Displasias vertebrales múltiples asociadas a Síndrome de Rokitansky: una causa poco frecuente de escoliosis congénita. A propósito de un caso / Multiple vertebral dysplasia associated with Rokitansky Syndrome: un uncommon cause of congenital scoliosis. Case report

Las displasias vertebrales son defectos del desarrollo que afectan principalmente a los cuerpos vertebrales, dando lugar a graves deformidades de la columna vertebral y de la caja torácica, en forma de escoliosis y cifoescoliosis congénitas. Pueden ser clasificadas en fallos de la formación, fallos de la segmentación o combinación de ambos. La localización y el tipo de defecto vertebral determinarán la gravedad de la curva patológica. Dichas anomalías pueden aparecer aisladas o asociadas a defectos neurales, viscerales y/o en las extremidades que deben ser descartados en el momento del diagnóstico, solicitando estudios genéticos y de imagen adicionales. El diagnostico precoz, así como el tratamiento rehabilitador con un exhaustivo seguimiento, son de vital importancia para prevenir la progresión de la escoliosis y las posibles complicaciones pulmonares. Presentamos un caso clínico muy poco frecuente, de múltiples anomalías vertebrales asociado a Síndrome de Rokitansky en una mujer que desarrolló escoliosis durante la pubertad (AU)

Vertebral dysplasia is a developmental defect, mainly of the vertebral bodies that cause severe spinal column and thoracic deformity that include congenital scoliosis and kyphoscoliosis. These vertebral anomalies can be classified as failure of formation, failure of segmentation, or a combination of both. The location and type of the vertebral defect determines the severity of the scoliosis. Is mandatory known that these abnormalities may be isolated or associated with concurrent neural, limb or visceral anomalies, which must be ruled out. Therefore additional imaging and genetical studies are necessary to provide evidence of these associated defects. Early diagnosis and rehabilitation treatment with exhaustive expectant watching are vital to prevent development of sever deformities and possible pulmonary complications. We report a representative case of multiple vertebral anomalies associated with Rokitansky Syndrome in a female who develops scoliosis during her puberty (AU)

Cell populations in the pineal gland of the viscacha (Lagostomus maximus). Seasonal variations.

Pineal samples of the viscacha, which were taken in winter and in summer, were analysed using both light and electron microscopy. The differences found between the two seasons were few in number but significant. The parenchyma showed two main cell populations. Type I cells occupied the largest volume of the pineal and showed the characteristics of typical pinealocytes. Many processes, some of which were filled with vesicles, could be seen in intimate contact with the neighbouring cells. The presence in the winter samples of "synaptic" ribbons and spherules, which were almost absent in the summer pineals, suggests a seasonal rhythm. These synaptic-like structures, as well as the abundant subsurface cisterns present in type I cells, appeared as basic differential features which allowed these cells to be distinguished from type II cells. These latter cells, which can be classified as interstitial cells, showed some other distinguishing features, such as irregular-shaped nuclei, abundant deposits of glycogen-like particles and structures of unknown function consisting of concentric cisterns surrounding a dense body. In the summer, interstitial cells displayed numerous large round bodies, which contributed to increase the cellular volume slightly. Regarding other constituents, like glial cell processes, vessels of non-fenestrated endothelium and sympathetic innervation, no qualitative differences were observed between the two seasons studied. We have presented here some morphological evidences of the circannual rhythm of the viscacha pineal, as well as ultrastructural criteria for distinguishing the main cell populations of this organ, which could be useful for studies carried out in other mammals.

Age-related morphometric changes in the pineal gland. A comparative study between C57BL/6J and CBA mice.

Relatively little is known about the effects of melatonin on the aging of the pineal, the organ which is the main place for synthesis of this hormone. Using simple morphometric methods, some parameters of the pineal gland, such as total volume, number of pinealocytes and pinealocyte volume were estimated in two mice strains: normal CBA and melatonin-deficient C57BL/6J. Two age groups, 6 weeks and 10 months, were studied in order to evaluate possible differential age-related changes between both strains. Pineals of both strains have similar morphometric and morphological features at 6 weeks of age. This suggests that pineal development, which has already concluded at 6 weeks of age, is not affected by the absence of melatonin synthesis in the pinealocytes. Later on, CBA pineal showed an increase in size caused by cellular hypertrophy. In contrast, the C57BL/6J pineal volume decreased by loss of pinealocytes in the same period of time. Semithin sections analysed by light microscopy did not show that this cell death was evident in the C57BL/6J strain at any of the ages studied. Thus, a gradual loss of pinealocytes could be hypothesised in these pineals. These results suggest that pineal melatonin could have a role in the maintenance of pinealocyte viability and the increase of pineal size which takes place after development. The abnormal pattern observed in the C57BL/6J pineal should be taken into account in future studies on this gland.

