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Grading of precancerous laryngeal lesions by multiparameter image analysis at separate epithelial layers.

In order to detect early precancerous changes which do not involve the whole thickness of the epithelium, we used a novel image analysing program based on an IBAS system (Kontron, Germany) to determine nuclear DNA content (NC) as well as average nuclear area (NA) and variation of nuclear area (VA), in the entire epithelium and in three sublayers, parabasal, intermediate, and superficial. DNA aneuploidy was found in only half of the cases classified as 'high-grade' (HG) lesions, comprising carcinoma in situ (CIS) and severe epithelial dysplasias (EDIII), and was chiefly demonstrable in the parabasal third of the epithelium. The other lesions were DNA euploid. HG lesions showed highly significant increases of NA and VA at the lower levels of the epithelium when compared with 'low-grade' (LG) lesions comprising moderate and mild epithelial dysplasias (EDII and EDI). Our data show that the combination of multiparameter image analysis with conventional morphology assists in the objective grading of precancerous lesions and permits the reliable detection of high-grade lesions.

Adult↗

Rapid prenatal diagnosis of Down syndrome using quantitative fluorescence in situ hybridization on interphase nuclei.

OBJECTIVES: Presently, conventional cytogenetic analysis of metaphase chromosomes remains the reference approach in prenatal diagnosis. However, this method is labor-intensive and time-consuming. The first step toward the rapid identification of aneuploidies is achieved by interphase fluorescence in situ hybridization (FISH) with centromeric or locus-specific probes. Spot counting using this type of probes is a reliable approach, but is very time-consuming with some technical and biological limitations. In this study, we present a new FISH method using image cytometry for the detection of trisomy 21 within interphase nuclei. METHODS: The method is based on a comparative quantitation of the fluorescence signals emitted by whole chromosome 21 and 22 painting probes cohybridized on interphase nuclei. The chromosomal imbalance was determined with an automated image cytometer by detecting an abnormal ratio of both fluorescence emissions when compared with the ratio obtained in normal cells. RESULTS: Ten blood samples and twenty amniotic fluids were analyzed. Results from FISH and standard cytogenetics were compared and 100% correlation was achieved. CONCLUSIONS: This method, which enables an easy detection of chromosomal imbalances without a need for metaphase preparations, can be applied to the diagnosis of trisomy 21 and extended to other disorders with chromosomal imbalances. Compared to other interphase FISH techniques, it avoids spot-scoring difficulties.

Adult↗

Primary culture of prostatic region entoderm of human fetal sinus urogenitalis: morphological, histochemical, and electrophoretic characteristics.

Primary cultures of entoderm from the prostatic region of the sinus urogenitalis obtained from 9 to 12-week-old human fetuses were established by explantation of presumptive prostate tissue on collagen. The predominant growth of entodermal cells made it possible to obtain cultures, without use of enzymes or EDTA, which were practically free of mesenchyme. Histochemical and electrophoretic methods demonstrated certain properties of the parent presumptive prostatic entodermal cells in the cultured cells. Karyological alterations observed during the course of cultivation are described.

Acid Phosphatase↗

Neuron development in the superior colliculus of the fetal mouse following maternal alcohol exposure.

Pregnant Swiss Webster mice were given a liquid diet with ethanol (EtOH) or isocaloric amounts of maltose dextrin on gestation day (GD) 0 through 18. On GD 18, maternal blood samples were obtained. Fetuses were then removed and fetal brains were prepared for light microscopy. Fetal weight was reduced in the EtOH-exposed group. The ratio of midbrain cross sectional area to cerebral aqueduct was reduced in the ethanol group, while the density of neuronal nuclear population in both the dense outer layer (DS) and sparse inner layer (SS) of the developing superior colliculus was increased. Mean nuclear volume was decreased in the SS.

Animals↗

A phylogenetic analysis of cordyliformes (Reptilia: Squamata): comparison of molecular and karyological data.

