Showing papers in "Tohoku Journal of Experimental Medicine in 1970"
TL;DR: Response characteristics of the previously categorized four types of cat retinal ganglion cells were investigated using light and dark spot stimuli by recordings of unit discharges from the optic tract, and phasic and tonic nature of these four type of cells were further clarified.
Abstract: Response characteristics of the previously categorized four types of cat retinal ganglion cells (ON-I, OFF-I, ON-II and OFF-II) were investigated using light and dark spot stimuli by recordings of unit discharges from the optic tract, and phasic and tonic nature of these four types of cells were further clarified. ON-I and OFF-I are phasic in nature and respond to only a transient increase and decrease in luminance, respectively. ON-II and OFF-II are tonic and continue to respond to a stationary light and dark contrast, respectively. Besides, a difference is also found between ON-I and ON-II in the firing patterns of the transient response to a bright spot stimulus. ON-I responds to the onset of a bright spot with an initial burst followed by dispersed discharges. In ON-II's transient response, initial discharge rate is as high as that of ON-I's burst, but in contrast with the case of ON-I's response, the discharge rate gradually decreases toward a mean rate of sustained responses to the spot.
43 citations
TL;DR: The distribution pattern of motoneurons in the rat's lumbar spinal cord which send axons to the sciatic nerve was studied by means of staining degenerated motor cells with toluidine blue after relevant roots or nerves had been sectioned or crushed.
Abstract: The distribution pattern of motoneurons in the rat's lumbar spinal cord which send axons to the sciatic nerve was studied by means of staining degenerated motor cells with toluidine blue after relevant roots or nerves had been sectioned or crushed. The columnar arrangement of the motor cells in the lumbar spinal cord of the normal rats was confirmed and presented. The degeneration picture of the rat motoneuron was presented, which was observed only in the large cells in the ventral horn and not in the smaller cells suggestive of γ-motoneurons. It was found that the sciatic motoneurons occupy the dorsolateral portion of the ventral horn and extend in proximocaudal direction from the mid L4 through L5 to the end of L6. It was proved that the tibial motoneurons innervating the extensors of lower hind-limb and foot are situated dorsolaterally in the sciatic portion of the columnar arrangement of the motor cells, while the peroneal motoneurons innervating the flexors of lower hind-limb occupy the medial section in the sciatic portion.
37 citations
TL;DR: The nerve fiber analysis of the rat dorsal and ventral spinal roots extending to the sciatic nerve and of the Sciatic branches such as the lateral and medial gastro-cnemius nerves and the cutaneous nerve innervating the lateral aspect of thigh was done.
Abstract: The nerve fiber analysis of the rat dorsal and ventral spinal roots extending to the sciatic nerve and of the sciatic branches such as the lateral and medial gastro-cnemius nerves and the cutaneous nerve innervating the lateral aspect of thigh was done. Fiber counting was also made by microdissection method. To know the distribution of afferent and efferent components in a nerve, deefferentation was made by sectioning the relevant ventral roots. Main results obtained were as follows:1) The sciatic nerve receives its constituent fibers mainly from L5 and partly from L4 and L6.2) In the dorsal roots examined, the fibers larger than 12μ occupy a rather small portion of the total composition, and the afferent component of the hind-limb muscle nerves practically lacks fibers larger than 12μ.3) The cutaneous nerve is devoid of efferent fibers and larger fibers characteristic of muscle nerves.4) The total number of a peripheral nerve composition corresponds quite well on both sides of an animal and among different animals.
28 citations
TL;DR: There was a remarkable difference in the amount of circulating blood in the penis between the two groups after the administration of 131I-human serum albumin.
Abstract: Seven and nine cases of organic and mental impotence, respectively, were examined for changes in circulating blood in the penis after the administration of 131I-human serum albumin. As a result, there was a remarkable difference in the amount of circulating blood in the penis between the two groups. This method of examination using an isotope was applied to patients in a painless testing situation. It was also simple enough to be performed at any clinic equipped with a renogram apparatus. These results require verification by further studies on a larger number of patients.
