The effect of table olive wastewater extract administration on the adult ovariectomised rat model of osteoporosis.

Recent efforts for alternative non-pharmaceutical treatments for postmenopausal osteoporosis are focused on nutritional measures. The aim of this study was to investigate the effect of table olive wastewater extract (OE) administration on bone mineral density (BMD) and biomechanical strength in ovariectomised rats. Thirty mature 9-month-old female Wistar rats were separated into three groups of ten: Control, Ovariectomised (OVX) and OVX + OE. BMD was measured before ovariectomy, 3 and 6 months afterwards. At the end of the study, blood, both femurs and tibias, internal organs and abdominal fat were collected. After 3 months, the percentage changes from baseline of the total and proximal tibial BMD of the OVX + OE group were both higher compared with the OVX group (P < 0·005). Similar results were found after 6 months, when the percentage changes from baseline of the total and proximal tibial BMD of the OVX + OE group were both higher compared with the OVX group (P < 0·005). Biomechanical testing of the femurs did not reveal any statistically significant difference between the groups. Body weights throughout the study, organs' and abdominal fat ratios to final body weight and blood results (alanine aminotransferase (ALT), gamma-glutamyltransferase (γ-GT), total cholesterol, HDL-cholesterol, LDL-cholesterol, Ca and P) were within normal limits and did not show any significant difference between the treated and untreated groups. As a conclusion, the administration of OE for 6 months protected tibial BMD loss in comparison with the untreated OVX group without causing adverse effects.

Effects of mechanical loading on the expression of pleiotrophin and its receptor protein tyrosine phosphatase beta/zeta in a rat spinal deformity model.

Mechanical loading of the spine is a major causative factor of degenerative changes and causes molecular and structural changes in the intervertebral disc (IVD) and the vertebrae end plate (EP). Pleiotrophin (PTN) is a growth factor with a putative role in bone remodeling through its receptor protein tyrosine phosphatase beta/zeta (RPTPß/ζ). The present study investigates the effects of strain on PTN and RPTPß/ζ protein expression in vivo. Tails of eight weeks old Sprague-Dawley rats were subjected to mechanical loading using a mini Ilizarov external apparatus. Rat tails untreated (control) or after 0 degrees of compression and 10°, 30° and 50° of angulation (groups 0, I, II and III respectively) were studied. PTN and RPTPß/ζ expression were evaluated using immunohistochemistry and Western blot analysis. In the control group, PTN was mostly expressed by the EP hypertrophic chondrocytes. In groups 0 to II, PTN expression was increased in the chondrocytes of hypertrophic and proliferating zones, as well as in osteocytes and osteoblast-like cells of the ossification zone. In group III, only limited PTN expression was observed in osteocytes. RPTPß/ζ expression was increased mainly in group 0, but also in group I, in all types of cells. Low intensity RPTPß/ζ immunostaining was observed in groups II and III. Collectively, PTN and RPTPß/ζ are expressed in spinal deformities caused by mechanical loading, and their expression depends on the type and severity of the applied strain.

Refined induction of anesthesia with remifentanil after bolus propofol administration in Landrace/Large White swine.

The authors report a prospective randomized blind study in which they used a refined anesthetic technique in male Landrace/Large White swine (n = 125 pigs, 19 ± 2 kg, 10-15 weeks old). The animals were first premedicated with ketamine, midazolam and atropine and then given a dose of 1, 2, 3, 4 or 5 µg remifentanil per kg body weight (dose amounts were randomly assigned) after a bolus dose of propofol. The authors assessed the intubation conditions (e.g., jaw relaxation and other parameters) 20 min after premedication and then 5 min after anesthesia induction. All animals that received each of the different remifentanil dose amounts were successfully intubated in less than 30 s. No animal developed apnea during intubation or experienced substantial reductions in heart rate or blood pressure (> 25%) between the two time points (20 min after premedication and 5 min after anesthesia induction). Overall intubation conditions were significantly better in animals that received 5 µg remifentanil per kg body weight than in animals that received other dose amounts (P < 0.001). The average time to intubation was significantly shorter for animals that received 5 µg remifentanil per kg body weight than for animals that received any of the other dose amounts (P < 0.001). The authors concluded that for this study, 5 µg remifentanil per kg body weight resulted in excellent intubating conditions in this swine breed.

