Biomedical subjects

E Hiyama

Publications and source records attributed to E Hiyama.

At least 37 records · Page 2Linked to original sources

PubMed2000

Generation of pro-inflammatory and anti-inflammatory cytokines in the gut in zymosan-induced peritonitis.

In major systemic inflammation such as severe peritonitis, various pro-inflammatory cytokines, such as TNF-alpha, IL-1 beta and IL-6, play important roles in the development of multiple organ dysfunction syndrome (MODS). The purpose of this study was to investigate the outflow of pro-inflammatory and anti-inflammatory cytokines from the efferent mesenteric lymphatic vessels under peritonitis. Mesenteric lymph samples were collected from adult male rats at 2, 4, 6, 8 and 10 hr after an intraperitoneal injection of zymosan at a dosage of 0.1 mg/g (non-lethal dose) or 0.5 mg/g (lethal dose). Blood samples were obtained at 10 hr after zymosan administration. The amounts of drained TNF-alpha and IL-6 in the lymph peaked at 2-4 hr and 4-8 hr after zymosan administration, respectively. The amounts of drained IL-10 in the lymph gradually increased until 10 hr. The amounts of drained TNF-alpha and IL-10 in the mesenteric lymph were significantly correlated with the dosage of zymosan. In conclusion, under intraperitoneal inflammation, pro-inflammatory cytokines (TNF-alpha and IL-6) increased in the mesenteric lymph and were drained into circulation. IL-10, one of the anti-inflammatory cytokines, also increased in the mesenteric lymph after several hours' delay and its increase was remarkable in several inflammations. These findings suggested that the gut might be one of the pro-inflammatory and anti-inflammatory cytokine-generating organs under peritonitis. The lymph-drained amounts of each cytokine under peritonitis are considered to differ with the time or severity of inflammation, which may cause different conditions in patients due to the imbalance of pro-inflammatory and anti-inflammatory cytokines.

Animals↗

PubMed2000

High telomerase activity is an independent prognostic indicator of poor outcome in colorectal cancer.

Telomerase activity and altered telomere length have been extensively studied in many kinds of malignant tumors for clinical diagnostic and/or prognostic utilities. In the present study, we investigated telomerase activity and telomere length in colorectal cancers and noncancerous colonic mucosa specimens in 100 patients between 1991 and 1996. To determine whether the level of telomerase activity or telomere length is a prognostic indicator of patient outcome, we followed these patients more than 3 years after surgery. Among 100 primary colorectal cancer specimens, 96 specimens had telomerase activity. Because noncancerous mucosa has some detectable telomerase activity, we divided the levels of telomerase activity into three categories: high (>50-fold more than that in noncancerous mucosa); moderate (10- to 50-fold); and low (<10-fold) levels. Among 100 cancer tissues, 28 showed moderate telomerase activity and 44 showed high telomerase activity. The frequency of tumors with moderate or high telomerase activity showed no significant relationship with any clinicopathological factors. The prognosis of the patients with high telomerase activity was significantly worse than that for patients with moderate and low telomerase activity (P < 0.01). Among the 87 patients with curative surgery, disease-free survival rate of those with high telomerase activity was also significantly poorer (P < 0.01). These results indicate that a high level of telomerase activity may be an independent prognosis-predicting factor in the patients with colorectal cancer.

Adult↗

PubMed2000

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between April 1997 and March 1998].

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in 19 facilities in Japan since July 1982. This paper describes the results obtained during the period from April 1997 to March 1998. The number of cases investigated as objectives was 215 for one year. A total of 420 strains (170 strains from primary infections and 250 strains from postoperative infections) were isolated from 174 cases (80.9% of total cases). In primary infections, the isolation rate of anaerobic bacteria was higher than in postoperative infections, while in postoperative infections, those of aerobic Gram-positive bacteria and Pseudomonas aeruginosa were higher than in primary infections. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by Staphylococcus aureus, which was frequently isolated from postoperative infections. Among anaerobic Gram-positive bacteria, Peptostreptococcus spp. and Streptococcus spp. were commonly isolated from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was most predominantly isolated from primary infections, followed by P. aeruginosa, Klebsiella pneumoniae in this order, and from postoperative infections, P. aeruginosa was most predominantly isolated, followed by E. coli and K. pneumoniae. Among anaerobic Gram-negative bacteria, Bacteroides fragilis group was the majority of isolates from both types of infections. We found neither vancomycin nor arbekacin resistant strains of S. aureus, and found no vancomycin resistant strains of Enterococcus spp. The susceptibility of P. aeruginosa against carbapenems did not decline in the year 1997, while resistance of B. fragilis group against cephems advanced increasingly.

