Biomedical subjects

M Kanda

Publications and source records attributed to M Kanda.

At least 127 records · Page 7Linked to original sources

PubMed1994

[A case of bilateral cerebellar peduncle infarction with bilateral hearing impairment of a sudden onset].

We reported a patient with bilateral cerebellar peduncle infarcts who had an abrupt onset of bilateral hearing loss. A hypertensive 56-year-old man suddenly experienced bilateral hearing loss without other accompanying neurological deficits. He was hospitalized and treated for "idiopathic deafness". In addition, dysarthria and ataxic gait appeared two days later and he was transferred to our hospital. On neurological examination, the patient presented with diplopia, neurosensory hearing loss (approximately 70 dB) ataxic dysarthria, bilateral cerebellar ataxia and bilateral Babinski's signs. Auditory brain stem evoked response demonstrated prolonged delay of interpeak latency between waves III-IV. CT and MRI revealed fresh ischemic lesions symmetrically located at the middle cerebellar peduncles and cerebellar medullary body. Cerebral angiography showed total occlusion of the left vertebral artery and a stenotic right vertebral artery at the ostium of the posterior inferior cerebellar artery. We postulated that hearing impairment in this patient resulted from transient ischemia of the bilateral auditory tract in the brain stem or the peripheral cochlear system, but the definitive cause of the transient hearing loss remains undetermined. Concomitant appearance of a symmetrical infarction at the cerebellar peduncles is rare. We suggest that a circulation defect involving a multivascular system, which resulted in "border zone infarction" occurred at these regions.

Arterial Occlusive Diseases↗

PubMed1994

Protective effect of the calcium antagonist NKY-722 against renal and arterial injuries in Dahl salt-sensitive rats.

OBJECTIVE: To study the effect of long-term administration of NKY-722 and nicardipine on renal dysfunction and morphological changes in the kidneys and arteries in Dahl salt-sensitive (Dahl-S) rats. DESIGN: Vehicle, NKY-722 and nicardipine were administered orally to Dahl-S rats fed a high-salt diet for 6 weeks. METHODS: Systolic blood pressure was measured once a week. At the last week blood and urine were collected and an autopsy was carried out. RESULTS: NKY-722 (1 mg/kg per day) lowered blood pressure reproducibly for 6 weeks, whereas nicardipine (3 mg/kg per day) showed a similar effect at week 1 only. NKY-722 tended to decrease blood urea-nitrogen, and reduced plasma creatinine and renin activity significantly. NKY-722 increased urine volume, urinary sodium, creatinine and protein excretions, but did not affect urinary N-acetyl-beta-D-glucosaminidase activity significantly. NKY-722 increased the glomerular filtration rate and reduced glomerulosclerosis and renal arterial injury morphologically. Nicardipine did not affect blood or urinary parameters, but reduced glomerular injury significantly. NKY-722 but not nicardipine reduced cerebral arterial injury. A lower dose of NKY-722 (0.3 mg/kg per day) did not affect blood pressure, blood or urinary parameters, but reduced glomerulosclerosis and renal arterial injury significantly. NKY-722 (1 mg/kg per day) and nicardipine (3 mg/kg per day) increased urinary 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and PGE2. NKY-722 but not nicardipine increased the 6-keto-PGF1 alpha:thromboxane B2 ratio in the thoracic aorta. CONCLUSIONS: NKY-722 improved the renal dysfunction, and reduced glomerular, renal and cerebral arterial injuries in Dahl-S rats. The effect of NKY-722 on glomerulosclerosis and arterial injuries is, at least partly, independent of blood pressure, and is probably related to the effect on eicosanoid metabolism.

Animals↗

PubMed1994

[Clinicopathological features and diagnostic points of uncommon pancreatic tumors].

Clinicopathological features of uncommon pancreatic tumors including solid cystic tumor (SCT), acinar cell carcinoma and pancreatoblastoma are described, based upon a literature survey and own experiences. They are often discovered by US and CT as asymptomatic pseudocystic tumor. SCTs almost always occur in young female and Pancreatoblastoma, in children less than five years old. The prognosis is very favorable in SCT, and relatively good in acinar cell carcinoma and pancreatoblastoma. Pancreatoblastoma is often associated with the elevation of serum AFP levels. Characteristic histological features and immunocytochemical features are also described, all of which are very different from those of usual pancreatic ductal carcinoma. Molecular biological features including the results of k-ras and p53 point mutation are also discussed. In addition to the clinicopathological features, these uncommon tumors are very different from usual ductal carcinoma in the molecular biological features.