A karyological study and the analysis of two mitochondrial genes were conducted in several species of cordyliformes from Madagascar. Both studies confirmed the monophyly of cordyliformes. The karyological conservatism and small genetic distance among mitochondrial genes observed in these species are in line with the hypothesis that all cordyliformes should be included in a single family. The two studies yielded contrasting results with regard to the relationships between the Malagasy species and the Cordylidae and Gerrhosauridae. Nonetheless, the consistency between the data from mitochondrial gene analysis and those of taxonomic studies based on morphological characters is more in favor of an affinity between Malagasy Zonosaurinae and Gerrhosauridae and suggests that the karyological similarities between the former and the Cordylidae may be due to plesiomorphy. Interesting, though not conclusive, data were also obtained on interspecific relationships among Zono-

Animals↗

Nuclear architecture of human pachytene spermatocytes: quantitative analysis of associations between nucleolar and XY bivalents.

Nucleolar association and heterochromatin coalescence have both been invoked as mechanisms involved in the origin of chromosomal associations between nucleolar bivalents themselves, as well as between these bivalents and the XY pair, during meiotic prophase in human spermatocytes. However, these mechanisms do not satisfactorily explain how associating bivalents meet each other within the nuclear space. To elucidate this problem, we have characterized different types of nucleolar-nucleolar and nucleolar-XY bivalent associations, and their frequencies, in light and electron microscope serial sections of spermatocyte nuclei. In the pachytene nucleus, nucleolar bivalent associations were found to involve only one nucleolar sphere of RNP granules connected through a fibrillar center to a chromatin mass composed of two, or more, nucleolar-bivalent short arms. Structural relationships between these elements were examined using 3D computer models of various nucleolar associations. XY and nucleolar bivalents were usually located towards the nuclear periphery associated with the inner face of the nuclear envelope. Some nucleolar bivalents, whether single or associated appeared beside or over XY chromatin. When nucleolar-bivalent short arms (BK) were found over nucleolar or over XY chromatin, their telomeres were unattached to the nuclear envelope and the corresponding synaptonemal complexes were not observed. Ninety nucleoli were found in sixty pachytene nuclei. Thirty six percent of these nucleoli were bound to associated BKs and the remaining 64% to single BKs. Over 40% of individual spermatocytes showed at least one cluster of associated BKs and about 20% presented single or multiple BKs associated with the XY pair. The frequencies of random BK associations, over the total or restricted areas of the nuclear envelope, were calculated according to a probabilistic nuclear model. A correspondence was found in comparing the observed frequencies of associated BKs with those calculated on the basis of bouquet formation. Such an analysis strongly suggests that the occurrence of associations between nucleolar bivalents may arise at random within the bouquet. Thus, the architecture of the meiocyte nucleus, particularly the organization of the bouquet, may be the primary mechanism by which nucleolar bivalents meet each other and, consequently, become associated either through common nucleolus formation or by heterochromatin coalescence.

Cell Nucleolus↗

Time-related changes in size of nuclei of pinealocytes in rats.

In a study of 96 adult male Sprague-Dawley rats, da- and time-related changes of the mean nuclear volume of pinealocytes were determined with the aim of testing the reproducibility of the karyometric findings described by Quay and Renzoni (1966). It is shown (i) that statistically significant differences exist between the central and peripheral mean volumes of pinealocyte nuclei/group of animals and time point (p less than 0.001), (ii) that the day and time related differences are statistically different in both regions (p less than 0.001), (iii) that in the center and periphery of the pineal body different diurnal patterns exist, and (iv) that the diurnal patterns are not parallel in the two regions. The question discussed is (i) whether or not probable superimposed infradian rhythms may account for the different diurnal patterns, and (ii) whether these patterns in the two regions indicate functional differences between the "cortex" and the "medulla" of the rat pineal body.

Analysis of Variance↗

Sizes and numbers of nuclei in the cortex of thymus glands of red-billed weavers Quelea quelea.

The cortex of the thymus glands of embryos, chicks, juveniles, fledglings and adults from several colonies of Quelea quelea were studied using an image analyser (Quantimet 720) to determine cell populations and nuclear sizes. Just prior to hatching the lobes showed a high level of mitosis and consisted of predominantly small lymphocytes. The larger glands of chicks and juveniles had higher cell populations; pyknotic cells and erythrocytes occurred free in the cortex. The lobes of adults were more variable but in general mitosis occurred in enlarging glands of adults from colonies with eggs; most lobes contained pyknotic cells but not in such high numbers as in lobes from chicks and fledglings. Erythrocytes were common, occurring in large numbers in the cortex in some birds. The factors affecting the interpretation of these data are discussed in detail.

