Biomedical subjects

T Kanno

Publications and source records attributed to T Kanno.

At least 235 records · Page 13Linked to original sources

PubMed1996

Deep hypothermia cardiopulmonary bypass and direct surgery of two large aneurysms at the vertebro-basilar junction.

This paper highlights two interesting cases of radial clipping of large aneurysms at the vertebro-basilar junction accompanied by a vascular anomaly, consisting of fenestration of the split basilar artery at its origin. Description of the inner and outer surface of the aneurysm were obtained pre-operatively, from analysis by 3D CT and 3D CT endoscopy of the form of the neck, parent vessels of the vertebral arteries on both sides, basilar artery and split basilar artery, as well as other details of branching. The neck exhibited a broad base in both cases. The height of the neck extended to the internal acoustic meatus, and it was possible to expose the circumference of the aneurysmal neck, peripheral basilar artery and both vertebral arteries proximally with an anterior, transpetrosal approach. Based on the size of the aneurysm and the site being the anterior surface of the brain stem, clipping (consisting of interruption of the occluded portion and reconstruction of the parent vessels) was performed. In the first case it was achieved protecting the brain by hypothermia and barbiturates under deep hypothermia with extracorporal circulation, and in the second case, a state of circulatory arrest was used. This paper documents the report of two cases along with other cases treated so far.

Adult↗

PubMed1996

Histochemical localization of carbonic anhydrase in the trachea of the guinea pig.

Tissue specimens from guinea pigs were examined using an enzyme-histochemical reaction to explore the presence of carbonic anhydrase (CA) activity in the trachea. CA activity was detected in a group of morphologically distinct epithelial cells, in goblet cells, and in glands of the tracheal mucosa. The epithelial cells showing CA activity were distributed singly and sparsely throughout the entire trachea. These cells showed a wide morphological variability and were clearly different from those forming the pseudostratified ciliated epithelium. Their number was higher in sections closer to the tracheal bifurcation than in those near the larynx. Although the nature of these cells is unknown, based on their morphological and histochemical characteristics and their distribution, they may represent a specialized chemoreceptor. To our knowledge, this is the first report of CA localized in tracheal epithelial cells.

Animals↗

PubMed1996

Three different point mutations in the butyrylcholinesterase gene of three Japanese subjects with a silent phenotype: possible Japanese type alleles.

OBJECTIVE: To investigate genetic mutations in three Japanese subjects homozygous for silent butyrylcholinesterase mutations. METHODS AND RESULTS: One of them was compound heterozygous for two mutations; GGA(Gly) to CGA(Arg) at codon 365 (G365R) and CAA(Gln) to TAA(Ter) at codon 119 (Q119X). The other two subjects were homozygous for different missense mutations: CGT(Arg) to TGT(Cys) at codon 515 (R515C) and G365R, respectively. Simple identification methods for all of the mutations were developed and applied for family analysis and to control individuals. Two mutations, G365R and R515C, have been reported in the Japanese population, while the nonsense mutation Q119X was discovered in the present study. Genetic heterogeneity between human populations with regard to the butyrylcholinesterase gene was suggested. CONCLUSIONS: Among the three mutations found in this investigation, one was novel, and none of these mutations have been reported outside Japan.

Adult↗

PubMed1996

Hyperbaric oxygen therapy to determine the surgical indication of moderate hypertensive intracerebral hemorrhage.

A new approach for the treatment of hypertensive intracerebral hemorrhage (ICH) is described. Patients with intracerebral hemorrhage were selected for surgical treatment on the basis of their response to hyperbaric oxygen. Patients who showed clinical improvement with hyperbaric oxygen therapy and underwent surgery showed a significantly improved outcome. On the other hand, patients who did not show any clinical Improvement with hyperbaric oxygen demonstrated a poor outcome even if surgery was performed. This comparative study verified the usefulness of hyperbaric oxygen therapy for selection of patients with ICH selection for surgery.

Cerebral Hemorrhage↗

PubMed1996

Effects of new titanium cerebral aneurysm clips on MRI and CT images.

