An Exploration of the Hydrogen Bond Donor Ability of Ammonia.

Ammonia is an important molecule due to its wide use in the fertiliser industry. It is also used in aminolysis reactions. Theoretical studies of the reaction mechanism predict that in reactive complexes and transition states, ammonia acts as a hydrogen bond donor forming N-H⋅⋅⋅O hydrogen bond. Experimental reports of N-H⋅⋅⋅O hydrogen bond, where ammonia acts as a hydrogen bond donor are scarce. Herein, the hydrogen bond donor ability of ammonia is investigated with three chalcogen atoms i. e. O, S, and Se using matrix isolation infrared spectroscopy and electronic structure calculations. In addition, the chalcogen bond acceptor ability of ammonia has also been investigated. The hydrogen bond acceptor molecules used here are O(CH3 )2 , S(CH3 )2 , and Se(CH3 )2 . The formation of the 1 : 1 complex has been monitored in the N-H symmetric and anti-symmetric stretching modes of ammonia. The nature of the complex has been delineated using Atoms in Molecules analysis, Natural Bond Orbital analysis, and Energy Decomposition Analysis. This work presents the first comparison of the hydrogen bond donor ability of ammonia with O, S, and Se.

An Experimental Exploration of C-H⋠⋠⋠X Hydrogen Bond in [CHCl3 -X(CH3 )2 ] Complexes (X=O, S, and Se).

Among the conglomeration of hydrogen bond donors, the C-H group is prevalent in chemistry and biology. In the present work, CHCl3 has been selected as the hydrogen bond donor and are X(CH3 )2 are the hydrogen bond acceptors. Formation of C-H⋅⋅⋅X hydrogen bond under the matrix isolation condition is confirmed by the observation of red-shift in the C-H stretching frequency of CHCl3 and comparison with the simulated spectra. Stabilisation energy of all the three complexes is almost equal although the observed red-shift for the C-H⋅⋅⋅O complex is less compared to the C-H⋅⋅⋅S/Se complexes. The nature and origin of the hydrogen bond have been delineated using Natural Bond Orbital, Atoms in Molecules, Non-Covalent Interaction analyses, and Energy Decomposition Analysis. Charge transfer is found to be proportional to the observed red-shift. This work provides the first impression of C-H⋅⋅⋅Se hydrogen bond and its comparison with C-H⋅⋅⋅O/S hydrogen bond interaction under experimental condition.

Hydrogen bond properties of Se in [ROH-Se(CH3)2] complexes (R = H, CH3, C2H5): matrix-isolation infrared spectroscopy and theoretical calculations.

Se is now considered as a potential centre for hydrogen bond interactions. The hydrogen bond acceptor ability of Se has been investigated in [ROH-Se(CH3)2] complexes (R = H, CH3, and C2H5) using matrix-isolation infrared spectroscopy and electronic structure calculations. The first impression of the IR spectra of the hydrogen bond complexes of [ROH-Se(CH3)2] in N2 and Ar matrices is presented here. Moreover, no spectroscopic data are available for the [HOH-Se(CH3)2] complex. Vibrational spectra in the OH stretching region indicate the formation of the [ROH-Se(CH3)2] complex under the matrix-isolation conditions. Comparison of the experimental spectra with the simulated vibrational frequencies at different levels of theory confirms the formation of the 1 : 1 cluster of [ROH-Se(CH3)2] stabilised by O-H⋯Se hydrogen bond interactions. Multiple conformers of the [CH3OH-Se(CH3)2] complex having marginally different stabilisation energies have been predicted from electronic structure calculations and signatures of the same have been observed under the cold conditions of matrix isolation. Conformer specific assignment of the 1 : 1 cluster of [C2H5OH-Se(CH3)2] (anti and gauche forms) has been carried out in both the matrices. Concentration dependent experiments indicate the formation of higher order clusters and/or mixed clusters along with the formation of a 1 : 1 cluster for CH3OH and C2H5OH. The nature of the selenium centred hydrogen bond has been delineated using AIM, NBO and energy decomposition analysis. A comparison of similar complexes of H2O, CH3OH, and C2H5OH with O, S and Se indicates that Se is not far away in hydrogen bond acceptor ability compared to O and S.

Competition between the hydrogen bond and the halogen bond in a [CH3OH-CCl4] complex: a matrix isolation IR spectroscopy and computational study.

