Cadmium-induced scale deformation in carp (Cyprinus carpio).
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Animals↗
Biomedical subjects
T Yoshitomi
Publications and source records attributed to T Yoshitomi.
Site-specific lead distribution in scales of lead-administered carp (Cyprinus carpio) by non-destructive SR-XRF analysis.
By utilizing non-destructive synchrotron radiation-excited X-ray fluorescence (SR-XRF), we observed the distribution of lead (Pb) in both ontogenic and regenerating scales of lead-administrated carp, Cyprinus carpio. The fish in the Pb-administered group were fed pellets containing 1 mg/g of Pb at a rate of 1.5% body weight per day for 30 days. In the ontogenic scales, Pb was highly accumulated near the basal edge of the scale and the accumulated amount decreased toward the focus of the scale. On the other hand, in the regenerating scales, high accumulation was observed near the basal edge and the accumulated amount remained high toward the focus. The present results of Pb accumulation correspond well with the region which is calcifying in the ontogenic and regenerating scales, and indicate that the distributions of Pb show when and how long Pb was administered.
Animals↗
Detection of lung lesions and lymph nodes with 201Tl SPET.
The aim of this study was to characterize lung lesions by means of the uptake, retention and washout of 201Tl, and to quantify the sensitivity of 201Tl SPET (single photon emission tomography) in detecting mediastinal and hilar lymph nodes. A total of 68 patients with lung lesions (tumours and inflammation) underwent both helical computed tomography (CT) and 201Tl SPET examinations. Uptake, retention and washout parameters were calculated from early and delayed 201Tl SPET by drawing regions of interest over the primary lesion and the background of the lung. The findings on 201Tl SPET were compared with those on CT and surgical findings. A significant difference in the retention index (RI) was observed between primary malignant and benign lesions. In detecting lymph nodes, the sensitivity, specificity and negative predictive value were 83%, 60% and 90% respectively for early 201Tl SPET, and 50%, 80% and 80% respectively for delayed 201Tl SPET. 201Tl SPET with semi-quantitative analysis, especially RI, helps to differentiate between malignant and benign lung lesions. Lymph nodes larger than 1 cm on CT but not showing 201Tl uptake could be considered non-metastatic lesions.
Adult↗
Tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 in cerebrospinal fluid from children with prolonged febrile seizures. Comparison with acute encephalitis/encephalopathy.
We investigated the levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 alpha (IL-1 beta), and IL-6 as proinflammatory cytokines in CSF to facilitate differentiation between acute encephalitis/encephalopathy and prolonged febrile seizures. We studied 20 children with prolonged febrile seizures and 23 with acute encephalitis/encephalopathy, including 8 with an acellular CSF. TNF-alpha, IL-1 beta, and IL-6 in CSF were measured by ELISA. We found that TNF-alpha, IL-1 beta, and IL-6 were undetectable in CSF of all children with prolonged febrile seizures and control subjects but that the concentrations of TNF-alpha was elevated in 11, of IL-1 alpha in 6, and of IL-6 in 17 of 23 children with acute encephalitis/encephalopathy. Twenty-two of 23 children with acute encephalitis/encephalopathy had elevated concentrations of one or more cytokine. Elevated concentrations of the CSF proinflammatory cytokines, TNF-alpha, IL-1 beta, and IL-6, indicate acute encephalitis/encephalopathy rather than febrile seizures.
Acute Disease↗
Radioligand binding characteristics of the endothelin receptor in the rabbit iris.
We previously suggested the presence of functionally atypical endothelin (ET) A receptors in the rabbit iris sphincter. Here, we further characterized the ET receptor by a radioligand-receptor binding study utilizing a membrane fraction of the rabbit iris. In addition, we functionally confirm the presence of an atypical ET(A) receptor in the iris dilator similar to that in the iris sphincter. In binding experiments, [125I]ET-1 was completely displaced by ET-3 in a biphasic fashion, but only partially by BQ-123 and ET(B) ligands. In the presence of RES-701, ET-3 and sarafotoxin (SRTX)-b completely displaced [125I]ET-1 in a monophasic fashion, but with shallow slopes. Moreover, ET-1, ET-3 and SRTX-b completely displaced [3H]BQ-123 with IC50 values of 0.8, 81 and 4.4 nM, respectively, but with slopes of ET-3 and SRTX-b being again shallow. In iris dilator muscles, ET-3 showed lower and SRTX-b showed higher contractile activities than ET-1. SRTX-c was inactive. BQ-123 more preferentially antagonized ET-3 and SRTX-b than ET-1, with the Schild plot slope of SRTX-b being shallow. Thus, functional experiments suggested the presence of atypical ET(A) receptors in the iris dilator similar to the iris sphincter. However, the binding experiments suggested the presence of rather typical ET(A)- and ET(B)-like receptors. Therefore, we apparently failed to show ET binding sites corresponding to functionally atypical ET(A) receptors.
