Search PubMed⌕ Search

Biomedical subjects

Y Iwata

Publications and source records attributed to Y Iwata.

At least 181 records · Page 10Linked to original sources
PubMed1989

Congenital absence of the portal vein.

A 14-year-old girl presented at the hospital after discovering an abdominal tumor. CT scan and ultrasonography indicated a hepatic tumor and also revealed the absence of the portal vein. The patient was admitted to excise the hepatic tumor. It was found that the venous blood from the small intestines flowed into the left renal vein and then emptied directly into the inferior vena cava. A tumor extending from the right lobe through the middle portion of the liver was excised. The postoperative course was satisfactory and marked regeneration of the residual hepatic tissue was observed. Also the blood level of ammonia in the superior mesenteric vein was low, approximately 120 micrograms/dl, compared to the normal value of 350 micrograms/dl in the portal vein. This low blood level may indicate the presence of some homeostatic control mechanism.

Adolescent↗
PubMed1989

The histotopography and ultrastructure of the thin limb of the Henle's loop: a scanning electron microscopic study of the rat kidney.

The three-dimensional construction of the thin limb epithelium was demonstrated in all four segments previously determined by transmission electron microscopy. Special reference was given to the pattern and extent of both intercellular and intracellular interdigitation. In the thin limb of short-looped nephrons, epithelial cells were simple polygonal in shape. The cells showed fine intercellular and intracellular interdigitations of basolateral microprojections. The upper descending thin limb of long-looped nephrons was characterized by well-developed intercellular and intracellular interdigitations. Both types of interdigitations showed a double structure, as they were composed of primary lateral processes or deep basal grooves, with numerous secondary microprojections on their walls. This segment additionally revealed apical interdigitations of small laminar processes, which caused the fine undulation of luminal cell boundaries. In the lower descending thin limb of long-looped nephrons, the intercellular and intracellular interdigitations also showed the double structure, though diminished in degree. This segment lacked the fine apical interdigitations. The ascending thin limb was characterized by an elaborate pectineal pattern of intercellular interdigitations, and by the absence of intracellular interdigitations. The intercellular interdigitations in this segment were formed by thin primary processes oriented parallel to each other. No secondary microprojections were found on their lateral surfaces.

Animals↗
PubMed1989

[Statistical analysis of trophoblastic disease in Kanagawa prefecture].

Two thousand one hundred and thirty-five cases of trophoblastic disease were registered in Kanagawa Prefecture in 7 years (from 1978 to 1984). The incidence of trophoblastic diseases, hydatidiform mole, partial mole, invasive mole, choriocarcinoma and persistent trophoblastic disease (PTD) was 3.22, 1.67, 1.20, 0.07, 0.06 and 0.20, respectively, per 1,000 live births. The incidence was constant for 7 years, and did not differ significantly from that of 16 prefectures in Japan. In Kanagawa, the incidence of hydatidiform mole was less and that of partial mole was more than those in the 16 prefectures. The incidence of invasive mole and choriocarcinoma was lower and that of PTD was higher than those in the 16 prefectures. Total incidence of invasive mole, choriocarcinoma and PTD was higher in the western part of Japan, and lower in the eastern and northern parts. Kanagawa Prefecture is between these two regions. The distribution by age of hydatidiform mole was high in 25-29 y.o. and over 40 y.o. The distribution by age of partial mole tended to be similar to that of hydatidiform mole, but less remarkable. The distribution by age of invasive mole and choriocarcinoma had 2 peaks of 30-34 y.o. and 45-49 y.o. The distribution by age of PTD was between that of hydatidiform mole and choriocarcinoma.

Adolescent↗
PubMed1989

[Pharmacokinetic and clinical studies on cefodizime in the field of obstetrics and gynecology].

Pharmacokinetic and clinical studies on cefodizime (THR-221, CDZM) were carried out and the following results were obtained. Concentrations of CDZM in serum and uterine tissues were determined from 38 to 282 minutes after drip infusion of 1 g CDZM. CDZM reached peak level of 25.0 micrograms/g or higher in each tissue during a period of 38 to 83 minutes. Concentrations of CDZM in the dead space exudate after drip infusion of 2 g CDZM were also studied. At 240 minutes after injection, CDZM concentration in exudate reached a peak of 46.88 micrograms/ml. These levels far exceeded MICs of CDZM against major pathogens most often isolated in the field of obstetrics and gynecology. CDZM was administered to 7 patients with their diseases diagnosed as pelvic peritonitis (4 cases) or acute adnexitis (3 cases) at a dose of 2-4 g per day for 6-14. days. Clinical response was good in all cases. Transient elevation of liver function was noticed in 2 cases. No other adverse reactions were noted during the study.

