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1.
J Periodontol ; 69(1): 84-91, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9527566

RESUMEN

The renewal of the free gingival margin epithelium in rats was studied evaluating 5-bromodeoxyuridine (BrdU) incorporation in proliferating cells by means of an immunocytochemical method. We found a close correspondence between light and electron microscopy patterns of BrdU incorporation at a nuclear level. BrdU was localized in the inner interchromatin regions in cells starting DNA synthesis, while it was localized in the peripheral heterochromatin domains in cells terminating the S phase. This possibility of discriminating cells in early S phase from cells in late S is able to provide far more information as to the time at which a labeled cell starts proliferation than that obtainable with 3H-thymidine autoradiography. This, in turn, permits detection of cells that start proliferation in a wide period of time by means of a single BrdU administration. Rats treated at 7 a.m. demonstrated higher proliferation than rats treated at 7 p.m., supporting the existence of circadian variations in the epithelial renewal. Proliferative events take place by consecutive activation of at least three replication waves, producing clusters of labeled cells which could be observed in rats sacrificed at 10 a.m. In rats treated once with BrdU at 7 a.m., the clusters were localized in both the basal and suprabasal layer of the epithelium; in rats further injected with BrdU at the same time, the clusters increased in size, progressively extending throughout the epithelium. In this way, the renewal of the free gingival margin epithelium does not proceed randomly, but by consecutive activation of discrete units or clusters of basal cells, which then extend to the upper layers. This can be followed at a morphological level as a progression of labeled cells, which move from the basal layer to the epithelium surface in approximately 82-85 hours.


Asunto(s)
Encía/citología , Fase S , Animales , Antimetabolitos/metabolismo , Autorradiografía , Bromodesoxiuridina/metabolismo , División Celular , Movimiento Celular , Núcleo Celular/metabolismo , Núcleo Celular/ultraestructura , Cromatina/metabolismo , Cromatina/ultraestructura , Ritmo Circadiano , ADN/biosíntesis , ADN/ultraestructura , Células Epiteliales/citología , Células Epiteliales/metabolismo , Epitelio/metabolismo , Encía/metabolismo , Heterocromatina/metabolismo , Heterocromatina/ultraestructura , Inmunohistoquímica , Masculino , Microscopía Electrónica , Ratas , Ratas Sprague-Dawley , Fase S/fisiología , Timidina , Tritio
2.
Histochem Cell Biol ; 105(1): 61-9, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8824907

RESUMEN

5-Bromodeoxyuridine (BrdU), a synthetic analogue of thymidine, has been utilized in vivo to detect the proliferation which occurs in the liver after two-thirds surgical hepatectomy. Immunocytochemical detection of BrdU incorporation has been carried out at both the morphological and flow cytometrical level, while structural changes of regenerating liver have been investigated, using Mallory-Azan-stained paraffin sections, by means of an image analyser. The results obtained show that in vivo DNA synthesis progression throughout S phase follows a pattern similar to that previously described in vitro in both 3T3 fibroblasts and Friend erythroleukemia cells and also demonstrate a precise correlation between morphological patterns of BrdU incorporating cells and their lobular distribution. Moreover, the activation of at least two proliferation waves can be detected from 18 to 34 h after hepatectomy: the former, starting from adjacent regions of contiguous lobules, apparently induces an irregular increase of lobular dimension; the latter, involving both inner and peripheral lobular domains, seems to be correlated with the appearance of nodule-like structures at the lobule periphery. In view of these results the role of the hepatic acinus and the hypothesis of a streaming of parenchymal cells during liver regeneration have been discussed.


