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1.
J Indian Assoc Pediatr Surg ; 29(3): 233-239, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38912025

RESUMO

Aims: Closure of congenital body wall defects in children can be a challenging task for the pediatric Surgeon. Biological prosthesis has been increasingly used for high-risk wound closure in adult patients with excellent outcomes and use in the pediatric population has also been reported. Here, we aim to study the outcome of abdominal wound repair with a tissue-engineered acellular bovine pericardial patch. Methods: Over a period of 21 months, a total of 15 children had undergone abdominal wound repair with bioprostheses, i.e., bovine pericardial patch at our institute. Patient demographics, cause of defect, an indication of patch use, rate of infection, postoperative recovery, recurrence, and outcome were studied. Results: A total of 15 patients underwent abdominal wall closure with acellular bovine pericardial patch. Nine out of 15 patients were neonates, of whom five had gastroschisis, two had a congenital diaphragmatic hernia, and two had ruptured omphalocele major. Of the rest 6 patients, 2 were patients of bladder exstrophy, 2 were older children of congenital diaphragmatic hernia with incisional hernias, and 2 were older children with omphalocele major. Out of the five patients with gastroschisis, two died during the early postoperative period due to sepsis. The wound healed in the rest 13 patients with mild skin dehiscence in two patients. Only one child had a recurrence. Conclusion: Reconstruction with acellular bovine pericardial patch is a viable option in children with high-risk abdominal wounds as it allows tensionless repair with excellent healing and minimal complications. Recurrence, if any, may disappear with time as remodeling of the prosthesis occurs along with the growth of the body wall of the child.

2.
Chemistry ; 29(45): e202300644, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37272320

RESUMO

Carbene-stabilized symmetrical and unsymmetrical dicationic tetraboranes, featuring an electron-precise tetraborane chain, were synthesized and fully characterized. Reactions of these tetraboranes with reductants/bases give rise to different outcomes according to the conditions employed, including: 1) reduction and rearrangement of the tetraborane chain to give a zwitterionic alkylidene borate-borenium species; 2) cleavage of the tetraborane chain to afford a 1,3-azaborinine; and 3) reduction of the supporting ligands to provide a diamino dipotassium salt. The zwitterionic alkylidene borate-borenium species can be viewed as an analogue of the base-stabilized diborenes. NMR spectroscopy and DFT calculations reveal a highly polarized B-B bond in the zwitterionic alkylidene borate-borenium, in which the formal oxidation states of the boron atoms can be considered as -1 and +2. These results suggest the considerable potential of tetraboranes as synthons for low-valent boron species.

3.
Fetal Pediatr Pathol ; 42(6): 972-978, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37584237

RESUMO

BACKGROUND: Giant congenital melanocytic nevus (GCMN) is characterized by its large size and potential for transformation into melanoma. It can be associated with other neural cristopathies, including neurofibroma, however, it has not previously been described with a congenital neurofibroma. CASE REPORT: A newborn girl presented with a large congenital neurofibroma arising in a bathing trunk type of giant congenital melanocytic nevus. CONCLUSION: Congenital neurofibromas can be associated with (or a component of) a GCMN.


Assuntos
Melanoma , Neurofibroma , Nevo Pigmentado , Neoplasias Cutâneas , Recém-Nascido , Feminino , Humanos , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/congênito , Nevo Pigmentado/diagnóstico , Nevo Pigmentado/congênito
4.
Acc Chem Res ; 54(5): 1260-1273, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33565872

