Clinical Characterization of Patients With Autosomal Dominant Short Stature due to Aggrecan Mutations

CONTEXT

Heterozygous mutations in the aggrecan gene (ACAN) cause autosomal dominant short stature with accelerated skeletal maturation.

OBJECTIVE

We sought to characterize the phenotypic spectrum and response to growth-promoting therapies.

PATIENTS AND METHODS

One hundred three individuals (57 females, 46 males) from 20 families with autosomal dominant short stature and heterozygous ACAN mutations were identified and confirmed using whole-exome sequencing, targeted next-generation sequencing, and/or Sanger sequencing. Clinical information was collected from the medical records.

RESULTS

Identified ACAN variants showed perfect cosegregation with phenotype. Adult individuals had mildly disproportionate short stature [median height, -2.8 standard deviation score (SDS); range, -5.9 to -0.9] and a history of early growth cessation. The condition was frequently associated with early-onset osteoarthritis (12 families) and intervertebral disc disease (9 families). No apparent genotype-phenotype correlation was found between the type of ACAN mutation and the presence of joint complaints. Childhood height was less affected (median height, -2.0 SDS; range, -4.2 to -0.6). Most children with ACAN mutations had advanced bone age (bone age - chronologic age; median, +1.3 years; range, +0.0 to +3.7 years). Nineteen individuals had received growth hormone therapy with some evidence of increased growth velocity.

CONCLUSIONS

Heterozygous ACAN mutations result in a phenotypic spectrum ranging from mild and proportionate short stature to a mild skeletal dysplasia with disproportionate short stature and brachydactyly. Many affected individuals developed early-onset osteoarthritis and degenerative disc disease, suggesting dysfunction of the articular cartilage and intervertebral disc cartilage. Additional studies are needed to determine the optimal treatment strategy for these patients.

Pediatric Markers of Adult Cardiovascular Disease

BACKGROUND

Cardiovascular diseases are the leading cause of death worldwide. While cardiovascular disease typically does not occur until adulthood, the pathogenesis of atherosclerotic cardiovascular disease starts in early childhood.

OBJECTIVE

The purpose of this review is to describe the evidence that the process of atherosclerosis begins in childhood, as well as identify the risk factors present in childhood that are associated with the presence of atherosclerotic cardiovascular disease in childhood as well as future cardiovascular events in adulthood.

RESULTS AND CONCLUSION

There is much accumulating evidence linking modifiable risk factors that are already present in childhood and that strongly predict future cardiovascular disease. The selective targeting of modifiable risk factors in childhood, including body mass index, holds promise in reducing the burden of adult cardiovascular disease. Future research studies should focus on elucidating the mechanisms which drive the pathogenesis of atherosclerosis in childhood and young adulthood, as well as identifying which interventions are most effective at limiting the progression of atherosclerosis and thus reducing future cardiovascular disease.

COI haplotype groups in Mesocriconema (Nematoda: Criconematidae) and their morphospecies associations

Without applying an a priori bias for species boundaries, specimen identities in the plant-parasitic nematode genus Mesocriconema were evaluated by examining mitochondrial COI nucleotide sequences, morphology, and biogeography. A total of 242 specimens that morphologically conformed to the genus were individually photographed, measured, and amplified by a PCR primer set to preserve the linkage between specimen morphology and a specific DNA barcode sequence. Specimens were extracted from soil samples representing 45 locations across 23 ecoregions in North America. Dendrograms constructed by neighbor-joining, maximum likelihood, and Bayesian Inference using a 721-bp COI barcode were used to group COI haplotypes. Each tree-building approach resulted in 24 major haplotype groups within the dataset. The distinctiveness of these groups was evaluated by node support, genetic distance, absence of intermediates, and several measures of distinctiveness included in software used for the exploration of species boundaries. Five of the 24 COI haplotype groups corresponded to morphologically characterized, Linnaean species. Morphospecies conforming to M. discus, Discocriconemella inarata, M. rusticum, M. onoense, and M. kirjanovae were represented by groups composed of multiple closely related or identical COI haplotypes. In other cases, morphospecies names could be equally applied to multiple haplotype groups that were genetically distant from each other. Identification based on morphology alone resulted in M. curvatum and M. ornatum species designations applied to seven and three groups, respectively. Morphological characters typically used for species level identification were demonstrably variable within haplotype groups, suggesting caution in assigning species names based on published compendia that solely consider morphological characters. Morphospecies classified as M. xenoplax formed a monophyletic group composed of seven genetically distinct COI subgroups. The species Discocriconemella inarata is transferred to Mesocriconema inaratum based on its phylogenetic position on the COI tree as well as previous phylogenetic analyses using 18S, ITS1, and cytochrome b nucleotide sequences. This study indicates that some of the species considered cosmopolitan in their distribution are actually multispecies polyphyletic groupings and an accurate assessment of Mesocriconema species distributions will benefit from molecular determination of haplotype relationships. The groups revealed by COI analysis should provide a useful framework for the evaluation of additional Mesocriconema species and will improve the reliability of designating taxonomic units in studies of nematode biodiversity. 

