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Biomedical subjects

H Azuma

Publications and source records attributed to H Azuma.

At least 181 records · Page 10Linked to original sources
PubMed1994

Effect of 15-deoxyspergualin on accelerated rejection in rat heart transplantation.

The effect of 15-deoxyspergualin (DSG) on accelerated rejection was evaluated using a rat heart transplantation model. Lewis rats (LEW, RT1l) served as the organ recipient and Brown Norway rats (BN, RT1n) as the donor. In the accelerated rejection model, the LEW recipient was sensitized with BN skin and BN heart was transplanted 7 days later; the heart graft was rejected within 2 days (n = 7). Histologically, the graft showed coagulation necrosis and hemorrhage throughout the myocardium. DSG (2.5 mg/kg/day) was administered to the recipient under the following three protocols: group 1: during the sensitization period (7 days); group 2: from 3 days after the sensitization to 2 days after grafting (7 days), and group 3: immediately after heart transplantation. The mean graft survival period in groups 1, 2, and 3 was 4.3 +/- 0.8 days (n = 7, p < 0.01 vs untreated host), 11.7 +/- 2.1 days (n = 7, p < 0.001, vs. untreated host), and 2.0 +/- 0 days (n = 6), respectively. The rejected grafts in groups 1 and 3 histologically showed coagulation necrosis and hemorrhage. By contrast, in group 2, the major histological change was interstitial lymphocyte infiltration and there were few findings such as coagulation necrosis or hemorrhage. In the complement-dependent cytotoxicity test, serum obtained at the second posttransplant day from the recipients treated in group 1 showed a high cytotoxicity level, although the cytotoxicity level of serum obtained from the recipients treated in group 2 was consistently low.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Nephron supply is a major determinant of long-term renal allograft outcome in rats.

The effects of augmenting the nephron supply on indices of allograft injury were assessed in a rat model of "chronic rejection." Orthotopic renal allotransplantation into unine-phrectomized rats was followed by excision (allograft-alone group) or preservation of the remaining native kidney (allograft+native kidney group) such that the total kidney complement was either the allograft alone, or the allograft plus one retained native kidney. After 18 wk, values for GFR (1.85 +/- 0.3 ml/min) and kidney weights (2.3 +/- 0.2 g) in allograft-alone rats were far in excess of corresponding values in the allograft of allograft+native kidney rats (0.88 +/- 0.1 ml/min and 1.1 +/- 0.5 g, respectively). Proteinuria (35 +/- 2 mg/d) and allograft glomerulosclerosis (24 +/- 8%) also characterized allograft-alone but not allograft+native kidney rats, in whom glomerular structure (allograft glomerulosclerosis, 4 +/- 1%; native kidney glomerulosclerosis, 0%) and glomerular functional integrity (proteinuria 7 +/- 0.7 mg/d) were well preserved. Thus, the observed allograft protection derived from the presence of a retained recipient native kidney supports the hypothesis that a single renal allograft contains insufficient nephrons to prevent progressive renal injury, implicating nephron supply as a major determinant of long-term allograft outcome.

Animals↗
PubMed1994

Electron microscopic studies on the inhibition of degranulation of rat mast cells by a novel anti-allergic agent, PTPC.

When rat mast cells sensitized by IgE antibody were exposed to antigen, transmission electron microscopy revealed alteration of the granules, cavity formation by fusion of the perigranular membrane and granule release by the fusion of the cavity membrane with the mast cell membrane. Scanning electron microscopy disclosed the extrusion of smooth and round bodies from pores formed on the cell surface. These changes were accompanied by the release of histamine. The inhibition of this degranulation by a novel anti-allergic agent, 6-(1-pyrrolidinyl)-N-(1H-tetrazol-5-yl)-2-pyrazinecarboxamide (PTPC), was evaluated quantitatively as an inhibition of the granule alteration and cavity formation. At a concentration of 100 nM, PTPC inhibited the granule alteration and cavity formation as well as histamine release. In the same concentration, PTPC significantly increased the cyclic AMP content in the mast cells. These results suggest that the inhibition of the morphological changes in mast cells by PTPC might be due to the increased cyclic AMP caused by the agent and plays an important role in the suppression of chemical mediators release.

Animals↗
PubMed1994

[Assessment of the volume of the mastoid air cell system using digital image processing].

