Biomedical subjects

S Fujimoto

Publications and source records attributed to S Fujimoto.

At least 37 records · Page 2Linked to original sources

PubMed2002

Eating epilepsy characterized by periodic spasms.

Seizures induced by eating are generally considered rare. Eating epilepsy is a kind of reflex epilepsy. We report two patients aged 11 and 16, with seizures provoked by eating. The eating-provoked seizures in both patients were a series of tonic spasms. Both ictal EEGs showed a periodic pattern characterized by diffuse high voltage slow wave. These findings were consistent with periodic spasms described by Gobbi et al. The ECD were widely distributed in both patients, although that of Patient 1 was partially clustered in the right frontal region. This is the first report of patients with periodic spasms induced by eating.

Adolescent↗

PubMed2002

Disorganization of honey-comb immunoreactive pattern of desmin and plectin in rat atrophic soleus muscle fiber induced by hindlimb suspension.

Immunoreactivity for desmin, plectin and alpha-actinin was investigated in rat atrophic soleus muscle fibers induced by hindlimb suspension between 1 and 4 weeks (hindlimb suspension group, HSG), and compared with that of the control group (CG). Some of the HSG for 4 weeks were allowed unrestricted cage activity for 2 weeks as the recovery group (RG). In the cross-sectioned muscle fibers of the CG, desmin and plectin showed honey-comb immunoreactive patterns extending throughout the sarcoplasm. Superimposed images by double immunofluorescence labeling showed overlapping of both immunoreactivities. In the longitudinally sectioned profiles, superimposed images of alpha-actinin and desmin were overlapped at the level of Z-discs. The focal disorganization of the above honeycomb immunoreactive patterns, followed by the reduction of the cross-sectional area (CSA) of atrophic soleus muscle fibers and the appearance of Z-streaming, uniquely arose in the HSG from the first week and extended throughout the sarcoplasm in proportion to the suspension period. Such honey-comb patterns of both desmin and plectin were already restored in the RG at 2 weeks, followed by the disappearance of Z-streaming, prior to the recovery of the CSA. These findings indicate that the disorganization of topological and structural relationships of desmin and plectin with Z-discs surrounding individual myofibrils is primarily evoked, which leads to Z-streaming of atrophic soleus muscle fibers, and that the restoration of the muscle activity results in an early arrangement recovery of desmin and plectin around myofibrils.

Animals↗

PubMed2002

Enhanced expression of endothelin-1 and endothelin-converting enzyme-1 in acute hypoxic rat aorta.

Deeply anesthetized male Wistar rats were perfused by Hanks' balanced salt solution bubbled with either 95%air and 5%CO2 (normoxic group) or 95%N2 and 5%CO2 (hypoxic group) from the thoracic aorta for 30 min, and the isolated abdominal aortae from both groups were used for electron microscopy, immunocytochemistry of endothelin (ET)-1 and ET-converting enzyme (ECE)-1, and in situ hybridization of preproET-1 mRNA. A remarkable increase in the number of Weibel-Palade (WP) bodies, storage sites of ET-1 and ECE-1, occurred in the hypoxic group when compared to the normoxic group. Immunoreactivities for ET-1 and ECE-1, and signals for preproET-1 mRNA were seen along the endothelia of both groups, but the intensities were significantly elevated in the hypoxic group. The increase in the number of ECE-1 immunoreactive gold particles was noticed especially in WP bodies in the hypoxic group. These findings indicate the enhancement of preproET-1 synthesis in the aortic endothelial cells as well as the acceleration of ET-1 processing in increased WP bodies in such cells in an experimentally hypoxic condition of the rat aortae.

Acute Disease↗

PubMed2001

Differential expression of rat brain caspase family proteins during development and aging.

It is well recognized that caspases are essential effector molecules for carrying out apoptosis in eukaryotic cells. The expression of rat brain caspase family proteins (caspase-2, -3, -6, -7, -8, -9, 10) in development and aging was assessed using immunochemical detection. All of these caspases were expressed in the rat brain. Immunoblot analysis of brain extracts from embryonic day 19 (E19) to postnatal 96-week-old rats indicated that cytosolic caspase-3, -7, -8, and -10 were highly expressed at E19, and decreased after birth. In contrast, cytosolic caspase-2, -6, and -9 were constitutively expressed from the early stages to 96 weeks of age. These results show that the expression of rat brain caspase family proteins is differentially regulated during the development and aging.