RESUMO

The coordination of an element-element σ bond to a transition metal (TM) is both a fundamentally intriguing binding mode and of critical importance to metal-mediated bond activation mechanisms and catalysis, particularly the hotly contested field of C-H activation. TM σ complexes of dihydrogen (i.e., H-H) and silanes (H-SiR3) have been extensively studied, the latter being of interest as models for the (generally unstable and unisolable) σ complexes of alkanes (i.e., H-CR3). TM σ complexes of hydroboranes and hydroborates (i.e., H-BR2, H-BR3, (H-)2BR2) are somewhat less well studied but similarly have relevance to catalytic borylation reactions that are of high current interest to organic synthesis. Our two research groups have made significant contributions to elaborating the family of σ-borane/-borate complexes using two distinct approaches: while the Ghosh group generally starts from hydrogen-rich tetracoordinate boron species such as borates, the Braunschweig group starts from hypovalent and/or hypocoordinate boron building blocks. Through these two approaches, a wide range of species containing one or two σ-bound B-H ligands have been prepared, some with additional chelating donor sites. Over the past 2 years, the body of work on σ-borane/-borate complexes from our two research groups has significantly expanded, with a combined nine published articles in 2019-2020 alone. Very recent work from the Braunschweig group has led to the synthesis of the first bis(σ)-borane complexes of group 6 metals, as well as the synthesis of a series of novel bis(σ)-borane and bis(σ)-borate complexes of ruthenium and iridium, the former being useful precursors for pentacoordinate borylene complexes of Ru. Recent work from the Ghosh group has uncovered a remarkable diversity of structures with σ(B-H)-bound ligands from the combination of borohydrides and nitrogen/chalcogen-containing groups and heterocycles. These reactions, while in some cases producing conventional scorpionate-type chelating products, more frequently undergo fascinating rearrangements with unpredictable outcomes. This Account aims to highlight this recent acceleration of research progress in this area, particularly the distinct but related approaches of-and complexes produced by-our two research groups, in addition to relevant works from other groups where appropriate.

5.
Fetal Pediatr Pathol ; 41(2): 330-333, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32720553

RESUMO

Background Gliomatosis peritonei (GP) is characterized by widespread implants of mature glial tissue in the peritoneum. It is most often associated with immature or mature ovarian teratomas. Case Report: A 6-month old infant developed isolated gliomatosis involving the tunica vaginalis following excision of an immature sacrococcygeal teratoma in the neonatal period. Conclusion: Tunica vaginalis gliomatosis can occur in the setting of a retroperitoneal extragonadal congenital immature teratoma.


Assuntos
Neoplasias Ovarianas , Neoplasias Peritoneais , Teratoma , Humanos , Lactente , Recém-Nascido , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/complicações , Neoplasias Peritoneais/patologia , Teratoma/patologia
6.
J Indian Assoc Pediatr Surg ; 27(3): 354-356, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35733597

RESUMO

Teratomas are common tumors in children. The most common sites are gonads, however, several extragonadal sites are well known such as sacrococcygeal region, mediastinum, head and neck, stomach, and vagina. Occasionally, teratomas occur in unusual sites which pose diagnostic difficulties. Here, we describe two cases of infantile teratomas with unusual presentation. The first case was a 6-month-old girl who presented with a mass in the right side of the abdomen. Computed tomography (CT) scan showed a solid-cystic mass in the right suprarenal region. The second was a 4-month-old boy who came with a huge abdominal mass. Contrast-enhanced CT showed a tumor arising from the jejunal mesentery. On microscopic examination, they were diagnosed as mature and immature teratoma, respectively. Although neuroblastoma is the most common infantile adrenal neoplasm, the possibility of teratoma should be considered for cystic adrenal lesions. Mesenteric teratoma can be difficult to distinguish radiologically from the more common lymphangioma; however, accurate diagnosis is important in view of long-term follow-up for teratomas because of the possibility of malignant transformation.

