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Biomedical subjects

S Sekiyama

Publications and source records attributed to S Sekiyama.

At least 19 recordsLinked to original sources
PubMed2005

Bio-sorption of acidic gelatine hydro-gels implanted in the back tissues of Fisher's rats.

Recent advance in tissue engineering therapy requires new scaffold materials. Acidic gelatine powders (10 wt%) were, thus, dissolved in water, were or were not cross-linked, and freeze-dried. After sterilization, prepared small sponges were implanted in 7-week-old Fisher's rats' subcutaneous tissues for up to 2 weeks. Sponges absorbed body fluid and changed into hydro-gels in vivo. Non-cross-linked hydro-gels were absorbed within 3 days, while cross-linked hydro-gels were eliminated after 7 days' implantation. Histological observations revealed that the common captivation process was mild while granulocytes and macrophages were encountered. Because acidic gelatine sponges can accommodate various basic growth factors, it can be speculated that prepared sponges might be used as short-time hydro-gel scaffolds and growth-factor carriers.

Absorbable Implants↗
PubMed1995

Microsatellite alterations in adenoma and differentiated adenocarcinoma of the stomach.

In order to elucidate the significance of the adenoma-carcinoma sequence in gastric carcinogenesis from a genetic point of view, we examined microsatellite alterations (replication error and loss of heterozygosity) on chromosomes 2p (D2S123), 3p (D3S1317), 5q (D5S409), 9p (IFNA), and 13q (D13S153) as well as p53 gene mutations in 13 adenomas and 23 differentiated adenocarcinomas including 8 early carcinomas of the stomach. Replication error was detected in only one of the adenomas (8%, 1/13) at the D5S409 locus and in none at the other loci, and loss of heterozygosity was also an infrequent event found in one adenoma (14%, 1/7 informative cases) at D5S409 and in none at the other loci. A p53 gene mutation was detected in one (8%, 1/13) of the adenomas. Thus, microsatellite alterations and p53 gene mutations are rare events in adenomas. In differentiated adenocarcinomas, replication error was detected in 4 (17%, 4/23) at single or multiple loci, and loss of heterozygosity was observed frequently at D3S1317 (25%, 3/12), D5S409 (67%, 6/9), and IFNA (26%, 5/19). Mutations in the p53 gene were detected in 9 (39%, 9/23) of the differentiated adenocarcinomas. Microsatellite alterations on several chromosomes and mutations in the p53 gene were frequent in differentiated adenocarcinomas, even those at an early stage. These results suggest that the adenoma-carcinoma sequence is relatively rare in gastric carcinogenesis, and that the majority of differentiated adenocarcinomas of the stomach may develop through a de novo pathway.

Adenocarcinoma↗
PubMed1995

Loss of heterozygosity on the short arm of chromosome 9 without p16 gene mutation in gastric carcinomas.

A putative tumor suppressor gene, p16 (MST1; multiple tumor suppressor 1/CDK4I; cyclin-dependent kinase 4 inhibitor), was isolated and mapped on the short arm of chromosome 9 (9p). The significance of p16 mutations in gastric tumorigenesis was examined by assessing p16 mutations as well as loss of heterozygosity (LOH) on 9p in 13 gastric adenomas and 45 adenocarcinomas. LOH on 9p (IFNA; alpha-interferon locus) was detected in 22% (5/23 informative cases) of differentiated adenocarcinomas, 10% (1/10) of undifferentiated carcinomas and none (0/6) of the adenomas. Although we found a sequence polymorphism at the second position of codon 99 (CGC/CAC) of the p16 in one gastric adenoma patient, no somatic mutations were detected in any of the gastric adenomas or adenocarcinomas. These results suggest that p16 mutations probably do not contribute to gastric tumorigenesis. However, these data suggest that another tumor suppressor gene on 9p (near the IFNA locus) may contribute to the progression of differentiated adenocarcinoma of the stomach.

Adenocarcinoma↗
PubMed1994

Intravascular malignant lymphomatosis manifesting clinically as bilateral sudden hearing loss and cytomegalovirus encephalitis.

A 49-year-old man developed bilateral sudden hearing loss followed by cerebral infarction and cytomegalovirus (CMV) encephalitis. Autopsy confirmed intravascular malignant lymphomatosis (IML). A literature review indicates that hearing loss can be the initial manifestation of IML and also that CMV infection is more than an opportunistic infection and may participate in the cognitive manifestations in IML.

Cytomegalovirus Infections↗
PubMed1993

Mesangial proliferative glomerulonephritis induced in rats by a lentil lectin and its antibodies.

Experimental glomerulonephritis was induced in rats to investigate the consequence of the antigen-antibody interaction on the surface of glomerular endothelial cells (GENs). A lectin, Lens culinaris hemoagglutinin (LCH), was first planted in the left kidney by isolated perfusion of a left kidney, and then the circulation was reestablished. Rabbit anti-LCH antibodies were injected from the tail vein 3 minutes after the recirculation of the left kidney, and acute glomerulonephritis ensued. Fifteen minutes after the injection, rabbit immunoglobulin G (IgG), rat C3, and LCH were observed exclusively on the surface of GENs. Accumulation of platelets was prominent. Three hours later, the immune deposits were seen in the subendothelial space, and the polymorphonuclear cells were the dominant infiltrate in the glomeruli. Up to the seventh day, immune deposits were seen in the subendothelial space, and the widening of this area was increasingly observed. Fourteen days later, immune deposits containing rat IgG were observed in the subepithelial area, but they were only occasionally seen in the subendothelial space and in the mesangial area. No crescent formation was seen at day 14, but the mesangial area was expanded, with an increased number of cells. The number of nuclei in the cross-section of a glomerulus increased after the induction of glomerulonephritis, but the number of leukocyte common antigen-positive cells (infiltrating cells) decreased gradually from day 4 to day 14. The staining of Thy-1.1, a marker of mesangial cell, was markedly enlarged in the glomerulus at day 14. These data suggest that mesangial proliferative glomerulonephritis can be induced by the antigen-antibody interaction on the surface of GENs.

