Search PubMed⌕ Search

Biomedical subjects

Y Iwai

Publications and source records attributed to Y Iwai.

At least 127 records · Page 7Linked to original sources
PubMed1994

[Bladder hernia: report of two cases].

Case 1. A 55-year-old male visited our hospital complaining of dysuria and two-staged micturition. Physical examination revealed a fist sized, elastic soft mass in the left inguinal region. Upright drip infusion pyelography (DIP) showed left inguinal hernia of the bladder. Retrograde urethrography showed bladder neck contracture and a diverticulum. Cystoscopy revealed a indentation in the left bladder wall. Urodynamic studies demonstrated organic obstruction in the lower urinary tract. From these findings, diagnosis was made as bladder hernia and bladder neck contracture. Resection of thin portion of the bladder wall and hernia repair, accompanied by prostatectomy, was performed. Case 2. A 37-year-old male visited our hospital with the history of ureteral stone and chronic prostatitis. Upright DIP incidentally revealed the small right inguinal bladder hernia. Because he had no complaint of dysuria and two-staged micturition, he was observed without surgical treatment.

Adult↗
PubMed1993

Ca2+ ionophore A23187-dependent stabilization of granulocyte-macrophage colony-stimulating factor messenger RNA in murine thymoma EL-4 cells is mediated through two distinct regions in the 3'-untranslated region.

We analyze the role of the Ca2+ ionophore A23187 in the induction of GM-CSF mRNA expression in EL-4 thymoma cells. Northern analysis shows that A23187 increases the half-life of GM-CSF mRNA. To identify potential Ca2+ response elements in the GM-CSF mRNA, we produced stable transfectants containing pRSV-CAT (EL-4cat) or hybrid constructs in which most of the GM-CSF 3'-untranslated region (EL-4gm) or the adenosine-uridine boxes alone (EL-4au) were placed in a downstream position from the CAT coding region. A23187 induces a 4.4-fold increase in CAT activity in EL-4cat cells and a 210-fold and 48-fold increase in CAT activity in EL-4gm and EL-4au cells, respectively. Actinomycin D chase experiments in transfected cells demonstrate that A23187 increases the half-life of CAT mRNA from 15 min to 3 h in EL-4au cells and more than 3 h in EL-4gm cells, suggesting that the effect of Ca2+ is mediated predominantly by the adenosine-uridine boxes with a smaller contribution from upstream regions. To map these upstream regions, we transfected cells with constructs containing mutations of the 3'-untranslated region. With two of these mutations, corresponding to a region located about 160 bases upstream of the adenosine-uridine boxes, CAT activity was induced only 50-fold compared to 200-fold in EL-4gm cells. These data indicate that two regions within the GM-CSF 3'-untranslated region interact to modulate Ca2+ effects on GM-CSF mRNA half-life.

Animals↗
PubMed1993

Vein graft replacement of the distal vertebral artery.

Vein graft reconstruction of the cervical portion of the vertebral artery has been commonly used for the treatment of atherosclerotic arterial disease. In this article, we describe two instances of vein graft replacement of the distal portion of the vertebral artery. In the first case, the vein graft was placed from C2 transverse foramen to the intradural portion of the vertebral artery to replace an artery abnormally encased and involved by meningioma. The grafting was done in this case to preserve the cerebrovascular reserve in a young patient. In the second case, a vein graft was placed from the extradural C1 portion to the intradural artery beyond the posterior inferior cerebellar artery. This was done to replace a segment of the artery involved by a giant aneurysm, which could not be clipped without occluding the parent artery. In this case, the vein graft replacement was necessitated by changes of somatosensory evoked potentials after the aneurysm was clipped, demonstrating the need to preserve the patency of the artery. Vein graft replacement of the proximal intradural vertebral artery is feasible by the combination of standard cerebro-vascular techniques and the exposures afforded by skull base surgery.

Adult↗
PubMed1993

Lacrimal secretion stimulants: sigma receptors and drug implications.

