Books on the topic 'Metabolic indicators'

Maximal oxygen uptake ( V O 2 · max), the highest rate at which an individual can consume O2 during exercise, is widely recognized as the best single measure of adults’ aerobic fitness.1,2 Maximal V O 2 · ultimately limits an individual’s capacity to perform aerobic exercise but it does not describe fully all aspects of aerobic fitness. The transient kinetics of V O 2 · best reflect the integrated response of the O2 delivery system and the metabolic requirements of the exercising muscle to rapid changes in exercise intensity. Furthermore, V O 2 · max is not the best index of an individual’s ability to sustain submaximal aerobic exercise and despite its derivation from anaerobic metabolism, measures of blood lactate accumulation during submaximal exercise provide useful indicators of aerobic fitness.As the assessment of V O 2 · kinetics is addressed in Chapter 22, in this chapter, we will focus on the assessment of V O 2 · max and blood lactate accumulation.

Sleep disorders are associated with several morbidities, most strongly with psychiatric disorders, cognitive impairment, and impaired quality of life, as well as with increased mortality. Sleep problems are common across the lifespan from childhood to adolescence and adulthood. Physiological sleep continuity with respect to circadian rhythms is considered to be important for the maintenance of cardiovascular, metabolic, and immune function, physiological homeostasis, and psychological balance. Nowadays, it is reasonable to include sleep disturbances among the top 10 potentially modifiable cardiovascular disease (CVD) risk factors. The links between sleep disorders and morbidity as CVD show bidirectional associations. Because these disorders are chronic, they may also have a deleterious societal impact on a patient’s employment status, ability to work, risk of accident, and health. The relationship between work performance and sleep quality is reciprocal and potentially complex. This chapter illustrates the principal sleep disorders and their relevance as indicators of health status.

Accumulating evidence indicates that cancer is a type of mitochondrial metabolic disease. Chronic damage to mitochondria causes a gradual shift in cellular energy metabolism from respiration to fermentation. Consequently, fermentable metabolites become the drivers of cancer. Mitochondrial injury can explain the long-standing “oncogenic paradox,” and all major hallmarks of cancer including genomic instability. Restriction of fermentable fuels therefore becomes a viable therapeutic strategy for cancer management. The ketogenic diet (KD) is a metabolic therapy that lowers blood glucose and elevates blood ketone bodies. Ketone bodies are a “super fuel” for functional mitochondria, but cannot be metabolized efficiently by tumor mitochondria. The efficacy of KDs for cancer management can be enhanced when used together with drugs and procedures (such as hyperbaric oxygen therapy) (that further target fermentation. Therapeutic ketosis can represent an alternative, nontoxic strategy for managing and preventing a broad range of cancers while reducing healthcare costs.

Metabolic syndrome is defined as the co-occurrence of metabolic risk factors for both type 2 diabetes and cardiovascular disease (i.e. abdominal obesity, hyperglycemia, dyslipidemia, and hypertension). Indeed, metabolic syndrome is an important risk factor for subsequent development of type 2 diabetes and/or CVD. Thus, the key clinical implication of a diagnosis of metabolic syndrome is the identification of a patient who needs aggressive lifestyle modification focused on weight reduction and increased physical activity. Multiple different phenotypes and ethnic-specific values for waist circumference are included within metabolic syndrome, with indications for differing treatment strategies. This book covers several aspects of metabolic syndrome, including its definition, diagnostic criteria, preventive measures, and treatment, as well as the possible association between ethnicity and the occurrence of metabolic syndrome.

The ketogenic diet is a metabolic therapy that provides an alternative strategy for seizure control in medication-resistant epilepsy. Many decades of continued use of diet therapy, amassing consistent observational evidence, was recently supported by a randomized, controlled study indicating benefit of diet treatment in children with refractory epilepsy as compared with a control group who continued with standard of care and delayed diet treatment for three months. Well-established uses include children with refractory, nonsurgical epilepsies and epileptic encephalopathies including infantile spasms and West syndrome, Lennox Gastaut syndrome, and Dravet and Doose syndromes. Current knowledge on the efficacy and role of diet therapy in these conditions are discussed.

