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Biomedical subjects

R Aoki

Publications and source records attributed to R Aoki.

At least 19 recordsLinked to original sources
PubMed2006

Flap-in-flap method for enhancing the advancement of a V-Y flap.

The V-Y principal is used in a number of flap reconstruction techniques. V-Y flaps suffer from design problems of the advancing edge, which is usually concave, trying to match another concave edge on the opposite side of the defect. The flap-in-flap technique uses a second V-Y flap at the advancing edge of the main flap to overcome this mismatch, and also improves the amount of advancement possible. The technique has been used in three patients, demonstrating reliability and a further advantage, which is the ability of the second flap to rotate at an angle to the main flap to aid in reconstructing a complex defect such as the alar base of the nose. Further experience with this technique should widen its applications.

Aged↗
PubMed2005

Penis reconstruction using three different operative methods.

To identify the relative success rates, including aesthetic success, of three penis reconstruction techniques, we reviewed 44 cases of penis reconstruction carried out over the past 12 years. The three operative methods we surveyed involved: lower abdominal pedicled fascia flaps; paraumbilical island flaps; and free forearm flaps. Reconstructions survived in only half of the patients receiving lower abdominal pedicled fascia flaps, but 100% success rates were obtained with paraumbilical island flaps and free forearm flaps. The paraumbilical island flap is safe in terms of its blood supply, and the operative procedure is relatively simple in that it does not require microsurgery. Although, the flap is thicker than the forearm skin flap, its shape is satisfactory in slim patients; furthermore, it can be defatted secondarily. The free forearm skin flap provides the best shape, but skilled microsurgery is necessary to carry out the procedure, and damage is likely to the forearm. In conclusion, the best methods to repair defects in the penis in our experience are the paraumbilical island flap and free forearm flap. Lower abdominal pedicled fascia flaps are unsuitable for penile reconstruction and should be used less often.

Abdomen↗
PubMed2005

A novel diagnostic method for evaluation of vascular lesions in the digestive tract using infrared fluorescence endoscopy.

BACKGROUND AND STUDY AIMS: We have developed an infrared fluorescence endoscope to evaluate gastrointestinal vascular lesions. Infrared endoscopy (IRE) after intravenous administration of indocyanine green (ICG) is used at present to examine vascular lesions such as esophageal varices. However, no previous study has compared the sensitivity of infrared fluorescence endoscopy (IRFE) with that of IRE. In this study, we compared the usefulness of IRFE and IRE. PATIENTS AND METHODS: For IRFE we used an infrared endoscope equipped with excitation and barrier filters and an intensified charge-coupled device camera. In preliminary experiments, the observable tissue depth was assessed by wrapping increasing numbers of layers of commercially available pork around a syringe containing a uniform concentration of ICG or by changing the concentration of ICG in a syringe covered by a piece of pork of uniform thickness. In the clinical part of the study, ICG was administered intravenously at different concentrations to patients with esophageal varices and the resulting infrared fluorescent images were evaluated. RESULTS: The preliminary experiments revealed that the depth of tissue that could be visualized was significantly greater in IRFE than it was in IRE (11.2 mm in IRFE vs. approximately 3.2 mm in IRE). Clear infrared fluorescence was obtained by IRFE at lower concentrations of ICG than the concentrations required to obtain clear images using IRE. In the clinical part of the study, clear infrared fluorescence was observed in a region where esophageal varices had been detected by conventional endoscopy when ICG was administered in doses of 0.005 mg/kg to 0.01 mg/kg, which was lower than the doses used in IRE. CONCLUSIONS: Compared with conventional IRE, IRFE facilitated the observation of deeper layers, and esophageal varices were observed by IRFE following the intravenous administration of a markedly reduced dose of ICG. IRFE, in combining the characteristics of reflected infrared light and fluorescence, may be a useful novel procedure in the diagnosis of vascular lesions in the gastrointestinal tract.

Aged↗
PubMed2005

Effect of famotidine on recurrent bleeding after successful endoscopic treatment of bleeding peptic ulcer.

