Fiber Bragg grating sensor for monitoring bone decalcification.

INTRODUCTION: Estimation of decalcification is a vital tool to discern bone health. Different techniques are used for its quantitative measurement, e.g. DEXA, QCT & QUS. All these techniques, although noninvasive, suffer from limitations such as radiation exposure and inaccurate values. Recently, fiber optic techniques are fast emerging for medical applications owing to their various attractive features like immunity to EMI/RFI, geometric versatility, chemical inertness, etc. MATERIAL AND METHODS: The effect of decalcification on strain response of a goat tibia was investigated in vitro using fiber Bragg grating (FBG) sensing technique. The bone was strained by using three-point bending technique and corresponding Bragg wavelength shifts were recorded. Two similar bone samples from the same animal were taken and one was partially decalcified. Strain response of decalcified and untreated bone was taken concurrently to monitor the effects of calcium loss and that of degradation with time. RESULTS AND CONCLUSION: The strain generated for same stress increased with greater degree of decalcification and a steep increase occurred after 2g calcium loss, indicating the onset of damage. The strain response, therefore gives a direct indication of the degree of calcium present in the bone. LEVEL OF EVIDENCE: Level III.

Factors predictive of tumor growth, tumor decalcification, choroidal neovascularization, and visual outcome in 74 eyes with choroidal osteoma.

OBJECTIVE: To evaluate choroidal osteoma for tumor growth, tumor decalcification, related choroidal neovascularization, visual acuity loss, and poor visual acuity. DESIGN: Retrospective nonrandomized single-center case series. SETTING: Ocular Oncology Service at Wills Eye Hospital, Thomas Jefferson University, Philadelphia, Pa. PARTICIPANTS: There were 74 eyes of 61 patients with choroidal osteoma evaluated between January 1, 1977, and January 1, 2003. MAIN OUTCOME MEASURES: The 5 outcome measures included tumor growth, tumor decalcification, related choroidal neovascularization, visual acuity loss of 3 or more Snellen lines, and poor visual acuity of 20/200 or worse. RESULTS: At 5 and 10 years, Kaplan-Meier analysis revealed tumor growth in 22% and 51% of eyes, tumor decalcification in 28% and 46% of eyes, choroidal neovascularization in 31% and 31% of eyes, visual acuity loss in 26% and 45% of eyes, and poor visual acuity in 45% and 56% of eyes, respectively. The clinical factor predictive of tumor growth was absent overlying retinal pigment epithelial alterations. The factor predictive of decalcification was irregular tumor surface. Of the 15 tumors that showed partial decalcification at the first visit, there was no further tumor growth in any case. Of the remaining 12 tumors that later developed decalcification, tumor growth, if it occurred, was along the margin opposite the decalcification. No tumor showed growth in the region of decalcification. Factors predictive of choroidal neovascularization included irregular tumor surface and subretinal hemorrhage. In 6 eyes that had both choroidal neovascularization and tumor decalcification, the neovascularization was detected prior to or at the same time as the decalcification. The factor predictive of visual acuity loss was presence of subretinal fluid whereas the factors predictive of poor visual acuity included symptoms and tumor decalcification. A comparison of eyes with subfoveal vs extrafoveal choroidal osteoma showed poor visual acuity in 15 (34%) of 44 eyes and 3 (10%) of 30 eyes, respectively. Eyes with decalcified choroidal osteomas manifested poor visual acuity in 13 (48%) of 27 eyes whereas those with nondecalcified tumors showed poor visual acuity in 5 (11%) of 47 eyes. CONCLUSIONS: Choroidal osteoma showed evidence of growth in 51% of eyes and decalcification in nearly 50% of eyes by 10 years. Tumors with any degree of decalcification at the initial visit showed no further growth. Overall, poor visual acuity of 20/200 or worse was found in 56% of eyes by 10 years, and decalcified subfoveal choroidal osteomas displayed a particularly poor visual prognosis.

Orbit deformities in craniofacial neurofibromatosis type 1.

