Biomedical subjects

H Seki

Publications and source records attributed to H Seki.

At least 37 records · Page 2Linked to original sources

PubMed2001

Expression of proteinases and inflammatory cytokines in subchondral bone regions in the destructive joint of rheumatoid arthritis.

OBJECTIVE: We previously described abnormalities in the bone marrow of patients with rheumatoid arthritis (RA), but were able to shed little light on the pathogenic roles of inflammatory cytokines and proteinases in joint destruction in the subchondral region in RA. This is the first report to describe the co-localization of cytokines and proteinases in this area. METHODS: Decalcified paraffin-embedded sections from 10 patients with RA and five patients with osteoarthritis (OA) were examined for the immunolocalization of cathepsins B, K and L and the localization of messenger RNAs for interleukin 1beta (IL-1beta), tumour necrosis factor alpha (TNF-alpha) and matrix metalloproteinase 9 (MMP-9). The cells were double-stained with anti-CD68 or anti-prolyl 4-hydroxylase (PH) antibody. RESULTS: An immunohistochemical study confirmed the expression of cathepsins B and L by CD68-positive mononuclear cells at the sites of significant cartilage and bone erosion from the subchondral region in all RA specimens. Osteoclast-like cells showed intense staining for cathepsin K and MMP-9. Osteoblast-like cells strongly expressed MMP-9. Analysis of serial sections revealed that expression of the IL-1beta and TNF-alpha genes occurred near that of the cathepsins and MMP-9 in the subchondral region. CONCLUSION: We conclude that inflammatory cytokines and tissue-damaging proteinases play important roles in joint destruction in the subchondral region in RA.

Adult↗

PubMed2001

Decrement of N20 amplitude of the median nerve somatosensory evoked potential in Creutzfeldt-Jakob disease patients.

We studied somatosensory evoked potentials (SSEPs) in eight Creutzfeldt-Jakob disease (CJD) patients presenting with subacute progressive dementia, generalized myoclonus, and characteristic periodic sharp wave complexes in EEG. Somatosensory evoked potentials were elicited by median nerve stimulation at the wrist. We compared SSEP findings with EEG and the clinical stage proposed by the Japanese Slow Virus Infection Research Committee (stage 1: early stage to stage 5: terminal stage). Until clinical stage 3, short-latency SSEPs showed normal findings despite the severely abnormal EEG. With the progression to clinical stages 4 and 5, however, the amplitude of N20 began to decrease and finally disappeared without prolongation of the latency of N20, whereas other short-latency components were preserved. We recorded giant SSEPs in two of three patients in stage 4, when the periodic sharp wave complex in EEG began to decrease in amplitude. The giant SSEPs decreased in amplitude with the progression of the illness. These findings suggest that the short-latency SSEP is relatively preserved until the middle phase of the disease but that it is eventually affected in the terminal phase. We conclude that our results are compatible with the CJD pathologic findings and that the amplitude of N20 reflects the extent of cortical damage in CJD patients.

Aged↗

PubMed2001

Gastrointestinal stromal tumour of the rectum.

Gastrointestinal stromal tumour (GIST) has been immunohistochemically defined as the tumour lacking differentiation towards either leiomyomatous tumour or schwannoma. We report a 75-year-old man who underwent an abdominoperineal resection of a large submucosal tumour of the rectum. The excised specimen was revealed to be an elastic soft tumour, 8 x 7 x 6 cm in size, which histologically consisted of spindle-shaped cells without nuclear atypia. The mitotic count was fewer than 2 per 10 high-power fields. The tumour cells were positive for staining of CD34 and c-kit protein, while the lesions were negative for alpha-smooth muscle actin, HHF-35, neuron-specific enolase, and S-100 protein. The diagnosis of GIST was confirmed by immunohistochemical examination of the tumour. From these findings, the present case is thought to be potentially malignant, and a long-term follow-up observation is needed for the case.

Aged↗

PubMed2001

Pharmacological profile of a new orally active growth hormone secretagogue, SM-130686.

