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K Sengoku

Publications and source records attributed to K Sengoku.

At least 19 recordsLinked to original sources
PubMed2002

A cytogenetic study of in-vitro matured murine oocytes after ICSI by human sperm.

BACKGROUND: The purpose of this study was to investigate the chromosomal complement and developmental potential of in-vitro matured murine oocytes following ICSI by human sperm. METHODS: Heterologous ICSI fertilization between mouse oocytes and human sperm was employed in order to overcome the reduced fertilization rates observed after conventional IVF due to zona hardening during in-vitro maturation, and to assess separately maternal and paternal chromosome complements. Cytogenetic analyses were performed in four types of oocytes: (i) in-vitro matured metaphase II (MII) oocytes; (ii) in-vivo matured MII oocytes; (iii) in-vitro matured oocytes after ICSI; (iv) in-vivo matured oocytes after ICSI. RESULTS: Activation rates after ICSI of in-vitro matured oocytes was lower than that of in-vivo matured oocytes (69.9 versus 97.2%, P < 0.01), and premature chromosomal condensation was only observed in in-vitro matured oocytes. However, there were no significant differences in developmental rates after successful activation between in-vivo and in-vitro matured ICSI oocytes (69.7 versus 76.6%). The incidences of aneuploidy and structural aberrations were similar between the ICSI embryos and non-ICSI (MII) oocytes. Furthermore, the frequency of chromosomal aberrations was not associated with in-vitro or in-vivo maturation. Similar analyses of paternal chromosomes indicated that there were no significant differences in the incidence of chromosomal aberrations between the embryos derived from in-vitro and in-vivo matured oocytes. CONCLUSIONS: These results suggest that in-vitro matured oocytes following ICSI do not lead to an increase in the frequency of aneuploidy and structural aberrations when human sperm are injected into mouse oocytes.

Aneuploidy↗
PubMed2001

Requirement of nitric oxide for murine oocyte maturation, embryo development, and trophoblast outgrowth in vitro.

We investigated the extent to which NO participates in the developmental competence (oocyte maturation, fertilization and embryo development to blastocyst) using an in vitro culture system adding sodium nitroprusside (SNP), NO donor, and NOS inhibitor (N-omega-nitro-L-arginine methyl ester, L-NAME). We also assessed the effects of NO/NOS system on blastocyst implantation using an in vitro trophoblast outgrowth assay. The treatment of low concentrations of SNP (10(-7) M) significantly stimulated meiotic maturation to metaphase II stages in cumulus enclosed oocytes. In contrast, 10(-3) and 10(-5) M L-NAME demonstrated a significant suppression in resumption of meiosis. This inhibition was reversed by the addition of SNP. No development beyond the four-cell stage was observed by the addition of high concentration of SNP (10(-3) M). Inhibition of embryo development, especially the conversion of morulae to blastocysts, was also observed in the treatment of lower doses of SNP (10(-5) and 10(-7) M). Similarly, inhibition of NO by NOS inhibitor resulted in the dose-dependent inhibition of embryo development and hatching rates, but the concomitant addition of SNP with L-NAME reversed the inhibitory effect by each SNP or L-NAME treatment. Furthermore, low concentration of SNP (10(-7) M) but not high concentration of SNP (10(-3) M) significantly stimulated trophoblast outgrowth, whereas the addition of L-NAME suppressed the spreading of blastocysts in a dose-dependent manner. These results suggest that NO may have crucial roles in oocyte maturation and embryogenesis including the process of implantation. The observed differences in required amount of NO and the sensitivity to cytotoxicity of NO in each developmental stage embryos may also suggest that NO/NOS system is tightly regulated in developmental stage specific manner.

Animals↗
PubMed2001

Cesarean section in a patient with syringomyelia.

PURPOSE: To describe the anesthetic management of Cesarean section in a patient with syringomyelia. CLINICAL FEATURES: A 27-yr-old pregnant woman with syringomyelia was scheduled to undergo elective Cesarean section. At the age of 25 yr, she had begun to experience headaches, and at the age of 26 yr, a diagnosis of syringomyelia of the upper spinal cord was made on the basis of magnetic resonance imaging findings. No symptoms other than headache were noted preoperatively. General anesthesia was used for the Cesarean section. After the administration of 1 mg vecuronium as a priming dose, 5 mg vecuronium were injected. At the onset of clinical muscle weakness, 225 mg thiamylal were promptly administered as the induction agent and the patient was intubated (timing principle with priming method) and pressure on the cricoid cartilage applied to prevent regurgitation of stomach contents. Anesthesia was maintained with oxygen, nitrous oxide and isoflurane at a low concentration. Mild hyperventilation was used throughout the procedure. Anesthesia and surgery proceeded without any problem, response to vecuronium was clinically normal and recovery was uneventful. Neurological status remained normal. CONCLUSION: We report the safe use of general anesthesia for Cesarean section in a patient with syringomyelia. Precautions were taken to avoid increases in intracranial pressure and our patient experienced no untoward neurologic event.