Aging↗

PubMed2001

Differential subcellular localization of caspase family proteins in the adult rat brain.

The distribution of the caspase family (caspase-2, -3, -6, -7, -8, -9, -10) was assessed using immunochemical detection of subcellular fractions of 8-week-old rat brain tissues. The present study demonstrated that the relative protein level of caspase-2, -3, -6, -8 and -10 was highest in the soluble cytosolic fraction, while that for caspase-9 was highest in the nucleus. We also found that caspase-3 and -6 were present at high levels and caspase-2, -8 and -9 at moderate levels in the nerve endings fraction as well as in the soluble cytosolic fraction. These results suggest that rat brain caspases are differentially expressed in the subcellular fractions of the rat brain, and that caspases not only contribute to the regulation of neuronal death, but also to synaptic plasticity.

Animals↗

PubMed2001

Endothelial nitric oxide synthase gene (NOS3) variant and hypertension in pregnancy.

Hypertension in pregnancy (HP), including preeclampsia, is known to be a multifactorial disease. Recently, a Glu298Asp variant of the endothelial nitric oxide synthase gene (NOS3) was identified as being associated with coronary spasm and myocardial infarction, whereas it has been reported that endothelial nitric oxide synthase plays a role in HP. We therefore performed an association study of the Glu298Asp variant with HP among 152 HP patients and 335 normal pregnant control individuals, in the context of other risk factors before pregnancy. The frequency of the variant GA+AA NOS3 genotypes was significantly higher in the patients (0.23) than in the controls (0.12) (P < 0.01). Multivariate analysis revealed that family history of hypertension, TT genotype of the angiotensinogen gene (AGT), GA+AA NOS3 genotype, and prepregnancy body mass index > or = 24 were independent potent risk factors, after adjustment for maternal age and parity. The odds ratios of the factors were 2.7, 2.3, 2.2, and 2.1, respectively. Our results suggested that the Asp298 of NOS3 is a potent, independent risk factor for HP.

Angiotensinogen↗

PubMed2001

Recovery of function and mass of endogenous beta-cells in streptozotocin-induced diabetic rats treated with islet transplantation.

Islet transplantation corrects chronic hyperglycemia by augmentation of insulin supply from the graft tissue, but the role of endogenous beta-cells after transplantation is not clear. In the present study, we examined endogenous beta-cell function after glucose homeostasis had been reestablished by islet graft in streptozotocin (STZ)-induced diabetic rats. Fed plasma glucose levels in diabetic rats transplanted with a large number of islets (2500 islets) into the left kidney capsule soon became lower (139.8 +/- 8.2 mg/dl) and close to the level in controls (129.7 +/- 11.3 mg/dl), and IPGTT exhibited a pattern of plasma glucose response almost identical to control. The insulin and DNA contents, islet area, and the distribution of beta-cells that were markedly deteriorated in islets of STZ rats were significantly restored in transplanted rats. The insulin release in response to glucose or alpha-ketoisocaproate was less in STZ rats, while in islets of transplanted rats the secretion recovered to levels similar to controls. On the other hand, arginine-induced insulin release was conversely hyperresponsive in STZ rats, but in transplanted rats, the response was decreased similar to controls. Thus, as the plasma glucose level normalizes, residual beta-cells show a recovery of function that cannot be accounted for by the increase in mass alone.

Animals↗

PubMed2001

Association of p53 gene mutations with sensitivity to TZT-1027 in patients with clinical lung and renal carcinoma.

