ABSTRACT
OBJECTIVE: The aim of this study was to conduct an in-depth survey of the psychiatric care provided for medically ill older adults in general hospitals in New Zealand (NZ). METHOD: As part of a larger survey of Consultation-Liaison Psychiatry (CLP) services for all ages in NZ (CLPSNZ-2), a 44-question survey was emailed to clinicians who were involved in providing psychiatric care for medically ill older adults at each of the 16 general hospitals with designated CLP services. RESULTS: Responses were obtained from 22 services at 16 hospitals - 14 CLP services and eight Psychiatry of Old Age (POA) in-reach services. These services were found to be under-resourced, operate with highly variable service models, and predominantly provide inpatient consultations. Services could be conceptualised as six prototypes with variations of POA in-reach to hospitals, scope of CLP cover and collaboration between services. CONCLUSION: The heterogeneity in the psychiatric care for medically ill older adults in NZ means that there is an urgent need to develop more consistent CLP service models that better serve the specialist needs of older adults, and establish the policies, resources and standards needed to support them.
Subject(s)
Mental Health Services , Psychiatry , Humans , Aged , Hospitals, General , New Zealand , Surveys and Questionnaires , Referral and ConsultationABSTRACT
Ultraviolet and infrared-ultraviolet (IR-UV) double-resonance photofragment spectroscopy has been carried out in a tandem mass spectrometer to determine the three-dimensional structure of cryogenically cooled protonated C-terminally methyl esterified leucine enkephalin [YGGFL-OMe+H](+). By comparing the experimental IR spectrum of the dominant conformer with the predictions of DFT M05-2X/6-31+G(d) calculations, a backbone structure was assigned that is analogous to that previously assigned by our group for the unmodified peptide [ Burke, N.L.; et al. Int. J. Mass Spectrom. 2015 , 378 , 196 ], despite the loss of a C-terminal OH binding site that was thought to play an important role in its stabilization. Both structures are characterized by a type II' ß-turn around Gly(3)-Phe(4) and a γ-turn around Gly(2), providing spectroscopic evidence for the formation of a ß-hairpin hydrogen bonding pattern. Rather than disrupting the peptide backbone structure, the protonated N-terminus serves to stabilize the ß-hairpin by positioning itself in a pocket above the turn where it can form H-bonds to the Gly(3) and C-terminus CâO groups. This ß-hairpin type structure has been previously proposed as the biologically active conformation of leucine enkephalin and its methyl ester in the nonpolar cell membrane environment [ Naito, A.; Nishimura, K. Curr. Top. Med. Chem. 2004 , 4 , 135 - 143 ].
Subject(s)
Enkephalin, Leucine/chemistry , Oligopeptides/chemistry , Drug Stability , Gases/chemistry , Models, Molecular , Protein Folding , Protein Structure, Secondary , Spectrophotometry, Infrared , Spectrophotometry, UltravioletABSTRACT
We employ cold ion spectroscopy (UV action and IR-UV double resonance) in the gas phase to unravel the qualitative structural elements of G-type alkali metal cationized (X = Li(+), Na(+), K(+)) tetralignol complexes connected by ß-O-4 linkages. The conformation-specific spectroscopy reveals a variety of conformers, each containing distinct infrared spectra in the OH stretching region, building on recent studies of the neutral and alkali metal cationized ß-O-4 dimers. The alkali metal ion is discovered to bind in penta-coordinate pockets to ether and OH groups involving at least two of the three ß-O-4 linkages. Different binding sites are distinguished from one another by the number of M(+)···OH···O interactions present in the binding pocket, leading to characteristic IR transitions appearing below 3550 cm(-1). This interaction is mitigated in the major conformer of the K(+) adduct, demonstrating a clear impact of the size of the charge center on the three-dimensional structure of the tetramer.
ABSTRACT
Ultraviolet photofragmentation spectroscopy and infrared spectroscopy were performed on two prototypical guaiacyl (G)-type dilignols containing ß-O-4 and ß-ß linkages, complexed with either lithium or sodium cations. The complexes were generated by nanoelectrospray ionization, introduced into a multistage mass spectrometer, and subsequently cooled in a 22-pole cold ion trap to T ≈ 10 K. A combination of UV photofragment spectroscopy and IR-UV double resonance spectroscopy was used to characterize the preferred mode of binding of the alkali metal cations and the structural changes so induced. Based on a combination of spectral evidence provided by the UV and IR spectra, the Li(+) and Na(+) cations are deduced to preferably bind to both dilignols via their linkages, which constitute unique, oxygen-rich binding pockets for the cations. The UV spectra reflect this binding motif in their extensive Franck-Condon activity involving low-frequency puckering motions of the linkages in response to electronic excitation. In the pinoresinolâ¢Li(+)/Na(+) complexes involving the ß-ß linkage, the spectra also showed an inherent spectral broadening. The photofragment mass spectra are unique for each dilignolâ¢Li(+)/Na(+) complex, many of which are also complementary to those produced by collision-induced dissociation (CID), indicating the presence of unique excited state processes that direct the fragmentation. These results suggest the potential for site-selective fragmentation and for uncovering fragmentation pathways only accessed by resonant UV excitation of cold lignin ions.