New Collaborative Research on Suicide Prevention, Practice, and Policy With American Indian and Alaska Native Communities Holds Promise for All Peoples

Youth suicide is increasing in the United States, with deaths among younger people of color driving this upward trend. For more than four decades, American Indian and Alaska Native (AIAN) communities have suffered disproportionate rates of youth suicide and years of productive life lost compared to other U.S. Races. The National Institute of Mental Health (NIMH) recently funded three regional Collaborative Hubs to carry out suicide prevention research, practice, and policy development with AIAN communities in Alaska and rural and urban areas of the Southwestern United States. The Hub partnerships are supporting a diverse array of tribally-driven studies, approaches, and policies with immediate value for increasing empirically driven public health strategies to address youth suicide. We discuss unique features of the cross-Hub work, including: (a) long-standing Community-Based Participatory Research processes that led to the Hubs' innovative designs and novel approaches to suicide prevention and evaluation, (b) comprehensive ecological theoretical approaches that contextualize individual risk and protective factors in multilevel social contexts; (c) unique task-shifting and systems of care approaches to increase reach and impact on youth suicide in low-resource settings; and (d) prioritization of strengths-based approaches. The work of the Collaborative Hubs for AIAN youth suicide prevention is generating specific and substantive implications for practice, policy, and research presented in this article at a time when youth suicide prevention is a dire national priority. Approaches also have relevance for historically marginalized communities worldwide.

Suicide Ideation and Depression Quality of Life Ratings in a Reservation-Based Community of Native American Youths and Young Adults

Suicide among adolescents is a significant public health concern in the U.S., especially within American Indian and Alaska Native (AIAN) communities. Lack of quality of life (QoL) estimates for both suicide ideation and depression specific to the AIAN population hinders the ability to compare interventions in cost-effectiveness analysis. We surveyed 200 AI youth and young adults from the Fort Apache Indian Reservation to estimate utility weights for experiencing suicide ideation and depression. Our results indicate that, on a scale of 0-100, with higher scores indicating better health, the general community rates both suicide ideation and depression at 15.8 and 25.1, respectively. These weights are statistically significantly different and lower than for other cultures. Culturally specific QoL values will allow the comparison and identification of the most effective and feasible interventions to reduce the suicide burden among tribal communities.

Sustaining suicide prevention programs in American Indian and Alaska Native communities and Tribal health centers

Background:

Research on sustaining community-based interventions is limited. This is particularly true for suicide prevention programs and in American Indian and Alaska Native (AIAN) settings. Aiming to inform research in this area, this paper sought to identify factors and strategies that are key to sustain suicide prevention efforts in AIAN communities.

Methods:

We used a modified Nominal Group Technique with a purposeful sample of N = 35 suicide prevention research experts, program implementors and AIAN community leaders to develop a list of prioritized factors and sustainability strategies. We then compared this list with the Public Health Program Capacity for Sustainability Framework (PHPCSF) to examine the extent the factors identified aligned with the existing literature.

Results:

Major factors identified included cultural fit of intervention approaches, buy in from local communities, importance of leadership and policy making, and demonstrated program success. Strategies to promote these factors included partnership building, continuous growth of leadership, policy development, and ongoing strategic planning and advocacy. All domains of the PHPCF were representative, but additional factors and strategies were identified that emerged as important in AIAN settings.

Conclusions:

Sustaining effective and culturally informed suicide prevention efforts is of paramount importance to prevent suicide and save lives. Future research will focus on generating empirical evidence of these strategies and their effectiveness at promoting program sustainability in AIAN communities.

Magnetic correlations in La2-xSrxCoO4 studied by neutron scattering: possible evidence for stripe phases

Spin correlations in La2-xSrxCoO4 (0.3 < or = x < or = 0.6) have been studied by neutron scattering. The commensurate antiferromagnetic order of La2CoO4 persists in a very short range up to a Sr content of x = 0.3, whereas small amounts of Sr suppress commensurate antiferromagnetism in cuprates and in nickelates. La2-xSrxCoO4 with x > 0.3 exhibits incommensurate spin ordering with the modulation closely following the amount of doping. These incommensurate phases strongly resemble the stripe phases observed in cuprates and nickelates, but incommensurate magnetic ordering appears only at larger Sr content in the cobaltates due to a reduced charge mobility.

Raman scattering in the Mott insulators LaTiO3 and YTiO3: evidence for orbital excitations

Raman scattering is used to observe pronounced electronic excitations around 230 meV--well above the two-phonon range--in the Mott insulators LaTiO3 and YTiO3. Based on the temperature, polarization, and photon energy dependence, the modes are identified as orbital excitations. The observed profiles bear a striking resemblance to magnetic Raman modes in the insulating parent compounds of the superconducting cuprates, indicating an unanticipated universality of the electronic excitations in transition metal oxides.

Determination of the orbital moment and crystal-field splitting in LaTiO3

Utilizing a sum rule in a spin-resolved photoelectron spectroscopic experiment with circularly polarized light, we show that the orbital moment in LaTiO3 is strongly reduced from its ionic value, both below and above the Ne el temperature. Using Ti L2,3 x-ray absorption spectroscopy as a local probe, we found that the crystal-field splitting in the t2g subshell is about 0.12-0.30 eV. This large splitting does not facilitate the formation of an orbital liquid.

