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Biomedical subjects

H Miyajima

Publications and source records attributed to H Miyajima.

At least 91 records · Page 5Linked to original sources
PubMed1992

Aniseikonia and stereoacuity in pseudophakic patients. Unilateral and bilateral cases.

PURPOSE: To evaluate the efficacy of intraocular lens (IOL) implant procedures, analyzing visual function of the operated eyes and the resulting binocular vision. METHOD: The authors measured aniseikonia and stereoacuity in patients with both bilateral and unilateral posterior chamber intraocular lenses (PC IOLs). The aniseikonia was measured with the New Aniseikonia Test; the stereoacuity was evaluated with the Titmus Stereotest. RESULTS: In 41 patients with bilateral PC IOLs, aniseikonia measured with the New Aniseikonia Test ranged from 0% to 4% (mean, 0.76%; standard deviation = 1.04%). The average stereoacuity evaluated with the Titmus test was 7.68 circles (less than 60 seconds; range, greater than 800 to 40 seconds of arc), with 36 of 41 patients (87.8%) showing a stereoacuity less than or equal to 100 seconds of arc. In 37 patients with unilateral PC IOLs, the aniseikonia ranged from 0% to 6% (mean, 0.97%; standard deviation = 1.13%). Their stereoacuity also ranged from greater than 800 to 40 seconds (mean, 7.67 circles) (less than 60 seconds). In this group, 34 of 37 (91.8%) patients showed a stereoacuity less than or equal to 100 seconds of arc. CONCLUSION: Although the problem of aniseikonia still remains, a significant number of patients attain good binocular function after unilateral and bilateral PC IOL implantation.

Adult↗
PubMed1992

Spontaneous follicular center cell lymphomas of B cell origin in cataract mice.

Spontaneous lymphomas from a strain of hereditary cataract (CAC-nct/+) mice were examined by light and electron microscopy and by immunohistochemical reaction for the mouse heavy and light immunoglobulin chains. Lymphomas occurred in 28 out of 45 male cataract mice and in 34 out of 52 females at 25 to 65 weeks of age. All of the lymphoma-bearing mice showed an enlargement of the spleen and mesenteric lymph nodes, and some mice also had hepatomegaly. Morphologically, all tumors were composed of a mixed population of small and large cells. Neoplastic cells had features of follicular center cell lymphomas, such as scant to moderate amounts of cytoplasm and cleaved and/or round nuclei with a large nuclear-to-cytoplasmic ratio. Large cells were often admixed with small cells, and had vesicular nuclei with prominent nucleoli juxtaposed to the nuclear membrane. Intracytoplasmic eosinophilic inclusions were observed in occasional cells, but Golgi apparatus was poorly developed and rough-surfaced endoplasmic reticulum was scant, unlike those in plasma cells. C-particles were seen in all lymphoma-bearing mice by electron microscopy. Intracisternal A-particles were detected in some mice. Immunohistochemically, neoplastic lymphoid cells were positive for the kappa light chain and the surface/cytoplasmic immunoglobulin M. These results indicate that lymphoid cell neoplasms found in hereditary cataract mice originate from follicular center B cells.

Animals↗
PubMed1992

Contrast visual acuities in cataract patients. I. Comparison with normal subjects.

Contrast sensitivity and glare sensitivity are often abnormal in cataract patients. However, despite significant subjective complaints, relatively good visual acuities often are obtained with high-contrast optotypes. Using Variable-Contrast Visual Acuity Charts (VCVAC), we measured visual acuities of 40 eyes of 24 normal subjects (visual acuity greater than or equal to 1.0) aged 41 to 72 years, and 40 eyes of 28 cataract patients (visual acuity greater than or equal to 0.6) aged 44 to 81 years. The VCVAC consists of 4 different charts (1-4). The contrast is 90% in charts 1 and 4, 15% in chart 2 and 2.5% in chart 3. Chart 4 is the reverse polarity of chart 1. The decrease of visual acuity compared with the high-contrast chart (chart 1) was larger in the cataract group with both in the 15% contrast (0.52 vs. 0.71 octave) and the 2.5% contrast (1.21 vs. 1.75 octaves). In cataract group, 23/40 eyes (57.5%) showed better visual acuity with chart 4 than that of chart 1. In addition to high-contrast optotypes, acuity measurements using intermediate- to low-contrast optotypes, combined with the reverse polarity chart, seem effective in analyzing the visual disabilities caused by early cataract.

Adult↗
PubMed1992

Contrast visual acuities in cataract patients. II. After IOL implantation.