Size and degeneration increase in herring bodies during aging in hamsters.

The hypothalamo-neurohypophysial tract of young, adult and aged male hamsters was studied at lateral and ventral regions of hypothalamus by means of electron microscopy. Neurosecretory swelling axons (Herring bodies) were usually found as classically described containing abundant neurosecretory granules, mitochondria, few microtubules and profiles of smooth endoplasmic reticulum in all groups of age. However, in aged hamsters, starting at 18-month-old subjects, we observed that the size of some neurosecretory axons was highly increased. Autophagic and degenerative features were seen in the larger ones. These data could suggest abnormal axonal storage or axonal transport blocked during aging. The implications in the role of hypothalamus-neurohypophysial system during aging are discussed.

Quantitative ultrastructural evidences suggest no age-related changes in biosynthesis and processing within parvocellular cells of the paraventricular nucleus in hamsters.

The parvocellular neurons of the parvocellular division of the paraventricular nucleus (PVPA) were studied in hamsters at six point ages (from 3 to 30 months old). Standard manual morphometric techniques were used to obtain data of parvocellular activity including nuclear and nucleolar size, as well as the percentage of the cell occupied by Golgi apparatus (GA), mitochondria and rough endoplasmic reticulum (RER). Other directly age-related parameters like amounts of nuclear invagination and lipofuscin have also been studied. No significant differences in the measured subcellular components were detected among groups studied, except slight increases in lipofuscin. No age-related changes were found in the synthesizing apparatus, but a significant decrease in the cell area was observed in older groups. This finding could suggest a reduction in absolute terms in the protein synthesis of the parvocellular neurons during aging. Ultrastructural morphometric observations in parvocellular neurons are discussed in relation to synthesizing activity and hormone production during aging.

The magnocellular neurosecretory system of the hamster hypothalamus: an ultrastructural and morphometric study during lifetime.

A quantitative study regarding the age-related changes occurring in the nucleus and the somatic organelles of neurosecretory magnocellular neurons of the hypothalamo neurohypophyseal system (HNS) was carried out in the hamster at six age-points during animal life. The magnocellular cells of both parts of the supraoptic nucleus (SON) and the paraventricular nucleus (PVN) of male Syrian hamsters between 3 and 30 months of age were examined ultrastructurally. Cells of all age groups present the same morphological ultrastructure. Standard manual morphometric techniques are used to calculate the following parameters related directly or indirectly with cellular activity: nuclear area, nucleolar area, nuclear invagination index and volumetric fractions of some intracellular structures (Golgi apparatus, mitochondria, rough endoplasmic reticulum and lipofuscin). With respect to the cell nucleus, the parameters are not modified during aging. No significant differences in the volume density of subcellular components, except lipofuscin, were detected at the age groups studies. However, there is a positive linear trend among all parameters and age except for the rough endoplasmic reticulum. Our results suggest maintenance of the synthetic activity of the magnocellular neurons in the hamster during aging but in no case an increase in their metabolic activity.

Ultrastructural and quantitative study of atypical age-related bodies in the hamster brain.

Atypical bodies (ABs), related to aging, are described in the central nervous system of normal aged hamsters. Our study used ultrastructural microscopy and quantitative stereology analysis to study these structures in the hypothalamus and brain stem of 3, 6, 12, 18, 24 and 30 month-old hamsters. We found that these complex bodies have an oval or a round profile with a core of fibrillar or tubular structures rounded by a cytoplasmic crown. We frequently observed accumulations of organelles displaying evidence of degeneration. We found that these structures did not appear until 12 months and their frequency increased with age from 12 to 30 months. Their size can range from 3 to 10 microns, although the median size is 6.5 +/- 0.49 microns in diameter. There is a significant correlation between the quantity of these ABs and the animal's age. Their appearance in both hamster and human normal aging can provide an appropriate animal model to yield more information about the normal aging process. This knowledge of the normal aging process in hamsters may also give new insights into which processes in the human brain occur with normal aging and which ones may be exacerbated as in Alzheimer's disease.

