Biomedical subjects

J Itoh

Publications and source records attributed to J Itoh.

At least 91 records · Page 5Linked to original sources

PubMed1992

Subcellular visualization of light microscopic specimens by laser scanning microscopy and computer analysis: a new application of image analysis.

To identify subcellular organelles or to observe their pathological changes in sections prepared for light microscopy, immuno- and/or enzyme histochemical staining for the marker substances or enzymes of those subcellular organelles are frequently employed. With conventional light microscopes (CLM), however, it is hardly possible to determine whether or not the target organelles are properly stained and to confirm their fine structure. In the present study, the laser scanning microscope (LSM) was employed to obtain highly contrasted images of histochemically stained subcellular organelles at the limit of resolution in light microscopy. To refine or characterize those images, images built up as electronic signals in LSM were further processed in the Image Analysis System (IAS) with pipeline. Thus, the approximate figures of subcellular organelles such as microtubules, endoplasmic reticula, secretory granules, and mitochondria were visualized in brightfield on sections prepared for light microscopy (paraffin, frozen sections and cultured living cells). The validity of the images obtained by LSM or LSM-IAS was confirmed by immunoelectron microscopy when possible. The LSM images of histochemically stained suborganelles of various cells were definitely improved (refined and/or strengthened) by processing them with IAS.

Endoplasmic Reticulum↗

PubMed1992

SF2457, a new antibiotic related to amicetin.

A novel nucleoside antibiotic, SF2457, was isolated from the fermentation broth of Nocardia brasiliensis SF2457. The structure of SF2457 was determined by degradation studies using alkaline hydrolysis and methanolysis. SF2457 is closely related to the amicetin group antibiotics. The antibiotic exhibited inhibitory activity against Gram-positive and Gram-negative bacteria.

Anti-Bacterial Agents↗

PubMed1992

Immunohistochemical analysis of GH-producing adenomas--with special emphasis on plurihormonality of individual tumor cells by double staining.

Forty-four human growth hormone (GH)-producing adenomas were investigated immunohistochemically for the concomitant localization of GH, prolactin (PRL), and glycoprotein hormone alpha subunit. Immunoreactivity for GH, PRL, and the alpha subunit was found in 44, 37, and 36 cases, respectively. By double immunohistochemical staining, 24 of 27 cases showed colocalization of GH and alpha subunit, with the numbers of tumor cells showing double staining varying from case to case. The colocalization of GH and alpha subunit was noted in some normal pituitary cells. In adenoma cells, the colocalization of GH and PRL, and PRL and alpha subunit, was observed in 9 and 12 cases, respectively. The normal pituitary gland showed only occasional colocalization of GH and PRL, or PRL and alpha subunit. We found that GH-producing adenomas are plurihormonal at the individual tumor cell level, with coexpression of GH-alpha subunit, GH-PRL, and PRL-alpha subunit. The colocalization of GH and alpha subunit may be an expression of a subpopulation of normal anterior pituitary cells (with GH-alpha subunit coexpression), but the more frequent coexpression of GH-PRL may be pathological, accompanying tumorigenesis of the anterior pituitary cells, in which a pituitary-specific transcriptional factor, pit-1, may play a role.

Adenoma↗

PubMed1992

An entirely suprasellar symptomatic Rathke's cleft cyst: case report.

An entirely suprasellar symptomatic Rathke's cleft cyst in a 21-year-old woman is reported. An unusual feature of this cyst was the fact that the subepithelial tissues were composed of pituitary gland cells. High resolution magnetic resonance imaging is sensitive in the detection of subtle suprasellar abnormalities. We review the literature regarding the embryological pathogenesis of Rathke's cleft cyst, with special reference to the entirely suprasellar type.

Adult↗

PubMed1992

[A longitudinal study of children with language delay at 3 years of age; later WPPSI and school attendance].

