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At least 775 records · Page 43Linked to original sources
PubMed1995

[The effect of a different energy supply for growing Great Danes on the body mass and skeletal development. 3. Clinical picture and chemical studies of the skeleton].

In growth studies with young Great Danes (0-6 months old), the effects of ad libitum (nine animals) or restricted feed supply (70-80% of ad libitum supply; 17 dogs, 9 of them bearing additional weight loads, 15% of body weight attached to the shoulder) were investigated with regard to development of the skeleton and bone composition. Growth disturbances of the skeleton were seen in every group, but the incidence increased with ad libitum feeding. Fast growth led to the valgus syndrome in fore- and hindlimbs, while hyperextensions of the carpal joint were seen, independently of the growth intensity. Weight loading in connection with energy restriction could not reproduce the same effects as ad libitum feeding. The mineral and protein concentrations in the bones (related to fat-free dry matter) were not affected either by the different feeding levels or by the weight loading.

Animals↗
PubMed1996

Septic tank burial: not just another skeleton in the closet.

Backed-up toilets lead to the discovery of a skeleton in the septic tank. Our challenges began with the excavation of this unconventional grave and progressed through recovery and examination of the skeleton, determination of the cause and manner of death, and ultimately, identification of the victim. Main aspects of the septic tank system are summarized, including functional theory, physical design and components, and general comments on use and maintenance. We discuss some basic principles applicable to the excavation and examination of any human skeletal remains, and offer a general approach to identification of the decedent.

Forensic Anthropology↗
PubMed1996

A giant protein associated with the anterior pole of a trypanosomatid cell body skeleton.

A megadalton protein was found to be a cytoskeleton component of the promastigote forms of the flagellate Phytomonas serpens. This protein migrated on sodium dodecyl sulfate polyacrylamide gel electrophoresis as a doublet of polypeptides with a molecular mass similar to muscle beta-connectin (titin) 2500-3000 kDa. A polyclonal antibody raised against this protein reacts, by immunoblot analysis, with Phytomonas serpens and two others Phytomonas species. In addition, the Phytomonas serpens protein was immunoprecipitated after being metabolically labeled with [35S]methionine. This antibody did not cross-react with the cytoskeletal proteins of Trypanosoma cruzi, Crithidia luciliae thermophila, Crithidia fasciculata and Leptomonas samueli or with beta-connectin (titin). Indirect immunofluorescence microscopy analysis revealed a punctate fluorescence staining at the anterior region of the parasite's body skeleton. Moreover, immunogold electron microscopy of cytoskeletal preparations and of thin sections of whole cells indicates that the giant protein appears to cap the anterior end of the cell body microtubules at the level of the junctional complex. We suggest that this giant protein may serve as a linker between the cell body skeleton and the flagellum membrane.

Animals↗
PubMed1996

[Structure of erythrocyte membrane skeleton].

Underlying the human erythrocyte membrane is a self-assembled network of proteins termed the membrane skeleton. This network plays a major role in conferring a biconcave shape on the normal erythrocyte and maintaining mechanical properties of the human erythrocyte membrane. Spectrin, actin, protein 4.1, adducin, tropomyosin, dematin and p55 are the principal components of the membrane skeleton. Lateral interactions among these proteins constitute the spectrin-based composite structure that is anchored to the bilayer through vertical interactions, one involving beta-spectrin, ankyrin and band 3, and the other through an interaction between protein 4.1 and glycophorin C. In this article reviewed are biochemical structure of the skeletal proteins, their interactions and regulations by various constituents based on recent studies.

Cytoskeleton↗
PubMed1996

Skeleton pattern and joint formation in chorioallantoic grafts lacking the anterior or posterior necrotic zones.

