Genomic variants within chromosome 14q32.32 regulate bone mass through MARK3 signaling in osteoblasts

Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass.     

Effects of laundry detergents on Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Euroglyphus maynei.

BACKGROUND: House-dust mites in clothing and bedding are the source of major allergens. Based on studies of Dermatophagoides pteronyssinus only, weekly washing in hot water is recommended to kill dust mites and remove allergens from clothing and bedding. However, in the United States, washing is most often done in warm or cold water, and other mite species are involved. OBJECTIVE: The purpose of this study was to investigate the lethal effects of various temperatures of hot water alone and hot, warm, and cold water containing detergents and chlorine bleach on Dermatophagoidesfarinae, D. pteronyssinus, and Euroglyphus maynei. METHODS: Mites were soaked in test solutions at various temperatures and for various lengths of time, allowed time to recover, and then analyzed for survival. RESULTS: D. farinae was the most temperature-sensitive and chlorine bleach-sensitive of the three species. In 50 degrees C water alone, 100% mortality for D. farinae was obtained in 10 minutes, whereas most D. pteronyssinus and E. maynei survived. However, 53 degrees C-soaks for 12 and 5 minutes were needed to kill all D. pteronyssinus and E. maynei, respectively. Laundry detergents at their recommended and doubled concentrations and chlorine bleach generally increased mite mortalities over water alone for the three species. Soaking for 4 hours in warm water containing various detergents alone induced mortalities of 19 to 50%, 2 to 35%, and 14 to 46% for D. farinae, D. pteronyssinus, and E. maynei, respectively. CONCLUSIONS: Washing bed linens weekly in warm water with a 4-hour presoak containing most detergents and bleach will kill most D. farinae and, depending on the detergent brand, moderate numbers of D. pteronyssinus. Four-hour soaks in warm water containing the recommended concentrations of various detergents alone also kills moderate numbers of D. farinae, D. pteronyssinus, and E. maynei. Therefore, the cumulative effect of weekly washing with long presoaks should significantly reduce mite levels over time in bed linens, particularly when mattresses and pillows are encased to prevent reinfestation.     

Soft tissue healing after parasagittal palatal incisions in segmental maxillary surgery: a review of 311 patients.

PURPOSE: This study retrospectively evaluated the soft tissue healing after using parasagittal soft tissue incisions for surgical segmental maxillary expansion. PATIENTS AND METHODS: The records of 311 patients (224 females, 87 males), with an average age of 28.5 years (range, 12 to 62 years) who had transverse maxillary hypoplasia, were retrospectively evaluated. All patients underwent segmental maxillary osteotomies, surgical maxillary expansion greater than 5 mm, and placement of midpalatal porous block hydroxyapatite (PBHA). Parasagittal palatal soft tissue incisions were used to facilitate expansion, minimize soft tissue damage, and maintain soft tissue coverage over the PBHA implants. At postoperative follow-up visits, any signs or symptoms of complications associated with the use of the parasagittal incisions were recorded. RESULTS: Average patient follow-up was 3.4 years (range, 1.0 to 7.2 years). In 293 patients (94%), the palates healed uneventfully without complications. Eighteen patients (6%) had complications; 9 (2.9%) had infections associated with the midpalatal implants, 8 (2.6%) had oronasal communications, and 1 (0.3%) had problems associated with a palatal wire. Six patients with midpalatal implant problems required removal of the implant, 4 patients required closure of their oronasal communications, and 1 patient required removal of a palatal wire. Therefore, 11 patients (3.5%) required minor secondary surgical procedures. No teeth or alveolar bone were lost in any of the cases. CONCLUSIONS: The use of parasagittal palatal incisions appears to be a safe technique for soft tissue management during large surgical maxillary expansions associated with segmental maxillary osteotomies and midpalatal placement of PBHA implants.     

