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Biomedical subjects

T Koike

Publications and source records attributed to T Koike.

At least 271 records · Page 15Linked to original sources
PubMed1998

Clinical applicability of the sweep frequency measuring apparatus for diagnosis of middle ear diseases.

OBJECTIVE: To develop a measuring apparatus that has the ability to sweep both frequency and external auditory meatus static pressure and can display measurement results in a three-dimensional expression. To measure the middle ear dynamic characteristics of normal-hearing subjects and of patients with this apparatus. DESIGN: Investigate 275 ears of 153 normal-hearing subjects and 72 ears with middle ear diseases. RESULTS: The measurement results show fairly distinctive patterns depending on the middle ear conditions, i.e., normal, ossicular chain separation, ossicular chain fixation, secretory otitis media, tympanic membrane perforation, and tympanic membrane atelectasis. The evaluation of patients with ossicular diseases revealed that the rate of correct diagnosis of ossicular chain separation is 84% and that of ossicular chain fixation is 74%. These diagnoses were confirmed by surgery. CONCLUSION: Displaying the measurement results in a three-dimensional expression is helpful to make correct diagnosis in clinical practice. It is especially easy to make a distinction between the ossicular chain separation and ossicular chain fixation. Therefore, it is concluded that this apparatus has a high degree of clinical applicability to the diagnosis of these diseases.

Acoustic Impedance Tests↗
PubMed1998

Herpes simplex virus hepatitis in macrophage-depleted mice: the role of massive, apoptotic cell death in pathogenesis.

Infection with herpes simplex virus or hepatitis viruses can lead to fulminant hepatitis, but there is controversy about the underlying conditions needed for such disease. To investigate how the impairment of host defences might be involved, macrophages were depleted by administration of silica to mice before intravenous injection with herpes simplex virus type 1 (HSV-1). Such mice died rapidly and their livers were yellowish and shrunken (acute yellow atrophy), and occasionally grossly haemorrhagic. Small foci of apoptotic cells developed in the liver lobules; these rapidly became confluent and zonal over time. The overall lesion pattern was similar to massive hepatic necrosis, and there was extensive HSV replication in the liver lesions. In the liver, DNA fragmentation characteristic of apoptosis followed the time course of HSV-1 propagation. These findings suggest that one of the underlying conditions for fulminant viral hepatitis may be inadequate macrophage response, and that the massive hepatic damage, often defined as cell necrosis, may actually be apoptosis of liver cells subsequent to virus infection.

Alanine Transaminase↗
PubMed1998

Vaginal birth after cesarean delivery: results in 310 pregnancies.

OBJECTIVE: To assess and compare the risk associated with a trial of vaginal birth after cesarean section (VBAC) with the risk of an elective repeat cesarean section. METHODS: A retrospective review of the records of 310 consecutive women who, at the Jichi Medical School Hospital in the 6-year period of 1990 through 1995, had previously undergone a primary cesarean section and gave birth to a singleton infant weighing > or = 2,000 g at > or = 36 weeks of gestation in a subsequent pregnancy. RESULTS: Elective cesarean sections were performed on 96 (31%) of 310 women, and VBACs were attempted by 214 women (69%). Vaginal deliveries were successful in 132 (43%) of the 310 pregnancies. No maternal death or perinatal deaths occurred in either group. A uterine rupture occurred in 2 (0.9%) of the 214 women who attempted a VBAC, and 5 women (2.3%) gave birth to neonates with a 1-minute Apgar score < or = 6. None of the 96 women who underwent an elective cesarean section had such complications, although the difference in these complication rates did not reach a significant level. CONCLUSIONS: A trial of a VBAC significantly reduced the rate of cesarean sections. Although the rates of uterine rupture and neonatal asphyxia were slightly higher in women who attempted a VBAC than in women who underwent an elective cesarean section, obstetricians should offer the option of a trial of labor, because more than one-half of the women with a previous cesarean delivery might have successful vaginal deliveries, and the VBAC-related maternal mortality rate does not reportedly differ between women undergoing a trial of labor and women undergoing an elective repeat cesarean section.

Adult↗
PubMed1998

A new endoscopic method of gastric acid secretory testing.

