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Biomedical subjects

S Yamazaki

Publications and source records attributed to S Yamazaki.

At least 415 records · Page 23Linked to original sources
PubMed1990

Evaluation of countermeasures for reduction of mouse airborne allergens.

Three kinds of countermeasures for reduction of mouse airborne allergens were evaluated with use of an air sampler and immunochemical methods. Mouse cages and the sampler were placed inside a flexible-film isolator, and concentrations of mouse major allergens in the air were measured. The levels of the airborne allergens, prealbumin and albumin, generated by 10 males, were 3,050 and 492 pg/m3, respectively. Those by 10 females were lower, 317 and 270 pg/m3, respectively. When mouse cages were covered with a filter cap, the airborne allergens inside the isolator were decreased by 90%. When corncob was used as bedding in place of wood shavings, the airborne allergens were decreased by 57 and 77%, respectively. Therefore, for reduction of mouse airborne allergens, we recommend using female mice, covering the cages with filter caps, and using corncob bedding.

Air Pollutants, Occupational↗
PubMed1990

Preoperative portal embolization to increase safety of major hepatectomy for hilar bile duct carcinoma: a preliminary report.

Extensive liver resection for hilar bile duct carcinoma with jaundice has high morbidity and mortality rates because of postoperative liver failure. To minimize postoperative liver dysfunction, a portal venous branch was embolized before surgery to induce atrophy of the lobe to be resected and hypertrophy of the contralateral lobe in 14 patients with hilar bile duct carcinoma. Bile was drained before surgery in 11 patients with jaundice. Portal embolization did not produce major side effects, and moderate increases of serum transaminase activity or bilirubin returned to baseline values within 1 week. Hepatectomy with bile duct resection and lymphadenectomy was performed 6 to 41 days after embolization, at which time the embolized lobe was atrophied in 12 of the patients. Extended right or left lobectomy or left trisegmentectomy (10, 3, and 1 cases, respectively) with biliointestinal reconstruction was performed. One patient with jaundice and suppurative cholangitis died 30 days after hepatectomy. Another patient died 3 months after surgery of aggravated hepatitis. After surgery, no bile leakage occurred and hyperbilirubinemia was usually moderate and reversible.

Aged↗
PubMed1990

[A case of malignant neuroepithelioma in the retroperitoneum].

Reported is a case of a malignant neuroepithelioma in the retroperitoneum. The patient was a 37-year-old male suffering from lumbago and edema of the lower extremities. After ultrasonography and a CT scan, a diagnosis of a retroperitoneal tumor was made and a surgical resection of the tumor was performed in October, 1985. The subsequent pathological diagnosis was malignant neuroepithelioma which showed epithelioid cell clusters that stained positively to NSE. Eleven months later, metastatic tumors were seen present in the lungs and the liver though they regressed markedly after adjuvant chemotherapy with ADM, CPM, and VCR. Forty-one months after his first operation, the patient continues to work. In this case, adjuvant chemotherapy has proved effective.

Adult↗
PubMed1989

Stability of human interferon-beta 1: oligomeric human interferon-beta 1 is inactive but is reactivated by monomerization.

Human interferon-beta 1 is extremely stable is a low ionic strength solution of pH 2 such as 10 mM HCl at 37 degrees C. However, the presence of 0.15 M NaCl led to a remarkable loss of antiviral activity. The molecular-sieve high-performance liquid chromatography revealed that, whereas completely active human interferon-beta 1 eluted as a 25 kDa species (monomeric form), the inactivated preparation eluted primarily as a 90 kDa species (oligomeric form). The specific activity (units per mg protein) of the oligomeric form was approx. 10% of that of the monomeric form. This observation shows that oligomeric human interferon-beta 1 is apparently in an inactive form. When the oligomeric eluate was resolved by polyacrylamide gel containing sodium dodecyl sulphate (SDS), it appeared to be monomeric under non-reducing conditions. Monomerization of the oligomeric human interferon-beta 1 by treatment with 1% SDS, fully regenerated its antiviral activity. These results suggest that the inactivation of the human interferon-beta 1 preparation was caused by its oligomerization via hydrophobic interactions without the formation of intermolecular disulphide bonds. These oligomers can be dissociated by SDS to restore biological activity.

Chromatography, High Pressure Liquid↗
PubMed1989

Evaluation of the prognosis for small hepatocellular carcinoma based on tumor volume doubling time. A preliminary report.

