Resistin: A reappraisal.

From a biological point of view, aging can be considered a progressive inability of an organism to react to stress, maintain homeostasis, and survive unfavourable changes during post-maturational life. The expression of several adipokines changes during aging and for some changes, a role in the onset of chronic disease and frailty has been proposed. Among adipokines, resistin was shown in recent studies to play a key role in aging. Resistin is a small secreted protein that regulates glucose metabolism in mammalians. High resistin levels induce insulin resistance and exert proinflammatory effects. Consistently, resistin has been shown to play a pivotal role in various metabolic, inflammatory, and autoimmune diseases. Herein, the role of resistin as a molecular link between aging and age-related conditions was reviewed and the clinical implications of this knowledge discussed.

Direct vertebral rotation and differently shaped dual rod translation technique in adolescent idiopathic scoliosis.

Direct vertebral rotation (DVR) is widely used to correct the axial deformity in adolescent idiopathic scoliosis (AIS). Indirect rotation techniques may help DVR in order to improve outcome. Vertebral translation technique combined with the use of two differently shaped rods resulted effective in reducing the rib hump deformity. The aim of this study is to describe the technique and evaluate the efficacy of combined DVR and vertebral translation technique on axial deformity correction. Mean follow-up was 2.7 years. Cobb angle, kyphosis angle, apical vertebrae axial rotation angle, SRS-22 questionnaire of 30 AIS patients treated with combined DVR and differently shaped dual rods translation technique were collected and compared preoperatively and postoperatively. At the last follow-up no screw pull-out, nonunion or loss of correction were recorded. The combination of DVR and differently shaped dual rods translation technique in AIS can provide good three-dimensional correction and improvement of patient's quality of life.

Validation of the Photography Method for Nutritional Intake Assessment in Hospitalized Elderly Subjects.

OBJECTIVE: The aim of the present study was to validate the photographic indirect method as an accurate and specific tool to assess nutritional intake in a cohort of elderly hospitalized patients. DESIGN: this is a prospective observational study. SETTING: hospital (geriatric acute ward and transitional care of IRCCSS AUO San Martino Hospital, Genoa, Italy). PARTICIPANTS: 255 consecutive elderly hospitalized patients. MEASUREMENTS: assessment of malnutrition by: Mini nutritional assessment (MNA) and abbreviated Comprehensive geriatric assessment (CIRS; Barthel index, SPMSE). The direct method (Gold standard): food dish weight (before lunch) and residual (after lunch) food dish weight and estimation of the percentage of eaten food and of residual food for each dish. The percentages of food intake and residual food were calculated according to the following formula: intake %= initial weight of the dishes- residual food weight)/ initial weight dish x100. The unit of variable was the percentage. The indirect photographic method with extrapolation of the lunch food intake by photographic method confronting initial meal and residual meal (25% quartile food dish estimation). RESULTS: The results showed a significant correlation between the direct method (weighing residual food) and the indirect photographic method(n=255; r=0.9735; p<0.001) as well as a significant positive correlation between the indirect photographic method and the food caloric estimation calculated by the direct method (n=255; r= 0.6489, p<0.001). Intraclass coefficient (ICC), showed a highly significant degree of agreement between the gold standard and the indirect photographic method (ICC: 0.69; p<0.0001). Additionally, the results showed a good inter rater agreement of the indirect photographic method (kappa-statistic measure of interrater agreement: (Z=13.04; p<0.001); agreement 70.29% e Kappa=0.5965) and a good specificity of the indirect method as it was independent on the single food item. CONCLUSIONS: The study originally provided the validation of the indirect photographic method for the assessment of nutritional intake in a vast cohort of hospitalized elderly subjects. The present results moved a step forward in the appropriate assessment of nutrition intake in frail elderly, providing an easy to use tool that may be incorporate in routine clinical practice for early and targeted therapeutic interventions.

Simultaneous double rod and en-bloc direct vertebral rotation technique for correction of main thoracic adolescent idiopathic scoliosis: retrospective analysis of 14 cases.