Adult↗
PubMed2001

Effects of supplementation with free radical scavengers on the survival and fertilization rates of mouse cryopreserved oocytes.

BACKGROUND: This study was conducted to investigate the effects of supplementation with free radical scavengers on the survival and fertilization rates of freeze-thawed mouse oocytes. METHODS: Superovulated oocytes with cumulus cells were cryopreserved by slow freezing in propanediol combined with a rapid thawing protocol. The cryopreservation medium was supplemented with the antioxidant enzymes superoxide dismutase (SOD) and catalase, and with the nitric oxide (NO) scavenger, haemoglobin (Hb). RESULTS: The addition of 50 IU/ml SOD showed significantly higher survival and fertilization capabilities compared with control (P < 0.01). Oocyte survival was greatly increased by concomitant addition of SOD with 10 IU/ml catalase (P < 0.01). On the other hand, the NO donor (sodium nitroprusside) inhibited survival and fertilization rates (P < 0.05). Significantly decreased survival and fertilization rates were also observed following the addition of high concentrations (10(-3) to 10(-6) nmol/l) of the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). In contrast, significantly better oocyte survival and fertilization rates were detected with low concentrations (10(-7) nmol/l) of L-NAME. Oocyte survival potential was significantly increased by addition of Hb (1 microg/ml, P < 0.05). Moreover, oocyte survival and fertilization rates were significantly promoted by the concomitant addition of SOD with Hb (P < 0.01). CONCLUSIONS: These results suggest that supplementation of free radical scavengers, particularly combinations of SOD with NO scavengers in freezing and thawing media, improved the post-thaw survival and fertilization rates of cryopreserved mouse oocytes.

Animals↗
PubMed2001

[Anesthetic management for thoracoscopic bullae resection using epidural anesthesia].

We report the anesthetic management for elective thoracoscopic bullae resection (TBR) using high thoracic epidural (TE) anesthesia in awake patients. Pain and cough reflex caused by the surgical procedure could be controlled well with high TE anesthesia using 20-25 ml of 2% lidocaine. Respiratory and hemodynamic conditions remained stable during the surgical procedure. High TE anesthesia using a large dose of local anesthetic is thought to be suitable for TBR.

Adult↗
PubMed2001

[Anesthetic management of two patients with insulinoma using propofol--in association with rapid radioimmunoassay for insulin].

We experienced anesthetic management of two patients with insulinoma in whom frequent hypoglycemic episodes with blood glucose levels of 39-42 mg.dl-1 had been observed. Each patient received epidural analgesia with a catheter inserted at the T 9/10 intervertebral space. Anesthesia was induced with propofol 80-100 mg and fentanyl 200 micrograms. Tracheal intubation was facilitated with vecuronium 6 mg. Anesthesia was maintained with continuous infusion of propofol and epidural anesthesia. Rapid measurements of immunoreactive insulin (IRI) were useful for localization of insulinoma during surgery. Perioperative plasma glucose levels could be maintained within normal ranges by continuous infusion of glucose. Rebound hyperglycemic episodes were not observed, and IRI was reduced after removal of the insulinoma. General anesthesia using propofol and epidural block is a useful choice for the anesthetic management of patients undergoing an operation for removal of an insulinoma.

Aged↗
PubMed2001

[A survey of 3,303 6th-year medical students from 36 universities concerning knowledge of resuscitation--more than 80% of medical students can not perform standard cardiopulmonary resuscitation?].

