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Biomedical subjects

A Shimizu

Publications and source records attributed to A Shimizu.

At least 253 records · Page 14Linked to original sources
PubMed1996

An in vitro investigation of the tooth strains associated with four different restorations in Class II cavity.

The purpose of this study was to examine tooth strains in Class II preparations. A Class II cavity was prepared in 16 permanent premolars, and a strain gauge was attached to the buccal surface of each tooth. Each cavity was then restored with bonded amalgam, bonded gallium, composite, or composite with a resin liner. The tooth strains created by these four restorations were determined and evaluated with a strain indicator. The results of this study indicated that composite restorations with and without resin liner created much greater strains to tooth structure than did bonded amalgam and bonded gallium restorations. The application of resin liner before placement of the composite was effective for decreased tooth strain.

Alloys↗
PubMed1996

A comparison of the food composition table-based estimates of dietary element intake with the values obtained by inductively coupled plasma atomic emission spectrometry: an experience in a Japanese population.

In order to make quantitative comparison between food composition table-based estimates and instrumental measures by inductively coupled plasma atomic emission spectrometry (ICP-AES), total food duplicates were collected from 232 adult women in 10 study regions in 9 Prefectures in Japan. Daily dietary intake of 5 elements, sodium (Na), potassium (K), phosphorus (P), calcium (Ca) and iron (Fe), were estimated from the weights of food items in each duplicate by use of food composition tables. Parallel to this the intakes were measured by wet-ashing of food duplicate homogenates followed by ICP-AES analysis. Because the emission intensity of K was significantly modified by Na co-present at various concentrations, K was measured after Na concentration was reduced to the value 150 mg/L by dilution. The comparison of the two sets of the results, the estimated values and the measured values, showed that the estimated values were significantly larger than the measured values in the cases of Na, K, Ca and P (the ratio of the estimated to the measured values: 118% for Na, 115% for K, 109% for Ca; and 130% for Fe), whereas the two values essentially agreed with each other in the case of P (ratio: 93%). The differences were too large for any nutritional evaluation to be made when the method of Bland and Altman is applied. The significance of the differences in relation to nutritional evaluation of element intake is discussed.

Adult↗
PubMed1996

Human herpesvirus-6-associated exanthema in a patient with acute lymphocytic leukaemia.

SUMMARY: We report the first case of human herpesvirus-6 (HHV-6) associated exanthema in a patient with acute lymphocytic leukaemia (ALL). We analysed DNA extracted from an exanthematous lesion using the polymerase chain reaction (PCR). DNA was positive for HHV-6 but negative for herpes simplex virus, varicella zoster virus, and cytomegalovirus. Immunohistochemical staining of the skin with monoclonal antibody against (HHV-6 confirmed the infection. The possibility of HHV-6 infection should be considered when an atypical skin rash is seen in patients with ALL.

Adult↗
PubMed1996

A synthetic peptide study on the molten globule of alpha-lactalbumin.

We investigated the conformations of peptides that encompass the B helix or C helix region formed in the molten globule of bovine alpha-lactalbumin to get information on the molecular mechanism that stabilizes the molten globule. The CD spectra show that the isolated B and C helices are intrinsically unstable. The chemical shifts, NOE connectivities, and CD spectrum indicate that no helical structure is induced in the C helix region (86-99) by extending the peptide sequence to include the hydrophobic cluster region (101-107), although the hydrophobic cluster region can be regarded as a possible initiation site for folding of the protein. We also clarified that the isolated B helix (23-34) peptide does not directly interact with the C helix or hydrophobic cluster region. These results suggest that the B and C helices in the molten globule are stabilized by their interaction with other parts of the protein.

Amino Acid Sequence↗
PubMed1996

Electrophysiologic effects of a class I antiarrhythmic agent, cibenzoline, on the refractoriness and conduction of the human atrium in vivo.

