Exercise performance in children and adolescents after surgical repair of tetralogy of Fallot.

Cardiopulmonary function studies at rest and during submaximal and maximal exercise were performed in 21 children and adolescents who had undergone surgical correction of tetralogy of Fallot. Maximal oxygen uptake of the patients was 84.6% of healthy peers matched for age and height. The reduced aerobic capacity can mainly be attributed to a reduction in stroke volume. In the presence of a reduced stroke volume normal cardiac output during submaximal exercise was achieved and maintained by an increase in heart rate. During maximal exercise, however, the heart rate did not exceed that of the healthy controls and the results for the children in this series are about 20% higher than those reported in the literature for adults who had undergone surgical repair of a tetralogy. Persistent impairment of cardiac function in patients with tetralogy of Fallot who have undergone corrective surgery may represent a residual outflow tract obstruction in the right ventricle, impaired function of the left ventricle or the result of restricted physical activity.


Pharmacokinetics of diazepam in disordered liver function.

The plasma elimination curves of diazepam following intravenous administration of 10 mg were studied in nine patients with cirrhosis of the liver and four patients without liver disease. The data were analyzed according to a two compartment model. The mean biological half-life (T/2) of diazepam was increased five-fold in patients with cirrhosis compared to the controls (164 hours vs. 32.1 hours). The plasma clearance of diazepam could be correlated neither with a quantitative measure of liver function, as estimated by galactose elimination capacity, nor to semiquantitative measures of liver function, such as serum albumin and prothrombin. It is suggested that the plasma clearance of diazepam is an inaccurate index of its rate of hepatic metabolism due to the complex kinetics of the drug.


Comparison of the pharmacokinetics of diazepam after single and subchronic doses.

In seven healthy male volunteers the effects of the pattern of dosing on the pharmacokinetics of diazepam have been studied. A cross-over design was employed that consisted of three parts: a single intravenous dose (0.1 mg/kg), and oral dosing (10 mg/day) for six days followed by an intravenous bolus (0.1 mg/kg) on the seventh day, followed by re-examination of a single intravenous dose after diazepam (D) and its major metabolite desmethyldiazepam (DD) had been completely eliminated. Plasma levels of D and DD were monitored by a specific, sensitive GLC-method. In younger patients (n = 5, age 29 - 35 years) the elimination half-life, T1/2(beta), of D was 33.9 +/- 10.6 h (mean +/- S.D.) after the single dose. The control study gave an almost identical result (35.7 +/- 12.1). After subchronic dosage in all patients T1/2(beta) showed a modest but significant prolongation (paired t-test p less than 0.01) to 52.9 +/- 17.4 h. It was caused by a significant decrease (p = 0.016) in total plasma clearance (Cl), from 26.0 +/- 10.8 ml/min. Older patients (age 43-60 years) showed the same phenomenon. Blood/plasma ratios remained constant indicating no change in protein binding. Biliary excretion of D was measured in five patients with a T-tube. Only negligible amounts (0.3 - 0.4%) of administered D were excreted within 3 days after subchronic dosage, which demonstrates a lack of enterohepatic cycling of D. After multiple administration of D, there was accumulation of DD to levels approximately five times higher than after a single dose. The possibility that the slower elimination of D after subchronic treatment might be caused by DD was also supported by experiments in dogs and rabbits. After pretreating rabbits with DD and maintaining a high DD plasma level, there was prolongation of T1/2(beta) from 2.7 h to 5.2 h, with a corresponding decrease of Cl from 101.6 ml/min to 23.4 ml/min. Similar results were obtained in dogs. It is concluded that the disposition of D is altered by subchronic use and may be regulated by the plasma DD concentration.


Coumarin-7-hydroxylase activity in microsomes from needle biopsies of normal and diseased human liver.

The specific activity of coumarin-7-hydroxylase was measured in liver microsomes from normal subjects and patients with liver disease. Liver specimens were obtained by needle biopsy and the microsomal fraction was separated by differential centrifugation. Its freedom from mitochondria was demonstrated by the absence of succinic dehydrogenase, a marker enzyme for mitochondria. Liver from healthy subjects showed variation in the specific activity of coumarin-7-hydroxylase from 0.16 to 0.65 nmol-mg-1-min-1, which is probably due to genetic factors. Patients with cirrhosis of the liver, chronic fatty hepatitis (chronic alcoholic hepatitis) and chronic active hepatitis showed a significantly lower mean hydroxylase activity. There was no significant difference in the mean level of hydroxylase between patients with subacute viral hepatitis or chronic persistent hepatitis and the normal controls.


Binding of four sulphonamides to human albumin.

The four sulphonamides studied--furosemide, tolbutamide, sulfafurazole and sulfonamidochlorobenzoic acid--bind to human albumin at the same sites but with decreasing affinity. These sites are also common to other drugs, namely acenocoumarin, chlorophenoxyisobutyric acid, phenylbutazone and warfarin. In plasma, the four sulphonamides considered bind mainly to albumin, but also, at higher concentrations, to globulins, to an extent that increases as their affinity for albumin lessens.


Pharmacokinetics and pharmacodynamics of alprenolol in the treatment of hypertension. II. Relationship to its effect on blood pressure and plasma renin activity.

The kinetics of alprenolol, in relation to its effect on blood pressure and plasma renin activity, have been studied in sixteen patients. A within-patient comparison was made between therapy for six weeks with placebo or alpronolol 200 mg thrice daily. Thirteen patients responded to alprenolol by a signoficant fall in blood pressure. In three other patients treatment did not lower blood pressure. In the group as a whole there was no significant correlation between the fall in systolic, diastolic or mean blood pressure, and the steady-state plasma alprenolol concentration, renin status, or degree of beta blockade. However, the thirteen responsive patients showed a significant relationship (p less than 0.05 - 0.001) between the log mean steady-state plasma alprenolol concentration and the hypotensive response.


Serum digoxin levels in patients of a general practice in Germany.

Serum digoxin levels were determined in 33 outpatients of a general practice in the countryside, on three occasions at intervals of 8 weeks. All the patients were on long term digoxin treatment, about 2 years on average. About 14 days after the first and the second visits the results of the measurements were sent to the patients, with a comment about their reliability in taking treatment according to the serum digoxin level. At the first visit half of the serum digoxin level were lower than 0.5 ng/ml; the mean serum concentration was 0.52 ng/ml. There was no correlation between serum concentration and age, dose or creatinine level; but there was with replies to the question about regularity of drug intake. The mean serum level at the second and the third visits was 0.88 ng/ml and 0.89 ng/ml, respectively. A correlation was found between the dose and the serum digoxin level. From these results it seems that compliance by the patient plays a major role in producing steady state levels of drugs.


Studies on the lymphocytes of sheep. I. Recirculation of lymphocytes through peripheral lymph nodes and tissues.

Recirculating lymphocytes were collected from the efferent ducts of peripheral somatic nodes and incubated in vitro with 51Cr. After washing, the labeled cells were returned to the sheep by i.v. injection. The partitioning of the labeled cells between blood and efferent (intermediate) lymph, or between efferent and afferent (peripheral) lymph was monitored for the next 24 h by assaying the radioactivity in appropriate samples of cells. The labeled lymphocytes took several hours to migrate through the nodes so that they equilibrated between blood and lymph in about 10 h. This pattern was not altered grossly during the inductive phase of an immune response. The small numbers of lymphocytes which migrated through peripheral tissues entered the lymph at least quickly as those that migrated through lymph nodes.


Suppressor cells in rabbit peripheral blood.

Rabbit peripheral blood leukocytes (PBL) added to cultures of autologous spleen cells, primed in vivo to sheep red cells, are able to suppress with high efficacy the secondary in vitro response of the spleen cells to that antigen. Removal of nylon wool adherent cells from PBL abolishes the suppressive effect. When the PBL are fractionated by velocity sedimentation the suppressor cells can be separated from the responding cells. The circulating lymphocytes, freed from the inhibiting effect, either by nylon wool absorption or by velocity sedimentation fractionation, are able to give a strong secondary in vitro anti-SRC response, in which the long latency period, usually observed when PBL are stimulated with antigen in culture, is abolished or at least reduced. The suppressor effect present in the PBL is not due to granulocytes, platelets or erythrocytes.


Ontogeny of adherent cells. I. Distribution and ontogeny of A cells participating in the response to sheep erythrocytes in vitro.

An adherent (A) cell function required for the in vitro antibody-forming response to sheep erythrocyte (SRBC) antigen has been demonstrated in a culture medium enriched with nucleic acid precursors and 2-mercaptoethanol. The essential function is fulfilled best by adult adherent cells of the spleen, to some extent by bone marrow and perhaps lymph node A cells, and poorly or not at all by peritoneal or lung A cells. Ontogenetic studies reveal the absence or inhibition of neonatal A cell synergistic function in the in vitro response to SRBC. The capacity of splenic adherent cells to collaborate with column-separated nonadherent cells appears only from the third or fourth day after birth, with ratio indices reaching levels significantly greater than nonsynergistic background by the fifth day and showing little further increase until the second week of age.


Cell surface immunoglobulin. XV. The presence of IgM and an IgD-like molecule on the same cell in murine lymphoid tissue.

The present studies were designed to determine whether IgM and "IgD" are on the same cell in the mouse. Thus, radioiodinated murine lymphocytes were treated with anti-mu and complement to kill IgM-bearing cells. The dead cells were removed by gradient centrifugation. Results indicate that a portion of the IgD is removed by depleting IgM-bearing cells. Using cells from thoracic duct or lymph nodes but not spleen, it was evident that some of the double bearers are large lymphocytes.


Concentrations of three hapten-binding immunoglobulins in pooled normal human serum.

The amount of natural anti-DNP-cap, anti-NIP-cap or anti-ABA-TYR in human IgM was measured by using immunoabsorbents and hapten elution. We found that 1.0% of pooled human IgM is specific for DNP-cap, 0.2% for NIP-cap and 0.02% for ABA-TYR. Haptens NIP and DNP were found to be cross-reactive when tested with natural antibodies even though they were not cross-reactive when tested with immune antibodies.


The effects of dantrolene sodium on cardiac and skeletal muscle in rats.

