Biomedical subjects

K Komatsu

Publications and source records attributed to K Komatsu.

At least 109 records · Page 6Linked to original sources

PubMed2000

Increased expression of S100A6 at the invading fronts of the primary lesion and liver metastasis in patients with colorectal adenocarcinoma.

Two members of the S100 gene family, S100A6 and S100A4 have been suggested to be associated with cancer invasion and metastasis. To study their involvement in the malignancy of human colorectal adenocarcinoma, we examined the protein expression levels of S100A6 and S100A4 in the primary colorectal adenocarcinoma (T) and paired adjacent normal colorectal mucosa (N) from 12 cases, quantitatively by Western blot analysis. In 11 of 12 and seven of 12 cases, S100A6 and S100A4 expression levels were higher in T than in N, respectively. Average S100A6 level in T was significantly higher than in N (about x 2.3;P = 0.001), whereas average S100A4 level in T was not. When S100A6 expression levels in three sets of matched samples of primary colorectal adenocarcinoma (T) and liver metastasis (M) were examined, S100A6 levels were higher in M than in T in two of three cases. Immunohistochemical analysis using monoclonal anti-S100A6 antibody showed that 23 of 42 (55%) primary colorectal adenocarcinoma and 15 of 16 (94%) liver metastasis specimens were positively stained. S100A6 immunostaining of primary colorectal adenocarcinomas was significantly more intense in the invading fronts with structural atypia than in central portions with glandular structure (P< 0.0001), whereas Ki-67 staining (a growth marker) was similar in these two portions. Interestingly, S100A6 and Ki-67 immunostaining patterns in liver metastases were also the same as in primary lesions. These results suggest that S100A6 is involved in the invasive process of human colorectal adenocarcinomas and that S100A6 expression levels decrease when carcinoma cells form glandular structure again at the central portions of metastatic nodules.

Adenocarcinoma↗

PubMed2000

Genetic heterogeneity of ribosomal RNA gene and matK gene in Panax notoginseng.

Previously, 185 ribosomal RNA gene and matK gene sequences of Chinese herbal medicines, Ginseng Radix, Panacis Japonici Rhizoma and Panacis Quinquefolli Radix were shown to correspond with those of the original plants, Panax ginseng, P. japonicus and P. quinquefolius, respectively, with the species-specific sequences especially for 18S rRNA gene sequences. In P. notoginseng and its derivative, Notoginseng Radix, however, we found two genetic groups with respect to both gene sequences. Five base substitutions were detected on both gene sequences and the homology between two groups was 99.7% for the 18S rRNA gene and 99.6% for the matK gene, respectively. One genetic group was found to have the identical sequences as those of P. ginseng.

Genetic Heterogeneity↗

PubMed2000

Serum levels of soluble IL-2 receptor, IL-12, IL-18, and IFN-gamma in patients with acute graft-versus-host disease after allogeneic bone marrow transplantation.

BACKGROUND: Acute graft-versus-host disease still represents the major factor that limits successful allogeneic bone marrow transplantation. Cytokines released by type 1 T-helper cells are thought to play a pivotal role in acute graft-versus-host disease. OBJECTIVE: This study was performed to investigate whether the serum levels of soluble IL-2 receptor, IL-12, IL-18, and IFN-gamma were associated with the manifestation of acute graft-versus-host disease. METHODS: Serum cytokine levels were measured by sandwich ELISA in 18 patients who underwent allogeneic bone marrow transplantation. RESULTS: Serum levels of soluble IL-2 receptor, IL-12, IL-18, and IFN-gamma were increased in patients in whom acute graft-versus-host disease developed. However, only serum soluble IL-2 receptor levels were significantly related to disease severity. Serum levels of IL-12 and IL-18, both of which are mainly produced by activated macrophages, were increased in different phases of acute graft-versus-host disease, especially grade I. Serum levels of soluble IL-2 receptor and IFN-gamma were significantly elevated in patients with fever. CONCLUSION: Serum levels of soluble IL-2 receptor were more closely related to the severity of acute graft-versus-host disease than those of IL-12, IL-18, and IFN-gamma.

Acute Disease↗

PubMed2000

Brief communication: heat-induced accumulation of p53 and hsp72 is suppressed in lung fibroblasts from the SCID mouse.

