Biomedical subjects

K Yoshikawa

Publications and source records attributed to K Yoshikawa.

At least 307 records · Page 17Linked to original sources

PubMed1997

A case of triple extramammary Paget's disease.

We report a 74-year-old Japanese man with triple extramammary Paget's disease; the genital and both of the axillar regions were simultaneously involved. Literature review revealed that 27 cases of triple extramammary Paget's disease have been reported in Japan, but there are no reports of triple extramammary Paget's disease from countries other than Japan, although 2 cases of double extramammary Paget's disease are reported. In all 28 cases, including our case, the genital lesion preceded the axillary lesions. All cases except one were male and only the exceptional female case was reported to have an the invasive tumor in the dermis. We speculate that extramammary Paget's disease may appear multi-centrically.

Aged↗

PubMed1997

A case of contact dermatitis due to impurities of cetyl alcohol.

A 29-year-old man being treated for itchy lesions on the amputation stump of the thigh became allergic to betamethasone valerate and gentamicin sulfate cream (Rinderon VG). Closed patch tests with all the ingredients of the cream revealed positive reactions to cetyl alcohol 30% to 5% pet. Gas chromatographic analysis of the cetyl alcohol in the cream base detected stearyl alcohol (C18), myristyl alcohol (C14) and lauryl alcohol (C12) in addition to the main component of cetyl alcohol (C16). Patch testing with 99% pure analytical reagent grade saturated alcohols (C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20) showed negative reactions. Thus, it is concluded that some minor impurities in cetyl alcohol not detected by gas chromatography might be the cause of this dermatitis.

Adult↗

PubMed1997

Cloning of genes coding for L-sorbose and L-sorbosone dehydrogenases from Gluconobacter oxydans and microbial production of 2-keto-L-gulonate, a precursor of L-ascorbic acid, in a recombinant G. oxydans strain.

We have purified L-sorbose dehydrogenase (SDH) and L-sorbosone dehydrogenase (SNDH) from Gluconobacter oxydans T-100 that showed an ability to convert D-sorbitol to 2-keto-L-gulonate (2-KLGA). A genomic library of Gluconobacter oxydans T-100 was screened with a probe, a 180-bp PCR product which was obtained from degenerate oligodeoxyribonucleotides based on the elucidated sequence of the purified SDH (used as primers) and the genomic DNA of G. oxydans T-100 (used as a template). From sequencing of the DNA from a clone positive to the probe, the SNDH and the SDH were estimated to be coded in sequential open reading frames with 1,497 and 1,599 nucleotides, respectively, which was confirmed by expression of the DNA in Escherichia coli that showed both enzymatic activities. The DNA was introduced to a shuttle vector which was prepared from a plasmid of G. oxydans T-100 and pHSG298 to obtain an expression vector designated pSDH155. The production of 2-KLGA by pSDH155 in G. oxydans G624, an L-sorbose-accumulating strain, was improved to 230% compared to that of G. oxydans T-100. Chemical mutation of the host strain to suppress the L-idonate pathway and replacement of the original promoter with that of E. coli tufB resulted in improving the production of 2-KLGA. Consequently, high-level production from D-sorbitol to 2-KLGA (130 mg/ml) was achieved by simple fermentation of the recombinant Gluconobacter.

Acetobacteraceae↗

PubMed1997

Antisweet natural products. XII. Structures of sitakisosides XI-XX from Stephanotis lutchuensis Koidz. var. japonica.

From the fresh stem of Stephanotis lutchuensis var. japonica, ten new oleanane-type triterpenoid glycosides, named sitakisosides XI-XX (1-10), were isolated. Their structures were determined on the basis of spectroscopic data and chemical evidence. The results show that all have a 3-O-beta-D-xylopyranosyl(1 --> 6)-beta-D-glucopyranosyl(1 --> 6)- beta-D-glucopyranosyl moiety and the aglycones of sitakisosides XI-XV, XVI and XVII, XVIII and XIX, and XX are sitakisogenin, chichipegenin, marsglobiferin and longispinogenin, respectively. Sitakisosides XI-XIII, XVI and XVIII, having an acyl group, showed antisweet activity.

Carbohydrate Sequence↗

PubMed1997

Measurement of replicative DNA synthesis (RDS) by a 5-bromo-2'-deoxyuridine (BrdU) labeling technique for detection of hepatocyte proliferation.

