Moving nursing innovation to prime time through the use of creative partnerships.

Nurses are well-positioned to solve many problems in healthcare through engagement in innovation. Support from healthcare organizations to facilitate creative partnerships may accelerate nurses' ability to innovate and improve job satisfaction. The value of creative partnerships is rooted in the diversity of experiences and skillsets of each project team member. While nurses may be content experts and key stakeholders, they often lack experience with project management, information technology, product development, and other important skills. We describe the use of co-creation approaches in creative partnerships with diverse stakeholders to enhance the ability of nurse-led project teams to build valuable and sustainable products or services.

Pursuit of an Electron Deficient Titanium Nitride.

The nitride salt [(PN)2Ti≡N{µ2-K(OEt2)}]2 (1) (PN- = (N-(2-PiPr2-4-methylphenyl)-2,4,6-Me3C6H2) can be oxidized with two equiv of I2 or four equiv of ClCPh3 to produce the phosphinimide-halide complexes (NPN')(PN)Ti(X) (X- = I (2), Cl (3); NPN' = N-(2-NPiPr2-4-methylphenyl)-2,4,6-Me3C6H22-), respectively. In the case of 2, H2 was found to be one of the other products; whereas, HCPh3 and Gomberg's dimer were observed upon the formation of 3. Independent studies suggest that the oxidation of 1 could imply the formation of the transient nitridyl species [(PN)2Ti(≡N•)] (A), which can either oxidize the proximal phosphine atom to produce the Ti(III) intermediate [(NPN')(PN)Ti] (B) or, alternatively, engage in H atom abstraction to form the parent imido (PN)2Ti≡NH (4). The latter was independently prepared and was found to photochemically convert to the titanium-hydride, (NPN')(PN)Ti(H) (5). Isotopic labeling studies using (PN)2Ti≡ND (4-d1) as well as reactivity studies of 5 with a hydride abstractor demonstrate the presence of the hydride ligand in 5. An alternative route to putative A was observed via a photochemically promoted incomplete reduction of the azide ligand in (PN)2Ti(N3) (6) to 4. This process was accompanied by some formation of 5. Frozen matrix X-band EPR studies of 6, performed under photolytic conditions, were consistent with species B being formed under these reaction conditions, originating from a low barrier N-insertion into the phosphine group in the putative nitridyl species A. Computational studies were also undertaken to discover the mechanism and plausibility of the divergent pathways (via intermediates A and B) in the formation of 2 and 3, and to characterize the bonding and electronic structure of the elusive nitrogen-centered radical in A.

An Unusual Cobalt Azide Adduct That Produces a Nitrene Species for Carbon-Hydrogen Insertion Chemistry.

A family of Co(II) complexes supported by the bulky, dianionic bis(pyrrolyl)pyridine pincer ligand pyrr2py [pyrr2py(2-) = 3,5-(t)Bu2-bis(pyrrolyl)pyridine] are reported in this work. These compounds include 1-OEt2, 1·toluene, and 1-N3Ad (Ad = 1-adamantyl), the latter which is prepared via addition of N3Ad to 1-OEt2 [1 = (pyrr2py)Co]. While complexes 1-OEt2 and 1-N3Ad are four-coordinate systems having a Co(II) ion confined in a cis-divacant octahedral geometry, complex 1·toluene possesses a Co(II) ion in a T-shaped environment where the toluene is interstitial and intercalated between two (pyrr2py)Co molecules. Complex 1-N3Ad is notable in that the organic azide binds to the metal through γ-N in a κ(1) fashion. Photolysis of 1-N3Ad results in N2 extrusion and formation of C-H insertion product [(pyrrpypyrrNHAd)Co] (2). We propose complex 2 form via insertion of the nitrene (NAd) into one (t)Bu C-H bond, thus resulting in a pincer ligand having a pendant secondary amine. Complexes 1-OEt2, 1·toluene, and 1-N3Ad and C-H insertion product 2 have been structurally characterized, and in the case of 1-OEt2, we also present electrochemical data.

Geriatric assessment factors are associated with mortality after hospitalization in older adults with cancer.