26 citations
TL;DR: The sero-immunity against ECHO 22 virus in children in the same district revealed that about half the infants under 6 months of age had positive neutralizing antibody against Echo 22 virus, and almost all children over a year of ageHad positive antibody.
Abstract: ECHO 22 virus was isolated from fecal specimens of 20 out of 29 premature infants in 1964, and was again isolated from 9 out of 36 infants during 1966 and 1967 in the same premature nursery. The infants discharging ECHO 22 virus were asymptomatic or of slight symptoms of upper respiratory tract infection and of mild diarrhea. The sero-immunity against ECHO 22 virus in children in the same district revealed that about half the infants under 6 months of age had positive neutralizing antibody against ECHO 22 virus, and almost all children over a year of age had positive antibody. The evidence of transplacental infection due to ECHO 22 virus was not obtained. ECHO 22 virus in premature infants would probably be transmitted from infants to infants. The source of infection was not determined.
25 citations
TL;DR: The lobular pattern of the liver was found entirely to depend upon the particular orientation of the afferent and efferent vessels, and the concept of the hepatic lobule as a preformed structural unit could not be sustained.
Abstract: The vascularization of the normal human liver as revealed by the graphical reconstruction of the vascular trees was characterized by regular inter. digitation of the portal and hepatic veins with uniform distance. The lobular pattern of the liver was found entirely to depend upon the particular orientation of the afferent and efferent vessels, and the concept of the hepatic lobule as a preformed structural unit could not be sustained. A histometrical method was described to estimate the length L of the shortest routes through points randomly taken in an-organ. The distribution of L could be approximated by a normal distribution, so that a ratio Lmax/Lmin, the largest and smallest Ls at 3σ;-level respectively, indicated the inequality in the length of the capillary routes and consequently the irregularity of the vascular interdigitation of each organ. The ratio was smallest in the liver with a value of about 3 and largest in the renal cortex exceeding 50 among the examined organs. In organs with small Lmax/Lmin, a non-regulatory and steady peripheral circulation was assumed, while alternate or regulatory flow, which developed from intermittent flow of the afferent vessels on account of their regulatory activity, was considered necessary to sustain the peripheral circulation of organs with large Lmax/Lmin.
21 citations
TL;DR: A linear figure was obtained which demonstrated a maturation pattern of the EEG basic waves of infants with advance in age.
Abstract: A simplified method for an evaluation of maturation patterns of the EEG waves of healthy infants under 12 months of age was reported. The EEG basic waves were divided into 10 bands according to frequency ranges (I-X bands). An averaged integrated voltage was calculated at each of the frequency bands (I-E%, II-E%, ....X-E%). When ‘R’=(E% of VIII+E% of IX)/(E% of II+E% of III) was claculated and plotted against the age in months, a linear figure was obtained which demonstrated a maturation pattern of the EEG basic waves of infants with advance in age.
20 citations
TL;DR: Measurement of intraluminal anorectal pressures and cineradiographic studies were carried out on infants and children with Hirschsprung's disease and patients who had undergone radical operation for the disease and revealed that propulsive movement of the ano-rectrum and ordinary recto-sphincteric reflex were recovered in patients treated byrectal myotomy with colectomy or Lynn's rectal myectomy.
Abstract: Measurement of intraluminal anorectal pressures and cineradiographic studies were carried out on 15 infants and children with Hirschsprung's disease and 18 patients who had undergone radical operation for the disease. The results were compared with those obtained from 50 normal infants and children. It was revealed that the chronic and severe constipation seen in Hirschsprung's disease was caused by lack of propulsive movement in aganglionic portion of the colon and absence of normal recto-sphincteric reflex. Studies on postoperative infants revealed that propulsive movement of the ano-rectrum and ordinary recto-sphincteric reflex were recovered in patients treated by rectal myotomy with colectomy or Lynn's rectal myectomy. On the other hand, recto-sphincteric reflex was not restored in those who had undergone Swenson's rectosigmoidectomy.