Adolescent idiopathic scoliosis (AIS) is a triplanar deformity associated with rib hump, especially when a principle thoracic curve is present. The aim of this study is to evaluate the results of AIS correction retrospectively, using simultaneous double rod derotation manoeuvre technique followed by en-bloc direct vertebral rotation (DVR). Fourteen patients were included in this study. Coronal and sagittal thoracic Cobb angle, global coronal balance, sagittal balance, rib hump prominence, Scoliosis Research Society outcome instrument score (SRS-22) and Walter Reed visual assessment scale (WR-VAS) values were recorded pre- and postoperatively and evaluated. Results were evaluated at a mean follow-up of 2 years. Good to excellent radiographic and clinical results were obtained in all patients. No major perioperative complications occurred. This technique has proved to be effective for surgical correction of the deformity in Lenke type 1 AIS with good clinical and radiological results and low rate of complications.

Pedicle screw insertion techniques: an update and review of the literature.

Pedicle screw construct have become one of the most practiced procedure in spinal surgery. Despite commonly used, questions remain about their safety especially for the thoracic spine and in deformity where difficulty in positioning can lead to pedicle breach and adjacent structures injury. Misplacement rates have been reported to be from 5 to 41% in the lumbar spine and from 3 to 55% in the thoracic spine. Hence, various procedures have been described in order to improve pedicle screw insertion accuracy. Aim of this study is to evaluate current concepts on pedicle screws placement techniques to better understand recent attitude and clarify some doubts when selecting the most proper method.

Vitamins D3 and K2 may partially counterbalance the detrimental effects of pentosidine in ex vivo human osteoblasts.

Osteoporosis is a metabolic multifaceted disorder, characterized by insufficient bone strength. It has been recently shown that advanced glycation end products (AGEs) play a role in senile osteoporosis, through bone cell impairment and altered biomechanical properties. Pentosidine (PENT), a wellcharacterized AGE, is also considered a biomarker of bone fracture. Adequate responses to various hormones, such as 1,25-dihydroxyvitamin D3, are prerequisites for optimal osteoblasts functioning. Vitamin K2 is known to enhance in vitro and in vitro vitamin D-induced bone formation. The aim of the study was to assess the effects of Vitamins D3 and K2 and PENT on in vitro osteoblast activity, to convey a possible translational clinical message. Ex vivo human osteoblasts cultured, for 3 weeks, with vitamin D3 and vitamin K2 were exposed to PENT, a well-known advanced glycoxidation end product for the last 72 hours. Experiments with PENT alone were also carried out. Gene expression of specific markers of bone osteoblast maturation [alkaline phosphatase, ALP; collagen I, COL Iα1; and osteocalcin (bone-Gla-protein) BGP] was measured, together with the receptor activator of nuclear factor kappa-B ligand/osteoproteregin (RANKL/OPG) ratio to assess bone remodeling. Expression of RAGE, a well-characterized receptor of AGEs, was also assessed. PENT+vitamins slightly inhibited ALP secretion while not affecting gene expression, indicating hampered osteoblast functional activity. PENT+vitamins up-regulated collagen gene expression, while protein secretion was unchanged. Intracellular collagen levels were partially decreased, and a significant reduction in BGP gene expression and intracellular protein concentration were both reported after PENT exposure. The RANKL/OPG ratio was increased, favouring bone reabsorption. RAGE gene expression significantly decreased. These results were confirmed by a lower mineralization rate. We provided in vitro evidence that glycoxidation might interfere with the maturation of osteoblasts, leading to morphological modifications, cellular malfunctioning, and inhibition of the calcification process. However, these processes may be all partially counterbalanced by vitamins D3 and K2. Therefore, detrimental AGE accumulation in bone might be attenuated and/or reversed by the presence or supplementation of vitamins D3 and K2.

Shape-invariant difference between two Gaussian Schell-model beams.

The difference between two Gaussian Schell-model cross-spectral densities can give a new genuine correlation function if suitable conditions are met. Generally speaking, the structure of such cross-spectral density changes in a complicated way upon propagation. We consider here the notable exception of shape-invariant beams, and we investigate their intensity and coherence properties. The modal analysis of this class of cross-spectral densities is exploited to devise a synthesis scheme for this type of beam.

Preservation of hamstring tibial insertion in anterior cruciate ligament reconstruction: a review of the current literature.