PURPOSE: Survival in older adults with cancer varies given differences in functional status, comorbidities, and nutrition. Prediction of factors associated with mortality, especially in hospitalized patients, allows physicians to better inform their patients about prognosis during treatment decisions. Our objective was to analyze factors associated with survival in older adults with cancer following hospitalization. METHODS: Through a retrospective cohort study, we reviewed 803 patients who were admitted to Barnes-Jewish Hospital's Oncology Acute Care of Elders (OACE) unit from 2000 to 2008. Data collected included geriatric assessments from OACE screening questionnaires as well as demographic and medical history data from chart review. The primary end point was time from index admission to death. The Cox proportional hazard modeling was performed. RESULTS: The median age was 72.5 years old. Geriatric syndromes and functional impairment were common. Half of the patients (50.4 %) were dependent in one or more activities of daily living (ADLs), and 74 % were dependent in at least one instrumental activity of daily living (IADLs). On multivariate analysis, the following factors were significantly associated with worse overall survival: male gender; a total score <20 on Lawton's IADL assessment; reason for admission being cardiac, pulmonary, neurologic, inadequate pain control, or failure to thrive; cancer type being thoracic, hepatobiliary, or genitourinary; readmission within 30 days; receiving cancer treatment with palliative rather than curative intent; cognitive impairment; and discharge with hospice services. CONCLUSIONS: In older adults with cancer, certain geriatric parameters are associated with shorter survival after hospitalization. Assessment of functional status, necessity for readmission, and cognitive impairment may provide prognostic information so that oncologists and their patients make more informed, individualized decisions.

Mononuclear and Terminally Bound Titanium Nitrides.

The Ti(III) azido complex (PN)2Ti(N3) (PN(-) = (N-(2-(diisopropylphosphino)-4-methylphenyl)-2,4,6-trimethylanilide), can be reduced with KC8 to afford the nitride salt [µ2-K(OEt2)]2[(PN)2Ti≡N]2 in excellent yield. While treatment of the dimer with 18-crown-6 yields a mononuclear nitride, complete encapsulation of the alkali metal with cryptand provides the terminally bound nitride as a discrete salt [K(2,2,2-Kryptofix)][(PN)2Ti≡N]. All complexes reported here have been structurally confirmed and also spectroscopically, and the Ti-Nnitride bonding has been probed theoretically via DFT-based methods.

The Dementia Friendly Hospital Initiative education program for acute care nurses and staff.

Individuals with Alzheimer's disease and other dementias have 3.2 million hospital stays annually, which is significantly more than older individuals without dementia. Hospitalized patients with dementia are at greater risk of delirium, falls, overwhelming functional decline that may extend the hospital stay, and prolonged or complicated rehabilitation. These risks highlight the need for staff education on the special care needs of this vulnerable population. This article describes a one-day education program, the Dementia Friendly Hospital Initiative, designed to teach staff how to provide the specialized care required by patients with dementia. Participants (N = 355) from five different hospitals, including 221 nurses, completed a pretest-posttest evaluation for the program. Changes in participants attitudes and practices, confidence, and knowledge were evaluated. Scores indicated significant improvement on the posttest. The evaluation provides further evidence for recommending dissemination of the Dementia Friendly Hospital Initiative.

Co-Design of a website for women with pelvic organ prolapse: A study protocol.

Background: Despite high reported prevalence of pelvic organ prolapse (POP), women report difficulties accessing evidence-based and reliable information about the condition. Many rely on social media and other popular and highly visible internet platforms which have been found to contain poor quality information that is difficult for the average patient to understand. The aim of the study is to co-design an information website for premenopausal women with POP. The website design will be based on the Website Developmental Model for the Healthcare Consumer (WDMHC) framework. Methods: A four phase process will be utilised as per the WDMHC framework: 1) User, task and environmental analysis; 2) Functional and representational analysis; 3) Cognitive walkthrough, keystroke level model, heuristic testing; 4) Content based testing, expert testing and user-based testing.Ethics approval has been obtained (LS-23-19-Carroll-Ful). Two groups of stakeholders will be recruited (i) patient group (ii) healthcare professional (HCP) group. Patient participants will be recruited from an online pelvic floor dysfunction (PFD) support group (n=950 members). A website designer and HCP stakeholders involved in the multidisciplinary team caring for women with POP will be invited to participate.Both groups will participate in separate co-design online workshops. Focus group workshops will be video-recorded, transcribed and imported into NVivo. Themes and subthemes will be developed.The website will be designed and disseminated to all participants for feedback. Cognitive walkthrough and heuristic testing will be undertaken. Following this, necessary modifications will be made to the website. Participants will then complete a modified System Usability Scale (SUS) and the eHealth Impact Questionnaire, while five HCPs will complete the DISCERN instrument. Conclusion: This study will inform the design and testing of an information website for women with POP. The website design and content will be informed by patient and HCP stakeholder voices and the health literacy literature.

