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Biomedical subjects

K Yamane

Publications and source records attributed to K Yamane.

At least 235 records · Page 13Linked to original sources
PubMed1990

Pathophysiological studies in the rat cerebral embolization model: measurement of epidural pressure and evaluation of tissue pH and ATP.

A rat embolization model was produced by occlusion of the main cerebral artery with a silicone cylinder embolus. Intracranial pressure was monitored by changes in epidural pressure (EDP), which was recorded by our designed flaccid microballoon. EDP changes could be divided into the two types: the first was moderate elevation, less than 20 mm Hg and the second was prominent, more than 20 mm Hg. Brain tissue pH on the embolized side showed heterogeneous changes composed of acidotic and alkalotic areas. Alkalotic change was frequently seen at the deep cerebrum which might be the result of plasma exudation due to disruption of blood-brain barrier (BBB). The degree of the EDP elevation was positively correlated with the extension of alkalotic area. Energy metabolism was also mainly disturbed in the deep cerebrum, but did not completely correspond to the pH change of the area. These results would indicate that embolization of the main cerebral artery could induce severe ischaemic insult on the deep cerebrum with massive brain swelling due to an early disruption of BBB.

Adenosine Triphosphate↗
PubMed1990

Ultrastructure of swollen proximal axons of anterior horn neurons in motor neuron disease.

We have investigated ultrastructurally swellings of the proximal axons directly connected with the somata of anterior horn cells in a patient with motor neuron disease. In the distal portion of the initial segment, the swellings consisted predominantly of increased amounts of neurofilaments running nearly parallel to the longitudinal axis together with other cytoplasmic organelles. In the first internode of the myelinated axon, as the swellings became larger, the neurofilaments lost their parallel orientation and became intermingled. Most of the cell bodies connected with the swellings and their dendrites showed no particular changes. The abnormal neurofilamentous accumulations in the proximal axons suggest abnormal axonal transport, which may be pathogenetically associated with motor neuron disease.

Aged↗
PubMed1990

Cloning and characterization of a Bacillus subtilis gene homologous to E. coli secY.

A 3.5-kb HindIII DNA fragment containing the secY gene of Bacillus subtilis has been cloned into plasmid pUC13 using the Escherichia coli secY gene as a probe. The complete nucleotide sequence of the cloned DNA indicated that it contained five open reading frames, and their order in the region, given by the gene product, was suggested to be L30-L15-SecY-Adk-Map by their similarity to the products of the E. coli genes. The region was similar to a part of the spc operon of the E. coli chromosome, although the genes for Adk and Map were not included. The gene product of the B. subtilis secY homologue was composed of 423 amino acids and its molecular weight was calculated to be 46,300. The distribution of hydrophobic amino acids in the gene product suggested that the protein is a membrane integrated protein with ten transmembrane segments. The total deduced amino acid sequence of the B. subtilis SecY homologue shows 41.3% homology with that of E. coli SecY, but remarkably higher homologous regions (more than 80% identity) are present in the four cytoplasmic domains.

Adenylate Kinase↗
PubMed1990

Processing of an NH2-terminally extended thermostable alpha-amylase by Bacillus subtilis alkaline protease.

To analyze the processing of extracellular enzymes of Bacillus subtilis, an NH2-terminally extended hybrid alpha-amylase [pTUBE638-alpha-amylase (E24)] was purified from the periplasm of E. coli(pTUBE638) as the substrate for the in vitro processing reaction, in which a 21-amino-acid extra-peptide was added at the NH2-terminus of the mature thermostable alpha-amylase. The extended peptide in pTUBE638-alpha-amylase (E24) was completely processed by the extracellular alkaline protease of B. subtilis alone at pH 7.5 to 10.0. The processing was inhibited by 2 mM PMSF. In contrast, the neutral protease did not process the extended peptide. The processing activity of the purified alkaline protease was fully active in 100 mM phosphate and glycine-NaCl-NaOH buffer while it was partially active in 100 mM Tris-HCl or MOPS buffer. The optimum pH of the activity ranged from 8.0 to 9.0, although the optimum pH of the alkaline protease activity toward casein and Azocoll was 10.5. The NH2-terminal amino acid sequences of the enzymes processed in vitro coincided with those of the mature extracellular thermostable alpha-amylases in the culture medium of B. subtilis (pTUBE638). The appearance of the processing activity of alkaline protease was correlated with the changes of the pH in the culture medium.

Amino Acid Sequence↗
PubMed1990

Artificial insertion of peptides between signal peptide and mature protein: effect on secretion and processing of hybrid thermostable alpha-amylases in Bacillus subtilis and Escherichia coli cells.