Metabolic alkalosis occurs in up 51% of abnormal acid-base samples in the hospital. It is characterized by a primary increase in bicarbonate concentration and is always associated with chloride depletion. In critically-ill patients, it is most often generated by diuretic administration, digestive losses, alkali administration, or rapid correction of hypercapnia. Even after all causal factor are removed, it can be maintained by blood volume depletion and potassium depletion. Metabolic alkalosis results in hypercapnia, hypoxaemia, cardiac arrhythmias, altered consciousness, and neuromuscular hyperexcitability. It is first treated by removing the causal factors, whenever possible. Maintaining factors must be reversed by sodium chloride and/or potassium chloride administration. Acetazolamide and renal replacement therapy, when given for specific indications, can also correct the alkalosis. Lysine and arginine chloride are no longer used. If metabolic alkalosis is severe or when other treatments are contraindicated or ineffective, hydrochloric acid infusion is useful. Dilute hydrochloric acid can be infused safely, provided adequate precautions are taken to prevent extravascular leakage, vessel damage, and tissue necrosis.

Peak V · O 2 limits the child’s capacity to perform aerobic exercise but it does not describe fully all aspects of aerobic fitness. Exercise of the intensity and duration required to elicit peak V · O 2 is rarely experienced by many young people.17,18 The vast majority ofhabitual physical activity is submaximal and of short duration and, under these circumstances, it is the transient kinetics of V · O 2 which reflect the integrated response of the oxygen delivery system and the metabolic requirements of the exercising muscle.19–21 Furthermore, peak V · O 2 is neither the best measure of a child’s ability to sustain submaximal aerobic exercise nor the most sensitive means to detect improvements in aerobic fitness after a training programme. Despite its origins in anaerobic metabolism, blood lactate accumulation is a valuable indicator of aerobic fitness and it can be used to monitor improvements in muscle oxidative capacity with exercise training in the absence of changes in peak V · O 2 .16,22 However, as V · O 2 kinetics is comprehensively reviewed in Chapter 22 and blood lactate accumulation during exercise is analysed in Chapter 8, we will focus herein on aerobic fitness as described by peak V · O 2 .

The book presents a novel theory of the origins of mind and consciousness dubbed the Cellular Basis of Consciousness (CBC). It argues that sentience emerged with life itself. The most primitive unicellular species of bacteria are conscious, though it is a sentience of a primitive kind. They have minds, though they are tiny and limited in scope. There is nothing even close to this thesis in the current literature on consciousness. Hints that cells might be conscious can be found in the writings of a few cell biologists, but a fully developed theory has never been put forward before. Other approaches to the origins of consciousness are examined and shown to be seriously or fatally flawed, specifically ones based on: (a) the assumption that minds are computational and can be captured by an artificial intelligence (AI), (b) efforts to discover the neurocorrelates of mental experiences, the so-called Hard Problem, and (c) looking for consciousness in less complex species by identifying those that possess precursors of those neurocorrelates. Each of these approaches is shown to be either essentially impossible (the AI models) or so burdened by philosophical and empirical difficulties that they are effectively unworkable. The CBC approach is developed using standard models of evolutionary biology. The remarkable repertoire of single-celled species that micro- and cell-biologists have discovered is reviewed. Bacteria, for example, have sophisticated sensory and perceptual systems, learn, form memories, make decisions based on information about their environment relative to internal metabolic states, communicate with one another, and even show a primitive form of altruism. All such functions are indicators of sentience. Conversations with a caterpillar function as a literary vehicle Finally, the implications of the CBC model are discussed along with a number of related issues in evolutionary biology, philosophy of mind, the possibility of sentient plants, the ethical repercussions of universal animal sentience, and the long-range impact of adopting the CBC stance.

Nerve biopsy is an important part of the diagnostic armamentarium in the evaluation of a number of diseases, including vasculitis, some hereditary neuropathies, toxic and metabolic neuropathies, inflammatory demyelinating conditions (such as chronic inflammatory demyelinating polyneuropathy), and neoplastic and nonneoplastic infiltrative diseases, such as sarcoidosis, amyloidosis, neurolymphomatosis, and other metastatic tumor infiltration. Options for nerve biopsy include whole-nerve biopsy (e.g., biopsy of the sural nerve, superficial peroneal nerve, or superficial sensory radial nerve) or targeted fascicular biopsy. This chapter identifies indications for nerve biopsy, discusses important considerations for choosing the biopsy target, and explains in detail the surgical procedure for common nerve biopsies.

