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Biomedical subjects

M Arai

Publications and source records attributed to M Arai.

At least 415 records · Page 23Linked to original sources

[A case of chronic thinner intoxication developing hyperkinésie volitionnelle three years after stopping thinner abuse].

We reported a 25-year-old male with chronic thinner intoxication. He had been sniffing thinner from the age of 15 to 20. Since the age of 20, he developed gait disturbance, weakness of lower extremities, and scanning speech. At the age of 23, three years after he stopped sniffing thinner, he had hyperkinésie volitionnelle (HV) of bilateral upper extremities. MRI study revealed diffuse high intensity areas in the cerebral white matter, thinning of the corpus callosum, and cerebellar and brainstem atrophy on T1 weighted images. On T2 weighted images, low intensity areas in the thalamus, the striatum, the anterior limb of the internal capsule, the tegmentum of midbrain, high intensity areas in middle cerebellar peduncle, the posterior limb of the internal capsule, the lateral part of the cerebral peduncle, and the cerebral white matter were noted. HV almost disappeared with 2.5 mg of clonazepam daily administered. The disappearance of HV by ischemic compression of his arm suggested that input from the periphery might be relevant to the etiology of HV. The time interval between exposure to thinner and the recognition of HV in our case was in agreement with that between the occurrence of cerebrovascular disease and the recognition of HV in the previous reports. We postulated that HV in this case was the manifestation of the denervation hypersensitivity in the dentatorubroolivary system.

Adult↗

[Traumatic bilateral MLF syndrome--a case report].

A case of traumatic bilateral medial longitudinal fasciculus (MLF) syndrome is reported. An 18-year-old man who had been struck on the occipital region in a traffic accident was admitted to our center. On admission, the consciousness evaluated by the Japan Coma Scale was 30. Skull X-ray film revealed a linear skull fracture of the left occipital bone. CT scan showed subdural hematoma in the right frontotemporal region, contusion of bilateral frontal lobes and the left cerebellar hemisphere, subarachnoid hemorrhage, and pneumoce phalus. Two weeks after the injury, his consciousness improved and he was diagnosed as having bilateral MLF syndrome. Barbiturate, dehydration and steroid therapy were added to for intracranial hemorrhage. One month later, MLF syndrome improved and he was discharged without any neurological deficit.

Accidents, Traffic↗

[Oculopharyngeal myopathy with autoimmune disease].

A 34-year-old woman had suffered from systemic lupus erythematosus (SLE) and autoimmune hemolytic anemia (AIHA) in the teen age. She developed progressive ptosis of the eyelids, and difficulty in swallowing and speaking for several years. Endocrinological studies showed primary hypothyroidism. A serum IgG level was elevated (1,973 mg/dl), and antinuclear antibody, thyroid test and microsome test were positive. A muscle biopsy showed massive inflammatory cell infiltrates in the perivascular area in addition to some myopathic change; some variation in fiber size. Immunological staining demonstrated most of these inflammatory cell infiltrates were CD3+ cells and CD4+ cells were counted more than CD8+ cells (CD4/CD8 = 2.3). The diagnoses were confirmed as oculopharyngeal myopathy and Hashimoto's disease. In addition, she had suffered from SLE and AIHA. Therefore we conclude that manifestation of this myopathy may be associated with some autoimmune process.

Adult↗

[A case of Hallervorden-Spatz syndrome with marked atrophy of the brainstem and cerebellum].

We report a 20-year-old female with Hallervorden-Spatz syndrome (HSS). This patient is the product of consanguineous parents. She developed genu valgum, tendency to fall and mental deterioration at the age of 6, decrease of the number of spoken words at the age of 14, dysarthria, unsteady gait, postural tremor of the upper extremities, dystonic posture of hands and double incontinence at the age of 16. Her disease progressed slowly. Neurological examination on admission revealed severe mental retardation, optic atrophy, forced grasping, hyperactive tendon reflexes in the upper extremities and bilateral Babinski sign. An extensive laboratory investigation including the leukocyte lysosomal enzymes, serum amino acid analyses, copper studies and ceruloplasmin were almost within normal limits. MRI, T2 weighted images, showed markedly decreased signal intensity in the globus pallidus but substantia nigra and increased signal intensity in diffuse cerebral white matter. T1 weighted images showed marked atrophy of the brainstem and cerebellum. She met the diagnostic criteria for HSS by Swaiman; we diagnosed her as HSS group II. HSS is characterized by the presence of many spheroids in the central nervous system which is similar to neuroaxonal dystrophy (ND). However, clinical and pathological differences exist between HSS and ND, the precise classification of the two conditions has remained controversial. Although there are many reported cases in which both conditions overlap, this is the first reported case that simultaneously demonstrates increased iron deposition in the globus pallidus, marked atrophy of the brainstem and cerebellum and typical clinical course compatible with HSS.