There has been a great deal of controversy concerning the development of pneumatization in the temporal bone. Many reports on the size of the mastoid air cell system have been discussed a planimetric X-ray method, however, there have been no techniques for direct volume measurement based on high-resolution computed tomography (CT). Discussion of the relationship between ear disease and pneumatization of the temporal bone requires three-dimensional measurement of the temporal bone in vivo. Recently, we developed such a technique by using digital image processing to measure the volume of the mastoid air cell system. With this technique, only the air cells and tympanic cavity, with a grey scale level similar to air outside the skull were easily selected on the CT films. Then, after image processing called "thresholding", only the areas and volumes of these extracted pneumatized parts were calculated. The volumes of the pneumatized parts of the temporal bone were calculated separately as partial volumes divided by several CT planes. The sum of the partial volumes was calculated as the total volume of the aerated cavity. This technique also made it possible to reconstruct a three-dimensional (3D) model of the air cell system for visual presentation. CT images of 43 normal temporal bones were analyzed. The average volume temporal bone pneumatization (including air cells and tympanic cavity) was about 6ml. There were no differences between pneumatization on the two sides in either sex. Comparisons of partial volumes of pneumatization in the temporal bone revealed that the volumes of portions including the tympanic cavity and its surrounding air cells and those of the antrum and its surrounding air cells were larger than those of other portions. 3D models of the air cell system revealed a variety of shapes. These findings indicated that this technique is not only useful for quantitative analyses but for easy subjective morphological analyses.

Adult↗
PubMed1994

[Computerized analysis of facial motions--objective evaluation of facial palsy].

The severity of facial palsy is often diagnosed using a scoring system. However, there have been some problems as to the objectivity and reproducibility of evaluations by this method. To solve these problems, a variety of new methods have been introduced. Compared to the simple scoring method, none of these methods seem to have gained wide-spread application in routine clinical practice. The development of our diagnostic system was inspired by the idea that numerical quantitation of shifting of marks on the face might be possible by means of digital image-processing. Using this method, only marks adhering to the face are extracted, and the shifting position of these marks is quantitatively analyzed. Detailed analysis of the facial movement requires full motion video images. We found that such video images were easily obtainable by application of a Quick Time Movie developed by Apple computer. Twelve healthy subjects served as normal controls. Seven patients were analysed as cases of facial palsy. The facial movements examined in this study consisted of eye-closing and whistling. A total of 20 black marks were used for adherence to the face. The image processing called thresholding leaves only black marks on the face and has made it possible to trace and measure these marks on the face. The shifting positions of the marks moving in accordance with facial movement, from the stationary phase until the maximum stage, were measured and traces were plotted on the coordinate axis. The shifting of the marks adhering to the face was numerically expressed as a trajectory investigation.(ABSTRACT TRUNCATED AT 250 WORDS)

Facial Muscles↗
PubMed1994

[Effects of Chinese medicine on bovine ciliary muscles].

We studied the effects and characteristics of Chinese medicines (Gorei-san (I), Saiko-keishi-to (II), Ryokei-jutsu-kan-to (III), Shokenchu-to (IV)), on the contractions (A) of bovine ciliary muscles. Ciliary muscle strips (width 4 mm x length 6 mm) were prepared and were contracted by a cholinergic agent, carbachol (10(-5)M). The 4 Chinese medicines were diluted to the concentrations of 10(-3)-10(-6) of each adult dosage per day. When these diluted medicines were added, all caused relaxations in a concentration-dependent manner. The percentages of (max B/max A) x 100 were: Gorei-san, 41 +/- 14 (%) (n = 6, mean +/- SD); Saiko-keishi-to, 37 +/- 18% (n = 6); Ryokei-jutsukan-to, 26 +/- 16% (n = 6); and Shokenchu-to, 10 +/- 5% (n = 6). Compared to the control group which did not receive Chinese medicines, drugs I, II and III showed statistically significant relaxation effects (p < 0.05). The amount of relaxation caused by these medicines (I-III) was 1/3-1/4 of the relaxation caused by a cholinergic antagonist, cyclopentlate (10(-5)M). The results suggest that Chinese medicines (I-III) produce moderate relaxation of ciliary muscles.

Animals↗
PubMed1994

[Characteristics of contraction force of bovine ciliary muscles caused by cholinergic agent].

