Osteogenic, stem cell and molecular characterisation of the human induced membrane from extremity bone defects.

OBJECTIVES: The biomembrane (induced membrane) formed around polymethylmethacrylate (PMMA) spacers has value in clinical applications for bone defect reconstruction. Few studies have evaluated its cellular, molecular or stem cell features. Our objective was to characterise induced membrane morphology, molecular features and osteogenic stem cell characteristics. METHODS: Following Institutional Review Board approval, biomembrane specimens were obtained from 12 patient surgeries for management of segmental bony defects (mean patient age 40.7 years, standard deviation 14.4). Biomembranes from nine tibias and three femurs were processed for morphologic, molecular or stem cell analyses. Gene expression was determined using the Affymetrix GeneChip Operating Software (GCOS). Molecular analyses compared biomembrane gene expression patterns with a mineralising osteoblast culture, and gene expression in specimens with longer spacer duration (> 12 weeks) with specimens with shorter durations. Statistical analyses used the unpaired student t-test (two tailed; p < 0.05 was considered significant). RESULTS: Average PMMA spacer in vivo time was 11.9 weeks (six to 18). Trabecular bone was present in 33.3% of the biomembrane specimens; bone presence did not correlate with spacer duration. Biomembrane morphology showed high vascularity and collagen content and positive staining for the key bone forming regulators, bone morphogenetic protein 2 (BMP2) and runt-related transcription factor 2 (RUNX2). Positive differentiation of cultured biomembrane cells for osteogenesis was found in cells from patients with PMMA present for six to 17 weeks. Stem cell differentiation showed greater variability in pluripotency for osteogenic potential (70.0%) compared with chondrogenic or adipogenic potentials (100% and 90.0%, respectively). Significant upregulation of BMP2 and 6, numerous collagens, and bone gla protein was present in biomembrane compared with the cultured cell line. Biomembranes with longer resident PMMA spacer duration (vs those with shorter residence) showed significant upregulation of bone-related, stem cell, and vascular-related genes. CONCLUSION: The biomembrane technique is gaining favour in the management of complicated bone defects. Novel data on biological mechanisms provide improved understanding of the biomembrane's osteogenic potential and molecular properties.Cite this article: Dr H. E. Gruber. Osteogenic, stem cell and molecular characterisation of the human induced membrane from extremity bone defects. Bone Joint Res 2016;5:106-115. DOI: 10.1302/2046-3758.54.2000483.

Hypothalamic KISS1 expression, gonadotrophin-releasing hormone and neurotransmitter innervation vary with stress and sensitivity in macaques.

The present study examined the effect of short-term psychosocial and metabolic stress in a monkey model of stress-induced amenorrhaea on the hypothalamic-pituitary-gonadal axis. KISS1 expression was determined by in situ hybridisation in the infundibular arcuate nucleus. Downstream of KISS1, gonadotrophin-releasing hormone (GnRH) axons in lateral areas rostral to the infundibular recess, serum luteinising hormone (LH) and serum oestradiol were measured by immunohistochemistry and radioimmunoassay. Upstream of KISS1, norepinephrine axons in the rostral arcuate nucleus and serotonin axons in the anterior hypothalamus and periaqueductal grey were measured by immunohistochemistry. Female cynomolgus macaques (Macaca fascicularis) characterised as highly stress resilient (HSR) or stress sensitive (SS) were examined. After characterisation of stress sensitivity, monkeys were either not stressed, or mildly stressed for 5 days before euthanasia in the early follicular phase. Stress consisted of 5 days of 20% food reduction in a novel room with unfamiliar conspecifics. There was a significant increase in KISS1 expression in HSR and SS animals in the presence versus absence of stress (P = 0.005). GnRH axon density increased with stress in HSR and SS animals (P = 0.015), whereas LH showed a gradual but nonsignificant increase with stress. Oestradiol trended higher in HSR animals and there was no effect of stress (P = 0.83). Norepinephrine axon density (marked with dopamine ß-hydroxylase) increased with stress in both HSR and SS groups (P ≤ 0.002), whereas serotonin axon density was higher in HSR compared to SS animals and there was no effect of stress (P = 0.03). The ratio of dopamine ß-hydroxylase/oestradiol correlated with KISS1 (P = 0.052) and GnRH correlated with serum LH (P = 0.039). In conclusion, oestradiol inhibited KISS1 in the absence of stress, although stress increased norepinephrine, which may over-ride oestradiol inhibition of KISS1 expression. We speculate that neural pathways transduce stress to KISS1 neurones, which changes their sensitivity to oestradiol.

Interleukin 1-beta upregulates brain-derived neurotrophic factor, neurotrophin 3 and neuropilin 2 gene expression and NGF production in annulus cells.

The relationship between disc cells, nerves and pain production in the intervertebral disc is poorly understood. Neurotrophins, signaling molecules involved in the survival, differentiation and migration of neurons, and neurite outgrowth, are expressed in non-neuronal tissues including the disc. We hypothesized that three-dimensional exposure of human disc cells to the proinflammatory cytokine IL-1ß in vitro would elevate neurotrophin gene expression levels and production of nerve growth factor (NGF). Cells isolated from Thompson grade III and IV discs were cultured for 14 days under control conditions or with addition of 10(2) pM IL-1ß; mRNA was isolated and conditioned media assayed for NGF content. IL-1ß exposure in three-dimensional culture significantly increased expression of neurotrophin 3, brain-derived neurotrophic factor, and neuropilin 2 compared to controls. IL-1ß-exposed cells showed significantly increased NGF production compared to controls. Findings support our hypothesis, expand previous data concerning expression of neurotrophins, and provide the first documented expression of neurotrophin 3 and neuropilin 2. Our results have direct translational relevance, because they address the primary clinical issue of low back pain and open the possibility of novel analgesic therapies using specific small-molecular antagonists to neurotrophins.

