The empty pelvis syndrome: a core data set from the PelvEx collaborative

BACKGROUND

Empty pelvis syndrome (EPS) is a significant source of morbidity following pelvic exenteration (PE), but is undefined. EPS outcome reporting and descriptors of radicality of PE are inconsistent; therefore, the best approaches for prevention are unknown. To facilitate future research into EPS, the aim of this study is to define a measurable core outcome set, core descriptor set and written definition for EPS. Consensus on strategies to mitigate EPS was also explored.

METHOD

Three-stage consensus methodology was used: longlisting with systematic review, healthcare professional event, patient engagement, and Delphi-piloting; shortlisting with two rounds of modified Delphi; and a confirmatory stage using a modified nominal group technique. This included a selection of measurement instruments, and iterative generation of a written EPS definition.

RESULTS

One hundred and three and 119 participants took part in the modified Delphi and consensus meetings, respectively. This encompassed international patient and healthcare professional representation with multidisciplinary input. Seventy statements were longlisted, seven core outcomes (bowel obstruction, enteroperineal fistula, chronic perineal sinus, infected pelvic collection, bowel obstruction, morbidity from reconstruction, re-intervention, and quality of life), and four core descriptors (magnitude of surgery, radiotherapy-induced damage, methods of reconstruction, and changes in volume of pelvic dead space) reached consensus-where applicable, measurement of these outcomes and descriptors was defined. A written definition for EPS was agreed.

CONCLUSIONS

EPS is an area of unmet research and clinical need. This study provides an agreed definition and core data set for EPS to facilitate further research.

Characterization of Distributive Mixing in Polymer Processing Equipment using Renyi Entropies

A new method for characterization of distributive mixing in processing equipment, based on Renyi entropies, was developed. This method was applied to a twin-flight single screw extruder, in which tracer positions were determined through computer simulations of the flow field. The various entropies were calculated using particle concentrations in equal area domains of the mixer. Renyi entropies, which are function of a parameter β, were calculated for extruders of different lengths. We discuss the merit of using Renyi entropies for different values of β by pointing to the different mixing characteristics they probe. The relative Renyi entropy varies between 0 and 1 and represents a measure of distributive mixing quality, with 1 corresponding to perfect mixing and 0 corresponding to poorest mixing. We compare this new method of distributive mixing characterization to traditional ones based on the concepts of Scale and Intensity of Segregation, and the calculations based on Pairwise Correlations and Correlation Sums. The results show good agreement between the relative Renyi entropy and the traditional methods. Other advantages of the Renyi entropy such as reduced calculation time and geometric independence are discussed. For the case of a twin-flight single screw extruder, it is shown that a longer extruder is not necessarily more beneficial to distributive mixing.

Vitamin D in Infant Formula and Enteral Products by Liquid Chromatography: Collaborative Study

Results from a collaborative study of a new liquid chromatographic (LC) method for determination ofvitamin D in infant formulas and enteral products are presented. Each of 15 laboratories was provided with 11 blind duplicate samples covering a range ofapproximately 200-500 International Units/quart (normal dilution), a system suitability sample, and the U.S. Pharmacopeia ergo- and cholecalciferol standards. Product types included liquid and powder forms of milk (whey and casein), soy, and hydrolyzed protein-based infant formulas and enteral products. The method includes a single liquid-liquid extraction following saponification, solid-phase extraction,and then concentration by evaporation. An isocratic, nonaqueous, chromatographic system with reversed-phase, zero end- capped C18 column, and UV detector set at 265 nm are used. Statistical evaluation ofdata from participating laboratories showthe average reproducibility and repeatability of the method across all samples to be excellent, with RSDR and RSDr values of 13.48 and 9.44, respectively, after elimination of out liers. The LC method for determination of vitamin D in infant formulas and enteral products has been adopted by AOAC INTERNATIONAL.