Questionnaires on knowledge of resuscitation were distributed to 3,303 6th-year medical school students from 36 universities. The questionnaire included 13 questions based on the 1992 guidelines for cardiopulmonary resuscitation. From the 13 questions, each student was instructed to select 6 questions concerning assessment of consciousness level, method for confirming respiration, method for securing the airway, method for confirming circulation, pressure points for cardiac massage, and the ratio of respiration and cardiac massage. If all of these six questions could not be answered correctly, it was considered that the student was not able to perform resuscitation according to the guidelines. At least one incorrect answer was given to the six questions by 84% of students, indicating that most medical students are not able to actually perform standard resuscitation. Possible reasons for these results may be the lack of desire on the part of students to master resuscitation, confusion over new findings concerning resuscitation and guideline, insufficient understanding of the difference between the guidelines and new findings by educators, and restricted teaching time for resuscitation. Possible ways to improve the situation include efforts to make students more responsible to master resuscitation, efforts to enhance students' desire to learn, adoption of more practical education, inclusion of such questions in graduation examinations and the national examination for a medical license, adherence by educators to the guidelines, and efforts by educators to make a clear distinction between the guidelines and new findings. With new guidelines for cardiopulmonary resuscitation due out in the year 2000, methods for teaching resuscitation should be reconsidered in order to ensure that all medical students can competently perform resuscitation.

Adult↗
PubMed2001

[Anesthetic management in a patient with Simpson-Golabi-Behmel syndrome].

We report the anesthetic management of a 4-yr-old boy with Simpson-Golabi-Behmel syndrome. This syndrome is an X-linked condition characterized by pre- and postnatal overgrowth with visceral and skeletal anomalies. Affected males have a distinctive facial appearance with wide nasal bridge, anteverted nostrils, wide-open mouth, enlarged tongue, and large protruding maxilla and jaw. Although it had been speculated preoperatively that airway management would be complicated by the macroglossia, there was no difficulty in endotracheal intubation in the present patient. Preparations for difficult airway management should be made by the anesthesiologist before induction of anesthesia.

Abnormalities, Multiple↗
PubMed2001

[Effects of lumbar sympathetic ganglion block in a patient with acquired lymphangioma].

A 70-year-old woman developed lymphangioma following surgery for cervical cancer and subsequent radiotherapy. The operation was performed 12 years ago, and a swelling of lower extremities was recognized 8 years ago. Her lower extremities became greatly edematous, and leakage of lymph to the groin was observed. We performed bilateral lumbar sympathetic ganglion block. After the block, lymphedema was relieved dramatically, and the leakage of the lymph to the groin was gradually reduced. We conclude that lumbar sympathetic ganglion block may be very effective in some patients with acquired lymphangioma.

Aged↗
PubMed2000

[Sick sinus syndrome (SSS) after induction of anesthesia in a patient with increased intracranial pressure and ischemic heart disease].

An 84-year-old male with increased intracranial pressure (ICP) and ischemic heart disease was scheduled to undergo brain tumor resection. After induction of anesthesia using midazolam, fentanyl and vecuronium, sinus bradycardia, junctional rhythm and escape-capture bigeminy were observed. In spite of intravenous administration of lidocaine and atropine, the bigeminy did not disappear. As he awoke from anesthesia, his cardiac rhythm changed from a bigeminal to a regular sinus rhythm. After extubation, sinus arrest, which continued for up to 4.8 seconds, appeared frequently. A temporary pacing catheter was inserted and ventricular pacing was started (mode VVI rate 50 min-1). Four days later, the patient was again scheduled to undergo brain tumor resection. After induction of anesthesia with the same drugs as used before, his cardiac rhythm gradually became bradycardic, and a complete pacing rhythm was observed throughout the surgical procedure. After the operation had been completed, his cardiac rhythm changed to a regular sinus rhythm. In addition to degenerative and ischemic changes in the SA node, an increase in ICP secondary to a brain tumor is thought to have induced sick sinus syndrome after the induction of anesthesia.

Aged↗
PubMed2000

[Present state and future in reproductive medicine].

It has been almost 21 years since the first birth of IVF baby and rapid advances in assisted reproductive technology (ART) have taken place. Today, several new technology have been developed such as microfertilization and cryopreservation of embryos and ART has become an important and popular tools for treatment of infertility patients with several causes. However, the take home baby rates have still been low around 15%. To improve the results in ART programs, the improvement of embryo viability and the solution of problems of implantation have been required. Recently, sequential culture media for production of high quality blastocysts have been developed and results have been as good as with co-culture. These culture media are now commercially available. Several authors reported that higher clinical pregnancy rate was achieved and high-order multiple pregnancy can be eliminated with blastocyst transfer. It has been expected that blastocyst transfer would become the means to solve the major problem that ART has faced such as the low take home baby rates and high-order multiple pregnancy.