3H-DTG (1.3-di(2-[5-3H]tolyl)guanidine) or 3H-haloperidol was added to sigma-receptors (25 nM) in the presence of 25 nM spiperone and incubated with increasing concentrations of bromhexine derivatives (phenylalkylamines; 10(-9) to 10(-2)M) in membrane homogenate suspensions. IC50 values for two derivatives ranged from 3.2 to 8.8 nM for both radioligands. A preferred derivative, 7A (N,N'-dimethyl-2-phenyl-ethylamine), yielded an IC50 of 7.8 nM for 3H-haloperidol but showed much less affinity in displacing 3H-DTG (IC50 = 900 nM). Applying the technic of Bromberg [Exp. Eye Res., 40:313-320, 1985], in vitro protein secretion rates were measured following stimulation of either lacrimal gland slices or isolated, intact lacrimocytes with the compounds. In vitro protein secretion rates exhibit a dose-response relationship with increases in protein release up to a concentration of 10(-8) to 10(-4) M for various derivatives of bromhexine and 10(-4) M for carbachol. By means of Schirmer strips, tear fluid was collected over a five minute period at 10 and 60 minutes post-dosing following the topical application (50 microliters) to the right eye of New Zealand white rabbits (n = 20-24) of 7A at various concentrations. Incubation of lacrimocytes with 7A alone (10(-4) M), with haloperidol (10(-4) M) alone or in combination show that 7A is acting as an agonist to stimulate protein release, whereas haloperidol is acting as an antagonist to inhibit release. In vivo protein secretion rates also show a dose-response curve (at both 10 and 60 minutes post-dosing) for 7A that reach a statistically significant maximum in the dosed eye at a concentration of 0.15% w/v. Analysis of protein extracts using size exclusion HPLC shows an increase in secretory proteins, particularly tear-specific prealbumin.

Animals↗
PubMed1993

Vein graft replacement of the middle cerebral artery after unsuccessful embolectomy: case report.

A forty-one-year-old man with a cavernous hemangioma of the right cavernous sinus underwent a preoperative cerebral angiogram and a balloon occlusion test of the internal carotid artery. During the operation to remove the cavernous sinus lesion, the ipsilateral electroencephalogram was found to be abnormal. An embolic occlusion of the M2 and M3 segments of the middle cerebral artery (MCA) was discovered. A platelet and thromboembolus was removed via multiple incisions, and flow was restored. The cavernous sinus lesion was removed uneventfully. At the end of the operation, the MCA was found to be reclotted. Flow was eventually restored by replacing the M2 segment of the MCA with a 2-cm saphenous vein graft. The patient recovered without any deficits of brain function and with transient deficits of Cranial Nerves III and VI. Computed tomography revealed infarcts in the temporal and parietal areas. When MCA embolectomy is unsuccessful, vein graft replacement should be considered to restore flow and to avoid major neurological deficits.

Adult↗
PubMed1993

Mammary tumour induction by pituitary grafting in male mice: an animal model for male breast cancer.

Isologous anterior pituitary grafting, 4 each, to 3-4-month-old SHN and SLN male mice resulted in an appearance of mammary tumours from 8 months of age and the incidence at 12 months reached 53.8% in each strain. All tumours were diagnosed as type B adenocarcinomas. In association with the results, normal mammary gland growth and mouse mammary tumour virus (MMTV)-gp52 antigen levels in the submaxillary glands were stimulated by the treatment in these strains. The effect of pituitary grafting was much less in GR/A male mice in which no mammary tumours appeared.

Adenocarcinoma↗
PubMed1993

New inhibitors of melanogenesis, OH-3984 K1 and K2. I. Taxonomy, fermentation, isolation and biological characteristics.

Melanogenesis inhibitors, OH-3984 K1 and K2 were isolated from fermentation broth of Streptomyces sp. OH-3984. OH-3984 K1 and K2 inhibited the melanogenesis of B16 melanoma cells at concentrations of 7.5 and 3.8 micrograms/ml, respectively, whereas inhibition of tyrosinase activity has not been observed. The microbial metabolites showed no antimicrobiological activities against Gram-positive and Gram-negative bacteria, fungi or yeast at a concentration of 1,000 micrograms/ml.

Anti-Bacterial Agents↗
PubMed1993

Hynapenes A, B and C, new anticoccidial agents produced by Penicillium sp. I. Production, isolation and physico-chemical and biological properties.

