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Biomedical subjects

S Iwamoto

Publications and source records attributed to S Iwamoto.

At least 109 records · Page 6Linked to original sources
PubMed1995

Association of human papillomavirus with malignant and premalignant lesions of the uterine endometrium.

The possible association of human papillomavirus (HPV) with endometrial hyperplasia and endometrial adenocarcinoma was investigated. DNA from frozen tissues of 30 endometrioid carcinomas of Japanese patients was tested for HPV DNA by Southern blot hybridization analysis. Screening with HPV type 58 probe under low stringency conditions showed the presence of HPV DNA in two of 30 endometrioid carcinomas. High stringency hybridization identified HPV type 16 in the two positive specimens. The presence of HPV was further analyzed by polymerase chain reaction (PCR)-Southern blot analysis of DNA from archival tissue blocks of the initial 30 endometrioid carcinomas as well as an additional 17 endometrioid carcinomas and 13 atypical hyperplasias of the endometrium from Japan and 38 endometrioid carcinomas from the United States. Polymerase chain reaction amplification using type 16-specific HPV primers for a portion of the E6 open reading frame was positive in six of 47 (13%) endometrioid carcinomas from Japan, including two in which HPV 16 was not detected by Southern blot analysis and two of 38 (5%) endometrioid carcinomas from the United States. Polymerase chain reaction amplification using L1 consensus sequence primers was positive for HPV in two of 13 (15%) endometrial hyperplasias, 13 of 47 (28%) endometrioid carcinomas from Japan, and six of 38 (16%) endometrioid carcinomas from the United States. Slot blot hybridization identified HPV type 16 in seven of the L1 PCR products, including all but one specimen testing positive for HPV type, 16 using E6 type specific primers. In situ hybridization was positive for HPVs 16/18 in glandular epithelial tumor cells in six of the PCR-positive specimens. An additional specimen showed staining for HPVs 16/18 in acellular luminal debris in association with squamous metaplasia of the tumor, but staining was negative in the glandular cells of the tumor. Human papillomavirus was not detected by in situ hybridization in the remaining specimen, which was PCR positive for HPV 16. In situ hybridization was weakly positive for HPVs 31/33/35 in one specimen and was weakly positive for HPVs 6/11 in benign endometrial epithelial cells but not in tumor cells of another specimen that tested positive for HPV by L1 PCR. Two dimensional gel electrophoresis performed on two specimens showed that HPV DNAs were integrated into cellular DNA with no episomal coexistence. These findings suggest that HPV, especially HPV 16, may play an etiologic role in a fraction of endometrioid adenocarcinomas.

Adult↗
PubMed1995

[Detection of chromosomal aberration using fluorescence in situ hybridization on breast cancer].

The relationship between interphase cytogenetics and prognostic factors, especially the grade of nuclear atypism, nuclear DNA content, histological lymph node metastasis and clinical data was examined in 48 primary breast cancer specimens (touch preparation). Using fluorescence in situ hybridization (FISH) with a chromosome-specific DNA probe, the copy number of pericentrometric sequences on chromosome 17 was examined within the interphase nuclei in touch preparations from the tumor. The copy number of chromosome 17 was correlated with the increase in the grade of nuclear atypism, tumor size, histological lymph node metastasis and nuclear DNA content. In the diploid type of nuclear DNA content, the copy number of chromosome 17 was correlated with the increase in the grade of nuclear atypism and histological lymph node metastasis. In conclusion, the numerical chromosomal aberrations detected by FISH were found in the DNA diploid cases by FCM. The detection of numerical chromosomal aberrations by FISH provide important information about the prognostic factors.

Breast Neoplasms↗
PubMed1995

[A case of occult cancer of pancreas which was appropriately resected by intra operative cytodiagnosis using a balloon catheter].

A new method of intraoperative cytodiagnosis was performed for one patient with occult neoplasms of the pancreas in order to locate the original site of cancer cells, using a balloon catheter. Cancer cells were detected in the pancreatic juice obtained from the pancreatic body only. The pancreatic body was removed, and the tail of the pancreas was anastomosed to the stomach. The post operative course was good without diabetes, and it was confirmed histologically that minimally invasive adenocarcinoma existed in the pancreatic body. Thus this procedure is beneficial because it can preserve as much pancreatic function as possible without losing the chance of cure by surgery.