To study the effect of inserted peptides on the secretion and processing of exported proteins in Bacillus subtilis and Escherichia coli, pBR322-derived DNA fragments coding for small peptides were inserted between the DNA coding for the 31 amino acid B. subtilis alpha-amylase signal peptide and that coding for the mature part of the extracellular thermostable alpha-amylase of B. stearothermophilus. Most of the inserted peptides (21 to 65 amino acids) decreased the production of the enzyme in B. subtilis and E. coli, the effect of each peptide being similar in the two strains. In contrast, with one peptide (a 21 amino acid sequence encoded by the extra DNA in pTUBE638), the production of alpha-amylase was enhanced more than 1.7-fold in B. subtilis in comparison with that of the parent strain. The molecular masses of the thermostable alpha-amylases in the periplasm of the E. coli transformants varied for each peptide insert, whereas those in the culture supernatants of the B. subtilis transformants had molecular masses similar to that of the mature enzyme. Based on the NH2-terminal amino acid sequence of the hybrid protein from pTUBE638, it was shown that in E. coli, the NH2-terminally extended thermostable alpha-amylase was translocated and remained in the periplasm after the 31 amino acid signal sequence was removed. In the case of B. subtilis, after the removal of a 34-amino acid signal sequence, the hybrid protein was secreted and processed to the mature form.

Amino Acid Sequence↗
PubMed1990

Endogenous AA metabolites and their possible role in tracheal smooth muscle tone in guinea pigs.

The effects of endogenous arachidonic acid (AA) metabolites on inherent tone and histamine-induced constriction were studied in guinea pig tracheal smooth muscle. Inhibitors of either cyclooxygenase (indomethacin) or lipoxygenase (AA 861) significantly diminished the inherent tone of the muscle. Antagonists of prostaglandins (SC 19220) or leukotrienes (FPL 55712) also diminished the inherent tone, whereas an inhibitor of thromboxane synthase (OKY 046) had no significant effect. These results show that the metabolites of the lipoxygenase pathway as well as prostaglandins also participate in the maintenance of inherent tone. To reexamine the previously reported augmentation of histamine constriction induced by the inhibitors and the antagonists, we compared the active tension of the muscle measured from the maximum relaxed level as the base line to eliminate the fluctuation of inherent tone. Such comparison revealed that the inhibitors and the antagonists have no augmentative effect on either the maximum response to histamine or the concentration required to produce 50% of maximum active tension and that there is functional synergism between the exogenously added histamine and the endogenously produced AA metabolites. Therefore the zero active tension is useful as a base line to compare the contractile response of a drug-treated preparation with that of a nontreated preparation.

Animals↗
PubMed1990

[Experience of carotid endarterectomy].

The clinical course of 45 patients treated by carotid endarterectomy over the past 5 years is described with emphasis on the following three points: 1) Diagnostic methods, namely digital subtraction angiography (DSA) and B-mode Doppler imaging technique; 2) surgical procedure using an improved shunt tube and surgical instruments; and 3) monitoring before and during surgery. All operations were conducted using a shunt. Morbidity and mortality rates were both 0%. Postoperative transient hemiparesis lasting for 6 hours was recognized in only four cases. The total percentage of correct diagnoses using intravenous DSA compared with conventional angiography was approximately 80%. The accuracy of the non-invasive B-mode Doppler technique in measuring the degree of constriction compared with conventional angiography was 84%. The shunt was made of silicone tubing and was based on a tube 30 cm in length and 3.5 mm in diameter which was a T-shaped loop. Different sized bulbs were fixed to each end of the tube to prevent extravascular deviation. Modified bulldog clamps and Sugita clips were used for fixation in the vessel. Regional cerebral blood flow (rCBF) measurement and electroencephalography (EEG) under contralateral Matas procedure were conducted before surgery, and cross circulation during short-term occlusion of the common carotid artery was evaluated. The emergence or increase of delta waves in EEG during occlusion was observed in six cases. The rCBF of the affected middle cerebral artery territory in these patients was lower than that in patients with no increase of delta waves. Furthermore, the mean stump pressure during surgery in cases with preoperative EEG changes was 40 mmHg and that in cases without changes was 63 mmHg; these values were significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Artery Thrombosis↗
PubMed1990

Expression of the beta-cyclodextrin glucanotransferase gene of an alkalophilic Bacillus sp. #1011 in Escherichia coli cells and characterization of the synthesized enzyme.

