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Biomedical subjects

K Sakai

Publications and source records attributed to K Sakai.

At least 235 records · Page 13Linked to original sources
PubMed2000

Secretion of adrenocorticotropic hormone induced by allergen inhalation in patients with atopic asthma.

Allergen inhalation in atopic patients results in cytokines production or release of preformed cytokines, some of which are known to induce adrenocorticotropic hormone (ACTH) secretion in experimental conditions. We examined whether allergen inhalation can induce ACTH secretion in vivo. A significant elevation of ACTH levels was observed in 2 and 24 hr after allergen inhalation challenge. However, methacholine challenge with the same degree of airflow limitation did not induce ACTH elevation, indicating that this may not be due to bronchoconstriction per se. Our results indicate that allergen inhalation can trigger ACTH secretion in patients with atopic asthma.

Adrenocorticotropic Hormone↗
PubMed2000

Effects of pH variation and NaCl on in vitro digestibility of cow's milk proteins in commercially available infant formulas.

Allergenicity and antigenicity of food proteins are generally dependent on their heat-stability and resistance to digestive enzymes. Using the methods of SDS-PAGE and immunoblots, we assessed peptic-digestibility of major milk proteins (casein, beta-lactoglobulin and alpha-lactalbumin) in commercially available infant formulas in acidic pH range (pH 1.5 to 4.0), and we also investigated the effect of NaCl on peptic-digestibility of cow's milk proteins at pH 2.0. The profile of peptic-digestion of casein was similar at pH range from 1.5 to 3.5 where the intact protein of casein rapidly disappeared, whereas slow digestibility of the protein was found at pH 4.0. Beta-lactoglobulin and alpha-lactalbumin were digested at pH range from 1.5 to 2.5 and were almost entirely resistant to peptic digestion at over pH 3.0. In the presence of NaCl at pH 2.0, casein showed a good digestibility by pepsin similar to that in the absence of NaCl, in contrast to beta-lactoglobulin and alpha-lactalbumin both having their peptic-digestibility decreased in the presence of 0.2 M NaCl. As the state of the stomach in new born infants shows low amounts of secretary pepsin and out of optimum pH of peptic activity, low digestibility of beta-lactoglobulin and alpha-lactalbumin in cow's milk based infant formulas at over pH 3.0 is supposed to be responsible for their allergenicity.

Animals↗
PubMed2000

[Psychological complexity of the figures and properties of retention in visual short-term memory].

We investigated how the physical variables of complex figures had effects on psychological complexity and recognition of complex figures. Complexity was objectively defined by the amount of convex parts and Perimeter/square root of Area (P/square root of A), which varied with both the number of convex parts and the length of one convex part. In complexity judgments the results showed that the judged complexity was not well predicted by P/square root of A, and that the amount of convex parts rather than P/square root of A had much influence on the judged complexity. In a recognition experiment, the results showed that performance was dependent on both the number of convex parts and the length of one convex part when P/square root of A was held constant. When P/square root of A was low and constant, performance tended to deteriorate with increasing the amount of convex parts. But when P/square root of A was high and constant, performance peaked at a convex parts value of 8, and deteriorated at higher or lower values of convex parts. The results indicated that both the number of convex parts and the length of one convex part were effective in deteriorating retention in visual short-term memory, and that P/square root of A had indirect influence on performance.

Adult↗
PubMed2000

[Successful treatment of a patient with recurrent ovarian clear cell adenocarcinoma under combination chemotherapy of 5-FU (civ) and low-dose CDDP (i.v.)].

Resistance to conventional chemotherapy including CDDP is the most important therapeutic problem in ovarian cancer. The combination chemotherapy of 5-FU (civ) and low-dose CDDP (i.v.) was applied to a patient with recurrent ovarian clear cell adenocarcinoma (stage IIa), which is often more resistant to systemic chemotherapy than other ovarian adenocarcinomas and is a poor prognostic factor. The patient underwent cytoreductive surgery. Then, 5-FU 375 mg/m2/day civ (days 1-5, 8-12, 15-19, 22-26) and CDDP 3.75 mg/m2/day i.v. (days 1-5, 8-12, 15-19, 22-26) were administered. After four courses of this treatment, there is no sign of recurrence. This result indicates that the combination of 5-FU and CDDP is useful in the treatment of recurrent ovarian cancers.

Adenocarcinoma, Clear Cell↗
PubMed2000

[A case of ascending aortic aneurysm with intrathoracic goiter].