Anti-Bacterial Agents↗

PubMed1999

Lack of CD44 variant 6 expression in advanced extrahepatic bile duct/ampullary carcinoma.

BACKGROUND: Transmembrane proteins of the CD44 family play roles in cell-cell and cell-matrix interactions, and their aberrant expression has been reported to be associated with the growth and metastasis of various tumors. The authors examined CD44 standard (CD44st) and CD44 variant 6 (CD44v6) expression in extrahepatic bile duct (EHBD)/ampullary carcinoma. METHODS: In 36 EHBD/ampullary carcinomas, immunohistochemical analyses with monoclonal antibodies against the human CD44st protein or CD44v6 protein were performed by the streptavidin-biotin immunoperoxidase method. The relation between expression of the proteins and lymph node metastases or patient outcome was investigated. To verify the lack of CD44v6 mRNA expression in tumors negative for CD44v6 staining, reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot hybridization were performed. RESULTS: Immunohistochemical analyses revealed that 13 of 36 carcinomas (36.1%) expressed the CD44v6 protein. Only 2 of 13 CD44v6-expressing primary tumors (15.4%) had regional lymph node metastases, whereas 14 of 23 tumors showing no CD44v6 expression (60.9%) had lymph node metastases (Fisher exact test, P<0.01). Moreover, a lack of CD44v6 expression was correlated significantly with poor prognosis (generalized Wilcoxon test, P<0.05). Eleven of 13 CD44v6 positive tumors showed CD44st expression, which also was correlated with prognosis. RT-PCR and Southern blot hybridization revealed a lack of CD44v6 mRNA expression in the tumors that were negative for CD44v6 staining. CONCLUSIONS: The results of the current study suggest that a lack of expression of CD44, especially CD44v6, is correlated with lymph node metastases and poor prognosis, and may be a prognostic factor for patients with EHBD/ampullary carcinoma.

Adult↗

PubMed1999

An additional dose of cefazolin for intraoperative prophylaxis.

We examined the pancreatic tissue concentrations of cefazolin in ten patients undergoing pancreatectomy, and determined the optimal intraoperative time to deliver a repeat dose of cefazolin. An intravenous bolus dose of 1 g cefazolin was administered at the time of skin incision. Peripheral blood, subcutaneous adipose tissue, and peritoneal samples were obtained intraoperatively every hour for 4 h after the antibiotic was first administered, and pancreatic tissue samples were obtained at the time of pancreatectomy. To determine adequate tissue levels of cefazolin, minimum inhibitory concentrations (MIC) were measured for four bacterial species, namely 360 isolates of methicillin-sensitive Staphylococcus aureus (MSSA), 204 isolates of Klebsiella pneumoniae, 314 isolates of Escherichia coli, and 30 isolates of Streptococcus spp. The antibiotic concentrations in adipose tissue and peritoneum 3 h after the administration of cefazolin were lower than the MIC80 for K. pneumoniae, E. coli, and Streptococcus spp. Most pancreatic tissue samples showed antibiotic concentrations greater than the MIC80 for these bacterial species; however, those from four patients complicated by severe chronic pancreatitis, massive intraoperative bleeding, or obesity showed concentrations lower than the MIC80. Thus, we recommend that a second dose of cefazolin be given 3 h after the first administration to maintain adequate levels of antibiotic activity.

Aged↗

PubMed1999

Surgical approaches for pancreatic ascites: report of three cases.