Adult↗

[Gene expression of MMPs and TIMPs in the process of hepatic fibrosis].

The matrix metalloproteinases (MMPs) gene family includes MMP-1 (interstitial collagenase), MMP-2 (72 kD type IV collagenase/gelatinase), MMP-3 (stromelysin/transin), MMP-7 (putative MMP; pump-1), MMP-8 (granulocyte collagenase) and MMP-9 (92 kD type IV collagenase/gelatinase). This gene family has the common characteristics in the gene structure as follows: All of MMPs have the active site metal ion-binding domain. All six enzymes are activated with the concomitant removal of N-terminal segment of the latent enzyme. The removed segment contains an unpaired cystein residue within the conserved amino acid sequence PRCGVPDV, located immediately adjacent to the proenzyme cleavage site. The authors showed the gene expression of MMP-1 in the process of hepatic fibrosis. The remarkable expression was noted on fibroblasts and macrophages within the newly-formed fibrous bands with lots of infiltrated lymphocytes. Liver cirrhosis did not showed the positive dots of MMP-1 mRNA. On the other hands, the expression of TIMP reported by Takahara et al., revealed the high level of expression in the advanced fibrosis.

Amino Acid Sequence↗

[Resistance to anticoagulant activity of heparin in a patient for cardiac surgery].

Resistance to anticoagulant activity of heparin was observed in a patient for cardiac surgery. The activated coagulation time (ACT) was maintained over 300 seconds with additional doses of heparin which mounted to the total of 29 ml in 3 hours during cardiopulmonary bypass. Although antithrombin-III activity was not measured in this case, the heparin resistance might have been caused by the decrease in the activity of antithrombin-III which might have resulted from the preoperative malnutrition, infection of urinary tract and/or institution of intraaortic balloon pumping (IABP).

Cardiac Surgical Procedures↗

Immunohistochemical localization of calretinin in the rat lateral geniculate nucleus and its retino-geniculate projection.

In the present study, we examined the distribution of calretinin-immunoreactive neuronal cell bodies and fibers in the lateral geniculate nucleus of the rat. In normal rats, clusters of immunoreactive cell bodies were found in: (i) the rostral portion of the ventral lateral geniculate nucleus pars medialis (VLGM), (ii) the intergeniculate leaflet (IGL), (iii) the intermediate region between the VLGM and the ventral lateral geniculate nucleus pars lateralis (VLGL), (iv) the caudomedial portion of the VLGM, and (v) the caudolateral portion of the VLGM. In the dorsal lateral geniculate nucleus (DLG), immunoreactive cell bodies were rarely observed. After uni- or bilateral eye enucleation, no significant alteration in the morphological features or distribution of immunoreactive cell bodies was detected in the lateral geniculate nucleus. In normal rats, immunoreactive fibers formed dense plexuses in: (i) the DLG, (ii) the external layer of the VLGL, (iii) the internal layer of the VLGL, (iv) the IGL, (v) the caudomedial portion of the VLGM, and (vi) the optic tract. After unilateral eye enucleation, immunoreactive fibers in the external layer of the VLG and in the optic tract almost totally disappeared on the contralateral side to the lesion. Unilateral eye enucleation caused a significant decrease of immunoreactive fibers in the DLG and in the internal layer of the VLGL, but a substantial number of immunoreactive fibers still remained there. In the IGL and the caudomedial portion of the VLGM, no observable alteration in the distribution of immunoreactive fibers was detected after uni- or bilateral eye enucleation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Isolation and characterization of type IX collagen-proteoglycan from the Swarm rat chondrosarcoma.

Type IX collagen was partially purified from the Swarm rat chondrosarcoma by a series of a conventional salting-out procedures. The preparation was further separated by anion exchange chromatography into an unbound and a bound fraction in an A230 ratio of about 5:1. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the bound fraction appeared as a broad band, whose molecular mass ranged from 250 to 270 kDa. Digestion with chondroitinase ABC reduced the apparent molecular mass of the bound fraction to about 250 kDa, a value comparable to the molecular mass of the unbound fraction. Tryptic peptide maps of the protein moieties of unbound and bound forms showed that their molecular structures were basically identical. A monoclonal antibody specific for LMW, one of the pepsin-resistant fragments of the rat sarcoma type IX, reacted with both the unbound and bound fractions. Together the results indicate that the unbound and bound fractions represent a type IX collagen devoid of the chondroitin sulfate chain and its proteoglycan form with covalently bound chondroitin sulfate, respectively. The extent of glycosaminoglycan attachment to type IX collagen molecules in rat chondrosarcoma (about 16%) is quite different from the extents described in chick embryo cartilage (about 80%), chick vitreous humour (100%) and bovine cartilage (less than 5%). Further studies on the neoplastic tissue will offer additional information regarding the biological basis and biological consequences of the glycosaminoglycan attachment to type IX collagen molecules.

