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Biomedical subjects

A Kojima

Publications and source records attributed to A Kojima.

At least 55 records · Page 3Linked to original sources
PubMed2000

[A survey on contamination by microorganisms and the effect of handwashing by doctors and nurses at the UOEH Hospital].

Handwashing is very basic and important in controlling nosocomial infection. We researched the effect of handwashing by doctors and nurses at the UOEH Hospital. One hundred and eight doctors and 114 nurses of 19 wards were examined. The number of bacteria was determined by a palm stamp check agar plate for general bacteria before and after handwashing. The difference in the condition of microorganism contamination among the wards was found by the number of bacteria before handwashing, and by comparing the number of bacteria before and after handwashing, the effect of handwashing was determined. Handwashing by water or soap is not effective in killing bacteria. Therefore, we suggest that doctors and nurses use an effective disinfectant when washing their hands before and after contact with patients. We also think that the results noted in this paper will help doctors and nurses to have a better understanding of the importance of infection control.

Bacteria↗
PubMed2000

Cloning and expression of a gene encoding the flagellin of Clostridium chauvoei.

Clostridium chauvoei is a causative agent of blackleg and the major protective antigen of the organism is the flagellar protein. Using an Escherichia coli expression library of the C. chauvoei Okinawa strain, we isolated the fliC gene encoding the flagellin protein. DNA sequence analysis revealed an open reading frame of 413 amino acid residues with a calculated molecular mass of 43819Da. Comparison of the sequence with those of flagellins from other bacteria showed considerable homology in the N-terminal and C-terminal domains. The glutathione-S-transferase (GST)-flagellin fusion protein and the purified FliC protein after removing the GST part with thrombin reacted with both polyclonal antisera and the non-protective monoclonal antibody (Mab), Mo-114. However, the protective Mab, Mo-41, which may recognize its conformational epitope, failed to react with both the GST-flagellin fusion protein and the purified FliC. Furthermore, the GST-flagellin fusion protein and the purified FliC induced very little protective immunity in mice. These results suggested that a conformation-dependent epitope play an important role in the development of immunity against blackleg.

Animals↗
PubMed2000

Apoptosis induced by chelation of intracellular zinc is associated with depletion of cellular reduced glutathione level in rat hepatocytes.

Zn(2+) has multiple implications in cellular metabolism, including free radicals metabolism and cell death by apoptosis. In the present study, we examined the role of Zn(2+) in the regulation of apoptosis in cultured rat hepatocytes. The chelation of Zn(2+) by a membrane permeable metal ion chelator, N, N, N', N'-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN), induced apoptosis. Addition of ZnSO(4) prevented TPEN-induced apoptosis. Unlike the effect of TPEN, a membrane impermeable metal ion chelator, diethylenetriamine pentaacetic acid (DTPA), did not induce apoptosis, indicating that chelation of intracellular Zn(2+) was required to trigger apoptosis. Caspase-3-like proteolytic activity, a general biochemical mediator of apoptosis in a variety of cells and tissues, was also activated with the treatment of TPEN but not DTPA. TPEN treatment, but not DTPA, also resulted in the depletion of intracellular reduced glutathione (GSH) but addition of Zn(2+) recovered the GSH level. N-acetyl-L-cysteine (NAC), a thiol antioxidant, prevented TPEN-induced apoptosis. These results taken together suggest that intracellular Zn(2+) interfere with the apoptosis process, possibly through the regulation of cellular redox potential involving GSH.

Acetylcysteine↗
PubMed2000

Polyamines and thiols in the cytoprotective effect of L-cysteine and L-methionine on carbon tetrachloride-induced hepatotoxicity.

The relationship between cellular glutathione (GSH), protein-SH levels, and lactate dehydrogenase (LDH), with respect to the effect of polyamines on the cytoprotective ability of L-cysteine and L-methionine, the most important components in the sulfur amino acid metabolic pathway, in carbon tetrachloride (CCl4)-induced toxicity in isolated rat hepatocytes was studied. CCl4 induced a LDH release and decreased cellular thiols and polyamines levels but treatment with L-cysteine and L-methionine reversed these decreases. Treating with methylglyoxal bis-(guanylhydrazone), MGBG, an irreversible inhibitor of S-adenosylmethionine decarboxylase, which is a key enzyme in spermidine and spermine biosynthesis, and therefore used to deplete cellular polyamines, prevented the protective effect of L-cysteine and L-methionine, but the addition of exogenous polyamines inhibited the influence of MGBG. These results suggest that the cytoprotective effect of L-cysteine and L-methionine in CCl4-induced toxicity were via maintenance of cellular polyamines, GSH and protein-SH concentrations and prevention of LDH leakage.

