Biomedical subjects

H Nishida

Publications and source records attributed to H Nishida.

570 records · Page 32Linked to original sources

PubMedDate not supplied

Evaluation of small caliber vascular prostheses implanted in small children: activated angiogenesis and accelerated calcification.

Healing characteristics of small-caliber vascular prostheses used in small children have rarely been observed because removing specimens are troublesome. Modified Blalock Taussig shunt procedures were performed using small caliber expanded polytetrafluoroethylene (ePTFE) vascular grafts and fabric grafts in 13 patients with congenital heart disease. At the time of total corrective procedures, a piece of 10 ePTFE grafts in 10 patients and six fabric grafts in four patients were removed from the distal pulmonary anastomosis, and evaluated. The implantation duration was from 11 months to 5 years and 7 months (mean, 2 years and 6 months). At removal, average patient age was 4 years and all grafts were patent. Microscopically, the wall of three ePTFE grafts were calcified, and macrophages were immunohistologically observed in the graft wall. Thrombus formation, intimal hyperplasia, and pannus detachment was common. In the fabric grafts, many capillaries infiltrated the interstices and often reached the lumen from the perigraft side. These results suggested that in cyanotic small children, angiogenesis in and around fabric grafts was active and calcification was accelerated in ePTFE grafts. Complete endothelialization throughout the length, caused by angiogenesis, might be possible in small children when highly porous fabric vascular prostheses are used.

Blood Vessel Prosthesis↗

PubMedDate not supplied

Staging hepatic tumors with CT and carbon dioxide.

OBJECTIVE: Carbon dioxide (CO2) intraarterial dynamic CT (CO2-IADCT) was used to observe the micro- and macrocirculation of hepatic tumors and hepatic parenchyma. MATERIALS AND METHODS: A total of nine patients with hepatic nodular mass [five patients with hepatocellular carcinoma (HCC), three with metastatic liver cancer originated from colon cancer, and one with cysts] were included in this study. Thirty to fifty milliliters of CO2 was injected into the proper or right hepatic artery, in approximately 15 s, using a manually operated syringe. Consecutive CT scans were performed with a slice thickness of 1 cm, using a TCT 900s (Toshiba Co., Tokyo, Japan), to evaluate visualization of hepatic arteries and portal veins around tumors, tumor vessels, and CO2 bubbles in tumors. RESULTS: The hepatic arteries and portal vein were revealed in all patients. The tumor vessels were observed in all patients with HCC except one patient who received chemoembolization before this procedure and one of three patients with metastatic liver cancer. The spotty CO2 deposits in the tumor were revealed in all patients, except in two patients with hepatic cysts and embolized HCC. No spotty deposits were seen in the normal liver tissue. CONCLUSION: Thus, CO2-IADCT provided visualization of tumor vessels, spotty deposits of CO2 in tumors, and retrograde visualization of the portal vein. This method seems to be useful for the precise evaluation of the staging of liver tumors.

Aged↗

PubMedDate not supplied

Cochlear microphonic potentials in patients with vestibular schwannomas.

We evaluated the cochlear function of 44 patients with unilateral vestibular schwannomas by measuring cochlear microphonic potentials (CM) in electrocochleography. We used short tone bursts with 0.5-, 1-, 2-, and 4-kHz frequencies as acoustic stimuli to evoke CMs, and determined CM detection thresholds. The CM detection thresholds in vestibular schwannomas ranged from normal to no response. Cochlear dysfunction was seen in 35 (79.5%) of the 44 cases; these patients had higher CM detection thresholds than normal subjects. Although a significant correlation was found between mean hearing level (0.5-4 kHz) and mean CM detection threshold (0.5-4 kHz), 20 patients had lower CM detection thresholds than were found using audiometry. This suggests that there is an additional retrocochlear component responsible for this hearing loss.

Adult↗

PubMedDate not supplied

Müllerian adenosarcoma of the uterus: report of a case with imprint cytology.