19 citations
18 citations
TL;DR: Human lymphocytes in heparinized blood were collected through a tetoron fiber column and autoradiography after continuous labeling with 3H-thymidine proved that entering of the lymphocytes into the DNA synthetic phase was suppressed by radiation.
Abstract: Human lymphocytes in heparinized blood were collected through a tetoron fiber column. About 5×105 lymphocytes in a milliliter of Eagle's essential moiium containing 20% autoserum were cultured with phytohemagglutinin (PHA) and exposed to x-irradiation. The results were as follows: (1) Morphological blast formation was not affected by x-rays below 300R. About 60% of lymphocytes could transform even after an exposure to 2, 000 R. (2) Autoradiography after continuous labeling with 3H-thymidine proved that entering of the lymphocytes into the DNA synthetic phase was suppressed by radiation. The percentage of cells entering the first DNA synthesis was dependent on the radiation dose; 96, 92, 73, 48, 37, 42 and 36% after the irradiation of 0, 150, 300, 500, 1, 000, 1, 500 and 2, 000R, respectively, 2 to 3 hours after the addition of PHA. (3) Accumulation of mitosis by coiehicine was prevented by irradiation depending on doses; 72, 36, 37, 8, 8 and 5% of original lymphocytes entered the first mitosis after the irradiation of 0, 140, 300, 500, 1, 000 and 2, 000R, respectively, at 2 to 3 hours culture. At about 2, 000R, not more than 10% of stimulated lymphocytes entered mitosis in 5 days' incubation.
16 citations
TL;DR: The metabolic fate of lysolecithin administered into the rat duodenal lumen was investigated, using lyso-(1-acyl)-leCithin labeled with (methyl-14C)-choline or (2-3H)-glycerol, and no definite evidence was obtained for the difference in 14C- and 3H-specific activities between the subfractions of intestinal lecithins.
Abstract: The metabolic fate of lysolecithin administered into the rat duodenal lumen was investigated, using lyso-(1-acyl)-lecithin labeled with (methyl-14C)-choline or (2-3H)-glycerol. Lecithin was the most radioactive in phospholipids of the tissues of the intestine and liver. Lecithin was subfractionated into 4 molecular species according to the degree of unsaturation. No definite evidence was obtained for the difference in 14C- and 3H-specific activities between the subfractions of intestinal lecithin. In liver lecithin, the 14C-specific activity was much higher in monoenoic and dienoic subfractions than in the other polyenoic ones. Appreciable portions of 3H-activity were incorporated into intestinal neutral lipids. The activity was the highest in triglyceride and moderate in diglyceride but showed only a trace in monoglyoeride. The 14C-activity was appreciably incorporated into the acid soluble fraction. Three radioactive compounds were detected in both tissues. In the intestine at 10 minutes' period, the activity was highest in glyceryl-phosphoryl-choline, remarkable in phosphoryl-choline and showed only a trace in free choline, but during 90 minutes' period the three compounds showed almost the same level of activity. In the liver at 90 minutes, the radioactivity was the highest in phosphoryl-choline, moderate in oholine, but negligible in glyceryl-phosphoryl-choline.
TL;DR: Clinical and postmortal findings of esophageal carcinoma in a 74-year-old woman with urinary activities of chorionic gonadotropin with choriocarcinoma mimicry were described, the first case report in the literature.
Abstract: Clinical and postmortal findings of esophageal carcinoma in a 74-year-old woman with urinary activities of chorionic gonadotropin were described. The tumor was anaplastic carcinoma with prominent pleomorphism of large carcinoma cells showing choriocarcinoma mimicry. Abundant evidence of choriocarcinoma was further presented by pulmonary and hepatic metastases. Cystic glandular hyperplasia of the endometrium mild in degree and signs of activity in ovarian stromal cells were observed. The significance of choriocarcinoma mimicry as a morphological expression of ectopic producton of chorionic gonadotropin was discussed. Ana-plastic large cell carcinoma with choriocarcinoma mimicry is extremely rare in the esophagus but will be unexceptionally capable of gonadotropin-secretion. This is the first case report in the literature.
