Search PubMed⌕ Search

Biomedical subjects

T Miki

Publications and source records attributed to T Miki.

At least 613 records · Page 34Linked to original sources
PubMed1993

Superior cervical ganglionic origin of sympathetic fibers in the facial nerve, and their preganglionic spinal inputs: a WGA-HRP study in Macaca fuscata.

The origin of sympathetic fibers in the facial nerve of Macaca fuscata was demonstrated using the HRP method. WGA-HRP injection into the facial nerve resulted in heavy labeling in the ipsilateral superior cervical ganglion. The majority of labeled neurons in the superior cervical ganglion had sizes ranging from 20 to 35 microns. In the present study it was of particular interest that labeled neurons are also found in the intermediolateral nucleus and lateral funiculus ipsilaterally at the level from the C8 to T4 spinal cord segments. Many labeled neurons in the lateral funiculus were located in close vicinity to the intermediolateral nucleus, and, characteristically, a few of these had a long dendrite extending to the lateral surface of the spinal cord. The labeling in the spinal cord appears to be caused by transneuronal transport of WGA-HRP.

Animals↗
PubMed1993

Effect of aminohydroxypropylidene diphosphonate on the bone metabolism of patients with parathyroid adenoma.

Aminohydroxypropylidene diphosphonate (APD), a potent inhibitor of bone resorption, is used to control hypercalcemia in various diseases. It is less effective, however, in the management of hypercalcemia induced by primary hyperparathyroidism. We investigated the effect of APD on the bone metabolism of five patients with parathyroid adenoma. Before parathyroidectomy, 30 mg of APD was administered intravenously. Serum calcium decreased in all cases one to two days after APD administration, although it did not decrease to the normal range. Serum phosphorus also decreased. Urine calcium and hydroxyproline excretion, markers of osteoclasts activity, decreased dramatically. Serum alkaline phosphatase (ALP) and osteocalcin, markers of osteoblast activity, decreased after APD administration. Serum intact parathyroid hormone (PTH) and 1,25-dihydroxy-vitamin D (1,25[OH]2D) increased. These results indicate that APD is partially effective in the management of preoperative serum calcium level in patients with parathyroid adenoma. As osteoclasts activity is inhibited by APD, osteoblasts activity is also suppressed. Elevation of PTH and 1,25(OH)2D after APD-induced decrease in serum calcium level may explain the partial and limited effect of APD on lowering serum calcium in patients with parathyroid adenoma.

Adenoma↗
PubMed1993

Structure-dependent antitumor activities of novel anthracyclines YM1, YM3, YM4 and YM6: drug transport properties and effects on biomacromolecule synthesis in drug sensitive and resistant leukemia cells.

The antitumor activities of four novel doxorubicin (DOX) analogues, YM1, YM3, YM4 and YM6 in relation to their structure and drug transport properties, have been investigated in U937 monocytic and CCRF-CEM lymphoid drug sensitive leukemia cell lines, as well as in CEM/VLB100, a drug resistant subline displaying high levels of P-glycoprotein. Treatment of all cell lines with YM1, 3, 4 and 6 produced a dose-dependent decrease in DNA, RNA and protein synthesis as measured by [3H]-thymidine, [3H]-uridine and [3H]-leucine uptake respectively. YM1 was more effective than YM3, YM4 or YM6 against the drug sensitive cells. The antitumor effects of all these DOX-analogues on macromolecule synthesis in U937 and CCRF-CEM cells were lower than that of DOX and epirubicin (EDR). A rapid accumulation of the novel anthracyclines was found in all cell lines compared with DOX or EDR. However, the maximal accumulation of the DOX-analogues was lower than that of EDR. There is a greater efflux from CCRF-CEM sensitive cells and less from CEM/VLB100 resistant cells of the DOX-derivatives when compared with EDR and DOX. Drug-induced cytotoxicity significantly correlated (P < 0.05) with drug retention levels in CCRF-CEM and U937 drug sensitive cells as indicated by an inverse correlation curve between anthracycline retention and drug-induced IC50 value. It was demonstrated that an increased level of drug retained within the sensitive cells would therefore produce a more cytotoxic effect of the drug. However, no such correlation was observed in CEM/VLB100 resistant cells. YM3 was shown to have an increased antitumor activity against CEM/VLB100 resistant cells compared with DOX with a lower resistance factor. These results showed that the antitumor effects of four novel DOX-analogues, like DOX or EDR, were associated with inhibition of DNA replication, transcription and translation. The finding that resistant leukemic cells are more susceptible to the cytotoxic effect of YM3 than DOX warrants further investigation to identify the intrinsic mechanism of resistance.