Arterial blood gases allow the assessment of patient oxygenation, ventilation, and acid-base status. Blood gas machines directly measure pH, and the partial pressures of carbon dioxide (PaCO2) and oxygen (PaO2) dissolved in arterial blood. Oxygenation is assessed by measuring PaO2 and arterial blood oxygen saturation (SaO2) in the context of the inspired oxygen and haemoglobin concentration, and the oxyhaemoglobin dissociation curve. Causes of arterial hypoxaemia may often be elucidated by determining the alveolar–arterial oxygen gradient. Ventilation is assessed by measuring the PaCO2 in the context of systemic acid-base balance. A rise in PaCO2 indicates alveolar hypoventilation, while a decrease indicates alveolar hyperventilation. Given the requirement to maintain a normal pH, functioning homeostatic mechanisms result in metabolic acidosis, triggering a compensatory hyperventilation, while metabolic alkalosis triggers a compensatory reduction in ventilation. Similarly, when primary alveolar hypoventilation generates a respiratory acidosis, it results in a compensatory increase in serum bicarbonate that is achieved in part by kidney bicarbonate retention. In the same way, respiratory alkalosis induces kidney bicarbonate loss. Acid-base assessment requires the integration of clinical findings and a systematic interpretation of arterial blood gas parameters. In clinical use, traditional acid-base interpretation rules based on the bicarbonate buffer system or standard base excess estimations and the interpretation of the anion gap, are substantially equivalent to the physicochemical method of Stewart, and are generally easier to use at the bedside. The Stewart method may have advantages in accurately explaining certain physiological and pathological acid base problems.

The physiology of insulin replacement therapy and the consequences of non-physiological treatment on carbohydrate and fat metabolism are reviewed. Historical aspects of long-acting and short-acting insulins are outlined, and current and future insulin preparations are described, including inhaled insulin. Implementation and refinement of the standard injected multiple dose insulin (MDI) regimen are described in detail. The current status of islet-cell and whole pancreas transplantation, their indications and impact on diabetes complications is reviewed.

Peak oxygen uptake (V̇O2) is the criterion measure of young people's aerobic fitness, and blood lactate accumulation (BLA) is a useful indicator of aerobic fitness with reference to the ability to sustain submaximal exercise. In sport and in everyday life it is the pulmonary (p)V̇O2 kinetics of the non-steady state which best assess the integrated responses of the oxygen delivery system and the metabolic demands of the exercising muscle. Data analysis using sophisticated modelling techniques has enhanced understanding of sexual dimorphism and the independent effects of chronological age, body size, and biological maturity on peak V̇O2 and BLA. The extant data on young people's pV̇O2 kinetic responses to step changes in exercise intensity are sparse, but describe intriguing chronological age and sex differences across exercise domains. However, independent effects of biological maturation are yet to be revealed.

Cardioprotective drugs are important in the treatment of patients at risk for or with documented cardiovascular disease. Beta-blockers are indicated after acute coronary syndromes, stable coronary artery disease, heart failure, and arrhythmias. Angiotensin-converting enzyme inhibitors (ACEi) are important in congestive heart failure, stable angina, post-acute myocardial infarction, and secondary prevention after any event or revascularization. Angiotensin receptor blockers are mainly alternative drugs for the same indications in case of intolerance to ACEi. Calcium channel blockers are first line medication for patients with isolated systolic hypertension, black people, and during pregnancy, in the presence of intermittent claudication, asymptomatic atherosclerosis, or metabolic syndrome. A polypill is a combination pill in which multiple medications effective in the prevention of cardiovascular disease (for example statins, antihypertensives, and aspirin) are put together in a single pill.

Cardioprotective drugs are important in the treatment of patients at risk for or with documented cardiovascular disease. Beta-blockers are indicated after acute coronary syndromes, stable coronary artery disease, heart failure, and arrhythmias. Angiotensin-converting enzyme inhibitors (ACEi) are important in congestive heart failure, stable angina, post-acute myocardial infarction, and secondary prevention after any event or revascularization. Angiotensin receptor blockers are mainly alternative drugs for the same indications in case of intolerance to ACEi. Calcium channel blockers are first line medication for patients with isolated systolic hypertension, black people, and during pregnancy, in the presence of intermittent claudication, asymptomatic atherosclerosis, or metabolic syndrome. A polypill is a combination pill in which multiple medications effective in the prevention of cardiovascular disease (for example statins, antihypertensives, and aspirin) are put together in a single pill.

