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Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 451 records · Page 25Linked to original sources
PubMed1989

Overt diabetes induced by overeating in neonatally STZ-treated impaired glucose tolerant mice: long-term follow up study.

This study has investigated the effect of a long period of overeating on the glycemic control and pancreatic beta-cell function in neonatally streptozocin treated impaired glucose tolerant mice. Neonatally streptozocin (60 mg/kg) treated male ICR mice with 150-200 mg/dl of fed blood glucose levels were divided into two groups at 6 weeks of age. One group was maintained on a cafeteria diet (SZC) and the other on ordinary mouse chow (SZ) until 30 weeks of age. Normal male ICR mice were divided into a cafeteria diet group (CC) and an ordinary chow group (Cont). SZC and CC consumed 134-124% of the caloric intake in SZ and Cont throughout the study. Marked elevation of the fed blood glucose level was observed and the glucose tolerance was progressively impaired in SZC. On pancreas perfusion at 30 weeks of age, insulin secretion to 30 mM glucose in SZC was significantly decreased compared with that in SZ. That in CC was slightly decreased compared with that in Cont. The pancreatic insulin concentration in SZC was significantly less than that in SZ. We conclude that chronic hyperglycemia, induced by the long period of overeating, accelerated the selective loss of beta-cell sensitivity to glucose. Even in normal mice that did not have marked hyperglycemia, insulin secretion to glucose was suppressed, probably by chronic stimulation of the beta-cell due to the long period of dietary excess.

Animals↗
PubMed1989

Interferon-induced resistance of tumor target cells against lysis by interleukin-2-activated killer cells.

IFN-gamma has been shown to decrease the susceptibility of target cells to NK cell-mediated cytotoxicity. In this report, the effect of IFN-gamma on the sensitivity of target cells to killing by various human lymphocyte cytotoxic activities such as NK/K, IL-2-augmented NK/K cell activity, and IL-2-activated killer activity were studied. Although NK-sensitive K562 cells showed marked resistance to NK cell activity as previously reported, the resistance was overwhelmed by augmentation of NK activity with IL-2. IL-2-activated killer cell activity, which can lyse NK-resistant tumor cell lines upon culture in IL-2, showed decreased cytotoxicity against most of the IFN-gamma-treated target cells tested. By contrast, no decrease of target cell sensitivity to K cells was observed, even though K cells were treated with IL-2. These findings suggest that as far as NK-resistant tumor cells are concerned, an IFN-dependent mechanism inhibits the Fc receptor-independent mediators of tumor surveillance, but not Fc receptor-dependent ones. This should be considered when planning adoptive immunotherapy of IL-2-activated killer cells for human malignancy.

Cytotoxicity, Immunologic↗
PubMed1989

Influence of vasopressin level on osmotic pressure and sodium concentration in plasma and cerebrospinal fluid in patients with intracranial lesions.

To study the influence of the vasopressin level on osmotic pressure and sodium concentration in plasma and cerebrospinal fluid (CSF), plasma and CSF were sampled simultaneously in 27 patients with central nervous system lesions. A significant elevation of arginine vasopressin (AVP) levels in plasma and CSF and a significant increase in the osmotic pressure gradients of plasma and CSF were observed in hyponatremic patients. The significant increases in the osmotic pressure gradients may be attributable to hemodilution and CSF concentration resulting from the elevated AVP level, because the sodium concentration gradients of plasma and CSF did not significantly increase. The elevated AVP levels in plasma and CSF and the increased osmotic pressure gradients of plasma and CSF normalized in parallel with improvement of consciousness. These findings suggest that the increased osmotic pressure gradients of plasma and CSF, derived from increased AVP secretion into blood and CSF, exacerbates brain edema induced by the primary lesion and may contribute to the clinical deterioration of some patients with intracranial lesions.

Arginine Vasopressin↗
PubMed1989

Formation of hydroxyapatite in hydrogels from tetracalcium phosphate/dicalcium phosphate mixtures.

Apatitic calcium phosphate cements, formed by the ambient reaction of tetracalcium phosphate (TTCP) with dicalcium phosphates (DCP), have been recently reported. H2O or dilute aq. H3PO4 (0.2%) is used as the liquid vehicle for this reaction. The aim of this study was to ascertain if hydroxyapatite (HAp) can form in self-cured hydrogel composites containing TTCP/DCP mixes. The setting times (ST) and diametral tensile strengths (DTS) of these hydrogel composites were also determined. The hydrogels were of two types: (1) vinyl thermosets derived from the copolymerization of HEMA (2-hydroxyethyl methacrylate) and cross-linking monomers, and (2) polyelectrolyte-based hydrogels formed from aq. poly(alkenoic acids), e.g., poly(acrylic acid). Cylindrical specimens 6 mm D x 3 mm H were prepared and stored in H2O for up to 30 days. The HEMA composites were hardened in 7-15 min by free radical initiation (benzoyl peroxide/tertiary aromatic amine). The polyelectrolyte cements were hardened in 6-8 min. After various periods of storage in H2O at 37 degrees C, some of the specimens were examined by X-ray spectroscopy for HAp. HAp formation was not observed in the HEMA composites even after 30 days of H2O storage but was detected in the polyacid cements. The 24-h DTS values of the HEMA composites (14-26 MPa) were higher than those of the polyacid cements (7-12 MPa). Both the H2O content and pH may thus be factors controlling the rate and extent of HAp formation in hydrogel composites containing TTCP/DCP mixtures.