Animals↗

Occurrence of collagen and proteoglycan forms of type IX collagen in chick embryo cartilage. Production and characterization of a collagen form-specific antibody.

Type IX collagen from chick embryonic cartilage is a proteoglycan bearing a single chondroitin sulfate chain covalently linked to the alpha 2(IX) polypeptide chain. We have isolated type IX collagen metabolically labeled with [3H]proline using an antibody to type IX collagen and have found that the molecule is synthesized in two forms, a collagen form (COLIX) and a proteoglycan form (PGIX). In cultured chondrocytes, the two forms of type IX collagen showed a different ability to be deposited in the matrix. We have suggested the possibility that both forms may arise from an alternative substitution of a chondroitin sulfate chain to the NC3 domain of the alpha 2(IX) chain. Based on the reported amino acid sequence at the NC3 domain of alpha 2(IX), we have synthesized undecapeptides containing the sequence around the glycosaminoglycan attachment site of the alpha 2(IX) chain. Antibody against the peptide, which was raised in rabbit, only recognized COLIX and made it possible to distinguish COLIX from PGIX. Evidence shows that this could be due to a difference in antigenicity of the NC3 domain of the alpha 2(IX) chain between COLIX and PGIX caused by the substitution of a chondroitin sulfate chain to the serine residue in this domain. Therefore, this antibody may be useful as a probe for studies on the functions of glycosaminoglycan substitution in type IX collagen.

Amino Acid Sequence↗

Evaluation of selected plants for their toxic effects in canaries.

Leaves or fruit from 14 plants considered to be toxic to pet birds were administered by gavage to 15 pairs of canaries (Serinus canaria). Each bird was given 0.12 to 0.70 g of plant material. One pair served as a control and was given distilled water. The plant materials were flash-frozen in liquid nitrogen, pulverized, and resuspended in deionized water for administration. Of the plants tested, 5 (oleander, lupine, foxglove, yew leaves, and dieffenbachia) were considered highly toxic and were associated with acute death of birds. The remaining plant samples caused no, or only transient, clinical illness.

Animals↗

Endothelin-1 stimulates c-fos mRNA expression and acts as a modulator on cell proliferation of rat FRTL5 thyroid cells.

In FRTL5 thyroid cells, endothelin (ET)-1 alone had no effect on DNA synthesis but caused a transient increase in c-fos mRNA levels and stimulated IGF-I induced DNA synthesis and cell proliferation. By contrast, ET-1 inhibited the stimulatory effects of TSH actions on DNA synthesis, cell proliferation and c-AMP production. 8-Bromo-cAMP-induced DNA synthesis was also inhibited by ET-1, suggesting that ET-1 exerts its inhibitory effects at step(s) involving cAMP production and post cAMP pathway. ET-1-induced suppression of TSH actions were reversed by a C-kinase inhibitor, H-7. These results suggest that the effect of ET on functions of FRTL5 cells is, at least, in part mediated by C-kinase dependent pathway.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

Evaluation of selected plants for acute toxicosis in budgerigars.

Pairs of budgerigars were given samples, by gavage, of plants considered potentially toxic to pet birds. Samples were prepared by flash-freezing and powdering fresh plant material in liquid nitrogen and resuspending the material in deionized water for administration. Of the 19 plants tested, only 6 induced clinical signs of illness; these plants included yew, oleander, clematis, avocado, black locust, and Virginia creeper (Taxus media, Nerium oleander, Clematis sp, Persea americana, Robinia pseudoacacia, Parthenocissus quinquefolio).

Acacia↗

Coronary angioplasty using an over-the-wire balloon catheter through a new 6 French guiding catheter.

