RESUMEN
Prediction of the timing of platelet recovery after chemotherapy and hematopoietic stem cell transplantation (HSCT) allows for optimal platelet transfusion. We assessed the clinical utility of the percentage value of the immature platelet fraction (IPF%) monitored using an XE-2100 automated hematology analyzer to predict the timing of platelet recovery after chemotherapy and HSCT. The IPF% was serially monitored in 31 patients with cancer who received 66 courses of chemotherapy and HSCT. In patients with cancer undergoing chemotherapy and HSCT, a transient increase in IPF% was observed 1-11 days prior to platelet recovery (>30 × 109 /l). In patients undergoing chemotherapy with a peak IPF% >10%, platelet recovery occurred significantly earlier than in those with IPF% peak values ≤10% (median periods were 2 and 5 days; P < 0.05). Platelet recovery appears to occur earlier in patients undergoing HSCT with a peak IPF% >10% than in those with IPF% peak values ≤10% (median periods were 2 and 6 days). Thus, the IPF% peak value is a useful parameter for predicting the timing of platelet recovery after chemotherapy and HSCT and has the potential to facilitate optimal platelet transfusion.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Neoplasias/sangre , Recuento de Plaquetas , Adulto , Anciano , Anciano de 80 o más Años , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/tratamiento farmacológico , Transfusión de Plaquetas , Reproducibilidad de los ResultadosRESUMEN
Platelet number is often used as an indicator of the severity of liver disease. Although inadequate thrombopoietin production and decreased platelet production have been proposed as major causes of cirrhotic thrombocytopenia, the underlying mechanism has not yet been fully clarified. We examined whether the measurement of the immature platelet fraction (IPF) in thrombocytopenic patients with liver dysfunction is useful as a rapid and noninvasive method for the differential diagnosis of chronic liver diseases. We examined 20 liver cirrhosis patients, 56 patients with chronic hepatitis, 9 patients with fatty liver, and 86 patients without liver disease. The percentage value of IPF (IPF%) was measured using an XE-2100 multiparameter automatic hematology analyzer. Using a receiver operating characteristic curve, we found diagnostic significance of the absolute platelet count and the absolute number of the IPF between cirrhotic patients and noncirrhotic patients, and developed a powerful multivariate discriminant analysis (MDA) function based on the platelet count and the IPF%. The diagnostic accuracy obtained by the MDA function was superior to that obtained by the absolute number of platelets and the IPF. We therefore propose our IPF% measurement for the diagnosis of liver cirrhosis.
Asunto(s)
Biomarcadores/sangre , Plaquetas/química , Cirrosis Hepática/diagnóstico , Hepatopatías/diagnóstico , Adulto , Anciano , Plaquetas/citología , Plaquetas/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Recuento de Plaquetas , Curva ROC , Estándares de Referencia , Trombocitopenia/diagnósticoRESUMEN
The tissue distribution of mouse polymeric immunoglobulin receptor (pIgR) has been demonstrated. By Northern blot hybridization, pIgR mRNA expression was detected in liver, intestine, stomach, lung and kidney. A weak expression was also detected in thymus by reverse transcriptase-polymerase chain reaction. The pIgR expression in kidney was further studied and confirmed that pIgR protein was actively synthesized in the epithelial cells of distal urinary tubule and of Henle's loop. Immunoelectron microscopical analysis showed the accumulation of pIgR-containing vesicles in the apical portion of distal urinary tubule epithelial cells.
