PubMed Health⌕ Search

Biomedical subjects

K Kanemitsu

Publications and source records attributed to K Kanemitsu.

At least 19 recordsLinked to original sources

Residual formaldehyde on plastic materials and medical equipment following low-temperature steam and formaldehyde sterilization.

We measured the amount of residual formaldehyde on 16 plastic materials and five medical devices following low-temperature steam and formaldehyde (LTSF) sterilization, based on the European Standard EN14180. The amounts of formaldehyde residue on the plastic materials were compared with that on a filter paper of similar dimensions. The amount of residual formaldehyde on polyamide 6, polyurethane, natural rubber and polyacetal was higher (21.9, 15.2, 3.0 and 2.1 times, respectively) than that on the filter paper. The amount of formaldehyde recovered from a breathing circuit, anaesthesia circuit, oxygen tubing, airway tube and tweezers was 260, 240, 594, 56 and 0 microg, respectively, following LTSF sterilization. Our results emphasize the need to verify the main material composing the medical equipment before LTSF sterilization, as the amount of formaldehyde retrieved following sterilization varies according to the material used for construction.

Cross Infection↗

Does incineration turn infectious waste aseptic?

Incineration of infectious waste is considered to be biologically safe. We performed basic experiments to confirm that bacillus spores are killed by incineration in a muffle furnace. Biological samples containing 10(6) spores of Bacillus stearothermophilus were placed in stainless steel Petri dishes and then into hot furnaces. The furnace temperature and duration of incineration were 300 degrees C for 15 min, 300 degrees C for 30 min, 500 degrees C for 15 min, 500 degrees C for 30 min and 1100 degrees C for 3 min. We confirmed that all spores of B. stearothermophilus were killed at each of these settings. The effect of incineration seems to be equivalent to that of sterilization, based on the satisfactory sterilization assurance level of 10(-6).

Geobacillus stearothermophilus↗

Pigment epithelium-derived factor induces pro-survival genes through cyclic AMP-responsive element binding protein and nuclear factor kappa B activation in rat cultured cerebellar granule cells: Implication for its neuroprotective effect.

Pigment epithelium-derived factor (PEDF) protects immature cerebellar granule cell neurons (CGCs) against apoptosis induced by K+ and serum deprivation. However, the precise mechanism of this protection remains unknown. We recently reported that the transcription factor nuclear factor kappa B (NF-kappaB) is activated in PEDF-treated CGCs. Although it is well known that NF-kappaB blocks apoptotic cell death through the induction of pro-survival factors, the effects of PEDF on the expression of these factors are not fully understood. In this study, we employed the use of reverse transcriptase-polymerase chain reaction to analyze the gene expression of certain pro-survival genes and found that genes such as c-IAP1, c-IAP2, FLIPs, A1/Bfl-1 and Mn-SOD were induced in PEDF-treated neurons. On the other hand, no induction was observed of the pro-apoptotic Bcl-2 family members Bax and Bid at any time from 3 to 24 h following PEDF addition. Furthermore, phosphorylation of cyclic AMP-responsive element binding protein (CREB) and increment of nuclear cyclic AMP-response element (CRE)-like DNA binding were observed in PEDF-treated CGCs. The anti-apoptotic effect of PEDF was blocked by overexpression of dominant negative CREB or a mutated form of IkappaBalpha. These results suggested that induction of both CRE- and NF-kappaB-dependent genes is required for the observed neuroprotective effects of PEDF on CGCs.

Animals↗

Evaluation of a fully automated system (RAISUS) for rapid identification and antimicrobial susceptibility testing of Staphylococci.

RAISUS is a system for rapid bacterial identification and antimicrobial susceptibility testing. RAISUS and VITEK showed 97.8% and 75.9% agreement in identification of 45 Staphylococcus aureus strains and 58 coagulase-negative staphylococci (CoNS), respectively, and RAISUS and CLSI (formerly NCCLS) methods showed 87.2% and 87.9% agreement in the MICs for S. aureus and CoNS, respectively. RAISUS provided these data within 3.75 h, suggesting its utility for clinical bacteriological laboratories.

