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Biomedical subjects

M Itoh

Publications and source records attributed to M Itoh.

At least 757 records · Page 42Linked to original sources
PubMed1992

Measurements of tumor blood flow using intraperitoneal deuterium and 2H-NMR spectroscopy.

Using i.p. delivered deuterated water, and 2H NMR spectroscopy, it is possible to non-invasively, serially, and quantitatively measure blood flow through tissue volumes as small as 0.05 ml. Measurements made with this technique show that changes in total tumor blood flow reflect local changes measured superficially by laser Doppler flowmetry, and that tumors of identical histology and size have heterogeneous blood flow rates. Finally, we have shown that tumors growing in an irradiated normal tissue have a lower blood flow rate which is manifest when tumors grow beyond 0.1 ml.

Animals↗
PubMed1992

Assessment of chemoembolization therapy for primary liver cancer using a stabilized adriamycin-lipiodol suspension.

We formulated a new lipiodol-Adriamycin suspension (ADM/lipiodol, 50 mg/10 ml) that remained stable for 48 h (half-life, 25 +/- 3 days). In five cases of hepatocellular carcinoma (HCC) resected after intra-arterial infusion of this agent, the ADM concentration in the tumor was quite high and the tumor necrosis rate was more than 80% on histological examination. Over a 5-year period, 180 patients with unresectable HCC underwent transcatheter arterial embolization therapy (TAE) in the presence or absence of this agent. The regimens consisted of suspension injection alone (A, n = 54), suspension injection + TAE using gelatin sponge (B, n = 29), TAE followed by suspension injection (C, n = 34), and TAE alone (D, n = 63). The estimated 1-year survival values determined for patients treated with these regimens were 70%, 73%, 43%, and 39% respectively, and the corresponding 3-year survival values were 27%, 31%, 15%, and 10%. The survival achieved using suspension injection was thus superior to that obtained using conventional TAE, and combined therapy with suspension injection followed by TAE seemed to enhance survival, although there were some biases in tumor size and in the stage of tumor progression. For patients with tumors measuring 5 cm or more in diameter, the survival obtained using regimen A was lower than that achieved using regimen D, but the combination of TAE and suspension injection improved the 1-year survival value obtained using regimen D from 34% to 52%. For patients with tumors measuring less than 5 cm in diameter, the survival achieved using regimen A was markedly better than that obtained using regimen D, although no difference was found between the survival value achieved using regimen A and that obtained using regimens B and C. On the basis of these results, our newly formulated ADM-lipiodol suspension was surmised to be effective by itself against relatively small HCC tumors, whereas it enhanced the efficacy of conventional TAE in large lesions.

Aged↗
PubMed1992

Intestinal tuberculosis: findings on double-contrast barium enema.

Seven cases of intestinal tuberculosis in an active stage were studied by the double-contrast barium enema (DCBE) method. Formerly, diagnosis of intestinal tuberculosis in the early stage by single-contrast barium enema (SCBE) and barium meals was based on functional phenomena, such as spasm and hypermotility of the ileocecal region. Presently, this can be better accomplished by DCBE. DCBE enables the detection of shallow ulcers with their characteristic elevated margins. These ulcers are frequently slim and transversally oriented. Confluence of ulcers may create whole girdle ulcers or affect entire segments. In more advanced stages, characteristic deformities, also evident by SCBE, such as symmetrical annular stenoses, shortening, retraction, pouch formation, and the frequently observed pathology of the ileocecal valve and the cecal region, acquire a new dimension with DCBE.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Amplexus induces surge of luteinizing hormone in male toads, Bufo japonicus.

At mating time in the wild, male toads (Bufo japonicus) exhibit a surge in circulating luteinizing hormone (LH) that is thought to result in spermiation. Experiments were performed to identify proximate control of this gonadotropin surge. Male toads migrating to a breeding pond were captured and put in plastic containers either with equal numbers of females or without females. All the males placed with the females clasped them in amplexus that lasted for about 12 hr. During this period, plasma LH and follicle-stimulating hormone levels increased progressively to about 25 and 2 times the initial levels, respectively, and then returned to the initial levels. No significant increases in plasma gonadotropin levels were observed in the males kept without females. These results suggest that the amplexus directly induced the LH surge, but do not preclude control by pheromonal or visual stimuli. To isolate effects of these factors, solitary male toads were kept with dummies of the female. The dummy was a block of "konnyaku," Japanese food whose component is mannan extracted from the root of a plant. Konnyaku is highly elastic, white in color, and virtually odorless. Thus, these dummies felt, but did not look or smell, realistic. All the males clasped their dummy and formed amplexus for 12 hr or more; an LH surge indistinguishable from that with the females was observed. It is concluded that the amplexus itself is the stimulus that induces the LH surge, and subsequent spermiation, in male toads. A strongly male-biased sex ratio, combined with a need to time spermiation precisely with actual mating, may have resulted in the evolution of this neuroendocrine reflex in male Bufo.