We investigated the effects of a class I antiarrhythmic drug, cibenzoline, on human atrial muscle in vivo. Electrophysiologic measurements were performed in 44 patients (mean age 49 +/- 15 years), before and after an intravenous infusion of cibenzoline 1.4 mg/kg in 5 min. Extrastimuli at a basic cycle length (BCL) of 500 ms were delivered from the right atrial appendage. The effective refractory period of the right atrium (ERP-A), the conduction time from the high right atrium to the coronary sinus, maximum conduction delay (Max. CD), repetitive atrial firing zone (RAFZ), fragmented atrial activity zone (FAAZ), and conduction delay zone (CDZ) were measured. Patients were divided into two groups according to whether repetitive atrial firing (RAF) was induced (group A, n = 18) or not (group B, n = 26). Cibenzoline increased ERP-A from 198 +/- 25 to 214 +/- 26 ms (p < 0.05) and decreased Max. CD from 55 +/- 23 to 43 +/- 19 ms (p < 0.05). There were significant decreases in the RAFZ (10 +/- 17 to 4 +/- 10 ms, p < 0.05), the FAAZ (20 +/- 25 to 12 +/- 18, ms p < 0.05), and the CDZ (41 +/- 21 to 32 +/- 19 ms, p < 0.05). Cibenzoline significantly increased ERP.A (186 +/- 25 to 212 +/- 26 ms, p < 0.05) in group A, but not in group B. There were significant decreases in the RAFZ [25 +/- 19 to 9 +/- 15 ms (p < 0.05) and FAAZ 22 +/- 29 to 11 +/- 21 ms, (p < 0.05)] in group A, but not in group B. The results suggest that cibenzoline can suppress paroxysmal atrial fibrillation by prolongation of ERP-A and may also have preferential effects on the substrate of atrial fibrillation and RAF.

Anti-Arrhythmia Agents↗
PubMed1996

Isolation of methicillin-resistant coagulase-negative staphylococci from chickens.

Methicillin-resistant coagulase-negative staphylococci were isolated from the nares and skin of 1- to 8-week-old healthy chickens in three flocks from a farm. Isolation of methicillin-resistant coagulase-negative staphylococci was positive for 72 (25.7%) of the 280 chickens tested, with the frequency varying from 2.2 to 100% according to flock. A total of 45 appropriate isolates were selected and subjected to identification. Of the 45 methicillin-resistant coagulase-negative staphylococcal isolates selected, 37 were identified as Staphylococcus sciuri, 5 were identified as Staphylococcus epidermidis, and 3 were identified as Staphylococcus saprophyticus. The distribution of the species was different among the flocks. Comparative analysis of the SmaI-digested chromosomal DNA by pulsed-field gel electrophoresis revealed that the isolates could have originated from a single clone of each of S. sciuri and S. saprophyticus and three clones of S. epidermidis. By two methods based on the PCR technique, the mecA gene was detected in all five representative isolates of each methicillin-resistant coagulase-negative staphylococcal clone. The nucleotide sequence of a PCR fragment obtained from an isolate of S. sciuri was completely identical to the corresponding region of mecA genes reported in human methicillin-resistant Staphylococcus aureus isolates and Staphylococcus epidermidis isolates. The representative methicillin-resistant coagulase-negative staphylococcal isolates were resistant to many beta-lactam antibiotics, and some isolates were also resistant to macrolide and aminoglycoside antibiotics. This is the first evidence of the existence of methicillin-resistant coagulase-negative staphylococci from animals possessing the mecA gene.

Animals↗
PubMed1996

Glomerular capillary regeneration and endothelial cell apoptosis in both reversible and progressive models of glomerulonephritis.

In summary, angiogenetic capillary regeneration with endothelial proliferation occurred among mesangiolytic lesions in Thy-1 GN, and the damaged glomerulus recovered its normal structure with the reconstruction of the capillary network. In anti-GBM GN on WKY rats, the damaged glomerulus showed rare capillary regeneration and progressed to global sclerosis. In Thy-1 GN, endothelial cell apoptosis was found in the regenerated capillaries with endothelial cell hypercellularity. On the other hand, in anti-GBM GN on WKY rats, the number of endothelial cell apoptosis increased during the evolution of glomerular sclerosis. We have concluded that glomerular capillary regeneration plays an essential role in the recovery of damaged glomeruli. Moreover, apoptosis is indispensable in regulating the number of intrinsic endothelial cells. We also found that endothelial apoptosis is important in progression of glomerular sclerosis.

Animals↗
PubMed1996

Rheumatoid factor in the serum of hepatitis C virus-infected patients: an increase in the titre during cold storage.

Storage of serum at 4 degrees C elevated the titre of rheumatoid factor (RF) as measured by nephelometry with IgG-coated latex in 12 of 38 specimens positive for hepatitis C virus. Increased RF following cold storage was not detected in HCV-negative sera. Most of the sera showing the cold-dependent elevation of RF had decreased complement hemolytic activity (CH50) after the cold storage. The RF titre elevated by cold storage decreased to the level of fresh serum by the addition of guinea pig serum as a complement supplement in a dose-dependent fashion. Thus, in the serum of some HCV-infected patients, the affinity of RF appears to be weak, and the binding between the RF and IgG coated on latex may be inhibited by the complement components of fresh serum.

