Impact of Degree of Ionization and PEGylation on the Stability of Nanoparticles of Chitosan Derivatives at Physiological Conditions.

Nowadays, the therapeutic efficiency of small interfering RNAs (siRNA) is still limited by the efficiency of gene therapy vectors capable of carrying them inside the target cells. In this study, siRNA nanocarriers based on low molecular weight chitosan grafted with increasing proportions (5 to 55%) of diisopropylethylamine (DIPEA) groups were developed, which allowed precise control of the degree of ionization of the polycations at pH 7.4. This approach made obtaining siRNA nanocarriers with small sizes (100-200 nm), positive surface charge and enhanced colloidal stability (up to 24 h) at physiological conditions of pH (7.4) and ionic strength (150 mmol L-1) possible. Moreover, the PEGylation improved the stability of the nanoparticles, which maintained their colloidal stability and nanometric sizes even in an albumin-containing medium. The chitosan-derivatives displayed non-cytotoxic effects in both fibroblasts (NIH/3T3) and macrophages (RAW 264.7) at high N/P ratios and polymer concentrations (up to 0.5 g L-1). Confocal microscopy showed a successful uptake of nanocarriers by RAW 264.7 macrophages and a promising ability to silence green fluorescent protein (GFP) in HeLa cells. These results were confirmed by a high level of tumor necrosis factor-α (TNFα) knockdown (higher than 60%) in LPS-stimulated macrophages treated with the siRNA-loaded nanoparticles even in the FBS-containing medium, findings that reveal a good correlation between the degree of ionization of the polycations and the physicochemical properties of nanocarriers. Overall, this study provides an approach to enhance siRNA condensation by chitosan-based carriers and highlights the potential of these nanocarriers for in vivo studies.

Synthesis and evaluation of diethylethylamine-chitosan for gene delivery: composition effects on the in vitro transfection efficiency.

Chitosan has been indicated as a safe and promising polycation vector for gene delivery. However its low transfection efficiency has been a challenging obstacle for its application. To address this limitation, we synthesized chitosan derivatives which had increasing amounts of diethylethylamine groups (DEAE) attached to the chitosan main chain. The plasmid DNA VR1412 (pDNA), encoding the ß-galactosidase (ß-gal) reporter gene was used to prepare nanoparticles with the chitosan derivatives, and the transfection studies were performed with HeLa cells. By means of dynamic light scattering and zeta potential measurements, it was shown that diethylethylamine-chitosan derivatives (DEAE(x)-CH) were able to condense DNA into small particles having a surface charge depending on the polymer/DNA ratio (N/P ratio). Nanoparticles prepared with derivatives containing 15 and 25% of DEAE groups (DEAE(15)-CH and DEAE(25)-CH) exhibited transfection efficiencies ten times higher than that observed with deacetylated chitosan (CH). For derivatives with higher degrees of substitution (DS), transfection efficiency decreased. The most effective carriers showed low cytotoxicity and good transfection activities at low charge ratios (N/P). Vectors with low DS were easily degraded in the presence of lysozyme at physiological conditions in vitro and the nontoxicity displayed by these vectors opens up new opportunities in the design of DEAE-chitosan-based nanoparticles for gene delivery.

Clinical and quality-of-life outcomes of a combined synthetic scaffold and autogenous tissue graft procedure for articular cartilage repair in the knee.