Anti-Bacterial Agents↗

Evaluation of a low-temperature steam and formaldehyde sterilizer.

We evaluated a low-temperature steam and formaldehyde (LTSF) sterilizer based on the draft European Standard prEN 14180. Microbiological tests were conducted on small and full loads using process challenge devices in five programs (P1-P5). With small loads all tests showed no growth of Bacillus stearothermophilus (ATCC7953) spores. However, positive cultures were observed with full-load tests using P5 (sterilization temperature, 50 degrees C). Our data indicated that the load influenced the efficacy of the LTSF sterilizer. Desorption tests were conducted to determine residual formaldehyde in indicator strips. The mean concentrations of formaldehyde in P1-P5 were 31.9, 56.3, 54.9, 82.2 and 180.6 microg, respectively, which are below the limits allowed by the draft Standard. Our results indicate that the LTSF sterilizer is useful for sterilization because of its excellent efficacy, short handling time, and safety.

Disinfectants↗

Antimicrobial activity of everninomicin against clinical isolates of Enterococcus spp., Staphylococcus spp., and Streptococcus spp. tested by Etest.

The in-vitro antimicrobial activity of everninomicin, a novel oligosaccharide antibiotic, was tested against clinical isolates of 11 methicillin-susceptible Staphylococcus aureus (MSSA) strains, 11 methicillin-resistant S. aureus (MRSA) strains, 22 Staphylococcus epidermidis strains, 23 Enterococcus faecalis strains, 23 Enterococcus faecium strains, 23 Enterococcus avium strains, 27 Streptococcus pneumoniae strains, 22 Streptococcus pyogenes strains, and 20 Streptococcus agalactiae strains. The minimum inhibitory concentrations (MICs) of everninomicin were determined by Etest and compared with those of vancomycin, teicoplanin, and minocycline. The Etest showed that everninomicin exhibited excellent activity (MIC, <0.016 to 1.5 microg/ml) against the gram-positive cocci tested. The antimicrobial activity of everninomicin against S. aureus and S. epidermidis was stronger than that of vancomycin, teicoplanin, and minocycline, in particular against MRSA, with an MIC50 of 0.38 microg/ml and an MIC90 of 0.5 microg/ml. Against strains of enterococci and streptococci, everninomicin was more active than vancomycin, but as active as teicoplanin.

Aminoglycosides↗

Characterization of MRSA transmission in an emergency medical center by sequence analysis of the 3'-end region of the coagulase gene.

The distribution of methicillin-resistant Staphylococcus aureus (MRSA) isolates at the St. Marianna University affiliated emergency medical center (EMC) was studied by sequence analysis of the 3'-end region of the coagulase gene. We collected a total of 42 MRSA isolates, consisting of 20 strains from the hospital environment, 13 strains from the nostrils or fingers of medical staff, and 9 strains from inpatients in the EMC. We compared our results with those from 27 stock strains of known coagulase serotype and 2 strains reported in the literature. All 69 strains tested have four to six tandem repeats in the 3'-end region of the coagulase gene. Among the 42 MRSA isolates collected, the base sequence of the 3'-end region of the coagulase gene was identical in 28 of them (67%). The number of isolates originating from the hospital environment, medical staff, and patients, respectively, that were identical to this representative strain were 18 (90%), 6 (46%), and 4 (44%). Phylogenetic analysis using the DNA sequences of the tandem repeat region demonstrated that almost all strains from the patients formed a concordant cluster with the representative strain from the hospital ward. We also assessed the value of sequence analysis of the 3'-end region of the coagulase gene as an epidemiological marker. Our results indicate that sequence analysis of the 3'-end region of the coagulase gene of MRSA may be a potent epidemiologic typing system.