Animals↗
Tc-99m-MIBI scintigraphy for detecting parathyroid adenoma and hyperplasia.
We performed scintigraphy with technetium-99m-methoxyisobutylisonitrile (MIBI) in 10 patients with parathyroid adenoma (7 lesions) or hyperplasia (9 lesions). Correlation between an amount of accumulation of MIBI and histological types of the lesions were evaluated with special reference to an amount of oxyphilic cell in the lesions. Selected lesions were also evaluated for mitochondrial density by electromicroscopy and showed increased mitochondrial density in the oxyphilic cells. All lesions equal to or above 220 mg showed positive scintigraphic results despite differences in cell types. Undetected lesions were all equal to or below 100 mg. The scintigraphic results for 2 lesions with abundant oxyphilic cells were both positive although those for 11 lesions with abundant chief cells only 6 were positive, probably because these lesions were smaller in the hyperplasia group. In conclusion, MIBI uptake in parathyroid lesions was not dependent on the cell type but either on the size or functional state of the lesions.
Adenoma↗
Scan findings of various myocardial SPECT agents in a case of amyloid polyneuropathy with suspected myocardial involvement.
A 31-year-old male having familial amyloid polyneuropathy underwent a Tc-99m(V)-DMSA study to evaluate the myocardial involvement. The patient also underwent T1-201, I-123-BMIPP and I-123-MIBG myocardial SPECT studies to evaluate blood perfusion, fatty acid metabolism and sympathetic function of the heart, respectively. Tc-99m(V)-DMSA SPECT showed uptake to the myocardium indicating myocardial involvement of amyloidosis. Both T1-201 and I-123-BMIPP studies showed normal uptake indicating normal blood perfusion and fatty acid metabolism but I-123-MIBG SPECT showed no uptake to the heart, indicating severe impairment of sympathetic function.
3-Iodobenzylguanidine↗
Separation of carp (Cyprinus carpio L.) thrombocytes by using a monoclonal antibody, and their aggregation by collagen.
A monoclonal antibody against carp peripheral blood leucocytes was produced, and its reactivity analysed by flow cytometry and electron microscopy. The antibody reacted positively with 10-35% of the cells in a fraction of lymphocytes and thrombocytes that was separated by flow cytometry. Electron microscopy using immunogold labelling showed that this antibody reacted strongly with thrombocytes, but not with other leucocytes. By using a magnetic separator, leucocytes that were positive and negative for this antibody were separated. The positive cells were uniform, spindle-type cells that aggregated in the presence of collagen, while the negative cells did not aggregate. Light and electron microscopy showed that many positive cells changed to a spherical form after the addition of collagen and then 40-60% of these cells aggregated.
Animals↗
[Effects of topical application of adrenergic agents on refraction and accommodation].
In an attempt to clarify the functional role of adrenergic receptors on accommodation, effects of various adrenergic agents on the state of accommodation were studied. Fifty-two emmetropic normal subjects (age: 19-28 y) participated in this study. We examined the effect of the alpha agonist phenylephrine hydrochloride (5%), the alpha 1 antagonist adrenergic bunazosin hydrochloride (0.1%), the beta antagonist timolol maleate (0.5%), the beta 2 antagonist betaxolal hydrochloride (0.5%), and the beta agonist isoproterenol hydrochloride (3%). Using an infrared optometer, the refraction, far point and near point of accommodation, resting point of accommodation (empty-field accommodation and dark focus of accommodation), and accommodative adaptation were measured before and after topical application of various adrenergic agents. Application of bunazosin slightly but significantly decreased the near point of accommodation. Isoproterenol evoked a hyperopic shift on the far point of accommodation. None of the agents had any effect on the resting point of accommodation. Accommodative adaptation was increased by timolol and betaxolol, and decreased by isoproterenol. We surmised that beta adrenergic agents exerted an indirect influence on the parasympathetic nervous system. The activation of beta receptors produced a hyperopic shift on the far point of accommodation and decreased accommodative adaptation, which suggests that activation of adrenergic receptors may reduce parasympathetic activity, hence affecting the state of accommodation.
Accommodation, Ocular↗
[Application of measuring 99mTc-MAG3 plasma clearance based on one-compartment model (MPC method) to pediatric patients].
