Książki na temat „Biochemical Investigations”

Investigating problems that present to emergency and urgent care areas is a crucial part of patient assessment and diagnosis. This chapter covers the common haematological, biochemical, and radiological investigations that may be required to accurately diagnose a patient’s problems. The common causes of abnormalities are listed for easy reference.

In this chapter an overview is provided of the investigations used in patients with systemic lupus erythematosus (SLE); these establish the abnormalities that can be found in each organ/system. Lupus is a very heterogeneous condition, affecting virtually every organ/system. In consequence, numerous investigations and tests are used to help make the diagnosis and define the extent of the organ/system involvement. The chapter is divided into investigations of the effects of SLE on the following systems: haematological, immunological, biochemical, renal, cardiovascular, pulmonary, gastroenterological, neurological, dermatological, and musculoskeletal. These targeted organ/system-based investigations can then be used to assess ongoing disease activity or the consequence of damage caused by previously active disease.

It is important for rheumatologists to have an understanding of biochemical tests including an awareness of their limitations. The biological variability of an analyte both within and between individuals, the limitations of the measurement technology, the sensitivity of laboratory internal quality control and external quality assurance procedures, as well as interlaboratory variations in practices including sample collection procedures, may all impact on the interpretation of a result. Biochemical tests are often requested to monitor organ-specific dysfunction arising as an adverse consequence of pharmacotherapy or as a component of a systemic rheumatic disease, although dysfunction may also reflect infection or coincidental pathology. Patients with rheumatic diseases are at high risk of renal and hepatic disease. Serum creatinine and its derivative estimated glomerular filtration rate (eGFR) are the most readily available surrogate markers of GFR and are used to assess renal impairment and monitor its course. However, the use of creatinine alone lacks sensitivity and a substantial loss of function must occur before creatinine levels are increased. Additional biochemical screening for kidney damage can be performed by assessment of glomerular integrity, including proteinuria or albuminuria and haematuria. A wide spectrum of rheumatic diseases can affect the liver with various degrees of involvement and hepatic pathology. These often present with cholestatic or hepatitic biochemical profiles. The medical management of rheumatic diseases also involves medications that are hepatotoxic, and routine monitoring of liver function is recommended. This approach is not problem-free and may be improved by quantitative determinations of non-invasive markers of liver fibrosis in the future. Together with imaging techniques, biochemical tests play an important role in the assessment and differential diagnosis of metabolic bone disease.

This chapter provides a brief overview of the more commonly available neurophysiology and neuroradiology techniques, guidance on how to perform a lumbar puncture, and a summary of biochemical, immunological, and genetic tests relevant to neurological disorders.

The lysosomal storage disorders (LSDs) are a group of inborn organelle disorders, clinically heterogeneous, and biochemically characterized by accumulation of nondegraded macromolecules primarily in the lysosomal and other cellular compartments. Given the common and essential cellular function of the lysosomal system in different organs and systems, patients afflicted with these disorders present a broad range of clinical problems, including neurological problems, visceromegaly, and skeletal deformities. Onset of symptoms may range from fetal period to adulthood. The neurological problems include developmental delay, seizures, acroparesthesia, motor weakness, muscle wasting, behavioral/psychiatric disturbances, cerebrovascular ischemic events, and extrapyramidal signs. Patients may present with symptoms later that include psychiatric manifestations, are slowly progressive, and may precede other neurologic or systemic features. Most of LSDs are autosomal recessive; however, a few are X-linked with symptpmatic female carriers (e.g., Fabry disease). In most of them, the diagnosis is established by biochemical and/or molecular assays. In terms of management, disease-modifying therapies include enzyme replacement, hematopoietic stem cell transplantation, and substrate reduction therapy. Patients and their families require genetic counseling regarding reproductive risks, disease prognosis, and therapeutic options. Investigations of disease molecular mechanisms provide insights into potential targets for the development of therapeutic strategies. Supportive care has been the key and essential for most LSDs, resulting in substantial improvement in quality of life of patients and families.

