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Biomedical subjects

A Sugita

Publications and source records attributed to A Sugita.

At least 19 recordsLinked to original sources
PubMed1996

Incidence of p53 and Ha-ras gene mutations in chemically induced rat mammary carcinomas.

To determine whether p53 alterations, which are frequent in human breast cancers, are also common in rat mammary tumors, we examined 40 tumors from 24 rats treated with 7,12-dimethylbenz[a]anthracene (DMBA) and 34 tumors from 14 rats treated with N-nitroso-N-methylurea (NMU) (an N-nitroso compound). DMBA and NMU are known genotoxic mutagens. The entire coding regions of the p53 and Ha-ras genes were examined for mutations by polymerase chain reaction single-strand conformational polymorphism analysis and by direct sequencing. One of the 40 DMBA-induced mammary tumors had a p53 mutation, a single-base substitution (AGC-->GGC) at codon 307, resulting in an amino-acid change from Ser to Gly. No mutations were found in NMU-induced tumors. The incidence of Ha-ras gene mutation was 79% (27 of 34) at codon 12 in the NMU group and 23% (nine of 40) at codon 61 in the DMBA group. Thus, p53 mutation, in contrast to Ha-ras mutation, did not seem to be a prerequisite for carcinogenesis in chemically induced rat mammary tumors.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1996

Increase in the 8-hydroxyguanine repair activity in the rat kidney after the administration of a renal carcinogen, ferric nitrilotriacetate.

One type of oxidative DNA damage, 8-hydroxyguanine (8-OH-Gua), is known to increase in rat kidney DNA after the administration of a renal carcinogen, ferric nitrilotriacetate (Fe-NTA). To determine the involvement of oxygen radicals in Fe-NTA carcinogenesis, we examined whether the 8-OH-Gua repair enzymes are induced in the rat kidney after Fe-NTA administration, in addition to our analysis of the 8-OH-Gua levels in the DNA, because the 8-OH-Gua repair activity is known to be induced in mammalian cells by oxidative stress due to ionizing radiation. The 8-OH-Gua repair enzyme activity was determined with an endonuclease assay using a 22-mer double strand DNA, which contains 8-OH-Gua at a specific position. A significant increase in the 8-OH-Gua repair activity was observed in the rat kidney after a single intraperitoneal injection of Fe-NTA (p < 0.01). This is the first report on the induction of the repair activity for 8-OH-Gua after treatment with a chemical carcinogen. This assay will be useful for evaluating the carcinogenicity of oxygen radical-forming chemicals.

Animals↗
PubMed1996

Role of protein phosphatase in malignant osteogenic and soft tissue tumors.

The expression of the three catalytic subunits of protein phosphatase (PP) type 1 and 2A, PP1 alpha, PP1 gamma 1, and PP2AC, was examined in osteogenic tumors and soft tissue tumors by immunohistochemical analysis. The percentage of cells stained positively with antiserum against PP1 catalytic subunit isoform PP1 gamma 1, was significantly higher in malignant osteogenic tumors (chondrosarcoma, osteosarcoma, and Ewing's sarcoma) and in malignant soft tissue tumors (liposarcoma and malignant fibrous histiocytoma [M.F.H.]) than in benign tumors (osteochondroma, osteoblastoma, ossifying fibroma, enchondroma and lipoma). Furthermore, the malignant tumor lesions showed a markedly high number of cells in the S-phase fraction of the cell cycle, as compared to benign tumors. These results suggest that PP1 gamma 1 is involved in the accelerated growth of malignant tumor cells.

Bone Neoplasms↗
PubMed1995

[The histological changes in the spinal cord following percutaneous cervical cordotomy (PCC) and correlation of these changes with the efficacy of PCC].

We observed the histological changes in the spinal cord following percutaneous cervical cordotomy (PCC) and correlation of these changes with the efficacy of PCC in 7 cases. A fine monopolar electrode which we used, measured 0.25 mm or 0.27 mm in diameter with exposed length of 2 mm. An oval or elliptical-shaped lesion, 1 to 3 mm in width and 3 to 4 mm in length, was observed in 6 of these cases. The main lesion was found in the anterolateral column in 5 cases. In 3 of these 5 cases, the whole anterolateral column had been destroyed, and in the other 2 cases dorsal one half to two thirds of it had been destroyed. In these 5 cases, pain sensation on the opposite side of PCC was lost for a long time and pain was relieved until death (21-239 days after PCC). In the other 2 cases the lesion in the anterolateral column was tenuous or unrecognizable, and the loss of pain sensation was temporary with pain recurring by the next day. This study showed that an oval or elliptical-shaped lesion was made in PCC and that in cases in which main lesion was located in the anterolateral column, pain relief was long lasting.

