RESUMEN
We investigated the optical transmission properties of one-dimensional photonic crystal (1D-PC) microcavity structures containing the liquid-crystalline (LC) perylene tetracarboxylic bisimide (PTCBI) derivative. We fabricated the microcavity structures for this study by two different methods and observed the cavity polaritons successfully in both samples. For one sample, since the PTCBI molecules were aligned in the cavity layer of the 1D-PC by utilizing a friction transfer method, vacuum Rabi splitting energy was strongly dependent on the polarization of the incident light produced by the peculiar optical features of the LC organic semiconductor. For the other sample, we did not utilize the friction transfer method and did not observe such polarization dependence. However, we did observe a relatively large Rabi splitting energy of 187 meV, probably due to the improvement of optical confinement effect.
RESUMEN
The effects of progesterone, dehydroepiandrosterone sulfate and 17beta-estradiol on the synthesis and degradation of hyaluronate were investigated using human uterine cervix fibroblasts. The cells were incubated with [3H]glucosamine in the presence of the hormones and then [3H]hyaluronate was isolated from the medium. The changes in the radioactivity of [3H]hyaluronate showed that progesterone suppressed hyaluronate synthesis by 22% of the control levels, while dehydroepiandrosterone sulfate and 17beta-estradiol enhanced it by 22% and 12% of the control levels, respectively. Furthermore, progesterone induced degradation of high-molecular-weight [14C]hyaluronate into low-molecular-weight hyaluronate (Mr approximately 40000). These results suggest that in cultured fibroblasts from the human uterine cervix progesterone converts hyaluronate metabolism from the synthesis phase to the degradation phase.
Asunto(s)
Cuello del Útero/metabolismo , Ácido Hialurónico/metabolismo , Progesterona/farmacología , Células Cultivadas , Cuello del Útero/efectos de los fármacos , Sulfato de Deshidroepiandrosterona/farmacología , Estradiol/farmacología , Femenino , Fibroblastos/metabolismo , Glucosamina/metabolismo , Humanos , Ácido Hialurónico/biosíntesis , Cinética , Técnica de Dilución de Radioisótopos , TritioRESUMEN
The effect of bright light on the retinas of developing albino rats was studied electron microscopically. The newly formed outer-segment lamellar membranes of newborn rats raised in continuous bright light appear to be less sensitive to the damaging effects of light, compared to those of rats raised under normal light conditions for at least two weeks. It seems to take about two days before the membranes show damage from continuous exposure to fluorescent lamps. The same brightness damages the adult outer segments within a few hours. Despite the severe damage to the outer segments, the rest of the retina develops normally for one month, and then the photoreceptor cells undergo degeneration. The retinas that have been exposed to bright light for two weeks after birth show considerable damage, but these retinas regenerate in six months.
Asunto(s)
Luz/efectos adversos , Retina/crecimiento & desarrollo , Enfermedades de la Retina/etiología , Animales , Animales Recién Nacidos , Cilios/ultraestructura , Femenino , Melanocitos/ultraestructura , Mitocondrias/ultraestructura , Células Fotorreceptoras/ultraestructura , Epitelio Pigmentado Ocular/patología , Embarazo , Ratas , Ratas Endogámicas , Retina/ultraestructura , Enfermedades de la Retina/patología , Factores de TiempoRESUMEN
A method was developed for evaluating the relative rate of conversion of [14C]-citrulline to [14C]arginine in vivo. By this method it was demonstrated that the conversion was almost completely abolished by functional nephrectomy, but not by functional hepatectomy. It was also demonstrated that functional nephrectomy caused a prompt increase in the citrulline concentration in the serum, while functional hepatectomy caused a rapid decrease in it. On the basis of these findings, it was concluded that the kidney was the main organ for synthesis of arginine from citrulline, which is supplied from the liver. Studies using this method also provided evidence suggesting that arginine formation from citrulline might be controlled by insulin and by negative feedback due to dietary arginine. In addition, in vivo experiments and perfusion experiments on isolated kidney showed that guanidinoacetic acid formation from citrulline was remarkable decreased in diabetic rats. Enzymological studies suggested that this decrease might be due to a change in glycine amidinotransferase [L-arginine:glycine amidinotransferase, EC 2.1.4.1] activity.