Asunto(s)
Túbulos Renales Distales/inmunología , Receptores de Inmunoglobulina Polimérica/inmunología , Animales , Inmunohistoquímica , Túbulos Renales Distales/ultraestructura , Ratones , Microscopía Inmunoelectrónica , Especificidad de Órganos , ARN Mensajero/metabolismo , Receptores de Inmunoglobulina Polimérica/biosíntesis , Receptores de Inmunoglobulina Polimérica/genéticaRESUMEN
Chlorophyll degradation was investigated in cells of a chlorophyll b-less mutant of Chlamydomonas reinhardtii under aerobic and anaerobic conditions. During degradation of chlorophyll under anaerobic conditions, chlorophyll catabolite P535, an open-tetrapyrrole, was not excreted, but pyropheophorbide a was accumulated as the end product with a transient accumulation of chlorophyllide a and pheophorbide a in cells, in contrast to the breakdown under aerobic conditions. It is likely that in the absence of oxygen, degradation of chlorophyll a proceeds to pyropheophorbide a by three consecutive reactions, dephytylation, metal-releasing and demethoxycarbonylation, and then stops due to a limitation of the oxygen that the monooxygenase reaction requires for bilin formation. A novel enzyme catalyzing demethoxycarbonylation of pheophorbide a was partially purified. The enzyme activity increased dependent on the age of cells, and its increase was completely suppressed by cycloheximide. Production of P535 was also dependent on cytoplasmic protein synthesis.
Asunto(s)
Chlamydomonas reinhardtii/metabolismo , Clorofila/análogos & derivados , Clorofila/metabolismo , Anaerobiosis , Animales , Chlamydomonas reinhardtii/enzimología , Chlamydomonas reinhardtii/genética , Clorofila/genética , Mutación , Inhibidores de la Síntesis de la Proteína/farmacologíaRESUMEN
The tooth in the gar-pike, Lepisosteus oculatus, an actinopterygian fish, is characterized by the occurrence of both enamel and enameloid, the former covering the tooth shaft and the latter, the tooth cap. Our previous research demonstrated that the enamel in this species was, as in the lungfish, immunoreactive for amelogenin, indicating its homologous nature with the mammalian tooth enamel, whereas the enameloid was completely immunonegative. The present study demonstrates that, during the early maturation stage of the enameloid formation, the inner enamel epithelial cells (IEECs) synthesize through a well-developed Golgi apparatus a fine-granular substance which is intensely immunoreactive for amelogenin. This substance was accumulated in a large saccule extended in a suprabasal zone of the cell; we were unable to find any morphological sign indicating a connection of the substance with the enameloid matrix. The abortive secretion of the enamel matrix-like substance in the IEEC during an enameloid formation was considered to be an instance of rudimental enamel formation. In the gar-pike, the synthesis of amelogenin in the IEEC has been demonstrated to occur independently from that of the enameloid matrix. The present findings demonstrate a prominent difference between the tooth enamel and enameloid.
Asunto(s)
Esmalte Dental/crecimiento & desarrollo , Esocidae/fisiología , Diente/crecimiento & desarrollo , Amelogenina , Animales , Esmalte Dental/ultraestructura , Proteínas del Esmalte Dental/biosíntesis , Proteínas del Esmalte Dental/ultraestructura , Células Epiteliales/metabolismo , Células Epiteliales/ultraestructura , Aparato de Golgi/metabolismo , Aparato de Golgi/ultraestructura , Inmunohistoquímica , Microscopía InmunoelectrónicaRESUMEN
Previous studies have demonstrated the morphological similarity of the enamel-like layer found in the teeth of the coelacanth, lungfish and gar-pike to the enamel of tetrapods. In order to clarify the phylogenetic continuity between both structures, tooth germs of the gar-pike were immunocytochemically studied using an anti-bovine amelogenin polyclonal antibody. Intense immunoreaction was shown over the enamel-like matrix layer. Certain cell organelles associated with the secretory pathway of the ameloblasts were recognized as immunoreactive. These results indicate that the enamel-like layer of the gar-pike is a tissue homologous with the mammalian enamel because both possess a common, amelogenin-like substance.