Age Factors↗

The effect of prolactin on kidney structure of the euryhaline teleost Gasterosteus aculeatus during adaptation to fresh water.

The effect of injections of ovine prolactin on kidney structure was examined in the first 10 days following transfer of seawater sticklebacks to fresh water. In hormone injected animals as well as in controls the glomeruli increase slightly in size after transfer. The podocytes intensify the secretion of mucopolysaccharides, which is indicative of increased turnover of the components of the glomerular basal lamina. The nuclei of the podocytes become enlarged, while those of the juxtaglomerular cells decrease in size. These changes are related to the well known rise of the glomerular filtration rate following transfer to fresh water. Structural indications that prolactin is involved in the control of glomerular filtration were not found. The epithelial cells of the three nephronic segments and of the ureter become considerably better developed after transfer to fresh water. Cell height, nuclear and mitochondrial volume, and surface of the membranes of the basal labyrinth increase in all tubular epithelia, although not to the same extent. Increases are moderate in the first proximal segment, but increasingly higher for the second proximal segment, collecting duct and the ureter. Especially the growth of membrane surface of the basal labyrinth, site of ion transport mechanisms, is impressive. In controls, values characteristic for freshwater fishes are reached in 6 to 9 days for all parameters for cellular development. Prolactin injections greatly stimulate growth rates in all tubular epithelia: freshwater values are reached within 3 days. No further increase was found, however.

Adaptation, Physiological↗

Ultrastructure of the endocrine cell types in the adenohypophysis of the teleost, Poecilial latipinna--a morphometric model.

A morphometric model providing detailed quantitative information on the ultrastructure of the adenohypophysial endocrine cells has been developed for Poecilia latipinna. The model consists of various morphological components quantified in terms of volumes, surfaces or numbers. For prolactin and growth hormone cells, appropriate results are expressed relative to the average volume of that cell type. The difficulties of quantifying EM data on pituitary glands, together with the various sources of error to which the data are clearly open, have been discussed. Some practical application of quantitative EM to problems in fish pituitary research are outlined.

Animals↗

Quantitative electron microscopic analysis of the stratified epithelium of normal human buccal mucosa.

The epithelium of normal human buccal mucosa was subjected to stereologic analysis. Ten biopsies were selected from a total of 20 specimens collected from 10 to 15 year old females, and processed for light- and electron microscopy. At two levels of magnification, electron micrographs were sampled from four strata in epithelial ridges and from three strata in regions over connective tissue papillae. Stereologic point counting based on a recently improved system for analyzing stratified epithelia was employed to analyze a toatl of 1820 electron micrographs. Buccal epithelium was found to be 0.48 mm thick, interdigitated by long, slender connective tissue papillae, and comprised of a narrow basal and suprabasal, and a broad, homogeneously structured spinous and surface compartment. From basal to surface layers, the epithelium displayed a differentiation pattern different from that of keratinizing epithelia. This pattern was a function mainly of a drastic density increase of cytoplasmic filaments of a constant 80 A diameter, a corresponding decrease of the cytoplasmic ground substance, the appearance of dark-cored membrane coating granules and individually varying amounts of glycogen deposition. It is suggested that the dense meshwork of filaments which fill 70% of the epithelial cytoplasm in a broad subsurface and surface layer, serves as the functional matrix for epithelial distensibility.

Adolescent↗

Subsarcolemmal mitochondria and capillarization of soleus muscle fibers in young rats subjected to an endurance training. A morphometric study of semithin sections.

Rats, 6 weeks old, were subjected to a program of endurance running for 3, 6 and 12 weeks. 0.5 to 0.8 mum thick sections of Epon embedded soleus muscles were studied with morphometric methods. In cross-sections the area occupied by subsarcolemmal mitochondria was independent of the age, but was 53% higher after 12 weeks of training. The mean depth of the zones with subsarcolemmal mitochondria increased only 15% to about 0.9 mum. Thus, the subsarcolemmal mitochondria showed a pronounced spreading at the muscle fiber surface in trained muscles.-The number of capillaries per fiber decreased slightly in controls and increased not significantly in trained muscles. It is concluded that the subsarcolemmal mitochondria supply the energy for the active transport of metabolites through the sarcolemma in oxidative muscle fibers, and that they are the limiting factor for endurance performance of the soleus muscle fibers because the changes in the capillarization were only small. It is suggested that the subsarcolemmal and the interfibrillar mitochondria have different functions and may therefore represent different types of mitochondria which can be distinguished by their morphology as well as by their biochemical properties.