The laboratory rat as an animal model for osteoporosis research.

Osteoporosis is an important systemic disorder, affecting mainly Caucasian women, with a diverse and multifactorial etiology. A large variety of animal species, including rodents, rabbits, dogs, and primates, have been used as animal models in osteoporosis research. Among these, the laboratory rat is the preferred animal for most researchers. Its skeleton has been studied extensively, and although there are several limitations to its similarity to the human condition, these can be overcome through detailed knowledge of its specific traits or with certain techniques. The rat has been used in many experimental protocols leading to bone loss, including hormonal interventions (ovariectomy, orchidectomy, hypophysectomy, parathyroidectomy), immobilization, and dietary manipulations. The aim of the current review is not only to present the ovariectomized rat and its advantages as an appropriate model for the research of osteoporosis, but also to provide information about the most relevant age and bone site selection according to the goals of each experimental protocol. In addition, several methods of bone mass evaluation are assessed, such as biochemical markers, densitometry, histomorphometry, and bone mechanical testing, that are used for monitoring and evaluation of this animal model in preventive or therapeutic strategies for osteoporosis.

A comparative anatomic and physiologic overview of the porcine heart.

Despite advances during the last 2 decades in every aspect of cardiovascular research (interventional cardiology, cardiopulmonary resuscitation, and so forth), Western societies still are plagued by the consequences of cardiovascular disease. Consequently the discovery of new regimens and therapeutic interventions is of utmost importance. Research using human subjects is associated with substantial methodologic and ethical considerations, and the quest for an appropriate animal model for the human cardiovascular system has led to swine. The porcine heart bears a close resemblance to the human heart in terms of its coronary circulation and hemodynamic similarities and offers ease of implementation of methods and devices from human healthcare facilities. A thorough comprehension of the anatomy and physiology of the porcine cardiovascular system should focus on differences between swine and humans as well as similarities. Understanding these differences and similarities is essential to extrapolating data appropriately and to addressing the social demand for the ethical use of animals in biomedical research.

Protective effect of Sideritis euboea extract on bone mineral density and strength of ovariectomized rats.

OBJECTIVE: The aim of this study was to investigate the potential protective effect of Sideritis euboea extract (SID), commonly consumed as "mountain tea," on bone mineral density (BMD) and the strength of the ovariectomized (OVX) rat model of osteoporosis. METHODS: Thirty-two 10-month-old Wistar rats were separated into controls (sham operated), OVX, and OVX plus SID in their drinking water (dose, 330 mg/kg body weight per day), starting immediately after OVX for 6 months. Tibial BMD at baseline and at 3 and 6 months post-OVX, three-point-bending of the femur, and body and uterine weight at the study end were examined. RESULTS: BMD percentage change from baseline of the whole tibia was similar in control and OVX + SID rats at 3 months (-3.02% vs -4.67%, P = not significant), revealing a strong osteoprotective effect. At 6 months, the corresponding changes were -6.02% versus -14.37%, P < 0.05, indicating a greater bone loss in treated rats, albeit significantly less than the OVX change (-20.46%; OVX vs OVX + SID, P < 0.05). The proximal (metaphyseal) tibial BMD percentage change from baseline to 3 and 6 months between the OVX and OVX + SID groups (-26.47% vs -15.57% and -31.22% vs -16.57%, respectively) was statistically significant, demonstrating that SID preserved the proximal tibial BMD of the OVX + SID group significantly. Three-point-bending showed a significant increase in the treated compared with the OVX groups. Body and uterine weights were similar in the OVX and treated groups. CONCLUSIONS: SID significantly protected tibial bone loss and improved femoral biomechanical strength in OVX + SID rats compared with OVX rats.