Asunto(s)
Bromodesoxiuridina/inmunología , Regeneración Hepática , Hígado/citología , Animales , Citometría de Flujo , Hígado/inmunología , Masculino , Ratas , Ratas Sprague-Dawley
3.
J Histochem Cytochem ; 43(4): 413-9, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7897182

RESUMEN

HeLa metaphase chromosome spreads were hybridized with centromeric biotinylated DNA probes and detected with gold-conjugated anti-biotin antibodies. Chromosomes were observed by an in-lens field emission scanning electron microscope (FEISEM), which permits detection of biological samples without any coating. DNA probes were well localized in the centromeric region of chromosomes and there was clear discrimination between 10 nm fibers that hybridized to DNA probes and those that did not hybridize. This approach shows that in situ hybridization can be directly visualized at the FEISEM level by evaluating only secondary electron emission, which allows physical localization of the hybridized probe with high resolution so that backscatter detection represents only a control. Because chromosomes maintain the 10-nm fiber organization after in situ hybridization procedures, our data suggest that this fiber represents the lowest order of chromatin arrangement that permits transitory DNA denaturation.


Asunto(s)
Centrómero/ultraestructura , Sondas de ADN , Microscopía Electrónica de Transmisión de Rastreo/métodos , Cromatina/ultraestructura , Células HeLa , Humanos , Metafase
4.
Chromosoma ; 103(6): 393-400, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7859559

RESUMEN

HeLa metaphase chromosomes were examined by means of "in lens" field emission scanning electron microscopy, which permits high resolution detection of uncoated biological samples. By using uncoated chromosomes as a model for comparison we report evidence of how traditional scanning electron microscopy techniques such as metal coating and conductive methods can generate errors in chromosome structure evaluation, since both give rise to morphological artifacts. By comparing the morphology of uncoated chromosomes obtained by two different isolation procedures, such as that utilized in standard cytogenetics and the polyamine method, we have drawn the following conclusions: (a) the standard cytogenetic method gives rise to a chromosome structure consisting of a flattened network of 10 nm fibers, in which higher order chromatin organization is absent. (b) Chromosomes obtained by the polyamine method show both three-dimensional profile and higher level folding of chromatin fibers, supporting the loop chromosome organization previously suggested by scanning electron microscopy observation of hexylene glycol isolated chromosomes.


Asunto(s)
Cromosomas Humanos/ultraestructura , Microscopía Electrónica de Rastreo/métodos , Células HeLa , Humanos , Metafase
5.
Boll Soc Ital Biol Sper ; 69(12): 735-40, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8003287

RESUMEN

In order to detect proliferative processes in human marginal gingiva in pathological conditions and after externalization of titanium implants, we have attempted BrdU incorporation after "in vitro" incubation of tissue fragments. In comparison with healthy controls, immunocytochemical detection of samples from patients affected by hypertrophic gengivitis shows a good number of proliferating cells in the basal layer of the epithelium, while only in one case can positiveness be detected after externalization of titanium implants. Since after reduction of inflammation by hygienic treatment a low number of proliferating cells can be observed only in the regions where pathological alterations are also present, we suggest that the increase in tissue proliferation may be closely dependent on the intensity of the inflammatory process. All these data demonstrate that in vitro BrdU incubation of tissue fragments represents a suitable method to evaluate cell proliferation in human tissue.


Asunto(s)
Implantes Dentales , Encía/patología , Adulto , Bromodesoxiuridina/metabolismo , División Celular , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Titanio
6.
Boll Soc Ital Biol Sper ; 69(12): 767-73, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8003292

RESUMEN

Here we investigate the kinetics of rat corneal epithelium at both single cell and tissue level by means of a BrdU-anti BrdU method. The results obtained have then been compared with those previously obtained by us in rat vocal cord epithelium. In this way two main aspects of BrdU incorporation can be indicated at both light and electron microscopy level. First, we report evidence of a new incorporation pattern corresponding to middle S phase, which is characterized by labelling distribution at the border between interchromatin and heterochromatin at ultrastructural level. Second, by comparing tissue incorporation in rats treated with BrdU at the beginning of light time and at the beginning of dark time, we show an increase of cell proliferation during the last hours of dark time and the first hours of light time. In this way, we demonstrate a different progression of circadian rhythms in peripheral regions of corneal epithelium in comparison with that previously observed in vocal cord epithelium.