Biological Transport↗
PubMed1993

Stabilization of lysozyme by the introduction of Gly-Pro sequence.

Three mutant lysozymes where the Asp101-Gly102 sequence of lysozyme was converted to Asp101-Pro102, Gly101-Pro102 and Pro101-Gly102 were prepared to investigate the effect of proline residues on the stabilization of proteins. The free energy changes of lysozymes for the unfolding in aqueous solution at pH 5.5 and 35 degrees C were 10.0, 10.1, 11.0 and 7.7 kcal/mol for wild type, Asp101Pro102, Gly101Pro102 and Pro101Gly102 lysozyme respectively. When the energy level in the unfolded state of wild type lysozyme was fixed at a standard level, the energy levels in the folded state of Asp101Pro102 and Pro101Gly102 lysozymes were found to be higher than that of wild type lysozyme on the basis of delta GD(H2O) and entropy losses of their polypeptide chains in the unfolded state. The presence of some strain in the folded state of these lysozymes was supported by both the calculation of conformational energy for a trans-L-prolyl residue [Schimmel, P.R. and Flory, P.J. (1968) J. Mol. Biol., 34, 105-120] and the analysis of structures of energy-minimized mutant lysozymes. Therefore, it is concluded that the formation of the Gly-Pro sequence is effective in avoiding possible strain in the folded state of a protein caused by the introduction of proline residue(s).

Amino Acid Sequence↗
PubMed1993

Strong inhibition of 2-amino-6-methyldipyrido[1,2-a:3',2'-d] imidazole-induced mutagenesis and hepatocarcinogenesis by 1-O-hexyl-2,3,5-trimethylhydroquinone.

The effects of 3-O-dodecylcarbomethylascorbic acid (3-O-DAsA), 3-O-ethylascorbic acid (3-O-EAsA) and 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ) on 2-amino-6-methyldipyrido[1,2-a:3',2'-d]-imidazole (Glu-P-1)-induced mutagenesis and hepatocarcinogenesis were examined. In a Salmonella assay, addition of 2.5 to 20.0 mg of HTHQ to Salmonella TA 98 in the presence of S-9 mixture dose-dependently inhibited Glu-P-1-induced mutagenesis. The highest dose showed a 99% reduction in revertants. 3-O-DAsA and 3-O-EAsA were without effect. In an animal study using the medium-term bioassay system for the detection of hepatocarcinogens or hepatopromoters in F344 male rats, treatment with Glu-P-1 alone was associated with a significant increase in the number and area of GST-P-positive foci (47.5 +/- 8.9 and 11.1 +/- 4.7, respectively). Combined treatment with 1.0% HTHQ significantly reduced the number and area of GST-P-positive foci (to 8.1 +/- 2.1 and 0.6 +/- 0.2) while 3-O-DAsA exerted marginal inhibition and 3-O-EAsA had no effect. On the other hand, all three of these compounds slightly enhanced the numbers and areas of foci when given alone. The results indicate that HTHQ is a potent chemopreventer of Glu-P-1-induced hepatocarcinogenesis.

Animals↗
PubMed1993

Do angiotensin converting enzyme inhibitors limit myocardial infarct size?

