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[Continuous remodeling of the skeleton. Growth factors and cytokines direct the activity].

Bone is living tissue perpetually undergoing metabolism in a process known as remodelling, a sequence of cellular events occurring throughout the skeleton. The process is initiated in response to bone resorption by multinucleated osteoclasts. The capacity to stimulate osteoclastic activity is a property common to a multiplicity of hormones and cytokines--e g, parathyroid hormone, vitamin D, thyroxine, interleukin-1 and tumour necrosis factor. There is also a group of growth factors and cytokines, such as interleukin-6 and interleukin-11, that serve as stimulators of osteoclastic recruitment. Following bone resorption by osteoclasts, osteoblasts are recruited to the resorption lacuna, where they secrete osteoid which is then mineralised to form mature bone. The coupling of bone resorption and formation is governed by growth factors embedded in the mineralised bone matrix and released during resorption. These include transforming growth factor beta, insulin-like growth factor. Osteoporosis is caused by imbalance between the resorption and formation phases of the remodelling cycle.

Adult↗

Effects of running on the torsional strength, morphometry, and bone mass of the rat skeleton.

Intensity and duration effects of weight-bearing exercise on the rat skeleton were investigated. Eighty-four 3-month-old female Sprague-Dawley rats were assigned to control and nine exercise groups. Exercised rats were run on a treadmill for either 30, 60, or 90 min.d-1 at low (Vo2max approximately 55%), medium (VO2max approximately 65%), or high (VO2max approximately 75%) intensity 4 d.wk-1 for 10 wk. Rat femurs, tibias, and vertebrae were harvested for torsional mechanical tests, bone density assessment, and morphometry. Our results indicate exercise has a significant effect (P < 0.05) on the femoral mechanical response (energy absorbed and twist angle), tibial morphometry (cortical bone area and thickness), and tibial and vertebral bone density measurements but had no effect (P > 0.05) on bone strength when compared with control values. Higher intensity exercise decreased tibial and femoral torque (P < 0.05). Long duration exercise increased tibial and femoral stiffness and decreased twist angle and energy absorbed (P < 0.05). These results indicate bone adapts to its loading environment by increasing bone mineral density, increasing cortical bone area, increasing stiffness, decreasing energy absorbed, and decreasing twist angle. High-intensity exercise decreased the maximum force the bone could withstand, whereas long duration exercise made the bone more brittle.

Absorptiometry, Photon↗

Successful treatment of the patients with malignant pleural effusion with BCG cell-wall skeleton.

The usefulness of the cell-wall skeleton of Mycobacterium bovis BCG (BCG-CWS) to the management of malignant pleural effusion is demonstrated in this report. In two patients with malignant pleurisy the oil-attached BCG-CWS reduced the pleural effusion in volume when injected intrapleurally. The following intradermal injections of BCG-CWS into the bilateral upper arms repeated monthly prevented the reaccumulation of the effusion and improved other clinical conditions of the patients. The possible mechanism responsible for this effect is discussed in relation to previous experimental and clinical studies.

BCG Vaccine↗

Immunotherapy of human lung cancer with BCG cell-wall skeleton.

Effect of BCG cell-wall skeleton (BCG-CWS) on the recovery of responsiveness of lymphocytes and the survival period was studied in patients with lung cancer. (a) Responsiveness of lymphocytes as demonstrated by proliferative response to phytohemagglutinin (PHA) or microcytotoxicity test with cultured cells of a bronchogenic carcinoma was depressed in the patients at later stages of cancer and it was restored by treatment with BCG-CWS in many of such patients. (b) Survival period of the patients at later stages such as III or IV was prolonged by treatment with BCG-CWS. Such an effect was detected even in the patients with carcinomatous pleuritis. (c) A close correlation was found between the reactivity such as PHA response or cytotoxicity and clinical course of the patients given BCG-CWS. Assay system with PHA response and microcytotoxicity test appears to be reliable in anticipating the prognosis and in following clinical course after the BCG-CWS treatment.