To express efficiently the gene for extracellular beta-cyclodextrin glucanotransferase (beta-CGTase) of an alkalophilic Bacillus sp. #1011 using the E. coli promoters (tac, trp and PL promoters), three DNA fragments starting from the nucleotide positions +1, -18, and -48 of the translation initiation site of the gene were prepared and they were fused with the promoters. The maximum production of the enzyme, which was located mainly (90%) in the periplasm of the E. coli strain, was observed in the combination of the trp promoter and the beta-CGTase gene starting from the -48 nucleotide position in the presence of the inducer, IAA. The production of the enzyme was increased to 5.5 times that by the E. coli harboring the original plasmid and to approximately 3 times higher than the extracellular production of the enzyme by the parental Bacillus sp. #1011. The properties including the stability and optimum in the high pH range (pH 9) of the extracellular beta-CGTase from the alkalophilic Bacillus was conserved in the periplasmic enzymes of the E. coli cells.

Amino Acid Sequence↗
PubMed1990

A case of congenital adrenal hyperplasia with concomitant abnormalities of steroid 21- and 11 beta-hydroxylase activities.

Abnormalities in the steroid 21-hydroxylase and 11 beta-hydroxylase activities were suspected in a 25-year-old female with congenital adrenal hyperplasia (CAH). The patient showed signs of masculinization such as hirsutism, amenorrhea, and enlarged clitoris, but the blood pressure was normal. Adrenocorticotropic was increased to 200 pg/ml. Plasma levels of deoxycorticosterone and 11-deoxycortisol as well as progesterone and 17-hydroxyprogesterone were elevated. Plasma cortisol level was normal at 5.8 micrograms/dl. CT scan revealed enlargement of the bilateral adrenal glands. This case suggests that enzyme abnormalities in CAH are more diverse than have been generally considered.

Adrenal Hyperplasia, Congenital↗
PubMed1990

[Hemodynamic studies on the vertebral artery system during the vertebral arterial surgery].

Few hemodynamic studies on the vertebral artery system in the human can be seen. The authors measured the vertebral arterial blood flow (VAF) with an electromagnetic flow meter in 45 patients who obtained vertebral arterial surgeries. The patients showing vertebrobasilar insufficiency such as vertigo and drop attack had serious kinking and stenosis at the first portion of the vertebral artery. The effects of induced hypotension by trimethaphan camsilate, induced hypertension by phenylephrine, cervical epidural anesthesia and induced hypertension under epidural anesthesia on the VAF were investigated. During the control state, mean systemic arterial blood pressure (SABP), mean VAF were 97 mmHg and 54 ml/min, respectively. The effects of varied SPBP were analyzed by (delta mean VAF/mean VAF)/(delta mean SABP/mean SABP), (delta V/delta S). The delta mean VAF and delta mean SABP indicated varied mean values of VAF and SABP, respectively. Mean SABP was varied significantly by about 25% in each method. The delta V/delta S in induced hypotension, induced hypertension, epidural anesthesia and induced hypertension under epidural anesthesia were -0.05, 0.07, 0.90 and 0.61, respectively, on the average. Induced hypotension by epidural anesthesia and induced hypertension under epidural anesthesia presented significant changes in mean VAF.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1990

[Tissue pH and energy metabolism in cerebral embolization model of rat].

Changes in brain tissue pH, ATP and NADH contents in the cerebral embolization model of Wistar rat were investigated by bioluminescence method. Under light anesthesia, main trunk of cerebral artery was embolized with a silicone cylinder (500 microns in diameter and 1 mm in length) through the cervical internal carotid artery. Rat brain was frozen in situ at 1 or 3 hours after embolization. In some rats Evans blue was injected into the peritoneal cavity 30 minutes before freezing. Caudate putamen and cortex were often acidotic but thalamus, hypothalamus, and hippocampus were composed of both acidotic and alkalotic area. Exudation of Evans blue was frequently detected in the alkalotic area. ATP was decreased partially in the acidotic area. In the alkalotic area ATP was decreased to mild to severe degree. Decreased ATP region in the acidotic area showed increased NADH content, whereas in the alkalotic area NADH was diffusely decreased. From these results, alkalosis may be induced by cerebral edema due to plasma exudation. The decrease of ATP and increase of NADH in the acidotic area may demonstrate the disturbance of oxidative phosphorylation under anaerobic glycolysis, and the decrease of ATP and decrease of NADH in the alkalotic area may demonstrate impairment of glycolysis mainly due to brain edema.

Acute Disease↗
PubMed1990

[Impaired cerebral circulation and the effect of glycerol infusion in the acute stage of hypertensive intracerebral hematoma].

