Biomedical subjects

K Higuchi

Publications and source records attributed to K Higuchi.

At least 19 recordsLinked to original sources

PubMed1992

Production and properties of novel human thyroid cancer specific monoclonal antibodies.

Monoclonal antibodies (TCM-7, -9 and -12) against human thyroid differentiated cancers were established by screening with human thyroid cancers, normal and benign thyroid tissue, and normal human serum protein. A monoclonal antibody (TCM-9) with strong specificity for human thyroid cancer but not for Graves' disease, adenoma or normal thyroid, was shown to recognize a 300 K protein but not to bind to native or mature human thyroglobulin. When TCM-9 was used in immunohistochemical staining tests on more than 30 types of non-thyroid lesions, no reactivity of TCM-9 was observed except with skin immature teratoma, lip squamous carcinoma and stomach adenocarcinoma, which revealed weak reactivities. TCM-9 also showed strong reactivity with two undifferentiated thyroid cancer cell lines and one tissue specimen. Thus TCM-9 is a novel monoclonal antibody against the thyroid cancer.

Adenocarcinoma↗

PubMed1992

Synaptic inhibition of accessory motoneurons evoked by stimulation of the trigeminal nerve in the cat.

Stimulation of the trigeminal nerve produced polysynaptic inhibitory postsynaptic potentials (IPSPs) in accessory motoneurons of the cat. This contrasts with the observation that dorsal cervical motoneurons responded with EPSPs to trigeminal stimulus. Stimulation of the rostral part of spinal trigeminal nucleus elicited di- or polysynaptic IPSPs in accessory motoneurons. Transection of the anterior funiculus at the upper cervical cord selectively abolished the IPSPs. The IPSPs were antagonized by systematically administrated strychnine but not bicuculline.

Accessory Nerve↗

PubMed1992

Afferent projections in the spinal accessory nerve to the facial motoneurons of the cat.

Stimulation of the accessory nerve evoked polysynaptic excitatory postsynaptic potentials (EPSPs) in the facial nucleus (FN) neurons of anesthetized cats. From the experiments with severance of C1-C3 dorsal roots, it is suggested that accessory afferents enter the brainstem through the accessory nerve. It was also found that stimulation of the solitary tract nucleus produced exclusively monosynaptic EPSPs in the FN neurons and the afferent volleys are most likely to be relayed at the solitary tract nucleus.

Accessory Nerve↗

PubMed1992

Evaluation of transcatheter arterial embolization with epirubicin-lipiodol emulsion for hepatocellular carcinoma.

A total of 18 patients with hepatocellular carcinoma (HCC) were treated by transcatheter arterial embolization (TAE) with a 4'-epi-doxorubicin (EDX)-lipiodol emulsion. Infusion of the EDX-lipiodol emulsion (EDX-L) via the hepatic artery was followed by the injection of gelatin sponge in 12 cases. The response and survival of these 12 patients following EDX-L treatment were compared with those of 42 subjects treated with a doxorubicin-lipiodol emulsion (DX-L) and those of 23 patients treated by TAE with gelatin sponge (GS) only. In the group treated with EDX-L, nine cases were AFP-positive in sera and four showed a decrease in serum AFP values to less than 10% of the pretreatment level. Seven cases showed a partial response, and nine cases showed no change in the size of the tumor. In the group treated with EDX-L, nine cases are alive, and the oldest has survived for more than 431 days since the treatment. The half-year survival value was 57%, and the 1-year survival value was 49%. These values did not differ significantly from those calculated for the group treated with DX-L. The 1-year survival value determined for patients treated with a lipiodol emulsion (EDX-L or DX-L) followed by GS was 65%, and the 2-year survival value was 39%. These results rates are significantly better than those obtained in patients treated with GS only (1-year survival, 39%; 2-year survival, 13%.

Aged↗

PubMed1992

Glial cyst of the pineal gland with characteristic computed tomography, magnetic resonance imaging, and pathological findings: report of two cases.