A case of the successful operation for ascending aortic aneurysm and intrathoracic goiter was described. A 71-year-old woman was admitted to our hospital for the treatment of ascending aortic aneurysm disclosed by the examination in another hospital. Preoperative chest CT showed ascending aortic aneurysm as large as 8 cm in diameter, and an upper mediastinal tumor compressing the main bronchus. The tumor was continuous with the right lobe of the thyroid. The excision of the tumor was performed through median sternotomy with cervical collar incison. After that, the replacement of the ascending aorta was carried out under cardiopulmonary bypass and hypothermic circulatory arrest. The histological examination of the resected specimen revealed adenomatous goiter without malignancy.

Aged↗
PubMed2000

[Anesthetic management in pediatric interventional cardiology].

Interventional cardiology (n = 108) and cardiac angiography (n = 481) procedures in pediatrics performed between January 1996 and December 1998 were reviewed. Means (SD) of duration of anesthesia for interventional cardiology and cardiac angiography were 245 (130) and 152 (48) minutes, respectively (P < 0.001). Incidences of long operations requiring over 6 hours of anesthesia were 12 and 0%, respectively (P < 0.001). Incidences of hemodynamic derangements were 17 and 2.9%, and catheter-related complications were 7.4 and 0.83%, respectively (P < 0.001). Incidences of ICU admission were 7.4 and 0.62% those of emergency surgery were 4.6 and 0%, and those of blood transfusion were 4.6 and 0%, respectively (P < 0.001). Incidences of cardiopulmonary resuscitation, and cardioversion were also higher in interventional cardiology (P < 0.05), and all these emergency cases were rescued successfully. The risk of cardiac angiography is higher compared with general surgery, and the risk of interventional cardiology is higher than cardiac angiography in pediatrics. This study reconfirms that anesthesiologists should play an active role in care of pediatric patients undergoing high-risk procedures outside the operating room.

Anesthesia, General↗
PubMed2000

Band-suppressed restoration of X-ray images blurred by body movement.

The restoration of X-ray images that have been blurred due to body movement are discussed. The observation system for these images is described using a mathematical model, and several restoration filters composed of a series of such models are proposed. These filters restore band-suppressed approximations of the original images. In addition, redundancy is introduced into these restoration filters in order to suppress additive noise. These filters are expanded to be applicable not only to parallel translations, but also to rotations by coordinate transformation. The proposed methods are applied to blurred X-ray images of a bone model of the elbow joint. The parameters of the restoration filter are estimated using a marker attached to the subject as a reference signal.

Artifacts↗
PubMed2000

Effect of amino acid mixtures on nasal allergic responses induced by toluene diisocyanate in mice.

We studied the effect of various amino acid mixtures on nasal allergy induced by the intranasal application of toluene diisocyanate (TDI) in mice. In Experiment 1 (Exp. 1), mice were fed a 25% casein, soy protein isolate (SPI), egg white protein (EW) or gluten diet. In Experiment 2 (Exp. 2), mice were fed a 25% amino acid mixture diets patterned after casein (AA-casein), SPI (AA-SPI), EW protein (AA-EW) or gluten (AA-gluten). In Experiment 3 3 (Exp. 3) we modified the glutamine/glutamic acid (Gln/Glu) concentrations in the amino acid mixtures. Mice were fed a 25% AA-SPI, low Gln/Glu AA-SPI (LG-AA-SPI), AA-EW or high Gln/Glu AA-EW (HG-AA-EW) diet. At the 5th week, mice were divided into sensitized (sen-) and non-sensitized (ns-) groups. The mice in sensitized groups were treated with two courses of intranasal application of toluene diisocyanate (TDI) in ethyl acetate for 5 consecutive days, separated by 9 days rest. The non-sensitized groups of mice were treated with a vehicle. Nine days after the second sensitization, all mice were provoked by TDI. Nasal responses and serum IgE concentration were studied. The findings of Exp. 1 showed that the sen-EW group exhibited a lower body weight gain, higher nasal symptom score and higher IgE concentration than the other sensitized groups. The findings dings of Exp. 2 showed that the sen-EW group had a lower body weight gain, higher nasal symptom score and higher IgE concentration than the other sensitized groups. In Exp. 3, the AA-EW group showed a higher total nasal score and IgE concentration than the HG-AA-EW group, however, the findings of LG-AA-SPI and AA-SPI were similar. These findings demonstrated that amino acid mixtures affect nasal allergy induced by the intranasal application of TDI in mice.

Administration, Intranasal↗
PubMed2000

Conformation and stability of thiol-modified bovine beta-lactoglobulin.

