PubMed Health⌕ Search

Biomedical subjects

H Iwasawa

Publications and source records attributed to H Iwasawa.

At least 37 records · Page 2Linked to original sources
PubMed1990

Tracheostomy--the horizontal tracheal incision.

The complication rate after emergency tracheostomy is two to five times greater than after elective procedures. One of the main causes of the high risk of complications in emergency tracheostomy appears to be the amount of time required to open the trachea. Therefore, simple and fast procedures are mandatory. We have developed a new procedure as follows: A horizontal skin incision is performed. Strap muscles are dissected and retracted laterally. A transverse cut between tracheal rings below the thyroid isthmus is performed up to membranous portion of the trachea. The cut ends of the trachea remain open naturally because of the elasticity of the trachea. Skin and tracheal cut-ends are then joined by interrupted sutures. We have used this procedure during the past three years and have not experienced any major complications. This demonstrates the clear advantage and the more physiological nature of the procedure over various other incisions of the tracheal wall.

Adult↗
PubMed1989

Gonadotropin-induced luminal formation in the seminiferous tubules and efferent ductules in young frogs: light and electron microscopic study.

To clarify the mechanism of fluid secretion in the testes at the time of gonadotropin-induced spermiation, young Rana nigromaculata were used. As a morphological index of fluid secretion, luminal formation of the seminiferous tubules, and efferent ductules were observed. The following changes were seen by the administration of hCG or frog pituitary: first, the luminal formation of the seminiferous tubules was seen; next, tubular expansion became evident, and finally, luminal formation and expansion were observed in the efferent ductules. These changes were preceded by the separation of cell contact among Sertoli cells and of cell contact between Sertoli cells and the cells of efferent ductules only in the center and the swelling of Sertoli cells and cells of efferent ductules. With regard to the flow of fluid at the time of spermiation, the present results indicate the possibility that there is a difference in the ability for fluid secretion between Sertoli cells and the ductule cells.

Animals↗
PubMed1989

Origin of somatic cells and histogenesis in the primordial gonad of the Japanese tree frog Rhacophorus arboreus.

Gonadal development in Rhacophorus arboreus, a sexually semidifferentiated type of tree frog, was observed by means of the electron microscope, and cell proliferation kinetics were examined autoradiographically. The genital ridge consisted of coelomic epithelial cells and primordial germ cells. The gonadal medulla was formed by the segregation of epithelial cells within the primordial gonad. Thereafter, the medullary cell mass was well developed and oogenesis began in the gonadal cortex, irrespective of genetic sex. During metamorphosis, the ovarian cavity was formed in the medullary mass. This ovarian structure developed further in females. In males, on the other hand, a layer of medullary cells comprising the epithelium of the ovarian cavity proliferated rapidly and reformed a large cell mass. The degeneration of ovarian follicles and the formation of cell cords (rudimentary seminiferous tubules) were seen in the cortex. These cell cords were separated from the superficial epithelium and continued to the medullary mass (rudimentary testicular rete). These results clearly indicate that both the cortical and medullary cells are derived from the coelomic epithelium and that the development of the cortex and medulla is not always antagonistic in the course of sexual differentiation.

Animals↗
PubMed1989

[Experimental study on the eye movements induced by the electrical stimulation of the cerebellar nucleus in the rabbit].

The purpose of this study is to investigate the induced eye movements by the cerebellar nuclei stimulation in the rabbits. Forty-five pigmented rabbits were used in this experiments. The cerebellar nuclei, especially medial nucleus, were stimulated electrically and the induced eye movements were observed. The results were as follows. 1. The horizontal nystagmus was produced by the electrical stimulation of the medial, anterior interposed, or posterior interposed nuclei. 2. The horizontal nystagmus towards the ipsilateral to the stimulated side was observed when the caudal portion of the medial nucleus was stimulated. On the other hand, the horizontal nystagmus towards the contralateral to the stimulated side was observed when the rostral portion of the medial nucleus was stimulated. 3. The latency of the field potential in the vestibular nucleus by stimulating the medial cerebellar nucleus, and that in the reverse situation, were 0.7 to 1.1 msec. 4. After the destruction of the lateral vestibular nucleus, no nystagmus was elicited by the stimulation of the medial cerebellar nucleus. From these results, it can be concluded that there is the monosynaptic connection between the medial cerebellar nucleus and the lateral vestibular nucleus. This indicates that the stimulation of the medial cerebellar nucleus produces the excitation of the vestibular nucleus via the cerebello-vestibular fibers and produces the nystagmus in the pigmented rabbits.