Postnatal development of cell types in the hamster Harderian gland.

The morphology, frequency, and distribution of mitotic cells in the epithelium of the Harderian gland was studied in the male and female hamster from birth to the ninetieth day of postnatal life using light and electron microscopic techniques. The results obtained show that there is a gradual decline in the mitotic activity of the Harderian gland as the animals become older which continues until sexual maturity is reached. The study did not find any morphological evidence for the existence of separate precursor cells for the different secretory cell types of the gland. Secretory cells seem to be a homogeneous population in the glands of hamsters younger than 20 days. Cells that could be interpreted as undifferentiated stem cells were not observed. Mitotic cells were observed randomly distributed within tubulo-alveoli, similar to those in interphase. The first sex differences were observed at day 20, when type II cells appeared in male glands. From this point, the percentage of type II cells rapidly increased in male glands. This increase was not accompanied by an increase in the global mitotic activity. However, at this age, male type II cells develop an intense mitotic activity. The observations obtained are in accordance with the hypothesis that the type I and type II cells have the same cell precursor.

New insights into the cytodynamics of the hamster Harderian gland as provided by the bromodeoxyuridine-labelling method.

The fourth week of postnatal life is a critical point in the development of the hamster Harderian gland. During this week, cells with large lipid vacuoles (type-II cells) appear in the male gland, marking a morphological sex difference that is notorious in adult animals. The origin and fate of type-II cells are controversial. To gain insight into the mechanisms by which type-II cells become a major cell type in the gland of adult male hamsters, bromodeoxyuridine (BrdU) labelling was used to assess the proliferative activity of both types of glandular cells in 28-day-old animals. To search for possible sex differences in the proliferative activity of this gland, female animals of the same age as the males were also studied. No difference was found in the overall labelling index (BrdU-labelled cells/100 cells) between males (1.8 +/- 0.1%) and females (1.5 +/- 0.1%). In the gland of the males, the specific labelling index of type-II cells (3.4 +/- 0.4%) was significantly higher than that of type-I cells (0.9 +/- 0.2%). Interestingly, the proportion of type-II cells present in the male glands at this age (36.6%) was significantly lower than that of type-I cells. Our results strongly suggest that the proliferation of type-II cells, rather than a continuous differentiation of these cells from preexisting type-I cells, is a major event in the achievement of the mature form of this gland. The results reported here counsel a reappraisal of current theories about the cytodynamics of the hamster Harderian gland.

Ultrastructural study of a special type of ependymal cell at paraventricular level of the golden hamster third ventricle.

The present paper describes the presence of a special cell located in the ependymal wall at the level of the paraventricular nucleus. At this level, ultrastructural observation of these ependymal cells, unlike most other mammalian species, shows the presence of nucleolus-like bodies in their cytoplasm and occasionally basal processes. These processes appear perpendicular to the ependymal surface and end in contact with the basal membrane of hypothalamic capillaries. Mitochondria, endoplasmic reticulum and numerous filaments are present in the basal processes. Nucleolus-like bodies or nematosomes consist of round or ovoid unbound masses of granular appearing material of variable density located in the apical cytoplasm of the cells. Some of their ultrastructural characteristics are similar to other ependymal specialized cells which are classically termed tanycytes. These findings point out the possibility that those special cells may also be implicated in a ventricle-blood vessel communication.

Hamster supraoptic nucleus: cytoarchitectural, morphometric, and three-dimensional reconstruction.