Adult↗
PubMed1995

Seton treatment for perianal Crohn's fistulas.

In this study, we evaluated the efficacy of long-term seton drainage in the management of 13 patients with severe perianal Crohn's fistulas which had proven to be intractable to conventional therapy. After adequate curettage of the fistulous tracts and infected tissue, either a Penrose drain or a fine polyethylene catheter was inserted to encircle the tracts and tied. Patients were followed up for a mean period of 12.1 months. Perianal pain disappeared or improved in all 13 patients, while the body temperature of all 7 with pyrexia dropped to within the normal range. Discharge disappeared or diminished in 77% (10/13) and tenderness disappeared or improved in 77% (10/13). Induration disappeared or improved in 69% (9/13). Overall, good results were achieved in 10 patients, although 3 required redrainage. In one of these patients, a good result was achieved after colostomy was performed for active intestinal disease. Nevertheless, 2 patients did not improve, one of whom required lay-open surgery after seton treatment. In 8 of the 13 patients, some seton drains were able to be removed, and none of the patients experienced any soiling or leakage. Thus, we conclude that seton treatment is worthwhile in the management of perianal Crohn's fistulas as it alleviates the symptoms and simplifies multiple tracts. Moreover, it preserves sphincter function, is less invasive, and can be managed easily.

Adult↗
PubMed1995

Cytochrome P4501A1 gene polymorphism and homozygous deletion of the glutathione S-transferase M1 gene in urothelial cancer patients.

Japanese urothelial (bladder, renal pelvis and ureter) cancer patients (n = 83) and community controls (n = 101) were compared for rates of polymorphism in exon 7 of the cytochrome P4501A1 (CYP1A1) gene or homozygous deletion of the glutathione S-transferase class mu (GSTM1) gene. A CYP1A1 polymorphism was detected in a HinCII polymorphism assay utilizing a primer with a single base pair mismatch. The frequency distribution of the CYP1A1 genotypes in urothelial cancer patients showed no significant difference from that in healthy controls. The increased frequency of homozygous deletions of GSTM1 gene loci in patients with urothelial cancer was statistically significant compared with the controls, 51 of 83 (61%) and 43 of 101 (43%) (odds ratio = .2.15, 95% confidence interval = 1.18-3.86). These results lead us to conclude that homozygous deletion of the GSTM1 gene may be associated with susceptibility to urothelial cancer.

Adult↗
PubMed1995

Observations on the growth rate of renal cell carcinoma.

We retrospectively reviewed the records of 18 patients to investigate the growth rate of renal cell carcinoma (RCC). Growth rates were calculated from two or more gross measurements of neoplastic foci in the kidney (6 cases) and lung (12 cases). RCCs in primary sites grew slowly and the tumor volume doubling time (DT) raged from 372 to 579 days (468 +/- 84.6). Pulmonary metastases present in 12 cases grew rapidly, with a DT ranging from 20 to 154 days (89.4 +/- 43.0). Tumors in both the kidney and lung were composed of cancer cells with equal proliferative activity, as determined by immunohistochemical analysis of argyrophilic nucleolar organizer regions and proliferating cell nuclear antigen activity. Thus, our results suggest that, in addition to the proliferative activity of cancer cells, the microenvironment of the specific region is an important determinant of the growth rate of cancer cells.

Adult↗
PubMed1995

[A survey of the inclinations of medical students towards becoming occupational physicians].

We conducted a survey to investigate medical students awareness of the activities of occupational physicians and their willingness to do postgraduate courses in this field. Those surveyed were fifth grade students in six universities in the Kinki district of Japan in 1993. In analyzing the responses of 368 eligible subjects, the response rate was 68.4% and the following results were obtained. 1) Only one of the 368 subjects expressed a desire to become an occupational physician after graduation, however 24.2% of those surveyed had considered becoming occupational physicians. More female students and, males over the age of 25, had considered becoming occupational physicians. Anxiety about a possible surplus of medical doctors in the near future was a factor that led them to consider becoming occupational physicians. 2) There were few negative responses concerning the activities of occupational physicians, even among those who had not considered becoming occupational physicians. 88.3% of those surveyed complained of a lack of information regarding postgraduate courses. 3) Responses were varied concerning conditions in the practice of occupational physicians. Those who had considered becoming occupational physicians were mostly concerned with the establishment of a system for the acceptance of occupational physicians in industry, while those who had not thought of becoming occupational physicians, considered practicing as occupational physicians as a sideline to regular clinic duties. 4) Having considered the above results and those of other researchers, we concluded that supplying more information related to the activities of occupational physicians and offering further postgraduate training programs in occupational medicine would encourage more medical students to become occupational physicians.