Animals↗
PubMed1991

A case of angiotropic large cell lymphoma manifesting nephrotic syndrome and treated successfully with combination chemotherapy.

A 52-year-old female had a nephrotic syndrome without neurological or dermatological manifestations. Renal biopsy revealed that glomeruli were filled with tumor cells which bore leukocyte common antigen and pan B cell marker. These cells occupied the capillary lumen and invaded into the mesangial area. Morphological alteration of endothelial cells and glomerular basement membrane were also noticed. The interstitium was well preserved. After five cycles of a combination chemotherapy, CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone), the second biopsy revealed that tumor cells disappeared from glomeruli showing mild sclerosis. Proteinuria became absent. This is the first report of an angiotropic large cell lymphoma manifesting a nephrotic syndrome and treated successfully by CHOP therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Simultaneous determination of FUC and PGM1 by isoelectric focusing.

This paper describes a simple procedure for the simultaneous detection of FUC and PGM1 in semen, seminal stains, dental pulps and hair roots after separation by isoelectric focusing using Ampholine pH 5-7. The gel plate was first stained for FUC using an agarose overlay with a buffer of pH 7.5. After reading the FUC types, the FUC overlay was removed and replaced with an agarose overlay for PGM. The results show that the method is useful in medicolegal individualization of seminal stains and teeth when only small samples have to be examined.

Dental Pulp↗
PubMed1989

[Therapeutic analysis of autopsy findings in oral cancer].

Thirty-four autopsied patients with oral squamous cell carcinoma were analyzed by multiple regression analysis. The following results were obtained. 1) The suggested metastatic spread was from the highest count of oral cancer patients with metastases in lung to lower key organs, reflecting the cascade theory. 2) Multiple regression analysis revealed that local recurrence was significantly related to the treatment method, indicating that multidisciplinary treatment would be needed. 3) Multiple regression analysis indicated that mediastinal lymph node metastasis was significantly related to both the age of the patient and the stage of cancer development. 4) Multiple regression analysis showed that distant metastasis was significantly related to both the stage and the spleen weight. 5) There were many patients with the pulmonary metastases undergoing irradiation which ranged from 40Gy to 60Gy on the primary tumor. 6) Results showed that immunotherapy tended to control pulmonary metastases.

Adult↗
PubMed1987

Localized oral amyloidosis: ultrastructural and immunohistochemical study.

An histopathological, ultrastructural and immunohistochemical study of localized amyloidosis in the floor of mouth of a 58-year-old male in good health is reported. The lesion was composed of nodular deposits of amyloid surrounded by fibroblastic or histiocytic cells, and metaplastic ossification was seen in some deposits. Ultrastructural findings disclosed typical amyloid fibrils with felt-like structure. Closely connected with the amyloid deposits were cells with active histiocytic or fibroblastic appearance. Their cytoplasm contained amyloid fibrils. At the outermost area of the amyloid deposits, bundles of amyloid fibrils projected from these cells into amyloid deposits. Amyloid protein of the present case did not react to any antisera using anti-AA, anti-A lambda, anti-A kappa and anti-prealbumin antisera. It can be assumed that histiocytes or fibroblasts play an important role in local amyloid formation, however, the nature of amyloid fibril protein in the present case is unknown.

Amyloid↗
PubMed1986

[An anatomo-clinical case of sequelae of acute encephalopathy. Infantile spasm with hypsarrhythmia].

Clinico-pathological studies of West syndrome are rather rare. A case of sequelae of acute encephalopathy which involved a nine-month-old boy with post-mortem data is reported. Birth and postnatal development had been normal until the onset of illness. Laboratory examinations ruled out bacterial or viral meningo-encephalitis and metabolic disorders. After the recovery from a coma lasting several days, spastic quadriplegia, severe mental retardation and intractable epileptic attacks were present. The latter were made of tonic spasms and myoclonic seizures. EEG records showed hypsarrhythmia. Neuropathological examination revealed almost symmetrical bilateral cystic cavities in the pontine tegmentum and lateral nuclei of both thalami. The corpus callosum was very thin. No finding suggested a congenital anomaly. In a search of the pathological basis for infantile spasms, this case was compared with the published data. It would appear that the lesions of the pontine tegmentum play a significant role in the pathogenesis of hypsarrhythmia or infantile spasms.

Acute Disease↗
PubMed1983

Peripheral calcifying epithelial odontogenic tumor.

Most of the calcifying epithelial odontogenic tumors (CEOT) are central lesions of the jaws, but the CEOT occurs infrequently on the gingiva. A cases of peripheral CEOT arising in the right upper molar gingiva of a 31-year-old Japanese woman is presented. A direct communication between the overlying gingival epithelium and the tumor was found by examination of serial sections. As a result, it was thought that one of the sources of peripheral CEOT might be gingival epithelium with potential proliferative activity.

Adult↗
PubMed1978

Median rhomboid glossitis associated with amyloid deposition.

There are some controversies over the pathogenesis and clinical features of median rhomboid glossitis. A case of median rhomboid glossitis associated with amyloid deposition was presented. Clinically there was no organ involved in amyloid other than the tongue. It was suspected that median rhomboid glossitis occurred first and that amyloid was induced later.

Amyloid↗