Skeletal pattern and joints formation were examined in chick limb bud grafts using the chorioallantoic grafting method which enabled the separation of the limb bud from the body wall and also restricted the influence of some of the morphogenetic zones of the limb. The embryonic chick limb buds from the experimental group were transplanted without the prospective anterior necrotic zone (ANZ) or the posterior necrotic zone (PNZ). Transplants with intact limb bud material served as the control group. Elimination of the ANZ or PNZ mainly affected the skeleton of the zeugopod and elbow joint. Most grafts lacking the ANZ or PNZ showed fusion of the ulna and radius and complete regression of the elbow joint. The most common abnormality was fusion of the humerus, ulna and radius into a single cartilaginous block which was rarely observed in control grafts. As the separation of the ulna and radius depends on cell death in the "opaque patch', it is likely that mechanical elimination of the ANZ or PNZ suppressed cell death in this zone and caused a typical fusion in the zeugopod skeleton and elbow joint and growth retardation in grafts lacking the ANZ or PNZ.

Animals↗
PubMed1997

Metastatic disease of the skeleton.

Metastatic cancer is among the most frequent causes of skeletal pain associated with a destructive bone lesion or pathologic fracture in adults. Patients with a known primary carcinoma should undergo systematic evaluation and monitoring to determine the extent of skeletal disease and risk of pathologic fracture. Patients without a known primary carcinoma who have symptoms consistent with metastatic disease of the skeleton present a diagnostic dilemma. Plain radiographs may not reveal a metastatic lesion until extensive marrow replacement has occurred. Bone scans are more sensitive than radiographs and provide a survey of the entire skeleton. However, increased uptake on a bone scan is not specific and some neoplasms are poorly detected by scintigraphy. Computed tomography can identify bone destruction or neoplastic bone formation that is not easily demonstrated by plain radiographs and can help the clinician assess the risk of pathologic fracture. Magnetic resonance imaging may be helpful in detecting and defining the extent and precise location of marrow lesions and soft tissue extension of neoplasms.

Bone Neoplasms↗
PubMed1997

Dose responses from inhaled monodisperse aerosols of 244Cm2O3 in the lung, liver and skeleton of F344 rats and comparison with 239PuO2.

The purpose of this study was to obtain information on the alpha-particle dose-response relationship of 244Cm in rats. Rats were exposed briefly by inhalation to graded levels of monodisperse aerosols of 244Cm2O3 heat-treated at 1150 degrees C. The initial lung burden (ILB) of each animal was determined by the use of the gamma-ray-emitting radionuclide 243Cm in the aerosols. Seven groups of 84-day-old F344/Crl rats (a total of 637 males and 645 females) were exposed once to 244Cm2O3 or sham-exposed to filtered ambient air. Mean ILBs of all rats per group ranged from 0.51 +/- 0.17 (+/-SD) to 240 +/- 82 kBq kg-1 body weight. Mean lifetime alpha-particle doses to the lungs per group ranged from 0.20 +/- 0.069 (+/-SD) to 36 +/- 6.5 Gy. After death, each rat was radiographed and necropsied. Dose-related increases occurred in incidences of benign and malignant lung neoplasms, except for the groups of rats with higher mean ILBs that were examined histologically (98 +/- 18 and 240 +/- 77 kBq kg-1 body weight) in which survival was markedly decreased. Also, average alpha-particle doses of 0.0014 +/- 0.00058 (+/-SD) to 0.17 +/- 0.091 Gy and 0.18 +/- 0.007 to 1.6 +/- 1.1 Gy were also absorbed by the liver and skeleton, respectively, in the rats in the different exposure groups. Primary liver neoplasms occurred in several rats. However, the incidence of these lesions was not related to dose. Increased incidences of bone neoplasms occurred only in rats receiving higher doses to the skeleton. Excess numbers of rats with lung neoplasms per 10(4) Gy to the lung per group ranged from 760 +/- 430 (+/- SE) at a mean dose of 0.48 Gy to 84 +/- 16 at a mean dose of 37 Gy. Risk factors for the lowest and highest ILB kg-1 body weight groups were not considered reliable because of large errors associated with these calculations and the life-span shortening in the highest ILB kg-1 group. Inhaled 244Cm2O3 appeared to be about 50% less effective as a lung carcinogen in rats compared to 239PuO2 at similar doses.

Aerosols↗
PubMed1997

Membrane skeletons in avian erythrocytes as revealed by the quick-freezing and deep-etching method.