Animals↗
PubMed1992

Cushing's syndrome induced by hypersecretion of cortisol from only one of bilateral adrenocortical tumors.

A case of Cushing's syndrome induced by the unilateral (right side) dominance of cortisol secretion in the face of bilateral adrenal tumors is reported. The adrenal tumor resected on the right side was a so-called black adenoma and histologically without any findings of nodular hyperplasia. After resection of the adrenal adenoma, no findings of cortisol hypersecretion from the remaining adrenal tumor on the left side were observed until the present, suggesting that the tumor of the left adrenal gland is a nonfunctioning adenoma. These data imply that the adrenal adenomas have primarily developed from the adrenal gland itself, rather than from micronodular hyperplasia by corticotropin stimulation, and that one of these tumors produces excess hormones initially by corticotropin stimulation, but the other remains in cell proliferation.

Adenoma↗
PubMed1992

Mutation of the HANA protein of Sendai virus by passage in eggs.

A study was made to elucidate the effect of host cells on the HANA protein of Sendai virus. Two strains of Sendai virus were isolated from an epidemic in an animal laboratory by inoculating the lung homogenate of a moribund mouse either into LLC-MK2 cells (Oh-L) or into the allantoic cavity of embryonated eggs (Oh-E). Oh-E agglutinated chicken red blood cells at 37 degrees (HA37+), while Oh-L did not (HA37-). When Oh-L was passaged in eggs, conversion of the HA37- virus to the HA37+ virus readily occurred. A single point mutation was recognized on the HANA protein of the HA37+ virus either at position 525 (Gln----Arg) or at position 198 (Leu----Phe). Hl test with monoclonal antibody revealed conformational changes around the receptor binding site. Neuraminidase activity was also affected by these mutations. The changes in these biological activities of the HANA protein seemed to allow the HA37+ virus to replicate in eggs. On the contrary, the HA37+ virus replicates as efficiently as the HA37- virus in LLC-MK2 cells and no reversion to the HA37- virus was observed. The overall results indicate that the passage of Sendai virus in eggs resulted in selection of viruses possessing a specific mutation on the HANA protein. The pneumopathogenicity in mice was not significantly different between the HA37- virus and the HA37+ virus, suggesting the existence of genes other than the HANA gene that determine mouse pathogenicity.

Amino Acids↗
PubMed1992

Inhibition of a novel model of murine experimental autoimmune orchitis by intravenous administration with a soluble testicular antigen: participation of CD8+ regulatory T cells.

Recently, we established a novel murine model of experimental autoimmune orchitis (EAO) in C3H/He mice by means of two sc injections of 1 x 10(7) viable syngeneic testicular germ cells (TC) without the use of any adjuvants. Using this model, an effective and reproducible system of immunoregulation in EAO was developed. The induction of this EAO was suppressed by pretreatment with five iv injections of a soluble (deaggregated) form of murine testicular antigen (mTA). The antigen, mTA, was prepared by acid extraction and ammonium sulfate precipitation of defatted testes and epididymides. The development of EAO and relevant delayed-type hypersensitivity was suppressed in an antigen-specific fashion, but anti-TC antibody formation was not affected. A single dose of cyclophosphamide at 2 days after the tolerogenic regime abrogated the unresponsiveness to EAO. Three doses of recombinant interleukin 2 at every other day starting on the next day of the last pretreatment did not overcome the unresponsiveness to EAO. CD8+ T cells isolated from the spleen of deaggregated mTA-pretreated animals could adoptively transfer suppression against EAO into naive recipients, whereas CD4+ T cells failed to transfer the suppression.

Animals↗
PubMed1992

The superior cervical ganglion: origin of sympathetic fibers in the facial and hypoglossal nerves in the cat.

Location of superior cervical ganglion (SCG) neurons, sending axons into the facial and hypoglossal nerves, was investigated in the cat by means of retrograde axonal transport of horseradish peroxidase (HRP). After wheat germ agglutinin conjugated HRP (WGA-HRP) was injected into these nerves, many retrogradely labeled neurons were found widely in the ipsilateral SCG, particularly around the caudal half of the SCG. These neurons were round or oval in shape and 70-80% of these were medium in size. In fluorescent experiments, fast blue (FB) was used in combination with diamidino yellow (DY). After injections of FB into the facial nerve and DY into the hypoglossal nerve, a few FB-DY double-labeled neurons occurred in the SCG ipsilaterally.