Asunto(s)
Arginina/biosíntesis , Glicina/análogos & derivados , Riñón/metabolismo , Animales , Arginina/farmacología , Citrulina/metabolismo , Diabetes Mellitus Experimental/metabolismo , Dieta , Glicina/biosíntesis , Hepatectomía , Insulina/farmacología , Masculino , Nefrectomía , Ornitina/sangre , RatasRESUMEN
Methods were developed for the radioisotopic assay of argininosuccinate synthetase [L-citrulline: L-aspartate ligase (AMP-forming), EC 6.3.4.5] and argininosuccinase [L-argininosuccinate arginine-lyase, EC 4.3.2.1]. The assay of argininosuccinate synthetase was based on the separation of [14C]argininosuccinate formed from aspartate and [carbamoyl-14C]citrulline in the presence of ATP from the substrate citrulline. For this, the product was converted to its anhydride form by boiling for 30 min at pH 2.0 followed by application on a column of Dowex 50W (pyridine form). Argininosuccinic anhydride was eluted with 0.3 M pyridine acetate buffer, pH 4.25, while citrulline was eluted with 0.1 M pyridine acetate buffer, pH 3.80. The assay of argininosuccinase was based on the separation of [14C]argininosuccinic acid formed from arginine and [U-14C]fumaric acid from the substrate fumarate on a column of Dowex 50W(H+ form). The argininosuccinic acid was adsorbed on the column and eluted with 1 M pyridine solution, while fumarate was not adsorbed. The distributions of these two enzymes in various organs and cell fractions were reinvestigated using these methods.
Asunto(s)
Argininosuccinatoliasa/análisis , Argininosuccinato Sintasa/análisis , Ligasas/análisis , Liasas/análisis , Animales , Argininosuccinato Sintasa/metabolismo , Radioisótopos de Carbono , Difosfatos/farmacología , Riñón/efectos de los fármacos , Riñón/enzimología , Hígado/efectos de los fármacos , Hígado/enzimología , Ratas , Fracciones Subcelulares/enzimologíaRESUMEN
Dorsal horn neurons chronically deafferented by peripheral nerve injuries acquire hypersensitivity to noxious input from outside the original receptive field. This study examines the effect of electrical nerve stimulation at the time of injury on such injury-induced hypersensitivity. The medial 3/8 of the dorsal horn laminae I/II around the junction of 4th and 5th lumbar segments (the tibial territory) was deafferented by transection of the ipsilateral tibial nerve in rats. At 2 days or 3 weeks postinjury, the hindpaw was injected with formalin to induce c-fos. At 2 days, neurons with induced c-Fos protein-like immunoreactivity (fos-neurons) were largely confined in the lateral 5/8 of laminae I/II (the peroneal and hip, thus P and H territory). At 3 weeks, fos-neurons significantly increased in the deafferented tibial territory. A similar increase was also noted in the P and H territory. Thus the dorsal horn neurons exhibited c-fos hyperinducibility, an indication of hypersensitivity. Electrical stimulation with a train of 150 shocks (10 V, 2 ms) of the proximal nerve stump immediately after transection prevented the c-fos hyperinducibility. The effect was greater with the stimulation frequency of 0.5 Hz than 0.1 Hz or 10 Hz. The stimulation had no effect on the c-fos inducibility at 2 days postinjury.