Asunto(s)
Proteínas del Esmalte Dental/metabolismo , Esmalte Dental/metabolismo , Peces/metabolismo , Germen Dentario/metabolismo , Amelogenina , Animales , Bovinos , Esmalte Dental/ultraestructura , Órgano del Esmalte/metabolismo , Órgano del Esmalte/ultraestructura , Peces/clasificación , Técnicas para Inmunoenzimas , Germen Dentario/ultraestructuraRESUMEN
Intracellular injection of horseradish peroxidase (HRP) into 58 masseteric motoneurons identified by antidromic activation was performed in cats under pentobarbital anesthesia. Monosynaptic EPSPs were evoked by masseteric nerve stimuli in 52 cells, and were absent in the remaining six cells. The antidromic nature of the evoked spikes was confirmed by IS-SD separation observed at high frequency (50 Hz) stimulation. Motoneurons with monosynaptic excitation from masseter afferents showed IPSPs following stimulation of lingual and inferior alveolar nerves. Motoneurons which did not show monosynaptic excitation from masseter afferents showed no IPSPs from the above nerves. There were no differences in cell size or the number of stem dendrites between motoneurons with and without monosynaptic EPSPs. No recurrent collaterals were observed in any motor axons. Motoneurons with monosynaptic EPSPs were located at all rostrocaudal levels throughout the trigeminal motor nucleus, whereas motoneurons without such EPSPs were encountered only at the middle level. Dendrites of motoneurons with monosynaptic EPSPs did not extend into the medial portion of the nucleus where motoneurons innervating the anterior belly of the digastric muscle were located. In contrast, motoneurons without monosynaptic EPSPs had dendrite branches extending well into the medial part. The results show that there are two subpopulations of masseteric motoneurons that differ in peripheral inputs as well as dendritic morphology.
Asunto(s)
Nervio Mandibular/fisiología , Músculo Masetero/inervación , Neuronas Motoras/fisiología , Nervio Trigémino/fisiología , Vías Aferentes/fisiología , Animales , Transporte Axonal , Gatos , Potenciales Postsinápticos Excitadores/fisiología , Peroxidasa de Rábano Silvestre , Potenciales de la Membrana/fisiología , Neuronas Motoras/citología , Sinapsis/fisiologíaRESUMEN
The nerve regenerative process has been investigated by many studies. However, the quantification of the degree of crush of peripheral nerves has not yet been performed. The aim of this study was to determine and standardize the ligature intensity and crush level of the hypoglossal nerve of guinea pigs. The compound action potentials evoked by electric stimulation were used as an index of the degree of nerve crush. To demonstrate nerve regeneration after ligating and crushing of the right hypoglossal nerve, fluorescein isothiocynate conjugated cholera toxin-B subunit (CTb-FITC) was injected into the intact fiber of the left hypoglossal nerve, and the central side from the crushed region of the right hypoglossal nerve fiber. The total cross sectional area of the retrograde-labeled hypoglossal motoneurons was investigated under a confocal laser scanning microscope. The results of the evaluation using CTb-FITC indicated that the nerve regeneration occurred from two weeks after crush and recovered in six weeks.
Asunto(s)
Nervio Hipogloso/fisiología , Regeneración Nerviosa , Potenciales de Acción , Animales , Toxina del Cólera , Femenino , Fijadores , Fluoresceína-5-Isotiocianato , Colorantes Fluorescentes , Cobayas , Traumatismos del Nervio Hipogloso , Masculino , Factores de TiempoRESUMEN
The mouse cDNA for apoptosis signal-regulating kinase 1 (ASK)1 was isolated. The overall amino acid sequence identity between the mouse and the human ASK1 was 91.9%. A database search revealed that the kinase domain of ASK1 is evolutionally well-conserved over species among nematode, fly, mouse and human. Northern blot analysis identified a 6-kb transcript of ASK1 which is expressed in the various mouse adult tissues including heart, brain, lung, liver and kidney. Immunohistochemical analysis of mouse embryos (17 days post coitum) revealed a localized expression of ASK1 in developing skin, cartilage and bone, suggesting a possible role for ASK1 in tissue development during embryogenesis as well as cytokine-induced apoptosis.
