Single-and double transition metal atoms anchored C2N as a high-activity catalyst for CO oxidation: A first-principles study.

The oxidation of CO has attracted great interest in recent years due to its important role in enhancing the catalyst durability in fuel cells and solving the growing environmental problems caused by CO emissions. Consequently, the catalytic oxidation of CO at double non-noble metal atoms anchored C2N is investigated using density functional theory (DFT) computations. All the screened Ti@C2N and Ti2@C2N are thermodynamically stable based on their binding energy calculations. The electronic characteristics, the natural bond orbital analyses (NBO), Frontier orbital, statistical thermodynamics, projected densities of states (PDOS) characteristics, non-covalent interactions (NCI), and quantum theory of atoms in molecules (QTAIM) descriptors of these systems have been examined to analyze the interaction process. Our comparative study suggested that the newly predicted double-atom catalyst (Ti2@C2N) is highly active for CO oxidation, which is a useful guideline for further development. The calculated static first-order hyperpolarizability (ßo) illustrated that the double-atom catalyst under investigation can be considered a potential candidate for non-linear optical behavior and could be used for NLO applications. CO oxidation on Ti2@C2N along the Eley-Rideal (ER) mechanism with a low energy barrier of 0.16 eV, which is smaller than the maximum energy barrier (0.73 eV) of CO oxidation along the Langmuir-Hinshelwood (LH) mechanism. Consequently, the ER mechanism is more favorable both thermodynamically and dynamically. This work can provide useful insights and guidelines for future theoretical and experimental investigations to promote the design and development of highly effective and low-cost non-precious-metal Ti2@C2N nanocatalysts towards CO oxidation at ambient temperature.

DFT study of adsorbing SO2, NO2, and NH3 gases based on pristine and carbon-doped Al24N24 nanocages.

The adsorption of SO2, NO2, and NH3 toxic gases on Al24N24 and Al24N23C nanocages was investigated by using density functional theory (DFT) calculations. The adsorption energies, frontier orbitals, charge transfer using natural bonding orbital (NBO) analysis, dipole moment, the partial density of states (PDOS), thermodynamic relationships, non-covalent interaction (NCI), and quantum theory of atoms in molecules (QTAIM) were considered. The results reveal that carbon-doped Al24N24 nanocage increases the adsorption energies for SO2 and NO2 gases while decreasing the adsorption energy of NH3 gas. The ΔG for all configurations were negative except the configurations A1 and G2 confirming the weak adsorption of these two complexes. In conclusion, Al24N24 and Al24N23C nanocages are in general promising adsorbents for the removal of SO2, NO2, and NH3 toxic gases. The Al24N24 and Al24N23C nanocages are ideal electronic materials.

Design and conduct of early clinical studies of immunotherapy agent combinations: recommendations from the task force on Methodology for the Development of Innovative Cancer Therapies.

The Methodology for the Development of Innovative Cancer Therapies task force considered aspects of the design and conduct of early studies of combinations of immunotherapy agents during their 2018 meeting. The task force defined the relevant data to justify combination clinical trials, which includes a robust hypothesis for the combination, pre-clinical data with evidence of efficacy and an understanding of the pharmacodynamics effects of each agent, and ideally evidence of single agent activity. Evaluation of pharmacodynamic biomarkers is critical in early phase combination trials, and should be incorporated into trial objectives and go/no-go decisions. The task force also identified the need to develop assessment tools and end points that capture the unique patterns of tumour responses to immunotherapy, including pseudoprogression and hyperprogression. At least one additional tumour measurement before baseline and an early CT scan (at 4 weeks for example) would help define the incidence of hyperprogression, although a common definition is needed. Finally, the task force highlighted substantial redundancy and inefficiency in the combination immunotherapy space, and recommended the adoption of innovative trial designs.

Hepatic steatosis is highly prevalent across the paediatric age spectrum, including in pre-school age children.

