Biomedical subjects

H Nakano

Publications and source records attributed to H Nakano.

At least 19 recordsLinked to original sources

PubMed1992

Induction of mammalian DNA topoisomerase I mediated DNA cleavage by antitumor indolocarbazole derivatives.

DNA topoisomerases have been shown to be important therapeutic targets in cancer chemotherapy. We found that KT6006 and KT6528, synthetic antitumor derivatives of indolocarbazole antibiotic K252a, were potent inducers of a cleavable complex with topoisomerase I. In DNA cleavage assay using purified calf thymus DNA topoisomerase I and supercoiled pBR322 DNA, KT6006 induced topoisomerase I mediated DNA cleavage in a dose-dependent manner at drug concentrations up to 50 microM, while DNA cleavage induced by KT6528 was saturated at 5 microM. The maximal amount of nicked DNA produced by KT6006 was more than 50% of substrate DNA, which was comparable to that of camptothecin. Heat treatment (65 degrees C) of the reaction mixture containing these compounds and topoisomerase I resulted in a substantial reduction in DNA cleavage, suggesting that topoisomerase I mediated DNA cleavage induced by KT6006 and KT6528 is through the mechanism of stabilizing the reversible enzyme-DNA "cleavable complex". Both KT6006 and KT6528 did not induce topoisomerase II mediated DNA cleavage in vitro. KT6006 and KT6528 were found to induce nearly identical topoisomerase I mediated DNA cleavage patterns, which was distinctly different from that with camptothecin. In contrast to the similarity between KT6006 and KT6528 in their structures and the nature of their cleavable complex with topoisomerase I, these drugs have different properties with respect to their interaction with DNA: KT6006 is a very weak intercalator whereas KT6528 is a strong intercalator with potentials comparable to that of adriamycin. These results indicate that KT6006 and KT6528 represent a new distinct class of mammalian DNA topoisomerase I active antitumor drugs.

Animals↗

PubMed1992

Antitumor quinolones with mammalian topoisomerase II mediated DNA cleavage activity.

Ninety quinolones were evaluated to determine whether their ability to induce mammalian topoisomerase II mediated DNA cleavage in vitro correlated with their antitumor activity in vivo. Ten quinolones generated linear DNA at a yield of more than 10% of substrate supercoiled DNA in the mammalian topoisomerase II mediated DNA cleavage assay. All of these compounds showed a significant increase in life span (greater than 20%) in the murine leukemia P388 model. These antitumor quinolones have closely related structures: two halogens at C-6 and C-8; and cyclopropyl at N-1 of quinolone skeleton. In contrast, many analogues of the above quinolones, as well as new quinolones used clinically as an antibacterial drug, did not induce the cleavable complex in vitro or show antitumor activity in vivo. These findings indicate that quinolone derivatives can be a promising new class of antitumor agent targeting mammalian topoisomerase II.

Animals↗

PubMed1992

D-galactosamine-induced cell damage enhances specific binding of prostaglandin E1 to rat hepatocytes.

Specific bindings of [3H]prostaglandin E1 ([3H]PGE1), 125I-glucagon and [3H]norepinephrine to D-galactosamine (GalN)-treated rat hepatocytes in primary culture were investigated. After a two hour-treatment with GalN (1 and 10mg/ml), hepatocytes showed an enhanced specific binding to [3H]PGE1, whereas 125I-glucagon binding was little affected and [3H]norepinephrine binding was strongly diminished. Scatchard plot analysis indicated an increase of binding sites of [3H]PGE1. This unusual manner of [3H]PGE1 binding is suggested to indicate a special property of PGE1 receptor and may be associated with the cytoprotective effect of prostaglandins.

Alprostadil↗

PubMed1992

Multivariate analysis of the histopathologic prognostic factors of cervical cancer in patients undergoing radical hysterectomy.