Adenocarcinoma↗
PubMed1994

Lymphotoxin lacks effects on 75-kDa receptors in cytotoxicity on U-937 cells.

We examined differences in cytotoxic activity between human lymphotoxin (LT) and tumor necrosis factor (TNF) as functions of their interaction with two types of TNF receptors, 55-kDa (p55R) and 75-kDa (p75R). Cytotoxic activity of LT was much lower than that of TNF on a human monocytic cell line, U-937, on which p75R was predominant. Monoclonal antibodies specific for p55R (htr-5 and htr-9) and p75R (utr-1) significantly diminished TNF cytotoxicity, whereas, utr-1 was only slightly inhibitory to LT cytotoxicity, and htr-5 reduced it significantly. TNF individual binding to p75R increased cytotoxic activity when p55R was occupied by htr-9 and a mutein of TNF which significantly lost affinity to p75R. However, LT binding to p75R did not increase. Scatchard analysis with [125I]LT and [125I]TNF showed that LT still had approximately half of the affinity to p75R and slightly less affinity to p55R than TNF. These results indicate slight cytotoxicity of LT compared to TNF, due to inability of LT to signal through p75R on U-937 cells without significant loss of affinity to p75R.

Humans↗
PubMed1994

An exon 28 mutation resulting in alternative splicing of the glycoprotein IIb transcript and Glanzmann's thrombasthenia.

The alternatively spliced from mRNA of platelet glycoprotein IIb (GPIIb) with a deletion of exon 28 (GPIIb-28) has been isolated from the HEL cell cDNA library. The defective expression on the surface of DNA cotransfected COS-1 cells with GPIIb-28 and GPIIIa cDNAs was described in an earlier report. We studied siblings with Glanzmann's thrombasthenia who expressed only the GPIIb-28 mRNA in their platelets. Flow cytometry showed that the patients' platelets failed to bind GPIIb/IIIa complex-specific and GPIIb-specific monoclonal antibody. Western blotting showed that the patients' platelets had defective GPIIb and have trace amounts of GPIIIa. Sequence analysis was performed after polymerase chain amplification of the patients' GPIIb and GPIIIa mRNAs. The patients' GPIIb cDNA had a deletion of the exon 28 nucleotides. The polymerase chain reaction (PCR) from exon 27 to 29 showed that the GPIIb-28 mRNA was 3% +/- 1.6% of the normally, spliced form in control platelets, and 61% in the megakaryoblastic cell line UT-7. The patients' platelets showed only the GPIIb-28. Family study and quantitative PCR studies showed that these patients were compound heterozygotes of two GPIIb gene defects. The father's allele is described in this report and involves skipping exon 28 secondary to a base substitution at codon Gln948, CAG-->TAG. The mother's allele appears to involve decreasing GPIIb mRNA levels in platelets. Our results indicate that the GPIIb-28 is not expressed on platelet membranes as a stable GPIIb/IIIa heterodimer or left as a monomer in platelets. Our studies confirm the previous data observed in COS-1 cells expressing recombinant GPIIb-28.

Alternative Splicing↗
PubMed1994

The prognostic significance of surgical margin in liver resection of patients with hepatocellular carcinoma.

OBJECTIVE: To evaluate the prognostic significance of surgical margin in liver resection of patients with hepatocellular carcinoma. DESIGN: Retrospective study. SETTING: The Center for Adult Diseases, Osaka, Japan, between 1980 and 1989. PATIENTS: One hundred eighty-five patients with hepatocellular carcinoma who underwent liver resection with complete extirpation. MAIN OUTCOME MEASURE: Cumulative survival rate. RESULTS: The patients were divided into a wide surgical margin group, in which the lesion was excised with a margin of 1.0 cm or more, and a narrow surgical margin group, in which the margin was less than 1.0 cm. No significant differences could be detected in survival rates for 3 years or longer. Mean +/- SE tumor sizes were 3.4 +/- 0.4 cm and 4.4 +/- 0.3 cm, respectively, in the wide and narrow surgical margin groups. The patients were divided into three groups according to tumor size: group 1, 2.0 cm or less in diameter; group 2, greater than 2.0 cm but 5.0 cm or less in diameter; and group 3, greater than 5.0 cm in diameter. In groups 2 and 3, no significant differences in survival rates were found between the wide and narrow surgical margin groups. In group 1, the survival rate was significantly higher in the wide surgical margin group than in the narrow surgical margin group (P < .05). CONCLUSIONS: Small hepatocellular carcinomas of 2.0 cm or less in diameter should be resected with an adequate surgical margin. However, surgical margin was not a significant factor in the resection of hepatocellular carcinomas larger than 2.0 cm.

