Gray platelet syndrome. Dissociation between abnormal sorting in megakaryocyte alpha-granules and normal sorting in Weibel-Palade bodies of endothelial cells.

The gray platelet syndrome (GPS) is a rare congenital bleeding disorder in which megakaryocytes and platelets are deficient in alpha-granule secretory proteins. Since the Weibel-Palade bodies (WPB) of endothelial cells as well as the alpha-granules contain the von Willebrand Factor (vWF) and P-selectin, we examined by transmission electron microscopy the dermis capillary network of two patients with GPS. Endothelial cells showed the presence of normal WPB with typical internal tubules. Using single and double immunogold labeling for vWF and P-selectin, we detected vWF within WPB, where it was codistributed with the tubules, whereas P-selectin delineated the outline of WPB. Therefore, the fundamental targeting defect in GPS is specific to the megakaryocytic cell line.

Ultrastructure of human umbilical vessels: a possible role in amniotic fluid formation?

Human umbilical vessels obtained from neonates delivered at term after uneventful pregnancies were examined by light and transmission electron microscopy, with the aim of determining whether or not their structure is compatible with possible fluid exchange between the circulating blood and Wharton's jelly. A comparison of arteries and veins showed that although these vessels have common characteristics, they differ in some elements of their fine structure. The endothelium of both vessels appeared to be highly active metabolically. In the artery, the endothelial cells often protruded into the lumen. This aspect was related to the fine filaments concentrated in the basal part of the cells. This zone, free of organelles, was absent in the venous endothelium, but here pinocytotic vesicles and Weibel-Palade bodies were more abundant. The media included the same elements but was much thicker in the arteries than in the veins. There were two cellular types: typical myocytes and myofibroblasts rich in organelles. Their cytoplasmic processes extended into the interstitial space which was occupied by a material with a loose structure, that is, material containing a well-developed ground substance at the expense of the elastic and collagen fibres. The ultrastructural features of the umbilical vessels suggest an increased endothelial permeability, and it is suggested that transfer across the umbilical vessels may play a role in the formation of amniotic fluid.

Ocular findings following intravitreal silicone injection.

In three cases of intraocular silicone oil injection in which the histologic picture is observed at different time intervals, emphasis is given to the fact that fibrous tissue formation around silicone vesicles is a rather constant complication and of early occurrence. Thus, we believe that the removal of liquid silicone from the eye should not take place later than two or three months after the injection. In our first reported case, there was an association of silicone oil injection and vitrectomy with retinal detachment procedures and sympathetic ophthalmia. In the absence of evident histologic or clinical proof, we do not consider silicone oil injection itself as having induced the mechanisms of sympathetic ophthalmia.

A hypothesis on the origin of the subcylindrical reserve cells of the endocervix.

The structural features of subcylindrical reserve cells of the endocervix are presented. Reserve cells varied in shape. They were randomly oriented and most had a bean-like or spindle shape. Some were loosely apposed with no desmosomes while others were separated by an intercellular matrix. Their nuclei were oval or fusiform, with a prominent nucleolus. Coarse chromatin plaques are distributed irregularly within the nuclei, and surface membrane showed cytoplasmic projections. Within the connective tissue, close to the basal membrane, could be found cells that showed the same structural features; some of them were partially enveloped by amorphous ground substance and collagen, and had small processes extending from the cell surface in the direction of the epithelial layer. Ultrastructural analysis of these cells disclosed some similarities with fibroblasts in the surrounding stroma, and suggested that they were primitive mesenchymal cells originating from Müllerian mesenchyme.

Morphological study of the chorio-allantoic fetal membranes.

Morphological study of the chorio-allantoic fetal membranes has demonstrated the existence of foot processes extending from the main body of amniotic cells and containing microfibrils arranged in dense bundles as described in podocytes of renal glomerulae; on the surface fronds and between their bases many small pits and caveolae are seen; in the cytoplasm of amniotic cells large vacuoles are present; they frequently distort the nuclei into crescentic shapes. In the chorion underlying the amnios, fibroblasts and Hofbauer cells are found; their surface often has overlapping filopidal projections. The syncytium bounding the intervillous space shows a marked resemblance to that of the villi. These morphological features seem to indicate that chorio-allantoic fetal membranes might be an important route for the transporting of fluid from the maternal blood in the intervillous space into the amniotic compartment.

Fetal membrane morphology and circulation of the liquor amnii.

