Bone morphogenetic proteins in a rabbit posterolateral spinal fusion model: an overview

Bol u slabinskom dijelu kralježnice je važan javnozdravstveni problem u cijelom svijetu. Kirurško liječenje uključuje spinalnu fuziju kao operativnu tehniku kojoj je cilj izazvati sraštavanje dva susjedna kralježka i postići njihovu imobilizaciju, u cilju sprječavanja pojave boli. Kako bi se postiglo sraštavanje, u spinalnim fuzijama se koristi nekoliko osteoinduktivnih materijala koji potiču stvaranje nove kosti između kralježaka. Najčešće korišteni materijal je autograft. Uporaba autografta sa sobom nosi i razne komplikacije te je postotak neuspjelih spinalnih fuzija relativno visok. Kako bi se postigao manji morbiditet i veća uspješnost spinalnih fuzija, na animalnim modelima su testirani razni materijali i molekule koji bi mogli zamijeniti trenutno korištene materijale i unaprijediti standardnu tehniku spinalne fuzije. Jedan od najperspektivnijih kandidata uključuje koštane morfogenetske proteine (BMP). Od svih koštanih morfogenetskih proteina, BMP2 i BMP7 su najčešće korišteni u animalnim modelima spinalne fuzije. Poslijednjih godina, u prektliničkim i kliničkim ispitivanjima se počeo koristiti i BMP6. U sklopu istraživanja potencijala koštanih morfogenetskih proteina kao alternative autograftu, provedena su mnoga istraživanja koja uključuju „proof of concept“ korak, pokuse učinkovitosti i sigurnosti, testiranje raznih nosača za BMP molekule te pokuse koji uključuju najčešće komplikacije. Ovaj rad donosi pregled dosadašnje uporabe koštanih morfogenetskih proteina u modelu posterolateralne spinalne fuzije kunića.Lower back pain is an important public health issue worldwide. In recent decades, interventional spine procedures, including spinal fusion surgeries have become common lower back pain therapy, with a 40% increase in the number of spinal fusions performed between 1998 and 2004. Spinal fusion is the surgical technique of joining two vertebrae so that they heal into a single, solid bone. This is done to prevent movement and occurrence of the pain. In order to achieve solid spinal fusion, various osteoinductive materials that stimulate the formation of the new bone are used in the spinal fusion procedure. Autograft is the most preferred osteoinductive material for spine fusion surgeries. However, the use of autografts is often associated with certain limitations and morbidity. Despite all efforts to improve the spinal fusion technique, the reported non-union rate remains high. All these shortcomings of the standard techniques have urged the development of alternative materials and/or supplements for bone grafting, to enhance new bone formation and facilitate more rapid and robust fusion, with lower morbidity and higher success. Recent efforts in the field have been focused on bone morphogenic proteins (BMP). Of all the bone morphogenetic proteins, BMP2 and BMP7 are most commonly used in animal models of spinal fusion. Both BMP2 and BMP7 have strong osteoinductive properties and their effect on the formation of new bone has been proven in many animal models. In recent years, pre-clinical and clinical trials have also begun for the use of BMP6. As part of enhancing the potential of bone morphogenetic proteins as an alternative for bone grafting, many studies have been carried out involving a “proof of concept” step, feasibility and efficacy trials, testing of various BMP carriers, and complication experiments. This paper provides an overview of the current use of bone morphogenetic proteins in a rabbit model of posterolateral spinal fusion

Bone morphogenetic proteins in a rabbit posterolateral spinal fusion model: an overview