Animals↗
PubMed2000

Anomalies of inferior vena cava and left renal vein: risks in aortic surgery.

Although most aortic surgery is now routinely performed without incident, major venous anomalies can cause unexpected bleeding. In the last 6 years, 4 of 166 patients undergoing abdominal aortic surgery at our institution were found to have a major venous anomaly, including a double inferior vena cava (2), a preaortic iliac vein confluence (1), and a circumaortic renal collar (1). The 3 men and 1 woman had a mean age of 62.3 years (range, 56 to 68 years). All four patients underwent surgery for an abdominal aortic aneurysm. Preoperative imaging revealed all of the venous anomalies except for the renal collar. Unexpected venous injuries complicated the operation in one patient who had a double inferior vena cava and an inflammatory abdominal aortic aneurysm and in the patient with the circumaortic renal collar. Major venous anomalies are rarely encountered in patients undergoing aortic surgery. Preoperative assessment and intraoperative awareness are important to prevent unexpected venous injuries. Patients with an anomaly of the left renal vein and an inflammatory abdominal aortic aneurysm are at a particularly high risk.

Aged↗
PubMed2000

Antimicrobial susceptibilities of enterococci isolated from faeces of broiler and layer chickens.

Enterococci were isolated from faecal droppings of chickens in broiler and layer farms and the susceptibilities to nine therapeutic antimicrobial agents and six growth-promoting antibiotics were determined by the agar dilution method. Resistance to therapeutic antimicrobial agents such as ampicillin, clindamycin, erythromycin, streptomycin, tetracycline or tylosin was more frequent in enterococcal isolates from broiler farms than in those from layer farms. Resistance to ofloxacin was rare, occurring in only one (0.7%) of the Enterococcus faecium isolates from broiler farms. Resistance to growth-promoting antibiotics such as avilamycin, salinomycin and virginiamycin was common among isolates from broiler farms. Of the E. faecium isolates from broiler farms, 12.4% were resistant to avilamycin and 27.4% were resistant to virginiamycin. Resistance to salinomycin was detected in all enterococcal species, ranging from 12.4% of E. faecium isolates to 50% of E. hirae isolates.

Animal Husbandry↗
PubMed2000

Antimicrobial susceptibility of Arcanobacterium pyogenes isolated from cattle and pigs.

The minimum inhibitory concentrations (MICs) of 18 antimicrobial agents were determined for 49 Arcanobacterium pyogenes isolates (42 bovine isolates and 7 porcine isolates). Benzylpenicillin and ampicillin were the most active antibiotics, with MIC ranges of < or = 0.0125-0.05 microgram/ml for both bovine and porcine isolates. All isolates were susceptible to penicillins and cephems. MICs for 90% of the isolates of dihydrostreptomycin, gentamicin and oxytetracycline for bovine isolates were > 100 micrograms/ml, 1.56 micrograms/ml and 25 micrograms/ml, respectively. More resistance to dihydrostreptomycin appeared among porcine isolates (85.7%) than among bovine isolates (52.4%). Resistance to gentamicin occurred in only 3 (7.1%) of the bovine isolates. Resistance to oxytetracycline also appeared more frequent among porcine isolates (85.7%) than among bovine isolates (57.1%). All bovine isolates were susceptible to erythromycin, tilmocosin and lincomycin, but two porcine isolates (28.6%) were simultaneously resistant to these antibiotics. Tiamulin was as active as tilmicosin, with an MIC for 50% of the isolates (MIC50) of 0.05 microgram/ml for both bovine and porcine isolates. The MIC50s of chloramphenicol and its derivatives florfenicol and thiamphenicol were all 1.56 micrograms/ml. The fluoroquinolones enrofloxacin and ofloxacin were not so active as penicillins and macrolides, with MIC50s of 0.78 microgram/ml and 1.56 micrograms/ml, respectively, for both bovine and porcine isolates.

Actinomycetaceae↗
PubMed2000

Rapid identification and differentiation of pathogenic clostridia in gas gangrene by polymerase chain reaction based on the 16S-23S rDNA spacer region.

