Single-step production of autologous bovine platelet concentrate for clinical applications in cattle.

Platelet concentrate (PC) is an alternative therapy to treat mastitis in dairy cattle and is an alternative treatment for reproduction problems such as endometritis. Unfortunately, double-centrifugation processing methods described are time-consuming, require specialized laboratory equipment, and are usually done in a heterologous way, which risks herd health. To overcome this limitation, we evaluated single-step bovine PC processing methods readily applicable to a farm setting using an autologous conditioned plasma (ACP) production system. We investigated the hematologic findings, cytokines, and growth factors of the obtained PC samples. Autologous conditioned plasma was prepared using whole blood (WB) from 4 cows (group 1) using single-step centrifugation and 16 different processing methods. The 2 protocols that yielded the highest ratio of platelet to white blood cell (WBC) concentration were ACP-1 [720 × g (2,200 rpm), 5 min] and ACP-2 [929 × g (2,500 rpm), 3 min]. They were subsequently reproduced and compared using WB from 8 cows (group 2). Hematologic findings were quantified, IL-1ß (cytokine) and growth factors [platelet-derived growth factor (PDGF), transforming growth factor (TGF)-ß, bovine fibroblast growth factor (b-FGF)] were measured, and enrichment factors were compared between samples and processing methods. Hematological characteristics and platelet enrichment varied markedly among tested protocols and all were statistically different from WB. Protocol ACP-2 resulted in significantly greater platelet enrichment (mean 169% of WB) than ACP-1 (125% of WB). We found no significant difference between the 2 ACP preparation protocols with regard to leukocyte reduction (7.53-9.75% WBC compared with WB) or growth factor enrichment (124-125% PDGF, 95-100% TGF-ß, 102-104% b-FGF, and 56-74% IL-1ß compared with WB). In conclusion, both ACP protocols yielded a platelet concentration shown to promote healing for clinical applications in cattle, and the ACP-2 protocol resulted in a greater degree of platelet enrichment. Therefore, this protocol could be used for ACP production for clinical applications in cattle.

[Angiomatoid fibrous histiocytoma of the radial pulse groove]. / Histiocytome fibreux angiomatoïde de la gouttière du pouls radial.

BACKGROUND: Angiomatoid fibrous histiocytoma (AFH) is a slowly progressing rare soft-tissue tumour of moderate malignant potential. It is most commonly seen in children and young adults. Clinically, the lesion is easily confused with a haematoma or soft-tissue haemangioma, and the radiological aspects are not specific. PATIENTS AND METHODS: A 16-year-old male patient presented with a nodular lesion situated very close to the right radial artery, vein and nerve and which had been developing for several years. Surgical resection was carried out with sparing of vasculonervous and functional structures. Histological examination revealed a tumour of plurinodular architecture, surrounded by a fibrous pseudocapsule consisting of histiocytoid or fusiform cells in short bundles associated with a mononuclear inflammatory reaction of nodular architecture. The tumour cells expressed the following immunomarkers: desmin, smooth muscle actin, CD99, and epithelial membrane antigen. Fusion transcript EWSR1-ATF1 was found. DISCUSSION: In this case, as occurs in the literature, a diagnosis of AFH was not made on clinical examination or imaging. The enlarged excision normally recommended was greatly restricted in our patient due to the complex localization of the lesion, which was in contact with major anatomical structures. The diagnosis was based on histological examination of the surgical excision and identification of the fusion gene. Long-term follow-up is required to detect local recurrence or metastasis. Management is decided in multidisciplinary meetings.

Anticoagulant activity of oral rivaroxaban in healthy dogs.

Rivaroxaban is an oral, direct factor Xa inhibitor used in human thrombotic disorders. In view of the in vitro concentration dependent anticoagulant effects of rivaroxaban in dogs, the time course of its anticoagulant effects was characterized in healthy dogs. Twenty-four healthy Beagles were randomized into three groups (n = 8 per group) and received orally either a placebo or 20 mg rivaroxaban once or twice at an 8 h interval. Fifteen blood samples were collected over a 30 h period, and blindly assayed for prothrombin time (PT), activated partial thromboplastin time (aPTT), tissue factor induced thrombin generation (TG) and anti-factor Xa activity. Thromboelastography (TEG) was evaluated at 0, 1, 4, 8 and 24 h. Peak/baseline anticoagulant effect ratios were analyzed with generalized linear models using ß distributions and times to return to baseline with survival analyses (α = 0.05). Peak/baseline anticoagulant effect ratios of PT, aPTT, anti-factor Xa activity, TG and R (TEG) differed significantly between placebo and both rivaroxaban groups (P <0.0001). The peak anticoagulant effect of rivaroxaban occurred 1.5 to 2 h after dosing. The median return to baseline occurred significantly sooner (P <0.01) with 20 mg rivaroxaban administered once (7.9-18.7 h) versus twice (17.5-26.8 h). The inter-individual variability differed amongst assays, but overall was moderate to large. No adverse effects were recorded. Twice oral administration of 2 mg/kg rivaroxaban at an 8 h interval maintained 24 h anticoagulant activity, but larger studies are needed to establish guidelines for the use of rivaroxaban in dogs.

