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Biomedical subjects

H Miyake

Publications and source records attributed to H Miyake.

At least 343 records · Page 19Linked to original sources

A new brain retractor. Technical note.

A new brain retractor is presented that can be applied easily and safely from any direction. It is particularly useful in the evacuation of intracerebral hematomas.

Brain↗

Urinary laminin P1 as an index of glycemic control in children with insulin-dependent diabetes mellitus.

OBJECTIVE: To evaluate the clinical meanings of urinary laminin P1, urinary laminin P1 concentrations in children with insulin-dependent diabetes mellitus (IDDM) were measured and compared with urinary levels of albumin, kappa light chain (kappa-LC), alpha 1-microglobulin (alpha 1-MG), beta 2-microglobulin (beta 2-MG), and n-acetyl-b-D-glucosaminidase (NAG). RESEARCH DESIGN AND METHODS: Forty-six children with IDDM and 31 age-matched controls were studied. The first urine in the morning was collected for three days and stored at -20 degrees C until assayed. The mean values were used for the study. Radioimmunoassay (RIA) was used to measure of laminin P1, kappa-LC, alpha 1-MG, and beta 2-MG. NAG and haemoglobin Aic (HbA1c) concentrations were measured by a colorimetric method and high-performance liquid chromatography, respectively. RESULTS: Urinary laminin P1 levels in IDDM were 54.2 + 3.4 (SE) mU/microM.Cr, significantly higher than those in control subjects (40.7 +/- 2.3 mU/microM.Cr, p < 0.01). In 10 out of 46 patients (21.7 percent), the values were higher than the mean +/- 2 SD of controls. Urinary albumin, kappa-LC, alpha 1-MG, beta 2-MG, and NAG in IDDM were higher than those in control subjects (p < 0.01). There were significant correlations between urinary laminin P1 levels and urinary albumin, kappa-LC, NAG, alpha 1-MG, and beta 2-MG. A significant correlation was also shown between urinary laminin P1 and HbA1c concentrations (p < 0.01). CONCLUSIONS: From the above results, we conclude that urinary laminin P1 concentrations could be one of the clinical indexes for glycemic control and damage of the glomerulus in IDDM.

Acetylglucosaminidase↗

Stimulation by nitric oxide synthase inhibitors of gastric and duodenal HCO3- secretion in rats.

The role of nitric oxide (NO) in the regulation of gastroduodenal HCO3- secretion was investigated in anesthetized rats using the NO biosynthesis inhibitor NG-nitro-L-arginine methyl ester (L-NAME). HCO3- secretion was measured at pH 7.0 using a pH-stat method in the chambered stomach in the presence of omeprazole or in the proximal duodenum. Intravenous administration of L-NAME (1-5 mg/kg) increased HCO3- secretion in a dose-dependent manner in both the stomach and duodenum, with a concomitant elevation of arterial blood pressure. The stimulatory effect of L-NAME on HCO3- secretion was mimicked by another NO synthase inhibitor, NG-monomethyl-L-arginine (50 mg/kg), but not by the enantiomer NG-nitro-D-arginine methyl ester, and was significantly antagonized by concurrent administration of L-arginine, but not D-arginine, at 200 mg/kg. The exogenous NO donor nitroprusside (4 mg/kg) by itself decreased the rate of HCO3- secretion and significantly antagonized the HCO3- stimulatory action of L-NAME. Furthermore, the increased HCO3- secretion caused by L-NAME was significantly attenuated by prior administration of atropine (1 mg/kg, s.c.) or indomethacin (5 mg/kg, s.c.) and by bilateral vagotomy but was not influenced by sensory deafferentation after capsaicin pretreatment, though none of the treatments had any effect on the changes in blood pressure induced by L-NAME. These results suggest that L-NAME stimulates HCO3- secretion in the gastroduodenal mucosa. This action is associated with the inhibition of NO biosynthesis and may be partly dependent on vagal-cholinergic innervation and mediated by endogenous prostaglandins.

Amino Acid Oxidoreductases↗

Results and prognostic factors in the radical sinus operation for chronic sinusitis.

Radical surgical procedures of the maxillary sinus with or without involvement of the ethmoid, sphenoid and frontal sinuses were performed in 382 adult patients in the Department of Otorhinolaryngology. Tokai University Hospital in the 8-year period from 1984 to 1991. Of 382 patients, the postoperative symptomatology was studied in 189 patients by mcans of questionnaires. The postoperative results were finally analyzed in 63 patients whose subjective symptoms and objective findings were completely recorded. The follow-up period was over 3 months and subjective postoperative improvement was achieved in 83% and objective postoperative improvement in 75%; the overall improvement rate was 73%. In an analysis of results of the radical surgical operation, it appeared that poor results were closely related to the following factors: (1) maxillary sinus mucosa with cellular infiltration or edematous changes; (2) multiplicity of bacterial species including Gram-negative rods isolated from maxillary sinus secretion; (3) poor mucociliary clearance function; and (4) unsatisfactory postoperative treatment.