Two cases of glial cyst of the pineal gland are documented. Preoperative computed tomography and magnetic resonance imaging revealed cystic lesions of the pineal region with contrast enhancement of the walls, suggesting neoplastic lesions rather than true cysts. However, the histopathological examination of the resected specimens revealed the presence of glial tissue and normal structure of pineal gland and capsule, characteristics that were consistent with those of glial cysts of the pineal gland. Headache and visual disturbance were resolved after total removal of the cysts.

Adolescent↗

PubMed1992

Undifferentiated carcinoma of the thyroid gland: sonographic findings.

We report high resolution sonographic (7.5 MHz) findings in four cases of undifferentiated carcinoma of the thyroid gland. Sonographic findings in these four cases included poorly marginated, hypoechoic masses associated with calcifications, and invasion of adjacent cervical structures. A knowledge of the sonographic features of undifferentiated carcinoma of the thyroid gland is of clinical importance, since the tumour has a grave prognosis, quite different from the relatively favourable prognosis of well differentiated thyroid carcinoma.

Adult↗

PubMed1992

Effect of sofalcone on localization of 15-hydroxyprostaglandin dehydrogenase, an enzyme that metabolizes prostaglandin E2, in rat gastric mucosa: an immunohistochemical study.

We identified the cells containing 15-hydroxyprostaglandin dehydrogenase (15-HPGD) in rat gastric mucosa and examined the effects of sofalcone on the localization of the enzyme by use of an immunohistochemical technique. Also, we investigated the effects of sofalcone on the localization of prostaglandin E2 (PGE2). Specific stainings for 15-HPGD and PGE2 were similarly observed in a granular pattern mainly in the cytoplasm of parietal and surface epithelial cells. The number of the stained cells for 15-HPGD, especially surface epithelial cells, decreased when rats were given sofalcone, with a concomitant increase in PGE2 staining. These results suggest that parietal and surface epithelial cells are responsible for the degeneration of PGE2 in the rat gastric mucosa, and that sofalcone increased the PGE2 level in the mucosa through inactivation of 15-HPGD in these cells, especially surface epithelial cells.

Animals↗

PubMed1992

Early ultrastructural changes of surface epithelial cells isolated from rat gastric mucosa after exposure to ethanol with or without 16,16-dimethylprostaglandin E2.

Early ultrastructural changes of surface epithelial cells isolated from rat gastric mucosa caused by 15% ethanol were studied. The effect of 16,16-dimethylprostaglandin E2 (16,16-dimethyl-PGE2) on these changes was also examined. Findings by transmission electron microscopy showed ballooning and decreased density of mitochondria in addition to loss of microvilli and partial disruption of the surface cell membrane in cells exposed to 15% ethanol, although the nucleus looked normal. These ultrastructures were well preserved even after exposure to 15% ethanol when the cells were treated with 10(-6) M 16,16-dimethyl-PGE2 beforehand. These results may indicate that the surface cell membrane and mitochondria are the major targets for early injury by ethanol and protection by 16,16-dimethyl-PGE2 in surface epithelial cells. The mechanism by which 16,16-dimethyl-PGE2 prevents the damage is not known.

Animals↗

PubMed1992

Immunohistochemical localization of cells that synthesize leukotriene B4 in human gastric mucosa.

We evaluated the cell location of leukotriene B4 (LTB4) in human gastric mucosa by immunohistochemistry using a novel fixation procedure with 0.5% glutaraldehyde-8% paraformaldehyde followed by periodate-lysine-2% paraformaldehyde. The location of LTA4 hydrolase, which synthesizes LTB4, was also investigated in human gastric mucosa. Staining for LTB4 was mostly in a granular pattern in the cytoplasm of parietal and surface epithelial cells. LTB4 was also stained in some vascular endothelial cells and a few polymorphonuclear cells in the lamina propria. LTA4 hydrolase was similarly stained in these cells. These results suggest that parietal, surface epithelial, and vascular endothelial cells are the cells that synthesize LTB4 in the human gastric mucosa. Polymorphonuclear cells might also synthesize a smaller amount of LTB4.