Cold Temperature↗
PubMed1996

Fatal subarachnoid hemorrhage from an inflammatory cavernous carotid artery aneurysm: failure of conservative treatment after early diagnosis--case report.

Inflammatory carotid artery aneurysm is a rare complication of acute paranasal sinusitis. A 50-year-old female presented with a ruptured giant carotid artery aneurysm secondary to infection of the sphenoid sinus and cavernous sinus. She had been healthy until 5 days before admission, when she developed orbital phlegmon and meningitis. She received antibiotic therapy for 10 days. Computed tomography (CT) of the brain 2 days after admission showed no abnormality. However, repeat CT on day 6 showed a round isodense mass in the suprasellar cistern suggesting a cerebral aneurysm. Twelve days after admission, she suffered a fatal subarachnoid hemorrhage. Cerebral angiography revealed a giant left cavernous carotid artery aneurysm with a very irregular shape. Autopsy found sphenoid sinusitis and osteomyelitis extending into the cavernous sinuses. Diagnosis of bacterial inflammatory aneurysms before rupture is very important. Appropriate surgical intervention should be considered if there is enlargement of the original aneurysm or appearance of a new aneurysm indicating a potentially dangerous situation.

Anti-Bacterial Agents↗
PubMed1996

Effect of chorioamnionitis on the levels of serum proteins in the cord blood of premature infants.

OBJECTIVE: To determine the relationships among complements, other serum proteins (including acute-phase reactant), and the cytokine interleukin-6. DESIGN: Prospective observational study. SETTING: A perinatal center, children's hospital, and research institute in Osaka, Japan. PATIENTS: Two hundred fifteen newborn infants ranging from 17 to 42 weeks in gestational age. MAIN OUTCOME MEASURES: We measured the serum levels of several proteins and complements in the cord blood of neonates with and without chorioamnionitis by immunological assays. RESULTS: The levels of C3d, haptoglobin, interleukin-6, IgM, C-reactive protein, and IgA were not influenced by gestational age, and levels of C5, C1q, C2, albumin, C9, and IgG were not influenced by chorioamnionitis status. The levels of C3, C4, CH50, factor B, and orosomucoid were influenced by both factors. CONCLUSIONS: Our investigation of the mutual relation of the data suggests that the increase of cytokine interleukin-6 affects each other component. We suggest that, compared with the serum levels of proteins in neonates with chorioamnionitis, levels in neonates without chorioamnionitis are more similar to those in the normal fetus.

Blood Proteins↗
PubMed1996

Apoptosis in progressive crescentic glomerulonephritis.

Recent studies in the experimental proliferative glomerulonephritis (GN) indicate that apoptosis is the major mechanism that mediates the resolution of glomerular hypercellularity during the repair process of experimental GN. The role of apoptosis during progressive GN, however, has not yet been well understood. We have, therefore, examined the role of apoptosis during the progression of experimental crescentic GN to end-stage renal failure. A progressive model of antiglomerular basement membrane GN was induced in Wistar-Kyoto rats with a single injection of anti-rat glomerular basement membrane antibody. Renal function and histologic studies were performed chronologically from Day 0 to Week 8 after disease induction. The incidence of apoptosis in glomeruli as well as glomerular crescents was examined during the progression of crescentic GN to end-stage kidney disease. Many leukocytes infiltrated glomeruli from the early phase of GN, and severe necrotizing and mesangiolytic glomerular damage was observed from Day 5 to Week 3. After glomerular damage, mesangial hypercellularity with mesangial cell proliferation and extracellular matrix accumulation began with crescent formation. Thereafter, glomerular inflammation continued with marked extracellular matrix accumulation until Week 4, and the renal function deteriorated. The proliferative glomerular lesions subsequently progressed to sclerotic lesions and eventually to chronic renal failure in Week 8. Although the number of proliferating cells and infiltrating leukocytes slowly decreased, glomerular inflammation resolved with scar formation as mesangial sclerosis. Significant apoptosis was present from Day 7 (mean +/- SEM, 0.53 +/- 0.12 cells/glomerular cross-section) and gradually increased in number with the proliferating lesions as glomerular inflammation continued. Moreover, apoptosis increased during the resolution of the glomerular inflammation, and many apoptotic cells were present in the sclerotic lesions in Week 8 (1.97 +/- 0.27 cells/glomerular cross-section). As glomerular inflammation subsided, cellular crescents progressed to fibrous crescents with a reduction of cellularity by Week 8, and apoptosis increased significantly within these lesions. These findings indicate that apoptosis plays an essential role in the resolution of intra- and extraglomerular inflammation and in the elimination of glomerular cells within the scarring regions for progressive crescentic GN. The regulation of the apoptotic phenomenon during crescentic GN may be important in the progression of glomerular inflammation and the development of pathologic glomerular sclerosis.

