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Biomedical subjects

A Amemiya

Publications and source records attributed to A Amemiya.

At least 19 recordsLinked to original sources
PubMed2002

Prenatal course and pregnancy outcome of fetuses with a transient nuchal translucency.

OBJECTIVES: This study was designed to correlate fetuses in a normal prenatal population who exhibited transient nuchal translucency (NT) with both prenatal course and pregnancy outcome. METHODS: The fetuses with abnormal NT were followed by ultrasonography at 1-2-week intervals during their prenatal course. Fetuses with NT who exhibited no detectable congenital malformations were defined as the NTO group; fetuses with abnormal NT and structural malformations but no chromosomal abnormalities were placed in the SM group; and fetuses with abnormal NT, structural malformations, and chromosomal abnormalities were categorized as the CA group. The groups were compared by: maternal age, weeks of gestation by ultrasound and the NT value at the initial exam, the maximum NT value, and the duration of abnormal NT. RESULTS: During the study period, 92 fetuses with abnormal NT were found, monochorionic twins excluded. Of the 92 fetuses, 80 were in the NTO group, 10 were in the SM group, and two were in the CA group. The maternal age and the gestational weeks at the initial diagnosis were not significantly different in the NTO and the SM groups. However, the NT value at the initial diagnosis, maximum NT value, and the duration of abnormal NT were significantly greater in the SM group than those values in the NTO group. CONCLUSIONS: Fetuses with transient nuchal translucency commonly had structural malformations, particularly fetuses with significant and large persistent NT.

Adult↗
PubMed2001

Minimally invasive surgery for lung cancer with coronary artery disease.

We report a 69-year-old woman with lung cancer and severe stenosis in the left anterior descending coronary artery. To perform a curative operation for the lung cancer without myocardial infarction, minimally invasive direct coronary artery bypass and left lower lobectomy with video-endoscopic assistance were performed simultaneously. There was no major complication, and she was discharged at 14 days after the operation. This procedure may be useful and safe for patients with lung cancer and coronary artery disease.

Adenocarcinoma↗
PubMed2000

The modified tangential irradiation technique for breast cancer: how to cover the entire axillary region.

PURPOSE: The two-portal tangential irradiation technique has usually been applied to breast cancer patients after breast-conserving surgery (1, 2) and is expected to irradiate the axillary lymph node region to some extent (3). We investigated the range of the axillary region covered by this technique and tried to devise an optimal irradiation technique (modified tangential irradiation) that would cover the axillary lymph node region properly. METHODS AND MATERIALS: We checked the status of the surgical clips left at axillary lymph node sites by reviewing the simulator films and planning CT scans of 63 patients who underwent axillary dissection of level I, I-II, or I-III lymph nodes. Then we created the modified tangential irradiation technique and applied this technique to 16 patients and checked the irradiation volume by CT scans. RESULTS: We found that all of the surgical clips on lateral-view simulator films were on the ventral side of the dorsal edge line of the humeral head. All but one clip were on the caudal side of the caudal edge line of the humeral head. Accordingly, it is possible to irradiate almost all axillary lymph node regions by setting the dorsal edge of the irradiation field on lateral-view simulator films at the dorsal edge of the humeral head and the cranial edge at the caudal edge of the humeral head. CONCLUSIONS: All breast tissue and the entire axillary lymph node region can be covered by the modified tangential irradiation technique without increasing the lung volume irradiated.

Adult↗
PubMed2000

Minimally invasive removal of infected pacemaker lead.

A 37-year-old woman with sick sinus syndrome suffered complications with recurring local infection at the generator pocket. Repeated debridement and antibiotic therapy was ineffective. Several attempts to remove leads via the implantation vein by direct traction were unsuccessful. We operated using cardiopulmonary bypass and applied a minimally invasive lower ministernotomy to obtain pleasing cosmetic results. After a right atriotomy, leads were removed. The minimally invasive approach gave satisfactory results, especially cosmetically.

