Subchondral osteopenia and accelerated bone remodelling post-ovariectomy - a possible mechanism for subchondral microfractures in the aetiology of spontaneous osteonecrosis of the knee?

Osteopenia and subchondral microfractures are implicated in the aetiology of spontaneous osteonecrosis of the knee. The ovine tibia shows significant alterations of the trabecular architecture within the subchondral bone of the medial tibial plateau post-ovariectomy, including reduced trabecular bone volume fraction. We hypothesise that accelerated subchondral bone resorption may also play a role in increasing microfracture risk at this site. 23 sheep were examined in this study; 10 of the sheep underwent ovariectomy (OVX), while the remainder (n=13) were kept as controls (CON). Five fluorochrome dyes were administered intravenously at 12 week intervals via the jugular vein to both groups, to label sites of bone turnover. These animals were then sacrificed at 12 months post-operatively. Bone turnover was significantly increased in the OVX group in both trabecular bone (2.024 vs. 1.047, p = 0.05) and within the subchondral bone plate (4.68 vs. 0.69 # / mm2; p \u3c 0.001). In addition to the classically-described turnover visible along trabecular surfaces, we also found visual evidence of intra-trabecular osteonal remodelling. In conclusion, this study shows significant alterations in bone turnover in both trabecular bone and within the subchondral bone plate at one-year post-ovariectomy. Remodelling of trabecular bone was due to both classically described hemi-osteonal and intra-trabecular osteonal remodelling. The presence of both localised osteopenia and accelerated bone remodelling within the medial tibial plateau provide a possible mechanism for subchondral microfractures in the aetiology of spontaneous osteonecrosis of the knee. Further utilisation of the ovariectomised ewe may be useful for further study in this field

Isolation, Characterization, and Mapping of a Human Acid β-Galactosidase cDNA

A λgt11 human testicular cDNA library was screened with degenerate oligonucleotide probe mixtures based on amino acid sequence data generated from cyanogen bromide fragments and tryptic fragments of purified human β-galactosidase.Six positive clones were identified after screening 2 x 106 plaques. The sequences of these six clones were determined and found to be derived from two different cDNAs. The sequence of the longest of these cDNAs is nearly identical to that recently determined by Oshima et al. (1988). It codes for a 76-kD protein and all 11 peptides that were generated from the purified enzyme. The second clone is shorter by 393 bp in the central portion of the coding region. Analysis by Northern blotting revealed the presence of a single mRNA species of 2.45 kb in lymphoblasts and testicular tissue. It is deduced from the amino acid sequence data that proteolytic processing of the precursor form of β-galactosidase must occur by cleavage in the carboxy-terminal portion of the polypeptide perhaps around amino acid 530 at a uniquely hydrophilic sequence. Using a probe generated from the 3\u27 region of the cDNA, we have mapped the locus coding for human β-galactosidase to chromosome 3p21-3pter

Biomechanical comparison of the pullout properties of external skeletal fixation pins in the tibiae of intact and ovariectomised ewes.

The pin-bone interface is the least stable component of the external skeletal fixator. Concerns exist regarding the ability to obtain adequate implant purchase in poor quality bone. Consequently, reduced bone quality has been viewed as a contra-indication for the use of external skeletal fixators. The aim of this study was to investigate the holding power of two different fixator pin designs in bone from entire and ovariectomised sheep. Thirty-two aged ewes were divided into two groups. Group 1 were controls, and Group 2 were ovariectomised (OVX). The ewes were sacrificed 12 months post-ovariectomy and five pairs of tibiae were harvested from each group. The holding power of cortical and cancellous fixator pins was assessed at five standardised locations on each tibia. An increase in mean cortical thickness was noted in the OVX group. The holding power of cancellous fixator pins was superior to that of cortical pins, irrespective of whether or not ovariectomy had been performed. Cancellous pins had an increased holding power in post ovariectomy bone compared to control bone. Cortical pin performance was not affected by ovariectomy. There was a lack of correlation between the incidence of insertional fractures of the far cortex and implant holding power. The results raise questions over the effectiveness of ovariectomy in establishing osteopaenic bone suitable for assessing implant performance, hence further investigations are warranted

Identification and assessment of intimate partner violence in nurse home visitation