BACKGROUND: Injuries to the articular cartilage of the knee often fail to heal properly due to the hypocellular and avascular nature of this tissue. Subsequent disability can limit participation in sports and decrease quality of life. Subchondral bone perforations are used for the treatment of small defects. Filling out the central portion in larger lesions becomes difficult, and scaffolds can be used as adjuvants, providing a matrix onto which the defect can be filled in completely. Also, autogenous cartilage grafts can be combined, acting as an inducer and improving healing quality, all in a single procedure. METHODS: This observational study evaluated the clinical and quality-of-life outcomes of patients with articular cartilage lesions of the knee undergoing repair via a microfracture technique combined with a synthetic scaffold and autogenous cartilage graft, with transosseous sutures and fibrin glue fixation, at 12 months of follow-up. Secondarily, it assessed whether combined procedures, previous surgical intervention, traumatic aetiology, lesion location, and age affect outcomes. The sample consisted of adult patients (age 18-66 years) with symptoms consistent with chondral or osteochondral lesions, isolated or multiple, ICRS grade III/IV, 2-12 cm2 in size. Patients with corrected angular deviations or instabilities were included. Those with BMI > 40 kg/m2, prior total or subtotal (> 30%) meniscectomy, second-look procedures, and follow-up < 6 months were excluded. Pain (VAS), physical activity (IKDC), osteoarthritis (WOMAC), and general quality of life (SF-36) were assessed. RESULTS: 64 procedures were included, comprising 60 patients. There was significant improvement (P < 0.05) in VAS score (5.92-2.37), IKDC score (33.44-56.33), and modified WOMAC score (53.26-75.93) after surgery. The SF-36 showed significant improvements in the physical and mental domains (30.49-40.23 and 46.43-49.84 respectively; both P < 0.05). CONCLUSIONS: Combination of microfractures, autogenous crushed cartilage graft, synthetic scaffold, and transosseous sutures with fibrin glue provides secure fixation for treatment of articular cartilage lesions of the knee. At 12-month follow-up, function had improved by 20 points on the IKDC and WOMAC, and quality of life, by 10 points on the SF-36. Age > 45 years had a negative impact on outcomes.

Magnesium Supplementation: Effect on the Expression of Inflammation Genes in Erlich's Tumor.

Magnesium supplementation may be beneficial for cancer patients due to its action as a modulator of cell proliferation and metabolism and its anti-inflammatory effect. Tumor metabolism can influence the bioavailability and absorption of nutrients, leading to an increase in the individual's nutritional needs. In this work, the effects of supplementing different dosages of magnesium chloride in mice with solid Ehrlich's tumors were investigated by analyzing their hematological, inflammatory and anthropometric biomarkers. Three dosages of magnesium chloride (MgCl2) were administered for 28 consecutive days. Animal welfare was assessed according to the criteria stipulated by the National Center for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs). The inverted grid method was used to analyze muscle strength and fatigue. Difference in expression of the Tumor Necrosis Factor (TNF-α) and the Growth Transformation Factor (TGF-ß1) genes was determined by the 2-ΔCt method. The hematological evaluation consisted of the erythrogram, white blood cell and platelet counts were used for the hematological evaluation and treatment cytotoxicity. Difference in the expression of the TNF-α and TGF-ß genes showed that the group that received a high dose of magnesium had a decrease in TNF-α and RNL, an improvement in well-being with a tendency to increase muscle strength and less tumor progression according to the days of treatment. The group that received a low dosage of magnesium had a smaller tumor volume and a more controlled tumor growth according to the days. The group that received an intermediate dosage presented cytotoxicity.

Evidence Supporting the Safety of Pegylated Diethylaminoethyl-Chitosan Polymer as a Nanovector for Gene Therapy Applications.

PURPOSE: Diethylaminoethyl-chitosan (DEAE-CH) is a derivative with excellent potential as a delivery vector for gene therapy applications. The aim of this study is to evaluate its toxicological profile for potential future clinical applications. METHODS: An endotoxin-free chitosan (CH) modified with DEAE, folic acid (FA) and polyethylene glycol (PEG) was used to complex small interfering RNA (siRNA) and form nanoparticles (DEAE12-CH-PEG-FA2/siRNA). Based on the guidelines from the International Organization for Standardization (ISO), the American Society for Testing and Materials (ASTM), and the Nanotechnology Characterization Laboratory (NCL), we evaluated the effects of the interaction between these nanoparticles and blood components. In vitro screening assays such as hemolysis, hemagglutination, complement activation, platelet aggregation, coagulation times, cytokine production, and reactive species, such as nitric oxide (NO) and reactive oxygen species (ROS), were performed on erythrocytes, plasma, platelets, peripheral blood mononuclear cells (PBMC) and Raw 264.7 macrophages. Moreover, MTS and LDH assays on Raw 264.7 macrophages, PBMC and MG-63 cells were performed. RESULTS: Our results show that a targeted theoretical plasma concentration (TPC) of DEAE12-CH-PEG-FA2/siRNA nanoparticles falls within the guidelines' thresholds: <1% hemolysis, 2.9% platelet aggregation, no complement activation, and no effect on coagulation times. ROS and NO production levels were comparable to controls. Cytokine secretion (TNF-α, IL-6, IL-4, and IL-10) was not affected by nanoparticles except for IL-1ß and IL-8. Nanoparticles showed a slight agglutination. Cell viability was >70% for TPC in all cell types, although LDH levels were statistically significant in Raw 264.7 macrophages and PBMC after 24 and 48 h of incubation. CONCLUSION: These DEAE12-CH-PEG-FA2/siRNA nanoparticles fulfill the existing ISO, ASTM and NCL guidelines' threshold criteria, and their low toxicity and blood biocompatibility warrant further investigation for potential clinical applications.