Contrast visual acuities were measured in 100 eyes of 75 patients who attained a best-corrected visual acuity of greater than or equal to 0.8 (20/25) after intraocular lens (IOL) implantation. The variable contrast visual acuity chart (VCVAC), with three contrast levels of 90, 15, and 2.5% and reverse polarity of 90% contrast, was used to measure contrast visual acuities. The follow-up period ranged from 3 to 35 months (mean 7.41). The mean visual acuities measured with the 90, 15, and 2.5% charts were 0.92 (SD = 0.11), 0.59 (SD = 0.13), and 0.33 (SD = 0.14), respectively. The mean visual acuity measured with the 90% reverse polarity chart was 0.97 (SD = 0.11). The decreases in visual acuities compared with the 90% contrast were 0.64 and 1.48 octaves in the 15% and the 2.5% contrast charts, respectively. The pattern of the contrast acuity profile was comparable to normal subjects, but in 28 of 100 (28%) eyes, the visual acuities measured with the reverse polarity chart were slightly better than those measured with the standard 90% contrast chart, suggesting that the glare effect still exists after IOL implantation, though to a lesser degree than in cataractous eyes.

Adult↗
PubMed1992

Spontaneous lesions in cynomolgus monkeys used in toxicity studies.

Spontaneous lesions in wild-caught, laboratory-maintained cynomolgus monkeys used in drug-toxicity studies were examined histopathologically in an effort to better distinguish toxic changes from spontaneous lesions and assess the toxicity of drugs more exactly. In the liver and kidney, where toxic changes are observed frequently, many spontaneous lesions were observed. Infiltration of mononuclear cells, vacuolization of the hepatocytes, dilatation of the renal tubules, and vacuolization of the renal epithelia were observed at a relatively high frequency. It is considered important to examine these changes carefully, because they closely resemble the changes recognized as toxic. Deposition of brownish pigment was observed in various organs such as the liver, kidney, spleen, intestinal tract, lung and brain, however the type of pigment differed among the organs, and histochemical examination revealed anthracosis or accumulation of hemosiderin, or melanin. Since the monkeys were caught in the wild, many parasitic lesions were observed especially in the large intestine and liver. Helminthous worms were frequently observed in the granulomas in the large intestine, however, no parasites were observed in the granulomas in the liver. Such lesions in the liver may be misinterpreted as toxic changes, when only scars or inflammatory lesions are observed.

Animals↗
PubMed1992

Syndrome of inappropriate secretion of antidiuretic hormone associated with multiple sclerosis.

A 63-year-old man who developed episodes of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) twice in the course of multiple sclerosis (MS) is reported. SIADH in this patient occurred only during the administration of antibiotics (sulbactam/cefoperazone, SBT/CPZ). At autopsy, demyelinating lesions in the optic nerves, cervical and thoracic spinal cord, and areas adjacent to the lateral ventricles were observed. Destruction and loss of neuronal cells were found in the supraoptic nuclei. Lymphocytic infiltration was observed in the area adjacent to the supraoptic nuclei. Destruction and swelling of axons and reactive astrocytic gliosis were observed in the hypothalamus. SIADH associated with MS is rare and the histological findings in such a case have not yet been reported. It is suggested that the development of SIADH in MS may be related to the damage in the supraoptic nuclei of the hypothalamus.

Cefoperazone↗
PubMed1992

Studies on contrast visual acuities in normal, cataractous and pseudophakic eyes.

Contrast sensitivity and glare sensitivity are often abnormal in cataract patients. However, despite significant subjective complains, relatively good visual acuities are obtained with high-contrast optotypes. Using Variable Contrast Visual Acuity Charts with contrast levels of 90, 15, and 2.5% and reverse polarity of 90% contrast, contrast visual acuities were measured in 24 normal subjects (40 eyes) (Landolt visual acuity > or = 1.0); 28 cataract patients (40 eyes) (Landolt visual acuity > or = 0.6); and 75 patients (100 eyes) [best-corrected Landolt visual acuity > or = 0.8 after intraocular lens (IOL) implantation]. The cataract group experienced the greatest decrease of contrast visual acuity when the high-contrast chart (chart 1) measurements were compared with the 15% (0.71 vs 0.52-0.64 octave) and the 2.5% contrast charts (1.75 vs 1.21-1.48 octaves), followed by the IOL group, and the normal subjects. In the cataract group, 23/40 eyes (57.5%) showed better contrast visual acuity with chart 4 than chart 1. Although much less in frequency, 28/100 (28%) eyes with IOLs also showed better contrast acuity measured with chart 4 than with chart 1. In addition to high-contrast optotypes, acuity measurements using intermediate- to low-contrast optotypes, combined with the reverse polarity chart, seem effective to analyze visual disabilities caused by early cataract. The pattern of the contrast acuity profile of the IOL patients was comparable to normal subjects, but the glare effect still existed after IOL implantation, though to a lesser degree than in cataractous eyes.