TL;DR: Autoradiographic studies on the synthesis of DNA in heart muscle cells of younger normal rats after administration of 3H-thymidine were made to add as evidence to cell division of heart muscle with postnatal growth of the heart.
Abstract: Autoradiographic studies on the synthesis of DNA in heart muscle cells of younger normal rats after administration of 3H-thymidine were made. The labeling index of heart muscle cells in 4 hours was 8.30% on the 2nd day of life and it gradually declined to 0.15% in 3 weeks. The labeling index of interstitial cells was 9.8% on the second day of life and it similarly declined to 1.0% in 3 weeks. These results are to be added as furthr evidence to cell division of heart muscle with postnatal growth of the heart.
TL;DR: Though colchicine yields rather ambiguous results, the autoradiographic studies gave definite evidence for cell division of heart muscle cells in experimental cardiac hypertrophy.
Abstract: In order to find DNA synthesis and mitosis of heart muscle cells in experimental cardiac hypertrophy, autoradiographic studies after 3H-thymidine administration and evaluation of mitosis after colchicine treatment were made on Goldblatt rats. The labeling index of heart muscle cells and of interstitial cells in 4 hours was 0.03-0.2% and 0.25-0.7%, respectively. Concomitant mitosis of labeled heart muscle cells and of interstitial cells was found in 0-0.1% and 0.1-0.3%, respectively. The mitotic figures were scarcely found after colchicine administration. Though colchicine yields rather ambiguous results, the autoradiographic studies gave definite evidence for cell division of heart muscle cells in experimental cardiac hypertrophy.
TL;DR: Findings suggest that hyperphenlyalaninemia may be a genetic variant of phenylketonuria, and Phenylalanine hydroxylase in the liver was found to be of about one-tenth the normal activity.
Abstract: A sibling case of hyperphenylalaninemia without phenylpyruvic aciduria was described. An oral loading of phenylalanine revealed a delay of clearance of serum phenylalanine, a slight elevation of serum tyrosine, and an increased urinary excretion of phenylpyTuvic acid and o-hydroxyphenylacetic acid. Phenylalanine hydroxylase in the liver was found to be of about one-tenth the normal activity. These findings suggest that hyperphenlyalaninemia may be a genetic variant of phenylketonuria.
TL;DR: Findings indicate that normal sugar-evoked potential is formed by two distinct mechanisms; relatively metabolism-independent and metabolism-dependent ones, and strongly suggest that the former responsible for the production of the immediate potential increment is directly associated with facilitated diffusion of sodium with sugar molecules on common mobile carriers.
Abstract: The sugar-evoked potential was recorded from everted sacs of the upper segment of toad intestine, and effects on this potential of anoxia, various metabolic inhibitors and ouabain were observed in a lowered external sodium concentratioai. Anoxia of a relatively short duration, KCN plus IAA, and ouabain caused a time-dependent decay of the evoked potential; inhibition of plateau formation, without affecting the imrnediat' potential increment significantly. DNP and prolonged anoxia depressed the size of the immediate increment, but the depression of the plateau was still more prominent. Fluoroacetate, KCN or IAA alone had no effect. Under inhibited conditions, phlorizin, applied at later phases of decaying sugar-evoked potential, produced a potential surge like the mirror-image of the decaying sugar-evoked potential and concurrent increases in sugar and sodium outflows. Similar surge could also be produced by lowering mucosal sugar concentration rapidly at a similar phase. These findings indicate that normal sugar-evoked potential is formed by two distinct mechanisms; relatively metabolism-independent and metabolism-dependent ones, and strongly suggest that the former responsible for the production of the immediate potential increment is directly associated with facilitated diffusion of sodium with sugar molecules on common mobile carriers.
TL;DR: The maturation of the EEG basic waves, expressed as the ‘R’, was definitely delayed in infants fed on mothers' milk whose serum folate levels were below the normal range and was observed to be kept over after the weaning period.
