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Biomedical subjects

H Oku

Publications and source records attributed to H Oku.

At least 19 recordsLinked to original sources
PubMed2006

Successful delivery after the transfer of twice-vitrified embryos derived from in vitro matured oocytes: a case report.

We report here the first case of successful pregnancy and delivery after the blastocyst transfer of twice-vitrified embryos produced following in vitro maturation (IVM) and ICSI. The patient received 5000 IU hCG on day 12 of the treatment cycle, and oocyte retrieval was carried out 36 h after hCG injection. A total of 22 immature oocytes were obtained. Following incubation for 26 h in IVM medium, 15 oocytes (68.2%) reached metaphase II stage. In total, 13 oocytes (86.7%) were fertilized after ICSI with the husband's sperm, and 11 embryos at the pronuclear stage and two cleaved embryos on day 2 were vitrified because of thin endometrial thickness. Eight cryopreserved embryos at the pronuclear stage were warmed and cultured until the day 3 stage. Three embryos were transferred, and three embryos were twice vitrified. Unfortunately, these transferred embryos did not implant. Three twice-vitrified embryos were rewarmed and cultured until the day 5 stage, and two embryos were transferred. The second transfer attempt of twice-vitrified embryos resulted in the full-term delivery of a healthy infant. This case report demonstrates that twice-vitrified embryos, developed using an IVM protocol, retain the developmental competence for full-term, healthy infants.

Adult↗
PubMed2006

Spontaneous scratching behaviour in DS-Nh mice as a possible model for pruritus in atopic dermatitis.

Itching is one of the major clinical symptoms in atopic dermatitis (AD) and complicates the management of this pathological condition. An animal model of AD-like pruritus would contribute to a better understanding of AD and could lead to the development of safe and effective antipruritic agents. DS non-hair (DS-Nh) mice raised under conventional conditions spontaneously develop pruritus, which is associated with a dermatitis similar to human AD. There is a significant positive correlation between disease severity and the period of scratching behaviour in DS-Nh mice. In the present study, we found that levels of histamine and nerve growth factor (NGF) in serum and/or skin tissue were higher in DS-Nh mice with AD-like dermatitis than in age-matched mice without dermatitis. The histopathological data indicated that nerve fibres extend into and mast cells infiltrate the surrounding area of the skin lesion. NGF production by XB-2 cells, which was derived from mouse keratinocytes, was enhanced by histamine via the H1 receptor. We also found that prolonged treatment with an H1-antagonist was effective against pruritus through depression of the production of NGF, which is thought to be generated by keratinocytes. We conclude that DS-Nh mice can serve as a suitable model for gaining a better understanding of pruritus in AD, and that prolonged treatment with an H1-antagonist may be beneficial in patients with AD-associated pruritus.

Animals↗
PubMed2005

Ocular blood flow changes after dynamic exercise in humans.

PURPOSE: To investigate control mechanisms for ocular blood flow changes after dynamic exercise using two different methods. METHODS: Changes over time in the tissue blood flow in the retina and choroid-retina of healthy volunteers were determined after dynamic exercise (Master's double two-step test), using scanning laser Doppler flowmetry (SLDF) and laser speckle flowgraphy (LSFG). Changes in intraocular pressure (IOP), blood pressure, plasma CO(2) gas concentration (pCO(2)), and levels of nitric oxide (NO) metabolites were examined. RESULTS: Retinal blood flow measured by SLDF increased significantly only at 15 min after exercise. In contrast, normalized blur (NB) values in the choroid-retina, obtained by LSFG, increased significantly up to 60 min after exercise. Ocular perfusion pressure (OPP), calculated from IOP and blood pressure, increased significantly immediately and 15 min after exercise. The plasma NO metabolite levels increased significantly, although pCO(2) levels were unchanged. CONCLUSIONS: Dynamic exercise changes OPP and produces increased tissue blood flow in the retina in the immediate postexercise period, while blood flow increases more persistently in the choroid-retina. Difference in control of blood flow in these two regions may be related to stronger autoregulatory mechanism of blood flow in the retina. Nitric oxide may play a role in the regulation of blood flow.

