Monitoring and maintaining bone health in patients with Turner syndrome.

INTRODUCTION: Subjects affected with Turner Syndrome (TS) suffer low bone mineral density and high risk of fracture from a young age. Estrogen deficiency is considered the main risk factor but other factors, such as intrinsic bone abnormalities, enhanced osteoclastogenesis, vitamin D deficiency and other comorbidities may contribute to the exalted bone fragility. AREAS COVERED: The authors performed a literature search in PubMed and EMBASE, using selected key words. They focused their search on pathogenetic mechanisms of osteoporosis in TS and updated the diagnosis, prevention and therapeutic interventions. EXPERT OPINION: Bone health is a concern in subjects with TS, and strategies to prevent osteoporosis and fractures should be considered from childhood. Advice on how to live a healthy lifestyle, including physical activity and correct nutrition, should be given during childhood in order to prevent bone impairment later in life. The screening for vitamin D deficiency should be performed between the ages of 9 and 11, and every 2-3 years thereafter. Early initiation of estrogen replacement therapy (ERT) between 11-12 years of age, prompt titration to the adult dose after 2 years, and long-term follow-up to guarantee compliance with ERT, are the key points of osteoporosis prevention in women with TS.

A case of dwarfism in 6th century Italy: Bioarchaeological assessment of a hereditary disorder.

OBJECTIVE: The skeletal remains of a short-statured individual (T17) are described and a differential diagnosis performed to determine the etiology of the condition. MATERIALS: An individual considered pathologically short in stature was discovered in the burial site of Piazza XX Settembre, Modena (northern Italy). METHODS: Morphological and morphometric analyses were performed, and T17 was compared to dwarfs from other localities and periods and to the adult female population from the same site. A paleopathological survey was undertaken to assess the degree of the skeletal elements of T17 were affected. RESULTS: T17 was a female, 20-30 years of age at death, with a stature of 128 cm and disproportionate dwarfism associated with congenital skeletal dysplasia. CONCLUSIONS: T17 likely affected by a form of hypochondroplasia. SIGNIFICANCE: Anatomical consequences of hypochondroplasia are presented, and the timeframe and associated burial goods suggest a 6th-century Lombard short stature belonging to one of the earliest Lombard settlements in Italy. SUGGESTIONS FOR FURTHER RESEARCH: Future genetic analysis would resolve if the mutation in the type 3 fibroblast growth factor receptor (FGFR3) is present in the remains of T17; however, it is not exclusivly linked to hypochondroplasia.

Assessment of Gross Fetal Malformations: The Modernized Wilson Technique and Skeletal Staining.

Teratology is the study of anatomical and physiological abnormalities, commonly known as birth defects. If an embryo is exposed to a harmful substance, or teratogen, during the critical period of development, an ensuing malformation may occur. These malformations and their associated mechanisms are studied and analyzed in laboratory animals in order to prevent them from occurring in humans. Rodents such as rats and mice have commonly been used in such studies because of their similarity to humans. In 1959, James G. Wilson designed, developed, and tested a protocol on how to observe and analyze structural malformations in rodent fetuses, which included: external examination, skeletal evaluation, soft tissue analysis, and data collection/analysis. For standardization purposes, i.e., to normalize findings from one lab to another, it is important that this protocol be followed with precision. Although many years have passed since Wilson initially created this protocol, it is still widely used to this day, and only minor changes have been made to his instructions such as the chemical reagents used in the experiments and methods of analysis of the experimental data. Such testing has resulted in major advances in the dissemination of teratology information, including the identification of an increasing number of teratogens and the understanding of the pathogenesis of birth defects. While mechanistically birth defect prevention will include the understanding of individual genomes and pharmacogenomics, overall, morphological assessment will still be required as an integral part of birth defects research. As the interaction between teratogenic and genetic factors is better understood, it is anticipated that the incidence of most types of defects will substantially be reduced.

Homeward Bound: A Case Series of Cross-Cultural Care at End of Life, Enhanced by Pediatric Palliative Transport.