Three hundred forty-five patients with invasive carcinoma of the uterine cervix, Stages Ib (211 patients) and II (134 patients), underwent radical hysterectomy and pelvic lymphadenectomy. The influence of histologic factors including histologic subtype, maximum depth of cervical stromal invasion, degree of stromal invasion, longitudinal tumor diameter, lymph-vascular space invasion, corpus invasion, parametrial invasion, vaginal invasion, and pelvic lymph node (PLN) metastases on survival were examined by multivariate analysis. Univariate analysis revealed that all the variables except corpus invasion and vaginal invasion were significant in survival (P less than 0.05). Among these variables, however, PLN metastases, histologic subtype, and longitudinal tumor diameter were identified as independent and significant prognostic factors by multivariate analysis using Cox regression models. The prognostic index (PI), defined by the model (an indicator of the patient's place in the prognostic spectrum), was able to divide the patients into three prognostic groups. The key factors in the definition of these groups were (1) squamous cell carcinoma, small tumor diameter, and no PLN metastases for the good prognostic group and (2) PLN metastasis in two or more node groups, adenocarcinoma with one positive PLN group, or squamous cell carcinoma with one PLN group and large diameter for the poor prognostic group. These prognostic findings could predict the prognosis more precisely than that of clinical staging.

Adult↗

PubMed1992

Secretion of genetically-engineered dihydrofolate reductase from Escherichia coli using an E. coli alpha-hemolysin membrane translocation system.

Secretion of fusion proteins composed of cytoplasmic protein dihydrofolate reductase (DHFR) and the Escherichia coli alpha-haemolysin (HlyA) C-terminal sequence was examined through the haemolysin secretion machinery of E. coli. DHFR of various lengths was combined with the HlyA C-terminal region, and both secretion and DHFR activity of the fusions were measured. The secretion was found to be inversely correlated with the intracellular DHFR activity. Moreover, when one amino acid (Ile155) in a beta-sheet of the DHFR C-terminal region was replaced with Lys, the enzymatically active DHFR fusion protein was secreted into the medium. We discuss the possibility of a relationship between folding and secretion of HlyA-fused protein in the HlyA secretion system.

Amino Acid Sequence↗

PubMed1992

A scintigraphic analysis of colonic movement in patients with colostomy: changes of colonic transit time after acquaintance with irrigation.

For the purpose of making a functional assessment of colostomy irrigation, eight patients were examined. Group A was composed of four patients whose experience of irrigation was less than one year. Group B was composed of four patients who had undergone irrigation for more than two years. The capacity of the remnant colon was determined by a barium enema. Next, 74 MBq of milking technetium 99 diethylene triamine penta-acetic acid (99mTc-DTPA) was instilled with a predetermined amount of water (37 degrees C). A dynamic scan was performed for 45 min. The mean evacuation time of Groups A and B were 6 min 56 s +/- 2 min 33 s and 13 min 27 s +/- 10 min 50 s, respectively. The mean half emptying time of Groups A and B were 142.5 s +/- 7.9 s and 309.0 s +/- 181.9 s. The results suggest that the remnant colon may be habituated with irrigation. Colostomy irrigation which uses a single instillation of a measured volume of tepid water is recommended.

Adult↗

PubMed1992

Focal nodular hyperplasia of the liver.

We present herein two successfully treated cases of focal nodular hyperplasia (FNH) of the liver, a relatively rare disease. Case 1 was a 3 year old child in whom typical FNH developed in the left lateral segment of the liver, whereas Case 2 was a 22 year old man in whom characteristic findings were lacking on preoperative diagnostic imaging. Scintigraphy was not performed in either case, however, postoperative histological examination confirmed FNH. Thus, in patients with a hypervascular tumor and normal liver function, FNH should be strongly suspected and a series of scintigraphy proposed. Both cases showed a negative association with oral contraceptive intake but no other obvious etiology was suggested.

Adult↗

PubMed1992

Intestinal tuberculosis: findings on double-contrast barium enema.