Bovine beta-lactoglobulin A assumes a dimeric native conformation at neutral pH, while the conformation at pH 2 is monomeric but still native. Beta-lactoglobulin A has a free thiol at Cys121, which is buried between the beta-barrel and the C-terminal major alpha-helix. This thiol group was specifically reacted with 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) in the presence of 1.0 M Gdn-HCI at pH 7.5, producing a modified beta-lactoglobulin (TNB-bIg) containing a mixed disulfide bond with 5-thio-2-nitrobenzoic acid (TNB). The conformation and stability of TNB-bIg were studied by circular dichroism (CD), tryptophan fluorescence, analytical ultracentrifugation, and one-dimensional 1H-NMR. The CD spectra of TNB-bIg indicated disordering of the native secondary structure at pH 7.5, whereas a slight increase in the alpha-helical content was observed at pH 2.0. The tryptophan fluorescence of TNB-bIg was significantly quenched compared with that of the intact protein, probably by the energy transfer to TNB. Sedimentation equilibrium analysis indicated that, at neutral pH, TNB-bIg is monomeric while the intact protein is dimeric. In contrast, at pH 2.0, both the intact beta-lactoglobulin and TNB-bIg were monomeric. The unfolding transition of TNB-bIg induced by Gdn-HCl was cooperative in both pH regions, although the degree of cooperativity was less than that of the intact protein. The 1H-NMR spectrum for TNB-bIg at pH 3.0 was native-like, whereas the spectrum at pH 7.5 was similar to that of the unfolded proteins. These results suggest that modification of the buried thiol group destabilizes the rigid hydrophobic core and the dimer interface, producing a monomeric state that is native-like at pH 2.0 but is molten globule-like at pH 7.5. Upon reducing the mixed disulfide of TNB-bIg with dithiothreitol, the intact beta-lactoglobulin was regenerated. TNB-bIg will become a useful model to analyze the conformation and stability of the intermediate of protein folding.

Animals↗
PubMed2000

Assessment of perioperative predictive factors influencing survival in patients with postinfarction ventricular septal perforation. Classified by the site of myocardial infarction.

BACKGROUND: The present study was designed to identify the perioperative factors and to consider a counterplan for the improvement of surgical results, based on the site of myocardial infarction. METHODS: Sixteen patients with postinfarction ventricular septal perforation underwent surgical repair. The operation was performed 5+/-3 days after the onset of ventricular septal perforation using the same method, an infarctectomy and reconstruction of the septum and right and left ventricular walls with a single Dacron patch. The ventricular septal perforation was anterior in 11 patients and posterior in 5. Preoperative hemodynamics between survivors and non-survivors were compared. Left ventricular wall motion was estimated using echocardiography by wall motion score (divided into 17 segments and each segment was graded on a fourpoint scale: normal, 0; hypokinetic, 1; severe hypokinetic, 2; a- or dyskinetic, 3) and summed up. RESULTS: The operative mortality was 36% in 11 patients with anterior ventricular septal perforation. In non-survivors compared to survivors, wall motion score was greater (25+/-4 vs 18+/-4, p<0.01) and all values were over 20. The value of the cardiac index divided by Qp/Qs was lower (0.98+/-0.09 vs 1.44+/-0.31, p<0.02) and all were under 1.1. In 5 patients with inferior ventricular septal perforation, the operative mortality was 40%. In non-survivors compared to survivors, wall motion score was greater (18, 18 vs 7, 2, 12) and the right atrial pressure was greater (18, 19 vs 10, 9, 9 mmHg) due to a right ventricular infarction. CONCLUSIONS: The patients with poor left ventricular wall motion were lost for reasons unrelated to the site of myocardial infarction. Moreover, a cardiac index over Qp/Qs in anterior ventricular septal perforation and the existence of a right ventricular infarction in inferior ventricular septal perforation was predictive of operative mortality.

Aged↗
PubMed2000

[Role of small dense low-density lipoprotein in coronary artery disease patients with normal plasma cholesterol levels].