AIM: We investigated the effect of acid suppression therapy on recurrent bleeding after successful endoscopic treatment of bleeding peptic ulcer. METHODS: A total of 400 patients with bleeding peptic ulcer received either intravenous infusion of famotidine (40 mg/day) (n = 207, 163 males, 44 females, mean age 61.5 years) or drip infusion of omeprazole (40 mg/day; n = 193, 134 males, 59 females, mean age 59.8 years) after successful endoscopic treatment. The fasting duration, hospital stay, volume of transfused blood, incidence of rebleeding and mortality were compared between the two groups. RESULTS: The incidence of rebleeding did not differ significantly between the famotidine group (9%) and the omeprazole group (8%). The mean hospital stay was significantly shorter in the omeprazole group (18.4 days) than in the famotidine group (21.5 days, P = 0.009). However, there was no statistically significant difference in fasting duration, volume of transfused blood or mortality. CONCLUSION: Our findings indicate that intravenous infusion of famotidine after successful endoscopic treatment is equivalent to drip infusion of omeprazole for prevention of recurrent bleeding.

Adolescent↗
PubMed2003

A rare case of intracranial metastatic amelanotic melanoma with cyst.

A rare case of intracranial metastatic amelanotic melanoma with cyst is presented. The patient was a 51 year old woman with a malignant melanoma arising on her right chest. Two years after a wide excision, skin and brain metastasis occurred. Brain magnetic resonance images demonstrated a tumour with a cyst in the left occipital lobe. Because the tumour showed low intensity on T1 weighted images and high intensity on T2 weighted images, the metastatic melanoma was identified as an amelanotic melanoma. Intracranial amelanotic melanoma is very rare, and there have been few reports of melanoma with cyst.

Brain Diseases↗
PubMed2002

Comparative functional morphology of the masticatory apparatus in the long-snouted crocodiles.

The masticatory muscles and their related structures of the skull were observed in the Indian gavial (Gavialis gangeticus), the false gavial (Tomistoma schlegelii), and the African slender-snouted crocodile (Mecistops cataphractus) to detail some morphological differences in comparison with the other crocodile species, and to compare and elucidate the functional strategy of themasticatory apparatus in these long-snouted species. The Musculus pterygoideus posterior was relatively smaller in the three species compared with many short-snouted crocodiles. It suggests that the masticatory power in fish-eating long-snouted species is not so high as in the short-snouted crocodiles, while the masticatory muscles were morphologically different among the three long-snouted species as follows. The M. pterygoideus posterior of the false gavial was extended in the lateral side of the lower jaw unlike the Indian gavial. The M. pseudotemporalis and the Fenestra supratemporalis were largely developed in the Indian gavial, however we suggest that the other two species possess the weak bundles in this muscle. The false gavial and the African slender-snouted crocodile have the pterygoid bone well-developed extending dorso-ventrally and it is suggested that the M. adductor mandibulae posterior attached to the pterygoid bone may be much larger than the Indian gavial. These data morphologically clarify the masticatory mechanism in the long-snouted crocodiles different from the short-snouted species, and demonstrate that the evolutional strategy to share the functional role in the masticatory muscles have been differently established between the Indian gavial and the other two species. We also obtained the morphological data in the fossil skull of the Machikane crocodile (Toyotamaphymeia machikanense) and concluded from the fossil characters that the considerable developments of the M.pterygoideus posterior and the M.pseudotemporalis in this species had not morphologically been consistent with both the Indian and false gavials.

Alligators and Crocodiles↗
PubMed2002

The microvascular augmented subdermal vascular network (ma-SVN) flap: its variations and recent development in using intercostal perforators.

In 1994 we reported the use of the microvascular augmented occipito-cervico-dorsal 'super-thin' flap for reconstruction of the cervical region in three cases. Since this preliminary report, we have performed a further 17 flaps, and the usefulness of the flap in the treatment of anterior cervical scar contractures in extensively burned patients has become apparent. Moreover, we have devised flaps with not only a narrow skin pedicle but also myocutaneous or island vascular pedicles. Various augmentation vessels, including myocutaneous perforators of the intercostal spaces in the back and chest, have also been used successfully. Here, we describe the microvascular augmented subdermal vascular network flaps that we have devised.