Impact of noncompliance with alendronate and risedronate on the incidence of nonvertebral osteoporotic fractures in elderly women.

AIMS: To evaluate the association between noncompliance with alendronate and risedronate and the risk of nonvertebral osteoporotic fracture in community-dwelling elderly women. METHODS: A nested case-control study was conducted using the Quebec administrative health databases. To be included in the cohort, women needed to be aged > or = 68 years and to have initiated treatment with alendronate or risedronate between 1 January 2002 and 31 March 2005. Cases consisted of all women with an incident nonvertebral osteoporotic fracture occurring > or = 1 year after initiation of therapy. Each case was matched with up to 20 controls using incidence density sampling, according to age (+/- 1 year) and follow-up duration. A woman was noncompliant if she had a medication possession ratio (MPR) <80% for total follow-up duration. Rate ratios (RR) for fracture were estimated through conditional logistic regression analysis, adjusting for potential confounders. RESULTS: Among the 30 259 women included in the cohort, 1036 nonvertebral fracture cases were identified and were matched to 20 069 controls. Compared with women with a MPR > or = 80%, those with a MPR < 80% had a greater risk of nonvertebral fracture [adjusted RR 1.27, 95% confidence interval (CI) 1.12, 1.44]. Considering hip fracture only, the multivariate model yielded similar results, (adjusted RR 1.28, 95% CI 1.02, 1.61). CONCLUSIONS: Among community-dwelling elderly women, noncompliance with alendronate or risedronate is associated with an increased risk of nonvertebral fracture.

Population-based study of the effectiveness of bone-specific drugs in reducing the risk of osteoporotic fracture.

AIM: Evidence supports bone-specific drugs (BSDs) efficacy in the fracture risk reduction. But treatment rates for osteoporosis among high-risk patients are far below the recommended guidelines. A major concern about BSDs is the lack of adherence with treatment. OBJECTIVE: To determine if BSDs decrease fracture risk in high-risk elderly women in real clinical setting. METHODS: A nested case-control design was used in a cohort of elderly women from the Quebec health databases. Women enter into the cohort if they are 70 years or older between 1995 and 2003. Nested case-controls were designed for women with a diagnosis of osteoporosis (OP) and for those with a prior fracture. All cases of fractures occurring during follow-up were matched with 10 randomly selected controls based on age, time period, bone mass density testing, and having a diagnosis of OP or a prior fracture. Use of BSDs before the index date was categorized as follows: short-term (< or =1 year), intermediate-term (>1 and < or = 3 years), and long-term (>3 years). We used an adjusted conditional logistic regression model to assess BSD effect on fracture. RESULTS: Among 3170 women who had a fracture, of these women, 1824 had OP and 1346 had a prior fracture. Only long-term exposure to BSDs among women with OP reduced the fracture risk by 16% (odds ratio: 0.84; 0.73-0.97). Among women with OP, a high number of medical services or use of anticonvulsants or narcotics increased the fracture risk by 12-73%. Among women with a prior fracture, a high number of medical services or risk of fall or use of benzodiazepines, antidepressants, or narcotics increased the fracture risk by 23-77%. CONCLUSION: The incidence of fractures decreased by 16% among women with OP when more than 80% of BSDs was used for at least 3 years. Among women with a prior fracture, fracture risk reduction was not significant. Exposure to BSDs among women with a prior fracture is troubling, given that only approximately 12% of these individuals were being treated, and only 2% was using BSDs for the long term.