Adult↗
PubMed2000

Plasma catecholamine responses during laparoscopic gynecologic surgery with CO(2) insufflation.

STUDY OBJECTIVE: To compare adrenergic-sympathetic responses during pelvic laparoscopic surgery with CO(2) insufflation with those during laparotomy. DESIGN. Prospective study (Canadian Task Force classification II-1). SETTING: Tertiary care university hospital. PATIENTS: Twenty-one infertile women with a clinical diagnosis of endometriosis. INTERVENTION: Plasma norepinephrine (NE) and epinephrine (E) levels were measured in patients undergoing laparoscopic or open pelvic surgery. MEASUREMENTS AND MAIN RESULTS: During laparoscopic surgery, increases in NE and E levels were correlated with arterial tension of CO(2) (PaCO(2)) and were greater in patients with a larger increase in PaCO(2) than in those undergoing laparotomy. Hemodynamic changes were also more evident during laparoscopic surgery, with larger PaCO(2) increases. CONCLUSION: The PaCO(2) increases due to CO(2) insufflation are associated with adrenergic-sympathetic activation and hemodynamic changes during laparoscopic pelvic surgery.

Adult↗
PubMed2000

Stress responses during laparoscopy with CO2 insufflation and with mechanical elevation of the abdominal wall.

STUDY OBJECTIVE: To compare the intensity of stress responses caused by laparoscopy combined with CO2 insufflation (CI) with those caused by mechanical elevation of the abdominal wall (MEA). DESIGN: Prospective study (Canadian Task Force classification I). SETTING: Tertiary care university hospital. PATIENTS: Thirty-one women. Intervention. Laparoscopy, 16 with CI and 15 with MEA. MEASUREMENTS AND MAIN RESULTS: Circulating levels of norepinephrine, epinephrine, cortisol, and interleukin (IL)-6 were compared in the two groups. Arterial partial pressure of CO2 (PaCO2) did not increase during laparoscopy by either method. Plasma norepinephrine and epinephrine levels increased after extubation in the MEA group but not in the CI group. Circulating cortisol levels in both groups increased during laparoscopy; mean intraoperative levels were higher in the CI group. Serum IL-6 levels increased after extubation in the MEA but not the CI group. Mean heart rate increased during laparoscopy in both groups, whereas blood pressure increased only in the CI group. More patients in the MEA group required postoperative analgesia. CONCLUSION: Laparoscopy with MEA caused more pronounced adrenosympathetic and cytokine responses than that with CI when PaCO2 was maintained within the range of normocapnia.

Carbon Dioxide↗
PubMed2000

The effect of melatonin on in vitro fertilization and embryo development in mice.

To examine the effect of melatonin on in vitro fertilization and embryonic development, mouse embryos after insemination in vitro were cultured in a physiological medium with or without melatonin. Melatonin increased the fertilization rate significantly at a concentration between 10(-6) and 10(-4) M (27.6 vs. 43.9 or 40.4%, P < 0.01). Furthermore, a significant increase in the rate of embryos reaching the four-cell stage (16.0 vs. 26.7%, P < 0.01), the eight-cell stage (12.1 vs. 25.8 or 23.5%, P < 0.01), and blastulation (8.9 vs. 23.5 or 17.5%, P < 0.01) was observed when the embryos were cultured in a medium containing 10(-8) or 10(-6) M melatonin. These results demonstrate that melatonin supports fertilization and early embryo development after in vitro fertilization.

Animals↗
PubMed2000

Melatonin secretion from organ-cultured pineal glands of rats: modulation by gonadectomy and gonadotropin-releasing hormone agonist administration.