7.
J Phys Chem A ; 125(4): 954-965, 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33480691

RESUMO

Pollution of water resources by various pollutants is a global environmental issue, particularly, dye pollution has a major contribution to it. From various studies, it is confirmed that adsorption is an excellent remediation technique compared to others. Mg-Al-layered double hydroxides (LDHs) intercalated with NO3- ions act as an effective adsorbent-removing ionic species like heavy metal and dyes. Another popular nanomaterial is graphene oxide (GO), which is successfully used as an adsorbent for different pollutants like dye and heavy metal ions. It is prepared based on the modified Hummers method. In this study, GO was introduced on the surface of LDH to improve its adsorption capacity. The adsorption process is well described by the Freundlich model. The maximum adsorption capacity was obtained at around 0.5 and 0.85 mmol of methylene blue (MB) per gram of Mg-Al LDH and modified Mg-Al LDH with GO, respectively. The reaction kinetics of MB with both adsorbents is determined to be the pseudo-second-order. To get more insights of the mechanism, molecular dynamics (MD) simulation was conducted among the modified Mg-Al LDH with GO and MB molecules at both low- and high-concentration environments, which demonstrated that the developed composite adsorbs MB molecules predominantly onto its GO surface and then the MB molecules are adsorbed by the LDH surface. C-H···O (2.49-3.04 Å) and pi-donor···H-O (2.45-3.05 Å) are the major driving forces behind the strong adsorbability. Besides, S···H-O, S···O,N···O-H, pi···lone pair, pi···sigma, pi···cation, and alkyl···hydrophobic interactions play important roles in stabilizing the MB molecules onto the surface of the composite.

8.
J Indian Assoc Pediatr Surg ; 26(5): 327-333, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34728919

RESUMO

BACKGROUND: Primary gastrointestinal lymphomas (PGIL) are uncommon in children and account for <5% of all pediatric malignancies. The objective of our study was to analyze the prognostic factors of pediatric PGILs with reference to its histological subtypes, stage, and outcomes using immunohistochemistry. MATERIALS AND METHODS: Twenty cases were studied over 11 years. Clinicopathological profiles, histological details, and immunohistochemical (IHC) profiles were analyzed. RESULTS: The mean age at the presentation was 6 years. Using IHC stains (CD CD10, CD19, CD20, CD3, terminal deoxynucleotidyl transferase, BCL 2 and 6, PAX 5, and MUM1), diffuse large B-cell lymphoma (DLBCL) was most prevalent (45%), followed by Burkitt lymphoma (35%) and lymphoblastic lymphoma (20%). DLBCLs (9) were classified using the Han's algorithm. Six were activated B-cell and 3 were germinal center B-cell subtypes. The cases of lymphoblastic lymphoma and those in Stage I disease had the best prognosis. CONCLUSION: Pediatric PGILs have variable presentation, outcomes, and diverse treatment modalities depending on the histological subtypes. A panel of IHC stains can be a useful adjunct for the categorization and prognosis of pediatric PGILs.

9.
Inorg Chem ; 59(17): 12494-12503, 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32806002

RESUMO

Syntheses, structures, and electronic properties of group 5 metal-thiolate complexes that exhibit unusual coordination modes of thiolate ligands have been established. Room-temperature reaction of [Cp*VCl2]3 (Cp* = η5-C5Me5) with Na5[B(SCH2S)4] led to the formation of [Cp*VO{(SCH2)2S}] (1). The solid-state X-ray structure of 1 shows the formation of six-membered l,3,5-trithia-2-vanadacyclohexane that adopted a chair conformation. In a similar fashion, reactions of heavier group 5 precursors [Cp*MCl4] (M = Nb or Ta) with Na5[B(SCH2S)4] yielded bimetallic thiolate complexes [(Cp*M)2(µ-S){µ-C(H)S3-κ2S:κ2S',S″}{µ-SC(H)S-κ2C:κ2S‴,S''''}] (3a: M = Nb and 3b: M = Ta). One of the key features of molecules 3a and 3b is the presence of square-pyramidal carbon, which is quite unusual. The reactions also yielded bimetallic methanedithiolate complexes [(Cp*Nb)2(µ-S)(µ-SCH2S-κ2S,S')(µ,η2:η2-BH3S)] (2) and [(Cp*Ta)2(µ-O)(µ-SCH2S-κ2S,S')(µ-H){µ-S2C(H)SCH2S-κ2S″:κ2S‴,S''''}] (4). Complex 2 contains a methanedithiolate ligand that stabilizes the unsaturated niobaborane species. On the other hand, one ((mercaptomethyl)thio)methanedithiolate ligand {C2H4S3} is present in 4, which is coordinated to metal centers and exhibits the {µ-κ2S″:κ2S‴,S''''} bonding mode. Along with the formation of 3b and 4, the reaction of [Cp*TaCl4] with Na5[B(SCH2S)4] yielded [(Cp*Ta)2(µ-S){µ-(SBS)S(CH2S)2(BH2S)-κ2B:κ2S:κ4S',S″,S‴,S''''}] (5) containing a trithiaborate unit (BS3). Complex 5 consists of pentacoordinate boron that resides in a square-pyramidal environment. All the complexes have been characterized by multinuclear NMR, UV-vis spectroscopy, mass spectrometry, and single-crystal X-ray diffraction studies.

