Endovascular Repair of Juxtarenal and Pararenal Abdominal Aortic Aneurysms Using a Novel Low-Profile Fenestrated Custom-Made Endograft: Technical Details and Short-Term Outcomes.

INTRODUCTION: The aim of this study is to share preliminary experiences and outcomes with a novel custom-made fenestrated TREO® Abdominal Stent-Graft System to treat juxtarenal and pararenal abdominal aortic aneurysms (AAAs). METHODS: Juxtarenal and pararenal AAA patients treated with the custom-made fenestrated TREO® Abdominal Stent-Graft System were included from 4 high-volume European academic medical centers from June 2021 to September 2023. Technical success and 30-day/in-hospital mortality and complications were analyzed. Technical success was defined as successful endovascular implantation of the stent graft with preservation of antegrade flow to the target vessels, and absence of type 1 or 2 endoleak (EL) at the first postoperative computed tomography angiography (CTA). RESULTS: Forty-two consecutive patients were included. The majority of the devices were constructed with 2 (N=4; 9.5%), 3 (N=9; 21.4%), or 4 (N=27; 64%) fenestrations. In 1 case, the device was constructed with a single fenestration (2.4%) and 1 device contained 5 fenestrations (2.4%); 17% had previous AAA repair. Target vessel cannulation with placement of a bridging stent was successful in all but 1 vessel (99, 3%). One aneurysm-related death occurred in the direct postoperative period and 2 limb occlusions necessitated reintervention during admission. In the median follow-up period of 101 (2-620) days, 3 more patients died due to non-aneurysm-related causes. Technical success was achieved in 90% of the cases. Nineteen ELs were seen on the first postoperative CT scan: 1 type 1b EL (N=1; 2%), 15 type 2 ELs (N=15; 36%), and 3 type 3 ELs (N=3%). Eleven patients received more than 1 CT scan during a median follow-up of 361 days (82-620): 3 type 2 ELs resolved and 1 type 3 EL was treated in this period. In the follow-up, 1 patient had a coagulation disorder that caused occlusions of the branches. CONCLUSION: The results of the first experiences using the custom-made fenestrated TREO® Abdominal Stent-Graft System in Europe are promising. There was a low short-term mortality and morbidity rate in these patients of which 17% had previous AAA repair. Mid-term and long-term follow-up data are needed to evaluate endograft durability and performance. CLINICAL IMPACT: This study shows the first experiences and short-term results of a novel low-profile custom-made device: the custom-made fenestrated TREO® Abdominal Stent-Graft System. Showing these results and experiences can help the physicians in clinical decision-making for their patients.

Trabecular and cortical bone involvement in rheumatoid arthritis by DXA and DXA-based 3D modelling.

Rheumatoid arthritis (RA) patients had a higher risk of developing low bone mineral density (BMD) or osteoporosis. RA patients on classic disease-modifying antirheumatic drug (c-DMARD) therapy showed significantly lower BMD than controls, while no significant differences in most parameters were found between RA patients receiving biological disease-modifying antirheumatic drugs (b-DMARDs) and controls. The 3D analysis allowed us to find changes in the trabecular and cortical compartments. INTRODUCTION: To evaluate cortical and trabecular bone involvement of the hip in RA patients by dual-energy X-ray absorptiometry (DXA) and 3D analysis. The secondary end-point was to evaluate bone involvement in patients treated with classic (c-DMARD) or biological (b-DMARD) disease-modifying antirheumatic drug therapies and the effect of the duration of the disease and corticosteroid therapy on 3D parameters. METHODS: A cross-sectional study of 105 RA patients and 100 subjects as a control group (CG) matched by age, sex, and BMI was carried out. BMD was measured by DXA of the bilateral femoral neck (FN) and total hip (TH). The 3D analyses including trabecular and cortical BMD were performed on hip scans with the 3D-Shaper software. RESULTS: FN and TH BMD and trabecular and cortical vBMD were significantly lower in RA patients. The c-DMARD (n = 75) group showed significantly lower trabecular and cortical vBMD than the CG. Despite the lower values, the b-DMARD group (n = 30) showed no significant differences in most parameters compared with the CG. The trabecular and cortical 3D parameters were significantly lower in the group with an RA disease duration of 1 to 5 years than in the CG, and the trabecular vBMD was significantly lower in the group with a duration of corticosteroid therapy of 1 to 5 years than in the CG, while no significant differences were found by standard DXA in the same period. CONCLUSIONS: RA patients had a higher risk of developing low BMD or osteoporosis than controls. RA patients receiving c-DMARD therapy showed significantly lower BMD than controls, while no significant differences in most parameters were found between RA patients receiving b-DMARDs and controls. 3D-DXA allowed us to find changes in trabecular and cortical bone compartments in RA patients.