BACKGROUND: It has been revealed that chemotherapy using DNA-damaging agents and radiotherapy were influenced by the p53 status of tumors; however, p53 status did not influence chemotherapy using antimicrotubule agents. To elucidate whether a novel antimicrotubule agent, TZT-1027, is influenced by the p53 status of tumors, the authors investigated the sensitivities of specimens obtained from patients with nonsmall cell lung carcinoma (NSCLC) and renal cell carcinoma (RCC) to various anticancer agents, including TZT-1027, and the status of the p53 gene in those specimens. METHODS: Twenty-nine NSCLC specimens and 22 RCC specimens were analyzed for their sensitivity to various anticancer agents and their p53 status. Sensitivities of the specimens to nine anticancer agents were determined by flow cytometric analysis. To determine p53 status, polymerase chain reaction amplification with primers for exons 5--9 was conducted, and the products were subjected to single-strand conformation polymorphism analysis. RESULTS: In the NSCLC specimens, anticancer agents, including TZT-1027, showed strong antitumor activity against 50--75% of specimens with the wild type p53 gene. TZT-1027 showed strong antitumor activity against 40% of specimens with the mutant type p53 gene, whereas DNA-damaging agents showed such activity only in 16--28% of specimens. In RCC specimens, TZT-1027 showed potent antitumor activity in 29% of specimens with the wild type gene, and DNA-damaging agents showed such activity in 6--18% of specimens. TZT-1027 showed strong antitumor activity in 40% of specimens with the mutant type p53 gene, whereas DNA-damaging agents showed such activity only in 0--20% of specimens. CONCLUSIONS: We found evidence to suggest that TZT-1027 was influenced less by the p53 status of specimens than DNA-damaging agents. Therefore, TZT-1027 is expected to show similar antitumor activity against tumors with a loss of p53 function as well as those with normal function of p53 in clinical fields.

Aged↗

PubMed2001

Localization of a novel susceptibility gene for familial ovarian cancer to chromosome 3p22-p25.

We performed genome-wide linkage analysis in 58 patients and nine unaffected members among 28 families with no mutation in BRCA1 or BRCA2, employing a set of 410 microsatellite markers. We initially screened the whole genome, including the X chromosome, by a non-parametric method using the GENEHUNTER program. As a result, chromosome 3p22-p25 showed a suggestive score for linkage [LOD = 3.49 and non-parametric LOD (NPL) = 2.77 at D3S3611] based on a multipoint analysis. Additionally, based on a two-point analysis using dense markers, this 3p22-p25 region showed a P-value < 0.05 at 10 markers and there is suggestive evidence for linkage at two markers within approximately 19 cM (NPL = 2.60 and 2.49 at D3S1597 and D3S3611, respectively). To explore whether the candidate gene in this 3p22-p25 region contributed to carcinogenesis of familial ovarian cancer in a similar fashion to the tumor suppressor gene, we performed loss of heterozygosity (LOH) analysis. It was observed that the frequency of LOH at four markers in this region was >50% only in tumor tissues from patients with no mutation in BRCA1 or BRCA2, not in those with a BRCA1 mutation.

Adult↗

PubMed2001

Heat shock restores insulin secretion after injury by nitric oxide by maintaining glucokinase activity in rat islets.

Heat shock protein (hsp), including hsp70, has been reported to restore the glucose-induced insulin release suppressed by nitric oxide (NO). However, the mechanism underlying this recovery remains unclear. In the present study, we examine the effects, in rat islets, of heat shock on insulin secretion inhibited by a small amount of NO and also on glucose metabolism, the crucial factor in insulin release. Exposure to a higher dose (15 U/ml) of interleukin-1beta (IL-1beta) abolished the insulin release by stimulation of glucose or KCl in both control and heat shocked islets. In rat islets exposed to a lower dose (1.5 U/ml) of IL-1beta, insulin secretion in response to glucose, but not to glyceraldehydes (GA), ketoisocaproate (KIC), or KCl, was selectively impaired, concomitantly with lower ATP concentrations in the presence of 16.7 mM glucose, while such suppression of insulin secretion and ATP content was not observed in heat shock-treated islets. NO production in islets exposed to 1.5 U/ml IL-1beta was significantly, but only partly, decreased by heat shock treatment. The glucose utilization rate measurement using [5-3H]-glucose and [2-3H]-glucose and the glucokinase activity in vitro were reduced in islets treated with 1.5 U/ml IL-1beta. In heat shock-treated islets, glucose utilization and glucokinase activity were not affected by 1.5 U/ml IL-1beta. These data suggest that heat shock restores glucose-induced insulin release inhibited by NO by maintaining glucokinase activity and the glucose utilization rate in islets in addition to reducing endogenous NO production.