Animals↗
PubMed1996

v-src interferes with the in vitro erythropoietic stimulatory ability of spleen stromal cells through repression of vascular cell adhesion molecule-1 and stem cell factor.

A mouse spleen stromal cell line, MSS62, can create an in vitro erythropoietic microenvironment in which development of erythropoietin-responsive progentor cells is stimulated by cell-cell contact via stem cell factor (SCF)/c-Kit and vascular cell adhesion molecule-1 (VCAM-1)/very late activation antigen-4 (VLA-4) interactions between stromal and erythroid cells. To find out the effect of src on the erythropoietic microenvironment, MSS62 cells were transfected with v-src oncogene, and its effect on erythropoietic stimulatory activity was measured. Transfectants with high v-Src activity showed reduction in erythropoietic stimulatory activity. A decrease in cell-surface VCAM-1 and SCF mRNA was accompanied by high v-Src activity. These results suggest that v-Src interferes with the erythropoietic stimulatory activity of the stromal cells through repression of VCAM-1 and SCF.

Animals↗
PubMed1996

[Molecular mechanisms for immunoglobulin class switching and IgE production].

Immunoglobulin (Ig) E, which causes the immediate allergic reaction, is produced by B lymphocytes through the class switching. Constant (C) region gene for epsilon heavy (H) chain is lying between C gamma and C alpha genes. Upon stimulation germline forms of the target CH genes of the class switch recombination are first specifically transcribed and spliced to form the germline transcripts in which upstream and downstream of the recombination target region (S region) are joined. These transcription and splicing are essential for class switching. Then, the second isotype Ig is simultaneously expressed with IgM most likely by trans-splicing. This process might be a regulatable intermediate. Finally, DNA recombination between S regions leads the CH genes lying in-between to looping-out deletion.

Animals↗
PubMed1996

Genomic DNA fingerprinting, using pulsed-field gel electrophoresis, of Staphylococcus intermedius isolated from dogs.

OBJECTIVES: To investigate the degree of polymorphism in the pulsed-field gel electrophoresis (PFGE) patterns of Staphylococcus intermedius and to assess the value of this typing method for discriminating strains. SAMPLE POPULATION: 52 S intermedius isolates from diseased and healthy dogs. PROCEDURE: Chromosomal DNA of S intermedius was digested with restriction endonuclease Sma I, and the fragments were separated by PFGE in a 1% agarose gel. RESULTS: Sma I cut the chromosomal DNA into 15 to 23 fragments ranging from about < 1 to 679 kb, and most of the detectable fragments were < 155 kb. Nine fragments, 115, 48, 33, 26, 16, 13, 10, 4, and < 1 kb, were shared by all or almost all (> 71%) of the strains examined. Of the 52 strains, each had a different pattern. S intermedius had a high degree of restriction fragment length polymorphism. The PFGE patterns obtained for S intermedius were stable and reproducible when the strains were tested in the different experiments. CONCLUSIONS: Genomic DNA fingerprinting by PFGE is an effective technique for discriminating S intermedius strains. The PFGE method appears to be a useful molecular marker for epidemiologic or ecologic studies of S intermedius.

Animals↗
PubMed1996

[Aortitis syndrome].

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Aortic Arch Syndromes↗
PubMed1996

Clinical characteristics of traumatic macular holes.

The clinical characteristics of 20 eyes of 20 consecutive patients with traumatic macular hole were studied retrospectively. The macular holes were elliptical with irregular edges in 19 eyes (95%) and ranged in size from 0.2 to 0.5 DD (disc diameter). Posterior vitreous detachment (PVD) was found in only 3 eyes (15%); the vitreous was detached from the macula in only one of these 3. Other conditions found in the 20 patients included commotio retinae, vitreous hemorrhage, hyphema, and choroidal rupture. These findings strongly suggest that most traumatic macular holes develop in the absence of PVD and that the pathogenesis is independent of the occurrence of PVD. We believe that the macular rupture (hole) is caused mechanically by the force of the impact on the posterior pole and the ocular deformity which result from blunt trauma.

Accidents↗