Asunto(s)
Apoptosis/genética , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Clonación Molecular , ADN Complementario/química , ADN Complementario/aislamiento & purificación , Humanos , Quinasas Quinasa Quinasa PAM , Ratones , Datos de Secuencia Molecular , Especificidad de Órganos/genética , Proteínas Serina-Treonina Quinasas/biosíntesis , Homología de Secuencia de Aminoácido , Especificidad de la EspecieRESUMEN
Gene expression and localization of amelogenin were studied in the developing rat incisor by the methods of in situ hybridization and immunohistochemistry. ISH revealed the first expression of amelogenin mRNA in the inner enamel epithelium of the cervical loop. The signals were clearly observed in pre-ameloblasts in the region bordering on predentin formation and became more intense toward the cells on the initial enamel matrix secretion. The maximal signals were found in the cytoplasm of secretory ameloblasts. From the terminal secretion zone, the signals then became gradually weaker toward the incisal edge but were still evident in the cytoplasm of shortening, transitional ameloblasts and those at the early maturation stage. No signals were found in the cells of the stratum intermedium and stellate reticulum throughout amelogenesis. Immunohistochemistry by means of an antibody against amelogenin C-telopeptide consisting of 12 amino acids revealed immunoreaction in the secretory ameloblasts reacting to the ISH. When a polyclonal antibody against amelogenin was used, immunoreaction was found in the distal ends of ruffle-ended ameloblasts (RA) in the maturation zone. Those results indicated that amelogenin is synthesized by ameloblastic cells from the inner enamel epithelium to the early maturation stage and is then resorbed by the RA.
Asunto(s)
Ameloblastos/metabolismo , Proteínas del Esmalte Dental/biosíntesis , Proteínas del Esmalte Dental/genética , Ameloblastos/citología , Amelogénesis/fisiología , Amelogenina , Animales , Bovinos , Proteínas del Esmalte Dental/análisis , Dentina/fisiología , Expresión Génica , Inmunohistoquímica , Hibridación in Situ , Incisivo/metabolismo , Odontoblastos/fisiología , Odontogénesis/fisiología , ARN Mensajero/análisis , Ratas , Ratas WistarRESUMEN
BACKGROUND AND METHODS: The expressions of TGF-beta 1 and Type I collagen mRNA were studied by in situ hybridization and immunohistochemistry then the secretory pathway of dentin phosphoprotein was investigated electron microscopic radioautography in rat incisors. RESULTS AND CONCLUSIONS: Expression of TGF-beta 1 mRNA was observed in dental papilla cells before dentin formation. The signals were most intense in pre- and postodontoblasts and during dentinogenesis, but became weaker in the secretory region during the dentin formation. Type I collagen mRNA was expressed in essentially the same as that of TGF-beta 1. These results suggest that TGF-beta 1 plays an important role in the differentiation of, and collagen synthesis by odontoblasts. Radioautography showed radioactivity in the rough endoplasmic reticulum 5 min after injection of 3H-serine. Silver grains were observed over the cylindrical portions of the cis-face of the Golgi apparatus at 10 min and over the cylindrical portions of the transface at 20 min. The secretory granules showed the strongest reaction between 20 min and 1 h after injection. At 45 min, a significant labeled band appeared at the mineralization front. The pathway of 3H-proline was essentially the same as that of 3H-serine, but 3H-proline moved more slowly. Secretory granules were heavily labeled from 30 min; no labeling was found at the mineralization front at 45 min. The labeling pattern with 3H-serine appears to be closely related to the localization of phosphoproteins. Dentin phosphoproteins are related to secretory granules and are secreted by odontoblasts as the mineralization front, being involved in the process of dentin mineralization.
Asunto(s)
Dentinogénesis/fisiología , Matriz Extracelular/metabolismo , Expresión Génica/genética , Fosfoproteínas/metabolismo , Factor de Crecimiento Transformador beta/genética , Animales , Autorradiografía , Colágeno/genética , Dentinogénesis/genética , Inmunohistoquímica , Hibridación in Situ , Microscopía Electrónica , ARN Mensajero/biosíntesis , Ratas , Ratas WistarRESUMEN
A 62-year-old man with adult T cell leukemia (ATL) presented with complaints of anorexia and abdominal fullness. Evaluation revealed ascites and pleural effusion, but no lymph node swelling, hepatosplenomegaly, or skin involvement. The diagnosis of ATL was made by the detection of specific surface markers for T lymphocytes in pleural effusion and ascitic fluid, and by determination of human T cell leukemia virus type I (HTLV-I) proviral DNA integration in mononuclear cells of pleural effusion. This case was considered a rare type of ATL with infiltration of the pleura and peritoneum.
