Biomedical subjects

M Iwabuchi

Publications and source records attributed to M Iwabuchi.

148 records · Page 9Linked to original sources

PubMedDate not supplied

Individual variation in semen parameters of healthy young volunteers.

Individual variation in semen parameters was investigated in healthy young volunteers. Semen samples were collected approximately once a month over a one-year period for a total of 93 samples (5 to 10 samples per subject) from 12 volunteers in their twenties. Semen analysis was carried out according to the WHO Manual. The amount of variation in each semen variable was calculated for each subject by dividing the maximum value by the minimum value. The results showed that the semen volume varied by 1.9+/-0.8 fold (1.3 to 4.2 fold), the sperm concentration by 4.8+/-4.3 fold (1.5 to 17.2 fold), the percentage of sperm with forward progression by 2.8+/-1.4 fold (1.6 to 6.4 fold), the percentage of sperm with rapid linear progression by 3.4+/-2.6 fold (1.7 to 10.9 fold), the percentage of sperm with normal morphology by 1.9+/-0.4 fold (1.3 to 2.4 fold), and the percentage of live sperm by 1.5+/-0.4 fold (1.1 to 2.6 fold). A between-group comparison showed significant differences in all of the variables except the percentage of sperm with normal morphology. These results suggest multiple and considerable semen analyses are needed when evaluating semen parameters.

Adult↗

PubMedDate not supplied

XX-male syndrome bearing the sex-determining region Y.

The case of a 25-year-old man who presented for evaluation of infertility is described. The physical examination revealed testicular atrophy without gynecomastia. Repeated seminal analyses showed azoospermia, and serum hormonal levels suggested a state of a hypergonadotropic hypogonadism. Chromosomal analysis demonstrated 46XX. Polymerase chain reaction revealed the existence of a sex-determining region Y. The etiology of this rare sex reversal syndrome is discussed and cases reported in Japan are reviewed.

Adult↗

PubMedDate not supplied

Immunohistochemistry of DNA fragmentation factor in human stomach and colon: its correlation to apoptosis.

DNA fragmentation factor (DFF) is an important factor in the pathway leading to apoptosis, which is activated by caspase-3 and is involved in the formation of nuclear DNA fragments. DFF is a heterodimic protein of 40kDa and 45kDa that becomes activated when DFF is cleaved by caspase-3. Of the two enzymatically cleaved fragments of DFF, it is the 40kDa fragment (DFF40) that is the active component of DFF and is responsible for triggering chromatin condensation when incubated with nuclei. However, the topological correlation between apoptosis and DFF expression in human tissues has not been examined. Therefore, in this study, we first immunolocalized DFF in non-neoplastic mucosa, hyperplastic polyp, adenoma and carcinoma of human stomach and colon. We then examined apoptosis in serial tissue sections. Labeling index (LI) of DFF and TUNEL positive cells in the same areas of serial tissue sections were obtained using computer-assisted image analysis. In the stomach, the DFF LI in non-neoplastic mucosa (9.8 +/- 5.0%, n = 3) and carcinoma (18.2 +/- 3.6, n = 3) were significantly lower than that of hyperplastic polyp (73.3 +/- 9.2%, n = 3) and adenoma (66.5 +/- 18.3%, n = 3) [p < 0.0001]. In colon, the DFF LI in non-neoplastic mucosa (10.2 +/- 6.4%, n = 3) was significantly lower than that of hyperplastic polyp (56.0 + 34.7%, n = 3) [p = 0.0013] and adenoma (30.1 +/- 16.3%, n = 3) [p = 0.0037]. Cells positive for DFF were much more widely distributed than TUNEL positive cells in both non-pathologic and pathologic mucosa of human stomach and colon. Notably, DFF positive cells were present beneath the TUNEL positive cells in non-pathological gastric and colonic epithelium. In addition, there was a significant positive correlation between DFF and TUNEL LIs in human stomach and colon [p < 0.0001]. These results suggest that DFF may be involved in the process of apoptosis in human gastric and colonic mucosa.

Apoptosis↗

PubMedDate not supplied

Serrated adenoma: a clinicopathological, DNA ploidy, and immunohistochemical study.

AIMS: Serrated adenoma (SA) is a relatively newly defined entity of colorectal neoplasm. In this study, we examined the cell proliferation, DNA ploidy, and clinicopathological features of SA in order to investigate its biological features. METHODS AND RESULTS: We reviewed 10,532 polypectomy specimens of the colorectum obtained from Japanese cases between 1974 and 1998 at Tohoku University Hospital. In total, 193 cases of SA were detected. We first examined clinical features of these cases by reviewing the charts, and then studied cell proliferation using immunohistochemistry of Ki-67 and topoisomeraseIIa, p53 immunoreactivity and DNA ploidy. Results were subsequently compared with those of tubular adenoma (TA) and hyperplastic polyp (HP). Mean size of SA (8.6 +/- 4.6 mm) was significantly larger than those of TA (7.3 +/- 4.6 mm) and HP (5.6 +/- 3.0 mm). More than 80% of SA were protuberant in macroscopic appearance. SA was located predominantly in the sigmoid colon and rectum. Incidences of concomitant carcinoma in HP, SA and TA were 0.4% (1 out of 263), 4.1% (8 out of 193) and 10.3% (809 out of 7838), respectively. Labeling indices for Ki-67 and topoisomeraseIIa in HP, SA and TA were as follows: Ki-67--24.2%, 30.8%, 39.5% and topoisomeraseIIa--15.3%, 16.1%, 23.9%, respectively. In SA, p53 immunoreactivity was detected in the intramucosal carcinoma co-existing with the serrated component. Two out of the ten SA cases examined demonstrated non-diploid patterns of DNA ploidy. CONCLUSION: SA is a distinct colorectal neoplastic lesion with the potential of malignant transformation similar to that of tubular adenoma.

Adenoma↗