Adolescent↗

Increased aspartate and glutamate levels in both gastric and colon cancer tissues.

The concentrations of free amino acid and protein-bound amino acid in gastric and colon cancers and also in normal tissues were measured and compared in order to investigate the differences in amino acid metabolism between these cancers. The examined materials were 20 specimens of gastric cancer, with 20 specimens of normal gastric full-thickness layers and 11 specimens of normal gastric mucosal layers, as well as 16 specimens of colon cancer, with 12 specimens of normal full-thickness layers and 16 specimens of normal colon mucosal layers. The amino acid pattern in gastric cancer was more similar to that in the gastric full-thickness layer than the gastric mucosal layer. On the other hand, the pattern in colon cancer was more similar to the colon mucosal layer than the full-thickness layer of normal colon tissue. Comparison between gastric and colon cancers showed that almost all of the protein-bound amino acid levels in gastric cancer were significantly higher than in colon cancer, while, conversely, all of the free amino acid levels except for aspartate, glutamate and glutamine were significantly lower in gastric cancer than in colon cancer. Both in the stomach and colon, the aspartate and glutamate levels in cancer tissues were significantly higher than in normal full-thickness or mucosal layers.

Aspartic Acid↗

Decrease in biliary excretion of copper in Long-Evans cinnamon (LEC) rats causing spontaneous hepatitis due to a gross accumulation of hepatic copper.

The concentration of biliary Cu was 0.12 +/- 0.01 microgram/ml in male LEC rats aged 14 weeks and 0.43 +/- 0.09 micrograms/ml in Fischer rats of the same age. When copper chloride (170 micrograms/kg b.w. as Cu) was infused intravenously (i.v.), the concentration of biliary Cu increased to only 0.21 +/- 0.06 microgram/ml 30 min after the infusion in LEC rats. In contrast, Fischer rats showed a concentration about 10 times higher (4.02 +/- 2.2 micrograms/ml) than that before the infusion. In Fischer rats pretreated with cadmium chloride, the biliary Cu concentration was 1.04 + 0.43 micrograms/ml 30 min after infusion of copper. Horseradish peroxidase (E.C.1.11.1.7) infused iv along with copper chloride was excreted into bile at a low level in LEC rats compared to Fischer rats. Our results suggest that the gross accumulation of hepatic Cu in the new, mutant LEC rats is due to a low excretion of Cu into bile and that the hepatobiliary dysfunction is related to spontaneous hepatitis.

Animals↗

[Idiopathic normal pressure hydrocephalus in elderly patients: its pathophysiology and diagnosis].

We described 10 cases of idiopathic normal pressure hydrocephalus (NPH) in elderly patients who had good results after shunting. Retrospective analysis of our cases offers the following results which indicate the pathogenesis and surgical selection of idiopathic NPH. 1) Most of the patients had risk factors of ischemic cerebrovascular disease and had multiple small ischemic lesions such as lacunae. 2) Cerebrospinal fluid (CSF) pressure is below 20mmHg in all cases and its response to acetazolamide loading was suppressed or almost lost in most of cases. 3) The volume of the lateral ventricle was slightly reduced after the effective operation. 4) Some of the patients showed clinical improvement even if they had symptoms for more than 2 years before treatment. Two primary theories exist concerning the cause of NPH. One is extraventricular obstruction to CSF flow at the level of the arachnoid villi or the basal cistern. The other is periventricular white matter ischemic damage which decreases the tensile strength of the ventricular walls and leads to ventricular dilatation. Tangential periventricular shearing force due to ventricular dilatation produces the symptom of NPH. Our results support these descriptions as the causes of idiopathic NPH in elderly patients. We noticed, firstly, involvement of the ischemic risk factor. Other findings implied decreased elasticity or compliance of the brain and the loss of the autoregulatory properties of cerebral circulation which accelerate the ischemic damage to the periventricular white matter. In understanding the etiology, it is important to know the fragility of the aged brain and the mechanical and hemodynamic stress to which it is subjected.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[A surgical case of solitary cerebral cysticercosis].

