RESUMEN
B/K protein is a recently isolated member of the double C2-like-domain protein family, which is highly abundant in rat brain. We generated high-titer rabbit polyclonal antibodies with specificity to the 55-kDa rat B/K protein, and examined the expression pattern of B/K protein in rat brain using an immunohistochemical staining method. Immunoreactivity to B/K protein was widely found in distinct regions of rat brain: strongly in the hypothalamus, most of the circumventricular organs, the locus coeruleus, the A5 neurons of the pons, and the anterior pituitary; moderately in the anterior olfactory nucleus, the raphe nucleus, the subfornical organ, and the median eminence; and faintly in the olfactory bulb, the telencephalon, the substantia nigra pars compacta, and the ventral tegmental area. In contrast, immunoreactivity to B/K protein was not observed in the thalamus, the cerebellum, the posterior pituitary, or the spinal cord. In most of the B/K-expressing neurons, immunoreactivity was expressed mainly in soma but not in nerve fibers. B/K was also expressed in nonneuronal cells such as the tanycytes and the subcommissural organ. In the vasopressin-secreting supraoptic and paraventricular nuclei of the hypothalamus, the site where B/K cDNA was originally isolated from, all of the neurons showing vasopressin immunoreactivity also expressed B/K protein, suggesting an overlap of their expression patterns.
Asunto(s)
Química Encefálica , Proteínas del Tejido Nervioso/análisis , Factores de Edad , Animales , Anticuerpos/aislamiento & purificación , Especificidad de Anticuerpos , Tronco Encefálico/química , Diencéfalo/química , Inmunohistoquímica , Masculino , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/inmunología , Estructura Terciaria de Proteína , Conejos , Ratas , Ratas Sprague-Dawley , Sinaptotagminas , Telencéfalo/químicaRESUMEN
It has been shown that flap endonuclease-1 (FEN-1), a structure-specific nuclease, acts on the removal of RNA primers during Okazaki fragment maturation in DNA synthesis. To study whether the gene expression of FEN-1 is inducible during cell proliferation, we analyzed the FEN-1 mRNA levels in actively growing cells and non-growing cells. The gene expression of FEN-1 was higher in mitotic cells than in resting cells, and was markedly decreased, especially, when terminal differentiation was induced in promyelocytic leukemia cells (HL-60 cells). The decline correlated substantially with the ceasing of DNA synthesis. In the examination of tissue-specific gene expression, the human testis, spleen, thymus and mucosal lining of colon tissues expressed this gene actively, whereas the prostate, ovary, small intestine and peripheral blood leukocyte hardly expressed it. In addition, FEN-1 was co-localized with the proliferating cell nuclear antigen (PCNA) in young rat kidney according to immunohistochemistry. These findings suggest that FEN-1 gene expression is inducible during cell proliferation for DNA synthesis, and is down-regulated during cell differentiation.
Asunto(s)
Replicación del ADN , Endodesoxirribonucleasas/genética , Animales , Diferenciación Celular , División Celular , ADN/análisis , ADN/biosíntesis , Endodesoxirribonucleasas/biosíntesis , Endonucleasas de ADN Solapado , Regulación Enzimológica de la Expresión Génica , Granulocitos/citología , Células HL-60 , Humanos , Inmunohistoquímica , Riñón/metabolismo , Activación de Linfocitos , Linfocitos/citología , Masculino , Antígeno Nuclear de Célula en Proliferación , ARN Mensajero/análisis , Ratas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Bazo/metabolismo , Testículo/metabolismoRESUMEN
Previous in vitro studies using cell cultures or brain slices have demonstrated that phospholipase D (PLD) in the nervous system is involved in the signaling mechanism in response to a variety of agonists. However, little is known about the pathophysiological role of PLD-mediated signaling in the adult brain. We examined the changes in the expression of a PLD isozyme, PLD1, in the adult rat hippocampus, using immunological approaches and an assay for PLD activity after transient forebrain ischemia (four-vessel occlusion model) that results in the selective delayed death of CA1 pyramidal cells and induces reactive astrocytes in the CA1 subfield. In the control hippocampus, PLD1 the level of immunoreactivity was very low. After ischemia, in parallel with the results of Western blot analysis and the PLD activity assay, immunohistochemical analysis of PLD1 demonstrated that the immunoreactive proteins peaked at 7-14 days and were most prominent in the CA1 and the dentate hilar region. The temporal and spatial patterns of immunoreactivity of both PLD1 and glial fibrillary acidic protein (GFAP) were very similar, indicating that reactive astrocytes express PLD1, confirmed by double staining for PLD1 and GFAP. These results demonstrate that reactive astrocytes upregulate PLD in vivo after injury in the adult rat hippocampus.