JLab measurement of the 4He charge form factor at large momentum transfers

The charge form factor of 4He has been extracted in the range 29  fm(-2) ≤ Q2 ≤ 77  fm(-2) from elastic electron scattering, detecting 4He recoil nuclei and electrons in coincidence with the high resolution spectrometers of the Hall A Facility of Jefferson Lab. The measurements have uncovered a second diffraction minimum for the form factor, which was predicted in the Q2 range of this experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the few-body problem.

A review of childhood and adolescent craniopharyngiomas with particular attention to hypothalamic obesity

BACKGROUND

Although craniopharyngiomas are considered "benign" neoplasms by the World Health Organization classification, these tumors may create significant morbidity and mortality in patients. Hypothalamic obesity is a frequent complication of craniopharyngiomas and is refractory to current management options.

PATIENTS/METHODS

We reviewed 24 cases of craniopharyngiomas treated from 1992 to 2010 in patients <18 years of age regarding clinical presentation, neuroimaging, recurrence, morbidity, and mortality, with particular attention to hypothalamic obesity.

RESULTS

Our cohort conformed to published data in regard to neuroimaging characteristics, and clinical findings in the areas of endocrine, visual, neurological, neurobehavioral, and hypothalamic domains. At last follow-up, 53% of our patients were overweight (8%) or obese (46%). Only 25% of our patients had a healthy body mass index. Contrasting these data with body mass indices at diagnosis, where 21% of patients were overweight and 17% were obese, we found that there was a significant trend towards obesity over time. A significant portion of our mortality appears to be related to complications of obesity. The Native American population in Arizona appears to have a statistically greater incidence of obesity in childhood. Despite our small sample size, 75% of our Native Americans were obese at last follow-up and accounted for 50% of the mortality.

CONCLUSION

Hypothalamic obesity is a significant complication of craniopharyngiomas associated with increased mortality. The development of hypothalamic obesity is influenced by premorbid obesity, genetics, and therapy received, specifically radiation. Because of the intractability of hypothalamic obesity, improved understanding of neuroendocrine mechanisms, genomics, and newer antiobesity medications will be necessary to curb this significant complication.

Pandemic H1N1 Influenza Infection and Vaccination in Humans Induces Cross-Protective Antibodies that Target the Hemagglutinin Stem

Most monoclonal antibodies (mAbs) generated from humans infected or vaccinated with the 2009 pandemic H1N1 (pdmH1N1) influenza virus targeted the hemagglutinin (HA) stem. These anti-HA stem mAbs mostly used IGHV1-69 and bound readily to epitopes on the conventional seasonal influenza and pdmH1N1 vaccines. The anti-HA stem mAbs neutralized pdmH1N1, seasonal influenza H1N1 and avian H5N1 influenza viruses by inhibiting HA-mediated fusion of membranes and protected against and treated heterologous lethal infections in mice with H5N1 influenza virus. This demonstrated that therapeutic mAbs could be generated a few months after the new virus emerged. Human immunization with the pdmH1N1 vaccine induced circulating antibodies that when passively transferred, protected mice from lethal, heterologous H5N1 influenza infections. We observed that the dominant heterosubtypic antibody response against the HA stem correlated with the relative absence of memory B cells against the HA head of pdmH1N1, thus enabling the rare heterosubtypic memory B cells induced by seasonal influenza and specific for conserved sites on the HA stem to compete for T-cell help. These results support the notion that broadly protective antibodies against influenza would be induced by successive vaccination with conventional influenza vaccines based on subtypes of HA in viruses not circulating in humans.