A surgical case of solitary cerebral cysticercosis is presented with a review of the literature. A 41 year-old female was admitted to our institute with generalized convulsion. Physical and neurological findings on admission were unremarkable. CT scan revealed a ring-like enhanced mass with perifocal edema in the right rectal gyrus. On MRI, the cyst wall showed iso-signal intensity on T1 weighted image (T1WI) and was markedly enhanced by gadolinium. The cyst fluid showed low signal intensity on T1WI and high signal intensity on T2-weighted image (T2WI). Obvious perifocal edema was seen on T2WI. Laboratory findings were all normal. The mass was totally removed surgically via the right subfrontal route. It was an extraaxial mass and had no attachment to the dura. Histological examination revealed the presence of the scolex, hooklets, and suckers, characteristic of cysticercus. The patient was administered praziquantel at 1200 mg/day for 3 days after surgery. In this case, Taenia solium could not be found in spite of various examinations and sexual transmission was also denied after interview. One possibility was transmission via fresh vegetables grown with excretal compost contaminated with the eggs of T. solium, as the patient often ate spicy pickles called Kimuchi imported from Korea. Physicians should be aware of the possibility of transmission via contaminated fresh vegetables in patients who have never even been to an endemic area, or who have never eaten raw pork.

Adult↗

[The effectiveness of radiotherapy for Merkel cell carcinoma].

Merkel cell carcinoma is a high-grade malignant tumor of the skin that tends to extend locally and metastasize to regional lymph nodes. Surgical resection is the treatment of choice, and the effectiveness of radiotherapy for this disease has not yet been established. We report two cases of biopsy-proven Merkel cell carcinoma effectively treated with radiotherapy. Histopathological examination of the resected specimens after radiotherapy of 50 Gy and 38 Gy, respectively, using 6 approximately 15 MeV electrons showed no malignant cells in either case. No evidence of recurrence or metastasis has been noted in 11 to 21 months after radiotherapy. To our knowledge, no case of Merkel cell carcinoma in which complete cure was obtained by radiotherapy alone has been reported previously. It is considered that preoperative radiotherapy would contribute to the management of this locally invasive but radiosensitive tumor.

Aged↗

Effects of FR 113680 and FK 224, novel tachykinin receptor antagonists, on cigarette smoke-induced rat tracheal plasma extravasation.

We examined the effects of novel tachykinin antagonists, FR 113680 (N alpha-[N alpha-(N alpha-acetyl-L-threonyl)-N1-formyl-D-tryptophyl]-N- methyl-N-phenylmethyl-L-phenylalaninamide) and FK 224 (N-[N2-[N-[N-[N-[2,3-didehydro-N-methyl-N-[N[3-(2-phenthylpheny l) - propionyl]-L-threonyl]-tyrosyl]-L-leucynyl]-D-phenylalanyl]-L-allo - threonyl]-L-asparaginyl]-L-serine nu-lactone) on rat tracheal plasma extravasation induced by cigarette smoke. Intravenous injection of FK 224 (0.032-3.2 mg kg-1) inhibited rat tracheal plasma extravasation induced by cigarette smoke and capsaicin. FR 113680 (32 mg kg-1 i.v.) also significantly inhibited cigarette smoke-induced plasma extravasation, whereas D-chlorpheniramine maleate, FPL 55712, atropine sulfate and indomethacin had no effect. Tracheal plasma extravasation induced by substance P (SP) and neurokinin A (NKA), but not histamine, was also reduced by intravenous administration of FR 113680 and FK 224. These findings suggest that cigarette smoke stimulates primary afferent sensory nerves, releases tachykinins and evokes plasma extravasation in rat trachea.

Amino Acid Sequence↗

Studies on neurokinin antagonists. 2. Design and structure-activity relationships of novel tripeptide substance P antagonists, N alpha-[N alpha-(N alpha-acetyl-L-threonyl)-N1-formyl-D-tryptophyl]-N- methyl-N-(phenylmethyl)-L-phenylalaninamide and its related compounds.

Continuing studies on the chemical modification of the previously reported novel tripeptide SP antagonist, N alpha-[N alpha-[N alpha- (tert-butyloxycarbonyl)glutaminyl]-N1-formyl-D-tryptophyl]phenylalanine benzyl ester [Boc-Gln-D-Trp-(CHO)-Phe-OBzl (1)], are described herein. We initially investigated the stability of 1 in guinea pig plasma and liver homogenate to elucidate the most labile part in the structure. It was consequently revealed that the benzyl ester part was easily hydrolyzed to produce the inactive acid analog. Thus we searched for a benzyl ester surrogate that would be more resistant to hydrolytic enzymes. This approach found an isosteric amide structure, N-methyl-N-(phenylmethyl)amide, suitable in terms of potency and stability. Subsequent modification of the amino terminal into N alpha-acetyl-L-threonine led to the most potent compound, N alpha-[N alpha-(N alpha-acetyl-L-threonyl)-N1-formyl-D-tryptophyl]-N- methyl-N-(phenylmethyl)-L-phenylalaninamide [Ac-Thr-D-Trp(CHO)-Phe-NMeBzl (5a, FR113680)]. This compound 5a potently blocked 3H-SP binding to guinea pig lung membranes with IC50 of (5.8 +/- 0.78) x 10(-9) M. In vitro, 5a inhibited SP-induced contraction of isolated guinea pig trachea strips with IC50 of 2.3 x 10(-6) M and caused no contraction when used alone in this preparation up to 3.2 x 10(-5) M. In addition 5a exhibited no effect on the contraction induced by histamine or acetylcholine. Intriguingly, it was demonstrated in vivo that 5a suppressed the SP-induced bronchoconstriction and airway edema in guinea pigs with ED50 of 0.42 mg/kg and 0.66 mg/kg, respectively, when administered intravenously.