Dantrolene sodium in different concentrations was administered to the spontaneously beating heart placed in a modified Langendorff apparatus. Heart frequency and contractility were recorded. Dantrolene sodium was also administered to the rat diaphragm. Twitch tension after indirect supramaximal stimulation was recorded. Dantrolene sodium produced a long lasting dose-dependent reduction of the contractility of the isolated rat heart up to 75% of control values. It had no effect on the heart frequency. The drug also decreased the force of contraction of the rat skeletal muscle in vitro to the same extent. The diaphragm appeared to be more sensitive to low concentrations of dantrolene sodium than was heart muscle i.e. the dose-response curve on rat diaphragm was flatter. It may be concluded however that higher concentrations of dantrolene sodium may effect the contractility of heart muscle as well and that this may have clinical implications.


Increase in the coronary vascular resistance by indomethacin in the isolated guinea pig heart preparation in the absence of changes in mechanical performance and oxygen consumption.

Experiments were performed in isolated guinea pig hearts, perfused at constant volume. Left ventricular pressure, left ventricular dp/dtmax, coronary vascular pressure and coronary venous pO2 were measured continuously. Indomethacin (1.4 X 10(-6) M) increased coronary vascular resistance by 15% over control (p less than 0.01) without altering the myocardial contractile force. When PGE2 (1.4 X10(-8) M) was subsequently added, it abolished the indomethacin action and lowered the coronary vascular resistance below the pre-indomethacin control value. This increase in coronary vascular resistance caused by indomethacin was also seen when the animals were pretreated with reserpine and/or the adrenoceptor blocking agents phenoxybenzamine and propranolol, but was prevented completely by previous addition of PGE2 (1.4 X 10(-7) M). The results provide evidence for possible involvement of endogenous prostaglandin-like substances in the maintenance of coronary vascular resistance in the isolated guinea pig heart.


Isoprenaline and canine cardiac refractory periods.

Atrioventricular refractory periods and their modifications induced by variable doses of sioprenaline have been investigated in dogs. Premature atrial stimuli (St2) were applied at variable intervals following regular stimuli (St1) which ensured atrial pacing. Atrial (AERP), nodoventricular (NERP) and global (GERP) effective refractory periods, as well as the global functional refractory period (GFRP) were determined before, during and after infusion of the drug. In low doses, isoprenaline did not significantly alter these various parameters. This confirms its lack of dromotropic effect on the healthy heart. In contrast, high doses of the drug significantly reduced the refractory periods, probably by simple correction of the negative dromotropic effects resulting from overstimulation. Also when the infusion was stopped, marked but reversible conduction depression was observed. It would appear that this reflects 'exhaustion' of cell metabolism induced by the drug.


The effects of amiodarone on the sinus node activity of the rabbit heart.

The action of amiodarone (1.5 X 10(-5) M) on sinus node activity of spontaneously beating isolated right atria of rabbit at 30 degrees C was investigated using a microelectrode technique. The drug significantly increased the action potential duration and decreased the slope of diastolic depolarization, both effects leading to a reduction of the sinus rate. In contrast to beta-blocking agents, amiodarone reduced but did not completely abolish the adrenergic effects on the sinus node activity. It is concluded that the amiodarone-induced bradycarida observed in clinical trials might be due to a direct effect of the drug on the sinus node.


Effect of probenecid on endogenous and exogenous 3,4-dihydroxyphenylacetic acid and homovanillic acid in the rat brain.

The two dopamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were measured in corpus striatum and hippocampus in rats after an intracerebroventricular injection of DOPAC or HVA. Probenecid 200 mg/kg i.p. increased the concentration of HVA by the same factor in both control animals and animals treated with HVA. Probenecid had no effect on the DOPAC concentration in control animals or in animals treated with DOPAC. After DOPAC intraventricularly some increase in the HVA concentration could be seen. Pargyline 75 mg/kg was given i.m. and the decline of HVA and DOPAC in corpus striatum was compared in animals with or without probenecid treatment (200 mg/kg i.p.). In the control animals DOPAC declined more rapidly than did HVA. In the probenecid-treated animals there was no change in the DOPAC curve while the HVA showed a slower elimination but still with an exponential curve. The conclusion is drawn that there is an active mechanism for the excretion of DOPAC which is not identical with the excretion mechanism for HVA. A considerable part of the dopamine is directly deaminated to DOPAC in vivo and some of this DOPAC is probably O-methylated to HVA.


Uptake and release of catecholamines in sympathetic nerve fibres in the spleen of the cod, Gadus morhua.

The effects of drugs known from mammalian experiments to interfere with uptake and release of adrenergic transmitters in the sympathetic nerve terminals have been investigated on perfused spleen and isolated spleen strips from the cod. Cocaine and desipramine inhibit the accumulation of 3H-noradrenaline in the perfused spleen, probably by interfering with uptake mechanisms. Both drugs also shift to the left the dose-response curves for noradrenaline and adrenaline on isolated strips, cocaine being most potent. The maximal contraction force of isolated strips also increases after cocaine when noradrenaline is the agonist, but not when methacholine is used or on chronically denervated strips. This effect of cocaine is therefore not due to a general postsynaptic effect. Tyramine and amphetamine both release stored 3H-noradrenaline from the perfused spleen, and tyramine also contracted the spleen strips. In contrast to the situation in mammals, the dose-response curve for tyramine is not affected by cocaine, and tyramine (up to 10(-3) M) present in the bath does not potentiate the dose-response curve for noradrenaline on isolated strips. Different uptake mechanisms for tyramine and noradrenaline into the nerve terminal are therefore suggested for the cod sympathetic fibres. The alpha-adrenoceptor blocking agent phentolamine produces an increase in overflow of label during nerve stimulation at 5Hz in the perfused spleen preloaded with 3H-noradrenaline. An alpha-adrenoceptor-mediated control of the release of catecholamines, similar to that in mammals, appears to be present in the cod.


Uptake and release of catecholamines in sympathetic nerve fibers in the spleen of the cod, Gadus morhua.

The effects of denervation or pretreatment with reserpine or 6-hydroxydopamine on the contractile responses of the cod spleen have been studied. The contraction produced by tyramine is abolished by pretreatment with reserpine or 6-hydroxydopamine and by denervation. The response to tyramine is restored in reserpine-treated strips after exposure to noradrenaline, but this is not the denervated or 6-hydroxydopamine-treated strips. The response to noradrenaline is potentiated by 6-hydroxydopamine treatment or denervation, while neither acute (2 days) nor chronic (8 days) reserpine treatment have any detectable effect. The effects of 6-hydroxydopamine and denervation are probably due to specific supersensitivity caused by the loss of the presynaptic uptake mechanisms on destruction of the nerve terminals, but contribution by a non-specific postsynaptic supersensitivity is not completely excluded. The effect of acetylcholine is also significantly potentiated by pretreatment with 6-hydroxydopamine or denervation, but not by reserpine, while the dose-response curve for carbachol is not affected by the specific cholinesterase inhibitor BW 284 C51, denervation or 6-hydroxydopamine. The degree of potentiation of the acetylcholine curve caused by both denervation and 6-hydroxydopamine treatment is very similar to that produced by BW 284 C51. It is concluded therefore, that the cholinesterase is associated with nerve fibres which are destroyed by denervation and 6-hydroxydopamine. Although the cod spleen receives both cholinergic and adrenergic sympathetic innervation all responses to nerve stimulation of the perfused spleen are abolished after 6-hydroxydopamine treatment. The possibility is suggested that the sympathetic fibres to the cod spleen represent a primitive type of neuron, with both catecholamines and acetylcholine present within the same terminals.


Enhancement of stereospecific opiate binding to neural membranes by phosphatidyl serine.

An effort was made to elucidate the possible involvement of phosphatidyl serine in the opiate receptor by examining stereospecific 3H-dihydromorphine binding to neural membrane preparations in the presence of exogenous phosphatidyl serine. The addition of phosphatidyl serine to suspensions of either synaptic membranes or a microsomal fraction significantly enhanced both high and lower affinity binding, the Kd's being 1.0 X 10(-9) and 5.7 X 10(-9) M without lipid and 5.0 X 10(-10) and 3.8 X 10(-9) M with added phosphatidyl serine. Phosphatidyl ethanolamine and lysophosphatidyl ethanolamine had an inhibitory effect on opiate binding. Sulfatides had a slight enhancing effect, while other acidic lipids and lecithin were without any effect. With the use of 3H-dansyl phosphatidyl serine it was established that sufficient exogenous lipid was associated with the membrane to account for the enhancement of opiate binding. The results were discussed from the standpoint of the modification of membrane lipids and their possible significance for the binding of opiates and other ligands. It is suggested that phosphatidyl serine may be an important component of the opiate pharmacophore.


Acute effects of morphine on regional brain levels of acetylcholine in mice and rats.

Morphine increased levels of acetylcholine in mouse striatum in a dose-dependent manner, the increase occurring at the lowest dose previously found to produce analgesia and coinciding with the time of peak analgesic effect. Naloxone blocked this increase. After repeated injections of high doses of morphine, no effect was seen. The hippocampus was the only other brain region showing an effect, and this after a high dose. In the rat, morphine (30 and 90 mg/kg) increased striatal acetylcholine levels. At these and lower doses (2.5 mg/kg and 10 mg/kg) the ratios in the striatum of levels of acetylcholine to levels of dopamine were significantly increased. Only at the highest dose did morphine increase the levels of dopamine in the striatum and of acetylcholine in the hippocampus. Morphine did not change the levels of dopamine in the striatum and of acetylcholine in the hippocampus. Morphine did not change the levels of norepinephrine in either the hypothalamus or cortex of the rat.


Specific patterns of neuron arrangement and of synaptic articulation in the medial geniculate body.

Golgi and electron microscopic analysis of the known cellular layers in concentric shells of the ventro-lateral portion of the medial geniculate body revealed a flat grid of high density neuropil filling the space between the geniculocortical relay cells, forming essentially a single cell layer in each lamina. The "skeleton" of this neuropil grid is made up by the interdigitating dendritic tufts of the geniculocortical relay cells, joined together by a rich system of desmosomoid adhesion plaques. The "holes" of the "skeleton" are filled in by the multilobed dendritic appendages of Golgi type II interneurons and the grape-like terminals of the inferior collicular specific afferents. Additional axon terminals of other sources--terminals of descending corticogenicular fibers, axons of the Golgi type II interneurons and terminals of the initial collaterals of the geniculocortical relay cells--contribute only to a very insignificant fraction of neuropil volume. The Golgi type II interneurons are oriented in perpendicular direction to the cell layers so that they may bridge with their dendrites several successive layers. Although the general expression "synaptic glomeruli" used in other relay nuclei for this type of specific synaptic arrangement is hardly applicable to this grid-like neuropil, the essential synaptic articulation pattern of all thalamic relay nuclei is well maintained. The specific inferior collicular afferents are presynaptic to both relay cell dendrites and to the multilobed dendritic appendages of Golgi type II cells, which in turn are presynaptic to the same dendritic regions of the relay cells receiving the bulk of the specific afferents.