PURPOSE: To investigate how DNA-dependent protein kinase (DNA-PK) contributes to p53-dependent signal transduction after heat shock, thermosensitivity and accumulation of p53 and hsp72 after heat shock in lung fibroblasts derived from the SCID mouse were analysed. MATERIALS AND METHODS: Thermosensitivity at 44 degrees C in colony-forming units and Western blot analysis of p53 and hsp72 were analysed. RESULTS: The results indicated that (1) the thermosensitivity at 44 degrees C of SCID cells was higher than that of parental cells and (2) heat-induced accumulation of p53 and hsp72 was abolished and suppressed in SCID cells as compared with that in parental cells respectively. CONCLUSIONS: The findings suggest that the catalytic subunit of DNA-PK may play an important role upstream of p53 and hsp72, which are possible determinants of cellular thermosensitivity.

Animals↗

PubMed2000

Improvement of ischaemia-reperfusion injury by lazaroid U74389G in rat lung transplantation model.

The effect of lazaroid 74389G on ischaemia-perfusion injury in a rat lung transplantation model was investigated using three administration methods. In all groups, the University of Wisconsin (UW) solution was used as a flush and preservation solution at 4 degrees C, and lungs were stored for 12 h. Group I rats (controls) were not given any lazaroid treatment. In group II, lazaroid U74389G was added to the UW solution (100 micromol/l). In group III, lazaroid (10 mg/kg) was intravenously injected in the donors 30 min before lung ischaemia. Group IV received lazaroid treatment by the combined methods of groups II and III. In all the experimental groups (II-IV), recipient rats were given lazaroid (6 mg/kg) intravenously 30 min before reperfusion. Lazaroid improved the gas exchange function (groups II, III and IV), reduced the tissue lipid peroxides (group II) and ameliorated histologic lung damage (group II). The results thus seemed to be better in group II than in groups III and IV.

Animals↗

PubMed2000

Pressor responses to serotonin injected into the nucleus tractus solitarius of Sprague-Dawley rats and spontaneously hypertensive rats.

Previous studies in rats have shown that injection of nanomoles of serotonin (5-hydroxytryptamine; 5HT) into the nucleus tractus solitarius (NTS) acts on 5HT3 receptors to increase arterial pressure (AP). We investigated the effect of 5HT in Sprague-Dawley (SD) rats and in spontaneously hypertensive rats (SHR). Injection of nanomoles of 5HT into the NTS of chloralose-anesthetized SD rats increased AP. This effect was inhibited by prior injection of 5HT3 receptor antagonist ondansetron. The GABA(A) receptor antagonist bicuculline did not inhibit the effect of 5HT. Bilateral injection of 5HT or ondansetron did not affect the baroreflex sensitivity. Bilateral injection of ondansetron did not alter AP. The pressor effect of 5HT was exaggerated in SHR. These results suggest that stimulation of 5HT3 receptors in the NTS increases AP independently of activation of GABAA receptors and the baroreflex sensitivity. Furthermore, this serotonergic system is supersensitive in the NTS of SHR.

Animals↗

PubMed2000

Stress-induced factor involved in flower formation of Lemna is an alpha-ketol derivative of linolenic acid.

A stress-induced substance(s) (factor C) incubated with norepinephrine (NE) has strong flower-inducing activity in Lemna paucicostata. We isolated an essential component (FIF) of factor C, and clarified its chemical structure as 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid, an alpha-ketol derivative of linolenic acid, which is formed via 9-hydroperoxy linolenic acid. Synthesized FIF showed flower-inducing activity after incubation with NE (factor C activity) equivalent to that formed in the stressed Lemna. Jasmonic acid and 13-hydroxy-12-oxo-9(Z),15(Z)-octadecadienoic acid (12,13-alpha-ketol linolenic acid), both of which are formed via 13-hydroperoxide of linolenic acid and all other derivatives of FIF synthesized by chemical and enzymatic processes failed to show the factor C activity. These results suggest that the molecular structure of FIF is very specific for the factor C activity.

Fatty Acids, Unsaturated↗

PubMed2000

GABAergic contribution to rat bladder hyperactivity after middle cerebral artery occlusion.

To evaluate the influences of gamma-aminobutyric acid (GABA) mechanisms on bladder hyperactivity after left middle cerebral artery occlusion, cystometric recordings were obtained from unanesthetized female rats. Intracerebroventricular administration of both muscimol (GABA(A) receptor agonist; 0.1-10 nmol) and baclofen (GABA(B) receptor agonist; 0.1-3 nmol) produced dose-dependent inhibitions of micturition with increases in bladder capacity (BC). The effects of high doses (1-10 nmol) were similar in sham-operated (SO) and cerebral-infarcted (CI) rats. However, lower doses of muscimol (0.1 or 0.3 nmol) and baclofen (0.1 nmol) reduced BC in CI rats. After bicuculline (GABA(A) receptor antagonist; 1 or 3 nmol) administration, BC in both SO and CI rats first decreased and subsequently increased. An increase in urethral pressure was observed after administration of bicuculline (3 nmol) but not with either muscimol or baclofen. Infarct volumes in muscimol-, bicuculline-, or baclofen-treated rats were not significantly different from those of vehicle-treated rats. These results suggest that GABAergic mechanisms inhibit the micturition reflex at the supraspinal level but that this can change as a result of CI.

