Search PubMed⌕ Search

Biomedical subjects

E Sakamoto

Publications and source records attributed to E Sakamoto.

At least 19 recordsLinked to original sources
PubMed2006

Effect of reclining and chin-tuck position on the coordination between respiration and swallowing.

Chin-tuck position and reclining posture have been used in dysphagia patients to prevent aspiration during swallowing. However, both behavioural treatments may affect respiratory function. This study was carried out to test the hypothesis that if chin-tuck posture and body reclining affected respiratory function, this would be associated with altered coordination between respiration and swallowing. To investigate this hypothesis, respiratory parameters and manometry were used in each of four combinations of reclining posture and chin-tuck position. In the 60 degrees reclining with 60 degrees chin-tuck position, duration of swallowing apnea (0.89 s.d. 0.17 s) and submental electromyography burst (2.34 s.d. 0.84 s) were significantly longer when compared to both upright sitting and 30 degrees reclining positions. We conclude that 60 degrees reclining from vertical with 60 degrees chin-tuck may affect oral processing stages which delay and reduce a variety of oropharyngeal movements. These in turn significantly influence the coordination between respiration and swallowing.

Adult↗
PubMed2005

Effect of mandibular position on upper airway collapsibility and resistance.

It has been proposed that advancement of the mandible is a useful method for decreasing upper airway collapsibility. We carried out this study to test the hypothesis that mandibular advancement induces changes in upper airway patency during midazolam sedation. To explore its effect, we examined upper airway pressure-flow relationships in each of 4 conditions of mouth position in normal, healthy subjects (n = 9). In the neutral position, Pcrit (i.e., critical closing pressure, an index of upper airway collapsibility) was -4.2 cm H(2)O, and upstream resistance (Rua) was 21.2 cm H(2)O/L/sec. In the centric occlusal position, Pcrit was -7.1 cm H(2)O, and Rua was 16.6 cm H(2)O/L/sec. In the incisor position, Pcrit was significantly reduced to -10.7 cm H(2)O, and Rua was significantly reduced to 14.0 cm H(2)O/L/sec. Mandibular advancement significantly decreased Pcrit to -13.3 cm H(2)O, but did not significantly influence Rua (22.1 cm H(2)O/L/sec). We conclude that the mandibular incisors' position improved airway patency and decreased resistance during midazolam sedation.

Adult↗
PubMed2004

Mouth-opening increases upper-airway collapsibility without changing resistance during midazolam sedation.

Sedative doses of anesthetic agents affect upper-airway function. Oral-maxillofacial surgery is frequently performed on sedated patients whose mouths must be as open as possible if the procedures are to be accomplished successfully. We examined upper-airway pressure-flow relationships in closed mouths, mouths opened moderately, and mouths opened maximally to test the hypothesis that mouth-opening compromises upper-airway patency during midazolam sedation. From these relationships, upper-airway critical pressure (Pcrit) and upstream resistance (Rua) were derived. Maximal mouth-opening increased Pcrit to -3.6 +/- 2.9 cm H2O compared with -8.7 +/- 2.8 (p = 0.002) for closed mouths and -7.2 +/- 4.1 (p = 0.038) for mouths opened moderately. In contrast, Rua was similar in all three conditions (18.4 +/- 6.6 vs. 17.7 +/- 7.6 vs. 21.5 +/- 11.6 cm H2O/L/sec). Moreover, maximum mouth-opening produced an inspiratory airflow limitation at atmosphere that was eliminated when nasal pressure was adjusted to 4.3 +/- 2.7 cm H2O. We conclude that maximal mouth-opening increases upper-airway collapsibility, which contributes to upper-airway obstruction at atmosphere during midazolam sedation.

Adult↗
PubMed2001

[Evaluation of polymerase chain reaction method for monitoring of fungal infection in compromised hosts].

Diagnosis of fungal infections in compromised hosts has been difficult because of insufficient sensitivity and specificity of conventional methods such as culturing and serum testing. Therefore, antifungal agents are usually started in febrile patients who are resistant to antibiotics even if these monitoring tests were negative. In this study, therefore, in order to increase the reliability of these monitoring, polymerase chain reaction (PCR) methods for detection of blood fungus were also performed in compromised hosts including 14 patients with hematological malignancies and one with solid tumor who were undergoing chemotherapies. From these patients, total of 56 peripheral blood samples was collected periodically, irrespective of the presence of infectious signs. At each time point of venopuncture, status of the patient was allocated to one of the followings: A, receiving an intravenous antifungal therapy because of sustaining fever which had not responded to prior antibiotic therapies and also positive for culturing and/or serum beta-D-glucan tests; B, receiving an additional intravenous antifungal therapy but negative for culturing and serum-tests; C, febrile but not yet receiving any intravenous fungal therapy; D, afebrile status. During the study, 10 blood samples from 3 patients were allocated in group A, and one sample of them was positive while remaining 9 were all negative for PCR. Six samples from 4 patients were in group B, and one was PCR positive while remaining 5 were negative. Fifteen samples from 7 patients were in group C, and 3 were positive and 12 were negative for PCR. Twenty-five samples were in group D, and 5 were positive and 20 were negative for PCR. Thus, the results from fungal PCR in these patients were in some case showed discrepancies from those expected from the clinical course and/or conventional monitoring tests. Further evaluation of fungal PCR may gain insight into the more precise diagnosis of fungal infection in these patients.