SM-130686, an oxindole derivative, is a novel orally active GH secretagogue (GHS) which is structurally distinct from previously reported GHSs such as MK-677, NN703 and hexarelin. SM-130686 stimulates GH release from cultured rat pituitary cells in a dose-dependent manner. Half-maximum stimulation was observed at a concentration of 6.3+/-3.4 nM. SM-130686-induced GH release was inhibited by a GHS antagonist, but not by a GH-releasing hormone antagonist. SM-130686 dose-dependently inhibited the binding of radiolabeled ligand, (35)S-MK-677, to human GHS receptor 1a (IC(50)=1.2 nM). This indicates that SM-130686 stimulates GH release through the GHS receptor. The effect of a single oral administration of SM-130686 on GH release in pentobarbital-anesthetized rats was studied. After treatment with 10 mg/kg SM-130686, plasma GH concentrations measured by radioimmunoassay significantly increased, reaching a peak at 20-45 min, and remained above baseline during the experimental period (60 min). The anabolic effect of repetitive SM-130686 administration was studied in rats. Rats received 10 mg/kg SM-130686 orally twice a day and were weighed every day for 9 days. At day 9 there was a significant increase in both the body weight and the fat free mass (19.5+/-2.1 and 18.1+/-7.5 g respectively). Serum IGF-I concentration was also significantly elevated 6 h after the last dose of SM-130686. An endogenous GHS ligand for the GHS receptor has recently been identified from stomach extract and designated as ghrelin. The GH-releasing activity in vitro relative to ghrelin (100%) was about 52% for SM-130686. It is likely that SM-130686 is a partial agonist for the GHS receptor. In summary, we describe here an orally active GHS, SM-130686, which acts through the GHS receptor. Repetitive administration of SM-130686 to rats, similar to repetitive administration of GH, significantly increased the fat free mass by an amount almost equal to the gain in body weight.

Administration, Oral↗

PubMed2001

[Survey of vaccination for physically-handicapped and epileptic children].

We studied immunization for 128 handicapped patients, from 3 to 15 years of age, in a Seishi Gakuen Hospital, with 8 vaccines: diphtheria-purified acellular pertussis-tetanus combined (DPT), BCG, polio, measles, rubella, mumps, varicella, and Japanese B encephalitis. The rate of vaccination in these patients was lower than in healthy children at 3 years of age in Kanazawa City. There was no significant difference between patients with and without epilepsy. The rate was higher in the hospitalized patients than in the outpatients. More than 90% of the hospitalized patients was immunized against influenza under informed consent in 1997 and 1998. Despite pandemics of influenza in Kanazawa City, where the hospital was located, the period of fever by influenza was significantly shorter in our patients in both 1997 and 1998 than in 1996. Although a half of our patients had epilepsy, they were safely vaccinated with few side effects.

Adolescent↗

PubMed2001

[A case of primary adenocarcinoma of the female urethra].

A 53-year-old female visited our hospital with a complaint of acute urinary retention. Transvaginal ultrasonography, computed tomography and magnetic resonance imaging showed extreme thickening of the urethral wall. Histopathological examination of the transvaginal needle biopsy suggested well-differentiated adenocarcinoma. She underwent total cysto-urethrectomy with partial vaginal wall resection and ileal conduit urinary diversion. Pathological diagnosis of the tumor was columnar adenocarcinoma invading into the vaginal wall and periurethral connective tissue. Fifty-eight cases of primary adenocarcinoma of the female urethra in the Japanease literature are briefly reviewed.

Adenocarcinoma↗

PubMed2001

Comparison of [(18)F]FDG PET and (201)Tl SPECT in evaluation of pulmonary nodules.