Adrenergic Fibers↗
PubMed1992

The carbohydrate deficient glycoprotein syndrome in three Japanese children.

We describe 3 children (from two families) with a multisystemic disorder characterized by mental retardation, nonprogressive ataxia, polyneuropathy, hepatopathy during infancy and growth retardation. Due to the clinical similarities to a recently recognized disorder associated with carbohydrate-deficient transferrin, we examined serum transferrin by means of isoelectric focusing, and found increases in disialo transferrin and asialotransferrin. Removal of sialic acid with neuraminidase revealed the same transferrin phenotypes as in their parents. Similarly, carbohydrate-deficient fractions of serum alpha 1-antitrypsin were also detected. Therefore, the diagnosis was made of the recently identified carbohydrate-deficient glycoprotein syndrome. This is a genetic disorder with distinctive clinical features and multiple carbohydrate-deficient glycoproteins. These seem to be the first reported Japanese patients with this syndrome.

Adolescent↗
PubMed1992

A neuropathological study of a case of the Prader-Willi syndrome with an interstitial deletion of the proximal long arm of chromosome 15.

An autopsy case, a 6-month-old girl, with an interstitial deletion of the long arm of chromosome 15;del(15)(q11.1q12) was reported. Muscle hypotonia, poor sucking and intermittent ocular deviation were noticed soon after birth. She also exhibited external features peculiar to the Prader-Willi syndrome (PWS). The muscle hypotonia persisted and head control was not achieved. She died at the age of 6 months due to bronchopneumonia. G-banding analysis of prometaphase chromosomes revealed a deletion of chromosome 15. Bronchopneumonia of the lungs and fatty metamorphosis of the liver were found. Neuropathological anomalies recognized were; disturbed undulating structures, resembling cortical micropolygyria and pachygyria, in the dentate nucleus and the inferior olivary nucleus, grumose degeneration of the nerve cells in the dentate nucleus, and heterotopia of middle-sized neurons in the cerebellar white matter. No abnormalities were observed in the hypothalamus-pituitary system. In some autopsy cases of PWS, cerebellar lesions have been reported. These might be related to the muscle hypotonia in PWS.

Brain↗
PubMed1992

Suppression of thyroid cell growth by serum IgG in Graves' disease.

To determine whether serum immunoglobulin in addition to epidermal growth factor (EGF) augment growth in human thyroid cells, effects of these factors on thyrocytes were tested using IgG derived from 34 patients with Graves' disease and 12 normal subjects. The cell growth was estimated by [3H]-thymidine uptake, cell cycle determined by FACS analysis and the expression of c-fos mRNA in monolayer thyrocytes enzymatically prepared from Graves' thyroid. The addition of IgG taken from patients with Graves' disease inhibited the [3H]-thymidine uptake compared to that taken from control subjects. IgG taken from Graves' disease suppressed EGF-induced increase of S + G2/M phase in cell cycle and the expression of c-fos mRNA, while those taken from normal subjects did not affect at all. [3H]-thymidine uptake was more suppressed by IgG from patients with a smaller-sized goiter than by those with a larger-sized one. There was a negative correlation between the suppression of [3H]-thymidine uptake and levels of TBII (p less than 0.05). There was no correlation between the degree of suppression and the levels of T3, T4, TSAb, TSBAb or MCHA. Thus, in conclusion, IgG derived from sera of Graves' may inhibit the growth of Graves' thyrocytes, leading to the determination of the goiter size.

Chromatography, DEAE-Cellulose↗
PubMed1992

Congenital alveolar adhesions.

We report an infant girl with congenital alveolar adhesions and a cleft palate. The mucosal bands were resected the day after birth. Stretching exercises of the mandible improved the range of movement at the temporomandibular joint. Two weeks of therapy were required before full mouth opening was possible. Previously reported patients and theories of embryogenesis are reviewed.

Alveolar Process↗
PubMed1992

Upper extremity aneurysm in infants.

We report a 2-month-old female infant with a false aneurysm of the brachial artery and an 8-month-old male infant with a true aneurysm of a common digital artery. These traumatic aneurysms in the upper extremity are extremely rare in infants. In the former infant, reanastomosis of the brachial artery was performed. In the latter infant, simple excision was successful.