In cattle, sheep, and other ruminants, clostridial myonecrosis (gas gangrene) is mostly caused by Clostridium chauvoei, C septicum, C novyi and C sordellii. A polymerase chain reaction (PCR) system using common primers designed from multiple alignment of the 16S rRNA and 23S rRNA genes of Clostridium species was developed to identify pathogenic clostridia. The PCR was performed with total DNA from 26 strains which included seven different Clostridia species. These bacteria were differentiated at species level by the different PCR product patterns. To characterise the 16S-23S rDNA spacer regions of these clostridia further, most PCR products of these bacteria were sequenced. The smallest PCR products of each bacterium represented the fundamental 16S-23S rDNA spacer region; larger PCR products of each bacterium were caused by insertion sequences, i.e. tRNA gene sequences. The authors' observations indicate that the PCR patterns of the 16S-23S rDNA spacer regions have the potential to be used as an identification marker of pathogenic clostridia in gas gangrene.

Animals↗
PubMed2000

Effect of brain-derived neurotrophic factor, nerve growth factor, and neurotrophin-3 on functional recovery and regeneration after spinal cord injury in adult rats.

This study examined whether continuous intramedullary infusion of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), or neurotrophin-3 (NT-3) had either an early neuroprotective effect or a delayed effect on regeneration after spinal cord injury (SCI) in adult rats. BDNF, NGF, NT-3 or vehicle was infused at a rate of 625 ng/h into the SCI site at T3 through an implanted cannula attached to an osmotic pump. This infusion was maintained for 14 days after a 35-g clip compression injury. At 4 weeks after injury, the axonal tracer fluorogold (FG) was introduced into the spinal cord caudal to the lesion and the animals sacrificed 3 days later following behavioral assessment. The inclined plane score was significantly higher in BDNF-treated animals (45 +/- 3 degrees) compared to control animals (36 -/+ 1 degrees) at 1 week after injury (p < 0.05), although the scores were not significantly different at later times. BDNF-treated animals also showed more FG-labeled cells in the red nucleus and sensorimotor cortex (1,638 +/- 350 and 124 +/- 83, respectively) compared to controls (1,228 +/- 217 and 36 +/- 15, respectively) and a lower percent cavitation at the injury site (21.4 +/- 10.4%) compared to control animals (32.3 +/- 11.7%). Invasion & proliferation of Schwann cells and formation of peripheral myelin were more prominent at the injury site in the BDNF-treated animals than in the other groups. These results indicate that continuous intramedullary infusion of BDNF provides neuroprotection and enhances some regenerative activity after SCI.

Animals↗
PubMed2000

Apoptosis induced by 1'-acetoxychavicol acetate in Ehrlich ascites tumor cells is associated with modulation of polyamine metabolism and caspase-3 activation.

The efficacy of the antitumor activity of 1'-acetoxychavicol acetate (ACA), reported to be a suppressor of chemically induced carcinogenesis, was evaluated in Ehrlich ascites tumor cells. ACA treatment resulted in changes in morphology and a dose-dependent suppression of cell viability. Apoptosis, characterized by nuclear condensation, membrane blebbing, cell shrinkage and a significant induction of caspase-3-like protease activity at 8 h in a time-course study were observed. Formation of apoptotic bodies was preceded by lowering of intracellular polyamines, particularly putrescine, and both dose- and time-dependent inhibitory and activation effect by ACA on ornithine decarboxylase (ODC) and spermidine/spermine N(1)-acetyltransferase (SSAT), respectively. Administration of exogenous polyamines prevented ACA-induced apoptosis represented by a reduction in the number of apoptotic bodies and also caused reduction in the induced caspase-3-like protease activity at 8 h. These findings suggest that the anticarcinogenic effects of ACA might be partly due to perturbation of the polyamine metabolic pathway and triggering of caspase-3-like activity, which result in apoptosis.

Acetyltransferases↗
PubMed2000

Epidermal growth factor and fibroblast growth factor 2 cause proliferation of ependymal precursor cells in the adult rat spinal cord in vivo.

