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PubMedDate not supplied

Growth mechanisms in skulls with facial clefts. Descriptive and experimental studies on the facial skeleton.

During postnatal growth, skulls of patients with untreated unilateral clefts of the alveolus and palate develop additional anomalies of the facial skeleton. Similar anomalies--a deviation of the upper jaw to the non-cleft side and retropositioning of the maxilla on the cleft side--develop in rabbits with the same type of cleft, surgically produced in the fourth week after birth. Based on a quantitative study of the postnatal growth of the rabbit skull under normal and various experimental conditions, a mechanisms is proposed for the late developement of anomalies of the facial skeleton in cleft-affected skulls.

Abnormalities, Multiple↗
PubMedDate not supplied

Functional factors in the red cell membrane: interactions between the membrane and its underlying skeleton.

Recent studies involving two abnormal red cell phenotypes (South-east Asian ovalocytosis and Leach phenotype) provide novel information concerning the nature and significance of interactions of both the anion transport protein AE-1 (syn. band 3) and Glycophorins C and D with the underlying skeleton. The location of Wra and Dia blood group antigens to mutations on AE-1 at residues 658 and 854 respectively, together with the availability of monoclonal antibodies recognising epitopes dependent upon the integrity of the third extracellular loop of AE-1, have allowed us to study the organisation of the membrane domain of the mutant AE-1 found in South-east Asian ovalocytes (AE-1 SAO). The results suggest that the organisation of the whole membrane domain of AE-1 SAO is abnormal and that the organisation of other integral membrane proteins like those involved in expression of Rh blood group antigens may also be affected. Increased homo- and hetero-associations involving AE-1 SAO and other integral proteins may in turn result in reduced membrane flexibility. Purified protein 4.1 binds with 50-fold higher affinity to protein 4.1 depleted normal red cell membranes than to protein 4.1 depleted red cell membranes of Leach phenotype which lack Glycophorin C (GPC) and Glycophorin D (GPD). Experiments using purified protein 4.1 and p55 together with synthetic peptides corresponding to different regions of the cytoplasmic domain of Glycophorins C and D (GPC/D) demonstrate that protein 4.1 interacts directly with GPC through residues 82-98. They also show that p55 binds to GPC through residues 112-128. Since p55 also binds directly to protein 4.1 it is clear that protein 4.1 can bind to GPC through two different sites either directly through residues 82-98 or indirectly through p55. These results show that GPC and GPD provide major attachment sites for the red cell skeleton via protein 4.1 and that p55 is part of this complex.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1987

A rapid method for preparing high quality alizarin stained skeletons of adult mice.

A simple three-day technique is described for preparing completely cleared and high quality alizarin stained total skeletons of adult mice. Unfixed specimens are partially macerated during staining. Older specimens are heated for 15 min in 1% KOH. A heated solution of benzyl and ethyl alcohol, glycerin, and water is used for final clearing and hardening. This procedure requires about 10 min work per specimen and greatly simplifies preparation of stained and cleared skeletons of adult mice. Another technique, giving slightly better preparations, but requiring 11-14 days, is also described.

Aging↗
PubMed2003

The use of rapid prototyping in the preoperative planning of distraction osteogenesis of the cranio-maxillofacial skeleton.

OBJECTIVE: In cranio-maxillofacial surgery, the principle of distraction osteogenesis (DO) can be used for the reconstruction of the deformed skull, midface complex, mandible and alveolar ridge. Optimal results can only be obtained with accurate planning of the osteotomies and accurate positioning of the distraction device. In addition, the surgical planning must be transferred very precisely to the patient in the operating theater. The clinical accuracy and utility of stereolithographic models in cranio-maxillofacial distraction osteogenesis of the midface, mandible and alveolar ridge will be demonstrated. MATERIALS AND METHODS: Thirteen patients were treated by DO in the cranio-maxillofacial skeleton. Five patients suffered from midface retrusion and were treated by a LeFort III advancement. One patient suffered from an aseptic necrosis of the condylar process of the mandible and had a reconstruction of the condylar process by DO. Seven patients underwent an osteotomy of the alveolar ridge of the mandible with subsequent placement of distraction screws and implants because of advanced atrophy of the mandible. Following preoperative acquisition and conversion of the CT-scan data, a model was fabricated by stereolithography (SLA). Simulation of the osteotomies and placement of distraction devices was performed on these models, then surgical guides were used to transfer the surgical planning to the patient in the operating theater. Pre- and postoperative facial photographs and X-rays were compared to evaluate the accuracy of the transfer procedure. RESULTS: In all cases, matching of pre- and postoperative facial photographs and X-rays showed reconstruction of the bony structures to be as accurate as planned on the SLA models. Transfer of the surgical plan by means of custom-made surgical guides was optimal in all cases. CONCLUSION: Preoperative planning of distraction osteogenesis of the cranio-maxillofacial skeleton and transfer to the operating theater by custom-made surgical guides remains the standard procedure for the planning of complex distraction cases. However, improvements in surgical simulation software and accurate virtual-reality surgery will probably make the use of these models redundant in the future.