Penicillium sp. FO-1611, a soil isolate, was found to produce a series of new anticoccidial compounds. Three active compounds, designated hynapenes A, B and C, were isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography, gel filtration on Sephadex LH-20 and preparative HPLC. Hynapenes inhibited the growth of Eimeria tenella in an in vitro assay using BHK-21 cells as a host. No schizont in the cells was observed at concentrations ranging above 123 microM, 34.7 microM and 34.7 microM for hynapenes A, B and C, respectively.

Chemical Phenomena↗
PubMed1993

Hynapenes A, B and C, new anticoccidial agents produced by Penicillium sp. II. Structure elucidation.

The structures of hynapenes A, B and C, novel anticoccidial agents, were determined by spectroscopic analyses. Hynapenes A, B and C were deduced to be (2E,4E)-5-(1,3,4-trihydroxy-2,6,8-trimethyldecalin)-2,4-p entadienoic acid, (2E,4E)-5-(1-ene-3-oxo-2,6,8-trimethyldecalin)-2,4-pentad ienoic acid and (2E,4E)-5-(3-ene-1-oxo-2,6,8-trimethyldecalin)-2,2,4-pent adienoic acid, respectively.

Chemical Phenomena↗
PubMed1993

Xanthoquinodins, new anticoccidial agents produced by Humicola sp. Production, isolation and physico-chemical and biological properties.

Humicola sp. FO-888, a soil isolate, was found to produce a series of new anticoccidial compounds. Five active compounds, designated xanthoquinodins A1, A2, A3, B1 and B2 were isolated from the fermentation broth of the producing strain by solvent extraction and HPLC. Xanthoquinodins inhibited the growth of Eimeria tenella in an in vitro assay system using BHK-21 cells as a host. No schizont in the cells was observed at concentrations of 0.02-0.2 micrograms/ml for xanthoquinodins A1, A3, B1 and B2 and at 0.02 micrograms/ml for xanthoquinodin A2.

Animals↗
PubMed1993

Diolmycins, new anticoccidial agents produced by Streptomyces sp. I. Production, isolation and physico-chemical and biological properties.

Streptomyces sp. WK-2955, a soil isolate, was found to produce a series of new anticoccidial compounds. Four active compounds, designated diolmycins A1, A2, B1 and B2, were isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography, gel filtration on Sephadex LH-20, and preparative HPLC. Diolmycins inhibited the growth of Eimeria tenella in an in vitro assay system using BHK-21 cells as a host. No schizont in the cells was observed at concentrations of 0.02-2.0 micrograms/ml for diolmycin A1, at 0.2-2.0 micrograms/ml for diolmycin A2, and at 20 micrograms/ml for diolmycins B1 and B2.

Animals↗
PubMed1993

Diolmycins, new anticoccidial agents produced by Streptomyces sp. II. Structure elucidation of diolmycins A1, A2, B1 and B2, and synthesis of diolmycin A1.

The structures of diolmycins A1, A2, B1 and B2, novel anticoccidial agents, were determined by spectroscopic analyses. Diolmycins A1 and A2 are stereoisomers with the structure of 1-(3-indolyl)-4-(p-hydroxyphenyl)-2,3-butanediol. From the chemical synthesis of the erythro-isomer, the relative configurations of diolmycins A1 and A2 were determined to be the erythro- and threo-isomers, respectively. The stereoisomers, diolmycins B1 and B2, were also deduced to be erythro- and threo-1,4-di-(p-hydroxyphenyl)-2,3-butanediol, respectively.

Butylene Glycols↗
PubMed1993

[Milk of calcium renal stone in a patient with ureteral tumor: a case report].

We report a case of milk of calcium renal stone within a calyceal diverticulum in the patient with left ureteral tumor. The patient was a 77-year-old-man with the chief complaint of asymptomatic microscopic hematuria. A plain film revealed round opaque calcific densities in the left kidney in the supine position and a dense crescent-shaped shadow with a horizontal border in the upright position. An intravenous pyelography showed left hydronephrosis and calculi within a calyceal diverticulum. Computed tomography in the supine position revealed layering of the calcifications in cystic lesion of the left kidney accompanied by left hydronephrosis due to a soft mass in the left ureter and a right renal cyst. Retrograde pyelography revealed a filling defect of the middle portion of the left ureter. Under the diagnosis of milk of calcium renal stone and left ureteral tumor, left total nephroureterectomy and partial cystectomy was performed. Pathological findings indicated transitional epithelium of the diverticulum wall and grade 1 transitional cell carcinoma of the left ureteral tumor.

