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Biomedical subjects

T Kanno

Publications and source records attributed to T Kanno.

At least 667 records · Page 37Linked to original sources
PubMed1966

The effects of external sodium and potassium concentration on the membrane potential of atrioventricular fibers of the toad.

Intracellular records were made from fibers in the A-V conducting system of isolated toad hearts. The A-V region was perfused with Ringer's solution of various K and Na concentrations. Resting potential in 2.8 mM [K]o was about 60 mv. Over the range 0.28 to 28 mM, resting potential diminished with increasing [K]o. Spontaneous action potentials appeared when [K]o was increased to 11.2 mM, and when resting potential had fallen to about 40 to 50 mv. Changes in [Na]o over the range 22 to 110 mM had a little effect on resting potential, but there was a linear relation between the peak value of the action potential and log [Na]o. Wenckebach periodicity was observed when [Na]o was lowered.

Action Potentials↗
PubMedDate not supplied

Characterization of secretory responses in exocrine pancreas of genetically obese Zucker rats.

Secretory responses of the exocrine pancreas in the obese Zucker rat with an inherited genetic disorder were compared with those in lean control rats. Amylase concentration in pancreatic acinar cells of obese rats was reduced to 62% of the control value, whereas trypsinogen concentration was increased to 269%. The activity ratio of amylase to trypsinogen in the pancreatic acini of obese rats was about one-fourth of that in controls. The activity ratio of amylase to trypsinogen in pancreatic juice released by stimulation with varying concentrations of CCK8 or carbachol in the obese rats was also reduced to one-fourth of that in control rats. The concentration of the secretagogs inducing half-maximal secretory responses (EC50) in the obese rats was almost identical to that in the controls. The downward shift of the dose-response relation for these secretagogs in the acini of obese rats was analogous to that in streptozotocin-induced diabetic rats, cold-exposed rats, or lactating rats, as demonstrated previously. The present results may be explained by the changes in enzyme content and secretory responses found in pancreatic acini of obese Zucker rats, which would be attributable mainly to congenital disturbance in "insulo-acinar axis."

Amylases↗
PubMedDate not supplied

Heterotaxy syndrome with pancreatic malrotation: CT features.

We report the case of an asymptomatic elderly man with heterotaxy syndrome who presented with incomplete pancreatic rotation and an aplastic pancreatic uncinate process, polysplenia, nonrotation of the intestine, a midline liver, a midline gallbladder, a right-sided stomach, and interruption of the inferior vena cava with azygos continuation. To our knowledge, pancreatic malrotation with resultant oblique placement has not been described in patients with heterotaxy syndrome, and we speculate that the pancreatic rotation was interfered with by the left lobe of the midline liver in the embryo.

Abnormalities, Multiple↗
PubMedDate not supplied

Potentiation of cholecystokinin-induced exocrine secretion by either electrical stimulation of the vagus nerve or exogenous VIP administration in the guinea pig pancreas.

In the anaesthetized guinea pig, the secretory responses (pancreatic juice flow and protein output) induced by electrical stimulation of the vagus nerve were not blocked by atropine but by hexamethonium. Excitation of the left vagus nerve induced by electrical stimulation significantly potentiated the C-terminal octapeptide of cholecystokinin (CCK-OP)-induced secretory responses. In the isolated perfused pancreas of guinea pig, the secretory responses induced by CCK-OP at concentrations in the physiological range were markedly potentiated by simultaneous stimulation with vasoactive intestinal peptide (VIP). However, the secretory responses induced by CCK-OP at higher concentrations were not potentiated but inhibited by simultaneous stimulation of VIP. The secretory responses induced by carbachol (CCh) at any concentrations were not potentiated but inhibited by simultaneous stimulation of VIP. These results support the view that VIP released from the nerve endings can potentiate the hormonal action of CCK-OP.

Animals↗
PubMedDate not supplied

Implementation of multi-vendor DICOM standard image transfer in hospital wide ATM network.

At Hamamatsu University Hospital, an ATM + FDDI network was installed in January 1995, when the hospital information system was upgraded. With its unique 'wheel' shape configuration, FDDI automatically backs up in case of an ATM switch failure. The authors implemented a DICOM image database server and DICOM viewer in the Hamamatsu University Hospital ATM + FDDI network. The DICOM standard worked well between different vendor products. In sending 512 x 512, 2 byte CT images, 40% of the transfer time was spent for the network data transfer, which is 70% of the theoretical value of 10 Mb peripheral transfer rate. Meanwhile, ATM load factor increased less than 0.5%. As we have a very fast data transfer network, we must check display speed, hard disc access time, PC bus speed, and display software, in order to enjoy the high speed network transfer fully. The sequence of image transmission within a study is not stated in the DICOM document and is depending on the server. Therefore, there should be an agreement between server and clients, still more than DICOM, in order to make better PACS.