Adolescent↗
PubMed1995

[Physical exercise and the skeleton].

The skeleton provides more than only a framework for the body. Bone is a calcified conjunctive tissue sensitive to various mechanical stimuli, mainly to those resulting from gravity and muscular contractions. Numerous animal and human studies demonstrate the importance of weight-bearing physical activity as well as mechanical loading for maintaining skeletal integrity. Lack of weight-bearing activity is dangerous for the skeleton: a decrease in bone mineral density (BMD) has been demonstrated in animals and humans under conditions of weightlessness or immobilization. Other studies have also reported a lower vertebral BMD among young amenorrheic athletes than among athletes with regular cycles and/or non athletes. The main factor responsible for this lower BMD in the amenorrheic athletes is the persistent low level of endogenous estrogen observed among these women. However this does not represent a premature and irreversible loss of bone mass since the resumption of menses following a decrease in training is the primary factor for a significant increase in vertebral BMD in these formerly amenorrheic athletes. A weight-bearing exercise is likely to be more beneficial at weight-bearing than at non weight-bearing sites, and hypogonadism resulting from very intensive training and exercise is more detrimental to trabecular than cortical bone. Bone deficit at non weight-bearing sites may be attenuated by maintenance of body weight. Nevertheless the etiology of "stress fractures" among athletes remains poorly understood, and the exact relationship between soft tissue mass and BMD is not clear. Osteoporosis, the most common bone disorder in France, is a pathological condition associated with increased loss of bone mass, resulting in a greater risk of fracture. Although symptoms of osteoporosis do not generally occur until after menopause, recent evidence suggests that bone loss starts much earlier in life. Therefore osteoporosis might be prevented by increasing peak bone mass and/or by slowering bone loss after menopause. Exercise such as resistance training or weight-bearing activities like running or walking have an osteogenic effect on increasing BMD in young people, and the decrease in BMD is slower in exercised than in non-exercised post-menopausal women. Nevertheless the influence of the length and of the intensity of such physical activities remain to be determined.

Animals↗
PubMed1996

Sinus skeletonization: a treatment for dural arteriovenous malformations of the tentorial apex. Report of two cases.

Two cases of dural arteriovenous malformation of the tentorial apex are presented. Both were treated surgically by means of a sinus skeletonization technique. The operative technique included a combined bioccipital and median suboccipital craniotomy in which the posterior third of the superior sagittal and the straight and bilateral transverse sinuses were skeletonized by incising the falx and the tentorium along the sinuses. Endovascular embolization was used prior to the surgical approach in one case. Clinical and angiographic cure was achieved in both patients, with a follow up of 4 years in the first case and 1 year in the second one. The surgical technique is described in detail.

Combined Modality Therapy↗
PubMed1976

X-ray fluorescence analysis of lead in human skeleton in vivo.

The lead concentration in the skeleton of living man was measured by X-ray fluorescence analysis. Five former workers from a metal industry were studied. The mean lead concentration in their skeletons was estimated to be 62 mug/g with a standard error of +/- 5 mug/g. A comparison with the "normal" skeletal concentrations of lead in people from southern Sweden showed the skeletal concentrations of the men studied to be about three to nine times higher.

Bone and Bones↗
PubMed1978

Effect of oil-attached BCG cell-wall skeleton and thymectomy on the incidence of lung cancer and amyloidosis induced by chemical carcinogens in rabbits.

