Malignant ectomesenchymoma of the orbit in a child: Case report and review of the literature

Malignant ectomesenchymoma is a rare soft tissue tumor of childhood composed of both mesenchymal and neuroectodermal elements. Reported sites of origin are head and neck, abdomen, perineum, scrotum, and extremities. A new case of an orbital ectomesenchymoma in a 7-year-old boy is presented. The clinical picture of the tumor, radiological findings, and its histopathologic and immunohistochemical characteristics are described. The patient was successfully treated with combined surgical resection and chemotherapy. All the other reported cases of malignant ectomesenchymoma with various sites of origin are also reviewed.     

Leukemic recombinations involving heterochromatin in myeloproliferative disorders with t(1;9)

The unbalanced t(1;9) is a rare, recurrent rearrangement in polycythemia vera (PV) resulting in trisomy of both 1q and 9p arms, whereas a balanced t(1;9)(q12;q12), to our knowledge, has never been reported before. We studied two patients with PV and one with idiopathic myelofibrosis bearing an unbalanced t(1;9) and one patient with essential thrombocythemia with a balanced t(1;9). In all cases fluorescence in situ hybridization showed that the breakpoints were located within the satellite II family of heterochromatin of chromosome 1 and the satellite III of chromosome 9. Heterochromatin breakage and reunion produce the unbalanced t(1;9) and may contribute to a gene dosage effect due to gains of 1q and 9p. Case 4 with the balanced t(1;9), however, suggests that translocation of heterochromatin close to critical genes could interfere with their function. The molecular event underlying juxtaposition of satellite II of chromosome 1 and the satellite III of chromosome 9 remains to be elucidated.     

Obesity and Metabolic Dysregulation in Children Provide Protective Influenza Vaccine Responses

The most effective intervention for influenza prevention is vaccination. However, there are conflicting data on influenza vaccine antibody responses in obese children. Cardio-metabolic parameters such as waist circumference, cholesterol, insulin sensitivity, and blood pressure are used to subdivide individuals with overweight or obese BMI into ‘healthy’ (MHOO) or ‘unhealthy’ (MUOO) metabolic phenotypes. The ever-evolving metabolic phenotypes in children may be elucidated by using vaccine stimulation to characterize cytokine responses. We conducted a prospective cohort study evaluating influenza vaccine responses in children. Participants were identified as either normal-weight children (NWC) or overweight/obese using BMI. Children with obesity were then characterized using metabolic health metrics. These metrics consisted of changes in serum cytokine and chemokine concentrations measured via multiplex assay at baseline and repeated at one month following vaccination. Changes in NWC, MHOO and MUOO were compared using Chi-square/Fisher’s exact test for antibody responses and Kruskal–Wallis test for cytokines. Differences in influenza antibody responses in normal, MHOO and MUOO children were statistically indistinguishable. IL-13 was decreased in MUOO children compared to NWC and MHOO children (p = 0.04). IL-10 approached a statistically significant decrease in MUOO compared to MHOO and NWC (p = 0.07). Influenza vaccination does not provoke different responses in NCW, MHOO, or MUOO children, suggesting that obesity, whether metabolically healthy or unhealthy, does not alter the efficacy of vaccination. IL-13 levels in MUO children were significantly different from levels in normal and MHOO children, indicating that the metabolically unhealthy phenotypes may be associated with an altered inflammatory response. A larger sample size with greater numbers of metabolically unhealthy children may lend more insight into the relationship of chronic inflammation secondary to obesity with vaccine immunity.     

Does hyaluronan improve embryo implantation?

PURPOSE OF REVIEW: Taking into consideration the increasing interest on hyaluronan and its biological as well as physiological properties, this review will focus on the role of this molecule in human embryo implantation. RECENT FINDINGS: Several studies have been performed up to date in order to assess whether the addition of hyaluronan in the human embryo culture system can improve pregnancy and implantation rates, including one retrospective and six randomized controlled trials. On the one hand, four of those studies showed significant increase in clinical pregnancy and/or implantation rates after using embryo transfer medium containing high concentration of hyaluronan. On the other hand, three studies did not demonstrate any significant improvement in clinical pregnancy and implantation rates. However, regardless of statistical significance, almost all studies demonstrate higher pregnancy and implantation rates after using embryo transfer medium containing high concentration of hyaluronan. SUMMARY: Up to date, the results regarding the role of hyaluronan in human embryo implantation are still conflicting and, thus, further prospective randomized clinical trials are necessary to draw solid conclusions.     

