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Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 361 records · Page 20Linked to original sources
PubMed1992

Deposition of loosely bound and firmly bound fluorides on tooth enamel by an acidic gel containing fluorosilicate and monocalcium phosphate monohydrate.

The amounts of loosely bound fluoride (F) deposited on human enamel by 4-min and 2-hour treatments with either acidulated phosphate fluoride (APF) or a monocalcium phosphate monohydrate and sodium hexafluorosilicate (MCPM-SHFS)-containing gel were measured with the use of a constant-composition F washing method. Enamel biopsies conducted before treatment and after washing were used to determine the firmly bound F uptake. The results showed that the MCPM-SHFS treatments produced significantly more loosely bound F than did the APF treatments. The 4-min treatment with either APF or MCPM-SHFS did not produce significant firmly bound F deposition, but the 2-hour treatments did, with that produced by MCPM-SHFS being significantly greater. The MCPM-SHFS gel, which had the same F content as APF and which may be applied to the proximal tooth surfaces in vivo without the use of a tray, has the potential to be more efficacious than APF because it deposits greater amounts of both loosely bound and firmly bound F.

Acidulated Phosphate Fluoride↗
PubMed1992

Effect of a two-solution fluoride mouthrinse on remineralization of enamel lesions in vitro.

A previous study showed that a two-solution fluoride (F) rinse deposited significantly more loosely-bound F on the tooth surface than did a sodium fluoride (NaF) rinse with the same F concentration (12 mmol/L). In the present study, this experimental rinse was evaluated for its ability to cause remineralization of enamel lesions in an in vitro pH-cycling model. Caries-like lesions were formed in the enamel of extracted human molars by means of a pH 4 demineralizing solution. Fifty-one approximately 120-microns-thick sections containing lesions were randomly divided into (1) control, (2) NaF rinse, and (3) two-solution F rinse groups. With the cut surfaces protected, the control samples were immersed in a pH 7 remineralizing solution for 12 days, and twice daily the sections were also exposed to a pH 4 demineralizing solution for 30 min. Samples in the NaF group received an additional one-minute rinse with a NaF (12 mmol/L) solution twice daily. Samples in the two-solution rinse group received the rinse treatment with a 12 mmol/L F solution prepared by combination of a Na2SiF6 and phosphate-containing solution with a calcium solution just before use. The mineral contents of the lesions were assessed by quantitative microradiography. The results showed that (1) no significant de- or remineralization was detected in the controls; (2) a 46% decrease in mineral loss (delta Z) of the lesion was produced by the NaF rinses; and (3) a 94% decrease in delta Z and a 20-microns-thick, mineral-dense surface-coating were produced by the two-solution F rinse treatment.

Apatites↗
PubMed1992

In vivo fluoride concentrations measured for two hours after a NaF or a novel two-solution rinse.

The concentrations of fluoride in various samples from the oral environment were measured at timed intervals after a novel rinse or a NaF rinse, both containing a total of 12 mmol/L (228 ppm) fluoride. The novel rinse consisted of two solutions mixed just before application: Part A contained calcium chloride and sodium acetate; part B contained a hydrolyzable source of fluoride (sodium hexafluorosilicate) and sodium phosphate. Samples were obtained as follows: Single-site plaque-fluid samples were obtained by centrifugation of first-molar plaque; pooled whole-plaque samples were collected from second molars; centrifuged, pooled whole-saliva was collected by vacuum. All samples were analyzed by micro-analytical methods. Results showed that, compared with NaF, the two-solution rinse produced significantly higher salivary fluoride concentrations, plaque-fluid fluoride concentrations, and acid-extractable fluoride in the whole plaque by factors of about 4, 2, and 6, respectively, at 120 min. The results of this study suggest that the new rinse may provide a greater cariostatic effect at the same fluoride dosage than does a NaF rinse.

Adult↗
PubMed1992

Structures of N-linked oligosaccharides of microsomal glycoproteins from developing castor bean endosperms.

The structures of sugar chains of the glycoproteins from the microsomal fraction of developing castor bean endosperms have been analyzed. The structural analyses were done by a fluorescence method combined with component analysis, exoglycosidase digestions, partial acetolysis, Smith degradation, and 1H-NMR spectroscopy. The estimated structures fell into three categories; the first was oligomannose-type, the second xylomannose-type, the third complex-type. Among these oligosaccharides, Man3Fuc1Xyl1GlcNAc2 (M3FX) and Man6GlcNAc2 (M6B) were the major structures. The structures of Man4GlcNAc2 (M4C) and Man4Xyl1GlcNAc2 (M4X) have also been found in the microsomal glycoproteins of the developing bean endosperms. These results could indicate that the structures of M4C, M4X, and M3FX are formed in the stage of sugar chain processing in the microsomal fraction, in which oligomannose-type sugar chains are modified into complex-type ones by several kinds of processing enzymes.