Morphological study of the human fetal membranes (at the term of pregnancy) shows that under the amniochorion lies the chorionic cytophoblast, which completely surrounds the amniotic cavity. Chorionic cytotrophoblast as well as parietal decidua persist until full term and remain well-developed. Within trophoblastic cells there are numerous canalicular formations bordered by microvilli resembling those observed between amniotic cells. The authors therefore believe that the circulation of amniotic fluid, after traversing the amnion, will continue through the intercellular canaliculi of the chorionic cytotrophoblast to reach the decidua parietalis. All the components of this complex membrane must play a part in the amniotic fluid circulation.

The basement membrane in the carcinoma in situ of the cervix: a morphological study.

A morphological study of the basement membrane in the carcinoma in situ of the cervix has been carried out. Undifferentiated carcinoma in situ that arises usually from the squamocolumnar junction and which extends into the endocervical canal, always shows a continuous and clearly delineated basement membrane, which runs parallel to the basal layer. It has a homogeneous appearance. The hemidesmosomes attached to the lamina propria are quite normal and there are no slender protrusions from basal cells into the lamina propria. Differentiated carcinoma in situ, that originates in the squamous epithelium of the portio, may extend either in the direction of vagina, or towards the endocervical canal. It is always underlined by a basement membrane loosely constituted of irregular of fragmented reticular fibers; it frequently looses its homogeneous appearance and may be dehiscent or duplicated. Basal cells send down small pseudopods or threadlike extensions into the lamina propria. The authors suggest that in the management of carcinoma in situ of the cervix, one should take into consideration the direction of spread and the stroma-invasion potential of the carcinoma. These histologic patterns carry with them a very important morphologic implication, namely 'cells differentiation' of the carcinoma.

[Lesions of coronary atherosclerosis in drug users. Preliminary studies]. / Lésions d'athérosclérose coronariennes chez les usagers de drogues. Etudes préliminaires.

A study of hearts removed during medicolegal autopsy of drug addicts after their sudden death demonstrated the constant presence of coronary lesions very similar to common atherosclerosis but remarkable by their magnitude, especially in patients dying at an age when atheromatous disease is relatively rare. Coronary circulation was studied in 10 cases by histoenzymatic, immunologic, histologic and ultrastructural examination of fresh and fixed tissues. The parietal thickening, noted in all cases to variable degrees, had provoked stenosis in several cases, preferentially in the proximal portion of the anterior interventricular vessel. On light and ultrastructural microscopy, the lesions observed were similar to atherosclerotic lesions, but differed in several respects and notably the absence of antiglobulin and the lack of increase of glycosaminoglycans. Although the relations between the drug and atheroma are undeniable, their mechanism is at present unknown.

["Vestigial cells" of the transitional area of the uterine-cervix. Comparative morphological study with the subcylindrical-reserve-cells (author's transl)]. / Les cellules "vestigiaires" de la zone de transition du col utérin. Morphologie et rapports avec les cellules subcylindriques de réserve.

The squamo-cylindrical junction represents a transitional area of unstable epithelium. It consists of slightly differentiated cells which disclosed resemblance in morphological pattern with germinal cells of the basal layer in the exocervical squamous epithelium. These unstable cells, according to the authors, may be derived from the cranial, most cephalic extend of the sinusal vaginal plate which had formed the epithelium of the entire vagina and the vaginal portion of the cervix up to the squamo-columnar junction. Ultrastructural analysis disclosed no similarities between cells of the squamo-columnar junction and subcylindrical reserve cells which exhibited sometimes resemblance to the "mesenchymal cells" found within the surrounding stroma.

[Endometriosis of the uterine cervix. A hypothesis on its histogenesis]. / L'endométriose du col utérin. Une hypothèse sur l'histogenèse.

Three cases of endometriosis of the cervix in association with the results of previous studies on the embryogenesis of the uterus made it possible during a morphological study for the authors to hypothesise that cervical endometriosis could develop in mullerian rests which persist in the stroma of the cervix. Menstrual blood incites the development, but degenerate menstrual fragments of endometrium do not implant to cause this development.

[Comparative morphological study of the peritoneal mesothelium and the germinal epithelium of the ovary. Histogenetic evidence for endometriosis]. / Etude morphologique comparée du mésothélium péritonéal et de l'épithélium germinatif de l'ovaire. Déduction histogénétique sur l'endométriose.

The purpose of this study was to evaluate comparatively the morphology of germinal epithelium and of peritoneal mesothelial cells in women with and without endometriotic foci. In women without enometriotic foci, transmission electron microscopy revealed that plasma membranes of both cell types can form villous process, and that tonofilaments can be found in the cytoplasm; the microfibrils are well defined and may be arranged in perinuclear location or closely packed on the surface. Desmosomes are occasionally found in both cell types. In endometriotic foci, located either in the peritoneum or in the ovary, invaginations of the mesothelium into the underlying stroma are frequently observed, contiguous to well defined endometriotic tubules, or glandlike crypts. These structures are lined by a layer of cuboidal or high columnar cells. The cell membranes are well defined and run parallel to one another; small widening of the intercellular spaces is occasionally associated with a desmosome in the apical portion of the cell. These features may reflect Mullerian induction.