Animals↗
PubMed1988

Relation between serum levels of tissue polypeptide antigen (TPA) and cancer antigen 125 (CA125) and their immunohistochemical identification in benign and malignant gynecological disease.

We studied immunohistochemical stains for TPA and CA125 in patients with benign and malignant gynecologic diseases. The results were as follows: (1) CA125 was not found in ovarian mucinous cystadenocarcinoma but was demonstrated immunohistochemically in 82% of ovarian serous cystadenocarcinomas and 83% of Krukenberg's tumors. (2) TPA was demonstrated in 65% of ovarian serous and 75% of ovarian mucinous cystadenocarcinomas, and in 58% of endometrial carcinomas. (3) TPA was found in all trophoblastic tumors examined, while CA125 was found in none. Eighty-three percent of patients with trophoblastic diseases had raised serum TPA levels. (4) When serum CA125 levels were raised CA125 was demonstrated immunohistochemically in 71% of patients with ovarian serous cystadenocarcinomas, 67% of patients with Krukenberg's tumors and 100% of patients with tubal carcinomas. (5) Despite elevated serum levels, CA125 and TPA were not identified by immunohistochemistry in 64% cases of benign ovarian disease and in 80% of patients with uterine myomata. (6) It would seem that CA125 was more easily released from tumor cells than TPA.

Antigens, Neoplasm↗
PubMed1988

Serum levels of six tumor markers in patients with benign and malignant gynecological disease.

We studied the pretreatment serum levels of 6 tumor markers in gynecological patients with and without malignant disease. The tumor markers were carcinoembryonic antigen (CEA), tissue polypeptide antigen (TPA), ferritin, Schwangerschaftsprotein 1 (SP1), Schwangerschaftsprotein 3 (SP3) and cancer antigen 125 (CA125). The results were as follows: (1) Serum CA125 and TPA levels were raised in 81% and 57% of patients with ovarian serous cystadenocarcinoma; CEA and SP3, in 52% and 43% respectively of patients with ovarian mucinous cystadenocarcinoma; CA125, TPA and SP3, in 76%, 48% and 48% respectively of patients with other ovarian malignancies; and TPA and SP3, in 56% and 40% respectively of patients with endometrial carcinoma. (2) Serum levels of TPA, ferritin and CA125 were more often raised with advancing stages of malignant disease. (3) Serum TPA levels were elevated in 55% of patients with stage I endometrial carcinoma, and serum SP3 levels were elevated in 35% of patients with a stage I malignant ovarian neoplasm and in 45% of patients with endometrial carcinoma. (4) One of the 6 tumor markers showed a raised level in 84% of patients with gynecologic malignancy as against 56% in those with benign gynecologic diseases.

Antigens↗
PubMed1988

Experiments with tissue cultures from a human ovarian serous cystadenocarcinoma producing cancer antigen 125 (CA125), tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA).

The patient was a 57-year-old woman with ovarian serous cystadenocarcinoma in FIGO clinical stage IV. Cancer antigen 125 (CA125), tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA) were immunohistochemically demonstrated in tumor cells, and the variations of serum CA125 and TPA levels reflected the clinical course. The tumor tissue obtained at exploratory laparotomy was minced with scissors, and transplanted subcutaneously into female nude mice for in vivo maintenance. The tumor cells from 5th generation nude mice were dispersed in Eagle's minimal essential medium supplemented with 10% fetal calf serum, and incubated in Falcon tissue culture dishes at 37 degrees C in 5% CO2 in air for in vitro maintenance. The results were as follows: Histopathologically the tumor transplanted into nude mice showed a cystadenocarcinoma, which closely resembled the original human tumor. Immunohistochemically CA125, TPA and CEA were demonstrated in the tumor transplanted into nude mice as well as in the original human tumor. From the growth curve in nude mice, the doubling time was estimated to be about 3.5 days. Serum TPA levels in nude mice were increased in proportion to the tumor growth after transplantation, but serum levels CA125 and CEA were normal. The concentrations of CA125 and TPA were increased in the conditioned media compared with the control media, although the elevated values were decreased with subsequent passages. CEA concentrations in the conditioned media were unchanged.