Seven cases of intestinal tuberculosis in an active stage were studied by the double-contrast barium enema (DCBE) method. Formerly, diagnosis of intestinal tuberculosis in the early stage by single-contrast barium enema (SCBE) and barium meals was based on functional phenomena, such as spasm and hypermotility of the ileocecal region. Presently, this can be better accomplished by DCBE. DCBE enables the detection of shallow ulcers with their characteristic elevated margins. These ulcers are frequently slim and transversally oriented. Confluence of ulcers may create whole girdle ulcers or affect entire segments. In more advanced stages, characteristic deformities, also evident by SCBE, such as symmetrical annular stenoses, shortening, retraction, pouch formation, and the frequently observed pathology of the ileocecal valve and the cecal region, acquire a new dimension with DCBE.

Acquired Immunodeficiency Syndrome↗

PubMed1992

Incidence of anti-HTLV-1 antibody in liver disease.

Positivity for serum anti-HTLV-1 antibody (anti-HTLV-1) in 171 patients with various chronic liver diseases and 22 asymptomatic hepatitis B virus (HBV) carriers was compared with that of 200 healthy controls in the Chikugo district of Japan. The rate of anti-HTLV-1 positivity in patients with liver disease was 8.1% (14/171) and was higher than that (3.5%: 7/200) in healthy controls, but the difference was not significant. However, in patients with liver disease with a history of blood transfusion, the positive rate was 18.4% (7/38) which was significantly higher than that for healthy subject (P less than 0.001). On the other hand, in 133 liver disease patients without blood transfusion, anti-HTLV-1 positivity was significantly higher (P less than 0.05) in patients with hepatitis B surface antigen (11.3%: 6/53) than in those without it (1.3%: 1/80). These data suggest that the high incidence of anti-HTLV-1 in our patients with liver disease was due to the transmission of HTLV-1 by the same routes (maternal transmission and blood transfusion) and probably at the same time as the hepatitis viruses (HBV and hepatitis C virus).

Adult↗

PubMed1992

Condyloma acuminatum in three-year-old girl.

Condyloma acuminatum has been thought to be rare in the pediatric age group because the mode of transmission is venereal. We report a case of a three-year-old girl with condyloma acuminatum. Mode of transmission of a viral agent and factors predisposing to infection are presented.

Child, Preschool↗

PubMed1992

Malignant mixed Müllerian tumor of the fallopian tube: report of two cases and review of literature.

Malignant mixed Müllerian tumors are usually found in the endometrium, vagina, cervix, and ovary. It is extremely rare for this tumor to arise in the fallopian tube, and to date only 37 tubal cases have been reported. We recently experienced 2 such cases. The clinical features, pathologic findings, diagnosis, therapy, and outcome of these 39 cases were reviewed. The clinical features and diagnosis were similar to those of primary carcinoma of the fallopian tube. Correct preoperative diagnosis was difficult. Histologically, 18 patients had homologous elements and 21 had heterologous elements in the sarcomatous components. The most common type of heterologous element was cartilage, followed by striated muscle and bone. The clinical stage (FIGO staging of ovarian carcinoma) was stage I in 15 cases, stage II in 11 cases, stage III in 8 cases, stage IV in 3 cases, and unknown in 2 cases. In all the patients except 1, the tumor was surgically removed. Postoperatively, radiotherapy was given to 9 patients, chemotherapy to 9 patients, and both to 2 patients. Sixteen patients died of the disease, after a mean period of 16.1 months. Of the 15 stage I patients, 10 survived more than 12 months. The most important prognostic factor was spread of the tumor at diagnosis.

Adolescent↗

PubMed1992

Fine-needle aspiration cytology in patients with gynecologic malignancies.

