Precision and accuracy of computed tomography foot measurements

OBJECTIVE

To test the accuracy and precision of computed tomography (CT) imaging for describing the 3-dimensional structure of the foot in patients with diabetes mellitus and peripheral neuropathy.

DESIGN

Experimental, test-retest.

SETTING

Clinical CT scanner at a local hospital.

SPECIMENS

Two tissue-equivalent phantoms and 6 cadaver feet.

MAIN OUTCOME MEASURES

Measurements taken from CT data of phantoms and cadaver feet were compared with physical (caliper) measurements. The feasibility of creating a computer-aided design/rapid prototyping 3-dimensional model from CT data was assessed by using 1 cadaver foot.

RESULTS

No bias was found for phantom or cadaver CT measurements compared with caliper measurements. The mean difference between repeat scans of cadaver feet (1 observer) was 0.1 +/- 0.8 mm and between observers, 0.4 +/- 0.8 mm. Comparing caliper measurements of the rapid prototype model and actual foot measurements revealed an error of 0.3 +/- 0.4 mm.

CONCLUSION

CT-based 3-dimensional imaging produced accurate and precise foot measurements, enabling description of internal and external structures. This capability will be coupled with plantar pressure measurements to improve our understanding and treatment of foot ulcers in people with diabetes.

Behavior of sewage sludge-derived PAHs on pasture

A field experiment was set up to investigate the retention of PAHs by pasture grass following sludge application. In addition to information on compound-specific loss rates, the influence of meteorological variables and sludge-pasture contact time on the weathering process were investigated. The rates of loss were compound specific with half-lives ranging from < 1 to 10 d. The lighter PAHs were rapidly lost from the grass surface primarily by volatilization. For the intermediate and heavier PAHs, loss was slower with rain playing an important role in the weathering process. Growth dilution was also important in reducing the contaminant levels in the grass. The effect of sludge-pasture contact time prior to weathering by rain on the residual levels remains unclear. In terms of risk of exposure, there is the potential for persistent organic contaminants to be introduced into the grazing animal food chain if sewage sludge is applied to pasture land.

Seasonal and species differences in the air--pasture transfer of PAHs

A field plot was established at a semirural site in the U.K. to investigate the atmospheric transfer of PAHs to different pasture species over the whole growing season. The PAHs displayed a range of partitioning behaviors in the atmosphere from exclusively gas phase to exclusively particle bound, resulting in different modes of deposition to the plant surface. The different pasture species had different plant and sward characteristics, e.g., leaf morphologies, yields, etc. For the majority of PAHs, the plant species displayed a seasonality in concentrations, with concentrations being higher in the winter than in the summer. For the lighter PAHs, this seasonality was absent with soil outgassing and/or summer sources of PAHs being implicated. Air-plant transfer factors (scavenging coefficients, with units m3/g dw) typically ranged between 4 and 52 during the summer, increasing to 8-88 during winter. Despite different plant and sward characteristics, the mixtures and concentrations of PAHs were similar for all the plant species. This indicates that there was little difference in the interception and retention behavior of the gas- and particle-phase PAHs. The implications of this for food chain transfer and air-vegetation modeling are discussed.

Microbial transformations of steroids--XII. Progesterone hydroxylation profiles are modulated by post-translational modification of an electron transfer protein in Streptomyces roseochromogenes

When Streptomyces roseochromogenes strain 10984 was incubated with exogenous progesterone for 25 h the major monohydroxylated metabolite, 16alpha-hydroxyprogesterone was produced in 3.6 fold excess to the minor metabolite 2beta,16alpha-dihydroxyprogesterone. In a reconstituted system containing highly purified progesterone 16alpha-hydroxylase cytochrome P-450, and electron transfer proteins ferredoxin-like redoxin (roseoredoxin) and redoxin reductase (roseoredoxin reductase), both metabolites were produced but in a 10:1 ratio. When S. roseochromogenes was pre-incubated for 8 h with 0.32 mM progesterone and the purified components of the hydroxylase system incubated as before, the ratio of 16alpha-hydroxyprogesterone to 2beta,16alpha-dihydroxyprogesterone produced decreased to 2.8:1, virtually identical to the ratio in whole cell transformations. Reconstitution assays containing all combinations of hydroxylase proteins purified from progesterone pre-incubated and control cells showed that the roseoredoxin was solely responsible for the observed changes in in vitro metabolite ratios. The fact that the lower 16alpha-hydroxyprogesterone to 2beta,16alpha-dihydroxyprogesterone ratio was also obtained when S. roseochromogenes was exposed to 0.335 mM cycloheximide for 8 h prior to the progesterone pre-incubation, pointed to post-translation modification of the roseoredoxin. Separation of two isoforms of roseoredoxin by isoelectric focusing supported this proposition.

