Stabilized Molecular Diphosphorus Pentoxide, P2O5L2 (L = N-Donor Base), in the Synthesis of Condensed Phosphate-Organic Molecule Conjugates.

Commercial phosphorus pentoxide reacts with some N-donor bases to give the adducts P2O5L2 and P4O10L3 (L = DABCO, pyridine, 4-tert-butylpyridine). The DABCO adducts were structurally characterized by single-crystal X-ray diffraction. It is proposed that P2O5L2 and P4O10L3 undergo interconversion through a "phosphate-walk" mechanism, which was evaluated using DFT calculations. P2O5(pyridine)2 (1) efficiently transfers monomeric diphosphorus pentoxide to phosphorus oxyanion nucleophiles, yielding substituted trimetaphosphates and cyclo-phosphonate-diphosphates (P3O8R)2- (R1 = nucleosidyl, phosphoryl, alkyl, aryl, vinyl, alkynyl, H, F). Hydrolytic ring-opening of these compounds forms linear derivatives [R1(PO3)2PO3H]3-, and nucleophilic ring-opening gives linear disubstituted [R1(PO3)2PO2R2]3- compounds.

Beyond Triphosphates: Reagents and Methods for Chemical Oligophosphorylation.

Oligophosphates play essential roles in biochemistry, and considerable research has been directed toward the synthesis of both naturally occurring oligophosphates and their synthetic analogues. Greater attention has been given to mono-, di-, and triphosphates, as these are present in higher concentrations biologically and easier to synthesize. However, extended oligophosphates have potent biochemical roles, ranging from blood coagulation to HIV drug resistance. Sporadic reports have slowly built a niche body of literature related to the synthesis and study of extended oligophosphates, but newfound interests and developments have the potential to rapidly expand this field. Here we report on current methods to synthesize oligophosphates longer than triphosphates and comment on the most important future directions for this area of research. The state of the art has provided fairly robust methods for synthesizing nucleoside 5'-tetra- and pentaphosphates as well as dinucleoside 5',5'-oligophosphates. Future research should endeavor to push such syntheses to longer oligophosphates while developing synthetic methodologies for rarer morphologies such as 3'-nucleoside oligophosphates, polyphosphates, and phosphonate/thiophosphate analogues of these species.

Synthesis of α,δ-Disubstituted Tetraphosphates and Terminally-Functionalized Nucleoside Pentaphosphates.

The anion [P4O11]2-, employed as its bis(triphenylphosphine)iminium (PPN) salt, is shown herein to be a versatile reagent for nucleophile tetraphosphorylation. Treatment under anhydrous conditions with an alkylamine base and a nucleophile (HNuc1), such as an alcohol (neopentanol, cyclohexanol, 4-methylumbelliferone, and Boc-Tyr-OMe), an amine (propargylamine, diethylamine, morpholine, 3,5-dimethylaniline, and isopropylamine), dihydrogen phosphate, phenylphosphonate, azide ion, or methylidene triphenylphosphorane, results in nucleophile substituted tetrametaphosphates ([P4O11Nuc1]3-) as mixed PPN and alkylammonium salts in 59% to 99% yield. Treatment of the resulting functionalized tetrametaphosphates with a second nucleophile (HNuc2), such as hydroxide, a phenol (4-methylumbelliferone), an amine (propargylamine and ethanolamine), fluoride, or a nucleoside monophosphate (uridine monophosphate, deoxyadenosine monophosphate, and adenosine monophosphate), results in ring opening to linear tetraphosphates bearing one nucleophile on each end ([Nuc1(PO3)3PO2Nuc2]4-). When necessary, these linear tetraphosphates are purified by reverse phase or anion exchange HPLC, yielding triethylammonium or ammonium salts in 32% to 92% yield from [PPN]2[P4O11]. Phosphorylation of methylidene triphenylphosphorane as Nuc1 yields a new tetrametaphosphate-based ylide ([Ph3PCHP4O11]3-, 94% yield). Wittig olefination of 2',3'-O-isopropylidene-5'-deoxy-5'-uridylaldehyde using this ylide results in a 3'-deoxy-3',4'-didehydronucleotide derivative, isolated as the triethylammonium salt in 54% yield.

Bacterial Phosphate Granules Contain Cyclic Polyphosphates: Evidence from 31P Solid-State NMR.