Biopsy↗

PubMed1992

[A case of obstructive ileus following the upper Gi barium swallow study with condensed barium due to severe constipation].

A 64-year-old woman visited my clinic with complaints of abdominal distension, constipation, and nausea. Since abdominal X-ray showed severe obstructive ileus following the upper GI barium swallow study, the patient was sent immediately to Saga Medical School Hospital for the emergency operation. As the result of the left hemicolectomy, two obstructive lesions were found at the sigmoid colon and the transverse colon. Nowadays, as the population of aged people increases and Japanese diet changes, colon cancers are increasing more rapidly. Since the half of colon cancers doesn't have any clinical symptoms of obstruction, the upper GI barium swallow study with condensed barium might lead a patient to some type of dangerous situation.

Adenocarcinoma↗

PubMed1992

[Seasonal variation of intraocular pressure after trabeculotomy].

The author reviewed the seasonal variation of intraocular pressure (IOP) in primary open angle glaucoma or late type developmental glaucoma to investigate possible relationships among seasonal variation of IOP, progression of visual field defects and the follow-up period between 53 eyes of 39 subjects with successful trabeculotomy (trabeculotomy group) and 45 eyes of 31 subjects with only medication (no operation group). IOPs in both groups were inclined to be low in summer and high in winter. Maximum seasonal variation of IOP and standard deviation of IOP during all follow-up periods which showed the degree of seasonal variation of IOP had no significant difference between the trabeculotomy group and the no operation group. These results showed that seasonal variation of IOP was not reduced even by successful trabeculotomy. The maximum seasonal variation of IOP and standard deviation of IOP had a tendency to be bigger in cases with progression of visual field defects than in cases with no progression of visual field defects, in both groups. Therefore, seasonal variation of IOP may be an important factor influencing the progression of visual field defects.

Follow-Up Studies↗

PubMed1992

Developmental and age-related changes in apolipoprotein B mRNA editing in mice.

Apolipoprotein B (apoB) mRNA is modified by a post-transcriptional editing reaction (C to U) changing a glutamine (CAA) to a translational stop codon (UAA) and producing apoB-48 mRNA in mammalian liver and intestine. Developmental and age-related changes in apoB mRNA editing were studied using two mouse strains with different aging processes (SAM-R/1 with a normal aging process and SAM-P/1 with an accelerated aging process). During growth of both strains, the proportion of unedited (apoB-100) mRNA decreased from 80% in the fetal liver at the 17th day of gestation to 30% in the liver of mature 2-month-old mice. Age-associated increase in the proportion of hepatic apoB-100 mRNA was observed from the age of 18 months in the SAM-R/1 strain. In the SAM-P/1 strain, apoB-100 mRNA in the liver continued to increase from the age of 10 months to death. The profiles of developmental and age-related changes in the proportion of two serum apoB isoproteins (apoB-100 and apoB-48) followed the extent of hepatic apoB mRNA editing. Age-related changes in the extent of apoB mRNA editing in the small intestine were not observed in either strain. A slight expression of apoB was detected by reverse transcriptase-polymerase chain reaction in the kidney, stomach, and colon, and age-associated change in the extent of editing was observed in the kidney. These correlated changes in apoB mRNA editing and serum apoB proteins suggest that RNA editing may be one mechanism involved in the regulation of lipoprotein biogenesis in biological development and in senescent mice. An age-associated decrease in the extent of hepatic apoB mRNA editing and increases of the proportion of serum apoB-100 protein were observed in senescent mice.

Aging↗

PubMed1992

[Pseudosarcomatous fibromyxoid tumor of the urinary bladder: a case report].