Adolescent↗
PubMed2002

An anatomical and clinical study of the dorsal intercostal cutaneous perforators, and application to free microvascular augmented subdermal vascular network (ma-SVN) flaps.

We report a two-part anatomical and clinical study whose aim was to map the dominant dorsal intercostal cutaneous perforators (DICPs), which are useful for microvascular augmentation of flaps raised from the skin of the back called subdermal vascular network (SVN) flaps, and to test their reliability in the clinical setting. In the anatomical arm of the study, using preserved cadavers, we macroscopically confirmed the location of DICPs, and performed micro-angiography of the dorsal skin to find each dominant DICP. In the clinical arm of the study, we confirmed the location of the dominant DICP during microvascular augmented SVN flap transfer. Postoperatively, posteroanterior radiographs of the chest were taken to locate vessel clips used to ligate the DICPs. The combined study results showed that the dominant DICP is the sixth or seventh in most instances, but there are some anatomical variations. If no dominant DICP is found in the sixth or seventh spaces, at least one DICP that is of sufficient calibre for microvascular augmentation can usually be found in the general vicinity, such as the fifth, eighth or ninth spaces. The clinical application of microvascular augmented SVN flaps, both pedicled and free, is presented.

Adult↗
PubMed2001

Identification of a novel kinesin-related protein, KRMP1, as a target for mitotic peptidyl-prolyl isomerase Pin1.

Mitosis utilizes a number of kinesin-related proteins (KRPs). Here we report the identification of a novel KRP termed KRMP1, which has a deduced 1780-amino acid sequence composed of ternary domains. The amino-terminal head domain is most similar to the kinesin motor domain of the MKLP-1 subfamily and has an intrinsic ATPase activity that is diminished by substituting the consensus Lys-168 with Arg. The central stalk domain is predicted to form a long alpha-helical coiled-coil, and can interact with each other in vivo. An in vivo labeling experiment revealed that KRMP1 is phosphorylated, and we also found that the region within the tail domain containing Thr-1604 as the cdc2 kinase phosphorylation site differs from the bimC box conserved in the bimC subfamily of KRPs. Immunofluorescence analysis showed that endogenous KRMP1 was localized predominantly to the cytoplasm during interphase and dispersed throughout the cell during mitosis. Consistent with this finding, overexpressed KRMP1 was detected in a complicated nuclear or cytoplasmic pattern reflecting multiple nuclear localization/export signals. Furthermore, KRMP1 interacted with the mitotic peptidyl-prolyl isomerase Pin1 in vivo, and an in vitro interaction was detected between the tail domain of KRMP1 and the WW domain of Pin1. Overexpression of KRMP1 caused COS-7 cells to arrest at G(2)-M, and co-expression of Pin1 reversed this effect, indicating their physiological interaction. Together, our results suggest that KRMP1 is a mitotic target regulated by Pin1 and vice versa.

Amino Acid Sequence↗
PubMed2001

Recombinant forms of tetanus toxin engineered for examining and exploiting neuronal trafficking pathways.

Tetanus toxin is a fascinating, multifunctional protein that binds to peripheral neurons, undergoes retrograde transport and trans-synaptic transfer to central inhibitory neurons where it blocks transmitter release, thereby, causing spastic paralysis. As a pre-requisite for exploiting its unique trafficking properties, a novel recombinant single chain was expressed at a high level in Escherichia coli as a soluble, easily purifiable protein. It could be activated with enterokinase to produce a dichain that matched native toxin in terms of proteolytic and neuroinhibitory activities, as well as induction of spastic paralysis in mice. Importantly, nicking was not essential for protease activity. Substitution of Glu(234) by Ala created a protease-deficient atoxic form, which blocked the neuroparalytic action of tetanus toxin in vitro, with equal potency to its heavy chain; but, the mutant proved >30-fold more potent in preventing tetanus in mice. This observation unveils differences between the intoxication processes resulting from retrograde transport of toxin in vivo and its local uptake into peripheral or central nerves in vitro, dispelling a popularly held belief that the heavy chain is the sole determinant for efficient trafficking. Thus, this innocuous mutant may be a useful vehicle, superior to the heavy chain, for drug delivery to central neurons.