Polyphosphates (polyPs) are ubiquitous polymers in living organisms from bacteria to mammals. They serve a wide variety of biological functions, ranging from energy storage to stress response. In the last two decades, polyPs have been primarily viewed as linear polymers with varying chain lengths. However, recent biochemical data show that small metaphosphates, cyclic oligomers of [PO3](-), can bind to the enzymes ribonuclease A and NAD kinase, raising the question of whether metaphosphates can occur naturally as products of biological activity. Before the 1980s, metaphosphates had been reported in polyPs extracted from various organisms, but these results are considered artifactual due to the extraction and purification protocols. Here, we employ nondestructive 31P solid-state NMR spectroscopy to investigate the chemical structure of polyphosphates in whole cells as well as insoluble fractions of the bacterium Xanthobacter autotrophicus. Isotropic and anisotropic 31P chemical shifts of hydrated whole cells indicate the coexistence of linear and cyclic phosphates. Under our cell growth conditions and the concentrated conditions of the solid-state NMR samples, we found substantial amounts of cyclic phosphates in X. autotrophicus, suggesting that in fresh cells metaphosphate concentrations can be significant. The cellular metaphosphates are identified by comparison with the 31P chemical shift anisotropy of synthetic metaphosphates of known structures. In X. autotrophicus, the metaphosphates have a chemical shift anisotropy that is consistent with an average size of 3-8 phosphate units. These metaphosphates are enriched in insoluble and electron-dense granules. Exogenous hexametaphosphate added to X. autotrophicus cell extracts is metabolized to trimetaphosphates, supporting the presence and biological role of metaphosphates in cells. The definitive evidence for the presence of metaphosphates, reported here in whole bacterial cells for the first time, opens the path for future investigations of the biological function of metaphosphates in many organisms.

Newly diagnosed papillary craniopharyngioma with BRAF V600E mutation treated with single-agent selective BRAF inhibitor dabrafenib: a case report.

We report a case of a patient with newly diagnosed, locally extensive and cystic, suprasellar papillary craniopharyngioma successfully treated with single-agent Dabrafenib. The patient was symptomatic with gait imbalance with falls, lethargic episodes, fatigue and incontinence. Diagnostic imaging demonstrated a cystic suprasellar tumor extending into the third ventricle causing obstructive hydrocephalus. The tumor was partially debulked, and bilateral shunts were placed. NGS sequencing demonstrated BRAF V600E mutation, and the patient was prescribed dual agent Dabrafenib and Trametinib. However, due to insurance denial for Trametinib, he only received single-agent Dabrafenib (150mg BID). The treatment resulted in a major response (over two years), including reduction of the tumor cyst, and improvement of the clinical symptoms. No adverse events have been reported. The patient continues on Dabrafenib (150 mg BID) with a steady reduction in tumor size, and improvement in cognitive function leading to independent living.

Nucleoside Tetra- and Pentaphosphates Prepared Using a Tetraphosphorylation Reagent Are Potent Inhibitors of Ribonuclease A.

Adenosine and uridine 5'-tetra- and 5'-pentaphosphates were synthesized from an activated tetrametaphosphate ([PPN]2[P4O11], [PPN]2[1], PPN = bis(triphenylphosphine)iminium) and subsequently tested for inhibition of the enzymatic activity of ribonuclease A (RNase A). Reagent [PPN]2[1] reacts with unprotected uridine and adenosine in the presence of a base under anhydrous conditions to give nucleoside tetrametaphosphates. Ring opening of these intermediates with tetrabutylammonium hydroxide ([TBA][OH]) yields adenosine and uridine tetraphosphates (p4A, p4U) in 92% and 85% yields, respectively, from the starting nucleoside. Treatment of ([PPN]2[1]) with AMP or UMP yields nucleoside-monophosphate tetrametaphosphates (cp4pA, cp4pU) having limited aqueous stability. Ring opening of these ultraphosphates with [TBA][OH] yields p5A and p5U in 58% and 70% yield from AMP and UMP, respectively. We characterized inorganic and nucleoside-conjugated linear and cyclic oligophosphates as competitive inhibitors of RNase A. Increasing the chain length in both linear and cyclic inorganic oligophosphates resulted in improved binding affinity. Increasing the length of oligophosphates on the 5' position of adenosine beyond three had a deleterious effect on binding. Conversely, uridine nucleotides bearing 5' oligophosphates saw progressive increases in binding with chain length. We solved X-ray cocrystal structures of the highest affinity binders from several classes. The terminal phosphate of p5A binds in the P1 enzymic subsite and forces the oligophosphate to adopt a convoluted conformation, while the oligophosphate of p5U binds in several extended conformations, targeting multiple cationic regions of the active-site cleft.

Golf cart associated traumatic brain injury.