Ultrastructure of chicken erythrocytes were examined by the quick-freezing and deep-etching (QF-DE) method. Some erythrocytes were fixed with paraformaldehyde and prepared with erythrocyte-splitting method or saponin treatment to remove soluble proteins before quick-freezing. Others were prepared in the cytosol buffer with the erythrocyte-splitting method to obtain natural state of cytoskeletons. Non-expanding membrane skeletons were highly condensed on the cytoplasmic side of lipid membrane in the paraformaldehyde-fixed specimens. Under unilateral extension of the specimens, long stretched filaments were connected alternately with condensed filamentous or granular structures under erythrocyte membranes. As the membrane skeletons got closer to the marginal bands, they become more dense network structures. Moreover, in the fresh unfixed specimens, dense networks of filaments were localized underlying erythrocyte membranes in a relatively intact state. Fine filaments connected the marginal microtubule bands to the cytoplasmic sides of erythrocyte membranes. The different distribution of each cytoskeletal component and the association of these structures may support the elliptocytic shape of chicken erythrocytes and resist the dynamic circumstance.

Animals↗
PubMed1997

A study of the growth changes in the maxillofacial skeleton of females with reversed occlusion: investigation by means of lateral x-ray cephalogram.

321 females with reversed occlusion from the ages of 6 to 20 were classified into 15 groups according to chronological age, and the changes of maxillofacial skeleton accompanying growth were investigated. Lateral cephalometric roentgenogram before treatment of the subjects were used for analyses and measurements of maxillofacial skeleton and overjet. The cephalometric analysis was standardized on the S-N plane, and 5 angular items and 6 linear distances were examined. The results of the investigation are summarized as follows: (1) angle ANB, the relationship between the upper and lower jaws, deteriorated to a minus degree from the age of 9 and became -3.3 degrees at the age of 14. Skeletal convexity became negative from the same age and was -7.3 degrees at the age of 14. Thus, the abnormal skeletal features progressed in this condition. (2) The Ar-Gn distance measurement gradually increased from the age of 6 to 18. The increase was 16.2 mm from 7 to 12, an increase of 3.2 mm yearly. (3) A high correlation (r = 0.99) was observed between angle ANB and Convexity. As well, a high coefficient of correlation (r = 0.87) was observed between skeletal convexity and soft tissue convexity. The change in soft tissue convexity may occur 3-4 years later than that of skeletal convexity. (4) The growth curve of Ar-Gn became a logistic curve with the point of deflection at the age of 10.87. The growth curves of S-Gn and N-Me became logistic curves in the same way.

Adolescent↗
PubMedDate not supplied

Implant reconstruction of the jaws and craniofacial skeleton.

Full oral rehabilitation with a high degree of success is now possible with osseointegrated implants. Osseointegration is a direct connection between living bone and the titanium implant at the level of the light microscope. Osseointegrated implants are currently used to replace single teeth, support fixed bridges and stabilize full dentures. These implants can also be placed extraorally for attachment of facial prosthesis. The surgical technique used to place implants intraorally into jaws or facial skeleton is performed in two stages using a local anesthetic and/or conscious sedation. During stage I surgery, holes are placed into the jaw using a series of gradually larger diameter burs until the desired diameter and depth of the bony preparation is achieved. The implant is then placed. The implant must remain undisturbed for 4 months for osseointegration to take place. Stage II surgery is then required to remove the mucosa over the implant and place the transmucosal abutment. After 1-2 weeks of healing, the restorative dentist can take an impression and fabricate the prosthesis. On occasion, it is necessary to augment the height and width of the atrophic jaw with autogenous or allogeneic bone grafts prior to implant placement. Bone grafts are sometimes placed on the floor of the nose or the floor of the maxillary sinus. Guided tissue regeneration is a technique used to generate bone within bony defects adjacent to implants. With long-term rates of success (5 years) of 99% for implants placed in the mandible and 95% for those placed in the maxilla, reconstruction of the jaws and cranial facial skeleton with osseointegrated implants has become the treatment of choice.

Bone Regeneration↗
PubMed1993

Test of the multifactorial aging method using skeletons with known ages-at-death from the Grant Collection.