Acetylcholine↗

Studies on neurokinin antagonists. 1. The design of novel tripeptides possessing the glutaminyl-D-tryptophylphenylalanine sequence as substance P antagonists.

To discover a novel and low molecular weight substance P (SP) antagonist we postulated that the essential binding domain of peptide ligands was only a small portion in the whole structure. On the basis of this assumption, we selected the known octapeptide SP antagonist D-Pro-Gln-Gln-D-Trp-Phe-D-Trp-D-Trp-Phe-NH2 (1) as a lead and synthesized its fragment tripeptides which were evaluated for their activity to block 3H-SP binding on guinea pig lung membranes. The protected tripeptide N alpha-[N alpha-[N alpha-(tert-butyloxycarbonyl)-L-glutaminyl]-N1-formyl-D-tryptophyl]- L-phenylalanine benzyl ester [Boc-Gln-D-Trp(CHO)-Phe-OBzl (4a)], corresponding to the Gln-D-Trp-Phe part of 1, exhibited 7-fold potent inhibitory activity in comparison with 1. Studies on structure-activity relationships revealed that the D-tryptophan, L-phenylalanine, and benzyl ester were quite important to maintain the high binding affinity. It was also indicated that 4a antagonized the SP-induced contraction of isolated guinea pig trachea strips (IC50 = 4.7 x 10(-6) M).

Amino Acid Sequence↗

Catecholamine alterations in experimental hydrocephalus.

Experimental hydrocephalus was induced in rats by intracisternal injection of kaolin suspension. The amounts of norepinephrine and dopamine were determined in the whole brain and specific brain regions at 1 week (acute phase) and 4 weeks (chronic phase). The turnover of catecholamine, an index of the activity of catecholamine-containing neurons, was determined by measuring the decrease in catecholamine contents 2 h after intraperitoneal injection of alpha-methyl-p-tyrosine (250 mg/kg), an inhibitor of tyrosine hydroxylase. We observed that the catecholamine contents in kaolin-induced hydrocephalus were not significantly different from control values. Following injection of alpha-methyl-p-tyrosine, there was decrease in levels of catecholamines in both control and hydrocephalic rats. This decrease was, however, significantly less in induced hydrocephalus than in control animals. This result suggested that in hydrocephalus, the activities of norepinephrinergic and dopaminergic neurons are reduced.

Animals↗

Adenomyomatosis of the gallbladder with subserosal fatty proliferation: CT findings in two cases.

Adenomyomatosis of the gallbladder is frequently seen in ordinary operative specimens. Subserosal fat may proliferate in the presence of adenomyomatosis, but the amount of subserosal fat may be quite variable. Typical and atypical computed tomographic (CT) findings in two cases of adenomyomatosis with subserosal fatty proliferation of the gallbladder are presented. The thick fatty layer surrounding the thickened gallbladder wall with intramural diverticula and stones, typical of CT findings, was seen in one case, and fat interspersed in the periphery of the thickened gallbladder wall without intramural stones, atypical of CT findings, was seen in a second case.

Adipose Tissue↗

Neurochemical effects in rats following gestational exposure to styrene.

Styrene was evaluated for the reproductive effects of pregnant rats and the neurochemical effects in the offspring of rats exposed during gestation. Pregnant Wistar rats were exposed to 0, 50, or 300 ppm styrene for 6 h/day during days 7 to 21 of gestation. No significant differences in the number of offspring delivered were observed between the exposed and control groups. Body weights at 1 day of age of the offspring whose mothers were exposed to styrene were significantly lower than those of the control group. Although, there were neither statistically significant differences of protein contents nor brain weights among styrene-exposed and their control offsprings of rats, analyses of neurotransmitter studies showed dose-dependent decreases of neuroamines, especially 5-HT (serotonin) and its metabolite 5HIAA (5-hydroxyindoleacetic acid) in the newborn offspring of styrene-exposed rats. The results suggest that gestational exposure to styrene at these concentrations does not produce apparent reproductive toxicity but affects the body weight of pups and causes lowering of the neurotransmitter levels in the brain.

Administration, Inhalation↗