Measurement of 99mTc-MAG3 plasma clearance based on 1-compartment model (MPC method) were applied to 12 pediatric patients and evaluated for the factors which might affect the calculated results. Depth correction is a critical factor for the measurement of renal uptake. Three different equations for estimating renal depth were compared with the real depth measured by ultrasonography. The equation proposed by K. Itoh was suitable though the equations by T. Ito and Raynaud were insufficient. Estimation of distribution volume, which is regarded as circulating plasma volume (CPV), is also critical for the calculation of MAG3 clearance by MPC method. Precisely, hematocrit measured by venous sampling and circulating blood volume (CBV) calculated as 7.5% of body weight are used for estimation of CPV. However, assumed CPV as 5% of body weight was acceptable if the hematocrit was not severely deviated from the normal value. Simplified MPC method utilizing two factors mentioned above gave a positive correlation with Russell's one point sampling method. In conclusion, MPC method is applicable for pediatric patients.
Adolescent↗
[Efficacy of Warm Touch warming system for hypothermia].
Anesthetized surgical patients frequently become hypothermic, because of decreased metabolic heat production, increased heat loss, surgical exposure, and dry respiration gases. Intraoperative hypothermia may trigger postoperative protein breakdown, shivering, myocardial ischemia, and many other problems. For that reason, heat conservation is a major anesthetic management. We determined the efficacy of Warm Touch warming system (Mallinckrodt Medical, Inc.) compared with that of a warming blanket. Sixteen patients undergoing oral and maxillo-facial surgery under neuroleptanesthesia were studied by measuring rectal and finger-tip skin temperature. Patients were divided in Warm Touch group (n = 8) using Warm Touch warming system Model 5100 and warming blanket group (n = 8) and the temperatures were measured every quarter over 60 minutes. Rectal temperature increased 0.62 degrees C after 60 minutes in the Warm Touch group, but significant changes were absent in warming blanket group. Temperature gradient between the rectum and finger-tip skin decreased markedly in the Warm Touch group. This study suggests that Warm Touch is useful to restore body temperature and to prevent postoperative problems arising from intraoperative hypothermia.
Body Temperature↗
Pharmacological characterization of endothelin receptors in the rabbit iris sphincter muscle: suggestion for the presence of atypical receptors.
Pharmacological profiles of endothelin (ET) receptors in the isolated rabbit iris sphincter were characterized. ET isopeptides caused dose-dependent contraction of the preparation. The respective EC50 values for ET-1, ET-2 and ET-3 were 39.4, 58.0 and 84.3 nM, so that ET-1 was twice as potent as ET-3. Sarafotoxin (SRTX) -b, an ET(A)/ET(B) non-selective agonist, caused very potent contraction with an EC50 of 1.13 nM. However, selective ET(B) receptor agonists SRTX-c and IRL 1620 showed no contractile activity up to 1 microM. BQ-123, a selective ET(A) receptor antagonist, shifted the dose-response curves of ET isopeptides to the right. The pA2 value for ET-1 was 5.52 with a slope of 1.06, which is not different from unity, and the pK(B) value for ET-2 was 5.06. Interestingly, very low doses of BQ-123 antagonized responses to ET-3 and SRTX-b, with a Schild plot slope of approximately 0.7 which is significantly different from unity, suggesting receptor heterogeneity. The abscissal intercepts of the Schild plots were -9.29 for ET-3 and -8.53 for SRTX-b. FR 139317, another ET(A) receptor antagonist, also preferentially antagonized responses to ET-3. RES-701-1, a selective ET(B) receptor antagonist, did not shift dose-response curves for ET-1 and ET-3. These results suggest that ET receptors in the rabbit iris sphincter muscle cannot be classified into the ET(A), ET(B) or ET(C) receptor subtypes, so far established. When compared to the established receptor subtypes, ET receptors in this preparation were quite different from the ET(B) receptor, but apparently showed a pharmacological profile most similar to the ET(A) receptor, suggesting the presence of heterogeneous and atypical ET(A) receptors.
Animals↗
Calcitonin gene-related peptide induced relaxation of the rabbit iris dilator muscle.
Calcitonin gene-related peptide (CGRP) and Substance P (SP) -immunoreactive nerves have been found in the anterior uvea of various mammalian species. Although SP is known to play a major role in control of pupil motility in rabbits, little is known about the effect of CGRP on the iris smooth muscles. We isolated iris sphincter and dilator muscles from rabbit eyes and investigated the mechanical responses and intracellular cyclic AMP (cAMP) levels in these muscles. CGRP (up to 0.1 microM) had no effect on either the resting muscle tone or the amplitude of contraction evoked by field stimulation of the sphincter. On the other hand, CGRP (0.1 microM) relaxed dilator muscle which had been pre-contracted by phenylephrine and reduced the amplitude of contraction evoked by field stimulation. These responses were antagonized by CGRP (8-37), a CGRP antagonist. The phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine (IBMX), dose-dependently inhibited the contraction evoked by field stimulation. However, 3 microM IBMX had no effect on CGRP inhibition of twitch contraction in this preparation. CGRP had little effect on cAMP production in dilator muscle either with or without IBMX. In conclusion, the miosis which occurs during an ocular inflammatory response, when both CGRP and SP are thought to be released from terminals of sensory neurons, results from CGRP relaxation of the dilator and from the strong contractile effect of SP on the sphincter. Adenylate cyclase activation does not seem to be involved in the relaxant effect of CGRP on the dilator.
