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Biomedical subjects

Y Yajima

Publications and source records attributed to Y Yajima.

At least 73 records · Page 4Linked to original sources
PubMed1997

[The ultrastructure of lens capsule abnormalities in Alport's syndrome].

The ultrastructure of lens capsule abnormalities in Alport's syndrome is reported. An anterior lens capsule from a 29-year-old patient with lenticonus who was affected by Alport's syndrome was obtained at phacoemulsification. The histopathological findings showed decreased thickness of the anterior lens capsule and there were many vertical capsular dehiscences localized at the inner part of the lens capsule. Almost every dehiscence was limited to the inner two-thirds of the capsule. One should be cautious in attempting intraocular lens implantation into the lens capsule, since the lens capsule may be fragile in this disease.

Adult↗
PubMed1997

Evidence for GABAA receptor-mediated inhibition in ambiguous motoneurons.

Laryngeal motoneurons in the nucleus ambiguus were activated antidromically to ipsilateral recurrent nerve stimulation in urethane-chloralose anaesthetized rats. GABAA agonist muscimol and the antagonist bicuculline were applied separately or together with GABA iontophoretically with a multibarrel pipette glued with a recording electrode. The majority of neurons (119/155) which did not respond to the recurrent nerve stimulation exhibited activities mostly related to inspiration. Other 32 neurons were classified as laryngeal motoneurons, according to the criteria. Bicuculline application antagonized GABAA-mediated inhibition while muscimol or GABA reversed this effect significantly. Dose dependent changes were observed for administration of these GABAA-related agents. It can be concluded therefore that laryngeal motoneurons received GABAA-mediated inhibition.

Animals↗
PubMed1996

Ultrastructural characterization of pharyngeal and esophageal motoneurons in the nucleus ambiguus of the rat.

The viscerotopic organization of the upper alimentary tract has been established in the nucleus ambiguus, but there is little information about the morphology of the individual neurons innervating the pharynx and esophagus. We studied the ultrastructure of pharyngeal (PH), cervical esophageal (CE), and subdiaphragmatic esophageal (SDE) motoneurons labeled by retrogradely transported wheat germ agglutinin conjugated horseradish peroxidase (WGA-HRP) in the compact formation of the nucleus ambiguus. WGA-HRP was injected into the lower pharynx, or the cervical and subdiaphragmatic esophagus of male rats. The retrogradely labeled PH neurons in the rostral portion of the compact formation were large (26.1 x 50.1 microns, 906.7 microns2), polygonal, and contained well-developed cell organelles with a round nucleus. Subsurface cisterns connected with rough endoplastic reticulum were often present near the postsynaptic membrane. Both CE and SDE neurons in the compact formation were medium-sized, round or oval, and contained well-developed cell organelles, although the SDE neuron was significantly larger than the CE neuron (24.9 x 33.6 microns, 593.0 microns2 in the SDE neuron, and 19.5 x 30.2 microns, 440.3 microns2 in the CE neuron). The average number of axosomatic terminals in a sectional plane was largest in PH neurons (29.0), smaller in CE neurons (7.9), and smallest in SDE neurons (4.2). The number of axosomatic terminals containing round vesicles (Gray's type I) was almost equal to that of terminals containing pleomorphic vesicles (Gray's type II) in PH and CE neurons, but there were few Gray's type II axosomatic terminals in SDE neurons. Desmosome-like junctions at somato-somatic or somato-dendritic apposition were often present in the area surrounding SDE neurons. There were also small unlabeled neurons (9.5 x 18.1 microns, 131.8 microns2) in the compact formation of the nucleus ambiguus. The small neurons contained poorly developed cell organelles and an irregular shaped nucleus with invaginated nuclear membrane, and had no Nissl bodies. These results indicate that PH neurons have the characteristics of somatic motoneurons, and that CE and SDE neurons are similar to visceral motoneurons.

Animals↗
PubMed1996

Effects of early insulin treatment on ultrastructural changes of glomeruli in diabetic rats revealed by the quick-freezing and deep-etching method.