Respirometric techniques coupled with laboratory-scale tests for kinetic and stoichiometric characterisation of fungal and bacterial tannin-degrading biofilms.

In environmental biotechnology applications for wastewater treatment, bacterial-based bioprocesses are mostly implemented; on the contrary, the application of fungal-based bioprocesses, is still challenging under non-sterile conditions. In a previous laboratory-scale study, we showed that when specific tannins are used as the sole carbon source, fungi can play a key role in the microbial community, under non-sterile conditions and in the long term. In a previous study, an engineered ecosystem, based on fungal tannin biodegradation, was successfully tested in a laboratory-scale bioreactor under non-sterile conditions. In the present study, a kinetic and stoichiometric characterisation of the biomass developed therein was performed through the application of respirometric techniques applied to the biomass collected from the above-mentioned reactor. To this aim, a respirometric set-up was specifically adapted to obtain valuable information from tannin-degrading fungal biofilms. A mathematical model was also developed and applied to describe both the respirometric profiles and the experimental data collected from the laboratory-scale tests performed in the bioreactor. The microbial growth was described through a Monod-type kinetic equation as a first approach. Substrate inhibition, decay rate and tannin hydrolysis process were included to better describe the behaviour of immobilised biomass selected in the tannin-degrading bioreactor. The model was implemented in AQUASIM using the specific tool Biofilm Compartment to simulate the attached fungal biofilm. Biofilm features and transport parameters were either measured or assumed from the literature. Key kinetic and stoichiometric unknown parameters were successfully estimated, overcoming critical steps for scaling-up a novel fungal-based technology for tannins biodegradation.

Discrimination of osteoporosis-related vertebral fractures by DXA-derived 3D measurements: a retrospective case-control study.

A retrospective case-control study assessing the association of DXA-derived 3D measurements with osteoporosis-related vertebral fractures was performed. Trabecular volumetric bone mineral density was the measurement that best discriminates between fracture and control groups. INTRODUCTION: The aim of the present study was to evaluate the association of DXA-derived 3D measurements at the lumbar spine with osteoporosis-related vertebral fractures. METHODS: We retrospectively analyzed a database of 74 postmenopausal women: 37 subjects with incident vertebral fractures and 37 age-matched controls without any type of fracture. DXA scans at the lumbar spine were acquired at baseline (i.e., before the fracture event for subjects in the fracture group), and areal bone mineral density (aBMD) was measured. DXA-derived 3D measurements, such as volumetric BMD (vBMD), were assessed using a DXA-based 3D modeling software (3D-SHAPER). vBMD was computed at the trabecular, cortical, and integral bone. Cortical thickness and cortical surface BMD were also measured. Differences in DXA-derived measurements between fracture and control groups were evaluated using unpaired t test. Odds ratio (OR) and area under the receiver operating curve (AUC) were also computed. Subgroup analyses according to fractured vertebra were performed. RESULTS: aBMD of fracture group was 9.3% lower compared with control group (p < 0.01); a higher difference was found for trabecular vBMD in the vertebral body (- 16.1%, p < 0.001). Trabecular vBMD was the measurement that best discriminates between fracture and control groups, with an AUC of 0.733, against 0.682 for aBMD. Overall, similar findings were observed within the subgroup analyses. The L1 vertebral fractures subgroup had the highest AUC at trabecular vBMD (0.827), against aBMD (0.758). CONCLUSION: This study showed the ability of cortical and trabecular measurements from DXA-derived 3D models to discriminate between fracture and control groups. Large cohorts need to be analyzed to determine if these measurements could improve fracture risk prediction in clinical practice.

Removal of Quebracho and Tara tannins in fungal bioreactors: Performance and biofilm stability analysis.