Pancreatic ascites can occur in association with the rupture of a pseudocyst or the disruption of a pancreatic duct during the natural course of chronic pancreatitis. We report herein the successful treatment of three patients with pancreatic ascites by performing a surgical procedure after 4-6 weeks of total parenteral nutrition (TPN) proved ineffective. The principles of our surgical procedure for pancreatic ascites are as follows: (1) minimum pancreatic tissue is resected; (2) surgical intervention to repair leaking sites is not necessary; (3) pancreatic duct drainage is facilitated by an intestinal Roux-en-Y loop; (4) An external drainage tube is inserted through the Roux-en-Y loop into the main pancreatic duct. All three patients who underwent our surgical procedure had a good outcome. Although the mean follow-up time is still only 18.3 months, their condition has improved, with no evidence of recurrent ascites. Thus, our surgical procedure should be considered as an appropriate treatment for pancreatic ascites because it can be applied for all types of leakage, including leakage from the posterior wall of pancreas; it preserves pancreatic function, especially endocrine function; and it enables preservation of the spleen.

Aged↗

PubMed1999

Down-regulation of KAI1 messenger RNA expression is not associated with loss of heterozygosity of the KAI1 gene region in lung adenocarcinoma.

KAI1, a metastasis suppressor gene of prostate cancer, is located on human chromosome 11p11.2. Down-regulation of KAI1 mRNA during tumor progression and metastasis has been reported for several kinds of cancer, but the mechanism of this down-regulation is not known. In the present study, our aim was to ascertain the relationship between down-regulation of KAI1 mRNA expression and KAI1 gene alterations in lung cancer. Forty-nine cases of adenocarcinoma of the lung were studied by reverse-transcriptase polymerase chain reaction (RT-PCR) assay of KAI1 mRNA and by immunohistochemical detection of KAI1 protein. In addition, markers of the microsatellite loci D11S1344 and D11S1326 were used to investigate loss of heterozygosity (LOH) and replication errors (RERs) of the KAI1 gene region. The RT-PCR assay showed that there was no correlation between KAI1 mRNA expression and either the age of the patients or tumor size. By contrast, KAI1 mRNA expression was significantly correlated with gender (P=0.047), metastasis to the lymph nodes or other organs (P=0.004), the histological grade of the tumor (P=0.036) and the pathological stage (P=0.049). Immunohistochemical staining showed that in one case without metastasis, loss of KAI1 mRNA was associated with invasion of the stroma by KAI1 protein-negative cancer cells. The numbers of informative cases by microsatellite analysis were 14 (28.6%) of 49 at D11S1344 and 27 (55.1%) of 49 at D11S1326; none of 49 adenocarcinomas showed LOH or RERs at these loci. These results suggest that down-regulation of KAI1 mRNA expression rarely if ever involves LOH or RERs of the KAI1 gene region in primary lung adenocarcinoma.

Adenocarcinoma↗

PubMed1999

Inhibitory effect of telomere-mimic phosphorothioate oligodeoxy nucleotides (S-ODNS) on human tumor cell lines.

To clarify the inhibitory effect of telomere-mimic oligonucleotides on human cancer cell lines, we synthesized 18-mers (18T; n = 3), 24-mers (24T; n = 4) and 30-mers (30T; n = 5) of telomere-mimic phosphorothioate oligodeoxy nucleotides [5'-d(TTA GGG)n-3'] and examined their effects on the proliferation of human tumor cells by XTT assay. After 7 days of continuous exposure to 24T and 30T at concentrations ranging from 0.1 to 10 microM, concentration-dependent cell growth inhibition was observed in MCF-7 clone E3, ZR-75-1, MDA-MB 231, Colo 201 and WiDr. All of these cell lines highly expressed telomerase using the telomeric repeat amplification protocol. None of these tumor cell lines were affected by 18T. In MCF-7, ZR-75-1 and Colo 201 cell lines, a more than 50% growth inhibition was obtained by 3 microM of 24T and 30T whereas, in MDA-MB 231 and WiDr cell lines, cell growth inhibition was less than 50%. 30T was more effective than 24T. Estrogen-dependent growth of both MCF-7 and ZR-75-1 was inhibited by 3 microM of 24T and 30T, however, in the absence of estrogen, no growth inhibition was seen. The MCF-10A cell line, which was developed from normal human breast tissue and expressed telomerase only weakly, was inhibited by 10 microM of 18T. In conclusion, these observations indicate that S-ODNs inhibit tumor growth in cell lines expressing telomerase in a concentration-dependent manner and that cell growth inhibition is dependent on the length of S-ODNs. In addition, the short-length S-ODNs may inhibit growth of cells weakly expressing telomerase, but not of cells with high telomerase expression.