We studied the contractions caused by the cholinergic agent carbachol on bovine ciliary muscles. Ciliary muscle strips (width 4 mm x length 6 mm) were prepared in the directions of the longitudinal and circular muscles. Contractions were measured with an isometric tension recorder. The concentration for 50% effective dose was 10(-7) M carbachol, and maximum contraction was obtained at 3 x 10(-6) M. Also, maximum contraction was obtained at a resting tension of 600 mg for the longitudinal direction and 400 mg for the circular direction. At a resting tension of 400 mg and concentration of 10(-5) M, average contraction for the longitudinal direction (L) was 335 +/- 106 mg (mean +/- SD, n = 20) and 104 +/- 52 mg (mean +/- SD, n = 20) for the circular direction (C). The ratio between L and C was about 3:1. The results suggest that bovine ciliary muscles have more ability to perform accommodation than in previous reports, and that the magnitude of contractions depends on the direction of the ciliary muscle fibers.

Animals↗
PubMed1994

[Mechanical characteristics of the bovine choroid].

We studied the mechanical relationship between the tension and the length of stretch of bovine choroids. Longitudinal and circular choroidal strips (4 mm x 6 mm) were prepared at 3 different locations (I. ora serrata, II. anterior to the equator, III. posterior to the equator). Using a force transducer and a potentiometer, changes in the tension and the length of stretch were recorded simultaneously. At a tension of 600 mg, longitudinal strips stretched more than circular strips at all 3 locations (p < 0.05). Longitudinal strips all stretched to almost the same length (about 1.3 mm), but circular strips stretched less in the order of I, II and III. These results suggest that there are mechanical characteristics in the bovine choroid allowing it to stretch more in the longitudinal direction than in the circular direction.

Animals↗
PubMed1994

Cytokines and adhesion molecules in chronic rejection.

Despite the increasing short-term success of clinical transplantation during recent years, many allografts, regardless of organ type, continue to be lost over the long term due to chronic rejection, despite improvements in immunosuppression and better patient management. Thus, as a long-term answer to an irreversible disease process, organ transplantation has not lived up to its potential. Although the host mechanisms leading to the process remain obscure, the progressive morphological changes evolving in the afflicted organs are well understood. Chronic rejection has long been thought to be an antibody-mediated event, as immunoglobulins and other circulating proteins are often associated with areas of vascular damage. It is becoming more clear, however, that a whole array of host defense factors, primarily, cytokines, lymphokines and adhesion molecules, are of critical importance in the process. This review summarizes various cytokines and their individual functions as well as adhesion molecules potentially involved in aspects of immune responsiveness, and placed in the context of chronic rejection.

Cell Adhesion Molecules↗
PubMed1994

Avascular necrosis of the femoral epiphysis complicating a minimally displaced fracture of solitary bone cyst of the neck of the femur in a child. A case report.

Reported herein is a rare case of a patient with a pathologic fracture through a cyst in the femoral neck that resulted in avascular necrosis of the femoral epiphysis. This type of necrosis is commonly understood to follow displaced fractures of the femoral neck in children, but has also been reported to follow undisplaced fractures.

Bone Cysts↗
PubMed1994

[Quantitative analyses for facial nerve MR imaging].

It is clear, from our clinical experience, that the facial nerve in patients with facial palsy is enhanced on magnetic resonance (MR) imaging after intravenous administration of gadolinium diethylenetriamine. However, some problems with clinical reliability persist. There have been reports that normal facial nerves often show enhancement on MR imaging. We also question whether there are any differences in the degree of enhancement between Bell's palsy and Ramsay Hunt syndrome. To solve these problems, analyses were conducted using a personal computer by means of digital image-processing to measure the gray scale levels of enhanced facial nerves on MR imaging films. Seventeen cases of Bell's palsy, eight cases of Ramsay Hunt syndrome and fourteen normal subjects whose facial nerves showed enhancement on MR imaging were selected for the analyses. The concept of a facial nerve/whole image ratio (F/W ratio), analyzing the degree of enhancement of the facial nerve quantitatively, is introduced in this paper. The F/W ratio is the ratio of the gray scale level of the facial nerve region to the highest gray scale level in the skull at the MR imaging film. When the F/W ratios of these subjects were analyzed, no significant differences were found between Bell's Palsy and Ramsay Hunt syndrome in the degree of enhancement; facial palsy cases showed quantitatively larger F/W ratios than normal subjects.