Saturable transport of gabapentin at the blood-brain barrier

Gabapentin readily crosses the blood-brain barrier and concentrates in brain tissue via an active transport process believed to be system-L. Blood-brain barrier system-L has a low K(m), making it particularly susceptible to substrate saturation. The purpose of this study was to determine whether the fraction of gabapentin crossing the blood-brain barrier remains constant over a broad range of doses. Using a rat model, microdialysis techniques were employed to determine if fluctuations in gabapentin concentrations in the brain extracellular fluid (ECF) coincided with proportional changes in plasma concentrations. Area under the concentration-time curve was calculated for plasma (AUCplasma) and brain extracellular fluid (AUCECF). The ratios of AUFECF to AUCplasma (AUCratio) and brain extracellular fluid to midpoint plasma gabapentin concentration for each collection interval (Cratio) were determined to provide indicators of the relative (i.e. fractional) amount of gabapentin crossing the blood-brain barrier. Analysis of the association between AUCECF and AUCplasma using linear regression analysis revealed a small, but significant relationship (r = 0.62; p < 0.01). Although higher AUCECF values were obtained with higher AUCplasma values, changes in AUCECF were less than proportional to observed changes in AUCplasma. Blood-brain barrier saturation of gabapentin transport was evident as the AUCratio decreased with increased AUCplasma. Collectively, these results support a trend towards saturation at higher plasma concentrations of the carrier-mediated transport mechanism of gabapentin through the blood-brain barrier.

The in vivo unidirectional conversion of nitro-D-arginine to nitro-L-arginine

We recently reported that nitric oxide synthase in the brain can be inhibited not only by nitro-L-arginine (L-NA) but also by its D-enantiomer nitro-D-arginine (D-NA). In the present study, we found that D-NA, when tested in vitro, was 400 times less potent than L-NA. However, when D-NA was injected in vivo, its L-enantiomer, L-NA, was found to rapidly appear in plasma samples (approximately 1 min), rose to a maximum concentration at 30 min (approximately 40% conversion), and remained at this plateau for about 5 h. This was consistent with the changes in blood pressure. There was no conversion of L- to D-NA. The results suggested that D-NA has very weak biological actions by itself, but when administered in vivo, D-NA can be converted to L-NA.

Determination of capsaicin and zucapsaicin in human serum by high-performance liquid chromatography with fluorescence detection

A reversed-phase high-performance liquid chromatographic (HPLC) assay was developed to analyze capsaicin and zucapsaicin (civamide) in human serum at concentrations from 1 to 100 ng/ml. Human serum specimens were extracted twice with hexane-methyl tert.-butyl ether (1:1). The chromatographic separation was carried out on a C18 column at 40 degrees C using a mobile phase consisting of 40% acetonitrile in water with 5% tetrahydrofuran and 1% acetic acid. The concentration of the eluting compounds was monitored by a fluorescence detector with excitation at 270 nm and an emission cutoff of 300 nm. No interferences were observed from the extract of blank serum. The standard curves were linear in the detection range. The relative standard deviation of the assay was better than 8.4%. The limit of detection was 0.5 ng/ml.

Determination of paromomycin in human plasma and urine by reversed-phase high-performance liquid chromatography using 2,4-dinitrofluorobenzene derivatization

A sensitive high-performance liquid chromatographic method for the determination of paromomycin in human plasma and urine was developed. Paromomycin was quantitated following pre-column derivatization with 2,4-dinitrofluorobenzene (DNFB). The chromatographic separation was carried out on a C18 column at 50 degrees C using a mobile phase consisting of 64% methanol in water adjusted to pH 3.0 with phosphoric acid. The eluents were monitored by UV detection at 350 nm. The linearity of response for paromomycin was demonstrated at concentrations from 0.5 to 50 microg/ml in plasma and 1 to 50 microg/ml in urine. The relative standard deviation of the assay procedure is less than 5%.

Nitric oxide (NO) is an endogenous anticonvulsant but not a mediator of the increase in cerebral blood flow accompanying bicuculline-induced seizures in rats

Neurons synthesize NO, which may act as a retrograde messenger, involved in either potentiating or depressing neuronal excitability. NO may also play a role in the cerebral vasodilatory response to increased neuronal activity (i.e., seizures). In this study, two questions were asked: (1) is NO an endogenous anticonvulsant or proconvulsant substance? and (2) is the cerebral blood flow (CBF) increase accompanying bicuculline (BC)-induced seizures mediated by NO? The experiments were performed in 300-400-g Wistar rats anesthetized with 0.6% halothane and 70% N2O/30% O2. CBF was measured using the intracarotid 133Xe clearance method or laser-Doppler flowmetry. EEG activity was recorded. Chronic treatment (4 days) with nitro-L-arginine (L-NA), a potent NO synthase (NOS) inhibitor (400 mg/kg total), suppressed brain NOS by > 97% and prolonged seizure duration from 6 +/- 1 (saline-treated controls) to 12 +/- 2 min. In the L-NA-treated group, the CBF increase was sustained as long as seizure activity remained, indicating that CBF was still tightly coupled to seizure activity. Interestingly, the supposed inactive enantiomer of L-NA, D-NA, also showed an inhibition of brain NOS activity, ranging from 87 to 100%. The duration of seizures in this group (average 8 +/- 2 min) corresponded directly to the magnitude of reduction in NOS activity (r = 0.83, P < 0.05). Specifically, the D-NA results indicated that NOS inhibition had to exceed 95% before any effect on seizure duration could be seen.(ABSTRACT TRUNCATED AT 250 WORDS)