Anastomosis, Surgical↗
PubMed1992

Age-dependent decrease in histamine H1 receptor in human brains revealed by PET.

Age-related changes in histamine H1 receptors were studied using [11C]pyrilamine or [11C]doxepin by positron emission tomography (PET). The frontal, parietal and temporal cortices showed age-related decreases in binding of approximately 13% per decade. In contrast, the thalamus showed no apparent decrease in binding during normal ageing because of its higher nonspecific binding. Post mortem studies also indicated that the nonspecific binding of [3H]pyrilamine in the thalamus was approximately 112% higher than that in the cortex. However, no significant decrease in histamine H1 receptors with age was observed by in vitro binding assays of autopsied human frontal cortex. Possible reasons are given for the larger effects of age observed in the PET study than in the in vitro post mortem binding study.

Adolescent↗
PubMed1992

Protection of gastric mucosa against ethanol-induced injury by intragastric bolus administration of epidermal growth factor combined with hydroxypropylcellulose.

Orally administered epidermal growth factor (EGF) has been shown to protect the gastric mucosa against injury induced by noxious agents. However, EGF administered by intragastric bolus appears to have less effect on the gastric mucosa because of its rapid excretion from the gastric lumen. In this study, mouse EGF given to rats by gastric intubation was confirmed to remain in the stomach at significantly high concentrations when given in combination with hydroxypropylcellulose (HPC), an agent that retards drug release. The residual mouse EGF levels in the gastric luminal content and tissue 3 h after administration of 50 micrograms/kg of EGF dissolved in 1 ml of 2% HPC were 30 and 60 times higher, respectively, than those obtained after EGF alone. Pretreatment with intragastric bolus administration of EGF and HPC at the same dose for 3 h attenuated significantly the development of gastric lesions induced by absolute ethanol compared to that with HPC alone, EGF alone, or saline (mean values of ulcer index: EGF + HPC, 14.3; HPC, 52.8; EGF, 50.7; and saline, 63.2 mm). There were no significant differences between the ulcer index in the HPC, EGF, and saline groups. The present study indicates that exogenous EGF given as an intragastric bolus protects the gastric mucosa against injury when combined with HPC, which can bind to EGF and prevent its rapid excretion from the gastric lumen.

Animals↗
PubMed1992

Suppression of efferent limb of testicular autoimmune response by a regulatory CD4+ T cell line in mice.

A murine T cell line (designated as C.Ts) as a mediator of suppression of experimental autoimmune orchitis (EAO) was established. The method of establishment of C.Ts cell line was preparing spleen cells from C3H/He mice hyperimmunized with testicular germ cells (TC) and the repeated selection of the lymphocytes in vitro by stimulation with mouse testicular antigens (mTA). The C.Ts cells were Thy1.2+, surface immunoglobulin-, CD3+, CD4+ and CD8-. The cells could suppress the induction of EAO when transferred into actively EAO-sensitized mice only at the pre-clinical stage of the disease (efferent limb of the autoimmune response). The transferred C.Ts cells significantly inhibited both cellular and humoral immune responses to TC in the recipients in an antigen-specific manner. The disease suppression by C.Ts cells was found to depend upon their cell number, and their suppressive activity was markedly augmented by in vitro stimulation with mTA.

Animals↗
PubMed1992

Abnormal production of B cell growth factor in patients with systemic lupus erythematosus.

In order to clarify the role of B cell growth factor (BCGF) in the pathogenesis of systemic lupus erythematosus (SLE), BCGF production by peripheral blood mononuclear cells (PBMC) and T cells was studied using a new bioassay for BCGF activity. For this purpose, we established an Epstein-Barr (EB) virus-transformed B cell line KS-3.F10 that proliferates only in response to two B cell-specific BCGF, low-mol. wt BCGF (LMW-BCGF) and high-mol. wt BCGF (HMW-BCGF). PBMC from active SLE patients produced less BCGF when stimulated with phytohaemagglutinin (PHA) compared with controls. The decreased BCGF production by PHA-stimulated PBMC from active SLE reverted to control values when SLE became inactive. However, PHA-stimulated T cells from active SLE patients produced more BCGF compared with controls, whereas those from inactive SLE showed normal BCGF production. Spontaneous BCGF production by T cells was not observed in active SLE patients. These findings suggest that decreased BCGF production by SLE PBMC is due to excessive BCGF consumption by B cells in vitro and that SLE T cells produce large amounts of BCGF with appropriate immune stimuli in vivo to promote polyclonal B cell activation.

Adolescent↗