Bacterial Typing Techniques↗

Quantitative determination of gelatinase activity among enterococci.

Gelatinase, hemolysin and aggregation substance have all been reported to be virulence factors of enterococci. In this study, gelatinase production was investigated in isolates of Enterococcus faecalis (n=93), E. faecium (n=49) and E. avium (n=36) recovered from hospitalized patients. Gelatinase was detected in 45% of E. faecalis isolates, but could not be detected in E. faecium and E. avium. Gelatinase activity was then measured by radial diffusion for the 42 gelatinase-positive E. faecalis isolates. To convert gelatinase activity into proteinase K activity, a standard curve was produced by placing different concentrations of proteinase K into wells in the gelatine plate. Gelatinase activity per E. faecalis colony ranged from 2.6 x 10(-7) to 2.2 x 10(-5) microg/ml, proportionate to the activity of proteinase K. An approximately 84-fold difference in gelatinase concentration was observed between the colony producing the highest amount and that producing the lowest amount. This method may be useful for determining the virulence of given isolates in relation to gelatinase production as it is quick, easy and inexpensive to perform.

Adult↗

Lymphatic spreading pattern of intrahepatic cholangiocarcinoma.

BACKGROUND: There have been very few reports on the pattern of lymphatic spread of intrahepatic cholangiocarcinoma. This pattern was elucidated to help define the rational extent of radical lymph node dissection. METHODS: Thirty-nine consecutive patients who underwent hepatectomy with radical lymph node dissection were reviewed retrospectively. RESULTS: Lymph node metastases were detected in 24 of the 39 patients (62%). The metastatic nodes were found in the hepatoduodenal ligament, along the common hepatic artery, around the abdominal aorta, on the posterior surface of the pancreas head, along the left gastric artery, along the superior mesenteric artery, around the celiac artery, along the lesser curvature of the stomach, and around the cardia. The nodal involvements along the left gastric artery, along the lesser curvature, or around the cardia were recognized only in the left peripheral and hilar types of cholangiocarcinoma, while all other sites included both the left or right peripheral type and the hilar type cholangiocarcinoma. CONCLUSIONS: Intrahepatic cholangiocarcinomas, irrespective of their intrahepatic location, mainly spread to the nodes in the hepatoduodenal ligament, then to the para-aortic nodes, retropancreatic nodes, or common hepatic artery nodes. In addition to these spreading routes, the left peripheral type or hilar type of cholangiocarcinoma tends to spread along the left gastric nodes through the lesser curvature.

Adult↗

Relatedness between the coagulase gene 3'-end region and coagulase serotypes among Staphylococcus aureus strains.

The 3'-end region of the coagulase gene from 22 strains of Staphylococcus aureus including 10 standard serotype strains was sequenced, and five subgroups with 4-8 tandem repeating units were distinguished among the tested strains. Phylogenetic analysis of the 3'-end region of the coagulase gene indicated that strains belonging to the same serotype were clustered in the same branch. A phylogenetic tree of the deduced amino acid sequences revealed that the C-terminal region might not be responsible for the epitope of the coagulase protein.

Bacteriological Techniques↗

Evaluation of the activity of antimicrobial agents against Legionella pneumophila multiplying in a human monocytic cell line, THP-1, and an alveolar epithelial cell line, A549.

The intracellular activity of three antimicrobial agents, erythromycin, clarithromycin, and ciprofloxacin, against Legionella pneumophila was examined in the human monocyte-derived cell line, THP-1, and the human alveolar epithelial cell line, A549. L. pneumophila multiplied by three- to four-log in THP-1 and by two- to three-log in A549 after 48-h incubation. The activity of the two macrolides was markedly greater in A549 than in THP-1, while ciprofloxacin exhibited similar activity in both cell lines. The intracellular concentrations of the two macrolides were markedly higher in A549 than in THP-1, while those of ciprofloxacin were almost equal in both types of cell lines. The intracellular activity of antimicrobial agents and the intracellular growth of L. pneumophila vary with different types of host cells.