BACKGROUND AND PURPOSE: The possible relationship of orbit deformities in neurofibromatosis type 1 (NF1) to plexiform neurofibromas (PNFs) have not been fully elucidated. Our purpose was to review orbital changes in patients with craniofacial NF1. METHODS: We retrospectively reviewed CT and MR imaging abnormalities of the orbit in 31 patients (18 male, 13 female; mean age, 14 years; age range 1-40 years) with craniofacial NF1. RESULTS: Orbital abnormalities were documented in 24 patients. Six had optic nerve gliomas with enlarged optic canals. Twenty had PNFs in the orbit or contiguous to the anterior skull. The posterior orbit was distorted by encroachment from an expanded middle cranial fossa in 13 patients, and 18 had enlargement of the orbital rim. Other changes included focal decalcification or remodeling of orbital walls adjacent to PNFs in 18 patients and enlargement of cranial foramina resulting from tumor infiltration of sensory nerves in 16. These orbital deformities were sometimes progressive and always associated with orbital infiltration by PNFs. CONCLUSION: In our patients with craniofacial neurofibromatosis, bony orbital deformity occurred frequently and always with an optic nerve glioma or orbital PNF. PNFs were associated with orbital-bone changes in four patterns: expansion of the middle cranial fossa into the posterior orbit, enlargement of the orbital rim, bone erosion and decalcification by contiguous tumor, and enlargement of the cranial foramina. Orbital changes support the concept of secondary dysplasia, in which interaction of PNFs with the developing skull is a major component of the multifaceted craniofacial changes possible with NF1.

Cerebrospinal fluid pterins and folates in Aicardi-Goutières syndrome: a new phenotype.

OBJECTIVE: To describe three unrelated children with a distinctive variant of Aicardi-Goutières syndrome (AGS) characterized by microcephaly, severe mental and motor retardation, dyskinesia or spasticity, and occasional seizures. RESULTS: Neuroimaging showed bilateral calcification of basal ganglia and white matter. CSF glucose, protein, cell count, and interferon alpha were normal. Abnormal CSF findings included extremely high neopterin (293 to 814 nmol/L; normal 12 to 30 nmol/L) and biopterin (226 to 416 nmol/L; normal 15 to 40 nmol/L) combined with lowered 5-methyltetrahydrofolate (23 to 48 nmol/L; normal 64 to 182 nmol/L) concentrations in two patients. The absence of pleocytosis and normal CSF interferon alpha was a characteristic finding compared to the classic AGS syndrome. Genetic and enzymatic tests excluded disorders of tetrahydrobiopterin metabolism, including mutation analysis of GTP cyclohydrolase feed-back regulatory protein. CSF investigations in three patients with classic AGS also showed increased pterins and partially lowered folate levels. CONCLUSIONS: Intrathecal overproduction of pterins is the first biochemical abnormality identified in patients with AGS variants. Long-term substitution with folinic acid (2-4 mg/kg/day) resulted in substantial clinical recovery with normalization of CSF folates and pterins in one patient and clinical improvement in another. The underlying defect remains unknown.

[Developmental osteopenia: decrease of bone mineral density or systemic impairment?]. / Osteopenia w wieku rozwojowym--obnizenie mineralizacji koscca czy zaburzenie ogólnoustrojowe?

In the quantitative evaluation of bone osteopenia is defined as a decrease of mineral density by more than 1 SD from the established normal values (age, sex, peak bone mass...). The border of osteopenia and osteoporosis is demarcated by -2.5 SD (T-score) in adults, while in children the most proper is considered to be -2.0 SD (Z-Score). The aim of the study was to determine whether developmental osteopenia is accompanied by biochemical abnormalities and what are clinical symptoms concomitant with this condition. The studies include 28 children aged 5-17 years, in whom no chronic disease, especially of locomotor system, was found. The basis for diagnosis was densitometric examination of bone, with DEXA method (densitometer by Lunar), vertebral column (Spine) in the pediatric program or for adults. The most frequent causes for referring to the examination were pain in the spine, limbs or history of multiple bone fractures. In the performed biochemical examinations hypomagnesemia, decreased concentration of 25OHD and PTH in blood serum, increased activity of bone isoenzyme of alkaline phosphatase as well as increased excretion of hydroxyproline in urine, were found in several children. In about 1/3 of the children low body mass, and in some cases also retardation of the bone age was revealed. The results of our studies allow a conclusion, that in children with certain clinical abnormalities from locomotor system osteopenia may take place. This disturbance is concomitant with various deviations in calcium-phosphate metabolism and requires adequate therapy. It may be supposed, that in the majority of children, osteopenia was caused by low dietary calcium intake, together with reduced physical activity and vitamin D deficiency. The observations and conclusions from the study are of important practical significance, because children with osteopenia are the risk group for the appearance of osteoporosis in their future life.

[Transient osteopenia of the hip in children]. / Przemijajaca osteopenia stawu biodrowego u dzieci.