The relationship of tumor volume doubling time to length of patient survival was investigated for 15 patients with small hepatocellular carcinoma smaller than 4.5 cm in diameter. The mean tumor volume doubling time of these 15 nodules was 102 +/- 77 days (mean +/- SD; range 41 to 305 days) before the initiation of a specific treatment for cancer. These doubling times tended to correlate with mitotic indexes of the tumors and the patients could be divided into two groups according to the therapeutic modalities used. Patients in Group A received systemic chemotherapy without response or nonspecific treatments for cancer. In this group, there was a positive correlation between tumor volume doubling time and survival length (r = 0.8812; P less than 0.025). Patients in Group B either received hepatectomy after transarterial embolization or systemic chemotherapy or received hepatectomy alone. In this group, early death occurred in patients who had shorter tumor volume doubling times. Three surgically treated patients in Group B were evaluated as having survived for a significantly long period as assessed from their tumor volume doubling times. These results indicate that tumor volume doubling time is one of the determining factors of survival length in patients with hepatocellular carcinoma, and, therefore, can be used in the evaluation of therapeutic efficacy.

Aged↗
PubMed1989

Inhibition of the infectivity and cytopathic effect of human immunodeficiency virus by water-soluble lignin in an extract of the culture medium of Lentinus edodes mycelia (LEM).

Inhibition of the infectivity and cytopathic effect of human immunodeficiency virus type 1 (HIV-1) by the immunoactive fractions obtained from LEM, which is an extract of the culture medium of Lentinus edodes mycelia, is reported. A purified fraction, EPS4, obtained from LEM by ethanol precipitation followed by hydrophobic chromatography and gel filtration chromatography completely inhibited the HIV-1 induced cytopathic effect in vitro at concentrations of greater than or equal to 10 micrograms/ml. Chemical and spectral analysis revealed that EPS4 is composed of water-soluble lignins containing minor amounts of protein (3.2%) and sugars (12.2%). Taken together with the previously reported observation that EPS4 promotes the activation of macrophages and the proliferation of bone marrow cells, the fraction appears to possess both an immunostimulating activity and an anti-HIV effect in vitro.

Amino Acids↗
PubMed1989

Incorporation of plasma [14C]palmitate into the hypoglossal nucleus following unilateral axotomy of the hypoglossal nerve in adult rat, with and without regeneration.

Incorporation of plasma [14C]palmitate into the hypoglossal nucleus of the rat following transection, with and without regeneration of the hypoglossal nerve, was studied using quantitative autoradiography. The left hypoglossal nerve of 3-month-old, male Fischer-344 rats was transected using either: (1) an R-operation, which allowed nerve regeneration; or (2) a D-operation, in which regeneration was prevented. One to 84 days after axotomy, [14C]palmitate was injected intravenously and its rates of incorporation into stable structures of the left and right hypoglossal nuclei were measured at 4 h after injection. Following the R-operation, incorporation into the left hypoglossal nucleus was increased during and following axonal regeneration (up to 23% compared to control side), whereas incorporation was decreased 6-7% in the absence of regeneration, using the D-operation. The time courses of incorporation in both cases corresponded to histological changes, especially cell membrane changes following axotomy and suggest that [14C]palmitate incorporation reflects regenerative and degenerative neuronal changes associated with changes in lipid synthesis.

Animals↗
PubMed1989

A temperature-sensitive defect of enterovirus 70 is located at the uridylylation of the genome-linked protein VPg in vitro.

The temperature-sensitive phenotype of enterovirus 70 (EV70) was examined by use of an in-vitro RNA replication system derived from a membrane fraction (crude replication complex, CRC) of EV70-infected HeLa cells. This system was capable of synthesizing the nucleotidyl proteins VPg-pU and VPg-pUpU. Formation of these nucleotidyl proteins was completely abolished when the in-vitro reaction was performed at the nonpermissive temperature for virus replication. Considering our previous observation that the defective stage of the temperature-sensitive growth of EV70 resides in the initiation step of RNA transcription in vivo, it is most likely that the lack of uridylylation of VPg at the restricted temperature in vitro is directly involved in the temperature-sensitive defect of virus growth in vivo.

Amino Acid Sequence↗
PubMed1989

Purification and some characteristics of a zinc metalloprotease from the venom of Bothrops jararaca (jararaca).