Ninety-four children (eighty-three boys and eleven girls), who were delayed in verbal expression (expressive language less than two-thirds of the standard for their chronological ages) at the age of three years, were evaluated for school attendance and intelligence at the age of six. The Yamada's Check List for Language Development and Wechsler Preschool and Primary Scale of Intelligence (WPPSI) were used to assess language problems and the intelligence quotient (IQ). Thirty children (32%) were delayed in verbal expression only, and sixty-four (68%) were delayed in both: verbal expression and comprehension were less than two-thirds of the standard for their chronological ages. Of children with delay in verbal expression only, 36% of them had low full-scale IQs (less than 70), and 27% had required special tutoring. Of children with delayed development of verbal expression and comprehension, 85% had low full-scale IQs, and 89% had required special tutoring or had attended schools for mentally retarded children. In expressive and comprehensive language delay, forty-one children avoided personal relations at the age of three years. Later thirty of these children were diagnosed as suffering from infantile autism. Poor mental outcome could be predicted by the delay of expressive and comprehensive language at the age of three years. The high prevalence of developmental disorders at later stages for the children in this study suggests the need for close monitoring of children with delayed language.

Child, Preschool↗

PubMed1991

Utility of an elevated plus-maze for dissociation of amnesic and behavioral effects of drugs in mice.

Learning and memory were previously evaluated by using the elevated plus-maze test in mice. We investigated whether this method could be used for the evaluation of amnesic properties of drugs, including those which alter behavior on the first (training) trial. Six drugs of different types, scopolamine, MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate), diazepam, butylscopolamine, methamphetamine and haloperidol were administered before training. The transfer latency of vehicle-treated mice on retention testing was significantly shorter than that on training. The transfer latencies in mice given scopolamine (1 and 3 mg/kg s.c.), butylscopolamine (6 mg/kg s.c.), methamphetamine (2 and 4 mg/kg i.p.), or haloperidol (0.4 mg/kg i.p.) were significantly prolonged on training compared with those of the corresponding vehicle groups. However, significant prolongation of the transfer latency in the retention test, compared to the vehicle groups, was observed only in mice given scopolamine (3 mg/kg s.c.), MK-801 (0.1 and 0.15 mg/kg i.v.), diazepam (4 mg/kg i.p.), or methamphetamine (4 mg/kg i.p.). These results suggested that the prolongation of the transfer latency on retention testing in the plus-maze method might be used as an indicator for impairment of learning and memory induced by the drugs which have amnesic properties, and is not related to the change in transfer latency on training.

Amnesia↗

PubMed1991

Hypocalcemic focal seizures in a one-month-old infant of a mother with a low circulating level of vitamin D.

We present a case of a one-month-old infant with hypocalcemia and rickets, with symptoms of focal seizures. The ictal EEG showed left occipital spikes spreading over all of the left hemisphere. From the laboratory studies, we concluded that a low maternal circulating level of vitamin D would cause infantile hypocalcemia and rickets, while immature renal response to parathyroid hormone and transient hypoparathyroidism in infancy would induce hyperphosphatemia. Hypocalcemia may be an important factor in the cause of focal seizures which start even after the age of one month. Further, investigation of maternal vitamin D levels should be done in infantile hypocalcemia.

Adult↗

PubMed1991

Expression of decay-accelerating factor is reduced on hyperplastic synovial lining cells in rheumatoid synovitis.

Decay-accelerating factor (DAF), a membrane inhibitor of homologous complement activation, is present in synovial cells lining joint space and detected in synovial fluid. DAF is considered to protect synovial membrane from complement-mediated injury associated with articular inflammation. We studied the immunohistopathological features of DAF molecules in synovial membrane of rheumatoid synovitis using a DAF-specific monoclonal antibody, 1C6. Reacting molecules with the 1C6 antibodies in synovial tissue extracts formed a 70-kD band in Western blot analysis. DAF was strongly detected on the flat synovial lining cells, but weakly on the hyperplastic and multi-layered lining cells in rheumatoid synovitis. The latter cells reacted with anti-Leu-M3 antibodies specific for a cell surface marker of activated macrophages, sometimes accompanied by C3 and IgM deposition on the superficial synovial membrane. These results suggest that active rheumatoid synovitis characteristically with hyperplastic synovial lining cells is out of control by DAF, thereby permitting further complement-mediated injury.