For most families, the preferred location of death for their child is home, yet most children still die in the hospital. Many children with life-threatening and life-limiting illness are medically dependent on technology, and palliative transport can serve as a bridge from the intensive care unit to the family's home to achieve family-centered goals of care. Palliative transport may also present an opportunity to prioritize cultural care and rituals at end of life which cannot be provided in the hospital. We describe a case series of pediatric patients from communities espousing markedly diverse cross-cultural values and limited financial resources. Specific cultural considerations at end of life for these children included optimizing the presence of the shared community or tribe, the centrality of healing rituals, and varied attitudes toward withdrawal of life-sustaining medical treatment. By addressing each of these components, we were able to coordinate palliative transport to enhance cross-cultural care and meaning at end of life for children with life-limiting illness.

MICROCOMPUTED TOMOGRAPHIC, MORPHOMETRIC, AND HISTOPATHOLOGIC ASSESSMENT OF CONGENITAL BONE MALFORMATIONS IN TWO NEOTROPICAL VIPERIDS.

Congenital malformations have been reported in all classes of vertebrates and may be a determinant of life span and survival. In reptiles, the incidence of congenital malformations can be associated with genetic and environmental causes, including pollution. The characterization of pathological processes involved in the development of congenital malformations of bone in snakes is rare in the literature, but is of great relevance in the field of reptile conservation and environmental health. We describe congenital bone lesions in 50 newborn jararaca (Bothrops jararaca) and 26 South American rattlesnakes (Crotalus durissus terrificus) born from wild-caught pregnant females in Southeastern Brazil. Lesions were evaluated by morphometric quantitative analysis, x-ray microtomography, and histopathologic descriptive analysis. Morphometric analysis showed that jararaca presented more severe axial lesions (kyphosis, scoliosis, and kyphoscoliosis) than rattlesnakes. Female rattlesnakes presented more severe axial lesions than did males. In rattlesnakes, spinal deformities were more frequently diagnosed in the caudal segment of the body. We present x-ray microtomographic assessments and images of malformed snakes (n=9) and characterized novel malformations, such as the agenesis of frontal, parietal, and supraoccipital bones in a jararaca specimen. Histopathologic findings included vertebral body fusion, myositis, coagulation necrosis, and disorganization of periaxial muscle fibers. The new methods and results presented in this study will be useful and informative for future research in pathology, teratology, embryology, and ecotoxicology in snakes.

Assessment of gross fetal malformations: the modernized Wilson technique and skeletal staining.

Teratology is the study of anatomical and physiological abnormalities, commonly known as birth defects. If an embryo is exposed to a harmful substance, or teratogen, during the critical period of development, an ensuing malformation may occur. These malformations and their associated mechanisms are studied and analyzed in laboratory animals in order to prevent them from occurring in humans. Rodents, such as rabbits, rats, and mice, have commonly been used in such studies because of their similarity to humans. In 1959, James G. Wilson designed, developed, and tested a protocol on how to observe and analyze structural malformations in rodent fetuses, which included external examination, skeletal evaluation, soft tissue analysis, and data collection/analysis. Although many years have passed since Wilson created this protocol, it is still widely used to this day, and only minor changes have been made to his instructions such as the chemicals used in the experiments and also the analysis of the experimental data. While only minor modifications have been made to this protocol since its beginning, major advances have been made in the dissemination of teratology information to the public such that information is now available through the Internet--information including the identification of an increasing number of teratogens and the understanding of the pathogenesis as it relates to the etiology of birth defects. Despite these advances, however, there has been little decrease in the overall incidence of major birth defects, although significantly improved reporting and ascertainment of birth defects must be factored into the equation in determining birth defect rates. Future birth defect prevention may be based on the understanding of individual genomes and pharmacogenomics, and as the interaction between teratogenic and genetic factors is better understood--with the hope that the incidence of both chemically induced and genetic defects will one day be substantially reduced.

Changes in bone structure of Corriedale sheep with inherited rickets: a peripheral quantitative computed tomography assessment.