Adult↗
PubMed1989

[A new apparatus using the Micro Ultra-Sonic Aspirator (MUSA) system for microneurosurgery].

Matsumoto was the first to present the NIIC UltraSonic Aspirator for CT guided stereotactic aspiration of intracerebral hematoma. Based on the NIIC Aspirator, the authors have developed a useful tool for microsurgery by adapting conventional ultrasonic aspirators. This was done by making the aspirator lighter and more handy for use during microsurgical procedures. A newly devised apparatus using the Micro Ultra-Sonic Aspirator (MUSA) was applied clinically to surgical treatment for brain tumors, arterio-venous malformations (AVMs) and intracerebral hematomas. Using the MUSA system, it became easier to remove successfully tumorous mass and the nidus of AVM, because it minimized the risk of injury to the normal structures such as the surrounding brain tissue, vascular systems and the cranial nerves.

Brain Diseases↗
PubMed1988

[Pulmonary dirofilariasis found unexpectedly during thymectomy].

A 56-year-old woman in Kitakyushu City was operated on after diagnosis of mediastinal tumor with myasthenia gravis. Besides the thymoma, a small nodule was palpated in the lower lobe of the left lung and biopsied. A segmented worm was found in sections of this granulomatous nodule. A cross section of the degenerated worm (400 X 310 micron) showed a 3-layered tegument and internal cuticular ridges with high lateral chords. The muscle layer consisted of high and polymyarian muscles. Based on these characteristics, this worm was identified as an immature dog heartworm, Dirofilaria immitis. The recent sharp increase of dirofilariasis cases reported in Japan is discussed.

Dirofilariasis↗
PubMed1988

An interposed superficial temporal artery graft bypass for anterior cerebral artery ischemia.

A new microsurgical revascularization technique for anterior cerebral artery ischemia is reported. An arterial graft bypass interposed between the superficial temporal artery and the distal anterior cerebral artery was successfully completed in a 43-year-old male with transient ischemic attacks in the anterior cerebral artery territory. The contralateral superficial temporal artery was harvested and used as an arterial graft. Both procedures were carried out with one single transcoronal scalp incision. The patient's postoperative cerebral angiogram revealed good filling of the area distal to the stenotic lesion of the anterior cerebral artery through the bypass graft. The patient was discharged with no neurological deficit and has been free of ischemic events for more than 2 years since the surgery. If the bilateral superficial temporal arteries are fairly well developed, the ipsilateral superficial temporal artery can be used as an arterial graft for revascularization of the anterior cerebral artery territory.

Adult↗
PubMed1988

Concentrations of alpha-1-antichymotrypsin and other acute phase reactants in patients with gastric cancer.

The serum levels of alpha-1-antichymotrypsin, immunosuppressive acidic glycoprotein, acid soluble glycoproteins, and sialic acid as acute phase reactants (APRs) and carcinoembryonic antigen (CEA) as a cancer-producing glycoprotein were measured preoperatively in 245 patients with gastric cancer who underwent gastrectomy and were treated with postoperative adjuvant chemotherapy or immunochemotherapy. The patients were classified into four groups: group A had normal leverl of serum CEA and APRs; group B had abnormal CEA levels; group C had normal levels of CEA and one or more abnormal levels of APRs; and group D showed abnormal levels of CEA and one or more abnormal levels of APRs. Groups A and B showed good survival rates, but groups C and D had poor rates. The patients in groups A and C who received immunochemotherapy exhibited significantly better survival rates than those treated with chemotherapy. The pretreatment of levels of CEA and APRs have potential as aids in prognosis and in the selection of suitable immunopotentiators and anticancer drugs for cancer patients.

Acute-Phase Proteins↗
PubMed1988

[Ossified choroid plexus papilloma--case report].