Use of molecular subtyping in surveillance for Salmonella enterica serotype typhimurium

BACKGROUND

Because Salmonella enterica serotype typhimurium is the most common serotype isolated from persons with salmonellosis in the United States, it is difficult to detect unusual clusters or outbreaks. To determine whether molecular subtyping could be useful in public health surveillance for S. enterica serotype typhimurium, the Minnesota Department of Health initiated the routine use of pulsed-field gel electrophoresis (PFGE) of isolates.

METHODS

Beginning in 1994, all S. enterica serotype typhimurium isolates submitted by clinical laboratories to the Department of Health were subtyped by PFGE. A standard questionnaire was used to interview patients about possible sources of infection.

RESULTS

From 1994 through 1998, 998 cases of infection with S. enterica serotype typhimurium were reported to the Minnesota Department of Health (4.4 cases per 100,000 person-years). PFGE was performed on 958 of the isolates (96 percent), and 174 different patterns were identified. Sixteen outbreaks with a common source were identified, accounting for 154 cases. PFGE subtyping made it possible to confirm 10 outbreaks that involved small numbers of cases in institutional settings. Of six larger, community-based outbreaks, four would probably not have been recognized without PFGE subtyping. These four outbreaks accounted for 96 of the 154 culture-confirmed outbreak cases (62 percent). Fifty-six of 209 isolates tested for antimicrobial susceptibility (27 percent) were resistant to at least five antimicrobial agents. The multidrug-resistant isolates identified had unique PFGE patterns.

CONCLUSIONS

Routine molecular subtyping of S. enterica serotype typhimurium by PFGE can improve the detection of outbreaks and aid in the identification of multidrug-resistant strains. Combining routine molecular subtyping with a method of rapid communication among public health authorities can improve surveillance for S. enterica serotype typhimurium infections.

Does early responsive parenting have a special importance for children's development or is consistency across early childhood necessary?

The role of early versus ongoing maternal responsiveness in predicting cognitive and social development was examined in home visits for mothers, full-term children (n = 103), and medically low-risk (n = 102) and high-risk (n = 77) preterm children at 5 ages. There were 4 maternal clusters based on warm and contingent responsiveness behaviors observed early (at 6, 12, and 24 months) and late (at 3 and 4 years): high early, high late; high early, low late; low early, moderate late; and low early, low late. Children, especially preterm children, showed faster cognitive growth when mothers were consistently responsive. Social growth was similar in the consistently responsive (high-high) and the early-responsive inconsistent (high-low) clusters, but greater deceleration at 4 years among children with mothers in the inconsistent cluster refuted the notion of a unique role for early responsiveness. The importance of consistent responsiveness, defined by an affective-emotional construct, was evident even when a broader constellation of parenting behaviors was considered.

Identification and characterization of two G protein-coupled receptors for neuropeptide FF

The central nervous system octapeptide, neuropeptide FF (NPFF), is believed to play a role in pain modulation and opiate tolerance. Two G protein-coupled receptors, NPFF1 and NPFF2, were isolated from human and rat central nervous system tissues. NPFF specifically bound to NPFF1 (K(d) = 1.13 nm) and NPFF2 (K(d) = 0.37 nm), and both receptors were activated by NPFF in a variety of heterologous expression systems. The localization of mRNA and binding sites of these receptors in the dorsal horn of the spinal cord, the lateral hypothalamus, the spinal trigeminal nuclei, and the thalamic nuclei supports a role for NPFF in pain modulation. Among the receptors with the highest amino acid sequence homology to NPFF1 and NPFF2 are members of the orexin, NPY, and cholecystokinin families, which have been implicated in feeding. These similarities together with the finding that BIBP3226, an anorexigenic Y1 receptor ligand, also binds to NPFF1 suggest a potential role for NPFF1 in feeding. The identification of NPFF1 and NPFF2 will help delineate their roles in these and other physiological functions.