Resectable pancreatic small cell carcinoma: The experience of two institutions and review of the literature

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Background: Primary pancreatic small cell carcinoma (SCC) is rare, with just over 30 cases reported in the literature. Only 7 of these patients underwent surgical resection with a median survival of 6 months. Prognosis of SCC is therefore considered to be poor, and the role of adjuvant therapy is uncertain. Here we report two institutions' experience with resectable pancreatic SCC.

Methods: Six patients with pancreatic SCC at the Johns Hopkins Hospital (4 patients) and the Mayo Clinic (2 patients) were identified from prospectively collected pancreatic cancer databases and re-reviewed by pathology. All six patients underwent a pancreaticoduodenectomy. Clinicopathologic data was analyzed, and the literature on pancreatic SCC was reviewed.

Results: Median age at diagnosis was 50 years (range 27-60). Half of the patients were male, and half were known smokers. All six masses were limited to the pancreatic head. Median tumor size was 3 cm, and all cases had positive lymph nodes except for one patient who only had five nodes sampled. There was no perioperative mortality, although three patients had postoperative complications. All six patients received adjuvant chemotherapy therapy, five of whom were given cisplatin and etoposide. Of these five patients, three were known to have received radiation, while the remaining two had a plan for radiation at an outside facility. Median survival was 20 months with a range of 9-173 months. The patient who lived for 9 months received chemotherapy only, while the patient who lived for 173 months was given chemoradiation with cisplatin and etoposide and represents the longest reported survival time from pancreatic SCC to date.

Conclusions: Pancreatic SCC is an extremely rare form of cancer with a poor prognosis. Patients in this surgical series showed improved survival rates when compared to prior experiences with both resected and unresectable cases. Cisplatin and etoposide appears to be the preferred chemotherapy regimen, although its efficacy remains uncertain, as does the role of combined modality treatment with radiation.

No significant financial relationships to disclose.

Widespread divergence between incipient Anopheles gambiae species revealed by whole genome sequences

The Afrotropical mosquito Anopheles gambiae sensu stricto, a major vector of malaria, is currently undergoing speciation into the M and S molecular forms. These forms have diverged in larval ecology and reproductive behavior through unknown genetic mechanisms, despite considerable levels of hybridization. Previous genome-wide scans using gene-based microarrays uncovered divergence between M and S that was largely confined to gene-poor pericentromeric regions, prompting a speciation-with-ongoing-gene-flow model that implicated only about 3% of the genome near centromeres in the speciation process. Here, based on the complete M and S genome sequences, we report widespread and heterogeneous genomic divergence inconsistent with appreciable levels of interform gene flow, suggesting a more advanced speciation process and greater challenges to identify genes critical to initiating that process.

Excess mortality following hip fracture: a systematic epidemiological review

This systematic literature review has shown that patients experiencing hip fracture after low-impact trauma are at considerable excess risk for death compared with nonhip fracture/community control populations. The increased mortality risk may persist for several years thereafter, highlighting the need for interventions to reduce this risk.Patients experiencing hip fracture after low-impact trauma are at considerable risk for subsequent osteoporotic fractures and premature death. We conducted a systematic review of the literature to identify all studies that reported unadjusted and excess mortality rates for hip fracture. Although a lack of consistent study design precluded any formal meta-analysis or pooled analysis of the data, we have shown that hip fracture is associated with excess mortality (over and above mortality rates in nonhip fracture/community control populations) during the first year after fracture ranging from 8.4% to 36%. In the identified studies, individuals experienced an increased relative risk for mortality following hip fracture that was at least double that for the age-matched control population, became less pronounced with advancing age, was higher among men than women regardless of age, was highest in the days and weeks following the index fracture, and remained elevated for months and perhaps even years following the index fracture. These observations show that patients are at increased risk for premature death for many years after a fragility-related hip fracture and highlight the need to identify those patients who are candidates for interventions to reduce their risk.

The potential effects on fracture outcomes of improvements in persistence and compliance with bisphosphonates

BACKGROUND

Osteoporotic fractures are a substantial public health burden worldwide. Evidence from studies show that treatments, such as bisphosphonates, which reduce the risk of fractures when taken regularly and long term, are being used irregularly and suboptimally. The objective of this study was to quantify the additional number of hip fractures prevented by improving persistence and compliance with bisphosphonates.

