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Biomedical subjects

K Sano

Publications and source records attributed to K Sano.

At least 595 records · Page 33Linked to original sources
PubMed1986

[Focal cerebral infarction in the rat: I. Operative technique and physiological monitorings for chronic model].

The purpose of this paper is to develop a new chronic model of focal cerebral infarction by occluding the middle cerebral artery (MCA) in the rat. The operative method and results of physiological monitoring before, during, and after operation are shown. In adult male Sprague-Dawley rats, the left MCA was occluded via trans-retro-orbital approach simply by retracting the temporalis muscle. This method was slightly modified from our original method for chronic experiments. In a group of rats, systemic arterial pressure and blood gases were monitored using a femoral arterial catheter before, during, and after the operation. In the other group, blood pressure by tail-cuff method, neurological findings, and body weight were examined for one week after the MCA occlusion. During the operation under the halothane anesthesia, systemic arterial pressure decreased about 30% comparing with preanesthetic normal value and then quickly returned to normal within 30 minutes after the operation. Body weight progressively decreased in the occluded group during the observation period of one week, although body weight in the sham-operated group decreased only for initial few days and recovered. No animal died during first one week. Slight right hemiparesis was observed only in the MCA occluded group for few days.

Animals↗
PubMed1986

[Focal cerebral infarction in the rat: II. Neuropathological study and local cerebral blood flow pattern].

We have recently reported that middle cerebral artery (MCA) occlusion in the rat produces a uniform pattern of cerebral ischemia in an acute phase. This study was done to determine if this model is also useful for quantitative evaluation of infarction size in a chronic phase. [Methods] Sprague-Dawley rats were anesthetized with halothane and left MCA was occluded via transretro-orbital approach. The following studies were done. Neuropathological study was done one week after MCA occlusion. After perfusion fixation, the brain was cut into 6 coronal slices and stained sections were examined. Local cerebral blood flow patterns were observed by 14C-iodoantipyrine autoradiographic technique 1, 2, and 5 days after the occlusion. [Results] Neuropathological studies invariably showed infarct in the cortex and the lateral part of the basal ganlia. The ratio of the infarct to the total areas of both hemispheres in 6 coronal sections was 14.05 +/- 2.66% (Mean +/- SD) in MCA occluded animals (N = 14) and 0.59 +/- 0.46% in sham operated animals (N = 12). Relative to the contralateral hemisphere, marked reduction in CBF was seen in the territory of the MCA and moderate reductions were also seen in the surrounding areas. The same pattern of increased CBF as previously reported was also seen in the ipsilateral substantia nigra and globus pallidus 1, 2, and 5 days after the occlusion. These results indicate the usefulness of this chronic focal cerebral infarction model in the evaluation of infarction.

Animals↗
PubMed1986

[An autopsy case of lung cancer in a young adult dwarf].

A 31-year-old man with peripheral squamous cell carcinoma is reported. By nature he was very small. On admission he was 140 cm tall, weighed 28 kg, and was complaining of chest pain of five years duration. A giant tumor in the right lung was found to be moderately differentiated squamous cell carcinoma. He also had congenital anomalies, such as crossed ectopic kidney with fusion, café-au-lait spots, inguinal hernia, simian line, etc. He had never been exposed to cancer-causing agents. In conclusion, genetic factors related to intrauterine growth retardation might have been linked to his oncodevelopmental mechanisms.

Adult↗
PubMed1986

[Treatable ischemic neuronal damage in the gerbil hippocampus].

The Mongolian gerbil is known to develop delayed neuronal death in the hippocampus following brief forebrain ischemia (Brain Res 239: 57-69). Morphological, biochemical, or electrophysiological studies on this neuronal injury have shown that neurons still retain potential reversibility at the earlier period of alteration. To examine this possibility, immediately following 5 min of ischemia in the gerbil, pentobarbital, diazepam, or nizofenone was injected. Seven days following ischemic insult, animals were perfusion fixed and neuronal density in the hippocampal CA1 subfield was counted. Most of the neurons in the CA1 sector survived ischemic insult when a drug was given, whereas most of them were lost without the treatment. The average neuronal density of treated groups showed a statistically significant (p less than 0.01) persistence compared with that of control group. The effective dosage of the drugs were 20-40 mg/kg in pentobarbital, 10-20 mg/kg in diazepam, and 12.5-25 mg/kg in nizofenone. On the other hand, when pentobarbital was injected 1 hr following ischemia, while neurons still remain intact morphologically, it showed no effect. This result indicates that the neuronal damage of "delayed neuronal death" type is reversible if treatment is instituted at an early period of cell change.