Charge-density-wave-induced modifications to the quasiparticle self-energy in 2H- TaSe2

The self-energy of the photohole in 2H-TaSe2 is measured by angle-resolved photoemission spectroscopy as a function of binding energy and temperature. In the charge-density wave (CDW) state, a structure in the self-energy is detected at approximately 65 meV that cannot be explained by electron-phonon scattering. A reduction in the scattering rates below this energy indicates the collapse of a major scattering channel with the formation of the CDW state accompanying the appearance of a bosonic "mode" in the excitation spectrum of the system.

Progesterone side-chain cleavage by Bacillus sphaericus

The side-chain of progesterone was cleaved by Bacillus sphaericus to produce two C-19 keto androstene steroids. The structures of these metabolites were androstenedione and 1-dehydroandrostenedione. High concentrations of glucose in the culture medium inhibited conversion of progesterone to these two metabolites.

The use of entomopathogenic fungi for the control of parasitic mites, Psoroptes spp

In vitro trials were carried out to evaluate the potential of fungal pathogens as biological control agents of parasitic mites, Psoroptes ovis (Hering) (Acari: Psoroptidae) from rabbit hosts (synonym: Psoroptes cuniculi). The fungus Hirsutella thompsonii Fisher showed no pathogenicity. Metarhizium anisopoliae (Metschinkoff), however, showed a high level of pathogenicity; 3 days after exposure to fungal conidia all mites were dead and 6 days after exposure 60% of the dead adult females, 10% of the dead adult males and 30% of the dead female nymphs had fungal hyphae protruding from their cuticular surface. There was a significant effect of conidial concentration on the number of mite cadavers that displayed fungal infection. Exposure to between 1x10(4) and 1x10(6) conidiaml(-1) resulted in 2-25% of the mites being infected. Mean infection levels were highest, 71%, when the mites were exposed to 1x10(7) conidiaml(-1). Similarly, there was a significant effect of conidial concentration on the time taken for the mites to reach 50% levels of mortality (LT(50)) The mean LT(50) value was approximately 2.7 days, when the mites were exposed to a solution of 1x10(7) and 1x10(8) conidiaml(-1) which was significantly shorter than controls exposed to 0.03% Tween-80 solution only. There was no significant effect of passaging the fungus, either once or twice, through the host on the subsequent infectivity of M. anisopliae. The potential for use of entornopathogenic fungi for the control of parasitic mites, particularly in relation to sheep, is discussed.

Expression of a novel neuropeptide Y receptor subtype involved in food intake: an in situ hybridization study of Y5 mRNA distribution in rat brain

Our group has reported on the cloning of a novel rat neuropeptide Y (NPY) receptor involved in NPY-induced food intake, the Y5 receptor. The distribution in rat brain of the mRNA encoding this receptor has been determined by in situ hybridization histochemistry, using radiolabeled oligonucleotide probes. Control experiments were carried out in cell lines transfected with either rat Y1 or rat Y5 cDNAs. With the exception of the cerebellum, only the antisense probes yielded hybridization signal in rat brain tissue sections. A number of brain regions contained hybridization signals indicative of Y5 mRNA localization. Chief among these were various hypothalamic nuclei, including the medial preoptic nucleus, the supraoptic nucleus, the paraventricular nucleus, and the lateral hypothalamus. Other regions with substantial hybridization signals included the midline thalamus, parts of the amygdala and hippocampus, and some midbrain and brain-stem nuclei. In general a low density of Y5 mRNA was observed in most cortical structures, with the exception of the cingulate and retrosplenial cortices, each of which contained a moderate abundance of Y5 hybridization signal. The distribution of this receptor mRNA is consistent with a role for the Y5 receptor in food intake and also suggests involvement in other processes mediated by NPY.