Animals↗
PubMed1988

Sequential changes in urinary catecholamine in the transition from benign to malignant hypertension in rats.

The sequential changes in 24-hour urinary norepinephrine (NE) and epinephrine (E) excretion levels were measured in spontaneously hypertensive rats (SHR) that received deoxycorticosterone acetate (DOCA) and 1% NaCl drinking water. These were compared with those from control SHR and similarly treated Wistar-Kyoto rats (WKY). Blood pressure, NE and E increased progressively in DOCA-SHR group, and NE (2392 +/- 94 vs. 998 +/- 49 ng/day) and E (250 +/- 21 vs. 116 +/- 6 ng/day) exceeded twice that of the control SHR group in the sixth week of DOCA treatment. In WKY rats, NE (1372 +/- 48 vs. 968 +/- 37 ng/day) and E (147 +/- 9 vs. 121 +/- 7 ng/day) levels were significantly higher in rats given DOCA than those in control group in the sixth week of the treatment, but were not so remarkably high as in DOCA-SHR group. A histological examination of DOCA-SHR kidneys revealed fibrinoid necrosis in the vascular walls. These data suggest that sympathoadrenal activity plays an important role in the development of malignant hypertension in DOCA-SHR group.

Animals↗
PubMed1987

Diazepam and endorphin independently inhibit ultrasonic distress calls in rats.

Ultrasonic distress calls elicited in male rats by footshock under inescapable conditions were suppressed by diazepam. The suppression was blocked by pretreatment with Ro15-1788 or CGS8216, selective benzodiazepine receptor antagonists, while an opiate antagonist naloxone failed to modify the effect of diazepam. In contrast, naloxone antagonized but Ro15-1788 and CGS8216 did not antagonize beta-endorphin which also suppressed the ultrasonic vocalization. These findings suggest that benzodiazepine and opioid receptors may contribute separately to antianxiety activity.

Animals↗
PubMed1985

Comparison of the intraperitoneal and intravenous routes of cisplatin administration in an advanced ovarian cancer model of the rat.

A model of human advanced ovarian cancer was made by intra-abdominal inoculation of a cloned ovarian adenocarcinoma cell line of the Sprague-Dawley rat (ROT68/C1) into isologous newborn rats. Intra-abdominal tumors and tumors metastatic to the lung developed in 100% of the animals within 3 weeks after inoculation. With use of this model the intraperitoneal and intravenous routes of cisplatin (cis-diamminedichloroplatinum) administration were compared with regard to both the pharmacokinetics and the antitumor activity. After 2 hours of administration the serum cisplatin values were greater following use of the intraperitoneal route than with use of the intravenous route. Cisplatin values in the intra-abdominal tumor tissues were greater after the intraperitoneal route of administration than the intravenous route, and the growth was suppressed more prominently after intraperitoneal administration. No difference in drug values in the kidney tissues was found between the two administration routes. Thus the intraperitoneal route of cisplatin administration seems to be much more effective against advanced ovarian cancer confined to intra-abdominal cavity than does the intravenous route.

Abdominal Neoplasms↗
PubMed1985

AFP-producing Sertoli-Leydig cell tumor of the ovary.

A tumor of the right ovary in a 21-year-old single woman is reported. Secondary amenorrhea, hirsutism, acne and deepening of the voice were associated with the tumor. Light and electron microscopic examinations showed that the tumor was composed of cells resembling Sertoli and Leydig cells of the testis in their cytology features and growth patterns. High levels of circulating dehydroepiandrosterone, androstenedione, testosterone and alpha-fetoprotein (AFP) were found preoperatively. Preoperative estrogen and progesterone levels were all slightly above the upper limits of normal for females. These hormone and AFP levels fell to within the normal range after removal of the tumor. Direct hormone and AFP production of this tumor was confirmed by immunohistochemical techniques and long-term cell cultures in vitro. This is possibly the first report on a Sertoli-Leydig cell tumor in which AFP has been identified in the patient's plasma, in part of the tumor cells and the culture fluid.

