Biomedical subjects

K Itoh

Publications and source records attributed to K Itoh.

At least 577 records · Page 32Linked to original sources

PubMed1997

The pressor response induced by repeated injections of neostigmine into the central nervous system is desensitized in adrenalectomized, but not in intact rats.

To investigate whether or not pressor responses to repeated stimulation of central cholinoceptive neurons are desensitized, mean arterial blood pressure (MAP) and heart rate (HR) were measured following repeated injections of neostigmine, an acetylcholinesterase inhibitor, into the third cerebral ventricle in conscious, unrestrained intact or adrenalectomized (ADX) rats. Neostigmine (5 x 10(-9) or 5 x 10(-8) mol) in 1 milliliter saline increased MAP dose-dependently and increased HR in intact rats. The peak values in MAP and HR after three repeated injections at 4 hour intervals did not wane. Neostigmine (5 x 10(-8) mol) also increased MAP in ADX rats, and the peak values after the first injection were higher in the ADX rats than in the intact rats. The pressor responses to the second and third injection, however, were less than to the first injection in the ADX rats. HR responses to the repeated injections in the ADX rats were identical to those in the intact rats. These findings suggest that the adrenal gland plays a role in antagonizing the development of desensitization in the neostigmine-induced pressor response.

Adrenalectomy↗

PubMed1997

Changes in normal vaginal flora of African green monkeys (Cercopithecus aethiops) during the menstrual cycle.

Changes in normal vaginal flora of African green monkeys associated with the estrous cycle were examined by the swab method. Bacteroidaceae, corynebacteria, and streptococci were predominant throughout the whole estrous cycle, although individual differences were great. It was also clear that all bacterial species tended to decrease in the menstrual phase. Lactobacilli, the most predominant bacteria in the normal vagina of humans, were detected only in very low numbers in the African green monkey, suggesting that the normal vagina of the African green monkey has a different ecosystem from that of normal human vaginal flora.

Animals↗

PubMed1997

Molecular cloning of mouse liver flavin containing monooxygenase (FMO1) cDNA and characterization of the expression product: metabolism of the neurotoxin, 1,2,3,4-tetrahydroisoquinoline (TIQ).

A mouse liver cDNA clone, MFMO1, coding for a flavin-containing monooxygenase (FMO) was isolated. This cDNA clone encoded a protein of 532 amino acids. Based upon its predicted amino acid sequence, this clone was assumed to belong to the FMO1 subfamily. The deduced amino acid sequence showed 94, 84, 83, and 83% identity with FMO1s of rats, pigs, rabbits and humans, respectively, while it showed only 50-59% identity with human FMO3 and FMO4, rabbit FMO2, FMO3, FMO4 and FMO5, and guinea-pig FMO2. RNA blot analysis showed that the mouse FMO1 was also expressed in the lung and kidney and to lesser extents in the heart, spleen, testis and brain. Mouse FMO1 expressed in yeast showed activities of thiobenzamide S-oxidation, and NADPH oxidation associated with the S- or N-oxidation of chlorpromazine, N,N-dimethylaniline, N,N-dimethyl-hydrazine, imipramine, nicotine, thioacetamide, thiourea and trimethylamine. Moreover, 1,2,3,4-tetrahydroisoquinoline (TIQ), a substance known to induce a parkinsonism-like syndrome in monkeys, was also metabolized by the mouse FMO1. The K(m) values for chlorpromazine, imipramine and TIQ were determined to be 2,4, 16.0, 435 mM, respectively. This is the first report to show that an expressed FMO can metabolize a neurotoxin, TIQ.

Amines↗

PubMed1997

Expression of MAGE genes in colorectal carcinomas.