A metalloprotease from Bothrops jararaca venom (J protease) was purified by DEAE-Sephacel, CM-cellulose, Sephacryl S-200 and Sephadex G-75 chromatograph. The proteolytic activity was inactivated by EDTA, o-phenanthroline and DTNB. Phosphoramidon and cysteine protease inhibitors (leupeptin, E64 and its derivatives) were inactive on this enzyme. J protease was activated by calcium and the metal content analysis showed the presence of one mole each of tightly bond zinc and calcium per mole of this J protease. The amino acid composition, N-terminal amino acid sequence (29 residues) and the cleavage sites on the oxidized insulin B chain and angiotensin I were determined.

Amino Acid Sequence↗
PubMed1989

Intrabronchial neurilemmoma--review of cases in Japan.

We recently encountered a case of intrabronchial neurilemmoma. The patient was a 15-year-old boy who had a wheeze. After observation with a bronchofiberscope, a wedge resection of the left main bronchus was performed. No postoperative complications nor recurrence was seen. To date, five cases of intrabronchial neurilemmoma have been reported in the Japanese Journals. Surgical removal was performed in 4 of 5 and bronchofiberscopic excision in 1. This paper summarizes the clinical features of these cases as well as our own case.

Adolescent↗
PubMed1989

Highly sensitive enzyme immunoassay of human interferon-beta 1.

A highly sensitive sandwich enzyme immunoassay for human interferon-beta 1 (HuIFN-beta 1) was developed. HuIFN-beta 1-containing samples and horseradish peroxidase (HRP)-labeled mouse anti-HuIFN-beta 1 monoclonal antibody (Fab') were incubated overnight at 2-10 degrees C in the wells of a 96-well microtiter plate, onto which affinity-purified rabbit anti-HuIFN-beta 1 polyclonal antibody was coated. The EIA was able to detect 0.5 IU/ml of HuIFN-beta 1, thus showing higher sensitivity than bioassay. The values obtained by the EIA closely paralleled those obtained by bioassay in the concentration which bioassay can detect. In order to detect the concentration below 0.5 IU/ml of HuIFN-beta 1, the avidin/biotin-amplified EIA was also developed. The use of biotinylated mouse anti-HuIFN-beta 1 monoclonal antibody (F(ab')2) and HRP-avidin in the EIA made it possible to detect 0.1 IU/ml of HuIFN-beta 1. These EIAs were applied for the studies such as process control of HuIFN-beta 1 production, pharmacokinetics of HuIFN-beta 1, and determination of serum level of HuIFN-beta 1 in healthy subjects.

Antibodies, Monoclonal↗
PubMed1989

An outbreak of gastroenteritis associated with acute rotaviral infection in schoolchildren.

In April 1988 a large outbreak of group C rotavirus infection associated with acute gastroenteritis occurred among schoolchildren and their teachers simultaneously at seven elementary schools in Fukui city, Japan. Of 3,102, 675 (21.8%) became ill. Clinical symptoms were mild, predominantly abdominal pain and vomiting, with diarrhea reported in only 27.6%. The outbreak subsided within 2 d. No pathogenic bacteria were found in fecal specimens; the virus particles detected by electron microscopy were morphologically indistinguishable from conventional infantile rotavirus. Immune electron microscopy showed that these virions formed large aggregates with convalescent serum and with the reference serum specific to group C rotavirus. Polyacrylamide gel electrophoresis showed similar RNA patterns for virus from this outbreak and typical group C rotavirus.

Acute Disease↗
PubMed1989

Mycobacterium avium infection through the alimentary tract in mice.

Intestinal infection by Mycobacterium avium was investigated in C57BL/6 and BALB/c mouse strains. Single intragastric administration of a massive dose (10(8] or multiple administration of a lower dose (10(7), 10 times) established infection principally in the mesenteric lymph-node (MLN); a continuous or intermittent fecal excretion of the bacilli was detected by 6-8 weeks after the administration. Based on three criteria--isolation of the organisms from the MLN and from feces, and detection of acid-fast bacilli in sections of the MLN--germ-free (GF) BALB/c mice exhibited clearer dose-effect relations than the flora-bearing (FB) counterparts. After intragastric administration, the organisms were probably trapped in the Peyer's patch and then transferred to the MLN at an early period (by 4-7 days), persistent infection thus being established in the MLN. Systemic involvement evolved both in athymic and euthymic mice after a prolonged period of time (more than 40 weeks) showing far more severe involvement in the former regardless of the presence of floral organisms.

Animals↗