Phytoliths as indicators of pedogenesis and paleoenvironmental changes in Spodosols of the state of Rio de Janeiro, Brazil.

This study aims to contribute toward a better understanding of the current biodiversity patterns existing in the Atlantic Forest of the state of Rio de Janeiro from a paleo-ecological approach. Three soil profiles, each formed from distinct source materials under varied climate and vegetation conditions were selected from the coastal regions of Rio de Janeiro, Brazil. Soil horizon samples for chemical and physical characterization were collected from 10 cm-interval depths, and the total organic carbon was determined in addition to performing isotype and phytolithic analyses. The phytolithic analysis associated with the isotopic techniques (δ13C) permitted the characterization of three stages of paleo-environmental evolution for the studied soils, presenting valid trends that indicate small variations within the phytosociological structure of the vegetation along a Spodosols line in the studied areas. These stages indicated that the phytolithic assemblage was formed from a vegetation profile containing more trees, adapted to conditions colder than the existing vegetation, although no environmental changes were detected using the isotopic data. The milder temperature conditions may have favored the pedogenetic processes of the spodic B horizon formation as well as the maintenance of the organic matter contained in the soil. This study serves as the first draft for the paleo-environmental association among the regions where the analyzed profiles are found.

In vivo therapeutic efficacy of TNFα silencing by folate-PEG-chitosan-DEAE/siRNA nanoparticles in arthritic mice.

BACKGROUND: Tumor necrosis factor-alpha (TNFα), a pro-inflammatory cytokine, has been shown to play a role in the pathophysiology of rheumatoid arthritis. Silencing TNFα expression with small interfering RNA (siRNA) is a promising approach to treatment of the condition. METHODS: Towards this end, our team has developed a modified chitosan (CH) nanocarrier, deploying folic acid, diethylethylamine (DEAE) and polyethylene glycol (PEG) (folate-PEG-CH-DEAE15). The gene carrier protects siRNA against nuclease destruction, its ligands facilitate siRNA uptake via cell surface receptors, and it provides improved solubility at neutral pH with transport of its load into target cells. In the present study, nanoparticles were prepared with siRNA-TNFα, DEAE, and folic acid-CH derivative. Nanoparticle size and zeta potential were verified by dynamic light scattering. Their TNFα-knockdown effects were tested in a murine collagen antibody-induced arthritis model. TNFα expression was examined along with measurements of various cartilage and bone turnover markers by performing histology and microcomputed tomography analysis. RESULTS: We demonstrated that folate-PEG-CH-DEAE15/siRNA nanoparticles did not alter cell viability, and significantly decreased inflammation, as demonstrated by improved clinical scores and lower TNFα protein concentrations in target tissues. This siRNA nanocarrier also decreased articular cartilage destruction and bone loss. CONCLUSION: The results indicate that folate-PEG-CH-DEAE15 nanoparticles are a safe and effective platform for nonviral gene delivery of siRNA, and their potential clinical applications warrant further investigation.

Diethylaminoethyl- chitosan as an efficient carrier for siRNA delivery: Improving the condensation process and the nanoparticles properties.

Chitosan has been indicated as a promising carrier for the preparation of small interfering RNA (siRNA) delivery systems due to its remarkable properties. However, its weak interactions with siRNA molecules makes the condensation of siRNA molecules into nanoparticles difficult. In this work, a non-viral gene delivery system based on diethylaminoethyl chitosan (DEAE-CH) derivatives of varied Mw (25-230 kDa) having a low degree of substitution of 15% was investigated. The presence of secondary and tertiary amino groups strengthened the interaction of siRNA and DEAE-CH derivatives of higher Mw (130 kDa to 230 kDa) and provided the preparation of spherical nanoparticles at low charge ratios (N/P 2 to 3) with low polydispersities (0.15 to 0.2) in physiological ionic strength. Nanoparticles prepared with all derivatives exhibited remarkable silencing efficiencies (80% to 90%) on different cell lines (HeLa, MG-63, OV-3) by adjusting the charge ratios. A selected PEG-folic acid labeled derivative (FA-PEG-DEAE15-CH230) was synthesized and its nanoparticles completely inhibited the mRNA expression level of TNF-α in RAW 264.7 macrophages. The study demonstrates that the insertion of DEAE groups provides improved physical properties to chitosan-siRNA nanoparticles and holds potential for in vivo applications.

