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H Sasamoto

Publications and source records attributed to H Sasamoto.

At least 19 recordsLinked to original sources
PubMed2006

Oesophageal squamous cell carcinoma may develop within a background of accumulating DNA methylation in normal and dysplastic mucosa.

BACKGROUND: Oesophageal squamous cell carcinoma (OSCC) often arises from preceding dysplastic lesions in the oesophageal epithelium. However, the molecular changes occurring in premalignant lesions are not well understood. An epigenetic change is an example of OSCC that may occur within the epithelium. AIM: To investigate the methylation status of multiple promoters in cancer-derived DNA, as well as in the background epithelium of OSCC, including dysplastic lesions and non-neoplastic mucosa. The normal epithelium from patients without cancer was also examined. The findings were correlated with the mutational status of p53. PATIENTS AND METHODS: 56 patients with advanced OSCC, 21 patients with intraepithelial neoplasia (IEN), 56 patients with a background of non-neoplastic epithelium, adjacent to the OSCC, and 42 normal control epithelia from healthy volunteers were studied. The promoter methylation status of SFRP1, SFRP2, DCC, APC, p16(INK4a), p14(ARF), MINT1, MINT2, MINT31, CACNA1G, COX2, DAPK, hMLH1 and MGMT was examined by methylation-specific single polymerase chain reaction or combined bisulphite restriction analysis. The mutation of p53 by direct sequencing was assessed. RESULTS: DNA methylation was observed in OSCC and in its background epithelium. The frequency of CpG island methylation increased from a baseline level in the background non-neoplastic epithelium, through IEN, to advanced OSCC. However, mutations in p53 were almost exclusively observed in IEN and OSCC. More extensive DNA methylation was seen in the neoplastic lesions (OSCC or IEN) having a p53 mutation than in those with wild-type p53. CONCLUSION: DNA methylation is present at low levels in the non-neoplastic oesophageal epithelium and appears to contribute to the progression of the dysplasia-carcinoma sequence in OSCC carcinogenesis.

Adult↗
PubMed2002

E2F-4 mutation in hereditary non-polyposis colorectal cancer.

Defects in the DNA mismatch repair function are known to cause microsatellite instability (MSI) in hereditary non-polyposis colorectal cancer (HNPCC) as well as in a subset of sporadic colorectal cancer (CRC). We previously reported that the E2F-4 gene, which encodes an important transcription factor in cell cycle control, had frequent tumor-specific mutations at a coding region of trinucleotide microsatellite (CAG)n in a subset of human sporadic CRC with high-frequency MSI (MSI-H). In this study, we assessed mutations of E2F-4 in HNPCC as well as other target genes of defective DNA mismatch repair function. Eighteen colorectal cancer (CRC) patients from 13 kindreds meeting the Amsterdam criteria for HNPCC were analyzed and compared to sporadic CRC patients with MSI-H. We detected mutations of E2F-4 at the same repeat sequence in HNPCC. The frequency of the E2F-4 mutation in HNPCC was comparable with that in sporadic CRC with MSI-H. E2F-4 was considered to be one of the important target genes responsible for the carcinogenesis of HNPCC.

Base Pair Mismatch↗
PubMed2001

Reduction of incretin-like salivatin in saliva from patients with type 2 diabetes and in parotid glands of streptozotocin-diabetic BALB/c mice.

AIM: Diabetic xerostomia is a typical syndrome in diabetic complication. We have reported that salivatin (salivary peptide P-C) derived from human saliva potentiates glucose-stimulated insulin release and inhibits arginine-stimulated glucagon release. The present study is aimed to gain further evidence on the physiological role by investigating the diabetic state-induced change in the amount of salivatin. METHODS: The amount of salivatin was measured in saliva taken from patients with type 2 diabetes with ELISA and with rabbit antiserum against human salivatin immunocytochemically in sections of parotid glands from streptozotocin-diabetic BALB/c mice. RESULTS: The amount of salivatin after a meal was reduced by diabetes in both human saliva and in the serous secretory granule of mouse parotid gland acinar cells. CONCLUSIONS: The above results suggest that salivatin lowers hyperglycaemia after meal and sustains the normal blood glucose levels by incretin-like mechanisms. The function may be damaged by diabetes, and this in turn might make the diabetes worse.