OBJECTIVE: To date, the effect of Helicobacter pylori on acid secretion remains controversial. To evaluate changes in the gastric acid secretory response before and after H. pylori eradication in a large number of patients, we devised a new endoscopic method of gastric acid secretory testing, the endoscopic gastrin test (EGT). METHODS: In EGT, endoscopy was begun 15 min after intramuscular injection of 4 microg/kg tetragastrin. Gastric fluid secreted between 20 and 30 min after gastrin injection was aspirated and collected during endoscopic examination. The amount of acid in the sample collected over this 10-min period was estimated by titration and expressed in H+ mEq/10 min. Fifteen subjects underwent a conventional secretory test using a nasogastric tube (conventional method) and EGT on different days to assess the correlation between results obtained with the two methods. In 10 of these subjects, EGT was repeated under the same conditions to assess its reproducibility. RESULTS: EGT values correlated very well with peak acid output determined by the conventional method (n = 15, r = 0.92) and had high reproducibility (n = 10, CV = 5.6). We noted that EGT takes just a little longer to perform than a routine endoscopic examination, and the influence of an endoscope in the stomach on acid secretion was not present. CONCLUSION: The EGT should be very useful as a rapid, simple substitute for conventional secretory testing when repeated gastric secretory tests are required, especially in investigating the effect of H. pylori on acid secretion in a larger population.

Adult↗
PubMed1998

Effects of chronic nitric oxide synthase inhibition on renal function and histology in polycythemic rats.

Augmented endogenous nitric oxide (NO) production may ameliorate derangement of renal functions or glomerular damage in polycythemia. To investigate this possibility, we examined the effect of NO synthase inhibition with N omega-nitro-L-arginine methyl ester (L-NAME; 50 mg/dl in drinking water) on renal functions and histology in heminephrectomized Sprague-Dawley rats treated for 4 weeks with recombinant human erythropoietin (rh-EP; 500 IU/kg on alternate days). L-NAME elevated the blood pressure which was aggravated by concomitant rh-EP and was ameliorated by treatment with a nonpeptide angiotensin type 1 receptor blocker (CV116; 60 mg/kg in chow). The hematocrit level was prominently increased by rh-EP. The glomerular filtration rate was impaired by L-NAME alone, but was maintained by concomitant administration of rh-EP or CV116. Micropuncture experiments revealed that the glomerular capillary pressure was similarly elevated by L-NAME alone or in combination with rh-EP. L-NAME significantly, although not prominently, aggravated glomerular sclerosis observed with rh-EP alone, and concomitant CV116 ameliorated the glomerular damage. These results suggest that, in polycythemia, enhanced NO production buffers the glomerular damage, and the balance between NO and angiotensin II may play an important role in maintaining renal function and glomerular structure.

Angiotensin Receptor Antagonists↗
PubMed1998

Epitopes on beta2-GPI recognized by anticardiolipin antibodies.

Anticardiolipin antibodies (aCL) found in sera from patients with antiphospholipid syndrome recognize a cryptic epitope that appears on the beta2-glycoprotein I (beta2-GPI) molecule when beta2-GPI interacts with a lipid membrane composed of negatively charged phospholipid or when beta2-GPI is adsorbed on a polyoxygenated polystyrene plate. A homology based model of beta2-GPI was constructed based on the NMR coordinates of sushi domains of human factor H. The conformation was like a cylinder consisting of five domains, its IV and V domains being glued by electrostatic interaction. We used phage-displayed random peptide libraries to search the epitopes of human aCL. Structures similar to consensus sequences selected by a biopanning method was found on domain IV of beta2-GPI.

Amino Acid Sequence↗
PubMed1998

Beta2-glycoprotein I as a 'cofactor' for anti-phospholipid reactivity with endothelial cells.

Beta2-glycoprotein I (beta2GPI) is a cofactor for anti-phospholipid (aPL) binding to cardiolipin (CL)-coated plates. Beta2GPI is also able to bind to endothelial cell (EC) membranes as supported by in-vivo as well as by in-vitro studies. The PL-binding site in the fifth domain of the molecule is involved in the adhesion to endothelium. Actually, specific mutations in this molecular portion abolish endothelium binding and a synthetic peptide spanning the sequence Glu274-Cys288 of the CL-binding site displays comparable adhesion to EC monolayers. Heparan sulphate appears to be one of the anionic EC membrane structures with which cationic beta2GPI interacts, as supported by studies with heparitinase-treated EC. Beta2GPI binding to EC might be related to its activity as endothelial growth factor or as a lipid-carrying glycoprotein. Adhesion of beta2GPI to endothelial membranes offers suitable epitopes for circulating aPL that, once bound, can induce cell activation

Amino Acid Substitution↗
PubMed1998

Antiphospholipid antibodies and atherosclerosis.