Amino Acid Sequence↗
PubMed2001

Human ABCA1 contains a large amino-terminal extracellular domain homologous to an epitope of Sjögren's Syndrome.

ABCA1 has been suggested to play a key role in cellular lipid release from peripheral cells. In order to study structure-function relationship of this protein, the protein product of a full-length human ABCA1 cDNA was examined for its functions and topological orientation. The electrophoretic mobilities of human ABCA1 expressed in transfected cells increased when treated with N-glycosidase F, suggesting that ABCA1 is highly glycosylated. The ABCA1 was photoaffinity-labeled with ATP and mediated the apoA-I-dependent-release of cholesterol and phospholipid. The influenza hemagglutinin (HA) epitope was introduced into the amino-terminus (N-HA) or between the residues 207 and 208 (207-HA) of the protein. While an antibody against the C-terminus peptide of ABCA1 detected both fusion proteins, an anti-HA antibody did not react with the N-HA fusion protein. Confocal microscopy demonstrated strong cell surface signal with the anti-HA antibody of nonpermeabilized HEK293 cells expressing the 207-HA fusion protein. The results suggested that the signal peptide in the amino-terminal region is cleaved off in its mature form and that the following large hydrophilic region is exposed to outside of cells unlike previously proposed models. We found that this amino-terminal extracellular domain contains a segment homologous to the autoantigen SS-N, an epitope of Sjögren's syndrome, and further identified that ABCA7 codes for the autoantigen SS-N.

ATP Binding Cassette Transporter 1↗
PubMed2000

Nationwide epidemiological survey of chronic pancreatitis in Japan.

The aim of this study was to estimate the number of patients treated for chronic pancreatitis in 1994 in Japan and to explore the clinico-epidemiological features of chronic pancreatitis. Two surveys were conducted. Stratified random sampling was used to select departments in which patients with chronic pancreatitis were treated, and two different questionnaires were administered to obtain relevant information. From the first survey, the total number of patients treated for chronic pancreatitis in Japan in the year 1994 was estimated as 32,000 (95% confidence interval, 25,000-39,000). Clinico-epidemiological features, based on the 2,523 patients reported from the second survey, were subsequently clarified. The sex ratio (male/female) of the patients was 3.5. Alcoholic pancreatitis was the most common type in males (68.5%), and idiopathic pancreatitis in females (69.6%). Compared with the findings in the last survey in 1985, the proportion of patients with alcoholic pancreatitis has decreased slightly, from 58.7% to 55.5%, while that of idiopathic chronic pancreatitis has increased in both males and females. Patients diagnosed by advanced techniques such as computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) accounted for 68.1% of the total. The number of patients with chronic pancreatitis treated in 1994 in Japan, was estimated as 32,000, with an overall prevalence rate of 45.4 per 100,000 population in males and 12.4 per 100,000 population in females.

Adolescent↗
PubMed2000

A fluorescent indicator for visualizing cAMP-induced phosphorylation in vivo.

We have developed a method for visualizing phosphorylation of proteins in living cells using a novel fluorescent indicator composed of two green fluorescent protein (GFP) variants joined by the kinase-inducible domain (KID) of the transcription factor cyclic adenosine monophosphate (cAMP)-responsive element binding protein (CREB). Phosphorylation of KID by the cAMP-dependent protein kinase A (PKA) decreased the fluorescence resonance energy transfer (FRET) among the flanking GFPs. By transfecting COS-7 cells with an expression vector encoding this indicator protein (termed ART for cAMP-responsive tracer), we were able to visualize activation dynamics of PKA in living cells.