Respiratory distress in infants may be caused by perinatal events and physiologic changes (e.g., lung immaturity, meconium aspiration, and persistent pulmonary hypertension); infectious processes; cardiovascular, neurologic, and metabolic abnormalities; as well as congenital lung abnormalities. Some of these may coexist, further complicating the diagnosis, clinical course, and management of the affected infant. Sound anesthetic management of congenital lung abnormalities requires a clear understanding of the pathophysiology of lung lesions and, in particular, the consequences of positive-pressure ventilation in patients with cystic and emphysematous lesions. Also critical is an appreciation for the physiologic differences in children undergoing thoracic surgery, indications for one-lung ventilation, age-appropriate lung isolation techniques, potential respiratory and cardiovascular complications that may occur during pediatric thoracic surgery, and the optimal choices for postoperative analgesia.

Traditional fears and misinformed concerns regarding youth resistance training have been replaced by scientific evidence that indicates regular participation in well-designed resistance-training programmes can be safe and effective for both children and adolescents. In addition to increasing muscular strength and power, regular participation in a structured resistance training-programme can increase bone mineral density, improve cardiovascular risk factors, fuel metabolic health, facilitate weight control, enhance psychosocial well-being, and prepare youth for the demands of daily physical activity and sport. An integrative approach to training, grounded in resistance exercise and motor skill development, can optimize children’s fitness potential and maximize their athletic performance while reducing the risk of sports-related injury. Qualified professionals are needed to plan, implement and progress developmentally appropriate resistance training to attain a level of muscular fitness that facilitates long-term physical development.

Ketogenic diets (KD)—high in fat, adequate in protein, and very low in carbohydrates—were developed almost a century ago and are still used clinically for drug-resistant epilepsy and some rare metabolic disorders. Possible new indications for cancers, diabetes, obesity, and neurodegenerative disorders are being trialed in humans based on a growing body of preclinical data showing efficacy. However the underlying mechanisms of KD remain incompletely understood. This chapter focuses on the neuroprotective effects of KD after spinal cord injury (SCI) and traumatic brain injury (TBI), and discusses possible mechanisms of action. It considers the possible role of ketone bodies as alternative fuels for mitochondrial energy utilization and the actions of ketones outside the mitochondria as agonists of antioxidant and anti-inflammatory pathways. It places these into context with the known pathophysiology of SCI and TBI, and discusses possible roles of KD and ketone bodies for their treatment.

Indications for parenteral nutrition 87Parenteral nutrition regimens 87Parenteral nutrition products 89Monitoring of parenteral nutrition 93Complications and their management 94Parenteral nutrition (PN) is the supply of nutrients directly into a vein. The first case report of successful long-term PN (in an infant with small-bowel atresia) was published in 1968; since that time products for PN have been developed and refined with the result that metabolic complications are less common, and use in clinical practice has become widespread. For children with short-bowel syndrome, protracted diarrhoea, or pseudo-obstruction PN has become a life-saving intervention. Although it is also widely used in the premature infant with immaturity of gastrointestinal function, the benefit in these patients is less well defined. This is reflected by wide variation in the approach to PN support on different neonatal units. The main indication for PN is when nutritional status cannot be maintained or restored to normal using enteral feeding....

Chronic kidney disease-mineral and bone disorders (CKD-MBD), calcium, phosphate, and parathyroid hormone are biomarkers of mortality and cardiovascular risk. Hyperphosphataemia is a prominent and pathophysiologically most plausible risk indicator. Calcium balance and load appear to be more important than serum concentrations. Parathyroid hormone is a less reliable marker with a relatively wide range extending above that applicable for a normal population especially when used as a singular laboratory parameter without additional assessment of bone metabolism, for example, bone-specific alkaline phosphatase and bone biopsy. There is not a single prospective controlled hard-outcome study that provides us with unequivocal evidence that such an isolated laboratory parameter-based treatment approach will lead to significant clinical improvements. As CKD-MBD is complex, clinical decisions would be made easier by informative prospective trials.