An inherited skeletal disease with gross and microscopic features of rickets has been diagnosed in Corriedale sheep in New Zealand. The aim of this study was to quantify the changes present in tibia from sheep with inherited rickets using peripheral quantitative computed tomography. In affected sheep, scans in the proximal tibia, where metaphysis becomes diaphysis, showed significantly greater trabecular bone mineral content (BMC) and bone mineral density (BMD). The sheep with inherited rickets had significantly greater BMC and bone area in the mid-diaphysis of the proximal tibia compared to control sheep. However, BMD in the mid-diaphysis was significantly less in affected sheep than in controls, due to the greater cortical area and lower voxel density values in affected sheep. From this it was concluded that the increased strain on under-mineralised bone in sheep with inherited rickets led to increased bone mass in an attempt to improve bone strength.

Dose-response relationships of rat fetal skeleton variations: Relevance for risk assessment.

In developmental toxicity studies, skeleton abnormalities found in fetuses at term are classified as variations or malformations. The relevance of skeleton variations for human risk assessment, however, is a controversial issue. This paper is a contribution to the discussion on the interpretation of fetal skeleton variations in the context of risk assessment. Dose-response relationships of skeleton variations and malformations induced by three antineoplastic drugs (FUDR: 5-fluoro-2'-deoxyuridine, HU: hydroxyurea and 6-MPr: 6-mercaptopurine-riboside) were evaluated. FUDR (0, 3, 14, 25, 35, 45, 55 and 65mg/kg body wt sc) and HU (0, 250, 300, 350, 400, 450, 500 and 550mg/kg body wt ip) were administered to rats on gestation day 11 (GD 11) while 6-MPr (0, 3, 7, 10 and 14mg/kg body wt sc) was given on GD 11, or on GD 12. Caesarean sections were performed on GD 21 and all fetuses were cleared and stained with alizarin red S for skeleton examination. Drugs given on GD 11 increased the incidence of thoracic and lumbar vertebra (dumbbell-shaped and bipartite ossification center (o.c.) and sternum (misaligned sternebrae) variations in a dose-dependent manner. Occurrence of zygomatic bone fused with maxilla (a variation in our rats) was also increased by HU and 6-MPr (GD 11) but it was not altered by FUDR. Spontaneous occurrence of wavy ribs was reduced by all treatments. Malformations such as cleft palate, tympanic bone absent and tibia absent were also increased in a dose-dependent manner by the three compounds. No observed effect levels (NOEL) for variations, irrespective of the compound administered, were generally lower than NOELs for malformations. In the discussion, we supported the view that any dose-related increase in the incidence of variations should be taken into account for determination of NOELs in routine studies. Increased occurrences of skeleton variations in term fetuses are also to be considered in risk assessment, unless experimental evidence exists that a particular change has no detrimental effect on the animal survival or health after birth or that it does not occur in humans.

Embryo/fetal toxicity assessment of lasofoxifene, a selective estrogen receptor modulator (SERM), in rats and rabbits.

BACKGROUND: The purpose of this study was to evaluate the effects of lasofoxifene, a selective estrogen receptor modulator (SERM), on rat and rabbit fetal development. METHODS: Lasofoxifene was administered orally to rats (1, 10, 100 mg/kg) between gestation days (GD) 6-17, and in rabbits (0.1, 1, 3 mg/kg) between GD 6-18. Maternal body weight and food consumption were monitored throughout pregnancy. Fetuses were delivered by Cesarean section on GD 21 in rats, and GD 28 in rabbits, to evaluate fetal viability, weight, and morphology. Drug concentrations in maternal plasma were measured in a separate cohort of animals at several time points commencing on GD 17 (rats) and 18 (rabbits). On GD 18 (rat) and GD 19 (rabbit) drug concentrations were measured in maternal plasma and in fetal tissue 2 hr post dosing to determine the fetal to maternal drug ratio. RESULTS: In rats, there were dose-related declines in maternal weight gain and food consumption. Post implantation loss was significantly increased at dosages of 10 and 100 mg/kg, and the number of viable fetuses was decreased at 100 mg/kg. The placental weights increased, whereas fetal weights decreased in a dose-dependent manner. Lasofoxifene-related teratologic findings were noted at 10 and 100 mg/kg and included imperforate anus with hypoplastic tails, dilatation of the ureters and renal pelvis, misaligned sternebrae, hypoflexion of hindpaw, wavy ribs, and absent ossification of sternebrae. In rabbits, neither maternal weight gain nor food consumption were affected during treatment. Between GD 26-28, there was a dose-dependent increased incidence of red discharge beneath the cages. At 1 and 3 mg/kg, resorptions and post-implantation loss increased. There were no significant external or visceral effects, but 3 mg/kg there was an increased incidence of supernumerary ribs. Although the maternal plasma Cmax and AUC(0-24) were dose-dependent, the exposures in the rat were many orders of magnitude greater than in the rabbit even for the same 1 mg/kg dose. The single time point fetal/maternal drug ratio was higher in the rat (1.3-0.78) than in the rabbit (0.21-0.16). CONCLUSION: In general, both maternal and fetal effects of lasofoxifene were similar to those reported with other SERMs. Although the incidence or severity of these effects was, in some instances, greater in the rat than in the rabbit, the doses and the resultant maternal and fetal exposures were many orders of magnitude higher in the rat, suggesting the rabbit to be more sensitive to the toxicological effects of lasofoxifene.

