The 14C incorporation into purine bases of fetal brains was investigated when DL-serine-3-14C, L-histidine-2-14C, or formate-14C was injected intraperitoneally to dams with or without pre-treatment with aminopterin. The radioactivity of 14C in fetal brain tissues was estimated on the 18th day of gestation. On the 11th day of gestation, DL-serine-3-14C, L-histidine-2-14C, or formate-14C was injected to dams intraperitoneally. In the case of aminopterin treatment, aminopterin, 0.076mg/kg, was injected intraperitoneally to dams on the 10th day of gestation. The results in these experimental conditions showed that the 14C incorporation from formate-14C into adenine of fetal brains and that from DL-serine-3-14C into guanine of fetal brains were impaired significantly by aminopterin injection to dams prior to injections of the labeled materials.
The pattern of serum heat-stable alkaline phosphatase (HSAP) of women in late pregnancy was examined and discussed in relation to the clinical course. Four types were recognized in the HSAP pattern. The unstable type was most closely related to the clinical course; that is, this type was observed in only 6 out of 79 cases of the normal group, whereas it was found in 12 out of 24 of the postdated group and 5 out of 10 of the toxemia group. The incidence of intra-uterine fetal distress and of placental dysfunction syndrome was also highest in the unstable type. The significance of the unstable type was stressed as an alarm signal for fetal life in the third trimester of pregnancy.
The constant pressure perfusion of the sinus node artery was performed on 12 dogs anesthetized with sodium pentobarbital (30mg/kg, i.v.). When acetylcholine (ACh) was infused continuously at different rates into the sinus node artery, the sinoatrial pacemaker was depressed and prefibrillatory stage was established at a suitable rate of infusion. Thus, a sustained atrial fibrillation was spontaneously induced or it was evoked by a single dose of either acetylcholine, norepine-phrine or nicotine during the infusion of acetylcholine. When the infusion of ACh at a higher rate depressed the sino-atrial node completely and escape A-N nodal rhythm took place, atrial fibrillation was never induced. Atrial fibrillation ceased suddenly and the sinus rhythm reappeared soon after the infusion was interrupted. This could be observed repeatedly. A single dose of atropine blocked the sustained atrial fibrillation, while propranolol and GEDTA could block it by infusion or intravenous administration. It is suggested that the prefibrillatory stage is necessary for maintenance of atrial fibrillation, and its mechanism is discussed.
Young rats fed on a diet low in either tyrptophan or methionine showed a retardation of growth as well as a decrease in serum protein level. A fall of γ-globulin was found in cases of the low tryptophan diet and that of albumin in those of low methionine diet. In the liver, a significantly low level of protein was found in tryptophan-deficient rats, whereas a considerable atrophy of the organ was observed in methionine-deficient rats. Increase of tryptophan content to 0.3g/100g diet could not raise the γ-globulin content over the values in the case of 0.2% trvptophan diet.
Unitary discharges were extracellularly recorded from cortical cells in the rabbit's visual area. Most of the cortical units were responsive to large-field illumination which was turned on and off at about 0.8/sec. Response characteristics of cortical cells were largely similar to those of retinal ganglion cells. One hundred and twenty-nine units which were analyzed successfully were categorized into four classes according to the features of their receptive fields: simple, asymmetric, complex and compound. Especially, compound receptive fields were so named on the basis of the finding that the whole receptive field consisted of three separable complex fields. A columnar arrangement of cortical neurons was suggested on the basis of the fact that the localization of the receptive fields of units involved in a particular column was almost identical in the visual field. No other common properties to specialize the column was detected. Most of the receptive fields of units which were localized in the visual streak were oval in shape with their long axis horizontal as described in retinal ganglion cells. It is likely that in the rabbit's visual cortex no more elaborate analysis is made on in-coming visual information, but rather some integrative action is carried out for further processing.
The mode of action of algesic agents administered into the mesenteric and femoral arteries through the chronically indwelling catheters was studied on 30 immature dogs, utilizing vocalization as an indicator of nociception. Since almost all puppies vocalized to nocive stimuli, the use of puppies was found to be advantageous for this sort of investigation. Bradykinin, eledoisin, histamine, acetylcholine and barium chloride administered into the mesenteric artery evoked vocalization without tachyphylaxis. Positive and negative dose-response relations were obtained for the duration and latency of vocalization respectively. Bradykinin and eledoisin were most potent and gave the dose-response relations with the least individual variations. 5-Hydroxytryptamine failed to cause vocalization. Atropine antagonized specifically the algesic action of acetylcholine, while tripelennamine and diphenhydramine antagonized that not only of histamine but also of acetylcholine and bradykinin. Papaverine blocked the effect of all of the algesic agents administered into the mesenteric artery but not that of bradykinin given into the femoral artery. Sodium salicylate and procaine blocked the effect of histamine and acetyylcholine given into the mesenteric artery and also abolished that of bradykinin injected into the femoral artery. However, sodium salicylate and procaine were ineffective against the action of bradykinin or eledoisin administered into the mesenteric artery.
The fibrous tissue in the biopsied bone marrow was serially observed in 157 patients with hematological disorders. An increase of argyrophil fibers was demonstrated in acute and chronic leukemias, erythroleukemia, malignant lym-phomas, carcinoma with metastasis to the marrow, polycythemia vera and primary myelofibrosis. The increase of argyrophil fibers was generally correlated with the grade of proliferation of the hematopoietic cells and its duration. Argyrophil fibers were reduced in aplastic anemia.
High concentrations of pressor enzyme have been found in amniotic fluid collected from normal and toxemic pregnant women at delivery. The enzyme activity was significantly increased in toxemia as compared with that in normal pregnancy. Physico-and pharmaco-chemically this pressor enzyme was similar to human renin and its reaction product with human plasma was similar to angiotensin. Probable sources of amniotic renin were discussed.
The fine structural localization of acid phosphatase activity in myeloma cells was determined in four cases of multiple myeloma. The four patients consisted of two with IgG myeloma, one with IgA myeloma and one with Bence-Jones protein myeloma. Light microscopic histochemistry using the azo dye method revealed intense acid phosphatase activity in all myeloma cells. Moreover, electronmicro-scopic histochemistry using the metal salt method demonstrated definite locali-zation of acid phosphatase activity in the cell. It was mainly observed in close association with granular endoplasmic reticulum as well as dense bodies and Golgi area. The acid phosphatase activity in granular endoplasmic reticulum may suggest some relationships between acid phosphatasc activity and immunoglobulin production in myeloma cells.
In order to demonstrate mitotic figures of the heart muscle cells and the interstitial cells during normal growth, colchicine was given to a total of 20 rats of various ages and mitosis in the myocardial cells was evaluated. The mitotic rate of heart muscle cells in 4 hours was 1.9-2.1% on the first day of life and it gradually decreased to 0.1% in 4 weeks and zero thereafter. The mitotic rate of interstitial cells was 2.0-2.2% on the first day of life and it similarly decreased to 0.1% in 6 months. These results seem to support our view that heart muscle cells and interstitial cells divide and increase in number with postnatal growth of the heart.