Regulation of the Ca2+-inhibitable adenylyl cyclase type VI by capacitative Ca2+ entry requires localization in cholesterol-rich domains

The endogenous Ca(2+)-inhibitable adenylyl cyclase type VI of C6-2B glioma cells is regulated only by capacitative Ca(2+) entry and not by a substantial elevation of [Ca(2+)](i) from either intracellular stores or via ionophore-mediated Ca(2+) entry (Chiono, M., Mahey, R., Tate, G., and Cooper, D. M. F. (1995) J. Biol. Chem. 270, 1149-1155; Fagan, K. A., Mons, N., and Cooper, D. M. F. (1998) J. Biol. Chem. 273, 9297-9305). The present studies explored the role of cholesterol-rich domains in maintaining this functional association. The cholesterol-binding agent, filipin, profoundly inhibited adenylyl cyclase activity. Depletion of plasma membrane cholesterol with methyl-beta-cyclodextrin did not affect forskolin-stimulated adenylyl cyclase activity and did not affect capacitative Ca(2+) entry. However, cholesterol depletion completely ablated the regulation of adenylyl cyclase by capacitative Ca(2+) entry. Repletion of cholesterol restored the sensitivity of adenylyl cyclase to capacitative Ca(2+) entry. Adenylyl cyclase catalytic activity and immunoreactivity were extracted into buoyant caveolar fractions with Triton X-100. The presence of adenylyl cyclase in such structures was eliminated by depletion of plasma membrane cholesterol. Altogether, these data lead us to conclude that adenylyl cyclase must occur in cholesterol-rich domains to be susceptible to regulation by capacitative Ca(2+) entry. These findings are the first indication of regulatory significance for the localization of adenylyl cyclase in caveolae.

Cutaneous manifestations of alcohol abuse

Alcohol consumption and abuse can have a variety of cutaneous manifestations. In addition to the well-recognized stigmata of the chronic alcoholic patient, even early abuse can result in distinctive skin changes or exacerbate existing cutaneous disorders. An accurate history of alcohol intake will facilitate recognition of these alcohol-induced cutaneous disorders and treatment resistance of dermatoses such as psoriasis as well as help decrease morbidity in surgical procedures. Familiarization with the spectrum of cutaneous manifestations of alcohol abuse and alcoholic liver disease can also allow for early detection and treatment in an attempt to minimize the medical consequences. We review the medical literature and discuss the spectrum of dermatologic disease associated with the use and abuse of alcohol.

Incidence of foodborne illnesses reported by the foodborne diseases active surveillance network (FoodNet)-1997. FoodNet Working Group

In 1997, the Foodborne Diseases Active Surveillance Program (FoodNet) conducted active surveillance for culture-confirmed cases of Campylobacter, Escherichia coli O157, Listeria, Salmonella, Shigella, Vibrio, Yersinia, Cyclospora, and Cryptosporidium in five Emerging Infections Program sites. FoodNet is a collaborative effort of the Centers for Disease Control and Prevention's National Center for Infectious Diseases, the United States Department of Agriculture's Food Safety and Inspection Service, the Food and Drug Administration's Center for Food Safety and Applied Nutrition, and state health departments in California, Connecticut, Georgia, Minnesota, and Oregon. The population under active surveillance for foodborne infections was approximately 16.1 million persons or roughly 6% of the United States Population. Through weekly or monthly contact with all clinical laboratories in these sites, 8,576 total isolations were recorded: 2,205 cases of salmonellosis, 1,273 cases of shigellosis, 468 cases of cryptosporidiosis, 340 of E. coli O157:H7 infections, 139 of yersiniosis, 77 of listeriosis, 51 of Vibrio infections, and 49 of cyclosporiasis. Results from 1997 demonstrate that while there are regional and seasonal differences in reported incidence rates of certain bacterial and parasitic diseases, and that some pathogens showed a change in incidence from 1996, the overall incidence of illness caused by pathogens under surveillance was stable. More data over more years are needed to assess if observed variations in incidence reflect yearly fluctuations or true changes in the burden of foodborne illness.

Life-cycle stage morphology of Psoroptes mange mites

Detailed life-cycle stage descriptions for the ectoparasitic mite Psoroptes ovis (Hering) (Acari: Psoroptidae) from rabbit hosts (syn. Psoroptes cuniculi) are presented. The results resolve a number of contradictions in the literature relating to the recognition of the life cycle stages of these mites. This study supports the view that there are two distinct male nymphal stages, both lacking dorsoposterior tubercles. The male tritonymph is significantly larger than the protonymph and has five pairs of metapodosomal setae rather than three. In addition, male tritonymphs have two pairs of cuticular pits on the central metapodosoma rather than the single pair of the protonymph. The results also show that the female protonymph can be distinguished from the male nymphal stages and the female tritonymph. Both female nymphal stages possess dorsoposterior tubercles, but the protonymph is significantly smaller than the tritonymph. In addition, the protonymph possesses three pairs of metapodosomal setae rather than five, one pair of cuticular pits rather than two, and a pulvillus on leg IV which is absent in the female tritonymph. The presence of dorsoposterior tubercles enables the female nymphs to be distinguished easily from the males. By contrast, distinguishing between the nymphal stages of the same sex relies on the identification of both the number of metapodosomal setae and cuticular pits. These descriptions are used to produce a key, which allows the various stages of both sexes to be distinguished.