OBJECTIVES: The relationship between plasma low-density lipoprotein (LDL) cholesterol and the risk of coronary artery disease (CAD) is known, but the other characteristics of LDL, particularly particle size and density, are unclear. The relationship between small dense LDL phenotype and non-diabetic, normocholesterolemic CAD was investigated in 70 patients with angiographically documented CAD, and 38 age-matched control subjects. METHODS: Peak LDL particle diameter was determined by using 2-16% polyacrylamide gradient gel electrophoresis. Small dense LDL phenotype was defined as particle diameter equal to or less than 255 A. RESULTS: LDL particle diameters in patients with CAD were significantly smaller than those in controls (252.4 +/- 6.9 vs 259.3 +/- 8.8 A, mean +/- SD, p < 0.0001). Prevalence of small dense LDL was markedly higher in patients with CAD (72%) than in subjects without CAD (24%). CAD patients had significantly lower high-density lipoprotein (HDL)-cholesterol and apolipoprotein A-I levels (39.3 +/- 8.8 vs 49.8 +/- 12.0, 108.1 +/- 20.6 vs 122.9 +/- 20.1 mg/dl), and higher lipoprotein (a) and apolipoprotein B levels (28.8 +/- 30.4 vs 16.8 +/- 18.8, 96.5 +/- 21.8 vs 80.2 +/- 14.9 mg/dl) than non-CAD subjects, whereas total cholesterol, LDL-cholesterol, triglyceride, remnant-like particle cholesterol and insulin levels were not increased in CAD patients compared with non-CAD subjects. Stepwise regression analysis revealed that LDL particle size was the most powerful independent determinant of CAD (F value = 20.04, p < 0.0001). Logistic regression analysis revealed that small dense LDL phenotype [relative risk (RR) of 7.0, 95% confidence interval (95% CI) 2.4-20.1], low HDL-cholesterol (RR of 5.6, 95% CI 2.1-15.2), and increased apolipoprotein B (RR of 5.8, 95% CI 1.8-18.5) were independently associated with incidence of CAD. CONCLUSIONS: High prevalence of small dense LDL is a leading cause of CAD with even normal cholesterol levels.

Aged↗
PubMed1999

Insulin-like growth factor-1 affects expressions of cyclin-dependent kinase 5 and its activator p35 in reperfused rat brain.

Insulin-like growth factor-1 (IGF-1) was applied topically on the brain surface of reperfused rat brain after 60 min of transient middle cerebral artery (MCA) occlusion. In contrast to the cases treated with vehicle, the infarct volume was greatly reduced at 24 h of reperfusion by the treatment with IGF-1. Immunohistochemical analysis in the MCA territory showed that the increase of cyclin-dependent kinase 5 (cdk5) was greatly reduced, and that the decrease of the critical regulatory subunit of cdk5, p35, was preserved with treatment of IGF-1. The present results suggest that IGF-1 has a significant effect on ameliorating brain injury after transient focal brain ischemia with affecting the expressions of cdk5 and its activator p35.

Animals↗
PubMed1999

Reduction of tyrosine kinase B and tyrosine kinase C inductions by treatment with neurotrophin-3 after transient middle cerebral artery occlusion in rat.

Infarct volume and immunoreactivities for trkB and trkC in rat brain were compared at 24 h after 90 min of transient middle cerebral artery occlusion (MCAO) between animal groups with or without neurotrophin-3 (NT-3, 10 microg/250 g animal). Treatment of rat brain with topical application of NT-3 significantly reduced infarct volume (P = 0.02) and trkB and trkC inductions. These data suggest that NT-3 reduced the ischemic injury along with the reduction of trkB and trkC inductions.

Administration, Topical↗
PubMed1999

Neural representation of a rhythm depends on its interval ratio.

Rhythm is determined solely by the relationship between the time intervals of a series of events. Psychological studies have proposed two types of rhythm representation depending on the interval ratio of the rhythm: metrical and nonmetrical representation for rhythms formed with small integer ratios and noninteger ratios, respectively. We used functional magnetic resonance imaging to test whether there are two neural representations of rhythm depending on the interval ratio. The subjects performed a short-term memory task for a seven-tone rhythm sequence, which was formed with 1:2:4, 1:2:3, or 1:2.5:3.5 ratios. The brain activities during the memory delay period were measured and compared with those during the retention of a control tone sequence, which had constant intertone intervals. The results showed two patterns of brain activations; the left premotor and parietal areas and right cerebellar anterior lobe were active for 1:2:4 and 1:2:3 rhythms, whereas the right prefrontal, premotor, and parietal areas together with the bilateral cerebellar posterior lobe were active for 1:2.5:3.5 rhythm. Analysis on individual subjects revealed that these activation patterns depended on the ratio of the rhythms that were produced by the subjects rather than the ratio of the presented rhythms, suggesting that the observed activations reflected the internal representation of rhythm. These results suggested that there are two neural representations for rhythm depending on the interval ratio, which correspond to metrical and nonmetrical representations.

Adult↗