Animals↗

PubMed2001

Prognostic significance of combined conventional and immunocytochemical cytology for peritoneal washings in endometrial carcinoma.

BACKGROUND: Noncancerous cells simulating adenocarcinoma cells may interfere with the analysis of peritoneal cytology (PC) in patients with endometrial carcinoma. Immunocytochemistry (ICC) may improve the diagnosis of PC. METHODS: PC slides from 115 patients with endometrial carcinoma were reviewed. Suspicious or positive cell clusters were recovered with a cell transfer method and were subjected to ICC for MOC-31, cytokeratin 5/6, and p53. Conventional Papanicolaou staining and ICC results were compared directly on the same cells. RESULTS: By combined conventional and immunocytochemical PC (CONV-ICC-PC), cytodiagnosis was positive in 18 of 115 patients (15.7%) and suspicious in 3 of 115 patients (2.6%). According to a multivariate Cox regression analysis of patients with tumors confined to the uterus that included grade, myometrial invasion, cervical involvement, and CONV-ICC-PC, only CONV-ICC-PC was an independent prognostic factor (P < 0.05). A multivariate analysis for all of the patients studied that compared CONV-ICC-PC with staging variables revealed that only peritoneal metastasis (P < 0.0001) and lymph node metastasis (P < 0.01) were independent prognostic factors. When peritoneal metastases were excluded, CONV-ICC-PC (P < 0.01) and lymph node metastasis (P < 0.0025) were the independent prognostic factors. By cell transfer and p53 immunostaining in samples from 14 patients with malignant cells in their peritoneal washings, no deaths occurred among 5 patients with negative p53, whereas 5 of 9 patients with positive p53 died of disease at the time of data analysis. CONCLUSIONS: MOC-31 immunostaining improves the diagnosis of PC in endometrial carcinoma. Positive PC is an important prognostic factor for patients with endometrial carcinoma confined to the uterus. The p53 positive cells in PC have possible prognostic significance.

Adult↗

PubMed2001

Cytosine-phosphoguanine methylation of estrogen receptors in endometrial cancer.

We hypothesize that estrogen receptors (ERs) are differentially expressed in endometrial cancer. To test this hypothesis, we investigated the expression profile of ERalpha (ERalpha-A, ERalpha-B, ERalpha-C) and ERbeta genes and CpG methylation status in endometrial cancer cell lines and tissues using reverse transcription-PCR and methylation-specific PCR and direct DNA sequencing. The results demonstrated that ERalpha-A, ERalpha-B, and ERbeta were normally expressed whereas ERalpha-C gene was inactivated in all endometrial cancer cell lines. We further investigated the mechanisms of ERalpha-C gene inactivation through CpG methylation pathways. The treatment with demethylating agent (5'-aza-2'-deoxycytidine) restored ERalpha-C gene expression in all endometrial cancer cell lines. We further confirmed these findings with methylation-specific PCR and direct DNA sequencing and found that only ERalpha-C was methylated on all five different CpG sites in all cell lines. We further analyzed 88 cancerous and 46 normal endometrial tissues. The results demonstrated that only ERalpha-C was inactivated and methylated in 94% of cancer tissues. In 32 pairs of cancerous and normal endometrial tissues from the same patient, ERalpha-C was methylated in 29 of 32 cancer tissues but unmethylated in all normal endometrial tissues. This is the first report that demonstrates selective ERalpha-C gene inactivation through CpG methylation pathway in uterine endometrial cancer.

CpG Islands↗

PubMed2001

Commitment to natural killer cells requires the helix-loop-helix inhibitor Id2.