Early maternal and child influences on children's later independent cognitive and social functioning

The present study examined whether parenting and child characteristics of 2- and 3 1/2-year-old children had common paths of influence on their 4 1/2-year independent cognitive and social functioning. Structural equation modeling was guided by hypotheses that assumed children's later independence is facilitated by specialized parental support in early social interactions. To address the importance of variability in early development for understanding children's later independence, we included 104 term and 185 preterm children, as they are known to differ in early skills. As predicted, mothers' maintaining of children's interests indirectly supported 4 1/2-year cognitive and social independence through a direct, positive influence on 2- and 3 1/2-year skills. Directiveness positively supported children's early cognitive and responsiveness skills but by 3 1/2 years, high levels of this behavior had a direct, negative influence on their cognitive and social independence at 4 1/2 years. Whereas high levels of maintaining interests across these ages support later independence, directiveness needs to decrease in relation to children's increasing competencies. Results support a theoretical framework that emphasizes the importance of the social context for understanding the origins of children's later independent functioning.

In vitro insecticidal effects of fipronil and beta-cyfluthrin on larvae of the blowfly Lucilia sericata

The insecticidal effects of the phenylpyrazole, fipronil, and a pyrethroid, beta-cyfluthrin, on larvae of the blowfly Lucilia sericata were determined in laboratory assays. When first stage larvae of L. sericata were reared on homogenized pig liver which had been treated with known amounts of test compounds, both fipronil and beta-cyfluthrin induced significant levels of mortality compared to acetone and water controls. However, fipronil was approximately 10 times more toxic than beta-cyfluthrin to L. sericata larvae following ingestion. Beta-cyfluthrin had little effect on mortality until concentrations of approximately 0.5 ppm were reached. In contrast, fipronil effected L. sericata mortality at a concentration of 0.05 ppm and 100% mortality was reached by 0.5 ppm. The lethal concentration (LC50) value for beta-cyfluthrin was 1.56 ppm as compared to 0.14 ppm for fipronil. Following contact of first and third stage larvae with cloth impregnated with known amounts of test compound, the mortality profiles of fipronil and beta-cyfluthrin were similar. At short contact times, the LC50 values for fipronil were lower than those for beta-cyfluthrin. However, at the highest contact time evaluated for the first stage larvae, 300 s, there was a reversal in this trend. The results suggest that the phenylpyrazole fipronil may represent a new potential insecticide for development against blowfly strike of sheep.

Galanin receptor subtypes

The neuropeptide galanin, which is widely expressed in brain and peripheral tissues, exerts a broad range of physiological effects. Pharmacological studies using peptide analogues have led to speculation about multiple galanin receptor subtypes. Since 1994, a total of three G-protein-coupled receptor (GPCR) subtypes for galanin have been cloned (GAL1, gal2 and gal3). Potent, selective antagonists are yet to be found for any of the cloned receptors. Major challenges in this field include linking the receptor clones with each of the known physiological actions of galanin and evaluating the evidence for additional galanin receptor subtypes.

Particles and vegetation: implications for the transfer of particle-bound organic contaminants to vegetation

This paper presents a comprehensive review of the mechanisms responsible for the transfer of atmospheric particulate deposition and soil particulate re-suspension onto vegetation. The nature of atmospheric aerosols and dry/wet particulate deposition are reviewed, together with information from the literature on radionuclides as tracers of the air particle/soil particle to vegetation transfer processes. Information from these fields is used to make inferences about the potential significance of these pathways in supplying particle-bound semi-volatile organic chemicals (e.g. polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls) to vegetation. Retention of compounds on particles brought to the above-ground plant surfaces is discussed. In the absence of definitive field/experimental studies, calculations are made drawing on the literature data to estimate the contributions of atmospheric and soil particle-bound organic contaminants to the plant concentration. These show that depending on the site-specific, species-specific and compound-specific scenarios considered, particulate-bound inputs may be negligible or may dominate the supply of organic contaminants to the above-ground portion of plants. However, field/experimental studies and direct measurements are needed to provide reliable quantitative data on this topic.