The three-dimensional ultrastructure of glomerular basement membrane (GBM) and mesangial matrix (MM) at an early stage of streptozotocin (STZ)-induced diabetes mellitus in rats was examined by the quick-freezing and deep-etching method. In diabetic rats, the GBM inner layer was diffusely enlarged and the meshwork structure not only in the GBM middle layer but also in the MM became markedly irregular due to the rupture of fine fibrils. This irregularity and enlargement of the mesh pores in diabetic rats developed during the experimental period and was significantly different from results in control rats. Insulin treatment from 1 week after STZ injection had significant effects in preventing the ultrastructural changes in the GBM and MM. It is suggested that early insulin treatment has significant effects in preventing size barrier disturbance of GBM and MM in STZ-induced diabetes.

Animals↗
PubMed1996

Hepatocellular carcinoma associated with anabolic steroid therapy: report of a case and review of the Japanese literature.

We report herein the case of a 35-year-old woman with aplastic anemia who developed hepatocellular carcinoma after long-term therapy with oxymetholone. She was treated with 60 mg/day of oxymetholone for 3 years (total dose 64.8 g). Alpha-fetoprotein, hepatitis B surface antigen, and hepatitis C antibody were all negative, but serum titers of carcinoembryonic antigen and carbohydrate antigen were elevated. Lateral segmentectomy of the liver was performed. The histopathological findings were compatible with those of multiple hepatocellular carcinoma without liver cirrhosis. Three years since the operation, the patient is doing well and no signs of tumor recurrence have been detected. According to our review of Japanese cases of hepatocellular carcinoma associated with anabolic steroid therapy, in all instances the tumors developed after long-term administration of anabolic steroids for hematologic diseases. In patients under long-term anabolic steroid therapy, routine screening of the liver by ultrasonography and computed tomography should be performed to detect liver tumors in the early stages.

Adult↗
PubMed1996

Is ACE gene polymorphism a useful marker for diabetic albuminuria in Japanese NIDDM patients?

OBJECTIVE: We studied the relationship between an insertion/deletion (I/D) polymorphism in the ACE gene and albuminuria/proteinuria in Japanese NIDDM patients. RESEARCH DESIGN AND METHODS: A total of 142 Japanese NIDDM patients (89 men, 53 women) with a known diabetes duration of 14 +/- 5 (mean +/- SD) years and an age of 56 +/- 6 years were divided into three groups according to the stage of nephropathy: 41 patients with normoalbuminuria, 47 patients with microalbuminuria, and 54 with overt proteinuria. The three groups were similar in age, diabetes duration, and recent HbAic level. RESULTS: The distribution of DD, ID, and II genotypes of the ACE gene did not differ among the three groups (10, 46, and 44% in the normoalbuminuric patients; 13, 53, and 34% in the microalbuminuric patients; and 15, 46, and 39% in the proteinuric patients, respectively). Meanwhile, the frequency of the D allele in the proteinuric male patients was slightly higher than in the normoalbuminuric male patients (45 vs. 27%, chi 2 = 3.9, P < 0.05), while the D allele frequency was nonsignificantly lower in the proteinuric female patients than in the normoalbuminuric female patients. CONCLUSION: These results did not support the hypothesis that the genotype of the ACE gene would be a clinically useful genetic marker for predicting the development of nephropathy in Japanese NIDDM patients. However, the role of D allele of ACE gene in the progression of nephropathy in male patients remains to be seen.

Albuminuria↗
PubMed1996

[A case of giant hepatocellular carcinoma successfully treated by arterial administration of SMANCS].

A 68-year-old male was referred to our hospital for the precise examination of a giant hepatic tumor detected in a mass survey. The lesion occupied most of the right hepatic lobe, further advancing to the medial segment of the left lobe. However, hepatic functions were well preserved (ICG K = 0.141). Considering the characteristic images of the lesion with positive anti-HCV and high titer of PIVKA II (0.860 AU/ml), the diagnosis was hepatocellular carcinoma. First arterial administration of SMANCS was performed on May in 1994, followed by 6 successive procedures with an interval of about 2 months (total dosage 36 mg), resulting in remarkable tumor shrinkage and tumor marker normalization. On January in 1995, a metastatic lesion to the right rib was controlled by 2 mg of SMANCS administered to the intercostal artery combined with radiation therapy (60 Gray). Frequent administrations of SMANCS caused no serious complications, and tumor feeders were well preserved. Therefore, arterial administration of SMANCS is thought to be one choice for the therapy of giant HCC with good functional reserve.