[Changes in the incidence and mortality rates of malignant melanoma in the Seine-Maritime region over a 20-year period]. / Évolution de l'incidence et de la mortalité du mélanome en Seine-Maritime sur une période de 20ans.

BACKGROUND: The aim of this study was to assess changes in the incidence and mortality rates of malignant melanoma (MM) over a 20-year period in a region without a cancer registry. METHODS: All cases of MM studied were collected retrospectively from the databases of six private and three hospital-based histopathology laboratories in the Seine-Maritime region covering three 24-month periods each 10years apart: 1988-1989, 1998-1999 and 2008-2009, The incidence and mortality rates were estimated based on data provided by French National Institute for Statistics and Economic Studies (Insee) and French National Institute of Health and Medical Research (Inserm). RESULTS: Over the 20-year period, the incidence of MM increased from 8.6 to 21.2/100,000inhabitants per year (+147%, P<0.0001) while the mortality rate rose from 1.3 to 2.8/100,000inhabitants per year (+115%, P=0.0003). The incidence of invasive MM increased by +110%, while the incidence of MM in situ increased by +456%. The incidence and overall mortality rate of invasive MM increased particularly during the first 10-year period: +62% (P<0.0001) and +77% (P=0.01) respectively, and to a much lesser extent during the last 10-year period: +30% (P=0.0007) and +22% (P=0.22) respectively. This slowdown in the incidence of invasive MM and in overall mortality rates was even more pronounced in women over the last 10years (+17 and +9%), whereas these rates continued to increase in men (+49% and +35%, respectively). In contrast, the incidence of MM in situ increased above all during this same period (+257%). CONCLUSION: This study shows that while the incidence and mortality rate of invasive MM has increased little over the last 10years in the Seine-Maritime region, the incidence of MM in situ continues to rise sharply.

Two length variants of the microsatellite FH2295 as markers for body size of female Portuguese water dogs.

Genetic studies in purebred Portuguese water dogs (PWD) have previously identified genetic loci controlling skeleton size. The FH2295 genetic marker was reported to control 43.6% of the size variation in this breed. In the present study, we amplified and sequenced the genomic DNA from female PWD of different sizes in the region of the FH2295 genetic marker. Polymerase chain reaction (PCR) products of 700 and 800 bp were generated and sequencing revealed the presence of a microsatellite marker including either 5 or 24 repeats of the tetranucleotide sequence "CTTT". Dogs were divided into groups based on their genotypes: homozygote for the short allele (II) or homozygote for the long allele (BB) or heterozygote (IB). The smallest dogs were homozygous with 24 repeats and the largest dogs were homozygous with five repeats. Genetic transmission of the microsatellite marker appears to follow Mendelian laws since all puppies born to a homozygous small dog genotyped "BB" included one or two "B" allele. We applied a PCR method to characterize the sequence of the previously identified dog genetic marker FH2295 and propose that the length of the microsatellite identified could be used as a predictor for the body size of female PWD.

Impact of UK National Guidelines based on FRAX®--comparison with current clinical practice.