[An integrated histogenetic concept of internal and external endometriosis]. / Une conception histogénétique unitaire des endométrioses internes et externes.

The authors have studied the embryology of the uterus and have studied the comparative morphology of the internal foci of endometriosis, as well as the endometrium itself during the menstrual cycle. These studies have led them to think that the foci of endometriosis, whether they are internal or external, come from cells of coelomic mesothelium that persists in the transitional zone between the myometrium and the endometrium of the uterus, or in the mesothelium that covers the ovary, the tube and the pelvis under the stimulus of substances that are present in degenerate endometrial tissues during menstruation. This unitary idea of histogenesis makes it possible to consider under one heading, if not to unite, all endometriosis occurring anywhere according to their histogenic presentation under the same conditions of the tissues that surround them. It also makes it possible to explain the morphological similarity of endometriosis with the endometrium, although the biological behaviour of the two tissues is different. There is therefore a relationship between endometrium and endometriosis but not a filial one.

[Intimate mechanism of premature separation of the normally inserted placenta]. / Mécanisme intime du décollement prématuré du placenta normalement inséré.

Retro-placental haemorrhage comes from rupture of patent utero-placental arteries which are neither sclerosed nor thrombosed. This applies whether the form of haemorrhage is minor (simple depression found when the placenta is examined) or grave with utero-placental apoplexy (with complete detachment of the placenta and syndrome of shock). The method by which the arteries rupture depend on the intensity and excessive duration of uterine contractions: --moderate; normal uterine contractions give rise to a prolonged blockage of the return circulation, whereas the arterial flow has not stopped. Rupture occurs because the distended utero-placental arterial wall bursts under the insult of raised pressure during the uterine contraction; --intense; these anomalies come from total blockage, both veinous and arterial, and the arterial rupture is due to anoxaemic necrosis of the utero-placental arterial wall. The rupture of the utero-placental arterial wall, which is normally very fragile because it has no elasticity in its musculature, gives the explanation for the histogenesis of retro-placental haemorrhages.

[New data on the morphology of the allanto-chorion fetal membranes]. / Nouvelles acquisitions sur la morphologie des membranes ovulaires, allanto-choriales.

The authors have carried out an electron microscopic study on the morphology of the allanto-chorial membranes of late pregnancy. The demonstration of these amniotic cells with their long pedicles which resemble those of renal podocytes, together with the presence of intercellular canals lined by long villi which themselves cross over with one another to make a grid, and the existence of intracellular canals that make transcytoplasmic tunnels, permit the authors to suggest that they are dealing with a morphological illustration of ultrafiltration processes. The authors suggest that the forces that bring about plasma filtration from the intervillous chamber towards the amniotic compartment crossing the allanto-chorial membranes are the same as those that cause glomerular filtration. These are hydrostatic pressure in the intervillous chamber and the oncotic pressure within the amniotic compartment.

[The histogenetic significance of dysplastic lesions of the cervix (author's transl)]. / Significations histogénétiques des lésions dysplasiques du col utérin.

From the morphological studies that they have carried out the authors describe dysplasias of the cervix of the uterus as a collection of lesions developed from the vestigial cells which are situated at the endo-exocervical junction. The embryological origin of this junction is the sinus. These dysplasias consist of cells with basophil cytoplasm with edges that are not sharp. These form streams which run from the external os of the cervix towards the endocervix, where they replace and disturb the cylindrical epithelium wherever they meet it. These lesions may take on two forms: regular or irregular according to the degree of nucleo-cytoplasmic disharmony. The slow and insidious evolution of these lesions must be distinguished from dystrophic endocervical lesions which are caused by a disturbance in the nutrition of the tissues, which itself is of hormonal or inflammatory origin, and from exocervical lesions which, in common with all lesions of the malpighian mucosa, can undergo atypical scarring.

[Structure and function of the fetal umbilical vessels]. / Structure et fonction des vaisseaux ombilicaux foetaux.