UNLABELLED: Recent reports have indicated the value of [(18)F]FDG PET and (201)Tl SPECT in diagnosing lung cancer. In this study, we compared the diagnostic value of FDG PET and (201)Tl SPECT in the evaluation of pulmonary nodules. METHODS: Sixty-three patients with 66 pulmonary nodules suspected to be lung cancer on the basis of chest CT were examined by FDG PET and (201)Tl SPECT (early and delayed scans) within a week of each study. For semiquantitative analysis, the standardized uptake value (SUV) or the tumor-to-nontumor activity ratio (T/N) (or both) was calculated. All of these lesions were completely removed thoracoscopically or by thoracotomy and were examined histologically. RESULTS: Fifty-four nodules were histologically confirmed to be malignant tumors, and 12 were benign. Both techniques delineated focal lesions with an increase in tracer accumulation in 41 of 54 lung cancers. (201)Tl SPECT on early or delayed scans (or both) identified 4 additional lung cancers that FDG PET images did not reveal: 3 bronchioloalveolar carcinomas and a well-differentiated adenocarcinoma. FDG PET identified 3 additional lung cancers that (201)Tl SPECT images did not reveal; 2 of these lung cancers were <2 cm in diameter. The mean FDG SUV and T/N of bronchioloalveolar carcinomas (2.06 +/- 0.76 and 3.49 +/- 1.03, respectively) were significantly lower than those of poorly differentiated adenocarcinomas (5.55 +/- 2.01 [P = 0.026] and 8.23 +/- 2.16 [P = 0.01], respectively). However, no significant difference was found in (201)Tl T/N on early and delayed scans between bronchioloalveolar carcinomas (1.64 +/- 0.29 and 1.87 +/- 0.42, respectively) and poorly differentiated adenocarcinomas (1.58 +/- 0.32 and 2.76 +/- 1.36, respectively). Of the 12 benign nodules, FDG PET and (201)Tl SPECT showed false-positive results for the same 7 benign nodules (58.3%) (4 granulomas, 1 sarcoidosis, 1 inflammatory pseudotumor, and 1 aspergilloma). Negative FDG PET findings and positive (201)Tl SPECT findings were obtained only for bronchioloalveolar carcinomas or a well-differentiated adenocarcinoma but not for other histologic types of lung cancers or benign pulmonary nodules. CONCLUSION: No significant difference was found between FDG PET and (201)Tl SPECT in specificity for the differentiation of malignant and benign pulmonary nodules. The degree of differentiation of lung adenocarcinoma correlated with FDG uptake but not with (201)Tl uptake. Bronchioloalveolar carcinoma (a well-differentiated, slow-growing tumor) findings typically were positive with (201)Tl but were negative with FDG. The combination of FDG PET and (201)Tl SPECT may provide additional information regarding the tissue characterization of pulmonary nodules.

Adenocarcinoma↗

PubMed2000

Anomalous substituent effects in the bischler-napieralski reaction of 2-aryl aromatic formamides

Treatment of some 1-naphthylformamides (or formanilides) possessing a 2,4,5-trioxygenated phenyl substituent at the 2-position with POCl(3) caused an unprecedented carbon insertion reaction into a benzene ring, producing 7-5 ring (azaazulene) systems as valence isomers of isoquinoline skeletons. Precise examination of this abnormal Bischler-Napieralski reaction (BNR) using various substrates led to the following scope and limitations: (i) the 7-5 ring systems were constructed when either 2-alkoxy-4, 5-methylenedioxyphenyl- or 4,5-dialkoxy-2-hydroxyphenyl-substituted formamides were used as a starting substrate; (ii) in the former case the formyl carbon was inserted into the C(1)-C(6) bond of the 2-phenyl group, and normal isoquinoline cyclization competed with an abnormal carbon insertion reaction; (iii) the presence of a hydroxy group at the 2'-position as in the latter cases caused exclusive carbon insertion, in which alternative C(1)-C(2) insertion products were quantitatively formed; (iv) 3, 6-dimethoxy-2-hydroxyphenyl-substituted formanilide electronically equivalent to 4,5-dialkoxy-2-hydroxy derivatives produced an indole-pyrone as an abnormal BNR product. Theoretical approaches using the PM-3 method indicated that these abnormal BNRs could be triggered by ipso attack at the 1'-position yielding spiro intermediates. Ring cleavege of the six-membered ring in the spiro intermediates to a ketene function followed by recyclization was proposed for the 2'-hydroxy-directed abnormal BNRs leading to the C(1)-C(2) insertion product or the indole-pyrone derivative.

Journal Article↗

PubMed2000

Modified guanidines as potential chiral superbases. 2. Preparation Of 1,3-unsubstituted and 1-substituted 2-iminoimidazolidine derivatives and a related guanidine by the 2-chloro-1, 3-dimethylimidazolinium chloride-induced cyclization of thioureas

Simple preparation methods for modified guanidines were explored for new chiral superbases. Thus, (4S,5S)-4,5-diphenyl- and diastereomeric cyclohexane-fused 2-iminoimidazolidines were prepared from (1S,2S)-1,2-diphenylethylenediamine and (1R,2R)- or (1S,2S)-1, 2-diaminocyclohexanes through cyclization of protected thiourea intermediates with 2-chloro-1,3-dimethylimidazolinium chloride (DMC) as a key reaction. In the (4S,5S)-4,5-diphenyl series 1-methyl-2-iminoimidazolidines and 2-diethylaminoimidazoline were also prepared as related guanidines.