Asunto(s)
Bromodesoxiuridina/metabolismo , Córnea/metabolismo , Animales , Bromodesoxiuridina/inmunología , División Celular , Ritmo Circadiano , Córnea/citología , Epitelio/metabolismo , Inmunohistoquímica , Masculino , Ratas , Ratas Sprague-Dawley
7.
Histochemistry ; 97(2): 181-7, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1559850

RESUMEN

In order to investigate at ultrastructural level the mechanism of DNA synthesis progression during the different moments of S-phase a bromodeoxyuridine-anti bromodeoxyuridine (BrdU-anti BrdU) method has been applied to synchronized 3T3 fibroblasts. After 30 min BrdU incorporation, five different labelling patterns can be identified and should be related to early, middle and late S-phase. These patterns are represented mainly by diffuse labelling localized in different nuclear domains and by quite rare cases in which the labelling is limited to isolated clusters of gold particles. After a 5-min pulse with BrdU it is possible to observe isolated clusters of gold particles at each moment of S-phase, which, however, exhibit the same distribution of the five principal labelling patterns observed after 30 min incorporation. In both cases labelling can be detected in the interchromatin regions during early S-phase, at the boundary between interchromatin and heterochromatin during middle S-phase and in the heterochromatin domains during late S-phase. Considering their size, the isolated spots of labelling could be interpreted as single replication units which are subsequently activated throughout the different moments of the S-phase.


Asunto(s)
Cromatina/metabolismo , ADN/biosíntesis , Fase S , Células 3T3 , Animales , Bromodesoxiuridina/metabolismo , Replicación del ADN , Citometría de Flujo , Inmunohistoquímica , Ratones , Microscopía Electrónica
8.
Boll Soc Ital Biol Sper ; 67(12): 1081-8, 1991 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1840800

RESUMEN

In order to investigate the kinetics of vocal fold epithelium a bromodeoxyuridine-anti bromodeoxyuridine method has been applied in vivo at both light and electron microscopy level. This method is able to define the length of both epithelium turnover and cell-cycle in basal elements, as well as the existence of a higher proliferation rate during night time in comparison with day time. Moreover distinct labeling patterns observed in incorporating cells allow us to define the precise localization in S-phase of cycling elements.


Asunto(s)
Pliegues Vocales/citología , Animales , Bromodesoxiuridina , Ciclo Celular , División Celular , Células Cultivadas , Replicación del ADN , Células Epiteliales , Cinética , Masculino , Microscopía Electrónica , Ratas , Ratas Sprague-Dawley , Fase S
9.
Dis Colon Rectum ; 30(6): 453-6, 1987 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3595365

RESUMEN

The colonic mucosa of patients with sigmoidostomies, who were operated on for rectal cancer, and treated thereafter for different periods of time with daily water irrigations to obtain complete evacuation, was investigated by histologic and histochemical methods. Microscopic examination of the test specimens showed that the epithelial continuity, the characteristic brush border, and the positive mucous reaction to PAS and Alcian blue-Alcian yellow methods were not significantly changed with respect to controls. In some test specimens a remarkable number of mitoses were evident in the crypts. Since this could result from water irrigation stimuli and/or might represent an early manifestation of a restored carcinogenetic process, specific investigations were performed on the 0-acylated sialic acids of the colonic mucins, which have been reported to represent markers of early malignant changes in colorectal epithelial cells. The results did not reveal alterations of the sialomucins in the treated specimens with respect to controls.