Animals↗

PubMed2000

Juxtaglomerular cell tumor of the kidney treated with nephron-sparing surgery.

A case of juxtaglomerular cell tumor of the right kidney is reported. A 30-year-old woman visited us with a complaint of headaches. Severe hypertension and an elevated level of plasma renin activity was seen at the initial evaluation. Computerized tomographic angiography revealed tumor vessels in the low-density mass in the right kidney. The preoperative diagnosis was renin-secreting tumor of the kidney, and nephron-sparing surgery was performed. The pathological findings showed a juxtaglomerular cell tumor. Postoperatively, prompt normalization of blood pressure and a reduced plasma renin activity level were observed.

Adenocarcinoma↗

PubMed2000

Excitatory amino acids in the rostral ventrolateral medulla support blood pressure in spontaneously hypertensive rats.

Injection of the excitatory amino acid (EAA) antagonist kynurenic acid (KYN) into the rostral ventrolateral medulla (RVLM) of anesthetized rats has no effect on arterial pressure. However, we recently reported that after inhibition of the caudal ventrolateral medulla, injection of KYN into the RVLM decreased arterial pressure to the same level as produced by complete inhibition of the RVLM. We have suggested that these results reflect tonically active EAA-mediated inputs to the RVLM producing both direct excitation of RVLM vasomotor neurons and indirect inhibition of these neurons. On the basis of this model, we hypothesize that the balance between these EAA-driven direct excitatory and indirect inhibitory influences on the RVLM may be altered in models of experimental hypertension. To begin to test this hypothesis, the effects of injecting KYN into the RVLM of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were compared. In chloralose-anesthetized WKY, bilateral injection of KYN into the RVLM did not alter arterial pressure, whereas similar injections in SHR reduced mean arterial pressure by approximately 40 mm Hg. After inhibition of the caudal ventrolateral medulla, which similarly increased arterial pressure in both strains, injection of KYN into the RVLM reduced mean arterial pressure to the same level as produced by autonomic blockade. These results suggest that the balance of excitatory and inhibitory influences on RVLM vasomotor neurons driven by tonically active EAA-mediated inputs to the RVLM is disrupted in SHR and may contribute to the hypertension in SHR.

Animals↗

PubMed2000

Bond strength of resin to acid-etched dentin studied by 13C NMR: interaction between N-methacryloyl-omega-amino acid primer and dentinal collagen.

The application of the hydrophilic methacrylate primer to acid-etched dentin increases the bond strength of the resin to the acid-etched dentin. However, the mechanism for the bonding of the resin to dentinal collagen through the primer remains to be determined. Before a more effective adhesive primer can be developed, we must understand the adsorption behavior of the primer to the dentinal collagen. The purpose of this study was to determine how 5 derivatives of N-methacryloyl-omega-amino acid (NMomegaA) primers enhance the bonding of the resin to acid-etched dentin. The interaction between the NMomegaA primers and dentinal collagen was studied by the 13C NMR technique, including the observation of spin-lattice relaxation times, T1. When the dentinal collagen was dispersed into the NMomegaA solution, the T1 values of the two carbonyl carbons attributed to the amide and the carboxylic acid in the NMomegaA molecule decreased dramatically. This result was due to the interaction between the amide group and the carboxylic acid group in the NMomegaA molecule and the dentinal collagen molecule. The T1 values of these carbonyl carbons decreased when the number of methylene groups in the NMomegaA molecule increased. The interaction became stronger as the number of methylene groups in the NMomegaA molecule was increased. Further, the bond strength of the resin to the acid-etched dentin primed with NMomegaA increased with a decrease in the T1 value of the amide carbonyl carbon. The strength of the interaction of the NMomegaA primer to the dentinal collagen molecule, determined by the 13C NMR technique, showed a direct correlation with the bond strength of the resin to acid-etched dentin that was treated with the NMomegaA primer.

Acid Etching, Dental↗

PubMed2000

Inhibitory effects of methanol extracts of herbal medicines on substance P-induced itch-scratch response.

