Bone Tissue In Animals Research Articles

DIFERENTES RESPOSTAS DO TECIDO ÓSSEO E ARTICULAR DE RATOS WISTAR, SUBMETIDOS A EXERCÍCIO RESISTIDO, APÓS LESÃO NERVOSA

Objetivo: analisar o efeito do exercício resistido de subida em escadas nos tecidos ósseo e articular, após lesão compressiva do nervo isquiático de ratos Wistar. Material e Métodos: 32 ratos foram divididos aleatoriamente em 4 grupos, com 8 animais em cada, G1 (controle), G2 (exercício), G3 (lesão) e G4 (lesão e exercício). Após a lesão nervosa G2 e G4 foram submetidos ao exercício resistido de subida em escada, durante 5 dias na semana, com intervalo de 2 dias, por 21 dias. Os animais foram eutanasiados e as articulações do joelho e tíbias do membro pélvico lesionado foram coletadas, e seguiram o processamento padrão para análises em microscopia de luz. Resultados: O tecido ósseo apresentou alterações significativas, em relação a análise morfométrica da área do canal medular e contagem e osteócitos, porém, não foi observada diferença significativa em relação a análise da espessura do osso cortical. Na cartilagem articular do joelho foram observadas discretas alterações morfológicas entre os grupos, como a presença de clones celulares no grupo G3 e remodelagem no grupo G4. Conclusão: a lesão do nervo isquiático em ratos Wistar trouxe efeitos deletérios ao tecido ósseo e articular. Também foi observado que o exercício físico resistido em subida de escada não trouxe alterações ao tecido ósseo dos animais, porém, foi eficaz ao retorno às características normais da cartilagem articular lesionada, e demonstrou aumento da evidencia da tidemark, em animais não lesionados.

Spectral analysis of allogeneic hydroxyapatite powders

In this paper we discuss the application of Raman spectroscopy to the in vitro analysis of the hydroxyapatite powder samples produced from different types of animal bone tissue during demineralization process at various acid concentrations and exposure durations. The derivation of the Raman spectrum of hydroxyapatite is attempted by the analysis of the pure powders of its known constituents. Were experimentally found spectral features of hydroxyapatite, based on analysis of the line amplitude at wave numbers 950-965 cm-1 ((PO4)3- (ν1) vibration) and 1065-1075 cm-1 ((CO3)2-(ν1) B-type replacement). Control of physicochemical properties of hydroxyapatite was carried out by Raman spectroscopy. Research results are compared with an infrared Fourier spectroscopy.

(Invited) ALD to Prevent Metal Transfer from Implants

Atomic layer deposition (ALD) coatings are used in this work to achieve beneficial effects on the surface of CoCrMo alloys used for biomedical applications. Model experiments of implantation into animal bone tissue are performed with uncoated and TiO2 coated samples. Micro X-ray fluorescence is used to map the elemental composition of samples. Results show barrier effect of the coating against the movement of metals from the implant toward the surrounding tissue, increasing with thickness. Moreover, the presence of TiO2 increase the corrosion resistance of the implant. Additional experiments proof that the transfer of ionic species through the same coating, in liquid environment may be exemplified as diffusion through continuous layer, which is also strictly controlled by the coating layer thickness. These evidences open several possibilities for the development of layer by layer structures, with tunable properties, making ALD a powerful tool for biomedical applications.