Hamstring graft (HG) used in anterior cruciate ligament (ACL) reconstruction undergoes a biological modification process called "ligamentization" in the early postoperative period that proceeds through three different phases: an early graft-healing phase with central graft necrosis, a phase of proliferation, and finally, a ligamentization phase toward the properties of the intact ACL. The fastening of this process could result in more aggressive rehabilitation protocols as well as faster sport resumption. A recent literature supports the preservation of HG tibial attachment in order to enhance "ligamentization" process. Aim of this literature review is to describe all the techniques described that spare HG tibial insertion and the obtained results in order to evaluate evidence that would substantiate the maintenance of HG tibial insertion in ACL reconstruction. A search was performed using the following keywords "ACL reconstruction" in combination with "hamstrings," "hamstrings insertion," "tibial insertion," "ligamentization," and "over the top"; 18 articles were found to be relevant. Among these, eight randomized clinical trials (RCTs) were found. The RCT analyzed presented a high number of biases regarding the analyzed topic, thus making impossible to draw definitive evidences to validate HG tibial insertion sparing in ACL reconstruction. Despite the satisfactory results in many clinical series and the promising results in anatomic and animal studies, well-designed prospective clinical trials with large cohort of patients associated with MRI evaluation are mandatory to assess the beneficial effects of HG attachment preservation in ACL reconstruction.

Comparison of the lactate minimum speed and the maximal lactate steady state to determine aerobic capacity in purebred Arabian horses.

AIM: To compare five different protocols for estimating the lactate minimum speed (LMS) with that for estimating the maximal lactate steady state (MLSS) in Arabian horses, in order to obtain a more rapid method for monitoring aerobic capacity and prescribing training schedules. METHODS: Eight purebred Arabian horses were conditioned to exercise on a treadmill for 12 days then submitted to three to five exercise sessions to determine the MLSS. Blood samples were collected from a jugular catheter at specific intervals for measurement of lactate concentrations. The MLSS was the velocity maintained during the last 20 minutes of constant submaximal exercise, at which the concentration of lactate increased by no more than 1.0 mmol/L. The LMS test protocols (P1 - P5) included a warm-up period followed by a high-intensity gallop. The speed was then reduced to 4 m/s, and the incremental portion of the test was initiated. In P1, P2, and P3, the velocity increment was 0.5 m/s, and the duration of each incremental stage was three, five and seven minutes, respectively. In P4 and P5, the velocity increments were 1.0 and 1.5 m/s, respectively, and the duration of the stages was fixed at five minutes each. A second-degree polynomial function was fitted to the lactate-velocity curve, and the velocity corresponding to the lowest concentration of lactate was the LMS. RESULTS: Only the mean LMS determined by P1 and P2 did not differ from the velocity determined by the MLSS test (p > 0.1). There was a strong correlation (r >0.6) between P1 and the MLSS velocity. A limits of agreement plot revealed that the best agreement occurred between the MLSS test and P1 (mean bias = 0.14 m/s), followed by P2 (bias = -0.22 m/s). The lactate concentrations associated with the various LMS protocols did not differ. CONCLUSIONS: This study shows the variation between protocols of the LMS test for determining the onset of blood lactate accumulation but also reveals that, at least for Arabian horses, the P1 protocol of the LMS has good agreement with the MLSS.

Long-lasting beneficial effects of periradicular injection of meloxicam for treating chronic low back pain and sciatica.

BACKGROUND: Chronic low back pain (LBP) and sciatica can occur without obvious structural causes and are often resistant to conventional analgesic drugs. The effect of periradicular injection of meloxicam on LBP with or without a radicular component was assessed. A secondary objective of this prospective observational study was to assess the effect of meloxicam on functional recovery. METHODS: Seventy-two patients (30 men, 42 women) with LBP and/or sciatica were followed for 90 days to six years after injecting 10 mg meloxicam in 10 mL saline at each of the involved dermatomal levels. A standard verbal rating scale (VRS) from 0=no pain to 10=severe pain was used for assessing LBP before the injection of meloxicam (at baseline) and at 1, 5, 10, 30 and 60 min, and 1, 5, 15, 30 and 90 days intervals after the injection. The meloxicam injection was repeated only if the VRS score remained >3. Rescue analgesic requirements and functional activity levels were also assessed from 30-90 days after the last injection of meloxicam. RESULTS: The mean baseline LBP score was 8.60 ± 1.50 (SD) despite the use of multi-modal analgesic regimens (NSAIDs, glucocorticosteroids, paracetamol, oral opioids, gabapentanoid compounds, epidural or periradicular steroid and/or local anesthetics) as well as laser treatments and physical therapy. The majority of patients reported that their pain intensity decreased by ~50% 1-2 min after the meloxicam injection was completed. Thirty-six patients (50%) required no further injections, 25 patients (35%) required a second injection after seven days, and 11 patients (15%) required a total of three injections. After the meloxicam treatment(s), only 10 patients (14%) required "rescue" analgesia with oral NSAIDs. All patients were able to increase their level of functional activity after the meloxicam treatment(s). CONCLUSION: Periradicular injections of meloxicam (10 mg) appear to be a useful alternative to opioid and non-opiod analgesics for patients with intractable LBP due to nerve root inflammation.