Neonatal Formulary bridges a gap between a standard formulary (stating doses, indications, etc.) and a standard neonatal textbook by expanding information about the conditions for which each drug is used. Much of drug use during pregnancy, lactation, and in neonates and young infants is ‘off license’ (i.e. using licensed drugs but for an indication that is outside the licensed use—in many cases simply because the studies and the licensing application did not include data about neonatal use). The book offers information to allow practitioners to make informed choices whether to use such a drug or not by presenting data from published studies to support such a use. Part 1 concentrates on drug prescribing and drug administration, presenting general information on drug storage, drug licensing, and drug prescribing. It also explains to the reader why the metabolism of drugs differs in premature and sick infants and why the practice of extrapolating doses from adult studies is wrong. Patient safety, excipients, and therapies that affect drug metabolism (such as therapeutic hypothermia) are also covered. Part 2 consists of drug monographs for over 250 drugs that may find use in the neonatal population but which nonetheless may also find use outside the neonatal unit. Each monograph is divided into sections covering use, pharmacology, treatment, drug interactions, or other administration information, supply, and administration, and references. The monographs also contain links to Cochrane Database of Systematic Reviews and national guidelines supported by bodies such as the National Institute for Health and Care Excellence or the Royal Colleges. Part 3 contains brief notes on a range of additional drugs and groups of drugs that are often taken by mothers during pregnancy, labour, or during breast feeding where effects on either the fetus or infant can be seen. This information will help to provide safe and effective prescribing of drugs to all mothers and their babies.

The well-known severity of cardiovascular disease in patients suffering from chronic kidney disease (CKD) requires an accurate risk stratification of these patients in several clinical situations. Imaging has been used successfully for such purpose in the general population and it has demonstrated excellent potential among CKD patients as well. Two main forms of arterial pathology develop in patients with CKD: atherosclerosis, with accumulation of inflammatory cells, lipids, fibrous tissue and calcium in the subintimal space, and arteriosclerosis. The latter is characterized by accumulation of deposits of hydroxyapatite and amorphous calcium crystals in the muscular media of the vessel wall, and is believed to be more closely associated with alterations of mineral metabolism than with traditional atherosclerosis risk factors. The result is the development of what appears to be premature arterial ageing, with loss of elastic properties, increased stiffness, and increased overall fragility of the arterial system. Despite intensifying research and increasing awareness of these issues, the underlying pathophysiology of the aggressive vasculopathy of CKD remains largely unknown. As a consequence, there are currently very limited pathways to prevent progression of vascular damage in CKD. The indications, strengths and weaknesses of several imaging modalities employed to evaluate vascular disease in CKD are described, focusing on coronary arterial circulation and the peripheral arteries, with the exclusion of the intracranial arteries.

Current applications of cardiac magnetic resonance offer a wide spectrum of indications in the setting of acute cardiac care. In particular, cardiac magnetic resonance is helpful for the differential diagnosis of chest pain by the detection of ischaemia, myocardial stunning, myocarditis, and pericarditis. Also, Takotsubo cardiomyopathy and acute aortic diseases can be evaluated by cardiac magnetic resonance and are important differential diagnoses in patients with acute chest pain. In patients with restricted windows for echocardiography, according to guidelines, cardiac magnetic resonance is the method of choice to evaluate complications of an acute myocardial infarction. In an acute myocardial infarction, cardiac magnetic resonance allows for a unique characterization of myocardial damage by quantifying necrosis, microvascular obstruction, oedema (i.e. area at risk), and haemorrhage. These features will help us to understand better the pathophysiological events during infarction and will also allow us to assess new treatment strategies in acute myocardial infarction. To which extent the information on tissue damage will guide patient management is not yet clear, and further research, e.g. in the setting of the European Cardiovascular MR registry, is ongoing to address this issue. Recent studies also demonstrated the possiblity to reduce costs in the management of acute coronary syndromes when cardiac magnetic resonance is integrated into the routine work-up. In the near future, applications of cardiac magnetic resonance will continue to expand in the acute cardiac care units, as manufacturers are now strongly focusing on this aspect of user-friendliness. Finally, in the next decade or so, magnetic resonance imaging of other nuclei, such as fluorine and carbon, might become a reality in clinics, which would allow for metabolic and targeted molecular imaging with excellent sensitivity and specificity.

