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S Kitamura

Publications and source records attributed to S Kitamura.

At least 775 records · Page 43Linked to original sources
PubMed1987

Synthesis of 11,12-leukotriene A4, 11S,12S-oxido-5Z,7E,9E,14Z-eicosatetraenoic acid, a novel leukotriene of the 12-lipoxygenase pathway.

A simple and efficient method for preparing 11,12-leukotriene A4 has been established by the stereospecific biomimetic route from arachidonic acid. 12S-Hydroperoxy-5Z,8Z,10E,14Z-eicosatetraenoic acid was synthesized using a partially purified 12-lipoxygenase of porcine leukocytes. The methyl ester of the compound was then chemically converted to two labile epoxides with a conjugated triene structure. These compounds were identified by proton NMR and mass spectrometry to be 11S,12S-oxido-5Z,7E,9E,14Z-eicosatetraenoic acid (11,12-leukotriene A4) and its geometric isomer.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1987

Rare case of the inferior mesenteric artery arising from the superior mesenteric artery.

The authors observed a variation of the inferior mesenteric artery, which arose from the superior mesenteric artery, in a 69-year-old Japanese male cadaver during dissection in 1984. In this case, no rudiment of the ordinary inferior mesenteric artery could be found on the abdominal aorta. There are few reports of this variation, and an extensive search of the available literature revealed only four cases, including two in Japan. Such a variation had been somewhat inadequately described as an "absence of the inferior mesenteric artery" in the previous reports, but we avoided this terminology, because all of the cases possessed an artery, which, though arising from the superior mesenteric artery instead of the abdominal aorta, had the same branches as a normal inferior mesenteric artery. Consistent with findings observed in the previous cases, the unusual inferior mesenteric artery arose as the first branch of the superior mesenteric artery, with the common trunk of both mesenteric arteries originating from the abdominal aorta at a level at which an ordinary superior mesenteric artery would arise. It is for this reason that we did not adopt another acceptable name, that is, "the common mesenteric artery," for this variation. The variation can be explained as the result of an unusual development of the embryonic artery system, which comprises a number of ventral splanchnic arteries interconnected by longitudinal anastomotic channels to supply the primitive digestive tube.

Aged↗
PubMed1987

Fibers supplying the laryngeal musculature in the cranial root of the rabbit accessory nerve: nucleus of origin, peripheral course, and innervated muscles.

The location of the rabbit laryngeal motoneurons whose axons traverse the cranial root of the accessory nerve was studied with injection of HRP or nuclear yellow into the laryngeal muscles in combination with the intracranial severing of either the rootlets of the vagus nerve or those of the cranial root. The motoneurons were located in the diffuse cell group that forms a subnucleus occupying the caudal two-thirds of the nucleus ambiguus and sending fibers to the inferior laryngeal nerve. The caudal one-third of the diffuse cell group supplying the lateral cricoarytenoid muscle, was occupied only by these motoneurons, whereas in its rostral two-thirds, they were intermingled with motoneurons having axons that traversed the vagal rootlets. The thyroarytenoid and posterior cricoarytenoid motoneurons are present in the rostral two-thirds of the diffuse cell group; axons of the former traversed the rootlets of the cranial root, and of the latter traversed the vagal rootlets. On the other hand, the medial scattered cell group, located in the rostral one-third of the nucleus ambiguus and sending fibers to the cricothyroid muscle via the superior laryngeal nerve, contained only motoneurons with axons traversing the vagal rootlets. The above findings clarified that fibers of the cranial root enter the inferior laryngeal nerve after joining the vagus, and then reach the adductor muscles for the vocal fold, with their neurons of origin in a caudal portion of the nucleus ambiguus. The vagal rootlet fibers, with their neurons of origin situated more rostrally in the nucleus, innervate the tensor and abductor muscles via the superior and inferior laryngeal nerve, respectively.

Accessory Nerve↗
PubMed1987

Localization of rabbit laryngeal motoneurons in the nucleus ambiguus.

The localization of rabbit laryngeal motoneurons in nucleus ambiguus was investigated using injection of a fluorescent labeling substance, i.e., nuclear yellow, into the individual laryngeal muscles. The nucleus ambiguus of the rabbit comprises four subnuclei, CoG, SGm, SGl, and DiG. The CoG is a group of compactly arranged neurons, and is situated in the rostral one-half of the nucleus. The SG, situated in its rostral one-third, is scattered around the CoG, with a subdivision into SGm and SGl. These subdivisions are medial and lateral to the CoG, respectively. The DiG is formed by diffusely arranged neurons, and is located in the caudal two-thirds of the nucleus. All labeled motoneurons were found in the ipsilateral nucleus ambiguus. The motoneurons supplying the cricothyroid muscle, which is innervated by the superior laryngeal nerve, were present in the SGm, with a clear rostralward segregation from the other motoneurons. The motoneurons supplying the muscles innervated by the inferior laryngeal nerve were located in the DiG, where they displayed a rostrocaudal myotopical arrangement in the order posterior cricoarytenoid, thyroarytenoid, and lateral cricoarytenoid. The posterior cricoarytenoid motoneurons were intermingled with the thyroarytenoid motoneurons in the rostral two-thirds of the DiG, and the former tended to be concentrated more rostrally than the latter. The lateral cricoarytenoid motoneurons were confined to the most caudal one-third of the DiG.

Animals↗
PubMed1987

Results of internal mammary artery-coronary artery bypass surgery and the characteristics of internal mammary artery grafts.