Synthetic models for the active site of the [FeFe]-hydrogenase: catalytic proton reduction and the structure of the doubly protonated intermediate.

This report compares biomimetic hydrogen evolution reaction catalysts with and without the amine cofactor (adt(NH)): Fe(2)(adt(NH))(CO)(2)(dppv)(2) (1(NH)) and Fe(2)(pdt)(CO)(2)(dppv)(2) (2) [(adt(NH))(2-) = HN(CH(2)S)(2)(2-), pdt(2-) = 1,3-(CH(2))(3)S(2)(2-), and dppv = cis-C(2)H(2)(PPh(2))(2)]. These compounds are spectroscopically, structurally, and stereodynamically very similar but exhibit very different catalytic properties. Protonation of 1(NH) and 2 gives three isomeric hydrides each, beginning with the kinetically favored terminal hydride, which converts sequentially to sym and unsym isomers of the bridging hydrides. In the case of 1(NH), the corresponding ammonium hydrides are also observed. In the case of the terminal amine hydride [t-H1(NH)]BF(4), the ammonium/amine hydride equilibrium is sensitive to counteranions and solvent. The species [t-H1(NH(2))](BF(4))(2) represents the first example of a crystallographically characterized terminal hydride produced by protonation. The NH---HFe distance of 1.88(7) Å indicates dihydrogen-bonding. The bridging hydrides [µ-H1(NH)](+) and [µ-H2](+) reduce near -1.8 V, about 150 mV more negative than the reductions of the terminal hydride [t-H1(NH)](+) and [t-H2](+) at -1.65 V. Reductions of the amine hydrides [t-H1(NH)](+) and [t-H1(NH(2))](2+) are irreversible. For the pdt analogue, the [t-H2](+/0) couple is unaffected by weak acids (pK(a)(MeCN) = 15.3) but exhibits catalysis with HBF(4)·Et(2)O, albeit with a turnover frequency (TOF) around 4 s(-1) and an overpotential greater than 1 V. The voltammetry of [t-H1(NH)](+) is strongly affected by relatively weak acids and proceeds at 5000 s(-1) with an overpotential of 0.7 V. The ammonium hydride [t-H1(NH(2))](2+) is a faster catalyst, with an estimated TOF of 58 000 s(-1) and an overpotential of 0.5 V.

Development and implementation of an electronic Clinical Dementia Rating and Financial Capacity Instrument-Short Form.

Introduction: To address the need for remote assessments of cognitive decline and dementia, we developed and administered electronic versions of the Clinical Dementia Rating (CDR®) and the Financial Capacity Instrument-Short Form (FCI-SF) (F-CAP®), called the eCDR and eFCI, respectively. Methods: The CDR and FCI-SF were adapted for remote, unsupervised, online use based on item response analysis of the standard instruments. Participants completed the eCDR and eFCI first in clinic, and then at home within 2 weeks. Results: Of the 243 enrolled participants, 179 (73%) cognitively unimpaired (CU), 50 (21%) with mild cognitive impairment (MCI) or dementia, and 14 (6%) with an unknown diagnosis, 84% and 85% of them successfully completed the eCDR and eFCI, respectively, at home. Discussion: These results show initial feasibility in developing and administering online instruments to remotely assess and monitor cognitive decline along the CU to MCI/very mild dementia continuum. Validation is an important next step.

Active-site models for the nickel-iron hydrogenases: effects of ligands on reactivity and catalytic properties.

