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Biomedical subjects

M Sakaguchi

Publications and source records attributed to M Sakaguchi.

At least 361 records · Page 20Linked to original sources
PubMed1991

Anterior communicating artery aneurysm in early childhood. Report of a case.

A case of an aneurysm of the anterior communicating artery in a 13-month-old child is presented. Sixty-six cases of cerebral saccular aneurysm in children under the age of 2 years found in the literature were analyzed. The characteristics that define this group of patients are a high frequency of large or giant aneurysms, a large proportion of aneurysms of the middle cerebral artery and the posterior circulation, and the frequent location at the peripheral site. Only three cases of anterior communicating artery aneurysm were reported in the literature. The authors discuss these characteristics on the basis of development of fetal cerebral vessels.

Cerebral Angiography↗
PubMed1991

Effect of maturation on activities of various proteases and protease inhibitors in the muscle of Ayu (Plecoglossus altivelis).

1. Increases in activities of muscle muticatalytic proteinase, modori-inducing proteinase (latent trypsin-like proteinase), cathepsin B and L-like proteases and cathepsin D were observed more markedly for male fish than female fish, in the spawning stage. 2. Decreases in inhibitory activities of muscle serine and cysteine protease inhibitors were observed more markedly for male fish than female fish in the spawning stage.

Amino Acid Sequence↗
PubMed1991

Synthesis of ascorbyl-2-phosphate by liver enzyme of rainbow trout Oncorhynchus mykiss.

1. Ascorbyl-2-monophosphate was enzymatically formed in the reaction mixture of L-ascorbic acid, pyrophosphate and the homogenate of rainbow trout Oncorhynchus mykiss liver. 2. The liver had the highest activity among the liver, spleen, kidney, stomach, pyloric caeca and intestine. 3. Pyrophosphate, triphosphate, ADP and ATP were good substrates as phosphoryl donors, but phosphoric acid and AMP were poor. 4. The optimum pH and temperature of AP-forming activity in the liver were around 5.0 and 30 degrees C, respectively. 5. The Km values for ascorbic acid and pyrophosphate were 370 and 83 mM, respectively.

Animals↗
PubMed1991

Monomorphic adenoma of the hard palate: report of a case.

A rare case of monomorphic adenoma of the hard palate in a 69-year-old female is presented. Her complaints were a slowly growing mass and occasional pain of the palate. The tumor was located in the posterior region of the hard palate, and it was approximately 1.5 x 1.5 cm in size. Under general anesthesia, the tumor was excised with a wide margin of normal tissue. The palatal bone was intact. Histological diagnosis was monomorphic adenoma, basal cell type.

Adenoma↗
PubMed1991

Evaluation of a new 2-nitroimidazole nucleoside analogue, RK-28 as a radiosensitizer for clinical use.

The experimental data previously reported on RK-28, a hypoxic cell sensitizer which is now being tested in a phase I clinical trial, are confusing. Some data indicate superiority of RK-28 over misonidazole (MISO), whereas others do not. This paper presents our experimental data on the efficacy, toxicity, and pharmacokinetics of RK-28, in comparison with those of MISO, and also summarizes the data of other investigators. In our experiments, RK-28 had a 1.5-2.5 times higher sensitizing activity in vitro on EMT6 and SCCVII cells than MISO, and the difference was larger when the pre-irradiation incubation time was longer. The latter was considered to be due to the time-dependent cellular uptake and reactivity of RK-28 with non-protein sulphydryls. In vivo, RK-28 was almost as efficient as or slightly inferior to MISO against SCCVII and EMT6 tumours when assayed with an in vivo/in vitro assay and a growth delay time assay. The LD50/7 by a single injection of RK-28 was half that of MISO, but when 60% of LD50/7 was injected into mice every day, the total dose that could be given was higher for RK-28 than for MISO. Pharmacokinetic studies using mice, rats, rabbits, and a dog showed that RK-28 was rapidly eliminated from the blood and various tissues. From our results it was concluded that the possible success of the clinical trial of RK-28 depends on its low cumulative toxicity.

Animals↗
PubMed1991

Yeast gene which suppresses the defect in protein export of a secY mutant of E. coli.