Tannins are polyphenolic compounds produced by plants that are used in the vegetable tanning of leather at industrial scale. Quebracho tannin and Tara tannin are intensively used by the tanning industry and are two of the most recalcitrant compounds that can be found in tannery wastewaters. In this study two reactors fed with Quebracho tannin and Tara tannin, respectively, were inoculated with polyurethane foam cubes colonized with a fungal strain biofilm of Aspergillus tubingensis MUT 990. A stable biofilm was maintained in the reactor fed with Quebracho tannin during 180 days of operation. Instead, biofilm got detached from the foam cubes during the start-up of the reactor fed with Tara tannin and a bacterial-based suspended culture was developed and preserved along the operational period (226 days). Soluble chemical oxygen demand removals up to 53% and 90% and maximum elimination capacities of 9.1 g sCOD m-3 h-1 and 37.9 g sCOD m-3 h-1 of Quebracho and Tara tannins, respectively, were achieved in the reactors without the addition of co-substrates. Next generation sequencing analysis for bacteria and fungi showed that a fungal consortium was developed in the reactor fed with Quebracho tannin while fungi were outcompeted by bacteria in the reactor fed with Tara tannin. Furthermore, Quebracho and Tara tannins were successfully co-treated in a single reactor where both fungi and bacteria were preserved.

Stability of fungal biomass continuously fed with tannic acid in a non-sterile moving-packed bed reactor.

A number of bacteria and fungi are known to degrade tannins. In this study, the efficiency of the white-rot fungus, Bjerkandera adusta MUT 2295, was evaluated for the treatment of a synthetic solution prepared with tannic acid. Tests were performed in continuously fed, bench-scale, packed-bed reactors, operated under non-sterile conditions with biomass immobilized within PolyUrethane Foam cubes (PUFs). The main parameters monitored to evaluate the process efficiency were: soluble Chemical Oxygen Demand (sCOD), Total Organic Carbon (TOC) removal, and activities. of Tannase and Lignin Peroxidase. At the end of the process, additional parameters were evaluated, including the increase of fungal dry weight and the presence of ergosterol. The reactor was operative for 210 days, with maximum sCOD and TOC removal of 81% and 73%, respectively. The reduction of sCOD and TOC were positively correlated with the detection of Tannase and Lignin Peroxidase (LiP) activities. Increases in biomass within the PUF cubes was associated with increases in ergosterol concentrations. This study proved that the fungal-based system tested was efficient for the degradation of tannic acid over a period of time, and under non-sterile conditions.

Effects of osteoporosis drug treatments on cortical and trabecular bone in the femur using DXA-based 3D modeling.

Effects of osteoporosis drugs on proximal femur cortical and trabecular bone were studied using dual-energy x-ray absorptiometry (DXA)-based 3D modeling method. Changes observed in this head-to-head study were consistent with those obtained using computed tomography in the literature. INTRODUCTION: The aim of the present study was to assess the effects of osteoporosis drugs on cortical and trabecular bone at the proximal femur using DXA-based 3D modeling. METHODS: We retrospectively analyzed 155 patients stratified by treatments: naive of treatment (NAIVE), alendronate (AL), denosumab (DMAB), and teriparatide (TPTD). DXA scans were performed at baseline and after treatment, and areal bone mineral density at spine and femur were measured. A software algorithm (3D-SHAPER) was used to derive 3D models from hip DXA scans and compute: trabecular and cortical volumetric BMD (vBMD), cortical thickness (Cth), and cortical surface BMD (cortical sBMD). Changes from baseline were normalized at 24 months and evaluated in terms or percentage. RESULTS: After 24 months, a non-significant decrease was observed for trabecular vBMD, Cortical sBMD, Cth, and cortical vBMD (- 2.3, - 0.8, - 0.3, and - 0.5%) in the NAIVE group. Under AL and DMAB, significant increases were observed in trabecular vBMD (3.8 and 7.3%), cortical vBMD (1.4 and 2.0%), and cortical sBMD (1.5 and 3.6%). An increase in Cth was observed in patients under DMAB (1.8%). Under TPTD, a significant increase in Trabecular vBMD was observed (5.9%) associated with a non-significant increase of Cth (+ 1%) concomitant with a decrease in cortical vBMD (- 1.1%). CONCLUSION: Results obtained in this head-to-head study are consistent with those obtained using computed tomography in the literature. DXA-based modeling techniques could complement standard DXA examination to monitor treatment effects on trabecular and cortical compartments.

Comparison of two different strategies of treatment with zoledronate in HIV-infected patients with low bone mineral density: single dose versus two doses in 2 years.