Relation of mothers' affective developmental history and parenting behavior: effects on infant medical risk

Mothers of infants with varying degrees of medical risk were grouped according to their perception of acceptance or rejection in childhood. Those who recalled the highest degree of acceptance showed greater warmth and flexibility as parents, regardless of their infants' degree of medical risk. However, infant medical risk was an important moderator in relations between maternal perceptions of childhood rejection and parental behavior.

Assessment of the diabetic foot using spiral computed tomography imaging and plantar pressure measurements: a technical report

Persons with diabetes mellitus (DM) and peripheral neuropathy are at high risk for skin breakdown due to unnoticed excessive pressures to the plantar foot during walking. We developed methods that combined spiral x-ray computed tomography (SXCT) imaging and plantar pressure analysis to quantify internal foot structure and external pressure during plantar loading. Methods were tested using a subject with DM who had a plantar ulcer, and a healthy control. SXCT measurements were within 2 mm of truth and SXCT plantar recordings were within 6.5% of walking trials. Hammer toe deformity (second toe), severe atrophy of the intrinsic muscles and less contact area during plantar loading, and a peak plantar pressure three times greater at the site of the ulcer were measured in the diabetic foot as compared with the healthy control. This preliminary investigation suggests that these methods are accurate for structural and pressure measurements of diabetic and healthy feet.

Microbial transformations of steroids-XI. Progesterone transformation by Streptomyces roseochromogenes-purification and characterisation of the 16alpha-hydroxylase system

Streptomyces roseochromogenes, NCIB 10984, contains a cytochrome P450 which, in conjunction with two indigenous electron transfer proteins, roseoredoxin and roseoredoxin reductase, hydroxylates exogenous progesterone firstly to 16alpha-hydroxyprogesterone and thereafter in a second phase bioconversion to 2beta,16alpha-dihydroxyprogesterone. The progesterone 16alpha-hydroxylase P450 and the two electron transfer proteins have been purified to homogeneity. A reconstituted incubation containing these three purified proteins and NADH, the natural electron donor, produced identical hydroxy-progesterone metabolites as in intact cells. Peroxy and hydroperoxy compounds act in a shortened form of the cycle known as the 'peroxide shunt' by replacing the natural pathway requirement for the electron donor NADH, the electron transfer proteins and molecular O2, the terminal electron acceptor. In an NaIO4 supported incubation, the initial rate of progesterone hydroxylation was marginally higher (1.62 mmol progesterone/mmol P-450/h) than in the reconstituted natural incubation (1.18 mmol progesterone/mmol P-450/h) but the product yield was significantly lower, 0.45 mol hydroxyprogesterone produced/mol P-450 compared to 6.0 mol hydroxyprogesterone produced/mol P-450. These yield data show that in the reconstituted natural pathway, progesterone 16alpha-hydroxylase P450 supports multiple rounds of hydroxylation in contrast to a likely single oxygenation by a minority of P450s in the peroxide shunt pathway.

Computer-assisted 3D reconstruction of serial sections of cortical bone to determine the 3D structure of osteons

The objective of this study was to create three-dimensional (3D) images for the histomorphological study of osteons. Medical imaging technology was used to register digitized 2D images of serial decalcified histological sections of bone, to segment the tissues of interest from the surrounding tissues, and to create 3D reconstructions from the segmented structures. Examination of the 3D reconstructions did not support suggestions in the literature that osteons have a spiraling organization. In contrast, the 3D reconstructions indicated that osteons have a complex pattern of organization that is dominated by branching. Examination of the reconstructions also suggested that osteons described in the literature as being dumbbell shaped are actually artifacts of the plane of sectioning. This study demonstrated the applicability of imaging and visualization technology developed for the 3D reconstruction of medical images to the reconstruction of digitized 2D images of serial sections of bone and additionally demonstrated the feasibility of using 3D reconstructions for the histomorphological study of osteons.