Asunto(s)
Ascitis/etiología , Leucemia de Células T/complicaciones , Derrame Pleural/etiología , Ascitis/diagnóstico , Resultado Fatal , Humanos , Leucemia de Células T/diagnóstico , Masculino , Persona de Mediana Edad , Derrame Pleural/diagnósticoRESUMEN
The present studies were undertaken to investigate the presence of common epitopes of mammalian amelogenins at the C-terminus and the possible functional importance of the conserved C-terminal domain in enamel mineralization during mammalian amelogenesis. Enamel proteins, including the intact amelogenins and their degraded polypeptides, were isolated from the secretory enamel of pig, cow, rat, and rabbit incisors. Rabbit and rat antipeptide sera, as well as rat anti-25 kD and 20 kD pig amelogenin sera, were used to identify the amelogenins among the isolated matrix proteins of each of the animal species. The antipeptide sera were developed previously (Aoba et al. [19]) using as immunogens the two synthetic peptides, C13 and C25, which correspond to the last 12 (plus Cys for KLH-conjugation) and 25 amino acid residues of pig intact amelogenin, respectively. Reactivity of the enamel proteins with each antiserum was examined by Western blot analysis. The results of immunoblotting showed that a few enamel matrix proteins in each of the mammalian species were recognized by the anti-C13 serum, specifically, pig amelogenin at 25 kD (and trace components at 27, 22, and 18 kD), cow amelogenin at 28 kD (trace components at 26, 22, 19, and 14 kD), rat amelogenins at 28 and 26 kD (and a trace component at 20 kD), and rabbit amelogenins at 24 and 21 kD (and a trace at 13 kD). The anti-C25 serum reacted additionally with pig amelogenin at 23 kD, cow amelogenin at 27 kD (a major matrix constituent), and rabbit protein at 19 kD.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Amelogénesis/fisiología , Proteínas del Esmalte Dental/inmunología , Proteínas del Esmalte Dental/fisiología , Esmalte Dental/metabolismo , Epítopos/inmunología , Epítopos/fisiología , Minerales/metabolismo , Amelogenina , Secuencia de Aminoácidos , Animales , Western Blotting , Calcificación Fisiológica , Bovinos , Esmalte Dental/fisiología , Proteínas del Esmalte Dental/análisis , Electroforesis en Gel de Poliacrilamida , Epítopos/análisis , Sueros Inmunes/inmunología , Sueros Inmunes/fisiología , Datos de Secuencia Molecular , Conejos , Ratas , Ratas Sprague-Dawley , PorcinosRESUMEN
The anaerobic threshold (AT) is used to determine the exercise capacity in patients with heart failure and healthy subjects. To determine the factors affecting AT, we determined the AT in healthy subjects, and examined the factors that determine AT in healthy subjects. One hundred and sixteen healthy subjects (79 men and 37 women) performed on a bicycle a stepwise increasing submaximal exercise. During the work test the parameters usually used in the detection of AT (Vo2, Vco2, VE), blood pressure, heart rate and oxygen saturation were recorded by a computerized system every minute. AT was determined from changes in ventilation and gas-exchange. The fat index was calculated from height and body weight measured at the beginning of the ventilatory function test. A significant correlation was obtained between AT and age, AT and fat index, AT and %VC, AT and maximum heart rate during exercise, AT and recovery rate of heart rate after exercise, and AT and Vo2 at rest. In addition, we examined the relationship among the parameters in 4 groups according to sex and age (30-49; younger, 50-69; older), because sex and age affected most parameters. We found a significant correlation between AT and fat index (older men and women), AT and %VC (younger and older women), AT and Vo2 at rest (younger and older men). We considered that the main factors that determined AT in healthy subjects were age, sex, fat index, %VC and Vo2 at rest.