Abstract: Maturation patterns of the EEG basic waves of breast-fed infants were studied longitudinally from 3 months to 29 months of life with special reference to their folate status. The basic waves of EEG were divided into ten bands (I-X bands) by means of an automatic analyzer specially adapted and ‘R’ =(E% of VIII+E% of IX)/(E% of II+E% of III) was used for an index of the evaluation of maturation patterns of the EEG basic waves. Serum folate levels of lactating mothers and of infants and urinary folate of infants were estimated at the time when the EEG was examined. The maturation of the EEG basic waves, expressed as the ‘R’, was definitely delayed in infants fed on mothers' milk whose serum folate levels were below the normal range. This tendency was observed to be kept over after the weaning period.
TL;DR: The physiological evidence of the efferent innervation to the chemoreceptor was sought in the carotid labyrinth of the toad and provoked an in-hibitory effect on chemosensory activity in ten of seventeen preparations.
Abstract: The physiological evidence of the efferent innervation to the chemoreceptor was sought in the carotid labyrinth of the toad. A few-fiber chemosensory preparation was splitted from the glossopharyngeal nerve at its peripheral cut end, and the rest part of the nerve was stimulated electrically. The stimulation reduced remarkably the chemosensory discharge in this nerve strand. To seek the derivation of these inhibitory fibers a few-fiber preparation was peeled from the intact glossopharyngeal nerve, and the sympathetic nerve and the vagus group root were stimulated respectively. The sympathetic stimulation provoked an in-hibitory effect on chemosensory activity in ten of seventeen preparations. In three of these ten the vagus group root stimulation was also effective. In one instance the vagus group root stimulation brought about the inhibitory effect, while the sympathetic did not. In the other six, no remarkable effect was obtained by both stimulations. The mechanism provoking these effects was discussed.
TL;DR: In this paper, the cardiac action of PGE1 and PGF1α were studied using the heart-lung preparation of the dog, and it was concluded that 98-99% of this compound was removed from the circulation during a single passage through the lung.
Abstract: 1. Using the heart-lung preparation of the dog, the cardiac action of PGE1 and PGF1α were studied. Injection of PGE1 into the left atrium resulted in a positive inotropic effect and an increase in the coronary flow. The positive inotropic effect was especially prominent in the failing heart. Heart rate remained unchanged. There was no tendency toward tachyphylaxis in the action of PGE1. 2. In view of the very slight increase in the oxygen consumption observed after PGE1 (average 5%), the increase in the coronary flow produced by PGE1 (average 21%) was taken to represent a direct dilator effect of this compound on the coronary vasculature. 3. When injected into the venous-supply tubing, fifty to eighty times as high a dose of PGE1 was necessary to produce the coronary flow increase of the same magnitude as when injected into the left atrium. Thus, it was concluded that 98-99% of this compound was removed from the circulation during a single passage through the lung. 4. In the heart-lung preparation of the dog, the action of PGF1α was quite feeble, although the effects produced by large doses of this compound were not essentially different from those produced by PGE1.
Journal Article•
TL;DR: The authors assume that naturally occurring catecholamines stimulate the cholinergic neuron at the presynaptic site through the α-receptors and thus, they are cholinerential in effect, causing the paradoxical response of the sinoatrial node.
Abstract: Direct perfusion of the sinus node artery under a constant pressure of 100mm Hg was arranged in the canine heart in vivo. The administration of dopamine, norepinephrine or epinephrine from 1 to 10μg into the sinus node artery often induced a deceleration of the sinus rhythm, but isoproterenol never caused such a paradoxical response. The higher the dose given, the more frequently was this paradoxical response observed. The participation of a cholinergic mechanism in this paradoxical response was proved by blocking it with atropine and by enhancing it with physostigmine. Furthermore such paradoxical responses were blocked by treatment with hemicholinium, hexamethonium or phenoxybenzamine, none of which blocked the muscarinic action of acetylcholine. The blocking effect of phenoxybenzamine was persistent and selective. The authors assume that naturally occurring catecholamines stimulate the cholinergic neuron at the presynaptic site through the α-receptors and thus, they are cholinergic in effect, causing the paradoxical response of the sinoatrial node.