Antibodies, Monoclonal↗

PubMed1991

Improvement of postoperative hypocalcemia by repeated allotransplantation of parathyroid tissue without anti-rejection therapy.

Long lasting postoperative hypocalcemia, an uncomfortable complication of a thyroid operation for hyperthyroidism, was treated with allotransplantation of parathyroid tissue. Small pieces of the parathyroid tissue offered from two unrelated donors were transplanted to an 18-year-old male with severe postoperative hypoparathyroidism. Prednisolone was given for 2 days, but no other immunosuppressive drugs were used. The remaining tissue was stored in frozen for the repeat transplantation. The functional activity of the frozen tissue was determined by the production of parathyroid hormone in the tissue culture medium adjusted to appropriate concentration of calcium. Loss of the graft function, probably due to rejection, was supplemented with repeated grafting. Hypocalcemia was improved by three times of transplantation using frozen tissue (once) and fresh tissue (twice). This preliminary trial demonstrates that the tissue transplantation of the parathyroid gland is effective to lessen the symptoms and medication of postoperative hypoparathyroidism.

Adolescent↗

PubMed1991

Cavernous angioma in the fourth ventricular floor--case report.

A rare case of cavernous angioma located in the fourth ventricular floor occurred in a 44-year-old female complaining of occipital headache, vomiting, diplopia, and dysarthria. Computed tomographic scans demonstrated a high-density area in the fourth ventricle and slight hydrocephalus. Magnetic resonance (MR) imaging showed a mixed intensity mass on T2-weighted images and high- or isointensity regions on T1-weighted images. The tumor was totally removed and histologically diagnosed as cavernous angioma. Postoperatively, ataxic gait, nausea, and vomiting disappeared gradually. MR imaging was useful to accurately evaluate the anatomic relationship between the lesion and the brainstem.

Adult↗

PubMed1991

[Arachidonic acid metabolism and effectiveness of aprotinin treatment during cardiopulmonary bypass].

Arachidonic acid metabolism was investigated in 30 open heart cases, utilizing nonpulsatile cardiopulmonary bypass (CPB), consisted of 15 untreated cases (Group I) and 15 cases treated with aprotinin mostly given into CPB circuit during CPB (Group II). In group I, arterial blood concentration of thromboxane B2 (TXB2, stable metabolite of thromboxane A2, pg/ml) significantly increased from 45.9 +/- 40.5 preoperatively to 560.2 +/- 381.5 (p less than 0.01) at 30 minutes of CPB (total bypass) and to 830.5 +/- 591.1 (p less than 0.005) at the end of CPB (partial bypass). TXB2 levels in pulmonary artery (PA) and left atrium (LA) did not significantly increase just before, 5 minutes of CPB as compared with preoperative value. At the end of CPB TXB2 levels in PA (625.0 +/- 186.3) and LA (817.0 +/- 320.0) were significantly higher than preoperative value. However there was no significant difference between PA and LA values. Contrarily in group II TXB2 levels were significantly suppressed as compared with the value at each corresponding time in group I. beta-thromboglobulin levels also changed almost parallel to TXB2 levels in both groups. In conclusion, arachidonic acid metabolic disorders could occur in CPB circuit rather than in pulmonary circulation during CPB. Aprotinin administration into CPB circuit suppressed to some extent the platelet activation.

Adult↗

PubMed1991

Pathogenic significance of serum components in the development of autoimmune polyarthritis in MRL/Mp mice bearing the lymphoproliferation gene.