The objective of the study was to evaluate the effect of pretreatments such as gonadectomy in male and female rats, and gonadotropin-releasing hormone agonist (GnRHa) administration in female rats, on levels of secretion of melatonin, using an organ culture of pineal glands. Gonadectomy 2 weeks before the animal was killed increased the amount of melatonin secreted into the medium by the pineal glands of female rats but not of male rats. The increase in in vitro melatonin secretion after ovariectomy in female rats was prevented by estrogen replacement. Ovariectomy 3 and 4 weeks before death also significantly increased the amount of melatonin secretion. Administration of GnRHa 2 weeks before decapitation significantly decreased serum estradiol concentrations and significantly increased melatonin secretion by the pineal glands of female rat. GnRHa administration 3 or 4 weeks before decapitation also significantly decreased serum estradiol concentrations, but did not increase pineal secretion of melatonin. The results indicate that ovariectomy increases melatonin secretion from organ-cultured pineal glands and that this increase is suppressed by estrogen in adult female rats. In contrast, orchiectomy in male rats does not influence in vitro secretion of melatonin. These results suggest that the GnRH-gonadotropin system may participate in the regulation of pineal melatonin secretion in adult female rats.

Animals↗
PubMed1999

Anti-nuclear antibodies in patients with premature ovarian failure.

We examined the prevalence of anti-nuclear antibodies (ANA) in 32 consecutive patients with premature ovarian failure with and without chromosomal abnormalities. Blood samples were taken for karyotype determination as well as detection of autoantibodies, X-terminal microdeletions and spontaneous follicular growth. The correlation between ANA positivity and the age at onset of amenorrhoea, as well as the presence of karyotype abnormalities, X-terminal microdeletions and follicular growth was determined. Ten of the 24 patients with normal karyotype and none of the 8 patients with karyotype abnormalities were ANA positive. ANA were found more frequently in patients with premature ovarian failure with normal karyotypes than in control amenorrhoeic patients (42 versus 6, P < 0.01). ANA were found in 77% (10/13) of premature ovarian failure patients with normal karyotypes who developed amenorrhoea at or under the age of 30 years, but not in the patients who developed amenorrhoea later in life. Follicular growth was evident in 50% (5/10) of karyotypically normal patients with ANA, 71% (10/14) of karyotypically normal patients without ANA and 38% (3/8) of patients with karyotype abnormalities. X-terminal microdeletions were not found in any of the patients studied. These results suggest that patients with premature ovarian failure and ANA are an aetiologically and clinically distinct group.

Adult↗
PubMed1999

Melatonin, its precursors, and synthesizing enzyme activities in the human ovary.

The presence of melatonin (N-acetyl-5-methoxytryptamine) and its precursors, serotonin (5-hydroxytryptamine) and N-acetylserotonin, was demonstrated in extracts of human ovary using reverse-phase high-performance liquid chromatography coupled with fluorometric detection. In addition, activities of two melatonin-synthesizing enzymes, arylalkylamine N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT), were found in human ovary homogenates. The apparent Michaelis constants for the substrates of NAT and HIOMT in the human ovary were similar to those reported for the pineal glands of humans and other mammals. These findings strongly suggest that the human ovary, like the pineal gland, may synthesize melatonin from serotonin by the sequential action of NAT and HIOMT.

Acetyl Coenzyme A↗
PubMed1999

Prenatal confirmation of the translocation between chromosome 15 and Y-chromosome by fluorescence in situ hybridization.

A 30-year-old woman and her husband visited our hospital with habitual abortion as the complaint. Chromosome examination revealed a normal 46, XX for her and 46, XY, 15, der (15) t (Y; 15) (q12; p12) for him. After her pregnancy amniocentesis was performed. The karyotype was 46, XX, 15, der (15) t (Y; 15) (q12; p12) pat. ish der (15) (DYZ1+). A female baby was delivered. The growth of the baby was normal at 12 months of age.

Abortion, Habitual↗
PubMed1999

[Role of irradiation in breast conservation therapy for breast cancer].