Predictive cytokine biomarkers of clinical response to glatiramer acetate therapy in multiple sclerosis

A prospective study of 62 patients with relapsing-remitting multiple sclerosis (RRMS) treated with Glatiramer acetate (GA) was conducted to evaluate the value of baseline and treatment-modulated cytokines in predicting the clinical response to the drug after 2years of therapy. There were 32 responders and 30 non-responders. GA upregulated Th2/regulatory cytokines and inhibited Th1 cytokines in sera or PBMC supernatants 3 and 6months into treatment. We found two prognostic models with clinical utility. A model based on IL-18 at baseline, the change in TNFa from baseline to 3months, the change in IL-4 from baseline to 6months, and the change in the log of the ratio of TNFa/IL-4 from baseline to 6months had an area under the curve (AUC) of 0.80. A high IL-18 level at baseline and a reduction of TNF-alpha over time are associated with a response to GA. Although the study identified predictive biomarkers of clinical response to GA, the results will need to be validated in other data sets.

Phase transition and surface sublimation of a mobile Potts model

We study in this paper the phase transition in a mobile Potts model by the use of Monte Carlo simulation. The mobile Potts model is related to a diluted Potts model, which is also studied here by a mean-field approximation. We consider a lattice where each site is either vacant or occupied by a q-state Potts spin. The Potts spin can move from one site to a nearby vacant site. In order to study the surface sublimation, we consider a system of Potts spins contained in a recipient with a concentration c defined as the ratio of the number of Potts spins N(s) to the total number of lattice sites N(L)=N(x)×N(y)×N(z). Taking into account the attractive interaction between the nearest-neighboring Potts spins, we study the phase transitions as functions of various physical parameters such as the temperature, the shape of the recipient, and the spin concentration. We show that as the temperature increases, surface spins are detached from the solid phase to form a gas in the empty space. Surface order parameters indicate different behaviors depending on the distance to the surface. At high temperatures, if the concentration is high enough, the interior spins undergo a first-order phase transition to an orientationally disordered phase. The mean-field results are shown as functions of temperature, pressure, and chemical potential, which confirm in particular the first-order character of the transition.

Laboratory tests to identify patients at risk of early major adverse events: a prospective pilot study

BACKGROUND/AIMS

To test whether commonly measured laboratory variables can identify surgical patients at risk of major adverse events (death, unplanned intensive care unit (ICU) admission or rapid response team (RRT) activation).

METHODS

We conducted a prospective observational study in a surgical ward of a university-affiliated hospital in a cohort of 834 surgical patients admitted for >24 h. We applied a previously validated multivariable model-derived risk assessment to each combined set of common laboratory tests to identify patients at risk. We compared the clinical course of such patients with that of control patients from the same ward who had blood tests but were identified as low risk.

RESULTS

We studied 7955 batches and 73,428 individual tests in 834 patients (males 55%; average age 65.8 ± 17.6 years). Among these patients, 66 (7.9%) were identified as 'high risk'. High-risk patients were older (75.9 vs 61.8 years of age; P < 0.0001), had much greater early (48 h) mortality (6/66 (9%) vs 4/768 (0.5%); P < 0.0001) and greater overall hospital mortality (11/66 (16.7%) vs 9/768 (1.2%); P < 0.0001). They also had more early (8/66 (12.1%) vs 14/768 (1.8%); P = 0.0001) and overall in-hospital unplanned ICU admissions (12/66 (18.2%) vs 18/768 (2.3%); P < 0.0001) and more early (26/66 (39.3%) vs 50/768 (6.5%); P < 0.0001) and overall in-hospital RRT calls (26/66 (39.4%) vs 55/768 (7.2%); P < 0.0001).

CONCLUSIONS

Commonly performed laboratory tests identify surgical ward patients at risk of early major adverse events. Further studies are needed to assess whether such identification system can be used to trigger interventions that help improve patient outcomes.

Temporal association of ambient temperature and relative humidity with Spirocerca lupi infection of Onthophagus sellatus: a 14-year longitudinal study