Described are new derivatives of the type [HNiFe(SR)(2)(diphosphine)(CO)(3)](+), which feature a Ni(diphosphine) group linked to a Fe(CO)(3) group by two bridging thiolate ligands. Previous work had described [HNiFe(pdt)(dppe)(CO)(3)](+) ([1H](+)) and its activity as a catalyst for the reduction of protons (J. Am. Chem. Soc. 2010, 132, 14877). Work described in this paper focuses on the effects on properties of NiFe model complexes of the diphosphine attached to nickel as well as the dithiolate bridge, 1,3-propanedithiolate (pdt) vs 1,2-ethanedithiolate (edt). A new synthetic route to these Ni-Fe dithiolates is described, involving reaction of Ni(SR)(2)(diphosphine) with FeI(2)(CO)(4) followed by in situ reduction with cobaltocene. Evidence is presented that this route proceeds via a metastable µ-iodo derivative. Attempted isolation of such species led to the crystallization of NiFe(Me(2)pdt)(dppe)I(2), which features tetrahedral Fe(II) and square planar Ni(II) centers (H(2)Me(2)pdt = 2,2-dimethylpropanedithiol). The new tricarbonyls prepared in this work are NiFe(pdt)(dcpe)(CO)(3) (2, dcpe = 1,2-bis(dicyclohexylphosphino)ethane), NiFe(edt)(dppe)(CO)(3) (3), and NiFe(edt)(dcpe)(CO)(3) (4). Attempted preparation of a phenylthiolate-bridged complex via the FeI(2)(CO)(4) + Ni(SPh)(2)(dppe) route gave the tetrametallic species [(CO)(2)Fe(SPh)(2)Ni(CO)](2)(µ-dppe)(2). Crystallographic analysis of the edt-dcpe compund [2H]BF(4) and the edt-dppe compound [3H]BF(4) verified their close resemblance. Each features pseudo-octahedral Fe and square pyramidal Ni centers. Starting from [3H]BF(4) we prepared the PPh(3) derivative [HNiFe(edt)(dppe)(PPh(3))(CO)(2)]BF(4) ([5H]BF(4)), which was obtained as a ∼2:1 mixture of unsymmetrical and symmetrical isomers. Acid-base measurements indicate that changing from Ni(dppe) (dppe = Ph(2)PCH(2)CH(2)PPh(2)) to Ni(dcpe) decreases the acidity of the cationic hydride complexes by 2.5 pK(a)(PhCN) units, from ∼11 to ∼13.5 (previous work showed that substitution at Fe leads to more dramatic effects). The redox potentials are more strongly affected by the change from dppe to dcpe, for example the [2](0/+) couple occurs at E(1/2) = -820 for [2](0/+) vs -574 mV (vs Fc(+/0)) for [1](0/+). Changes in the dithiolate do not affect the acidity or the reduction potentials of the hydrides. The acid-independent rate of reduction of CH(2)ClCO(2)H by [2H](+) is about 50 s(-1) (25 °C), twice that of [1H](+). The edt-dppe complex [2H](+) proved to be the most active catalyst, with an acid-independent rate of 300 s(-1).

A New Route to Azadithiolato Complexes.

The reaction of [(MeC(5)H(4))(2)Ti(SH)(2)] with cyclic imines with the formula (CH(2)NR)(3) gives 2-aza-1,3-dithiolato chelate complexes [(MeC(5)H(4))(2)Ti{(SCH(2))(2)NR}] (1, R = Ph; 2, R = Me; 3, R = CH(2)Ph). These compounds demonstrate that azadithiolate ligands can exist on mononuclear metal centers. The complexes were characterized by (1)H NMR spectroscopy, ESI-mass spectrometry, and X-ray crystallography. Variable-temperature (1)H NMR studies reveal that the dithiolate ligands undergo ring inversion like other dithiatitanacyclohexanes. Treatment of [(MeC(5)H(4))(2)Ti{(SCH(2))(2)NPh}] (1) with [Fe(benzylideneacetone)(CO)(3)] afforded [Fe(2){(SCH(2))(2)NPh}(CO)(6)] in good yield.

Polypharmacy in hospitalized older adult cancer patients: experience from a prospective, observational study of an oncology-acute care for elders unit.