Adult↗
PubMed1992

[Gene expression in lactate dehydrogenase-A subunit deficiency].

A 33-year-old female complained of muscle pain and stiffness after severe exercise from the age of nine. Her sister also had similar symptoms. Consanguinity was found in her parents. Neither muscle wasting nor weakness was detectable. The activity of LDH in the muscle was decreased less to than 8% of normal value. The isoenzyme pattern of the muscle LDH revealed only one band of B4. The levels of blood lactate did not rise on anaerobic exercise, while a marked increase of pyruvate was found. Northern blot analysis showed that the ratio of LDH-A transcript to beta-actin transcript in the patient was similar to that in a normal subject. RNA preparations were reverse-transcribed, amplified by a polymerase chain reaction (PCR), and separated by electrophoresis. The size of PCR product corresponding to exon 6 was decreased. The nucleotide sequence of this product was determined and a 20 bp deletion was found. This mutation results in a frame-shift translation and premature termination. The predicted incomplete LDH-A subunit contains only 259 instead of 331 amino acids. Immunofluorescence for LDH-A subunit could be seen within the cytoplasm and on the surface membrane of the muscle fibers in our patient as well as control subjects by the immunohistochemical studies. These findings suggest that LDH-A mRNA is transcribed in a truncated form and an enzymatically inactive protein is produced in the patient's muscles.

Adult↗
PubMed1992

[A case of chronic toluene poisoning with myopathic changes].

We reported a 27-year-old man, who had inhaled toluene vapor for 11 years and developed both polyneuropathy and myopathy. He gradually developed progressive muscular weakness in the limbs 2 months after the last inhalation and became nonambulant. Neurological examination revealed distal dominant muscular weakness and hypoactive deep tendon reflexes, especially in the legs. The cranial nerves were intact and neither sensory disturbances nor cerebellar signs were observed. Laboratory studies demonstrated mildly elevated serum CK value, but serum electrolytes and urinalysis were normal. Electromyogram showed a neurogenic pattern in the limbs and also a myogenic in the gastrocnemius muscle. Motor nerve conduction velocities were delayed in the limbs. The sural nerve biopsy specimens showed demyelination, myelin avoids, and axonal swelling compatible with toxic neuropathy. The muscle biopsy of the gastrocnemius revealed necrotic muscle fibers, vacuolated muscle fibers, phagocytosis, a disordered intermyofibrillary network, and small group atrophy on light microscopy. On electron microscopy, two outstanding findings were observed; the first, dilatation and proliferation of the membrane system, and the second, appearance of irregular membrano lamellar structures and vacuoles associated with abnormal membrane system. These histological findings suggest that toluene may affect directly the membrane system of muscle fibers and consequently induce rhabdomyolysis.

Adult↗
PubMed1991

Suppression by IL-2 of IgE production by B cells stimulated by IL-4.

IgE production was obtained from B cells of BALB/c or nude mice when these cells were cultured with IL-4 plus LPS. IL-2 added to these cultures at the start (day 0), 1 or 2 days later completely suppressed the production of IgE. The production of IgG1 was also inhibited, but only if IL-2 was added on day 0. The production of other isotypes (IgM, IgG2a, IgG2b) was only slightly decreased by addition of IL-2. No suppression of IgE or IgG1 production was observed if monoclonal anti-IL-2 was added, whereas anti-IFN-gamma had no effect on the suppression of the production of these isotypes. The expression of CD23 on the third day of culture on B cells stimulated with LPS and IL-4 was markedly decreased when IL-2 was added to the cultures on day 0. Addition of monoclonal anti-IL-2 suppressed all effects produced by IL-2, whereas addition of anti-IFN-gamma had no effect. These results show that the suppression by IL-2, at least for the first signaling processes, are different from the suppression produced by IFN-gamma.

Animals↗
PubMed1991

Immunomodulator, LZ-8, prevents antibody production in mice.