The hypothesis has been proposed that cell proliferation, or replicative DNA synthesis (RDS) in S-phase cells, is a nongenotoxic (Ames-negative) mechanism involved in tumorigenesis, providing a very useful conceptual basis for carcinogen testing. In this present study, hepatocyte RDS experiments were conducted using 5-bromo-2'-deoxyuridine (BrdU) labeling in combination with histopathological observation, comparing our results with earlier findings for in situ [3H]thymidine (TdR) labeling. The present BrdU data proved to be consistent with the previous TdR data in all but one case. Hepatocyte RDS induction was observed for some chemicals without hepatotoxicity. BrdU labeling in combination with histopathological observation is therefore a reliable approach to assessment of test compound effects in vivo.

Animals↗

PubMed1997

[Toxicokinetics of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in mice and rats during 13-week dietary administration].

Toxicokinetics of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate(NS-21), a new drug for the treatment of urinary frequency and incontinence, were studied in mice and rats during a 13-week dietary administration to determine the toxicokinetic profiles of NS-21 and its active metabolite (+/-)-4-ethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride (RCC-36) in dietary carcinogenicity studies. Male and female mice were given the drug in the diet at doses of 0(control), 30, 100 and 300 mg/kg/day, and male and female rats were given the drug at doses of 0(control), 10, 30 and 100 mg/kg/day. The chosen doses and means of administration were identical to those of a 78-week dietary carcinogenicity study in mice and 2-year dietary carcinogenicity study in rats. The plasma concentrations were measured on the first and the last day of the administration. For every treatment period, the plasma concentrations of NS-21 and RCC-36 increased with dose in mice and rats. The sum of the area under the concentration-time curve(AUC) of NS-21 and RCC-36 was 2694 to 8614 ng.hr/ml in the maximum dose of mice, and 2232 to 3593 ng.hr/ml in the maximum dose of rats through the administration period. These results show that, when compared with therapeutic dose in humans(682 ng.hr/ml at 10 mg/body/day), the total maximal exposure to NS-21 and RCC-36 in the earlier dietary carcinogenicity studies were estimated to be 4 to 13 times higher in mice, and 3 to 5 times higher in rats.

Administration, Oral↗

PubMed1997

Preoperative detection of the composition of atherosclerotic plaque in the carotid artery using ultrasonography and magnetic resonance imaging.

Preoperative identification of the components of atherosclerotic plaque was attempted using ultrasonography in five patients and magnetic resonance (MR) imaging in three patients before carotid endarterectomy. The correlation between surgical and histological findings, and preoperative ultrasonography and MR imaging was evaluated. Plaque consisting predominantly of calcification appeared as bright echo on ultrasonography and was tough. Plaque consisting predominantly of hemorrhage was echolucent, appeared as low intensity on T2-weighted MR images and was fragile. Such preoperative assessment of plaque composition using ultrasonography and MR imaging is useful for manipulation of atherosclerotic plaque during carotid endarterectomy.

Aged↗

PubMed1997

[Study on the surgical treatment for pulmonary metastasis from renal cell carcinoma].

BACKGROUND: Pulmonary resection for metastatic renal cell carcinoma were studied to assess the indication of surgical management. METHODS: Between January, 1981 and December 1994, 17 consecutive patients (14 men and 3 women) underwent complete pulmonary resection for metastatic renal carcinoma. Median age was 61 years (range, 45 to 73 years). Eleven were appeared lung metastasis after resection of primary tumor. Median time between nephrectomy and pulmonary resection was 32 months (range, 0 to 127 months). RESULTS: There were no operative deaths. One patient had solitary metastasis, 4 had two, 2 had three, 2 had four, one had seven, one had eight and 6 had more than twenty-two. Segmental resection was performed in 12 patients, lobectomy in 2, lobectomy and segmentectomy in 3 and segmentectomy for total lobes in 3. Four patients had another site operation of renal metastasis, brain tumor resection, chest wall and ribs resection, contra-lateral adrenalectomy and contralateral partial nephrectomy. Median follow-up was 44 months (range, 10 to 129 months). The cause specific survival rate and disease free survival after pulmonary resection was 55 and 48 percent at 5 years and 27 and 14 percent at 10 years, respectively. CONCLUSION: Pulmonary resection for metastatic renal cell carcinoma was considered effective in some selected slow-growing cases. Multiple and both lungs metastases is not contraindication and the patients under 10 metastatic focuses had good prognosis.

Aged↗

PubMed1997

Korormicin, a novel antibiotic specifically active against marine gram-negative bacteria, produced by a marine bacterium.