Types of interneurons and their participation in the neuronal network of the medial geniculate body.

Three different types of interneurons can be separated in the Golgi picture, and many of their details can be identified under the electron microscope, in the medial geniculate body (MGB) of the cat: (1) typical short axon Golgi II. cells of the thalamic type, (2) somewhat larger Golgi type II cells with medium range axon, and (3) spidery neurogliform short axon cells. The most distinctive features of the two first types (1) and (2) are their irregular drumstick shape appendages, increasing in number as well as in length and irregularity of their stalks towards the periphery of the dendrites. These appendages form the vast majority of synaptic profiles in the aggregations of synaptic neuropil (glomeruli) of the nuclei, and they are both presynaptic and postsynaptic by the usual standards applied for the evaluation of the polarity of synapses. The characteristic beaded dendrites of the (3) neurogliform cell type can be recognised particulary easily in the electron microscopic picture. They are both presynaptic and postsynaptic in structural polarity. All identified process profiles of interneurons contain flattened (F-type) or pleomorphic synaptic vesicles. Membrane contacts, in which the interneurons appear to be presynaptic are either of the symmetric (Gray type II) or of an intermediate type. The membrane contacts of postsynaptic portions of the interneurons are usually of the asymmetric type (Gray type I) and the presynaptic profiles contain round (R-type) vesicles. The larger one have been shown already earlier to be derived from specific sensory (inferior collicular) afferents, while many of the smaller ones could be identified in the present study as being derived from cortico-geniculate descending pathways, arising from the auditory areas. Some of the synaptic contacts of the interneurons are apparently derived from other interneurons, the presynaptic profiles being often equivocal or more likely of axonal origin (all interneurons have clear axons in the Golgi picture). The occurrence of three distinct types of interneurons--probably all of inhibitory nature--the complexity in synaptic arrangement, and more particularly in the dendritic linkage of numerous synaptic sites does not favour such simple explanations as surround inhibition by forward or by backward inhibition, but suggests more sophisticated modes of impulse processing in the MGB.


Adapting reflexes controlling the human posture.

Doubt about the role of stretch reflexes in movement and posture control has remained in part because the questions of reflex "usefulness" and the postural "set" have not been adequately considered in the design of experimental paradigms. The intent of this study was to discover the stabilizing role of stretch reflexes acting upon the ankle musculature while human subjects performed stance tasks requiring several different postural "sets". Task specific differences of reflex function were investigated by experiments in which the role of stretch reflexes to stabilize sway doing stance could be altered to be useful, of no use, or inappropriate. Because the system has available a number of alternate inputs to posture (e.g., vestibular and visual), stretch reflex responses were in themselves not necessary to prevent a loss of balance. Nevertheless, 5 out of 12 subjects in this study used long-latency (120 msec) stretch reflexes to help reduce postural sway. Following an unexpected change in the usefulness of stretch reflexes, the 5 subjects progressively altered reflex gain during the succeeding 3-5 trials. Adaptive changes in gain were always in the sense to reduce sway, and therefore could be attenuating or facilitating the reflex response. Comparing subjects using the reflex with those not during so, stretch reflex control resulted in less swaying when the task conditions were unchanging. However, the 5 subjects using reflex controls oftentimes swayed more during the first 3-5 trials after a change, when inappropriate responses were elicited. Four patients with clinically diagnosed cerebellar deficits were studied briefly. Among the stance tasks, their performance was similar to normal in some and significantly poorer in others. Their most significant deficit appeared to be the inability to adapt long-latency reflex gain following changes in the stance task. The study concludes with a discussion of the role of stretch reflexes within a hierarchy of controls ranging from muscle stiffness up to centrally initiated responses.


Effect of peripheral anatomy on the fine structure and histochemistry of the Rolando substance: degenerative atrophy of central processes of pseudounipolar cells.

Disappearance of fluorid-resistant acid phosphatase activity from the ipsilateral Rolando substance after transection of the peripheral nerve, is shown to be due to the cessation of enzyme supply from dorsal root ganglion cells to their central terminals. This is accompanied by (or ensues in consequence of) a fine structural derangement of these terminals ("degenerative atrophy"). Fine structural alterations of axon terminals undergoing degenerative atrophy, though similar to some extent to those seen during early phases of a Wallerian degeneration, are markedly different. Also myelinated nerve fibers, both in the dorsal horn and in dorsal columns, are affected by degenerative atrophy. This important, new trophical feature of sensory ganglion cells suggests a delicate metabolic balance between peripheral and central axonal branches of bipolar (pseudounipolar) cells. Degenerative atrophy raises serious implications in evaluating hodological experiments based upon Wallerian degeneration and offers new perspectives for theoretical and clinical neurology.


Inhibitory interaction between the vestibulo-ocular reflexes arising from semicircular canals of rabbits.

In anesthetized albino rabbits, electric pulse stimulation was applied to ampullary branches of the vestibular nerve. Reflex discharges evoked from a canal in an extraocular muscle were depressed very effectively by conditioning stimulation at a certain other canal. The present systematic survey revealed that this reflex depression occurred specifically in 3 combinations of conditioning and testing canals; 1. anterior and posterior canals of the same side; 2. anterior and posterior canals of the opposite sides; and 3. horizontal canals of the two sides. Occurrence of postsynaptic inhibition in oculomotor neurons, on the other hand, was indicated by appearance of slow muscle potentials in extraocular muscles. It was confirmed that this motoneuronal inhibition did not contribute to the reflex depression in the above combination (1). Even in combinations (2) and (3), the accompanying motoneuronal inhibition was eliminated by adjusting intensities of canal stimuli or by severing its pathway in the medulla, or it was discriminated from the reflex depression by their different latencies and time courses. Hence, it was concluded that the reflex depression was attributable, at least largely, to non-motoneuronal inhibition, presumably postsynaptic inhibition at relay neurons for vestibulo-ocular reflexes. Slow muscle potentials evoked from a canal were also used as testing responses, but their depression could not be detected after conditioning at other canals.


The social consequences of teenage parenthood.

The adolescent mothers consistently experienced great difficulty in realizing their life plans, when compared with their classmates who did not become pregnant premaritally in their early teens. Marital instability, school disruption, economic problems, and difficulty in family size regulation and child-rearing were some of the complications brought on by their premature, unscheduled childbearing.


Fertility control services for adolescents: access and utilization.

More than one million teenagers get pregnant each year; six in 10 pregnancies end in live births--the rest in induced or spontaneous abortions. More than one-third of the births are out of wedlock. Yet, two-thirds of teenage pregnancies and half of the births are not intended. Some two million teenagers at risk of unintended pregnancy are now using effective birth control methods; but two millions are still denied them.


Teenagers: fertility control behavior and attitudes before and after abortion, childbearing or negative pregnancy test.

Following abortion or delivery, teenagers' knowledge and use of effective contraception improved markedly; but those who had negative pregnancy tests continued to take risks--and to get pregnant--subsequently. Most sexually active teenagers were poorly educated on the facts of reproduction, and began to have intercourse before seeking contraception.


Circadian rhythms and photoperiodic time measurement in mammals.

Many mammalian species display seasonal breeding patterns correlated with annual cycles of change in the physiology and morphology of the reproductive system. Such annual reproductive cycles are often photoperiodically controlled (i.e, the annual change in day length determines when reproductive activity begins and when it ends within the annual cycle). Photoperiodic control of seasonally appropriate changes in reproductive activity is dependent on an endogenous time measuring process. Among mammals the physiological basis of photoperiodic time measurement has been studied most extensively in the golden hamster. Studies with this species indicate that photoperiodic time measurement is executed by the circadian system. The time measuring process depends on a circadian oscillation of responsiveness to light with properties similar to those of the hypothetical rhythm originally proposed by Bünning to explain photoperiodic phenomena in plants. The available evidence strongly suggests the participation of the pineal gland and the suprachiasmatic nucleus (SCN) in the photoperiodic regulation of mammalian reproductive cycles. However, little is known regarding concrete physiological mechanisms, and the extent to which the SCN and the pineal gland may participate in the time measuring process per se remains to be determined.


Renal prostaglandins in relation to sodium regulation and hypertension.

The renal inner medulla is very rich in prostaglandins as well as in the enzymes that biosynthesize prostaglandins. When given intravenously, prostaglandin E or A will cause a natriuresis. Using a quick-freeze method one can measure the in vivo concentration of prostaglandins in the kidney. After a high NaCl intake for 2 weeks, the prostaglandin E2 (PGE2) concentration in rat kidneys decreases 40% below control. After 2 weeks of a low NaCl diet, the intrarenal PGE2 concentration approximately doubles. Blockers of prostaglandin synthesis have recently been shown to cause a natriuresis. These observations are compatible with the possibility that intrarenal PGE2 acts locally as an antinatriuretic hormone. Intrarenal prostaglandins may also have a role in certain forms of hypertension. The interstitial cells of the renal papilla appear to be able to secret antihypertensive humoral substances and can also synthesize prostaglandins. They have diminished numbers of cytoplasmic lipid granules in several forms of experimental hypertension. Moreover, using the quick-freeze method, the kidneys of "post-salt" hypertensive rats have a 36% lower intrarenal PGE2 level than is present in "post-salt" normotensive controls. Moreover, the kidneys from Kyoto spontaneously hypertensive rats have almost a three times greater intrarenal PGF2alpha concentration from Kyoto normotensive controls. The abnormal prostaglandin concentrations in these two types of hypertension may constitute key integral features of the control mechanisms through which the kidney brings about high blood pressure.


An outbreak of methylmercury poisoning due to consumption of contaminated grain.