Carcinoma, Acinar Cell↗

PubMed1993

Segregation of cerebrorubral and cerebellorubral synaptic inputs on rubrospinal neurons of fetal cats as demonstrated by intracellular recording.

Cerebrorubral and cerebellorubral inputs are localized to distal dendrites and somata of red nucleus neurons in adult cats, respectively. To examine if this segregation is established early in development, we performed intracellular recording from rubrospinal neurons of fetal cats aged from embryonic day 58 to 65. Stimulation of the contralateral cerebellar nuclei evoked excitatory postsynaptic potentials (EPSPs). EPSPs were also induced by stimulation of the ipsilateral pericruciate cortext but they were much slower in time course and smaller in amplitude compared to cerebellar ones. We suggest that cerebrorubral and cerebellorubral synapses are segregated on soma-dendritic membrane of rubrospinal neurons early in development.

Animals↗

PubMed1993

Breeding cycles and fecal gonadal steroids in the brown dipper Cinclus pallasii.

Breeding cycles and fecal gonadal steroids were investigated in free-living brown dippers, Cinclus pallasii. The brown dippers were marked with colored leg bands, and their behavior was observed by a field scope. The breeding season was divided into six stages according to the behavior observed; winter territory-defending, nest-building, copulation, incubation, nestling, and fledgling stages. Fecal pellets on the stones in their territories were collected and the levels of immunoreactive estradiol-17 beta (E2) and testosterone (T) in 10 mg feces were measured by radioimmunoassay. Levels of fecal E2 were high only during the copulation stage, which lasted for a few weeks, in all females of the three pairs observed. In contrast, T levels in the feces of males increased in late winter when intensive territory-defending behavior was observed, and remained high until the end of the breeding season. T levels during the nest-building stage and the copulation stage were similar to those during other nesting stages. When the birds breed only once a year, the duration of high levels of T was shorter than that of the pair with the second clutch. T levels in the feces of females showed a similar pattern to E2 levels.

Animals↗

PubMed1993

Somatostatin-induced contraction mediated by endothelial TXA2 production in canine cerebral arteries.

Whether somatostatin causes endothelium-dependent contraction (EDC) in isolated canine basilar arteries was examined. Somatostatin (10(-8)-10(-6) M) caused transient contractions in a dose-dependent manner. These contractions were abolished by removal of the endothelium, while the contractile response to neuropeptide Y occurred even after removal of the endothelium. The EDC induced by somatostatin (10(-7) M) was affected by neither atropine (10(-6) M) nor cyclo-somatostatin (10(-5) M), which suggests that the EDC is not due to release of endogenous acetylcholine and that the endothelial somatostatin receptor is different from hormonal somatostatin receptors. The somatostatin-induced EDC was attenuated by cyclooxygenase inhibitors (aspirin and indomethacin), thromboxane A2 (TXA2) synthetase inhibitors (OKY-064 and RS-5186), and TXA2 antagonists (ONO-3708 and S-145), which suggests that the endothelium-derived contracting factor is TXA2. These findings demonstrate that somatostatin causes EDC via activation of TXA2 synthesis in canine cerebral arteries.

Animals↗

PubMed1993

Clinical applications of ICG Finger Monitor in patients with liver disease.

The indocyanine green (ICG) Finger Monitor system is a non-invasive indication of ICG concentrations in the blood. In this study, significant correlation was found between the sensor signal voltage and plasma ICG concentrations ranging from 0.04 mg/dl to 1.0 mg/dl (r = 0.998, P < 0.001) in vivo. The ICG clearance curve showed an initial sharp rise 20-30 s after bolus injection, followed by a small rise. The concentration then deceased exponentially. In 196 patients with chronic liver disease, there was a close correlation between the KICG (plasma disappearance rate) and R15 (blood retention ratio at 15 min) (r = 0.886, P < 0.001, r = 0.912, P < 0.001) and corresponding values calculated by the conventional ICG method. In 263 cases with chronic liver disease, the plasma disappearance rates calculated using this monitor (mean +/- S.D.) were 0.156 +/- 0.064 (n = 20) in the control group, 0.129 +/- 0.060 (n = 92) in the chronic hepatitis group, 0.048 +/- 0.025 (n = 59) in the cirrhosis group and 0.059 +/- 0.03, (n = 92) in the group with hepatocellular carcinoma. A significant difference in the plasma disappearance rate and blood retention ratios 15 min after injection of ICG using this system was observed between control cases and the chronic hepatitis and cirrhosis groups (P < 0.0001). In 36 cases, the time from injection to the appearance of ICG in the fingertip significantly decreased in the cirrhosis group (P < 0.01). The ICG Finger Monitor system was shown to be useful clinically as well as for research due to its accuracy and non-invasive nature.