The parasitic nematode Spirocerca lupi causes major morbidity and mortality in dogs. The scarab beetle Onthophagus sellatus is its major intermediate host in Israel. We investigated the prevalence of beetle infection by S. lupi in different years between 1994 and 2008. The average monthly maximum and minimum relative humidity (RH) and ambient temperature (AT) throughout the study period were calculated based on daily meteorological data. The infection prevalence decreased over the study period, possibly due to a chronological change resulting from increased preventive treatment of dogs against S. lupi, or climate change. Multivariate analysis was performed for these two hypotheses. Under the first hypothesis, chronological change was forced into the model, and environmental variables were inserted stepwise. The final model included beetle-collection date, minimum RH (RH min) during the month preceding beetle collection, its interaction with maximal AT (AT max) during that same month, and the interaction of maximal RH (RH max) and AT max, during the month of beetle collection. Under the second hypothesis, chronological change was not forced. The final model included RH max during the month of beetle collection, average RH (RHave) during the month preceding beetle collection, and its interaction with AT max during the latter month. The results suggest that under both hypotheses, RH and AT during the month preceding beetle collection influence S. lupi's ability to develop and survive in O. sellatus, and may be used to predict the risk to dogs of S. lupi infection.

Index for Simultaneous Dispersive and Distributive Mixing Characterization in Processing Equipment

Computer simulation of agglomerate dispersion and sequential distribution of all particles obtained in the system allows us to evaluate the overall mixing efficiency of processing equipment. Evaluation was based on a specific mixing index, calculated using the Shannon entropies for different size fractions. The index can be tailored to give preference to different particle size distributions, thus relating the quality of mixing to specific properties of the final product.

Dynamics of Filler Size and Spatial Distribution in a Plasticating Single Screw Extruder – Modeling and Experimental Observations

A model of agglomerate break-up, incorporating both rupture and erosion, is employed to predict the dynamics of filler size distribution in a plasticating single screw extruder. Filler spatial distribution along the extruder length was also ascertained and direct comparison of experimental and computational data proved to be satisfactory. The method was also used to investigate the effect of material properties, operating conditions and extruder geometry on the dynamics of agglomerate dispersion along a single screw extruder. Generally, dispersion levels were primarily governed by the magnitude of the hydrodynamic stresses developed in the extruder and the residence time in the melt.

Modeling of Agglomerate Dispersion in Single Screw Extruders

A model for solid agglomerate dispersion in single screw extruders is proposed. The model combines numerical simulations of flow patterns in the metering section of a single screw extruder with a Monte Carlo method of clusters rupture and erosion mediated by a local fragmentation number. Particle size distributions and Shannon entropy are used for mixing characterization. The model is quite general and can be adapted for different polymer-additive systems as well as for different processing equipment.

Weight change associated with corticosteroid therapy in adolescents with systemic lupus erythematosus

Physical appearance is very important to adolescents and weight gain secondary to corticosteroid (CS) treatment may have a direct impact on adolescent development. Understanding weight gain in adolescents with SLE who are being treated with CS will help clinicians develop strategies for prevention of nonadherence, obesity and eating disorders in this population.

Methods:

Patients aged 11–18 years old with newly diagnosed SLE between January,1995 and December, 2006 were identified through the Rheumatology database at the Sickkids hospital, Canada. All charts were reviewed. Patients were categorized based on final BMI status as normal, overweight and obese. Risk factors for being obese were examined by logistic regression model analysis.

Results:

Of 236 patients, 78% fulfilled the criteria. 85% were female with mean age at onset of diagnosis was 14 ± 1.7 years. Mean duration of CS treatment was 50 ± 31 months and mean cumulative CS dosage was 34.11 ± 32.7 g of prednisone. At baseline, 10% had BMI >25 kg/m2 while at the end of the study, 20% were overweight and 10.4% were obese. In addition, 61% gained <10 kg while 15% gained ≥20 kg. Initial BMI was a significant predictors for final BMI (OR = 27.59, 95%CI = 6.04–126.09, p < .001) while male (OR = 8.50, 95%CI = 2.95–24.5, p < 0.000) and cumulative CS dosage (OR = 1.53, 95%CI = 1.05–2.23, p < .05) were the significant predictors for weight gain >10 kg. Duration of CS treatment did not correlate with obesity.

Conclusion:

Although a significant number of patients became overweight or obese after being treated with CS, most gained <10 kg. Obesity secondary to CS treatment in SLE patients was significantly correlated with baseline BMI, gender and cumulative CS dosage.