Methanol (CH3OH) is the simplest alcohol and carbon tetrachloride (CCl4) is widely used as a solvent in the chemical industry. CH3OH and CCl4 are both important volatile substances in the atmosphere and CCl4 is an important precursor for atmospheric ozone depletion. Moreover, mixtures of CH3OH and CCl4 are an important class of non-aqueous mixtures as they exhibit a large deviation from Raoult's law. The specific interaction between CH3OH and CCl4 is not yet investigated experimentally. The interaction between CH3OH and CCl4 at the molecular level can be twofold: hydrogen bond (O-HCl) and halogen bond (C-ClO) interaction. One halogen bonded minimum and two hydrogen bonded minima are identified in the dimer potential energy surface. Herein, the 1 : 1 complex of [CH3OH-CCl4] has been characterised using matrix-isolation infrared spectroscopy and electronic structure calculations to investigate the competition between hydrogen bonded and halogen bonded complexes. Vibrational spectra have been monitored in the C-Cl, C-O, and O-H stretching regions. The exclusive formation of halogen bonded 1 : 1 complexes in argon and nitrogen matrices is confirmed by a combination of experimental and simulated vibrational frequency, stabilisation energy, energy decomposition analysis, and natural bond orbital and atoms-in-molecules analyses. This investigation helps to understand the specific interactions in the [CH3OH-CCl4] mixture and also the possibilities of formation of halogen bonded atmospheric complexes that may influence the atmospheric chemical activities, and enhance aerosol formation and deposition of CCl4.

Superselective intraarterial cerebral infusion of cetuximab with blood brain barrier disruption combined with Stupp Protocol for newly diagnosed glioblastoma.

OBJECTIVE: We describe the first case of a novel treatment for a newly diagnosed glioblastoma (GBM) using superselective intraarterial cerebral infusion (SIACI) of cetuximab after osmotic disruption of the blood-brain barrier (BBB) with mannitol. A 51year-old female underwent craniotomy for removal of a right frontal GBM. Pathology confirmed EGFR amplification, and she underwent three treatments of SIACI of cetuximab to the tumor site. The first treatment was given within a week of starting standard of care chemoradiation (Stupp protocol), which is a combination of radiation treatment (2 Gy per/ day x 30 days, total of 60 Gy) and oral temozolomide (75 mg/m2). The second and third SIACI of cetuximab were administered 3 and 6 months later, while the patient continued on maintenance temozolomide. Post-radiation changes on MRI were stable, and there were no signs of recurrence at 4 and 6 months post-resection. Herein, we detail the technical aspects of this novel treatment paradigm and suggest that SIACI of cetuximab after BBB disruption using mannitol, combined with the standard of care chemoradiation therapy, may be an effective treatment method for newly diagnosed EGFR amplified glioblastoma.

Intraoperative MRI for resection of intracranial meningiomas.

OBJECTIVE: To examine whether intraoperative MRI can enhance safety and extent of resection of complex intracranial meningiomas, given its positive role in the resection of malignant brain tumors and pituitary tumors. METHODS: Over a ten-year period, 70 operations were performed on 66 patients with intracranial meningiomas using the compact, mobile PoleStar N20 iMRI navigation system. A retrospective review was conducted examining patient demographics, surgical characteristics, and outcomes. RESULTS: 36 meningiomas were above the skull base and 30 were of the skull base. Four (5.7%) operations were done for recurrent meningiomas. 63 patients (95.5%) had WHO grade I and 3 patients (4.5%) had WHO grade III meningiomas. 9 (12.8%) patients required additional tumor resection based on iMRI findings, and in 4 patients (6%) iMRI imaging allowed for avoidance of additional dissection near critical neurovascular structures. CONCLUSIONS: Up to 15.7% of patients had surgery positively affected by intraoperative imaging either improving the resection or avoiding unnecessary additional dissection which could potentially harm critical neurologic structures. As iMRI becomes more widely available it may be valuable to use in an appropriate subset of patients with intracranial meningiomas.

Long-term benefit of intra-arterial bevacizumab for recurrent glioblastoma.

OBJECTIVE: Standard treatment for recurrent GBM is not yet established. We present a case demonstrating the benefit of intra-arterial (IA) bevacizumab with blood brain barrier disruption (BBBD) for the treatment of recurrent GBM. A 31 year-old man diagnosed with GBM, following primary resection, received temozolomide. After a second resection, he received one dose of IA bevacizumab with BBBD using mannitol, preventing regrowth for 2.5 years. Following tumor regrowth, the patient received another dose of IA bevacizumab with BBBD, which has prevented regrowth for another year.

Apparent diffusion coefficient changes predict survival after intra-arterial bevacizumab treatment in recurrent glioblastoma.