BACKGROUND: The present paper describes the cytoarchitectonic, morphometric, and three-dimensional characteristics of the golden hamster supraoptic nucleus (SON) in order to provide an anatomical basis for subsequent morphofunctional studies that use this species as an experimental animal. The dimensions (volume and length) and the number of cells of each part of the supraoptic nucleus were obtained, as well as morphometric parameters of their neurons (cross-sectional area and maximum and minimum diameters). A three-dimensional reconstruction of hamster SON has been made in order to know the spatial morphology of this nucleus and to reveal the structural differences between both parts. METHODS: Ten male adult golden hamsters (Mesocricetus auratus) were used. Animals were anaesthetized and transcardially perfused with 4% paraformaldehyde in 0.1 M phosphate buffer at pH 7.2. The hypothalamic area from seven animals was dissected out, dehydrated, and embedded in paraffin. Serial sections of 10 microns were cut in a coronal plane. Sections were stained with thionin, dehydrated, cleared in eucalyptol, and mounted with Eukitt. To prove the neurosecretory nature to the SON, every fourth section was immunostained against neurophysin by using the peroxidase-antiperoxidase method. To study the neuronal morphometric parameters, all magnocellular neurons of the SON were drawn in sections separated 80 microns with the aid of a camera lucida under 500x magnification. Serial 50 microns thick frozen sections of the hypothalamus from three animals were drawn with camera lucida to determine the volume of the two parts of the SON and to make the three-dimensional reconstruction. RESULTS: The SON extends rostrocaudally 1.98 +/- 0.03 mm from the preoptic area to the tuberal hypothalamic area. Two classical parts can be clearly delimited: principal (SONp) and retrochiasmatic (SONr). The neuronal population of the two parts of the SON appears constituted only by magnocellular neurons. The volume of the SONp is 0.039 +/- 0.03 mm3 and contains about 762 +/- 93 magnocellular cells, with a density of 19,151.8 cells/mm3. The volume of the SONr is 0.126 +/- 0.03 mm3 and contains about 1,296 +/- 132 neurons with a density of 10,536.6 cells/mm3. The three-dimensional reconstruction reveals that the SONp appears located in a more cephalic, lateral, and dorsal position than the SONr, and a clear discontinuity between the two parts is observed. CONCLUSIONS: The present study shows that the classically termed SON, in the hamster, clearly consists of two spatially separated neural populations. The SONr is longer than SONp and has the larger volume and higher number of neurons; however, the neurons of the SONr are smaller in cell area than those of the SONp.

Effects of ovariectomy and ageing on the structure and ultrastructure of the female Syrian hamster Harderian gland: a stereological analysis.

The effects of ovariectomy and ageing on the structure and ultrastructure of the Syrian hamster Harderian gland were investigated by techniques of quantitative stereology. Tissues were obtained from intact 6-month-old, sham-operated 6-month-old, ovariectomized 6-month-old, intact 18-month-old and ovariectomized 18-month-old female hamsters. Glands from both ovariectomized and aged hamsters showed comparable qualitative and quantitative characteristics. They showed histological alterations that included thinning of the tubule walls, lowering of luminal porphyrins, invasion of lumina by neutrophils and the occurrence of interstitial porphyrins. Glands from both ovariectomized and aged hamsters showed statistically significant differences from control animals in relation to numerical density and cellular size. Finally, quantitative studies with the electron microscope revealed significant decreases in the volume densities of the cytoplasmic organelles concerned with secretion. These results support the hypotheses that the secretory activity of the female hamster Harderian gland is influenced, directly or indirectly, by ovarian hormones, and that many of the age-related modifications of the Harderian gland reflect alterations in ovarian function.

A morphometric and fine structural study of the myoepithelial cells in the hamster harderian gland.

Myoepithelial cells were structurally and morphometrically studied in the hamster Harderian gland. Myoepithelial cells appeared as irregularly shaped cells with a central body containing the nucleus and numerous long cytoplasmic processes embracing the basal surface of the secretory cells. The main identifying feature of myoepithelial cells was the numerous myofilaments that occupied much of the cytoplasm. Quantitative studies with the electron microscope revealed significant differences between male and female glands, being either volume fraction and numerical density of myoepithelial cells higher in female glands than in male glands. No evidence of cellular size variation between sexes was found. Cell number differences, rather than cell size, were responsible for the sex difference. The functional significance of this sex difference is discussed in relation to the different secretory activity of the Harderian gland in the two sexes.

An electron microscopic study of the harderian gland of the Syrian hamster with particular reference to the processes of formation and discharge of the secretory vacuoles.