Intravenous injection of oil-attached BCG cell-wall skeleton showed potent preventive activity for induction of lung cancer by the intrabronchial instillation of chemical carcinogens (3-methylcholanthrene, 4-nitroquinoline 1-oxide) in rabbits. On the other hand, the thymectomized rabbits developed lung cancer by instillation of chemical carcinogens at an 80% incidence, compared to 47.2% in the controls. There were no differences in the appearance of amyloidosis between thymectomized and BCG cell-wall skeleton-treated rabbits and the controls.

4-Nitroquinoline-1-oxide↗
PubMed1997

Coronary artery skeleton detection based on topographic features.

A new approach to the problem of detecting the skeletons of coronary arteries in coronary angiograms is proposed. The digitized grayscale coronary angiograms are regarded as noisy sampling of the underlying continuous surface. After the application of Gaussian filtering to reduce noise, the topographic features of the smoothed image are detected based on first and second order image derivatives. Then, the candidate arteries skeleton points are detected based on the observation that arteries are smooth elongated objects having approximately a Gaussian smoothed semi-elliptical profile. Experimental results on real digitized coronary angiograms are presented.

Algorithms↗
PubMed2000

S values for radionuclides localized within the skeleton.

UNLABELLED: Calculations of radiation absorbed dose to the active marrow are important to radionuclide therapies such as radioimmunotherapy and bone pain palliation. In diagnostic nuclear medicine, calculations of the effective dose for radiopharmaceutical procedures also require the assessment of radiation dose to the skeletal endosteum. We have previously reported the development of 2 3-dimensional electron transport models for assessing absorbed fractions to both marrow and endosteum in trabecular and cortical bone, respectively. Here, we extend these calculations to the assignment of radionuclide S values. METHODS: Data published in International Commission on Radiological Protection Publication 70 were used to develop tables of masses for total marrow space, active and inactive marrow, endosteum, and bone matrix within 22 skeletal sites in the adult. Using our site-specific tissue masses, along with electron absorbed fractions given by our 3-dimensional transport models, radionuclide S values (electron and beta particle components only) were subsequently calculated using the MIRD schema for 32P, 33P, 89Sr, 90Sr, 90Y, 117mSn, 153Sm, 169Er, 177Lu, and 186Re. Specific consideration was given to the trabecular active marrow as both a source and a target region. RESULTS: Site-specific radionuclide S values are reported for 22 skeletal sites, for 9 source-target tissue combinations within trabecular bone, and for 6 source-target tissue combinations within cortical bone. Skeletal-averaged S values are also provided. CONCLUSION: A fully documented model is presented for the adult for use in radionuclide dosimetry of the skeleton. The model is based on both the latest international recommendations for skeletal tissue masses and results from three-dimensional electron transport calculations within the skeleton. Comparisons are additionally made against the radionuclide S values published in MIRD Pamphlet No. 11 and those calculated using the MIRDOSE2 and MIRDOSE3 computer codes. Differences in these datasets vary with the source-target combination considered and may be attributed to 1 of 3 causes: (a) assumptions on reference target masses, (b) transport models used to assign absorbed fractions, and (c) implicit assumptions made in considering the trabecular active marrow as both a source and a target tissue.

Adult↗
PubMed2000

Differentiation between occupational and dietary-related intake of barium in the skeleton.

On the basis of the reconstruction of general nutritional patterns by trace element data on historic populations, an examination on occupational Ba intakes in the skeleton was carried out for a historical metallurgy population. The concentrations of the trace elements Ba, Sr, and Pb as well as the matrix element Ca were determined by AAS analysis. Their correlations within the population were analysed statistically. Evidence of a correlation between Ba and Sr concentrations and the lack of a correlation between Ba and Pb concentrations is interpreted as evidence for a probably solely dietary-related Ba intake in the skeleton. Ba intake from working in ore smelting plants is therefore unlikely or at least insignificant. These conclusions are supported by analysis results of modern food items from the catchment area of the historical population. A sufficient Ba supply through rye was determined, thereby explaining the concentration of Ba in the bone material of the historic population.

Barium↗
PubMed2000

Evaluation of bone formation in fetal skeletons following prenatal paracetamol administration in single alizarin-stained specimens in Wistar rats.