Aims and objectives: To develop strategies for the identification and assessment of intimate partner violence in a nurse home visitation programme. Background: Nurse home visitation programmes have been identified as an intervention for preventing child abuse and neglect. Recently, there is an increased focus on the role these programmes have in addressing intimate partner violence. Given the unique context of the home environment, strategies for assessments are required that maintain the therapeutic alliance and minimise client attrition. Design: A qualitative case study. Methods: A total of four Nurse–Family Partnership agencies were engaged in this study. Purposeful samples of nurses (n = 32), pregnant or parenting mothers who had self-disclosed experiences of abuse (n = 26) and supervisors (n = 5) participated in this study. A total of 10 focus groups were completed with nurses: 42 interviews with clients and 10 interviews with supervisors. The principles of conventional content analysis guided data analysis. Data were categorised using the practice–problem–needs analysis model for integrating qualitative findings in the development of nursing interventions. Results: Multiple opportunities to ask about intimate partner violence are valued. The use of structured screening tools at enrolment does not promote disclosure or in-depth exploration of women\u27s experiences of abuse. Women are more likely to discuss experiences of violence when nurses initiate nonstructured discussions focused on parenting, safety or healthy relationships. Nurses require knowledge and skills to initiate indicator-based assessments when exposure to abuse is suspected as well as strategies for responding to client-initiated disclosures. Conclusion: A tailored approach to intimate partner violence assessment in home visiting is required. Relevance to clinical practice: Multiple opportunities for exploring women\u27s experiences of violence are required. A clinical pathway outlining a three-pronged approach to identification and assessment was developed

Association of DC-SIGN Promoter Polymorphism with Increased Risk for Parenteral, but Not Mucosal, Acquisition of Human Immunodeficiency Virus Type 1 Infection

There is considerable debate about the fundamental mechanisms that underlie and restrict acquisition of human immunodeficiency virus type 1 (HIV-1) infection. In light of recent studies demonstrating the ability of C type lectins to facilitate infection with HIV-1, we explored the potential relationship between polymorphisms in the DC-SIGN promoter and risk for acquisition of HIV-1 according to route of infection. Using samples obtained from 1,611 European-American participants at risk for parenteral (n = 713) or mucosal (n = 898) infection, we identified single-nucleotide polymorphisms in the DC-SIGN promoter using single-strand conformation polymorphism. Individuals at risk for parenterally acquired infection who had −336C were more susceptible to infection than were persons with −336T (odds ratio = 1.87, P = 0.001). This association was not observed in those at risk for mucosally acquired infection. A potential role for DC-SIGN specific to systemic acquisition and dissemination of infection is suggested

Effect of Addition of an Intimate Partner Violence Intervention to a Nurse Home Visitation Program on Maternal Quality of Life: A Randomized Clinical Trial

Importance: Intimate partner violence (IPV) is a public health problem with significant adverse consequences for women and children. Past evaluations of a nurse home visitation program for pregnant women and first-time mothers experiencing social and economic disadvantage have not consistently shown reductions in IPV. Objective: To determine the effect on maternal quality of life of a nurse home visitation program augmented by an IPV intervention, compared with the nurse home visitation program alone. Design, Setting, and Participants: Cluster-based, single-blind, randomized clinical trial at 15 sites in 8 US states (May 2011-May 2015) enrolling 492 socially disadvantaged pregnant women (≥16 years) participating in a 2.5-year nurse home visitation program. Interventions: In augmented program sites (n = 229 participants across 7 sites), nurses received intensive IPV education and delivered an IPV intervention that included a clinical pathway to guide assessment and tailor care focused on safety planning, violence awareness, self-efficacy, and referral to social supports. The standard program (n = 263 participants across 8 sites) included limited questions about violence exposure and information for abused women but no standardized IPV training for nurses. Main Outcomes and Measures: The primary outcome was quality of life (WHOQOL-BREF; range, 0-400; higher score indicates better quality of life) obtained through interviews at baseline and every 6 months until 24 months after delivery. From 17 prespecified secondary outcomes, 7 secondary end points are reported, including scores on the Composite Abuse Scale, SPAN (Startle, Physiological Arousal, Anger, and Numbness), Prime-MD Patient Health Questionnaire, TWEAK (Tolerance/Worry About Drinking/Eye-Opener/Amnesia/C[K]ut Down on Drinking), Drug Abuse Severity Test, and the 12-Item Short-Form Health Survey (physical and mental health), version 2. Results: Among 492 participants enrolled (mean age, 20.4 years), 421 (86%) completed the trial. Quality of life improved from baseline to 24 months in both groups (change in WHOQOL-BREF scores from 299.5 [SD, 54.4] to 308.2 [SD, 52.6] in the augmented program group vs from 293.6 [SD, 56.4] to 316.4 [SD, 57.5] in the standard program group). Based on multilevel growth curve analysis, there was no statistically significant difference between groups (modeled score difference, -4.9 [95% CI, -16.5 to 6.7]). There were no statistically significant differences between study groups in any of the secondary participant end points. There were no adverse events recorded in either group. Conclusions and Relevance: Among pregnant women experiencing social and economic disadvantage and preparing to parent for the first time, augmentation of a nurse home visitation program with a comprehensive IPV intervention, compared with the home visitation program alone, did not significantly improve quality of life at 24 months after delivery. These findings do not support the use of this intervention. Trial Registration: ClinicalTrials.gov Identifier: NCT01372098