1. Effects of captopril, ramiprilat and Hoe 140, a specific bradykinin receptor antagonist, on infarct size were assessed in a rabbit model of myocardial infarction. 2. Rabbits were untreated or pretreated with 0.5 mg/kg of captopril, 0.05 mg/kg of ramiprilat or 20 nmol/kg of Hoe 140 before 30 min coronary artery occlusion and 72 h reperfusion. 3. Captopril and ramiprilat treatment reduced systemic blood pressure by about 10 mmHg without alteration of heart rate, and the dose of Hoe 140 almost completely blocked hypotensive response to intravenous injection of bradykinin (100 ng/kg). 4. Infarct size expressed as percentage of area at risk was 44.5 +/- 3.3% in the control group, 41.9 +/- 1.6% in the captopril group, 51.8 +/- 2.7% in the ramiprilat group and 46.7 +/- 2.2% in the Hoe 140 group. All percentages were not significantly different. 5. These data suggest that angiotensin converting enzymes (ACE), with or without sulfhydryl groups do not limit myocardial infarct size and that endogenous bradykinin in ischaemic myocardium does not play a major protective role against ischaemic myocardial necrosis.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1993

Structural and functional characterization of rev-like transcripts of equine infectious anemia virus.

Three cDNA clones representing structurally distinct transcripts were isolated from a cDNA library prepared from cells infected with equine infectious anemia virus (EIAV) by using a probe representing the S3 open reading frame, which is thought to encode Rev. One species, designated p2/2, contained four exons and was identical to a previously described polycistronic mRNA that encodes Tat. This transcript was predicted to also direct the synthesis of a truncated form of the transmembrane protein and a putative Rev protein whose N-terminal 29 amino acids, derived from env, are linked to S3 sequences. The second cDNA, p176, also consisted of four exons which were generated by two of three of the same splicing events that occur with p2/2 but not with the Tat mRNA. The alternative splice site giving rise to the second exon of p176 results in a bicistronic message that would encode the same transmembrane and Rev proteins as p2/2. The first exon of the third transcript, p20, was identical to those of p2/2 and p176 but was spliced directly to S3. This monocistronic message could encode a second form of Rev that lacks env sequences, provided that Rev synthesis would initiate at a non-AUG codon. The coding capacity of each cDNA was assessed in a eukaryotic system using S3 antisera. Two putative Rev proteins with apparent molecular masses of 18 and 16 kDa were expressed by p2/2 and p176, while p20 expressed only a 16-kDa species. Analysis of EIAV-infected cells with S3 antisera revealed the presence of an 18-kDa protein. Surprisingly, the same protein was detected in purified virions. By using a reporter construct, the chloramphenicol acetyltransferase gene linked to EIAV env sequences, we were able to demonstrate greatly enhanced chloramphenicol acetyltransferase activity in cells cotransfected with this construct and any of the three cDNAs.

Amino Acid Sequence↗
PubMed1993

Expression cDNA cloning of a transforming gene encoding the wild-type G alpha 12 gene product.

Using an expression cDNA cloning approach, we examined human tumor cell lines for novel oncogenes that might evade detection by conventional techniques. We isolated a transforming sequence that was highly efficient in transforming NIH 3T3 mouse fibroblasts. DNA sequence analysis identified the gene as the human homolog of a recently cloned alpha subunit of mouse GTP-binding protein G alpha 12. NIH 3T3 cells transfected with G alpha 12 cDNA grew in soft agar and were tumorigenic in nude mice. There were no apparent mutations in the cloned cDNA in comparison with a G alpha 12 cDNA clone isolated from a normal human epithelial cell library, implying that overexpression alone was sufficient to cause NIH 3T3 cell transformation. The observed altered growth properties mediated by G alpha 12 showed a certain degree of dependency on serum factors, and its mitogenic potential was also potently inhibited by suramin treatment.

3T3 Cells↗
PubMed1993

Close linkage of the gene for Werner's syndrome to ANK1 and D8S87 on the short arm of chromosome 8.