Amino Acid Sequence↗
PubMed2000

Recent molecular approaches to elucidate the mechanism of embryo implantation: trophinin, bystin, and tastin as molecules involved in the initial attachment of blastocysts to the uterus in humans.

Elucidation of the implantation mechanism in humans at the molecular level has been difficult because of methodological restrictions. Instead of using human materials during the implantation period, two human tumor cell lines that respectively mimic the biological behaviors of a blastocyst and uterine luminal epithelial cells were utilized successfully to identify three novel adhesion molecules named trophinin, bystin, and tastin. Trophinin is a membrane protein strongly expressed both on the apical surface of the trophectoderm of a simian blastocyst and at a putative implantation site of the human endometrium. Bystin and tastin are cytoplasmic proteins that associate with trophinin by presumably forming an active adhesion machinery. The expression patterns of these molecules are suggestive of their involvement in the initial blastocyst attachment to the uterus as well as in the subsequent placental development. Future perspectives in molecular implantation research are also discussed in relation to breakthroughs in assisted reproduction.

Animals↗
PubMed2000

Gonadotropin-releasing hormone analogue therapy for peritoneal inclusion cysts after gynecological surgery.

OBJECTIVE: The purpose of this report is to estimate the effectiveness of gonadotropin-releasing hormone analogue (Gn-RHa) therapy for peritoneal inclusion cysts. METHODS: Patients who had cystic masses that developed after gynecological surgery and were strongly suspected of being peritoneal inclusion cysts based on the results of ultrasound, magnetic resonance imaging (MRI), and tumor marker studies, were treated with a Gn-RHa (buserelin acetate or leuprorelin acetate). Buserelin acetate was administered at a dose of 900 microg/day, and leuprorelin acetate at a dose of 3.75 mg/month. Ultrasonography was performed in the outpatient clinic every 2 weeks after the start of administration to measure the diameter of cysts. RESULTS: We treated 8 patients with peritoneal inclusion cysts conservatively with a Gn-RHa. The cysts resolved in 7 of the patients. Two of them developed a recurrence, but further Gn-RHa therapy was followed by complete resolution of the cysts in one patient and we resume Gn-RHa therapy to the other patient. The peritoneal inclusion cysts failed to shrink in only one patient. CONCLUSION: It is suggested that Gn-RHa therapy is effective in some cases of peritoneal inclusion cysts.

Adult↗
PubMed2000

Sleep patterns and total mortality: a 12-year follow-up study in Japan.

A population-based cohort study was conducted to assess the relationship between total mortality and self-reported sleep patterns as regards not only to sleep duration but also subjective sleep quality. A total of 5,322 inhabitants in Gifu Prefecture, Japan, completed a self-administered questionnaire on health status and lifestyles including habitual sleep patterns, and were followed-up for an average of 11.9 years. Relative risks were computed by using Cox proportional hazards models. Both longer and shorter sleep, compared to 7-8 hour-sleep, was related to significantly increased risk of total mortality in males (relative risk [RR] for > or = 10 hours = 1.94, and RR for < 7 hour = 1.90), but not in females. Females complaining of poor awakening state experienced a higher mortality risk compared to those who woke up normally (RR: 1.97). Males who usually fell asleep easily showed a marginally lower mortality risk compared to those who fell asleep normally (RR: 0.70). Female users of sleeping pills were at an elevated risk (RR: 1.89). These findings were almost unchanged after adjustment for sleep duration and other confounders. Poor self-reported quality of sleep seemed to be associated with an increased risk of mortality independently of sleep duration.

Adult↗
PubMed2000

Rotation of subjective vertical is an important factor of visually-induced motion sickness.

Motion of visual scene (optokinetic stimulus) projected on a wide screen frequently induces motion sickness. Rotational movements of 3D visual images were analyzed to examine what factors are effective in visually-induced motion sickness and how the gravity contributes to its inducement. While an angle of a rotational axis of 3D visual image from the gravitational direction and its angle from the subjective vertical which was perceived by viewers through 3D visual image were varied, the severity of visually-induced motion sickness was measured.

Adult↗