10.
Inorg Chem ; 58(15): 9992-9997, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31322868

RESUMO

A series of hydroborated η4-σ,π-alkene-borane complexes have been synthesized from the reaction of ruthenium-bis(σ)borate complex [Cp*Ru(µ-H)2BH(S-CH═S)] (1) and terminal as well as internal alkynes. Likewise, the reactions of manganese-bis(σ)borate complexes [Mn(CO)3(µ-H)2BHNCSC6H4(NL)] (L = NCSC6H4 or H) were explored with terminal alkynes that yielded boratabutadiene complexes [Mn(CO)3{(NCSC6H4)2N}{(R1MeC)═B(HC═CHR1)}] [R1 = phenyl (4a) or p-tolyl (4b)] via triple hydroboration of alkynes. These complexes feature a boratabutadiene ligand that is coordinated to a metal through the η4-CBCC mode. To the best of our knowledge, these are the first examples of η4-E-boratabutadiene-coordinated manganese complexes generated by the trans-hydroboration of alkynes. The steric and electronic effects of the borate ligands have been demonstrated using a less sterically hindered manganese-bis(σ)borate complex, [Mn(CO)3(µ-H)2BH(HN2CSC6H4)], that generated monohydroborated complexes [(CO)3Mn(µ-H)2(HN2CSC6H4)B(R1C═CHR2)] (for 6, R1 = Ph and R2 = H; for 7, R1 = p-Tol and R2 = H; for 8, R1 = R2 = Ph). Theoretical studies using density functional theory methods and chemical bonding analyses established the bonding and stability of these species.

11.
Inorg Chem ; 58(4): 2346-2353, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30707017

RESUMO

The field of diborinane is sparsely explored area, and not many compounds are structurally characterized. The room-temperature reaction of [{Cp*RuCl(µ-Cl)}2] (Cp* = η5-C5Me5) with Na[BH3(SCHS)] yielded ruthenium dithioformato [{Cp*Ru(µ,η3-SCHS)}2], 1, and 1-thioformyl-2,6-tetrahydro-1,3,5-trithia-2,6-diborinane complex, [(Cp*Ru){(η2-SCHS)CH2S2(BH2)2}], 2. To investigate the reaction pathway for the formation of 2, we carried out the reaction of [(BH2)4(CH2S2)2], 3, with 1 that yielded compound 2. To the best of our knowledge, it appears that compound 2 is the first example of a ruthenium diborinane complex where the central six-membered ring [CB2S3] adopts the chair conformation. Furthermore, room temperature reaction of 1 with [BH3·thf] resulted in the isolation of agostic-bis(σ-borate) complex, [Cp*Ru(µ-H)2BH(S-CH═S)], 4. Thermolysis of 4 with trace amount of tellurium powder led to formation of bis(bridging-boryl) complex, [{Cp*Ru(µ,η2-HBS2CH2)}2], 5, via dimerization of 4 followed by dehydrogenation. Compound 5 can be considered as a bis(bridging-boryl) species, in which the boryl units are connected to two ruthenium atoms. Theoretical studies and chemical bonding analyses demonstrate the reason for exceptional reactivity and stability of these complexes.