Carbohydrate Sequence↗
PubMed1992

Glycinin A4A5 subunit digesting protease in soybean seeds.

Endopeptidase was partially purified from the globulin fraction of 4-hr-imbibed soybean seeds. The protease fraction obtained had proteolytic activity on the glycinin A4A5 subunit at both pH 4 and 8. A suitable peptidic substrate for the endopeptidase was isolated from the tryptic digest of the carboxymethylated A4A5 subunit. Using the tryptic peptide of glycinin A5 subunit, a simple assay system for the soybean endopeptidase activity has been established. The activity was significantly inhibited by phenylmethylsulfonyl fluoride, indicating the endopeptidase is a serine protease.

Amino Acid Sequence↗
PubMed1992

Acute toxicity of tri-n-butyltin chloride (TBTC) in the Syrian golden hamster.

The effects of tri-n-butyltin chloride (TBTC) on Syrian golden hamsters were studied. TBTC in single doses of 0, 29.6, 44.4, 66.7, 100 or 150 mg/kg were given to 10 male hamsters in each group and the mortality rates were determined two weeks thereafter. They were 0% (0/10), 0% (0/10), 10% (1/10), 10% (1/10), 30% (3/10) and 70% (7/10) for 0, 29.6, 44.4, 66.7, 100 and 150 mg/kg groups, respectively. In the case of females, seven groups consisting of 10 animals each were given TBTC at doses of 0, 29.6, 44.4, 66.7, 100, 150, or 225 mg/kg. The mortality rates determined two weeks after the TBTC treatment were 0% (0/10), 10% (1/10), 10% (1/10), 0% (0/10), 40% (4/10), 30% (3/10) and 90% (9/10) for 0, 29.6, 44.4, 66.7, 100, and 225 mg/kg groups, respectively. Based on these mortality data, the LD50s via oral administration were determined as 146.9 mg/kg (95% C.I. 111.8-193.3 mg/kg) for the male and 172 mg/kg (95% C.I. 127.2-233.4 mg/kg) for the female. Regarding pathological changes, animals experienced lesions in the bile duct, such as the dilatation of the common bile duct and cholestasis, and/or adhesion of the bile duct to the liver, gallbladder, pancreas and duodenum. In a separate experiment, a single dose of 44.4 mg/kg TBTC was administered orally to 12 male hamsters, then the concentrations of TBTC and its metabolite, di-n-butyltin chloride (DBTC), in the liver were analyzed by means of gas chromatography for 14 days after the treatment. The maximum concentrations of TBTC and DBTC appeared one day after the administration, and decreased rapidly thereafter. The concentration of DBTC was found to be higher than that of TBTC throughout the experimental period.

Alanine Transaminase↗
PubMed1992

Malignant lymphoma in the mesentery with immune thrombocytopenia.

A 69-year-old man was referred to our hospital for further evaluation of an abdominal mass. After admission, he was suspected of having a malignant mesenteric tumor. Laboratory data disclosed thrombocytopenia with increased levels of platelet-associated immunoglobulin G. On surgery, the tumor involved the ileal mesentery, invading the urinary bladder and mucosal surface of the terminal ileum. The diagnosis of mesenteric lymphoma with immune thrombocytopenia was made. Complete remission was obtained after surgery and the subsequent three courses of combination chemotherapy. However, thrombocytopenia still persisted. This rare presentation is discussed with a review of the available literature.

Aged↗
PubMed1992

Contralateral development of acute subdural hematoma following surgery for chronic subdural hematoma--case report.

An unusual case of acute subdural hematoma developed after drainage of chronic subdural hematoma in a 71-year-old male. The acute subdural hematoma was located over a membranous layer in the subdural space similar to the outer membrane of the chronic subdural hematoma. Intraoperatively, bleeding from the bridging vein and oozing from the superior sagittal sinus were observed. The membranous layer probably separated from the dura mater following decompression after drainage of the contralateral hematoma, and this separation then damaged the bridging vein and superior sagittal sinus, resulting in the acute subdural hematoma.

Acute Disease↗
PubMed1992

Histopathological reactions of calcium phosphate cement.

Calcium phosphate cement (CPC) consisting of Ca4 (PO4)2O and CaHPO4 (2H2O) was recently developed. This study evaluated in vivo aspects of CPC and CPC mixtures compared to those of commercial hydroxyapatite (HP) and several endodontic materials: Grossman's cement (GC), calcium hydroxide-iodine paste (CHP) and gutta-percha plate (GP). Biocompatibility of subcutaneous implants in Donryu rats was evaluated after one month. Results showed very slight inflammatory reactions from CPC, CPC mixtures and HP. The materials were surrounded by thin fibrous connective tissues with a small number of lymphocytes and plasma cells. Severe inflammatory reactions were provoked by GC. Granulation tissues induced by CHP resembled those of pseudoxanthomatous granuloma. The GP material was encapsulated by relatively thick fibrous connective tissues with little inflammatory reactions.