Despite a worldwide consensus on the indication for breast conservation therapy (BCT), the proportion of patients treated with BCT in Japan was only 29.2% in 1997. Indications of BCT and opinions against increasing the number of BCT in Japan are discussed along with the concept of evidence-based medicine (EBM). It is evident that in Japan as well, 70% to 90% of patients with breast cancer can be treated with BCT. The main aim of irradiation in BCT is to reduce inbreast recurrences (IBR), and randomized controlled trials have confirmed that irradiation to the breast reduces IBR. Currently, much concern is being directed to the issue of surgical margins in partial mastectomy, i.e., the definition of positivity of margins and how to treat margin-positive cases. The role of boost irradiation to the tumor bed and irradiation to lymph node areas are also discussed.

Breast Neoplasms↗
PubMed1998

Characteristics of mutations in the p53 gene of oral squamous-cell carcinomas associated with betel-quid chewing in Sri Lanka.

Oral squamous-cell carcinoma (SCC) is the most common neoplasm in Sri Lanka, accounting for approximately 30% of all cancers in males. Epidemiologic evidence indicates that there is an unequivocal relationship between betel chewing and oral carcinogenesis, suggesting that there may be specific genetic targets of betel-quid ingredients. The p53 gene has been indicated to be a tumor-suppressor gene that is found in mutated form in common human cancers; however, there are few reports about "carcinogen-specific" p53 mutation. Because of this background, primary resected specimens from 23 oral SCCs, 7 leukoplakias and 2 oral submucous fibrosis were collected from oral SCC patients in Sri Lanka and were used for p53 mutation analysis. Exons 5 through 8 of the p53 gene were examined by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing. Mutations in the p53 gene were frequent (10/23) in oral SCC specimens from Sri Lanka. Moreover, the mutations clustered significantly in exon 5 (7/10) of the p53 gene, and small deletions and inclusions other than point mutations were observed. These results indicate that 1) betel-quid chewing may cause specific genetic changes, including mutation in the p53 gene; 2) mutations in the p53 gene are not rare events in SCC patients who are betel-quid chewers, which contrasts with other reports; 3) exon 5 of the p53 gene could be one of the specific targets for some betel-quid ingredients; and 4) betel-quid chewing may be a critical environmental factor in the development of oral SCC.

Adult↗
PubMed1998

Orexins and orexin receptors: a family of hypothalamic neuropeptides and G protein-coupled receptors that regulate feeding behavior.

The hypothalamus plays a central role in the integrated control of feeding and energy homeostasis. We have identified two novel neuropeptides, both derived from the same precursor by proteolytic processing, that bind and activate two closely related (previously) orphan G protein-coupled receptors. These peptides, termed orexin-A and -B, have no significant structural similarities to known families of regulatory peptides. prepro-orexin mRNA and immunoreactive orexin-A are localized in neurons within and around the lateral and posterior hypothalamus in the adult rat brain. When administered centrally to rats, these peptides stimulate food consumption. prepro-orexin mRNA level is up-regulated upon fasting, suggesting a physiological role for the peptides as mediators in the central feedback mechanism that regulates feeding behavior.

Animals↗
PubMed1998

The expression pattern of endothelin 3 in the avian embryo.

We investigated the expression pattern of the endothelin 3 gene, of which the mutation, as well as mutation of its receptor (endothelin-B receptor), affects the development of two neural crest derivatives: enteric nervous system and melanocytes. After previous work showing that these neural crest derived cells express endothelin-B receptor or its subtype endothelin-B2 receptor in the avian embryo, we have demonstrated that endothelin 3 is expressed by the environment of enteric nervous system and melanocyte precursors.

Animals↗
PubMed1998

The expression patterns of endothelin-A receptor and endothelin 1 in the avian embryo.

We investigated the expression pattern of the endothelin-A receptor and endothelin 1 genes, the mutations of which affect the development of the mesectodermal derivatives of the neural crest. We show here that endothelin 1 is expressed by the environment of the cephalic neural crest cells invading branchial arches. Later on, while the neural crest-derived tissues of the head continue to express endothelin-A receptor, endothelin 1 is no longer expressed in their environment.

Animals↗