Calcium Phosphates↗
PubMed1989

[Activity of serum arylsulfatase B in nasal allergy patients].

Although the arylsulfatase B has been reported to inactivate slow reacting substance of anaphylaxis (SRS-A) in vitro there has not been studied about the relation between this enzyme and nasal allergy in vivo. The present study was done to examine the serum level of arylsulfatase B in 73 nasal allergy patients and 13 normal controls. Serum arylsulfatase activity was quantified by measurement of the hydrolysis product (p-nitrocatechol) generated by the interaction of this enzyme and a substrate (p-nitrocatechol sulfate, Sigma). The results are summarised as follows; 1. Arylsulfatase B activity is significantly elevated in sera of nasal allergy patients than in that of normal subjects. 2. There are no correlation between the enzyme activity and the number of peripheral blood eosinophiles. 3. There is tendency the severe the nasal obstruction, the lower the level of the enzyme activity.

Chondro-4-Sulfatase↗
PubMed1989

[Studies on recent clinically isolated Staphylococcus aureus--drug susceptibility and incidence of MRSA in clinical isolates].

Susceptibility of various antimicrobial agents against clinically isolated Staphylococcus aureus was evaluated by Kirby Bauer methods. The incidence of MRSA (Methicillin cephem resistant Staphylococcus aureus) was also investigated. When S. aureus was isolated from urine, the clinical background of the case was further studied. The results are listed below; 1) M1N0 showed the highest susceptibility rate (83.1%) against 537 strains of S. aureus tested, followed by CMZ (63.7%) and CET (63.5%). The susceptibility rate of DMPPC was 41.9%. The incidence of MRSA was 31.3%. 2) In effusion, MRSA was most highly isolated (72.2%). 3) S. aureus isolated from blood and sputa was relatively more resistant to beta-lactams. 4) Strains from urine showed relatively high susceptibility rates. No MRSA was isolated from urine. 5) Thirteen out of twenty-four cases, whose urines were proven to be S. aureus positive, were polymicrobial infection patients.

Adolescent↗
PubMed1989

A case of carmofur-induced leukoencephalopathy--MR images and CT findings.

In a patient with carmofur-induced leukoencephalopathy with a fairly good prognosis, serial MR images demonstrated reversible abnormal signal intensity areas located in the cerebral white matter surrounding the lateral ventricles. These findings suggested that the edematous change together with demyelination of the white matter is important in the pathogenesis underlying carmofur-induced leukoencephalopathy.

Aged↗
PubMed1989

[An in vitro study of dentin hypersensitivity using calcium phosphate cement].

Calcium phosphate remineralizing slurry (CPRS), consisting of an equimolar mixture of tetracalcium phosphate (TTCP) and dicalcium phosphate dihydrate (DCPD), has previously been shown to form hydroxyapatite (HAp) spontaneously at physiological pH. Since considerable amounts of HAp may be formed in situ by CPRS, it may be effective for desensitizing hypersensitive dentin by obturating exposed dentinal tubule openings. In the present study, the effects of topically applied CPRS to etched dentin surfaces were investigated. The samples were randomly divided into 3 groups: (1) the control specimens were soaked in a saliva-like (SL) solution (2) the specimens received either 10-minute or 1-hour treatment with CPRS and (3) the specimens were treated with viscous CPRS, containing carboxymethyl cellulose (CMC) gel, for 8 hours. The SEM observations revealed that the control specimens were covered with a thin layer of plate-like crystals indicative of octacalcium phosphate (OCP). No significant penetration of the crystals into the dentinal tubules was detected. In CPRS group, the 10-minute treatment produced a 10 to 15 microns thick dense layer of precipitation consisting of needle-, rod-, and plate-like crystals. The 1-hour treatment produced a similar precipitation except that the crystals were mostly needle-like. A cross section view of the samples indicated remarkable penetration of the crystals into the tubules, thus providing significant obturation of tubule openings. Samples in the CMC-gel group were covered with an even more impervious layer of precipitation consisting of crystals of a variety of morphologies.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium Phosphates↗
PubMed1989

A new quantitative method for measuring oxygen extraction fraction by positron emission tomography: theory and simulation studies.