Adult↗
PubMed2005

Synthesis, crystal structure and molecular conformation of Nalpha-Boc-L-leucyl-(Z)-beta-(3-pyridyl)-alpha,beta- dehydroalanyl-L-leucine methyl ester.

A protected tridehydropeptide containing (Z)-beta-(3-pyridyl)-alpha,beta-dehydroalanine (Delta(Z)3Pal) residue, Boc-Leu-Delta(Z)3Pal-Leu-OMe (1), was synthesized via Erlenmeyer azlactone method. X-ray crystallographic analysis revealed that the peptide 1 adopts an extended conformation, which is similar to that of a Delta(Z)Phe analog, Boc-Leu-Delta(Z)Phe-Leu-OMe (2).

Crystallography, X-Ray↗
PubMed2004

Role of IL-18 in pathogenesis of endometriosis.

BACKGROUND: Endometriosis is a complex disease associated with a wide range of immune responses, including pain, adhesion, exudation of peritoneal fluid, elevation of cytokine levels and generation of autoantibodies. Interleukin (IL)-18 is a strong pleiotropic cytokine known to be involved in various immune diseases. The aim of this study is to elucidate the role of IL-18 in the pathogenesis of endometriosis. METHODS: IL-18 and IL-1beta concentrations were measured in the peritoneal fluid and sera of 39 endometriosis patients and 15 control women. Expression of IL-18 and IL-18 receptor alpha-chain (IL-18Ralpha) was analysed in endometriotic tissues immunohistochemically. The effects of IL-18 on cyclooxygenase (COX)-II gene expression were analysed in peritoneal fluid monocytes and endometriotic cells of endometriosis patients. RESULTS: IL-18 concentrations in the peritoneal fluid of endometriosis patients averaged 592.57 +/- 108.27 pg/ml, significantly higher than 260.50 +/- 55.88 pg/ml in non-endometriotic samples. IL-18 concentrations in the serum did not differ significantly between endometriosis and control patients. Similarly, no significant differences were observed in IL-1beta concentrations in either the peritoneal fluid or the serum. IL-18 and IL-18Ralpha were expressed in endometriotic tissues. IL-18Ralpha expression was also observed in cells infiltrating into the inflammatory area of the endometriosis patients. COX-II was induced in peritoneal fluid monocytes and in endometriotic cells in response to IL-18 stimulation. CONCLUSIONS: The elevation of IL-18 in the peritoneal fluid of endometriosis patients and the induction of COX-II in peritoneal monocytes by IL-18 suggest that IL-18 plays a pathogenic role in endometriosis.

Adult↗
PubMed2004

Facile synthesis of Nalpha-protected-L-alpha,gamma-diaminobutyric acids mediated by polymer-supported hypervalent iodine reagent in water.

Hofmann rearrangement of Nalpha-Boc-L-Gln-OH mediated by a polymer-supported hypervalent iodine reagent poly[(4-diacetoxyiodo)styrene] (PSDIB) in water afforded Nalpha-Boc-L-alpha,gamma-diaminobutyric acid (Boc-Dab-OH, 1) in 87% yield. Nalpha-Z-derivative (Z-Dab-OH, 2) was prepared with PSDIB in 83% yield. Since the reaction of Nalpha-Fmoc-Gln-OH by this procedure did not proceed because of the insolubility of Fmoc-Gln-OH in aqueous media, we synthesized Fmoc-Dab(Boc)-OH (5) from 2 in 54% yield. Polymyxin B heptapeptide (PMBH) which contains four Dab residues was successfully synthesized in a solution-phase synthesis.

Amino Acids↗
PubMed2004

Pirfenidone attenuates expression of HSP47 in murine bleomycin-induced pulmonary fibrosis.