Comparing histological data from different brains: Sources of error and strategies for minimizing them

The recent development of brain atlases with computer graphics templates, and of huge databases of neurohistochemical data on the internet, has forced a systematic re-examination of errors associated with comparing histological features between adjacent sections of the same brain, between brains treated in the same way, and between brains from groups treated in different ways. The long-term goal is to compare as accurately as possible a broad array of data from experimental brains within the framework of reference atlases. Main sources of error, each of which ideally should be measured and minimized, include intrinsic biological variation, linear and nonlinear distortion of histological sections, plane of section differences between each brain, section alignment problems, and sampling errors. These variables are discussed, along with approaches to error estimation and minimization in terms of a specific example—the distribution of neuroendocrine neurons in the rat paraventricular nucleus. Based on the strategy developed here, the main conclusion is that the best long-term solution is a high-resolution 3D computer graphics model of the brain that can be sliced in any plane and used as the framework for quantitative neuroanatomy, databases, knowledge management systems, and structure–function modeling. However, any approach to the automatic annotation of neuroanatomical data—relating its spatial distribution to a reference atlas—should deal systematically with these sources of error, which reduce localization reliability.     

Tooth movement and cytokines in gingival crevicular fluid and whole blood in growing and adult subjects.

INTRODUCTION: Tooth movement has been studied largely with respect to the force required for tipping when pressure distribution varies along the length of the periodontal ligament. But important factors for effective canine translation include the nature and magnitude of applied stress and the patient's cell biology. The purpose of this research was to test 3 hypotheses: (1) the velocity of tooth translation (v(t)) is related to applied stress and growth status, (2) a threshold of stress accounts for the lag phase, and (3) v(t) is correlated with the ratio (AI) of 2 cytokines (IL-1beta, IL-1RA) measured in gingival crevicular fluid (GCF) and stimulated whole blood (SWB). METHODS: Continuous maxillary canine retraction stresses of 13 kPa and 4, 26, or 52 kPa were applied bilaterally in 6 growing and 4 adult subjects for 84 days. Dental models and GCF samples were collected at 1- to 14-day intervals. Cytokines were measured in GCF and SWB cell cultures. RESULTS: V(t) was positively related to stress and was higher in growing subjects (P = .001). It was also related to AI(GCF) in growers (R2= 0.56) and nongrowers (R2= 0.72). Canines moved with 52 kPa showed a lag phase, and postlag phase AI(GCF) was twice that of lag phase AI(GCF). Mean v(t) and associated AI(GCF) during the postlag phase were nearly double the values for canines moved with 13 and 26 kPa. SWB production of cytokines was dose-dependent. For growing subjects, SWB IL-1RA was correlated with v(t) (R = 0.70-0.72), and AI(SWB) and IL-1beta concentrations were correlated with AI(GCF) (R = 0.73-0.78). CONCLUSIONS: V(t) varied with growth status and stresses < or = 52 kPa; stresses of < 52 kPa showed no lag phase; and equivalent stresses yielded subject-dependent differences in v(t), which correlated with cytokines in GCF and SWB.     

PET measurement of cardiac and nigrostriatal denervation in Parkinsonian syndromes.