Asunto(s)
Genes fos/genética , Fibras Nerviosas/fisiología , Neuronas Aferentes/fisiología , Traumatismos de los Nervios Periféricos , Médula Espinal/fisiología , Animales , Desnervación , Estimulación Eléctrica , Electrofisiología , Masculino , Dolor/fisiopatología , Ratas , Ratas Sprague-Dawley , Médula Espinal/citología , Médula Espinal/metabolismo , Sinapsis/fisiología , Nervio Tibial/fisiologíaRESUMEN
Inhibitory post-synaptic potentials (IPSPs) were studied in neurons of presubiculum, parasubiculum and medial entorhinal cortex in horizontal slices from rat brains. Isolated IPSPs were evoked by extracellular electrical stimuli in the presence of glutamate receptor antagonists. Cellular morphology was identified using Neurobiotin labeling. IPSPs were compared: (a) across morphological cell types, (b) across laminae within regions, and (c) across regions. IPSPs were visible in stellate and pyramidal cells from layers II, III, and V of all retrohippocampal areas during bath application of glutamate antagonists. Qualitative and quantitative differences in IPSPs were only found when comparing responses by superficial layer II, III cells to responses by deep layer V cells. Responses by stellate and pyramidal cells within the same or adjacent layers did not differ, nor did responses differ from region to region. All cell types exhibited an early hyperpolarizing response. The majority (85%) of superficial layer cells in all regions, regardless of cell shape, exhibited a second hyperpolarizing component. Fewer (50%) deep layer cells exhibited the late peak with similar long latencies. IPSPs were typically larger in superficial layer cells. IPSPs were comprised of GABAA and GABAB (gamma-aminobutyric acid) receptor-mediated components. With repetitive stimulation, the peak amplitude of the GABAA receptor-mediated component decreased with successive stimuli, but stabilized during the first five or fewer stimuli to a level that did not vary with stimulation frequency. The GABAB receptor-mediated component also stabilized, but the final amplitude appeared to decrease as the stimulation frequency increased. With high-frequency repetitive stimulation, both components of the IPSP showed summation. We conclude that the most meaningful distinction for IPSPs among retrohippocampal neurons is a laminar distinction, between superficial and deep layer neurons, and not one across cell shape or retrohippocampal subregion. These laminar differences can contribute to synchronous activity by deep layer neurons and restrict the activity of superficial layer neurons.
Asunto(s)
Corteza Entorrinal/fisiología , Hipocampo/fisiología , Receptores de GABA/fisiología , Animales , Baclofeno/análogos & derivados , Baclofeno/farmacología , Estimulación Eléctrica , Potenciales Evocados/fisiología , Antagonistas del GABA/farmacología , Técnicas In Vitro , Masculino , Inhibición Neural/fisiología , Picrotoxina/farmacología , Ratas , Ratas Sprague-Dawley , Receptores de GABA/efectos de los fármacosRESUMEN
The retrohippocampal cortices form the transition between neocortex and the hippocampus. Area CA3 of the hippocampus and the entorhinal cortex (EC) of the retrohippocampal region are established as brain regions that generate epileptiform activity. Interictal activity generated in EC consists of a primary population burst followed by multiple afterdischarges. The presubiculum is similar to EC in its six-layered structure, but lacks a columnar circuitry that the EC possesses. Isolated presubicular tissue cannot generate afterdischarges and isolated subicular tissue generates no spontaneous activity under some conditions. We report epileptiform activity in combined presubiculum-subiculum slices that consists of synchronous population bursts and multiple afterdischarges. Intracellular and field potential recordings reveal two re-entrant paths for interaction of presubicular and subicular neurons. We demonstrate a deep presubicular input to subiculum and separate return paths from subicular bursting neurons onto deep and superficial layer pre-/parasubicular neurons. Recordings from subicular cell apical dendrites showed repetitive burst firing during sustained depolarizing current injection. We conclude that re-entrant activity in a presubiculum-subiculum circuit generates epileptiform activity in both regions. Presubicular inputs to subiculum depolarize apical dendrites which can then burst repetitively. These bursts are transmitted back to the presubiculum. We suggest that iterations on this circuit act to prolong the dendritic depolarization of subicular bursting neurons and to entrain the activity across subicular cells resulting in multiple afterdischarges.
