Epiphysis Sixth sense
In addition to loss of stature and asymmetric growth abnormalities, slipped capital femoral epiphysis ( 25 Gy)53 and avascular necrosis ( 30 Gy)54 also occur following hip irradiation. Significant craniofacial growth abnormalities can also occur following WBRT. In one study, abnormalities were more common more severe at 24 Gy versus 18 Gy.55
Type I The whole epiphysis is separated Type 2 The epiphysis is displaced, carrying with it a small, triangular metaphyseal fragment (the commonest injury). Type 3 Separation of part of the epiphysis. Type 4 Separation of part of the epiphysis, with a metaphyseal fragment. Type 5 Crashing of part or all of the epiphysis. 78. Type 1 injuries (a) The epiphysis is separated from the shall without any accompanying fracture. I'llis may follow trauma in childhood (illustrated is a traumatic displacement of the distal femoral epiphysis) or result from a birth injury. It may occur secondary to a joint infection, rickets or scurvy. Reduction by manipulation is usually easy in traumatic lesions, and the prognosis is g
The embryos of Nelumbo (hydrophyte) and Ceratophyllum (hydatophyte) lack epiphysis and hypophysis. In the embryo of Nelumbo the main root is substituted by the adventive roots during germination. The latter originate at the base of plumule leaves at the later stages of embryogenesis. However, the embryo of Nelumbo is bipolar from the very beginning of its development 38, 39 . The embryos of parasitic plants can serve as best model for investigation on reduction of typical initials of epiphysis and hypophysis of shoot and root apices (Fig. 10). A considerable peculiarity of its genesis is great variability of the first developmental stages. It is displayed in the diverse contribution of ca and cb derivatives into the formation of embryo body. For example, in Aeginetia indica even the first few divisions are irregular, so that the type of embryogenesis can not be elucidated.
Chromaffin cells, P-pancreatic cells, and PC12 cells, ATP induces an inward current, and increases Ca2+ influx and hormone release. In a subpopulation of pituitary cells, as well as in a subpopulation of chromaffin and insulin-secreting cells, ATP also releases Ca2+ i from internal stores bathed in Ca2+-deficient medium. Finally, ATP is cosecreted during agonist-and depolarization-induced secretion of catechola-mines and gonadotropins. In the pineal gland, ATP potentiates the effect of noradrenaline in N'-acetyl-5-hydroxytryptamine production.
The distance lain between a fixed landmark ( the plate ) and the tip of the epiphysis is periodically evaluated in order to assess the axial growth of the transferred fibula. A failure in longitudinal growth and premature closure of the growth plate have been observed in 5 patients. In two cases the graft was supplied by the peroneal artery which is a controversial pedicle in order to vascularize the epiphysis. Our experience seems to confirm the opinion of those authors who state that the peroneal artery supplies only the shaft of the fibula and that the peroneal pedicle should be enhanced with an epiphyseal artery, usually the descending genicular artery, when the epiphysis is a component of the graft.24 The plastic properties of the epiphysis after its transfer in heterotopic location have been evaluated comparing radiographs and three-dimensional T.C. scans taken at different times. The remodeling observed in wrist reconstruction have been quite significant in most...
The stability of the shoulder depends on appropriate soft tissue reconstruction. Note the strip of biceps femoris tendon which is usually anchored to the glenoid in order to improve the stability of the joint. The rotator cuff is sutured contouring the fibular epiphysis. The soft tissue repair around the transferred epiphysis is complicated by the potential danger for the epiphyseal vascular network related to direct reinsertion on the bone of the rotator cuff and deltoid. For this reason the muscles are just sutured around the fibular head and the strip of biceps femoris tendon is anchored to the glenoid achieving acceptable stability (Fig. 10D.4). In some cases, however, a proximal displacement of the physis does occur due to anatomical discrepancy and insufficient stabilization.
The pineal gland, located in the posterior cerebrum, releases the hormone melatonin, which regulates the body's circadian rhythms and possibly its sexual cycles as well. Melatonin is normally synthesized and secreted beginning shortly after dusk throughout the night and ending around dawn. It thus corresponds with the individual's normal sleep-wake cycle. Melatonin may play an important role in humans adapting to shift work. It is promoted as a nutritional supplement to help people get a good night's sleep.
Metaphyseal side of the plate is nourished by vessels from the shaft (M). In the tibia (I) the epiphysis is supplied by extra-articular vessels. Vessels to the femoral head (2) lie close to the joint space and epiphyseal plate (P). There is a variable (up to 25 ) contribution from the ligamentum teres. Epiphyseal displacements may lead to avascular necrosis or growth arrest. The head of radius is similarly at risk. C capsule. A articular cartilage. 74. Pressure epiphyses (a) Pressure epiphyses are situated at the ends of the long bones and lake part in the articulations. The corresponding epiphyseal plates are responsible for longitudinal growth of the hone (circumferential growth is controlled by the periosteum). Note (I) epiphysis. (2) epiphyseal plate. (3) metaphysis. (4) diaphysis.
The brainstem comprises the midbrain, pons and medulla oblongata. It is directely connected with the diencephalon, composed by thalamus, pineal body, posterior commissure, habenula, and stria medullaris. From anterior to posterior it can be divided into pes, tegmentum and tectum. The tectum of the brainstem is represented by the quadrigeminal plate, while the tectum of the pons and medulla is the cerebellum. The main pathways and nuclei of the brainstem are described in chapters 4 and 5.