Animals↗
PubMed2001

[Long-term survival of a patient with postoperative liver metastasis of stage IVa gallbladder cancer responding to hepatic arterial infusion chemotherapy].

A 58-year-old man was diagnosed as having advanced gallbladder cancer (T4, P0, H0, N0, stage IVa) with direct invasion to the liver, transverse colon and duodenum. Therefore, extended cholecystectomy and bile duct resection with a partial resection of the transverse colon and the duodenum were performed in March 1992. Histopathological examination revealed moderately differentiated tubular adenocarcinoma of si, ly1, v1, hinf3, binf3, n0. Three years and eight months after the operation, multiple liver metastases were diagnosed by abdominal CT. Repeated hepatic arterial infusion chemotherapy with 5-FU 500 mg/body/w, MMC 4 mg/body/2w and EPI 40 mg/body/4w was performed starting in January 1996. Four months later, the lesions in the liver were reduced in size, and abdominal CT 10 months after the chemotherapy showed a partial response. However, the liver metastasis of the right lobe was enlarged on an abdominal CT in August 1997. Repeated hepatic arterial infusion chemotherapy with the same regimen was performed again starting in March 1998. Ten months later, the liver metastasis was slightly enlarged, but the greater part of the metastasis showed necrosis on an abdominal CT in January 1999. However, peritonitis carcinomatosa was observed later and the patient died 8 years after the operation.

Adenocarcinoma↗
PubMed2000

A triangle lattice model that predicts transmembrane helix configuration using a polar jigsaw puzzle.

We developed a method of predicting the tertiary structures of seven transmembrane helical proteins in triangle lattice models, assuming that the configuration of helices is stabilized by polar interactions. Triangle lattice models having 12 or 11 nearest neighbor pairs were used as general templates of a seven-helix system, then the orientation angles of all helices were varied at intervals of 15 degrees. The polar interaction energy for all possible positions of each helix was estimated using the calculated polar indices of transmembrane helices. An automated system was constructed and applied to bacteriorhodopsin, a typical membrane protein with seven transmembrane helices. The predicted optimal and actual structures were similar. The top 100 predicted helical configurations indicated that the helix-triangle, CFG, occurred at the highest frequency. In fact, this helix-triangle of bacteriorhodopsin forms an active proton-pumping site, suggesting that the present method can identify functionally important helices in membrane proteins. The possibility of studying the structure change of bacteriorhodopsin during the functional process by this method is discussed, and may serve to explain the experimental structures of photointermediate states.

Algorithms↗
PubMed1998

Immunocytochemical localization of salivary peptide P-C in human submandibular gland.

Human saliva contains a proline-rich polypeptide, salivary peptide P-C, which potentiates insulin release and reduces glucagon release from perfused rat pancreas to decrease blood glucose level. To elucidate the process of secretion into humoral fluid of this peptide morphologically, we investigated ultrastructural localization of P-C in human submandibular gland by immunogold technique with anti-peptide P-C whose specificity to P-C was confirmed by immunoblotting. The labeling with gold particles which represents the distribution of P-C-like-immunoreactivity (P-C-LI) was detected in the secretory granules and rough endoplasmic reticula of the acinar serous cells and in few mucosa cells. P-C-LI was also observed in the lumen of striated duct but not intracellularly in the ductal cells themselves, indicating that P-C is not probably reabsorbed there. These results suggest that salivary peptide P-C is present in acinar serous cells, is secreted into the oral cavity, and may be reabsorbed through the digestive tract to modulate the blood glucose level after feeding.

Aged↗
PubMed1991

Extracellular production of mouse interferon beta by the Bacillus subtilis alpha-amylase secretion vectors: antiviral activity and deduced NH2-terminal amino acid sequences of the secreted proteins.