The multifactorial aging method has been shown to be a highly reliable method of skeletal aging because it incorporates age information from as many age indicators as are available for each skeleton (Lovejoy et al.; Am. J. Phys. Anthropol. 68:1-14, 1985). The present study was a blind test to assess its accuracy on a skeletal sample composed of 55 individuals with verified death certificates (Grant Collection, University of Toronto). Three authors (C.O.L., M.E.B., and K.F.R.), with no access to the death certificate ages, independently seriated and aged the sample using three to four criteria: auricular surface, pubic symphysis, and radiographs of the proximal femur and clavicle. Summary ages were then calculated for each individual in the sample. The authors' independent summary age estimates showed strong correlations with one another (r = 0.84-0.89). Multifactorial age estimates correlated better with real age than did those from any single indicator used. The mean error (averaging 8.7 years) for summary age was at least 1 year less than that for any single indicator. Average bias ranged from -0.7 (underage) to 1.4 (overage) years. These results indicate that utilization of several age indicators, weighted according to their reliability, helps control for variation in the changes that occur with age in any single morphological indicator. This method may therefore be considered one of the most accurate available for the determination of skeletal age-at-death, particularly for paleodemographic analysis.

Adult↗
PubMed1965

HUMAN SKELETONS OF TEHUAC'AN.

The oldest series of human skeletons in the New World shows a high incidence of traumatic lesions during the early nomadic hunting and gathering phase, dental patterns which reflect the transition to an agricultural economy, some evidences of microevolution occurring in a local population, and one probable example of pre-Columbian syphilis.

Agriculture↗
PubMed2001

Cranial and hand skeleton in fragile X syndrome.

The purpose of the present study was to track prenatally observed skeletal deviations in radiographs from fragile X syndrome children and young adults in a search for improvement of early diagnostics of fragile X syndrome. The material consisted of craniofacial profile radiographs and hand radiographs from six males age between 2 years 9 months and 20 years 3 months. Craniofacial radiographs showed normal morphology of the nasal bone in all cases. In five cases the sella turcica could be analyzed. In two cases the anterior wall of the sella was oblique, and in two cases the dorsum sellae appeared short. In one case the sella turcica had normal structure. In two cases, the cervical column was suitable for examination. In one, body fusion and short arcus occurred. Of the six hand radiographs analyzed, the hand skeleton appeared normal in the youngest male. In the other five cases there was a deviant location of the carpal bones in the developmental field corresponding to the first finger. Skeletal maturity was delayed in all cases. In conclusion, the prenatally registered morphological deviations in the skeletal development of fragile X syndrome fetuses were found in 5 of 6 fragile X males and young adults. We suggest that a skeletal analysis be considered in the phenotypic classification of children with fragile X syndrome.

Adolescent↗
PubMed2002

Scoring system for estimating age in the foot skeleton.

This study assesses chronological age of immature individuals from the degree of ossification evident in the foot skeleton. We considered all tarsal and ray bones in various combinations to determine the most sensitive indicators of chronological age. Skeletal maturity was rated according to a subjective but simple scoring system applied to radiographs of normal feet of children of known chronological age. Scales for assessing the primary center of ossification, secondary center of ossification, and state of fusion are defined. In general, as expected, females show earlier onset of skeletal maturity than males; in particular, females in our sample are skeletally mature in most elements beginning 48 months prior to the earliest incidence of skeletal maturity in males for the same bones. Females in our sample show a marked tendency toward skeletal maturity of all elements by 150 months of age, while males do not show the same tendency until approximately 200 months of age. In general within each sex, consecutive states of fusion show broad overlap in range of chronological age within each bone. Combining scores from several different bones enables a reasonable estimate of potential age in a test application of the model.

Adolescent↗
PubMed1980

Sex differences in the ilia of a known sex and age sample of fetal and infant skeletons.

Ilia from a known sex, race, and age sample of fetal and infant skeletons from the collections of the Smithsonian Institution were evaluated for six metric and one nonmetric characters. Three indices calculated from the measurements were analyzed. The nonmetric trait was examined for fit with known sex. The three indices failed to show significant sex differences. The nonmetric trait, Auricular Surface Elevation, proved dependable (91% accurate) for the male Fetal and Six Month age groups.

Age Factors↗
PubMed1985

The skeleton of early Eocene Cantius, oldest lemuriform primate.

