[Facial injuries in a young child and reconstruction using plastic surgery--an unusual sequella]. / Traumatisme facial chez le jeune enfant et reconstitution en chirurgie plastique--séquelle inhabituelle.

We report a case similar to that of Kaban (1990) showing that intraossous sutures of facial bones can modify or inhibit growth of teeth. In our case, the upper left permanent incisive and the upper left permanent second molar did not grow normally because of the intraosseous sutures required for bone fixation. The permanent mandibular canines did not develop their normal radicular structure either as a result of the initial trauma or due to surgical repositioning manipulations of the bone fragments of the middle part of the face.

[The action of short-range low-intensity infrared laser irradiation on the functional and metabolic parameters of the isolated rat myocardium in hypoxia]. / Deistvie nizkointensivnogo infrakrasnogo lazernogo oblucheniia blizhnego diapazona na nekotorye funktsional'no-metabolicheskie parametry izolirovannogo miokarda krys pri gipoksii.

It was found that infrared laser radiation (IRL) reduces the sparing action of acute hypoxia on ventricular transport function of low-resistant animals and accelerates the recovery of the function during the post-hypoxia period. The effect was caused by the IRL affecting directly the speed of perfusion through the myocardium and thus the latter's breathing rate. The protective effect of the IRL was practically absent in highly resistant animals, which may be indicative of the existence of basic differences in the regulatory systems which is responsible for local vasodilation and supply of oxygen to cells, and which participates in the formation of resistance of cardiomyocytes to oxygen shortage.

Functional anatomy of the larynx.

The larynx should be thought of as a sphincteric valve mechanism in the neck. It is composed of a relatively rigid skeleton and an inner lining, which passively is displayed as a series of elastic folds. These folds are anchored superiorly to the skull base and inferiorly to the trachea. Active folding and unfolding are accomplished by external and internal muscle activity to meet the various functional demands placed upon the larynx.

Primary palatal development in the chick.

Seventy-nine chick embryos were examined by light microscopy and scanning electron microscopy to determine the mechanism of primary palatal development. Fusion between two discrete processes, the medial nasal and maxillary prominences, was found to be necessary for formation of a complete primary palate. This was one component of a three-stage process that included: (1) invagination of the nasal pit prior to the appearance of the facial prominences; (2) fusion between the medial nasal and maxillary processes caudal to the nasal groove; (3) rupture of the bucconasal membrane. The lateral nasal and maxillary prominences were found to be part of the same tissue mass. Mergence was proposed as a mechanism for the obliteration of the groove between these two localized prominences. These results were compared with those obtained by other authors for primary palate formation in rodents and man.

Secondary palatal development in the New Zealand white rabbit: a scanning electron microscopic study.

Examination of surface topography in prefusion stages of secondary palatal development in rabbit embryos reveals a sequence of alterations in the surface cells of the epithelium along the medial margins of the palatal processes. A progressive increase in cellular protrusions resembling lamellipodia and filopodia, as well as cellular necrosis, is observed in those areas that undergo fusion. The changes precede fusion and are restricted to fusion sites. Prior to and at the time of epithelial contact between palatal processes, many long slender cellular protrusions are seen bridging the gap between the approximating tissues. The localization of the epithelial alterations and the appearance of similar cellular morphology in other embryonic epithelial fusion events strongly suggest: either an active role of the epithelial cells in the fusion of the secondary palate, or some common fundamental biochemical events that may facilitate or are responsible for the initial adhesion of such tissues.

Distribution of glycogen in prefusion human palatal epithelium.

Various stages of embryonic human secondary palatal development were examined for the presence of epithelial glycogen. Utilizing periodic acid-Schiff's reagent staining of thick plastic sections and osmium ferrocyanide enhancement of thin sections, dramatic changes in epithelial glycogen distribution were noted during palatogenesis. Prior to fusion, the epithelium destined to adhere in the midline exhibited a marked diminution of glycogen in the superficial cell layer. This cell layer was composed of slender dense cells and cuboidal cells undergoing lysis. Adjacent nonfusing epithelium was markedly different and contained large glycogen reserves in its superficial cell layer. Glycogen may play a role either as precursor for specific adhesive macromolecules or as a physical agent capable under the influence of appropriate enzymes of causing cell lysis.

Extracellular coat in developing human palatal processes: electron microscopy and ruthenium red binding.

The prefusion epithelium of human palatal processes was examined for evidence of specialization which might facilitate epithelial adherence with the opposing palatal process. A surface coat stained with ruthenium red (RR) was found on all apical aspects of the palatal epithelium. In the prefusion regions, RR staining was also observed in the spaces between the superficial cells of the epithelium and in necrotic cells. Adjacent oral and nasal epithelium excluded the RR below the level of the apical junctional complex. In the absence of RR, a dense material was observed in the most superficial intercellular spaces of the prefusion region. Many superficial cells in the area were in various stages of necrosis. The combination of degenerating surface cells and an accumulation of a poly-anionic substance such as glycoprotein may facilitate epithelial adherence between opposing human palatal processes.

Cytological observations of the ovarian epithelium in mammals during the reproductive cycle.

We have studied the ovarian epithelijm at various stages of the reproductive cycle in a number of mammalian species utilizing light microscopy, scanning microscopy, the freeze-fracture technique, transmission microscopy and by employing specialized tracers that use lanthanum and horseradish peroxidase. We found that the epithelial cells are joined by incomplete tight junctions, gap junctions, and desmosomes. The cytoplasmic matrix contains a large irregularly shaped nucleus, few microtubules, microfilaments, mitochondria, endoplasmic reticulum and a host of coated and non-coated vesicles of varying diameters. The saccules comprising the large Golgi complex and its companion vesicles are associated with a basal body-centriole complex: some of these saccules and affiliated vesicles are acid phosphatase positive. Surface modifications of ovarian epithelial cells include numerous microvilli, some of which have a bulbous tip, and plications of the lateral plasma membrane which are thought to accomodate volume changes of the ovary during follicular development. Many coated and non-coated endocytotic caveolae were found on these cells, particularly in the basal area. These caveolae internalized exogeneously administered horseradish peroxidase. We view the marked endocytotic activity as an efficient transport mechanism for partially removing substances from the interstitium of the ovary and the peritoneum.