To find factors participating in protein translocation in yeast, we screened a yeast genomic library for genes which, when introduced into Escherichia coli, suppressed secY24, a temperature sensitive mutation of an essential integral membrane protein (SecY) required for protein export. We isolated and characterized a gene (YSY6) which improved the translocation of the OmpA protein in mutant strain IQ85(secY24). It could also suppress another mutant [rplO215(Am)], in which the level of expression of the SecY protein is decreased at high-temperature. The YSY6 gene encodes a small amphiphilic peptide consisting of 65 amino acids, which can be expressed in E. coli cells.

Amino Acid Sequence↗
PubMed1991

Existence of exine-free airborne allergen particles of Japanese cedar (Cryptomeria japonica) pollen.

We investigated whether exine-free pollen allergen particles exist together with the intact pollen grains of Japanese cedar (Cryptomeria japonica) in the air during the pollen season in Yamagata City. First, we separated the allergen particles in an Andersen multi-stage air-sampler according to their aerodynamic diameters. The amount of major allergen (Cry j I) on each stage of the sampler was determined by a sensitive fluorometric sandwich ELISA, and the pollen count of the same samples was done by light microscopy after Carberla staining. Cry j I was found in stages 1 to 6, whereas most of intact and ruptured pollen grains were microscopically observed only in stages 1 and 2. Second, we suctioned the air through a tandem membrane filter system (the first filter, Nuclepore filter with 5 microns-pores; and the second, Millipore filter with 0.3 micron-pores). None of the pollen grains was detectable on the 0.3 micron-pore filter with light microscopy. However, Cry j I was detectable in the aqueous extract from the second filter. From these results, we concluded that pollen-free Cry j I existed in the air of Yamagata City during the pollen season.

Air Pollutants↗
PubMed1991

Release of calcitonin gene-related peptide from nerve terminals in rat skeletal muscle.

1. The amount of calcitonin gene-related peptide (CGRP) released from the isolated rat soleus muscle was measured by enzyme immunoassay. 2. When the soleus muscle was exposed to a solution containing high K+ (20-100 mM) in the presence of tetrodotoxin, the amount of CGRP released into the bathing medium increased with an increase in the K+ concentration. 3. The exposure to 100 mM-K+ did not increase CGRP release from chronically denervated soleus muscles or from pieces of the soleus nerve separated from the muscle. 4. The amount of CGRP released from the isolated muscle by 100 mM-K+ depended on the external Ca2+ concentration. The slope of the relation between the amount of CGRP release and the Ca2+ concentration was less than one on double logarithmic co-ordinates. 5. Following chronic section of the lumbar ventral roots, the mean amount of CGRP released from the soleus muscle by 100 mM-K+ was reduced by 28%, compared with that observed in normal muscle. 6. Antidromic stimulation of the lumbar dorsal roots at an intensity three times the threshold for most excitable sensory fibres failed to induce CGRP release from the soleus muscle, whereas stimulation at intensities 50-100 times the threshold increased significantly the amount of CGRP release from the muscle. 7. Stimulation of the muscle nerve at an intensity sufficient to activate the alpha-motor fibres did not release CGRP from the soleus muscle or from the diaphragm. 8. It is concluded that the major source of CGRP released from skeletal muscle is A delta- and/or C sensory terminals and that the Ca2+ dependence of CGRP release is less steep than that reported for acetylcholine release at neuromuscular junctions.

Animals↗
PubMed1991

Alternative pathway for induction of human immunodeficiency virus gene expression: involvement of the general transcription machinery.