Discontinuation of antiresorptive therapies: a comparison between 1998-2001 and 2002-2004 among osteoporotic women.

CONTEXT: Studies having reported high rates of discontinuation of antiresorptive therapies (ART) may not reflect their actual use. OBJECTIVES: We compared probability of discontinuation among women aged 70 yr or older with a diagnosis of osteoporosis or recent osteoporotic fracture having started ART (alendronate, risedronate, cyclical etidronate, raloxifene, nasal calcitonin) between 1998-2001 or 2002-2004. PATIENTS AND METHODS: We constructed two cohorts of women using Régie de l'Assurance Maladie du Québec databases. Discontinuation was defined as a lapse of 30 d or longer after completion of a refill. Switching from one ART to another was allowed. Probability of discontinuation was estimated using Kaplan-Meier analysis. Multivariate Cox models were used to identify potential determinants of ART discontinuation over 1 yr. RESULTS: After 1 yr, probability of discontinuation was slightly lower in the 2002-2004 cohort than the 1998-2001 cohort (52.2 vs. 57.5%; P < 0.001). This difference remained significant after adjusting for determinants [adjusted rate ratio (RR) 0.92, 95% confidence interval (CI) 0.87-0.98]. Significant determinants of ART discontinuation within 1 yr included bone mineral density testing (RR 0.77; CI 0.73-0.82) performed within 2 yr prior to initiation of therapy and having consulted more than two pharmacies (RR 1.15; CI 1.06-1.25) in the year before starting therapy. In the 2002-2004 cohort, when switching was allowed, women initiating a once-weekly regimen of alendronate or risedronate did not show a 1-yr risk of discontinuation different from women initiating daily regimens of the same drugs (RR 0.90; CI 0.82-1.00). CONCLUSIONS: Even if new dosing regimens were introduced, discontinuation of ART among osteoporotic women remains high.

Label-free potentiometric biosensor based on solid-contact for determination of total phenols in honey and propolis.

We developed a label-free potentiometric biosensor using tyrosinase extracted from Musa acuminata and immobilized by covalent bond on a surface of a solid-contact transducer. The transducer was manufactured containing two layers. The first layer contained a blend of poly(vinyl) chloride carboxylated (PVC-COOH), graphite and potassium permanganate. On this layer, we deposited a second layer containing just a mixture of poly(vinyl chloride) carboxylated and graphite. On the last layer of the transducer, we immobilized the tyrosinase enzyme by reaction with N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride. The solid-contact potentiometric biosensor presented at low detection limit of 7.3×10-7M and a linear range to catechol concentration between 9.3×10-7M and 8.3×10-2M. This biosensor was applied to determine the amount of total phenols in different samples of honey and propolis. The results agreed with the Folin-Ciocalteu method.

Modulation of insulin-like growth factor 1 levels in human osteoarthritic subchondral bone osteoblasts.

Human osteoarthritis (OA) is characterized by cartilage loss, bone sclerosis, osteophyte formation and inflammation of the synovial membrane. We previously reported that OA osteoblasts (Ob) show abnormal phenotypic characteristics possibly responsible for bone sclerosis and that two subgroups of OA patients can be identified by low or high endogenous production of prostaglandin E2 (PGE2) by OA Ob. Here, we determined that the elevated PGE2 levels in the high OA subgroup were linked with enhanced cyclooxygenase-2 (COX-2) protein levels compared to normal and low OA Ob. A linear relationship was observed between endogenous PGE2 levels and insulin-like growth factor 1 (IGF-1) levels in OA Ob. As parathyroid hormone (PTH) and PGE2 are known stimulators of IGF-1 production in Ob, we next evaluated their effect in OA Ob. Both subgroups increased their IGF-1 production similarly in response to PGE2, while the high OA subgroup showed a blunted response to PTH compared to the low OA group. Conversely, only the high OA group showed a significant inhibition of IGF-1 production when PGE2 synthesis was reduced with Naproxen, a non-steroidal antiinflammatory drug (NSAID) that inhibits cyclooxygenases (COX). The PGE2-dependent stimulation of IGF-1 synthesis was due in part to the cAMP/protein kinase A pathway since both the direct inhibition of this pathway with H-89 and the inhibition of EP2 or EP4 receptors, linked to cAMP production, reduced IGF-1 synthesis. The production of the most abundant IGF-1 binding proteins (IGFBPs) in bone tissue, IGFBP-3, -4, and -5, was lower in OA compared to normal Ob independently of the OA group. Under basal condition, OA Ob expressed similar IGF-1 mRNA to normal Ob; however, PGE2 stimulated IGF-1 mRNA expression more in OA than normal Ob. These data suggest that increased IGF-1 levels correlate with elevated endogenous PGE2 levels in OA Ob and that higher IGF-1 levels in OA Ob could be important for bone sclerosis in OA.