Animals↗
PubMed1985

Comparison of the modes of action of Ca2+ ionophore A23187 and thrombin in protein kinase C activation in human platelets.

In human platelets, the Ca2+ ionophore A23187 stimulated the phosphorylation of a 40 kDa protein and myosin light chain (MLC) to the same extents as those induced by thrombin, but the doses of A23187 for 40 kDa protein phosphorylation were higher than those for MLC phosphorylation, although the doses of thrombin for both reactions were nearly the same. Moreover, A23187 produced much less diacylglycerol than thrombin. However, the sites of the 40 kDa protein phosphorylated by the action of A23187 and thrombin were identical, and the 40 kDa protein phosphorylation induced by A23187 and thrombin was inhibited by tetracaine, an inhibitor for protein kinase C. Neither A23187 nor thrombin induced the production of a catalytic fragment of protein kinase C which might be generated by limited proteolysis with Ca2+-dependent protease. These results indicate that A23187 induces protein kinase C activation which phosphorylates the 40 kDa protein, but higher doses of A23187 are required for the activation of this enzyme than for the activation of MLC kinase.

Blood Platelets↗
PubMed1985

Involvement of protein kinase C in pulmonary surfactant secretion from alveolar type II cells.

The purpose of this study is to clarify the involvement of protein kinase C in pulmonary surfactant secretion from adult rat alveolar type II cells in primary culture. Surfactant secretion in vitro is stimulated by at least two classes of compounds. One class, (e.g. terbutaline) increases intracellular cyclic AMP, whereas the other class (e.g. 12-O-tetradecanoylphorbol 13-acetate (TPA] does not. TPA has been shown to activate protein kinase C in other cell systems. In our studies, 1-oleoyl-2-acetyl-sn-glycerol (OAG), which is a direct activator of protein kinase C, stimulated [3H] phosphatidylcholine secretion by alveolar type II cells in a dose- and time-dependent manner. Tetracaine, which is an inhibitor of protein kinase C, inhibited the TPA-induced secretion of [3H]phosphatidylcholine from alveolar type II cells in a dose-dependent manner. However, tetracaine had no effect on terbutaline-induced secretion. The effects of terbutaline and OAG upon surfactant secretion were significantly more than additive, but those of TPA and OAG were less than additive. The specific activity of protein kinase C was 6-fold higher than cyclic AMP-dependent protein kinase found in type II cells when both kinases were assayed using lysine-rich histone as a common phosphate acceptor. Ninety-four per cent of protein kinase C activity was recovered in the cytosolic fraction of unstimulated type II cells, and 40% of activity in cytosolic fraction was translocated to particulate fraction upon treatment with TPA. As observed in other tissues, protein kinase C of alveolar type II cells was highly activated by 1,2-dioleoyl-sn-glycerol or TPA in the presence of Ca2+ and phosphatidylserine. These results suggest that pulmonary surfactant secretion in vitro is stimulated by both protein kinase C and cyclic AMP-dependent protein kinase.

Animals↗
PubMed1985

Construction of novel shuttle vectors and a cosmid vector for the glutamic acid-producing bacteria Brevibacterium lactofermentum and Corynebacterium glutamicum.

Novel cloning vectors for glutamic acid-producing bacteria have been constructed. Two cryptic plasmids, pAM330 from Brevibacterium lactofermentum and pHM1519 from Corynebacterium glutamicum, were used as precursors, and recombined with pBR325 or pUB110. Resultant composite plasmids were able to propagate and to express the CmR or KmR phenotype in B. lactofermentum and C. glutamicum. A smaller, high-copy-number plasmid, pAJ43, was also isolated following deletion of a part of the pAM330-pBR325 composite plasmid. Furthermore, a cosmid vector, which can be packaged and transduced through phage infection, has been developed using a cohesive-end fragment of the f1A phage and plasmid pAJ43. These plasmids are suitable for use as cloning vectors in the glutamic acid-producing bacteria.

Brevibacterium↗
PubMed1985

Effect of leucine on intestinal absorption of tryptophan in rats.

1. To elucidate the causal relation between leucine and the lowering of hepatic NAD content of rats fed on a leucine-excessive diet (Yamada et al. 1979), the effect of leucine on intestinal absorption of tryptophan was investigated. 2. Co-administration of [3H]tryptophan and leucine, with leucine at ten times the level of tryptophan, delayed absorption of L-[side chain 2,3-3H]tryptophan from the digestive tract and incorporation of [3H]tryptophan into portal blood, the liver and a protein fraction of the liver. After 120 min, more than 95% of tryptophan was absorbed whether [3H]tryptophan was administered with or without leucine. 3. Co-administration of a mixture of ten essential amino acids, in proportions simulating casein, with [3H]tryptophan markedly delayed absorption of tryptophan from the digestive tract. The addition of supplementary leucine to the amino acid mixture, however, caused no further delay. 4. In rats prefed a leucine-excessive diet for 1 week [3H]tryptophan was absorbed at the same rate as in rats fed on a control diet. 5. The results indicate that competition between tryptophan and leucine for intestinal absorption did not cause lowering of hepatic NAD.

