Publications by authors named "Nakatsuka T"

Collagen matrix substitute dermis, or artificial dermis, has recently been developed to induce angiogenesis and fibroplasia in deep, poorly vascularized tissue defects, and its use is desirable as a means of achieving effective treatment with less invasion. However, it is difficult to apply collagen matrix to pressure ulcers, because they are usually accompanied by infection with discharge of excessive amounts of exudate or pus and generally exposed to external forces that prevent graft fixation. To overcome these difficulties, the authors demonstrated a novel procedure to exclude unfavorable exudate and external forces.

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Microvascular free tissue transfer has gained world-wide acceptance as a means of reconstructing post-oncologic surgical defects in the head and neck region. Since 1977, the authors have introduced this reconstructive procedure to head and neck reconstruction after cancer ablation, and a total of 2372 free flaps were transferred in 2301 patients during a period of over 23 years. The most frequently used flap was the rectus abdominis flap (784 flaps: 33.

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High intensity static magnetic fields, when applied to the whole body of the anesthetized rat, have previously been reported to decrease skin temperature. The hypothesis of the present study was that in diamagnetic water, molecules in the air play significant roles in the mechanism of skin temperature decrease. We used a horizontal cylindrical superconducting magnet.

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In spite of their popular uses as recreational drugs and their potential therapeutic uses, little direct information has been obtained about the synaptic effects of cannabinoids in the human brain. In the present study, patch-clamp recordings were performed on granule cells of the human dentate gyrus and the effects of cannabinoid receptor-1 (CB1) activation on inhibitory synaptic activity were examined. Activation of CB1 receptors by WIN55212-2 significantly suppressed both frequency and amplitude of spontaneous inhibitory synaptic currents (IPSCs) to about 50% of control.

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Objectives/hypothesis: For reconstruction after subtotal or total glossectomy, both preserving the larynx and maintaining postoperative swallowing and speech functions can greatly improve quality of life; however, postoperative functional results are often unstable. Our experiences suggest that insufficient flap volume in the oral area and postoperative prolapse of the preserved larynx affect postoperative function. The objective was to investigate the relations of the shape of the reconstructed tongue to postoperative swallowing and speech functions.

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Using spinal cord slice preparations and patch-clamp recordings in lamina II and lamina V regions, we tested a hypothesis that P2X receptor subtypes differentially modulate glutamate release from primary afferent terminals innervating different sensory regions. We found that activation of P2X receptors by alpha,beta-methylene-ATP increased glutamate release onto >80% of DH neurons in both lamina regions. However, two distinct types of modulation, a transient and a long-lasting enhancement of glutamate release were observed.

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P2X receptors have been suggested to be expressed on the central terminals of A delta-afferent fibers innervating dorsal horn lamina V and play a role in modulating sensory synaptic transmission. These P2X receptors have been widely thought to be P2X2+3 receptors. However, we have recently found that P2X receptor-mediated modulation of sensory transmission in lamina V is not inhibited by trinitrophenyl-adenosine triphosphate (TNP-ATP), a potent antagonist of P2X1, P2X3 homomers, and P2X2+3 heteromers.

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The GABA/glycine-mediated inhibitory activity in the substantia gelatinosa (SG) of the spinal cord is critical in the control of nociceptive transmission. We examined whether and how SG inhibitory activity might be regulated by neuronal nicotinic receptors (nAChRs). Patch-clamp recordings were performed in SG neurons of spinal slice preparations from adult rats.

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Studies using molecular markers have revealed that planarians possess a highly organized brain. Here we separated brain neurons from dissociated planarian head cells by fluorescence activated cell sorting (FACS), and characterized them by single cell PCR analysis and cell culture. Dissociated cells were labeled with three different fluorescent dyes, Hoechst 33258, Merocyanine 540, and Propidium Iodide (PI), and fractioned by FACS.

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Mice are popular animals for biomedical studies, but few skin flap models have been reported in them. To investigate the ischaemia/reperfusion phenomenon in skin flaps, we first investigated the vascular anatomy of murine dorsal skin and then designed a suitable murine dorsal skin flap model. In 120 mice, six distinct vascular patterns were identified, one being seen in 111 mice (93%).

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Since ischemia-reperfusion injury continues to be a major problem in reconstructive microsurgery, improvement of experimental models is still desirable. We developed a model that allows direct visualization of flap microcirculation in mice by intravital microscopic techniques. A newly designed skinfold chamber was installed on the dorsum of mice, and microcirculation was inspected with an intravital microscope.

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Male rats were treated with a muscarinic receptor antagonist at 3, 10, and 100mg/kg/day for 4 weeks prior to mating with untreated females and their reproductive status was determined on gestation days (GD) 15-17. Treatment-related decreases in the pregnancy rate were observed at 100mg/kg/day without any effects on mating performance. Impairment of male fertility by this compound was also observed after treatment for 1 week, but there were no effects after a 1-week withdrawal period suggesting reversibility of the effect.