Human immunodeficiency virus type 1 (HIV-1) is viable and mitogen inducible in the absence of its binding sites for the inducible transcription factor NF-kappa B. We have investigated alternative mechanisms for induction of HIV-1 transcription. Using transient transfection assays, we found that transcription from an HIV-1 LTR containing mutant kappa B sites was activated 10- to 20-fold in a variety of human cell types by the phorbol ester phorbol myristate acetate (PMA). The promoter elements conferring this inducibility were localized to the region downstream of nucleotide -70, which contains the TATA and TAR elements and binding sites for transcription factors Sp1 and LBP-1. Synthetic promoters containing only Sp1 sites and a TATA element were also induced in transfection experiments as well as in in vitro transcription experiments with T-cell nuclear extracts. Moreover, promoters containing a TATA box in the absence of Sp1 sites or Sp1 sites in the absence of a TATA box were equally inducible in vitro, as was an RNA polymerase III promoter. The activities of RNA polymerases II and III and of the 38-kDa TATA-binding protein transcription factor IID (TFIID), were not induced by PMA, but electrophoretic mobility shift assays revealed a highly inducible protein-DNA complex that interacted specifically with the TATA sequence. This protein-DNA complex appeared to be much larger than that found with the 38-kDa human TFIID expressed in bacteria. Taken together, these data suggest that a component of the general transcription machinery, and possibly a TFIID-associated protein, is induced in T cells by PMA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Cyclosporine induced nephrotoxicity and juxtaglomerular apparatus in mice].

To elucidate the relationship between Cyclosporine (Cs) induced nephrotoxicity and juxtaglomerular (JG) apparatus, we carried out biochemical and morphological experiments using mice. Adult male ICR strain mice weighing about 40 g were used. The mice were divided into 2 groups: the Cs group (Cs 50 mg/kg/day was orally given for 14 consecutive days) and the control group (olive oil for 14 days). Urine was stored for 24 hours on the day 0, 7 and 14 and urine volume and concentrations of urinary creatinine (u-Cr) and urinary potassium (u-K) were measured in each group. All the mice were sacrificed and examined on the 15th day. Concentrations of serum creatinine (s-Cr), serum potassium (s-K), plasma renin activity (PRA), plasma aldosterone (Ald) were noted in each group. The kidneys were also examined histologically with light and electron microscopes. The Cs group showed significant increases of s-K, PRA and Ald and a significant decrease of creatinine clearance compared with the control group. Histologically, the Cs group demonstrated focal vacuolar changes in the proximal tubular cells and an increase in the number of granules in the JG cells. Each granule of the Cs group was larger than that of the control group. Cs certainly stimulates the renin-angiotensin-aldosterone system and causes consequently a secondary aldosteronism.

Animals↗
PubMed1991

[Cyclosporine induced nephrotoxicity and renal blood flow].

To elucidate the relationship between cyclosporine (Cs) nephrotoxicity and renal blood flow (RBF), we carried our experiments using rats. Adult male Wistar strain rats each weighing about 100 g were used. Rats were divided into 2 groups; the Cs group (Cs 50 mg/kg/day was intraperitoneally given for 10 consecutive days) and the control group (normal saline solution for 10 consecutive days). The renal cortical blood flow was measured in each group by electrolytic hydrogen gas clearance method. We also carried out renal angiography with barium sulfate (BaSO4). Then we measured blood vessel area/renal sagittal section area ratio and the diameter of interlobar arteries. The Cs group showed a significant decrease of renal cortical blood flow compared with the control group. On the other hand there was no significant change in renal angiogram. In conclusion, Cs decreased renal cortical blood flow. We suppose that vascular resistance increased following afferent arteriolopathy caused by Cs administration.

Animals↗
PubMed1991

[The role of surgery in the treatment of chronic empyema].

For the last ten years we had 56 patients operated for the empyema which occupied almost all the thoracic cavity. We evaluated their postoperative pulmonary functions and their sequelae. The pathological features of the resected lung and empyema wall were also examined. Surgical procedures consisted of 25 extraperiostal air plombage, 14 pleuropneumonectomy, 8 decortication, and 9 other procedures (lobectomy, muscle-flap, omental flap, and others). Preoperative %VC of patients with extraperiostal air plombage, those with pleuropneumonectomy, those with decortications and those with other procedures were 59.6 +/- 12.6, 46.4 +/- 11.1, 63.0 +/- 10.1, and 53.8 +/- 11.7 respectively. Of 11 patients who developed severe respiratory impairments (%VC less than 40 and/or FEV 1/VC predicted less than 30) post operatively, 4 had extraperiostal air plombage, 4 had pleuropneumonectomy, and 3 had other procedures. In general, degree of respiratory impairment was more severe in patients who underwent multiple surgical procedures. Of 18 patients who survived 5 years or more, %VC was under 50% in 9, and of those nine patients five had 30% decrease in VC compared to the preoperative values and there were 2 patients with extraperiostal air plombage in whom extreme shrinkage and deformity of hemithorax were observed though they had neither additional surgeries nor recurrences. Hemangioma was often seen on the walls of empyema and in some they became so large as to cause mediastinal shift. There were patients with round atelectasis, which, we thought, could have caused abscess or inflammatory granuloma.