Asunto(s)
Astrocitos/metabolismo , Astrocitos/fisiología , Isquemia Encefálica/metabolismo , Fosfolipasa D/metabolismo , Prosencéfalo/metabolismo , Prosencéfalo/fisiopatología , Animales , Western Blotting , Isquemia Encefálica/fisiopatología , Hipocampo/metabolismo , Hipocampo/fisiopatología , Inmunohistoquímica , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
Examining the distribution of osteopontin (OPN) in the rat brain using in situ hybridization, it was found that OPN mRNA was restricted to likely neurons in the olfactory bulb and the brain stem; it was not detected in the telencephalon and the diencephalon. In addition, Northern blot analysis showed a confined expression only in the brain stem with higher level in the pons and the medulla than in the midbrain. In the brain stem, it was found in functionally diverse areas including motor-related areas, sensory system and reticular formation. This specific but widespread distribution suggests that OPN may play an important role in the adult rat brain.
Asunto(s)
Encéfalo/metabolismo , ARN Mensajero/metabolismo , Sialoglicoproteínas/genética , Animales , Northern Blotting , Tronco Encefálico/metabolismo , Hibridación in Situ , Neuronas/metabolismo , Bulbo Olfatorio/metabolismo , Osteopontina , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
The birthdates of GABAergic amacrine cells in the rat retina were investigated by immunocytochemistry using anti-GABA and anti-bromodeoxyuridine (BrdU) antisera. The ratio of co-localization of GABA to BrdU increased gradually from embryonic-day 13 (E13) and showed a peak value on E18 in the central retina and on E20 in the periphery. After birth, until postnatal-day 3 (P3), a few co-localized cells were observed in the inner nuclear layer (INL). However, in the peripheral retina, co-localized cells were observed in the INL and ganglion cell layer until P5. Our results suggest that the birthdates of GABA-immunoreactive cells vary, depending on cell-type and that there is a temporal lag in the GABA-immunoreactive cell production in the peripheral retina relative to the central retina.
Asunto(s)
Bromodesoxiuridina/metabolismo , Retina/embriología , Células Ganglionares de la Retina/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Animales , Animales Recién Nacidos , Femenino , Humanos , Inmunohistoquímica , Embarazo , Ratas , Ratas Sprague-Dawley , Retina/citologíaRESUMEN
We investigated the spatial and temporal expression of osteopontin (OPN) mRNA following transient forebrain ischemia in rats. Experiments were carried out using a four-vessel occlusion model for forebrain ischemia. The transient induction of OPN mRNA after global ischemia occurred earlier in the striatum than in the hippocampus. It was pronounced in the dorsomedial striatum close to the lateral ventricle and in the CA1 subfield and the subiculum of the hippocampus before microglial cells became more reactive. It also could be detected in the dentate hilus and to a marginal extent in the CA3. Our results suggest that the hippocampus and the striatum following global forebrain ischemia upregulate OPN mRNA in different spatiotemporal profiles.
Asunto(s)
Isquemia Encefálica/metabolismo , Cuerpo Estriado/metabolismo , Hipocampo/metabolismo , Prosencéfalo/fisiopatología , ARN Mensajero/biosíntesis , Sialoglicoproteínas/genética , Regulación hacia Arriba/fisiología , Animales , Northern Blotting , Isquemia Encefálica/fisiopatología , Hibridación in Situ , Masculino , Microglía/metabolismo , Osteopontina , Fosfoproteínas/metabolismo , Ratas , Ratas Sprague-Dawley , Sialoglicoproteínas/biosíntesisRESUMEN
Major intestinal injury may be present with very subtle clinical and/or imaging findings. Sometimes, delayed intestinal stenosis may occur even several months after the blunt abdominal trauma. We present a 12-year-old boy with delayed jejunal stenosis following blunt abdominal injury in a car collision. Computed tomography (CT) scan showed streaky infiltrates in the mesentery and fluid densities in the bilateral anterior pararenal spaces as well as enhancement of bowel wall on the 2nd day after trauma. A "bird-beak" sign at the proximal jejunum with diffuse mucosal swelling of jejunal loops were seen on barium follow-up study on the 7th day. Complete obstruction at the duodenojejunal junction was identified by the follow-up barium examination on the 29th day.