BACKGROUND: The prevalence of non-alcoholic fatty liver disease (NAFLD) in children is 8% in the general population, and 34% in the context of obesity. There is a paucity of data on the prevalence of hepatic steatosis in healthy children in Ontario. AIMS: To determine the prevalence of hepatic steatosis using abdominal computed tomography (CT) scans in a cohort of previously healthy children across the paediatric age spectrum in Ontario, Canada, and to determine any association between measures of abdominal adiposity and hepatic steatosis. METHODS: Retrospective review of the SickKids Trauma Database from 2004-2015. Previously healthy children ages 1-17 years having undergone an abdominal CT scan as a part of routine trauma assessment were included, and those with an intra-abdominal injury excluded. Steatosis was defined as a difference between liver and spleen attenuation ≤-25HU. The percentage of the total area occupied by abdominal subcutaneous adipose and visceral adipose tissue was measured. Anthropometrics and baseline demographics were collected. RESULTS: A total of 503 (51% male) children with mean (±SD) age 9.5 ± 4.5 years and weight z-score of 0.37 ± 1.05 were studied. Seventy-seven (15%, 95% CI [12%-18%]) had hepatic steatosis; no differences found between sexes or across age quartiles. The abdominal subcutaneous adipose tissue area was greater in those with hepatic steatosis compared to those without (32% [22-42] vs 24% [17-36], P = 0.003). The visceral adipose tissue area was significantly greater in older children ≥9.8 years with hepatic steatosis (7.7% [5.1-10] vs 6.6% (4.9-8.5), P = 0.04). CONCLUSION: Hepatic steatosis was highly prevalent in previously healthy children in Ontario, including children of pre-school age. We found an association between hepatic steatosis and abdominal subcutaneous adipose tissue, and in older children with visceral adipose tissue.

Comprehensive analysis of the clinical immuno-oncology landscape.

Advances from immuno-oncology (IO) are changing the standard of care of many types of cancer, and the paradigm of cancer treatments and drug development is being rewritten on a regular basis. Moreover, an unprecedented number of new investigational agents and companies are entering the field of IO. As such, it has become challenging for oncology physicians conducting clinical trials, industry veterans developing IO drugs, and even regulators reviewing novel IO agents to keep track of the rapidly evolving landscape. To help the key stake holders in the field understand the latest IO landscape, we sought to present an unbiased, neutral, scientifically curated, and timely updated analysis of all the current IO agents in clinical development and the clinical trials testing these agents. We based our analyses on information collected from numerous trusted and publicly available sources. We have developed two databases. One database tracks 2004 IO agents (940 in clinical stage and 1064 in preclinical stage) against 303 targets, from 864 companies; the other tracks 3042 active clinical trials of these agents with a target enrollment of 577 076 patients. This report provides key analyses of these data. Furthermore, we will discuss a number of important and actionable trends in the current IO landscape: a large number of companies developing agents against the same IO targets; a rapid increase in the number of anti-PD-1/L1 combination studies, many of which are testing the same combinations and following inefficient patterns; and a significant increase in the number of small, investigator-initiated studies. For each of the findings, we speculate the causes and discuss a few initiatives that aim to address some of these challenges. Finally, by making these landscape analyses available, we aspire to inform the cancer community as they seek to strive for efficiencies and innovation while avoiding duplication.

A comparative theoretical study of metal functionalized carbon nanocones and carbon nanocone sheets as potential hydrogen storage materials.