Adult↗

PubMed1993

Effect of single base substitutions at glycine-870 codon of gramicidin S synthetase 2 gene on proline activation.

The mutant gene coding for a proline-activating domain (grs2-pro) was cloned and sequenced from Bacillus brevis Nagano, BII-3 strain, which produces gramicidin S synthetase 2 defective in proline-activation. By comparison of the nucleotide sequence with the wild-type sequence, a single point mutation was found at the 2609th guanine, which was replaced with adenine, resulting in the change of the 870th glycine to glutamic acid. Homology search for the deduced amino acid sequence of grs2-pro gene revealed that the 870th glycine was conserved in adenylate-forming enzymes, and its flanking sequence was highly conserved among the aminoacyl adenylate-forming enzymes, such as antibiotic peptide synthetases: gramicidin S synthetase 1 and 2 (GS1, GS2), tyrocidine synthetase 1 (TS1), and delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase (ACVS); and other aminoacyl adenylation enzymes: alpha-aminoadipate reductase (LYS2), EntF, and AngR. On the other hand, this flanking sequence was not conserved in the other adenylate-forming enzymes lacking amino acid activation, such as acetyl-CoA synthetase, long-chain acyl-CoA synthetase, luciferase, and 4-coumarate CoA ligase. Single base substitutions at the 870th GGG codon were carried out by oligonucleotide site-directed mutagenesis. Four mutagenized clones were isolated, containing grs2-pro genes which exchange 870-Gly for alanine, valine, arginine, and tryptophan. The translated products from these clones could scarcely catalyze proline-dependent ATP-32PPi exchange reaction. The coil structure of 870-Gly region was lost in the mutants. These results suggest that the 870-Gly residue of grs2-pro protein is essential for aminoacyl-adenylation in the antibiotic peptide synthetase family.

Amino Acid Isomerases↗

PubMed1993

Effects of aibellin, a novel peptide antibiotic, on rumen fermentation in vitro.

A new icosapeptide, aibellin, markedly modified rumen fermentation in vitro. Batch culture experiments with mixed rumen microorganisms showed that 12.5 to 25 mg/L of aibellin enhanced propionate production and reduced methanogenesis without significantly affecting production of total VFA, protozoal survival, or cellulose digestion. Aibellin had essentially the same effects in continuous culture with hay powder and concentrate. Monensin (5 mg/L) had similar effects on propionate production and methanogenesis, but total VFA, protozoa, and cellulolysis were decreased even by this low concentration of monensin. Commercially available peptide antibiotics also were compared with aibellin. Of the antibiotics examined, only graminicidin D (7.5 to 15 mg/L) enhanced propionate production and reduced methanogenesis. However, gramicidin D decreased total VFA, protozoa, and cellulolysis even at 7.5 mg/L. Alamethicin (7.5 to 15 mg/L), which resembles aibellin in its structure, did not increase propionate production but raised the percentage of propionate because of reduced production of total VFA. Alamethicin depressed methanogenesis but also decreased protozoal survival and cellulose digestion. These in vitro experiments indicate that aibellin could be a useful and potent modifier of rumen fermentation.

Alamethicin↗

PubMed1992

Insulin inhibits norepinephrine overflow from peripheral sympathetic nerve ending.

The effects of insulin on peripheral nervous system are unknown. We therefore studied the effects of insulin on sympathetic nerve activity in isolated mesenteric arteries of Sprague-Dawley rats. The overflow of norepinephrine (NE) by electrical stimulation was used as the index of sympathetic nervous system activity. Insulin (0.5 to 1U/l) decreased the NE release in a dose-dependent fashion. This inhibitory effect was, however, reversed by either 5 x 10(-5)M cocaine or 5 x 10(-4)M ouabain treatment. Thus, we postulate that insulin attenuates NE overflow from peripheral sympathetic nerve endings, probably due to enhanced NE reuptake.