The sexual abuse of young people with a disability or chronic health condition

For several reasons, children and youth with a disability or chronic health condition are at an increased risk of sexual abuse. Health care providers, along with parents and caregivers, need to maintain a high level of suspicion concerning possible sexual abuse of this population. Physicians especially need to advocate for policies to prevent or detect abuse in hospitals, schools and other institutional settings. Such policies include the thorough screening and monitoring of employees and volunteers; chaperoning physical examinations and treatment procedures; supervising outings; and ensuring an institutional culture that promotes patient privacy. In addition, physicians should promote patient self-awareness and empowerment, and provide early anticipatory guidance concerning sexuality, personal empowerment and abuse risks. The present document replaces the previous Canadian Paediatric Society position statement published in 1997.

Perceptions of transitional care needs and experiences in pediatric heart transplant recipients

Survival following pediatric heart transplantation (HTx) continues to improve. The transition from pediatric to adult care is becoming a pivotal stage in the ongoing medical management of this population. Published data support enhanced outcomes for adolescent patients with increased attention to transitional care. The purpose of this study was to explore the 'transition experience' of adolescent HTx recipients and families. All teens (12-18 years) and parents at a single-center HTx program were invited to participate in semistructured interviews. Qualitative, phenomenological methodology was used to build theoretical knowledge and guided the data collection and analysis. The study population included 14 patients (7 males) with a mean age of 15.7 +/- 1.8 years (11.7-17.8 years) and at a mean of 4.1 +/- 3.3 years post-HTx (0.3-9.2 years) at the time of study participation. Major themes identified included: (i) adolescent disinterest and apathy regarding transition to adult care versus parental anxiety about their child's eventual departure from the pediatric transplant center, (ii) perceived differences in pediatric versus adult care and (iii) identification of strategies described as helpful in facilitating the transition. Understanding the experiences and perceptions of adolescent HTx recipients and their parents is crucial to planning effective transitional care and necessary for evidenced-based practice.

Treating hypertension in type II diabetic patients with device-guided breathing: a randomized controlled trial

The objective of the study was to evaluate the efficacy of device-guided breathing to lower blood pressure (BP) in hypertensive type II diabetic patients. A randomized controlled trial was carried out in four urban family practice clinics in Israel. Non-insulin-dependent diabetic, hypertensive patients with uncontrolled BP, receiving antihypertensive therapy or those non-medicated were enrolled. Baseline characteristics of the 66 patients who completed the study (33 intervention and 33 control) were: 62% men, age 62+/-8 years (mean+/-s.d.); body mass index 29+/-5 kg/m2; systolic BP 148+/-11 mm Hg and diastolic BP 81+/-9 mm Hg. The intervention group used a device (RESPeRATE), which interactively guides the user towards slow and regular breathing by synchronizing respiration voluntarily to musical tones for 15 min daily for an 8-week period. The control group continued with their regular treatment. BP was measured in the clinic at baseline, after 4 weeks and at 8 weeks. Medication was unchanged for 4 weeks prior to and during the study period. The main outcome measure was the office BP change from baseline to the end of the 8-week period. BP was reduced in the treatment group (mean+/-s.e.) systolic -10.0+/-1.8 mm Hg and diastolic -3.6+/-1.3 mm Hg (P<0.0001 and P<0.01), but not in the controls +1.6+/-2.1 and -1.0+/-1.4 mm Hg P>0.4 and P>0.4, respectively. Test for between group difference P<0.0001 and P=0.08. The subjects were highly compliant with the treatment, performing 75% of the requested exercise sessions. Greater BP reduction was observed with increased compliance with device usage (P=0.01 and P=0.001). It is concluded that self-treatment with device-guided breathing at home for 8 weeks by non-insulin-dependent diabetic patients was associated with a substantial reduction in office systolic BP.

A new necessary condition on interaction graphs for multistationarity

We consider a dynamical system, described by a system of ordinary differential equations, and the associated interaction graphs, which are defined using the matrix of signs of the Jacobian matrix. After stating a few conjectures about the role of circuits in these graphs, we prove two new results relating them to the dynamic behaviour of the system: a sufficient condition for qualitative unstability, and a necessary condition for the existence of several stationary states. These results are illustrated by examples of regulatory modules in two variables, such as those occurring in biological networks.