OBJECTIVES: Given the need for easily managed treatment of osteoporosis in HIV-infected patients, we evaluated the efficacy and tolerability of two doses of zoledronate, by comparing three groups of patients: those with annual administration, those with biennial administration (one dose in 2 years) and a control group with no administration of zoledronate. METHODS: We randomized (2:1) 31 patients on antiretroviral therapy with low bone mineral density (BMD) to zoledronate (5 mg administered intravenously; 21 patients) plus diet counselling and to a control group (diet counselling; 10 patients). At week 48, patients treated with zoledronate were randomized again to receive a second dose (two-dose group; n = 12) or to continue with diet counselling only (single-dose group; n = 9). Changes in lumbar spine and hip BMD and bone turnover markers were compared. RESULTS: The median percentage change from baseline to week 96 in L1-L4 BMD was -1.74% [interquartile range (IQR) -2.56, 3.60%], 7.90% (IQR 4.20, 16.57%) and 5.22% (IQR 2.02, 7.28%) in the control, two-dose and single-dose groups, respectively (P < 0.01, control vs. two doses; P = 0.02, control vs. single dose; P = 0.18, two doses vs. single dose). Hip BMD changed by a median of 2.12% (IQR -0.12, 3.08%), 5.16% (IQR 3.06, 6.74%) and 4.47% (IQR 1, 5.58%), respectively (P = 0.04, control vs. two doses; P = 0.34, two doses vs. single dose). No differences between the two-dose and single-dose groups were detected in bone markers at week 96. CONCLUSIONS: The benefits for BMD of a single dose of zoledronate in 2 years may be comparable to those obtained with two doses of the drug after 96 weeks, although this study is insufficiently powered to exclude a real difference. Future studies should explore whether biennial administration of zoledronate is a useful alternative in the treatment of osteoporosis in HIV-infected patients.

Is bone microarchitecture status of the lumbar spine assessed by TBS related to femoral neck fracture? A Spanish case-control study.

UNLABELLED: Bone mineral density (BMD) as assessed by dual energy X-ray absorptiometry (DXA) constitutes the gold standard for osteoporosis diagnosis. However, DXA does not take into account bone microarchitecture alterations. INTRODUCTION: The aim of our study was to evaluate the ability of trabecular bone score (TBS) at lumbar spine to discriminate subjects with hip fracture. METHODS: We presented a case-control study of 191 Spanish women aged 50 years and older. Women presented transcervical fractures only. BMD was measured at lumbar spine (LS-BMD) using a Prodigy densitometer. TBS was calculated directly on the same spine image. Descriptive statistics, tests of difference and univariate and multivariate backward regressions were used. Odds ratio (OR) and the ROC curve area of discriminating parameters were calculated. RESULTS: The study population consisted of 83 subjects with a fracture and 108 control subjects. Significant lower spine and hip BMD and TBS values were found for subjects with fractures (p < 0.0001). Correlation between LS-BMD and spine TBS was modest (r = 0.41, p < 0.05). LS-BMD and TBS independently discriminate fractures equally well (OR = 2.21 [1.56-3.13] and 2.05 [1.45-2.89], respectively) but remain lower than BMD at neck or at total femur (OR = 5.86 [3.39-10.14] and 6.06 [3.55-10.34], respectively). After adjusting for age, LS-BMD and TBS remain significant for transcervical fracture discrimination (OR = 1.94 [1.35-2.79] and 1.71 [1.15-2.55], respectively). TBS and LS-BMD combination (OR = 2.39[1.70-3.37]) improved fracture risk prediction by 25 %. CONCLUSION: This study shows the potential of TBS to discriminate subjects with and without hip fracture. TBS and LS-BMD combination improves fracture risk prediction. Nevertheless, BMD at hip remains the best predictor of hip fracture.

Relationships between physical exercise practice, dietary behaviour and body composition in female university students.