Object: Although contact sport-related head injuries are frequently reported, golf cart accidents may have significant consequences including severe traumatic brain injury (TBI) or head injury. As no standardized regulations exist, this mechanism may be underreported. Methods: A retrospective review of TBI or cranial trauma after a golf cart accident at a level I trauma center over 5 years were performed. Data regarding age, sex, race, initial Glasgow Coma Scale score, alcohol status, type and location of the injury, and outcomes were analyzed and reported in terms of Modified Rankin Scale (MRS). Results: A total of 23 patients with TBI or cranial trauma following golf cart accident were identified. The mean age was 36 years old with the most common injury being skull fracture followed by acute subdural hematoma. Most patients had good outcomes, MRS 0-3, at discharge, but like most forms of TBI, surgical interventions, intracranial pressure monitoring, post-traumatic seizures, hydrocephalus, and death did occur. Conclusions: Head injuries sustained by golf cart accidents are not insignificant and may be underreported. More awareness of these injuries and safety guidelines are needed.

Gamma Knife Stereotactic Radiosurgery in Combination with Bevacizumab for Recurrent Glioblastoma.

BACKGROUND: Prior retrospective and prospective studies suggest improved survival with the use of stereotactic radiosurgery (SRS) and bevacizumab in the treatment of limited-volume glioblastoma (GBM) recurrences. METHODS: We retrospectively reviewed our experience with gamma knife SRS in combination with bevacizumab for the treatment of focal GBM recurrence during 2009-2015. Outcomes include overall survival, progression free survival (PFS), and radiation-related adverse events. Kaplan-Meier methods and multivariable Cox proportional hazards models were performed for survival analysis. RESULTS: Within a median of 13.7 months after diagnosis, a total of 45 patients with GBM underwent gamma knife SRS and bevacizumab treatment. Median age was 57 years (range: 20-78 years) and 63.3% were women. The median Karnofsky Performance Score (KPS) at recurrence was 80 (range: 40-100). Sixty-four percent of patients had single radiosurgery target (range: 1-4) and median target volume and margin dose were 2.2 cm3 (range: 0.1-25.2 cm3) and 17.0 gray (Gy) (range: 13-24 Gy), respectively. Median PFS and overall survival were 9.3, 31.0 months following diagnosis, and 5.2, 13.3 months after SRS, respectively. Factors associated with poor outcomes were KPS ≤70, SRS dose <18 Gy, and use of <2 chemotherapy agents prior to SRS. No radiation-related adverse events occurred. CONCLUSIONS: SRS in combination with bevacizumab can be safely used to treat focal GBM recurrence. KPS, radiation dose, and multi-agent chemotherapy usage prior to SRS demonstrated significant impact on PFS. Bevacizumab may provide clinically relevant radioprotection.

Zirconium complexes supported by a ferrocene-based ligand as redox switches for hydroamination reactions.

The synthesis of (thiolfan*)Zr(NEt2)2 (thiolfan* = 1,1'-bis(2,4-di-tert-butyl-6-thiophenoxy)ferrocene) and its catalytic activity for intramolecular hydroamination are reported. In situ oxidation and reduction of the metal complex results in reactivity towards different substrates. The reduced form of (thiolfan*)Zr(NEt2)2 catalyzes hydroamination reactions of primary aminoalkenes, whereas the oxidized form catalyzes hydroamination reactions of secondary aminoalkenes.

Functionalization of Intact Trimetaphosphate: A Triphosphorylating Reagent for C, N, and O Nucleophiles.

Trimetaphosphate (TriMP, [P3O9]3-) reacts with PyAOP ([(H8C4N)3PON4C5H3][PF6]) to yield an activated TriMP, [P3O9P(NC4H8)3]- (1), incorporating a phosphonium moiety. Anion 1 is isolated as its bis(triphenylphosphine)iminium (PPN) salt in 70% yield and phosphorylates nucleophiles with elimination of phosphoramide OP(NC4H8)3. Treatment of 1 with amines HNR1R2 generates [P3O8NR1R2]2- (2a: R1 = R2 = Et; 2b: R1 = H, R2 = tBu) in greater than 70% yield as mixed PPN and alkyl ammonium salts. Treatment of 1 with primary alcohols in the presence of a tertiary amine base results in salts of intact TriMP alkyl esters [P3O9R]2- (3a: R = Me; 3b: R = Et) in greater than 60% isolated yield. Reaction of 1 with [PPN][H2PO4] provides orthophosphoryl TriMP (4, [P4O12H2]2-) in 40% yield as the PPN salt. Treatment of 1 with Wittig reagent H2CPPh3 (4 equiv) provides phosphorus ylide [P3O8CHPPh3]2- (5) in 61% yield as a mixed salt. Ylide 5 reacts with water to provide [P3O8Me]2- (6) and with aldehydes to give olefins [P3O8CHCHR]2- (7a: R = H; 7b: R = 4-C6H4Br), products in which one TriMP oxygen is replaced by a phosphonate P-C linkage. Treatment of intact TriMP derivatives 2a, 2b, 3a, and 7a with aqueous tetrabutylammonium hydroxide results in ring opening to linear triphosphate derivatives. X-ray crystal structures are provided for salts of 1, 2a, 3a, and 4.