Animals↗

PubMed1992

Osteosarcoma resembling osteoblastoma and its heterotransplantation into nude mice.

We describe a case of bone tumor in the left tenth rib that was diagnosed as a low-grade osteosarcoma resembling osteoblastoma. This diagnosis was supported by clinical, radiologic, and histologic findings. Specimens of this tumor were transplanted into nude mice, and the morphology of the transplanted tumors was examined. The transplanted tumors were similar histologically to the parent tumor. Ultrastructurally, the transplanted osteoblasts showed irregular, indented nuclei, dilated endoplasmic reticulum, and varying amounts of intercellular junctional complexes. Our transplantable tumor could be valuable as an experimental model for studies on this tumor type.

Animals↗

PubMed1992

[A case report of multiple pulmonary tumors as a sole manifestation of synovial sarcoma].

A 47-year-old woman was admitted to our hospital for cough and dyspnea. Roentgenologic studies and bronchoscopy revealed multiple lung tumors one of which obstructed the right main bronchus. Right pneumonectomy was performed for the pending obstruction of the trachea. The tumor in the right S1 was found to be protruding into the trachea through the right B1 and the main bronchus in a polypoid fashion. The pathological diagnosis of synovial sarcoma was made on the basis of the characteristic biphasic structure composed of spindle cells and epithelioid cells forming gland-like spaces. Three years and eight months after the pneumonectomy, a nodule in the tendon of the extensor hallucis longus muscle became palpable. It was also a synovial sarcoma pathologically. Synovial sarcoma is a soft tissue sarcoma which usually arises in the extremities. It is very rare for pulmonary metastasis of this tumor to be found while the primary tumor is undetectable.

Female↗

PubMed1992

[Histological evaluation of intra-arterial infusion and systemic chemotherapy of pancreatic carcinomas].

Histological analyses of 16 autopsies of pancreatic carcinoma [9 cases after intra-arterial infusion chemotherapy (IAC), and 7 cases of systemic chemotherapy (SC)] were performed. Histological effects of chemotherapy (Shimosato) were seen in 15 cases, but less than 5 Grade II a. cases of IAC and 4 cases of SC showed Grade IIa, 3 cases of IAC and 3 cases of SC showed Grade I. The ratio of Grade IIa was almost the same in IAC and SC. But histologically, anaplastic change, sarcomatous change and Bizarre cells, immunohistologically positive to anti-EMA and Vimentin antibody, were dominant in IAC. And clinically, serum tumor markers (CEA, CA19-9) were fewer in almost all the cases in IAC. These results may suggest that the anti-tumor effect of IAC was greater than the histological appearance.

Adenocarcinoma↗

PubMed1991

Hepatoid adenocarcinoma of the renal pelvis producing alpha-fetoprotein of hepatic type and bile pigment.

A right renal pelvic mass in a 72-year-old man was resected. The histologic appearance of the tumor was a mixture of tubular adenocarcinoma cells and hepatoid neoplastic cells, and there was a resemblance to hepatoid adenocarcinoma. The intraoperative level of serum alpha-fetoprotein (AFP) was calculated to be 2246 ng/ml, and the postoperative level ranges from 183.6 to 285.6 ng/ml. Lectin binding assays showed that the serum AFP was the hepatic carcinoma type. In a hepatoid portion, an iron-negative, brown to green pigment was positive for bile. Alpha-fetoprotein was immunohistochemically evident in the neoplastic cells. In addition to the hepatic differentiation, the tumor had differentiated into intestinal absorptive or pancreatobiliary tract cells, as deduced from the frequent presence of spicular bodies, a unique light microscopic feature equivalent to microvilli with an actin core. The hepatoid adenocarcinoma is a distinct type of AFP-producing carcinoma present in the organs with epithelium of endodermal origin. Hepatoid adenocarcinoma in the renal pelvis may arise from a metaplasia of neoplastic mesonephric cells into endodermal cells.

Adenocarcinoma↗

PubMed1991

Endothelial cells modulate the vasoinhibitory effect of NKY-722, a Ca2+ channel antagonist, in canine mesenteric arteries.