AbstractSystemic lupus erythematosus (SLE) is a chronic, relapsing, inflammatory, often febrile multisystemic disorder, characterized by involvement of the skin, joints, visceral organs, and serosal membranes. Symptoms and manifestations vary widely over an unpredictable relapsing and remitting course.The presentation of SLE can range from mild forms to severe disease requiring hospitalization. Most commonly it manifests as a combination of constitutional symptoms, particularly fatigue and fever, with cutaneous, musculoskeletal, mild haematological, and serological involvement; however, when renal, haematological or central nervous system disease predominate it can be more severe, even life-threatening. There is a tendency for the disease pattern present at the time of onset to prevail during subsequent exacerbations.Investigating SLE depends to an extent on the presentation of the individual. However a number of haematological, biochemical and immunological investigations provide useful diagnostic information, either for the disease itself or in context of organ system involvement, and should be performed routinely.The presence of lupus nephritis should be considered in any lupus patient with impaired kidney function, proteinuria, hypertension, or an active urine sediment; the gold standard investigation in this context is a kidney biopsy. Glomerular immune complex deposition is the hallmark of lupus nephritis and underpins the International society of Nephrology/Renal Pathology Society classification of lupus nephritis.The diagnosis of SLE is based upon the presence of clinical and/or laboratory features and immunological markers that meet the various published diagnostic criteria. In 2012, lupus nephritis identified on kidney biopsy became an independent diagnostic criterion.This chapter goes through the clinical manifestations, investigations (including a detailed look at the kidney biopsy) and a review of the latest published diagnostic criteria.

A practical step-by-step guide to the aetiology, clinical features, differential diagnosis, investigation and appropriate management of common biochemical emergencies in patients with uderlyng malignancies.

In clinical practice, laboratory tests play a major role in the investigation of underlying diseases predisposing to osteoarthritis (OA) (e.g. metabolic and genetic causes) and in the differential diagnosis of other joint disorders, particularly autoimmune and crystal-related arthropathies. In terms of diagnosis and management of OA, there is still no recommendation in guidelines for the use of laboratory tests. However, an increasing number of potential applications of laboratory tests in OA are emerging. In this regard, research investigating the role of vitamin D and other substances such as inflammatory markers, cytokines, and adipokines in the OA process is helping to reveal novel pathophysiologic mechanisms and, consequently, new possible therapeutic approaches. Furthermore, biochemical markers of cartilage, bone, and synovium metabolism is a growing field in OA and may also contribute to the diagnosis of early OA stages, assessment of prognosis, and management, once properly validated.

Disorders of bone mineralization cause rickets in children and osteomalacia in adults. Both remain common in developing countries. Incidence in Western countries had declined since the fortification of foodstuffs, but appears to be increasing again. Calcium and inorganic phosphate are the key precursors for bone mineralization and growth. The commonest aetiology of osteomalacia is vitamin D deficiency, primarily due to low dietary intake and inadequate sun exposure. In the last decade gene mutations have been identified that are responsible for inherited rickets and osteomalacia, particularly those that result in phosphate deficiency, hypophosphatasia, and vitamin D receptor or metabolizing enzyme mutations. Additionally, the pathogenesis of tumour-induced osteomalacia is becoming better understood. Osteomalacia may present as bone pain and tenderness, muscle pain and weakness, and skeletal deformity or fracture. Key investigations include biochemical assessment and plain radiographs. Radioisotope bone scans and bone biopsy may be considered in selected cases. Differential diagnoses include osteoporosis, seronegative arthritides, and localized soft tissue disorders. Treatment, guided by the underlying aetiology, aims to reduce symptoms, fracture risk, bone deformity and sequelae. Vitamin D deficient patients require vitamin D and calcium replacement.

Disorders of bone mineralization cause rickets in children and osteomalacia in adults. Both remain common in developing countries. Incidence in Western countries had declined since the fortification of foodstuffs, but appears to be increasing again. Calcium and inorganic phosphate are the key precursors for bone mineralization and growth. The commonest aetiology of osteomalacia is vitamin D deficiency, primarily due to low dietary intake and inadequate sun exposure. In the last decade gene mutations have been identified that are responsible for inherited rickets and osteomalacia, particularly those that result in phosphate deficiency, hypophosphatasia, and vitamin D receptor or metabolizing enzyme mutations. Additionally, the pathogenesis of tumour-induced osteomalacia is becoming better understood. Osteomalacia may present as bone pain and tenderness, muscle pain and weakness, and skeletal deformity or fracture. Key investigations include biochemical assessment and plain radiographs. Radioisotope bone scans and bone biopsy may be considered in selected cases. Differential diagnoses include osteoporosis, seronegative arthritides, and localized soft tissue disorders. Treatment, guided by the underlying aetiology, aims to reduce symptoms, fracture risk, bone deformity and sequelae. Vitamin D deficient patients require vitamin D and calcium replacement.