Aged↗
PubMed1995

The presence of 2-keto-3-deoxygluconic acid and oxoaldehyde dehydrogenase activity in human erythrocytes.

2-Keto-3-deoxygluconic acid (3-DGA) is produced from 3-deoxyglucosone (3-DG:a highly reactive glycation intermediate) through oxidation by the enzyme oxoaldehyde dehydrogenase (OAD) in animals. We developed a specific assay method for 3-DGA using high-performance liquid chromatography [Fujii, E. et al. (1994) J. Chromatogr. B 660, 265-270] and measured it in the hemolysate and plasma of diabetic patients and healthy subjects. Both human erythrocytes and plasma contained considerable amounts of 3-DGA. However, human erythrocyte contained about 30-50 times higher 3-DGA than human plasma did and also had the same ability to convert 3-DG to 3-DGA as OAD had. Erythrocyte 3-DGA levels of diabetic patients were 990 +/- 370 nmol/gHb (n = 57, Mean +/- SD) and were significantly higher compared with healthy subjects (527 +/- 194 nmol/gHb, n = 7, p < 0.01). In all diabetic patients and healthy subjects (n = 64), there was only one patient who had a very low level of erythrocyte 3-DGA and lacked the ability to convert 3-DG to 3-DGA. When erythrocytes were incubated at 37 degrees C for 8 hours in phosphate buffer containing 0.35 mM 3-DG, 3-DG was easily taken into the erythrocytes and was converted to 3-DGA. Our results suggest the contribution of OAD not only to the prevention of glycation of hemoglobin but also to that of blood vessels by scavenging plasma 3-DG into erythrocytes.

Adult↗
PubMed1995

Three-dimensional ultrastructure of human glomerular basement membrane by a quick-freezing and deep-etching method.

The three-dimensional ultrastructure of glomerular basement membrane (GBM) in surgically resected human kidneys was observed by the quick-freezing and deep-etching method. In three layers of human GBM, the middle layer exhibited polygonal meshwork structures, which were composed of fine fibrils. In addition, the outer and inner layers were formed by lines of perpendicular fibrils, which connected the epithelial or endothelial cell surfaces with the meshwork structures of the middle layer. These ultrastructures might correspond to the three layers, such as lamina densa and laminae rara externa and interna, which were also observed on conventional ultrathin sections. It is concluded that the human GBM has the same meshwork structures and perpendicular fibrils as those previously observed in animals and that these structures may act functionally as size and/or charge barriers.

Adult↗
PubMed1995

High-resolution and analytical electron microscopic studies of new crystals induced by a bioactive ceramic (diopside).

Diopside has been developed for use in dental root implants and for the filling of bone defects. In previous studies, diopside developed hydroxyapatite (HA) on its surface and achieved a direct bond with bone. The purpose of this study was to investigate the mechanism of crystal formation on the diopside surface. We ultrastructurally evaluated the interface between new diopside-induced crystals and diopside. Specimens were prepared in three experiments: (1) Granular diopside was immersed in simulated body fluid (SBF); (2) granular diopside was implanted into a cavity in rabbit bone; and (3) a diopside dental root implant was implanted into a Japanese monkey. The specimens were examined by contact microradiography, high-resolution transmission electron microscopy, and analytical electron microscopy. In the experiment with SBF, many platelet-like crystals formed in the diopside surface layer. The lattice of diopside and that of the new crystals were very close, but no clear continuation of the lattice was observed. In the experiments which used a rabbit and a monkey, contact microradiography showed close contact between bone and diopside. High-resolution transmission electron microscopy revealed crystal growth from the diopside surface layer, and continuity between the diopside lattice and that of the new crystals. The morphological characteristics of the new crystals and the results of these analyses suggest that these new crystals are HA. With regard to the mechanism by which crystals are formed on the diopside surface layer, it is possible that epitaxial crystal growth could originate as a nucleus on the surface. In this case, epitaxial crystal growth of primarily octacalcium phosphate (OCP) may have occurred, and this may have changed to HA by a phase transition. However, epitaxial growth of OCP on the diopside surface is still highly speculative, since there is no direct supporting evidence.