We have previously described how T and natural killer (NK) lineage commitment proceeds from common T/NK progenitors (p-T/NK) in the murine fetal thymus (FT), with the use of a clonal assay system capable of discriminating p-T/NK from unipotent T or NK lineage-committed progenitors (p-T and p-NK, respectively). The molecular mechanisms controlling the commitment processes, however, are yet to be defined. In this study, we investigated the progenitor activity of FT cells from Id2-/- mice that exhibit defective NK cell development. In the Id2-/- FT, NK cells were greatly reduced, and a cell population that exclusively contains p-NK in the wild-type thymus was completely missing. Id2-/- FT progenitors were unable to differentiate into NK cells in IL-2-supplemented-FT organ culture. Single progenitor analysis demonstrated that all Id2-/- fetal thymic progenitors are destined for the T cell lineage, whereas progenitors for T/NK, T, and NK cell lineages were found in the control. Interestingly, the total progenitor number was similar between Id2-/- and Id2+/+ embryos analyzed. Expression of Id2 was correlated with p-NK activity. Our results suggest that Id2 is indispensable in thymic NK cell development, where it most probably restricts bipotent T/NK progenitors to the NK cell lineage.

Animals↗

PubMed2001

Diminished beta-adrenoceptor-mediated relaxation of femoral arteries from young spontaneously hypertensive rats.

A beta-adrenoceptor agonist, norepinephrine (NE)-induced relaxation in the presence of an alpha-adrenoceptor antagonist and indomethacin was investigated in isolated femoral arteries from 5-week-old Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). NE elicited endothelium-dependent and -independent relaxation in WKY. In endothelium-intact WKY artery, the NE-induced relaxation was reduced by nitro L-arginine (L-NA) and methylene blue. The residual response to NE in the presence of L-NA was further reduced by tetraethylammonium (TEA). Glibenclamide attenuated the NE-induced, endothelium-independent relaxation in WKY. In SHR, on the other hand, the relaxation to NE was solely endothelium-independent, unaffected by a combination of L-NA and TEA and inhibited by glibenclamide. The relaxation in response to NE in SHR was less than that in WKY, regardless of the presence and absence of endothelial cells. When WKY and SHR were treated for 10 days with captopril, the response to NE was increased not only in WKY but also in SHR. The relaxation in captopril-treated SHR consisted of endothelium-dependent and -independent components. The former was attenuated by L-NA and to a greater extent by TEA with L-NA. Sodium nitroprusside- and forskolin-induced, endothelium-independent relaxations in SHR were not significantly different from those in WKY. Captopril did not affect the response to these drugs. The present results indicate that the relaxation to NE is in part mediated by NO and a vasorelaxing factor distinct from NO in WKY but not in SHR. It is suggested that NE-induced, endothelium-independent relaxation in both groups is in part mediated by ATP-sensitive K+ channels. It is also suggested that in SHR, captopril increases the response to NE through increases in endothelial production of NO and the non-NO vasorelaxing factor.

Acetylcholine↗

PubMed2001

Mechanisms of hydrogen peroxide-induced relaxation in rabbit mesenteric small artery.

The effects of hydrogen peroxide were studied on isolated rabbit mesenteric small artery; rabbit superior mesenteric artery and mouse aorta were also studied as reference tissues. For mesenteric small artery, hydrogen peroxide (1 to 100 microM) relaxed a norepinephrine-stimulated artery in a concentration-dependent manner. The relaxation was not significantly affected by removal of the endothelium and was less pronounced in arteries contracted with high-KCl solution plus norepinephrine than in those contracted with norepinephrine alone. The relaxation response to hydrogen peroxide was increased by isobutylmethylxanthine and zaprinast, inhibited by diclofenac, methylene blue and dithiothreitol and unaffected by atropine, tetraethylammonium, superoxide dismutase, deferoxamine, dimethyl sulfoxide or the Rp stereoisomer of adenosine cyclic monophosphothioate. Hydrogen peroxide shifted concentration-contractile response curves for norepinephrine to the right and downwards. Norepinephrine and caffeine elicited a transient, phasic contraction of the mesenteric small artery exposed for 0.5, 1 and 2 min to a Ca2+-free solution. Hydrogen peroxide inhibited the norepinephrine-induced contraction, and to a lesser extent the caffeine-induced contraction, and verapamil did not alter the contraction to norepinephrine. These pharmacological properties of hydrogen peroxide were similar to those of 8-bromo cGMP; 8-bromo cGMP inhibited more potently the norepinephrine-induced than the KCl-induced contraction and the contraction elicited by norepinephrine in Ca2+-free solution. The present results suggest that hydrogen peroxide induces endothelium-independent relaxation of the rabbit mesenteric small artery precontracted with norepinephrine. The effects of hydrogen peroxide may be at least in part mediated by cGMP and cyclooxygenase products in the vascular smooth muscles now used.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed2001

Progesterone receptor B gene inactivation and CpG hypermethylation in human uterine endometrial cancer.