An outbreak of methylmercury poisoning took place in the fall and winter of 1971-72 in Iraq. Six thousand five hundred and thirty cases were admitted to hospitals throughout the country and 459 died in hospital. The outbreak was the result of eating homemade bread prepared from wheat treated with a methylmercury fungicide. The wheat was intended for planting purposes only. Signs and symptoms of poisonings in adults indicate that the major site of action of this form of mercury is the central nervous system. Severe brain damage also resulted from prenatal exposure when the mother ingested large amounts of the contaminated bread. The frequency of signs and symptoms in an exposed population was found to be related to the estimated maximum blood levels, i.e., the concentration in blood at the end of exposure. A small percentage of the population exhibited a significant increase in complaints of paresthesia at maximum blood levels in the range of 240 to 480 ng Hg/ml. At higher blood levels a greater proportion of the population complained of paresthesia and other signs and symptoms became apparent.


Evaluation of intramuscular 15(s)-15-methyl prostaglandin F2 alpha tromethamine salt for induction of abortion, medications to attenuate side effects, and intracervical laminaria tents.

Sixty gravidas 8 to 20 menstrual weeks' gestation were studied to evaluate (1) the efficacy of intramuscularly administered 15(S)-15-methyl prostaglandin F2alpha tromethamine (15(S)-Me-PGF2alpha) as an abortifacient; (2) the effectiveness of prochlorperazine and Lomotil for attenuation of vomiting and diarrhea; and (3) the practicability of augmenting this prostaglandin dose schedule with intracervical laminaria tents. Group I subjects received 250 mug of 15(S)-Me-PGF2alpha intramuscularly every 2 hours for the initial 24 hours and 500 mug for the next 24-hour period. Group II received the same dose schedule of prostaglandin and prearranged doses of prochlorperazine and Lomotil. Group III received the same dose schedule of prostaglandin after intracervical laminaria tents had been inserted, and prochlorperazine and Lomotil were administered by the prearranged dose schedule. It appears that (1) the 15(S)-Me-PGF2alpha was effective in inducing abortion; (2) a significant decrease in body temperature occurred; (3) the abortifacient effectiveness of this prostaglandin dose schedule was not altered by the regimen of prochlorperazine and Lomotil; (4) only diarrhea was significantly attenuated with the regimen of prochlorperazine and Lomotil; and (5) laminaria augmentation was not useful.


Intrauterine extra-amniotic 15(s)-15-methyl prostaglandin f2 alpha for induction of early midtrimester abortion.

Twenty-six patients 13 to 15 weeks pregnant received extraovular 15(S)-15-methyl prostaglandin F2 alpha in a dosage of 1 mg every 18 to 24 hours for three doses. Twenty-five (96%) of the patients aborted; fifteen patients aborted incompletely. The mean induction-to-abortion time was 15.8 hours. A decrease in plasma progesterone levels could not be consistently correlated with abortifacient activity, and there was no statistically significant relationship between abortion time and parity or gestational age. One patient failed to abort after 36 hours of therapy and was aborted by curettage. She was the only patient who developed a postabortion uterine infection. Results with the extraovular technique appear to be similar to those with the intra-amniotic and the intramuscular prostaglandin techniques. Therefore, extraovular administration may be useful for inducing abortion in patients who are in the early midtrimester of pregnancy.


The detection of ovulation by intravaginal telemetry.

Following ovulatory control cycles in four celibate, healthy women, 27 to 34 years of age, basal body temperatures (BBT) were obtained in three cycles, utilizing a transistorized transvaginal telemeter. The electronic signals were collected on an automatically activated cassette receiver and later translated into temperature readings. The results were compared with values obtained simultaneously with a standard metabolic oral thermometer. The vaginal temperatures were consistently lower than the oral readings and offered a more sensitive and reproducible method of obtaining BBT. However, this system is very complex, requiring well-informed, highly motivated patients, and should be viewed currently as an investigative tool.


Sutureless vasectomy, an improved technique: 1300 cases performed without failure.

Thirteen hundred bilateral, partial vasectomies have been performed for sterilization, without a failure. The procedure utilizes (1) a small, single incision; (2) no sutures; (3) cautery of each vas deferens lumen with a hand-held, battery-operated, disposable, hot-wire cautery; and (4) sealing of the proximal vas deferens in its sheath with a single tantalum clip. No spermatic granulomas were noted using this technique.


Varicocelectomy in the subfertile male: a ten-year experience with 295 cases.

During a 10-year period 295 varicocelectomies were performed in subfertile males. Results of follow-up studies indicate the following: (1) Semen quality improved in a meaningful manner in 58% of men following varicocelectomy. The improvement, except at times for motility, was often only modest. The semen improved in 46% of men with a preoperative average count of less than 10 million/ml and in 70% whose count was 10 million/ml or more. (2) The stress pattern of sperm morphology was seen prior to surgery in 93% of the men. (3) The pregnancy rate for the entire series was about 41%. Men with a preoperative count of 10 million/ml or more achieved a 48% conception rate and those with a count of less than 10 million/ml succeeded 35% of the time. Only 7% of the pregnancies occurred without a concomitant improvement in the semen quality. (4) Men with moderate- and large-sized left varicoceles fared better than those with small-sized varicoceles. (5) Varicocelectomy, when varicocele and poor semen quality coexist, is a justified procedure in the treatment of the infertile couple.


Linear and quantitative migration of stored sperm through cervical mucus during the periovular period.

The ability of stored spermatozoa to penetrate fresh samples of cervical mucus obtained from 23 patients during 47 menstrual cycles was studied, utilizing an in vitro test. The determination of daily hormonal and gonadotropin values allowed an accurate realationship to be established between the results of sperm-mucus interaction and the environmental milieu. Cervical mucus was found to be effectively penetrable only on day -1 and day 0 when considered with respect to the plasma luteinizing hormone surge. Correlation was apparent between the ability of sperm to penetrate and the favorable clinical parameters of cervical assessment.


Serum luteinizing hormone, follicle-stimulating hormone, and testosterone responses to gonadotropin-releasing factor in males with varicoceles.

Five infertile males, ages 25 to 35, with oligospermia and varicocele had following gonadotropin-releasing hormone (LRF) infusion a rise of serum follicle-stimulating hormone, luteinizing hormone, and testosterone levels which was not different from that of normal fertile males. The response of these hormones to LRF infusion was unaltered by spermatic vein ligation, but a significant elevation of the sperm count occurred. Thus, improvement in sperm count following spermatic vein ligation is not mediated via changes in peripheral gonadotropin or testosterone concentrations.


Detection of human chorionic gonadotropin in blood of regularly bleeding women using copper intrauterine contraceptive devices.

Highly sensitive and specific radioreceptorassay and radioimmunoassay of human chorionic gonadtropin (hCG) have been used in the detection of hCG in random serum samples during the luteal phase of the menstrual cycles of 200 women and in daily serum samples obtained a few days prior to expected ovulation through the luteal phase in 3 women with regular bleeding patterns and using a copper intrauterine device (IUD). Twelve to nineteen per cent of IUD users showed hCG in serum during the luteal phase, indicating that the presence of the IUD, while permitting fertilization, probably causes interference through degeneration of the blastocyst and consequent lack of implantation.


Embryotoxicity of leukocyte extracts and its relationship to intrauterine contraception in humans.

Twelve human uteri containing intrauterine contraceptive devices (IUDs) and ten uteri without IUDs were obtained at hysterectomy. Samples of fluid were collected from the uterine lumina by absorbing the fluid in small pieces of lens paper. In the samples of luminal fluid we measured the concentration of beta-galactosidase, an enzyme which is present in human neutrophilic leukocytes and whose concentration in luminal fluid should correlate with the local inflammatory response to the intrauterine foreign body. In the samples of fluid from IUD-bearing uteri, the concentration of beta-galactosidase was significantly (P less than 0.0005) greater than that in luminal fluid from control uteri, the averages of the two groups differing by 3.8 units. To determine whether a foreign-body response of this magnitude could have any effect on preimplantation embryos, we cultured mouse embryos from day 4 to day 7 of development in culture media to which extracts of human leukocytes were added. All mouse embryos were killed when the culture media contained enough leukocyte extract to give beta-galactosidase concentrations of 0.5 unit or higher. Thus mouse embryos were killed by leukocyte extracts whose beta-galactosidase concentrations were actually less than the concentration of this marker enzyme measured in IUD uterine fluid. This comparison indicates that the luminal fluid in IUD-bearing uteri contains leukocyte break-down products in sufficient concentration to be lethal for preimplantation embryos.


Surface changes of the rat embryo before implantation.

Study of the rat embryo surface under the scanning electron microscope shows the superficial structure of the pellucid membrane as a perforated network cover which does not change throughout the preimplantation period (1 to 41/2 days). Dissolution of the pellucid membrane by brief ATP treatment reveals a zygotic surface which changes from day to day. The number and length of microvilli increase with development. At the early blastula stage there is a great heterogeneity of microvilli of different size and shape as well as large membranous ruffles mainly located at one pole of the embryo. The significance of these structures may relate to the changing metabolic requirements of the developing embryo and to the invasive properties of the trophoblast.


Measurement of androstanediol in plasma in a radioimmunoassay using celite column chromatography.

A rapid and relatively simple, but specific, radioimmunoassay for the potent androgen, androstanediol (3 alpha-diol), is described. Despite the availability of a nonspecific C-19 androgen antibody requiring a 17 beta-hydroxy group, androstanediol can be measured in plasma by prior purification of a plasma solvent extract using a Celite microcolumn. Values obtained do not differ from those previously reported using more complicated chromatographic techniques.


Preliminary results of the endometrial and ovarian response to luteal phase norgestrel.

Luteal phase administration of dl-norgestrel, in doses of 10 mg to two groups of women with ovulatory cycles, did not significantly affect the length of the menstrual cycles, the duration of menses, or the endometrium whether given on a 5-consecutive day (group A) or 5-alternate day schedule (group B). Serum progesterone levels decreased in 9 of 11 patients in group A from a pretreatment level of 1431 ng/100 ml to 568 ng/100 ml and then to 419 ng/100 ml for the first and third treatment cycles, respectively; corresponding values for group B were 1149 ng/100 ml, 237 ng/100 ml, and less than 100 ng/100 ml, respectively. No adverse reactions were noted in any of the subjects; Papanicolaou smears remained class I, blood chemistry values showed no significant changes from pretreatment values, and no pregnancies occurred during treatment.


Interaction of lectins with surface membrane receptors of animal cells. I. Factors responsible for agglutinability of human, rabbit, and sheep erythrocytes with concanavalin A.