Using two Bacillus subtilis alpha-amylase secretion vectors, mouse interferon-beta (IFN-beta) cDNA was expressed. Ten kinds of mature and hybrid forms of biologically active mouse IFN-beta proteins were synthesized in B. subtilis and were secreted into the culture medium. Similar amounts of proteins, which were determined by immunoblot analysis, were secreted from the B. subtilis transformants, while the antiviral activity in the medium was markedly different in each one of them. The highest antiviral activity was observed in a hybrid protein, in which eleven amino acids consisting of the prosequence of alpha-amylase (eight amino acids) and three amino acids encoding in the HindIII linker DNA were assumed to be extended in front of the Leu residue at position 6 of the mature form of mouse IFN-beta. Its activity was higher than that of the mature form of the mouse IFN-beta secreted from a B. subtilis transformant. These results indicate that the amino acid sequence around the NH2-terminal region of the mouse IFN-beta is closely related to the antiviral activity, but the NH2-terminal amino acid is not. The hybrid proteins of mouse IFN-beta show no interferon activity against a human cell line, HEL.

Amino Acid Sequence↗
PubMed1989

Signal peptide of Bacillus subtilis alpha-amylase.

Mature alpha-amylase of Bacillus subtilis is known to be formed from its precursor by the removal of the NH2-terminal 41 amino acid sequence (41 amino acid leader sequence). DNA fragments coding for short sequences consisting of 28 (Pro as the COOH terminus) 29 (Ala), 31 (Ala), and 33 (Ala) amino acids from the translation initiator, Met, in the leader sequence were prepared and fused in frame to the DNA encoding the mature alpha-amylase. The secretion activity of the 33 amino acid sequence was nearly twice as high as that of the parental 41 amino acid sequence, whereas the activity of the 31 amino acid sequence was 75% of that of the parent. In contrast, almost no secretion activity was observed with the 28 and 29 amino acid sequences. The signal peptide cleavage site of the precursor expressed from the plasmid encoding the 33 amino acid sequence was located between Ala and Leu at positions 33 and 34 and that from the 31 amino acid sequence between Thr and Ala at positions 33 and 34. The NH2-terminal amino acid from the latter corresponded to the 3rd amino acid of the mature enzyme. These results indicated that the functional signal peptide of the B. subtilis beta-amylase consists of the first 33 amino acids from the initiator, Met.

Amino Acid Sequence↗
PubMed1989

[Efficacy of etoposide in bone metastasis of breast cancer].

We have used ADM, MMC, CDDP and other drugs for a case of bone metastasis of breast cancer, but the bone destruction was advanced and she could not walk. We have also used etoposide, a new chemotherapeutic drug, for the same case. Two months later bone sclerosis was seen by X-ray film and pain disappeared. Bone sclerosis then advanced after 6 months, she has begun to stand, and after 8 months she has been able to walk with a cane. There was no severe side effect. Etoposide was very effective for bone metastasis of the breast cancer.

Bone Neoplasms↗
PubMed1985

Active forms of chymotrypsin C isolated from autolyzed porcine pancreas glands.

Four active forms of chymotrypsin C (C1, C2A, C2B, and C3) were isolated from the autolyzed porcine pancreas glands. Their molecular weights were estimated by SDS-polyacrylamide gel electrophoresis to be 29 100 for C1, 26 300 for C2A and C3, and 25 500 for C2B. The kinetic analyses of esterase activity of the enzymes toward Ac-LLeu-OEt and Ac-LPhe-OEt showed that chymotrypsin C1 hydrolyzed the two substrates more efficiently than did chymotrypsin C3. Chymotrypsin C1 consisted of chain A (H-Cys-...-Asn-OH, Mr 886) and chain BC (H-Val-...-Lys-OH, Mr 28 200). Chymotrypsin C3 consisted of the two components of C3L and C3S that could be dissociated in the presence of 2.3% SDS. C3L consisted of the chain A and the chain C (H-Ser-...-Lys-OH, Mr 13 600). C3S was the chain B (H-Val-...-Lys-OH, Mr 11 800). These kinetic and chemical analyses show that chymotrypsins C1 and C3 correspond to chymotrypsin A delta and A alpha, respectively.