METHODS

The study population included patients prescribed alendronate or risedronate in the UK General Practice Research Database. Individualized probabilities of fracture and death during bisphosphonate therapy and of treatment persistence and compliance were estimated by age, gender, dosage, calendar year and clinical risk factors using Cox regression. Persistence was calculated by measuring repeat prescribing and compliance by estimating the medication possession ratio. A unique patient-based decision model was then developed using these probabilities. By varying the persistence and compliance probabilities in the simulation, the fracture outcomes with different scenarios were then evaluated. The outcomes were simulated over a 4-year period (maximum of three years of bisphosphonate use followed by 1 year of offset). It was assumed that the bisphosphonate users had experienced similar fracture reductions as observed in clinical trials.

RESULTS

The study population included 44 531 patients. Modelling showed that improvement of the 3-year persistence by 10% (over current persistence) would prevent an additional 14.4 hip fractures per 10 000 patients with weekly treatment. If weekly was substituted with yearly treatment (refill once a year), an additional 68.4 hip fractures (per 10 000 patients) would be prevented. If 3-year persistence improved by 10% with yearly treatment, an additional 78.5 hip fractures would be prevented compared to monthly bisphosphonates. The effects of this substitution were largest in elderly patients and in women.

CONCLUSION

Improvements in treatment persistence and compliance may improve the impact of bisphosphonates in reducing the risk of fractures. Yearly administration may also improve the impact on fracture risk reduction, unless long-term persistence is substantially reduced.

Determinants of non-compliance with bisphosphonates in women with postmenopausal osteoporosis

OBJECTIVE

To identify determinants of non-compliance with bisphosphonates in women with postmenopausal osteoporosis. By considering the year of the introduction of weekly bisphosphonates important additional information is obtained.

METHODS

New female users of daily or weekly alendronate or risedronate between 1999 and 2004, aged >or= 45 years were identified from PHARMO RLS, including drug-dispensing and hospitalisation data of > 2 million residents of the Netherlands. One-year compliance with bisphosphonates was measured using the Medication Possession Ratio (MPR). To identify determinants of non-compliance, non-compliant women (MPR < 50%) were compared to compliant women (MPR >or= 80%). The effect of patient age, prescriber, initial dosing regimen, gastrointestinal adverse events, co-medication and fractures on non-compliance was investigated.

RESULTS

The study cohort included 8822 new users of bisphosphonates, of whom 5079 (58%) were compliant and 2720 (31%) were non-compliant after 1 year. Only 1023 women (11%) had a MPR between >or= 50% and < 80%. Daily dosing at start, increased number of co-medications and new use of intestinal agents in the year after starting bisphosphonates were independently associated with an increased odds of non-compliance. In contrast, higher age, first prescription from a specialist, osteoporosis related hospitalisation and use of NSAIDs in the year preceding bisphosphonate therapy decreased the odds of non-compliance.

CONCLUSION

This study revealed several determinants of non-compliance with bisphosphonates, the best controllable being the type of initial bisphosphonate, with daily dosing leading to more non-compliance than weekly dosing. However, compliance for both regimens is suboptimal, pointing to an unmet medical need.

Loss of treatment benefit due to low compliance with bisphosphonate therapy

Among 8,822 new female bisphosphonate users, non-compliant bisphosphonate use was associated with a 45% increased risk of osteoporotic fracture compared to compliant use (MPR >or=80%). Classifying compliance into five categories, fracture risk gradually increased with poorer compliance. These results emphasize the importance of treatment compliance in obtaining maximal treatment benefit.

INTRODUCTION

Bisphosphonates are widely used to treat osteoporosis and reduce fracture risk. Low compliance is frequent and will limit treatment benefit.

METHODS

New female users of alendronate or risedronate between 1999-2004, aged >or=45 years were identified from PHARMO-RLS, including drug-dispensing and hospitalization data of >or= 2 million residents of the Netherlands. Patients were followed until first hospitalisation for an osteoporotic fracture, death, or end of study period. Compliance with bisphosphonates during follow-up was measured over 90-day intervals using Medication Possession Ratio (MPR). The association between compliance and fracture risk was analyzed using time-dependent Cox-regression.

RESULTS

The study cohort included 8,822 new female bisphosphonate users, contributing in total 22,484 person-years of follow-up. During follow-up, 176 osteoporotic fractures occurred (excluding the first six months). Non-compliant bisphosphonate use was associated with a 45% increased fracture risk compared to compliant use (MPR >or= 80%). Classifying compliance into five categories, fracture risk gradually increased with poorer compliance (p-value <0.05 for trend). A MPR <20% was associated with an 80% increased fracture risk compared to a MPR >or= 90%.