A novel antibiotic named korormicin was isolated from the marine bacterium, Pseudoalteromonas sp. F-420. This strain was isolated from the surface of a macro alga Halimeda sp. collected from Palau (the Republic of Belau). The planar structure of korormicin was determined by the result of 2D NMR studies and mass spectral data. Korormicin had specific inhibitory activity against marine Gram-negative bacteria, but was inactive against terrestrial microorganisms.

Anti-Bacterial Agents↗

PubMed1997

Presurgical identification of extradural nerve root anomalies by coronal fat-suppressed magnetic resonance imaging: a report of six cases and a review of the literature.

In an attempt to depict the anatomy of the nerve roots, we obtained magnetic resonance (MR) images of the lumbar spine in the coronal plane with the frequency-selective fat-suppression technique. With this technique, extradural anomalies were identified in 20 (6.7%) of 300 patients. We report the appearance on coronal MR images of six surgically confirmed extradural anomalous nerve roots together with the myelography findings. These include type Ia, type Ib, and type 3 anomalies. These are readily recognized and allow detailed evaluation of the type of nerve root anomaly.

Adult↗

PubMed1997

[Metabolic imaging of human brain tumors: H-1 chemical shift imaging and PET].

Positron Emission Tomography(PET) and Proton Chemical Shift Imaging(1H-CSI) has provided a cerebral metabolism. The glucose analog fluorine-18 fluorodeoxy-glucose(FDG) and amino acid analog 11C-L-methionine is the most commonly used PET tumor tracer. This time we compare with 1H-CSI and PET in gliomas and metastatic brain tumor with computer-assisted fusion images. We experienced some cases of the brain tumor. One case is metastatic brain tumor after radiation therapy, localized in right parietal hemisphere, with hemorrhage, and slightly accumulated Gd-DTPA in tumors. 11C-methionine PET demonstrates defects in tumors, but slight accumulated surrounding tumors. Accumulation of PET lesion is not elevated choline in CSI, but lactate is accumulated in tumors. Choline signal elevation seen in brain neoprasms, associated with increased cellular proliferation. Accumulation of PET and another accumulation of lactate in tumor are not demonstrate recurrence. Fusion image of PET and CSI is useful in understanding metabolism of brain tumor.

Aspartic Acid↗

PubMed1997

Herpetiform pemphigus showing reactivity with pemphigus vulgaris antigen (desmoglein 3)

We report a patient with herpetiform pemphigus (HP) who showed reactivity only with pemphigus vulgaris (PV) antigen but not with pemphigus foliaceus (PF) antigen. Direct and indirect immunofluorescence revealed keratinocyte cell surface staining in the lower layers of the epidermis, where desmoglein 3 (Dsg3) is expressed. Immunoblot analysis, using ethylenediamine tetra-acetic acid-separated human epidermal extracts, revealed that the patient's serum recognized only a 130-kDa polypeptide which co-migrated with Dsg3. By antigen-specific immunoadsorption studies, using desmoglein 1 (Dsg1) and Dsg3 recombinant protein produced by baculovirus expression system, immunoreactivity of the patient's serum was completely adsorbed by Dsg3 alone, but not by Dsg1. These results indicate that this HP patient produced only anti-Dsg3 autoantibodies and no other autoantibodies against components of the keratinocyte cell surface. HP could be a variant of PV, in addition to PF, with unique clinical and histological features.

Autoantigens↗

PubMed1997

Laparoscopic adrenalectomy: comparison with the conventional approach.

Laparoscopic adrenalectomy (LA) was performed on 14 patients with adrenal tumors. Herein we describe the laparoscopic procedure and the patients' clinical course compared with those of patients who underwent the conventional posterior or transabdominal approach (PA, TA). The 14 patients included four men and 10 women aged 28 to 69 years. Clinical diagnoses in this series were primary aldosteronism in seven patients, Cushing's adenoma in four patients, and nonfunctioning tumor in three patients. Maximum diameters of the adrenal tumors ranged from 10 to 48 mm. In all patients, the adrenal tumors were removed successfully. The mean operating time was longer for LA- than for PA- or TA-treated patients (185 versus 99 and 143 min), whereas the mean blood loss was smaller for LA- or PA-treated (92 and 126 ml) than for TA-treated patients (407 ml). The patients' postoperative condition, as assessed in terms of the number of febrile days, leucocytosis, and elevation of C-reactive protein value, was significantly better with LA. In addition, the frequency of administration of analgesics was lower and the time required until the patient could walk were shorter after LA than after PA and TA. In conclusion, laparoscopic adrenalectomy appears to be a minimally invasive and safe therapeutic option that may become a standard procedure for adrenal surgery.