Beta2-Glycoprotein I (beta2-GPI) is a major antigen for anticardiolipin antibodies (aCL) induced in patients with antiphospholipid syndrome and their antigenic epitopes are cryptic. The epitopes appear on the surface of beta2-GPI molecule only when beta2-GPI interacts with lipid membranes containing negatively charged phospholipids or polyoxygenated polystyrene surface. Our data also indicated that CuSO4-oxidized low density lipoproteins (oxLDL) are subsequently targeted by beta2-GPI and aCL; however, malonedialdehyde (MDA)-modified LDL were recognized neither by beta2-GPI nor aCL. Beta2-GPI binding to LDL was rapidly increased by incubation with CuSO4. Oxidation of lipoproteins was accompanied with the increment of thiobarbituric acid-reactive substances (TBARS) and denature of apolipoprotein. Ligands on LDL for beta2-GPI seemed to be intermediate oxidative derivatives which were extractable into the chloroform phase by Bligh and Dyer's extraction, but not MDA. Further, immune responses against beta2-GPI, as an anti-atherogenic protein, were demonstrated to induce atherogenic effect in in vitro oxLDL uptake by macrophages.

Antibodies, Anticardiolipin↗
PubMed1998

Cloning, sequencing, and expression of the Bombyx mori receptor for Bacillus thuringiensis insecticidal CryIA(a) toxin.

Bacillus thuringiensis strains produce insect-specific Bt toxins. Bt CryIA(a) toxin binds to a 175-kDa glycoprotein (BtR175) on the microvillus membranes of columnar cells in the Bombyx mori midgut and causes lysis of the cells. BtR175 was purified, and its cDNA was cloned. The cDNA encodes a newly identified 193.3-kDa preproprotein form of BtR175 that includes nine extracellular cadherin repeats, a 23.5-kDa membrane-proximal domain, a membrane-spanning region, and a 13.6-kDa cytoplasmic domain. Spodoptera frugiperda cells transfected with a recombinant baculovirus DNA carrying the cDNA produced a 175-kDa protein that reacted with anti-BtR antibodies and the Bt CryIA(a) toxin.

Amino Acid Sequence↗
PubMed1998

Subclinical alterations in coagulation and fibrinolysis in patients undergoing autologous peripheral blood stem cell transplantation.

We monitored 30 laboratory hemostatic parameters in an attempt to better comprehend alterations in coagulation and fibrinolysis in 10 patients with hematological malignancies subjected to autologous peripheral blood stem cell transplantation (APBSCT). These parameters were assessed before and just after high-dose conditioning chemotherapy, on days 1, 7, 14 and 28. Although, clinical manifestations associated with fibrino-coagulation disorders never occurred, including veno-occlusive disease, a statistically significant increase was seen in 7 of 30 parameters, compared to values seen before conditioning chemotherapy. These were subdivided into early and late phase parameters. The early phase parameters, which increased during the first day after the conditioning chemotherapy was given, then returned to baseline values, included protein C, plasma tissue factor and tissue-plasminogen activator. The late phase parameters, which increased over baseline values during days 7 to 28, included free-protein S, fibrinogen, plasmin-alpha2-plasmin inhibitor complex and soluble-thrombomodulin. The increase of early phase parameters, as produced by the liver and by endothelial cells, may reflect tissue damage by conditioning chemotherapy. Late phase parameters increased in parallel with C-reactive protein, which suggests a correlation with the degree of inflammation, such as the presence of infective disease during neutropenia. These subclinical alterations in coagulation and fibrinolysis which take on a biphasic pattern during the course of APBSCT should be kept in mind by the attending physicians during therapy.

Adolescent↗
PubMed1998

IgA class anti-beta2-glycoprotein I in patients with systemic lupus erythematosus.

OBJECTIVE: To search for a possible relationship between the presence of IgA class anti-beta2-glycoprotein I antibody (abeta2-GPI) and clinical manifestations, including thrombotic episodes, in patients with systemic lupus erythematosus (SLE). METHODS: Serum IgA abeta2-GPI levels in 124 Japanese patients with SLE were measured using a phospholipid independent enzyme immunoassay. Relationships to clinical histories and to various laboratory data including IgG and IgM class abeta2-GPI were examined. RESULTS: Twenty-five percent of patients with SLE were positive for IgA abeta2-GPI. Patients with a history of thrombosis had significantly higher probabilities for positivity of IgA abeta2-GPI, compared to those without. The presence of IgA abeta2-GPI was correlated with presence of lupus anticoagulant and/or biological false positive result for serological syphilis test. Titer of IgA abeta2-GPI significantly correlated with values of IgG abeta2-GPI, IgM abeta2-GPI, and anti-DNA antibodies. CONCLUSION: The presence of IgA abeta2-GPI may be related to the occurrence of thrombosis in patients with SLE. Measurements of IgA abeta2-GPI may be of value for evaluating risk of thrombosis in patients with SLE.