Four hundred five fine-needle aspiration (FNA) cytologies were obtained from 352 sites in 287 patients with gynecologic malignancies. The majority of specimens were aspirated for recurrent or metastatic disease. The most common clinical diagnosis was cervical carcinoma (128 cases) followed by ovarian carcinoma (80 cases) and others (79 cases). The sites of FNA were lymph node (134 cases), retroperitoneal lymphocyst (57 cases), pelvic mass (52 cases), subcutaneous mass (34 cases), and others (75 cases). Of 335 sites excluding inadequate specimens, 162 (48.4%) revealed malignant cells. There was no difference in the accuracy of FNA between diseases in the superficial sites and those in the deep sites. However, the sensitivity for local recurrent diseases was lower than that for primary or metastatic diseases (86.4% vs 100.0%). The overall accuracy of FNA cytology was 95.2%, and it was satisfactory for the diagnosis of gynecologic malignant diseases. FNA should be repeated if the initial FNA specimen is inadequate for diagnosis. When distinct malignant cells are observed in FNA cytology, a biopsy may be omitted.

Biopsy, Needle↗

PubMed1992

Detection of Clostridium botulinum in natural sweetening.

Various sugar products were examined for contamination with C. botulinum spores. Type A, B and C spores were detected in three of 56 samples of sugar for apiculture, which may attest the significance of bee-feed as a source of contamination of honey. The heavy contamination of honey with C. botulinum spores sometimes encountered, however, can not be explained unless some other factors, e.g., that allowing germination and multiplication of the spores somewhere during honey production, are found. Type A spores were detected in some samples of raw sugar and molasses and also in two of 41 samples of brown sugar lump, but not in refined sugar or other various samples taken at a sugar factory or in sugar cane left on the field in Okinawa. The fact that some natural sweetenings are contaminated with C. botulinum spores, even in low concentrations, may be food-hygienically important.

Animals↗

PubMed1992

The temporal relationship between the onset of rapid eye movement period and the first micturition thereafter in the human fetus with advance in gestation.

The objective of this study was to investigate whether micturition occurs, temporally related to the onset of the rapid eye movement (REM) period, in the human fetus. The study was made on 139 fetuses at 33-36 weeks and 153 at 37-41 weeks gestation. The discrepancies between the expected (F(exp)) and observed (F(obs)) frequencies of time lag between the onset of the REM period and the first micturition thereafter were assessed using the goodness-of-fit test. At 33-36 weeks gestation, there was no statistical difference between F(obs) and F(exp) (P greater than 0.05). At 37 weeks onwards, however, significant differences were noted between F(obs) and F(exp) (P less than 0.005). Seventy-two percent of all micturitions occurred within eight minutes after the onset of the REM period. This indicates that there is a temporal relationship between the onset of the REM period and the first micturition thereafter, at term, during 37-41 weeks of gestation.

Embryonic and Fetal Development↗

PubMed1992

Regional differences of phospholipase A2 activity in the rabbit oviductal epithelium.

To evaluate the biosynthesis of prostaglandins in the oviducts, phospholipase A2 (EC 3.1.1.4) activities were first measured in the epithelial cells obtained from rabbit oviducts. At least four kinds of phospholipase A2 (PLA2) activities with respect to calcium dependency and pH requirement were observed. There were two calcium-dependent, pH optima of 7.5 and 8.5 activities, and two calcium-independent, pH optima of 4.0 and 8.0 activities. One of those activities, a calcium-dependent and alkaline active PLA2 activity of the epithelial cells was then compared between the ampullary portion and the isthmic portion of the oviducts. The activity was significantly higher in the ampullary epithelium than in the isthmic epithelium (223.2 +/- 57.2 or 103.8 +/- 32.3 pmol/min/mg, p < 0.05). These results support the idea that the production of prostaglandins, which is dependent upon the activity of the arachidonate cascades, was higher in the ampullary portion of oviduct than that in the isthmic portion. The PLA2 activity of the ampullary epithelium may thus play an important role in the regulation of smooth muscle contractility and ciliary movement.