Modulation of the vasoinhibitory effect of NKY-722 by vascular endothelial cells was studied in canine mesenteric arteries. A high concentration of NKY-722 accumulated in the endothelium-intact arteries and its accumulation in endothelium-removed arteries was significantly less. The vasoinhibitory effect of NKY-722 in endothelium-intact arteries was significantly weaker than that in endothelium-removed arteries. These results suggest that endothelial cells can attenuate the vasoinhibitory effect of NKY-722.

Animals↗

PubMed1991

HTLV-I associated myelopathy (HAM) after blood transfusion in a patient with CD2+ hairy cell leukemia.

Hairy cell leukemia complicating hemolytic anemia developed in a 46-year-old woman. Morphologically and cytochemically typical hairy cells were found to express both CD20 and CD2 antigens. Expression of surface IgG of kappa-chain type and the rearrangement of Ig but not T-cell receptor beta genes confirmed a B-cell origin of the leukemia. Blood transfusion was followed by disappearance of the hemolysis and a marked improvement of the leukemia. However, the patient developed progressive spastic spinal paraplegia about seven months after transfusion and was diagnosed as having HTLV-I associated myelopathy (HAM) by the demonstration of HTLV-I antibodies in serum and cerebrospinal fluid. HTLV-I infection via the transfusion may have been involved in the hematologic improvement seen in this patient. Autopsy showed demyelination, vacuolar degeneration, gliosis, and perivascular cuffing in the white matter of spinal cord without evidence of leukemic infiltration.

Anemia, Hemolytic↗

PubMed1991

Characterization and location of the L-proline activating fragment from the multifunctional gramicidin S synthetase 2.

Gramicidin S synthetase 2 (GS2) derived from Bacillus brevis is a multifunctional single polypeptide (Mr 280,000) with a 4'-phosphopantetheine residue covalently bound to the enzyme. When GS2 was treated with trypsin or chymotrypsin, fragments with some activity were liberated. The molecular mass of the L-proline activating fragment was 114 kDa on SDS-PAGE. This fragment, when incubated with gramicidin S synthetase 1 (GS1) in the presence of phenylalanine and proline, produced D-Phe-L-Pro dipeptide. The fragment accepted D-phenylalanine from GS1 in the absence of L-proline. The L-proline activating fragment was shown to lack pantothenic acid by microbiological assay. On the other hand, the L-leucine activating fragment, which was partially purified, contained a large amount of pantothenic acid, although it did not form the D-Phe-L-Pro dipeptide. These results indicate that the L-proline activating site is located near an acceptor site for D-phenylalanine on GS2, but that it is not adjacent to a 4'-phosphopantetheine group. The N-terminal sequence (15 amino acid residues) of the L-proline activating fragment obtained by trypsin treatment was identical with that of GS2, indicating that the L-proline activating site is located at the N-terminus of the native synthetase. The N-terminal sequence of GS2 has been matched with the amino acid sequence deduced from the nucleotide sequence 71 bp downstream of the stop codon of the GS1 gene except that the first initiator methionine was not detected.

Amino Acid Isomerases↗

PubMed1991

The nucleotide sequence for a proline-activating domain of gramicidin S synthetase 2 gene from Bacillus brevis.

A fragment encoding proline-activating domain (grs 2-pro) of gramicidin S synthetase 2 (GS 2) was found in an 8.1-kilobase pairs (kb) DNA fragment of Bacillus brevis Nagano, which contained the full length of GS 1 gene (grs 1). The clones designated GS719 and GS708, which expressed gramicidin S synthetase 1, were elucidated to express immunoreactive proteins to GS 2 antibodies with approximate molecular weights of 115,000, 105,000 (GS719), and 110,000 (GS708). The partial purification of the gene products of these clones was carried out using DEAE-Sepharose CL-6B column chromatography. The immunoreactive proteins to GS 2 antibodies were separated from gramicidin S synthetase 1 protein and had specific proline-dependent ATP-32PPi exchange activity. The nucleotide sequence for the proline-activating domain in the 8.1-kb insert was determined. This fragment was 2,879 base pairs long, and encoded 959 amino acids. The calculated molecular weight of 111,671 was consistent with the apparent molecular weight of 115,000 found in SDS-PAGE of the immunoreactive products to GS 2 antibodies. The open reading frame for this protein followed grs 1 gene, though two were separated by a 73-base pair noncoding sequence, and remained open to the end.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Isomerases↗