Bone changes

The reactions in this section are grouped into classifications based on bone changes, similar to those used for the oxidation reactions. These sections are (A reactions involving replacement of oxygen by hydrogen, (B) reactions in whicr... 

Observe the patient for changes in clinical features hepatomegaly, jaundice, and bone changes will usually resolve in 3 months. 

Calcium and magnesium deficiency also occur in some patients with the malabsorption syndrome and this may lead to tetany or bone changes. Low blood calcium levels may result from decreased absorption associated with lack of effective compensatory parathyroid activity. In patients in whom secondary hyperparathyroidism is effective, extensive loss of calcium from the bones may occur. The cause of the defective absorption of calcium in patients of the sprue group is complex and not yet fully understood (B3, Dl, Jl, M7, Nl). It is important that complications such as calcium or magnesium deficiency should be corrected before the final steps of definitive diagnosis are attempted. If this is not done, the secondary effects may obscure the results of other tests. 

Paget s disease is an uncommon disorder of bone characterized by mixed lytic and sclerotic bone changes. 

Biochemical changes such as increased aminolaevulinate excretion and inhibition of amino-laevulinate dehydrase may be detected in urine and blood, respectively, at blood lead levels of 0.4 to 0.6 mg mL-1. Anemia is a late feature, however. Neurotoxicity may be detectable at blood lead levels of 0.8 to 1.0 mg mL-1. At blood lead levels greater than 1.2 mg mL-1, encephalopathy occurs. Peripheral nerve palsies are rare, and the foot and wrist drop, which were once characteristic of occupational lead poisoning, only occur after excessive exposure and are now rarely seen. Similarly, seizures and impaired consciousness may result from involvement of the CNS. Bone changes are usually seen in children and are detected as bands at the growing ends of the bones and a change in bone shape. 

The age period of the disease is clearly defined, and even in the earliest stages suggestive symptoms are usually present. Radiology may help, although in the early stages bone changes may be absent. Estab-... 

Sotaniemi, E.A., et al. Radiologic bone changes and hypocalcemia with anticonvulsant therapy in epilepsy. Ann Intern Med, 1972 77 389-394... 

The minerals in bone change as an animal ages. Juvenile or immature bone contains amorphous calcium phosphate or the mineral brushite (CaHPO 2H20). Mature bone contains the mineral hydroxyapatite (Ca5(P04)3(0H)), but with some modifications. There tends to be some internal crystal disorder within bone apatite, and the carbonate radical may substitute for phosphate. Calcium deficiency and other health problems may affect the composition and properties of bone. 

The clinical features of the disease include hypothermia, arterial mpture, and bone changes. Patients are found to have extremely low levels of copper in the fiver, brain, and serum as well as having very low ceruloplasmin levels. These all are due to the basic biochemical defect of severely reduced abihty to absorb copper from the intestine and a disturbance in the intracellular transport of copper. ... 

Pretreatment features Facies, hypothermia None Treatment Hypothermia, failure to thrive, facies bone changes, vascular abnormalities, abnormal hair ... 

One female and one male patient had hyperparathyroidism with elevated serum alkaline phosphatase activities and extensive bone changes characteristic of generalized osteitis fibrosa cystica. In both instances, the serum acid phosphatase activity of the serum fell to normal values after removal of the parathyroid adenoma despite transitorily increased serum alkaline phosphatase activity. The fifth patient was a female with osteopetrosis involving the major part of the skeleton. The serum acid phosphatase was 8.7 K.A. units, the highest in the control series— yet the serum alkaline phosphatase was within normal limits. It would appear, therefore, that some patients with skeletal disease may have a slight but definitely elevated serum acid phosphatase activity, at least as determined by the Gutman method (GIO, G14), which cannot be explained by concurrent prostatic carcinoma or by a spillover of alkaline phosphatase activity to a pH of 5.0. 

It is important to detect bone changes as early as possible, since a timely reduction in deferoxamine dosage or a switch to deferiprone can prevent serious skeletal injury. 

Chan YL, Li CK, Pang LM, Chik KW. Desferrioxamine-induced long bone changes in thalassaemic patients— radiographic features, prevalence and relations with growth. Clin Radiol 2000 55(8) 610-14. 

Radiological bone changes have also been reported after rubella immunization (118). 

Peters ME, Horowitz S. Bone changes after rubella vaccination. Am J Roentgenol 1984 143(l) 27-8. 

Nutritional Support. Adults and children fed intravenously without addition of sufficient copper to the nutrient regimen develop symptomatic copper deficiency. The hematological changes of hypochromic anemia and neutropenia are reversed by copper supplementation. Similar effects have been reported during prolonged enteral feeding via jejunostomy. Children may also develop the typical bone changes mentioned above. 

Grunebaum M, Horodniceanu C, Steinherz R. The radiographic manifestations of bone changes in copper deficiency. Pediatr Radiol 1980 9 101-4. 

P -Thaiassemia (p-Thaiassemia Major). Sometimes called Cooley s anemia after the physician who in 1925 first described the condition in the children of Italian and Greek immigrants in New York by noting that these children failed to grow, had frequent infections, appeared pale and malnourished, had splenomegaly, and had facial bone changes. 

Fig. 9.4 Osteoblast secretion and matrix vesicle formation. The outer surface of all bones is covered by fibroblast-like cells that differentiate into pre-osteoblasts that secrete osteoid matrix to remodel the surface as necessary. The surface osteoblasts extend into the osteoid tissue by long processes that attach to osteocytes (fully differentiated, nondividing osteoblasts) within the bone. Changes in the environment may be sensed by the osteocytes, which transmit them as remodeling signals to the osteoblasts. The osteoid matrix is filled with many small membrane-covered matrix vesicles containing various amounts of precipitated basic calcium phosphate (white circles) (Modified from Fig. 22-52 in The Molecular Biology of the Cell. B. Alberts et al., 4th Ed. 2002. Garland Science, Taylor Francis Group, New York)...

R18. Rosenoer, V. M., Bone changes in Wilson s disease. In Wilson s Disease, Some... 

For example, people who eat com have higher ratios of carbon isotopes in their bones. Changes in this isotope ratio in prehistoric bone can indicate when com becomes an important component of the diet. Such studies have been done both in Mexico to ascertain when com was first domesticated and in North America to record when this important staple first arrived. Analysis of carbon isotopes from human bone collagen in Mexico indicates that a heavy dependence on com began around 4500 bc. 

Bone changes observed on radiographs 10-14 days after the onset of infection. Technetium and gallium scans positive as early as 1 day after the onset of infection... 

The evaluation of a patient who potentially may have osteomyelitis has several unusual aspects. Radiographs of the involved area should be obtained however, bone changes characteristic of osteomyelitis... 

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