Adult↗
PubMed1994

Apoptosis of acinar cells in the pancreas of rats fed on a copper-depleted diet.

Male Fischer 344 rats weighing 80-90 g were fed on a copper-depleted diet supplemented with 0.6% triethylenetetramine tetrahydrochloride (a copper chelator), and the death of pancreatic acinar cells of these rats was investigated morphologically and biochemically. The weight of the pancreas of these rats decreased from 3 weeks after feeding, and concomitantly the percentage of dead acinar cells increased to the maximum in about the 5th week and decreased subsequently. These dead acinar cells showed light microscopic and electron microscopic characteristics of apoptosis. Furthermore, the electrophoretic pattern of DNAs extracted from the pancreas having many dead acinar cells showed a ladder-like distribution, characteristic of apoptosis. The present results indicate that feeding of rats on a copper-depleted diet supplemented with a copper chelator results in apoptosis of acinar cells of the pancreas.

Animals↗
PubMed1994

Flow cytometric analysis of phenotypes of canine red blood cells with FITC-labeled Clerodendron trichotomum lectin.

Canine red blood cells were divided into a positive type (C type) and a negative type (c type) by a agglutination test with Clerodendron trichotomum lectin (CTL). Blood cells changed from c to C type after suffering from mammary tumor were named cm. The c type blood cells treated with neuraminidase were named cn. These red blood cells were studied with flow cytometry using a directly fluoresceinated CTL. Positive percents of C type, cm type, and cn type were 49.3%, 43.8% and 81.0% respectively. While C showed one peak in histogram, cm showed two peaks. The positive peak in the cm blood cells suggested an appearance of a new blood cell population with a novel sugar chain structure after suffering from the tumor.

Animals↗
PubMed1994

Lymphotoxin and TNF differ greatly in capacity to induce differentiation of human myeloblastic leukemia ML-1 cells.

We found that recombinant and natural lymphotoxin differ from TNF in that they only marginally induce differentiation of human myeloblastic leukemia ML-1 cells. Even at 1,000-fold concentrations, lymphotoxin was significantly less potent than TNF. Lymphotoxin competitively, but not completely, inhibited TNF-induced differentiation. Based on studies of the two types of TNF receptors (55 kDa and 75 kDa) using monoclonal antibodies, the binding activity of lymphotoxin to the receptors was less than 1/3 that of TNF, but lymphotoxin could bind to both TNF receptors. Both receptors were involved in induction of differentiation by TNF. However, lymphotoxin, differed from TNF; it seemed to be weak in sending signals for differentiation through the 75 kDa receptor.

Cell Differentiation↗
PubMed1993

Isolation of a new cDNA clone encoding an Rh polypeptide associated with the Rh blood group system.

The polymerase chain reaction (PCR) was used to amplify Rh-related cDNAs from erythroid cells cultured by the selective two-phase liquid culture system for human erythroid progenitors in peripheral blood. Direct sequencing based on PCR presents heterozygous bands. Two Rh polypeptide cDNAs have been isolated from the PCR products and tentatively designated RhPI cDNA and RhPII cDNA. Both cDNA clones have an open reading frame composed of 1251 nucleotides. The RhPI cDNA clone shows a single nucleotide substitution with no amino acid substitution compared with the published sequence. The RhPII cDNA clone, on the other hand, differs from the above by 41 nucleotide substitutions with the open reading frame, resulting in 31 amino acid substitutions.

Amino Acid Sequence↗
PubMed1993

Point mutation in the band 4.2 gene associated with autosomal recessively inherited erythrocyte band 4.2 deficiency.