We studied the effects of newly developed aneurysm clips made of a titanium alloy (manufactured by Aesculap, A.G.) on the quality of MR and CT images. Prior to clinical application in twenty patients, the effects of five types of conventional aneurysmal clips on MR images were examined utilizing a phantom. When compared with conventional aneurysm clips, the new titanium clips produce only limited artifacts and yielded improved images in patients who underwent aneurysm clipping post-operative.

Aged↗

PubMed1996

Stereoscopic synthesized brain-surface imaging with MR angiography for localization of a peripheral mycotic aneurysm: case report.

A patient with subacute bacterial endocarditis and a peripheral mycotic aneurysm is presented. We used a combined multi-slice surface anatomy scanning (SAS) and contrast-enhanced MR angiography image to determine the exact location of the small lesion by applying a skin marker on the scalp and visualizing the relationship of the marker to the brain surface structures and to the lesion. This technique was useful for the removal of a small peripheral aneurysm using only a limited craniotomy.

Aged↗

PubMed1996

Clinical usefulness of 3-D CT endoscopic imaging of cerebral aneurysms.

Usefulness of endoscopic imaging of cerebral aneurysms is presented. 3-D luminal images were obtained using a new processing technique which extracts CT numbers in the boundary region between the vessel wall and contrast media filled in the vascular lumen. Clinical application of this technique to complicated large cerebral aneurysms showed that, with this 3-D CT endoscopic imaging, anatomical details of cerebral aneurysms such as the orifice of the aneurysm, intraluminal thrombus, and calcification of the wall could be clearly demonstrated. Using a 3-D imaging method by Helical CT virtual views of various surgical approaches were compared preoperatively. With this technique, not only virtual surgical views of aneurysms and related vasculature, but also surgical views after virtual resection of skull base bone to a desirable extent are freely available. We operated on two large, complicated aneurysms and one broad-based aneurysm after obtaining 3-D CT endoscopic images of the aneurysms. Such information was found to be very useful for determining difficult and complicated cerebral aneurysms and broad-based aneurysms for coil embolization or direct open surgery.

Angioscopy↗

PubMed1996

Surgical treatment of internal carotid siphon aneurysms.

Surgical treatment of internal carotid artery aneurysms around the carotid siphon is discussed. The surgical approach to the aneurysms in this region, is as follows: 1. A fronto-temporal approach with the patient in a 45 degrees semi-sitting position to decrease venous pressure. 2. A Dolenc approach cutting a part of the dura mater of the superior orbital fissure to facilitate removal of the anterior clinoid process and unroofing of the optic canal. 3. Opening the medial triangle followed by transection of the optic canal dural sheath. Carotid siphon aneurysms can be divided into three groups anatomically; aneurysms of the ophthalmic segment (C2), those of the clinoid segment (C3), and those of the horizontal segment (C4). We present 29 cases of aneurysms arising from the C2 or C2/3 segment, 14 cases arising from the C3 or C3/4 segment, and 11 cases arising from the C4 segment. Anatomic localization of the aneurysms was established preoperatively by angiography and three-dimensional CT imaging. Small aneurysms of the ophthalmic segment projecting infero-medially can be clipped using a contralateral approach via the prechiasmatic root. Aneurysms of the ophthalmic segment projecting superiorly can be clipped following resection of the anterior clinoid process. The clinoid process should be resected intradurally with direct visualization of the aneurysms. Straight side-angled clips are suitable for these aneurysms. Carotid cave aneurysms, which include aneurysms of the ophthalmic segment oriented infero-medially and of the clinoid segment projecting postero-medially, can be clipped using curved fenestrated clips via Dolenc's extradural approach. For accurate clipping, opening of the medial triangle and full mobilization of the IC at the clinoid segment and optic nerve by unroofing the optic canal are required. Aneurysms of the horizontal portion are clipped after full exposure of the artery in the cavernous sinus only when the aneurysms are large and symptomatic. We used the fronto-temporal and Dolenc approaches and applied fenestrated clips to aneurysms oriented or postero-medially and straight or oblique clips to aneurysms projecting antero-laterally. Out of 40 aneurysms which underwent surgical clipping, 37 resulted in good post-operative recovery. There were three deaths secondary to complications of vasospasm and three cases with post-operative visual loss. The classification of these aneurysms and the surgical techniques we employed are discussed in detail.