Asunto(s)
Umbral Anaerobio/fisiología , Adolescente , Adulto , Factores de Edad , Anciano , Niño , Ejercicio Físico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/fisiopatología , Factores SexualesRESUMEN
Morphological differentiation of the distal ends of ameloblasts (AMs) from the late presecretory to early secretory zones of the rat upper incisor was studied by electron microscopy. Preameloblasts (PAs) showed a high columnar shape, with the nucleus located in the basal portion. The Golgi apparatus occupied the supranuclear region with type-1 vesicles, and microvilli were present at the distal cell membrane. Coarse-textured material was observed inside the type-1 vesicles and in the lateral intercellular spaces as well as along the distal cell membrane, whereas fine-textured material was found along the distal cell membrane. Near the region of initial enamel formation, large matrix islands were found in the lateral intercellular space. A thin electron-dense layer was observed on the dentin surface. This layer might have occurred as a result of diffusion after degradation of the coarse- or fine-textured material into a finer substance in the extracellular spaces. In the region of initial enamel formation, the distal cell membrane of AMs was flat, but shallow and narrow membrane invaginations were associated with the cell membrane close to the matrix islands. In the region of inner enamel formation, a cone-shaped Tomes' process was formed between large matrix islands which had developed in the intercellular spaces between the lateral portions of the distal ends of AMs. It was considered that the membrane invaginations which had existed at the distal end of PAs moved lower toward the distal terminal bar, thereafter becoming microvilli.
Asunto(s)
Ameloblastos/ultraestructura , Amelogénesis , Ameloblastos/fisiología , Animales , Diferenciación Celular , Membrana Celular/ultraestructura , Núcleo Celular/ultraestructura , Masculino , Microvellosidades/ultraestructura , Orgánulos/ultraestructura , Ratas , Ratas Endogámicas , Vacuolas/ultraestructuraRESUMEN
In order to clarify connections between epithelium and mesenchymal tissue in the early stage of odontogenesis, the formation of ectomesenchymal contacts and the presence of coarse-textured material at the interface between ameloblasts (AMs) and odontoblasts (ODs) on growing rat incisors were studied by electron microscopy. The presecretory zone was classified into five regions according to the ultrastructure of each preameloblast (PA). The region where collagen fibrils could be observed was designated PZ-2, the region where predentin existed PZ-3, the region where the basal lamina began to disappear PZ-4, and the region where the basal lamina had disappeared PZ-5. In PZ-2, the cytoplasmic processes of PAs penetrated the basal lamina and reached the dental papilla cells. In some locations, ectomesenchymal contacts were also observed, in which the cytoplasmic processes of the PAs were in contact with those of the preodontoblasts (POs). In PZ-3, the distal cytoplasm contained large amounts of type-1 vesicles, and secretory granules. In the distal membrane of the PA, membrane invaginations containing fibrillar structures were visible. Also in some areas, the cytoplasmic processes at the distal ends of the PAs invaded the predentin. In the predentin, a large amount of coarse-textured material, considered to be the precursor of the enamel matrix, was observed. In PZ-3, a large number of cytoplasmic processes extended into the predentin, while in PZ-4, microvillus-like processes extended from the distal ends of the PAs, showing a high frequency of ectomesenchymal contact. It was suggested that secretory activity of the PAs was induced after ectomesenchymal contact had been accomplished, but that the PAs did not undergo morphological change into secretory ameloblasts.
Asunto(s)
Ectodermo/ultraestructura , Mesodermo/ultraestructura , Odontogénesis , Diente/ultraestructura , Ameloblastos/ultraestructura , Animales , Dentina/ultraestructura , Incisivo , Masculino , Microscopía Electrónica , Odontoblastos/ultraestructura , Ratas , Ratas EndogámicasRESUMEN
The purpose of this study is to characterize regional myocardial alternations of reflected ultrasound throughout a cardiac cycle in normal and ischemic myocardium. Integrated ultrasonic backscatter (2-5 MHz) gated R wave of ECG was measured at the base, middle and apex in 4 dogs, and the apex before and after ischemia in other 4 dogs. Quantitative ultrasonic backscatter (IB) was reflected to a steel reflector. At the apex and middle, where a cyclic pattern of IB was discernible, maximum values were recorded near end diastole and minimum near end systole. The amplitude of the variation of IB throughout a cardiac cycle for each region increase progressively from base to middle to apex. Time-averaged IB over a cardiac cycle (averaged IB) was similar for each area of the heart (base = -50.6 +/- 0.5 dB (mean +/- SE), middle -49.4 +/- 0.5 dB, apex -49.7 +/- 0.6 dB. p = NS for comparison of any two regions). After occluding left anterior descending coronary artery for 30 minutes, the variation of IB was markedly blunted and averaged IB increased significantly (-47.5 +/- 0.5 dB. p less than 0.01 compared with preocclusion (-50.8 +/- 0.5 dB]. These results suggested that IB and averaged IB may permit assessment of intrinsic geometrical changes throughout a cardiac cycle (contractile properties) and histological changes respectively.