Computer Communication Networks↗
PubMedDate not supplied

Transtrochanteric anterior rotational osteotomy for slipped capital femoral epiphysis: a report of five cases.

We have performed a transtrochanteric anterior rotational osteotomy on five patients with severe chronic slipped capital femoral epiphysis. Four patients were free from clinical symptoms, whereas one patient continued to feel a dull pain in the hip. Radiographic evaluation indicated that the osteotomy was able to correct even a severe slip without any deformity around the trochanteric region. There were complications in two cases: a posteromedial tilt at the osteotomy site and a focal avascular necrosis in the anterolateral epiphysis.

Adolescent↗
PubMedDate not supplied

Great earthquakes and medical information systems, with special reference to telecommunications.

The Hanshin-Awaji earthquake in January 1995 caused the greatest number of deaths and injuries in Japan since World War II. Various weaknesses of modern information systems were exposed during and after the earthquake. The authors carried out a questionnaire survey to investigate the current state of hospital information and to examine the kinds of information needed immediately after an earthquake. The survey results show that information about the ability to admit new patients and the availability of medical supplies is necessary immediately after such a disaster. These results will be useful for planning countermeasures against this kind of disaster.

Communication↗
PubMedDate not supplied

Temperature dependence of processes proximal and distal to the glucose-induced [Ca2+]i rise in stimulus-secretion coupling in rat pancreatic islets.

Cooling is known to inhibit glucose-induced insulin secretion from pancreatic islets, but temperature-dependent processes in stimulus-secretion coupling remain unclear. In the present study, we examined the effects of cooling on the glucose-induced increase in cytoplasmic Ca2+ concentration ([Ca2+]i) and concomitant insulin secretion in rat pancreatic islets to analyze the temperature dependence of processes proximal and distal to the Ca2+ signal in stimulus-secretion coupling. Rat pancreatic islets were isolated and perifused. [Ca2+]i was measured using fura-2. Glucose (15 mM) caused a triphasic [Ca2+]i response in single islets at 35 degrees C: an initial decrease and a transient increase followed by a gradual increase, on which series of Ca2+ transients were frequently superimposed. Cooling to 30 and 25 degrees C caused slower and smaller [Ca2+]i responses with a Q10 (temperature coefficient) of 1.8. Glucose caused biphasic insulin secretion at 35 degrees C, which was inhibited by cooling, with a Q10 of 11.6. The ratio of glucose-induced insulin secretion to [Ca2+]i rise (IS/Ca) was calculated to represent the efficiency of Ca2+ to cause exocytosis. The Q10 value of the ratio of IS/Ca was 6.6. The Q10 values of the ratio of IS/Ca in the responses to high K+ (30 mM), carbamylcholine (100 microM) and glibenclamide (2 microM) were 5.6, 3.8, and 13.0, respectively. These values were greater than the Q10 values of corresponding [Ca2+]i responses: 1.2, 1.4, and 1.8, respectively. From these results, we conclude that cooling inhibits not only the glucose-induced [Ca2+]i rise but also Ca(2+)-activated exocytosis, and that the latter is much more sensitive to cooling than the former.

Animals↗
PubMedDate not supplied

Effects of corticosteroids on cytosolic free calcium concentration of the rat adrenal zona glomerulosa cell.

In the perfused cells isolated from the rat adrenal zona glomerulosa, deoxycorticosterone, aldosterone and dexamethasone (10 microM-1 mM) significantly inhibited elevation of the cytosolic concentration of calcium ion [Ca2+]c caused by a preceding stimulation with angiotensin II (ANG II) or high K+. The inhibition of [Ca2+]c was observed within a few minutes after application of the corticosteroids. The resting level of [Ca2+]c was reduced by aldosterone, whereas it was not significantly altered by deoxycorticosterone or dexamethasone. Since it is well established that the elevation of [Ca2+]c is required for the secretory responses to ANG II or high K+, the present results are compatible with a view that aldosterone secretion from the cortical cells in response to the secretagogues may, in turn, be attenuated by corticosteroids, including aldosterone itself.

Aldosterone↗
PubMedDate not supplied

Acidification of extracellular environment inhibits CCK-8-induced Ca2+ entry into pancreatic acinar cells of rat evaluated by a Mn(2+)-quenching method.