Duration of Conservation of Plague Microbe (Yersinia pestis) Genes in Mammalian Bone Remains

Objective of this work was to determine the long-term preservation of Yersinia pestis DNA, detected by polymerase chain reaction (PCR) in the bone tissue of rodents, and to quantify content changes over time under the influence of biotic and abiotic factors. Materials and methods. After death of model animals infected with virulent Y. pestis strain, their skeletons were freed from soft tissues and placed in the environments where conditions were close to the natural ones. The study of bone remains for the presence of Y. pestis DNA fragments was held immediately after the death of the animals, and then, twice a year. Results and conclusions. The data obtained allow for dividing all the fossil remains of the fallen from plague infection mammals into three separate groups: with high, medium, and low content of bacteria. Further study demonstrates that reduction of Y. pestis DNA concentration in bone tissue of animals after six months of storage does not occur. After a year, a sharp decrease (100-fold) of observable material dilutions for which the identification of detected plasmids is still possible, is registered. After one and a half year of observation, the genes of plague microbe in the bones of experimental animals could not be found. In order to increase the information content of the study of this type of material put forward has been proposal to reestablish the system of observation sites to collect castings and bone remains of mammals.

Atomic layer deposition to prevent metal transfer from implants: An X-ray fluorescence study

We show that Atomic Layer Deposition is a suitable coating technique to prevent metal diffusion from medical implants. The metal distribution in animal bone tissue with inserted bare and coated Co–Cr alloys was evaluated by means of micro X-ray fluorescence mapping. In the uncoated implant, the migration of Co and Cr particles from the bare alloy in the biological tissues is observed just after one month and the number of particles significantly increases after two months. In contrast, no metal diffusion was detected in the implant coated with TiO2. Instead, a gradient distribution of the metals was found, from the alloy surface going into the tissue. No significant change was detected after two months of aging. As expected, the thicker is the TiO2 layer, the lower is the metal migration.

Effects of Zolendronate in Chronic Periapical Lesions: An Experimental Study in Rats

This study evaluated the histopathological features of chronic periapical lesions and adjacent bone tissue in animals treated with zolendronate. Study Design: Forty male rats were used. Initially, the pulps of the first mandibular molars were exposed. Subsequently, the animals were divided into 8 groups: GI and GII - Periapical lesion induction (PLI) and weekly intraperitoneal administration (WIPA) of saline solution for 4 and 8 weeks, respectively; GIII and GIV–PLI and WIPA of zolendronate (0.15 mg/kg/week) for 4 and 8 weeks; GV and GVI–WIPA of saline solution for 4 and 8 weeks and subsequent PLI; GVII and GVIII - WIPA of zolendronate for 4 and 8 weeks and subsequent PLI. Results: Periapical lesions were characterized by chronic inflammation, with no difference between groups. No osteonecrosis was observed in any specimen. Conclusion: Chronic periapical lesions apparently are not a risk factor for osteonecrosis induced by bisphosphonates.

Ação local do alendronato sódico na reparação óssea de ratos espontaneamente hipertensos (SHR)

The arterial hypertension is a disorder characterized by relevant alterations in the bone tissue. The sodium alendronate is indicated in the treatment of bone diseases, because of its affinity with the hydroxyapatite, inhibiting the bone reabsorptions. To analyze local action of the sodium alendronate in the bone repair of spontaneously hypertensive rat (SHR). A bone defect was created in the left femur of 80 rat. In agreement with the material used at the place, four groups were created: control (C), starch (St), alendronate 1 mol (A1) and alendronate 2 mol (A2). After 7 and 21 days, the animals were sacrificed. Histomorfometrical and histological analyses were accomplished and the data were submitted the variance analysis (ANOVA) and test of Tukey (5%). At 7 days, in the area of the defect, conjunctive tissue with hemorrhage and inflammation in all of the groups was observed. Some presented osteoid matrix. The groups A1 and A2 presented, further, a fibrin net. At 21 days, the bone trabeculae practically closed the extension of the defect in the groups C and St. In the group A1 of male animals, trabeculae were observed that irradiated from the medullary canal to the area of the defect. In the groups A1 and A2, only presence of conjunctive fabric with low osteoid deposit was observed. An outstanding histological discovery was the formation of extracortical subperiosteal bone tissue in animals of the groups A1 and A2. The administration of sodium alendronate did not contribute to bone repair in SHR rat, but possibly has been responsible for the extracortical bone formation observed.