The purpose of the present study was to clarify the mechanism of reduction in cerebral blood flow (CBF) in the acute stage of hypertensive intracerebral hematoma and the effect of glycerol infusion on the reduced CBF. We examined 55 cases. Thirty-eight cases showed putaminal hematoma and 17 presented thalamic hematoma. The range of consciousness was from alert to stupor. CBF was measured by single photon emission CT with Xe-133 inhalation within five days after the onset of the hemorrhage. A CBF map was obtained at a slice 5 cm above the OM-line and mean CBF of the affected and non-affected hemispheres was calculated. In 20 of 55 cases, 500 ml of glycerol was intravenously infused for 60 minutes and thereafter CBF was measured again. Epidural pressure was also recorded at the affected frontal area during glycerol infusion in three of the 20 cases. CBF reduced more profoundly in the area around the hematoma on the CBF map. Mean CBF of the affected hemisphere was negatively correlated with the volume of hematoma by a quadratic regression. After glycerol infusion, 13 of 20 cases showed a significant increase in mean CBF of the affected hemisphere, while the other seven cases showed no increase. Mean CBF increased with a higher percentage in cases with ventricular hemorrhage than without ventricular hemorrhage. In three cases where epidural pressure was measured during glycerol infusion, mean CBF increased and epidural pressure decreased. The increase in mean CBF was proportional to a rise in perfusion pressure calculated as pressure difference between mean systemic arterial pressure and mean epidural pressure, indicating impaired autoregulation in these cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

[Xenon enhanced dynamic computed tomography of the lung; regional ventilation measurement].

CT-functional images (CT-FI's) were created from Xe-dynamic CT data of 10 patients with chronic pulmonary emphysema and 6 volunteers with normal lung. In CT-FI's of normal lungs, the values of washin and washout parameter of outer zone were larger than those of inner zone. In CT-FI's of chronic pulmonary emphysema, the values of washin parameter of inner zone were larger than those of outer zone and the value of washout parameter of outer zone were larger than those of inner zone. CT-FI's proved to helpful in evaluating the axial distribution of ventilation dynamics in chronic pulmonary emphysema.

Administration, Inhalation↗
PubMed1989

Functions of the COOH-terminal region of cyclodextrin glucanotransferase of alkalophilic Bacillus sp. #1011: relation to catalyzing activity and pH stability.

Cyclodextrin glucanotransferase (beta-CGTase) of alkalophilic Bacillus sp. #1011 degrades starch to mainly beta-cyclodextrin (beta-CD). This enzyme is considered to contain an extra-polypeptide in its COOH-terminal region in addition to its NH2-terminal domain which exhibits the starch-degrading activity. To analyze the functions of this extra-polypeptide in the beta-CGTase, two mutated enzymes, in which DNA regions encoding 10 or 13 amino acids from the COOH-terminus were deleted, were obtained. The mutated enzymes degraded starch to glucose, maltooligosaccharides and alpha-CD, in addition to beta-CD. Furthermore, the pH stability of the mutated enzymes in the alkaline pH range (pH 9-11) was reduced.

Bacillus↗
PubMed1989

Swellings of proximal axons in a case of motor neuron disease.

Serial semithin sections of lumbar anterior horn cells from a patient with rapidly progressive sporadic motor neuron disease were searched for direct connections between swellings of neuronal processes and perikarya. Focal swellings of the proximal axons were not uncommonly seen to be connected directly to perikarya. These swellings varied in shape and size and some were identified as spheroids. Most of the cell bodies connected with swellings showed otherwise normal architecture. These observations suggest that the focal swellings of proximal axons, particularly the distal portion of the initial segment and the first internode of the myelinated axon, indicate an early pathological change, and may represent functionally and morphologically vulnerable sites.

Aged↗
PubMed1989

Interleukin-1-inhibitory IgG in sera from some patients with rheumatoid arthritis.

Inhibition of interleukin-1 alpha (IL-1 alpha) activity was detected in 7 of 41 serum samples from patients with rheumatoid arthritis (RA). These 7 sera inhibited not only IL-1 alpha-induced endothelial cell adherence to neutrophils, but also IL-1 beta-induced endothelial cell adherence, although to a lesser extent. These sera showed no influence on tumor necrosis factor-induced endothelial cell adherence. No inhibitory activity was found in 40 sera from normal control subjects. Studies to further examine these effects included gel filtration analysis of 2 of the RA sera. The inhibitory activity was eluted near Mr 158 kd and above Mr 250 kd. Analysis by protein A affinity chromatography showed that IL-1-inhibitory activity was present in protein A-binding fractions. Purified IgG (by DE-52 column chromatography) from RA patients was found to be as potent an inhibitor as the protein A-binding fractions, which suggests that the major inhibitory activity in RA sera is attributable to IgG molecules. These purified IgG molecules also inhibited IL-1-induced proliferation of mouse thymocytes but did not influence IL-2-dependent proliferation of the CTLL-2 murine T cell line. The 7 patients whose sera showed IL-1-inhibitory activity had mild RA and low titers of rheumatoid factor. The findings, taken together, suggest a possible regulatory role of IL-1-inhibitory IgG in RA disease activity.

Adult↗