AIM: The relationship between female body composition, total energy expenditure and physical exercise energy expenditure is not very strong because women can compensate by increasing their energy intake. The aim of this study was to investigate the relationship between total minutes of exercise per week, dietary habits and body composition in female university students using physical activity and the habit to cook as covariates. METHODS: Fifty-one female university students were investigated for body composition, dietary habits, aerobic fitness, physical activity and physical exercise practice. Participants were grouped in three sub-samples (1, 2 and 3) according to the 33rd and 66th percentiles of weekly minutes (min/wk) of training. RESULTS: Group 1 had 0.00 min/wk, group 2 had 95±35.59 min/wk and group 3 had 231.66±85.97 min/wk of training. Sub-samples did not differ for IPAQ parameters while differed for aerobic fitness (P=0.001). Group 3 had a higher energy intake (EI) (P=0.008), a higher intake of lipids (P=0.017), saturated (P=0.042) and monounsaturated fat (P=0.024) and a lower intake of carbohydrates (P=0.007). Group 3 maintained the higher EI and the worse composition of lipid intake considering the habit to cook as covariate. Group 3 also had higher muscle mass. CONCLUSION: In order to positively affect body composition, in the sedentary women it is enough to control the energy balance, whereas in those that trained regularly it is necessary to control both energy balance and composition of daily meals.

A global sensitivity analysis approach applied to a multiscale model of microvascular flow.

A global sensitivity analysis of a multiscale computational model of microvascular flow is presented. A total of 140 simulations have been completed and analyzed varying 6 input parameters and considering their effects on 7 output variables. Interestingly, the vascular network topology has been found as a determinant factor for both vasculature-related and interstitium-related quantities. Regarding the firsts, the vascular network topology has obtained a score of 5.5/6 and 6/6 for average and spatial distribution respectively (where 6 is the maximum and 1 is the minimum). On the other hand, considering interstitium-related quantities, the score is 4/6 and 5/6 for average and spatial distribution respectively. These results suggest that the network topology has a significant influence on the outcome of the computational analysis.

Men suffer vertebral fractures with similar spinal T-scores to women.

OBJECTIVE: To evaluate the applicability of the WHO densitometric criteria for the diagnosis of spinal osteoporosis in men and to compare it with women with vertebral fractures, as well as to analyze the role of vertebral dimensions in the development of spinal fractures. METHODS: For these purposes we analyzed, using DXA, vertebral projected area and lumbar bone mineral density (BMD), as well as T and Z-scores in lumbar spine in a cohort of 66946 individuals; 2556 of these subjects had one or more atraumatic vertebral fracture (396 men and 2160 postmenopausal women). RESULTS: Men and women with fractures showed significantly lower mean BMD, T-score and Z-score values than individuals without fractures while vertebral dimensions were similar in both groups of patients. When comparing men and women with vertebral fractures, the former showed a significantly greater projected area (46.89+/-5.5 vs. 39.13+/-4.6 cm(2) p<0.001) and lumbar BMD (0.991+/- 0.21 vs. 0.938+/- t0.19 g/cm(2) p<0.001). However, the median lumbar T-score values were similar for both sexes (-2.3 in women vs. -2.2 in men; p: NS). In addition, a similar percentage of men and women with vertebral fractures showed T-score values <-2.5 in the lumbar spine (44% vs. 46%, p=NS). CONCLUSION: We conclude that although men with vertebral fractures have greater vertebral dimensions and BMD than women, the lumbar T-scores are similar. Therefore, it seems reasonable to adopt the same T-score values for the diagnosis of osteoporosis in men and women.

Effect of cellulose as co-substrate on old landfill leachate treatment using white-rot fungi.

Conventional wastewater treatment technologies are ineffective for remediation of old LandFill Leachate (LFL), and innovative approaches to achieve satisfactory removal of this recalcitrant fraction are needed. This study focused on old LFL treatment with a selected fungal strain, Bjerkandera adusta MUT 2295, through batch and continuous tests, using packed-bed bioreactors under non-sterile conditions. To optimize the process performance, diverse types of co-substrates were used, including milled cellulose from beverage cups waste material. Extracellular enzyme production was assayed, in batch tests, as a function of a) cellulose concentration, b) leachate initial Chemical Oxygen Demand (COD) and Soluble COD (sCOD), and c) co-substrate type. Bioreactors were dosed with an initial start-up of glucose (Rg) or cellulose (Rc). An additional glucose dosage was provided in both reactors, leading to significant performance increases. The highest COD and sCOD removals were i) 63% and 53% in Rg and ii) 54% and 51% in Rc.

Enrichment of activated sludge in a sequencing batch reactor for polyhydroxyalkanoate production.