Animals↗

PubMed1992

Changes in pupillary diameter in relation to eye-movement and no-eye-movement periods in the human fetus at term.

OBJECTIVE: The aim of our study was to reveal whether pupils dilate and constrict in a time sequence in the human fetus and to assess the relationship between changes in pupillary diameter and eye-movement-no-eye-movement periods. STUDY DESIGN: We simultaneously observed pupil and eye movement with real-time ultrasonography in 30 human fetuses at 36 to 41 weeks' gestation. Eighteen were excluded because of data loss. Statistical analysis of pupillary diameter changes were made on the remaining 12 fetuses with the least median of squares regression. RESULTS: Pupillary diameters were found to be differentiated with statistical significance into two groups: 9.7% for the dilated pupil (median 3.0 mm) and 90.3% for the constricted pupil (1.7 mm). The percentage of dilated pupils during the eye-movement period (14.3%) was significantly greater than that during the no-eye-movement period (2.3%; Wilcoxon rank sum test, p < 0.0001). CONCLUSION: These findings indicate a close relation between pupillary dilatation and eye-movement periods in the human term fetus.

Eye Movements↗

PubMed1992

Efficacy of a low-dose leuprolide acetate depot in the treatment of uterine leiomyomata in Japanese women.

OBJECTIVE: To compare the efficacy of two different doses, 1.88 mg and 3.75 mg, of a monthly depot injection of a gonadotropin-releasing hormone agonist (GnRH-a) in the treatment of uterine leiomyomata. DESIGN: A prospective randomized study. SETTING: Hospital department of gynecology and obstetrics. PATIENTS: Forty-one premenopausal Japanese women, 25 to 53 years of age, with uterine leiomyomata. INTERVENTIONS: Depot type of GnRH-a, leuprolide acetate (LA) 1.88 mg or 3.75 mg was administered subcutaneously every 4 weeks for 24 weeks. MAIN OUTCOME MEASURES: Efficacy of treatment was assessed in terms of uterine volume, serum levels of estradiol (E2), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and adverse symptoms during treatment. RESULTS: In both groups, a significant reduction in uterine volume, 52% in 1.88 mg group and 47% in 3.75 mg group, was obtained at week 24, with near maximal reduction (41%, 45%) apparent by 12 weeks. No significant difference was observed between the groups in percent uterine volume reduction at each treatment week. Both groups showed significant and equal suppression of serum levels of E2, LH, and FSH. In addition, the incidence of adverse symptoms was not significantly different between the two groups. CONCLUSIONS: Monthly injection of 1.88 mg or 3.75 mg LA depot has equivalent treatment efficacy in reducing uterine volume. Twelve weeks of treatment is enough to obtain near maximal reduction.

Adult↗

PubMed1992

The characteristics of erythrocyte Na+ transport systems in normal pregnancy and pregnancy-induced hypertension.

OBJECTIVE: To assess the role Na plays in the pathogenesis of pregnancy-induced hypertension (PIH). METHODS: We assessed Na and K content, the maximum number of ouabain binding sites, Na(+)-Li+ countertransport and Na(+)-K+ cotransport in erythrocytes from women with untreated PIH, normal pregnant women and healthy non-pregnant women. RESULTS: In normal pregnancy, the Na content of erythrocytes decreased, accompanied by the activation of Na excretion systems. In women with PIH, the Na content of erythrocytes and the Na(+)-K+ cotransport activity significantly increased, whilst erythrocyte K content and the maximum number of ouabain binding sites significantly decreased, compared with observations in normal pregnancy. In both normal pregnancy and PIH, there were no differences in Na(+)-Li+ countertransport. CONCLUSIONS: These results suggest that the increase of erythrocyte Na content in women with PIH may be contributed to by a reduction in the number of ouabain binding sites, whilst Na(+)-K+ cotransport and Na(+)-Li+ countertransport may compensate for this effect in women with PIH.

Adult↗