Werner's syndrome (WRN) is a rare autosomal recessive disorder characterized by the appearance of features of premature aging in a young adult. Skin fibroblasts from WRN patient demonstrate slow growth, reduced life span in vitro and mutator phenotype. The genetic defect in WRN is unknown. We have studied 23 WRN patients mainly from first or second cousin marriage and have applied homozygosity mapping to search for the WRN locus. A peak lod score of 5.58 at a recombination fraction of 0.03 was obtained with D8S87. We confirmed that the WRN locus was located on the short arm of chromosome 8, 8p11.2-p12.

Adult↗
PubMed1993

Separation and determination of phospholipids in plasma employing thin-layer chromatographic plate with concentration zone or solid phase extraction.

Two efficient extraction methods for phospholipids have been established employing a TLC plate with a concentration zone or a solid-phase extraction cartridge. First, small amounts of five authentic phospholipids, 10 to 100 micrograms each, were separated on a TLC plate with a concentration zone. These phospholipids were not adsorbed to the silica gel of this TLC plate and the substrates were recovered in good yields. Second, a solid-phase extraction cartridge containing NH2-modified silica gel was able to retain all of the authentic phospholipids among C18-, diol-, and CN-modified silica gel and silica gel beds. Elution of neutral and acidic phospholipids from the NH2-cartridge was carried out with a chloroform-methanol mixture and a chloroform-methanol-28% ammonium mixture containing 0.05 M ammonium acetate, respectively. Recovery tests on the above two methods were carried out by conventional capillary gas chromatography. Thus, not less than 95% of each phospholipid was recovered from the TLC plate or NH2-cartridge in a 10 to 100 micrograms sample range. Also, the standard deviation of repeatability of recovery for phosphatidylcholine by solid phase extraction at a 10 micrograms sample range was favorable at sigma = 2.8. This method of separation was applied to determination of the fatty acid compositions of phospholipids in small amounts of plasma.

Adsorption↗
PubMed1993

[Molecular genetic analysis of sporadic Alzheimer's disease].

The authors report the clinical findings and the results of molecular genetic analysis of 8 patients with sporadic Alzheimer's disease. Differential diagnosis was carried out on the basis of familial history, laboratory data, brain imaging analysis using CT, MRI and SPECT. According to the clinical stage criteria made by Cummings and Benson, 6 cases were in stage 1 and the remaining 2 in stage 2. Recently, it was reported that affected members from 6 Japanese kindreds with familial Alzheimer's disease (FAD) had missense mutation in exon 17 of the gene for beta/A4 amyloid precursor protein (APP). Amino acid substitution (Val-Ile) at codon 717 by this mutation was considered to be responsible for FAD in these kindreds. We used genomic DNA from 8 sporadic cases to determine whether the disease in these families is associated with an APP 717 mutation and the mutated codons, 102, 117, 129, 178, and 200, on the gene for proteinase-resistant prion protein (Prp) which causes transmissible dementia, Creuzfelt-Jacob disease (CJD) and Gerstmann-Sträussler syndrome (GSS). The results showed that there were no mutations on these genes in 8 patients. It would be necessary to analyze DNA from patient with sporadic Alzheimer's disease to examine the mutations found in the APP gene and Prp gene of heredity Alzheimer's disease patients.

Aged↗
PubMed1993

[Two cases of Werner's syndrome treated with penetrating keratoplasty].

Cataract is one of the typical ocular manifestations of Werner's syndrome. In contrast to cataract in normal elderly persons, cataract in patients with Werner's syndrome is known to be associated with degenerative corneal changes after cataract surgery. Among the corneal changes bullous keratopathy occurs in almost 100% of patients with Werner's syndrome after cataract surgery. Although penetrating keratoplasty appears to be the best treatment for bullous keratopathy, there have been few reports on bullous keratopathy in patients with Werner's syndrome. Here we report two patients with Werner's syndrome who underwent penetrating keratoplasty for the treatment of bullous keratopathy. In both cases, visual acuity was improved, suggesting that penetrating keratoplasty is a recommendable treatment for bullous keratopathy in patients with Werner's syndrome.