The human genes MAGE-1 and MAGE-3 encode tumor rejection antigens recognized on melanoma cells by cytotoxic T lymphocytes (CTL). These antigens are potentially useful as targets for specific immunotherapy. Expression of MAGE genes in some malignant tumors has been reported, but MAGE gene expression in colorectal carcinomas has not been studied adequately. Therefore, we studied MAGE-1,2,3, and 4 a/4 b expression at the mRNA level, in 40 cases of surgery for colorectal carcinoma, using the reverse transcription polymerase chain reaction (RT-PCR). MAGE-1,2,3, and 4 a/4 b genes were expressed in 3 (7.5%), 6 (15.0%), 13 (32.5%), and 5 (12.5%), respectively, of these 40 cases. A total of 19 of the 40 samples (47.5%) expressed at least one of the MAGE genes. The relationships between clinicopathologic factors and MAGE gene expression were also examined. The frequency of lymph node metastasis was significantly higher in MAGE-3-positive than in MAGE-3-negative cases (p < 0.05). All these cases classified as Duke's D expressed the MAGE-3 gene. This rate of expression was significantly higher than that for all other the Duke's classifications together (p < 0.05). Our findings suggest that MAGE-specific immunotherapy against colorectal carcinomas may be feasible.

Aged↗

PubMed1997

Development of cancer vaccine by tumor rejection antigens.

Identification of the MAGE genes allowed us the molecular approach to identify genes encoding tumor rejection antigens expressed on human cancer cells. MAGE-1 proteins are normal tissue antigens compartmentalized in the particular testicular cells playing an important role in the early phase of the spermatogenesis. The MAGE-1, -2, -3, -4 and -6 genes are preferentially expressed in many different cancers at both the mRNA and protein levels. The MAGE genes, particularly MAGE-1, became positive in relatively advanced stages of cancers and recurrent cancers. Approximately one-third to half of human cancers except for myelo-monocytic leukemia expressed at least one of these MAGE genes. The MAGE gene products shall be appropriate target molecules for development of new cancer vaccine.

Animals↗

PubMed1997

[Preoperative localization of enlarged parathyroid glands by 99mTc-MIBI scintigraphy].

BACKGROUND: Recent studies have shown that 99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI), a new agent for myocardial perfusion imaging, can be successfully applied to parathyroid imaging. We evaluated the efficacy of 99mTc-MIBI scintigraphy for preoperative localization of enlarged parathyroid glands in patients with hyperparathyroidism. PATIENTS AND METHODS: From June 1994 to September 1996, 24 patients with biochemical confirmation of hyperparathyroidism were studied with 99mTc-MIBI scintigraphy prior to operation. Eleven patients had primary hyperparathyroidism (PHPT) and 13 had secondary hyperparathyroidism (SHPT) associated with chronic renal failure, including one patient with recurrent disease after subtotal parathyroidectomy. A positive 99mTc-MIBI scan for an enlarged gland was defined as an area of persistent focal uptake on the delayed image acquired at 150 min after intravenous injection of 600 MBq of 99mTc-MIBI. RESULTS: Of 11 patients with PHPT, 10, were found to have solitary parathyroid adenomas at surgery and one patient had primary hyperplasia. 99mTc-MIBI scintigraphy accurately detected 9 of 10 adenomas and 2 of 3 hyperplastic glands with no false positive results. Both of the two glands that were not detected by 99mTc-MIBI weighed 200 mg. The mean weight of the 11 glands that were visualized was 1264 mg (range 300 approximately 4300 mg). The sensitivity and predictive value positive for PHPT were 84.6% and 100%, respectively. In 13 patients with SHPT, all of 49 parathyroid glands were identified during surgery, with 43 hyperplastic glands and 6 normal-size glands. Of 43 hyperplastic glands, 28 were detected by 99mTc-MIBI and there was significant difference between the mean weight of these 28 glands (999 mg, range 290 approximately 2630 mg) and that of the 15 nonimaged hyperplastic glands (283 mg, range 90 approximately 540 mg). None of the six normal glands were imaged with 99mTc-MIBI. One patient had a false positive scan caused by a thyroid nodule. The sensitivity and predictive value positive for SHPT were 65.1% and 96.6%, respectively. CONCLUSION: 99mTc-MIBI scintigraphy is an excellent imaging method for localization of enlarged parathyroid glands in patients with hyperparathyroidism, especially with PHPT. However, it has the difficulty to demonstrate enlarged glands smaller than 300 mg in weight.

Adult↗

PubMed1997

[Rapid onset of hemolytic anemia after allogeneic bone marrow transplantation from an unrelated ABO major mismatched donor].