An anterolateral approach is recommended in order to expose the anterior tibial neurovascular bundle. The dissection is carried out in the intermuscular space between tibialis anterior and extensor digitorum longus muscles. The latter, and the peroneus longus are then sharply detached from their proximal insertion in order to dissect the upper part of the pedicle and the fibular epiphysis. An adequate muscular cuff must be preserved around the epiphysis to reduce the risk of damaging the small epiphyseal artery which supplies the growth plate (arrow). Fig. 10D.2. An anterolateral approach is recommended in order to expose the anterior tibial neurovascular bundle. The dissection is carried out in the intermuscular space between tibialis anterior and extensor digitorum longus muscles. The latter, and the peroneus longus are then sharply detached from their proximal insertion in order to dissect the upper part of the pedicle and the fibular epiphysis. An adequate muscular...
In cases of intraepiphyseal resection, where just a thin part of the epiphysis and the articular surface are saved, the use of concentric assembling allows for minimal juxta-articular osteosynthesis with the use of multiple screws. When the growth plate is preserved, bone fixation is performed by passing Kirschner wires through the epiphysis in order to prevent ephiphysiodesis. At the other end of the combined graft, fixation is usually achieved using plate and screws. If sufficient bone is spared at both ends of the resection, rigid fixation is carried out using a long plate, which crosses both osteotomies.
The superior and posterior part of the midbrain is called the tectum. There are two enlargements on both sides of the tectum known as the colliculi. The superior colliculus controls visual reflexes such as tracking the flight of a ball, while the inferior colliculus controls auditory reflexes such as turning toward the sound of a buzzing insect. Above and between the colliculi lies the pineal gland, which contains melatonin, a hormone that greatly influences the sleep-wake cycle. Melatonin levels are high when it is dark and low when it is light. High levels of melatonin induce sleepiness, which is one reason that people sleep better when it is darker. Another structure near the colliculi is the periaqueductal gray (PAG) area of the ventricular system. Stimulation of the PAG helps to block the sensation of pain.
Longitudinal section of an epiphysis growth plate. Sample sizing comparisons between the larger nonproliferating cells with the proliferating cells are extremely difficult with this tissue. Any result must also consider the difference in the size of the active small cells and the less active larger cells. Longitudinal section of an epiphysis growth plate. Sample sizing comparisons between the larger nonproliferating cells with the proliferating cells are extremely difficult with this tissue. Any result must also consider the difference in the size of the active small cells and the less active larger cells.
As disease progresses, vasogenic oedema is seen, with characteristic changes in brain tissue density and electrolyte levels. The blood-brain barrier is progressively more damaged. Trypanosomes infiltrate areas of cerebral parenchyma with relatively little blood-brain barrier (e.g. pineal gland, median eminence) and spinal sensory ganglia. Except in terminal disease, trypanosomal invasion of brain tissue is rare.
Moreover, harvesting of an osteomuscular flap is possible by including part of the internal oblique muscle attached to the bone. Even an osteomusculocutaneous flap has been described based on both the deep and superficial iliac pedicles. Thus, the VICG can be raised as a double-pedicle flap to ensure viability of the soft tissue component when placement of the flap will result in alteration of the skin-bone relationship. Epiphysis transfer is not feasible, in contrast to the vascularized fibular graft.
In growing patients, if the metadiaphyseal tumor does not involve the growth plate and resection can be performed preserving the epiphysis, combined allograft reconstruction with minimal fixation of the graft (Kirschner wires or screws) can avoid epiphysiodesis (Fig. 10C.4). Our experience has shown that, in spite of the relatively less rigid fixation, the vascularized fibula provides the necessary biological activity to enhance bone union and a rapid recovery of the patient.
Epiphyseal transfer is a new tool in the armamentarium of microvascular bone reconstruction and offers the attractive possibility to reconstruct long bone defects and to prevent future limb discrepancy in one stage operation. Its clinical application is reserved to those cases where the original epiphysis has been resected or destroyed for traumatic, congenital or neoplastic reasons. The specificity of indication and some doubts on technical aspects account the relative rarity of reports referring to clinical series in the international literature. Our experience, however, allowed to refine the operative technique and to check its reliability on the basis of the observation of 20 patients who underwent surgery over a period of eight years. The majority of the vascularized fibulae showed continual and consistent axial growth after their transfer in heterotopic location and resulted to be the best available option in dealing with such a complex clinical problem.
In the peromelic type and in transverse growth arrest, distal implantation of two toes has been sometimes functionally disappointing, leading to difficulties in the manipulation of small objects and providing a weak pincer . An alternative approach, when there is good wrist mobility, is more proximal implantation. We have modified14 the Furnas18 and Vilkki26 procedure consisting in implanting a great toe or a second toe on the lateral aspect of the diaphysis of the radius. Instead, we insert a second toe in front of the small palm , on the anterior aspect of the radius, distal to the epiphysis.14 This has several advantages it gives us the opportunity to use more tendon transfers, easily available in this proximal site, to better balance the toe. The mobility of the wrist facilitates a good pinch, compensating for the usually limited mobility of the second toe (32 in our experience). A deep web is provided by lifting a flap distally based on the hand, the dorsal aspect of the toe...
RORP is expressed in the brain and retina and functions as a cell-type-specific activator with constitutive activity. RORP is activated by melatonin, the pineal gland hormone, and a class of thiazolidine-diones having antiarthritic activity. However, these observations are controversial because they have not been reproduced in other laboratories.