Adenocarcinoma↗

[The discovery of a horse skeleton from the 17th century in Kiesen in Bern canton].

In 1968 a skeleton of a horse was found in Kiesen (Switzerland). This discovery could be dated by radiocarbon method: According to that this 13 years old gelding with a withers-height of 135 to 140 cm must have lived during the first third of the 17th century. Apparently it died by an accident. The bones are fully documented with pictures and scales and the findings described and discussed in detail.

Animals↗

[Bone density in axial and peripheral skeleton and mineral density of the entire body as an age dependent factor in a population sample of healthy women].

Bone mineral density has been measured with dual energy X-ray absorptiometry (DEXA) in both axial and peripheral skeleton of 208 randomly selected healthy women aged between 20 and 80 years. Examined women have been stratified into the age groups of every 10 years. Bone mineral density has been measured in lumbar spine L2-L4 (AP), L2-L3 (Lat.) and proximal femur together with total body mineral density in every examined woman. The obtained results are considered reference values for the Polish population.

Absorptiometry, Photon↗

[Association of DNA with the nuclear skeleton].

A significant functional role is ascribed to DNA association with the nuclear skeleton. Specific proteins tightly bound to DNA have been discovered. According to one point of view these proteins perform constant attachment of DNA to the nuclear matrix, however, according to other authors this complex exists in transcribed genes only. In proliferating cell DNA is anchored by DNA-topoisomerase II and DNA-polymerase alpha. Except for proteins this function is performed by glycoproteins, neutral and phospholipids, RNA. Three types of specific DNA sequences have been elucidated: 1. AT-rich enhancers (SAR); 2. GC-rich origins of replication; 3. centromere and satellite DNA. In places of binding to the nuclear matrix DNA bears the numerous defects of secondary structure. Based on different criteria several types of DNA complexes with nuclear matrix proteins are distinguished: 1. resistant (lamina) and sensitive (intramolecular fibrils) to chelating agents; 2. formed by transcriptional complexes (transitory) and origins of replication (constant); 3. tight (resistant to salt-urea solutions, formed by replicative complex proteins) and weak (sensitive).

Animals↗

Augmentation of the craniofacial skeleton with porous hydroxyapatite granules.

Augmentation of the craniofacial skeleton with porous hydroxyapatite granules (Interpore 200) has been performed in 52 sites on 43 patients. Follow-up extends to 5 years, and 26 patients have been followed for greater than 1 year with excellent results. The procedure has been used for reconstruction of congenital and posttraumatic deformities and for purely aesthetic purposes. Areas that have benefited from hydroxyapatite augmentation include the skull, zygomaticomaxillary region, lateral mandible, perialar region, periorbital area, and temporal region. There have been no cases of infection, and only two patients have required minor revisions. Resorption has not occurred.

Adult↗

Associations in the hominoid facial skeleton.

A comparative study has been made of the correlations between numerous linear and angular dimensions of the facial skeleton of man and the three great apes. The Varimax (rotated orthogonal) factor analysis was found to be an essential aid in analysing the very large correlation matrices obtained. It indicated that three groups of association can be identified in the hominoid skull. The first reflects co-ordonated variation in total skull size; the second, co-ordinated variation within common anatomical regions; the third, co-ordination between the jaws and dentition. A broadly similar pattern was found in each group for all four genera. The principal contrasts between man, on the one hand, and the apes, on the other, were found in groups 1 and 2. The most prominent of these was a generally much tighter degree of association between the size and position of upper and lower jaws in the apes, and a consequently reduced tendency for disruption of the occlusal relationship of the teeth.

Animals↗

[The usefulness of the skeleton in the diagnosis of malformation].

Most malformation syndromes (70%) show evidence of skeletal anomalies, mainly in the vertebral bodies and in the bony segments of the limbs. This explains the importance of studying the skeleton when faced with any multi-malformation syndrome, using techniques like CT, MRI, echography and densitometry as well as standard radiology. To increase the quantity of information available for diagnostic purposes it would be profitable to create a data bank containing all the possible radiological findings encountered in the numerous multi-malformation syndromes.