The hydrogen storage of Ti functionalized carbon nanocones and carbon nanocone sheets is investigated by using the state-of-the-art density functional theory calculations. The Ti atom prefers to bind at the hollow site of the hexagonal ring. The average adsorption energies corrected for dispersion forces are -0.54 and -0.39 eV per hydrogen molecule. With no metal clustering, the system gravimetric capacities are expected to be as large as 9.31 and 11.01 wt%. The hydrogen storage reactions are characterized in terms of simulated infrared spectra, projected densities of states, kinetics, and statistical thermodynamics. The free energies and enthalpies of the Ti functionalized carbon nanocone meet the ultimate targets of the Department of Energy for all temperatures and pressures. The closest reactions to zero free energy occur at 378.15 K/2.961 atm for carbon nanocones and 233.15 K/2.961 atm for carbon nanocone sheets. The translational component is found to exert a dominant effect on the total entropy change with temperature. More promising thermodynamics are assigned to the hydrogenation of Ti functionalized carbon nanocone sheets at 233.15 K. As the temperature is increased, the lifetimes of the hydrogen molecules adsorbed at the surface drop and the rate constants increase. At fixed pressure, the rate constants of hydrogenation of Ti functionalized carbon nanocones are smaller than those of Ti functionalized carbon nanocone sheets, while the lifetimes are greater.

Role of cationic size in the optical properties of the LiCl crystal surface: theoretical study.

The size of the cations (either Ca(2+), Sr(2+), Ga(+), or Au(+)) at the F(A1)-type color centers on the (100) surface of LiCl crystal plays an important role in the optical properties of this surface. In this work, double-well potentials at this surface were investigated using ab initio quantum mechanical methods. Quantum clusters were embedded in simulated Coulomb fields that closely approximate the Madelung fields of the host surface, and the ions that were the nearest neighbors to the F(A1) site were allowed to relax to equilibrium. The calculated Stokes-shifted optical transition bands, optical-optical conversion efficiency, and relaxed excited states of the defect-containing surface, as well as the orientational destruction of the color centers, recording sensitivity, exciton (energy) transfer, and the Glasner-Tompkins empirical relation were all found to be sensitive to the size of the dopant cation.

Magnetic resonance signal, rather than tendon volume, correlates to pain and functional impairment in chronic Achilles tendinopathy.

PURPOSE: To depict abnormal tendon matrix composition using magnetic resonance imaging (MRI) in chronic Achilles tendinopathy, and correlate intratendinous signal alterations to pain and functional impairment. MATERIAL AND METHODS: MRI of the Achilles tendon was performed on 25 patients with chronic Achilles tendinopathy (median age 50, range 37-71 years). All patients suffered from pain in the mid-portion of the Achilles tendon. Intratendinous signal was calculated from five different sagittal sequences, using a computerized 3D seed-growing technique. Pain and functional impairment were evaluated using a questionnaire completed by patients. RESULTS: Severity of pain and functional impairment correlated to increased mean intratendinous signal in the painful tendon in all MR sequences (P < 0.05, median r = 0.38, range 0.28-0.43 for pain; P < 0.05, median r = 0.48, range 0.29-0.49 for functional impairment). However, tendon volume did not correlate to pain or functional impairment (P > 0.05). Difference in mean intratendinous signal between symptomatic and contralateral asymptomatic tendons was highly significant in all sequences (P < 0.05) except on T2-weighted images (P = 0.6). CONCLUSION: Severity of pain and disability correlated to increased MR signal rather than to tendon volume in patients with unilateral mid-portion chronic Achilles tendinopathy.

Magnetic resonance imaging in chronic Achilles tendinopathy.