Hyperhomocysteinaemia (HHC) may occur as a result of a variety of inherited and acquired conditions ranging from mild and benign to severe and life threatening, and there is a higher probability that they will first manifest during early adulthood rather than infancy, with acquired forms commonly presenting into old age. Milder forms of HHC may exist without homocystinuria, and screening tests relying on the presence of homocystine in the urine will give a false negative result. Methylcobalamin is an essential cofactor for methionine synthase, a key enzyme in the homocysteine remethylation pathway: consequently, investigation for inherited abnormalities of intracellular B12 metabolism forms an integral part of the biochemical investigation of HHC. Additionally, there are acquired forms of HHC, notably those involving vitamin B12 deficiency and malabsorption. Mild to moderate HHC has also been associated with alcohol abuse, excessive caffeine intake, hypothyroidism, and poor renal function.

This chapter tells you how homeostasis in the body is achieved. Contributing factors such as stress, hormones, and the automatic nervous system are integrated into the discussion in a thoughtful way. The problem of cold postoperative patients is thoroughly referenced to modern investigation. Diabetes, how surgery destabilizes diabetics, and how to use insulin is explained. Malignant hyperthermia, thyroid storm, and acid—base disorders are all problems that can occur in the recovery room and guidelines for the management of these patients are outlined. Hydrogen ions affect haemoglobin and biochemical reactions and can cause acidosis and alkalosis—this chapter outlines how to interpret the blood gas results. How to distinguish between respiratory and metabolic causes of acid—base disorders is simply and clearly explained.

Biogenic monoamine disorders are a group of inherited diseases characterized by a defect in the synthesis, transport, or degradation of catecholamines and serotonin. The phenotype mostly reflects the pattern and severity of the monoamine deficiency. Movement disorders due to cerebral dopamine deficiency are almost always prominent, mostly in the form of dystonia and/or parkinsonism. These disorders are potentially devastating yet treatable. Early diagnosis and treatment are crucial to prevent ongoing brain dysfunction. Detection of hyperphenylalaninemia in a neonate could be a good clue to the diagnosis. Final diagnosis is often based on a detailed biochemical investigation of the cerebrospinal fluid and can be confirmed by molecular analysis. Treatment is aimed at restoring neurotransmitter homeostasis using monoamine precursors, monoamine agonists, and inhibitors of monoamine degradation. It also comprises the control of hyperphenylalaninemia and the prevention of cerebral folate deficiency, when applicable.

Oxford Desk Reference: Endocrinology provides an overview of the principles of endocrinology, a detailed pathophysiology of disorders of the endocrine system, and practical advice on the clinical presentation of the spectrum of endocrine disease. Written by over 100 international experts, it discusses the diagnosis, management, and relevant genetic and immunological aspects of endocrine disorders. Whilst discussion of common endocrine conditions is comprehensive, it also includes rare syndromes with useful guidance on screening and follow-up. Providing clinical advice to endocrinologists, general physicians, and specialist nurses, it also includes background to biochemical, immunological, genetic, and epidemiological aspects of endocrinology. It is extensively cross-referenced, with suggestions for further reading, includes links to recent international guidelines, and is illustrated throughout with diagrams, tables, and radiological images. There is a quick reference section which covers algorithms for investigation and management of commonly encountered clinical scenarios for use in the clinic. There is an outpatient resource for explanation of endocrine conditions to patients using diagrams of common conditions while in the clinic, in addition to patient support groups and advice, and discussion on legal aspects of medicine and driving regulations. This should be a very useful resource for all involved in the assessment and management of any patient with any form of a possible endocrine disorder.

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.