We investigated the mitogenic effect of continuous intrathecal infusion of epidermal growth factor (EGF) or fibroblast growth factor 2 (FGF2) on ependymal precursor cells of the adult rat spinal cord in vivo. Either EGF, FGF2, EGF plus FGF2, or artificial cerebrospinal fluid (aCSF) was infused at a flow rate of 0.5 microl/h (15 ng/h of EGF or FGF2) for 3 or 14 days into the intrathecal space at T1 through a catheter attached to an osmotic minipump. To assess proliferation, the bromodeoxyuridine (BrdU) labeling index (LI) in the ependyma at T1 was calculated at 3 or 14 days. At 3 days there was no statistical difference in LI between these groups, but at 14 days the LI was significantly higher in the EGF plus FGF2 group (27.2% = 16.0%) than in the aCSF group (5.4% +/- 4.7%; p < 0.05). With EGF alone or FGF2 alone, the LI increases were not significantly different from the aCSF group. With EGF plus FGF2 for 14 days, some BrdU-positive cells in the ependyma also expressed nestin. These results suggest that the intrathecal infusion of EGF plus FGF2 has a mitogenic effect on precursor cells in the ependyma of the adult rat spinal cord.

Animals↗
PubMed2000

Quantitative planar imaging method for measurement of renal activity by using a conjugate-emission image and transmission data.

We are proposing a method to accurately measure renal activity in renography using Tc-99m labeled tracers. This method uses a conjugate-view image and transmission data for attenuation correction, the triple energy window (TEW) method for scatter correction, and background correction techniques that consider the source volume for accurate background activity correction. To examine this method in planar imaging, we performed two renal phantom studies with various uniform background activity concentrations. One study used two ideal box-shaped kidney phantoms with a thickness of 2 or 4 cm in a water tank and the other study employed two real kidney-shaped phantoms in a fillable abdominal cavity. For these studies the kidney phantom-to-background activity concentration ratio (S) was changed from 5 to infinity. The transmission data were obtained with an external Tc-99m line array source. The anterior- and posterior-view emission images were acquired with a dual-headed gamma camera simultaneously and the TEW method was used to correct scatter for the emission and transmission images. The results showed that this method with both the accurate background correction and scatter correction could give depth-independent count rates and could estimate the true count rate with errors of less than 5% for all S values. However, if either accurate background correction or scatter correction was performed alone, the absolute error increased to about 50% for the smaller S values. Our proposed method allows one to accurately and simply measure the renal radioactivity by planar imaging using the conjugate-emission image and transmission data.

Kidney↗
PubMed2000

Contribution of proliferating leukocytes to phenotypic change in smooth muscle cells during the development of coronary arteriosclerosis in transplanted hearts.

BACKGROUND: It is well known that coronary arteriosclerosis after heart transplantation is concentric and rich in smooth muscle cells (SMCs); however, the role played by rejection in the intimal thickening caused by SMCs in coronary arteriosclerosis remains unclear. In this study, we examined the process of intimal hyperplasia caused by SMCs and evaluated the relationship between the differentiation state of SMCs and local inflammation caused by rejection. METHODS: Lewis rat hearts were heterotopically transplanted into F344 rats (allotransplantation group) or other Lewis rats (isotransplantation group). Cyclosporin A (5 mg/kg/day) was injected intramuscularly for 20 days after transplantation in both groups. The transplanted hearts were examined immunohistochemically using several monoclonal antibodies; namely, HHF-35, CGA7, vimentin, alpha-actin, HIS36, R73 and proliferating cell nuclear antigen (PCNA). To evaluate the degree of local immunological response caused by rejection, the anti-PCNA antibody was used. To reveal the subtypes of proliferating cells in the thickened intima, HIS36 and R73 antibodies were used. RESULTS: In the allotransplantation group, SMCs in the media began to undergo a phenotypic change toward a poorly differentiated state 30 days after transplantation. Intimal hyperplasia was observed 60 days after transplantation, the thickened intima being composed mainly of dedifferentiated SMCs with abundant PCNA(+), most of which were macrophages and T cells. The state of differentiation of SMCs in the thickened intima 90 days after transplantation varied from a dedifferentiated to a highly differentiated state. These changes were strongly correlated with the expression of PCNA. CONCLUSION: The expression of PCNA was strongly correlated with the differentiation state of SMCs. Thus, local inflammation caused by rejection may play an important role in the initiation of phenotypic change in SMCs.

Animals↗
PubMed2000

Identification of monoclonal insulin autoantibodies in insulin autoimmune syndrome associated with HLA-DRB1*0401.