LZ-8, a new and recently discovered immunomodulator from Ganoderma lucidum, has been shown to have immunosuppressive activity in vivo and to be a member of the immunoglobulin superfamily. In this paper we examined the in vivo effect of LZ-8 on antibody production using the hepatitis B surface antigen (HBs Ag) in mice. LZ-8 had mitogenic activity in vitro towards spleen cells of C57BL/10 (B10) and C57BL/10BR (B10BR) as previously shown towards those of DBA/2 mice. B10 and B10BR mice produced anti-HBs Ag antibody by the twice sensitization of the antigen while intraperitoneal administration of LZ-8 twice weekly into the mice (8 and 12 mg/kg) greatly prevented the production of antibody to HBs Ag (83.3-96.8% inhibition). We further examined the effect of LZ-8 administration on mitogen responsibility of spleen cells and on the T-cell subset population in both the spleen and lymph node but no significant differences were observed between the LZ-8 treated and untreated mice. These results suggest that the immunosuppressive activities of LZ-8, previously shown, such as the prevention of systemic anaphylaxis and the Arthus reactions, were caused by the blocking of antigen-specific antibody production.

Adjuvants, Immunologic↗
PubMed1990

Tumor promoting effect of goitrogens on the rat thyroid.

To evaluate the mechanism of the promoting effect of goitrogens on thyroid tumorigenesis, well-known goitrogens having different pharmacologic action, i.e., thiourea, phenobarbital sodium (PB), potassium thiocyanate (KSCN), and 3,4,5,6-tetrachloro-2',4',5',7'-tetraiodo-fluorescein sodium salt (Rose Bengal B, FD&C Red No. 105) (FR105) were administered to the DHPN-initiated and non-initiated F344 male rats in the drinking water for 25 weeks. Remington's iodine deficient diet (I-def) was fed as a positive control. These goitrogens showed significant tumor promoting effect or promoting tendency on the rat thyroids. According to the changes in thyroid morphology and thyroid-related hormone titers observed in the present study, we proposed to classify goitrogens at least into 2 groups, i.e., iodine deficiency-type promoters and the iodine excess-type promoters. The former contains goitrogens inducing TSH-stimulated diffuse goiter composed of uniform follicles with activated tall follicular epithelial cells, such as thiourea, KSCN and PB, and the latter contains goitrogens inducing colloid goiter composed of a mixture of colloid-rich follicles with flat follicular cells and normal-looking follicles with cuboidal follicular cells, such as FR105. This classification may be useful for the risk assessment of goitrogens.

Animals↗
PubMed1990

Spontaneous lesions in beagle dogs used in toxicity studies.

Spontaneous histopathologic lesions were examined in 276 young beagle dogs (8 to 15 months old) used in toxicity studies. Mononuclear cell infiltration in the liver was observed with the highest incidence (more than 95%). Calcium deposition in the kidney, mononuclear cell infiltration in the salivary glands, pigmentation in the spleen, and cortical atrophy in the thymus were seen with relatively high incidences (more than 30%). The incidence of mononuclear cell infiltration in the gallbladder, vacuolization of the tubular epithelium in the kidney, and vacuolization of the zona glomerulosa cell in the adrenal gland showed differences between the sexes. No abnormalities were seen in the spinal cord, sternum, and femur. Although most lesions observed are considered to be age-related, several were considered to be due to congenital anomalies observed in some organs.

Animals↗
PubMed1990

[Experimental study on the healing processes after the immediate reconstruction of maxillary bone defect--fresh autogenous iliac bone graft].

This study was designed to investigate the healing processes of fresh autogenous bone grafted from iliac to maxillary bone defect, which was an artificial oro-antro fistula and covered with submucosal flap made by ckeek mucosa. The experiments were carried out in vivo on adult mongrel dogs ranging 7,14,30,90,180 and 360 days postoperatively. Radiographic and histological investigations were made to evaluate details, further study has made by means of X-ray contact microradiography (CMR), tetracycline (TC) labeling and angiographic images. Results 1. Radiographic findings, the grafted bone remained unchanged until 14 days postoperatively. The bone bridge formation between host and grafted bone was completed after 30 days in all of the cases. Bone resorption can be observed at 90 days postoperatively, which were as much as one second or one third of grafted. But thereafter there were no changes on the grafting bone area, that is to say, bone resorption ceased and stabilised. 2. Histological findings, inflammatory changes can be mainly observed at the early postoperative stages. And osteoclasts and new bone formation can be observed along the host bone. On 14th postoperative day, all of the grafted bone cells turned to necrosis. Osteoclasts and the new bone formation were observed in that area. 30th postoperative day, new bone formation made connector between host and grafted bone area. And medullary cavity of the grafted bone was filled with fibrous connective tissue, new bone formation and bone resorption occurred at the same spot. On 90th day old grafted bone was scattered like an island among new bones. In 180 days, grafted area was nearly normal maxilla. 3. 7th postoperative day, inflammatory changes can be mainly observed on the mucosal bed of the grafted bone, those diminished in 14 days. It was completely changed to dense fibrous connective tissue. 4. Angiographic images, vascularization to medullary cavity of the grafted bone started on 7 days. In 14 days, vascularization filled about half of the grafted bone. Vascularization was also observed a little in cortical bone. It was completed throughout the entire grafted bone in 30 days and it connected with the host bone. In 180 days, the grafting bone was nearly normal angiographic image. 5. Contact microradiogram, the new bone formation was partially observed in the host bone in 7 days. In 14 days, the bone bridges formation started. It was almost completed in 30 days after transplantation. In 180 days, it was entirely completed. 6. Tetracycline labeling, the host bone was labelled weakly in the early postoperative stages.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