Abnormalities, Multiple↗

[Injuries of the thoracic skeleton].

Injuries of the thoracic skeleton are an important indicator of other, relevant traumatic changes after a polytrauma. Most fractures occur in the ribs, followed by fractures of the clavicle, the scapula and the sternum. Because of their high kinetic energy, car accidents are the main reason for thoracic fractures. The basic radiologic tool is the a.p. projection of the thorax in supine position; in addition, other conventional x-ray examinations or computed tomography are performed. Most thoracic fractures are treated conservatively, only in few cases (instability of the thorax, risk of pseudoarthrosis, incongruence of joint surfaces) surgical procedures are used.

Clavicle↗

Regulation of linkages between the erythrocyte membrane and its skeleton by 2,3-diphosphoglycerate.

In addition to reducing hemoglobin-O2 affinity, 2,3-diphosphoglycerate (DPG) is known to modulate the mechanical properties of the erythrocyte membrane. By fluorescence spectroscopy and differential scanning calorimetry, we demonstrate that DPG binds the cytoplasmic domain of erythrocyte membrane band 3 in two stages characterized by apparent KD values of approximately approximately 2 and 12 mM. DPG was also shown to perturb the stability of ankyrin, protein 4.1, and protein 4.2 in situ and to directly bind to protein 4.1. In studies of membrane-skeleton interactions, DPG was observed to inhibit the fast and slow phases of ankyrin binding to band 3 and to reduce both the number of ankyrin sites and affinity of ankyrin for each class of site. The inhibition was biphasic, similar to the band 3-DPG binding isotherm; however, at physiological DPG concentrations a reduction in only 15% of the ankyrin sites was observed. In contrast, inhibition of protein 4.1 binding to the membrane reached 65% at physiological DPG concentrations (approximately approximately 5.9 mM); at more elevated concentrations, blockade was nearly quantitative, affecting glycophorin and band 3 sites alike. Taken together with previous observations, these data suggest that DPG's effect on O2 delivery may extend beyond its well recognized impact on hemoglobin-O2 affinity.

2,3-Diphosphoglycerate↗

[MR tomography (MRT) of the skeleton, peripheral soft tissues and joints--current overview].

A review: The skeleton, the peripheral soft tissues, and the joints have become important indications to use MRI routinely. About 25-35% of daily examinations focus on these anatomic sites. Superior contrast resolution, the option of different imaging planes, and the unsurpassed visualization of bone marrow, fibrous and hyaline cartilage, ligaments, and tendons are the reasons for the overwhelming success of this imaging method. MRI often provides the direct way to diagnosis. More and more the so-called "step by step" approach to diagnosis by imaging methods is being abandoned in favor of the primary use of MRI. The present survey summarizes the main indications for MRI in the field of the musculoskeletal system, in adults as well as in children. Special topics like tumors, inflammation, ischemia, and trauma are discussed. Some anatomic sites like the carpal joint, the shoulder, and the knee are presented in more detail.

Adult↗

The morphometric study of the 19-day chicken embryo skeleton (gallus domesticus).

A series of 40 chicken embryos were processed after 19 d of incubation by dissection, diaphanisation, skeleton stained with alizarin red and examined by image analysis. Six bones (femur, tibiotarsus, tarsometatarsus, humerus, ulna and carpometacarpus) and 4 parameters (perimeter, area, the largest and the smallest Feret diameter) were evaluated. The smallest Feret diameter proved unusable. The coefficients of variation for the other 3 parameters were comparable for the 6 bones. All the bones were valuable for comparing morphometric values between a control population and a population treated with a xenobiotic in order to quantify the chemical's influence on ossification.

Animals↗

[Characteristics of skulls of ancient skeletons from the province of Xinjiang in China].