UNLABELLED: The main objective of this thesis was to evaluate and monitor the morphological response following treatment interventions in patients with chronic Achilles tendinopathy by using different MRI techniques. For this purpose, we investigated different types of sequences, including gadolinium contrast medium-enhanced T1-WI images (CME T1-WI), and developed a precise method to measure tendon volume and mean intratendinous signal of the Achilles tendon. Study I aimed at evaluating 15 patients with chronic, painful Achilles tendinosis, before and 2 years after surgical treatment. There was marked regression of the intratendinous signal postoperatively. The most sensitive sequence for depicting an intratendinous lesion in this study was CME T1-WI images. They showed a regression of the intratendinous signal abnormality from 13/15 patients preoperatively to 4/15 postoperatively. The clinical outcome was excellent in eight, good in five, fair in one and poor in one patient. In study II, the early contrast agent enhancement in the dynamically enhanced MRI signal (DEMRI) was correlated with the histopathologic findings in 15 patients with chronic Achilles tendinopathy. Early contrast enhancement (within the first 72s) was seen in DEMRI in the symptomatic Achilles tendons, with a significant difference compared to the asymptomatic contralateral tendons. Increased severity of tendon changes, including fiber structure abnormality, increased vascularity, rounding of nuclei, and increased amount of glycosaminoglycans, correlated to CME. In study III, we developed a computerized 3-D seed-growing MRI technique to measure tendon volume and mean intratendinous signal. This technique showed an excellent inter- and intra-observer reliability. The technique was also used to follow up prospectively the tendon adaptation and healing described in studies IV-VI. In study IV, using serial MRI during a period of 1 year, we evaluated the biological effect of tendon repair following iatrogenic tendon injury by five transversal ultrasound-guided core biopsies employing a needle technique in chronic Achilles tendinopathy. Alterations found during healing, such as tendon volume and intratendinous reactive changes, could be monitored by MR imaging, and subsided as noted in the 7- and 12-month follow-ups. In study V, we evaluated the effect of treatment with a 3-month, daily performed, heavy-loaded calf-muscle strength training program in 25 patients who had been suffering from chronic, painful Achilles tendinopathy. Tendon volume decreased by 14%, and the mean intratendinous signal by 23%. The clinical outcome was improved. In study VI, we revealed tendon adaptation immediately following calf-muscle strength training. An MRI examination within 30min of the performed exercises resulted in increased total tendon volume (12%) and mean intratendinous signal (31%). CONCLUSION: MRI techniques can be used as an adjunct to clinical evaluation by monitoring morphological effects following different treatment interventions, thereby adding evidence in clinical studies on patients with chronic Achilles tendinopathy.

Tendon injury and repair after core biopsies in chronic Achilles tendinosis evaluated by serial magnetic resonance imaging.

OBJECTIVE: To evaluate the morphological response and healing process after transverse ultrasound guided core biopsies in chronic Achilles tendinosis using serial magnetic resonance imaging (MRI) over a period of one year. METHODS: The study included 10 patients. Six had five transverse core biopsies and were longitudinally evaluated by MRI before the biopsies and then after one week, three months, seven months, and one year. These patients started a three month eccentric training programme one to two weeks after the biopsy. Four "non-biopsied" and untreated patients were used for comparison. The clinical outcome was categorised according to the level of pain and performance. RESULTS: The MRI one week after the biopsies showed an increase in tendon volume (T1-WI) and mean signal intensity (PD-WI) of 29% and 30% (p = 0.04). During follow up, tendon volume and mean signal intensity gradually decreased. One year after the biopsy, the tendon volume had decreased by 20% and the intratendinous signal by 28% compared with the index MRI (p = 0.04). The untreated patients showed an increase in both tendon volume (39%, p = 0.06) and intratendinous signal (37%, p = 0.14) at the one year follow up. After one year, pain and performance had improved in the treated patients but not the untreated patients. CONCLUSION: Five transverse ultrasound guided core biopsies induced a lesion in the diseased Achilles tendon. Alterations during healing such as tendon size and intratendinous signal intensity could be evaluated by MRI. The tendon alterations had decreased one year after the core biopsies.

Spectral studies and molecular orbital PPP-calculations of some azo-dyes.

The UV, IR and 1H-NMR spectra of some 4-(R-phenyl azo) 1-hydroxy 2-naphthoic acid derivatives are studied. The effects of substituent groups and the solvent polarity on electronic spectral, IR bands and 1H-NMR proton chemical shifts are considered, the molecular orbital calculations obtained are rationalized quantitatively with that obtained practically using the PPP-model with configuration interaction (CI).