While the calcification has been documented radiologically in 4 - 25 percent of the cases with choroid plexus papilloma, the ossification of choroid plexus papilloma has been reported only in 3 cases on literature. In this paper, we present a case of large ossified choroid plexus papilloma in the right lateral ventricle. A 35-year-old man was admitted with left hemiparesis and headache. Skull X-rays showed an abnormal calcified mass (25 mm x 23 mm x 14 mm) in the right temporal region. CT scan revealed an abnormal high density area protruding into the right lateral ventricle, and a low density area at the right corona radiata. Operation was carried out with a right temporal craniotomy. The mass was yellowish-elastic hard and protruded into the right inferior horn of the lateral ventricle. The histological examination of surgical specimen showed an ossified choroid plexus papilloma with some bone marrow formation and numerous calcification. Calcification of choroid plexus papilloma is found frequently, but ossification is a very rare neuropathological abnormality. Bone and/or cartilage formation in neuroepithelial neoplasms is an unusual event histopathologically. Several mechanisms have been proposed, such as (1) metaplasia of connective tissue, (2) transformation of neuroepithelial cells to mesenchymal tissue, (3) teratomatous nature, (4) heteroplasia, (5) mixed mesenchymal-neuroepithelial nature, and (6) ossification as an end stage of mucoid degeneration. In our case, it was considered that the bone formation resulted from metaplasia of connective tissue of choroid plexus papilloma.

Adult↗
PubMed1988

[The development of a new operating hysteroscopic fiberscope and its clinical application].

A new operating hysteroscopic fiberscope consisting of soft and rigid parts (4.8mm outer diameter) was developed with the support of Fuji Photo Optical Company. The working part of the scope can be divided into three sections: A flexible soft front section, a rotary rigid middle section and a flexible self retained semirigid rear section. With these functional parts the intrauterine target can be approached directly to perform the following operations. 1. Directed intrauterine biopsy. Thirty-five patients diagnosed as having endometrial polyp (13), submucous myoma (8), endometrial hyperplasia (4), endocervical polyp (3), endometrial carcinoma (2) and others (5) underwent direct biopsy with hysteroscopic control. No cervical dilatation or anesthesia was necessary. 2. Transcervical recanalization. In six cases of proximal tubal occlusion, a ureteral catheter or a percutaneous coronary balloon angiocatheter was introduced into the tubal ostium of the obstructed side to resolve the occlusion successfully with concomitant laparoscopy. 3. Hysteroscopic chorionic villus sampling. Chorionic villus sampling was performed with a ureteral catheter under direct hysteroscopic control and ultrasound guidance in eighteen pregnant women at from seven to fourteen gestational weeks. In fifteen cases, the samplings were performed satisfactory. 4. Removal of a lost IUD. Three cases of lost IUD underwent hysteroscopic removal without difficulty. Our results have proved that this scope is a very useful tool for intrauterine operations.

Adult↗
PubMed1988

[Identification of location of electrode tip during percutaneous retrogasserian glycerol injection (PRGI) with blink reflexes elicited by direct stimulation of trigeminal complex (DBR)].

In order to identify the location of the electrode tip during percutaneous retrogasserian glycerol injection (PRGI), the blink reflex (DBR) following direct stimulation of the trigeminal complex (the gasserian ganglion, trigeminal rootlets, or the 3rd division of the trigeminal nerve) was obtained from 6 patients with trigeminal neuralgia. 1) The waveform of the DBR was very similar to that of the blink reflex (BR) elicited by percutaneous stimulation of the 1st division of the trigeminal nerve. However, the latency of early reflex (R1) as well as late reflex (R2) of the DBR was approximately 2 msec shorter than that of the conventional BR. 2) When the electrode tip was introduced into the gasserian ganglion, the DBR showed the largest response under the same recording condition, whereas the DBR was not recorded when the tip of the electrode was placed into either the arachnoid space or the subdural space. The each DBR response, however, showed the same configuration when the electrode tip was situated at the territory of the 1st, 2nd or 3rd division of the trigeminal nerve within the gasserian ganglion or the trigeminal cistern. 3) The DBR always appeared under the anesthesia with the intravenous administration of 10 mg diazepam and 30 mg pentazocine. 4) Based on the present study, the DBR proved to be an usuful parameter in determining whether the electrode tip is introduced into the trigeminal complex or not, particularly in the case of patients having no reliable sensory response to electrical stimulation.

Aged↗