Adult↗
PubMed2000

Concurrent induction of two chiral centers from symmetrical 3, 4-disubstituted and 3,3,4-trisubstituted 4-pentenals using Rh-catalyzed asymmetric cyclizations

Asymmetric cyclization of symmetrical 3,4-disubstituted and 3,3, 4-trisubstituted 4-pentenals was studied using Rh-complexes with chiral ligands. The cyclization of symmetrical 4-pentenals 4a,b by a neutral Rh[(R)-BINAP]Cl afforded cis-3,4-disubstituted (4R)-cyclopentanones 9a,b of >95% ee in 25-31% yields; on the other hand, the cyclization of 4a-c by a cationic Rh[(R)-BINAP]ClO(4) afforded trans-3,4-disubstituted (4S)-cyclopentanones 10a-c of >95% ee in 70-81% yields. All stereoisomers could be stereoselectively made by the selection of a neutral or cationic Rh-complex, and (R)- or (S)-BINAP ligand. The Rh-catalyzed cyclization could be applied to the construction of cyclopentanones 17 and 18 bearing a chiral quaternary carbon. The cyclization by the cationic Rh[(R)-BINAP]ClO(4) afforded the optically active trans-3,3, 4-trisubstituted cyclopentanones 18a-c of 92-95% ee in 75-83% yields. The catalytic cycle was also studied by using deuterium aldehyde, and the tentative mechanisms of the enantio- and diastereoselection were proposed.

Journal Article↗
PubMed2000

Application of Rh-catalyzed cyclization to the formation of a chiral quaternary carbon.

Rh-Catalyzed cyclization was applied to the formation of a chiral quaternary carbon. It has become clear that the Rh-complex can discriminate between isopropenyl and 2-isopentenyl (or isopentyl) substituents, and the cyclization afforded 3,3,4-trisubstituted cyclopentanones with a chiral quaternary carbon in a stereoselective manner. The cyclization of 4-pentenals 6a, b by an achiral neutral Rh(PPh3)3Cl afforded 3,3,4-cis-trisubstituted cyclopentanones (+/-)-7a,b in 86-96%, and the cyclization by a cationic Rh[(R)-BINAP]CIO4 afforded 3,3,4-trans-trisubstituted cyclopentanones (-)-8a, b of 82-86% ee in 88-98% yields. The mechanism of stereoselection by Rh-complexes is also discussed.

Catalysis↗
PubMed1999

Treatment strategy for mucin-producing intrahepatic cholangiocarcinoma: value of percutaneous transhepatic biliary drainage and cholangioscopy.

Intrahepatic cholangiocarcinomas that secrete macroscopically excessive mucin into the biliary system are rare, and few of the previously reported cases have achieved a curative resection. We defined these tumors as "mucin-producing intrahepatic cholangiocarcinomas" and clarify the optimal preoperative and surgical management for them. Eleven patients with mucin-producing intrahepatic cholangiocarcinomas underwent surgical resection in our department. The clinical, radiologic, surgical, and pathologic findings were studied. The clinical presentation of the 11 patients included repeated abdominal pain, jaundice, and fever. Conventional cholangiographies, such as percutaneous transhepatic cholangiography or endoscopic retrograde cholangiography, could not offer precise information about tumor location and extension because of abundant mucin in the biliary system. Using percutaneous transhepatic biliary drainage (PTBD) and percutaneous transhepatic cholangioscopy (PTCS), we were able to drain the mucin and determine precisely the cancer extension into intrahepatic segmental bile ducts. Based on these findings, various types of liver resection with or without extrahepatic bile duct resection were planned, and 10 patients obtained curative resection. The cumulative 5-year survival rate after curative resection was 78%. In patients with mucin-producing intrahepatic cholangiocarcinoma, PTBD and PTCS are important for evaluating the cancer extension. Rational surgery based on accurate preoperative diagnosis improved the prognosis of patients with this disease.

Adult↗
PubMed1999

Semiquantitative evaluation of alpha1A-adrenoceptor subtype mRNA in human hypertrophied and non-hypertrophied prostates: regional comparison.