Amino Acids↗
PubMed1984

[Floating knee fracture (ipsilateral fracture of the femur and tibia)--treatment by closed Ender nailing].

Fourteen cases of ipsilateral fractures of the femur and tibia (floating knee fracture) were reviewed and patients were graded according to the type of fracture and the method of treatment. Using the criteria for assessment described by Karlström and Olerud, patients were graded as excellent, good, fair and poor. Excellent results were achieved in five patients, good in three and fair in six. When the fracture extended into the knee, it caused knee problem in three out of five. In ten cases the femoral shaft fractures were nailed and in five both bones were nailed. Nailing of both femur and tibia gave good or excellent result in all five cases. As the comminution is often severe in the cases of floating knee fracture, intramedullary nailing by Küntscher may be difficult. We have introduced a closed Ender nailing for femoral and tibial shaft fractures and we have found that this method is also useful for the floating knee fracture. It is advantageous for this type of fracture, because it is technically simple, it has wide indications and it results in rapid bone union without knee disturbance.

Adolescent↗
PubMed1980

Evaluation of pericardial effusion with computed tomography.

Evaluation of pericardial effusion was attempted with computed tomography in 11 patients. The volume and distribution of pericardial fluid were assessed with satisfactory resolution and the nature of the fluid was estimated by the difference in x-ray transparency (CT numbers). The volume of pericardial fluid calculated by tomographic methods ranged from 25 ml. to 585 ml. and agreed well with the surgically drained fluid volume. The CT numbers of the pericardial effusion due to renal or heart failure, acute viral pericarditis, hypothyroidism, and hemopericardium were +12 to +13, +20, +28 to +30, and +26 to +40, respectively. Therefore the volume and gross nature of the pericardial fluid could be estimated noninvasively with computed tomography.

Acute Disease↗
PubMed1980

Evaluation of cardiac diseases with computed tomography.

Fifty-six consecutive patients with various cardiac diseases were studied with a third-generation whole body computed tomographic system. Enhancement was performed by intravenous injection of angiographic contrast medium. Identification of the great vessels, atria and ventricles, and evaluation of abnormalities in these structures were possible by cardiac computed tomography. For example, enlarged left ventricle in the left ventricular volume load, enlarged right ventricle in the right ventricular volume load or hypertrophied interventricular septum in idiopathic hypertrophic subaortic stenosis were revealed with a satisfactory resolution. Pericardial effusion and intracardiac thrombi were most precisely assessed by computed cardiac tomography.

Adult↗
PubMed1980

Holter system electrocardiographic studies on 617 cases.

Holter system electrocardiograms were recorded for 617 patients who were treated at the Department of Cardiology, Tokai University Hospital. In cases of arrhythmia, ventricular premature contraction (VPC) was the most predominant, in 291 cases (69%) out of 423 with arrhythmia, followed by 59 (14%) with supraventricular premature contraction (SVPC), 23 (5.4%) with paroxysmal atrial tachycardia, 17 (4%) with second degree A-V block and 10 (2.3%) with transient atrial fibrillation (AF). In addition, nine (2.1%) cases of ventricular tachycardia (VT), one (0.2%) of transient ventricular fibrillation (VF) and one (0.2%) of third degree A-V block were found in particularly severe arrhythmia cases. Six out of nine cases of VT were cases of acute myocardial infarction (AMI) and all died suddenly while in the hospital or after discharge. Mild or moderate changes in ST-T were often observed even in normal subjects. Of the 617 cases, only 18 (2.9%) showed a significant elevation or depression of ST. Among these, three definitely had variant angina pectoris (Prinzmetal type). The above results indicate Holter EKGs are very useful for the diagnosis of arrhythmia and can also be used as a means of evaluating the prognosis in some cases, but there still are some problems in connection with its use for the diagnosis of ischemic heart disease except for the diagnosis of variant angina pectoris.

Adolescent↗