TL;DR: Skin specimens taken from one patient with solitary mastocytosis and four patients with urticaria pigmentosa were examined under a fluorescence microscope and some of mast cells in the dermis showed intense yellow fluorescence, which was no doubt due to the presence of serotonin or its immediate precursor, 5-hydroxytryptophan.
Abstract: With use of the formaldehyde condensation method of Flack and Hillarp, skin specimens taken from one patient with solitary mastocytosis and four patients with urticaria pigmentosa were examined under a fluorescence microscope. In the case of solitary mastocytosis, some of mast cells in the dermis showed intense yellow fluorescence, which was no doubt due to the presence of serotonin or its immediate precursor, 5-hydroxytryptophan. In four cases of urticaria pigmentosa, no yellow fluorescence could be detected on the mast cells infiltrated around the vessels. However, there were a few mast cells which showed yellow fluorescence, in the dermis of a patient with urticaria pigmentosa. From a biochemical point of view, human mast cells, too, seem to consist of two distinctly different types of cells: monoamine-forming and non-amine-forming mast cells.
TL;DR: It was concluded that the heart weight and heart muscleVolume increased in the hypertensive group, and the increase in heart muscle volume was due to an increase in the cell number.
Abstract: The total numbers of heart muscle cells and of interstitial cells were estimated in the Goldblatt rats by a histometrical method. The thickness of muscle fibers and the length of muscle cells were also estimated. The heart weight and heart muscle volume increased significantly in the hypertensive group. The total number of heart muscle cells was 30-54 millions in the hypertensive group, while it was 25-38 millions in the control group. The total number of interstitial cells was 88-102 millions in the hypertensive group and 72-87 millions in the control group. There was a significant increase of both cells in the hypertensive group. Both the total number of heart muscle cells and that of interstitial cells were proportional to the heart muscle volume. There were no significant differences in the thickness of muscle fibers and in the length of muscle cells between the two groups. It was concluded that the heart weight and heart muscle volume increased in the hypertensive group, and the increase in heart muscle volume was due to an increase in the cell number. Hyperplasia of the muscle cells rather than their hypertrophy was regarded as the major process underlying cardiac hypertrophy.
TL;DR: It was concluded that the fast synchronous wave was monosynaptic and its specific features were due to the poor functional connection between primary afferents and motoneurons.
Abstract: When a hind-limb muscle nerve or a lumbar dorsal root of rats was stimulated, a fast and well-synchronized wave could be lead off from the appropriate lumbar ventral root and was named ‘the fast synchronous wave’. While this fast synchronous wave resembled in shape and appearance to the cat monosynaptic reflex, it differed in some features from the latter, i.e., rather long latency, absence of post-tetanic potentiation and not being most excitable of all the reflex components. To testify whether the fast synchronous wave is monosynaptic or not, and if monosynaptic, to what causes its characteristics should be attributed, electrophysiological technique and Nauta method were employed. It was concluded that the fast synchronous wave was monosynaptic and its specific features were due to the poor functional connection between primary afferents and motoneurons.
TL;DR: The concept of the pathogenesis of monoclonal gammopathies presented herein is based on the view that lymphomas, immunologic deficiency diseases, and autoimmune diseases form a 'trinity' pathogenetically and etiologically.