Bol u slabinskom dijelu kralježnice je važan javnozdravstveni problem u cijelom svijetu. Kirurško liječenje uključuje spinalnu fuziju kao operativnu tehniku kojoj je cilj izazvati sraštavanje dva susjedna kralježka i postići njihovu imobilizaciju, u cilju sprječavanja pojave boli. Kako bi se postiglo sraštavanje, u spinalnim fuzijama se koristi nekoliko osteoinduktivnih materijala koji potiču stvaranje nove kosti između kralježaka. Najčešće korišteni materijal je autograft. Uporaba autografta sa sobom nosi i razne komplikacije te je postotak neuspjelih spinalnih fuzija relativno visok. Kako bi se postigao manji morbiditet i veća uspješnost spinalnih fuzija, na animalnim modelima su testirani razni materijali i molekule koji bi mogli zamijeniti trenutno korištene materijale i unaprijediti standardnu tehniku spinalne fuzije. Jedan od najperspektivnijih kandidata uključuje koštane morfogenetske proteine (BMP). Od svih koštanih morfogenetskih proteina, BMP2 i BMP7 su najčešće korišteni u animalnim modelima spinalne fuzije. Poslijednjih godina, u prektliničkim i kliničkim ispitivanjima se počeo koristiti i BMP6. U sklopu istraživanja potencijala koštanih morfogenetskih proteina kao alternative autograftu, provedena su mnoga istraživanja koja uključuju „proof of concept“ korak, pokuse učinkovitosti i sigurnosti, testiranje raznih nosača za BMP molekule te pokuse koji uključuju najčešće komplikacije. Ovaj rad donosi pregled dosadašnje uporabe koštanih morfogenetskih proteina u modelu posterolateralne spinalne fuzije kunića.Lower back pain is an important public health issue worldwide. In recent decades, interventional spine procedures, including spinal fusion surgeries have become common lower back pain therapy, with a 40% increase in the number of spinal fusions performed between 1998 and 2004. Spinal fusion is the surgical technique of joining two vertebrae so that they heal into a single, solid bone. This is done to prevent movement and occurrence of the pain. In order to achieve solid spinal fusion, various osteoinductive materials that stimulate the formation of the new bone are used in the spinal fusion procedure. Autograft is the most preferred osteoinductive material for spine fusion surgeries. However, the use of autografts is often associated with certain limitations and morbidity. Despite all efforts to improve the spinal fusion technique, the reported non-union rate remains high. All these shortcomings of the standard techniques have urged the development of alternative materials and/or supplements for bone grafting, to enhance new bone formation and facilitate more rapid and robust fusion, with lower morbidity and higher success. Recent efforts in the field have been focused on bone morphogenic proteins (BMP). Of all the bone morphogenetic proteins, BMP2 and BMP7 are most commonly used in animal models of spinal fusion. Both BMP2 and BMP7 have strong osteoinductive properties and their effect on the formation of new bone has been proven in many animal models. In recent years, pre-clinical and clinical trials have also begun for the use of BMP6. As part of enhancing the potential of bone morphogenetic proteins as an alternative for bone grafting, many studies have been carried out involving a “proof of concept” step, feasibility and efficacy trials, testing of various BMP carriers, and complication experiments. This paper provides an overview of the current use of bone morphogenetic proteins in a rabbit model of posterolateral spinal fusion

Role of Sirt3 in Differential Sex-Related Responses to a High-Fat Diet in Mice

Metabolic homeostasis is differently regulated in males and females. Little is known about the mitochondrial Sirtuin 3 (Sirt3) protein in the context of sex-related differences in the development of metabolic dysregulation. To test our hypothesis that the role of Sirt3 in response to a high-fat diet (HFD) is sex-related, we measured metabolic, antioxidative, and mitochondrial parameters in the liver of Sirt3 wild-type (WT) and knockout (KO) mice of both sexes fed with a standard or HFD for ten weeks. We found that the combined effect of Sirt3 and an HFD was evident in more parameters in males (lipid content, glucose uptake, pparγ, cyp2e1, cyp4a14, Nrf2, MnSOD activity) than in females (protein damage and mitochondrial respiration), pointing towards a higher reliance of males on the effect of Sirt3 against HFD-induced metabolic dysregulation. The male-specific effects of an HFD also include reduced Sirt3 expression in WT and alleviated lipid accumulation and reduced glucose uptake in KO mice. In females, with a generally higher expression of genes involved in lipid homeostasis, either the HFD or Sirt3 depletion compromised mitochondrial respiration and increased protein oxidative damage. This work presents new insights into sex-related differences in the various physiological parameters with respect to nutritive excess and Sirt3

CraniometricalAnalysis and Determination of Sexual Dimorphism in Brown Bear (Ursus arctos L.) from Croatia