INTRODUCTION: On available anthropological material of seven skulls that dates back to the 3800 B.P. to the 2000 B.P., taken from various archaeological sites of Xinjiang area in China, the racial characteristics were studied. The investigated skulls are part of the collection of the prehistoric skeletons housed at the Institute of Archaeology in Beijing. METHOD: Anthropological examination comprised measuring of 32 cranial diameters and calculation of 18 cranial indices, and morphological analyses of 26 traits of the skull and 36 epigenetic characteristics. RESULTS: Three skulls were excavated in Hejing cemetery dated in 1800 years B.P. The skulls are mesocranic, acrocranic and metriocranic (Tab. 1) with outstanding occipital tori and flattening in the lambdoid region (Tab. 2). The orbits are quadrangular, glabella is small with sharp supraorbital margin, the palate is narrow, the mandible is gracile. The fourth skull was excavated in Alagou cemetery from about 2700-2000 years B.P. The skull also possesses western racial characteristics similar to the East Mediterranean type. The fifth skull is from Zhaosu cemetery dated in about 2400-1800 years B.P. The skull is mesocranic with the high cranial vault, broad forehead and quadrangular orbits. The sixth and seventh skulls belonged to the Pfoto-European type. They are excavated in the Gumogou cemetery (about 3800 years B.P.) and in Quinghai region. Among the studied skulls there was no case showing Mongoloid characteristics. Data concerning the epigenetic characteristics (Tab. 3) suggest differences in frequency of certain traits (Os Japonicum, torus palatinus, processus paracondylaris, foramen spinosum bridging) found in investigated material in comparison with findings in other European populations. DISCUSSION: On the basis of the obtained results and investigations of Chinese scientists, it can be concluded that Western racial elements with primitive morphological characteristics had entered from Central Asia into Xinjiang area at least by the early Bronze Age. Other racial elements close to that of the East Mediterranean entered into the western part of Xinjiang several centuries B.C.E. Mongoloid racial elements have not been found in our material. Only about 10 percent among 274 crania investigated by Chinese anthropologists were described as Mongoloid in morphology. The late emergence of the East Mongoloid population, about 300 years B.P. that appeared in small groups, contributes to the conclusion that eastward movement of the Western race to Xinjiang was more rapid than the westward movement of Mongoloid people in that period.

Cephalometry↗

The collagen skeleton of the cat testis. A scanning electron microscopy study after 2N-NaOH maceration.

Testes from adult cats were studied by means of scanning electron microscopy (SEM) after 2N-NaOH maceration method which selectively digests cells and tissue compounds. As seen by this technique, the testis appears covered by a dense fibroconnective tunica albuginea that divides partially the organ by sending septa into the parenchyma. The interstitium is made up by a rich connective tissue composed by randomly-arranged fine collagen bundles that clearly outline the spaces occupied by the seminiferous tubules. The basement membrane of the seminiferous tubules consists in two rough layers of collagen fibers that in some places leave small fenestrations. The three-dimensional arrangement of collagen fibers in the interstitium outlines a system of cavities likely to be lacunar spaces for Leydig cells and vascular imprints. Especially, the above chemical technique followed by deep observations under the SEM allowed a clear and complete view of the real three-dimensional microarchitecture of the connective tissue of the testis. Therefore, the collagen component was revealed to actually form a unique and complex skeleton for the whole organ. This three-dimensional figure closely follows indeed the classical histological compartmentalization of the testis with a better insight of its spatial microtopographical features. Moreover, this structural pattern is also likely to give rise to very fine morphofunctional subcompartmentalization, especially regarding the basement membrane of the seminiferous tubules and the lacunar spaces for Leydig cells including satellite vessels.

Animals↗

Avoiding pitfalls and managing complications of aesthetic contouring of the craniofacial skeleton.

Contouring of the facial skeleton has become applicable to a wide spectrum of patients. Although complications do occur, they now can be managed in a safe and predictable fashion. Moreover, it has been our experience that through increased use and attention to the tenets described in this article, the incidence of postoperative complications is significantly reduced.

Craniofacial Abnormalities↗