12.
Angew Chem Int Ed Engl ; 58(49): 17684-17689, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31553103

RESUMO

The room-temperature reaction of [Cp*TaCl4 ] with LiBH4 ⋅THF followed by addition of S2 CPPh3 results in pentahydridodiborate species [(Cp*Ta)2 (µ,η2 :η2 -B2 H5 )(µ-H)(κ2 ,µ-S2 CH2 )2 ] (1), a classical [B2 H5 ]- ion stabilized by the binuclear tantalum template. Theoretical studies and bonding analysis established that the unusual stability of [B2 H5 ]- in 1 is mainly due to the stabilization of sp2 -B center by electron donation from tantalum. Reactions to replace the hydrogens attached to the diborane moiety in 1 with a 2 e {M(CO)4 } fragment (M=Mo or W) resulted in simple adducts, [{(Cp*Ta)(CH2 S2 )}2 (B2 H5 )(H){M(CO)3 }] (6: M=Mo and 7: M=W), that retained the diborane(5) unit.

13.
Inorg Chem ; 57(17): 10896-10905, 2018 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-30124293

RESUMO

In an effort to synthesize chalcogen-rich metallaheteroborane clusters of group 5 metals, thermolysis of [Cp*TaCl4] (Cp* = η5-C5Me5) with thioborate ligand Li[BH2S3] was carried out, affording trimetallic clusters [(Cp*Ta)3(µ-S)3(µ3-S)3B(R)], 1-3 (1, R = H; 2, R = SH; and 3, R = Cl). Clusters 1-3 are illustrative examples of cubane-type organotantalum sulfido clusters in which one of the vertices of the cubane is missing. In parallel to the formation of 1-3, the reaction also yielded tetrametallic sulfido cluster [(Cp*Ta)4(µ-S)6(µ3-S)(µ4-O)], 6, having an adamantane core structure. Compound 6 is one of the rarest examples containing the µ4-oxo unit with a heavier early transition metal, i.e., tantalum. In an effort to isolate selenium analogues of clusters 1-3, we have isolated the trimetallic cluster [(Cp*Ta)3(µ-Se)3(µ3-Se)3B(H)], 4, from the thermolytic reaction of [Cp*TaCl4] and Li[BH2Se3]. In contrast, the thermolysis of [Cp*TaCl4] with Li[BH2Te3] under the same reaction conditions yielded tantalum telluride complex [(Cp*Ta)2(µ-Te)2], 5. Compounds 1-4 are hypo-electronic clusters with an electron count of 50 cluster valence electrons. All these compounds have been characterized by 1H, 11B{1H}, and 13C{1H} NMR spectroscopy; infrared spectroscopy; mass spectrometry; and single-crystal X-ray crystallography. The density functional theory calculations were also carried out to provide insight into the bonding and electronic structures of these molecules.