We have characterized HLA and insulin autoantibodies in a Japanese female patient with insulin autoimmune syndrome. Serological HLA typing demonstrated the patient had HLA-DR4, and DNA typing showed she had HLA-DRB1*0401 which has not been reported in patients with insulin autoimmune syndrome in Japan. A single binding affinity of insulin autoantibodies was demonstrated by Scatchard analysis and immunoglobulin class of insulin autoantibodies was exclusively IgG-kappa. HLA-DRB1*0406 is strikingly associated with patients with insulin autoimmune syndrome who have polyclonal insulin autoantibodies. The present report demonstrated the first Japanese patient with insulin autoimmune syndrome carrying HLA-DRB1*0401 who was revealed to have monoclonal insulin autoantibodies. The present results indicate that HLA molecules are the major determinants of polyclonal insulin autoantibodies and monoclonal insulin autoantibodies in insulin autoimmune syndrome.

Aged↗
PubMed2000

Macrophage inflammatory protein 3alpha transgene attracts dendritic cells to established murine tumors and suppresses tumor growth.

Dendritic cells (DCs) are powerful antigen-presenting cells that function as the principal activators of T cells. Since the human CC chemokine, macrophage inflammatory protein 3alpha (MIP-3alpha), is chemotactic for DCs in vitro, we hypothesized that adenovirus-mediated gene transfer of MIP-3alpha (AdMIP-3alpha) to tumors might induce local accumulation of DCs and inhibit growth of preexisting tumors. AdMIP-3alpha directed expression of mRNA and protein in vitro, and the supernatant of A549 cells infected with AdMIP-3alpha was chemotactic for DCs. In vivo, injection of AdMIP-3alpha into subcutaneous tumors resulted in local expression of the MIP-3alpha cDNA and in the local accumulation of DCs. In four syngeneic tumor models, growth of established tumors was significantly inhibited compared with untreated tumors or tumors injected with control vector, and in all but the poorly immunogenic LLC carcinoma model, this treatment increased survival advantage of the preexisting tumors. In all four tumor models, intratumoral injection of AdMIP-3alpha induced the local accumulation of CD8b. 2(+) cells and elicited tumor-specific cytotoxic T-lymphocyte activity, and adoptive transfer of splenocytes of animals receiving this treatment protected against a subsequent challenge with the identical tumor cells. In wild-type but not in CD8-deficient mice, AdMIP-3alpha inhibited the growth of tumors. Finally, AdMIP-3alpha also inhibited the growth of distant tumors. This strategy may be useful for enlisting the help of DCs to boost anti-tumor immunity against local and metastatic tumors without the necessity of ex vivo isolation and manipulation of DCs.

Adenoviridae↗
PubMed2000

Causes of late mortality in patients with disabling intermittent claudication.

The long-term prognosis of patients suffering from intermittent ischemic claudication is reportedly worse than that of the normal population. The outcome of patients with ischemic claudication admitted to hospital was reviewed retrospectively to identify the causes of late death. The cumulative survival rates for patients with claudication were 94.6% at 1 year, 79.4% at 3 years, 67.3% at 5 years and 37.4% at 10 years. The 3 major causes of death, that is, ischemic heart disease, malignancy, and cerebrovascular accident, were equally common. The younger patients tended to die of ischemic heart disease, whereas the older patients died of cerebrovascular accidents. Malignancies caused a similar number of late deaths in all age groups. These results suggest that specific care should be given to patients with intermittent claudication based on the age-related causes of death.

Actuarial Analysis↗
PubMed2000

Rapid and direct detection of clostridium chauvoei by PCR of the 16S-23S rDNA spacer region and partial 23S rDNA sequences.

Clostridium chauvoei causes blackleg, which is difficult to distinguish from the causative clostridia of malignant edema. Therefore, a single-step PCR system was developed for specific detection of C. chauvoei DNA using primers derived from the 16S-23S rDNA spacer region and partial 23S rDNA sequences. The specificity of the single-step PCR system was demonstrated by testing 37 strains of clostridia and 3 strains of other genera. A 509 bp PCR product, which is a C. choauvoei-specific PCR product, could be amplified from all of the C. chauvoei strains tested, but not from the other strains. Moreover, this single-step PCR system specifically detected C. chauvoei DNA in samples of muscle from mice 24 hr after inoculation with 100 spores of C. chauvoei, and in clinical materials from a cow affected with blackleg. These results suggest that our single-step PCR system may be useful for direct detection of C. chauvoei in culture and in clinical materials from animals affected with blackleg.

Animals↗