Facial Nerve↗
PubMed1994

[AML1 gene rearrangements, but no 8;21 translocation in a child with acute myeloblastic leukemia (M2)].

A 3-year-old girl developed fever and bilateral exophthalmos. Her initial peripheral blood counts on admission were; Hb8.7 g/dl, Plt. 10.6 x 10(4)/microliters, and WBC 30,890/microliters with 31% peroxidase-positive blasts, some of which contained Auer rods. The bone marrow smears showed 22% blasts with a certain degree of maturation. She was diagnosed as having M2 type AML. Computed tomography revealed bilateral retoro-orbital tumor. The bone marrow karyotype showed no 8;21 translocation but a loss of one sex chromosome. Molecular analysis of the bone marrow cells disclosed rearrangements of the AML1 gene. Chimeric mRNA coded by the AML1-MTG8 gene was also detected by the RT-PCR method. We concluded that this patient had a masked 8;21 translocation in her leukemic cells.

Child, Preschool↗
PubMed1994

[DNA analysis of cytochrome b positive chronic granulomatous disease (a case report)].

A patient was diagnosed as having chronic granulomatous disease (CGD). This case seems to have been transmitted in an X-linked from judging from the family history. We had previously suggested that the patient's cytochrome b was normal both qualitatively and quantitatively. Thus, we thought that there might be mutation in the gp91-phox (one of the two components of cytochrome b) gene affecting electron transport but leaving other functions intact. To confirm this speculation, we performed DNA analysis. Complementary DNA (cDNA) was obtained from messenger RNA (mRNA) derived from peripheral blood lymphocytes. By using primers specific for the gp91-phox cDNA, the cDNA was amplified by polymerase chain reaction (PCR). The amplified cDNA was then ligated into Blue Script vector and transfected into E. coli (JM109) in order to clone the cDNA of gp91-phox. Then, the cloned cDNA was sequenced. Sequence analysis showed that the nucleotides 1521-1525 were deleted and a new sequence of 8 nucleotides was substituted. This mutation converted Glu-Lys-Thr into His-Ile-Trp-Ala. To confirm that the mutated allele came from the patient's mother; we performed mismatched PCR. PCR using a mutated allele could produce approximately 250 base pair products only when the patient's cDNA was used. PCR using a wild type primer could produce 250 base pair products only when cDNA from a healthy donor was used.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Congenital histidine-rich glycoprotein deficiency.

The proband, a 43-year-old woman, suffered from right transverse sinus thrombosis during oral contraceptive treatment. A month after stopping the drug, her plasma activities of antithrombin III, protein C, protein S, heparin cofactor II, plasminogen and plasminogen activator inhibitor were normal, but her plasma histidine-rich glycoprotein (HRG) level was only 21% of the normal level of 109.5 +/- 51.5% (mean +/- 2 SD). The HRG concentrations in her plasma determined on four different occasions over 6 months were similar. She showed no clinical signs of liver insufficiency or sepsis. Low levels of plasma HRG (20% to 35% of normal) were also found in her aunt, uncle and two daughters. These results suggest that congenital HRG deficiency is inheritary in this family.

Adult↗
PubMed1993

Congenital plasminogen deficiency caused by a Ser572 to Pro mutation.

We used a polymerase chain reaction (PCR) strategy and restriction fragment polymorphism analysis to evaluate all 19 exons of the plasminogen (PLG) gene in a Japanese patient with congenital PLG deficiency and her family members. She presented with cerebral infarction. Sequence analysis following amplification of each exon and its flanking regions showed a single T to C transition in exon 14, which changed a Ser572 codon (TCC) to Pro572 codon (CCC). Since this mutation generates a new Fok I site, the Fok I digestion pattern of the PCR-amplified exon 14 fragments from each family member was analyzed. In all cases, the patterns were consistent with the activities and antigen levels of plasma PLG in those members. Furthermore, all PCR-amplified exon 14 fragments from 15 normal individuals were not restricted with Fok I endonuclease. We conclude that a T to C transition in exon 14 identified in the propositus is responsible for PLG deficiency inherited in this Japanese family with thrombotic episodes.

Adult↗