The expressions of two isoforms of human progesterone receptor (PR) are under the control of the two different promoters. Recent studies revealed differences between these isoforms, PRA and PRB, in their expression and function in endometrial cells. Aberrant methylation of normally unmethylated CpG islands has been associated with inactivation of several genes in human cancers. In this study, we investigated the methylation status and the expression of the two different PR isoforms, PRA and PRB, in uterine endometrial carcinoma (UEC) using methylation-specific PCR (MSP), reverse transcription-PCR (RT-PCR), the 5' rapid amplification of cDNA ends method (5'RACE), and immunohistochemical staining. The results of RT-PCR and 5'RACE suggest that only PRB is inactivated, although PRA is activated in all UEC cell lines. Treatment with a demethylating agent, 5-aza-2'-deoxycytidine, restored PRB expression in all cell lines, suggesting that inactivation of this gene is through methylation. By MSP and direct DNA sequencing, PRB was methylated, whereas PRA was unmethylated in all of the cell lines. To determine the methylation status of PRB in UEC patients, we investigated 83 cancerous and 33 normal samples. Sixty-two of 83 cancer samples had only methylated alleles of PRB, although all cancer samples had only unmethylated PRA alleles. Seventy-one of 83 cancer samples were negative for PRB expression. All 62 cancer samples that had only methylated PRB alleles were negative for PRB expression. No significant changes were observed in PRA methylation status or immunohistochemistry positivity in normal and cancer samples. To determine whether de novo methylation of PRB occurred in UEC patients, we studied 32 pairs of cancer and normal samples from the same patient. Twenty of 32 cancer samples had only methylated PRB alleles, although all 32 normal samples had only unmethylated PRB alleles. The loss of unmethylated alleles was well correlated with negativity in immunohistochemical staining for PRB. This is the first report of the selective methylation and the subsequent silencing of PRB in uterine endometrial cancer.

Alleles↗

PubMed2001

Prenatal diagnosis of agnathia-holoprosencephaly: three-dimensional imaging by helical computed tomography.

We report a case of agnathia-holoprosencephaly which was prenatally diagnosed based on helical computed tomography (CT) images obtained at 23 weeks of gestation. Ultrasound examination first showed the presence of alobar holoprosencephaly, but the facial structures were not clearly detailed. However, three-dimensional imaging by helical CT precisely demonstrated the most striking feature of agnathia: absence of the mandible. This technique provided us valuable information that contributed to the in utero diagnosis. In utero helical CT is a useful examination tool for the diagnosis of osteogenic abnormalities.

Adult↗

PubMed2001

Pharmacokinetics of dicrofenac after its intrarectal and intracolostomal administration to rabbits with rectal resection or colostoma construction.

We investigated the pharmacokinetics of diclofenac, one of the important analgesics in palliative care, after its intrarectal and intracolostomal administration to rabbits with rectal resection or colostoma construction. In rectal-resected rabbits, its bioavailability after rectal administration was significantly lower than that in normal rabbits, and furthermore that after intracolostomal administration was significantly lower than that in rectal-resected rabbits. This decreased bioavailability in rabbits with rectal resection and colostoma construction was thought to be due to the increased first-pass effect. With increase in the dose up to 1.5-fold, the plasma concentrations in both rectal-resected and colostoma-constructed rabbits increased to the normal rabbit level. These results indicate that the bioavailability of diclofenac sodium after its rectal and intracolostomal administration decreases, and that an increased dose can restore the decreased plasma concentration. There was no difference in the plasma concentration with diclofenac sodium suppositories between administration into the normal rectum and the remaining rectum following colostoma construction, and the remaining rectum was found to be a useful administration route for suppositories. Therefore, it was indicated that when administering diclofenac sodium suppositories to rectal-resected and colostoma-constructed patients, the dose should be increased, because the pharmacokinetics of diclofenac was similar in rabbits and human.

Administration, Oral↗