A new rapid radiological procedure for routine teratological use in bone ossification assessment: a supplement for staining methods.

BACKGROUND: Presently, bone ossification is assessed by the study of single-stained fetal bones (alizarin red-S) or double-stained bones and cartilaginous structures (alcian blue followed by alizarin red-S). Both methods, especially double-staining, are labor-intensive, time-consuming, and provide qualitative information regarding skeleton ossification. Quantitative evaluation of ossification is more difficult and is usually based on determination of calcium and other minerals in the bone by means of atomic absorption spectrometry. Here we introduce a simple new method that allows quantitative determination of skeleton ossification before routine staining examination. METHODS: Fetuses delivered by laparotomy on the 16th and 21st day of gestation as well as 1-day-old rat pups were examined. The fetuses and pups were prenatally subcutaneously exposed to sodium valproate or to physiological saline. Lateral, prone, and supine digital radiograms of each fetus were taken using the Digora-Soredex digital radiography system and the Planmeca Intra intraoral X-ray machine. According to the best visualization, the data concerning vertebra were analyzed. All the fetuses were then routinely double-stained using alcian blue and alizarin red-S. RESULTS: Malformations of axial skeleton (rib, sternum, and thoracic and sacral vertebra) were found in valproate-treated groups. Unlike cartilage malformations, the bone changes were detected in similar frequency in radiological and staining methods. Differences in densities according to the degree of ossification in the vertebral arches and bodies at different levels of the vertebral column, between drug-treated and negative control groups were noted. CONCLUSIONS: The preliminary results suggest that digital radiography examination is a useful method in determining delaying of skeleton ossification not detectable by other methods. It balances qualitative and quantitative aspects of the presently used methods and is also simple, objective, fast, and relatively inexpensive.

Natural history study of pseudoachondroplasia.

Pseudoachondroplasia (PSACH) is a well-characterized autosomal dominant dwarfing condition. A great deal of information is available about orthopedic complications, but little is known about extraskeletal complications in adulthood. This study was undertaken to delineate the natural history of PSACH at all ages. Seventy-nine individuals responded to an extensive questionnaire that included information about deformities, operations, general health, chronic diseases, and reproduction. PSACH individuals were ascertained through the University of Texas Medical Genetics patient population, a genetic linkage study, and the social organization, Little People of America. The results show that PSACH individuals with a family history do not have a distinct or more severe phenotype than new mutation cases. There were not differences in the number of orthopedic complications, operations, or number of offspring between these two groups. Less than half of affected adults reported having total hip replacement surgery, which was less common than previously reported. Extraskeletal complications were generally uncommon. There were four cases of cancers in 41 individuals queried. Premature osteoarthritis was the major health problem for PSACH individuals. PSACH individuals are generally healthy but have problems associated with debilitating osteoarthritis.

Assessment of the magnetic field distribution in yellow and red bone marrow by the MAGSUS technique.