A 41-year-old man was referred to our clinic for gross hematuria. Cystoscopy revealed a 6 x 5 x 5 cm wide-based tumor located at the dome of the bladder. Pathological diagnosis of the biopsy was pseudosarcomatous fibromyxoid tumor. Microscopically this tumor was composed of spindle cells and myxoid stroma, and immunohistochemical and ultrastructural studies showed benign characteristics of this tumor. Therefore partial cystectomy was performed. It is important to recognize the histological characteristics of this essentially benign condition so that total cystectomy can be avoided.

Adult↗

PubMed1991

Polymorphism of apolipoprotein A-II (apoA-II) among inbred strains of mice. Relationship between the molecular type of apoA-II and mouse senile amyloidosis.

Three types of apolipoprotein A-II (apoA-II) proteins (A, B and C) were predicted from the nucleotide sequence of apoA-II cDNA. Substitution of amino acid residues was noted at four positions (type A: Pro-5, Asp-20, Met-26, Ala-38; B: Pro-5, Glu-20, Val-26, Val-38; C: Gln-5, Glu-20, Val-26, Ala-38). Each type was identifiable by digestion of amplified apoA-II DNA by PCR, using restriction-fragment-length polymorphism of the apoA-II gene for restriction enzymes Cfr13I and MspI. The molecular type of apoA-II was determined among 23 strains of mice including nine of the senescence accelerated mouse series developed in our laboratory. Examination of types of apoA-II and amyloid deposition in the F2 and F3 hybrid mice showed that apoA-II amyloid deposition was present only in the mice homozygous for type C apoA-II and which were 12-17 months of age. The molecular type of apoA-II may be a factor involved in the development of senile amyloidosis in mice.

Aging↗

PubMed1991

Effects of endothelins on signal transduction and proliferation in human melanocytes.

We demonstrate here that human melanocytes could be regulated by endothelin (ET) derivatives, potent vasoconstrictive peptides synthesized by endothelial cells, to stimulate their proliferation and melanization via a receptor-mediated signal transduction pathway. Receptor-binding assay using [125I]ET indicated that unlabeled ET-1 or ET-2 competitively inhibited each binding of labeled ETs to melanocytes with a concentration for half-maximal inhibition (IC50) of 0.7 or 0.9 nM, respectively. The dissociation constant (Kd) and the number of sites of the specific bindings of ET-1 and those of ET-2 were almost the same (Kd: 1.81 nM, binding sites: 7.0-8.0 x 10(4) per cell). Upon incubation with cultured cells, the mass contents of inositol 1,4,5-trisphosphate and intracellular calcium level were substantially increased by 10 nM ET-1, ET-2, and ET-3, but not by big-ET with maximal response at 80-130-s postincubation. The addition of ET-1 and ET-2 at 1-50 nM concentrations caused human melanocytes to significantly stimulate DNA [( 3H]thymidine incorporation) and melanin synthesis (3H2O release and [14C] thiouracil incorporation). Furthermore, ETs exhibited an additive stimulatory effect on basic fibroblast growth factor-stimulated DNA synthesis. In a long-term serum-free culture system, the strongest stimulation of growth by 10 nM ET-1 or ET-2 was observed in the presence of 10 nM cholera toxin and 0.2% bovine pituitary extract, resulting in a 4.5-fold increase in cell number for 12 culture days. These findings strongly suggest involvement of ET in the mechanism regulating proliferation and melanization of human melanocytes.

Binding, Competitive↗

PubMed1991

Effect of progesterone on renin secretion in endometrial stromal, chorionic trophoblast, and mesenchymal monolayer cultures.