Asunto(s)
Epilepsia/fisiopatología , Potenciales Postsinápticos Excitadores/fisiología , Hipocampo/fisiología , Neocórtex/fisiología , Neuronas/fisiología , Animales , Electrofisiología/métodos , Hipocampo/fisiopatología , Técnicas In Vitro , Masculino , Potenciales de la Membrana , Modelos Neurológicos , Neocórtex/fisiopatología , Ratas , Ratas Sprague-Dawley , Tiempo de ReacciónRESUMEN
Intracellular and field potential recordings were taken from the lateral nucleus of the amygdala in a rat horizontal brain slice preparation that included hippocampal formation. Pyramidal cells comprised the majority of labeled cells (77%). Electrophysiological classification based on hyperpolarizing or depolarizing afterpotentials subdivided both the pyramidal and non-pyramidal cell classes, although pyramidal cells tended to have hyperpolarizing afterpotentials (70%) and non-pyramidal cells tended to have depolarizing afterpotentials (63%). Synchronous population bursts were triggered with single extracellular stimuli in the deep layers of entorhinal cortex. These events propagated from deep layers of entorhinal cortex into the lateral nucleus of the amygdala. Latencies were consistent with a direct entorhinal to amygdala projection. Individual lateral nucleus neurons exhibited responses ranging from a long burst response that included an initial period of 200 Hz firing and a tail of gamma frequency firing lasting over 100 ms (grade 1) to an epsp with no firing (grade 4). Half of pyramidal cells responding to events initiated in entorhinal cortex were found to receive epsps strong enough to trigger firing. Only one stellate neuron fired in response to entorhinal stimulation. Excitatory postsynaptic responses included NMDA and non-NMDA receptor mediated components. We demonstrate that synchronous population events can propagate from entorhinal cortex to the lateral nucleus of the amygdala and that pyramidal neurons of the lateral nucleus are more common targets than stellate neurons. We conclude that other synchronous events such as sharp waves and interictal spikes can spread from entorhinal cortex to amygdala in the same manner.
Asunto(s)
Potenciales de Acción/fisiología , Amígdala del Cerebelo/fisiología , Sincronización Cortical/métodos , Corteza Entorrinal/fisiología , Vías Nerviosas/fisiología , Neuronas/fisiología , 6-Ciano 7-nitroquinoxalina 2,3-diona/farmacología , Potenciales de Acción/efectos de los fármacos , Amígdala del Cerebelo/citología , Amígdala del Cerebelo/efectos de los fármacos , Animales , Tamaño de la Célula/fisiología , Dendritas/efectos de los fármacos , Dendritas/fisiología , Dendritas/ultraestructura , Estimulación Eléctrica , Corteza Entorrinal/citología , Antagonistas de Aminoácidos Excitadores/farmacología , Masculino , Inhibición Neural/efectos de los fármacos , Inhibición Neural/fisiología , Vías Nerviosas/citología , Neuronas/citología , Neuronas/efectos de los fármacos , Picrotoxina/farmacología , Piperazinas/farmacología , Ratas , Receptores de GABA-A/efectos de los fármacos , Receptores de GABA-A/metabolismo , Receptores de N-Metil-D-Aspartato/efectos de los fármacos , Receptores de N-Metil-D-Aspartato/metabolismoRESUMEN
c-fos and zif268 expression were assessed by immunocytochemistry for c-Fos and Zif268 proteins in the sensory trigeminal nuclear complex following noxious mechanical stimulation of the mandibular incisor pulp of rats. Marked up-regulation of both immediate early genes was observed in the subnucleus oralis ipsilateral to the stimulation. Cavity preparation of the dentine without reaching the pulp did not cause significant up-regulation detectable by immunocytochemistry. These results provide evidence that noxious dental signals reach the ipsilateral subnucleus oralis and up-regulate the transcription of immediate early genes c-fos and zif268.
Asunto(s)
Proteínas de Unión al ADN/genética , Pulpa Dental/metabolismo , Regulación de la Expresión Génica/fisiología , Genes Inmediatos-Precoces , Genes fos , Proteínas Inmediatas-Precoces , Factores de Transcripción/genética , Núcleos del Trigémino/metabolismo , Animales , Proteína 1 de la Respuesta de Crecimiento Precoz , Estimulación Eléctrica , Inmunohistoquímica , Masculino , Ratas , Ratas Sprague-Dawley , Estrés MecánicoRESUMEN
Changes in the expression of immediate early gene c-fos by noxious mechanical stimulation to the mandibular incisor pulp of rats were immunohistochemically examined in the hippocampus (Ammon's horn and dentate gyrus) and the retrohippocampus (subiculum, presubiculum, parasubiculum and entorhinal cortex). The highest control levels were found in subiculum, CA1, dentate and deep medial entorhinal cortex. Lower, but substantial levels were present in the other areas. Whereas weak dentinal stimulation caused increases in c-fos expression in some regions which were not statistically significant, strong tooth pulp stimulation caused a bilateral decrease in c-fos expression in every region except contralateral subiculum. These decreases reached statistical significance in superficial layer parasubiculum bilaterally (p<0.01), bilateral CA1 and ipsilateral side of superficial layer of medial entorhinal cortex (p<0.05). We suggest that inhibitory circuitry in hippocampal formation regions may be activated by peripheral noxious somatosensory inputs and this change in activity is accompanied by a change in the expression of the immediate early gene, c-fos.