Effects of the halogenido ligands on the Kumada-coupling catalytic activity of [Ni{tBuN(PPh2)2-κ2P}X2], X = Cl,Br, I,complexes

Novel nickel(ii) complexes bearing (^tbutyl)bis(diphenylphosphanyl)amine and different halogenido ligands, [Ni(P,P)X₂] = [Ni{^tBuN(PPh₂)₂-κ²P}X₂], (X = Cl, Br, I) are prepared, characterized by IR and NMR spectroscopy, mass spectrometry and X-ray crystallography, and tested as catalysts in the Kumada cross-coupling reaction of model substituted iodobenzenes and p-tolylmagnesium bromide. The data obtained together with DFT calculations indicate that these new catalysts operate in the Ni(i)–Ni(iii) mode. The highest catalytic activity and selectivity are exhibited by [Ni(P,P)Cl₂], which is most easily reduced by the used Grignard reagent to the Ni(i) state. This process is much more energy demanding in the case of the bromido and iodido complexes, causing the appearance of the induction period. [Ni(P,P)Cl₂] is also very active in the cross-couplings of substrates with iodine atoms sterically shielded by ortho substituents. The data obtained are in good accordance with the described positive effect of the increased electron-releasing power of N-substituents R′ on the overall catalytic performance of [Ni{R′N(PPh₂)₂-κ²P}X₂] complexes.

Novel nickel(ii) complexes [Ni(P,P)X₂] = [Ni{^tBuN(PPh₂)₂-κ²P}X₂], X = Cl, Br, I, are prepared, characterized by IR and NMR spectroscopy, mass spectrometry and X-ray crystallography, and tested as catalysts in the Kumada cross-coupling reaction.

In recent years, the chemical and catalytic properties of transition metal complexes bearing N-functionalized bis(diphenylphosphanyl)amine ligands, R′N(PPh₂)₂, have been under consideration.^1,2 For instance, chromium complexes with this type of ligand are known to oligomerize various olefins.^3–8 In addition, a large number of [M{R′N(PPh₂)₂-κ²P}X₂] complexes, M = Ni, Pd, Pt; X = Cl, Br, I (see Scheme 1), exhibiting small P–M–P bite angles, were recently reviewed.² Selected palladium(ii) complexes bearing X = Cl,^9–14 Br,^14,15 I,^14,16 catalyze the Suzuki–Miyaura and Heck coupling reactions. Some structurally characterized Ni(ii) analogous complexes bearing X = Cl,^17–28 Br,^18,29–37 I,^18,36,38 catalyze polymerization of norbornene^20,21 or oligomerization (X = Br,^32,34 I,³⁸) and polymerization (X = Br²⁹) of ethene. It should be stressed that nickel(ii) complexes of this family are only moderately active catalysts in the Suzuki–Miyaura reaction.³⁵ On the other hand, they exhibit a considerable catalytic activity and acceptable selectivity in the Kumada coupling reaction.^23,35Open in a separate windowScheme 1General structure of the studied complexes [M(P,P)X₂], M = Ni, Pd, Pt; X = Cl, Br, I; R'' = ((S)-CHMePh), (CH₂)₃Si(OCH₃)₃, ^tBu.Kumada coupling is one of the most important C–C coupling reactions³⁹ for a wide range of purposes, including pharmaceutical applications.⁴⁰ Although palladium-based complexes are mostly the first choice catalysts for this coupling,^41–43 complexes of other transition metals such as iron,^44,45 and nickel^46,47 are also used. We have already investigated the catalytic activity of [Ni{R′N(PPh₂)₂-κ²P}X₂], R′ = (S)-CHMePh; X = Cl, Br,³⁵ and R′ = (CH₂)₃Si(OMe)₃; X = Cl,²³ in homogeneous systems to extend the scope of nickel(ii) catalysts in this reaction. The latter catalyst has also been anchored onto mesoporous molecular sieves, thus providing an active heterogenized catalyst.²³ In homogeneous catalytic reactions, both catalysts bearing R′ = (S)-CHMePh) showed a substrate conversion (68% for X = Cl and 63% for X = Br),³⁵ significantly lower compared to that of the catalyst with R′ = (CH₂)₃Si(OMe)₃ and X = Cl (79%).²³ These results suggested that the increased electronegativity of coordinated halogenido ligands and the increased electron-donating power of the R′ moiety have positive effects on the catalytic efficiency of this type of nickel(ii) complexes. In the work presented herein, the effects exerted by the identity of halogenido ligands X⁻ and the R′ moiety on catalytic activity and selectivity were further assessed by exploring three novel complexes, [Ni{^tBuN(PPh₂)₂-κ²P}X₂], X = Cl, Br, I, henceforth referred to as [Ni(P,P)X₂], bearing the strongly electron-releasing ^tbutyl (^tBu) group as R′.