Heat shock protein (HSP) 47, a collagen-specific molecular chaperone, is involved in the processing and/or secretion of procollagen. The present study was undertaken to investigate whether treatment with the antifibrotic drug pirfenidone attenuates the bleomycin (BL)-induced overexpression of HSP47 in the lungs. Male ICR mice were intravenously injected with BL or saline (SA). Pirfenidone or control drug (CD) was administered 14 days after commencement of BL or SA, and continued throughout the course of the experiment. The mice were randomly divided into three experimental groups: 1) SA-treated with CD (SA group); 2) BL-treated with CD (BL group); and 3) BL-treated with pirfenidone (pirfenidone group). Lungs of the pirfenidone group showed a marked reduction of fibrotic lesions compared with the corresponding BL group. Immunohistochemical studies showed that BL treatment significantly increased the number of macrophages, myofibroblasts, HSP47-positive type II pneumocytes and HSP47-positive interstitial spindle-shaped cells. Treatment with pirfenidone significantly reduced the number of these cells compared with the corresponding BL group. Furthermore, treatment with pirfenidone significantly suppressed the BL-induced increase of the positive ratio of HSP47 and alpha-smooth muscle actin to interstitial spindle-shaped cells. The present study results showed that pirfenidone inhibited heat shock protein 47-positive cells and myofibroblasts, the principal cells responsible for the accumulation and deposition of extracellular matrix seen in pulmonary fibrosis.

Analysis of Variance↗
PubMed2003

Conformation of the transmembrane domains in peripheral myelin protein 22. Part 1. Solution-phase synthesis and circular dichroism study of protected 17-residue partial peptides in the first putative transmembrane domain.

Charcot-Marie-Tooth disease (CMT) is the most commonly inherited peripheral neuropathy. DNA duplication and point mutation of the gene encoding peripheral myelin protein 22 (PMP22) have been found in CMT type 1A dominants. To investigate the influence of the point mutation of PMP22 on the secondary structure, protected partial peptides in the putative first transmembrane domain, wild type Boc-IVLH(Bom)VAVLVLLFVSTIV-OMe (1) and its Pro16 mutant Boc-IVLH(Bom)VAVPVLLFVSTIV-OMe (2) were synthesized. Circular dichorism (CD)-spectral analysis suggested that peptide 1 adopts a stable alpha-helical conformation in membrane-mimetic solvent,1-BuOH/1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) system. On the contrary, the mutant 2 favors beta-sheet conformation in the same solvent system. Interestingly, alpha-helix to beta-sheet transition of 2 was observed at higher contents of 1-BuOH than 70%.

Amino Acid Sequence↗
PubMed2002

Onset of complete atrioventricular block 15 years after ventricular septal defect surgery.

A 4-month-old girl with a ventricular septal defect underwent cardiac surgery. During the operation, complete atrioventricular block (CAVB) occurred, but on postoperative day 16 it converted to normal sinus rhythm with persistent complete right bundle branch block and left anterior hemiblock. Fourteen years after the operation, second-degree atrioventricular block was detected, but her general condition was good. Fifteen years after the operation, CAVB occurred. The intracardiac electrophysiologic recording revealed A-H and H-V block. A permanent pacemaker was implanted, and following the implantation she completely recovered.

Adolescent↗
PubMed2002

Off-pump coronary bypass grafting to double vessel disease with the pharmacological assist of esmolol. An experimental study.

BACKGROUND: To demonstrate the surgical efficacy and safety of off-pump coronary bypass grafting to double- or triple-vessel disease, we performed off-pump double bypass grafting using a brief local coronary occlusion with the pharmacological assist of esmolol. METHODS: These experiments were conducted in 30 canine hearts with the left internal thoracic artery (ITA) grafted to the circumflex coronary artery (CFX) and the right ITA grafted to the left anterior descending coronary artery (LAD), off pump, using a brief local coronary occlusion through the left minithoracotomy. The coronary anastomosis was performed using a brief local occlusion of the coronary artery. An anastomosis between the left ITA and the CFX was done first, and then the right ITA and the LAD were anastomosed. Thirty animals were divided into 2 groups, group A (n=15) receiving esmolol just before (10 mg/kg on a bolus) and during the coronary artery occlusion (500 microg/kg/min continuously), and group B (n=15) without administrating esmolol as a control. RESULTS: Operative deaths were 4 in group B and all of group A animals survived (p<0.05). All deaths were attributable to ventricular arrhythmias during/after coronary occlusion. Group B animals necessitating longer coronary occlusion time (more than 15 min) were more likely to fibrillate and more difficult to resuscitate than group A animals requiring coronary occlusion time more than 15 min. Segmental shortening on the echocardiogram demonstrated no significant difference between group A and B in both anterior and posterior wall segment. However, echocardiogram in animals necessitating coronary occlusion time more than 15 min demonstrated that segmental shortening in group A were better than in group B (18 vs 11%, p<0.05), and comparatively greater but not significant in the posterior wall (19 vs 14%). CONCLUSIONS: The use of esmolol may be recommended to off-pump coronary bypass even to the double-vessel bypass, in order to make off-pump approach safer.