Anti-Bacterial Agents↗

Comparative uptake of grepafloxacin and ciprofloxacin by a human monocytic cell line, THP-1.

The present study was designed to compare the uptake of grepafloxacin by a human monocytic cell line, THP-1, with that of ciprofloxacin. THP-1 cells were incubated with 20 microg/ml of either drug, and the entry of the drugs into the cells was determined using a velocity gradient centrifugation technique and HPLC assay. Antibiotic uptake by the cells was expressed as the ratio of the intracellular to the extracellular drug concentration (IC/EC). Grepafloxacin entered THP-1 cells readily within 5 min, and at steady-state (37 degrees C; 60 min), the IC/EC ratio of grepafloxacin (11.9 +/- 1.7; n = 13) was about 2.4-fold higher than that of ciprofloxacin (5.0 +/- 1.3; n = 13). The ratios decreased at low incubation temperature (4 degrees C), in paraformaldehyde-treated dead cells, and at low extracellular pH (pH 6.0), but were not influenced by high extracellular pH (pH, 9.0). Characterization of fluoroquinolone uptake suggests that these drugs penetrate the THP-1 membrane by passive diffusion, and also, in part, via an active transport system. We also examined the uptake of the two fluoroquinolones in phorbol 12 myristate 13-acetate (PMA)-stimulated adherent THP-1 cells (THP-1 macrophages). The IC/EC ratios for both fluoroquinolones in the THP-1 macrophages were significantly higher than those in the THP-1 monocytes. Further the uptake of three other fluoroquinolones, levofloxacin, tosufloxacin, and sparfloxacin, by THP-1 monocytes was examined in comparative studies. The IC/EC ratio of grepafloxacin was comparable to that of sparfloxacin and significantly higher than that of the other fluoroquinolones. Our results indicate that grepafloxacin exhibits better intracellular accumulation than ciprofloxacin and other fluoroquinolones in human monocytic and macrophage-like cells.

Anti-Infective Agents↗

Intraductal papillary tumors of the pancreas. Histopathologic correlation of MR cholangiopancreatography findings.

PURPOSE: To evaluate MR cholangiopancreatography (MRCP) findings of intraductal papillary tumors of the pancreas and correlate them with histopathology. MATERIAL AND METHODS: Seventeen patients with intraductal papillary tumor of the pancreas underwent MRCP before surgery. MRCP findings were correlated to histopathology with regard to the presence of septa and excrescent nodules in the cystic lesion, communication between the cystic lesion and the main pancreatic duct (MPD), degree of dilatation of MPD, and dilatation of the common bile duct (CBD). RESULTS: MRCP demonstrated septa in 17 cases (100%), excrescent nodules in 8 cases (47.1%), communication between the intraductal papillary tumor and the MPD in 14 cases (82.3%), dilatation of MPD over 50% in 6 cases (35.3%), and dilatation of CBD in 3 cases (17.6%). These findings showed excellent correlation with histopathology. The septum on MRCP corresponded with a layer of connective tissue with pancreatic duct epithelium. Excrescent nodules in the carcinomas consisted not only of malignant cells, but also of dysplasia and adenoma. Excrescent nodules in adenomas were consistent not only with minimal papillary growth of adenoma, but also with proliferation of fibrosis, and hematoma and organized fibrin with minimal fibrosis. Pancreatic tissue was affected by chronic pancreatitis in all cases. Cases with dilatation of CBD on MRCP were due to microscopic invasion by the carcinoma. CONCLUSION: MRCP appearances of intraductal papillary tumors are well correlated with the findings at histopathology.

Adenocarcinoma, Papillary↗

Evaluation of a human monocytic cell line THP-1 model for assay of the intracellular activities of antimicrobial agents against Legionella pneumophila.