OBJECTIVE: To assess whether clinician-determined treatment intervention thresholds are in line with the assessment of fracture risk provided by FRAX® and treatment recommendations provided by UK guidelines produced by the National Osteoporosis Guidelines Group (NOGG). DESIGN, PATIENTS AND MEASUREMENTS: This was a retrospective cohort analysis of 288 patients consecutively referred for dual-energy X-ray absorptiometry (DXA) scanning from primary care immediately prior to the introduction of the FRAX® algorithm. In addition to DXA assessment, patients completed a clinical risk factor questionnaire which included risk factors used in the FRAX® algorithm. Initial risk assessment and treatment decisions were performed after DXA. FRAX® was used, retrospectively, with femoral neck T-score, to estimate fracture risk which was applied to NOGG to generate guidance on treatment intervention. Clinician- and NOGG-determined outcomes were audited for concordance. RESULTS: There was concordance between clinician and NOGG treatment decisions in 215 (74.6%) subjects. Discordance was observed in 73 (25.3%) subjects. In the discordant group, seven subjects were given lifestyle advice when NOGG recommended treatment, 42 given treatment when NOGG recommended lifestyle advice only, and 24 were referred to a metabolic bone clinic for further evaluation. The reasons for treatment differences in subjects recommended treatment by clinician but not NOGG were largely (90.2%) attributed to the use of lumbar spine bone mineral density (BMD). CONCLUSIONS: There is high concordance between clinician-determined and FRAX®-NOGG intervention. The absence of spine BMD from FRAX® is the primary source of discrepancy. This study provides some assurance of the validity of the treatment thresholds generated from FRAX®-NOGG in 'real-world' usage.

Pediatric in vivo cross-calibration between the GE Lunar Prodigy and DPX-L bone densitometers.

Dual energy x-ray absorptiometry (DXA) machine cross-calibration is an important consideration when upgrading from old to new technology. In a recent cross-calibration study using adult subjects, close agreement between GE Lunar DPX-L and GE Lunar Prodigy scanners was reported. The aim of this work was to cross-calibrate the two machines for bone and body composition parameters for pediatrics from age 5 years onwards. One-hundred ten healthy volunteers aged 5-20 years had total body and lumbar spine densitometry performed on DPX-L and Prodigy densitometers. Cross-calibration was achieved using linear regression and Bland-Altman analysis. There was close agreement between the machines, with r2 ranging from 0.85 to 0.99 for bone and body composition parameters. Paired t-tests demonstrated significant differences between machines that were dependent on scan acquisition mode, with the greatest differences reported for the smallest children. At the lumbar spine, Prodigy bone mineral density (BMD) values were on average 1.6% higher compared with DPX-L. For the total body, there were no significant differences in BMD; however, there were significant differences in bone mineral content (BMC) and bone area. For small children, the Prodigy measured lower BMC (9.4%) and bone area (5.8%), whereas for larger children the Prodigy measured both higher BMC (3.1%) and bone area (3.0%). A similar contrasting pattern was also observed for the body composition parameters. Prodigy values for lean body mass were higher (3.0%) for small children and lower (0.5%) for larger children, while fat body mass was lower (16.4%) for small children and higher (2.0%) for large children. Cross-calibration coefficients ranged from 0.84 to 1.12 and were significantly different from 1 (p<0.0001) for BMC and bone area. Bland-Altman plots showed that within the same scan acquisition modes, the magnitude of the difference increased with body weight. The results from this study suggest that the differences between machines are mainly due to differences in bone detection algorithms and that they vary with body weight and scan mode. In general, for population studies the differences are not clinically significant. However, for individual children being measured longitudinally, cross-over scanning may be required.

The relationship between lean body mass and bone mineral content in paediatric health and disease.

INTRODUCTION: The correct interpretation of DXA data is critical to the diagnosis and management of children with suspected bone disease. This study examines the various influences on bone mineral content (BMC), as measured by dual-energy X-ray absorptiometry (DXA). MATERIALS AND METHODS: Six hundred and forty-six healthy school children and forty-three children with chronic diseases, aged 5-18 years, had their lumbar spine and whole body measured using a Lunar DPX-L DXA scanner. RESULTS: Stepwise linear regression identified lean body mass (LBM) as the strongest single predictor of BMC in the lumbar spine and the total body. A significant gender difference was observed in the relationship between BMC and LBM with girls having significantly more bone per unit LBM from 9 years of age in the spine and 13 years of age in the total body. To investigate the relationship between LBM and BMC in children with chronic disease, a two-stage algorithm based upon calculation of Z scores from the normative data was applied. Stage 1 assessed LBM for height and stage 2 assessed BMC for LBM. Ten children with spinal muscular atrophy had a mean LBM for height Z score of -1.8(1.4) but a mean BMC for LBM Z score of 1.2(1.3) indicating their primary abnormality was reduced muscle mass (sarcopenia) with no evidence of osteopenia. In contrast, 21 children with osteogenesis imperfecta had a mean LBM for height Z score of 0.4(1.7) but a mean BMC for LBM Z score of -2.5(1.8) indicating normal LBM for size but significantly reduced BMC for LBM (i.e. osteopenia) confirming a primary bone abnormality. A third group consisting of 12 children with low trauma fractures demonstrated little evidence of sarcopenia [mean LBM for height Z score -1.1(2.1)] but significant osteopenia [mean BMC for LBM Z score -1.9(1.5)]. CONCLUSION: The results from this study demonstrate how the relationship between height and lean body mass, and lean body mass and bone mineral content can be a useful method of diagnosing osteoporosis in children and how the relationships can be used to identify if the primary abnormality is in muscle or bone.