Use of Anticoagulation Agents After Traumatic Intracranial Hemorrhage.

OBJECTIVE: Anticoagulant therapy (ACT) after traumatic intracranial hemorrhage may lead to progression of hemorrhage, but in the presence of thromboembolic events, the clinician must decide if the benefits outweigh the risks. Currently, no data exist to guide therapy in the acute setting. METHODS: We retrospectively identified all patients admitted to our institution with traumatic intracranial hemorrhage that received intravenous heparin, full-dose enoxaparin, or warfarin during their initial hospitalization over a 3-year period. We reviewed their demographics, hospital course, clinical indication and timing for initiation of ACT, and complications. RESULTS: A total of 112 patients were identified. The median age and Glasgow Coma Scale score of these patients was 50.5 years and 9.5, respectively. Twenty-two patients required neurosurgical procedures for their presenting injury, including intracranial pressure monitors and/or open surgeries. Fifty-four patients had deep vein thrombosis or pulmonary embolism prior to initiation, and the remaining 20 patients had preexisting conditions or other indications for initiating ACT. The median time from injury to starting ACT was 8 days. Immediate complications occurred in 6 patients; however, none of these patients required a neurosurgical intervention. Delayed complications included progression of acute to chronic subdural hematoma that required intervention in 2 patients. One patient died from delayed hemorrhage. CONCLUSIONS: For this patient population, the risk of immediate and delayed intracranial hemorrhages from initiating ACT therapy in intracranial injury must be weighed against the morbidity of delaying treatment. Although further studies are needed, our review provides the first rates of complications for this patient population.

Disseminated Phaeohyphomycosis with Brain Abscess and Biliary Invasion Due to Bipolaris spp. in an Immunocompetent Patient.

Bipolaris is a dematiaceous fungus seen in the skin, nasal sinuses, and occasionally in the central nervous system. We present an immunocompetent female with bilateral dural-based abscesses caused by a Bipolaris species. The patient had no involvement of the sinuses with the fungus but was later found to have a significant Bipolaris infection of her biliary tree.

Use of anti-platelet agents after traumatic intracranial hemorrhage.

OBJECTIVE: To evaluate the risk of hemorrhagic complications associated with starting anti-platelet therapy (APT) after acute traumatic intracranial hemorrhage (tICH) and to examine the frequency of thrombotic complications. PATIENTS AND METHODS: We retrospectively identified all patients admitted to our institution with tICH that received APT during their initial hospitalization over a three-year period. We reviewed their demographics, hospital course, clinical indication and timing for initiation of APT, and complications. RESULTS: A total of 222 patients were identified. The median age and Injury Severity Score (ISS) was 61 and 21, respectively. Fifty (23%) patients required neurosurgical procedures. APTs were initiated due to a history of APT use in 91 patients (41%) and blunt cerebrovascular injury in 86 patients (38.6%). The median time from injury to starting APT was 4 days. Immediate complications including new or worsening hemorrhage occurred in 1 (<1%) patient. Delayed hemorrhagic complications occurred in 6 (4.7%) patients. Thrombotic events occurred in 21 (9.4%) patients prior to starting APT. Thirteen (5.8%) of these were potentially preventable. CONCLUSION: The risk of immediate and delayed intracranial hemorrhages from initiating APT after tICH must be weighed against the morbidity of delaying indicated thrombotic prophylaxis. Our initial data indicates that hemorrhagic complications are infrequent, and thrombotic complications can have significant clinical consequences. Our retrospective review provides the first rates of complications for this patient population.

Structure-function analysis of delta trafficking, receptor binding and signaling in Drosophila.