In a search for new anti-pruritic drugs we screened methanol extracts of 33 herbal medicines which have been used for cutaneous diseases for their antipruritic activity using substance P (SP) as a pruritogen in mice. When administered perorally 30 min before SP injection, methanol extracts of 6 of these herbal medicines, the root of Scrophularia ningpoensis Hemsl., the root of Patrinia villosa (Thunb.) Juss, the fruit of Forsythia suspenna Vahl, the rhizome of Cimicifuga dahurica (Turcz.) Maxim., the aerial part of Schizonepeta tenuifolia Briq. and the fruit of Cnidium monnieri (L.) Cuss, inhibited SP-induced itch-scratch response at a dose of 200 mg/kg with-out affecting locomotor activity. Dose dependence of these 6 extracts (50-500 mg/kg) was investigated and all of them inhibited SP-induced itch-scratch response, with extracts from Scrophularia ningpoensis, Schizonepeta tenuifolia and Cnidium monnieri showing particularly significant inhibition. The results suggest that these 6 methanol extracts have inhibitory activity against SP-induced itching.

Animals↗

PubMed2000

Paradoxical progression of biliary strictures against recovery of biochemical parameters under ursodeoxycholic acid treatment in a case of primary sclerosing cholangitis with ulcerative colitis.

Ursodeoxycholic acid (UDCA) treatment for primary sclerosing cholangitis (PSC) has been considered a rational therapy, though its effectiveness in the clinical course is still open to discussion. In this report, we describe a 22-year-old man with PSC at an early stage, which was associated with ulcerative colitis (UC). He showed progressive strictures of bile ducts over a 1.5-year period in spite of an improvement in the biochemical parameters by UDCA treatment. Therefore, care should be taken in interpreting the effectiveness of UDCA, because the biochemical parameters may not change in parallel with the clinical course of PSC.

Adult↗

PubMed2000

Development of a digital image database for chest radiographs with and without a lung nodule: receiver operating characteristic analysis of radiologists' detection of pulmonary nodules.

OBJECTIVE: We developed a digital image database (www.macnet.or.jp/jsrt2/cdrom_nodules.html ) of 247 chest radiographs with and without a lung nodule. The aim of this study was to investigate the characteristics of image databases for potential use in various digital image research projects. Radiologists' detection of solitary pulmonary nodules included in the database was evaluated using a receiver operating characteristic (ROC) analysis. MATERIALS AND METHODS: One hundred and fifty-four conventional chest radiographs with a lung nodule and 93 radiographs without a nodule were selected from 14 medical centers and were digitized by a laser digitizer with a 2048 x 2048 matrix size (0.175-mm pixels) and a 12-bit gray scale. Lung nodule images were classified into five groups according to the degrees of subtlety shown. The observations of 20 participating radiologists were subjected to ROC analysis for detecting solitary pulmonary nodules. Experimental results (areas under the curve, Az) obtained from observer studies were used for characterization of five groups of lung nodules with different degrees of subtlety. RESULTS: ROC analysis showed that the database included a wide range of various nodules yielding Az values from 0.574 to 0.991 for the five categories of cases for different degrees of subtlety. CONCLUSION: This database can be useful for many purposes, including research, education, quality assurance, and other demonstrations.

Adult↗

PubMed2000

Increased expression of S100A6 (Calcyclin), a calcium-binding protein of the S100 family, in human colorectal adenocarcinomas.

The expression of S100A6 (also known as Calcyclin/2A9/ 5B10/PRA) in surgically resected human colorectal adenocarcinomas was examined to investigate whether S100A6 plays a role in the malignancy of human tumor cells. Western blot analysis using the lysates from colorectal adenocarcinomas and adjacent normal mucosa from 10 patients revealed that the average S100A6 level of adenocarcinomas was significantly higher (about 2.4-fold) than that of normal mucosa. Immunohistochemical analysis using formalin-fixed paraffin-embedded surgical specimens and monoclonal anti-S100A6 antibody (mAbA6) demonstrated that 2(5%) of 42 normal mucosa and 6 (46%) of 13 adenoma specimens were mAbA6-positive and showed granular staining localized at the supranuclear regions of epithelial cells, whereas 23 (55%) of 42 adenocarcinomas and 13 (100%) of 13 carcinoma cells that metastasized to the liver were mAbA6-positive and showed diffuse cytoplasmic staining. A significant correlation between S100A6 expression and Dukes' tumor stage or lymphatic permeation but not with other clinicopathological factors was shown. S100A6 was stained more intensely in peripheral portions than in central portions of adenocarcinomas, whereas Ki-67 (a growth marker) was stained equally in these two portions. These results suggest that S100A6 may be involved in the progression and invasive process of human colorectal adenocarcinomas.