Animals↗
PubMed1992

[A case of chronic scrotal hematocele and review of the literature].

A 38-year-old man visited our hospital because of swelling of left scrotal content. He had no history of trauma of scrotum, fever, pain or dysuria. Physical examination revealed a tumor larger than a fist in the left scrotum. Ultrasonography revealed an echogenic mass with echolucent area in the scrotum. Surgical extirpation of the left scrotal tumor was performed under the diagnosis of left testicular tumor. The mass was encapsulated by a white fibrous membrane and was 700 g in weight. The tumor contained 200 ml of dark brown pus-like material. Histological examination revealed deposition of cholesterine crista and infiltration of lymphocyte in tunica vaginalis with extremely atrophic testis, destructive spermatogenesis and atrophic epididymis. Twenty one cases of chronic scrotal hematocele have been reported in the Japanese literature. The age of the patients reported was 38 to 77 years old with a mean age of 65 years. Orchiectomy was done under the diagnosis of testicular tumor in 20 of the 21 cases. Our case was thought to be of an idiopathic chronic scrotal hematocele. The disease should be considered even in the absence of a particular cause such as injury and inflammation of scrotal content.

Adult↗
PubMed1992

[Intracranial primary malignant lymphoma following Behçet's disease--case report].

We reported a case of intracranial primary malignant lymphoma following Behçet disease treated with colchicine. A 43-year-old female with a past history of oral ulcer and folliculitis visited the Department of Ophthalmology on December, 1990, because of her impaired visual acuity. A diagnosis of uveitis due to incomplete type Behçet disease was made from funduscopic examination and her past history. She had been received 1.0mg/day colchicine for six months in the outpatient clinic. She was referred to our department on August 19, 1991, with nausea and headache. On admission, neurological examination revealed slight right cerebellar ataxia showing dysmetria and dysdiadochokinesis. Computed tomography scan and magnetic resonance images demonstrated a malignant lymphoma in the left cerebellar hemisphere. Stereotaxic biopsy resulted in the B cell type malignant lymphoma (Diffuse large cell type). Galliumscintigraphy, physical examination and peripheral blood examination disclosed no systemic abnormalities. There was a reduction of lymphocyte's response to PHA (phytohemagglutinin) stimulation (1.24). The tuberculin reaction was negative. Colchicine was discontinued and the therapy with radiation and prednisolone (20 mg/day) was started under the diagnosis of intracranial primary malignant lymphoma. She was discharged without any neurological deficits on November 25, 1991. She still suffers from impaired visual acuity, but has no problems in daily life. To our knowledge no intracranial primary malignant lymphoma following Behçet disease has been reported previously. The relationship between Behçet disease treated with colchicine and the occurrence of malignant lymphoma is discussed. In our case we speculated that malignant lymphoma might have occurred in an immunosuppressive state due to administration colchicine.

Adult↗
PubMed1992

[Cerebrovascular CO2 reactivity in patients with dementia due to multiple infarction in the territory of the perforating artery].

In order to clarify the pathophysiology of dementia due to multiple infarction in the territory of the perforating artery, the reactivity of cerebral vessels to increased carbon dioxide tension was examined in patients with multiple cerebral infarction with or without dementia. The subjects studied were 11 patients with multi-infarct dementia (MID) (age 57-82 years old, mean +/- S.D. 72 +/- 8) and 16 patients with multiple infarction without dementia (MI) (age 51-81 years old, mean +/- S.D. 69 +/- 9). The diagnosis of cerebral infarction was based on the clinical signs and symptoms and findings of magnetic resonance imaging (MRI). Only patients with cerebral infarction located in the perforator territories were included in this study. Dementia was diagnosed by DSM-IIIR criteria. The extent of periventricular high intensity area (PVH) on the T2-weighted image of MRI was classified into 3 subgroups by the criteria of Gerard et al with some modifications. Cerebral blood flow (CBF) was measured by the 133Xe intravenous injection method using a Cerbrograph (Novo), and gray matter flow (F1) and initial slope index (ISI) were calculated. The cerebrovascular reactivity to CO2 was estimated as the increase in F1 or ISI per unit increase in PaCO2 (delta F1/delta PaCO2 or delta ISI/delta PaCO2, respectively) during inhalation of 5% CO2 and as %increase in F1 or ISI per unit increase in PaCO2 (delta F1%/delta PaCO2 or delta ISI%/delta PaCO2, respectively) during inhalation of 5% CO2. 1. CO2 reactivity in both groups. delta F1/delta PaCO2 in the MI and MID groups were 3.2 +/- 1.4 ml/100 g/min/mmHg and 2.0 +/- 1.4, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Acute undifferentiated leukemia from the viewpoints of diagnosis and therapy].