Adult↗
PubMed1985

Characterization of human embryonal carcinoma cell lines derived from testicular germ-cell tumors.

Four human embryonal carcinoma (EC) cell lines (ITO, NEC 8, NEC 14, NEC 15) derived independently from testicular germ-cell tumors were established in vitro. In their xenografted tumor tissues, all of them exhibited histological characteristics consistent with EC. The cell-biological characterization of these human EC cell lines was investigated with reference to well-known murine EC cell lines. This included examination of their morphology, growth, tumorigenic potential, karyotype, cell-aggregate formation, HLA expression, large glycopeptides, AFP and HCG production, plasminogen-activator secretion, and LDH profiles. Three (ITO, NEC 14, NEC 15) of these human EC cell lines shared cell-biological characteristics consistent with typical EC, but one of them (NEC 8) differed from the others with respect to its rapid growth, high tumorigenic potential, formation of solid cell aggregates, and less differentiated, solid histological pattern. Thus, it is suggested that there are several developmentally different types of human EC cells. The relationship between the properties of these human EC cell lines and their differentiation potential is discussed.

Adult↗
PubMed1985

[A new in vitro chemosensitivity test. Individualized chemotherapy against ovarian cancer and its clinical effect].

A new in vitro chemosensitivity test was developed from comparative studies on the cytotoxicity of anticancer drugs against human tumor tissues xenografted into nude mice and their cultivated cells in vitro. Half a gram of the material was sufficient to examine the sensitivity of the tissues to 10 kinds of potential anticancer drugs and the results were obtained within 24 hours. The test was applied to all of 20 patients with advanced ovarian cancer. The predictive accuracy was 58% in 12 evaluable patients. This response rate was higher than those of conventional combination chemotherapy with or without cisplatin and adriamycin. Individual ovarian cancers showed different sensitivities to the drugs. These results indicate that heterogeneity of sensitivity to anticancer drugs exists among individual ovarian cancers and that our new type of in vitro chemosensitivity test is useful for selecting the most effective drugs for each individual type of ovarian cancer.

Adult↗
PubMed1985

[Effects of neonatal androgenization on 7,12-dimethylbenz[a] anthracene-induced rat endometrial carcinogenesis].

Effects of neonatal androgenization on 7,12-dimethylbenz[a]anthracene (DMBA)-induced endometrial carcinogenesis in Sprague-Dawley rats are studied. Testosterone propionate (1.25 mg) was injected subcutaneously into 110 2-day-old rats. At 8 weeks of age, a pellet containing 0.2 or 1mg DMBA was introduced into each uterine horn of both neonatally intact control rat (NR) and neonatally androgenized rat (ASR). All rats were killed at 24 or 48 weeks of age. The results were as follows. Vehicle group: No malignant uterine tumor was observed during both 16- and 40-week observation periods in either 122 horns of NR or 98 of ASR. 0.2 mg DMBA treated group: No malignant uterine tumor was detected in either 80 NR or 72 ASR during a 16-week observation period. Although three malignant uterine tumors were found among 72 NR during a 40-week observation period, no malignant uterine tumor was observed in 30 ASR. 1mg DMBA treated group: Although one malignant uterine tumor of 16 NR was found during a 16-week observation period, no malignant uterine tumor was observed in 20 ASR. Four malignant uterine tumors of 168 NR induced by DMBA were histologically 2 squamous cell carcinomas and two sarcomas. As mentioned above, although four malignant uterine tumors were induced by DMBA in 168 NR, no malignant uterine tumor was found in 122 ASR. These results seem to indicate that neonatal androgenization suppressed the induction of malignant rat uterine tumors by DMBA.

9,10-Dimethyl-1,2-benzanthracene↗