Cataract Extraction↗
PubMed1993

[The effect on age for the relationship between hypertension and glucose intolerance].

Recently, high frequencies of glucose intolerance and insulin resistance have been reported in patients with hypertension. However, both blood pressure and glucose tolerance are influenced by age. To investigate the effect of age on the interaction between blood pressure and glucose tolerance, we analyzed blood pressure and glucose tolerance in otherwise healthy subjects (n = 576) who underwent an oral glucose tolerance test and blood pressure measurement as a part of a healthy care program. The prevalence of DM and IGT were significantly higher in the hypertensive group than in the normotensive group. When the subjects were divided into three groups according to their age (less than 50 years old, between 50 and 60 years old and more than 60 years old), the prevalence of glucose intolerance (DM or IGT) was significantly higher in the hypertensive group than in the normotensive group in subjects under 50 years old, but not in subjects between 50 and 60 years old or over 60 years old. In the subjects classified as having normal glucose tolerance, the incremental area of glucose under the curve of 75g-OGTT was significantly higher in the hypertensive group than in the normotensive group. These data suggest that hypertension is associated with glucose intolerance in Japanese population and that age significantly affects this interaction.

Aged↗
PubMed1993

[Neoadjuvant therapy for prostatic cancer].

Neoadjuvant therapy for prostatic cancer might be important to increase cure rates of the disease and preservability of the organs. There were 43 cases in a period of 1975-1990 in which total prostatectomy were performed after neoadjuvant therapy. According to the clinical stage, there were 14 cases in B, 23 in C, 4 in D1 and 2 in D2. The median duration of neoadjuvant therapy was 4 months. Clinical response of the prostate in 37 evaluable cases was as follows; 6 cases were PR (16%), 12 cases were MR (32%) and 19 cases were NC (52%). Histopathological effect was as follows; 5 cases were grade 0a (12%), 12 cases were grade 0b (28%), 16 cases were grade 1 (37%), 8 cases were grade 2 (19%) and 2 cases were grade 3 (5%). In 2 cases with histopathological effect of grade 3, lymph node metastases were thought to have obviously disappeared. Histopathological effect seemed related to clinical response. In cases given neoadjuvant therapy for less than 2 months, no adequate clinicopathological effect was obtained. Cases that could achieve downstaging were 8; 1 in grade 0a, 2 in grade 1, 3 in grade 2 and 2 in grade 3. These results suggest that neoadjuvant therapy plays an important role in advanced prostatic cancer.

Aged↗
PubMed1993

[Successful interferon therapy of renal cell carcinoma with tumor thrombus extending into the inferior vena cava--a case report].

It is a fact that there are few effective drugs available except for interferon for that treatment of renal cell carcinoma, and the efficacy rate of interferon is less than 10% even if multiple drug regimens are included. We have experienced a case of renal cell carcinoma in whom interferon therapy was successful in reducing the primary lesion and tumor thrombus extending into the inferior vena cava. A 57-year-old man was admitted to our department with a complaint of macroscopic hematuria. Computed tomography and magnetic resonance imaging revealed a right renal tumor and the tumor thrombus. Because of the past history of his myocardial infarction, a radical operation was considered risky. So we started interferon therapy. Four months after the start of interferon therapy, the primary lesion and the tumor thrombus markedly reduced in their size, and the clinical response was evaluated as partial response by response criteria for urological cancer treatment. Therefore, radical nephrectomy and tumor thrombectomy were performed with extracorporeal circulation. Histopathologically, necrosis and lymphocyte infiltration into the cancer cell focus were seen, and these immunologic reactions were considered at the affection of interferon. In some case, interferon therapy is a useful and safe in the treatment of the primary lesion of renal cell carcinoma, and further investigation must be studied.

Carcinoma, Renal Cell↗
PubMed1993

[Struma ovarii].

Explore the source record for details and available documents.

Adult↗