Asunto(s)
Miocardio/patología , Ultrasonografía , Animales , Enfermedad Coronaria/diagnóstico , Perros , Procesamiento de Imagen Asistido por ComputadorRESUMEN
Rabbit polyclonal antibodies against bovine amelogenins and enamelins which did not show any cross-reaction were raised, and ultrathin sections of rat incisors were examined by the protein A-gold and ABC methods. The immunoreactivity of amelogenins was found in dense granules in the intercellular spaces between preameloblasts, and later over the fine- and coarse-textured material. The immunoreactivity was present over the cell organelles associated with the secretory pathway, as well as pale and dark lysosomes of the presecretory and secretory ameloblasts. Here the enamel was immunolabeled in the intercrystal spaces. The immunoreactivity in multivesicular bodies was stronger in preameloblasts than in secretory ameloblasts. In the region of second ruffle-ended ameloblasts at the maturation stage, the immunolabeling was intense in the ruffled-border, but in the rough endoplasmic reticulum and Golgi apparatus, the immunolabeling was much weaker than at the secretory stage. The immunolabeling for enamelins showed essentially the same intracellular topographical pattern as that for amelogenins by the secretory stage, but was weaker. The immunoreactivity was found mainly attached to the enamel crystals. Double immunostaining of amelogenins and enamelins revealed that both immunoreactivities were present over the same cell organelles associated with secretion and lysosomal systems. It is suggested that the presecretory and secretory ameloblasts are actively involved in the secretion, degradation and resorption of enamel proteins, and that multivesicular bodies and lysosomes in the cells take part in these processes. Ameloblasts are considered to be related to the synthesis of enamelins.
Asunto(s)
Ameloblastos/metabolismo , Proteínas del Esmalte Dental/análisis , Ameloblastos/análisis , Ameloblastos/ultraestructura , Amelogenina , Animales , Gránulos Citoplasmáticos/análisis , Proteínas del Esmalte Dental/metabolismo , Retículo Endoplásmico/análisis , Inmunohistoquímica , Lisosomas/análisis , Microscopía Electrónica , Orgánulos/análisis , Ratas , Ratas Endogámicas , Coloración y EtiquetadoRESUMEN
The secretory pathway of dentin phosphoproteins in rat incisors was studied by electron microscopic radioautography after the injection of 3H-serine, and the results were compared with those using 3H-proline as a tracer. Five min after injection of 3H-serine, radioactivity was found in the rough endoplasmic reticulum. At 10 min, silver grains were observed over the spherical portions of the cisface of the Golgi apparatus. At 20 min after injection, silver grains were seen over the cylindrical portions of the transface of the Golgi apparatus. The secretory granules showed the strongest reaction from 20 min to 1 hr. At 45 min, a significant labeled band appeared at the mineralization front. At 1 hr, the labeling at the mineralization front began to appear in the mineralized dentin, and after 12 hr this labeled band was located within the mineralized dentin. The pathway of 3H-proline was essentially the same as that of 3H-serine, but 3H-proline moved more slowly than 3H-serine, especially in transit from the rough endoplasmic reticulum to the Golgi apparatus. Secretory granules were heavily labeled from 30 min to 1 hr after injection of 3H-proline; no labeling was found at the mineralization front at 45 min. The labeling seen initially over the predentin was over the mineralized dentin no earlier than 6 hr after injection. The labeling pattern with 3H-serine is closely related to the localization of phosphoproteins, whereas the pattern with 3H-proline reflects the production of collagen rather than of phosphoproteins. The present radioautographic results indicate that dentin phosphoproteins are related to secretory granules and are secreted by odontoblasts at the mineralization front and also that phosphoproteins are involved in the process of mineralization of the circumpulpal dentin.