Chitosan derivatives for gene transfer: effect of phosphorylcholine and diethylaminoethyl grafts on the in vitro transfection efficiency.

The purpose of this work was to improve the functional properties of chitosan for gene transfer by inserting phosphorylcholine (PC) and diethylaminoethyl (DEAE) groups into the main chain. A series of derivatives containing increasing contents of DEAE and a fixed content of PC groups were synthesized and characterized, aiming to evaluate the effect of these groups on the nanoparticles' properties and the in vitro transfection efficiency. The derivatives were soluble at physiological pH levels and all derivatives were less cytotoxic than the control, the lipid lipofectamine. The obtained derivatives complexed pDNA into nanoparticles with smaller sizes and higher zeta potentials than plain chitosan. The in vitro transfection was performed with nanoparticles prepared at pH 6.3 and 7.4 and the results showed that nanoparticles prepared with derivatives containing 20% of PC groups (PC18-CH) and high degrees of substitution by DEAE (PC20-CH-DEAE100, CH-DEAE80, CH-DEAE100) displayed the better transfection efficiencies in HeLa cells, reaching relative values comparable to lipofectamine. The most effective derivative, PC18CH, was selected for complexation with siRNA and its complexes demonstrated an in vitro knockdown efficiency highly dependent on the N/P ratio. Our combined results indicated that, by means of controlled modifications, the limitations of chitosan can be overcome to obtain more effective carriers based on chitosan, and the derivatives here studied hold potential for in vivo studies.

Physicochemical characterization of nanoparticles formed between DNA and phosphorylcholine substituted chitosans.

The interactions between phosphorylcholine-substituted chitosans (PC-CH) and calf-thymus DNA (ct-DNA) were investigated focusing on the effects of the charge ratio, the pH, and phosphorylcholine content on the size and stability of the complexes using the ethidium bromide fluorescence assay, gel electrophoresis, dynamic light scattering, and fluorescence microscopy. The size and colloidal stability of deacetylated chitosan (CH/DNA) and PC-CH/DNA complexes were strongly dependent on phosphorylcholine content, charge ratios, and pH. The interaction strengths were evaluated from ethidium bromide fluorescence, and, at N/P ratios higher than 5.0, no DNA release was observed in any synthesized PC-CH/DNA polyplexes by gel electrophoresis. The PC-CH/DNA polyplexes exhibited a higher resistance to aggregation compared to deacetylated chitosan (CH) at neutral pH. At low pH values highly charged chitosan and its phosphorylcholine derivatives had strong binding affinity with DNA, whereas at higher pH values CH formed large aggregates and only PC-CH derivatives were able to form small nanoparticles with hydrodynamic radii varying from 100 to 150 nm. Nanoparticles synthesized at low ionic strength with PC-CH derivatives containing moderate degrees of substitution (DS=20% and 40%) remained stable for weeks. Photomicroscopies also confirmed that rhodamine-labeled PC(40)CH derivative nanoparticles presented higher colloidal stability than those synthesized using deacetylated chitosan. Accordingly, due to their improved physicochemical properties these phosphorylcholine-modified chitosans provide new perspectives for controlling the properties of polyplexes.

Trends and determinants of antiresorptive drug use for osteoporosis among elderly women.

