Showing papers in "The Bulletin of Tokyo Medical and Dental University in 1986"

Cerebral extracellular potassium concentration change and cerebral impedance change in short-term ischemia in gerbil.

Abstract: Extracellular potassium and calcium ion concentration, field potential (Fp), local EEG and cortical impedance were measured continuously in the cortex and hippocampus of the pentobarbital anesthetized gerbils subjected to 5-minute ischemia produced by bilateral carotid occlusion. Extracellular potassium ([K+]e) and extracellular calcium ([Ca++]e) showed a triphasic change during ischemia followed by a biphasic change after recirculation. The EEG became flat within about 20 seconds. There was a sharp increase in the [K+]e and a sharp decrease in the [Ca++]e, which coincided with the sharp increase in the Fp around one and a half minutes. The impedance increased simultaneously with a large amplitude change of EEG. The [Ca++]e continued to decrease for another 1-2 minutes before returning to the normal values after recirculation whereas the [K+]e began to decrease immediately. The extracellular space (ECS) did not change until depolarization. The rise of the [K+]e and [Ca++]e in the pre-depolarization phase was not explained by the shrinkage of the ECS. The possible explanation for the change of the [Ca++]e in ischemia was discussed.

Role of traumatic subdural fluid collection in developing process of chronic subdural hematoma.

Abstract: We investigated the role of traumatic subdural fluid collection in the genesis of chronic subdural hematoma (CSDH) in 43 consecutive patients with traumatic subdural fluid collection. Traumatic subdural fluid collection was found in 43 (6%) of 715 patients who underwent CT scans because of head injury. Twenty-four of the 43 patients were more than 65 years of age and this problem occurred in 30% of the 79 head-injured patients over 65 years of age. In 20 (Group 1) of the 43 patients CSDH subsequently developed. During the same period, 30 other patients were treated for CSDH. Twenty-four (Group 2) of these 30 patients had a history of head injury more than two weeks prior to the developing signs and symptoms and had hyper- or iso-dense hematomas on their first CT scan. It may have been that they too first had a traumatic subdural collection. Forty to sixty percent of the patients with asymptomatic traumatic subdural fluid collection may develop CSDH, and this may occur especially in the older patients. Careful observations after the head injury are particularly important in the aged because of the frequent occurrence of traumatic subdural fluid collection and the subsequent development of CSDH.

Genetic study on ossification of posterior longitudinal ligament.

Abstract: Family studies and blood grouping tests were conducted in an attempt to elucidate the etiology and genetic mechanism of ossification of posterior longitudinal ligament of the spine (OPLL). Analysis of the collected date revealed the following results: Testing of inheritance pattern Fitness of OPLL to the hypotheses of simple recessive inheritance, simple dominant inheritance and multifactorial inheritance was tested, but fitness to any one of these hypotheses was statistically denied. Analyses of OPLL and genetic markers A comparative study was made between the OPLL patients and healthy donors residing in Tokyo on the phenotype frequency of the blood groups (eight systems), serum groups (six systems) and red cell enzyme groups (three systems). A significant association of OPLL with MN blood groups, Hp types and PGM1 types was observed. Examination of the correlation after combining MN and Hp showed the coefficient of contingency to be C = 0.6739 and that after the multiple combination of MN, Hp and PGM1 revealed the coefficient of contingency to be C = 0.8923, indicating a remarkably high correlation.

Study on ectopic calcification in bone marrow of rat tibia caused by vinblastine.

Abstract: Contact microradiographic study and histological study were performed to investigate the sequential changes in the bone marrow after a large dose of vinblastine or colchicine administration. Rats were injected intravenously with various dose of vinblastine or colchicine. The following dynamic histological changes were noted in the bone marrow in the vinblastine 2.0 mumol/kg and colchicine 2.5 mumol/kg-injected groups: Necrosis of the bone marrow cells was observed in the early stage and the necrotic bone marrow cells were replaced by many fibroblast-like cells. After that, the fibroblast-like cells disappeared and the network-like calcified tissue replaced the region where the fibroblast-like cells existed previously. The osteoblasts were lined on the surface of the ectopic calcified tissue and then the osteoblasts were replaced by the typical osteoclasts. In consequence of this dynamic alteration of the cells, the ectopic calcified tissue decreased and the normal bone marrow cells increased in the bone marrow cavity. The ectopic calcification could hardly be observed in the area where the fibroblast-like cells had not appeared. These findings suggested that the markedly proliferated fibroblast-like cells in the marrow cavity after the administration of vinblastine or colchicine may differentiate to osteoblasts and that the osteoclasts may be derived from the bone marrow cells which had already recovered from the toxic effect of the drugs. The mechanism of the dynamic histological changes in the bone marrow remains to be investigated.