A study of various factors influencing the Con A-mediated cell agglutinability failed to reveal any correlation between the agglutinability and the binding capacity of Con A-agglutinable and non-agglutinable human, rabbit, and sheep erythrocytes. Treatment with trypsin and neuraminidase on the one hand and chondroitin sulphate, polyvinylpyrrolidone and polylysine on the other hand made the agglutination of human erythrocytes possible, promoted the agglutination of rabbit erythrocytes, but had almost no effect on sheep erythrocytes, which agglutinated only after treatment with pronase or polylysine. The negligible effects of low temperature, NaN3, cytochalasine B and theophylline on cell agglutinability indicate that neither membrane fluidity, metabolic energy, cAMP, nor the microfilamentous apparatus are likely to play any important role in the Con A-mediated agglutination of erythrocytes. Differences in agglutinability between erythrocytes obtained from different animal species and subjected to different treatments with enzymes and polymers are explained as being due to alterations in the surface charge and the zeta potential.


Enhancement of antibody response to soluble HSA antigen of young rabbits pretreated with deoxyribonucleic acids from adult donors.

Rabbits were injected with one dose of 2-4 mg. isolated nuclear DNA (from spleens of adult donors) at 3-5 days of age and their antibody response to a later administered soluble HSA antigen was followed. A) Rabbits receiving antigen only at 9 days of age, without previous DNA, did not form antibodies even after the second dose of HSA antigen given at 8 weeks of age. Nor were antibodies detected in the serum of rabbits treated before antigen, i.e., at 4-5 days of age, with DNA-N (from spleens of non-immunized rabbits), or DNA-P (from spleens of the pig immunized with a different antigen). Only rabbits treated with DNA-Ia (from spleens of rabbits immunized with soluble HSA antigen) formed antibodies to HSA antigen given at 9 days after birth. Antibodies were detectable in the serum at 21 days after antigen administration and retained increased levels as long as 50 days after the first dose of antigen. B) When HSA antigen was injected at 17-18 days after birth, even the DNA-N (4 mg.) given at 3-5 days after birth increased the antibody response in the recipients. Substantial acceleration and increase in antibody formation was obtained in rabbits treated with DNA-Ib after birth as compared to control rabbits (after antigen only with DNA). On the contrary, DNA-H from spleens of rabbits intensively immunized with HSA in adjuvant, given in a larger dose (4 mg.), suppressed the antibody response of rabbits over 8 weeks of age after the second dose of antigen. DNAs from spleens of immunized donors injected into rabbit offspring, without subsequent HSA antigen administration, did not lead to the appearance of detectable anti-HSA antibodies in the serum of young rabbits under the conditions of our experiments A and B. Long-term effects of DNAs injected in the postnatal period into rabbits on their immune response are discussed.


Decreased in vitro incorporation of 3H-thymidine into spleen cell DNA of antigenically stimulated rabbits treated in the postnatal period with nucleic acid from adult donors.

Spleen cell DNA from 6-month-old rabbits, that has received the first dose of soluble HSA antigen at 9 days of age and the second at 2 months of age and did not form antibodies incorporated 3H-thymidine in vitro as early as 1 hour after restimulation of rabbits with HSA antigen in vivo. The incorporation rate (in muCi/mg.) of isolated cellular DNA was higher than that of DNA from rabbits that had been pretreated with nuclear DNA from the spleens of adult non-immunized rabbits or from the spleens of pigs immunized with a different antigen (DNP-BGG), 4-5 days before the first dose of antigen. The inhibitory effect of pig DNA was stronger. Decreased incorporation of DNA was noted at 8 hours after restimulation of rabbits treated in the same manner as the previous group. The difference between the incorporation rate at 1 hour and at 8 hours after the restimulation was most marked in the DNA obtained from rabbits not treated with nuclear DNA in the postnatal period. The activity of lymphoid cell DNA after antigenic stimulation is discussed.


The intersex difference in the production of alloantibodies and growth of tumour allografts in mice.

The comparisons of immune responses to tumour allografts in male and female mice showed the following intersex differences: 1. Production of humoral antibodies is, in general, higher in females; since, however, the time course of titres differs for haemagglutinating and cytotoxic antibodies as well as with the sex, the titre of the same antibody may be higher in males at certain time intervals when the peak is delayed and the production in females is already declining. 2. In recipients specifically presensitized with spleen extract as well as in controls, the growth of allogeneic tumour (SaI) exhibits quantitative intersex differences being reduced in females. In the initial phase of growth, following the spleen extract, the facilitation (enhancement) of the tumour allograft is apparent olny in males, whereas in females it is delayed. 3. The facilitating effect of antibodies passively transferred from males or females corresponds mainly to the sex and strain of the recipient, only rarely to the sex of the producer. 4. In CBA strain mice, females are more resistant to the growth of SaI and also mortality from the primary tumour is lower in females; in contrast, the frequency of metastases in females is higher. 5. In the IC strain, where the sex effect on tumour growth is particularly pronounced, the consequences of castration were concordant with the inferred hormonal control of the allograft response: in males, the relatively high percentage of lethal spontaneous takes (60%) was reduced following castration (to 13%), whereas the opposite trend was observed in females, namely an increase from 0% in sham-operated controls to 23% in the castrated group.


Development of immunity against antigens of the A and B blood groups during postembryogenesis in chickens.

51Cr-labelled erythrocytes were injected into young chicks, F1 hybrids of the inbred chicken lines, from hatching to 2 months of age. The onset of immunity was measured by means of elimination of labelled red blood cells. It was found that with the B-locus difference between donors and recipients the immune response developed from 4 days of age to the end of the first week, whereas with the A-locus difference it developed during the second week of life. The onset of immunity is delayed in inbred chickens compared to outbred chickens, because we have used one alloantigen difference.


[Increased immune reactivity of exacerbated visceral lupus erythematosus: II. Reason and pathogenetic significance].

The sera of patients suffering from acute phase Lupus erythematosus visceralis contains factors inducing an increased blastoid transformation of lymphocytes: 1. one or some factors having a molecular weight ranging from 7.8 X 10(5) to 1.5 X 10(6) daltons. This active principle was shown to increase specifically the transformation of only the autologous lymphocytes. These high-molecular weights components are supposed to be antigen-antibody-complexes. 2. Beside those high-molecular weight components also low-molecular weight factors could be shown to increase the transformation of lymphocytes as well. By contrast these latter factors stimulate the transformation of autologous as well as homologous lymphocytes. The low-molecular weights components are stable after an incubation for 30 min after 56 degrees C and have molecular weights of about 7.5 X 10(4) and 1.6 X 10(5) daltons, respectively. Supposed the low molecular weight factors of the sera of exacerbated Lupus erythematosus visceralis are mitogenic lymphokines the increased activity of those mediators should possess pathogenic significance.


[Hyde's nodular prurigo: an electronmicroscopic study].

Electron microscopic studies were carried out on cutaneous lesions in one case of prurigo nodularis Hyde. The cells of the basal layer partly showed large paranuclear vacuoles, which were sometimes divided by thin membrane structures. The intercellular space of the stratum basale and stratum spinosum was usually dilated, exhibiting acantholytic phenomen. Furthermore, numerous cells of these layers contain vacuolic-like mitochondria and polymorphous granular structures. Melanocytes and Langerhans-cells have not been observed, however, Merkel-cells were found in the basal layer, containing characteristic electrondense granules measuring 80 to 100 nm in diameter. The stratum granulosum frequently showed large intercellular complexes of numerous desmosomes, which sometimes were forming desmosomal bridges crossing the intercellular space. The capillaries in the dermis were usually widened and frequently surrounded by edematous alterations. The cytoplasm of the endothelial cells appeared very electrondens. Numerous unmyelinated axons were observed within the subepidermal zone containing mitochondria and single granules, measuring 80 to 100 nm in diameter.


Sensitization and testing of guinea pigs with nickel sulfate.

Experiments in passive transfer of nickel allergy require highly sensitive guinea pigs and a reliable and technically usable test method. A comparison was made between two sensitization methods, the guinea pig maximization test of MAGNUSSON and KLIGMAN (MK) and a combined injection and painting method devised by POLAK and TURK (PT). Intradermal injection was chosen as test method. The reactions to the test were greater than those of normal animals and the differences were statistically significant. With testing before the start of sensitization it was found difficult to obtain highly sensitive animals (tolerance). PT painting resulted in rather higher sensitivity with Triton X-100 than with sodium lauryl sulphate. In a comparison between the MK and PT methods, no difference in effectiveness was found provided that the animals had not been pretested. Repeated PT injections and paintings caused a further increase of the sensitivity, but the toxicity of nickel is a limiting factor.


Acid hydrolase activity in normal human callus and in psoriatic scales.

The activities of 14 acid hydrolases have been measured in normal human callus and in psoriatic scales. Values for the scales were much higher than for callus. The increase is believed to be the result of two factors: an increased synthesis of these enzymes by the psoriatic lesion and a diminished degree of inactivation during the keratinization process.


Syphilis, homosexuality and legislation.

The proportion of cases with fresh syphilis in males contracted by homosexual contacts in Helsinki before and after the change of the criminal law in 1971 was studied. Since 1971, homosexuality is by law no longer a crime in Finland. In 1964, only 2% of males with fresh syphilis admitted a homosexual contact. The same figure was 8% in 1970, and increased to about 50% in 1974 and 1975. It was concluded that a change of legislation concerning homosexuality, probably by several different routes, changed the proportion of cases of detected homosexually transmitted early syphilis. This was thought to be of special importance for case finding and controlling of the spread of syphilis.


Modality differences in the habituation and dishabituation of cardiac responsiveness in the human newborn.

The relative efficacy of (1) repeated auditory and somesthetic stimulation for the habituation of cardiac acceleration responses and (2) intramodal and cross-modal stimulation for the dishabituation of cardiac responses was studied in 45 full-term 2-day-old infants. Although the stimuli were equally effective initially, repeated presentation of the somesthetic stimulus had a greater decremental effect than repeated presentation of the auditory stimulus. The stimuli were equally effective in producing dishabituation when in a different modality from that of the habituating stimulus (cross-modal) but not when in the same modality (intramodal). Changes in the locus of stimulation without a change in modality were ineffective for producing dishabituation. The findings indicate the human newborn discriminates auditory and somesthetic inputs effectively and equally but does not discriminate contralateral from ipsilateral stimulation in either modality.