CONCLUSIONS

These results show a statistically significant association between level of compliance with bisphosphonates and level of fracture risk, emphasizing the importance of treatment compliance in obtaining maximal treatment benefit.

Salmon calcitonin: a review of current and future therapeutic indications

Salmon calcitonin, available as a therapeutic agent for more than 30 years, demonstrates clinical utility in the treatment of such metabolic bone diseases as osteoporosis and Paget's disease, and potentially in the treatment of osteoarthritis. This review considers the physiology and pharmacology of salmon calcitonin, the evidence based research demonstrating efficacy and safety of this medication in postmenopausal osteoporosis with potentially an effect on bone quality to explain its abilities to reduce the risk of spine fracture, the development of an oral salmon calcitonin preparation, and the therapeutic rationale for this preparation's chondroprotective effect in osteoarthritis.

Measurements of the proton elastic-form-factor ratio mu pG p E/G p M at low momentum transfer

High-precision measurements of the proton elastic form-factor ratio, mu pG p E/G p M, have been made at four-momentum transfer, Q2, values between 0.2 and 0.5 GeV2. The new data, while consistent with previous results, clearly show a ratio less than unity and significant differences from the central values of several recent phenomenological fits. By combining the new form-factor ratio data with an existing cross-section measurement, one finds that in this Q2 range the deviation from unity is primarily due to G p E being smaller than expected.

Influences of a Relaxation Intervention on Perceived Stress and Power Spectral Analysis of Heart Rate Variability

This study was designed to determine whether power spectral analysis (PSA) of heart rate variability (HRV) can detect change in autonomic tone following a relaxation intervention called therapeutic touch (TT). Thirty healthy subjects underwent TT by one of three TT practitioners using the steps developed by Krieger and Kunz (The Therapeutic Touch, Prentice-Hall, 1979). Both subjects and TT practitioners were monitored by continuous electrocardiographic monitoring (Holter) before (15 minutes), during, and after (15 minutes) TT was administered. Subjects and TT practitioners completed a visual analogue scale (VAS) of perceived stress before and after TT. Change scores for VAS and PSA of high-frequency/low-frequency (HF/LF) ratios were compared for the 2-minute interval before TT began and the end of TT and the end of the recovery period, using t tests. VAS scores decreased (less stress) from before to after TT for both subjects (p < 0.0005) and TT practitioners (p < 0.0005). Mean HF/LF ratios increased significantly to reflect greater parasympathetic dominance from before TT to the end of treatment for subjects (p = 0.006), but not for TT practitioners. However, further analysis revealed that this change was due to an exaggerated HF/LF response from four outliers (p < 0.0005). Data collected in this study did not reveal differences between these four subjects and the rest of the sample. There were no significant changes in HF/LF ratios from the end of TT to end of recovery for either group. Further research is needed to determine why some subjects may have greater change in autonomic tone in response to relaxation in order to be able to predict who will demonstrate physiologic response to relaxation interventions.

Deletion of the carcinoembryonic antigen-related cell adhesion molecule 1 (Ceacam1) gene contributes to colon tumor progression in a murine model of carcinogenesis

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a glycoprotein that is part of the carcinoembryonic antigen and the immunoglobulin superfamilies. We have shown that it functions as a tumor suppressor and that this function depends upon the presence of the longer CEACAM1 cytoplasmic domain. In this report, we describe the generation of a Ceacam1-/- mouse. The Ceacam1-/- colon exhibits increased in vivo proliferation relative to the wild-type counterpart with a corresponding decreased expression of the p21(Cip1) and p27(Kip1) Cyclin D kinase inhibitors. The colonic villi undergo decreased apoptosis. Out of 35 litters of mice, no spontaneous tumors in any tissues normally expressing CEACAM1 were found over the lifespan of the animals, suggesting that CEACAM1 may not be involved in initiation of tumor development. However, when mice are treated with azoxymethane to induce colonic tumors, we find that Ceacam1-/- mice developed a significantly greater number of tumors than their littermate controls. Moreover, the tumor size was greater in the knockout mice relative to that in the wild-type mice. These results indicate that deletion of CEACAM1 favors progression of colon tumorigenesis.