MRL/Mp mice bearing the lymphoproliferation gene (lpr) (MRL/Mp-lpr/lpr) spontaneously develop polyarthritis, associated with autoimmune traits, including rheumatoid factor production, which resembles rheumatoid arthritis. To investigate possible arthritogenic activity of serum of these mice, intraarticular injections of the serum components to knee joints of nonarthritic MRL/Mp mice not bearing the lpr gene (MRL/Mp(-)+/+) were performed. Two fractions from the serum were obtained by a gel chromatography. The void fraction (VF), but not the nonvoid fraction (NVF), induced acute inflammatory lesions in the joints by single injection, and destructive arthritis by repeated injections. VF had immune complex activity, and contained a large amount of cryoglobulin, which in itself was found arthritogenic. These findings indicate that the serum components of MRL/Mp-lpr/lpr mice have a potency to cause destructive arthritis. These results are direct evidence in a syngeneic animal model system, which suggests the pathogenic significance of serum components in rheumatoid arthritis.

Animals↗

PubMed1991

[Exacerbation of partial seizures in a case with heterotopic gray matter using antiepileptic drugs].

A two-year-old, right-handed girl was admitted to our hospital with a history of partial seizures. The first seizure, conjugated eye movements and head turning to the right, occurred at the age of 24 months. Later, she suffered from several seizures daily at the age of 34 months. At the age of 35 months, she was admitted to our hospital. On admission her neurological examination was normal. EEG showed a left parietal spike focus. A computed tomographic scan showed a small hyperdense area in the left parietal lobe without contrast enhancement. She was treated with carbamazepine (CBZ : 6 mg/kg/day). When seizures occurred several times within an hour, intravenous or rectal administration of diazepam (DZP : 0.3 mg/kg/dose) was added. However, she complained of sleepiness. The seizures occurred more frequently than before, 50 to 80 times daily, and became secondarily generalized. We thought that the exacerbation of the seizures resulted from the somnolence caused by DZP and CBZ. Consequently, these drugs were discontinued, and phenytoin was begun. She has since been free of seizures for two years. Approximately one year after the discontinuance of DZP and CBZ, heterotopic gray matter and abnormal gyri involving the left parieto-temporal lobe were found by magnetic resonance imaging (MRI). MRI is useful for detecting small heterotopic gray matter. To summarize this case, one should consider the possibility that excessive polytherapy induces seizures, particularly in patients with structural brain abnormalities such as heterotopic gray matter.

Brain↗

PubMed1990

Effects of DM-9384 in a model of amnesia based on animals with GABAergic neuronal dysfunctions.

The effects of N-(2,6-dimethyl-phenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide (DM-9384), a cyclic derivative of GABA, were investigated and compared with those of aniracetam in an animal model of amnesia, using a passive avoidance task with animals that have GABAergic neuronal dysfunctions. Pre- and post-training administration of DM-9384 and aniracetam ameliorated bicuculline-induced amnesia, as indicated by parameters such as % retention and step-down latency. DM-9384 ameliorated picrotoxin-induced amnesia when administered pre-training, but not when administered post-training. Aniracetam failed to improve the picrotoxin-induced amnesia. DM-9384 displaced [3H]muscimol binding to GABAA receptors (-log IC50 = 8.07 M; Hill value = 0.23 +/- 0.04), but failed to displace about 20% of the specific muscimol binding, whereas aniracetam showed only a weak effect (-log IC50 = 3.63 M; Hill value = 0.37 +/- 0.06). From these results, it appears that DM-9384 ameliorated the GABA antagonist-induced amnesia by interacting with some GABAA receptors directly and/or indirectly.

Amnesia↗

PubMed1990

The accumulation of 11C-methionine in cerebral glioma patients studied with PET.

Fourteen patients with cerebral gliomas were studied with positron emission tomography (PET) using L-[methyl-11C]methionine (11C-MET). Positive images of tumour were obtained in all cases regardless of histological grades. The analysis of differential absorption ratio (DAR) showed the higher accumulation of 11C-MET in high grade gliomas than in low grade gliomas. PET study with 11C-MET will be of great value not only in delineating the location of gliomas, but also in making a qualitative diagnosis from the view point of the biological properties of gliomas.

Adult↗

PubMed1990

Utility of an elevated plus-maze for the evaluation of memory in mice: effects of nootropics, scopolamine and electroconvulsive shock.