BACKGROUND: A novel Oncology-Acute Care for Elders (OACE) unit that uses an interdisciplinary team to enhance recognition and management of geriatric syndromes in hospitalized older adult cancer patients has been established at Barnes-Jewish Hospital (St. Louis, Missouri). The OACE team includes a clinical pharmacist whose primary role is to improve the appropriateness of prescribing. OBJECTIVE: Using polypharmacy as the prototypical geriatric syndrome addressed by the OACE team, the objective of this study was to document the processes of communication of an interdisciplinary team and the impact on polypharmacy when the treating physician did not participate in the daily interdisciplinary team rounds. METHODS: This was a prospective, observational study of older cancer patients admitted to the OACE unit. We tracked processes and outcomes of interdisciplinary communication regarding medications by prospectively recording OACE team recommendations and evaluating the frequency of implementation of these recommendations through a chart review. Treating physicians, who did not attend team rounds, received these recommendations on a communication form placed in the patient's chart. RESULTS: Forty-seven patients were included in the study. The mean (SD) age was 73.5 (7.5) years. Twenty-one percent (10/47) of patients were prescribed > or =1 Beers medication as part of their home-care regimen before admission to the OACE unit. The OACE team made 51 medication recommendations, and 42 of those recommendations (82%) were implemented. Twenty-five patients (53%) had an alteration in their medication regimen; 13 (28%) had a potentially inappropriate medication discontinued. A medication error was corrected in ~1 of every 8 patients (6/47 [13%]). CONCLUSIONS: We found that polypharmacy was common in older cancer patients and increased during hospitali-zation. We also found that most OACE team recommendations communicated to physicians were implemented even though the primary physicians were not members of the OACE team. Future randomized trials are needed to assess the impact of the OACE team model of care on adverse events, survival, and cost in hospitalized older adult cancer patients.

Target pattern recognition by complement proteins of the classical and alternative pathways.

The complement system is a major component of the innate defence of animals against invading microorganisms, and is also essential for the recognition and clearance of damaged or structurally-altered host cells or macromolecules. The system is activated by three different pathways, each of which responds, using different recognition molecules, to a very wide range of activators. The recognition protein of the complement classical pathway, C1q is described in detail here, with comparisons to the alternative pathway.

Molecular titanium nitrides: nucleophiles unleashed.

In this contribution we present reactivity studies of a rare example of a titanium salt, in the form of [µ2-K(OEt2)]2[(PN)2Ti[triple bond, length as m-dash]N]2 (1) (PN- = N-(2-(diisopropylphosphino)-4-methylphenyl)-2,4,6-trimethylanilide) to produce a series of imide moieties including rare examples such as methylimido, borylimido, phosphonylimido, and a parent imido. For the latter, using various weak acids allowed us to narrow the pK a range of the NH group in (PN)2Ti[triple bond, length as m-dash]NH to be between 26-36. Complex 1 could be produced by a reductively promoted elimination of N2 from the azide precursor (PN)2TiN3, whereas reductive splitting of N2 could not be achieved using the complex (PN)2Ti[double bond, length as m-dash]N[double bond, length as m-dash]N[double bond, length as m-dash]Ti(PN)2 (2) and a strong reductant. Complete N-atom transfer reactions could also be observed when 1 was treated with ClC(O)tBu and OCCPh2 to form NCtBu and KNCCPh2, respectively, along with the terminal oxo complex (PN)2Ti[triple bond, length as m-dash]O, which was also characterized. A combination of solid state 15N NMR (MAS) and theoretical studies allowed us to understand the shielding effect of the counter cation in dimer 1, the monomer [K(18-crown-6)][(PN)2Ti[triple bond, length as m-dash]N], and the discrete salt [K(2,2,2-Kryptofix)][(PN)2Ti[triple bond, length as m-dash]N] as well as the origin of the highly downfield 15N NMR resonance when shifting from dimer to monomer to a terminal nitride (discrete salt). The upfield shift of 15Nnitride resonance in the 15N NMR spectrum was found to be linked to the K+ induced electronic structural change of the titanium-nitride functionality by using a combination of MO analysis and quantum chemical analysis of the corresponding shielding tensors.

Complement factor H interferes with Mycobacterium bovis BCG entry into macrophages and modulates the pro-inflammatory cytokine response.

Mycobacterium tuberculosis is an accomplished intracellular pathogen, particularly within the macrophage and this is of the utmost importance in the host-pathogen stand-off observed in the granuloma during latent tuberculosis. Contact with innate immune molecules is one of the primary interactions that can occur with the pathogen M. tuberculosis once inhaled. Complement proteins may play a role in facilitating M. tuberculosis interactions with macrophages. Here, we demonstrate that factor H, a complement regulatory protein that down-regulates complement alternative pathway activation, binds directly to the model organism M. bovis BCG. Binding of factor H reaches saturation at 5-10µg of factor H/ml, well below the plasma level. C4 binding protein (C4BP) competed with factor H for binding to mycobacteria. Factor H was also found to inhibit uptake of M. bovis BCG by THP-1 macrophage cells in a dose-dependent manner. Real-time qPCR analysis showed stark differential responses of pro- and anti-inflammatory cytokines during the early stages of phagocytosis, as evident from elevated levels of TNF-α, IL-1ß and IL-6, and a concomitant decrease in IL-10, TGF-ß and IL-12 levels, when THP-1:BCG interaction took place in the presence of factor H. Our results suggest that factor H can interfere with mycobacterial entry into macrophages and modulate inflammatory cytokine responses, particularly during the initial stages of infection, thus affecting the extracellular survival of the pathogen. Our results offer novel insights into complement activation-independent functions of factor H during the host-pathogen interaction in tuberculosis.