Breast Neoplasms↗

PubMed1999

Rapid detection of MYCN gene amplification and telomerase expression in neuroblastoma.

Amplification of the MYCN gene and high telomerase activity predict a poor prognosis for the patients with neuroblastoma. We used PCR techniques for rapid detection of MYCN gene amplification and human telomerase reverse transcriptase (hTERT) expression in neuroblastoma specimens. The detection of MYCN gene amplification is based on differential PCR in which three primer pairs were used to coamplify a 178-bp fragment of target MYCN gene with two reference gene fragments, a 237-bp of p53 exon 7 and a 120-bp of beta-globin exon 3, in a single tube of 40 surgically resected tumor samples. MYCN amplification was identified by this differential PCR in all 10 samples carrying more than 10 copies (already known to have MYCN gene amplification by Southern blot analysis). There were no false-negative or false-positive cases, and the relative intensity of MYCN bands in the differential PCR correlated significantly with the copy number determined by Southern blot analysis (y = 0.99, P<0.0001). This protocol was also applicable in the biopsy or aspirated samples, as well as the paraffin-embedded tissues, and in detecting intratumoral heterogeneity. Using RT-PCR procedures, hTERT mRNA expression was detectable in all 13 tumors with high telomerase activity. These nonradioisotopic PCR-based protocols for detecting MYCN gene amplification and hTERT mRNA expression are rapid and reliable and are likely to be useful to determine the biological behavior of neuroblastoma.

Biomarkers, Tumor↗

PubMed1999

Genetic analysis with calcium-induced calcium release test in Japanese malignant hyperthermia susceptible (MHS) families.

Some genetic studies have shown a linkage between malignant hyperthermia susceptibility (MHS) and chromosome 19q or the skeletal muscle ryanodine receptor (RYR1) gene. Some types of MHS seem to be caused by an abnormality of calcium-induced calcium release (CICR). We analyzed the linkage of RYR1 gene polymorphisms in Japanese MHS families and investigated the correlation between genetic evidence of RYR1 gene mutations and an accelerated rate of CICR. We studied 63 subjects who were referred to our institute for investigation of MHS. CICR rates were measured by the skinned fiber method in 23 subjects. DNA samples were collected from 63 individuals belonging to 22 unrelated families. Restriction fragment length polymorphism (RFLP) analyses on the RYR1 locus and hypervariable microsatellite analysis were performed. We found one family with a linkage between acceleration of the CICR mechanism and a group of RFLPs. In CICR tests, ten of the 11 patients who had presented with fulminant MH showed accelerated rates of CICR. Analysis for the mutation C1840T, which was performed in 63 samples, did not demonstrate an alteration in any of the patients. Although we found heterozygotes in RFLP studies, we did not recognize a specific relationship between the acceleration of CICR and the RFLPs. We suggest a linkage between the acceleration of CICR and an abnormal human RYR1 gene in MHS. These results also suggest that heterogeneity exists for MH. We conclude that genetic tests cannot replace CICR tests or caffeine-halothane contracture tests with muscle biopsy as a diagnosing test for MH in the near future.

Calcium↗

PubMed1999

Analysis of mec regulator genes in clinical methicillin-resistant Staphylococcus aureus isolates according to the production of coagulase, types of enterotoxin, and toxic shock syndrome toxin-1.