Career Choice↗
PubMed1995

Surgery for Crohn's anal fistulas.

The aim of this study was to analyze the features of Crohn's anal fistulas and to evaluate the efficacy of seton treatment. In 119 patients with Crohn's disease, the incidence of anal fistula was 56% (67/119), with no significant difference in the incidence among patients with ileitis, colitis, and ileocolitis. "Intractable" anal fistulas were found in 17% of patients with ileitis, compared to 64% of those with colitis (P = 0.051) and 68% of those with ileocolitis (P = 0.014). Seton treatment, i.e., non-cutting, long-term seton drainage, was performed for 21 patients (5 with intersphincteric, and 16 with transsphincteric fistulas). In the 16-month follow up, 9 patients required redrainage for recurrent fistulous abscess, mainly because of progressive colorectal disease. Finally, a good result was obtained in 17 of the 21 patients (81%) and no recurrent fistulous abscess developed in the 8 patients in whom all setons were removed. Anal continence was preserved in all the patients. These results indicate that anal fistulas with Crohn's ileitis were cured more easily than those with colitis or ileocolitis, and that seton treatment was effective for intersphincteric fistula with multiple fistula openings and for transphincteric fistulas in patients exhibiting remission of intestinal Crohn's disease.

Crohn Disease↗
PubMed1994

[Theoretical analysis about an optimal screening interval for renal cell carcinoma].

In recent years the number of incidentally detected renal cell carcinoma (RCC) has increased. It is undoubtedly true that ultrasonography is the most useful tool to detect RCC in small size. However, the optimal interval of ultrasound examination is unknown. To elucidate this, we investigated the growth rate of RCC during the period of non-treatment in 6 patients. Their growth was slow and the tumor volume doubling time ranged 372 to 579 (468 +/- 84.6) days. Based on this growth rate, we conclude that we can detect the majority of RCC ranging from 1.5 to 3 cm in diameter if ultrasonography is repeated every 3 years and that the age of subjects for screening is over 40 years.

Adult↗
PubMed1993

Survival with colorectal cancer in ulcerative colitis. A study of 102 cases.

OBJECTIVE: This study was undertaken to correlate postoperative survival of patients with ulcerative colitis-associated colorectal cancer with the stage, configuration, size, and mucin content of the tumor. SUMMARY BACKGROUND DATA: The factors influencing prognosis in colorectal cancer in the general population are well accepted, but less is known about their influence in cases of colorectal cancer associated with ulcerative colitis. METHODS: The authors reviewed the records of 102 patients with ulcerative colitis-associated colorectal cancer admitted to The Mount Sinai Hospital between 1959 and 1988. Tumors were classified on independent pathologic review according to histologic stage, configuration, size, and mucin content. Comparisons among survival curves were tested by the generalized Wilcoxon test. Cox regression models were used to examine the joint effects of selected clinicopathologic features on postoperative survival rates. RESULTS: Complete follow-up was obtained for 93 patients (92%). Overall 5-year actuarial survival was 52%. When factors were analyzed one at a time, survival was significantly poorer among patients with advanced cancer stage, larger tumor size, infiltrating and ulcerating configuration, and high mucin concentration. On multivariate analysis by the Cox regression model, however, only cancer stage emerged as a factor independently predicting survival. CONCLUSIONS: For colitis-associated colorectal cancers, as for noncolitic cancers, histologic stage is the most important variable determining postoperative survival. The distribution of stages in our series and the survival rates within each stage did not differ appreciably from the distributions and survival rates reported for noncolitic colorectal cancers.

Adult↗
PubMed1993

[Postoperative recurrence form of Crohn's disease: comparison between perforating and non perforating types].

Postoperative recurrence rate and recurrence form were analyzed in two clinical forms of Crohn's disease at primary resection, one of which was perforating and the other was non perforating. Forty four patients with Crohn's disease were included in this study, 18 of them were perforating type and 26 were non perforating type. Crude recurrence rates were 39% (7/18 cases) in perforating type group and 54% (14/26 cases) in non perforating type group, which were not significantly different. Cumulative recurrence rates 5 years after initial operation were 58% in perforating type group and 47% in non perforating group without statistically significance. The recurrence form was perforating type more frequently in perforating type group (86%) than non perforating group at primary resection (29%) with statistically significance (p = 0.013). Postoperative recurrence form had a tendency to be similar to the form at primary resection. It was suggested from this study that Crohn's disease had two different disease entities; perforating and non perforating types and that postoperative recurrence should be examined carefully from the view of primary resection.

Adolescent↗