An improved method for the detection of IgE antibody of defined specificity by ELISA using rat monoclonal anti-IgE antibody.

An improved method for the detection of IgE antibody of defined specificity by ELISA using rat monoclonal anti-IgE antibodies is described. The innovation consists of coating the plates first by a monoclonal rat anti-murine IgE antibody, adding the sera to this antibody-coated plates and then adding the biotin-conjugated antigen after the sera. The plates are then reacted with streptavidin-peroxidase and developed. This procedure eliminates possible competitions with other isotypes of the same specificity. The method is useful especially to quantitate IgE with defined specificity in the presence of high amounts of isotypes of the same specificity.

Animals↗
PubMed1989

Induction of mitochondrial serine:pyruvate aminotransferase of rat liver by glucagon and insulin through different mechanisms.

Studies were performed in the rat liver to examine whether or not insulin as well as glucagon causes the induction of mitochondrial serine:pyruvate aminotransferase (SPTm) [EC 2.6.1.51] and if so, whether the mechanisms of induction are similar or different for the two hormones. Not only glucagon but also insulin induced SPTm. Cell-free translation assaying and RNA blot analysis showed that both hormones cause an increase in the hepatic level of mRNA for the precursor of SPTm. Their effects were virtually additive, and the time course of the increase in the mRNA level differed between the hormones. The maximal increase induced by glucagon was observed 3.5 h after the hormone injection while that by insulin was found after 6 h. The increase in the mRNA due to insulin was completely inhibited by the co-administration of cycloheximide, while that due to glucagon was not. The finding suggests that a newly synthesized, insulin-dependent protein(s) is involved in the regulation of the mRNA level by insulin. On the other hand, hydrocortisone treatment selectively suppressed the increase in the mRNA due to glucagon. These data indicate that the synthesis of the mRNA for SPTm is regulated by glucagon and insulin through different mechanisms. The size of the hormone-induced mRNA for SPTm gradually decreased with time, but the cell-free translation products did not exhibit size alteration. RNase H digestion to remove the poly(A) tail of the mRNA indicated that shortening of the poly(A) sequence might be responsible for the time-dependent size alteration of the mRNA.

Animals↗
PubMed1989

Purification and characterization of the active serine: pyruvate aminotransferase of rat liver mitochondria expressed in Escherichia coli.

In the previous study (Oda, T., et al. (1985) Eur. J. Biochem. 150, 415-421), we isolated a cDNA clone which expressed in Escherichia coli a specific size of product having the activity of rat liver serine:pyruvate aminotransferase (SPTm). This specific product (SPT10) was purified to homogeneity through three different column chromatographies. The amino acid composition and N-terminal amino acid sequence of the purified enzyme agreed with those predicted from the nucleotide sequence of cDNA and showed that SPT10 consists of the whole amino acid sequence of mature SPTm and several extra amino acid residues at the N-terminus. The catalytic and physical properties of SPT10, such as substrate specificity, Km for alpha-keto acids, electric charge, and quaternary structure, were all very similar to those of SPTm. Using several cDNA clones which lack a 5'-terminal sequence corresponding to a portion of the N-terminal amino acid sequence of SPTm, we examined the expression profile of the specific product in bacteria transformed with each cDNA clone. The products encoded by these cDNAs were segregated into inclusion bodies and were neither catalytically active nor easily solubilized by sonication. In contrast, the inclusion bodies were not formed in the bacteria transformed with the cDNA clone for SPT10.

Amino Acid Sequence↗