A 46-year-old woman with chronic myelogenous leukemia received allogeneic bone marrow transplantation from an unrelated human leukocyte antigen (HLA) matched (but mixed lymphocyte culture (MLC) positive to graft-versus host disease (GvHD) donor. The blood type of the recipient was A type Rh (+) while the donor blood type was B type Rh (+). The patient received busulfan 8 mg/kg, cyclophosphamide 120 mg/kg, and total-body irradiation 10 Gy before bone marrow transplantation. Short-term administration of methotrexate and cyclosporin was given for prophylaxis of GvHD. The mononuclear cells harvested from the donor were concentrated by COBE Spectra before bone marrow transplantation. Although engraftment of transplanted bone marrow in the recipient was confirmed on day 11, the patient suffered from severe anemia on day 10. Since the direct Coombs' test to A type red blood cells was positive, and anti-A antibody titer increased 16-fold, we diagnosed her anemia as hemolytic anemia caused by ABO mismatched transplantation. In addition to hemolytic anemia, she had skin symptoms of acute GvHD grade II, microangiopathic hemolytic anemia, and died of multiple organ failure on day 44. This experience indicated that some allogeneic transplant recipients are at risk of severe hemolytic anemia in the early stage after unrelated ABO mismatched donor and that it is necessary to establish proper treatment and prophylaxis.

ABO Blood-Group System↗

PubMed1997

Subclinical Fabry's disease occurring in the context of IgA nephropathy.

A 28-year-old male patient with both IgA nephropathy and an unusual case of Fabry's disease has been followed for 10 years. Diagnosis of both these diseases was made by histological examination of renal biopsy tissues and the enzyme activities of alpha-galactosidase A. Serial biopsies revealed the hithertofore unrecognized process of glomerular glycolipid accumulation peculiar to Fabry's disease at the initial stages of the disease. Physical examinations and routine laboratory analyses failed to show significant signs of Fabry's disease throughout the 10-year period. While alpha-galactosidase A activity is markedly decreased in the plasma of this patient as in classical Fabry hemizygotes, the activity in leukocytes and culture fibroblasts showed a considerable residual activity. Fabry's disease associated with IgA nephropathy apparently is extremely rare, and the present subclinical case is unique in that the early stages of substrate accumulation are demonstrable.

Adult↗

PubMed1997

[Quantitative analysis in nuclear nephrourology: clearance, uptake and transit time].

Radionuclide renal study is only a method that can provide anatomical as well as functional information on the kidney. There have been many reports on quantification of the renal function using radionuclides. They are summarized to two groups: blood and/or urine sampling method and external counting method. The former is accurate and reproducible in quantification of the renal function, but is rarely applicable in a routine practice due to technical complexity. On the contrary, the external counting method by means of a gamma camera and dedicated computer system is simple and practical in a routine use, but is less in reliability of quantitated renal function than sampling method. In this paper, technical and diagnostic characteristics of the quantitative methods on renal function using the radionuclide are reviewed.

Algorithms↗

PubMed1997

[Idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia in a patient who died of progressive peripheral polyneuritis and cerebral dysfunction].

We reported a 59-year-old woman who received a diagnosis of psoriasis vulgaris at the age of 35 and had been under medical treatment. She was admitted to our department on August 16, 1993 because of lymphadenopathy, arthralgia and neuralgia. We observed cervical and axillar lymphadenopathy 1-3 cm in diameter, anemia and leukothrombocytosis. Elevated levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and immunoglobulin G (IgG), but not M-protein were observed by immunological analysis of the serum. Bone marrow aspiration biopsy revealed hypercellularity with myeloid hyperplasia and slight increase in plasma cells. Elevated levels of serum interleukin-6 (IL-6) and granulocyte colony-stimulating factor (G-CSF) were detected; IL-6 was 62.1 pg/ml and G-CSF was 66 pg/ml, but IL-1 alpha, IL-1 beta and TNF-alpha were within the normal range. Idiopathic plasmacytic lymphadenopathy (IPL) with polyclonal hyperimmunoglobulinemia was diagnosed by lymph-node biopsy and the patient received following treatment with prednisolone and hydroxyurea. Leukocytes, platelets and skin eruptions increased again when the steroid dose was tapered, so we changed treatments to MP (melphalan, prednisolone) therapy. In addition, various neurological abnormalities such as convulsions, loss of consciousness and peripheral polyneuritis were observed. Despite treatment her condition deteriorated and she finally died. Very few reports show these neurological abnormalities in IPL or Castleman's disease therefore we think this is a very rare case.