The paper describes the start up of a process for the production of polyhydroxyalkanoates (PHAs) from activated sludge. The excess sludge from a wastewater treatment plant was inoculated in a lab-scale sequencing batch reactor (SBR) to be enriched under aerobic conditions through intermittent feeding with a mixture of organic acids. Enriching of activated sludge was monitored through the measurement of polymer concentrations either in the mixed liquor or in the microbial biomass. The bacterial population dynamics during the SBR start up was followed through denaturing gradient gel electrophoresis and the main species present at the steady state were identified. All the measured parameters significantly changed in the SBR during first two weeks after the inoculum was seeded into the reactor, they then stabilized. At the steady state, the SBR produced 2.6 gVSSl(-1) d(-1), with a PHA content of 11% (on a COD basis). The enriched microbial biomass was then transferred into a batch reactor where the bacterial polymer content was increased through a new feeding. In the final batch stage, maximum storage rate and maximum polymer content in the biomass were 405 mgCOD gCOD(-1) h(-1) and 44% (on a COD basis), respectively. The PHA storage from the enriched microbial biomass was about 20 times faster and the PHA content was about 4 times higher than that of the inoculated activated sludge. Observations by fluorescence microscopy showed that the majority of microorganisms in the enriched biomass could be stored. Among the numerically most representative genera in the enriched biomass, Thauera, Candidatus Meganema perideroedes, and Flavobacterium were identified.

Comparison between different bone treatments on areal bone mineral density (aBMD) and bone microarchitectural texture as assessed by the trabecular bone score (TBS).

PURPOSE: The objective of the study was to assess longitudinal effects of different osteoporosis treatments on TBS and aBMD at lumbar spine. METHOD: We analyzed 390 patients (men: 72; women: 318; age>40 years; mean follow-up of 20 months and BMI<37 kg/m(2)). We stratified the cohort by treatments: Naive of treatment (Naive, n=67), Calcium and Vitamin D (CaVitD, n=87), Testosterone (Te, n=36), Alendronate (AL, n=88), Risedronate (Ri, n=39), Denosumab (Dmb, n=43) and Teriparatide (PTH, n=30). The follow-up changes from baseline were normalized at 24 months. RESULTS: After 24 months, Naive group TBS decreased by 3.1% (p<0.05) whereas a non-significant increase was observed for spine aBMD (Δ=+0.5%). Compared to the Naive group, significant improvement (p<0.05) was observed in both TBS and aBMD for Te, AL, Ri, Dmb and PTH groups and in the CaVitD group for TBS. At the end of the follow-up, significant improvement have been observed for aBMD in Te (+4.4%), AL (+4.1%), Ri (+4.8), D (+8.8%) and PTH (+8.8%) groups. Significant improvement was observed only in the AL (+1.4%), Dmb (+2.8%) and PTH (+3.6%) groups for TBS. CONCLUSION: As expected, TBS of Naive subjects decreased with age. As expected a TBS preservation has been observed under AL and Ri. Te and CaVitD effects on TBS were evaluated for the first time: a similar preservation effect has been observed. A significant TBS increase was observed under Denosumab and PTH. TBS could be a useful tool to monitor treatment effects.

Fragilidad relativa de fémures osteoporóticos evaluados con DXA y simulación de caídas con elementos finitos guiados por radiografías de urgencias / Relative fragility of osteoporotic femurs assessed withDXA and simulation of finite element falls guided byemergency X-rays

OBJETIVO: El diagnóstico de osteoporosis se ha fundamentado en la medición de la densidad mineral ósea, si bien esta variable tiene una capacidad limitada en la discriminación de pacientes con o sin fracturas. La aplicación del análisis de elementos finitos (FE) sobre imágenes volumétricas de tomografía computarizada ha mejorado la clasificación de sujetos hasta 90%, aunque la dosis de radiación, complejidad y coste no aconsejan su práctica regular. Nuestro objetivo es aplicar el análisis FE a modelos tridimensionales con absorciometría radiológica dual (3D-DXA), para clasificar pacientes con fractura osteoporótica de fémur proximal y sin fractura. MATERIAL Y MÉTODOS: Se seleccionó una cohorte de 111 pacientes con osteoporosis densitométrica: 62 con fractura y 49 sin ella. Se utilizaron modelos FE sujeto-específicos para el impacto, como la simulación estática de la caída lateral. Las simulaciones de impacto permiten identificar la región crítica en el 95% de los casos, y la respuesta mecánica a una fuerza lateral máxima. Se realizó un análisis mediante un clasificador discriminativo (Support Vector Machine) por tipo de fractura, tejido y género, utilizando las mediciones DXA y parámetros biomecánicos. RESULTADOS: Los resultados mostraron una sensibilidad de clasificación del 100%, y una tasa de falsos negativos de 0% para los casos de fractura de cuello para el hueso trabecular en las mujeres. Se identifica la variable tensión principal mayor (MPS) como el mejor parámetro para la clasificación. CONCLUSIÓN: Los resultados sugieren que el uso de modelos 3D-DXA podría ayudar a discriminar mejor a los pacientes con elevado riesgo de fracturarse