Aged↗
PubMed1991

A case of acute myelomonocytic leukemia with subconjunctival tumor.

A subconjunctival tumor in a 29-year-old woman with acute myelomonocytic leukemia was reported. The tumor was located in the bulbar conjunctiva of her left eye, with vasodilatation and slight elevation. The pathological examination of the tumor revealed infiltration by myelomonocytic leukemia cells. The patient developed numerous skin tumors simultaneously with the conjunctival tumor and died two months thereafter despite intensive reinduction chemotherapy. The clinical course of the patient suggested that subconjunctival tumor is a clinically important sign of acute relapse in myelomonocytic leukemia.

Adult↗
PubMed1991

[Pharmacokinetics of cefodizime in patients undergoing hemodialysis].

The object of this study was to establish the most effective regimen of cefodizime (CDZM) for patients with chronic renal failure undergoing hemodialysis (HD). T 1/2 beta of CDZM upon 1 g intravenous administration was 3.50 +/- 0.72 hours in an on-HD group, and it was 11.26 +/- 3.89 hours in an off-HD group. When CDZM was administered consecutively at a dose of 1 g or 2 g only after HD, the serum concentration of CDZM was maintained at levels sufficient to exert antibacterial activity, and no tendency for accumulation was observed. The most effective regimen of CDZM to HD patients, therefore, has been that in which concluded to administration was done only after completion of HD, in a dose of 1 g for mild infections and that of 2 g for severe infections.

Cefotaxime↗
PubMed1991

A group of novel latent serine proteinases degrading myosin heavy chain in fish muscle.

Through a study on thermal degradation of fish jelly products, the existence of a group of latent trypsin-like serine proteinases was demonstrated in fish muscle. These proteinases share common properties in existing as latent forms (being activated by heating around neutral pH in the presence of NaCl), having trypsin-like serine proteinase properties and showing strong myosin heavy chain degrading activity. This group of proteinases could be classified into four subtypes according to the intracellular localization (sarcoplasmic and myofibril-associated types) and the optimum temperature range (50 and 60 degrees C types).

Animals↗
PubMed1991

[Kinetics of the falling of airborne mite allergens (Der I and Der II)].

A futon (Japanese quilt) was beaten to disperse mite allergens into the air in a closed room, and the airborne allergens were collected both by Andersen air sampler for particle size analysis and by slit air sampler for kinetic analysis of the clearing of the allergens from the air. After extraction of the allergens from the agar plates in the samplers, two kinds of major mite allergens (Der I and Der II) were immunochemically quantitated. We found that the aerodynamic diameters of both allergens were mainly above 5.5 microns, and that airborne allergen levels decreased to about 10% of the starting level in 30 minutes, indicating the rapidity of the falling of both allergens.

Air Pollutants↗
PubMed1991

[Evaluation of different treatments of Japanese bed quilts for reducing mite allergens].

We evaluated the effectiveness of different treatments of Japanese bedquilt (futon) in reducing mite allergens: vacuum-cleaning, beating plus vacuum-cleaning and washing of the whole futon in water. Before and after these treatments, small amounts of cotton were taken out of the futon and mite allergens were extracted from the cotton into water. The absolute contents of two kinds of major allergens of two Dermatophagoides species were immunochemically quantitated. We found that beating and vacuum-cleaning reduced the allergen contents by only about 40%, whereas washing reduced the allergens by more than 90%. Therefore, for reducing airborne mite allergens generated from futon, we think that washing the whole futon in water is the most effective method.

Allergens↗