Porodica medvjeda (Ursidae) sposobna je pod utjecajem okoli ša i načina prehrane ispoljavati znatne razlike morfoloških obilježja. Cilj ovo ga rada bio je napraviti kraniometrijsku analizu populacije smeđeg medvjeda (Ursus arctosL.) u Hrvatskoj, kako bi se odredile kraniometrijske karakteri stike populacije te utvrdile razlike među spolovima. Istraživanjem su bile obu hva ćene ukupno 34 lubanje smeđeg medvjeda, od čega je 13 (38,24 %) pripadalo životinjama ženskog spola, 20 (58,83 %) životinjama muškog spola, dok za jednu (2,93 %) lubanju nisu postojali podaci o spolu. Na svakoj je lu banji izmjereno ukupno 49 mjera. Osim nekih kraniometrijskih obilježja, obra dom mjera je određeno i 16 graničnih vrijednosti koje mogu poslužiti za determinaciju spola. Određivanjem korelacije između ukupne duljine lubanje i zigomatične širine izračunata je jednadžba regresije za te dvije mjere. Pri us po redbi kraniometrijskih značajki medvjeda iz Hrvatske s medvjedima iz Slo vačke, zaključujemo da su mužjaci u Hrvatskoj i Slovačkoj približno jednaki, dok su ženke u Hrvatskoj manje nego one u Slovačkoj. Medvjedi iz Hrvatske manji su od onih iz Rumunjske, s time da je između mužjaka manja razlika, dok je između ženki zabilježena statistički značajna razlika.Family of bears (Ursidae) have a potential to exhibit various characteristics under the influence of environment and nutrition. The goal of this paper was to analyze craniometrical measurements of brown bear (Ursus arctosL.) population from Croatia with objectives to define them, as well as to determinate differences between sexes. A total of 34 skulls have been V. Farkaš, T. Gomerčić, M. Sindičić, V. Slijepčević, Đ. Huber, A. Frković, S. Modrić: KRANIOMETRIJSKA... Šumarski list br. 9–10, CXXXIII (2009), 527-537 studied, out of which 13 (38,24 %) belonged to female animals, 20 (58,83 %) to males, while sex was not identified for one (2,93 %) skull. All skulls belonged to adult animals, with the average age of 8,4 years (range 3 to 20 years). A total of 49 measurements were taken on each skull with the 0,1 mm precision, so totally 829 craniometrical measurements have been statistically analyzed. Statistically significant difference between the sexes has been observed in 42 (85,72 %) cra niometrical measurements, while for totally 16 (32,65 %) measurements it has been observed that males are absolutely bigger than the female bears (meaning that the smallest males were bigger than the biggest females). For those 16 measures we have defined border values that could help in sex determination. Correlation and equation of regression were calculated for total length of skull and zygomatic breadth. Corelation was r = 0,7961 for male bears and r = 0,6812 for females, while equaton of regression for calculation of zygoma tic width using total skull length was: for males - zygomatic width = 0,8365 total skull length - 79,105; for females – zygomatic width = 0,6867 total skull length - 31,247. In comparison of skull features of bears from Croatia with the ones from Slovakia we have found that male bears were almost the same while Croatian females were smaller. Bears in Croatia were smaller than the ones in Romania but the differences among males were smaller, while the females were significantly larger in Romania

Glucagon-like peptide-1 mediates effects of oral galactose in streptozotocin-induced rat model of sporadic Alzheimer’s disease

Insulin resistance and metabolic dysfunction in the brain are considered to be the pathophysiological core of sporadic Alzheimer's disease (sAD). In line with that fact, nutrients that could have therapeutic effects at this level have been investigated as possible targets in AD therapy. Galactose, an epimer of glucose, may serve as an alternative source of energy, and given orally may stimulate secretion of the incretin hormone glucagon-like peptide-1 (GLP-1). Our preliminary research indicated that oral galactose might prevent development of memory impairment in a rat model of sAD generated by intracerebroventricular administration of streptozotocin (STZ-icv). Here, we explored whether chronic oral galactose treatment could have beneficial effects on cognitive deficits already manifested at the time of initiation of galactose treatment in adult STZ-icv rats (treatment initiated 1 month after STZ-icv injection). The results clearly show that a 2-month exposure to oral galactose (200 mg/kg/day administered in a drink ad libitum) normalises impaired learning and memory functions. Memory improvement was accompanied by an improvement in brain glucose hypometabolism measured by 18fluorodeoxyglucose-positron emission tomography neuroimaging and by increments in active GLP-1 plasma levels as well as by an increased expression of GLP-1 receptors in the hippocampus and hypothalamus. Our findings provide strong evidence of beneficial effects of oral galactose treatment in the STZ-icv rat model of sAD and present possible underlying mechanisms including both direct effects of galactose within the brain and indirect GLP-1-induced neuroprotective effects that might open a new, dietary-based strategy in sAD treatment

Iron overload in aging Bmp6−/− mice induces exocrine pancreatic injury and fibrosis due to acinar cell loss