Asunto(s)
Pulpa Dental/fisiología , Hipocampo/metabolismo , Nociceptores/fisiología , Proteínas Proto-Oncogénicas c-fos/biosíntesis , Animales , Pulpa Dental/inervación , Corteza Entorrinal/citología , Corteza Entorrinal/metabolismo , Hipocampo/citología , Masculino , Neuronas/metabolismo , Dolor/metabolismo , Estimulación Física , Ratas , Ratas Sprague-DawleyRESUMEN
Patch-clamp recordings were used to examine the osmosensitivity and mechanosensitivity of neurons in the caudal part of the nucleus tractus solitarius in coronal slices from rat brain. Firing rates and membrane potentials were measured as slices were exposed to perfusate which varied in its osmolality and/or sodium concentration. In all cells tested, the responses to change in the sodium concentration of perfusate were duplicated by osmolality changes of sucrose or mannitol. When nucleus tractus solitarius cells were tested with changes in pressure applied via the pipette, responses to positive or negative pressure paralleled their responses to osmotic stimulation. We suggest that a mechanosensitive receptor exists on osmosensitive neurons within the nucleus tractus solitarius, and this receptor may be responsible for changes in the firing rate and membrane potential which occur in the nucleus tractus solitarius neurons.
Asunto(s)
Neuronas/fisiología , Núcleo Solitario/citología , Núcleo Solitario/fisiología , Equilibrio Hidroelectrolítico/fisiología , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Diuréticos Osmóticos/farmacología , Soluciones Hipertónicas/farmacología , Soluciones Hipotónicas/farmacología , Técnicas In Vitro , Masculino , Manitol/farmacología , Técnicas de Placa-Clamp , Estimulación Física , Ratas , Ratas Sprague-Dawley , Cloruro de Sodio/farmacología , Estimulación Química , Sacarosa/farmacología , Equilibrio Hidroelectrolítico/efectos de los fármacosRESUMEN
We examined the effect of propofol and thiopental, intravenous anesthetics, on the hyperpolarization-activated inward current (I(H)), whose functional role on the neuronal activity has been evaluated. Whole-cell recordings of I(H) evoked by hyperpolarizing step pulses were taken from hippocampal CA1 neurons in rat brain slices. Propofol reduced I(H) current in a dose-dependent manner. However, thiopental had no significant effect on the activation of I(H). According to the functional role of I(H), the suppression of I(H) should result in a reduction of neuronal activity. We suggest that the effectiveness of propofol as an anticonvulsant or an antiemetic is associated with the blockade of the I(H) channel.
Asunto(s)
Anestésicos Intravenosos/metabolismo , Hipocampo/efectos de los fármacos , Canales Iónicos/efectos de los fármacos , Inhibición Neural/efectos de los fármacos , Neuronas/efectos de los fármacos , Propofol/metabolismo , Receptores de GABA-A/efectos de los fármacos , Animales , Membrana Celular/efectos de los fármacos , Membrana Celular/fisiología , Relación Dosis-Respuesta a Droga , Hipocampo/citología , Hipocampo/metabolismo , Canales Iónicos/metabolismo , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Inhibición Neural/fisiología , Neuronas/metabolismo , Técnicas de Cultivo de Órganos , Técnicas de Placa-Clamp , Farmacocinética , Ratas , Ratas Sprague-Dawley , Receptores de GABA-A/metabolismo , Tiopental/farmacocinéticaRESUMEN
Responses to glucose of spontaneously active neurons were investigated by extracellular recording in the rat area postrema slice preparations (in vitro). Among 67 spontaneously active neurons, 16 neurons displayed a marked increase or decrease in discharge rate in response to increases or decreases of the glucose concentration in perfusate. These results confirm the existence of glucose-responsive neurons within the area postrema suggested in prior in vivo experiments. Response to CCK or dopamine was also examined on the isolated area postrema slices. The neuron that showed a marked increase in discharge rate responding to glucose elicited a marked increase of discharge rate in response to 2.1 microM CCK, suggesting that glucose and CCK affect the same neurons. Some neurons showed a marked increase or decrease in the discharge rate in response to 20 microM dopamine, but these neurons showed neither response to CCK nor to glucose. It is likely that different neuronal networks in the area postrema contribute to control of ingestion and to initiation of nausea.