Animals↗

A karyometric and stereologic study of the effects of gonadotrophin and testosterone on the interstitial gland of the testis of intact and endoxan treated rats.

Adult male rats were treated daily for 18 days with endoxan in doses of 4 mg/kg of body weight or testosterone in doses 2.5 mg per rat. For the last 5 days of the experiment some of the rats received gonadotrophin injections in doses of 50 I.U. Karyometric and stereologic studies were undertaken on paraffin sections of the testes stained with haematoxylin and eosin. Endoxan treatment decrease the nuclear volume of the Leydig cells and lowers the volume fraction occupied by the interstitial gland in the testis. These changes were accompanied by a decrease in the intensity of reaction for acid phosphatase, non-specific esterases and 3-beta-hydroxy-steroid dehydrogenase. Testosterone injected alone or jointly with endoxan resulted in more pronounced changes than following treatment with endoxan alone. As expected, gonadotrophin injections into intact rats resulted in a marked increase in nuclear volume of the Leydig cells and in the volume fraction of the interstitial gland. This effect of gonadotrophin on the interstitial gland of the rat testis was partially inhibited by endoxan treatment. It follows from these experiments that endoxan impairs the functional activity of the interstitial gland of the rat testes by lowering the endogenous gonadotrophin levels, as well as by direct action on the Leydig cells.

Acid Phosphatase↗

Morphological definition of thymocyte subpopulations.

An attempt was made to distinguish immature from mature, immunocompetent thymocytes in the adult mouse using morphological criteria. All procedures enriching for competent thymocytes also enrich small cells whose morphology is very similar to the small thymocytes that have been described in the medulla of the thymus (Abe and Ito, 1970). A heterogeneity of competent thymocytes is likely since the enriched populations always contain a number of medium sized cells. These latter cells show spontaneous DNA-synthetic activity and are probably the source of thymus proliferative activity. Owing to their characteristic morphology these two cell types might represent the precursors for each of the two differentiated T cell types that have been found to occur in delayed type hypersensitivity (Matter, 1974).

Animals↗

The paramedial neurosecretory cells of the suboesophageal ganglion of the cricket, Teleogryllus commodus (walk.).

Ovariectomy, performed immediately after the final hatch, caused a reduction of stainable (neurosecretory?) MATERIAL IN THE PARAMEDIAL NEUROSECREtory cells (PNC) (A-type) of the suboesophageal ganglion in 10 day-old females of Teleogryllus commodus (Walk.). A concomitant increase in nuclear volume and in the incorporation of 35S-cysteine indicates increased synthesis of neurosecretory material. From these findings it is concluded that more stainable material is secreted in the cerebral neurohaemal organ after ovariectomy. A functional relationship between the PNC and the ovaries is suggested.

Animals↗

Cytometric investigations in histochemically identified neurons--changes of fluorescence intensities and nuclear diameters in dopamine neurons of the arcuate nucleus in the cycling rat.

The relative formaldehyde-induced fluorescence intensities and the diameter of cell nuclei of fluorescent perikarya of the arcuate nucleus were recorded in serial cross-sectioned hypothalamic arcuate nuclei of regularly cycling rats (5 estrous and 4 proestrous animals). Stress-induced changes of cytometric parameters were avoided by preadaptation of animals to handling procedures. Dopamine neurons in a 75 micrometer thick periventricular layer of the arcuate nucleus exhibited significantly smaller nerve cell nuclei and significantly reduced relative fluorescence intensities in proestrous rats. Both of these cytometric parameters indicate a decrease in the activity of periventricular dopamine neurons of the arcuate nucleus. The reported findings might support the hypothesis that dopamine inhibits the release of LH-RH.

Animals↗