Propagation of cross-spectral densities from spherical sources.

We show that the cross-spectral density in the far zone of a homogeneous spherical source can be described as a low-pass filtered version of that existing across the source surface. We prove that, to an excellent approximation, the corresponding filter with respect to a (normalized) spatial frequency ξ has a functional structure of the form √(1-ξ2), for 0≤ξ≤1. The cases of spatially incoherent and Lambertian sources are treated as significant examples.

Blood-saving techniques.

Major surgery is associated with intraoperative and postoperative bleeding, generally treated with homologous blood transfusions, which carry the risk of infection, allergic reactions, or incompatibility as well as a number of organizational and economic problems. Transfusion strategies and steps to minimize perioperative bleeding are needed. Another resource is drugs; human recombinant erythropoietin, aprotinin, and some analogues of lysine have been used to reduce the rate of allogenic transfusions in the perioperative period. The safest method is autologous blood transfusions through predeposits and hemodilution; however, it can only be used for elective surgery. Autologous transfusion techniques include blood collection, both intraoperatively, as described by Orr, and postoperatively, as introduced by Borghi in 1984, which enables the continuous monitoring of postoperative bleeding. Blood collection can also be performed during emergency surgery, reducing the rate and costs of homologous transfusions.

Partially correlated thin annular sources: the vectorial case.

We develop an electromagnetic analysis for partially correlated thin annular sources. The elements of the correlation matrix are assumed to depend only on the angular distance between two typical points. For any such source, we show how the modal expansion can be found. Correlation changes upon free propagation are discussed. Further, examples and possible synthesis schemes are presented.

Nonquantum entanglement resolves a basic issue in polarization optics.

The issue raised in this Letter is classical, not only in the sense of being nonquantum, but also in the sense of being quite ancient: which subset of 4x4 real matrices should be accepted as physical Mueller matrices in polarization optics? Nonquantum entanglement or inseparability between the polarization and spatial degrees of freedom of an electromagnetic beam whose polarization is not homogeneous is shown to provide the physical basis to resolve this issue in a definitive manner.

A complete characterization of pre-Mueller and Mueller matrices in polarization optics.

The Mueller-Stokes formalism that governs conventional polarization optics is formulated for plane waves, and thus the only qualification one could require of a 4 x 4 real matrix M in order that it qualify to be the Mueller matrix of some physical system would be that M map Omega((pol)), the positive solid light cone of Stokes vectors, into itself. In view of growing current interest in the characterization of partially coherent partially polarized electromagnetic beams, there is a need to extend this formalism to such beams wherein the polarization and spatial dependence are generically inseparably intertwined. This inseparability brings in additional constraints that a pre-Mueller matrix M mapping Omega((pol)) into itself needs to meet in order to be an acceptable physical Mueller matrix. These additional constraints are motivated and fully characterized.

Synthesis of electromagnetic Schell-model sources.

A procedure for the synthesis of the most general electromagnetic Schell-model light source is proposed. It makes use of the generalized van Cittert-Zernike theorem to produce the electromagnetic source starting from a primary spatially incoherent source, characterized by a suitable position-dependent polarization matrix. By resorting to the spectral decomposition of the polarization matrix, it is shown how such an incoherent source can be synthesized by using a Mach-Zehnder interferometer, with suitable amplitude transmittances placed in its arms, fed by two mutually uncorrelated laser beams. Examples are given for the case of electromagnetic Gaussian Schell-model sources.

Modal expansion for J0-correlated electromagnetic sources.

We introduce a class of sources that turn out to be J0 correlated in a scalar description but exhibit varied correlation properties when examined in electromagnetic terms. We prove that a modal expansion can be built explicitly for any of these sources and give an example to illustrate the richness of their behavior.

Realizability condition for electromagnetic Schell-model sources.

The set of functions that appear in the correlation matrix of an electromagnetic source must satisfy the constraint of nonnegative definiteness. Here we derive a necessary and sufficient condition for nonnegativeness for the class of electromagnetic Schell-model sources. This result also suggests a possible synthesis procedure for this type of source. As an illustration, two specific examples of electromagnetic Schell-model sources are discussed.