FA(I):A(+) and FA(II):Cu(+) laser activity and photographic sensitization at the low coordinated surfaces of AgBr ab initio calculations.

The twofold potentials of F(A)(I):Au(+) and F(A)(II)Cu(+) color centers at the low coordinated surfaces of AgBr thin films in providing tunable laser activity and photographic sensitization were investigated using ab initio methods of molecular electronic structure calculations. Clusters of variable size were embedded in simulated Coulomb fields that closely approximated the Madelung fields of the host surfaces, and the nearest neighbor ions to the F(A) defect site were allowed to relax to equilibrium in each case. Based on the calculated Stokes shifted optical transition bands and horizontal shifts along the configuration coordinate diagrams, both F(A)(I):Au(+) and F(A)(II):Cu(+) color centers were found to be laser active. The laser activity faded quickly as the bromide ion coordination decreased from 5 (flat) to 4 (edge) to 3 (corner) and as the size of the impurity cation increased from Cu(+) to Au(+). The latter relation was explainable in terms of the axial perturbation of the impurity cation. The smallest calculated Stokes-shift at the corner surface suggested that emission had the same oscillator strength as absorption. All relaxed excited states RESs of the defect containing surfaces were deep below the lower edges of the conduction bands of the defect free ground state surfaces, indicating that F(A)(I):Au(+) and F(A)(II):Cu(+) are suitable laser defects. The probability of orientational destruction of the two centers attributed to the assumed RES saddle point ion configurations along the <110> axis was found to be directly proportional to the size of the impurity cation, with activation energy barriers of about 0.655-3.294 eV for Cu(+), and about 1.887-3.404 eV for Au(+). The possibility of exciton (energy) transfer from the sites of higher coordination to those of lower coordination is demonstrated. The more laser active F(A)(II):Cu(+) center was more easily formed than the less laser active F(A)(I):Au(+) center. The Glasner-Tompkins empirical relation was generalized to include F(A) centers at the low coordinated surfaces of silver bromide thin film. As far as color photographic sensitization is concerned, the lowest unoccupied molecular orbitals of the selected dye molecules in the excited states were high enough for electron injection. F(A) defect formation and rotational diffusion of silver clusters reduced the energy gaps between the excited dye molecules and the lower edges of the conduction bands and allowed for hole injection. About 54-60% of the reduction of silver ions at the flat surface of AgBr was attributed to the host anions and F(A) defect formation, leaving about 40-46% for the reduction of photoelectrons as well as the electrons of the developer or dye molecules. The unrelaxed rotational diffusions of the central Ag(4) by 90 degrees decreased the latter percentage, but were severely hindered by activation energy barriers.

Dynamic contrast-enhanced mr imaging and histopathology in chronic achilles tendinosis. A longitudinal MR study of 15 patients.

PURPOSE: To evaluate the value of dynamic contrast-enhanced MR imaging (DEMRI) and its correlation to symptoms and histopathology in chronic Achilles tendinosis. MATERIAL AND METHODS: Fifteen patients with severe symptoms underwent DEMRI preoperatively and 2 years postoperatively. US-guided core biopsies of tendinosis tissue were obtained preoperatively and the specimens were analyzed using a semiquantitative protocol. DEMRI was evaluated by calculating the area under curve (AUC) of signal alteration and the static MR by a semiquantitative grading scale. A questionnaire and clinical examination evaluated the clinical outcome. RESULTS: Early contrast enhancement (first 72 s) was seen in DEMRI at tendon lesions of the symptomatic Achilles tendons with a significant difference to asymptomatic contralateral tendon that revealed no or mild enhancement. Increased severity of tendon pathology (including fiber structure abnormality, increased vascularity, rounding of nuclei and increased amount of glycosaminoglycans) was correlated to both dynamic and static signal enhancement. Two years following surgical treatment, the signal alterations showed regression of early contrast enhancement (AUC decreased from 9 preoperatively to 2 postoperatively). The clinical outcome was as follows: 8 patients excellent, 4 good, 2 fair and 1 poor. CONCLUSION: Patients with chronic painful achillodynia showed an early contrast-agent enhancement corresponding to the tendon lesion. Increased enhancement correlated to increased severity of tendon histopathology and patient symptoms. Two years after surgical treatment the contrast-agent enhancement decreased.