Anatomical and behavioral effects of colchicine administration to rats late in utero.

Offspring from pregnant rats injected with 4mg/kg body weight colchicine on Embryonic Days 18, 19, and 20 were found to have isocortical and hippocampal structures greatly reduced in mass when examined at birth. Cells with pyknotic nuclei were found in Layers 5, 4, and 3 of the cerebral isocortex, the habenula, and anterior medial nuclei of the thalamus. Brains taken at Postnatal Days 22 and 132 were reduced in overall size, and had a 20-30% reduction of cells at the vertex of the neocortex with up to 50% reduction in the thickness of the corpus callosum. A decrease in activity, an increase in fearfulness and/or decreased tendency to explore, reduced error scores on the Hebb-Williams maze, poor performance on the Maier elevated maze, and a lessened sensitivity to sound-induced seizures were correlated with these anatomical changes.


Weak inhibitory behavioral effects of postnatal! preweaning taurine injections in rats.

The behavior of rats injected once every 2 days between Postnatal Days 4 and 20 with 62.5 mug/g or 125 mug/g body weight of taurine was compared with saline- or .5 M NaCl-injected litter-mate controls. Taurine-injected rats ran significantly less in the running wheel test and displayed lower response/reinforcement ratios following step-like changes in DRL reinforcement schedules. The quicker adjustments to the changes in DRL schedules did not occur immediately but during sessions following the change. We concluded that taurine administration during early juvenile development could weakly influence adult inhibitory behavior.


Peculiarities in the changes of catecholamine level in the brain, blood, and adrenals of dogs and rats in ontogenesis.

The norepinephrine content of the whole brainstem and of its different parts and the epinephrine and norepinephrine (NE) content in the blood and adrenals in dogs and rats during ontogenesis were studied. The catecholamine (CA) level in the blood and different parts of the dog brainstem increased to the age of 20-30 days and then decreased. The NE value of the whole dog brainstem increased to the age of 9-30 days, and then decreased. The content of NE of the rat brainstem increased to the age of 120 days and then decreased. The amount of CA of the dog and rat adrenals increased progressively from birth to adulthood. The CA brain and adrenal level of dogs during postnatal ontogenesis was lower than in rats.


Visual sensitivity to orientation of rectangles in mice with retinal degeneration.

C3H/HeJ male mice, an inbred strain showing retinal degeneration (rd), and normal-eyed DBA/IJ male mice were studied in a task requiring discrimination of horizontally and vertically oriented rectangles. The apparatus was modified Yerkes discrimination apparatus. The mice were given 30 days of discrimination training, 10 trials/day, after which 10 more trails were given on the 31st day with positive and negative cues reversed. Both strains showed a highly significant decrease in errors during acquisition, the rd strain making significantly fewer errors than the DBA/IJ animals. Reversal of the cues brought about a sharp increase in percentage of errors.


The development of passive and active avoidance learning in the cat.

Kittens of 25 and 50 days of age were tested on a passive avoidance task in a 2-compartment black-white shuttle box. Latency to enter the dark side of the box was the same for both groups on Day 1, but the latency to enter the dark side on Day 2 was much shorter for the younger kittens. Other kittens were trained in a step-up active avoidance task also at 25 and 50 days of age. No differences were found in active avoidance performance between the younger and older animals, indicating that active and passive avoidance tasks may possibly reflect separate developmental processes that mature at different rates in the cat.


The pineal gland and the development of salt intake patterns in male rats.

The effect of gonadectomy, sham-gonadectomy, pinealectomy, and sham-pinealectomy on the concentration of NaCl in the total volume of fluid drunk per day ([NaCl]) in male rats offered a free choice between water and 3% saline was measured. Neonatal gonadectomy increased [NaCl] I in adult males but had no effect on immature rats. If the rats, however, were neonatally pinealectomized as well as gonadectomized, the increase of [NaCl] I also appeared in the immatures. Neonatal sham-pinealectomy decreased [NaCl] I in immature and adult rats, both gonadectomized and sham-gonadectomized. In adult neonatally gonadectomized males the effects of sham-pinealectomy did not occur in those animals actually pinealectomized. The role of the pineal gland in the regulation of water and salt intake is discussed in relation to the function of hypothalamus, neonatal stress, and sexual maturation.


The organization of sleep and wakefulness after maternal separation in young rats.

Two-week-old infant rats were studied before and after 24 hr of maternal absence. This experience produced an increase in time spent awake, a reduction in time spent in paradoxical sleep (PS), and an increased frequency of state transitions with more frequent and shorter periods of both slow-wave sleep (SWS) AND PS. Body movements were increased and nonnutritive sucking decreased during PS after separation. Other aspects of sleep organization were relativly stable: the pattern of probability of direction of state transitions, the integration of the physiological and behavioral determinants of state, the pattern and amount of nonnutritive sucking, and the underlying PS cycle period. These findings, and the results of 2 control experiments, suggest that some aspects of the prolonged absence of the mother produce a shift in the infant's central neutral state regulation through processes yet to be understood.


Acquisition and retention of habituation in the preweanling rat.

The acquisition and retention of habituation to air-puff was studied in rats on Days 1-19 postpartum. Animals of all ages demonstrated habituation but the rate of habituation varied with age: slower on each successive day from Day 1 to Day 8, but thereafter more rapid on each successive day. This peak of elicited responding is discussed in relation to the peak of spontaneous activity at Day 16 and to the pattern of neural development, including changes in acetylcholinesterase, norepinephrine, and serotonin, measured during the preweaning period. All ages showed 30-min retention of habituation, with 60-min retention developing after the 1st week. No evidence of 24-hr retention appeared at any age.


Effects of neonatal thyroid hormone stimulation and differential preweaning rearing on open-field behavior in adult rats.

In 2 experiments, rats were given a mixture containing high doses of 1-tri-iodothyronine and 1-thyroxine-sodium on Day 4 after birth (Group T). Controls (C) received equivalent amounts of saline. During the preweaning period, half of the litters in the T and C groups were raised in an impoverished (I) condition, and half in an enriched (E) condition. Open-field ambulation, rearing, defecation, and, in Experiment 2, grooming behavior was recorded during a 4-day period at 210 days (Experiment 1) and at 90 days of age (Experiment 2). A consistent augmenting action of neonatal hormone stimulation on ambulation and rearing was found for both males and females. Hormone-treated animals did not habituate their rate of general motor activity with repeated testings in the open-field. An over-all pattern of a larger effect of hormone-treatment in the I condition than in the E condition was noted, particularly among the females. Thus, the experience of preweaning enrichment partly "normalized" the open-field behavior of the T groups. The results are discussed in relation to an hypothesis concerning the interaction of rate of development of the central nervous system and environmental stimulation in determining later behavior.


Growth in the Hubbard broiler: increased size following early handling.

Hubbard cockerels, 1 day of age (n = 91), were divided into 3 handling groups: (1) chicks from the 5-Day group were removed from the brooder and isolated at 22 degrees C for 3 min on each of the first 5 days; (2) chicks from the 15-Day group received this treatment for 15 days; and (3) Control chicks were not handled. Within each group half were fed broiler starter for 5 weeks, and half were fed layer starter which produces slower growth. On Days 28, 35, 42, and 49 the average weight of 5-Day birds was significantly higher than that of Controls; 15-Day birds weighed slightly less than birds in the 5-Day group. The weight advantage of the 5-Day birds occurred with both starter rations, at all weighing periods, and did not appear to reflect increased food consumption. Similarities between these findings and results obtained with rodents were noted.


Protein deprivation in primates. VIII. Early behavior of progeny.

Infant rhesus monkeys whose mothers were fed diets providing 1, 2, or 4 g of protein/kg body weight/day during pregnancy were tested on 13 behavioral tests during their first 60 days of life. (The diets had been shown to affect significantly the weights and blood protein concentrations of both pregnant and nonpregnant females.) The tests samples a wide range of behaviors, including visual and auditory perception, feeding reflexes, and locomotion. Despite the maternal dietary differences, the performances of infants on all tests were comparable in all groups. These data contrast with the finding of persistent deficit in rats born of protein-deprived mothers.


Visual evoked response (VER) changes during maturation in the Weddell seal.

Visual evoked responses (VER'S) were recorded from the cortex of immature Weddel seals, 3-365 days of age. Results indicated a high degree of maturity at birth evident from the multiphasic array of waveforms and the comparatively short onset latency of the VER. At low intensities, single flashes evoked an immature secondary response. Topographical distribution of VER's were confined largely to the gyrus immediately adjacent to midline, from the posterior aspect near lambda to the vertex. Recordings from CI-744 dosed seals displayed a well-demarcated developmental sequence of VER's, contrary to VER's recorded in flaxedilized seals. Onset latency and waveform configuration changed concomitantly as a function of age. During the postnatal period from birth to weaning, VER changes were related to major behavioral events such as the seal's first encounter with swimming and diving at 2 weeks of age and weaning at 6 weeks of age.


Gastrointestinal myoelectrical activity during the postoperative period in man.

Myoelectrical activity of the gastrointestinal tract has been studied in the postoperative period of 13 patients who underwent cholecystectomy. The recordings have been performed by means of extracellular electrodes which were implanted at the levels of stomach, jejunum, ileum and colon during the surgical procedure. The records showed that fast activity is always persistent while the basic electrical rhythm is greatly disorganized during the immediate postoperative period. Such a characteristic pattern of the electrical activity suggested that the lack of peristaltic and propulsive movements, always noted during this period, is not correlated with a disappearance of gastrointestinal contractions, but only with a disturbance in their coordination.


Carcinomas of the colon in Buffalo strain rats given intraperitoneal injections of methylazoxymethanol acetate.

Buffalo strain male and female rats were given methylazoxymethanol acetate (20% solution) intraperitoneally 20 mg/kg body weight weekly for 9 weeks, and killed 27 weeks later. Carcinomas of the large intestine, predominantly in the descending colon, developed in some of the rats. The incidence was higher in male than in female rats. Polypoid carcinomas were observed more often in male rats and sessile carcinomas with metastases in the female rats. Carcinomas were not observed in organs other than the large intestine.


Transit time changes with age in the gastrointestinal tract of the rat.

Using 85Sr-labelled microspheres as nonabsorbable markers, the effect of age on gastrointestinal propulsion motility was determined in conscious rats. There was no significant correlation between the gastric emptying rate or the propulsion motility of the small intestine and the age of the rats. However, the transit time of the intestinal content in the caecum in adult (17- to 20-month-old) rats was about fivefold the value found in weanling (19-day-old) rats. Also the transit time of the large intestine was found to be prolonged by about 70% during the life span investigated.