Myeloperoxidase (MPO)- and Sudan Black B-not more than 3%-positive, esterase staining-negative, lymphoid, megakaryocyte lineage and erythroid surface marker-negative and electron microscopic platelet peroxidase-negative acute leukemia (AL) was diagnosed as acute undifferentiated leukemia (AUL), and myeloid marker (CD13, CD33), electron microscopic MPO (EMMPO), and DNA analysis of immunoglobulin heavy chain and T cell receptor as well as chemotherapy and its reactivity were examined. Of 239 cases of AL, 10 (4.2%) were AUL, and of these 10 cases, 9 were CD13 or CD33-positive AML-MO (MO) cases. Of 9 cases examined for EMMPO, 4 (44%) were positive, and of 3 cases of MO subjected to DNA analysis, 1 and 1 showed rearrangements of immunoglobulin heavy chain and T cell receptor beta chain, respectively. Of 6 cases of MO on myeloid induction therapy, 1 and 1 showed complete remission (CR) and partial remission (PR), respectively, each having lymphoid genotype, and 4 showed no remission (NR), being 3 of them EMMPO-positive. Of 2 cases on lymphoid induction therapy, 1 and 1 showed CR and NR, respectively, the former being EMMPO-positive MO. BHAC-EM therapy with behenoyl cytosine arabinoside, VP-16 and mitoxantrone performed on 2 cases refractory to any one of both these myeloid and lymphoid induction therapies led to CR in all these 2 cases.

Adolescent↗
PubMed1992

[Neuromyopathy induced by halothane anesthesia and muscle relaxants for status asthmaticus--report of 2 patients].

Two patients with status asthmaticus (a 30-year-old female and a 48-year-old male) who developed flaccid quadriplegia and sensory impairment of glove and stocking type after treatment with halothane, muscle relaxants (pancuronium and vecuronium) and steroid are described. They noted motor and sensory impairment immediately after recovery from control ventilation for treatment of status asthmaticus. Histochemical examinations of biopsied muscle demonstrated the necrosis and regeneration of muscle fibers and small diameters in type I fibers. These results suggested that the involvement of muscle (myopathy) was a consequence of the harmful action of halothane and muscle relaxants together with steroids on muscle fibers with subclinical fragility. The sensory impairment (neuropathy) was considered to have been produced mainly by the halothane together with muscle relaxants and aminoglycosides.

Adult↗
PubMed1992

[A case of complete response of locally advanced breast cancer to arterial infusion chemotherapy: cannulation through the right femoral artery and combined use of G-CSF].

We reported a case of locally advanced breast cancer who was cannulated into the right internal thoracic artery through the right femoral artery by Seldinger's method for intra-arterial chemotherapy and obtained good results. In general, aggressive chemotherapy is often accompanied by bone marrow suppression necessitating discontinuation of chemotherapy. However, this patient recovered from this complication by G-CSF. It was suggested that Seldinger's method is suitable for locally advanced breast cancer and that G-CSF has an immediate effect of bone marrow suppression caused by aggressive chemotherapy.

Administration, Oral↗
PubMed1992

[Assessment of pre-term uterine contractions by characterization of the power spectra of abdominal surface potentials (ASP)].

The prognosis of pre-term labor in the absence of complications such as PROM is dependent on the strength of the uterine contractions, which are dependent on the sensitivity of the myometrium, expressed in terms of bio-electric potentials. Our electromyography were obtained from pregnant ewes, and these were correlated with abdominal surface potentials (ASP) obtained from human volunteers, to see if impending premature labor could be detected and the prognosis predicted. 1) The EMG tracings obtained from pregnant ewes were submitted to a power spectrum analysis. 2) EMG tracings revealed an increase in power output with the advance of labor, but power spectra varied with the stage of labor. 3) Uterine contractions not leading to cervical ripening had a low power output with a low frequency range. 4) Ewes in true labor had EMG's at a high power output of low frequency waves. 5) Ewes in pre-term labor leading to cervical ripening had power outputs similar to ewes in true labor, but the power spectra of the former were wider in range. 6) ASP tracing revealed an increasing power output with increasing uterine contractile activity and power spectra correlated well with the EMGs obtained from ewes. In conclusion, since ASP findings were in good correlation with EMGs obtained directly from the myometrium, we hope that this method may be developed into a practical non-invasive method for detecting and assessing uterine contractions.

Abdomen↗