13C-NMR relaxation in glycogen

This study is the first report on the multiexponential T₂ relaxation of the ¹³C-1 carbon of glycogen. In contrast to T₁ relaxation, which does not display observable multiexponential decay behavior, T₂ relaxation is described by a continuous distribution of T₂ times. Changes in molecular weight and sample viscosity, which affect the overall mobility of the glycogen particle have little influence on T₁ and T₂ relaxation times. This is in contradiction with earlier results that T₂ is dominated by the overall motion of the glycogen particles [L.-H. Zang Biochemistry 29, 6815–6820 (1990)]. T₁ depends strongly on the external field B_o and is almost temperature independent in the range 23–37°C whereas T₂ is field independent and varies appreciably with temperature. The experimental T₁ and T₂ relaxation data are shown to be consistent with existing theoretical models for relaxation, suitably modified to include a distribution of correlation times for the internal motions. The presence of fast decaying components (short T₂) in the FID implies broad line components in the frequency spectrum and the corresponding need to appropriately set the integration limits for the quantification of the glycogen peak.     

Radiographic comparison of two glenoid preparation techniques in total shoulder arthroplasty

We compared the prevalence of periglenoid radiolucencies between two glenoid component preparation techniques used in total shoulder arthroplasties. Seventy-two consecutive patients with primary osteoarthritis had total shoulder arthroplasties using one prosthetic system with flat-back keeled polyethylene glenoid components. Thirty-seven shoulders had glenoid implants that were cemented after standard curettage preparation of the keel slot. Thirty-five shoulders had glenoid implants that were cemented after using bone compaction to prepare the keel slot. The immediate postoperative and 2-year postoperative radiographs were examined to evaluate the presence and progression of periglenoid radiolucencies. The curettage group had a higher rate (38%) of keel radiolucencies than the compaction group (11%) seen on the immediate postoperative radiographs. Both groups had progression of periglenoid radiolucencies with time. Progression of the radiolucent lines was worse in the curettage group 2 years after arthroplasty. Preparation of the glenoid component keel slot with the bone compaction technique seems to achieve better fixation of flat-back keeled polyethylene glenoid components in total shoulder arthroplasties.     

Chondroitins 4 and 6 sulfate in osteoarthritis of the knee: a randomized, controlled trial

OBJECTIVE: To determine whether chondroitin sulfate (CS) is effective in inhibiting cartilage loss in knee osteoarthritis (OA). METHODS: In this randomized, double-blind, placebo-controlled trial, 300 patients with knee OA were recruited from an outpatient clinic, from private practices, and through advertisements. Study patients were randomly assigned to receive either 800 mg CS or placebo once daily for 2 years. The primary outcome was joint space loss over 2 years as assessed by a posteroanterior radiograph of the knee in flexion; secondary outcomes included pain and function. RESULTS: Of 341 patients screened, 300 entered the study and were included in the intent-to-treat analysis. The 150 patients receiving placebo had progressive joint space narrowing, with a mean +/- SD joint space loss of 0.14 +/- 0.61 mm after 2 years (P = 0.001 compared with baseline). In contrast, there was no change in mean joint space width for the 150 patients receiving CS (0.00 +/- 0.53 mm; P not significant compared with baseline). Similar results were found for minimum joint space narrowing. The differences in loss of joint space between the two groups were significant for mean joint space width (0.14 +/- 0.57 mm; P = 0.04) and for minimum joint space width (0.12 +/- 0.52 mm; P = 0.05). CS was well tolerated, with no significant differences in rates of adverse events between the two groups. CONCLUSION: While there was no significant symptomatic effect in this study, long-term treatment with CS may retard radiographic progression in patients with OA of the knee. However, the clinical relevance of the observed structural results has to be further evaluated, and further studies are needed to confirm the structural effects of CS.     

A method for rapid mouse siderocyte enrichment

OBJECTIVE: Iron overload is a key contributor to the pathogenesis of multiple disorders including the sideroblastic anemias. The specific iron compounds present in tissues or cells that are the target of iron deposition remain poorly understood, but there is evidence that some forms are magnetically active. We have developed a simple and specific method to purify iron-overloaded red blood cells using magnetic affinity columns. Here we describe this method and characterize purified Sod2-deficient siderocytes. MATERIALS AND METHODS: RBC derived from mice transplanted with Sod2-deficient hematopoietic stem cells served as a source of iron-laden cells. Purification was based upon the observation that iron deposits in Sod2-deficient cells are "magnetically susceptible" and allow for retention of iron-laden cells in a strong magnetic field. Peripheral blood from Sod2-deficient chimeric mice was passed through magnetic separation columns; iron-overloaded cells were eluted and characterized by flow cytometry, Western blot, and microscopy. RESULTS: We were able to purify 2.8% of the total red cells as iron-laden siderocytes. The magnetically purified Sod2-deficient cells were predominantly identified as reticulocytes. They had numerous siderotic granules, produced enhanced levels of reactive oxygen species, and showed increased protein oxidative damage, mitochondrial enrichment, and mitochondrial hyperpolarization. CONCLUSIONS: Our method can be used to purify iron-laden cells as well as iron-associated subcellular fractions prepared from iron-loaded tissues, allowing elucidation of the structure, location, and protein composition of such iron deposits. This data will help develop our understanding of the pathogenesis of SA and other disorders characterized by iron overload.     