Current applications of cardiac magnetic resonance offer a wide spectrum of indications in the setting of acute cardiac care. In particular, cardiac magnetic resonance is helpful for the differential diagnosis of chest pain by the detection of ischaemia, myocardial stunning, myocarditis, and pericarditis. Also, Takotsubo cardiomyopathy and acute aortic diseases can be evaluated by cardiac magnetic resonance and are important differential diagnoses in patients with acute chest pain. In patients with restricted windows for echocardiography, according to guidelines, cardiac magnetic resonance is the method of choice to evaluate complications of an acute myocardial infarction. In an acute myocardial infarction, cardiac magnetic resonance allows for a unique characterization of myocardial damage by quantifying necrosis, microvascular obstruction, oedema (i.e. area at risk), and haemorrhage. These features will help us to understand better the pathophysiological events during infarction and will also allow us to assess new treatment strategies in acute myocardial infarction. To which extent the information on tissue damage will guide patient management is not yet clear, and further research, e.g. in the setting of the European Cardiovascular MR registry, is ongoing to address this issue. Recent studies also demonstrated the possiblity to reduce costs in the management of acute coronary syndromes when cardiac magnetic resonance is integrated into the routine work-up. In the near future, applications of cardiac magnetic resonance will continue to expand in the acute cardiac care units, as manufacturers are now strongly focusing on this aspect of user-friendliness. Finally, in the next decade or so, magnetic resonance imaging of other nuclei, such as fluorine and carbon, might become a reality in clinics, which would allow for metabolic and targeted molecular imaging with excellent sensitivity and specificity.

Current applications of cardiac magnetic resonance offer a wide spectrum of indications in the setting of acute cardiac care. In particular, cardiac magnetic resonance is helpful for the differential diagnosis of chest pain by the detection of ischaemia, myocardial stunning, myocarditis, and pericarditis. Also, Takotsubo cardiomyopathy and acute aortic diseases can be evaluated by cardiac magnetic resonance and are important differential diagnoses in patients with acute chest pain. In patients with restricted windows for echocardiography, according to guidelines, cardiac magnetic resonance is the method of choice to evaluate complications of an acute myocardial infarction. In an acute myocardial infarction, cardiac magnetic resonance allows for a unique characterization of myocardial damage by quantifying necrosis, microvascular obstruction, oedema (i.e. area at risk), and haemorrhage. These features will help us to understand better the pathophysiological events during infarction and will also allow us to assess new treatment strategies in acute myocardial infarction. To which extent the information on tissue damage will guide patient management is not yet clear, and further research, e.g. in the setting of the European Cardiovascular MR registry, is ongoing to address this issue. Recent studies also demonstrated the possiblity to reduce costs in the management of acute coronary syndromes when cardiac magnetic resonance is integrated into the routine work-up. In the near future, applications of cardiac magnetic resonance will continue to expand in the acute cardiac care units, as manufacturers are now strongly focusing on this aspect of user-friendliness. Finally, in the next decade or so, magnetic resonance imaging of other nuclei, such as fluorine and carbon, might become a reality in clinics, which would allow for metabolic and targeted molecular imaging with excellent sensitivity and specificity.