The MAGSUS imaging technique has been shown to provide insights into the distribution of the macroscopic and microscopic static magnetic field without requiring further data processing. Applications of the MAGSUS technique on bone marrow are reported in more detail in this article. Effects of the superposition of water and lipid signals and of considerable transverse relaxation on MAGSUS imaging are demonstrated, and adapted imaging parameters are presented. Examples of applications on marrow with different physiological and pathological compositions and different locations are shown. Appropriate adjustments for a reliable estimation of the trabecular density in peripheral yellow marrow and for an assessment of the field distribution in hemopoietic red marrow are reported. Osteoporotic peripheral marrow with reduced amount of trabecular structures and alterations due to osteodystrophia deformans can be simply revealed by this method. An estimation of the trabecular density can also be performed by MAGSUS in vertebral bodies of hematologically unaffected persons, but the interindividually differing amount of paramagnetic depositions in the marrow (e.g., hemosiderin) must be taken into account.

Teratological assessment of stobadine after single and repeated administration in mice.

Teratological studies were performed with stobadine, a compound with antiarrhythmic and antihypoxic activity. Single i.v. injections of stobadine in the form of dihydrochloride (DH 1011) to ICR mice on days 3, 6, 9 or 12 of gestation at doses of 1 and 3 mg kg-1 had no teratogenic effect. Slight fetal toxicity was manifested by decreased fetal weight after treatment on days 3 and 6, increased incidence of rudimentary ribs after treatment on days 9 and 12 of gestation and non-significantly increased postimplantation loss after injection on day 6 of gestation. The effect of repeated oral administration in the form of dipalmitate salt (DP 1031) was studied in doses of 12.2, 61.0 and 122.0 mg kg-1 on days 4-16 of gestation. Oral exposure to 61.0 mg kg-1 DP 1031 resulted in significant reduction of implantations, live fetuses and litter weight, and after 122.0 mg kg-1 DP 1031 the fetal weight was significantly decreased. External and skeletal examinations of the fetuses revealed no evidence of teratogenesis. The relevance of the two routes of stobadine administration for risk involvement is discussed.

Assessment of the effect of n-butanol given to female rats in drinking water on fertility and prenatal development of their offspring.

Female rats were given aqueous solutions of n-butanol containing 0.24, 0.8 and 4% n-butanol (0.3; 1.0 and 5.0 g/kg/day) for 8 weeks before and during gestation. The control animals received tap water. The experiment was performed in two stages. The first comprised of the assessment of the oestrous cycle before exposure and then during 4-5 and 7-8 weeks of exposure, and the second stage of the fertility of female rats and their foetal development. The duration of the cycle and its individual stages in the control and the exposed females were similar. It was found that n-butanol alcohol is a foetotoxic agent and produces developmental anomalies in a foetus's skeleton and central nervous system.

High resolution metrical analysis applied to the assessment of damage associated with induced mutations in the mouse.

Morphometric methods were used to investigate variation in the skeletons of 1030 offspring produced from matings of male DBA/2J by female C57BL/6J mice. 751 offspring originated from males that had received a single intraperitoneal injection of ethyl nitrosourea (EtNU) at a dose of 250 mg/kg. The remainder of the mice served as controls. The male parents of the controls were injected only with the buffer used as vehicle for the EtNU. Offspring were obtained for 3 weeks following injection. The treated males were then sterile for about 8 weeks. Immediately after the sterile period another sample of progeny was obtained. In the treated group, litter sizes at birth and weaning were reduced and survival to adulthood was lower. However, none of the differences were statistically significant. The skeletons were evaluated by two independent approaches. The first relied upon gross observation for unusual phenotypic variation, the second on a series of metrical measurement and coordinate data. A considerable amount of variation was recorded by both approaches. Some of the variants were severe but others were mild and perhaps of little or no importance to the health of the mice. The gross observation method produced no evidence for increased mild or severe variants in any group of offspring from the treated mice. The metrical methods also showed no evidence for treatment-related effects in offspring produced during the first 3 weeks of mating. However, in offspring produced after the sterile period, a pronounced, very highly statistically significant increase in all levels of metrical variation was observed. This treatment group revealed both increased variant measures and increased numbers of mice with variant measures. Much of this variation was so slight that it would have escaped notice were it not for the exacting measurements used in the analysis. Our morphometric approach is an analytically powerful tool, suitable for detecting variation in virtually any biological structure that can be measured. If the increased variation reported here is due to induced mutations, the effects would be consistent with that expected from slightly harmful mutations distributed throughout the mouse genome. It is appropriate to consider such effect in connection with genetic risk estimation.