Asunto(s)
Traumatismos Abdominales/complicaciones , Obstrucción Intestinal/etiología , Heridas no Penetrantes/complicaciones , Niño , Humanos , Masculino , Factores de Tiempo , Tomografía Computarizada por Rayos XRESUMEN
Expression of ciliary neurotrophic factor (CNTF) was observed in reactive astrocytes in injured spinal cord of the adult rat. After unilateral incision of the dorsal funiculus at a midthoracic level, the rats were sacrificed on the day of postoperation (DPO) 3, 7, 14 or 28. Western blot analysis of spinal cord extracts showed that the intensity of the CNTF-immunoreactive band of 24 kDa was increased on DPO 3 and 7 and decreased on DPO 14. CNTF- or glial fibrillary acidic protein (GFAP)-like immunoreactivity was also increased progressively in the injured dorsal funiculus and adjacent gray matter. Double immunofluorescence histochemistry revealed that all CNTF-like immunoreactive cells showed GFAP-like immunoreactivity. The CNTF upregulation in the reactive astrocytes may play important roles in repair process after spinal cord injury.
Asunto(s)
Astrocitos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Traumatismos de la Médula Espinal/metabolismo , Médula Espinal/metabolismo , Animales , Western Blotting , Factor Neurotrófico Ciliar , Inmunohistoquímica , Masculino , Ratas , Ratas Sprague-Dawley , Médula Espinal/patología , Traumatismos de la Médula Espinal/patología , Distribución TisularRESUMEN
Recent evidence indicates that neuropathic pain from partial peripheral nerve injury is maintained by electrophysiologically abnormal signals from injured sensory neurons. To gain an insight into the mechanisms underlying this electrophysiological abnormality, we examined the effects of S1 spinal nerve transection on the membrane properties of S1 dorsal root ganglion neurons one to two weeks after injury. This injury produced significant action potential broadening [40% (1 ms) in C-, 149% (1.5 ms) in A delta- and 84% (0.5 ms) in A alpha/beta-cells], which was primarily due to the enhancement of the "shoulder" appearing on the falling phase of the action potential in C- and A delta-cells and the emergence of a shoulder in A alpha/beta-cells, and significant cell-type specific changes in the time-course of the rising phase of the action potential; i.e. an increase in rise time (A delta: 35%, 0.15 ms; A alpha/beta: 13%, 0.04 ms) and a decrease in the maximal rate of rise (A delta: 17%, 77 V/s; A alpha/beta: 13%, 79 V/s). In addition, the nerve injury led to a significant reduction of the rheobase, an index of neuronal excitability, in all types of cells (by 41% in C-, 71% in A delta- and 59% in A alpha/beta-cells). The reduction of rheobase in A-cells was associated with a concomitant increase in apparent input resistance (by 269% in A delta- and 192% in A alpha/beta-cells), which was measured near the resting membrane potential. By contrast, the rheobase reduction in C-cells was associated with a concurrent depolarizing shift (approximately 4 mV) of the resting membrane potential. The nerve injury-induced reduction of rheobase was not accompanied by related change in input resistance or threshold potential in any of the cell populations. The present results indicate that chronic peripheral axotomy of dorsal root ganglion neurons, which gives rise to neuropathic pain, produces profound changes in the action potential waveform of dorsal root ganglion neurons in a cell type-specific fashion. Furthermore, the results suggest that the axotomy increases the excitability of dorsal root ganglion neurons not by altering input resistance (i.e. leak conductance) or threshold potential, but by increasing apparent input resistance near the resting membrane potential in A-cells and decreasing the resting membrane potential in C-cells.
Asunto(s)
Ganglios Espinales/fisiopatología , Conducción Nerviosa/fisiología , Neuralgia/fisiopatología , Neuronas/fisiología , Nervios Espinales/fisiopatología , Potenciales de Acción , Animales , Axotomía , Membrana Celular/fisiología , Modelos Animales de Enfermedad , Estimulación Eléctrica , Ganglios Espinales/fisiología , Masculino , Neuronas Aferentes/fisiología , Ratas , Ratas Sprague-Dawley , Nervios Espinales/fisiologíaRESUMEN
Microcolon is a radiological finding of a colon of tiny caliber on barium enema examination. There are no absolute standards for measurement of this condition which is probably caused in utero by lack of appropriate distention of the colon with intramural content. A review was undertaken of 228 barium enema examinations of newborns admitted to Mackay Memorial hospital from January 1987 to December 1988. Twenty cases (8.7%) were regarded by the same radiologist as microcolon. Among them, ileal atresia was found in nine cases (45%); colonic atresia in two cases (10%); total colon agangliosis in three cases (15%); prenatal volvulus in two cases (10%); meconium ileus in two cases (10%); duplication of ileum in one case (5%): and megacystis-microcolon-intestinal hypoperistasis (MMIHS) in one case (5%). The characteristic features of plain abdomen and barium enema study were discussed. The finding of a microcolon on contrast enema study in newborn with lower gastrointestinal obstruction signifies that it may rise from lower gastrointestinal obstruction above colon, external compression, or motility disorder of the intestine itself. The outcome of microcolon seems to depend on its underlying causes. In those caused by obstruction, only the caliber may return to normal within days after removal of the obstruction.