14.
Inorg Chem ; 57(3): 985-994, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29336563

RESUMO

Synthesis and structural elucidation of various electron precise group 5 dimetallaheteroboranes have been described. Room temperature reaction of [Cp2VCl2] with Li[BH3(EPh)], generated from the treatment of LiBH4·THF and Ph2E2 (E = S or Se), for 1 h in toluene, followed by thermolysis, led to the formation of bimetallic complexes [{CpV(µ-EPh)}2{µ-η2:η2-BH3E}], 1 and 2 (1: E = S and 2: E = Se), and [{CpV(µ-SePh)}2{µ-η2:η2-BH(OC4H8)Se}], 3. One of the striking features of these compounds is that they represent a rare class of distorted tetrahedral clusters having bridging hydrogens. Evaluating the skeletal electron pairs and bonding types, compounds 1, 2, and 3 may be considered as isoelectronic with our earlier reported [(CpV)2(B2H6)2]. In an attempt to synthesize the Nb analogues of 1-3, room temperature reactions of [CpNbCl4] and Li[BH3(EPh)] (E = S or Se) were carried out that afforded compounds [{CpNb(µ-EPh)}2{µ-η2:η2-B2H4E}], 4 and 5 (4: E = S and 5: E = Se). The solid-state X-ray structures of both 4 and 5 exemplify electronically saturated [M2B3] systems, and their geometries are analogous to that of [(Cp*MoCl)2B3H7]. For the extension of this work, reaction of [Cp*TaCl4] (Cp* = η5-C5Me5) with Li[BH3(SePh)] was carried out that yielded a tantalaselenaborane cluster [(Cp*Ta)2(µ-Se)B3H6Se(C6H5)] (6). All the new compounds have been characterized using 1H, 11B{1H}, 13C{1H} NMR, UV-vis absorption, and IR spectroscopy, mass spectrometry, and X-ray diffraction studies.

15.
Fetal Pediatr Pathol ; 37(5): 377-386, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30358469

RESUMO

BACKGROUND: Pleuropulmonary blastoma (PPB) is a childhood malignancy known to be associated with congenital pulmonary airway malformation (CPAM). CASE REPORT: An 18 months boy presented with respiratory distress. Computed tomography (CT) scans revealed a large right-sided lung mass. Fine needle aspiration cytology (FNAC) showed sheets and clusters of small round to oval cells with scanty cytoplasm. The possibility of PPB was suggested. Trucut biopsy from the mass confirmed the diagnosis of PPB, of at least type II. The child had earlier been diagnosed as CPAM for which he had undergone lobectomy at six months, which on review was diagnosed as PPB I. CONCLUSION: We describe the cytological and histological findings of a case of PPBII/III evolving from a PPB I originally thought to be a CPAM type IV. This supports the theory that PPB I may progress to a more aggressive type II with time, and highlights the importance of the adequately treating the PPB I to prevent this transformation.


Assuntos
Blastoma Pulmonar/patologia , Malformação Adenomatoide Cística Congênita do Pulmão/diagnóstico , Malformação Adenomatoide Cística Congênita do Pulmão/patologia , Erros de Diagnóstico , Humanos , Lactente , Masculino , Blastoma Pulmonar/diagnóstico
16.
Chemistry ; 23(41): 9812-9820, 2017 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-28444699

RESUMO

A series of new bis(σ)borate and agostic complexes of group 7 metals have been synthesized and structurally characterized from various borate ligands, such as trihydrobis(benzothiazol-2-yl)amideborate (Na[(H3 B)bbza]), trihydro(2-aminobenzothiazolyl)borate (Na[(H3 B)abz]), and dihydrobis(2-mercaptopyridyl)borate (Na[(H2 B)mp2 ]) (bbza=bis(benzothiazol-2-yl)amine, abz=2-aminobenzothiazolyl, and mp=2-mercaptopyridyl). Photolysis of [Mn2 (CO)10 ] with Na[(H3 B)bbza] formed bis(σ)borate complex [Mn(CO)3 (µ-H)2 BHNCSC6 H4 (NR)] (1; R=NCSC6 H4 ). Octahedral complex [Re(CO)2 (N3 C2 S2 C12 H8 )2 ] (2) was generated under similar reaction conditions with [Re2 (CO)10 ]. Similarly, when [Mn2 (CO)10 ] was treated with Na[(H3 B)abz], bis(σ)borate complex [Mn(CO)3 (µ-H)2 BH(HN2 CSC6 H4 )] (3) and the agostic complex [Mn(CO)3 (µ-H)BH(HN2 CSC6 H4 )2 ] (4) were formed. To probe the potential formation of agostic complexes of the heavier group 7 metals, we carried out the photolysis of [M2 (CO)10 ] with Na[(H2 B)mp2 ] and found that [M(CO)3 (µ-H)BH(C5 H4 NS)2 ] (5: M=Re; 6: M=Mn) was formed in moderate yield. Complexes 1 and 3 feature a (κ3 -H,H,N) coordination mode, whereas 4, 5, and 6 display both (κ3 -H,N,N) and (κ3 -H,S,S) modes of the corresponding ligands. To investigate the lability of the CO ligands of 1 and 3, we treated the complexes with phosphine ligands that generated novel bis(σ)borate complexes [Mn(µ-H)2 (BHNCSC6 H4 )(NR)(CO)2 PL2 L'] (R=NCSC6 H4 ; 7 a: L=L'=Ph; 7 b: L=Ph, L'=Me) and [Mn(µ-H)2 BHN(NCSC6 H4 )R(CO)2 PL2 L'] (R=NCSC6 H4 ; 8 a: L=L'=Ph; 8 b: L=Ph, L'=Me). Complexes 7 and 8 are structural isomers with different coordination modes of the bbza ligand. In addition, DFT calculations were performed to shed some light on the bonding and electronic structures of these complexes.

