. Following a single dose, alloantigens from ischaemic liver had an increased immunogenicity (which could be reduced through perfusion) as compared to control (extracts from healthy liver). Following three larger doses of ischaemic liver extracts, the effect was tolerogenic. Possible mechanism of the altered immunogenicity of alloantigens due to ischaemization of the liver tissue and the effect of perfusion are discussed.


Study of thymus and peripheral lymphocyte populations characterized by the dominant nucleolar type.

In neonatally thymectomized mice and in "B" mice obtained by adult thymectomy, lethal irradiation and repopulation with foetal liver cells, blood lymphocytes were classified according to their nucleolar morphology as revealed by toluidine blue staining. A majority of the "active", i.e., RNA-synthesizing cells were found to be thymus-dependent. Direct evidence was obtained by testing the "active" lymphocytes for their sensitivity to anti- serum in vitro. During postnatal ontogenesis, the frequency distribution of individual  nucleolar types of lymphocytes tends to reflect the developmental changes in the organ tested. The decline of "active" lymphocytes in the thymus has its counterpart in their increase in the lymph nodes and peripheral blood. In hydrocortisone-treated mice, the most affected lymphocytes were those from the thymus cortex -- both the prevalent population of cells with micronucleoli and the "active" lymphocytes -- whereas the active small lymphocytes in the medulla (resembling those from peripheral blood and probably also their precursors) were relatively hydrocortisone-resistant.


A note on the preparation of particulate material for an electron microscopic study.

Modifications of two rapid and satisfactory procedures of purification of minute biological particulate material for electron microscopic observations were described. These modifications eliminate the alterations of the investigated particles and the possibility of their artificial disintegration. In addition, these procedures preserve the grouping of the particles as compared with the original suspensions. The dialysis is made directly on the grids coated with the supporting formvar membrane. In the second procedure the filtration of the soluble components of the material into the agar is combined with the transfer of the particles on the membrane covered grids.


Horizontal distribution of three dehydrogenases in the cow snout epidermis.

A technique is described for quantifying enzyme activities in the various layers of the epidermis of the cow snout. Values for glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and lactate dehydrogenase are reported. In general, the amount of each enzyme is largest in the basal layers and diminished towards the stratum corneum. The exception was G6PD whose highest peak of activity was in the region of the stratum spinosum.


Determination of protoporphyrin in plasma and suction-blister fluid from light-irradiated and non-irradiated skin in protoporphyria patients.

At various times of the year the protoporphyrin level in the plasma of 11 patients with erythropoietic protoporphyria was determined. In the winter as well as in the summer, when the patients received carotenoids, an area on one forearm of 10 patients was irradiated with artificial (xenon arc) light, after which suction blisters were made on both forearms. Protoporphyrin levels were determined in the plasma and in the blister fluid from both areas. Suction-blister fluid was considered representative of the interstitial fluid in the dermis. In the winter the protoporphyrin levels of the blister fluid from the irradiated area were significantly higher than in the fluid from the non-irradiated area. In the summer this difference was not significant. The possible implications of these findings are discussed.


Quantitative detection and typing of HBs Ag and anti-HBs by radioimmunoassay techniques.

Small polystyrene tubes coated with purified anti-HBs were used as solid-phase substrate for the detection of HBsAg and anti-HBs by RIA procedures. This substrate yields highly sensitive, reproducible and homogeneous results. The sensitivity and the kinetics of various solid-phase RIA procedures for anti-HBs detection were explored. The preliminary heating of sera at 56 degrees C for 30 min is needed, in order to remove a thermolabile aspecific inhibitor, which is not identifiable with complement. In particular, an RIA procedure is suggested, based upon preincubation of serum to be tested with a serum containing low amounts of HBsAg (count ratio to negative sera = 10:1) and suitable for the combined detection and quantitation of HBsAg and of anti-HBs. The results are expressed as HBs Units, which provide a simple and standardizable unit allowing estimation of HBsAg and anti-HBs amounts over a range of as much as one million values. A number of RIA procedures were also studied for typing HBsAg and anti-HBs, which are also suitable to evaluate 'in vitro' the degree of cross immunity among the various subtypes.


The problem of purification of HBs antigen.

Purification techniques utilized until now do not allow to obtain an HBs antigen totally free from one or more protein constituents of the serum. The authors describe the method which has given the best results; this method combines the utilization of silicate, Sephadex G200 and ultracentrifugation. The authors then determined the nature of the relations between HbsAg and the serum proteins. They have perfected a screening technique allowing to detect the immune complexes by means of a tetanus antigen-tetanus antitoxin model. Sixty-nine patients with viral hepatitis A and B were tested. It was observed that the immune complexes are in relation with the IgM which are themselves correlated with the rheumatoid factor: the mu chains found in purified HBsAg could correspond to the rheumatoid factor reacting with the Fc of IgG bound to HBsAg.


Anti-HBsAg assay using the Ausria system with standard antigen dilutions.

A simple modification of the radioimmunoassay Ausria I and Ausria II was employed for detecting anti-HGsAg using the inhibition of a constant amount of HBsAg. The highest incidence of anti-HGsAg was demonstrated in follow-up patients recovering from viral hepatitis B (82%) and in hemophilia patients (79%). Lower frequencies were observed in patients with chronic aggressive hepatitis or liver cirrhosis (23%), patients with chronic rheumatoid arthritis (16%), family contacts of patients with viral hepatitis B (10%) and blood donors (3.4%). No difference in sensitivity for the presence of anti-HBsAg was found between the Ausria I and the Ausria II test.


Detection of anti-HBs in two groups of institutionalized people by solid-phase radioimmunoassay using human labelled antibody.

A modification of Ausria II-125 solid-phase radio-immunoassay has been performed for the detection of anti-HGs in sera from 217 subjects living in two institutions. 129 subjects were mentally retarded and belonged to an institution; the other 88 were healthy people living in another institution, 74 of whom were residents and 14 members of the assistance staff. These 88 subjects were tested again three months later. Contemporaneously HBsAg was tested by Ausria II-125. Out of 129 mentally retarded subjects, 18 (13.9%) were positive for anti-HBs and 6 (4.6%1 for HBsAg. Out of 88 apparently healthy residents and members of the assistance staff, anti-HBs was detected in 24 (27.3%) and in 25 (28.4%), in the first and second bleeding, respectively; the distribution of anti-HBs carriers between residents and staff was quite similar. The screening of anti-HBs by rHA, performed in the same 88 subjects, showed a greater sensitivity than RIA modified in detecting anti-HBs carriers. Our findings outline the importance of the detection of anti-HBs as a marker of the virus B infection.


A rapid hemagglutination test for the detection of HBsAg.

Demonstration of the advantages of the direct passive hemagglutination test in comparison with the radioimmunoassay: simplicity, speed, lower costs and relatively high specificity.