The relationship between hemochromatosis and diabetes has been well established, as excessive iron deposition has been reported to result in impaired function of the endocrine and exocrine pancreas. Therefore, the objective of the present study was to analyze the effects of iron accumulation on the pancreata and glucose homeostasis in a bone morphogenetic protein 6‑knockout (Bmp6‑/‑) mouse model of hemochromatosis. The sera and pancreatic tissues of wild‑type (WT) and Bmp6‑/‑ mice (age, 3 and 10 months) were subjected to biochemical and histological analyses. In addition, 18F‑fluorodeoxyglucose biodistribution was evaluated in the liver, muscle, heart, kidney and adipose tissue of both animal groups. The results demonstrated that 3‑month‑old Bmp6‑/‑ mice exhibited iron accumulation preferentially in the exocrine pancreas, with no signs of pancreatic injury or fibrosis. No changes were observed in the glucose metabolism, as pancreatic islet diameter, insulin and glucagon secretion, blood glucose levels and glucose uptake in the liver, muscle and adipose tissue remained comparable with those in the WT mice. Aging Bmp6‑/‑ mice presented with progressive iron deposits in the exocrine pancreas, leading to pancreatic degeneration and injury that was characterized by acinar atrophy, fibrosis and the infiltration of inflammatory cells. However, the aging mice exhibited unaltered blood glucose levels and islet structure, normal insulin secretion and moderately increased α‑cell mass compared with those in the age‑matched WT mice. Additionally, iron overload and pancreatic damage were not observed in the aging WT mice. These results supported a pathogenic role of iron overload in aging Bmp6‑/‑ mice leading to iron‑induced exocrine pancreatic deficiency, whereas the endocrine pancreas retained normal function

Evaluation of Effectiveness of a Novel Multicomponent Mycotoxins Detoxification Agent in the Presence of AFB1 and T-2 Toxin on Broiler Chicks

This experimental study was conducted to determine the ability of a novel mycotoxins detoxification agent (MR) at a concentration of 0.2% to reduce the toxicity of aflatoxin B1 (AFB1) or T-2 toxin, alone or in combination, and to examine its effect on performance, pathohistological changes (PH) and the residue of these toxins in the tissues of broiler chicks. A total of 96 broiler chicks were divided into eight equal groups: group C, which served as control (without any additives); group MR, which received the novel detoxification agent (supplemented with 0.2%); group E-I (0.1 mg AFB1/kg of diet); group E-II (0.1 mg AFB1/kg of diet + MR 0.2%); group E-III (0.5 mg T-2 toxin/kg of diet); group E-IV (0.5 mg T-2 toxin/kg of diet + 0.2% MR); group E-V (combination of 0.1 mg AFB1/kg, 0.5 mg T-2 toxin/kg of diet); and group E-VI (combination of 0.1 mg AFB1/kg, 0.5 mg T-2 toxin + 0.2% MR). Results indicate that feeds containing AFB1 and T-2 toxin, alone or in combination, adversely affected the health and performance of poultry. However, the addition of MR to diets containing AFB1 and T-2 toxin singly and in combination exerted a positive effect on body weight, feed intake, weight gain, feed efficiency and microscopic lesions in visceral organs. Residual concentration of AFB1 in liver samples was significantly (p < 0.05) decreased when chicks were fed diets supplemented with 0.2% of MR

Autologous blood coagulum containing rhBMP6 induces new bone formation to promote anterior lumbar interbody fusion (ALIF) and posterolateral lumbar fusion (PLF) of spine in sheep

resent study, we evaluated an autologous bone graft substitute (ABGS) composed of recombinant human BMP6 (rhBMP6) dispersed within autologous blood coagulum (ABC) used as a physiological carrier for new bone formation in spine fusion sheep models. The application of ABGS included cervical cage for use in the anterior lumbar interbody fusion (ALIF), while for the posterolateral lumbar fusion (PLF) sheep model allograft devitalized bone particles (ALLO) were applied with and without use of instrumentation. In the ALIF model, ABGS (rhBMP6/ABC/cage) implants fused significantly when placed in between the denuded L4- L5 vertebrae as compared to control (ABC/cage) which appears to have a fibrocartilaginous gap, as examined by histology and micro CT analysis at 16 weeks following surgery. In the PLF model, ABGS implants with or without ALLO showed a complete fusion when placed ectopically in the gutter bilaterally between two decorticated L4-L5 transverse processes at a success rate of 88% without instrumentation and at 80% with instrumentation ; however the bone volume was 50% lower in the instrumentation group than without, as examined by histology, radiographs, micro CT analyses and biomechanical testing at 27 weeks following surgery. The newly formed bone was uniform within ABGS implants resulting in a biomechanically competent and histologically qualified fusion with an optimum dose in the range of 100 g rhBMP6 per mL ABC, while in the implants that contained ALLO, the mineralized bone particles were substituted by the newly formed remodeling bone via creeping substitution. These findings demonstrate for the first time that ABGS (rhBMP6/ABC) without and with ALLO particles induced a robust bone formation with a successful fusion in sheep models of ALIF and PLF, and that autologous blood coagulum (ABC) serves as a preferred physiological native carrier to induce new bone at low doses of rhBMP6 and to achieve a successful spinal fusion