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Background: In living-related partial liver transplantation, the feasibility and safety of using left-sided liver grafts from donors with aberrant hepatic arteries remains to be evaluated.

Methods: Between 1996 and 2000, we harvested left-sided liver grafts from 101 living donors. Hepatic arterial variation in the donors was classified into three types: type I (n=69), normal anatomy; type II (n=24), aberrant left hepatic artery arising from the left gastric artery; and type III (n=8), replaced right hepatic artery arising from the superior mesenteric artery.

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CATCH 22 syndrome is characterized by cardiac defects, abnormal facial features, thymic hypoplasia, cleft palate, and hypocalcemia. It results from a deletion within chromosome 22q11. This syndrome is not a simple disease.

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Objectives/hypothesis: Defects of the lateral and superior oropharyngeal wall are difficult to reconstruct because of their complicated anatomy and the possibility of causing velopharyngeal incompetence. The objective was to investigate problems of reconstruction and postoperative velopharyngeal function.

Study Design: Defects were classified into three types (I, II, and III) according to their extent.

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Background: Free jejunal grafts are commonly used for reconstruction after surgery for hypopharyngeal and cervical esophageal cancer. However, few reports have addressed postoperative morbidity at the abdominal donor site.

Methods: Preoperative morbidity and postoperative complications were analyzed in 126 patients in whom free jejunal grafts had been harvested from 1992 through 1996.

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Objective: To report a case showing patient noncompliance, supported by outcomes of pharmacokinetic analysis of theophylline as a surrogate drug.

Case Summary: A 45-year-old woman with severe hypertension was treated with a variety of oral antihypertensive drugs, but there was no improvement in her elevated blood pressure. Since we suspected that her intestinal drug absorption capacity was impaired, a theophylline absorption test was performed.

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Using a spinal cord slice preparation and patch-clamp recordings from spinal cord dorsal horn neurons, we examined excitatory and inhibitory circuits connecting to lamina V neurons after the activation of afferent central terminal vanilloid receptor-1 (VR1) receptors and P2X receptors. We found that single neurons in lamina V often received excitatory inputs from two chemically defined afferent pathways. One of these pathways was polysynaptic from capsaicin-sensitive afferent terminals.

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To investigate whether hyperthermic preconditioning can actually protect skin flaps against ischemia/reperfusion injury, the authors first developed a new skin-flap model in 15 mice, a dorsal bipedicle island skin-flap model. Then, another 75 mice were separated into five groups. Mice in Groups 1 to 4 received the same hyperthermic preconditioning, but had different recovery times of 6 hr, 24 hr, 48 hr, and 72 hr, respectively.

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Amrinone is a selective phosphodiesterase III inhibitor that increases cyclic adenosine monophosphate by preventing its breakdown. It is effective in the treatment of congestive heart failure because of its ability to increase myocardial contractility and vascular smooth muscle relaxation. This study was designed to clarify the potential efficacy of amrinone in plastic surgery by clinically assessing its ability to enhance flap blood flow after reconstructive surgery and relieve intraoperative vasospasm.

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Effects of ATP on substance P immunoreactivity were examined in cultured dorsal root ganglion neurons. We found that treatment of dorsal root ganglion neurons with ATP significantly depleted substance P immunoreactivity on the neurites and somata of the neurons. The effects of ATP were significantly inhibited by the purinergic P2 receptor antagonists suramin (30 microM) and pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (10 microM).

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For this article, 178 consecutive cases of mandibular reconstruction using microvascular free flaps and performed from 1979 to 1997 were studied. The purpose of this report is to compare flap success rates, complications, and aesthetic and functional results. The ages of the 131 men and 47 women ranged from 13 to 85 years, with an average of 55 years.

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Presynaptic ATP P2X receptors have been proposed to play a role in modulating glutamate release from the first sensory synapse in the spinal cord. Using spinal cord slice preparations and patch-clamp recordings from dorsal horn neurons in lamina V of the rat spinal cord, we showed that the activation of P2X receptors by alpha,beta-methylene-ATP (alphabetam-ATP) resulted in a large increase in the frequency of spontaneous EPSCs (sEPSCs) and miniature EPSCs (mEPSCs). The increases in mEPSC frequency by alphabetam-ATP were not blocked by the Ca(2+) channel blocker, 30 microm La(3+), but were abolished in a bath solution when Ca(2+) was omitted.

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The deep circumflex iliac myocutaneous perforator (DCIP) flap with iliac crest was used to reconstruct oromandibular defects in 10 patients. In seven of the patients a dominant perforator was found preoperatively using a Doppler flowmeter; in five of these seven patients a DCIP flap was successfully transferred. In two of the seven patients the dominant perforators were too narrow: one patient underwent a standard osteocutaneous flap transfer and one patient underwent a second flap transfer.

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