AIM: It has been established that women who have had a first osteoporotic fracture are at a significantly greater risk of future fractures. Effective antiresorptive treatments (ART) are available to reduce this risk, yet little information is available on trends in ART drug use among the elderly. The objective is to estimate the rate ratio (RR) of having an ART prescription filled among elderly women and its relation to selected determinants from 1995 through 2001. METHOD: A cohort design was used. Through random sampling, we selected 40% of the women aged 70 years and older listed in the Régie de l'assurance maladie du Québec (RAMQ) health database. The women were grouped into four cohorts (for 1995, 1996, 1998 and 2000). January 1 was established as the index date within each cohort (1995, 1996, 1998 and 2000). The dependent variable was the RR of having at least one prescription of ART drugs filled during the year following the index date among women with and without prior use. ART users were divided in two groups: bone-specific drugs (bisphosphonates, calcitonin, raloxifen) and HRT (hormone replacement therapy). The independent variable was whether or not (control) there had been an osteoporotic-related fracture. The RR was determined for having at least one prescription of bone-specific drugs or of HRT filled during the year following the index date using a Cox regression adjusted for age, chronic disease score (CDS) and prior bone mineral density (BMD) test. RESULTS: Crude rates of BMD testing (per 500 person-years) ranged from 20.4 (1995) to 41.1 (2000) in women who had had an osteoporotic-related fracture, and from 4.4 to 15.3 in controls. The crude rate of women (per 100 person-years) who had had an osteoporotic-related fracture and who took at least one bone-specific drug during follow-up ranged from 1.9 in 1995 to 31 in 2000 among those with prior osteoporotic-related fracture, and from 0.5 in 1995 to 11 in 2000 for controls; the corresponding figures for HRT ranged 6.7 in 1995 to 13 in 2000, and from 8.4 in 1995 to 11 in 2000 respectively. BMD test is the only major factor affecting the adjusted RR of having a prescription filled for bone-specific drugs (RR of 10.44; 6.91-15.79 in 1995 and RR of 3.68; 3.30-4.10 in 2000) or HRT (RR of 2.08; 1.64-2.64 in 1995 and RR of 1.44; 1.17-1.77 in 2000), particularly among women who had not had prior use. The fact of having a fracture status does significantly affect the RR of having at least one bone-specific drug prescription filled only among women without prior use (RR of 1.71; 1.26-2.33 in 1996 and RR of 1.77; 1.44-2.19 in 2000). The fact of being younger did not affect the RR of having at least one prescription of bone-specific drugs filled, but being younger increased the RR of filling a prescription of HRT. CONCLUSIONS: Significant change was seen over time in the number of BMD tests ordered and ART use. Effective osteoporosis interventions are not optimal in the treatment of elderly women in a Canadian health-care system who have had an osteoporotic fracture, given that approximately 25% of women who had had an osteoporotic-related fracture were users of ART.

Artrite séptica do quadril na criança: análise do resultado do tratamento cirúrgico, com seguimento médio de 10,3 anos / Septic arthritis of the hip in children: analysis of surgical treatment results with an average follow-up of 10,3 years

Os autores avaliaram 20 pacientes submetidos a tratamento cirúrgico por artrite séptica do quadril no período de novembro de 1964 a março de 1988 no Hospital de Clínicas da UFPR. A média de idade no momento do atendimento foi de 9,3 anos, com seguimento médio pós-operatório de 10,3 anos. Os resultados foram classificados segundo os critérios de Griffin & Green, dos pontos de vista clínico e radiográfico. A análise estatística mostrou que os melhores resultados foram obtidos nos casos em que o tratamento foi instituído assim que surgiram os sintomas e quando foi utilizada instilaçäo-aspiraçäo após a drenagem cirúrgica. Näo houve diferença estatisticamente significativa nos resultados dos nossos pacientes em relaçäo às diversas faixas etárias estudadas

Mesotelioma peritoneal: relato de um caso / Peritoneal mesothelioma: a case report

Os autores apresentam o caso de um paciente de 38 anos portador de mmesotelioma peritoneal cujas manifestaçöes clínicas de ascite recidivante e rebelde a terapêutica com diuréticos, dor abdominal, alteraçöes do comportamento e derrame pleural apontavam a evoluçäo clínica agressiva de tal patologia abdominal ainda sem terapêutica específica eficaz