A patient who represented acute hemolytic crisis was studied. Analysis of the erythrocyte membrane proteins by SDS-PAGE revealed a deficiency of band 4.2. In the family, the sister of the patient who had been clinically normal was also shown to be deficient in band 4.2. Binding studies showed that the propositus' membranes were able to bind normal band 4.2 protein as much as control. It was suggested that the binding sites for the protein were prepared on the membrane. We analyzed the band 4.2 cDNA of the propositus and detected a mutation that changes a codon for alanine to one for threonine at residue 142. Band 4.2 exon III of genomic DNA which included the mutation site was amplified and sequenced directly in the family members, and it was revealed that only the homozygotes of the mutation allele manifested band 4.2 deficiency and the parents, who were heterozygotes, showed normal amounts of band 4.2. Recently, the same mutation was reported as Protein 4.2NIPPON in another 4 cases (Bouhassira et al. Blood 1992: 79: 1846-1854). This study supports the hypothesis that this mutation is the pathogenetic cause of band 4.2 deficiency and not a polymorphism.

Adult↗
PubMed1993

Effects of surgical orthodontic treatment for malalignment due to the prolonged retention of deciduous canines in young dogs.

This study was conducted to clarify the effects of surgical orthodontic treatment for malalignment caused by the prolonged retention of deciduous canines in young dogs. Fifty-five dogs with malocclusion or pre-malocclusion were divided into two groups. Group 1 received surgical orthodontic treatment (32 dogs) using modification of Ross and Yamane's method of treating for malalignment due to prolonged retention of deciduous canine teeth; Group 2 received no treatment (23 dogs). Occurrence of malocclusion 1-3 weeks after treatment of the group receiving surgery was only 3.8%. However, malocclusion was seen in 73.4% of the non-treatment group approximately 2 years after the first examination. Surgical orthodontic treatment was very useful in treating malalignment due to prolonged retention of deciduous canines in young dogs.

Animals↗
PubMed1993

Estimating the age at death in a group of historically unknown adults.

Ten diaphysis specimens of femurs and humeri from a total of 4 bodies, three excavated from 14th-15th century graves. (Muromachi period) and one from a tomb of the 7th century (period of ancient burial mounds), were examined using histomorphological methods to estimate their ages. The estimation formula was established using humeri (72 specimen) and femurs (71 specimen) from Japanese aged between 26 and 75 years. The formula was prepared based on a multiple regression analysis of the following 3 items: number of osteons/mm2, mean diameter of osteons, and mean diameter of the Haversian canals. Four estimation formulas were established based on the humeri from all subjects, the femurs from all subjects, the humeri from subjects between 26 and 55, and the femurs from subjects between 26 and 53, respectively. Since the age of the excavated human bones was unknown, we used morphological age estimates (e.g. attrition of teeth, cranial suture closure and similar items) for comparison. Histological and visual estimates correspond in 2 of the 10 cases, but the histological age estimates were higher than the visual estimates in the other cases. In 4 of the 10 cases, age estimates produced by the formulas for younger ages were lower than those by the formulas for all age groups. Thus the formulas for younger ages were not so successful.

Adult↗
PubMed1993

Failure of FK-506, a new immunosuppressant, to prevent cerebral vasospasm in a canine two-hemorrhage model.

In order to clarify the possible role of immunological reaction in the pathogenesis of cerebral vasospasm, the authors examined the prophylactic effect of the immunosuppressant agents FK-506 and cyclosporin A on chronic vasospasm in a canine two-hemorrhage model. While a mean constriction of the basilar artery to 81.0% +/- 4.0% (+/- standard error of the mean) occurred on Day 2 and to 63.8% +/- 3.5% on Day 7 in the untreated group, constriction to 77.9% +/- 3.4% on Day 2 and 62.8% +/- 3.0% on Day 7 was demonstrated in the FK-506-treated group (difference not significant). This tendency was also noted in the cyclosporin A-treated group, with basilar artery constriction to 81.8% +/- 3.7% and 56.3% +/- 2.7%, respectively (difference not significant). The histological changes of the basilar artery, including corrugation of the elastic lamina, detachment of endothelial cells, and vacuolar formation in the smooth-muscle layer were not different in the two treated groups and the one control group. Since these immunosuppressant agents are known to inhibit the release of interleukin-2 (IL-2), the level of IL-2 was examined in the cerebrospinal fluid of patients with cerebral vasospasm. While interleukin-1 gradually increased in level as time passed, the level of IL-2 was consistently low during the course of the study, indicating less participation of IL-2 in the pathogenesis of cerebral vasospasm. This clinical observation matched the experimental results. The authors conclude that cell-mediated immunoreaction, initiated mainly by IL-2, plays little role in the pathogenesis of cerebral vasospasm.

Animals↗