Adrenal Gland Neoplasms↗

PubMed1997

[Distribution of amyloid precursor protein mRNA in Alzheimer brain tissues].

This study aimed to provide clear data on the localization of the mRNA for the amyloid precursor protein (APP) in human brain. It is known to occur in neurons but the possible localization in other type of brain cells is controversial among several authors. A cDNA probe constructed by polymerase chain reaction for APP, which was not specific for a particular isoform, gave punctate staining and showed a clear localization not only in neurons but in astrocytes in all brains, as well as in the reactive microglia associated with senile plaques in Alzheimer disease. A cRNA probe gave more diffuse staining of neurons and glia.

Aged↗

PubMed1997

[A case of porencephaly with mirror movements: pathophysiological investigation by using long-latency long-loop reflex and dipole tracing method].

We report a 42-year-old left-handed woman with congenital right hemiparesis and bilateral mirror movements in the hands. She had a porencephaly of the left hemisphere and the brain MRI demonstrated cortical and subcortical defect of the left hemisphere from Brodmann's area 6 to 40 including the left motor cortex. By electrical stimulation of the left median nerve at the wrist, N20 of the somatosensory evoked potential was recorded in the right postcentral gyrus by using the dipole tracing method. Long-loop reflexes from the bilateral thenar muscles were recorded and their latencies were almost the same. The stimulation of the right median nerve did not evoke N20, nor long-loop reflex. These electrophysiological findings suggest that the reorganization of the motor system made the right motor cortex to innervate bilateral hands, and caused bilateral mirror movements. In other words, the mirror movements managed to relieve the paralysis of the right hand though the damage of the left motor cortex was present. In the previous literature we are able to find hypotheses regarding the mechanism of mirror movements in congenital hemiparesis. Here we discussed about the reorganization of the motor system in the damaged brain.

Cerebral Cortex↗

PubMed1996

Antimutagenic activity of extracts from Japanese eggplant.

Using the Salmonella/microsome assay, the antimutagenic effects of specific components of the extracts from eggplant fruits were investigated. The eggplant fruit juice exhibited an antimutagenic activity against 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) induced mutagenicity. In some of the fractions extracted with several organic solvents (acetone, petroleum ether, ethyl acetate; and methanol), the activity was recognized. No mutagenicity or toxicity for Salmonella typhimurium TA98 in the presence of S9 mixture was observed with any of the extracts. It is suggested that there are multiple components of the activities that exist in the eggplant fruit. We isolated lutein from the 84% methanol (methanol/water, v/v) layer, pheophorbide or chlorophyllide from the 70% methanol layer and tannins containing sugar-moieties from the water layer. Pheophytin a and b, Mg-free derivatives of chlorophyll a and b, were isolated from the petroleum ether layer as possible antimutagens. The pheophytin a with S9 mix inhibited by 30-40% the mutagenicity of Trp-P-2.

Antimutagenic Agents↗

PubMed1996

Daunomycin unfolds compactly packed DNA.

Daunomycin is an antitumor antibiotic known to inhibit DNA replication and transcription. Although the inhibition is assumed to be caused by a direct interaction of the drug with DNA, the exact effect of daunomycin on the higher order DNA structure remains uncertain. We studied the effect of daunomycin on DNA compacted states using fluorescence and electron microscopies. Structural changes in individual DNA molecules were examined under the following conditions. T4 phage DNA (166 kbp) was first compacted by spermidine followed by the addition of daunomycin to the compacted DNA. A direct observation of individual single duplex DNAs by fluorescence microscopy indicated that daunomycin induced unfolding of the compacted DNA. Electron microscopic observation of the morphological changes of the higher order DNA structure supported the results obtained by fluorescence microscopy. We discuss here the mechanisms of the unfolding of the compacted structure following intercalation of daunomycin into DNA particularly in terms of the free energy.

Antibiotics, Antineoplastic↗

PubMed1996

Folding and aggregation of DNA chains induced by complexation with lipospermine: formation of a nucleosome-like structure and network assembly.

Dioctadecylamidoglycylspermine (DOGS) is a cationic lipid vector capable of efficiently introducing DNA into various eukaryotic cells. We investigated the higher-order structure of the DNA/DOGS complex using fluorescence and electron microscopy. Our results show that the DNA/DOGS complex exhibits a nucleosome-like structure in which DNA wraps around an aggregate of DOGS molecules. In addition, DNA/DOGS complexes tend to associate with each other to form network structures. The resulting network assembly may play a role in effective gene transfection.

Animals↗