We examined the intracellular activities of 11 antimicrobial agents against Legionella pneumophila using a human monocyte-derived cell line, THP-1. Colony counting and microscopic examination of L. pneumophila co-incubated with THP-1 cells (5 x 105 cells/well) were performed. Both extra- and intra-cellular multiplication of L. pneumophila were observed and were dependent on the inoculum of L. pneumophila in the culture; L. pneumophila did not grow in the cell culture medium alone. Light microscopic examination confirmed that extracellular L. pneumophila originated from THP-1 cells disrupted by bacterial multiplication. L. pneumophila multiplied by 3-4 logs after 24 h incubation with THP-1 cells and their number remained stable at 106-107 cfu/mL until 72 h. The results of viability studies using four antimicrobial agents-ciprofloxacin, erythromycin, minocycline and rifampicin-demonstrated that our system was suitable for the intracellular activity assay. We used a concept of 'minimum extracellular concentration inhibiting intracellular multiplication' (MIEC) to evaluate the intracellular activity of antimicrobial agents. The MIECs of three beta-lactams were markedly higher than their conventional MICs while those of macrolides, quinolones, rifampicin and minocycline were similar to their MICs. Our results suggest that evaluation of the clinical efficacy of drugs against L. pneumophila should include determination of their intracellular activity against the bacteria, which could be measured using our assay system in THP-1 cells.

Anti-Bacterial Agents↗

Value of extended resection and intraoperative radiotherapy for resectable pancreatic cancer.

Since 1984 intraoperative radiotherapy (IORT) combined with extended resection for pancreatic cancer has been performed in our clinic to prevent local recurrence. Following extended resection, a dose of 30 Gy of 9- to 12-MeV electrons is administered to the operative field, including the paraaortic area from the diaphragm above to the inferior mesenteric artery below. The 5-year survival rate was 15.3% in all 37 cases, 20.2% in patients who had macroscopic tumor clearance, and 16.9% in patients with stage IVa tumor according to the Japanese classification. In autopsies of 10 patients who underwent combined therapy, four had local recurrence enclosed by thick, firm connective tissue. There was no local control recurrence in two patients who underwent noncurative resection. Enhanced local control induced by the combined therapy, however, has only a limited impact on overall survival because of the systemic spread of disease, especially hepatic metastases. At present, as we have no effective treatment for hepatic metastases, it is important to perform an extended resection with IORT on carefully selected patients. The combined therapy may offer the best approach to control local recurrence when dealing with advanced, but not highly advanced, cancer as defined by the stage of tumor. Therefore a combination of IORT and extended resection can have an impact on the results of surgical treatment for pancreatic cancer when anticancer treatment of hepatic metastases is established.

Adult↗

Removal and inactivation of hepatitis B virus from contaminated pooled plasma in a large-scale manufacturing process for factor VIII and human serum albumin.

BACKGROUND AND OBJECTIVES: The Japanese Red Cross Society recalled one lot of monoclonal-antibody-purified factor VIII (F VIII) and two lots of human serum albumin (HSA) 5 months after preparation of the final products, because of a procedural error that led to contamination by a unit of plasma positive for hepatitis B surface antigen (HBsAg). We evaluated the effectiveness of virus inactivation/removal in a large-scale process for manufacturing F VIII and HSA. MATERIALS AND METHODS: HBV DNA in the retained samples in process was measured by the polymerase chain reaction (PCR). The kinetics of virus inactivation by solvent-detergent (S/D) treatment was examined using model viruses. We also did a look-back survey of the patients who received corresponding products. RESULTS: Contaminated hepatitis B virus (HBV) DNA became undetectable beyond fraction S IV-I in the albumin process and immunoaffinity chromatography in the F VIII process, respectively. The model viruses were inactivated within 5 s by S/D treatment. There is no evidence that patients were infected by HBV after transfusion of these products. CONCLUSION: We conclude that virus inactivation/removal was effectively achieved in a large-scale manufacturing process for F VIII and HSA.

Factor VIII↗