Biomedical subjects

J Itoh

Publications and source records attributed to J Itoh.

At least 19 recordsLinked to original sources

PubMed1992

Continuous recording of changes in intracranial pressure using interference echoes of ultrasonic wave: a preliminary report of practicality and clinical evaluation.

We attempted to examine intracranial pressure (ICP) noninvasively using probes receiving interference echoes of ultrasound from thin layers between the skull and the surface of the cerebrum. The reception of echo through bone flaps less than 5-mm thick was good. Normal adults (4) and patients (4) were examined by attaching ultrasound probes to the frontotemporal scalp. Recordings were performed during rest, Valsalva maneuver, hyperventilation, and pumping of a shunt-flushing device. Ultrasound recordings of ICP were compared with those of the scalp using two different time windows. The effect of scalp vessels on the ultrasound recordings of ICP was evaluated. The waves from a pressure transducer and the ultrasound probe were similar. This method was found to be useful for ICP recording.

Adolescent↗

PubMed1992

Tumor diagnosis by PET: potential of seven tracers examined in five experimental tumors including an artificial metastasis model.

The potential of seven tracers for the metabolic imaging of tumors by positron emission tomography was studied using five experimental tumor models. The tracers examined were 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG), 2-deoxy-2-[18F]fluoro-D-galactose (2-[18F]FdGal) and 2-deoxy-2-[18F]fluoro-L-fucose (2-[18F]FdFuc) for investigating energy metabolism. L-[methyl-11C]Methionine ([11C]Met) and 6-[18F]fluoro-L-fucose (6-[18F]FFuc) were used for assessing protein and glycoprotein synthesis, while [3H]thymidine ([3H]Thd) and 2-deoxy-5'-[18F]fluorouridine ([18F]FdUrd) were used to investigate nucleic acid metabolism. The highest mean uptake by the five different tumors was found for [3H]Thd, followed in order by [18F]FDG, [11C]Met, 2-[18F]FdGal, [18F]FdUrd, 2-[18F]FdFuc and 6-[18F]FFuc. The tumor-to-tissue uptake ratios indicated that the nucleosides, [11C]Met and 6-[18F]FFuc were better tracers in the brain region. All the tracers except for the fucose analogs were suitable for the thoracic region, while [11C]Thd and [18F]FDG were superior in the abdominal region. In comparison with the primary tumor model of Lewis lung carcinoma (3LL), [3H]Thd uptake in the artificial metastatic 3LL model showed the maximum enhancement, followed by [18F]FDG, [11C]Met and the other tracers. The [18F]FDG uptake correlated with the [3H]Thd uptake. [18F]FdUrd, 6-[18F]FFuc and 2-[18F]FdGal could be used for distinguishing different types of tumors. The combined use of these radiotracers can possibly allow the assessment of tumor metabolism, and this indicates the viability of tumors.

Animals↗

PubMed1992

Spinous process-splitting laminoplasty using hydroxyapatite spinous process spacer.

Between February 1986 and August 1989, 45 patients with cervical myelopathy were treated by spinous process-splitting laminoplasty. Hydroxyapatite intraspinous spacers were used to maintain the enlargement of the cervical spinal canal. The shape of this spacer is trapezoidal. After sagittal splitting of the spinous process, the spacer was inserted between the two halves and affixed with the wire. Histologic study showed there was good fusion between the spacer and bone. In all cases, good enlargement of the cervical spinal canal was achieved. Spacer displacement, wire breakage, and postoperative infection were not seen. There was no postoperative neurologic deterioration. Computed tomography showed that the width of the cervical spinal canal was maintained.

Animals↗

PubMed1992

Spontaneous development of pancreatitis in the MRL/Mp strain of mice in autoimmune mechanism.

MRL/Mp mice are known to have autoimmune disease-prone genetic background, which contributes to the development of a lethal autoimmune disease at an early age in association with the lymphoproliferative gene, lpr. In this study, we found that MRL/Mp mice, not bearing lpr (MRL/Mp-(+)/+), spontaneously developed pancreatitis at a late stage of life, which was histopathologically characterized by destruction of pancreatic acinar cells with mononuclear cell infiltration. In female 34-38-weeks-old mice the incidence of pancreatitis reached 74%, whereas the male mice developed the disease with a reduced incidence, at a later stage of life and with a reduced severity. Cell infiltrates in the affected lesions were composed predominantly of CD4+ cells and to lesser extent Mac-2+ macrophages. Adoptive transfer of the spleen cells obtained from pancreatitis-bearing female mice generated pancreatitis in female normal mice, but not in the male mice. Transfer of the serum of pancreatitis-bearing mice failed to induce any pancreatic lesions. These findings indicate that pancreatitis in MRL/Mp-(+)/+ mice may be mediated by cellular autoimmune mechanism. This may present a useful concept for analysis of the developmental mechanisms of human chronic pancreatitis in an aspect of autoimmunity.

Animals↗

PubMed1992

Application of two-color immunofluorescence staining to demonstration of T-cells and HLA-DR-bearing cells in rheumatoid synovitis.

We studied the localization of T-cells and HLA-DR antigen-bearing (DR+) cells in rheumatoid synovitis by employing an improved two-color immunofluorescent staining (TCIF) technique. With this technique we have successfully identified DR+ activated T-cells in the inflammatory synovium. T-cells expressed HLA-DR antigen when they were in contact with DR+ antigen-presenting cells (APC). In addition, activated T-cells showed characteristic distribution within the synovium: they were found around high endothelial venules, within lymphoid follicles, and in hyperplastic synovial lining, suggesting their involvement in the development of rheumatoid synovial lesions via interaction with synovial DR+ APC lineage cells. These findings may contribute to better understanding of the role of activated T-cells in the histogenesis of rheumatoid synovitis, a typical chronic inflammatory lesion.

Arthritis, Rheumatoid↗

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↗