Amino Acids, Essential↗
PubMed1985

Comparative studies on methods of isolating rat epidermal cells.

Epidermal basal cells have been prepared using trypsin or dispase to remove the epidermal sheet from the skin. In addition, for trypsin, the "immersion method" and the "flotation method" have been described. However, there has been no study that quantitatively compares these methods using the same animal, making their usefulness difficult to evaluate. In this report, comparative studies on these methods were undertaken concurrently with newborn and adult rats. The flotation method using trypsin was found to be preferable to the immersion method, because separation of the epidermal sheet by the former method was easier than by the latter. Then, the flotation method using trypsin was compared with the isolation method using dispase, and quantitative estimation was made of the yield, viability, and the number of attached epidermal cells. The dispase method was found to be superior to the trypsin method, especially for cell yield, which was about four times as high as with the latter method. Furthermore, cells dissociated with dispase showed a higher rate of viability and attachment to culture dishes than those done with trypsin. These results clearly demonstrated that the dispase method is more useful for preparing epidermal basal cells than the trypsin method.

Animals↗
PubMed1985

Mode of inhibitory action of bilirubin on protein kinase C.

Ca2+-activated, phospholipid-dependent protein kinase (protein kinase C) is widely distributed in mammalian tissues. Accumulating evidence has revealed that protein kinase C as well as cAMP-dependent protein kinase plays important roles in various cellular functions. The purpose of this study is to examine the effect of bilirubin on protein kinase C and cAMP-dependent protein kinase activity in a cell-free system as a cause of bilirubin toxicity to the central nervous system. Bilirubin inhibited protein kinase C activity in a dose-dependent manner. This effect was markedly diminished by the addition of human serum albumin at a molar ratio of bilirubin to albumin of less than 1.0. Kinetic analysis revealed that bilirubin did not compete with phospholipid, diacylglycerol, or calcium. Bilirubin also inhibited cAMP-dependent protein kinase, but did not compete with cAMP. The inhibitory effect of bilirubin on protein kinase C seems to be irreversible because removal of bilirubin by Sephadex G-25 column chromatography did not restore the protein kinase C activity. Observations reported herein suggest that bilirubin, especially in its free form, induces an irreversible change to the catalytically active site of protein kinase C.

Animals↗
PubMed1985

Decrease of extracellular fluid in dog submandibular glands during secretion under arterial clamping conditions.

Microscopic observations were made of volume changes in ECF of the dog submandibular glands during resting state and stimulated state without blood supply. The interlobular space, one of the compartments of ECF, decreased significantly during stimulation when blood supply was absent. The results show that the interlobular space plays an important role as a reservoir of fluid in salivary secretion.

Animals↗
PubMed1985

Detection of the bleeding source from small intestine: intraoperative endoscopy and preoperative abdominal scintigraphy by technetium 99m pertechnetate.

Bleeding ulcerative lesions of the small intestine often present difficult diagnostic problems. Useful techniques to establish a diagnosis include abdominal scintigraphy using technetium 99-m pertechnetate and intraoperative endoscopic examination of the intestine. Our experience with these techniques is based on 25 patients who were treated in 1974-1983. In 18 adults, the diagnoses included Crohn's disease, non-specific ulcers and intestinal tuberculosis. In 6 of the 18 adults, the source of bleeding was difficult to determine during laparotomy and diagnosis was established by intraoperative endoscopic examination. In the seven children, the diagnoses included ectopic gastric mucosa and lymphoid hyperplasia. In the children, abdominal scintigraphy was used as a preoperative measure to detect the bleeding source.

Adolescent↗
PubMed1985

Determination of the complete nucleotide sequence of the Brevibacterium lactofermentum plasmid pAM330 and the analysis of its genetic information.

The complete nucleotide sequence of the plasmid pAM330 derived from Brevibacterium lactofermentum ATCC 13869 was determined using the dideoxy chain termination method. Analysis of the sequence allowed us to observe seven open reading frames, one of which showed the presence of the promoter and the Shine-Dalgarno (SD) sequences upstream from the initiation codon.

Base Sequence↗