The transmembrane proteins Delta and Notch act as ligand and receptor in a conserved signaling pathway required for a variety of cell fate specification events in many organisms. Binding of Delta to Notch results in a proteolytic cascade that releases the Notch intracellular domain, allowing it to participate in transcriptional activation in the nucleus. Recent research has implicated the endocytic and ubiquitylation machinery as essential components of Delta-Notch signaling. Our analysis of chimeric and missense Delta variants has delineated a number of structural requirements for Delta trafficking, receptor binding, and signaling. We find that while the Delta N-terminal domain is necessary and sufficient for binding to Notch, the integrity of the epidermal-growth-factor-like repeat (ELR) 2 is also required for Notch binding. Screening of 117 Delta mutant lines for proteins that exhibit aberrant subcellular trafficking has led to the identification of 18 Delta alleles (DlTD alleles) that encode "trafficking-defective" Delta proteins. We find, unexpectedly, that many DlTD alleles contain missense mutations in ELRs within the Delta extracellular domain. Finally, we find that two DlTD alleles contain lysine missense mutations within the Delta intracellular domain (DeltaICD) that may identify residues important for DeltaICD mono-ubiquitylation and subsequent Delta endocytosis and signaling.

Fuzzy simultaneous measurement of two polarization vector components.

The advent of quantum computers threatens the security of conventional encryption schemes (e.g., those based upon the excessive amount of computational time that might be required to guess your password). Quantum encryption is intended to restore the security by basing it instead upon the impossibility of the simultaneous measurement of two noncommuting operators. I derive a measurement associated with the angular momentum lowering operator, which describes a simultaneous (yet realizable) measurement of two noncommuting spin-vector components. Correlations between two such detectors are also discussed and compared with the conventional Stern-Gerlach results.

Surgery of brain metastases--is there still a place for it?

The role of surgery in the treatment of metastatic brain tumors has always been a source of controversy. It was only in the early 1990s that two randomized prospective trials demonstrated that surgery plus radiation therapy improved survival in patients with single metastatic brain tumors vs. radiation therapy alone. This paper reviews these articles as well as other evidence outlining management options for multiple brain metastases. An attempt has been made to better define the role of surgery in brain metastases. The prognostic factors for brain metastases after surgery are also reviewed and the data comparing stereotactic radiosurgery to surgery is examined. A short description of surgical planning, operative techniques and tools, followed by a discussion on complication avoidance before, during, and after surgery is included.

Biophysical measurement of brain tumor cohesion.

An advantage of using 3D multicellular spheres to study tumor biology is that they better approximate the interactions encountered by cells in vivo. Our previous studies have shown that the process of spheroid formation is governed by the same thermodynamic principles driving the formation of liquid droplets. This liquid-like behavior enables us to measure a key property influencing tumor behavior, namely, intercellular cohesion. We have developed a method, tissue surface tensiometry (TST), to measure the cohesivity, expressible as surface tension (sigma), of tissue aggregates under physiologic conditions. This study utilizes TST to measure the cohesivity of 3 widely used malignant astrocytoma cell lines of different in vitro invasive potentials. We compare invasiveness with aggregate cohesivity and with the expression of N-cadherin, a key mediator of cell-cell cohesion in neural tissues. We show that the cell lines exhibit liquid-like behavior since they form spheroids whose surface tension is both force- and volume-independent; that aggregates from each cell line have a distinct surface tension that correlates with their in vitro invasive capacity; that dexamethasone (Dex), a widely used therapeutic agent for the treatment of tumor-related cerebral edema, increases aggregate cohesivity and decreases invasiveness; that dexamethasone treatment decreases invasion in a dose-dependent manner but only when cells are in direct contact with one another; and that dex-mediated decreased invasiveness correlates with increased aggregate cohesivity as measured by TST but not with N-cadherin expression or function. Our results demonstrate that for these cell lines, cohesivity is an excellent predictor of in vitro invasiveness.

Phosphorus hyperfine structure in the electronic spectrum of the HPCl free radical.

The 444 nm 2 0 (1) bands of the A 2A'-X 2A" transition of the jet-cooled HP 35Cl and HP 37Cl radicals have been studied at high resolution using the pulsed electric discharge technique with a precursor mixture of PCl3 and H2. Spectra recorded with linewidths of approximately 360 MHz revealed resolved hyperfine structure in both isotopomers arising from the excited state Fermi contact interaction of the unpaired electron with the magnetic moment of the 31P nucleus, with aF'=0.0641(10) cm(-1) and 0.0636(31) cm(-1) for HP 35Cl and HP 37Cl, respectively. No contribution from the ground state, or excited state contributions from the hydrogen or chlorine nuclei were resolved, confirming ab initio predictions that HPCl is a p pi radical in the X state, and an s sigma radical with a substantial contribution from the phosphorus 3s atomic orbital in the A state. The free atom comparison method has been used to estimate that the singly occupied molecular orbital in the excited state has 14% phosphorus 3s character.