The main purpose of this study was to compare semiquantitatively the amount of alpha1a-adrenoceptor subtype mRNA in urethral, central and peripheral areas in benign hypertrophied prostates and non-hypertrophied prostate by the competitive reverse transcriptase polymerase chain reaction (RT-PCR) method. Prostates from twenty cases of men with benign prostatic hypertrophy (BPH) and 5 cases of bladder tumor without BPH were obtained for this study. The mRNA was extracted from the urethral, central and peripheral areas of each prostate, and quantitative RT-PCR was performed using the ratio of PCR product of alpha1a-adrenoceptor mRNA/beta2-microglobulin mRNA. The ratio for the central area of the hypertrophied prostate was significantly greater than that for the same area of the non-hypertrophied prostate (p < 0.05). In contrast, the urethral area showed no significant difference between the two prostate conditions. The central area of the hypertrophied prostate showed the tendency to have an increased alpha1a-adrenoceptor mRNA level compared with the urethral area, though no statistical difference was recognized because of the high standard error. Regional differences in the alpha1a-adrenoceptor mRNA in the non-hypertrophied prostate were rarely observed. The present finding demonstrates that the increased alpha1a-adrenoceptor mRNA content found in the hypertrophied prostate (1) was due to that in the central area.

Aged↗
PubMed1999

Cathepsin Y (a novel thiol enzyme) produces kinin potentiating peptide from the component protein of rat plasma.

Rat spleen cathepsin Y (a novel enzyme) that produces bradykinin (BK) potentiating peptide (BPP) from rat plasma was isolated, characterized and its amino acid sequence was deduced from cDNA cloned by reverse transcription-polymerase chain reaction (RT-PCR). We propose the name cathepsin Y for this enzyme considering its origin, characteristics and the amino acid sequence. BPP potentiates not only BK but also lysyl-BK (lysBK) and T-kinin (TK) action on uterus contraction. The structure of BPP is Pro-Pro-Pro-Leu-Gly-Pro-Gly-Ser. The magnitude of the potentiation of BK activity by synthesized BPP was seven-fold when equivalent quantities added to BK and 23-fold when the level is doubled. The precursor proteins that produce BPP by the action of cathepsin Y are eluted into two fractions when the heated plasma was applied to a negative ion exchange column. Structure relationships between these two proteins are now under investigation. In this paper, we report on the characteristics and the amino acid sequence of rat spleen cathepsin Y, its structure and the potentiating activity of BPP, and isolation of the precursor protein.

Amino Acid Sequence↗
PubMed1999

Value of percutaneous transhepatic portography before hepatectomy for hilar cholangiocarcinoma.

BACKGROUND: The diagnostic value of percutaneous transhepatic portography (PTP) for assessing cancer invasion of the portal bifurcation in patients with hilar cholangiocarcinoma has not been studied previously. METHODS: From April 1977 to March 1998 combined hepatobiliary and portal vein resection was performed in 45 patients. In 25 patients, PTP was carried out before operation and the resected portal bifurcation was examined histologically. Correlation between portographic and microscopic findings at the portal bifurcation was studied retrospectively. RESULTS: Portographic and microscopic findings were classified into three groups (type A, B or C, and grade 0, I or II respectively) according to the findings at the portal bifurcation. There was a significant correlation between the portographic type and degree of cancer invasion (P = 0.0001). In seven of the eight patients with type A portograms, there was no microscopic cancer invasion of the portal bifurcation. In 15 of the 17 patients with type B or C portograms, cancer invasion was found microscopically. All patients with microscopic grade II invasion had type C portograms. CONCLUSION: PTP can be used to evaluate cancer invasion of the portal bifurcation with sufficient reliability for preoperative staging of hilar cholangiocarcinoma.

Adult↗
PubMed1999

[A case of internal hernia through a defect in the falciform ligament treated with laparoscopic surgery].

A 22-year-old male was admitted to our hospital with abrupt onset of upper abdominal pain. Abdominal US and CT revealed dilatation of the small intestine between the abdominal wall and a lateral segment of the liver. After a diagnosis of an internal hernia through a defect in the falciform ligament, emergency surgery was performed. Laparoscopic investigation showed incarceration of the small intestine in a defect of the falciform ligament. After releasing an incarceration, the hernia orifice was opened to prevent relapse. He was discharged on the 4th postoperative day. Internal hernia through a defect in the falciform ligament is extremely rare, with six reported cases including our own in Japan. Characteristic images of abdominal US and CT enable preoperative diagnosis of this condition. Surgery should be performed at an early stage after onset. In patients with no prior history of surgery, laparoscopic techniques may be useful.

Adult↗
PubMed1998

Characterization of the effects of gabapentin and 3-isobutyl-gamma-aminobutyric acid on substance P-induced thermal hyperalgesia.