Animals↗
PubMed1995

Purification and characterization of bone morphogenetic protein derived from bovine bone matrix.

Bone morphogenetic protein (BMP) was extracted from bovine bone matrix and purified. The 6M guanidine-HCL soluble fraction and the final purified substance were bioassayed by implantation of about 3 mg into the thigh muscles of C3H strain mice. These specimens induced new bone in three weeks when implanted into muscle pouches of the C3H mouse. The final fraction purified by liquid chromatography (fraction III) was shown to be homogeneous by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis (SDS-PAGE). The molecular weight of the bovine bone matrix-derived BMP was estimated to be about 14-18 kDa in MW. The main components correspond to a MW of 18 kDa and 14 kDa when they are compared with the mobilities of standard proteins. These were invariably present in fractions with osteoinductive activity.

Animals↗
PubMed1995

Microvascular free tissue transfer in oral and maxillofacial reconstruction.

Forty-two patients with head and neck cancer were submitted to microvascular reconstructive procedures. We divided patients in three groups; a first group of 30 patients, in whom the oral floor (8 patients), the part of tongue (14 patients), the lower gingiva (6 patients) and the oropharynx (2 patients) were reconstructed using various sizes of forearm flaps; a second group of 7 patients who underwent buccal mucosa reconstructions with the forearm flaps; and a third group of 5 patients who received rectus abdominis flaps for total tongue reconstruction. Three illustrative cases, one from each group, are presented in detail. Good results were obtained in 39 patients (94%), with both functional and morphological rehabilitation. There were three flap losses due to thrombosis of the microvascular anastomoses. There was no surgical mortality. The average operating time was about 10 hours in total. We concluded that there is a place for these complex procedures in the treatment of selected cases of head and neck tumors.

Adult↗
PubMed1994

Quantitation of the glycation intermediate 3-deoxyglucosone by oxidation with rabbit liver oxoaldehyde dehydrogenase to 2-keto-3-deoxygluconic acid followed by high-performance liquid chromatography.

A simple and sensitive method for the detection of 3-deoxyglucosone was developed using oxidation with crude oxoaldehyde dehydrogenase to 2-keto-3-deoxygluconic acid followed by high-performance liquid chromatography (HPLC). Oxoaldehyde dehydrogenase was prepared from rabbit liver and partially characterized. 2-Keto-3-deoxygluconic acid produced from 3-deoxyglucosone by oxoaldehyde dehydrogenase was derivatized with 1,2-diamino-4,5-methylenedioxybenzene, and the fluorescent products were detected and quantitated by HPLC using a solvent containing borate. In the presence of borate, 2-keto-3-deoxygluconic acid was completely separated from N-acetylneuraminic acid. The detection limit of 3-deoxyglucosone was 2.5 pmol/injection (10 microliters) at a signal-to-noise ratio of 3. This method was used to confirm the inhibitory effect of aminoguanidine on glycation.

Aldehyde Oxidoreductases↗
PubMed1994

[Case report of sister with Duane's syndrome and PGA, or myasthenia gravis].

We report a case of polyglandular autoimmune syndrome (PGA) complicated by Duane's syndrome. The patient was 44-year-old female with marked limitation of abduction in the left eye, lethargy, nonhomogeneous facial pigmentation, goiter, and oligomenorrhea. A diagnosis of chronic thyroiditis was first made to explain the patient's symptoms. Laboratory examinations were performed. Plasma ACTH level was high and plasma cortisol was low, and there was no response to the ACTH stimulation test. The presence of primary adrenocortical deficiency was confirmed. Moreover, primary gonadal failure was also present, and the diagnosis of PGA type II was made. The patient's elder sister had myasthenia gravis which is a condition known to occur with PGA type II. Therefore, the sister was also suspected to have PGA type II, as the syndrome can occur in family members. However, since she had been receiving large doses of steroids for her myasthenia gravis, laboratory findings were inconclusive. Duane's syndrome, which is characterized by congenital oculomotor disturbance, was also seen in the sister. It is still unknown whether the familial occurrence of Duane's syndrome has a genetic basis. There have been reports of congenital disorders occurring in combination with autoimmune diseases. Further investigation into the relationship between congenital anomalies and autoimmune diseases is necessary.

Adult↗