An elevated plus-maze consisting of two open and two enclosed arms was employed for an evaluation of memory in mice. Mice in the plus-maze escaped from the open arm to the enclosed arm because mice apparently dislike open and high spaces. The time it took for the mice to move from the open arm to the enclosed arm (transfer latency) was recorded. The transfer latency after the 2nd day was significantly shorter than that on the 1st day when it was recorded at a rate of one trial a day for 5 days. The transfer latency on the 2nd day was significantly prolonged in the mice administered electroconvulsive shock (300 V, 1 s) or scopolamine (20 micrograms, ICV) immediately after the first trial compared to the transfer latency in the control group. The prolongation of transfer latency in the mice administered an electroconvulsive shock was reversed by pretreatment with aniracetam (20 mg/kg, PO), but not tacrine and physostigmine. The prolongation of transfer latency in the mice administered scopolamine was reversed by pretreatment with aniracetam (10 and 20 mg/kg, PO) tacrine (1 and 3 mg/kg, PO), or physostigmine (0.025-0.2 mg/kg, IP). These results suggest that transfer latency may be one of the parameters of learning and memory.

Amnesia↗

PubMed1990

Cerebral ischemia model with conscious mice. Involvement of NMDA receptor activation and derangement of learning and memory ability.

During anesthesia in mice, both common carotid arteries were tied loosely with an overhand knot suture (an occluder), while two snares (releasers) were placed in the knot so that it could be repeatedly tightened to occlude the arteries and loosened again to allow for reperfusion while the mice were conscious and unrestrained. The incidence of mortality as well as impairment of brain metabolism depended upon the length of cerebral ischemia. Cortical electroencephalogram (EEG) clearly reflected the regional ischemia as evidenced by electrical quiescence. Less mortality was observed with ischemic mice treated with dextrorphan (30 mg/kg p.o.). On day 1 (24 hr after ischemia), there were impairments in complex motor coordination, multichoice swim performance, and step-through or thermal pain-motivated avoidance responses. Thereafter, the battery of tests progressively improved. This improvement depended on the period of resumption of cerebral blood flow; the 7-day, postischemic lapse significantly reduced the deficit observed. Reduction in the degree of habituation of exploratory activity was also clearly observed following ischemic insult. Dextrorphan (1-30 mg/kg i.p.) given to ischemic mice was effective in the habituation and step-through-type passive avoidance test paradigms. In conclusion, 1) the decline in cognition as observed with ischemic mice is due to the temporal and reversible derangement of their neuronal networks; 2) excessively released glutamate is probably of major pathogenic importance in the consequences of cerebral ischemia based on the positive results of the N-methyl-D-aspartate receptor antagonist, dextrorphan; 3) the simple technique could be useful in elucidating the pathophysiologic mechanisms of ischemically elicited derangement of the cerebral organization; and 4) the model could be used to assess the efficiency of drugs with high clinical predictivity.

Animals↗

PubMed1990

Detection of mRNAs of carcinoembryonic antigen and nonspecific cross-reacting antigen genes in colorectal adenomas and carcinomas by in situ hybridization.

Expression of mRNAs of carcinoembryonic antigen (CEA) and nonspecific cross-reacting antigen (NCA) genes in colorectal carcinomas and adenomas was investigated by in situ hybridization (ISH) with specific biotinylated probes. Hybridization was clearly detected throughout the cytoplasm of 7 out of 15 adenomas and 13 out of 15 carcinomas with the CEA cDNA probe, and in 6 out of 15 adenomas and 10 out of 15 carcinomas with the NCA cDNA probe. The intensity of signal appeared to be stronger in carcinomas than that in adenomas, and the CEA and NCA mRNAs were expressed together in most of the positive tissue specimens. On the other hand, noninvaded tissues adjacent to the carcinoma did not show any signal except for 4 cases faintly stained with the NCA probe. This finding was partly confirmed by Northern blot analysis which indicated that the specific bands for the CEA and NCA mRNAs were more intense in RNAs from carcinoma tissues than in those from adjacent noninvaded tissues. These data suggest that the ISH technique with biotinylated probes could be of use for analyzing expression and localization of CEA and related genes on tissue sections.

Adenoma↗