A morphological study carried out using electron microscopy has shown that there is an endothelium in the umbilical blood vessels consisting of intercellular spaces which interdigitate with one another and that are not specialization in junction complex. The endothelial cells are rich in their typical organ structure and have pinocytotic vesicles. There media contains a muscular coat which is thicker in the artery than in the veins. The smooth muscle cells also show pinocytotic vesicles. This morphological state leads the authors to two groups of thought: There is active diffusion by a process of "plasma perfusion" from the lumen of the vessels through the vascular wall which forms a physiological system for taking up fluids which in turn is capable of providing for the energy and plastic requirements of the umbilical vessels: The umbilical arteries, because of their thick muscular tunic and because of the ability of the lumen to dilate as there is an absence of an internal elastic membrane, can function not only as tubes for conducting blood but also as organs that regulate the blood flow. On the other hand the umbilical vein, which cannot stretch and cannot retract because its wall is so thin, behaves as an organ to return the blood flow, particularly because it does have an inner limiting layer preventing over-stretching.

[Reabsorption of amniotic fluid through parietal fetal membranes. A hypothesis based on an ultrastructure study]. / Réabsorption du liquide amniotique au niveau des membranes ovulaires pariétales. Une hypothèse reposant sur une étude ultrastructurale.

Recent investigations have shown that the link between water transport and solute transport in epithelia is made possible by subcellular structure build on a striking geometrical plan, namely, long and narrow dead end channels. The most striking feature of our electron microscopic study of the amnion as well as the chorionic cytotrophoblast, was the demonstration of the existence of intercellular channels running between the lateral sides of the cells with typical junctional complexes sealing their proximal ends; thus they constitute long and narrow dead-end channels. In the amnion, these channels open through the basal lamina into the connective tissue, and in the chorionic cytotrophoblast they open in the direction of the decidua. This situation seems to indicate that fluid emerges from the open mouth of the amniotic intercellular channels and then continues to flow into the channels of the cytotrophoblast, across its podocytic processes, to be dumped into the decidua, and finally drained by maternal decidual vessels. This morphological study suggests that parietal fetal membranes might be an important route for transport of solute and fluid from the liquor amnii into the maternal circulation.

[New findings on the embryogenesis of the vagina]. / Nouvelles acquisitions sur l'embryogenèse du vagin.

The authors have studied a series of twelve embryos between 4 and 8 weeks of age and 21 fetuses between 9 and 25 weeks of gestation. From this material they have made a study of the embryogenesis of the vagina, which shows that the whole of the vagina, and not only the lower third or fifth, is derived from the vaginal plate, this latter is the result of proliferation and fusion of the two sino-vaginal bulbs. This study supports the unitary theory ascribing formation of the vagina to ascension and extension of the vaginal plate which is derived from the cloacal sinus.

[Reconstruction of the medial collateral ligament of the knee in rats using a free autogeneic transplant of fascia lata, ligament or tendon]. / Reconstruction du ligament collatéral latéral du genou du rat par un transplant libre autogène constitué de fascia lata, de ligament ou de tendon.

After resecting the lateral collateral ligament of the knee in 56 male mature rats, the authors replaced it by an autogenous transplant of the same size, made of fascia lata, ligament or patellar tendon. The authors then studied this transplant after an evolution of 2 days to 5 1/2 months. This lapse of time can be divided into three stages: an initial stage (first week), marked by transplant necrosis and acute inflammation--an early stage (from the second to the fourth week), which shows the migration of the cells from the host to the transplant and the rebuilding of collagen fibers. Tissues with a loose, extensible, but weak texture, such as the fascia lata, are totally colonized by the fibroblasts. Tissues with a dense, strong, but less extensible texture, as the patellar tendon, are soon destroyed and recolonized at the periphery, whereas their center is destroyed and recolonized by fibroblasts later and more irregularly--a late phase of consolidation (from the second to the fifth month), which shows the rebuilding of a dense collagen network and its reorientation. In fascia lata transplants, this new collagen is homogeneous and is made of parallel bundles. In tendon transplants, the network is not homogeneous. It has a persistent nodular aspect at the periphery and well-oriented bundles, separated by calcified or granulomatous foci at the center. In the case of ligament transplants, the new collagen network shows an intermediate aspect between the two described above. The weakest regular connective tissues are the best for ligamentoplasties, and tendons are the worst.

[Tarsal tunnel syndrome caused by granulomatous arteritis of an artery supplying the posterior tibial nerve. Apropos of a case]. / Syndrome du canal tarsien par artérite granulomateuse de l'artère nourricière du nerf tibial postérieur. A propos d'un cas.

A patient presented with a tarsal tunnel syndrome due to granulomatous arteritis of the artery supplying the tibial nerve. The pathogenicity of these types of lesion is discussed based on findings during operation, and a logical therapeutic attitude established: early opening of the tarsal tunnel with interfascicular neurolysis of the tibial nerve.