BACKGROUND: Müllerian adenosarcoma is a rare morphologic variant of uterine sarcoma that, although well described histologically, is scarcely mentioned in the cytologic literature. CASE: A 75-year-old female was suspected of having atypical endometrial hyperplasia on an endometrial smear. However, subsequent imaging techniques revealed the presence of a bulky, polypoid mass filling the uterine cavity. On pathologic examination of the hysterectomy specimen, the polypoid tumor was diagnosed as mullerian adenosarcoma, homologous, with sarcomatous overgrowth, in which the sarcomatous component was compatible with high grade endometrial stromal sarcoma. Imprint smears of the tumor consisted of two morphologic patterns, sarcomatous and glandular. The sarcomatous tumor cells, with coarse chromatin and relatively scant cytoplasm, formed small aggregates or appeared alone. These cells were semiround or oval and had conspicuous nucleoli. In addition to these observations, small and large clusters of glandular cells with mild atypism were interspersed with the sarcomatous cells. CONCLUSION: Cytologic examination of müllerian adenosarcoma well reflects its pathologic features.

Adenosarcoma↗

PubMedDate not supplied

Peripheral primitive neuroectodermal tumor of the vulva: report of a case with imprint cytology.

BACKGROUND: Peripheral primitive neuroectodermal tumor (PNET) of the vulva is an extremely rare disease, and, to our knowledge, only two cases have been previously reported. CASE: A 45-year-old woman presented with a mass in the right labium major. Three years after removal of the tumor, she noticed a new lesion in the same place and underwent a partial vulvectomy. The imprint cytology of the recurrent tumor showed a monomorphic appearance, composed of small round cells with scant cytoplasm against a hemorrhagic background. These tumor cells were loosely connective, but rosettelike structures were observed focally. On pathologic examination, the neoplasm was composed of small round tumor cells showing sinusoidal, diffuse or micropapillary growth. Immunohistochemically, the neoplastic cells stained positively for neuron-specific enolase, vimentin and HBA 71 and negatively for cytokeratin, HBA 45 and muscle-specific actin. The morphologic characteristics of the disease were well expressed in the imprint cytology, and this influenced the selection of immunohistochemical studies. CONCLUSION: Cytologic examination for vulvar tumors, even imprint cytology, can be a useful tool in obtaining an accurate pathologic diagnosis of a rare disease, such as peripheral PNET.

Antigens, Neoplasm↗

PubMedDate not supplied

Electrocochleographic study of sudden deafness.

By performing electrochleography (AP, SP and CM) on 34 patients with sudden deafness, it was thought that the pathophysiology of this disease could be deduced. The various waveform patterns of AP and SP responses obtained in cases of sudden deafness were classified into the following types: 1) AP high response; 2) decreased AP high response; 3) AP low response; 4) dominant -SP; 5) -SP or +SP; and 6) AP, SP no response. The cases showing the type of dominant -SP and AP high response had satisfactory prognoses. In these cases the sensory epithelium and the cochlear nerve seemed to indicate a reversible condition being affected by the temporary functional block. Furthermore, it seemed to indicate that the neural regions related to the source of AP(N1) response were impaired in cases in which CM were recorded at normal response threshold in spite of the absence of AP(N1) response. In the unsatisfactory prognosis cases with decreased AP high response, AP low response and AP, SP no response in which only the extremely low or depressed CM responses could be recorded, it seemed that the sensory epithelium and the cochlear nerve were affected permanently, although the degree of impairment varied.

Acoustic Stimulation↗

PubMedDate not supplied

Electrocochleographic study in patients with vestibular schwannomas and U-shaped audiograms.

To determine the nature of sensorineural hearing loss in the middle-frequency range (U-shaped audiogram), we compared the differences in electrocochleographic findings for 15 ears with vestibular schwannomas and 10 ears without tumours. Short-tone bursts of 0.5, 1, 2, and 4 kHz were used to evoke cochlear microphonics (CM). Ears with tumours had normal or lower CM detection thresholds than ears without tumours. Input-output curves for 1-kHz frequency were normal in 10 ears with tumours and in 1 ear without tumours. These indicate that tumour ears have no or mild cochlear dysfunction. In addition, CM detection thresholds of ears with tumours were lower than audiometric thresholds, particularly at the 1- and 2-kHz region. These findings suggest that the loss seen by audiometry in ears with vestibular schwannomas was from a retrocochlear component.

Adult↗

PubMedDate not supplied

A new electrode (HN-5) for CM measurement in extratympanic electrocochleography.