Asunto(s)
Colon/patología , Colostomía , Mucosa Intestinal/patología , Neoplasias del Recto/cirugía , Irrigación Terapéutica , Anciano , Anciano de 80 o más Años , Colon/análisis , Humanos , Mucosa Intestinal/análisis , Persona de Mediana Edad , Mitosis , Mucinas/análisis , Ácidos Siálicos/análisis , Sigmoidoscopía
10.
Pediatr Med Chir ; 9(1): 85-7, 1987.
Artículo en Italiano | MEDLINE | ID: mdl-3628057

RESUMEN

Vesico-ureteral reflux (VUR) associated to neurogenic bladder dysfunctions is well known as pathologic entity; in particular, its radiologic and urodynamic aspects have been widely debated in recent years, even in infancy and childhood. In our study, histologic features of the vesico-ureteral junction have been investigated in a group of patients with neurogenic bladder and VUR, who underwent antireflux surgery. Structural aspects of these vesico-ureteral junctions have been then compared to refluxing junctions taken from non-neurogenic bladders and non-refluxing junctions from normal bladders.


Asunto(s)
Uréter/patología , Vejiga Urinaria Neurogénica/patología , Reflujo Vesicoureteral/patología , Niño , Preescolar , Femenino , Humanos , Hipertrofia , Masculino , Vejiga Urinaria Neurogénica/complicaciones , Reflujo Vesicoureteral/complicaciones
11.
Pediatr Med Chir ; 9(1): 83-4, 1987.
Artículo en Italiano | MEDLINE | ID: mdl-3628056

RESUMEN

Primary vesico-ureteral reflux (V.U.R.) in children has been widely investigated in several reports in the last two decades, but the morphologic aspects of refluxing vesico-ureteral junction are still incompletely codified or incompletely described. The authors report the results of a histologic study on the terminal refluxing ureter in a group of 20 patients with primitive V.U.R., random chosen from a series of over 400 subjects who underwent antireflux surgery for primitive V.U.R. at the Pediatric Surgery Department of the University of Bologna. Connections between muscular hypertrophy and reflux degree are herein reported and discussed.


Asunto(s)
Uréter/patología , Reflujo Vesicoureteral/patología , Niño , Preescolar , Femenino , Humanos , Hipertrofia , Masculino , Reflujo Vesicoureteral/cirugía
13.
Physiol Chem Phys Med NMR ; 17(3): 247-54, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-4095168

RESUMEN

The proton longitudinal relaxation time of regenerating rat liver has been found to increase during the first 24 hours after hepatectomy and to drop back to normal in the following hours. The decreased relaxation rate may be related to the increase of the water mobility due to the expansion of the intercellular spaces during the massive proliferation of the first day, or to the increased cell hydration which is known to occur during active cell proliferation. Equations have been derived for the proliferation process, and the competing inhibition process, active from the 24th hour, which can quantitatively account for the proton relaxation behaviour.


Asunto(s)
Regeneración Hepática , Hígado/metabolismo , Animales , División Celular , Cinética , Espectroscopía de Resonancia Magnética/métodos , Masculino , Ratas , Ratas Endogámicas , Factores de Tiempo
15.
Acta Biomed Ateneo Parmense ; 54(3): 207-29, 1983.
Artículo en Italiano | MEDLINE | ID: mdl-6228087

RESUMEN

Research has been made on the progesterone-induced effects upon endometrium on impuberal rats (either intact, or castrated, or castrated and adrenalectomized, or hypophysectomized) after an acute or a protracted treatment, which were made every third hour all through the day. It resulted that the hormone basically shows two distinct activities. The first one causes a modest awakening of the anabolical functions both in the lining and in the glandular epithelia, which results in the building up of small amounts of lipid and glycogen. The second one involves the lamina propria as well, and brings about morphological effects which can be superposed on those induced by estrogens. The former seems an autonomous activity and can mainly be found after long-lasting treatments. The latter, on the contrary is influenced by the administration time and can be detected only during a.m. treatments whereas it cannot be detected during p.m. and night treatments. Besides it is influenced by the hypophysal activity and in particular by gonadotropins. The possible mechanism of these influences are discussed.