Bleomycin dose modification in Hodgkin disease (HD) treated with ABVD: Patient characteristics, treatment outcomes, and association with mixed cellularity (MC) histology

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Background: Bleomycin used in the ABVD regimen is associated with a risk of pulmonary toxicity (10 - 19%). Pts with early signs of suspected bleomycin toxicity are often treated with modifications of the regimen. We conducted a retrospective study of patients with HD at our institution in whom bleomycin dose was modified or discontinued during their course of therapy with ABVD. Their response to modified therapy and possible predisposing factors were analysed. Methods: IRB approval was obtained for this study. Tumor registry data for adult pts diagnosed with HD between 2004 and 2006 were analysed for age, stage, sex, histology, smoking history, reduction in bleomycin dose and outcomes. Results: 38 pts were diagnosed with HD at our institution during this time period. Histology: NS: n=15(39.4%), MC: n=16(42.1%), NLP: n=2(5.2%), LR: n=2(5.2%). Histology NOS: n=4(10.5%). 8 pts with bleomycin dose modifications were identified. Pt. characteristics : Med.age 46 yrs (28- 64 ), M:F3:5; 7 of 8 were newly diagnosed and one pt had recurrent HDs. Stages: Stg I: n = 1; Stg II: n= 3; Stg III: n = 3, Stage IV: n= 1, B symptoms : n = 3. Histology: MC (n = 6), NS (n = 1). Unk n=1. 4 of 8 pts were ex-smokers. One patient never received bleomycin due to initial poor PFTs. 7 pts had bleomycin discontinued due to symptoms and decrease in DLCO during their treatment. One patient was continued on 50% reduced dose bleomycin for 2 cycles prior to discontinuation of bleomycin. The distribution of the number of patients discontinuing bleomycin by cycle of treatment is as follows: C#2: n=1; C#3: n=2; C#4: n=1; C#5: n=2. The complete response rate was 100% in this group despite bleomycin dose modification. There were no relapses after a median follow up of 18 mos (range: 8- 33). One patient treated for recurrent HD had severe pulmonary toxicity and did not receive any further treatments. All other patients completed their intended cycles of treatment. Conclusions: Despite bleomycin modification in this small series of pts treated initially with ABVD, DFS remains excellent with no noted relapses at this early follow up. Majority of pts requiring dose modifications had MC histology. Further trials are needed to evaluate the role of bleomycin in the ABVD regimen.

No significant financial relationships to disclose.

Upper genitourinary tract transitional cell carcinoma (TCC): Long-term outcome data from a large single institutional series

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Background: TCC of the upper urinary tract (renal pelvis and ureters) is a relatively rare entity and carries a poor prognosis. Literature regarding long term outcomes are lacking. We embarked on a review of pt records to evaluate patterns of practice: ie adjuvant therapies and survival outcomes of pts treated at our tertiary care institution. Methods: IRB approval was obtained for this retrospective analysis. Tumor registry data were analysed for all adult pts with TCC of the renal pelvis and ureter diagnosed from 1995 to 2005. Only patients with locoregionally confined disease were included in this study. Pt characteristics recorded: age, sex, site of disease, stage, grade, treatment modalities and survival outcome. Results: 175 patients were identified. Med. age: 75 yrs (range 40–90). Gender: M:F:107:68; Sites: Renal Pelvis: n=128; Ureters: n=47; Stages: Stg 0: n=46 (26.28%), Stg I: n=68 (38.85%), Stg II: n=19 (10.85%), Stg III: n=29 (16.57%), Stg IV (excl. M1):n=13 (7.4%). Gr 1: n=13 (7%), Gr 2: n=49 (28%), Gr 3: n=78 (45%), Gr 4: n=20 (11%); Unknown n=14 (8%). Gr 3/4 distribution for Stages 0, I, II, III, and IV were 17 (37%), 32 (47%), 15 (72%), 23 (79%) and 11 (84%) respectively. Treatment Modalities: All pts were treated with surgical resection; adjuvant chemotherapy was utilized in Stg I: 5/68; Stg II: 3/19; Stg III: 5/29; Stg IV: 1/13 pts. Adjuvant RT was administered in Stg III: 1/29; Stg IV: 3/13 pts. Med. survival and OS at 1, 2, 5 and 10 yrs are shown in Table 1 for all pts treated with surgical resection alone as standard therapy. Med. Survival of all patients who received any adjuvant therapy was 24 mos. Conclusions: Increasing frequency of higher grade disease was present in higher stage patients. Long term survival of early stage disease despite surgical resection is poor with 5 year OS of 45–62% in Stages 0-II and worse with higher stages III and IV with 5 yr OS of 17- 21%. Clearly, better adjuvant or neo-adjuvant strategies are needed to improve this dismal prognosis.