Journal Article↗

PubMed2000

Modified guanidines as potential chiral superbases. 3. Preparation Of 1,4,6-triazabicyclooctene systems and 1,4-disubstituted 2-iminoimidazolidines by the 2-chloro-1,3-dimethylimidazolinium chloride-induced cyclization of guanidines with a hydroxyethyl substituent

Simple preparation methods of modified guanidines have been explored as potential chiral superbases. Thus, 3,7,8-trisubstituted and 3,6,7, 8-tetrasubstituted 1,4,6-triazabicyclooctene systems were prepared from (1S,2S)-1,2-diphenylethylenediamine through stepwise 2-chloro-1, 3-dimethylimidazolinium chloride (DMC)-induced cyclizations of protected thioureas to the corresponding 2-iminoimidazolidines and then of 2-(2-hydroxyethylimino)imidazolidines to the bicyclic systems. Linear guanidines with a 2-hydroxyethyl functional group were prepared by the reaction of carbodiimides with 2-amino alcohols. Reaction of linear-type guanidines with DMC followed by base treatment afforded 1,4-disubstitued 2-iminoimidazolidines. Furthermore, another type of 1,4,6-triazabicyclooctene was also prepared through double DMC-induced cyclization of guanidines with two 2-hydroxyethyl substituents.

Journal Article↗

PubMed2000

Biosorption of Heavy Metal Ions to A Marine Microalga, Heterosigma akashiwo (Hada) Hada.

A fundamental study of the application of marine microalga to the aqueous-phase separation of toxic heavy metals was carried out. The biosorption characteristics of cadmium and lead ions were determined with marine microalga, Heterosigma akashiwo (Hada) Hada, which was inactivated by steam sterilization. A simple metal-binding model was used for the description of metal-binding data. The results showed that the biosorption of bivalent metal ions to H. akashiwo was due to monodentate binding to two different types of acidic sites: carboxylic- and phosphatic-type sites. Copyright 2000 Academic Press.

Journal Article↗

PubMed2000

Immunostained cathepsins B and L correlate with depth of invasion and different metastatic pathways in early stage gastric carcinoma.

BACKGROUND: With the recent development of minimal treatment for early stage gastric carcinoma, identifying specific indicators of the metastatic potential of primary tumors has become more important. Cathepsin B and cathepsin L, both lysosomal cysteine proteases, degrade the extracellular matrix during tumor progression. Although many studies have shown their relation to human cancer progression, little is known about their roles in the early stage. The clinicopathologic significance of cathepsins was therefore studied in early stage gastric carcinoma. METHODS: Expression of both cathepsins was studied immunohistochemically in 51 tissue specimens from gastric carcinomas that invaded the submucosal layer or muscularis propria. The relation between their expression and clinicopathologic factors was analyzed. RESULTS: Both cathepsins were expressed at higher levels in tumors that invaded the muscularis propria than in those within the submucosa (P < 0.05). In addition, tumors with lymphatic invasion showed higher cathepsin B expression than those without it (P < 0.05), whereas tumors with venous invasion showed higher cathepsin L expression than those without it (P < 0.05). No other clinicopathologic factors correlated with expression of either cathepsin. CONCLUSIONS: Tumors with overexpression of cathepsins have powerful potential for invasiveness in the early stage of gastric carcinoma. Moreover, the authors hypothesize that cathepsins may be one of the determinants of the metastatic route. To the authors' knowledge, this is the first report on specific proteases concerning the mode of metastasis, and the results of this study suggest that therapeutic strategies for early stage gastric carcinoma might need to be changed according to the status of cathepsins.

Adult↗

PubMed2000

Adsorption of Water-Soluble Proteins onto Bubbles in Continuous Foam Separation.

The mechanism of water-soluble protein enrichment in continuous foam separation was studied. The liquid flow rate and the protein concentration in the foam phase were measured at various heights from the interface between the bulk liquid and foam layer, and the intrinsic values at the interface were estimated by the extrapolation method to determine the accurate adsorption density on the bubble surface. Ovalbumin (OA) and hemoglobin (HB) were used as the soluble proteins. The solution pH values were varied from 3.5 to 6.0 for OA and from 6.0 to 8.0 for HB. The experimental isotherms for OA and HB were compared to the Langmuir isotherm, and the two adsorption parameters of the equilibrium constant, K, and the saturated density, gamma, at each pH were determined. Both gamma values obtained for OA and HB showed maxima at their isoelectric point (pH 4.6 for OA and pH 6.8 for HB). Assuming that OA and HB molecules are spherical in shape and are adsorbed on the bubble surface in a close-packed structure at saturation, the calculated diameters for OA and HB molecules were quite similar to the literature values. The variation in gamma for both OA and HB is discussed qualitatively in relation to the net charge of the protein molecule. Copyright 2000 Academic Press.

Journal Article↗

PubMed2000

Multiple telescoping anastomosis on an artery.