17.
Chemistry ; 23(72): 18264-18275, 2017 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-28949073

RESUMO

In a quest for efficient precursors for the synthesis of boratrane complexes of late transition metals, we have developed a useful synthetic method using [L'M(µ-Cl)Clx ]2 as precursors (L'=η6 -p-cymene, M=Ru, x=1; L'=COD, M=Rh, x=0 and L'=Cp*, M=Ir or Rh, x=1; COD=1,5-cyclooctadiene, Cp*=η5 -C5 Me5 ). For example, treatment of Na[(H3 B)bbza] or Na[(H2 B)mp2 ] (bbza=bis(benzothiazol-2-yl)amine; mp=2-mercaptopyridyl) with [L'M(µ-Cl)Clx ]2 yielded [(η6 -p-cymene)RuBH{(NCSC6 H4 )(NR)}2 ] (2; R=NCSC6 H4 ), [{N(NCSC6 H4 )2 }RhBH{(NCSC6 H4 )(NR)}2 ] (3; R=NCS-C6 H4 ), [(η6 -p-cymene)RuBH(L)2 ] (5; L=C5 H4 NS), and [Cp*MBH(L)2 ] (6 and 7; L=C5 H4 NS, M=Ir or Rh). In order to delineate the significance of the ligands, we studied the reactivity of [(COD)Rh(µ-Cl)]2 with Na[(H3 B)bbza], which led to the formation of the isomeric agostic complexes [(η4 -COD)Rh(µ-H)BHRh(C14 H8 N3 S2 )3 ], 4 a and 4 b, in parallel to the formation of 16-electron square-pyramidal rhodaboratrane complex 3. Compounds 4 a and 4 b show two different geometries, in which the Rh-B bonds are shorter than in the reported Rh agostic complexes. The new compounds have been characterized in solution by various spectroscopic analyses, and their structural arrangements have been unequivocally established by crystallographic analyses. DFT calculations provide useful insights regarding the stability of these metallaboratrane complexes as well as their M→B bonding interactions.

18.
Fetal Pediatr Pathol ; 36(4): 325-331, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28541826

RESUMO

BACKGROUND: Epithelioid sarcoma is a heterogeneous tumor with 2 subtypes, classic and proximal. The proximal variant is more aggressive and occurs in proximal location in young adults. CASE REPORT: We present a proximal epithelioid sarcoma in the leg of an 8 year old girl with rhabdoid morphology and scattered osteoclastic giant cells. Nuclear INI-1 was retained. Despite wide local excision, local recurrence occurred at 8 months. Following re-excision, she developed a chest wall metastasis after 9 months. CONCLUSION: Epithelioid sarcoma, proximal type with osteoclastic giant cells in the pediatric age group has not been reported previously and should be considered in the differential diagnoses of tumors with epithelioid cell morphology and scattered osteoclastic giant cells. Retained INI expression helped to differentiate this tumor from malignant rhabdoid tumor.