Ultrasound-guided percutaneous biopsies of the semitendinosus muscle following ACL reconstruction--a methodological description.

PURPOSE: To evaluate whether the ultrasound-guided biopsy technique could be used to analyse the histochemical profile of m. semitendinosus following ACL reconstruction with autologous semitendinosus tendon graft. MATERIAL AND METHODS: Sixteen patients were included in the study. During ACL surgery, specimens from m. semitendinosus were obtained via open biopsy. Ultrasound-guided biopsies from m. semitendinosus were performed 7 - 11 months postoperatively from operated leg (n = 16) and non-operated leg (n = 8). RESULTS: Two biopsy samples were pooled and formed a specimen of approximately 150 fibres. For fibre type composition, there was correlation between open biopsy and ultrasound-guided biopsy data, (P = 0.003, r = 0.89). The r-value for mean fibre area was 0.72 (P = 0.06). The methodological error for fibre type 1 % and mean fibre area was 9 %. Postoperatively, no significant differences were found in fibre type composition or fibre type areas between the operated and non-operated leg. CONCLUSION: Ultrasound-guided biopsy is an easy and safe technique that can be used for scientific studies and in clinical practice where biopsy from small muscles or from special location in muscles, such as in ruptures, scars or others is needed.

Semitendinosus muscle in anterior cruciate ligament surgery: Morphology and function.

PURPOSE: To evaluate the fate of the hamstring muscles in general and the semitendinosus muscle in particular, after anterior cruciate ligament (ACL) reconstruction with an autologous semitendinosus tendon graft from the ipsilateral side. TYPE OF STUDY: Prospective consecutive case series investigation. METHODS: Included were 16 consecutive patients, 14 male and 2 female, with a mean age of 26 years. The inclusion criterion was chronic unilateral ACL insufficiency with no concomitant knee ligament injuries. ACL reconstruction was performed with a quadruple semitendinosus tendon graft using the EndoButton technique (Acufex, Mansfield, MA). Intraoperatively, muscle specimens were taken from the semitendinosus muscle on the harvested side. Follow-up at a minimum of 6 months included clinical examination, isokinetic strength performance, magnetic resonance imaging (MRI) of the thigh and knee, and ultrasound-guided muscle biopsy procurement from the semitendinosus muscle for histochemical and enzymatic analyses. RESULTS: Of the patients, 75% showed regeneration of their semitendinosus tendons. The neotendons all inserted below the knee joint where they had fused with the gracilis tendon to a conjoined tendon inserting in the pes anserinus. The semitendinosus muscle had a smaller cross-sectional area on the operated side but none showed total atrophy. Less atrophy was present in the patients with a regenerated semitendinosus neotendon compared with those without regeneration (P =.029). In the latter group the semimembranosus muscle seemed to compensate for this with hypertrophy (P =.019). Cross-sectional muscle fiber areas, the relative number of each fiber type and oxidative potential as estimated by citrate synthase activity, showed no significant differences between the operated and nonoperated legs. The isokinetic strength of the hamstrings and quadriceps was significantly lower in the operated leg than in the nonoperated leg. CONCLUSIONS: With this surgical technique, the semitendinosus muscle can recover and the tendon has, according to the MRI images, a great potential to regenerate after its removal.

Measurement of mycophenolate mofetil effect in transplant recipients.