A new electrode (HN-5) for measuring cochlear microphonics (CMs) in extratympanic (ET) electrocochleography (ECochG) has been developed. The HN-5 electrode consists of a silver wire 2 mm in diameter and 5.0 cm in length connected to a low noise cable. The HN-5 electrode showed low impedance and excellent frequency characteristics. Using the dummy ear, artefact contamination tests, such as electromagnetic induction and mechanical vibration, were performed with the HN-5 electrode and various other electrodes. In the HN-5 electrode, artifact contaminations were kept within acceptable noise levels, whereas in the smaller electrodes, the measurable artifact contaminations were larger. The CMs were measured from subjects with normal hearing. CM findings obtained using the HN-5 electrode did not differ from those obtained by transtympanic (TT) ECochG, apart from their amplitude. HN-5 overcame the major disadvantage of the ET ECochG and provided a very favourable signal-to-noise ratio, resulting in repeatable response signals averaged from the same relatively small number of samples as those of TT ECochG. This resulted in successful CM measurements of ET ECochG.

Adult↗

PubMedDate not supplied

A comparison of extratympanic versus transtympanic recordings in electrocochleography.

Detection thresholds, amplitudes and input output curves of cochlear microphonics (CMs), and action potentials (APs) determined by extratympanic electrocochleography (ET ECochG) were compared with those determined by transtympanic (TT) ECochG in the same ears. Two groups were studied: 12 ears in 9 volunteers with normal hearing, and 6 ears in 6 subjects with sensorineural hearing loss. Short tone bursts with frequencies of 0.5, 1, 2 and 4 kHz were used as acoustic stimuli to evoke CMs, and a click was presented to measure the APs. In both groups, although the two approaches produced large differences in amplitudes, nearly identical values were obtained for the CM and AP detection thresholds. The CM and AP input-output curves obtained from mean amplitudes at each intensity in normally-hearing ears had similar slopes with the two approaches. These findings demonstrate the clinical usefulness of ET ECochG.

Adult↗

PubMedDate not supplied

Inhibition of tumor necrosis factor-stimulated human peripheral blood polymorphonuclear cell iodination by sera from various cancer patients.

Tumor necrosis factor (TNF) dose- and time-dependently stimulated the iodination (incorporation of radioactive iodine into an acid-insoluble fraction) of human peripheral blood polymorphonuclear cells (PMN). The addition of sera obtained from patients with brain tumors, or gastric, pancreatic, hepatocellular, common bile duct or lung carcinoma significantly inhibited TNF-stimulated PMN iodination, whereas sera of normal volunteers were, in general, not inhibitory. TNF-stimulated iodination of human peripheral blood monocytes was almost eliminated by brain tumor patient sera, but was significantly enhanced by normal human sera. Specific [135I] TNF binding to the PMN receptors was significantly increased in the presence of either patient sera or normal sera. These data suggest some mechanism other than modification of TNF receptor binding for expression of the inhibitory action of cancer patient serum.

Adolescent↗

PubMedDate not supplied

Estimation of the kinetics of iodized oil injected into the feeding artery of hepatocellular carcinoma using dynamic computed tomography.

The distribution of iodized oil (Lipiodol) after its injection in hepatocellular carcinoma (HCC) was evaluated by dynamic computed tomography (CT) in 10 patients. Following the injection of Lipiodol into the hepatic artery, two patterns were observed. In type I (4/10 tumors) Lipiodol retention began at the tumor periphery and then spread contiguously towards the central portion. In type II (6/10 tumors), the accumulation began at the periphery, but then skipped directly to the central portion of the tumor. Hypervascular tumors were predominantly type I, and avascular or hypovascular tumors were all type II. This difference in Lipiodol kinetics suggests that lipid-based intra-arterial (i.a.) chemoembolization should precede the i.a. infusion of water-soluble chemotherapeutic agents or injection of solid embolic materials in hypervascular tumors.

Aged↗

PubMedDate not supplied

Perinatal health care in Japan.

The maternal and infant health care system and vital statistics in Japan are reviewed. The improvement of socioeconomic conditions, higher education for women, comprehensive health care provided by the government, regionalization for high-risk pregnancy, medical advances in the care of pregnant women and neonates, the significant decline of perinatal and neonatal mortality rates in recent decades are all contributing factors in improved maternal-infant health care. On the basis of recent statistics showing that the survival rate of extremely low birth weight infants increased over 80%, the viability limit defined by Eugenic Protection Act was amended in 1991 from 24 to 22 completed weeks of gestation.

Adolescent↗