Assuntos
Células Gigantes/patologia , Osteoclastos/patologia , Proteína SMARCB1/biossíntese , Sarcoma/patologia , Neoplasias de Tecidos Moles/patologia , Criança , Feminino , Humanos , Perna (Membro) , Recidiva Local de Neoplasia/patologia , Sarcoma/metabolismo , Neoplasias de Tecidos Moles/metabolismo
19.
Chemistry ; 22(23): 7871-8, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27097988

RESUMO

Thermolysis of [Cp*Ru(PPh2 (CH2 )PPh2 )BH2 (L2 )] 1 (Cp*=η(5) -C5 Me5 ; L=C7 H4 NS2 ), with terminal alkynes led to the formation of η(4) -σ,π-borataallyl complexes [Cp*Ru(µ-H)B{R-C=CH2 }(L)2 ] (2 a-c) and η(2) -vinylborane complexes [Cp*Ru(R-C=CH2 )BH(L)2 ] (3 a-c) (2 a, 3 a: R=Ph; 2 b, 3 b: R=COOCH3 ; 2 c, 3 c: R=p-CH3 -C6 H4 ; L=C7 H4 NS2 ) through hydroboration reaction. Ruthenium and the HBCC unit of the vinylborane moiety in 2 a-c are linked by a unique η(4) -interaction. Conversions of 1 into 3 a-c proceed through the formation of intermediates 2 a-c. Furthermore, in an attempt to expand the library of these novel complexes, chemistry of σ-borane complex [Cp*RuCO(µ-H)BH2 L] 4 (L=C7 H4 NS2 ) was investigated with both internal and terminal alkynes. Interestingly, under photolytic conditions, 4 reacts with methyl propiolate to generate the η(4) -σ,π-borataallyl complexes [Cp*Ru(µ-H)BH{R-C=CH2 }(L)] 5 and [Cp*Ru(µ-H)BH{HC=CH-R}(L)] 6 (R=COOCH3 ; L=C7 H4 NS2 ) by Markovnikov and anti-Markovnikov hydroboration. In an extension, photolysis of 4 in the presence of dimethyl acetylenedicarboxylate yielded η(4) -σ,π-borataallyl complex [Cp*Ru(µ-H)BH{R-C=CH-R}(L)] 7 (R=COOCH3 ; L=C7 H4 NS2 ). An agostic interaction was also found to be present in 2 a-c and 5-7, which is rare among the borataallyl complexes. All the new compounds have been characterized in solution by IR, (1) H, (11) B, (13) C NMR spectroscopy, mass spectrometry and the structural types were unequivocally established by crystallographic analysis of 2 b, 3 a-c and 5-7. DFT calculations were performed to evaluate possible bonding and electronic structures of the new compounds.

20.
Fetal Pediatr Pathol ; 35(4): 251-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27182845

RESUMO

Rhabdomyosarcoma (RMS) is one of the common malignant tumors in the pediatric age group. There is only a single case report of primary renal alveolar RMS. Fine needle aspiration (FNA) findings of primary renal RMS has not been reported so far. Hence we present an unusual case of primary alveolar RMS of the kidney. An 11 year old boy presented with an abdominal mass. On FNA a diagnosis of undifferentiated sarcoma and anaplastic Wilms tumor were considered. The tumor was resected and showed histopathological features of alveolar rhabdomyosarcoma. He developed multiple bony metastases and succumbed to the illness despite aggressive chemotherapy. RMS of the kidney should be considered in the differential diagnosis of children with a renal mass, and may have an aggressive clinical course with bone metastases.


Assuntos
Neoplasias Ósseas/secundário , Neoplasias Renais/patologia , Rabdomiossarcoma Alveolar/secundário , Biomarcadores Tumorais/análise , Criança , Evolução Fatal , Humanos , Imuno-Histoquímica , Masculino
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