Renin messenger ribonucleic acid expression has been shown in decidual tissue and endometrium, but weakly in chorion laeve, suggesting decidua as a primary source of uteroplacental renin. We proposed to confirm active renin secretion by endometrial stromal cells and examined the effect of progesterone-induced decidualization on secretion. Separate monolayer cultures of endometrial stroma, trophoblast, and mesenchymal cells were established and maintained for 10 to 15 days. Active renin concentration was measured with radioimmunoassay for angiotensin I generation and expressed as picograms per milliliter of angiotensin I generation per 10(5) cells. Active renin concentration was high in control secretory endometrial stromal cells (513 pg/ml) compared with trophoblast (none) and mesenchymal cell cultures (74 pg/ml). Marked decrease in active renin secretion occurred in control endometrial stromal cells (days 13 to 15, 86 pg/ml), whereas progesterone-induced decidualization sustained and increased secretion (days 13 to 15, 1017 pg/ml). This renin activity was quantitatively inhibited in culture fluid assays by specific human renal renin antibody in serial dilutions. Renin activity measurements before and after trypsin activation showed the majority of renin (91.15%) in the inactive form and a smaller fraction (8.85%) in the active form. Immunohistochemistry with the use of specific human renal renin antibody confirmed the presence of renin and its stimulation by progesterone in endometrial stromal cells. Progesterone had minimal effect on mesenchymal cells. These data confirmed endometrial stromal cells as a significant source of active renin and showed that progesterone induced a marked increase in this production.

Chorion↗

PubMed1991

Atrial and brain natriuretic peptide in adrenal steroidogenesis.

We elucidated the role of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in human and bovine adrenocortical steroidogenesis. The urinary volume, sodium excretion and cyclic GMP (cGMP) excretion and plasma cGMP were markedly increased by the synthetic alpha-human ANP (alpha-hANP) infusion in healthy volunteers. Plasma arginine vasopressin (AVP) and aldosterone levels were significantly suppressed. Both ANP and BNP inhibited aldosterone, 19-OH-androstenedione, cortisol and DHEA secretion dose-dependently and increased the accumulation of intracellular cGMP in cultured human and bovine adrenal cells. alpha-hANP significantly suppressed P450scc-mRNA in cultured bovine adrenal cells stimulated by ACTH. Autoradiography and affinity labeling of [125I]hANP, and Scatchard plot demonstrated a specific ANP receptor in bovine and human adrenal glands. Purified ANP receptor from bovine adrenal glands identified two distinct types of ANP receptors, one is biologically active, the other is silent. A specific BNP receptor was also identified on the human and bovine adrenocortical cell membranes. The binding sites were displaced by unlabelled ANP as well as BNP. BNP showed an effect possibly via a receptor which may be shared with ANP. The mean basal plasma alpha-hANP level was 25 +/- 5 pg/ml in young men. We confirmed the presence of ANP and BNP in bovine and porcine adrenal medulla. Plasma or medullary ANP or BNP may directly modulate the adrenocortical steroidogenesis. We demonstrated that the lack of inhibitory effect of alpha-hANP on cultured aldosterone-producing adenoma (APA) cells was due to the decrease of ANP-specific receptor, which caused the loss of suppression of aldosterone and an increase in intracellular cGMP.

Adrenal Cortex↗

PubMed1991

Cystic papillary carcinoma of the thyroid gland: a new sonographic sign.

Cystic thyroid lesions are generally considered to be benign and managed by repeated aspiration and/or biopsy. We report characteristic sonographic signs in eight cases of cystic papillary carcinomas of the thyroid gland. In all eight cases, ultrasonography (US) revealed mostly cystic lesions with solid excrescences protruding into the cyst. These nodules contained multiple punctate echogenic foci suggesting calcification. In three of these cases the initial fine needle aspiration biopsy was negative. The 'calcified nodule in cyst' sign was found to be very specific for cystic thyroid carcinoma in a review of the ultrasound findings in 115 patients with nodular thyroid lesions. Careful evaluation and/or surgery should be recommended in patients who have such characteristic sonographic findings even if the fine needle aspiration result is negative.

Adult↗