PURPOSE: Superselective intra-arterial cerebral infusion (SIACI) of bevacizumab (BV) has emerged as a novel therapy in the treatment of recurrent glioblastoma (GB). This study assessed the use of apparent diffusion coefficient (ADC) in predicting length of survival after SIACI BV and overall survival in patients with recurrent GB. METHODS: Sixty-five patients from a cohort enrolled in a phase I/II trial of SIACI BV for treatment of recurrent GB were retrospectively included in this analysis. MR imaging with a diffusion-weighted (DWI) sequence was performed before and after treatment. ROIs were manually delineated on ADC maps corresponding to the enhancing and non-enhancing portions of the tumor. Cox and logistic regression analyses were performed to determine which ADC values best predicted survival. RESULTS: The change in minimum ADC in the enhancing portion of the tumor after SIACI BV therapy was associated with an increased risk of death (hazard ratio = 2.0, 95% confidence interval(CI) [1.04-3.79], p = 0.038), adjusting for age, tumor size, BV dose, and prior IV BV treatments. Similarly, the change in ADC after SIACI BV therapy was associated with greater likelihood of surviving less than 1 year after therapy (odds ratio = 7.0, 95% CI [1.08-45.7], p = 0.04). Having previously received IV BV was associated with increased risk of death (OR 18, 95% CI [1.8-180.0], p = 0.014). CONCLUSION: In patients with recurrent GB treated with SIACI BV, the change in ADC value after treatment is predictive of overall survival.

Durability of single dose intra-arterial bevacizumab after blood/brain barrier disruption for recurrent glioblastoma.

BACKGROUND: Bevacizumab (BV) has been used to treat recurrent glioblastoma with a progression free survival of approximately 3-3.5 months. Typically, it is administered intravenously every 2-3 weeks at dosages ranging from 5-15 mg/kg. Serious side effects include GI tract perforations, hematologic disorders, intracranial hemorrhage, and malignant hypertension. We hypothesized that selective intracranial intra-arterial infusion (SIACI) of BV following blood/brain barrier disruption (BBBD) with mannitol may allow for reduced dosage, lower toxicity, and equivalent or superior progression free survival (PFS). METHODS: Sixteen patients (8 males & 8 females) with a mean age of 55 years (range 27-68), KPS>70, and recurrent glioblastoma were enrolled. All patients underwent super-selective catheterization and were given a single intra-arterial dose of 15 mg/kg BV following osmotic blood/brain barrier disruption with mannitol to the arteries supplying the tumor. The patients had no additional treatment following that initial SIACI mannitol and BV until they met criteria for progression. PFS was assessed using modified Response Assessment in Neuro-Oncology (RANO) criteria. RESULTS: Median progression free survival from only one dose of SIACI mannitol and BV was 3.9 months. Side effects included seizure in 2 patients, and headache in 1 patient. Seizures were well controlled with medications, and there were no serious toxicities. There were no endovascular-related complications. CONCLUSION: SIACI of mannitol and BV at 15mg/kg allows for similar or better PFS compared to biweekly treatments of IV BV at 10mg/kg. The dosage required is lower and side effects were minimal and well tolerated. Future larger trials are warranted to assess whether repeated less frequent IA mannitol and BV may be superior to biweekly IV administration as a monotherapy.

Intra-arterial cetuximab for the treatment of recurrent unresectable head and neck squamous cell carcinoma†.

IMPORTANCE: Management of recurrent head and neck squamous cell carcinoma is a common and challenging clinical problem in head and neck oncology. OBJECTIVE: Here we present the first reported case of super-selective intra-arterial (SSIA) microcatheter based local delivery of cetuximab for head and neck cancer. This technical report describes the techniques used to deliver the SSIA dose of cetuximab, as well as the patient outcome. DESIGN: This technical report is part of an ongoing Phase I Clinical Trial. SETTING: The New York Head and Neck Institute (NYHNI) is a full-service otolaryngology and neurosurgery department at Lenox Hill Hospital, part of the Northwell Health System. The NYHNI serves a diverse patient population with a wide range of head and neck diseases in a tertiary hospital setting. INTERVENTION: SSIA Cetuximab. PARTICIPANT: A patient presents to our clinic with recurrent unresectable squamous cell carcinoma of the nasopharynx. He is recruited into the first cohort of a phase I clinical trial to assess the safety of SSIA cetuximab, dose starting at 100mg/m2. Adjuvant chemo-radiation therapy is also given. MEASURES: Safety, as measured by toxicity of SSIA cetuximab. RESULTS: SSIA Cetuximab has been demonstrated to be a safe and feasible procedure in this technical report. CONCLUSIONS: This case illustrates technical feasibility and a very preliminary assessment of the safety of a novel delivery of a biologic agent for squamous cell carcinoma of the head and neck, which is part of an ongoing phase I clinical trial. TRIAL REGISTRATION: NCT02438995.