Histomorphometric study on growing condyle of rat.

Abstract: The purpose of this study was to carry out the histomorphometric assay on the mandibular condylar tissue of the growing rats. Male rats of the Wistar strain at the age of 3, 4, 6, 8 and 10 weeks were used. All rats were injected intravenously with tetracycline and calcein, respectively. They were killed 12 hours after calcein injection. Before embedding in acrylic resin, 3 reference points were marked directly on each condyle to establish the reference plane for the histomorphometry on the ground section. After preparing the ground section, the growth rate of the condyle was obtained by measuring the distance of the two different fluorescent labeling lines. Furthermore, the age-related changes of the relative distribution of the bone, calcified cartilage and prebone (uncalcified bone matrix) were measured under a light microscope by using a grid on the eyepiece reticle. The number of osteoblasts and osteoclasts were also calculated in the same specimen. The following results were obtained: The thickness of the cartilaginous layer and the growth rate of the endochondral bone formation decreased with age. The relative ratio of the bone area in the subchondral tissue increased constantly with age.

Hepatocellular carcinoma presenting extrahepatic obstructive jaundice due to bile duct invasion--clinicopathological study of two cases.

Abstract: Two rare cases of autopsy and surgery presenting extrahepatic biliary obstruction due to intrabile-duct growth of hepatocellular carcinoma were reported. Clinically obstructive jaundice was predominant in comparison with the other symptoms in both cases. In one autopsy case, hepatocellular carcinoma developed in the right lobe of the cirrhotic liver (posthepatitic). It involved the secondary branch of the right hepatic duct and grew into the common hepatic duct. In the other case of surgical operation, hepatocellular carcinoma, which developed in the posterior portion of the right lobe of the cirrhotic liver (posthepatitic), destroyed the posterior wall of the bifurcation of the bilateral hepatic duct and obstructed the common hepatic duct due to the intraductal cancer growth. From the site of the bile duct invasion or permeation by the tumor, two cases were classified into the peripheral (the former case) and proximal (the latter case) types, respectively. Furthermore, as far as obstructive jaundice is clinically concerned, the possibility should be kept in mind that hepatocellular carcinoma may proliferate into the large bile ducts, apart from that of cholangiocarcinoma or cholelithiasis.

A simplified method of xenon-enhanced CT for regional cerebral blood flow (rCBF) measurement with reference to clinical experiences.

Abstract: We introduced a simplified method of xenon-enhanced CT (SXe-CT) for obtaining the topographic regional cerebral blood flow (rCBF) map. In the SXe-CT, we used the method of brief (three to four minutes) inhalation of 40% xenon. To shorten the period of xenon inhalation, we substituted a predetermined brain-blood partition coefficient (L) in the entire brain for the directly estimated L to calculate the rCBF value. Because of its non-invasiveness and simplicity, the SXe-CT can be applied to the patients with diseases in the central nervous system (CNS) without any difficulties. During the past three years, we performed the SXe-CT on 150 occasions in 100 subjects, including those with moyamoya disease, other ischemic cerebrovascular diseases, arteriovenous malformations and normal pressure hydrocephalus. In this paper, the rCBF values of seven normal healthy adults with a mean age of 24 years are reported and the flow maps of some cases of CNS diseases are presented. The normal mean value of the hemispheres was 53, those of the gray matter were in the range of 38 to 72, those of the white matter were in the range of 26 to 35 and those of the basal ganglia and thalamus were 55 to 88 (values are given in ml/100 g/min). The SXe-CT has potential advantages in obtaining clinically useful rCBF measurements.