A mathematical method has been developed by which the cerebral extraction fraction of oxygen (OEF) administered in a bolus can be quantitatively measured and compared with a previously established method by Mintun et al. Successive injection of three tracers are required: 15O-labeled O2 as a test tracer, a diffusible tracer as a reference tracer and also as a flow tracer, and a tracer for cerebral blood volume (CBV). No decay correction or calibrations between head and arterial measurements are required. Simulation studies have shown that the calculated OEF values are less sensitive to measurement errors in CBV, cerebral blood flow, partition coefficient, time shift effect and tissue inhomogeneity than in the previous method.

Brain↗
PubMed1989

[Clinical study of norfloxacin in the treatment of acute epididymitis].

The efficacy and safety of Norfloxacin were studied in the treatment of 20 patients with acute epididymitis. Norfloxacin was orally administered at a dose of 200 mg 3 times a day for 14 days. Clinical efficacy rate on the 7th day was 95% (19/20), excellent in 9 cases, moderate in 10 cases and poor in 1 case, and on the 14th day was 95% (18/19), excellent in 12 cases, moderate in 9 cases and poor in 1 case. On the 14th day, fever, pain and swelling had disappeared in 8 cases (in 2 cases on the 7th day). The efficacy on the 14th day was further investigated compared to that on the 7th day. Before treatment with Norfloxacin, in 13 of the 20 patients, pyuria was observed. Cultivating the bacteria was isolated in 4 of the 13 patients. Norfloxacin remarkably affected the treatment of these patients with pyuria and bacteriuria. In the treatment with Norfloxacin, the count of leukocytes, erythrocyte sedimentation rate and CRP were obviously improved. Side effects and abnormal clinical laboratory findings were not observed. From these results, Norfloxacin 600 mg/day, t.i.d was considered useful and safe in the treatment of acute epididymitis.

Acute Disease↗
PubMed1989

[Consecutive changes of R-R interval variation on ECG after abstinence in male alcoholics].

Heart rate variation were studied in 37 male alcoholics (age: 46.0 +/- 7.4 years old, duration of habitual drinking: 23 +/- 8 years.) who were admitted in Kurihama National Hospital within 48 hours of last drinking. The coefficient of variation (CV value = (standard deviation/mean R-R interval) X 100) of 100 successive R-R intervals in ECG during supine resting position was measured consecutively on admission, 7th, and 30th hospital day. The CV values on admission (2.50 +/- 0.81) and on 7th day (2.60 +/- 0.87) were significantly lower than those on 30th day (3.41 +/- 1.06, p less than 0.001). In 10 alcoholics, CV values were also measured on 60th day (3.32 +/- 1.18), which were not significantly different from that on 30th day (3.17 +/- 1.18). The ratio of CV to standard prediction value (CV/(-0.066 X age + 6.480)) were 0.67 +/- 0.24, 0.68 +/- 0.21 and 0.90 +/- 0.28 on admission, 7th and 30th day, respectively. The ratio on admission and on 7th day were significantly lower than those on 30th day (p less than 0.001). These findings are suggesting that the disturbance of heart rate variation in alcoholics is reflecting the deterioration of autonomic nervous system on alcohol withdrawal stage.

Adult↗
PubMed1989

[Intra-arterial chemotherapy with angiotensin II in metastatic carcinoma of the liver using implantable pump].

Nine patients with metastatic carcinoma involving the liver were treated by hepatic arterial chemotherapy with Angiotensin II (AGT II) using a subcutaneous implanted pump. There were two primary lesions in the breast, one in the stomach, three in the colon and three in the rectum. Every patient received intra-arterial bolus injection of 5-FU and Adriamycin with 3 mcg of AGT II weekly at our outclinic. Of 7 evaluable patients, 6 responded clinically with PR (response rate, 85.7%). No adverse effects were noted in relation to AGT II. AGT II combined with chemotherapy is therefore a safe and effective method for even outpatients with liver metastases.

Adult↗
PubMed1989

[Various methods of catheter placement in hepatic arterial infusion--technique of catheter placement via a femoral artery].

A comparative analysis of the individual techniques was performed on a total of 106 cases undergoing various methods of catheter placement in hepatic infusion. The comparison of laparatomy (n = 44) with a percutaneous method (n = 62) disclosed a higher incidence of peptic ulcer in the latter. When two modes of percutaneous approach, including a trans-left subclavian arterial method (n = 36) and a trans-femoral arterial method (n = 26), were compared, a shorter average catheterization time (approximately 70 minutes) and a higher selective insertion rate (92.3%) were noted in the trans-femoral approach. For these reasons, our department adopts the trans-femoral method as the percutaneous method of choice. It is advisable for further studies to be made in order to clarify indications for the individual techniques and for anti-complication measures.

Catheterization, Peripheral↗