Brain Diseases↗

PubMed1997

Differentiation of renal cell carcinomas from angiomyolipomas by ultrasonic frequency dependent attenuation.

PURPOSE: We determined the usefulness of ultrasonic frequency dependent attenuation in differentiating hyperechoic renal cell carcinoma from angiomyolipoma. MATERIALS AND METHODS: Frequency dependent attenuation values were determined in 29 renal cell carcinomas and 13 angiomyolipomas. RESULTS: Frequency dependent attenuation values were significantly lower in renal cell carcinomas than in angiomyolipomas (0.42 versus 0.76 dB./cm./MHz.). Two of the renal cell carcinomas were as hyperechoic as the angiomyolipomas but they were clearly differentiated by the low frequency dependent attenuation. Two other renal cell carcinomas exhibited high values because of the abundance of fibrous tissue. However, they were readily diagnosed by the typical low echoic B-mode images. Frequency dependent attenuation did not differ between histological types of renal cell carcinoma. One angiomyolipoma that was poor in fat and rich in muscle components had an exceptionally low frequency dependent attenuation. Therefore, frequency dependent attenuation values can be regarded as an inversion of computerized tomography numbers. CONCLUSIONS: Frequency dependent attenuation measurement is a promising diagnostic aid in differentiating hyperechoic renal cell carcinomas from angiomyolipomas.

Adult↗

PubMed1997

[A case of myasthenia gravis associated with systemic lupus erythematosus and pemphigus erythematosus].

A 34-year-old woman was admitted to our hospital because of ptosis, dysarthria, muscle weakness of upper limbs and skin lesions. At the age of 22 years, she was diagnosed as having systemic lupus erythematosus (SLE) due to the presence of arthritis and high titer of antinuclear antibody. On admission, the high antiacetylcholine receptor antibody titer, along with the positive tensilon test and electromyography established a diagnosis of myasthenia gravis (MG). The demonstration of anti-intercellular antibodies both in cutaneous tissue and blood confirmed the diagnosis of pemphigus. MRI showed hypertrophic thymus. After thymectomy, the myasthenic symptoms aggravated and SLE and pemphigus erythematosus relapsed despite anti-cholinesterase treatment with plasmapheresis. She was then placed on corticosteroid therapy with an improvement of her all symptoms. This very rare case of MG associated with SLE and pemphigus erythematosus suggests that these diseases share common immunological abnormalities.

Adult↗

PubMed1997

[Record and preservation of ultrasound images and computer-assistant analysis--estimation of digital filing system and texture analysis].

Digital filing systems have advanced with computer technology and are among the most interesting modalities for recording and preserving ultrasound images. The benefits are reduced expense, superior imaging, and ease in searching previous records compared with those factors in conventional constant film, videotape, and other storage systems. Computer-assisted analysis of digital images for automatic differentiation of diseases has recently been studied. Conventional quantitative estimation methods of tissue characterization or histogram are not easy to apply to clinical studies because these methods are time-consuming, and require a specialized machine for this propose. We propose a new method of texture analysis of echo images. This new method depends on the echo-texture of the organ, and can clearly differentiate liver cirrhosis from normal liver. These new digital techniques for clinical studies may facilitate examination.

Diagnosis, Computer-Assisted↗

PubMed1997

Role of the stem cell factor (SCF) receptor and the alternative forms of its ligand (SCF) in the induction of long-term growth by stroma cells.

Self renewal and differentiation of hematopoietic stem cells is regulated by the hematopoietic microenvironment. The Stem Cell Factor (SCF) has been shown to be one of the essential factors that governs stem cell maintenance. In this abstract we describe a functional analysis of the membrane bound and soluble SCF within the context of stroma cocultures with hematopoietic cells. We report that transmembrane SCF is essential for long term growth, whereas soluble SCF supports only short term proliferation of stroma dependent hematopoietic cells. We also show that the SCF/c-kit interaction can be substituted by an unknown mechanism. To determine the molecular mechanism involved in maintenance of hematopoietic cells on stroma we analyzed the c-kit expression during coculture. We demonstrate that c-kit expression was downregulated during coculture. Downregulation was induced by the coculture itself and not by external factors.

Animals↗

PubMed1997

Analysis of specific accumulation of radiolabeled anti-carcinoembryonic antigen monoclonal antibody CEA 102 in colorectal cancer using computed radiography.