The course and results of treatment of 4 boys with transient osteopenia of the hip are presented. Mean age of patients at the onset of symptoms was 9 years 5 months (range 5 years 3 months-14 years 6 months). Pain at exertion and limp dominated in all cases. Quadriceps atrophy was a constant finding and hip rotation was restricted in 3 cases. Laboratory findings were normal except for the elevated ESR. Radiography and CT showed diffused osteopenia within femoral neck and head. Bone scan was abnormal in 3 cases. Weight bearing restriction and exercises introduction resulted in ceasing of the symptoms within 3 months.

[X-ray densitometry and biochemical parameters of bone tissue metabolism in patients with vibration disease]. / Rentgenodensitometricheskie i biokhimicheskie pokazateli metabolizma kostnoi tkani u bol'nykh vibratsionnoi bolezn'iu.

To reveal systemic and local osteoporosis, the authors studied biochemical markers of bone metabolism in vibration disease patients. The vibration disease patients appeared to have the most frequent and marked osteoporosis in peripheral bones--hands (in 90% of cases) and forearms (in 66.7%). Prevalence of systemic osteoporosis and osteopenia reached 11.7 and 48.3% in the select respectively. According to biochemical markers, bone reconstruction state was characterized by moderately intensified bone resorption and diminished bone formation.

[Prevalence of bone decalcification in the treatment of Crohn's disease]. / Prevalence odvápnení kostí pri lécbe Crohnovy nemoci.

In clinically active Crohn's disease the bone mineralization is impaired due to calcium malabsorption by the inflamed intestinal wall which is potentiated by diarrhoea and the thus accelerated transit time. To this we must add the shortening of the gut after operations, the inadequate dietary calcium supply or possibly calcium elimination in case of concurrent lactose intolerance. Corticoid treatment leads also to deterioration of bone mineralization. This is the reason why the authors assessed in 98 patients with Crohn's disease the bone mineralization, using the method of clavicular bone index (NIBA). Then treatment was started: a high protein diet, calcium forte, Ossin (sodium fluoride), vitamin D forte, anabolics and regular physical exercise. Check-up examinations after one year revealed that the index was restored in the majority of patients (60.84%) to normal. The above treatment is thus effective. It must be, however, regular and of a long-term character, in some patients it must extend over many years. We had, however, also patients who although subjected to an extensive resection of the gut and treated for prolonged periods with corticoids, had permanently an index between 100 and 120% without treatment.

Comparison of the hardness change and mineral loss in enamel by dimethyl ammonium fluoride (alpha C12 DMEAHF) or NaF treatment under intra oral cariogenicity test conditions.

Changes in hardness as well as in Ca and P were determined in enamel slabs after treatment with 3% sucrose together with NaF or alpha C12 DMEAHF (both containing 0.006% F-) under Intra Oral Cariogenicity Test conditions. NaF treatment resulted in a hypermineralization of the surface of the enamel lesion suggesting formation of CaF2. Treatment with ammonium fluoride along with the same low F- concentration inhibits the caries process completely and seems to be a very promising anticaries agent.

Hardness changes and mineral loss in enamel during the intra oral cariogenicity test in the presence of 0.125% EHDP with or without 0.1% F-.

The effects of a high EHDP concentration (0.125%) were measured under Intra Oral Cariogenicity Test (ICT) conditions in the presence or absence of F- (0.1%). EHDP as well as EHDP supplemented with F- inhibited the softening of enamel slabs to a similar extent as measured by microhardness. Measurements of the calcium and phosphate levels as a function of depth showed that the addition of F- to the EHDP solution further decreased mineral loss in the deeper layers. The results suggest that the inhibition of demineralization of the enamel by EHDP and F- is due to inhibition of acid production by microorganisms.

Evaluation of factors associated with glucocorticoid-induced osteopenia in patients with rheumatic diseases.

In 161 ambulatory rheumatic disease patients receiving long-term prednisone therapy, diaphyseal mass (DM) and metaphyseal mass (MM) of the forearm were measured by single photon absorptiometry, and bone radiographs were reviewed when available. Multivariate analysis of treatment and patient characteristics demonstrated that glucocorticoid-induced osteopenia (defined as an elevated DM:MM ratio) and bone fractures occurred with similar frequency in patients of each sex, in whites and blacks, in patients with various rheumatic diseases, and in patients receiving different regimens of prednisone therapy. However, large cumulative doses of prednisone were associated with elevated DM:MM ratios as well as with bone fractures, and menopause or age greater than or equal to 50 years (males or females) was associated with bone fractures. We conclude that long-term therapy with various prednisone regimens results in glucocorticoid-induced osteopenia and fractures. This affect is cumulative, occurs in all patient groups, and results in more bone fractures in certain groups.