Effects of L-glutamine on various gastric lesions in rats and guinea pigs.

Effects of L-glutamine on gastric lesion models in rats and guinea pigs were studied. Shay ulceration in rats was not inhibited by oral L-glutamine. Although stress-induced gastric lesions in intact rats were not inhibited by L-glutamine, a strong antagonism of gastric lesions was induced in pylorus-ligated rats under the same stress by the amino acid. Histamine-induced gastric lesions in intact rats and guinea pigs were also markedly inhibited by L-glutamine. L-Glutamine inhibited the gastric lesions in rats induced by compound 48/80 but not significantly. Reserpine- or serotonin-induced gastric lesions in rats were not affected by L-glutamine. The mechanism of L-glutamine protection was discussed.


The role of the digestive tract in cholesterol metabolism.

New studies have permit to reevaluate the importance of the digestive tract in each of the mechanisms regulating cholesterol turnover. Particularly, the role of the digestive trace in the rat cholesterol synthesis was underestimated. Is there a similar situation in man?


Gastric clearance of serum albumin in patients with alcoholic liver cirrhosis.

Gastric albumin clearance studies were carried out in 26 patients with alcoholic cirrhosis and in 10 control subjects. The mean clearance was significantly higher in patients than in control subjects. An increased protein gastric loss in cirrhotic patients was observed only in presence of gastritis. The presence or absence of distended esophageal varices did not influence the protein loss.


High serum glutamic acid levels in patients with carcinoma of the pancreas.

High levels of glutamic acid and normal levels of glutamine were found in the blood of all but one of ten patients with carcinoma of the pancreas. No changes of the concentration in blood of these two amino acids were observed in 49 patients suffering from several diseases including malignant tumours. Although the mechanism of the rise of serum glutamic acid is difficult to explain at present, it may have some diagnostic value.


Serum gastric concentration after sham feeding and feeding under the influence of propranolol in man.

The influence of propranolol, 50 mug/kg administered intravenously, on the gastrin concentration during sham feeding and after a test meal was studied in eight normal subjects. beta-Adrenergic blockade had no inhibitory effect on the gastrin response to feeding. Sham feeding did not provoke a significant rise of serum concentration; however, in three subjects a definite gastrin response occurred in the presence of beta-adrenergic blockade.


Gastric secretory response to cholinergic stimulation in rats chronically pretreated with pentagastrin or histamine in depot form.

Rats pretreated by daily depot injections of pentagastric for 24 days, responded with a significant increase of gastric secretion volume, and HC1 concentration and output, when infused intravenously with bethanechol chloride. In these rats, the total weight of the stomach and the height of the fundic mucosa were also increased. Pretreatment with histamine had no effect on rat gastric tissue or gastric secretion, under identical conditions of stimulation.


The effect of intravenous infusion of synthetic human gastrin-I on lower esophageal sphincter (LES) pressure in the dog and its relation to gastrin level.

To demonstrate the relation between gastrin level and lower esophageal sphincter (LES) pressure, experiments with intravenous infusions of synthetic human gastrin-I (SHG-I) were performed in anaesthetized dogs. The results show that infusions with 5 mug-kg-1-h-1 SHG-I have an initially increasing effect on LES pressure but produce unphysiologically high gastrin blood levels. Physiological levels of gastrin were measured only using an infusion dose of 0.5 mug-kg-1-h-1, which was below the threshold for increasing LES pressure.


Histamine-stimulated gastric secretion in rats with chronic renal insufficiency.

Chronic uremia was induced by long-term maintenance of rats which had undergone sub-total nephrectomy, with sham-operated rats serving as controls. Chronic gastric cannulas and chronic vascular catheters (vena cava) were installed and the rats were stimulated with intravenous infusion of histamine. In uremic rats, the volume of gastric juice, output of HC1 and H+ concentration were significantly higher than in the controls during the 6-hour secretion experiments.


Serum proinsulin in normal and gestational diabetic pregnancy.

The concentration of proinsulin-like components (PLC) in serum has been determined by gel filtration on samples obtained from eight normal pregnant women and eight nonobese gestational diabetics. The normal women were investigated early in pregnancy and all subjects were investigated in mid pregnancy, late pregnancy, and postpartum. At each occasion, samples were obtained after an overnight fast and after glucose ingestion. In both groups, the concentration of PLC in serum after overnight fast rose with gestation as well as after glucose ingestion, but there were no significant differences between mean levels of PLC of the normals and the gestational diabetics. With gestation, serum insulin rose in parallel with PLC in either group. The proportion of total insulin immunoreactivity composed by PLC thus remained constant and, furthermore, the proportions of PLC in gestation were equal to those observed postpartum. Four to six weeks after delivery, the basal concentration of PLC in serum was higher in the gestational diabetics than in the normals, whereas the concentrations of insulin were equal. Since the biological potency of proinsulin is much less than that of insulin, the results exclude the possibility that the decrease of glucose tolerance in normal pregnant women and gestational diabetics is due to an increased concentration of proinsulin in serum.


Serum insulin levels in school children aged 9--12 in Westland, Holland.

In a study of risk factors for cardiovascular disease in 2388 school children aged 9--12 years carried out in Westland, Holland, serum insulin levels at one hour after an oral challenge of 50 g glucose were measured in a systematically selected subsample of 715 children. The distribution and associations of serum insulin in these children are described. The mean insulin values were 24.6 muU/ml for boys and 32.0 muU/ml for girls. The difference between these means was statistically significant and remained so even taking measures of adiposity into account. Insulin values were positively related to levels of plasma sugar and systolic blood pressure in both sexes.


Effects of exogenous hormones and glucose on plasma levels and hepatic metabolism of amino acids in the fetus and in the newborn rat.

The present study examines the role of insulin, glucagon and cortisol in the regulation of gluconeogenesis from lactate and amino acids in fetal and newborn rats. Injection of glucagon in the full-term fetal rat caused a rise in glucose (and insulin) and a fall in blood levels of most individual amino acids, stimulated hepatic accumulation of 14C-amino isobutyric acid and 14C-cycloleucine and increased the conversion of 14C lactate, alanine and serine to glucose in vivo and in vitro (liver slices). Such changes were equivalent to the changes seen in 4 h old newborn rats. When glucagon was administered at birth, little difference was observed between control and treated animals in plasma amino acids and a smaller increment in conversion of 14C substrate to glucose occurred. By contrast, insulin injection at birth caused hypoglycemia, suppression of levels of certain amino acids and inhibition of conversion of 14C substrates into glucose. Glucose injection at birth caused elevated glycemia and plasma insulin and suppression of most amino acid levels and of conversion of 14C substrate into glucose. Cortisol injection at birth caused a marked, generalized by hyperaminoacidemia, a stimulation of glucagon secretion and of conversion of 14C substrates into glucose. These observations support the thesis that glucagon plays a major role in the induction of hepatic gluconeogenesis and that insulin acts as an antagonist hormone.


Circadian variation of serum glucose, C-peptide immunoreactivity and free insulin normal and insulin-treated diabetic pregnant subjects.

To examine differences among pregnant diabetic and nondiabetic subjects, serum glucose, and immunoreactivity of C-peptide, free and total insulin were measured at hourly intervals during a 24--h third trimester metabolic ward evaluation. Six normals, three mild, and four juvenile-onset type diabetics were studied. Diets were identical for all subjects. Mild diabetics differed from juvenile diabetics by having significant residual pancreatic B-cell function, as measured by C-peptide immunoreactivity. Short and intermediate acting insulins given once or twice daily to diabetics maintained serum glucose levels within the normal range throughout the 24 h. Despite wide variation in serum total insulin levels, peripheral free insulin concentrations in well-controlled diabetics fell within a relatively narrow range that was higher than in controls. Infants of the diabetic subjects were comparable to the offpsring of the control women.


Thermosensitivity of nuclear RNA polymerase during the in vitro senescence of mouse fibroblasts.

Embryonic mouse fibroblasts divide approximately twelve times in vitro prior to cessation of mitotic activity. During this period of cellular senescence the thermosensitivity of the RNA polymerase activity of isolated nuclei has been examined as a means of detecting the possible accumulation of defective enzyme molecules, as has been found by other workers for several cytoplasmic enzymes during the ageing of human fibroblasts in vitro. The total RNA polymerase activity of nuclei isolated from old (10th generation) cells is more thermoresistant than that of young (2nd generation) cells. However, the net RNA polymerase activity of nuclei from non-dividing (confluent) cells is more thermoresistant than that of exponentially growing cells of the same age. When allowance is made for the state of growth of the cultures, little difference is seens in the thermosensitivity of the activities of nuclei from old and young cells. Neither is there any difference between the thermosensitivity of the net activity of an established line of murine fibroblasts (L-cells) and cells in primary culture. Preheating nuclei increases the inhibition of their total RNA polymerase activity by alpha-amanitin, indicating that RNA polymerase II is the most heat resistance species present. There appears to be no difference between the thermosensitivity of the alpha-amanitin sensitive and resistance species of the enzyme in the nuclei of old and young cells. It is concluded that old cells resemble non-dividing young cells in containing a higher proportion of RNA polymerase II in their nuclei, resulting in greater thermoresistance of the total RNA polymerase activity over that of exponentially growing cells. However, there appears to be no increase in thermosensitivity of the enzymes with age.


Embryo cell surfaces--lectin binding and cell proliferation.

The interaction between chick embryo fibroblasts and various lectins has been studied at different stages of embryo development. There is evidence that Robinia lectin, Dolichos lectin, and Concanavalin A decrease cell number and proportion of cells incorporating [3H] thymidine in case of 8- and 10-day-old chick embryo fibroblasts, whereas they stimulated the proliferation of 16-day-old embryo cells. No effect was noticed in 12-day cells. These results suggest that some cell surface changes occur during embryo development. The site number of Dolichos lectin remains the same during embryo development, and the affinity constant decreases. The site number of Robinia lectin and Concanavalin A decreases from the 8th to the 12th day of development, and slowly increases on the 16-day cells, the affinity constant remaining rather constant. The results indicate that the age-dependent effect of lectin on embryo cells could not be directly related to the number of lectin-binding sites. Competitive binding experiments revealed that Dolichos receptor sites were distincts from binding sites of Robinia lectin and Concanavalin A, and Robina receptor sites distinct from those of concanavalin A. Lectin effects on embryo fibroblasts were very specific as determined by inhibitory assays.