Carotid Artery Diseases↗

PubMed1996

New jet irrigation bipolar system.

Irrigation bipolar systems are particularly useful for the washout of hematomas in subarachnoid hemorrhage during the acute stage of surgery and for preventing adherence of tissue to the bipolar tips during coagulation. These systems have become essential tools, and numerous improvements have been made to them. First, regarding the flow volume, both the interval of droplets and the size of individual water droplets can be adjusted. Second, this system is equipped with two major functions. The first is a preirrigation function, in which a small amount of irrigation water flows before operation of the bipolar coagulation. This wets the bipolar tips, eliminating any heat remaining from the previous use. Another function is postirrigation; after the coagulation has stopped, continuous irrigation is quickly provided to achieve a standby state by cooling down the tissue and the tips of the bipolar forceps. By using both of these functions, mild coagulation without adherence of burned tissue and clots to the bipolar forceps and minimization of residual heat during frequent use can be achieved. This article describes the new jet irrigation bipolar system and the use of an actual system that combines jet irrigation functions with the new cooling functions.

Electrocoagulation↗

PubMed1996

Perimetric [Ca2+]i rise and exocytosis detected by ultraviolet laser scanning confocal microscopy in rat peritoneal mast cells.

It has been reported that in dialysed mast cells an increase in mean [Ca2+]i is neither necessary nor sufficient for secretion; however, it is possible that juxtamembranal [Ca2+]i may exceed the mean [Ca2+]i before exocytosis. The present study was carried out to analyse spatial and temporal dynamics of [Ca2+]i and concomitant exocytosis in intact rat peritoneal mast cells using UV laser scanning confocal microscopy. Stimulation with Compound 48/80 (16 microM) increased mean [Ca2+]i, causing an initial rapid elevation from 40 to 200 nM, which lasted for 6 s and was followed by a delayed secondary increase to 600 nM. Exocytotic images were seen in the cell perimeter 16 s after the stimulation. Perimetric and nuclear [Ca2+]i increased to several mumoles per litre, while that in the intermediate region remained low. In a Ca(2+)-deficient environment, Compound 48/80 still increased perimetric [Ca2+]i to micromolar values and induced exocytosis. This study clearly indicates, for the first time, that a perimetric increase in [Ca2+]i to micromolar levels precedes exocytosis, in intact, as opposed to permeabilized cells.

Animals↗

PubMed1996

Pituitary adenylate cyclase-activating polypeptide causes rapid Ca2+ release from intracellular stores and long lasting Ca2+ influx mediated by Na+ influx-dependent membrane depolarization in bovine adrenal chromaffin cells.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has been reported to increase intracellular Ca2+ concentrations ([Ca2+]i) and catecholamine release in adrenal chromaffin cells. We measured [Ca2+]i with fura-2 and recorded ion currents and membrane potentials with the whole cell configuration of the patch-clamp technique to elucidate the mechanism of PACAP-induced [Ca2+]i increase in bovine adrenal chromaffin cells. PACAP caused [Ca2+]i to increase due to Ca2+ release and Ca2+ influx, and this was accompanied by membrane depolarization and inward currents. The Ca2+ release was suppressed by ryanodine, an inhibitor of caffeine-sensitive Ca2+ stores, but was unaffected by cinnarizine, an inhibitor of inositol trisphosphate-induced Ca2+ release. Ca2+ influx and inward currents were both inhibited by replacement of extracellular Na+, and Ca2+ influx was inhibited by nicardipine, an L-type Ca2+ channel blocker, or by staurosporine, a protein kinase C (PKC) inhibitor, but was unaffected by a combination of omega- conotoxin-GVIA, omega-agatoxin-IVA, and omega-conotoxin- MVIIC, blockers of N-, P-, and Q-type Ca2+ channels. Moreover, 1-oleoyl-2-acetyl-sn-glycerol, a PKC activator, induced inward currents and Ca2+ influx. These results indicate that PACAP causes both Ca2+ release, mainly from caffeine-sensitive Ca2+ stores, and Ca2+ influx via L-type Ca2+ channels activated by membrane depolarization that depends on PKC-mediated Na+ influx.