The lipid-secreting cells of the Harderian gland of the Syrian hamster were studied using light, transmission, and scanning electron microscopy. Three morphologically different secretory cell types are identified in the gland: type I and II cells of the male gland and, distinct from either, the female gland cell. In all secretory cell types, lipid droplets in the cytoplasm were surrounded by unit membranes. Ultrastructural evidence of the involvement of the Golgi apparatus in the formation of the secretory vacuoles was obtained. The process of secretion involved the fusion of the boundary unit membrane of the vacuole with the plasma membrane and the release of the vacuolar content alone into the lumen. No evidence of holocrine processes was observed in this study. In addition to lipids, vacuoles contained materials whose solubility properties clearly differed from those of lipids. There appear to be variations in the ultrastructural characteristics of the vacuole content of the different types of secretory cell.

An ultrastructural study of myoepithelium maturation during postnatal development of the hamster Harderian gland.

This study reports the ultrastructural cell modifications in the myoepithelium of the Harderian gland during the postnatal development of the Syrian hamster. Tissues were obtained from male and female hamsters at days 1, 3, 5, 7, 10, 12, 15, 17, 20, 27, 37, 46 and 90 after birth, and processed for transmission electron microscopy. Electron microscopy was coupled with point counting methods to quantitate changes in several subcellular organelles during the course of myoepithelial cell maturation. The myoepithelial cells in this gland remained immature at birth. The earliest age of development when organized bundles of microfilaments were observed was 7 days. By the 12th day, the myoepithelial cells had developed most of their specific characteristics and resembled the mature form. Myoepithelial cells mature synchronously with each other and with the secretory cells. No undifferentiated myoepithelial and myoepithelial cells, the secretory endpieces of the adult hamster Harderian gland contain a third cell type which resembles the myoepithelial cell in shape and has an extremely electron-lucent cytoplasm lacking microfilament bundles.

Postnatal development of the harderian gland in the Syrian golden hamster (Mesocricetus auratus): a light and electron microscopic study.

The main objective of the present investigation was to study the morphological and chronological aspects of the development of the Harderian gland in the Syrian golden hamster. Tissues were obtained from male and female hamsters at days 1,3,5,7,10,12,15,17,20,27,37,46, and 90 after birth and processed for light and transmission electron microscopy. The present observations indicate that a well-defined temporal sequence in microscopic and ultrastructural modification is recognizable in the development of the hamster Harderian gland. Four stages of development were proposed. Between days 1-5 (first stage), the gland shows characteristics of an immature structure. The glandular cells contain many free ribosomes, few and small organelles, and large irregular-shape nuclei. Between days 7-17 (second stage), there is a marked increase of organelles involved in synthesis and secretion. The gland begins the secretion of lipids and porphyrins, but no morphological differences between male and female glands are observed. Between days 20-36 (third stage), the morphological differences between the two sexes appear and progressively develop. In 45-day-old hamsters, the Harderian gland possesses the structural characteristics of adult glands, and further developmental changes are essentially quantitative in nature (fourth stage). At all stages of development, the population of secretory cells has a uniform appearance. The morphological results are discussed as well as the possible relationship of this temporal sequence with hormonal changes.

Supraependymal cell clusters and invaginations in the epithalamic third ventricle of the rabbit (Oryctolagus cuniculus).

Supraependymal cell clusters and deep invaginations of the ependymal wall, situated in the epithalamic area of the third ventricle of the rabbit have been precisely located by means of semithin serial sections. A study of these structures has been carried out using optical transmission and scanning electron microscopy. The round shaped supraependymal cell clusters revealed two types of cells: type I, of central location and bearing the morphological features of neurons and type II, located peripherically and of possible ependymary origin and nature. In the same epithalamic region, deep invaginations of the ventricular wall, lined by ependymal cells of similar morphology to those coating the rest of the third ventricle, are described. The functional role of both structures is discussed.

Cell types of the third ventricle wall of the rabbit (Oryctolagus cuniculus).

A comparative study using optical and electron transmission and scanning microscopes was carried out to determine the cells that comprise the wall of the third ventricle of the rabbit (Oryctolagus cuniculus). Three cell types have been distinguished: type I cells are the most numerous and may present a flat, cubical or cylindrical aspect, with cilia and microvilli at their apical end. Type II cells have an irregular elongated morphology, lack cilia on their luminal end and show functional characteristics of secretory cells. Type III cells are also elongated, and bear irregular protrusions at the apical end. A long process at the basal end of these cells goes deep into the neuropil and becomes related with neurons or blood vessels; these correspond to tanycytes.