Adrenergic beta-Antagonists↗
PubMed2002

[Pitfall of modified ultrafiltration in pediatric cardiac surgery].

Since June, 1998, modified ultrafiltration (MUF) was performed for 92 consecutive children who underwent cardiac surgery using cardiopulmonary bypass, except those with atrial septal defect. Among 92 cases, MUF could not be completed in two cases because of the accident that many air bubbles were found in the arterial line of the CPB circuit. The causes of such trouble were discussed.

Cardiopulmonary Bypass↗
PubMed2001

Analysis of microsatellite instability and loss of heterozygosity in uterine endometrial adenocarcinoma.

Microsatellite instability (MSI) and loss of heterozygosity (LOH) were examined in 60 cases of uterine endometrial adenocarcinoma, using 13 microsatellite markers. In non-Smad-related regions, MSI and LOH were noted in 13 of 60 (21.7%) and in 20 of 60 (33.3%) cases, respectively. Genetic alternation of TGF-beta RII was noted in 1 of 60 cases (1.7%). The frequency of MSI and LOH was highest in Stages III and IV, respectively. Cases with G2 carcinoma showed the highest frequency, but LOH frequency did not differ among G1, G2, and G3 carcinoma cases. In Smad-related microsatellite regions, MSI and LOH were noted in 10 of 60 (16.7%) and in 12 of 60 (20.0%) cases, respectively. The frequency of MSI and LOH was highest in Stages III and IV, respectively. LOH was seen only in the Smad2 gene but not in the Smad4 gene. Our results suggest that the alterations in MSI and LOH were associated with middle and late stages of carcinogenesis of endometrial carcinoma. Both MSI and LOH tended to show an association with moderate to severe atypia of carcinoma. Our results also suggest that genetic alteration of the Smad2 gene is more responsible for endometrial carcinogenesis than that of the Smad4 gene. However, the TGF-beta type II receptor gene was considered a minor target of genetic instability in endometrial carcinogenesis.

Adenocarcinoma↗
PubMed2001

Crystal structure of a depsipeptide, Boc-(Leu-Leu-Lac)3-Leu-Leu-OEt.

A sequential polydepsipeptide, Boc-(Leu-Leu-Lac)3-Leu-Leu-OEt (1) (Lac = L-lactic acid residue) has been synthesized by the segment condensation method. The sequential unit of 1, -Leu-Leu-Lac-, is consisted of two amino acid residues and one hydroxy acid residue. X-ray diffraction measurement with an imaging plate detector and a direct-methods procedure of Shake-and-Bake successfully revealed the crystal structure of 1. In the solid state, the 11-mer depsipeptide, 1, have clear alpha-helical conformation even with the three ester linkages.

Crystallization↗
PubMed2001

Antipruritic and antidermatitic effect of extract and compounds of Impatiens balsamina L. in atopic dermatitis model NC mice.