Asunto(s)
Endometrio/efectos de los fármacos , Hormona Folículo Estimulante/farmacología , Hormona Luteinizante/farmacología , Progesterona/farmacología , Adrenalectomía , Factores de Edad , Animales , Castración , Endometrio/ultraestructura , Femenino , Hipofisectomía , Ratas
17.
Boll Soc Ital Biol Sper ; 55(19): 1993-8, 1979 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-122059

RESUMEN

The study concerns the action of dehumidified or humidified gas on the pulmonary lining layer. The results of our research suggest that water vapor used in artificial ventilation may be an important determining factor of the respiratory problems reported by clinicians in man. Important modifications of the lining layer of the alveolar epithelium occur, accompanied by more important alterations, including those of the content of the alveolus, all of which contribute to the pulmonary edema observed.


Asunto(s)
Dióxido de Carbono/farmacología , Oxígeno/farmacología , Alveolos Pulmonares/efectos de los fármacos , Animales , Epitelio/efectos de los fármacos , Edema Pulmonar/etiología , Ratas , Síndrome de Dificultad Respiratoria/etiología
18.
Basic Appl Histochem ; 23(1): 13-23, 1979.
Artículo en Inglés | MEDLINE | ID: mdl-92309

RESUMEN

Using electron microscopy we have examined the lining layer of the rat pulmonary alveolus. This layer appears as a morphological entity 1-3 days after birth: it is composed at first of a filamentous Ruthenium Red-negative material derived from lamellar bodies, and subsequently (4 days after birth) of a homogeneous Ruthenium Red-positive material. This latter material, which corresponds to the epithelia lining of the alveolus typical of adult rats, is presumably derived from a mixture of the filamentous material produced by the lamellar bodies, and a material produced by the alveolar cells 4 days after birth which contains acidic groups which bind Ruthenium Red.


Asunto(s)
Alveolos Pulmonares/ultraestructura , Envejecimiento , Animales , Feto , Microscopía Electrónica , Alveolos Pulmonares/crecimiento & desarrollo , Ratas , Rojo de Rutenio , Coloración y Etiquetado
19.
Boll Soc Ital Biol Sper ; 55(2): 129-35, 1979 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-17955637

RESUMEN

The study concerns the contents of the rat alveolus during the course of development. This contents in the fetus is composed exclusively of lamellar bodies, with tubular myelin figures connected to them; in the neonates is composed also of material layered on the surface of the alveolar cells which is initially filamentous, osmiophilic and ruthenium red-negative, then, later on, homogeneous and ruthenium red-positive.


Asunto(s)
Alveolos Pulmonares/ultraestructura , Animales , Animales Recién Nacidos , Feto , Microscopía Electrónica , Modelos Animales , Muramidasa/ultraestructura , Alveolos Pulmonares/anatomía & histología , Alveolos Pulmonares/crecimiento & desarrollo , Ratas , Ratas Wistar , Rojo de Rutenio , Coloración y Etiquetado
20.
Ateneo Parmense Acta Biomed ; 49(4): 355-69, 1978.
Artículo en Italiano | MEDLINE | ID: mdl-754697

RESUMEN

The research regards the action of rapidly and slowly absorbed testosterone in the adenohypophysis of female impuberal rats. The results are that the rapidly adsorbed testosterone if administered in small quantities stimulates the activity of synthesis in the FSH cells, if administered in large quantities stimulates the activity of synthesis both in the FSH cells and in the LH cells. The slowly absorbed testosterone stimulates again the activity of synthesis only of the FSH cells. Both rapidly absorbed and slowly absorbed testosterone inhibit the release activity in both the FSH cells and the LH cells.


Asunto(s)
Adenohipófisis/efectos de los fármacos , Testosterona/farmacología , Animales , Femenino , Hormona Folículo Estimulante/biosíntesis , Inyecciones Intraperitoneales , Hormona Luteinizante/biosíntesis , Adenohipófisis/metabolismo , Adenohipófisis/ultraestructura , Ratas , Testosterona/administración & dosificación
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