Carcinoplacental alkaline phosphatase. Base level and hormone-induced activity associated with events in the cell cycle.

Using HeLa TCRC-1, a cell line which is monophenotypic with respect to the Regan isoenzyme of alkaline phosphatase, we have examined the factors which influence its expression in relation to events of the cell cycle. DNA synthesis is not required for hormone induction of the Regan isoenzyme as in the presence of hydroxyurea, a specific inhibitor of DNA synthesis, we found induction to occur. Additionally, when partially synchronised cells were allowed to leave the S period prior to hormone treatment, and hydroxyurea was added to prevent cells from entering the next S period, hormone induction of the Regan isoenzyme was still observed. This indicates that initiation of expression of hormone-induced carcinoplacental alkaline phosphatase occur prior to the DNA synthetic phase of the cell cycle. We propose a hypothetical two-step mechanism of hormone induction to interpret the present findings in relation to previous results.


Decidualisation in the prepuberal rat uterus.

Decidualisation has been experimentally induced in the prepuberal rat. It is morphologically similar to that obtained in the adult. The cytodifferentiation includes the formation of binucleated cells and extensive specialised cellular junctions. Furthermore, blastocysts from adults transferred into uterine horns of immature specimens implant and develop, indicating that the decidual response they induce is functionally comparable to the uterine response at the time of nidation in the fertilised adult. The model of the experimental decidual induction in the immature is used to study the ontogenic processes of uterine maturation. Preliminary observations indicate that the 7-10-days period might be of significance in the maturation of the rat uterus.


The effect of isoproterenol upon the chemical composition of plasma membranes in the mouse parotid gland.

A single intraperitoneal injection of isoproterenol induces resting cells from the acini of the mouse parotid gland to enter the proliferative cycle. Parotid plasma membrane from non-stimulated and isoproterenol-treated mice were prepared by differential centrifugation of the homogenates. Comparing the chemical composition of plasma membranes from non-stimulated and isoproterenol-treated mice, no variation in the phospholipid/protein ratio was observed. However, the levels of neutral sugars, hexosamines and sialic acid falls drastically in the early prereplicative phase. The decrease in neutral sugars and hexosamines in plasma membranes caused by isoproterenol is imitated by pilocarpine, which induces secretion but little or no increase in DNA synthesis. However, pilocarpine does not mobilize sialic acid from the plasma membrane. Moreover, dosis of isoproterenol that elicits secretion but not mitosis in the acinar cells, does not induce the movement of sialic acid from the plasma membrane. The mobilization of sialic acid from plasma membranes caused by isoproterenol was also demonstrated in an in vitro system. Treatment of the plasma membrane with chloroform/methanol shows that around 60% of the sialic acid is present in the less polar phase. We conclude that the separation of sialic acid from the plasma membrane is one of the early steps in the sequence of events leading to DNA synthesis and cell division in the isoproterenol-stimulated parotid gland of mice.


Thymus-derived striated muscle clones. An ultrastructural analysis of cell differentiation.

Myogenic clones can be induced in thymus reticulum cultures from adult mice. We investigated the differentiation and maturation of myogenic cells by combined ultrathin section and freeze etching analyses. New insights into the development of cell membranes and cytoplasmic organelles will be discussed in the light of previous investigations of embryonic muscle cell cultures.


Mechanisms of cell interaction during primary embryonic induction studied in transfilter experiments.

The transmission mechanisms operative at different stages of neutralisation during primary embryonic induction of the newt Triturus vulgaris were studied in experiments employing Nuclepore filters placed between interactive tissue explants. The transmission time of the neuralising effect was determined with 0.2 mum Nuclepore filter. In another series of experiments the transformation of neuralised ectoderm by archenteron roof mesoderm into other parts of the CNS was studied. Although sufficiently long induction times were used no transformation into hindbrain structures could be induced across filters with pore sizes from 0.1 mum to 1.0 mum. However, electron microscopy demonstrated cytoplasmic penetration into 0.6 mum filters at 15 h of induction. The results speak against free long-range diffusion of inductive material at the stage of transformation of the neuralised ectoderm to more caudal parts of CSN and warrant a more detailed structural study of the transmission phenomenon in question.


Distribution of acid phosphatase in chick Hensen's node.

Acid phosphatase distribution and yolk drop ultrastructure in Hensen's node of chick blastoderm at Hamburger-Hamilton stages 3 and 4 are described. At stage 3 large deposits of the reaction product are localised in type-A yolk drops, where signs of intensive degradation are seen. It seems that during this degradation lipid droplets are being formed in the degrading yolk drops. Partly digested yolk drops with a vesicular appearance are extruded from the cells, especially in deeper layers of the node. The phosphatase reaction product is also distributed into intercellular spaces. At stage 4 the cells of the node are more vacuolated and contain acid phosphatase and electron-dense yolk drops in lesser amounts. The possible physiological role of acid phosphatase in Hensen's node during gastrulation is discussed.


Changes in expression of fibroblast surface antigen (SFA) during cytodifferentiation and heterokaryon formation.

Fibroblast surface antigen (SF antigen, SFA) is a major glycoprotein antigen detected in connective tissue cells (primitive mesenchymal cells, fibroblasts, and astroglial cells). In this study the expression of SFA was followed during differentiation of the mesenchymal cells of the mouse metanephros and during heterokaryon formation produced by Sendai-virus induced fusion of human fibroblasts and chick red blood cells. It was demonstrated by immunofluorescence that SFA was lost from the kidney mesenchymal cells when they differentiate into epithelial cells of the secretory tubuli. During this process SFA became detectable in the basement membrane formed around the tubuli. In cell fusion experiments human SFA which was present as fibrillar network on the surface of cultured fibroblasts, was gradually lost from the heterokaryons when the incorporated chick nuclei became activated. These two sets of experiments indicate that SFA can be used as a phenotypic marker of cytodifferentiation.


Studies on the organisation of the chicken genome and its expression during myogenesis in vitro.

DNA from the chicken genome was analysed both by isopycnic centrifugation in cesium salt density gradients and by reassociation analysis using hydroxyapatite (HAP) chromatography. Centrifugation in neutral CsCl revealed a single non-Gaussian band skewed toward the heavy side, but no discrete satellite components. In heavy metal (Ag+ or Hg++)-Cs2SO4 gradients, 4-8 satellite bands were revealed, comprising 5-9% of the total DNA. Purification of the satellites and recentrifugation in neutral CsCl demonstrated that 80-90% of this DNA would band in the shoulder, with the remainder in the main band. These satellites can account at most for 30% of the heavy shoulder DNA, thus most of the heavy shoulder DNA must be of lower repetition frequencies. Reassociation analyses of chicken DNA demonstrated that the complexity of the non-repetitive DNA is 9.49 X 10(8) nucleotide pairs, equivalent to about 90% of the haploid genome. Repetitive DNA comprises only 8-10% of the genome and has the following composition, relative to total DNA: 3.7% intermediate repetitive, 1.9% highly repetitive, and 3.9% "zero-time binding" DNA. This unusually low repetitive DNA content may be related to the small genome size of chickens, relative to other vertebrates, and to the presence of many microchromosomes in the chicken karyotype. Total cell RNA extracted from perfusion myoblasts, post-fusion myotubes, and myoblasts grown in BrdU was incubated in large excess with 3H-TdR labelled non-repetitive DNA and the resulting hybrids assayed by HAP chromatography. The amount of non-repetitive DNA represented in the RNA was found to increase from 7-8% in the myoblast stage to 10-11% in myotubes. An even smaller proportion, about 5%, is represented in the RNA of myoblasts prevented from differentiating by growth in BrdU.


Combination effect of citrinin and other chemicals on rat kidney tumorigenesis.

Histological studies were made on the nephrotoxic effect of citrinin on the kidneys of rats, with or without previous treatment with the nephrotoxic chemicals, N-(3,5-dichlorophenyl)succinimide (NDPS) and N-nitrosodimethylamine (DMN). Oral administration of 0.02% or 0.05% citrinin alone caused signs of kidney injury but did not induce kidney tumors. On treatment with DMN alone, 8 of 14 rats (57.1%) developed kidney tumors; two (14.3%) were renal cell tumors, eight (57.1%) embryonal cell tumors, and one (7.1%) hemangioendothelioma. On the other hand, kidney tumors developed in 18 of 19 rats (94.7%) and 13 of 15 rats (86.7%) by the administration of 0.02% and 0.05% citrinin, respectively, after DMN. The tumors in these two groups were diagnosed histologically as renal cell tumors in 18 (94.7%) in group IV and 13 (86.7%) in group III, and as embryonal cell tumors in 14 (73.7%) in group IV and 9 (60.0%) in group III. Thus, in groups treated with citrinin after DMN the incidence of renal cell tumors was much greater and the incidence of embryonal cell tumors slightly greater than in the group treated with DMN alone. Kidney tumors developed in 4 of 18 rats (22.2%) treated with 0.02% citrinin after NDPS, but treatment with NDPS alone did not induce kidney tumors. Thus, treatment with citrinin changes the histological type and incidence of kidney tumors in rats induced by DMN. Moreover, this study confirms that citrinin in combination with NDPS can induce kidney tumor in rats, which was renal cell tumor (adenoma) histologically.


In vitro transformation of newborn hamster cells induced by sodium nitrite.

The in vitro carcinogenicity of sodium nitrite was examined. Addition of a high concentration of sodium nitrite (50 mM or 100 mM) to mass cultures of newborn hamster cells for 24 hr resulted in morphological transformation of the cells. The shortest time required for morphological transformation after this treatment was 21 days. Two of 5 transformed cultures produced progressively growing tumors when injected into young adult hamsters. These tumors were diagnosed as fibrosarcomas. In two control cultures of the same experimental groups, transformed cells appeared 10 weeks or more later than those in treated cultures. The chromosomes were analysed at several stages of transformation. In the early stages of transformation, chromosome number varied widely from near diploid to tetraploid, but later they became near diploid. Morphological alteration caused by sodium nitrite was also seen in a short-term assay, in which hamster embryonic cells (1 x 10(4) cells/60 mm dish) were treated and morphology was observed 8 days after the treatment.