1-Methyl-3-isobutylxanthine↗
[Effects of topical application of isopropyl unoprostone on refraction and accommodation].
The effect of topical application of prostaglandin-related compound isopropyl unoprostone on refraction and accommodation were examined. Topical application of isopropyl unoprostone obviously reduced the intraocular pressure, but no significant change in refraction was observed. Amplitude of accommodation, i.e., near point and far point of accommodation, were kept unchanged, although isopropyl unoprostone produced a slight hyperopic shift in dark focus of accommodation. These findings suggest that the reduction of intraocular pressure needs to be explained by a mechanism other than the relaxation of ciliary muscles.
Accommodation, Ocular↗
[Objective visual field measurement using "pupil perimetry"].
In an attempt to measure the visual field objectively, we developed a system of "Pupil Perimetry". An infrared pupillometry machine was linked to a Goldmann perimeter to record the visual field by mapping the change in the pupil area (mm2) at each target location within the field. We decreased the background intensity to 10Asb to get maximum pupil response. The target was exposed for 0.25 seconds with an intensity of 1,000 Asb. Pupil response was observed up to 90 degrees laterally and 60 degrees nasally across a meridian in normal subjects. Visual fields obtained from patients with homonymous hemianopsia, glaucoma and Leber's optic neuropathy were compatible with a field obtained by a Humphrey field analyzer (FHA) 30-2 program. Pupil perimetry is a useful tool for measuring the visual field objectively.
Adult↗
Effect of histamine and substance P on the rabbit and human iris sphincter muscle.
BACKGROUND AND METHODS: In an attempt to clarify the functional action of histamine and substance P on atropine-resistant miosis, we isolated rabbit and human iris sphincter muscles and investigated their mechanical properties using the isometric tension recording method. RESULTS: Substance P dose-dependently contracted the rabbit iris sphincter, but had no effect on the human iris sphincter. In the rabbit iris sphincter, histamine reduced the amplitude of twitch contraction evoked by field stimulation but had no effect on carbachol-induced contraction. Thioperamide, but not mepyramine or cimetidine, partially antagonized the histamine-induced reduction in the amplitude of twitch contractions. In the human iris sphincter, on the other hand, histamine dose-dependently provoked contraction and the amplitude of histamine-induced contraction was affected neither by atropine nor by indomethacin. CONCLUSIONS: These results provide evidence that histamine has strong contractile effect on the human iris sphincter muscle; the rabbit iris sphincter muscle, however, apparently lacks functional histamine receptors. In rabbits, exogenously applied histamine only activates H3 receptors located on the cholinergic nerve terminal, hence the excitatory neuro-effector transmission is suppressed. Thus, histamine may have an important roles in atropine-resistant miosis in humans, but not in rabbits.
Animals↗
Role of baroreflex and central alpha2-adrenergic receptor systems in the diurnal variation of blood pressure and heart rate in normotensive and hypertensive rats.
1. To elucidate whether baroreflex could contribute to manifest the diurnal blood pressure variations (DBPV) in normotension and hypertension, DBPV were recorded continuously via a femoral artery in awake normotensive (NT) rats and spontaneously hypertensive rats (SHR) with and without sinoaortic denervation (SAD). To determine the role of central alpha2-adrenergic receptor system in DBPV in hypertension, guanabentz (0.5-1.0 mu g/kg per min) was infused in SHR. 2. There were no differences in mean arterial pressure (MAP) variability (SD) of MAP of 24 h (MAP -- SD/MAP) and SD of 24 h heart rate (HR -- SD/HR) between SHR and NT. SAD did not elevate MAP and HR in both SHR and NT. 3. However, in SAD rats, MAP -- SD/MAP was significantly greater than those in sham-operated rats in both SHR and NT, while MAP -- SD/MAP and HR -- SD/HR did not show any difference between the two groups even after SAD. On the other hand, SAD did not augment HR -- SD/HR in either strain. 4. During guanabentz infusion, MAP was significantly lowered in sham-operated and SAD -- SHR. Moreover, MAP -- SD/MAP was significantly reduced in sham-operated, but it was not in SAD -- SHR. 5. These findings suggest that baroreflex could suppress tonically the diurnal change of blood pressure in NT and SHR. The regulation of diurnal blood pressure by baroreflex via a central alpha-adrenergic receptor system may be altered in SHR.
Adrenergic alpha-2 Receptor Antagonists↗
Antihypertensive effect of taurine on salt-induced hypertension.
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Animals↗