[Table: see text]

No significant financial relationships to disclose.

Social constructions of gender roles, gender-based violence and HIV/AIDS in two communities of the Western Cape, South Africa

The links between gender roles, gender-based violence and HIV/AIDS risk are complex and culturally specific. In this qualitative study we investigated how women and men in two black communities in the Western Cape, South Africa, constructed their gender identities and roles, how they understood gender-based violence, and what they believed about the links between gender relations and HIV risk. First we conducted 16 key informant interviews with members of relevant stakeholder organisations. Then we held eight focus group discussions with community members in single-sex groups. Key findings included the perception that although traditional gender roles were still very much in evidence, shifts in power between men and women were occurring. Also, gender-based violence was regarded as a major problem throughout communities, and was seen to be fuelled by unemployment, poverty and alcohol abuse. HIV/AIDS was regarded as particularly a problem of African communities, with strong themes of stigma, discrimination, and especially 'othering' evident. Developing effective HIV/AIDS interventions in these communities will require tackling the overlapping as well as divergent constructions of gender, gender violence and HIV which emerged in the study.

Post-Peninsular War activities of Sir James McGrigor (1771-1858), Wellington's Director-General of the Army Medical Department

James McGrigor (1771-1858) entered the Army Medical Department in September 1793, when he purchased a Surgeoncy in De Burgh's regiment. He transferred to the Blues (the Royal Horse Guards) in 1804 and shortly afterwards his organizational skills were recognized by the Duke of York. In 1811, he recommended McGrigor to Wellington, who commanded the British Forces in the Peninsula, and McGrigor joined Wellington in January 1812. As a result of his outstanding achievements during the Peninsular War, McGrigor was knighted in 1814. He later played a critical role in the post-Peninsular War Army by elevating the academic standard of the intake of medical officers as well as improving the standard of those who wished to gain promotion in the service. He established an extensive Anatomy, Pathology and Natural History Museum and the reference library at Fort Pitt at Chatham in Kent. He retired at the beginning of 1851, and died in London in April 1858, aged 87. In 1863, the museum collections were moved initially to the Army Medical School at Netley. At a later date these collections were dispersed and their present whereabouts are unknown. A significant proportion of his library is presently located in the Contemporary Medical Archives Centre on permanent loan in the library of the Wellcome Institute for the History of Medicine.

Genealogy of John and Charles Bell: their relationship with the children of Charles Shaw of Ayr

The Reverend William Bell had six children who survived infancy. Two of his sons entered the legal profession and two other sons became distinguished anatomists and surgeons--John Bell, said for 20 years to have been the leading operating surgeon in Britain and throughout the world--and Sir Charles Bell, possibly the most distinguished anatomist and physiologist of his day. Information is not known about the fifth son or their sister. Charles Shaw, a lawyer of Ayr, had four sons and two daughters who survived infancy. Two of his sons, John and Alexander, became anatomists and later surgeons at the Middlesex Hospital, and both worked closely with Charles Bell at the Great Windmill Street School of Anatomy. His third son entered the law and his fourth son became a distinguished soldier. The two daughters of Charles Shaw married into the Bell family: Barbara married George Joseph Bell and Marion married Mr (later Sir) Charles Bell.

Validating the Subcutaneous Model of Injectable Autologous Cartilage Using a Fibrin Glue Scaffold

PURPOSE

To create and validate an injectable model for autologous in vivo cartilage engineering with ultimate clinical applicability in human subjects.

HYPOTHESIS

Cartilage can be generated subcutaneously using fibrin glue and autologous chondrocyte components.