OBJETIVE: The diagnosis of osteoporosis has been based on the measurement of bone mineral density, although this variable has a limited capacity in discriminating patients with or without fractures. The application of finite element analysis (FE) on computed tomography volumetric images has improved the classification of subjects by up to 90%, although the radiation dose, complexity, and cost do not favor their regular practice. Our objective is to apply FE analysis to three-dimensional models with dual-energy x-ray absorptiometry (3D-DXA), to classify patients who present osteoporotic fracture of the proximal femur and those without fracture. MATERIAL AND METHODS: A cohort of 111 patients with densitometric osteoporosis was selected: 62 with fracture and 49 without it. Subject-specific FE models for impact were used, such as static simulation of lateral fall. Impact simulations allow identifying the critical region in 95% of cases, and the mechanical response to maximum lateral force. An analysis was performed using a discriminative classifier (Support Vector Machine) by fracture type, tissue and gender, using DXA measurements and biomechanical parameters. RESULTS: The results showed a classification sensitivity of 100%, and a false negative rate of 0% for cases of neck fracture for trabecular bone in women. The variable major main stress (MPS) is identified as the best parameter for the classification. CONCLUSION: The results suggest that using 3D-DXA models help in order to better discriminate patients with raised fracture risk

Bone mass changes during pregnancy and lactation in the rat.

We examined bone mass changes in the total, axial, and appendicular skeleton as well as in the different subareas of femur and tibia in rats fed on a normal calcium diet. A total of 16 virgin Wistar rats, approximately 5 months of age (270+/-30 g), were assigned to two groups of eight rats each. One group was mated and, for each pregnant rat, a nonpregnant control rat was studied simultaneously. Weaning was performed when the pups reached 38+/-3 g body weight. At the beginning (t = 0), on the first day postpartum (t = 22 days), and at weaning (t = 45 days), total skeleton bone mineral content (BMC), area, and bone mineral density (BMD) were determined by dual-energy X-ray absorptiometry (DXA) in vivo under anesthesia. Body weight increased significantly during pregnancy (p < 0.05) and decreased at weaning, whereas control rats showed a slow, gradual increment without reaching a significant difference. During pregnancy, BMC and area of the total skeleton increased significantly in pregnant rats, but the changes in BMD were not different compared with the control group. A completely different pattern was observed between groups during the 23 days of lactation. While the skeleton continued to grow in the control group (BMC and area increased), the total skeleton of lactating rats showed no change in area (size), small decreases in BMC, and a significant decrease in BMD (p < 0.05). Consequently, although BMC and BMD of both groups were similar at the time of delivery, BMC was 12.0% lower and BMD 4.9% lower at the end of lactation in the lactating rats compared with the control group. The contribution of the maternal skeleton to the lactation period was not similar; that is, the areas with the highest trabecular component showed the greater average differences in BMD at the time of weaning (proximal tibia -19.9%, distal femur -12.6%, spine -10.9%) (p < 0.05), compared with relatively minor, nonsignificant losses in areas where cortical bone predominates (distal tibia -5%, middle tibia -5.2%). Our experimental results demonstrated the usefulness of DXA in vivo to visualize changes in BMD during the reproductive cycle of the rat. Moreover, the data confirm that normal pregnancy in the rat appears to exert little influence on bone, whereas lactation induces significant bone loss, mainly in the areas of predominant trabecular bone.

Autoantibodies and endothelial dysfunction in well-controlled, uncomplicated insulin-dependent diabetes mellitus patients.