Bone density and body composition in children with growth hormone insensitivity syndrome receiving recombinant IGF-I.

OBJECTIVE: There are few reports of the metabolic action of insulin-like growth factor 1 (IGF-I) in vivo. Growth hormone insensitivity syndrome is a good model to examine the effects of IGF-I deficiency. This study was designed to assess body composition and bone density in children with growth hormone insensitivity syndrome before and after receiving treatment with recombinant IGF-I. DESIGN: A prospective longitudinal study. PATIENTS: Four prepubertal boys age 6.1-9.8 years with short stature due to growth hormone insensitivity syndrome. MEASUREMENTS: Assessment of body fat by skinfold thickness measurements and dual energy X-ray absorptiometry (DXA) was made during the first 6 months of recombinant IGF-I treatment. Assessment of lumbar spine bone density by DXA was performed prior to IGF-I treatment and during the subsequent five years. RESULTS: Each child showed a significant reduction in fat mass (0.26-1.22 kg) after 6 weeks of IGF-I treatment. Bone density prior to treatment was reduced in comparison to age-matched controls but calculated volumetric bone density was within the normal range. Volumetric bone density progressively improved over the 5-year treatment period. CONCLUSIONS: Children with growth hormone insensitivity syndrome exhibit a metabolic response to IGF-I within 6 weeks analogous to that seen in GH-deficient children receiving GH. Bone density when corrected for body size is within normal limits and demonstrates a response to IGF-I, confirming the anabolic action on bone.

Nod genes and Nod signals and the evolution of the Rhizobium legume symbiosis.

The establishment of the nitrogen-fixing symbiosis between rhizobia and legumes requires an exchange of signals between the two partners. In response to flavonoids excreted by the host plant, rhizobia synthesize Nod factors (NFs) which elicit, at very low concentrations and in a specific manner, various symbiotic responses on the roots of the legume hosts. NFs from several rhizobial species have been characterized. They all are lipo-chitooligosaccharides, consisting of a backbone of generally four or five glucosamine residues N-acylated at the non-reducing end, and carrying various O-substituents. The N-acyl chain and the other substituents are important determinants of the rhizobial host specificity. A number of nodulation genes which specify the synthesis of NFs have been identified. All rhizobia, in spite of their diversity, possess conserved nodABC genes responsible for the synthesis of the N-acylated oligosaccharide core of NFs, which suggests that these genes are of a monophyletic origin. Other genes, the host specific nod genes, specify the substitutions of NFs. The central role of NFs and nod genes in the Rhizobium-legume symbiosis suggests that these factors could be used as molecular markers to study the evolution of this symbiosis. We have studied a number of NFs which are N-acylated by alpha,beta-unsaturated fatty acids. We found that the ability to synthesize such NFs does not correlate with taxonomic position of the rhizobia. However, all rhizobia that produce NFs such nodulate plants belonging to related tribes of legumes, the Trifolieae, Vicieae, and Galegeae, all of them being members of the so-called galegoid group. This suggests that the ability to recognize the NFs with alpha-beta-unsaturated fatty acids is limited to this group of legumes, and thus might have appeared only once in the course of legume evolution, in the galegoid phylum.

Characterization of the common nodulation genes of the photosynthetic Bradyrhizobium sp. ORS285 reveals the presence of a new insertion sequence upstream of nodA.

We isolated and characterized nodA genes from photosynthetic and non-photosynthetic rhizobia nodulating the legume genus Aeschynomene, and found that the nodA sequence from photosynthetic stem-nodulating bacteria was phylogenetically distant from the other already described nodA genes. Characterization of the photosynthetic strain ORS285 common nod gene cluster (nodABC) showed, upstream of nodA, the presence of a new insertion sequence element belonging to the IS3 family and specific to a group of photosynthetic strains from Aeschynomene.

Bone density in the Asian thalassaemic population: a cross-sectional review.