The study was undertaken to evaluate the effect of paracetamol on skeleton in Wistar rats. The drug was administered orally, once a day, in three doses: P1--3.5 mg/kg, P2--35.0 mg/kg, P3--350.0 mg/kg. The foetuses were delivered by laparotomy on the 21st day of pregnancy and fixed in alcohol. The skeletons were stained with alizarin. Insignificant differences of bone malformations were found.

Abnormalities, Drug-Induced↗
PubMed2000

Did ossification of the posterior longitudinal ligament of the spine evolve in the modern period? A paleopathologic study of ancient human skeletons in Japan.

OBJECTIVE: To investigate the historical origins of ligamentous ossifications of the spine in Japan. METHODS: We studied skeletons of Jomonese of the period 5000-2300 years BP, of Japanese of the 17th-19th century Edo Period, and of Ainu of the 18th-20th century in Japan with special emphasis on spinal ligament ossifications as in the posterior longitudinal ligament. A comparison to our previous study on ancient Chinese skeletons was done. RESULTS: Cervical ossification of the posterior longitudinal ligament (OPLL) was the only ossification that increased significantly in prevalence in people of the near-modern period in comparison to the Neolithic gathering-hunting people. CONCLUSION: Socioeconomic changes from a subsistence gathering-hunting economy to the near-modern livelihood depending on rice-eating and a diet high in vegetable protein are speculated to be responsible for the prevalence increase of cervical OPLL.

Adult↗
PubMed2000

[Surgical treatment of metastases from thyroid cancer in the axial skeleton. A retrospective study of 18 cases].

Between 1990 and 1997, 18 patients with a mean age of 55.5 years (11 females, 7 males) underwent surgical treatment for a metastasis from thyroid cancer involving the axial skeleton. At the time of surgery all patients had a poor prognosis: 7 metastases revealed the thyroid cancer, all 18 patients had a neurological or mechanical complication, 9 had multiple metastases, all were over 40 years of age. After arteriography with embolization, the surgical procedure consisted of curettage of the tumor and reconstruction, followed by treatment with iodine 131. The survival rate 3 years after surgery was 50%. At the last review, the functional outcome was good and 17 patients had total neurological recovery. Four complications occurred: 1 operative hemorrhage, 3 postoperative infections. Four patients had local recurrence of the metastasis with a one-year survival rate of 20%. When the thyroid cancer was revealed by the axial metastasis, the 3-year-survival rate was 42%. In cases with huge metastases, the 3-year-survival rate was 71%. It appears from these data that surgical treatment of metastases from thyroid cancer in the axial skeleton still achieves a good functional outcome even in cases where neurological or mechanical complications had occurred before surgery.

Adult↗
PubMed2003

Elasticity of the human red blood cell skeleton.

We have measured by optical tweezers micromanipulations the area expansion and the shear moduli of spectrin skeletons freshly extracted from human red blood cells, in different controlled salinity conditions. At medium osmolarity (150 mOsm/kg), we measure KC=9.7+/-3.4 microN/m, muC=5.7+/-2.3 microN/m, KC/muC=2.1+/-0.7. When decreasing the osmolarity, both KC and muC decrease, while KC/muC is nearly constant and equal to about 2. This result is consistent with the predictions made when modeling the spectrin skeleton by a two-dimensional triangular lattice of springs. From the measured elastic moduli we estimate the persistence length of a spectrin filament: xi approximately 2.5 nm at 150 mOsm/kg.

Elasticity↗
PubMed1976

Osteoblastomas of the axial skeleton shown by skeletal scanning: case report.

Two patients with osteoblastoma of the axial skeleton showed intense uptake of 99mTc-polyphosphate and 99mTc-diphosphonate on skeletal scans. Although this lesion is uncommon, it should be included in the differential diagnosis for young patients who show abnormal accumulation of 99mTc-phosphates in the axial skeleton.

Adult↗
PubMed2000

[DNA typing of old skeletons and teeth with fluorescence tagged short tandem repeats].

In order to identify the individual status of old human skeletons and teeth, studies were conducted on DNA extraction. The extracted DNA was then amplified and automatic typed with 373A sequence's gene scan system (made by PE Company) and fluorescence tagged Hum vWA, Hum LPL kit. This is a rapid, convenient and effective method in DNA typing of old skeletons and teeth in forensic investigation.

Alleles↗