BACKGROUND: Immunosuppression involves the nature of the immunosuppressive agents and individual differences in patient factors. We investigated whether the effect of mycophenolate mofetil (MMF) is measurable using an in vitro measure of immunocompetence and related its effects to cyclosporine (CsA) in vitro. METHODS: Liver or kidney transplant recipients receiving prednisone; CsA or tacrolimus; and MMF, azathioprine (AZA), or neither, were studied. Immunocompetence was assessed by one-way mixed lymphocyte culture using patients' peripheral blood leukocytes (PBL) and three validated stimulators. The effect of immunosuppressive agents added in vitro on normal PBL stimulation by Staphylococcus enterotoxin B was determined by the carboxyfluorescein diacetate succinimidyl ester measurement of division. RESULTS: Patients receiving MMF had an average immunocompetence level of 12+/-23, compared with 39.7+/-65 and 25.5+/-42 for those receiving AZA or neither AZA nor MMF, respectively. Thus, there was an approximately 80% suppression of the response in the MMF group. Assessment of normal cell division revealed that CsA allowed multiple cell generations but suppressed the numbers of cells in each, whereas MMF blocked proliferation into subsequent generations. Addition of clinically relevant levels of mycophenolic acid, the active agent for MMF, added to more moderate levels of CsA, was required to achieve greater than 80% suppression, consistent with the degree of immunocompetence depression measured in patients. CONCLUSIONS: These data provide the novel finding that the effect of MMF treatment on patients is measurable in their PBL as decreased immunocompetence in vitro. The effect of MMF on normal PBL approximates the 80% inhibition that we found in patients. Moreover, the effect of MMF on cell division provides a rationale for the superior effectiveness of regimens including MMF.

MR evaluation of chronic Achilles tendinosis. A longitudinal study of 15 patients preoperatively and two years postoperatively.

PURPOSE: To evaluate surgically treated patients with chronic Achilles tendinosis by MR. MATERIAL AND METHODS: Gd-contrast-enhanced (CME) T1-, precontrast T1-, PD- and T2-weighted images were obtained preoperatively and 2 years following surgical treatment on 15 middle-aged patients with severe symptoms of chronic Achilles tendinosis. MR evaluation included the depiction of intratendinous signal alterations and their volume, and also measurement of tendon diameter. A questionnaire and clinical examination evaluated the clinical outcome. RESULTS: The most sensitive sequence to depict an intratendinous lesion was the CME T1-WI. There was marked regress of the estimated volume of the intratendinous signal alteration from a median of 1.2 cm3 preoperatively to 0.0 cm3 postoperatively on CME T1-WI. CME T1-WI showed a regress in intratendinous signal abnormality from 13 out of 15 patients preoperatively to 4 of 15 patients 2 years postoperatively. The a.p. dimension was 9 mm at both MR occasions. The clinical outcome was excellent in 8, good in 5, fair in 1 and poor in 1 patient. CONCLUSION: Surgical treatment of chronic Achilles tendinosis and its healing resulted in a decrease or elimination of the intratendinous signal alteration correlating to an improved clinical outcome 2 years postoperatively.

B7-DC, a new dendritic cell molecule with potent costimulatory properties for T cells.

Dendritic cells (DCs), unique antigen-presenting cells (APCs) with potent T cell stimulatory capacity, direct the activation and differentiation of T cells by providing costimulatory signals. As such, they are critical regulators of both natural and vaccine-induced immune responses. A new B7 family member, B7-DC, whose expression is highly restricted to DCs, was identified among a library of genes differentially expressed between DCs and activated macrophages. B7-DC fails to bind the B7.1/2 receptors CD28 and cytotoxic T lymphocyte-associated antigen (CTLA)-4, but does bind PD-1, a receptor for B7-H1/PD-L1. B7-DC costimulates T cell proliferation more efficiently than B7.1 and induces a distinct pattern of lymphokine secretion. In particular, B7-DC strongly costimulates interferon gamma but not interleukin (IL)-4 or IL-10 production from isolated naive T cells. These properties of B7-DC may account for some of the unique activity of DCs, such as their ability to initiate potent T helper cell type 1 responses.