UNLABELLED: As survival improves in beta-thalassaemia, osteoporosis is emerging as a significant problem. This study examines bone mineral density (BMD) of thalassaemic patients of Asian origin (age range 9.5-24 y) to evaluate the extent of problems in this group and identify potential risk factors. Eleven patients were scanned using dual-energy X-ray absorptiometry. BMD z-scores and the bone mineral apparent density (BMAD) z-scores were calculated, to correct for short stature. All but three patients had lumbar spine BMD and BMAD z-scores below the mean. Three patients had BMAD z-scores more than 2.5 standard deviations below the mean. A negative correlation between age and BMAD was seen, as was an association between endocrine disorders and decreased bone density. CONCLUSION: The data confirm significant reductions in BMD in the Asian thalassaemic population, even after correcting for body size. Further research is needed to identify risk factors and means of prevention.

Use of quantitative ultrasound to assess bone status in children with juvenile idiopathic arthritis: a pilot study.

Periarticular osteoporosis around inflammed joints and generalized osteoporosis have been shown to be markers of disease activity and severity in children with juvenile idiopathic arthritis (JIA). Bone mineral density (BMD) in adults can be assessed precisely by dual X-ray absorptiometry (DXA), but this technique has not been used widely in children. Quantitative ultrasound (QUS) may provide an alternative method for assessment of bone status. The aim of this pilot study was to compare QUS to DXA in assessing generalized osteoporosis in a cohort of patients JIA. Twenty-two Caucasian children (15 females, 7 males) with JIA of duration 19-142 months (mean 71 mo) and age 7-17 yr were recruited. Total body and lumbar spine BMD and bone mineral content (BMC) were measured by DXA using standard procedures on a Lunar DPX-L scanner. QUS was performed using Myriad SoundScan 2000. Speed of sound (SOS) was measured at the right midtibia. The DXA results were compared to QUS using linear regression analysis. Spine and total body BMD measured by DXA correlated significantly with tibia SOS (spine: r = 0.57, p < 0.007; total body: r = 0.68, p < 0.001). Spine BMC was similarly related to SOS as BMD (r = 0.58, p < 0.007). Individual patient weight and height were strong predictors of BMD, but only moderate predictors of SOS. The mean spine BMD was lower in the JIA patients compared to the normal ranges (mean Z-score of -1.19). BMD Z-scores were negatively associated with disease duration. Patients taking steroids were associated with lower Z-scores. In conclusion, SOS shows a significant correlation with BMD as measured by DXA, albeit with wide 95% confidence intervals in this small pilot study. QUS was also well tolerated and was technically easy to perform in these children. With the added advantage that it is free from radiation risk, further assessment of this potentially valuable tool for measuring bone status in children is warranted.

Bradyrhizobium sp. Strains that nodulate the leguminous tree Acacia albida produce fucosylated and partially sulfated nod factors.

We determined the structures of Nod factors produced by six different Bradyrhizobium sp. strains nodulating the legume tree Acacia albida (syn. Faidherbia albida). Compounds from all strains were found to be similar, i.e., O-carbamoylated and substituted by an often sulfated methyl fucose and different from compounds produced by Rhizobium-Mesorhizobium-Sinorhizobium strains nodulating other species of the Acaciae tribe.

[Inpatient and outpatient follow-up of grade I malignant melanoma]. / Etude comparative du suivi des malades atteints de mélanome de stade Ien pratique libérale et hospitalière.

BACKGROUND: In 1995, the French consensus conference on management of patients with grade I malignant melanoma recommended clinical examination for patient monitoring. To date, only one survey has been conducted to evaluate these recommendations and their consequences, providing no means of assessing follow-up practices. The aim of this study was to assess follow-up practices in patients with grade I malignant melanoma followed in an outpatient private practice setting and in a hospital setting with regular appointments. PATIENTS AND METHODS: This retrospective study was conducted in collaboration with private practice and hospital dermatologists, all members of an association of continuing medical education. Medical records of 584 patients with grade I malignant melanoma who had undergone surgery between January 1, 1991 and December 31, 1995 were reviewed. Three hundred twenty-nine patients were followed in an exclusively outpatient setting by their private dermatologist and 265 were followed in a hospital setting. Follow-up data were: age, sex, date of surgical excision of the melanoma, Breslow thickness, date of each follow-up visit, presence of possible metastases and mode of diagnosis. RESULTS: Patient features were different in the two groups: mainly greater Breslow thickness and more frequent metastatic course in patients followed in a hospital setting. Among all patients, 65 (11 p. 100) developed metastases. Diagnosis of metastasis was made clinically in 95 p. 100 whatever the mode of monitoring considered. The number of patients lost to follow-up was 11p. 100 among those followed in a hospital setting and 42 p. 100 in those followed in a private practice setting. Patients lost to follow-up had a higher risk of developing metastasis as their average Breslow thickness was 1.7 mm. CONCLUSION: This study shows that patients followed in a hospital setting have a more severe prognosis than patients followed in private practice. It confirms that systematic use of complementary tests is of little interest in detecting metastases since over the period considered, the diagnosis of metastasis was made clinically in most cases. It also discloses difficulties encountered in exclusively outpatient follow-up as a high number of patients were lost to follow-up in this setting. A systematic appointment fixed by the private dermatologist during the follow-up period appears to be needed to ensure good quality follow-up. Such an appointment system should help reduce the number of patients lost to follow-up.