Adenocarcinoma↗

PubMed2000

Prediction of in vivo drug-drug interactions between tolbutamide and various sulfonamides in humans based on in vitro experiments.

Drug-drug interactions between tolbutamide and sulfonamides have extensively been reported. We attempted to predict the in vivo interaction between tolbutamide and sulfonamides from the in vitro metabolic inhibition studies. The inhibition constant (K(i)) was derived from the inhibitory effects of eight sulfonamides (sulfaphenazole, sulfadiazine, sulfamethizole, sulfisoxazole, sulfamethoxazole, sulfapyridine, sulfadimethoxine, and sulfamonomethoxine) on tolbutamide metabolism. We found that the inhibitory effect of sulfaphenazole was greatest among the eight sulfonamides examined. Furthermore, the contribution of each P450 enzyme to tolbutamide metabolism was investigated by using recombinant P450 enzymes. Although cytochrome P450 (CYP) 2C8, 2C9, and 2C19 metabolized tolbutamide, the main enzyme involved was CYP2C9. The K(i) values of several sulfonamides were comparable between human liver microsomes and recombinant CYP2C9. The maximum unbound plasma concentration of sulfonamides in the portal vein was calculated from literature data on the pharmacokinetics of sulfonamides. Using the K(i) values obtained from in vitro inhibition studies, the degree of increase in tolbutamide area under the plasma concentration-time curve (AUC) was predicted. About 4.8- and 1.6-fold increases in tolbutamide AUC were predicted by coadministration of sulfaphenazole and sulfamethizole, respectively, which agreed well with the reported increases in humans. Furthermore, the increase in tolbutamide AUC by coadministration of sulfadiazine, sulfisoxazole, and sulfamethizole was predicted to be 1.5- to 2. 6-fold, although the corresponding in vivo effects have not been reported. It is concluded that some of these sulfonamides have to be carefully coadministered with CYP2C9 substrates such as tolbutamide although coadministration of sulfaphenazole needs the greatest care.

Adult↗

PubMed2000

[Primary AA type amyloidosis of the urinary bladder: a case report].

Primary amyloidosis of the urinary bladder is a rare disease entity. A total of 61 cases have been reported in the Japanese literature, and most of them were AL type amyloidosis. We report here a case of primary AA type amyloidosis. A 52-year-old man presented with a chief complaint of asymptomatic gross hematuria. Cystoscopy revealed yellowish elevated lesions, transurethral mucosal biopsies were performed, and the histopathological diagnosis indicated a primary AA type amyloidosis of the urinary bladder. Systemic amyloidosis was clinically eliminated. The yellowish lesions in the bladder through cystoscopy disappeared spontaneously one year later without any specific treatment, but periodical work-up may be necessary to rule out recurrence of the disease or bladder tumor.

Amyloidosis↗

PubMed2000

Effects of aniracetam on bladder overactivity in rats with cerebral infarction.

Aniracetam has been used to improve the mental condition of patients with cerebrovascular disease. Previous studies have demonstrated that aniracetam activates the residual functions of cholinergic neurons in damaged brain areas. In this study, the effects of aniracetam on bladder overactivity after left middle cerebral artery occlusion were assessed through oral or i.c.v. administration in sham-operated and cerebral infarcted rats. Oral administration of aniracetam (100 and 300 mg/kg) resulted in a significant and dose-dependent increase in bladder capacity in cerebral infarcted rats but had no effect on bladder capacity in sham-operated rats. Intracerebroventricular administration of aniracetam (0.25 and 2.5 microg/rat) resulted in a significant and dose-dependent increase in bladder capacity in cerebral infarcted rats but not in sham-operated rats. Aniracetam had no significant effect on bladder contraction pressure or micturition threshold pressure in either sham-operated or cerebral infarcted rats. Furthermore, i.c.v. administration of atropine (1 microg/rat), a muscarinic acetylcholine receptor antagonist, completely inhibited the enhancing effects of aniracetam on bladder capacity in cerebral infarcted rats. The effects of aniracetam on bladder overactivity are thought to be mediated in part by activation of cholinergic inhibitory mechanisms in the brain. These results indicate that aniracetam may improve the neurogenic voiding dysfunction observed in patients with cerebrovascular disease.

Animals↗