Efficacy of alphacalcidol and calcitriol in primary and corticosteroid-induced osteoporosis: a meta-analysis of their effects on bone mineral density and fracture rate

Vitamin D metabolites alphacalcidol and calcitriol (D-hormones) have been investigated for two decades, but few and conflicting results are available from high-quality randomized controlled trials. Our objectives were to provide an evidence-based update quantitatively summarizing their efficacy on bone mineral density (BMD) and fracture rate. We performed a systematic research of any randomized controlled trial containing relevant data, peer review, data extraction and quality scoring blinded for authors and data sources, and comprehensive meta-analyses of the relevant data. Inclusion criteria were: randomized controlled study, calcitriol or alphacalcidol, BMD or fractures in healthy/osteopenic/osteoporotic patients exposed or not to corticosteroids (CS). Analyses were performed in a conservative fashion using professional dedicated softwares and stratified by outcome, target patients, study quality, and control-group type. Results were expressed as effect size (ES) for bone loss or relative risk (RR) for fracture while allocated to D-hormones vs control. Publication bias and robustness were investigated. Of the trials that were retrieved and subsequently reviewed, 17 papers fitted the inclusion criteria and were assessed. Quality scores ranged from 20 to 100%, the mean (standard deviation) being 72 (22)%. Calcitriol and alphacalcidol were found to have the same efficacy on all outcomes at p>0.13. We globally assessed D-hormones effects in preventing bone loss in patients not exposed to CS, and found positive effect: ES=0.39 (p<0.001). For lumbar spine, this particular effect was 0.43 (p<0.001). D-hormones significantly reduced the overall fracture rates: RR=0.52 (0.46; 0.59) and both vertebral and non-vertebral fractures: RR=0.53 (0.47; 0.60) and RR=0.34 (0.16; 0.71), respectively. No statistical difference in response was observed between results from studies on healthy and osteoporotic patients or depending on the fact that controls were allowed to calcium supplementation. Treatment with D-hormones was evaluated for maintaining spinal bone mass in five trials of patients with CS-induced osteoporosis, and provided ES=0.43 at p<0.001. Only two studies specifically addressed the effects of calcitriol on spinal fracture rate. None of them provided significant results, and the global RR did not reach the significance level as well: RR=0.33 (0.07; 1.51). Our data demonstrated efficacy for DH on bone loss and fracture prevention in patients not exposed to CS and on bone loss in patients exposed to CS, in the light of the most reliable scientific evidence. Their efficacy in reducing the number of fractures in patients exposed to CS remains to be determined.     

Invasive Streptococcus pneumoniae in France: antimicrobial resistance, serotype, and molecular epidemiology findings from a monthly national study in 2000 to 2002

A study of 257 French invasive pneumococci isolated between 2000 and 2002 showed high rates of nonsusceptibility to penicillin and macrolides (50%), contrasting with a low frequency of resistance to amoxicillin or levofloxacin (<1%) and tolerance to vancomycin (0%). The genetic homogeneity of some serogroups, including serogroup 1, enhanced the risk of epidemiological changes.     

Radiation dose, chemotherapy and risk of soft tissue sarcoma after solid tumours during childhood

Soft tissue sarcoma (STS) is one of the most frequent second primary cancer that occurs during the first 20 years following treatment for a solid cancer in childhood. Our aim was to quantify the risk of STS as a second malignant neoplasm and to investigate its relationship with radiotherapy and chemotherapy. A cohort study of 4,400 3-year survivors of a first solid cancer diagnosed during childhood in France or the United Kingdom, between 1942 and 1985, was followed 15 years on average. In a partially nested case-control study, we matched 25 cases of STS and 121 controls for sex, type of first cancer, age at first cancer and duration of follow-up. Sixteen STS occurred in the cohort, as compared to 0.3 expected from the general population (Standardized Incidence Radio, SIR = 54 (95%CI: 34-89)). The SIR was 113 (95% CI: 62-185) after chemotherapy plus radiotherapy (13 STS), whereas it was 28 (95%CI: 2-125) after chemotherapy alone (1 STS) and 19 (95%CI: 3-60) after radiotherapy alone (2 STS). After adjustment for treatment, there was no evidence of variation in the annual excess of incidence or in the SIR with either age at first cancer or time since 1st cancer. In the case-control study, the risk of a STS was increased with the square of the dose of radiation to the site of STS development and with the administration of Procarbazine. The increased risk of soft tissue sarcoma that occurred after childhood cancer is independently related to exposure to radiotherapy and Procarbazine. A closer surveillance of children treated with this treatment combination is strongly recommended.     