Asunto(s)
Ventrículos Cerebrales/efectos de los fármacos , Glucosa/farmacología , Neuronas/efectos de los fármacos , Animales , Ventrículos Cerebrales/citología , Técnicas In Vitro , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
It is well known that the body temperature increases during food intake. However, probably because of high thermal conduction within the body, it is rather difficult to determine the main organ that is the source of participates heat production in association with food intake. Our study revealed that increased temperature in the liver during food intake was more predominant than that in the other parts of the abdomen. To further confirm this, we attempted to measure the temperature of both the liver and blood in the portal vein, simultaneously. The temperature of the liver was always higher than that of the portal blood. This implies that hepatic thermogenesis is continuous. The difference between these two temperatures may indicate whether or not hepatic thermogenesis contributes to the increase in body temperature during food consumption. It becomes apparent that the participation of thermogenesis of the liver, along with that of the brown adipose tissue in body temperature increase, is influenced by the composition of food, such as high or low protein in the diet.
Asunto(s)
Regulación de la Temperatura Corporal , Ingestión de Alimentos , Hígado/fisiología , Alimentación Animal , Animales , Fenómenos Fisiológicos Sanguíneos , Capsaicina/farmacología , Caseínas/farmacología , Ritmo Circadiano , Proteínas en la Dieta/farmacología , Masculino , RatasRESUMEN
Sequential combinations of chemotherapy with biological response modifiers has recently been evaluated as systemic treatment for patients with advanced melanoma. The response rates of the chemoimmunotherapy were reported to be higher than conventional treatment using chemotherapy or biological agents alone. To investigate the effectiveness of such chemoimmunotherapy, we evaluated the antitumour effect of sequential chemoimmunotherapy in vivo using a B16 mouse melanoma system. In this sequential regimen, administration of cisplatin (CDDP) was followed by interferon-beta (IFNbeta) and interleukin-2 (IL-2). This combination therapy synergistically inhibited the growth of B16-F1 melanoma and prolonged the survival of mice bearing B16-F1. In contrast, this therapy did not show any antitumour effect on B16-F10 melanoma. The exact mechanism of the antitumour effect is not clear, but the following results were noted: no synergistic effect of this therapy was detected in nude mice, neutralizing anti-IFNgamma antibody significantly blocked the antitumour effect of this therapy, and the number of apoptotic melanoma cells was significantly increased in melanoma tissues removed from mice treated with this therapy. These results demonstrated the potent immunological antitumour effect of this sequential chemoimmunotherapy.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Inmunoterapia , Interleucina-2/uso terapéutico , Melanoma Experimental/terapia , Neoplasias Cutáneas/terapia , Animales , División Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/inmunología , Cisplatino/administración & dosificación , Femenino , Interferón beta/administración & dosificación , Melanoma Experimental/mortalidad , Melanoma Experimental/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Desnudos , Metástasis de la Neoplasia , Neoplasias Cutáneas/mortalidad , Neoplasias Cutáneas/patología , Tasa de Supervivencia , Células Tumorales CultivadasRESUMEN
We developed a method to evaluate cell adherence to different intraocular lens (IOL) materials in one eye in which we coated one half of the anterior surface of a poly(methyl methacrylate) (PMMA) IOL with poly(dimethyl siloxane), a silicone material. The lenses were implanted in the anterior chamber of rabbit eyes without lens extraction. Postoperative cellular reaction on the IOL surfaces was studied by specular microscopy. The IOLs were fixed in situ, removed from the eyes, and stained with hematoxylin-eosin so we could evaluate the cell population on the silicone and PMMA surface. Fewer cells were scattered on the silicone surface than on the PMMA surface. This method excludes surgical effects and allows a comparison of various IOL materials in the same eye.