The intrinsic resistance of methicillin-resistant Staphylococcus aureus (MRSA) is frequently explained by the production of an additional penicillin-binding protein (PBP), which is encoded by the mecA gene. The mec regulator genes, mecR1 and mecI, was identified in mecA-carrying Staphylococcus aureus N315. Between February and March, 1993, 179 clinical MRSA isolates were collected from institutions in Hiroshima prefecture. According to serological types of coagulase, enterotoxins, and toxic shock syndrome toxin-1 (TSST-1) productions, these strains were classified into 6 groups. In 53 strains chosen from all groups, mec regulatory gene distributions were divided into two groups; one with whole regulatory genes and another with the lacking region, including 3'-partial region of the mecR1 gene and mecI gene. This same deletion was detected across the different groups, suggesting that the deletion occurred at the ancestral strain before branching according to coagulase or enterotoxin productions. The strains with this lacking region showed a high-level of resistance to methicillin, while the strains with whole regulatory genes consisted of low and high levels of resistant strains. The highly resistant strains with whole regulatory genes were found to harbor a point mutation in the mecI gene. The basal levels of mecA gene transcription were elevated in the strains with the lacking region or the mecI point mutations. These data suggest that deletion or mutation of the mecI gene, the repressor on the mecA gene, might play an important role in methicillin resistance in clinical isolates of MRSA.

Bacterial Proteins↗

PubMed1998

Expression of telomerase activity in human endometrium is localized to epithelial glandular cells and regulated in a menstrual phase-dependent manner correlated with cell proliferation.

Telomerase activity is observed in most malignant tumors and germ cells, whereas normal somatic cells usually do not express it. Human endometrium is composed of glandular and stromal components and exhibits dramatic changes in proliferative activity during the menstrual cycle, which is exquisitely regulated by estrogen function. We previously reported that normal human endometrium expresses telomerase activity. However, it remains unclear which of the above components are the major sources of telomerase activity and how levels of telomerase activity are regulated over the menstrual cycle. Quantitative analysis of telomerase activity revealed that it changes dramatically over the course of the menstrual cycle and is strictly regulated in a menstrual-phase-dependent manner. Maximal activity equivalent to that in endometrial cancer was present in late proliferative phase, and minimal activity in late secretory phase. Postmenopausal endometrium and endometrium treated with anti-estrogen drugs exhibited decreased telomerase activity. Testing isolated epithelial glandular cells and stromal cells, we found that telomerase activity was localized to epithelial glandular cells. In situ RNA hybridization analysis also revealed epithelial-specific expression of human telomerase RNA. In vitro analysis of cultured epithelial cells demonstrated that telomerase activity is correlated with epithelial proliferation but not affected by estrogen treatment. These findings suggest that expression of telomerase activity is specific to epithelial cells and linked to cell proliferative status. The involvement of estrogen in telomerase regulation remains to be elucidated.

Cell Division↗

PubMed1998

Age-dependent telomere shortening is slowed down by enrichment of intracellular vitamin C via suppression of oxidative stress.

Telomeres in eukaryotic somatic cells are destined to the age-dependent shortening, which has not been demonstrated to correlate to direct lesion of telomeric DNA by reactive oxygen intermediates (ROI); still less explicable is the inhibitory effect of ROI-scavenging on telomere shortening. Here, we succeeded in artificial slowdown of age-dependent telomere shortening to 52-62% of the untreated control, in human vascular endothelial cells, by addition of the oxidation-resistant type of ascorbic acid (Asc), Asc-2-O-phosphate (Asc2P), which concurrently achieved both extension of cellular life-span and prevention of cell size enlargement indicative of cellular senescence. The results are attributable to a 3.9-fold more marked enrichment of intracellular Asc (Asc(in)) by addition of Asc2P, subsequently dephosphorylated before or during transmembrane influx, than by addition of Asc itself, and also attributed to diminution of intracellular ROI to 53% of the control level by Asc2P; telomerase activity was at a trace level and underwent an age-dependent decline, which was significantly decelerated by Asc2P. Thus, age-dependent telomere-shortening can be decelerated by suppression of intracellular oxidative stress and/or by telomerase retention, both of which are achieved by enriched Asc(in) but not by extracellular Asc overwhelmingly more abundant than Asc(in).

Ascorbic Acid↗

PubMed1998

Telomerase activity in rheumatoid synovium correlates with the mononuclear cell infiltration level and disease aggressiveness of rheumatoid arthritis.