Scintigraphic imaging with (123)I-metaiodobenzylguanidine ((123)I-MIBG) has demonstrated extensive losses of cardiac sympathetic neurons in idiopathic Parkinson's disease (IPD). In contrast, normal cardiac innervation has been observed in (123)I-MIBG studies of multiple-system atrophy (MSA) and progressive supranuclear palsy (PSP). Consequently, it has been hypothesized that cardiac denervation can be used to differentiate IPD from MSA and PSP. We sought to test this hypothesis by mapping the distribution of cardiac sympathetic neurons in patients with IPD, MSA, and PSP by using PET and (11)C-meta-hydroxyephedrine ((11)C-HED). Also, the relationship between cardiac denervation and nigrostriatal denervation was investigated by measuring striatal presynaptic monoaminergic nerve density with PET and (11)C-dihydrotetrabenazine ((11)C-DTBZ). METHODS: (11)C-HED and (11)C-DTBZ scans were obtained for patients with IPD (n = 9), MSA (n = 10), and PSP (n = 8) and for age-matched control subjects (n = 10). Global and regional measurements of (11)C-HED retention were obtained to assess the extent of cardiac sympathetic denervation. (11)C-DTBZ binding was measured in the caudate nucleus, anterior putamen, and posterior putamen. RESULTS: As expected, extensive cardiac denervation was observed in several of the patients with IPD. However, substantial cardiac denervation was also seen in some patients with MSA and PSP. (11)C-DTBZ studies demonstrated striatal denervation in all patients with IPD and in most patients with MSA and PSP. No correlation was found between cardiac (11)C-HED retention and striatal (11)C-DTBZ binding. CONCLUSION: Cardiac sympathetic denervation was found to occur not only in IPD but also in other movement disorders, such as MSA and PSP. This finding implies that scintigraphic detection of cardiac sympathetic denervation cannot be used independently to discriminate IPD from other movement disorders, such as MSA and PSP. Cardiac sympathetic denervation was not correlated with striatal denervation, suggesting that the pathophysiologic processes underlying cardiac denervation and striatal denervation occur independently in patients with parkinsonian syndromes. These findings provide novel information about central and peripheral denervation in patients with neurodegenerative disorders.     

Use of the risk-rescue rating scale with adolescent suicide attempters: A cautionary note

The assessment of the medical lethality and intent of suicide attempts has been considered an important area of research for those interested in suicide. The current study examined the usefulness of the Risk-Rescue Rating Scale with 109 adolescent suicide attempters and found a restricted range of variability, which, in turn, resulted in poor interrater reliability on a number of items. Results suggest that the Risk-Rescue Rating Scale is of limited usefulness with adolescents, and alternative approaches to assessing lethality and suicidal intent with this age group are discussed.     

Keratinocyte conditioned medium abrogates the modulatory effects of IGF-1 and TGF-β1 on collagenase expression in dermal fibroblasts

Overexpression of wound healing-promoting factors such as transforming growth factor-1 (TGF-beta1) and insulin-like growth factor-1 (IGF-1) during the healing process has been implicated in the development of dermal fibrosis in patients following thermal injury, surgical incision, and deep trauma. However, the mechanism through which the expression of these two fibrogenic factors is slowed down and/or abrogated in the late stages of the healing process is not known. Here, we hypothesize that keratinocyte-releasable factors counteract the fibrogenic role of both IGF-1 and TGF-beta1 in fibroblasts. To test this hypothesis, the levels of collagenase (MMP-1), as an index for extracellular matrix degradation, in dermal fibroblasts in response to either keratinocyte-conditioned medium (KCM) or our recently identified keratinocyte-releasable stratifin in the presence and absence of either IGF-1, TGF-beta1, or both were evaluated. The results of Northern analysis showed a significant increase in collagenase mRNA expression in cells treated with KCM in the presence of both IGF-1 and TGF-beta1. The effect was, at least in part, due to keratinocyte-derived stratifin that was present in KCM. This was ascertained as the levels of MMP-1 mRNA were markedly reduced when cells were treated with stratifin-immuno-depleted KCM. The results of Western blot analysis showed an increase in the level of MMP-1 protein in stratifin-treated fibroblasts and this was consistent with the level of MMP-1 mRNA expression detected by Northern analysis. However, in contrast to KCM, whose efficacy on MMP-1 expression was modestly reduced by either IGF-1 and TGF-beta1, or a combination of both, these factors abrogated the MMP-1 stimulatory effect of stratifin in fibroblasts. In summary, the results of this study revealed that both stratifin and KCM stimulate the expression of MMP-1-in fibroblasts and this effect can be abrogated by either IGF-1, TGF-beta1, or a combination of both.