Antineoplastic potency of arylchloroethylurea derivatives in murine colon carcinoma

In a search for new antineoplastic agents the lead compound N-(4-tert-butylphenyl)-N'-(2-chloroethyl)urea (CEU-22) of a series of 1-aryl-3-(2-chloroethyl)ureas and its iodinated bioisostere CEU-98, were previously selected on the basis of their cytotoxicity and the potent tropism for the intestinal tract (evidenced for CEU-22). In this study, we investigated the antitumour profile of these two drugs for the indication of colon cancer. In vitro, we found that micromolar concentrations of both CEU-22 and CEU-98 inhibited proliferation of DLD-1, Caco-2, HT-29, SW-948 and CT-26 lines. In vivo, a high inhibition of tumour growth and a life span increase were observed when BALB/c mice grafted subcutaneously with CT-26 cells received 5 daily intratumoural injections of each drug. When administered by the intraperitoneal route according to an intermittent schedule starting Day 1 or Day 7 post-implant, only CEU-98 demonstrated antitumour activity ( T / C = 29% for the Day-1,5,9-treatment versus 40% for the Day-7,11,15-treatment) and a life span increase around 40% for the two protocols. These results make CEU-98 a candidate for further investigations with a view to developing an efficacious treatment of colorectal cancer.     

Acupuncture in the prophylactic treatment of migraine without aura: a comparison with flunarizine

OBJECTIVES: In a randomized controlled trial extending over 6 months, we evaluated the effectiveness of acupuncture versus flunarizine in the prophylactic treatment of migraine without aura. METHODS: One hundred sixty women with migraines were randomly assigned to acupuncture treatment (group A, n = 80) or to an oral therapy with flunarizine (group F, n = 80). In group A, acupuncture was carried out in weekly sessions for the first 2 months and then once a month for the next 4 months. The same acupoints were used at each treatment: LR3 Taichong, SP6 Sanyinjiao, ST36 Zusanli, CV12 Zhongwan, LI4 Hegu, PC6 Neiguan, GB20 Fengchi, GB14 Yangbai, EX-HN5 Taiyang, GV20 Baihui. In group F, 10 mg flunarizine were given daily for the first 2 months and then for 20 days per month for the next 4 months. RESULTS: The frequency of attacks and use of symptomatic drugs significantly decreased during treatment in both groups. The number of attacks after 2 and 4 months of therapy was significantly lower in group A than in group F, and analgesic consumption was significantly lower in group A at 2 months of treatment. At 6 months no such differences existed between the two treatment groups. Pain intensity was significantly reduced only by acupuncture treatment. Side effects were significantly less frequent in group A. CONCLUSIONS: Acupuncture proved to be adequate for migraine prophylaxis. Relative to flunarizine, acupuncture treatment exhibited greater effectiveness in the first months of therapy and superior tolerability.     

Tocilizumab controls bone turnover in early polymyalgia rheumatica

ObjectivesThis study explores changes in the bone homeostasis by testing the N-terminal collagen type I extension propeptide (PINP) marker for osteo-formation and the carboxy-terminal region of collagen type I (CTX-I) marker for osteo-resorption in patients taking tocilizumab for polymyalgia rheumatica (PMR).MethodsTwenty patients were included in the prospective open-label TENOR study (Clinicaltrials.gov NCT01713842) and received three monthly tocilizumab infusions, followed by corticosteroids starting at week (W) 12. PINP and CTX-I were tested at inclusion (W0), after tocilizumab but before steroid initiation (W12), at the end of the protocol (W24) and were compared to healthy controls. Information regarding disease activity, bone mineral density using scanographic bone attenuation correlation (SBAC), inflammatory parameters and interleukin (IL)-6 levels were collected during the follow-up of the patients.ResultsPMR patients were characterised by a reduction in bone mineral density and a higher level of CTX-I relative to healthy controls matched in age and sex at baseline. PINP levels increased at W12 (P < 0.001, versus W0) following tocilizumab introduction and CTX-I levels decreased at W24 and after steroid initiation (P = 0.001, versus W0). Such modifications explain the altered correlation observed between PINP and CTX-I at W0 (r = 0.255 at W0 versus r = 0.641 in healthy controls) and its correction after treatment (r = 0.760 at W12 and r = 0.767 at W24). Finally, greater changes in PINP were observed in patients whose circulating IL-6 levels decreased after tocilizumab therapy.ConclusionsControl of bone turnover, in part through the inhibition of the IL-6 axis, is observed during tocilizumab and subsequent steroid treatment of PMR.