The telescoping anastomotic technique was carried out four times on the rat femoral artery in order to examine whether the technique could safely be used three to four times for repair of an artery that was injured at two different sites. In addition, the technique was repeated five and six times to determine the maximum number of anastomosis that could be performed on an artery and to clarify problems of the telescoping anastomosis. In the rats in which the anastomosis was carried out four and five times, 100% patency was obtained, while the first occlusion occurred in a graft on which the anastomosis was repeated six times. The telescoping technique appeared to safely be used three or four times for repair of an artery that had been divided at two sites if tension of the repaired vessel was kept low by the grafting, and torsion of the graft and deformities of the inserted vessel were minimal.

Animals↗

PubMed2000

Ectopic calcification following tibial fracture: property analysis.

We present a patient whose ectopic calcification following deep posterior compartment syndrome was studied by electron microscopy, chemical analyses, and X-ray diffraction. The patient complained of a toe flexion deformity following a tibial fracture which he sustained 18 years earlier. Damage to the peroneal artery was demonstrated by magnetic resonance angiography, suggesting that the patient had had deep posterior compartment syndrome in the past. A large radiopaque mass, identified in the flexor hallucis longus muscle by radiographs and computed tomography, was resected, resulting in a dramatic improvement of the toe deformity. The resected material was analyzed in detail. It included no osseous tissue, and was not birefringent under a polarizing microscope, being compatible with ectopic calcification rather than ossification. On electron microscopy the material was found to be an assembly of tiny rods. Chemical and X-ray diffraction analyses suggested a carbonate-containing apatite as the most probable substance.

Adult↗

PubMed2000

Acylated delphinidin 3-rutinoside-5-glucosides in the flowers of Petunia reitzii.

Two acylated anthocyanins were isolated from selected individuals of Petunia reitzii, and identified to be delphinidin 3-O-[6-O-(4-O-(4-O-(6-O-(trans-caffeoyl)-beta-D-glucopyranosyl)-tr ans-p-coumaroyl)-alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside]- 5-O-[beta-D-glucopyranoside] and delphinidin 3-O-[6-O-(4-O-(4-O-(beta-D-glucopyranosyl)-trans-p-coumaroyl)-alph a-L-rhamnopyranosyl)-beta-D-glucopyranoside]-5-O-[beta-D-glucopyranoside ]. Nine known anthocyanins were also identified.

Acylation↗

PubMed2000

Differences in the floral anthocyanin content of red petunias and Petunia exserta.

In order to resolve a conflict between previous papers regarding the floral anthocyanins of red flowers of Petunia exserta, a naturally occurring species, the HPLC profile of this species was compared with that of commercial red garden petunias. Both HPLC profiles extremely superficially resemble each other in terms of relative amounts and retention times of the major anthocyanins. However, co-elution on HPLC of the mixed sample resulted in clear separation of the components. Three major anthocyanins in red petunias were determined to be cyanidin 3-sophoroside, cyanidin 3-glucoside and peonidin 3-glucoside, which exhibited similar behaviors on HPLC to delphinidin 3-glucoside. delphinidin-3-rutinoside and petunidin 3-rutinoside, respectively, the major floral anthocyanins of P. exserta.

Anthocyanins↗

PubMed2000

Ecological adaptation and acclimatization of natural freshwater phytoplankters with a nutrient gradient.

Ecological adaptation and acclimatization of natural phytoplankters within a nutrient gradient were studied in an oligotrophic pond with special reference to the diel fluctuations of cell volumes and frequency of dividing cells (FDC) at each season using an in situ gradostat. The predominant phytoplankters (Cryptomonas ovata in spring and autumn, Crucigenia rectangularis in summer and Chlamydomonas elongus in winter) exhibited moderately phased division during each season. These diel cycles could be regressed onto a sine curve to give a highly significant fit. The diel patterns in all gradostat chambers and periods were almost the same except for slight variations in the FDC. This shows that the diel pattern of cell division was governed mainly by the light:dark cycle during the 24 h, without regard to trophic differences of the aquatic environment. The mean growth rates of most phytoplankters were higher in the mesotrophic zone than in the eutrophic zone during each season. In winter, the growth rate of Chlamydomonas elongus was evidently greater during the seventh day of the experiment (Period III) than during the first day (Period I) in the mesotrophic chamber. As Chlamydomonas species occur as mesotrophic species in natural waters, Chlamydomonas elongus must acclimatize easily from the oligotrophic habitat to the mesotrophic environmental condition.

Journal Article↗