A recently discovered partial skeleton of the adapid Cantius trigonodus from the early Eocene Willwood Formation of the Bighorn Basin, Wyoming, documents substantial new information about the anatomy of the oldest lemuriform primates. It is very similar in all features to its descendant, middle Eocene Notharctus, and both exhibit numerous resemblances to certain extant Malagasy lemurs, particularly Lepilemur, Propithecus, Lemur, and Hapalemur griseus. Like these forms, Cantius had relatively long hind limbs and short forelimbs. Forelimb traits (prominent brachialis flange of the humerus, well-developed olecranon process of the ulna, and strong shafts of the ulna and radius) suggest active use of the forelimbs in progression. Specializations in the hind limb (e.g., expanded articular surface of the femoral head, narrow and elevated patellar trochlea and prominent lateral trochlear ridge, posteriorly oriented femoral and tibial condyles, narrow and elongate talus, and hallucal metatarsal with prominent peroneal tubercle) indicate capabilities for leaping and for powerful grasping with an opposable hallux. Cantius was presumably primitive in having a relatively long ischium and much more distal inferior tibial tuberosity than most extant lemurs--traits suggesting that powerful extension of the thigh and flexion at the knee were important in its locomotion and posture. We interpret Cantius as an active arboreal quadruped with a propensity for leaping. The existence of this skeletal structure in one of the oldest primates of modern aspect suggests that it represents the primitive lemuriform morphology.

Animals↗
PubMed2002

Duplication of the Hoxd11 gene causes alterations in the axial and appendicular skeleton of the mouse.

The Hox genes encode a group of transcription factors essential for proper development of the mouse. Targeted mutation of the Hoxd11 gene causes reduced male fertility, vertebral transformation, carpal bone fusions, and reductions in digit length. A duplication of the Hoxd11 gene was created with the expectation that the consequences of restricted overexpression in the appropriate cells would provide further insight into the function of the Hoxd11 gene product. Genetic assays demonstrated that two tandem copies of Hoxd11 were functionally indistinguishable from the normal two copies of the gene on separate chromosomes with respect to formation of the axial and appendicular skeleton. Extra copies of Hoxd11 caused an increase in the lengths of some bones of the forelimb autopod and a decrease in the number of lumbar vertebrae. Further, analysis of the Hoxd11 duplication demonstrated that the Hoxd11 protein can perform some functions supplied by its paralogue Hoxa11. For example, the defects in forelimb bones are corrected when extra copies of Hoxd11 are present in the Hoxa11 homozygous mutant background. Thus, it appears that Hoxd11 can quantitatively compensate for the absence of Hoxa11 protein, and therefore Hoxa11 and Hoxd11 are functionally equivalent in the zeugopod. However, extra copies of Hoxd11 did not improve male or female fertility in Hoxa11 mutants. Interestingly, the insertion of an additional Hoxd11 locus into the HoxD complex does not appear to affect the expression patterns of the neighboring Hoxd10, -d12, or -d13 genes.

Animals↗
PubMedDate not supplied

Axial and appendicular skeleton of Homo antecessor.

The human trunk and limb bones recovered from the Gran Dolina site, in the Sierra de Atapuerca (Burgos, Spain) are studied. All these fossils were excavated at the level called TD6 between 1994 and 1995 and have been dated in excess of 780,000 years ago. These remains have been recently attributed to a new Homo species named Homo antecessor. Axial (vertebrae and ribs) and part of the appendicular (clavicles, radii, femur and patellae) skeleton are studied here. Hand and foot bones have been studied elsewhere (Lorenzo et al., 1999). Four is the minimum number of individuals represented by the postcranial remains recovered up to now. All elements are briefly described anatomically, measured and compared with other fossil hominids and modern humans in order to establish, as far as possible, what postcranial morphology characterized this new species of our genus. The H. antecessor postcrania, generally, display a set of morphological traits that are more similar to modern humans than to the Middle and Upper Pleistocene European hominids. Our results do not contradict the previous phylogenetic analysis, i.e., that H. antecessor represents the last common ancestor for H. sapiens (modern humans) and H. neanderthalensis (Neandertals).

Age Determination by Skeleton↗