Effect of subchronic exposure to tetradifon on bone remodelling and metabolism in female rat

This study investigates the effect of subchronic exposure to tetradifon, an organochlorine pesticide with an oestrogen-like structure, in female rat. A single cumulative dose of 2430 mg/kg BW was administrated orally for 12 female rats of 190 g BW. Twelve non-treated additional rats have served as controls. Animals were sacrificed after 6 and 12 weeks of treatment. We studied bone remodelling through histomorphometry and scanning electron microscopy (SEM) analyses. The serum and the right femora were used to determine phosphatase alkaline (AlkP) and/or calcium and phosphorus content. No sign of toxicity was observed until the end of the experiment. The SEM results revealed no structural alteration of the treated animal bone tissue. However, in both treated groups, we have noted an increase in the trabecular distance and a heterogeneous aspect of the endosteum that could be explained by bone-remodelling disturbance, with relative delay of ossification. Following histomorphomotric analysis, these results were coupled with significant increases in Tb.Th and OS/BS. Elsewhere, tetradifon intoxication increased significant serum AlkP level in the group treated for 12 weeks, which could be explained by an osteoblastic hyperactivity. Tetradifon intoxication decreased significantly bone calcium end phosphorus contents. Tetradifon seems not to exert major effects on bone remodelling. However, the osteoblastic hyperactivity could be explained by the oestrogen-like activity of tetradifon and its fatty metabolism. In fact, oestrogen inhibits bone remodelling, and enhances bone formation, which could result in an increase of the osteoid surface and explain the relative delay of ossification. To cite this article: R. Badraoui et al., C. R. Biologies 330 (2007).

Structural forms of fluorides in bone tissue of animals under chronic fluoride intoxication

High-resolution solid-state 19F NMR method has been used to examine the chemical structural forms of fluorine introduced into the bone tissue of experimental animals (Vistar rats) exposed to 30 day fluoride inhalation. It is shown that in the bone tissue three structural forms of fluorides are deposited: a solid phase of F-apatite and mobile nanoparticles of CaF2 and MgF2 (or KMgF3) with the ratio of fluorine concentration in these three forms ∼2:2:1. During the following 30 day rehabilitation this ratio remains constant, the total fluorine content in the bone tissue decreases ∼3 times and the F-apatite phase transforms into disordered (F, OH)-apatite. A protective effect of the zeolitic enterosorbent (klinoptilolite) on fluorine binding in the intoxication process was found, as well as the promotional effect of this enterosorbent on fluorine excretion during the postfluoride rehabilitation.

Biocompatibilidade do cimento de fosfato de cálcio implantado no rádio de coelhos

OBJETIVO: Avaliar a biocompatibilidade do cimento de fosfato de cálcio, para verificar sua eficácia como possível substituto ósseo. MÉTODOS: No presente trabalho, foi utilizado cimento de fosfato de cálcio em rádio de 8 coelhos, separados em dois grupos (GI e GII), referentes aos tempos de observação de 12 e 26 semanas pós-operatórias, a fim de se observar as reações entre este biomaterial e o tecido ósseo do animal. Foram feitas análises radiográficas e de densitometria óptica, além de microscopia óptica e eletrônica de varredura. RESULTADOS: Observou-se, ao final do experimento, que o cimento à base de fosfato de cálcio foi parcialmente reabsorvido durante o tempo de observação de 26 semanas, apresentando biocompatibilidade, com ausência de reações indesejáveis que pudessem ser atribuídas aos implantes. CONCLUSÕES: O cimento à base de fosfato de cálcio foi biocompatível e parcialmente reabsorvido no período de 26 semanas de observação. Tempos maiores de observação são necessários para a avaliação da reabsorção.