OBJECTIVE: To determine whether the presence of telomerase activity in synovial tissues could provide insights into the pathogenesis of rheumatoid arthritis (RA). METHODS: Synovial tissue samples obtained from patients with RA or osteoarthritis (OA) were examined for telomerase activity using the telomeric repeat amplification protocol (TRAP). RESULTS: Telomerase activity was detected in over half the RA synovial tissues (14/25, 56%) but in no OA synovial tissue samples (0/15). Telomerase activity was detected in the mononuclear cells isolated from telomerase-positive RA synovial tissue, but not in cultured adherent cells. In RA synovial tissue with positive telomerase activity mononuclear cell infiltration levels were increased (p < 0.001). In addition, patients with RA with positive telomerase activity had undergone joint operations at an earlier age (p = 0.030) and more often (p = 0.023) compared to those without telomerase activity. CONCLUSION: Telomerase activity in RA synovial tissue is likely derived from infiltrating mononuclear cells and may be involved in the pathogenesis of RA. Clinically, the presence of telomerase activity in RA may be an indicator of a more aggressive phenotype.

Aged↗

PubMed1998

[Relationship between telomere length and clinical and biological characteristics of the cancers with telomerase reactivation].

Activation of telomerase and stabilization of telomeres are considered to be necessary for immortalization of human tumor cells. Telomerase activity and telomere lengths were examined in adult and childhood cancer tissues. High telomerase activity was detected in over 40% samples. In these cases, the lengths of telomeres varied in wide range and the short telomere length significantly correlated with high proliferative index. The patients with short telomeres demonstrated poorer prognosis than other patients. These findings suggest that the short telomeres might be related with the malignant potential in cancers with high telomerase activity.

Adult↗

PubMed1998

[Telomerase activity in pancreatic juice for the preoperative diagnosis of pancreatic cancer].

Although many diagnostic challenges have been tried in pancreatic cancer, its prognosis still remains poor. One of the reason that it is difficult to diagnose using present diagnostic procedure in early stage of pancreatic cancer. Therefore, we tried new procedure using telomerase activity from pancreatic juice. In this study, telomerase was assayed by use of pancreatic duct cells obtained preoperatively from 32 cases with pancreatic duct abnormalities. Telomerase activity was undetectable in all 17 subjects with benign pancreatic diseases, whereas 13 (87%) of 15 subjects with pancreatic cancer had detectable telomerase activity. Interestingly, we also detected telomerase activity in the case of carcinoma in situ. If future studies confirm, the detection of telomerase activity of pancreatic duct cells may become an useful tool for diagnosis of pancreatic cancer, perhaps at early stages.

Adult↗

PubMed1998

[Telomerase activity as a novel marker of lung cancer].

Telomerase activity is found in more than 80% of human malignant neoplasms, including lung cancer. Markers with high incidence in malignant samples and very low incidence in benign samples are useful in clinical diagnosis of cancer. Thus, telomerase activity in clinical materials may become a novel tumor marker of existing lung cancer cells. Moreover, since activation of telomerase is associated with cellular immortality and its activity level is quite different between lung cancer tissues, the activity level may become an indicator of some biological features in lung cancer.

Biomarkers, Tumor↗

PubMed1998

[Advance of research on telomerase].

Telomerase, a ribonucleoprotein enzyme which can compensate for the erosion of telomeric repeats each cell division, is considered to be associated with cellular immortality. The genes encoding the major components of human telomerase, TERC for telomerase RNA component, TEP1 for a human homolog of p80, and TERT for catalytic subunit, have been cloned. In addition, TERF1 and TERF2, encoding telomeric repeat binding proteins, have been cloned and shown to be involved in telomere length regulation and the protection of chromosome end fusions, respectively. Although the activity level of telomerase is similar at each stage of the cell cycle in telomerase-positive cells, it is generally upregulated with cellular proliferation and repressed with withdrawal from cell cycle. Although biological mechanisms regulating telomerase activity and telomere length remain elucidated, telomerase activity can be detected in approximately 85% of human malignant neoplasms, and the telomerase is a promising and novel tumor marker for clinical diagnosis of cancer, as well as a novel target of anticancer therapy.

Cell Cycle↗