A new 6 French (F) guiding catheter with a large, teflon-coated internal lumen (4.2F) was developed, permitting use of the standard ultralow profile (less than 3F) over-the-wire system. This small coronary angioplasty system (6F-PTCA) was evaluated in 48 lesions in 45 of 137 patients (33%) who underwent coronary angioplasty between September 1990 and January 1991. The mean age was 64 years (range 49 to 82); 37 (82%) were male. The procedure was via the brachial artery in 28 patients (62%). The overall primary success rate was 96%. It was 100% via the brachial artery and 90% via the femoral artery. There were no major complications. The puncture compression time with the 6F-PTCA via the brachial artery and via the femoral and with 8F-PTCA via the femoral was 3.8, 9.6, and 16.9 hr, respectively (P less than 0.001), although the procedure time of the 6F-PTCA via brachial and via femoral and of the 8F-PTCA was not significantly different. The mean hospital stay was 3.1, 4.5, and 5.5 days, respectively (P less than 0.01). A small hematoma occurred in 2 patients (4.4%) after the 6F-PTCA and in 3 (3.3%) after 8F-PTCA, and a large hematoma (greater than 5 cm) was noted in 7 patients (7.6%) after 8F-PTCA. These results indicate that coronary angioplasty using the over-the-wire system through the new 6F guiding catheter is technically feasible. Moreover, this approach, especially when advanced via the brachial artery, could shorten the hemostasis time and facilitate early ambulation.

Aged↗

Characterization of a novel mRNA expressed by neurons in mature brain.

In previous studies, differential hybridization screening of an activated murine T-lymphocyte cDNA library identified an interleukin 2-responsive mRNA, designated F5, expressed in lymphoid tissues and brain only. We now report characterization of a full-length clone isolated from an adult mouse brain cDNA library. Neither the nucleic acid nor amino acid sequences demonstrated similarity to reported sequences. On Southern blotting, the protein coding sequence hybridized to genomic DNA from a variety of species. On Northern blotting, F5 mRNA was expressed in adult mouse brain, spinal cord, eye, and dorsal root ganglia but not in peripheral nerve. In situ hybridization studies demonstrated prominent expression by neurons in brain. F5 mRNA expression was undetectable in embryonic rat cerebral hemisphere and low until postnatal day 21. F5 is a novel mRNA selectively expressed by proliferating lymphocytes and mature neurons.

Amino Acid Sequence↗

Expression of the neu proto-oncogene by Schwann cells during peripheral nerve development and Wallerian degeneration.

The neu gene, which encodes a putative tyrosine kinase growth factor receptor termed p185neu, was originally identified as a dominant transforming gene in neurogliomas and schwannomas induced by transplacental treatment of rat embryos with ethylnitrosourea. The present studies were undertaken to determine the expression pattern of the neu gene in peripheral nerve. Northern blot analysis of total RNA isolated from rat sciatic nerves demonstrated prominent neu mRNA expression on postnatal days 1 and 7, with substantially lower expression up to adulthood. Immunohistochemical studies confirmed expression of p185neu by Schwann cells (SC) in developing sciatic nerve and minimal p185neu immunoreactivity in adult nerves. However, neu mRNA and p185neu protein progressively increased following sciatic nerve transection in adult animals. In addition, neu mRNA and p185neu were found in neonatal rat sciatic nerve SC and several SC-derived cell lines. In resting SC, neu mRNA was expressed at a low level, but was greatly increased by treatment with forskolin and glial growth factor. These studies demonstrate that the neu gene and its protein product, p185neu, are expressed by SC both in vivo and in vitro and suggest that p185neu plays a role in the regulation of SC proliferation or differentiation.

Animals↗

Expression of the T-lymphocyte activation gene, F5, by mature neurons.

F5 was first identified as an mRNA expressed by activated but not resting T-lymphocytes. Subsequent studies suggested that it also is selectively expressed by mature neurons. Although the F5 protein coding sequence is highly conserved, the function of the F5-encoded protein is unknown. The present studies were undertaken to define the anatomic distribution, cellular specificity, and developmental pattern of F5 mRNA expression in the mouse nervous system, addressing specifically the question of whether the expression pattern of F5 corresponds to that of known ligand-receptor or signal-transduction systems. The use of a nonradioactive in situ hybridization method and paraffin-embedded sections provided excellent morphological preservation and a high degree of cellular resolution. F5 mRNA was detected in the central nervous system, peripheral nervous system, and retina in cells having the location and morphological features of neurons. Combined in situ hybridization histochemistry for F5 mRNA and immunofluorescence staining for cell-specific markers confirmed that neurons expressed F5 mRNA but astrocytes did not. The neuronal expression of F5 mRNA had two interesting features. First, the level of expression appeared to correlate directly with the size of the neuronal perikarya, the length of the axonal projection, or the extent of dendritic arborization. Second, F5 mRNA appeared late in post-natal development. These observations are of interest because of preliminary data suggesting that F5 may function as a substrate for protein kinase C, which demonstrates a similar expression pattern in the nervous system.

Animals↗