BACKGROUND

To date, cartilage engineering studies have been limited by several factors. Immunocompromised animals and nonautologous chondrocytes have been successfully used to create cartilage, but results using identical designs failed in immunocompetent subjects. Recent studies using more biocompatible tissues and matrices have been performed with both in vitro and in vivo steps. Although successful, several problems are notable. In vitro cartilage displays a poor modulus of elasticity, even after in vivo implantation. Variable deformation and volume loss occurs when in vitro specimens are matured in vivo. These concerns limit the clinical utility of these methods. We therefore set out to create autologous cartilage using a model that was clinically feasible, easy to create, and could be performed with very low patient harvest morbidity.

MATERIALS AND METHODS

Eight New Zealand white rabbits underwent a unilateral harvest of ear cartilage. Samples were then digested using standard methods. Cell counts and survival assays were performed before implantation. One sample of fibrin glue (Tisseel) and chondrocytes was injected subcutaneously into each donor rabbit and then left in situ for 3 months. A second sample with both basic fibroblast growth factor (b-FGF) and insulin-like growth factor (IGF)-1 in the injection suspension was also assessed (for a total of 16 samples). After harvest, analysis of overall volume, histology, and chondrocyte drop out counts was performed.

RESULTS

Cartilage formation occurred in 8 of 14 (57%) specimens that were obtained at the time of sacrifice. Of note, 6 of 7 (85%) non-growth-factor containing samples yielded positive results. Comparison with the success rate using concomitant growth factors (2/7) showed a negative effect on cartilage yield (P = .015). Chondrocyte survival, based on chondrocyte dropout counts, was not effected. Angiogenesis appeared to correlate with cartilage formation in the central regions of the implant. Alcian blue demonstrated the presence of active matrix deposition, and elastin Verhoff-van Geison (EVG) stains were positive, showing an elastic cartilage phenotype. Very limited osteoid formation was seen in successful implants. Failed implants demonstrated avascular necrosis, giant cell reactions, and inflammatory infiltrates.

CONCLUSIONS

This study validates the subcutaneous site as a recipient bed for the engineering of autologous cartilage in vivo. It also represents the first subcutaneous implantation of fibrin glue and chondrocytes in an immunocompetent host as well as the first published report of elastic cartilage generation in vivo. Although the model needs to be further streamlined to increase yields and overall volume, this study clearly demonstrates the feasibility of in vivo chondrogenesis (85% success). The addition of FGF and IGF-1 at the concentrations used negatively influenced cartilage yield. However, extrapolation of these results to other combinations or concentrations can not be done, and this issue deserves further investigation.

Vitamin D receptor gene allelic variants, bone density, and bone turnover in community-dwelling men

The role of vitamin D receptor (VDR) gene polymorphisms in the determination of bone mass and bone turnover is controversial in women. The aim of the study was to determine whether VDR polymorphisms are associated with indices of bone mineral density (BMD) (by dual-energy X-ray absorptiometry and by ultrasound) and/or with bone turnover and muscle strength, factors related to both BMD and fracture risk. For this purpose, we investigated a cohort of community-dwelling men >70 years (n = 271) and a group of healthy control subjects between the ages of 20 and 50 years (n = 137). VDR TaqI, ApaI, and FokI genotypes were determined using enzymatic restriction digestion of polymerase chain reaction (PCR) fragments. In the elderly group, the lowest BMD value at the femoral neck and at the calcaneus was observed in subjects with the "At-At" haplotype genotype, with differences between extreme haplotype groups ("At-At" vs. noncarriers of the "At" allele) ranging from 5.8% to 34.3% (p < or = 0.05). Moreover, at the different subregions of the distal forearm and the tibia, the lowest BMD estimates were consistently associated in both elderly and younger men with the "At" haplotype allele, although this did not approach statistical significance. Elderly subjects with the "At-At" genotype had a significantly higher serum osteocalcin level. BMD was not significantly related to the FokI VDR polymorphism at any of the assessed skeletal sites, nor were any of the biochemical markers associated with the FokI VDR genotype. There were no differences between genotype groups for any of the indices of muscle strength. The present study indicates that the VDR genotype is associated with BMD in healthy community-dwelling elderly men and tends to be associated with biochemical markers, particularly of bone formation, in elderly men.