Patients with insulin-dependent diabetes mellitus (IDDM) are well known to be at high risk of vascular disease, and dysfunction of vascular endothelium is considered as an early step in the development of diabetic complications. Because of the involvement of autoimmunity in the pathogenesis of IDDM, our aim was to assess, in 45 IDDM patients without clinically evident vascular complications, whether early signs of endothelial cell dysfunction were correlated to alterations of the immune system. IDDM patients were characterized by significantly increased serum levels of C-reactive protein, of polymorphonuclear cells-derived elastase, of endothelin-1 (ET-1) and of thrombomodulin, while plasma concentrations of fibronectin (FNT) were significantly decreased, with a statistically significant inverse correlation between ET-1 and FNT values. The presence of circulating immune complexes (CIC) was investigated in 36 out of our 45 IDDM patients, and values above the cut-off were found in 17 (47.2%) of them. One-third of all patients showed values above the cut-off for IgG-aCL. In IDDM patients, at variance from the control group, the levels of ET-1 were directly correlated to those of von Willebrand factor, of anticardiolipin beta(2)-GPI and of CIC, with an inverse correlation with plasma FNT. An association between antiphospholipid antibodies and endothelial dysfunction and/or activation is therefore suggested, pointing to a synergism, in the early phases of IDDM vascular disease, between generation of autoantibodies and endothelial activation.

Osteoporosis with vertebral fractures associated with pregnancy and lactation.

Three cases of young women who developed severe vertebral osteoporosis after pregnancy and during lactation are described. These patients shared several features: a low-calcium diet during most of their lives, very-low body weight in two patients, and a positive family history of osteoporosis in two patients. Initial studies disclosed vertebral fractures, severely diminished bone mineral density of the spine (Z score = -3.3 to -4.1), and a less severely affected bone mineral density of the hip (Z score = -1.6 to -2.3). During the prolonged follow-up of these patients, treated with oral biphosphonates, vitamin D, and calcium, an improved clinical response with a marked recovery of spine bone mineral density was observed. Poor general nutrition, low calcium intake, and a positive family history of osteoporosis appear to be strong risk factors for pregnancy- and lactation-associated osteoporosis. Although the mechanism of action is uncertain, calcium, vitamin D, and antiresorptive agents may have been beneficial in the treatment of this severe disorder.

[Olpadronate prevents cortical and trabecular bone loss induced by supraphysiological dosis of thyroxine in ovariectomized rats]. / El olpadronato previene la pérdida de hueso cortical y trabecular inducida por dosis suprafisiológicas de tiroxina en ratas ovariectomizadas.

The aim of the present report was to clarify the effect of excess T4 on axial and peripheral bone mineral density (BMD) in estrogen-depleted rats. The protective effect of olpadronate (Olpa) on axial and peripheral bone mass in thyroxine-treated rats was also investigated. Female Sprague-Dawley rats were used: SHAM, OVX + Vh, OVX + Olpa (0.3 mg/kg/week), OVX + T4 (250 micrograms/kg/day) and OVX + T4 + Olpa rats. OVX + Vh group presented a BMD lower than SHAM in the tibia (p < 0.01) but not in femur or lumbar spine; the middle tibia BMD did not change but it was lower at the distal (pns.) and proximal levels (p < 0.003) in OVX + Vh. OVX + T4 rats presented a BMD significantly lower than OVX + Vh rats in total tibia (p < 0.02), femur (p < 0.006) and lumbar spine (p < 0.006). Moreover the BMD was lower in all studied areas of the tibia, but it was statistically significant only at the middle level (p < 0.004). OVX + Olpa rats had a BMD higher than OVX + Vh rats in femur (p < 0.002), lumbar spine (p < 0.0001), total (p < 0.001) and proximal tibia (p < 0.001). Surprisingly, total and proximal tibia BMD values in OVX + Olpa rats presented a BMD significantly higher than OVX + T4 rats in femur (p < 0.001), lumbar spine (p < 0.001), tibia (p < 0.001) and proximal tibia (p < 0.0001). It is important to point out that OVX + T4 + Olpa BMD was significantly higher than in SHAM rats at the lumbar spine, total and proximal tibia (p < 0.01). The present study suggests that although supraphysiological thyroid hormone affected both cortical and trabecular bone, under estrogen-depleted conditions, the cortical bone appears to be more sensitive than the trabecular bone to T4 treatment. We also found that Olpa could prevent the peripheral and axial bone loss induced by thyroid hormone excess.