Adrenal Glands↗

PubMed1996

Nested PCR for detection and typing of porcine reproductive and respiratory syndrome (PRRS) virus in pigs.

A nested polymerase chain reaction (PCR) was developed to detect porcine reproductive and respiratory syndrome (PRRS) virus. A common primer set for European and North American type isolates of PRRS virus was designed for reverse transcription PCR, and a specific primer set for each of the 2 type isolates was designed for nested PCR. The PCR that used a specific primer set detected the corresponding type of the virus at a level equivalent to 1 TCID50/100 microliters, but not the other type of isolates. Therefore, the method clearly differentiated the 2 types of virus from each other. The detection of PRRS virus by the nested PCR was as sensitive as virus isolation in cultures of porcine alveolar macrophages from infected pigs at the acute stages, and was more sensitive from pigs at the convalescent stages. The infecting virus type was determined by use of 2 specific primer sets even when virus isolation was negative in naturally infected pigs. It was concluded that the nested PCR is useful for diagnosis and typing of PRRS virus and studies of persistent infection by the virus.

Animals↗

PubMed1996

Characteristics of major structural protein coding gene and leader-body sequence in subgenomic mRNA of porcine reproductive and respiratory syndrome virus isolated in Japan.

Nucleotide sequence, 1713nt in length, of porcine reproductive and respiratory syndrome virus (PRRSV) isolated in Japan was determined. The sequence encompassed 3 overlapping open reading frames (ORFs), ORF5 to ORF7. These ORFs encodes major structural proteins of PRRSV. The deduced amino acid sequence of each ORF showed higher than 87.5% identity with an American isolate, and lower (54.6 to 80.5%) identity with an European isolate. This result supported a previous report about antigenic characteristics of the EDRD-1 strain. Leader-body junction sequence in subgenomic mRNA of the EDRD-1 strain was determined by sequencing cDNA clones of subgenomic RNAs. A common sequence motif of 5 nucleotide, represented by UA(A/G)CC, was identified as the junction sequence.

Amino Acid Sequence↗

PubMed1996

Contribution of Na+/Ca2+ exchanger in maintaining [Ca2+]c at a stable state in rat pancreatic islets.

The effects of lowering extracellular Na+ concentration [Na+]o, on cytosolic Ca2+ concentration, [Ca2+]c were examined by a microfluorimetric method using fura-2 in perifused preparations of isolated rat pancreatic islets. The total replacement of extracellular Na+ (Na+o) by equimolar N-methyl-D-(--)-glucamine caused a rapid rise in [Ca2+]c, and partial replacement of Na+o resulted in correlative rises in [Ca2+]c in accordance with the magnitude of reduced [Na+]o. The rise in [Ca2+]c induced by Na+o removal was strongly inhibited in the Ca2+o-deficient environment or by Ni2+. The [Ca2+]c rise, however, remained almost unchanged in the presence of nifedipine or SK&F 96365, and was enhanced by the addition of ouabain. The electrochemical gradients for Ca2+ (delta mu Ca2+) and Na+ (delta mu Na+) were calculated to be 39.08 and 12.8 kJ/mol, respectively, in this study, indicating a stoichiometry of 3Na+: 1 Ca2+. These results indicate that, in rat pancreatic islets, the rise in [Ca2+]c induced by lowering [Na+]o is mainly due to Ca2+ entry medicated by the Na+/Ca2+ exchanger operating with the stoichiometry of 3Na+:1 Ca2+, and that the Na+/Ca2+ exchanger plays an important role in maintaining stable-state [Ca2+]c.

Animals↗

PubMed1996

Inhibition of neutrophil-superoxide generation by alpha-tocopherol and coenzyme Q.