Female↗
PubMed1999

Requirement of sperm-oocyte plasma membrane fusion for establishment of the plasma membrane block to polyspermy in human pronuclear oocytes.

We investigated whether the incorporation of the sperm membrane into the oolemma contributes to the human plasma membrane block to polyspermy. We used zona pellucida-free oocytes fertilized by intracytoplasmic sperm injection (ICSI) or activated by parthenogenetic activation. Only two of the 35 pronuclear oocytes fertilized by spermatozoa (control) demonstrated one single penetrating spermatozoa. In contrast, the majority of ICSI and parthenogenetically activated pronuclear oocytes were penetrated with an average of three spermatozoa per oocyte. The number of fused and binding spermatozoa of ICSI and parthenogenetically activated oocytes were significantly higher than in control oocytes (3.5+/-0.6 and 4.3+/-0.6 for ICSI; 3.0+/-0.3 and 3.8+/-0.4 for activated and 0.2+/-0.1 and 0.6+/-0.2 for controls, respectively, P < 0.01). Furthermore, the cortical granules were released from the cortex of ICSI and calcium ionophore-puromycin-activated pronuclear oocytes to the same extent as that of pronuclear oocytes fertilized by spermatozoa. These results suggest that the establishment of the plasma membrane block to sperm penetration in the human oocyte may require a fusion process between sperm and oocyte plasma membranes.

Cell Membrane↗
PubMed1999

The clinical efficacy of low-dose step-up follicle stimulating hormone administration for treatment of unexplained infertility.

The present study was designed to compare the clinical efficacy of low-dose step-up follicle stimulating hormone (FSH) administration with conventional FSH protocol (FSH was injected daily starting with a dose of 150 IU), both combined with intrauterine insemination (IUI), for the treatment of unexplained infertility. A total of 97 unexplained infertility couples was randomly assigned to one or other of the two treatment groups, either conventional FSH with IUI (48 patients) or low-dose step-up FSH with IUI (49 patients), and only the first treatment cycle was evaluated in each protocol. The difference in pregnancy rates per cycle was not statistically significant between the low-dose FSH group and the conventional group [seven of 49 (14.3%) and seven of 48 (14.6%) respectively]. A significant reduction in the incidence of ovarian hyperstimulation syndrome (OHSS) was observed in the low-dose group (8.3% versus 27.1%, P < 0.05). The incidence of moderate OHSS requiring hospitalization was reduced significantly in the low-dose group (low-dose 0% versus conventional 16.7%, P < 0.01). However, the low-dose protocol did not completely prevent multiple pregnancies. Our results suggest that the low-dose step-up FSH treatment appeared to be useful for the treatment of unexplained infertility because of the high pregnancy rates and the significant decrease in the incidence of OHSS.

Adult↗
PubMed1998

A SacII polymorphism in the human ASCL2 (HASH2) gene region.

The mouse achaete-scute homolog-2 gene (Ascl2 or Mash2) encodes a transcription factor playing a role in the development of the trophoblast. The Ascl2 gene is paternally imprinted in the mouse, but whether this applies to its human homolog is unknown. In the present study, we found a SacII polymorphism in the possible 3' untranslated region (UTR) of the gene. It would be very useful to determine definitively whether the gene is imprinted, as well as to analyze the allelic methylation status of the gene.

Alleles↗
PubMed1998

Effects of low concentrations of nitric oxide on the zona pellucida binding ability of human spermatozoa.

OBJECTIVE: To investigate the direct effects of sodium nitroprusside, a nitric oxide donor, on the fertilizing ability of human spermatozoa in vitro. DESIGN: Prospective, controlled in vitro study. SETTING: IVF Unit, Medical College Hospital. PATIENT(S): Women undergoing conventional IVF. INTERVENTION(S): Human spermatozoa samples were incubated with a nitric oxide donor and a nitric oxide quencher, carboxy-imidazolineoxyl N-oxides. MAIN OUTCOME MEASURE(S): The capacitation and the acrosome reaction rates were determined by chlortetracycline assay. Sperm zona pellucida binding and sperm penetration into oocytes were determined using the hemizona assay and the human aged zona-free oocyte sperm penetration assay. RESULT(S): High concentrations of sodium nitroprusside (10(-3) and 10(-5) M) inhibited sperm motility and viability. In contrast, low concentrations of sodium nitroprusside (10(-7) and 10(-8) M) did not affect motility and resulted in increased capacitation (47 +/- 6% at 10(-7) M, 42 +/- 6% at 10(-8) M, and 24 +/- 4% in controls, respectively, P < 0.01). A twofold increase in the hemizona index occurred compared to the matched control. However, low levels of sodium nitroprusside treatment did not affect the acrosome reaction and human zona-free oocyte sperm penetration rates. CONCLUSION(S): Low concentrations of nitric oxide may have some physiologic role in fertilization through the enhancement of capacitation and zona pellucida binding but not by the induction of the acrosome reaction or the facilitation of penetration into oocytes.

