1,721,009 research outputs found
Etude au microscope electronique a balayage de structures tubulaires ciliees presentes dans la lame propre de la trachee du rat
No full textSulla presenza di strutture tubulari ciliate nella lamina propria del ratto. Osservazioni al MES
No full textHistology of the exocrine pancreas
No full textThe morphology of the exocrine secretory unit of the pancreas, i.e. the
pancreatic acinus, is reviewed. The histological features of the acini and their
relation with the duct system are described. The acinar three-dimensional
architecture was studied by means of different ultrastructural techniques, some
of which are complementary. The fine structure and morphodynamics of the acinar
cells are also described. In addition, the location of the organelles in specific
cytoplasmic domains and their close morphofunctional relationship with the
sequential stages of secretion of the digestive enzymes are specially emphasized.
Finally, morphological approaches are suggested to achieve a better comprehension
of the physiological and pathological pancreatic activities whose morphodynamics
need to be further elucidated or are almost totally unknow
3D ultrastructure of the zona pellucida: a comparative analysis of the human and mouse model.
No full textabstract pubblicato su Human Reproduction
New Trends in Microanatomy of Reproduction. Marcello Malpighi Series: Vol. 6. In: ITALIAN JOURNAL OF ANATOMY AND EMBRYOLOGY;
No full textLo scheletro fibromuscolare del corpo luteo. Eleborazione di un modello esemplificativo tridimensionale
No full textLateral costal artery: accessory thoracic vessel of clinical interest
No full textThe lateral costal artery (LCA), a supernumerary branch of the internal thoracic artery (ITA), occurs in several ethnic groups on one side of the thorax or on both, in 15-30% of cases. It has been considered responsible for the "steal-syndrome" of the coronary blood after coronary artery bypass grafting and it used occasionally for myocardial revascularization. To clarify its functional significance, an interpretation based on our findings and human and comparative anatomy and embryology has been attempted. We report on a case where a right LCA of about 2 mm in caliber, rising from the ITA 2.5 cm below the subclavian, coursed as far as the 4th intercostal space for a distance of 13 cm after the anterior axillary line. Anastomosing with the intercostal arteries, it can act as a blood derivative circuit of the thoracic wall. Embryologically, this artery, like the normal parietal arteries of the trunk, might form a longitudinal channel connecting the intersegmental arteries. In mammals having a thoracic cage transversely restricted (quadrupeds), the ITA is more lateral than in primates having a circular thorax, and gives off a ventral branch toward the sternum. It might be hypothesized that the sternal branch occurring in quadrupeds, undergoing adaptation to the thoracic shape of primates, may become the main trunk of the ITA, whereas the LCA may be the remnant of the ITA of quadrupeds. Because the LCA ran partly along the "milk line" of humans, it might be regarded as a supernumerary mammary artery. (C) 2004 Wiley-Liss, Inc
Scanning electron microscopy of stellate cells of mammalian adrenal cortex as revealed by NaOH maceration
No full textAfter removal of connective tissues by the NaOH maceration method, adrenal gland
stellate cells of monkeys, rats and rabbits were studied by scanning electron
microscopy. The stellate cells were situated in the perivascular and interstitial
spaces and showed an ovoid cell body with numerous round or flat processes.
Through these processes they were in contact with other adjacent stellate cells
and thus formed a continuous cellular net around capillaries and parenchymal
cells. This net, which probably provides a cellular scaffolding for the gland,
may also play additional roles such as capillary contraction and nutrition for
adjacent parenchymal cell
Ultrastructural characteristics of human granulosa cells in a coculture system for in vitro fertilization
No full textThe use of somatic cells for cocultures during in vitro fertilization (IVF) is
currently finalized to obtain a higher number of healthy and viable embryos with
a high potential of implantation. Among the different cell lines that can be used
as feeder cells for cocultures, granulosa cells (GCs) are autologous cells, safe
and easy to recover. The aim of the present study was to analyze the fine
structure of human GCs used in a coculture system to evaluate, from a
morphodynamic point of view, their role in supporting embryo development. GCs
were collected during oocyte pick-up, 36 h after human chorionic gonadotropin
administration, from patients undergoing IVF procedures, who had given their
informed consent to be included in this protocol. After coculture, GCs were fixed
and processed for light microscopy (LM) and transmission electron microscopy
(TEM). By LM, GCs appeared as clusters of loosely packed cells, irregularly
rounded or polyhedral in shape, varying in diameter from 18 to 25 microm. Mitotic
cells, as well as regressing elements (with pyknotic nuclei or dense cytoplasm)
and cell fragments were occasionally observed. By TEM, the plasma membrane was
irregular due to the presence of cytoplasmic evaginations. Linear and annular gap
junctions between neighboring GCs were found. GC nuclei, rounded and
eccentrically located, contained finely dispersed chromatin, one (often two)
prominent nucleoli and, infrequently, peripheral patches of heterochromatin.
Numerous organelles populated the GC cytoplasm, among them, mitochondria were
rod-shaped or elongated, usually provided with tubular-vesicular cristae but
occasionally showing atypical, longitudinally oriented cristae. Membranes of
smooth endoplasmic reticulum, Golgi stacks and vesicles, secretory-like granules,
cisternae of rough endoplasmic reticulum (RER), free ribosomes and polysomes,
lysosomal-like bodies, microfilaments, and lipid droplets were also seen in the
GC cytoplasm. In most cells, RER was scarcely represented and numerous lipid
droplets filled the perinuclear space. On the contrary, some GCs contained an
abundant RER and rare lipid droplets scattered in the cytoplasm. In conclusion,
our data demonstrated the presence, in a coculture system, of GCs provided with
ultrastructural characteristics typical of healthy, metabolically active, mostly
steroidogenic cells. Protein-synthetic cells have also been detected. These data,
evaluated at the light of biochemical and clinical studies, sustain the
capability of human GCs cocultures to positively affect early embryo development
in vitro by the secretion of steroids and proteins, putative "embryotrophic"
factor
An unusual peritoneal fossa: anatomic report and clinical implications
No full textThe peritoneal fossae are usually related to rotation and adhesion of the
abdominal viscera to the posterior abdominal wall during fetal development,
and/or the presence of retroperitoneal vessels running just under the peritoneum
and raising serosal folds. These fossae, therefore, are regarded as congenital
and have been considered clinically and surgically as sites of internal abdominal
hernias. The authors describe a peritoneal fossa interposed between the fourth
portion of the duodenum and the abdominal aorta. Due to a scoliosis of the lumbar
column, the abdominal aorta had shifted to the left of the duodenum, stretching
two semilunar avascular peritoneal folds connecting the vessel with the ascending
duodenum. These two folds bounded above and below an entrance into a fossa lined
by the posterior parietal peritoneum and bordered by the fourth portion of the
duodenum on the right and the aorta on the left. This recess extended as far as
the anterior surface of the second and third lumbar vertebrae. On the basis of
the anatomic findings, the authors suggest that acquired fossae, because of their
size and topography, may play a part in the etiopathogenesis of internal
abdominal hernia
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