The specific accumulation of radiolabeled anti-carcinoembryonic antigen (CEA) monoclonal antibody (MoAb) CEA 102 in colorectal cancers was investigated by autoradiography of surgical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with [13I]-labeled intact CEA 102 or its F(ab')2. Primary tumor and liver metastases were successfully detected by external scanning with gamma camera in four cases. Autoradiographic study using FCR showed predominant localization of [13I]-labeled CEA 102 in primary tumors and liver metastases in all cases. Even the small-sized liver metastasis (0.5 cm) was clearly visualized. The pixel distribution curves showed the heterogeneity of the distribution of administered MoAb in the tumors. In the quantitative distribution analysis of CEA 102, the uptake of the primary tumor was 10-fold greater than that of the normal colon mucosa. These results suggest that MoAb has great potential in radioimmunodetection as well as possible use in antibody-directed therapy.

Antibodies, Monoclonal↗

PubMed1997

[Assessment of cerebral circulation using echo planar imaging--basic analysis in quantitating the mean transit time, cerebral blood flow, and cerebral blood volume].

The mean transit time (MTT), cerebral blood flow (CBF) and cerebral blood volume (CBV) using echo planar imaging (EPI) in 22 aged volunteers were measured based on moment analysis and gamma variate method. The first peak of signal intensity curve (p delta R2.) and the area under the curve after the first peak (AUC) were calculated according to the height over area method, as a convenient quantification. Then, MTT, CBF, and CBV were compared with AUC/p delta R2, p delta R2, and AUC, respectively. There was a good correlation between each other parameter (r = 0.67 - 0.92, every p < 0.001). The slow upward slope and the low peak height, however, caused a larger error between each other parameter.

Blood Flow Velocity↗

PubMed1997

Controllability of temporomandibular joint loading by coordinative activities of masticatory muscles: a two-dimensional static analysis.

Masticatory and bite forces, when applied to the teeth, generate tremendous compressive energy in the temporomandibular joint (TMJ). Excessive 'TMJ loading', if left untreated, deteriorates articular functions. Normally, it is controlled, to a certain extent, by stomatognathic means. In an attempt to clarify this control mechanism, we analyzed the relationship between TMJ loading and the activities of the masticatory muscles, by employing a static two-dimensional jaw model. This comprises two rigid bodies, the upper and lower jaws, including three dominant muscles, i.e. the masseter, the anterior portion of the temporalis and the lateral pterygoid. Static equilibrium analyses determined that TMJ loading can be minimized, under controlled bite conditions, by pointing the loading vector in a direction solely indicated by individual morphological factors, such as the position and orientation of the masseter and the temporalis. This theoretically optimum direction of TMJ loading was also anatomically acceptable, because the load is applied exactly to those portions of the articular disk and mandibular head that can most easily sustain it. Interestingly, this factor was absolutely independent of both the activities of the lateral pterygoid and the direction of bite force. Consequently. TMI loading can be minimized, by coordinating the activities of the masseter and the anterior portion of the temporalis.

Bite Force↗

PubMed1997

[Evaluation of clinical utility of 111In-DTPA-IgG scintigraphy in the detection of inflammation/infection--a report of multicenter phase III clinical trials].

This is the report of phase III study to evaluate the safety and utility of 111In-DTPA-IgG in patients with strongly suspected inflammation/infection. One hundred and forty five patients with suspected sites of inflammation/infection were enrolled in the study. Only a few adverse experiences in one patient were reported, which were interpreted as having a possible relationship to the agent. A total of 171 suspected sites (12 in head and neck, 39 in thorax, 44 in abdomen and pelvis, 62 in musculoskeletal system, and 14 in other regions) were evaluated by investigators at each institute. Out of 171 sites, 18 were determined to be unevaluable, and 12 false negative and 5 false positive cases were observed. Overall sensitivity and specificity was 89.8% and 85.7%, respectively, and the agent proved to be effective in detecting lesions anywhere throughout the body. The analysis of data from this Phase III study indicates that 111In-DTPA-IgG is well-tolerated in patients and effective in determining focal sites of inflammation/infection although the physiological accumulation in some tissues such as the sinus or liver and possible excretion into the gastrointestinal tract may make it difficult to localize lesions.

Aged↗