Bones are multifunctional passive organs of movement that supports soft tissue and directly attached muscles. They also protect internal organs and are a reserve of calcium, phosphorus and magnesium. Each bone is covered with periosteum, and the adjacent bone surfaces are covered by articular cartilage. Histologically, the bone is an organ composed of many different tissues. The main component is bone tissue (cortical and spongy) composed of a set of bone cells and intercellular substance (mineral and organic), it also contains fat, hematopoietic (bone marrow) and cartilaginous tissue. Bones are a tissue that even in adult life retains the ability to change shape and structure depending on changes in their mechanical and hormonal environment, as well as self-renewal and repair capabilities. This process is called bone turnover. The basic processes of bone turnover are: • bone modeling (incessantly changes in bone shape during individual growth) following resorption and tissue formation at various locations (e.g. bone marrow formation) to increase mass and skeletal morphology. This process occurs in the bones of growing individuals and stops after reaching puberty • bone remodeling (processes involve in maintaining bone tissue by resorbing and replacing old bone tissue with new tissue in the same place, e.g. repairing micro fractures). It is a process involving the removal and internal remodeling of existing bone and is responsible for maintaining tissue mass and architecture of mature bones. Bone turnover is regulated by two types of transformation: • osteoclastogenesis, i.e. formation of cells responsible for bone resorption • osteoblastogenesis, i.e. formation of cells responsible for bone formation (bone matrix synthesis and mineralization) Bone maturity can be defined as the completion of basic structural development and mineralization leading to maximum mass and optimal mechanical strength. The highest rate of increase in pig bone mass is observed in the first twelve weeks after birth. This period of growth is considered crucial for optimizing the growth of the skeleton of pigs, because the degree of bone mineralization in later life stages (adulthood) depends largely on the amount of bone minerals accumulated in the early stages of their growth. The development of the technique allows to determine the condition of the skeletal system (or individual bones) in living animals by methods used in human medicine, or after their slaughter. For in vivo determination of bone properties, Abstract 10 double energy X-ray absorptiometry or computed tomography scanning techniques are used. Both methods allow the quantification of mineral content and bone mineral density. The most important property from a practical point of view is the bone’s bending strength, which is directly determined by the maximum bending force. The most important factors affecting bone strength are: • age (growth period), • gender and the associated hormonal balance, • genotype and modification of genes responsible for bone growth • chemical composition of the body (protein and fat content, and the proportion between these components), • physical activity and related bone load, • nutritional factors: – protein intake influencing synthesis of organic matrix of bone, – content of minerals in the feed (CA, P, Zn, Ca/P, Mg, Mn, Na, Cl, K, Cu ratio) influencing synthesis of the inorganic matrix of bone, – mineral/protein ratio in the diet (Ca/protein, P/protein, Zn/protein) – feed energy concentration, – energy source (content of saturated fatty acids - SFA, content of polyun saturated fatty acids - PUFA, in particular ALA, EPA, DPA, DHA), – feed additives, in particular: enzymes (e.g. phytase releasing of minerals bounded in phytin complexes), probiotics and prebiotics (e.g. inulin improving the function of the digestive tract by increasing absorption of nutrients), – vitamin content that regulate metabolism and biochemical changes occurring in bone tissue (e.g. vitamin D3, B6, C and K). This study was based on the results of research experiments from available literature, and studies on growing pigs carried out at the Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences. The tests were performed in total on 300 pigs of Duroc, Pietrain, Puławska breeds, line 990 and hybrids (Great White × Duroc, Great White × Landrace), PIC pigs, slaughtered at different body weight during the growth period from 15 to 130 kg. Bones for biomechanical tests were collected after slaughter from each pig. Their length, mass and volume were determined. Based on these measurements, the specific weight (density, g/cm3) was calculated. Then each bone was cut in the middle of the shaft and the outer and inner diameters were measured both horizontally and vertically. Based on these measurements, the following indicators were calculated: • cortical thickness, • cortical surface, • cortical index. Abstract 11 Bone strength was tested by a three-point bending test. The obtained data enabled the determination of: • bending force (the magnitude of the maximum force at which disintegration and disruption of bone structure occurs), • strength (the amount of maximum force needed to break/crack of bone), • stiffness (quotient of the force acting on the bone and the amount of displacement occurring under the influence of this force). Investigation of changes in physical and biomechanical features of bones during growth was performed on pigs of the synthetic 990 line growing from 15 to 130 kg body weight. The animals were slaughtered successively at a body weight of 15, 30, 40, 50, 70, 90, 110 and 130 kg. After slaughter, the following bones were separated from the right half-carcass: humerus, 3rd and 4th metatarsal bone, femur, tibia and fibula as well as 3rd and 4th metatarsal bone. The features of bones were determined using methods described in the methodology. Describing bone growth with the Gompertz equation, it was found that the earliest slowdown of bone growth curve was observed for metacarpal and metatarsal bones. This means that these bones matured the most quickly. The established data also indicate that the rib is the slowest maturing bone. The femur, humerus, tibia and fibula were between