Asunto(s)
Recuento de Células , Lentes Intraoculares , Animales , Materiales Biocompatibles , Adhesión Celular , Células Gigantes , Macrófagos , Metilmetacrilato , Metilmetacrilatos , Conejos , SiloxanosRESUMEN
The locomotor activity of mice was recorded after administration of d-methamphetamine-HCl (1.5, 2.5, 5.0 and 7.5 mg/kg body weight) and/or ethanol (0.8 and 1.6 g/kg body weight). Mice injected with lower doses of d-methamphetamine (1.5 or 2.5 mg/kg) showed a marked increase in locomotor activity, while in those with higher doses of d-methamphetamine (5.0 or 7.5 mg/kg), locomotor activity was not further enhanced, but slightly decreased. Administration of ethanol inhibited the stimulated locomotor activity caused by low doses of d-methamphetamine (1.5 or 2.5 mg/kg), while the stimulation of motility after higher doses of d-methamphetamine (5.0 or 7.5 mg/kg) was potentiated by administering ethanol. Although apparent inhibition and stimulation of d-methamphetamine-induced locomotor activity of mice due to ethanol was observed, it is suggested that mice administered ethanol showed the decreased sensitivity to d-methamphetamine by plotting total locomotor activity of mice against doses of d-methamphetamine administered. The half maximum effective dose of d-methamphetamine for locomotor activity was increased from 1.5 mg/kg to 3.0 mg/kg by concomitant administration of 1.6 g/kg ethanol.
Asunto(s)
Etanol/farmacología , Metanfetamina/farmacología , Actividad Motora/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Masculino , Metanfetamina/metabolismo , RatonesRESUMEN
We have examined changes in rectal temperature of mice after subcutaneous administrations of d-methamphetamine alone or methamphetamine plus morphine. Methamphetamine 5 mg/kg produced slight hyperthermia, while simultaneous administration of morphine (25-100 mg/kg), which alone produces hypothermia, potentiated markedly the increase in body temperature by methamphetamine. Methamphetamine showed a hyperthermic effect in a dose-dependent manner in the presence of morphine. The hyperthermia due to methamphetamine plus morphine was avoided by pretreatment with 10 mg/kg naloxone. When animals were pretreated with 2.5 mg/kg haloperidol, hyperthermia due to methamphetamine alone was completely abolished, while that due to methamphetamine plus morphine was still observed. These results showed that dopamine may be implicated in methamphetamine hyperthermia and a haloperidol-nonsensitive mechanism may be involved in the methamphetamine-morphine hyperthermia.
Asunto(s)
Regulación de la Temperatura Corporal/efectos de los fármacos , Fiebre/inducido químicamente , Haloperidol/farmacología , Metanfetamina/toxicidad , Morfina/toxicidad , Naloxona/farmacología , Animales , Sinergismo Farmacológico , Masculino , Ratones , Actividad Motora/efectos de los fármacosRESUMEN
Whether the pathologic origin of white matter lesions in Fukuyama type of congenital muscular dystrophy (FCMD) is delayed myelination or dysmyelination is a controversial issue. This study investigated pathologic distribution in white matter with heavily T(2)-weighted images using fluid-attenuated inversion recovery (FLAIR) pulse sequence. For detection of abnormal white matter lesions, FLAIR images were approximately twice as sensitive as T(2)-weighted images and five times as sensitive as T(1)-weighted images of spin echo sequence. The distribution of the white matter lesions was disseminated and not correlated with cortical disarrangement. The distribution was not consistent with delayed myelination. These findings support the evidence found using in vitro proton-NMR spectroscopy that the pathologic origin of white matter lesions is dysmyelination. When conventional magnetic resonance imaging is used, masked white matter lesions are easy to misidentify as delayed myelination instead of disseminated developmental dysmyelination. The lesions in the white matter of FCMD are masked because of brain development.