Coronary artery bypass grafting utilizing the internal mammary artery (IMA) was performed in 108 patients with an operative mortality (less than 1 month) of 0% and a hospital mortality of 1.9%. The IMA was used most often in the left anterior descending artery system in combination with saphenous vein grafts (SVG) to the right and left circumflex artery systems. Although the IMA flow was smaller than the SVG flow when measured intraoperatively by an electromagnetic flow meter, postoperative clinical, electrocardiographic, isotopic, angiographic and coronary sinus flow-metric studies all demonstrated that the IMA can respond well to myocardial blood flow demand both at rest and during exercise, resulting in excellent clinical improvements with no detectable signs of flow deficiency. In addition, no signs of ischemia were detected in any of the 15 patients with stenosis in the left main trunk treated with an IMA graft. The IMA graft appears to have a great adaptive capacity to meet increased myocardial demand. Postoperative angiography performed at an average of 3 months after surgery in 60 unselected patients demonstrated an IMA patency rate of 98% in comparison with 88% patency in SVGs to the left anterior descending artery (p less than 0.05). Not only the patency rate, but also the graft wall characteristics were much better in IMA grafts than in SVGs. Some SVGs showed marked wall irregularity as early as 3 months after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Effects of cigarette smoking on metabolic events in the lung.

Nicotine and cigarette smoke extract show acute physiological effects: increasing tracheal pressure (PTR), pulmonary artery pressure (PPA), systemic blood pressure (PSYST), and left atrium pressure (PLA); and decreasing cardiac output (QAORTA) and blood flow to the left lower lobe (QLLL). In addition, cigarette smoking induces bronchoconstriction, thus decreasing peak flow, FVC, and FEV1.0 in healthy subjects. It has also been demonstrated that cigarette smoking caused temporary slowing of mucociliary clearance in the lung and that cigarette smoke increases the activity of aryl hydrocarbon hydroxylase which metabolizes benzo[alpha]pyrene. We demonstrated that serum angiotensin I converting enzyme (ACE) activity showed a significant increase immediately after smoking and returned to the control level 20 min after smoking. We also demonstrated that plasma histamine levels showed a marked decrease after smoking. Furthermore, the effects of cigarette smoke and related substances on prostaglandin, thromboxane, testosterone, cyclic nucleotides metabolism, and protein synthesis were also investigated.

Angiotensin I↗
PubMed1987

Observation of lymph nodes and great vessels in the mediastinum by endoscopic ultrasonography.

The mediastinum was studied by endoscopic ultrasonography in 121 lung cancer patients. This method facilitates the observation of the lymph nodes, the large vessels and heart in the mediastinum in real time and dynamically. In this paper, the orientation of mediastinal lymph nodes was ultrasonographically studied. This method can detect lymph nodes as small as 3 mm in diameter, and very highly those in bracheobronchial, subaortic, subcarinal, and hilar regions. The mediastinal vascular structures were also easily detected. This method can provide full clinical applicability for analysis of mediastinal involvements in lung cancer patients.

Endoscopes↗
PubMed1987

Correlative analysis of longitudinal changes in bronchoalveolar lavage, 67gallium scanning, serum angiotensin-converting enzyme activity, chest X-ray, and pulmonary function tests in pulmonary sarcoidosis.

Despite the relatively high cost and complicated procedures, Gallium-67 (67Ga) scanning and bronchoalveolar lavage (BAL) are increasingly advocated as more sensitive indicators of disease activity in sarcoidosis than chest X-ray and serum angiotensin-converting enzyme activity (SACE). To evaluate the clinical usefulness of 67Ga scanning and BAL, we followed 31 patients with pulmonary sarcoidosis, using these four parameters, at 9- to 24-month intervals over periods of 9 to 48 months. We obtained 68 complete evaluations. Close correlations were observed among chest X-ray, 67Ga scanning, SACE, and the percentage of lymphocytes in BAL fluid (p less than 0.1 to 0.001). Longitudinal changes were also well correlated in these four parameters (p less than 0.001) and paralleled the changes in vital capacity (p less than 0.01 to 0.001). However, we were unable to predict the patients' outcome from the initial evaluation of these four parameters. These results suggest that, in terms of their usefulness for estimating disease activity, the differences among these four indicators are negligible. We therefore conclude that chest X-ray and SACE sufficiently reflect disease activity and that, at present, routine evaluation by 67Ga scanning and BAL are not necessarily indicated in the long-term management of pulmonary sarcoidosis.

Adult↗
PubMed1987

Nicotinamide N-oxide reductase activity in bovine and rabbit eyes.

The nicotinamide N-oxide reductase activity of a variety of ocular tissues was investigated. The 9,000g supernatant of ciliary body, retinal pigment epithelium-choroid, iris, retina and cornea, but not lens, exhibited reductase activity under anaerobic conditions when supplemented with 2-hydroxypyrimidine, an electron donor of aldehyde oxidase. Among these tissues, the highest activity was observed with ciliary body. When the 9,000g supernatant of ciliary body was fractionated, the 2-hydroxypyrimidine-linked reductase activity was mainly associated with the cytosolic fraction and was markedly inhibited by menadione, an inhibitor of aldehyde oxidase. Similarly, in the presence of 2-hydroxypyrimidine, the cytosolic fraction of rabbit ciliary body exhibited nicotinamide N-oxide reductase activity which was susceptible to inhibition by menadione. These facts strongly suggest that aldehyde oxidase present in mammalian eyes is involved in the reduction of nicotinamide N-oxide to nicotinamide.

Aldehyde Oxidase↗