Neuro-oncology biotech industry progress report.

The Brain Tumor Biotech Center at the Feinstein Institute for Medical Research, in collaboration with Voices Against Brain Cancer hosted The Brain Tumor Biotech Summit at in New York City in June 2015. The focus was once again on fostering collaboration between neuro-oncologist, neurosurgeons, scientists, leaders from biotechnology and pharmaceutical industries, and members of the financial community. The summit highlighted the recent advances in the treatment of brain tumor, and specifically focused on targeting of stem cells and EGFR, use of prophage and immunostimulatory vaccines, retroviral vectors for drug delivery, biologic prodrug, Cesium brachytherapy, and use of electric field to disrupt tumor cell proliferation. This article summarizes the current progress in brain tumor research as presented at 2015 The Brain Tumor Biotech Summit.

Superselective intraarterial cerebral infusion of cetuximab after osmotic blood/brain barrier disruption for recurrent malignant glioma: phase I study.

Objective To establish a maximum tolerated dose of superselective intraarterial cerebral infusion (SIACI) of Cetuximab after osmotic disruption of the blood-brain barrier (BBB) with mannitol, and examine safety of the procedure in patients with recurrent malignant glioma. Methods A total of 15 patients with recurrent malignant glioma were included in the current study. The starting dose of Cetuximab was 100 mg/m(2) and dose escalation was done to 250 mg/m(2). All patients were observed for 28 days post-infusion for any side effects. Results There was no dose-limiting toxicity from a single dose of SIACI of Cetuximab up to 250 mg/m(2) after osmotic BBB disruption with mannitol. A tolerable rash was seen in 2 patients, anaphylaxis in 1 patient, isolated seizure in 1 patient, and seizure and cerebral edema in 1 patient. Discussion SIACI of mannitol followed by Cetuximab (up to 250 mg/m(2)) for recurrent malignant glioma is safe and well tolerated. A Phase I/II trial is currently underway to determine the efficacy of SIACI of cetuximab in patients with high-grade glioma.

Neuroprotection Trials in Traumatic Brain Injury.

Traumatic brain injury (TBI) is a significant cause of mortality and morbidity worldwide. Current treatment of acute TBI includes surgical intervention when needed, followed by supportive critical care such as optimizing cerebral perfusion, preventing pyrexia, and treating raised intracranial pressure. While effective in managing the primary injury to the brain and skull, these treatment modalities do not address the complex secondary cascades that occur at a cellular level following initial injury and greatly affect the ultimate neurologic outcome. These secondary processes involve changes in ionic flux, disruption of cellular function, derangement of blood flow and the blood-brain barrier, and elevated levels of free radicals. Over the past few decades, numerous pharmacologic agents and modalities have been investigated in an attempt to interrupt these secondary processes. No neuroprotective agents currently exist that have been proven to improve neurologic outcome following TBI. However, these trials have contributed significantly to the understanding of the clinical sequelae of TBI and to improvements in the quality of care for TBI. With the experience and insights that have been accrued with the trials to date, we will be able to optimize future trial designs and refine established neurologic endpoints to better identify new therapeutic agents and further improve neurologic outcomes from this often devastating condition.

Electronic and vibrational spectra of protonated benzaldehyde-water clusters, [BZ-(H2O)n≤5]H+: evidence for ground-state proton transfer to solvent for n ≥ 3.