Geriatric assessment as predictors of hospital readmission in older adults with cancer.

BACKGROUND: Hospital readmission is a common, costly problem. Little is known regarding risk factors for readmission in older adults with cancer. This study aims to identify factors associated with 30-day readmission in a cohort of older medical oncology patients. SETTING/PARTICIPANTS: Adults age 65 and over hospitalized to an Oncology Acute Care for Elders Unit at Barnes-Jewish Hospital. MEASUREMENTS: Standard geriatric screening tests were administered in routine clinical care. Clinical data and 30-day readmission status were obtained through medical record review. RESULTS: 677 patients met the inclusion criteria. 77% were white and 53% were male. Thoracic (32%), hematologic (20%), and gastrointestinal (18%) malignancies were most common. The 30-day unplanned readmission rate was 35.2%. Multivariable analyses identified complete dependence in feeding (odds ratio [OR], 3.70; 95% confidence interval [CI], 1.29-10.65), and some dependence (1.58, 1.04-2.41) and complete dependence (2.64, 1.70-4.12) in housekeeping, prior to admission, as associated with higher odds of readmission. Age<75 (1.49, 1.04-2.14), African-American race (1.59, 1.06-2.39), potentially inappropriate medications (1.36, 0.94-1.99), and higher-risk reasons for index admission (1.93, 1.34-2.78) also increased odds of readmission. These factors were organized into a prognostic index. CONCLUSION: Hospital readmission was common and higher than previously reported rates in general medical populations. We identified several previously unrecognized factors associated with increased risk for readmission, including some geriatric assessment parameters, and developed a practical tool that can be used by clinicians to assess risk of 30-day readmission.

Engineering Cellular Resistance to HIV-1 Infection In Vivo Using a Dual Therapeutic Lentiviral Vector.

We described earlier a dual-combination anti-HIV type 1 (HIV-1) lentiviral vector (LVsh5/C46) that downregulates CCR5 expression of transduced cells via RNAi and inhibits HIV-1 fusion via cell surface expression of cell membrane-anchored C46 antiviral peptide. This combinatorial approach has two points of inhibition for R5-tropic HIV-1 and is also active against X4-tropic HIV-1. Here, we utilize the humanized bone marrow, liver, thymus (BLT) mouse model to characterize the in vivo efficacy of LVsh5/C46 (Cal-1) vector to engineer cellular resistance to HIV-1 pathogenesis. Human CD34+ hematopoietic stem/progenitor cells (HSPC) either nonmodified or transduced with LVsh5/C46 vector were transplanted to generate control and treatment groups, respectively. Control and experimental groups displayed similar engraftment and multilineage hematopoietic differentiation that included robust CD4+ T-cell development. Splenocytes isolated from the treatment group were resistant to both R5- and X4-tropic HIV-1 during ex vivo challenge experiments. Treatment group animals challenged with R5-tropic HIV-1 displayed significant protection of CD4+ T-cells and reduced viral load within peripheral blood and lymphoid tissues up to 14 weeks postinfection. Gene-marking and transgene expression were confirmed stable at 26 weeks post-transplantation. These data strongly support the use of LVsh5/C46 lentiviral vector in gene and cell therapeutic applications for inhibition of HIV-1 infection.

Ferrous Carbonyl Dithiolates as Precursors to FeFe, FeCo, and FeMn Carbonyl Dithiolates.