BACKGROUND: The authors sought to characterize the pharmacologic characteristic and site of action of gabapentin (Neurontin) in a model of thermal hyperalgesia induced by intrathecal substance P administration. METHODS: Rats were prepared with long-term lumbar intrathecal catheters. Hind paw withdrawal latency was determined using a radiant heat stimulus focused through a glass surface onto the plantar surface of the paw. RESULTS: Within 5 min after intrathecal injection of substance P (30 nmol), hind paw withdrawal latency fell from 11 to 8 s. Gabapentin given intrathecally or intraperitoneally produced dose-dependent reversal of the thermal hyperalgesia, with complete reversal (ED100) occurring at 163 microg for intrathecal and 185 mg/kg for intraperitoneal administration. S(+)-3-isobutyl-gamma aminobutyric acid, but not R(-)-3-isobutyl-gamma aminobutyric acid, also produced dose-dependent reversal of the intrathecal substance P-induced thermal hyperalgesia (intrathecal ED100, 65 microg and intraperitonal ED100, 31 mg/kg). The effects of intraperitoneally administered gabapentin and 3-isobutyl-gamma aminobutyric acid were reversed by intrathecal pretreatment with D-serine (100 microg) but not by L-serine. All effects were observed at doses that had little effect on motor function or spontaneous activity. Intrathecal N-methyl-D-aspartate (2 nmol) induced thermal hyperalgesia, which was blocked by gabapentin (100 mg/kg intraperitoneally) and S(+)-3-isobutyl-gamma aminobutyric acid (30 mg/kg intraperitoneally). CONCLUSIONS: The structure-activity relationship and the stereospecificity noted after intrathecal delivery suggest that gabapentin and S(+)-3-isobutyl-gamma aminobutyric acid act at a common spinal locus to modulate selectively a facilitated state of nociceptive processing.

Acetates↗
PubMed1998

The pattern of infiltration at the proximal border of hilar bile duct carcinoma: a histologic analysis of 62 resected cases.

OBJECTIVE: To clarify the importance of different patterns of infiltration at the proximal border of hilar bile duct carcinomas. SUMMARY BACKGROUND DATA: There are few detailed pathologic studies on the proximal resection margins in patients with hilar bile duct carcinoma. METHODS: Serial sections of 62 specimens of resected hilar bile duct carcinoma were examined histologically to determine the involved layers and routes of invasion at the proximal border. The degree of cancer extension was determined, and the relation between the length of the tumor-free resection margin and postoperative anastomotic recurrences was analyzed. RESULTS: Mucosal extension was predominant in papillary and nodular tumors, but submucosal extension was predominant in diffusely infiltrating and nodular-infiltrating tumors. Submucosal extension usually consisted of direct or lymphatic invasion. The mean length of submucosal extension was 6.0 mm. Superficial spread of cancer, defined as mucosal extension of more than 20 mm from the main lesion, was seen in 8 specimens. No patient had an anastomotic recurrence when the tumor-free resection margin was greater than 5 mm. CONCLUSIONS: The pattern of infiltration at the proximal border of resected hilar bile duct carcinomas is closely related to the gross tumor type. The length of submucosal extension is usually less than 10 mm. Superficial spread of cancer is seen in more than 10% of cases. A tumor-free proximal resection margin of 5 mm appears to be adequate in hilar bile duct carcinoma.

Adult↗
PubMed1998

Structure of genes for cecropin A and an inducible nuclear protein that binds to the promoter region of the genes from the silkworm, Bombyx mori.

Cecropins are a family of antibacterial peptide synthesized in insects as a response to bacterial infection. To study the regulation of the immune genes in insects, two cecropin A genes were cloned and sequenced from the silkworm, Bombyx mori. The two genes, CecA1 and CecA2, encoded identical preprocecropin A, having one intron of 609 bp and 929 bp, respectively. The 5'-upstream regions of the genes contained a NF-kappa B like element and IL-6-RE Type I element. Electrophoretic mobility shift assay revealed that a nuclear protein of fat body which specifically bound to the kappa B-like element was activated by injection of the larvae with peptidoglycan.

Amino Acid Sequence↗
PubMed1996

The thiol enzyme from rat spleen that produces bradykinin potentiating peptide from rat plasma.

We have focused our studies on a thiol-dependent enzyme of 37 kilodaltons (kDa) that produces a bradykinin (BK) potentiating peptide. The molecular mass of the peptide was estimated to be around 750 Da and its amino acid composition was Pro4 Gly2 Leu1 Ser1 with a proline and a serine at the N- and C-terminals, respectively. Biological activity was assayed by means of uterus contraction. The enzyme differs from Cathepsin L or B by virtue of its immunological reactivity and enzyme kinetics. The inhibitors used were leupeptin, antipain, E-64 and chymostatin in order of effectiveness. The low molecular SH reagents also diminished the enzyme activity. Among the metal ions tested, Cu2+ and Zn2+ inhibited the reaction.

Animals↗