The fluorescence of fura 2, a Ca(2+)-sensitive dye, is quenched in the presence of other divalent cations such as Mn2+. This characteristic of the dye provides a useful measure for investigating the role of Ca2+ in cellular functions. The present experiments were thus designed to examine the effects of extracellular pH (pHo) on cholecystokinin octapeptide (CCK-8)-induced Ca2+ entry into isolated perifused pancreatic acini of the rat using a Mn(2+)-quenching method. At a standard pHo (7.4), addition of Mn2+ (1 mM) during continuous stimulation with 100 pM CCK-8 quenched fura 2 fluorescence excited by both excitation wavelengths of 340 and 380 nm. Lowering pHo to 6.0 weakened the quenching, whereas elevating pHo to 8.0 during the stimulation accelerated the quenching compared with that at standard pHo. Accordingly, when acinar cells were stimulated continuously with 100 pM CCK-8 at pHo 6.0, the second sustained increase in cytosolic Ca2+ concentration ([Ca2+]i) was decreased compared with that at pHo 7.4, but the [Ca2+]i increase reappeared when the pHo was neutralized from 6.0 to 7.4 even after cessation of the stimulation. The second sustained increase of [Ca2+]i was achieved at pHo 8.0, but it declined rapidly when CCK-8 stimulation was terminated and pHo was simultaneously restored to 7.4. Amylase release induced by continuous stimulation with 100 pM CCK-8 showed a biphasic time course. A second sustained phase of amylase release was significantly reduced at pHo 6.0, but amylase release increased again when pHo was restored to 7.4. These results indicate that extracellular pH modifies the extent of secretagogue-induced Ca2+ entry into the pancreatic acinar cell, and the inhibitory effects of lowered pHo on the secretory response are largely due to a limited increase in [Ca2+]i.

Amylases↗
PubMedDate not supplied

Preparation of heat-labile antigens on air-dried cytologic specimens for immunocytochemical analysis.

OBJECTIVE: To demonstrate the efficacy of Zamboni's solution and storage medium for immunocytochemistry of Ki-67, p53 tumor suppressor gene product and CD3 on long-preserved, air-dried cytologic specimens. STUDY DESIGN: Air-dried imprint cytologic specimens obtained from 13 lymphatic tissues and 13 colorectal cancers were fixed with Zamboni's solution and stored for various periods in storage medium including 50% glycerol at -10 to -20 degree C. Mouse monoclonal antibody PC, PAb 1801 and anti-Leu-4 were used for immunostaining. RESULTS: Immunocytochemical identification of Ki-67, p53 and CD3 was possible on specimens stored for 36, 32 and 16 weeks, respectively. CONCLUSION: Our method, using Zamboni's solution and storage medium, is feasible for immunocytochemistry on long-preserved, air-dried cytologic specimens using the three antibodies were employed.

Air↗
PubMedDate not supplied

Results of combined-modality therapy for primary and secondary malignant lymphoma of the central nervous system (CNS).

PURPOSE: We consider that whatever the vital prognosis of secondary CNS lymphoma (SCNSL), its local control is as serious as that of primary CNS lymphoma (PCNSL). In this study, both the treatment outcomes and local control of patients with SCNSL and PCNSL were compared, with the aim of improving the treatment of SCNSL. MATERIALS AND METHODS: This study included 11 patients with PCNSL and 14 with SCNSL treated from January 1984 to October 1997. PCNSL patients underwent partial tumor resection and received systemic chemotherapy. All SCNSL patients received systemic chemotherapy, and eight also received intrathecal anticancer drug infusion. Nine PCNSL patients and 11 SCNSL patients underwent whole-brain radiation therapy with 4-MV photons. Among the SCNSL patients, three patients underwent localized-brain irradiation and two patients also received whole-spine irradiation. RESULTS: Five-year survival rates were 34% for PCNSL and 33% for SCNSL. In SCNSL, survival times after CNS involvement were very short, irrespective of treatment. One-year local control rates after CNS irradiation were 38% for PCNSL and 14% for SCNSL. Recurrence was mainly found in the cranial region, in seven of 11 PCNSL patients and 10 of 14 SCNSL patients. CONCLUSIONS: Patients with SCNSL had a poor prognosis, and local control in them was more problematic than in patients with PCNSL. It is necessary to develop new combined modality therapy for patients with SCNSL,including the participation of a radiation oncologist, before the disease becomes progressive.

Adult↗
PubMedDate not supplied

Calcification of the vertebral artery.

A series of 3,648 computed tomographic (CT) scans was reviewed to determine the incidence of intracranial vertebral artery calcification. Calcification was identified in one or both vertebral arteries in 3.4% and was more frequent in the higher age groups. Skull radiographs demonstrated vertebral artery calcification in only one of 48 patients in whom CT studies showed it. A high correlation was observed between vertebral artery calcification on CT and vertebral artery stenosis on cerebral angiography.

Adult↗