Abstract: KANOH, T. The Behavior of Immunoglobulin in Monoclonal Gammopathies and Their Classification and Pathogenesis. Tohoku J. exp. Med., 1970, 102 (4), 369 401•\\Quantitative measurements of immunoglobulins were made in sera from 203 patients with monoclonal gammopathies. In IgG myeloma the serum IgG concentration averaged six times the normal level, in IgA myeloma 15 times, and in IgD myeloma 370 times the normal values of respective proteins. In primary macroglobulinemia the average serum level of IgM was 38 times higher than normal. The serum levels of the normal immunoglobulin classes were markedly decreased in these diseases, including Bence-Jones myeloma and biclonal myeloma. Various mechanisms were proposed to account for the reduction of normal immunoglobulins. On the other hand, in benign monoclonal gammopathy there was usually no reduction of normal immunoglobulins. However, in patients with cancer and IgG or IgA-M-components IgM levels were decreased. The reason for lowered IgM value remains obscure. It was of special interest that one of the patients with a potentially malignant type appeared to be developing myeloma. A marked reduction of the normal immunoglobulin classes seems to be a poor prognostic sign in patients with M-components in the absence of myeloma. Since patients with lymphoma have a marked tendency to hypogammaglobulinemia and closely resemble a primary-malignant group, immunoglobulin changes in patients with lymphomas and M-components are more complicated. A classification of monoclonal gammopathies was proposed on the basis of their pathogenesis after the consideration of our data as well as those from the literature. The concept of the pathogenesis of monoclonal gammopathies presented herein is based on the view that lymphomas, immunologic deficiency diseases, and autoimmune diseases form a 'trinity' pathogenetically and etiologically.•\\monoclonal immunoglbulins; monoclonal gammopathy; plasma cell myeloma
TL;DR: In patients with ventricular septal defect (VSD), physiological medial regression does not take place, and the muscular coat retains or increases its neonatal thickness, which is correlated with pulmonary blood pressure level and can be expressed by an exponential function of blood pressure.
Abstract: In normal postnatal development, physiological regression of the muscular coat is accomplished to the major part in the first 6 months. Thereafter, the medial thickness still continues slowly to diminish and practically attains the level of normal adults in 4 years. With the present histometrical method, the medial thickness at an arterial radius of 100 μ was estimated at 9.8 μ immediately after birth, was reduced to 6.8 μ in 6 months, to 6.5 μ in a year and to 5.9 μ in 4 years, while the value for normal adults was 5.4 μ. In patients with ventricular septal defect (VSD), physiological medial regression does not take place, and the muscular coat retains or increases its neonatal thickness. The medial thickness is correlated with pulmonary blood pressure level and can be expressed by an exponential function of blood pressure. Pulmonary hypertension in VSD is correlated with the dimension of septal defect. Medial hypertorphy in VSD is probably associated with increased vascular resistance of pulmonary circulation.
TL;DR: A new method to estimate the DNA synthetic time and mitotic time of heart muscle of rats from single autoradiographic specimen was described and a method to approach the postsynthetic time was mentioned.
Abstract: A new method to estimate the DNA synthetic time and mitotic time of heart muscle of rats from single autoradiographic specimen was described. If the postsynthetic time is negligible, the DNA synthetic time of heart muscle cells is 15-16 hours in 2-day-old, 1- and 2-week-old rats. The mitotic time of heart muscle cells is 7-11 hours. The DNA synthetic time of interstitial cells is 15-18 hours in 2-day, 1-, 2- and 3-week-old rats. The mitotic time of interstitial cells is 7-9 hours. The DNA synthetic time was also calculated from the estimation of cell number and the results were compared with the above mentioned values. In addition, a method to approach the postsynthetic time was mentioned.
TL;DR: The increase in DNA content seems to indicate the increase in the number of heart muscle cells as well as of interstitial cells in experimental cardiac hypertrophy.
Abstract: Total DNA content of the whole heart muscle of the Goldblatt rats was chemically determined, and the DNA content per single nucleus of the heart muscle cell and of the interstitial cell was determined by the microspectrophotometric method, in order to substantiate the assumption of cell division of the heart muscle in experimental cardiac hypertrophy. Total DNA content of the whole heart muscle and the DNA content per 100mg of heart weight in the hypertensive group was significantly higher than those in the control group. The DNA content per nucleus of the muscle cell and of interstitial cell was found to be constant in both groups. It seems that the increase in DNA content indicates the increase in the number of heart muscle cells as well as of interstitial cells.