Intravenous pamidronate in juvenile osteoporosis.

AIMS: To investigate the use of the aminobisphosphonate, disodium pamidronate, in children with vertebral osteoporosis. METHODS: Five children (aged 10-15 years) with vertebral osteoporosis who developed compression fractures in the thoracic and/or lumbar spine as a consequence of five different conditions, received treatment with intravenous disodium pamidronate in doses ranging from 0.5 to 12 mg/kg/y. RESULTS: Each child had rapid pain relief following the first treatment, followed by large increments in lumbar spine bone density over one year; the change in bone density standard deviation score ranged from 0.5 to 2.5 with percentage increments of 26% to 54%. CONCLUSION: Intravenous pamidronate appears to be a useful therapeutic option in childhood osteoporosis, but its use in children must still be regarded as experimental and therefore closely monitored.

Isolation and characterization of canthaxanthin biosynthesis genes from the photosynthetic bacterium Bradyrhizobium sp. strain ORS278.

A carotenoid biosynthesis gene cluster involved in canthaxanthin production was isolated from the photosynthetic Bradyrhizobium sp. strain ORS278. This cluster includes five genes identified as crtE, crtY, crtI, crtB, and crtW that are organized in at least two operons. The functional assignment of each open reading frame was confirmed by complementation studies.

A comparison of performance of three gamma camera systems for positron emission tomography.

The development of coincidence positron imaging using a gamma camera should significantly increase PET utilization. This study has compared the performance of three such systems with each other and with an equivalent single photon emission computed tomography (SPECT) measurement. A Carlson phantom, which consisted of a 20 cm diameter cylinder containing areas of uniform activity, hot lesions, cold lesions and orthogonal alternate hot and cold lines, was filled with an activity of 18F chosen to try and best exploit each camera and imaged for a fixed time (27 min). The image quality of 9 mm thick slices in each section of the phantom was compared visually. Several image quality parameters were also compared including line source resolution and noise equivalent count rate. There were considerable differences in PET image quality between the three cameras but all were at least as good as the SPECT image. The full width at half maximum (FWHM) resolution of all systems was similar (approximately 4.5 mm) but the maximum noise equivalent count rates in a 20 cm cylinder were significantly different (6.3, 2.6 and 1.6 kcps) (where cps is counts per second) and correlated with the phantom image quality.

Factors influencing the speed of sound through the proximal phalanges.

The amplitude-dependent speed of sound (AD-SOS) in the proximal phalanges is reported to be sensitive to osteoporotic changes. We investigated the influence of bone thickness and cortical thickness on AD-SOS. Phantoms made of Perspex were designed to simulate different bone width (11-16 mm) and cortical thickness (3-7.5 mm). The phantoms were designed with two opposing flat and cylindrical surfaces. The effect of cortical thickness was examined by drilling holes (simulating the medullary canal) of different diameters (1-7 mm) in the middle of the Perspex cylinders. The effect of sample thickness was investigated on solid Perspex phantoms of varied lengths. The standardized precision errors of AD-SOS measurement in vivo and in vitro on volunteers and phantoms were 2.8 and 0.9%, respectively. AD-SOS was influenced by the bone width, cortical thickness, and location along the phalanx. A decrease in either cortical width or cortical thickness resulted in a decrease in AD-SOS. The effect is dependent on whether the contact surface is curved or flat. It is possible that a curved surface has a focusing effect on the wave through the porous core, whereas for a flat surface, the path of the waves might not pass through the center. When cortical thickness and bone width were expressed as a ratio, there was a linear relationship between this ratio and AD-SOS through the phantoms. AD-SOS was independent of thickness for samples greater than 11 mm.