We examined the effects of a 35% ethanol extract (IB) from the petals of Impatiens balsamina L. and the principal active compounds from IB on chronic and serious pruritus and the development of dermatitis using NC mice, a model of atopic dermatitis. IB at 100 mg/kg significantly inhibited serious scratching behaviour in the NC mouse with established dermatitis when administered i.v. 1 h before, or p.o. 24 h before the measurement. A 10 microg/kg dose of kaempferol 3-rutinoside and 2-hydroxy-1,4-naphthoquinone (lawsone) isolated from IB also inhibited scratching behaviour in the NC mouse with established dermatitis. When 4-week-old NC mice with no symptoms were administered orally 100 mg/kg/day of IB until 13 weeks of age, protection was also noted against scratching behaviour during the development of dermatitis. IB was effective for the prevention and treatment of atopic dermatitis.

Animals↗
PubMed2001

Modified ultrafiltration may improve postoperative pulmonary function in children with a ventricular septal defect.

To evaluate the effectiveness of modified ultrafiltration (MUF) on ventricular septal defect (VSD) repair in children, we retrospectively examined 10 patients who underwent VSD repair with MUF at the Kinki University School of Medicine hospital between June 1998, and December 1998 (MUF group). These patients were compared with 14 patients who underwent the same procedure without MUF (control group) between January 1997 and June 1998. Systolic blood pressure and hematocrit values increased significantly during MUF. By the time of postoperative transfer to the intensive care unit, PaO2 was higher in the MUF group than in the control group (503.3 +/- 112.2mmHg vs 376.3 +/- 149.2mmHg; P = 0.0491), whereas A-aDO2 was lower in the MUF group than in the control group (171.9 +/- 109.2mmHg vs 301.1 x 150.4mmHg; P = 0.0449). These findings demonstrate that MUF had a beneficial effect on pulmonary function in children who underwent surgery to repair a VSD.

Cardiopulmonary Bypass↗
PubMed2001

Treatment of deep infection following thoracic aorta graft replacement without graft removal.

Deep infection following thoracic aortic replacement constitutes an extremely serious and life-threatening complication, and its treatment remains a challenge to surgeons. We report our experience involving five patients in whom deep infection occurred around the graft. Four of the five patients were treated by emergency surgery and one was treated by elective surgery. Surgical procedures performed including hemiarch replacement in one case, total arch replacement in one case, suspension of aortic valve and ascending aorta replacement in one case, Bentall procedure in one case, and descending aorta re-replacement in one case. Methicillin-resistant Staphylococcus aureus was detected in four patients, methicillin-resistant Staphylococcus epidermidis in one, and Aspergillus in one patient from purulent discharge at the operative site. Reoperative debridement and irrigation drainage were carried out at an early phase of infection. Intermittent irrigation following the reoperation was performed in all cases. In addition, muscle flap filling or omental translocation was carried out in three patients. Although the reported principle of treatment for arterial graft infection is extraanatomical bypass or rereplacement after removal of the infected graft, such procedures may be technically difficult and have a high risk at the thoracic level. Local anti-septic irrigation, administration of antibiotics, and vascular-rich tissue filling are useful procedures, and it appears that it is not always necessary to remove prosthetic grafts.

Adult↗
PubMed2001

Surgical strategy for left ventricular free wall rupture after acute myocardial infarction.

BACKGROUND: Left ventricular free wall rupture is usually fatal without surgical intervention. However, the most appropriate surgical procedure remains controversial. METHODS: Seventeen patients (14 men, 3 women) who developed left ventricular free wall rupture after acute myocardial infarction were treated surgically. Their mean age was 65.4 years (range, 55 to 79 years). The following surgical procedures were performed: infarctectomy and patch reconstruction in 1 patient, direct closure with or without patch covering in 4 patients, simple patch covering anchored by running suture in 4 patients, and a sutureless technique in 7 patients. Endventricular patch closure was performed in 1 patient with ventricular septal perforation. RESULTS: One of 3 patients with a blow-out type rupture and 1 of 13 patients with an oozing type rupture died shortly after operation. The overall surgical mortality rate was 11.8%. CONCLUSIONS: Selection of the optimal procedure for each cardiac condition is important for obtaining good results. For patients with ongoing squirting bleeding, patch covering is the technique of choice. For oozing, the sutureless technique is preferable.

Aged↗