Comorbidities in polycystic ovary syndrome: their relationship to insulin resistance.

The polycystic ovary syndrome (PCOS) affects 5-10% of women of child-bearing age, and the diagnosis carries with it associated metabolic and cardiovascular risk factors that are likely linked to insulin resistance. Consequently, women affected by PCOS are at significant risk for developing type 2 diabetes mellitus, cardiovascular disease, and obstructive sleep apnea. Aggressive screening for glucose intolerance and cardiovascular risk factors should be performed in all PCOS patients, and, when indicated by symptomatology, affected women should be screened for sleep apnea. Long-term goals of therapy should focus on prevention of these comorbidities.

Acceptability of formulations and application methods for vaginal microbicides among drug-involved women: results of product trials in three cities.

BACKGROUND AND OBJECTIVES: Female-controlled methods of HIV prevention, such as vaginal microbicides, are urgently needed, particularly among drug-involved women. Acceptability research is critical to product development. GOAL: To assess the acceptability of forms and application methods for future microbicides. DESIGN: Eighty-four drug-involved women were introduced in groups to three lubricant products, asked to try each for 3 weeks, and scheduled for individual follow-up interviews. RESULTS: Participants and their partners felt positive about the products, and expressed willingness to use microbicides if they were shown to be effective against HIV. Women agreed on product characteristics that influenced their reactions (e.g. ease of insertion, degree of "messiness"), but often disagreed on whether their reactions to these characteristics were positive or negative. CONCLUSION: Development of acceptable and effective HIV-prevention products depends on understanding the interaction between characteristics of the products and the characteristics and perceptions of women. Levels of sexual risk and acceptability factors based on drug-use patterns, race and ethnicity, culture, age, and types and attitudes of male partners suggest that a "one size fits all" approach will not win broad acceptance among drug-involved women.

Bridgeport's Teen Outreach and Primary Services (TOPS) project: a model for raising community awareness about adolescent HIV risk.

The Greater Bridgeport Adolescent Pregnancy Program (GBAPP), based on its skills in sex education, pregnancy, and sexually transmitted disease prevention, developed the Teen Outreach and Primary Services (TOPS) project, an innovative teen-focused community outreach model to expand and ensure access to health and support services for primarily underserved minority adolescents and young adults at risk for or living with the human immunodeficiency virus (HIV). TOPS is supported by the Special Projects of National Significance Program, HIV/Acquired Immunodeficiency Syndrome (AIDS) Bureau, Health Resources and Services Administration. The target population for TOPS is inner-city minority youth (ages 15-24 years) at high risk for HIV or HIV positive. Services ranging from outreach to intensive case management were provided to 2173 youth in the project. The number of HIV-positive youth has increased from three in the first year of the project to 17 in 1997. TOPS provides outreach, case management, HIV counseling and testing, risk-reduction activities, and referrals for housing, entitlements, specialty HIV clinics, and substance abuse counseling and treatment. A group of peer educators has been recruited from among the target population and is trained and paired with the staff to provide outreach services, peer counseling, and education, and to assist with recreational opportunities.

Selection of a standard hospital mattress: data-based decision making.

By means of a scientific method, standard hospital mattresses were evaluated for pressure-relieving properties and patient comfort. Vendors' written materials and product demonstrations led to the initial selection of seven mattresses. On the basis of findings from a survey of staff nurses and environmental services and pressure readings obtained with three healthy volunteers, three mattresses were selected for intensive evaluation. Eighteen mattresses (six of each type) were placed in six clinical care units; at 2-week intervals, interface pressure readings (occipital, sacral, and heel) were performed on patients by means of a computerized measurement system. Caregiver and patient questionnaires (n = 100) were analyzed for clinical significance and patients' responses. We conclude that there are no significant differences among the three mattresses tested in pressure-reducing capabilities, nursing functions, or patient comfort.

Pharmacy mass casualty disaster plan implemented after the train wreck.

The involvement of a hospital pharmacy department in a mass casualty disaster revealed strengths and weaknesses of the department's disaster response plan. Effective communication and notification within the pharmacy department and the need to plan to have pharmacists in the triage area to determine patients' lost medications are important areas that the department had not practiced in disaster drills.

Primary nursing in the infant special care unit.

Primary nursing is the involvement of one registered nurse in the 24-hour care of a patient throughout the hospital stay. The role of the primary care nurse and how that role evolved in an infant special care unit is described.

Indications for a long stem femoral component in total hip replacement.

A series of 11 patients who underwent total hip arthroplasty with a long stem femoral component was reviewed. The longest period of followup was five years, average three years. Patients included two women and eight men whose ages ranged from 41 to 67 years. The indications for a long stem femoral component resulted from motor vehicle trauma in three patients, iatrogenic trauma in two patients, neoplastic involvement of the femoral shaft in two patients, and weakened bony stock in four patients. Average hospital stay was five weeks. There were no early deep infections, no postoperative dislocations, and no neurovascular complications. One patient sustained a nonfatal pulmonary embolus. One patient died from overwhelming femoral osteomyelitis three years after surgery. One patient underwent hemipelvecromy for recurrent neoplastic disease three years after surgery. One patient died from pulmonary metastasis two years after surgery.