the values of these features for the metatarsal, metacarpal and rib bones. The rate of increase in bone mass and length differed significantly between the examined bones, but in all cases it was lower (coefficient b <1) than the growth rate of the whole body of the animal. The fastest growth rate was estimated for the rib mass (coefficient b = 0.93). Among the long bones, the humerus (coefficient b = 0.81) was characterized by the fastest rate of weight gain, however femur the smallest (coefficient b = 0.71). The lowest rate of bone mass increase was observed in the foot bones, with the metacarpal bones having a slightly higher value of coefficient b than the metatarsal bones (0.67 vs 0.62). The third bone had a lower growth rate than the fourth bone, regardless of whether they were metatarsal or metacarpal. The value of the bending force increased as the animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. The rate of change in the value of this indicator increased at a similar rate as the body weight changes of the animals in the case of the fibula and the fourth metacarpal bone (b value = 0.98), and more slowly in the case of the metatarsal bone, the third metacarpal bone, and the tibia bone (values of the b ratio 0.81–0.85), and the slowest femur, humerus and rib (value of b = 0.60–0.66). Bone stiffness increased as animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. Abstract 12 The rate of change in the value of this indicator changed at a faster rate than the increase in weight of pigs in the case of metacarpal and metatarsal bones (coefficient b = 1.01–1.22), slightly slower in the case of fibula (coefficient b = 0.92), definitely slower in the case of the tibia (b = 0.73), ribs (b = 0.66), femur (b = 0.59) and humerus (b = 0.50). Bone strength increased as animals grew. Regardless of the growth point tested, bone strength was as follows femur > tibia > humerus > 4 metacarpal> 3 metacarpal> 3 metatarsal > 4 metatarsal > rib> fibula. The rate of increase in strength of all examined bones was greater than the rate of weight gain of pigs (value of the coefficient b = 2.04–3.26). As the animals grew, the bone density increased. However, the growth rate of this indicator for the majority of bones was slower than the rate of weight gain (the value of the coefficient b ranged from 0.37 – humerus to 0.84 – fibula). The exception was the rib, whose density increased at a similar pace increasing the body weight of animals (value of the coefficient b = 0.97). The study on the influence of the breed and the feeding intensity on bone characteristics (physical and biomechanical) was performed on pigs of the breeds Duroc, Pietrain, and synthetic 990 during a growth period of 15 to 70 kg body weight. Animals were fed ad libitum or dosed system. After slaughter at a body weight of 70 kg, three bones were taken from the right half-carcass: femur, three metatarsal, and three metacarpal and subjected to the determinations described in the methodology. The weight of bones of animals fed aa libitum was significantly lower than in pigs fed restrictively All bones of Duroc breed were significantly heavier and longer than Pietrain and 990 pig bones. The average values of bending force for the examined bones took the following order: III metatarsal bone (63.5 kg) <III metacarpal bone (77.9 kg) <femur (271.5 kg). The feeding system and breed of pigs had no significant effect on the value of this indicator. The average values of the bones strength took the following order: III metatarsal bone (92.6 kg) <III metacarpal (107.2 kg) <femur (353.1 kg). Feeding intensity and breed of animals had no significant effect on the value of this feature of the bones tested. The average bone density took the following order: femur (1.23 g/cm3) <III metatarsal bone (1.26 g/cm3) <III metacarpal bone (1.34 g / cm3). The density of bones of animals fed aa libitum was higher (P<0.01) than in animals fed with a dosing system. The density of examined bones within the breeds took the following order: Pietrain race> line 990> Duroc race. The differences between the “extreme” breeds were: 7.2% (III metatarsal bone), 8.3% (III metacarpal bone), 8.4% (femur). Abstract 13 The average bone stiffness took the following order: III metatarsal bone (35.1 kg/mm) <III metacarpus (41.5 kg/mm) <femur (60.5 kg/mm). This indicator did not differ between the groups of pigs fed at different intensity, except for the metacarpal bone, which was more stiffer in pigs fed aa libitum (P<0.05). The femur of animals fed ad libitum showed a tendency (P<0.09) to be more stiffer and a force of 4.5 kg required for its displacement by 1 mm. Breed differences in stiffness were found for the femur (P <0.05) and III metacarpal bone (P <0.05). For femur, the highest value of this indicator was found in Pietrain pigs (64.5 kg/mm), lower in pigs of 990 line (61.6 kg/mm) and the lowest in Duroc pigs (55.3 kg/mm). In turn, the 3rd metacarpal bone of Duroc and Pietrain pigs had similar stiffness (39.0 and 40.0 kg/mm respectively) and was smaller than that of line 990 pigs (45.4 kg/mm). The thickness of the cortical bone layer took the following order: III metatarsal bone (2.25 mm) <III metacarpal bone (2.41 mm) <femur (5.12 mm). The feeding system did not affect this indicator. Breed differences (P <0.05) for this trait were found only for the femur bone: Duroc (5.42 mm)> line 990 (5.13 mm)> Pietrain (4.81 mm). The cross sectional area of the examined bones was arranged in the following order: III metatarsal bone (84 mm2) <III metacarpal bone (90 mm2) <femur (286 mm2). The feeding system had no effect on the value of this bone trait, with the exception of the femur, which in animals fed the dosing system was 4.7% higher (P<0.05) than in pigs fed ad libitum. Breed differences (P<0.01) in the coross sectional area were found only in femur and III metatarsal bone. The value of this indicator was the highest in Duroc pigs, lower in 990 animals and the lowest in Pietrain pigs. The cortical index of individual bones was in the following order: III metatarsal bone (31.86) <III metacarpal bone (33.86) <femur (44.75). However, its value did not significantly depend on the intensity of feeding or the breed of pigs.