Aged↗
PubMed1993

The effect of gamma-ray-induced radicals on activities and membrane structure of Sendai virus in aqueous solutions.

The effects of gamma-ray-induced radicals on the activities of viruses and membrane proteins were studied with Sendai virus in aqueous suspensions with or without additives including OH scavengers. The activities measured were hemagglutination and hemolysis located in the viral membrane. The changes in the protein components of viruses were analyzed at the same time by polyacrylamide gel electrophoresis (PAGE). 2-Mercaptoethanol (70 mM) and p-aminobenzoic acid (1 mM), both known as OH scavengers, fully protected the viral activities from gamma-ray-induced inactivation. Deaeration of virus suspensions by bubbling argon through the suspension did not affect the inactivation curve of the activities of the virus. Conspicuous changes in the membrane-associated glycoprotein bands found by PAGE analysis generally coincided with the findings in the activities of the virus. These findings suggest that OH radicals are the major damaging species acting on the glycoproteins in the membrane, and result in the inactivation of viral functions. In spite of strong OH scavenging ability, t-butanol resulted in the enhancement of inactivation and a decrease in the intensity of glycoprotein bands in the PAGE pattern. This finding, which is seemingly contradictory to the above conclusion, is discussed in terms of the action of alcohol radicals generated after OH scavenging. In particular, the possibility is pointed out that the membrane structure is affected by the reaction with the alcohol radicals, causing a crucial alteration of embedded proteins.

Aminobenzoates↗
PubMed1992

Binding of sequence-specific proteins to the adenosine- plus uridine-rich sequences of the murine granulocyte/macrophage colony-stimulating factor mRNA.

Adenosine+uridine (AU)-rich sequences in the 3' untranslated region (3'UTR) of the mRNA of many cytokines and oncogenes play an important role in mediating RNA degradation. Among the cytokines containing such AU-rich sequences in their 3'UTR is the hematopoietic growth factor granulocyte/macrophage colony-stimulating factor (GM-CSF). GM-CSF gene expression in T cells is regulated by modulation of mRNA half-life. Transfection studies using murine EL-4 thymoma cells have demonstrated that degradation depends on the presence of specific elements in the 3'UTR, including the AU-rich sequences. A number of AU-binding factors have recently been discovered, suggesting that specific regulation may occur through specific protein-mRNA interaction(s). We present evidence from gel-shift analyses and label-transfer experiments that murine cells contain proteins that bind specifically to AU-rich sequences. Three major proteins of 33, 39.5, and 42 kDa are detected. Phorbol ester treatment of cells does not alter the abundance or apparent binding affinity of the proteins. The 33-kDa protein is present in the cytoplasm of murine and human cells, whereas the 39.5- and 42-kDa proteins are present in murine extracts only. Constitutively expressed AU-binding proteins of the type that we describe may function by directing mRNA degradation in the absence of a stimulus to the contrary.

3T3 Cells↗
PubMed1992

Giant basal prolactinoma extending into the nasal cavity.

An unusual case of a giant prolactinoma extending to the nasopharynx and nasal cavity is presented. A 35-year-old man admitted for nasal obstruction and visual disturbances was found to have bilateral anosmia, right homonymous hemianopsia, and a right hemiparesis. The serum prolactin level was 13,300 ng/mL. Radiological examination revealed a large mass invading the skull base and extending into the suprasellar region and the left frontal lobe superiorly and into the nasopharynx inferiorly. Subtotal removal was done through a bilateral orbitofrontal craniotomy, which was followed by radiotherapy and bromocriptine administration. Immunohistochemical analysis confirmed a prolactinoma. The rarity of such a tumor, its location and extension, and the usefulness of magnetic resonance imaging and immunohistochemistry are stressed. Pertinent literature is reviewed.

Adult↗