Acrosome↗
PubMed1997

Analysis of the Rb gene and cyclin-dependent kinase 4 inhibitor genes (p16INK4 and p15INK4B) in human ovarian carcinoma cell lines.

In the present study, we analyzed human ovarian carcinoma cell lines for abnormalities in the tumor suppressor gene Rb (retinoblastoma) and in cyclin-dependent kinase 4 (CDK4) inhibitor genes (p16INK4 and p15INK4B) using molecular biology techniques. For the Rb gene, in all six cell lines (PA-1, Caov-3 and -4, OVCAR-3, SK-OV-3, and Kuramochi), Rb gene abnormality was not detected using Southern blotting. In the Caov-3 cell line transcripts were not detectable by either Northern blot or polymerase chain reaction. Sequence analysis of the entire coding region of the Rb gene revealed point mutations (AAC to GAC) resulting in codon 123 (Asn to Asp) changes in the Caov-4 cell line. In the PA-1 cell line both wild-type Rb and mutant-type Rb (codon 798: CGG to TGG) were expressed, and in the OVCAR-3 cell line both wild-type Rb and mutant-type Rb (codon 704: ATG to GTG) were expressed. In four of six human ovarian carcinoma cell lines Rb gene abnormality was detected. For the p16INK4 and p15INK4B genes, only the SK-OV-3 cell line had abnormalities. There was a gene rearrangement or minor deletion of the p16INK4 gene in the SK-OV-3 cell line, while the p15INK4B gene was deleted in this cell line. In the SK-OV-3 cell line no mRNAs of p16INK4 and p15INK4B were expressed. At the point of Rb gene inactivation, we can explain five cell lines of six: four cell lines had abnormalities in the Rb gene itself, which is another mechanism by which the Rb gene is inactivated, while one cell line (SK-OV-3) had abnormalities in CDK4 inhibitor genes, another of the inactivation mechanisms of the Rb gene. These data suggest that abnormalities of Rb and CDK4 inhibitor genes (p16INK4, p15INK4B) may be involved in human ovarian carcinogenesis.

Carcinoma↗
PubMed1997

The chromosomal normality of unfertilized oocytes from patients with polycystic ovarian syndrome.

The present study was designed to compare the cycle characteristics of in-vitro fertilization (IVF) and the chromosomal normality of oocytes in patients with polycystic ovarian syndrome (PCOS) with those of patients with tubal factor infertility. In all, 28 cycles of 24 PCOS patients and 55 cycles of 31 patients with tubal factor infertility (control) were investigated. Although a significantly greater number of oocytes were retrieved from PCOS patients (mean +/- SD: 15.6 +/- 6.4 versus 9.0 +/- 4.0, PCOS versus control group, P < 0.05), the percentage of fertilized oocytes was significantly lower in the PCOS group compared with controls (40.1 versus 73.8%, P < 0.01). The pregnancy rate per embryo transfer did not differ between the two groups. Cytogenetic analysis was performed on 74 oocytes from PCOS patients and 73 oocytes from control patients. In the PCOS group, 10 of the 74 oocytes (13.5%) demonstrated aneuploidy, four (5.4%) oocytes were diploid and six (8.1%) oocytes were metaphase II with a prematurely condensed sperm chromosome (PCC). In the tubal infertility group, nine of the 73 (12.3%) oocytes showed aneuploidy, four (5.5%) oocytes were diploid and five (6.8%) oocytes were found to have PCC. There was no significant difference in the aneuploidy, diploidy and PCC rates between the two groups. These results suggest that the reduced fertilization observed in PCOS is not attributable to chromosomal aberrations or immaturity of oocytes recruited from patients with PCOS.

Adult↗