Reported are complexes of the formula Fe(dithiolate)(CO)2(diphos) and their use to prepare homo- and heterobimetallic dithiolato derivatives. The starting iron dithiolates were prepared by a one-pot reaction of FeCl2 and CO with chelating diphosphines and dithiolates, where dithiolate = S2(CH2)22- (edt2-), S2(CH2)32- (pdt2-), S2(CH2)2(C(CH3)2)2- (Me2pdt2-) and diphos = cis-C2H2(PPh2)2 (dppv), C2H4(PPh2)2 (dppe), C6H4(PPh2)2 (dppbz), C2H4[P(C6H11)2]2 (dcpe). The incorporation of 57Fe into such building block complexes commenced with the conversion of 57Fe into 57Fe2I4( i PrOH)4, which then was treated with K2pdt, CO, and dppe to give 57Fe(pdt)(CO)2(dppe). NMR and IR analyses show that these complexes exist as mixtures of all-cis and trans-CO isomers, edt2- favoring the former and pdt2- the latter. Treatment of Fe(dithiolate)(CO)2(diphos) with the Fe(0) reagent (benzylideneacetone)Fe(CO)3 gave Fe2(dithiolate)(CO)4(diphos), thereby defining a route from simple ferrous salts to models for hydrogenase active sites. Extending the building block route to heterobimetallic complexes, treatment of Fe(pdt)(CO)2(dppe) with [(acenaphthene)Mn(CO)3]+ gave [(CO)3Mn(pdt)Fe(CO)2(dppe)]+ ([3d(CO)]+). Reduction of [3d(CO)]+ with BH4- gave the Cs -symmetric µ-hydride (CO)3Mn(pdt)(H)Fe(CO)(dppe) (H3d). Complex H3d is reversibly protonated by strong acids, the proposed site of protonation being sulfur. Treatment of Fe(dithiolate)(CO)2(diphos) with CpCoI2(CO) followed by reduction by Cp2Co affords CpCo(dithiolate)Fe(CO)(diphos) (4), which can also be prepared from Fe(dithiolate)(CO)2(diphos) and CpCo(CO)2. Like the electronically related (CO)3Fe(pdt)Fe(CO)(diphos), these complexes undergo protonation to afford the µ-hydrido complexes [CpCo(dithiolate)HFe(CO)(diphos)]+. Low-temperature NMR studies indicate that Co is the kinetic site of protonation.

Engineering HIV-1-resistant T-cells from short-hairpin RNA-expressing hematopoietic stem/progenitor cells in humanized BLT mice.

Down-regulation of the HIV-1 coreceptor CCR5 holds significant potential for long-term protection against HIV-1 in patients. Using the humanized bone marrow/liver/thymus (hu-BLT) mouse model which allows investigation of human hematopoietic stem/progenitor cell (HSPC) transplant and immune system reconstitution as well as HIV-1 infection, we previously demonstrated stable inhibition of CCR5 expression in systemic lymphoid tissues via transplantation of HSPCs genetically modified by lentiviral vector transduction to express short hairpin RNA (shRNA). However, CCR5 down-regulation will not be effective against existing CXCR4-tropic HIV-1 and emergence of resistant viral strains. As such, combination approaches targeting additional steps in the virus lifecycle are required. We screened a panel of previously published shRNAs targeting highly conserved regions and identified a potent shRNA targeting the R-region of the HIV-1 long terminal repeat (LTR). Here, we report that human CD4(+) T-cells derived from transplanted HSPC engineered to co-express shRNAs targeting CCR5 and HIV-1 LTR are resistant to CCR5- and CXCR4- tropic HIV-1-mediated depletion in vivo. Transduction with the combination vector suppressed CXCR4- and CCR5- tropic viral replication in cell lines and peripheral blood mononuclear cells in vitro. No obvious cytotoxicity or interferon response was observed. Transplantation of combination vector-transduced HSPC into hu-BLT mice resulted in efficient engraftment and subsequent stable gene marking and CCR5 down-regulation in human CD4(+) T-cells within peripheral blood and systemic lymphoid tissues, including gut-associated lymphoid tissue, a major site of robust viral replication, for over twelve weeks. CXCR4- and CCR5- tropic HIV-1 infection was effectively inhibited in hu-BLT mouse spleen-derived human CD4(+) T-cells ex vivo. Furthermore, levels of gene-marked CD4(+) T-cells in peripheral blood increased despite systemic infection with either CXCR4- or CCR5- tropic HIV-1 in vivo. These results demonstrate that transplantation of HSPCs engineered with our combination shRNA vector may be a potential therapy against HIV disease.