Prenatal and postnatal assessment of Maneb-exposed CD-1 mice.

Skeletons of CD-1 mice exposed in utero during days 6 to 15 of gestation by gavage of their dams with 1200 mg/kg/day of Maneb in 1.0% carboxymethylcellulose (CMC), were examined between 60 and 65 days postnatal (DPN) for the 88 variants of the skeletal variant assay system (SVAS). Of the 58 variants that appeared, 13 differed (P less than 0.01) from untreated (UNTD), and 15 from vehicle-treated (VEH), despite absence of malformations at birth, weaning, or time of sacrifice. Major changes in frequencies of Parted Frontals, Abnormal Metoptic Roots, Reduced Articular Processes of the Thoracic (Th) Vertebrae, and Carpal Fusions occurred. Several variants affecting the Spinous Process of Th2 occurred in significant proportions as an unusual effect of this compound. In a series of 20 Maneb-treated litters dissected at 18 days post coitus (DPC), of 168 live fetuses, 9 had minor abnormalities, one was exencephalic, and 14 showed growth retardation. Prenatal mortality (20%) was higher than in UNTD (7.5%); litter size and litter weight were not significantly reduced. Ossification of cervical vertebral centra, and caudal vertebrae were significantly reduced, sternebra and limb ossification were not. Occurrence of 14-Ribs was increased. Although maternal mortality complicates interpretation, both traditional prenatal and postnatal examination focusing primarily on the skeleton revealed effects of exposure in the absence of frank malformations.

Skeleton, blood vessels and viscera: overlooked targets in fetuses of small species during the external examination for teratogenicity assessment.

Due to the translucency of the skin and underlying soft tissues, the external examination of near-term mouse fetuses can be extended to parts of the skeletal, visceral and vascular systems which are not taken into account in the protocols of teratogenicity tests. The importance of such visualization for improving the accuracy of such tests is discussed.

Assessment of adult skeletons to detect prenatal exposure to trypan blue in mice.

A Skeletal Variant Assay System (SVAS) consisting of a group of 88 spontaneously occurring qualitative variations of the adult mouse skeleton was studied in CD-1 mice which had been exposed in utero by way of three daily ip injections of their dams on days 7-9 of gestation with trypan blue. Treatment groups received daily doses of 0.25 cc of 0, .037, .075, .15, or .30% trypan blue dissolved in 0.9% NaCl. Two separate series of experiments were performed, and skeletons were examined at 62 +/- 2 days postnatal. Sixty-six and 58 of the variants occurred in the two series, respectively. Frequencies of occurrence of substantial numbers of variants differed from Untreated (UNTD) and Vehicle-Treated (VEH) values in a dose-related manner for both series. At the high dose 18 and 22 variants occurred with significantly different (P less than .01) frequencies from UNTD in the two series. Contrasting high-dose animals with vehicle controls revealed significant differences in 24 and 17 variants. There were 13 and 14 variants in the two series, respectively, which differed from both UNTD and VEH. If one considers differences at P less than .01 in one comparison and P less than .05 in the other, then 22 and 18 variants qualify as being significantly different from both controls in the two series. Agreement between the two series was excellent regarding which variants were affected. Several differed significantly from both UNTD and VEH in both series of experiments. Among these were a number which appeared more or less specific to trypan blue exposure. They include Dyssymphysis of the Atlas, Carpal Fusions, and Tarsal Fusions. Although increased frequency of an Interfrontal bone is seen with several treatments, the magnitude of the response and the low doses at which it is elicited are unique to trypan blue exposure. Numerous low-dose effects are striking in this set of experiments, making the SVAS a very sensitive indicator of trypan blue exposure. In addition to the variants mentioned, a large cluster of cervical (C) vertebrae variants, including dyssymphyses, fusions, imperfect transverse foramina of C1 and C2, and accessory transverse foramina of C3-C6, as well as vertebral fusions at various levels (especially cervical, sacral, and caudal), appear to be the principal effects of exposure to this compound. In addition, rib malformations at the high dose level, and increased frequency of occurrence of 27-presacral vertebrae at all dose levels, were important effects.(ABSTRACT TRUNCATED AT 400 WORDS)