Effects of various derivatives of alpha-tocopherol (VE) and coenzyme Q (CoQ) on superoxide (O2.-) generation of neutrophils and protein kinase C (PKC) activity were examined. VE and CoQ8 inhibited O2.- generation of neutrophils stimulated by a protein kinase C mediated process monitored by cytochrome c reduction and spin trapping methods. The inhibitory action was observed not only with alpha-tocopherol, but also with beta-, gamma-, delta-tocopherols and with tocol which is a chemical similar to VE but lacking methyl groups on the chromanol ring structure and which is not a radical scavenger. By contrast, no inhibition was observed with 2-carboxy-2, 5, 7, 8-tetramethyl-6-chromanol (CTMC, trolox) or 2, 2, 5, 7, 8,-pentamethyl-6-chromanol (PMC) which are water soluble VE derivatives having radical scavenging activity. Compounds having a similar isoprenoid chain, such as CoQ, also have inhibitory activity on PKC-dependent O2.- generation of neutrophils. The inhibitory activity of CoQ derivatives is dependent on the length of the unsaturated isoprenoid chain. CoQ derivatives having 16, 24 and 32 carbon isoprenoid chains corresponding to CoQ4, 6, and 8 inhibited O2.- generation but 4 and 40 carbon isoprenoid chains corresponding to CoQ2 and 10 had no inhibitory activity on O2.- generation. Alpha-tocopherol and CoQ inhibited PKC activity but the ID50 for O2.- generation and PKC activity was different for each compound. However, no direct relationship between VE content and O2.- generation of neutrophils was observed. These results suggest that isoprenoids of VE and CoQ participate in the inhibition of the NADPH oxidase activation system through modulation of the neutrophil membrane probably by the inhibition of PKC.

Animals↗

PubMed1996

Oxygen-dependent inhibition of neutrophil respiratory burst by nitric oxide.

Effect of nitric oxide (NO) on the respiratory burst of neutrophils was examined under different oxygen tensions. Phorbol myristate acetate (PMA) stimulated oxygen consumption and superoxide (O2) generation in neutrophils by a mechanism which was inhibited reversibly by NO. The inhibitory effect of NO increased significantly with a decrease in oxygen tension in the medium. The inhibitory effect of NO was suppressed in medium containing oxyhemoglobin (HbO2), a NO scavenging agent. In contrast, 3-morpholinosydnonimine (SIN-1), a compound that rapidly generates peroxynitrite (ONOO-) from the released NO and O2-, slightly stimulated the PMA-induced respiratory burst. These results suggested that NO, but not ONOO-, might reversibly inhibit superoxide generation by neutrophils especially at physiologically low oxygen tensions thereby decreasing oxygen toxicity particularly in and around hypoxic tissues.

Animals↗

PubMed1996

[Establishment of reference intervals and physiological parameters for 13 serum proteins in healthy Japanese adults].

Using a nephelometry with a new calibrator in which values were assigned from EU/CRM470, a new international reference preparation, we have established for the first time the reference intervals of 13 different serum proteins in Japanese adults. Based on the NCCLS guideline C28-P, a new statistical and concrete procedure was revised and used for this study. It is clearly shown here that standardisation of serum proteins can be possible under the qualified assay system, making it possible to share the reference intervals among laboratories under well-controlled quality assurance. New aspects of serum protein variations were discovered in relation to physiologic changes and life styles.

Adult↗

PubMed1996

[Practical subjects of reference interval].

A concept of reference interval was first proposed by Dybkaer in 1973 in order to avoid an ambiguous definition of so-called normal range. This concept was succeeded by IFCC Expert Panel on Theory of Reference Value and the recommendation for the concept of reference value was documented in 1987 from IFCC scientific committee. Finally, NCCLS proposed the document for Reference Interval, how to determine, utilize the reference interval in clinical laboratory, in 1992. In this paper, how to determine and utilize the reference interval in clinical laboratory are described and discussed based on the concepts of NCCLS and IFCC.

Humans↗