Vibrational and electronic photodissociation spectra of mass-selected protonated benzaldehyde-(water)n clusters, [BZ-(H2O)n]H(+) with n ≤ 5, are analyzed by quantum chemical calculations to determine the protonation site in the ground electronic state (S0) and ππ(*) excited state (S1) as a function of microhydration. IR spectra of [BZ-(H2O)n]H(+) with n ≤ 2 are consistent with BZH(+)-(H2O)n type structures, in which the excess proton is localized on benzaldehyde. IR spectra of clusters with n ≥ 3 are assigned to structures, in which the excess proton is located on the (H2O)n solvent moiety, BZ-(H2O)nH(+). Quantum chemical calculations at the B3LYP, MP2, and ri-CC2 levels support the conclusion of proton transfer from BZH(+) to the solvent moiety in the S0 state for hydration sizes larger than the critical value nc = 3. The vibronic spectrum of the S1 ← S0 transition (ππ(*)) of the n = 1 cluster is consistent with a cis-BZH(+)-H2O structure in both electronic states. The large blueshift of the S1 origin by 2106 cm(-1) upon hydration with a single H2O ligand indicates that the proton affinity of BZ is substantially increased upon S1 excitation, thus strongly destabilizing the hydrogen bond to the solvent. The adiabatic S1 excitation energy and vibronic structure calculated at the ri-CC2/aug-cc-pVDZ level agrees well with the measured spectrum, supporting the notion of a cis-BZH(+)-H2O geometry. The doubly hydrated species, cis-BZH(+)-(H2O)2, does not absorb in the spectral range of 23 000-27 400 cm(-1), because of the additional large blueshift of the ππ(*) transition upon attachment of the second H2O molecule. Calculations predict roughly linear and large incremental blueshifts for the ππ(*) transition in [BZ-(H2O)n]H(+) as a function of n. In the size range n ≥ 3, the calculations predict a proton transfer from the (H2O)nH(+) solvent back to the BZ solute upon electronic ππ(*) excitation.

Infrared spectrum of the Ag(+)-(pyridine)2 ionic complex: probing interactions in artificial metal-mediated base pairing.

The isolated pyridine-Ag(+)-pyridine unit (Py-Ag(+)-Py) is employed as a model system to characterize the recently observed Ag(+)-mediated base pairing in DNA oligonucleotides at the molecular level. The structure and infrared (IR) spectrum of the Ag(+)-Py(2) cationic complex are investigated in the gas phase by IR multiple-photon dissociation (IRMPD) spectroscopy and quantum chemical calculations to determine the preferred metal-ion binding site and other salient properties of the potential-energy surface. The IRMPD spectrum has been obtained in the 840-1720 cm(-1) fingerprint region by coupling the IR free electron laser at the Centre Laser Infrarouge d'Orsay (CLIO) with a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer equipped with an electrospray ionization source. The spectroscopic results are interpreted with quantum chemical calculations conducted at the B3LYP/aug-cc-pVDZ level. The analysis of the IRMPD spectrum is consistent with a σ complex, in which the Ag(+) ion binds to the nitrogen lone pairs of the two Py ligands in a linear configuration. The binding motif of Py-Ag(+)-Py in the gas phase is the same as that observed in Ag(+)-mediated base pairing in solution. Ag(+) bonding to the π-electron system of the aromatic ring is predicted to be a substantially less-favorable binding motif.

Gas-phase spectroscopy of synephrine by laser desorption supersonic jet technique.

In our previous work, we found that synephrine has six conformers in the gas phase, while adrenaline, which is a catecholamine and has the same side chain as synephrine, has been reported to have only two conformers. To determine the conformational geometries of synephrine, we measured resonance enhanced multiphoton ionization, ultraviolet-ultraviolet hole burning, and infrared dip spectra by utilizing the laser desorption supersonic jet technique. By comparing the observed infrared spectra with theoretical ones, we assigned geometries except for the orientations of the phenolic OH group. Comparison between the determined structures of synephrine and those of 2-methylaminno-1-phenylethanol, which has the same side chain as synephrine but no phenol OH group, leads to the conclusion that the phenolic OH group in synephrine does not affect the conformational flexibility of the side chain. In the case of adrenaline, which is expected to have 12 conformers if there are no interactions between the catecholic OH groups and the side chain, some interactions possibly exist between them because only two conformations are observed. By estimation of the dipole-dipole interaction energy between partial dipole moments of the catecholic OH groups and the side chain, it was concluded that the dipole-dipole interaction stabilizes specific conformers which are actually observed.

Fistula between degenerated uterine leiomyoma and the bladder: case report.

Most common reason for the vesicouterine fistula is a cesarean section; no cases were reported of degenerated uterine leiomyoma communicating with the urinary bladder. We report a case of fistulous communication between the degenerated leiomyoma and the bladder. The patient's initial clinical presentation was consistent with recurrent UTI. She underwent multiple examinations including cystoscopy, cystouretrography, retrograde pyeolography, and MRI. The ultimate treatment was an exploratory laparotomy and en-block resection of the bladder wall, fistula tract, and degenerated leiomyoma. Fistula can develop between the bladder and degenerated leiomyoma and could be one of the reasons for the chronic pelvic pain and dysuria.