Antibodies, Anticardiolipin↗
PubMed1998

[Antiphospholipid syndrome].

Antiphospholipid antibodies (aPL) are a family of autoantibodies with specificity for negatively charged phospholipids, or more accurately for their complex to phospholipid binding proteins. Their presence is associated with arterial/venous thrombosis and recurrent pregnancy loss. These clinical manifestations with the persistence of aPL are recognized as antiphospholipid syndrome(APS), one of the most common acquired thrombophilia. beta 2-glycoprotein I(beta 2GPI) bears the epitope(s) for anticardiolipin antibodies (aCL) on its molecule, and lupus anticoagulant activity depends on the presence of beta 2GPI or prothrombin. Thus phospholipid binding proteins may have some crucial roles in the pathophysiology of thrombotic events in APS. It has been hypothesized that aPL bind to cells and induce procoagulant activity via phospholipid binding proteins.

Abortion, Habitual↗
PubMed1998

Hematopoietic cytokine-dependent differentiation to eosinophils and neutrophils in a newly established acute promyelocytic leukemia cell line with t(15;17).

We recently established an acute promyelocytic leukemia (APL) cell line (HT93) that has the capacity to differentiate into neutrophils and eosinophils in response to all-trans retinoic acid (ATRA) and human hematopoietic cytokines. The cells had a myeloblastic morphology, were positive for surface CD33, CD34, and CD56, and showed the following karyotypes: 46, XY, t(1;12)(q25;p13), 2q+, t(4;6)(q12;q13), and t(15;17)(q22;q11). When the cells were cultured with ATRA, they showed nuclear segmentation and developed secondary granules consisting in part of neutrophils and eosinophils. In the presence of ATRA and granulocyte colony-stimulating factor (G-CSF), the cells showed polymorphonuclear neutrophil differentiation accompanied by expression of surface CD11b, CD15, CD10, positive activity for neutrophil alkaline phosphatase (NAP), and NAP mRNA expression. In cultures with ATRA and granulocyte-macrophage colony-stimulating factor (GM-CSF), IL (interleukin)-3, or IL-5, HT93 showed remarkable eosinophil maturation at day 8 as determined by luxol fast blue staining, in addition to expression of eosinophil peroxidase and major basic protein. These results indicate that HT93 is an APL cell line with the ability to differentiate into neutrophils and eosinophils, and that these lineages are dependent on the CSF added. HT 93 should prove to be a useful model in analyzing the effects of hematopoietic cytokines on proliferation, differentiation, and maturation of hematopoietic progenitors.

Alkaline Phosphatase↗
PubMed1998

[Correlation between 13C-urea breath test and gastric histological findings in Helicobacter pylori positive patients].

13C-urea breath test (UBT), available for diagnosis of Helicobacter pylori (HP) in the stomach, measures the 13CO in the breath in which 13C urea is resolved in the stomach by urease derived from HP. Accordingly UBT is useful for a test of HP infection. This study is aimed at clarifying the relationship between the UBT and gastric histological findings. For this study we selected 63 patients with HP infection who showed both positive UBT and positive histological diagnosis. Briefly in the UBT procedure, the patients were given 13C-urea (100 mg dissolved 100 ml water) in a fasting state and kept in the left decubitus position for 5 minutes, and then the patients were asked to expire into testing bags before and 20 minutes after administration of the urea. Biopsy specimens were taken endscopically from the gastric antrum and the body. The specimens of all patients showed positive CLO test. HP organisms, inflammation, activity, and atrophy of the gastric specimens, were expressed in score from 0 to 3 according to the Update Sydney system. The UBT values were high correlated with the increase of HP organisms. The UBT was 11.8, 26.3, and 37/1000 in the groups with the scores of 0.1, and 2 in the number of HP organisms from the gastric body, respectively. The UBT was 19.2, 22.2, 36.1, 26.7/1000 in the groups with scores of 0, 1, 2, and 3 for the specimens from the antrum, respectively. The results show that there is a positive correlation between the UBT values and HP organisms. As a result, the UBT correlated with the activity score. Grade of gastric mucosal atrophy was expressed histologically in scores of 0,1,2, and 3. The UBT was 29.4, 19.1, 17.5, and 9.3/1000 in the groups with scores 0,1,2, and 3 in the grades of gastric atrophy from the gastric body, respectively. There was a negative correlation between the UBT values and the grade of gastric atrophy. We conclude that the UBT values which indicate the number of HP organisms can be used not only for diagnosis of HP infection but also the quantitative index of HP load.

Adult↗