Surface modification of Al 2O 3 bioceramic by NH +2 ion implantation

Ion implantation technique was applied to graft the NH 2 amidogen radicals onto the surface of Al 2O 3 bioceramic. Fourier transform infrared spectroscopy (FTIR) was used to confirm the presence of the implanted radicals on the Al 2O 3 ceramic surface. It was found that the amount of grafted amidogen radicals was proportional to the dosage of NH + 2 ions used during the ion implantation. Furthermore, when implantation energy of 100 keV was used, maximum amount of NH 2 radicals would be grafted on the Al 2O 3 ceramic surface. The biocompatibility of the implanted Al 2O 3 ceramic was also investigated, and the results indicate that the implanted surface has better biocompatibility with animal bone tissue than the plain ceramic surface.

Anabolic actions of parathyroid hormone on bone.

PHYSICIANS have traditionally considered PTH to be an agent that is catabolic to the skeleton. However, as early as 60 yr ago, Albright and his colleagues (1) and later Selye (2) noted that the peptide extract could also be anabolic to the skeleton, producing increases in bone tissue in animals. The potential for an agent that can increase bone mass and hence reverse the skeletal defect in patients with osteoporosis is great, particularly if in doing so it also repairs microarchitectural damage. The agents currently available in the United States for treatment of osteoporosis, estrogens and salmon calcitonin, primarily stabilize bone mass and prevent further loss of bone, although a transient small increment in mass is often reported, particularly in patients with elevated levels of bone remodeling. This increase is not a true anabolic effect but is related to the temporal effects on turnover in which resorption declines initially followed by a reduction in formation that may take several months. Fluoride, in contrast, does increase bone mass by a true anabolic action, but there is controversy about the quality of the bone formed. Two recent controlled studies failed to find a reduction in fracture recurrence (3, 4), although the dose may have been excessive, and consequently, fluoride is currently not approved for treatment of osteoporosis in the United States. Thus, if PTH is capable of improving bone mass and quality, the peptide will have a potential therapeutic role in osteoporosis. This review summarizes the data available to date, starting at the cellular level.

Drill bit failure without implant involvement — an intraoperative complication in orthopaedic surgery

The aetiology, frequency and consequences of drill bit failure during surgical intervention in human and animal bone tissue are investigated and discussed to provide the surgeon confronted with this problem with a scientifically based procedure. The literature on this subject is rather inadequate, i.e. only one publication in the last decade could be found dealing with this topic and this was a veterinary case. The Laboratory for Experimental Surgery in Davos has received several enquiries from the medical profession worldwide as to correct procedure in the case of drill bit failure. Three sources of information were investigated in order to furbish a reply to these enquiries, these were the AO/ASIF documentation centre in Berne, a survey of 280 surgeons and orthopedic doctors in Switzerland and a survey of 83 AO/ASIF foundation members. One broken tap (tool steel) was removed two years after the operation and metallographic investigations carried out. A frequency of 3 drill bit failure per 1000 internal fixations (0.3 %) is apparent in nearly all data. The reasons for drill bit failure were investigated. Drill bit failure occurs more frequently in the proximal femur and when using angled plates. On the basis of this enquiry the following guidelines can be offered to the surgeon. A broken drill bit which is not in contact with an implant can be left in the body without any risk of delayed recovery. However, if the drill fragment is situated near a joint or if it can be easily removed without further trauma to the bone, then it should be removed. Once the fracture has healed the broken drill bit should be removed along with the implant provided no exceptional difficulties are involved.

Measurements of Strontium-90 in the Australian Environment up to December 1960

THE survey of strontium-90 in representative materials from the Australian environment, commenced in 1957, has continued. As moro than 60 per cent of tho population resides in five capital cities—Perth, Adelaide, Melbourne, Sydney and Brisbane—the sampling programme was designed to represent these population groups. In previous reports1,2 data were presented for human bone tissue and precipitation to June 1960, and for dietary materials, soil and animal bone tissue to December 1958. The present communication gives the results, in Tables 1A and B, from the examination of human bone tissue for the period July–December 1960. Table 2 summarizes data for other materials for the years 1959 and 1960.