Slicing technique for tooth specimens in histological preparation.

Abstract: A slicing technique for the preparation of a tooth specimen is described. A low speed saw (ISOMET) was used for this modified technique. It is a slicing machine fitted with a diamond-impregnated cutting disc of 0.5 mm in thickness. The formalin was used for lubrication to serve as both a coolant and a fixative simultaneously. It is thought that the preparation will not damage or disturb the surface of the tooth specimen by careful management under 200 rpm with a loading of 50 grams. The cutting of slices can be controlled by adjusting the specimen arm with a micrometer to the desired thickness. A high quality histological preparation can be obtained when the specimen is sliced as mentioned above soon after it is removed from the living body before decalcification. By the observation of specimens such as the resected jaw bone or other large hard tissue specimens, it is suggested that the sliced specimens of 2 mm in thickness can be obtained routinely for histological study by using this method.

Characteristic distribution density of organelles in the cytoplasm of respective kinds of cell lineages of ascidian embryos

Abstract: In the early embryos of the ascidian (Halocynthia roretzi), regional cytoplasmic differences arise just after fertilization. We successively studied the characteristic features of the cytoplasm of those regions in the embryonic cells during the entire ontogenic process from the unfertilized egg to the tadpole larva. The embryos and larvae were fixed in a mixture of osmium and glutaraldehyde, and the distribution of the organelles in the entire cytoplasm was observed with light and electron microscopy. According to the analysis of the distribution density of the organelles which occupied a given area of the cytoplasm on the section, we introduced the "organelle region" in the cytoplasm and further calculated the approximate area ratios of the "organelle regions" in the cytoplasm of each cell lineage. As a result, it was demonstrated that the characteristic distribution mode was already present in the cytoplasm of the cell lineages of the 8-cell-stage embryos. The features of the cytoplasm in each embryonic cell lineage, moreover, reflected those of the corresponding larval tissue. Our results not only demonstrate that the structural tissue specificity is expressed at an extremely early stage during the ascidian embryogenesis but also suggest that the corresponding functional differentiation among the cell lineages occurs early.

Nucleotide sequence of exon I of the rat c-K-ras gene.

Abstract: We have isolated a DNA fragment containing exon I of rat cellular proto-oncogene of K-ras and sequenced the exon I. The obtained sequence was compared with that of the corresponding region in viral oncogene of Kirsten strain of murine sarcoma virus (Ki-MSV). The results showed that the exon I sequences of cellular K-ras genes in rat and human cells could encode the same amino acid sequence, while the viral K-ras gene could code for two different amino acids corresponding to the 12th and 37th positions from the N-terminus of K-ras gene product. The amino acid substitutions found between viral and cellular K-ras genes are discussed in relation to the transforming ability of Ki-MSV.

Definition of mixing rate of indicator by indicator dilution method: evaluation of relationship between mixing rate of indicator and cardiac output determination.

Abstract: It is generally agreed that complete mixing of the indicator is one of the most important factors of the indicator dilution method, however, no clear definition of the mixing state has been established. We established a formula for the mixing rate of the indicator by the indicator dilution method, using the concept of entropy in the information theory, and compared the mixing rate of indocyanine green in one mixing chamber (left ventricle) with that in the two mixing chamber system (including the aortic system). The mixing rate of the indicator (M) is shown as M(%) = 100 H/Hcm = -100 (lk sigma ni = 1 Ci + log Ci + log k) (l & k: correction factors in each dye dilution curve, C: mean concentration of the indicator in the region). Left heart and aortic catheterizations by retrograde femoral and carotid artery approach were performed in five anesthetized dogs. Simultaneous dye dilution curves were recorded at the aortic root and at the bifurcation of the abdominal aorta, following the injection of indocyanine green (2.5 mg/1 ml of indocyanine green for each injection) by impulse into the left ventricle at the endsystole, triggered on the R wave of ECG, using the automatic injector devised by the authors. Twenty-five pairs of dye dilution curves were obtained by simultaneous recording in the aortic root and the abdominal aorta under several hemodynamic conditions, and the cardiac output, mean circulation time and the mixing rate of the indicator were determined.(ABSTRACT TRUNCATED AT 250 WORDS)